Cover Illustrations The original watercolor paintings on the cover were commissioned for Carlos Ochoa's book: The Potatoes of South America: Bolivia, and were painted by artist Franz Frey. This authoritative and scholarly publication represents the cul- mination of a lifetime of study by Ochoa and is Volume 1 of a series to be publish- ed by Cambridge University Press and CIP. Both Ochoa and Frey have exten- sive professional experience with CIP, where they collaborated on the paintings. Dr. Donald Ugent, ethnobotanist, Southern Illinois University, and Linda Peterson, former CIP editor, translated and edited the book, and were also con- tracted by CIP to produce a portfolio of 25 of Frey's paintings: The Potatoes of South America: Bolivia, A Portfolio of Fine Botanical Prints. The larger-format portfolio prints are reproduced from the plates in the Ochoa book. The Potatoes of South America: Bolivia is available from Cambridge University Press, The Edinburgh Building, Shaftes- bury Road, CB2 2RU, England. The portfolio is available from CIP. DD DD FRONT 1 . Solanum acau/e Bitter. 2. Solanum bombycinum Ochoa. ( BACK 3. Solanum infundibuliforme Philippi. 4. Solanum vidaurrei Gardenas. ·- International Potato Center Annual Report 1990 Worldwide Potato and Sweet Potato Improvement International Potato Center Apartado 5969, Lima, Peru 1990 The lntemational Potato Center (CfP) is a nonprofi t, autonomous scientific institution established in 1971 by agreement with the Government of Peru . The Center develops and disseminates knowledge to facilitate use of the potato and sweet potato as basic foods in the developing world . CIP is one of 13 nonprofit international research a nd training centers supponed by the Consultative Group for International Agricultural Research (CGIAR). The CGIAR is sponsored by the Food and Agriculture Organization (FAO) of the United Nations. the United Nations Development Programme (UNDP), and the Inter- national Bank for Reconstruction and Development (World Bank) , and comprises more than 45 countries, international and regional organizations, and private foundations. In I989, through the CGIAR, CIP received funding from the following donors: the governments of Australia, Austria , Belgium, Finland, France , Germany, India, Italy, Japan , Netherlands, Norway, People's Republic of China, Philippines, Spain , and Switzerland; the Canadian International Develop- ment Agency (CIDA); the Danish Inte rnational Development Agency (DANIDA) ; the European Economic Community (EEC); the Farmer Com- munity Development Foundation ; the German Agency for Technical Cooperation (GTZ); the lnter- Ame.rican Development Bank (IDB); the International Board for Plant Genetic Resources (IBPGR); the International Fund for Agricultural Development (JFAD); McDona ld's Corporation; Pepsico Foods Inte rnational ; the Rockefeller Foundation; the Swedish Agency for Research Cooperation wi th Developing Countries (SAREC); the United Kingdom Overseas Development Administration (UKODA) ; the United States Agency for Inter- national Development (USAID); the OPEC Fund for International Development ; the United Nations Development Programme: the World Bank (IBRD); and the Consultative Group Secretariat. The 1990 Annual Report is published in English and Spanish by the International Potato Center (CIP). This repon covers the period from I November 1988 to 31 October 1989. Mention of specific products by trade name does not imply endorsement of or discrimination against such products by CI P. Citation: International Pota to Center. 1990. Annual Report CIP 1990. Lima. Peru. 258 p. Printed by the International Potato Center. Apartado 5969. Lima. Pe ru. July 1990. Copies printed: 3500. Contents , ' Board of Trustees II Foreword IV CIP: Programmed for Change VII CIP Collaborative Regional Bridges and Country Networks xv Agroecological Zones and CIP Regional Network XVI Global Regional Contact Points XVII Regional Feature XIX Summary of Research Programs XXIII RESEARCH THRUSTS I Collection, Maintenance, and Utilization of Unexploited Genetic Resources 1 II Production and Distribution of Advanced Genetic Material 15 III Control of Bacterial and Fungal Diseases 31 IV Control of Virus and Virus-Like Diseases 51 v Integrated Pest Management 63 VI Warm-Climate Potato and Sweet Potato Production 77 VII Cool-Climate Potato and Sweet Potato Production 91 VIII Postharvest Technology 101 IX Seed Technology 113 x Food Systems Research 135 Highlights of Information Sciences and Training Activities 155 List of Abbreviations and Acronyms A-1 Papers Published in Scientific Journals A-5 Conference Papers and CIP Publications A-13 R esearch and Consultancy Contracts in 1990 A-19 CIP Staff A-35 Financial Statements A-43 CGIAR Information A-52 Board of Trustees Executive Committee Program Committee II DR. DAVID CALL, Chairperson Dean College of Agriculture and Life Sciences Cornell University Ithaca, New York 14853 U .S.A. DR. DELY GAPASIN , Chairperson Deputy Director Philippine Council for Agriculture and Resources Research and Development (PCARRD) Los Banos, Laguna Philippines DR. AURELIANO BRANDOLINI Director General Istituto Agronomico per l'Oltremare (IAO) Via Cocchi 4 Firenze V Italy DR. STACHYS N . MUTURI Director of Research Development Ministry of Research, Science & Technology P.O. Box 30568 Nairobi, Kenya · DR. JOHN M EAGHER, Secretary 3 Kingfield Court Burwood, Victoria 3125 Australia D R. L ANDER PACORA Executive Director FUNDEAGRO Av. Javier Prado Oeste 1894 San Borja Lima, Peru DR. LINDSEY I NNES Scottish Crop Research Inst. lnvergowrie, Dundee DD2 5DA Great Britain DR. RICHARD L. SA WYER Director General International Potato Center Apartado 5969 Lima , Peru DR. SHEN JINPU Deputy Director Chinese Academy of Agricultural Sciences Bai Shi Qiao Ju No. 30 West Suburb of Beijing Beijing, People's Republic of China lJJ Foreword W e are now shaping CIP's strategic planning for the 1990s, building upon two years of intensive self study and analysis, as well as our recent external management and program reviews. And each step of our programming for change draws upon CIP's unique, widely decentralized institutional approach, which has been clearly approved by the donors and by our national program partners. With almost 20 years of experience, we are looking at the lessons learned alongside our collaborators in over 80 countries, and we are asking for their continuing input. However, CIP's phasing of the self-study into the external review process was the first attempt at a comprehensive review of a decentralized Center within the CGIAR. Thus, we are busy implementing some of the immediate plans, while sorting out priorities for the next decade. In the accompanying lead article, I've summarized some major events, issues, and values that are combined in our institutional philosophy and global approach to potato and sweet potato research and development. There you will find a broader historical background, as well as a more detailed analysis of recent events at CIP. Here in the Foreword, I've chosen to address three key issues highlighted by the review process, which can help guide our thinking and actions as we develop our strategy in collabora- tion with our colleagues throughout the global networks. Strategic Plan IV Our strategy to meet 21st-century needs stems directly from CIP's initial Profile of 1979, which was a first in strategic planning within the CGIAR; however, our recent reviews highlighted the need to re-assess and adapt our Centerwide operations to keep pace with fast-changing technology and shifting political and economic events. Although we have regularly used our strategic plan as a working blueprint, an updated plan can help focus on specific current needs identified in our recent studies, particularly for the sweet potato research that more recently became a part of our mandate. The external review teams, as well as the TAC and our donors, have discussed CIP's role in association with other Centers with responsibilities for sweet potato research. When our work with sweet potatoes began with special project funds in 1986, sweet potato research also was included in the mandates of two other Centers. CIP received its first core funding for this commodity in 1988. However, in 1987, IITA discontinued research with sweet potatoes, and the board of A VRDC decided to phase out of sweet potato research in 1990. Thus, as we update 'the strategic plan, CIP is the only Center working with sweet potatoes, which suggests both a clearer and stronger global role for CIP. We recognize that priorities set within the overall strategy must take into account continuing rapid shifts in a maturing research community, as well as in farmer/consumer needs and food requirements. Both potatoes and sweet potatoes will have to play a greater role in the future; thus our plan must provide a good indication of future needs and how they will be met. Probably CIP's greatest challenge during the next five years will be that of fitting potatoes and sweet potatoes into farming systems based on cereals and agroforestry, using good land already under cultivation. Center Impact Donors indicated that they would like to have impact identified as early as possible in the life of a Center. Recent reviews of CIP, and other Centers, also have stressed the need to identify impact. A special challenge for CIP will be to develop short-term criteria to measure impact, which will be comparable with criteria that have characterized the successes of the "green revolution." Even in the sophisticated research and seed production environments of North America and Europe, adoption of new potato improvements is a lengthy process. An average of 25 years may be required for adoption - from the first cross leading to a new variety until a superior potential variety has been identified, named, and grown on 4,000 hectares in farmers' fields. And 4,000 hectares is a small parcel compared to the millions of hectares of cereals that gave us the "green revolution." Clearly, assessment of the "bottom line" impact is crucial, but we must also find indicators that can clearly predict potential impact, giving some measure of progress and achievement before final results are in hand. And, in thv process of assessing individual Center impact, full credit must be given to our developing-country partners, with whom we share all our achievements. They continue to be the key players in CIP's overall strategy. v Evaluating Cf P's Decentralized Approach V I Allhough the donors and reviewers had special praise for CIP's heavily decentralized approach, it seems likely that Centers using such a broad- based approach will require an external review different from that of Centers where most aclivities are based at headquarters. Clearly the donors need the reviews to justify current financing and Lo support newly identified needs; however, some combinations of a self-study and modified external reviews probably will be needed to effectively evaluate a center that has most of its staff posted away from headquarters. In the body of Lhis report , we have documented the work of our staff and the ir collaborative efforts with colleagues in nalional programs and allied institutions, which will continue as the cent ral force driving all CIP efforts. Whatever methods used to assess the Centers in the future, or to measure their impact, the potenlial for a "green revolulion" in the 1990s will likely be found in an increased role for Lhese scientists as they work wilh intensively produced crops such as Lubers, rool crops, and vegetables in the farming systems of Asia and Africa. CIP: Programmed for Change Within the CGIAR system, CIP has eamed special recognition for its decentralized institutional approach to research and development on a global basis. In the following account, Dr. Sa1ryer, director of the Center since its beginning in 1971, outlines both the philosophy and the historical events that have shaped this approach over the last two decades. CIP's current global operations are briefly described on pages XV to XVIII, with the map of collaborative networks showing the interactive flow of CIP research and development throughout the world. The Center is one of 13 sister institutions in the CGIAR, which is described on the final page of this report. CI P's donor organizations and mandate are listed foil owing the title page. Cf P's Early Years: A Different Path A s conceptualized in the early 1960s, the first Centers developed from plans that called for extensive campuses and facilities for headquarters that were basically self-contained. They were established to become Centers of excellence through their own facilities, staffing, and the support provided. At CIP, we took a very different route. We also established key basic facilities, but our Center of excellence has been built upon bridges of collaboration that span national programs around the world (see maps, page XV). We interchange expertise with these programs while working on priority problems of potato and sweet potato improvement. Our headquarters in Peru is located near the original home of the potato, where the greatest diversity of wild species still exists. Thus, our initial efforts were to establish a world collection of native cultivars and wild species, and to develop methods for identifying and eliminating diseases, so that clean material could be provided to potato breeders around the world. To help earmark materials and support breeders' work priorities, research sta tions were established within specific agroecological zones in Peru (page XVI). Three of these were in warm- to hot-climate tropical ecologies. Peru is only a short distance .south of the equator, with wide variations in ecology, from the hot tropics of the Amazon basin to the cool highlands of the Andes. VII VIII At these sites, we started to look at the classical problems that potato scientists had been working on for years, such as late blight, viruses, and seed production. However, we realized that world statistics on food production indicated that potato production was increasing most rapid- ly in Asia and Africa on a percentage basis. In many countries, potatoes had only recently begun to be used as a staple-food commodity, as well as a vegetable. We needed to determine first-hand what the problems were and where help would be needed from an international center. Thus we concentrated only a portion of our resources at head- quarters and established a network of regional research stations around the world. Their major responsibility would be to link us with the countries of the region so we could best provide our three major services: research, training, and communications. Our regional programs quickly started to feed information back to us, greatly influencing our research priorities. We found that: 1. Potato could no longer be considered a cool season, northern- latitude or highland crop since it also was being grown in the warm and hot climates of the tropics. 2. The dependency on imported seed was· the factor most limiting the use of the tremendous nutritional value of the potato. As a single food for survival, there is no other major plant food which approaches the nutritional quality of the potato. 3. Only scant human capital had been invested in potato research and development in many countries, and these limited resources were scattered among institutions. A high priority was assigned to helping national potato programs, which we could backstop in responding to the needs of their farmers. 4. The "green revolution" with the cereals had become a major recognized breakthrough in agriculture in the 1970s. Countries that had thought that major portions of their populations would always be hungry were achieving self-sufficiency in rice. And, in their search for alternative crops, the potato was found to have exceptional promise for diversification: the crop grows quickly and has high nutritional value, good cash crop return, and high levels of production per unit area per unit of time. The potato also fits well within cereal-based farming systems. 5. The Food and Agriculture Organization's (FAO) statistics on potato production are misleading, because much of the produc- tion never entered the channels from which F AO usually obtained their data. Nevertheless, their statistics showed that potatoes were increasing faster than any other major food commodity in Africa and Asia. These are the principal influences that helped determine CIP's research priorities, including our decision to place major research emphasis on potatoes for the warm and hot tropics. Although it is sometimes argued that we have pushed the potato into climates for which it is not suited, the facts are that we are serving the needs of developing countries where potatoes are already being grown. Such countries have steadily mounting needs for this food to feed their rising populations. Setting Priorities As our regional network was set in place, our regional staff and the national program scientists soon let us know that bacterial wilt - brown rot was as important as late blight in many potato-producing areas. As the potato moved into the warmer tropics, whole new lists of pests and diseases were being encountered that had never been found in the northern-latitude countries that were exporting the seed. For example, the tuber moth was never mentioned as a major problem in the initial planning conference held in 1972, although participants came from developing and developed countries around the world where potatoes were important. The regional. research structure and our collaborators' feedback to headquarters have been a key influence in helping set our research priorities. This input is a principal reason that our research today is aimed at improving potatoes grown in developing countries of the warm and hot tropical climates. Achievements and Lessons Learned Many readers of this Report have participated actively in the research that stems from our decentralized work. Our combined efforts have IX x ~ven the potato a very favorable position in today's agriculture, pointing to an even greater role that the crop must play in meeting tomorrow's food needs. Early on, when we began building a world germplasm collection for use by breeders of today and of future generations, we started to look at ways of producing seed in warm tropical climates. With production from imported seed, the cost of seed alone could be over 50 percent of the production costs in many countries. After learning how to multiply imported seed with low levels of virus build-up in tropical climates, we moved on to rapid multiplication and true seed research. Adaptations of these techniques are now in place in many countries around the world. Local seed production was essential in shifting the role of the potato from that of a relatively expensive vegetable to that of a staple food. As local seed production programs have come on line, attitudes of policy makers have changed rapidly. Even in lowland tropical countries such as Vietnam, potatoes have become the second-highest priority food commodity. The ability to store planting materials from harvest to planting be- came a second major concern. Many countries were depending on expensive refrigerated storages. CIP's diffused-light technique was our first major research result to spread rapidly around the world. Our collaborative bridges around the world gave us the ability to distribute potential varietal material from developed and developing countries to other areas of the world where it would be useful. We did not have to wait for our own material to become available. Although CIP is less than 20 years old, developing countries are now receiving a steady flow of excellent potential varieties with built·in resistances to the pests and diseases of warm tropical climates. In addition, we have been distributing the excellent material from other breeding programs that may fit national program requirements. In my opinion, the major impact of CIP reaches beyond the research that has been accomplished; our most enduring achievement has been in helping build the. national potato programs across the developing world, through training, consultancies, and the establishment of net- works. In many countries where there was not a single man-year invested in potato research in 1972, there are today well-trained scientists work- ing as national teams for potato research and seed production. Our support for potato production in the warm tropics of Africa and Asia has only begun. We are still using less than 10% of the wild species available to help solve varietal adaptation and resistance problems. Much of our research for seed production programs, such as the place of true seed in seed programs, is only now coming on line. The new tools of biotechnology, which are so easy to use with the potato, are just beginning to be available. CIP, with its decentralized program and collaborative bridges, has a solid base of operations to respond to the potato improvement needs of national programs, and to adjust quickly to their changing conditions. Our Future As we look at the role the potato must play in meeting the food needs of the global village, we have to examine past and present trends. The proven production and nutritional values of the potato will be needed to a much greater extent in future years. Over the next two decades, agriculture will be faced with its greatest obstacles since early civiliza- tions began their systematic development of food systems for survival. Tomorrow's major obstacles include: 1. Population increases The world's population will double in approximately two decades. The World Bank Atlas shows many developing countries with annual population increases of 3% to 4%, clearly indicating that many popula- tion-control programs have been unsuccessful. Many of the burdens of these failures are passed on for agriculture to remedy. 2. Scarcity of good land Many of the countries with the highest annual rates of increase in population are running out of good land for cultivation. Often they turn to marginal lands with fragile ecologies to try to stay abreast of food needs. Recent statistics on current population concentration and the related pressures on land are well described in an IRED Forum publi- cation: "If our world were a village of 1,000 people, in the village would be 564 Asians, 210 Europeans, 86 Africans, 80 South American_s, and 60 XI xrr North Americans. Of these peopie, 60 persons would have half the income, 500 would be hungry, 600 would live in shantytowns, 700 would be illiterate." Thus it is clear that most of the inqeases in food production must be grown on the good land now under production. And this is going to require a major change to include the more intensively produced vegetables and tuber-root crops within the annual food production systems where cereals are now usually followed by other cereals. 3. ·Concern for the environment The world is finally catching up with the fact that the environment has bee!). too long forgotten as a major concern in agricultural programs, population control, and industrial development. The Bruntland report for the United Nations has rightfully triggered international concern, and has resulted in the implementation of programs that will affect how we work, how we play, and the food we eat in the immediate future. The Plan on Environmental Policy of the Dutch government, "To Choose or to Lose," may well become a model for the European Economic Com- munity. It recommends a very ambitious, and necessary, full-scale ap- plication of known technology, if the goals for our environment are to be achieved while agricultural production increases. 4. 17ie International Agricultural Research Community A major positive force for further development has evolved over the past 20 years through the system of international agricultural research centers (IARCs) that specifically address major food-production problems of developing countries. These Centers have programs of research, training, and information exchange that are gradually joining the agricultural research world into a united community. Their efforts .draw upon the combined strengths of developed and developing countries, the p,ublic and private sector, and the IARCs. 17iere must be no doubt about the pivotal role that this international center system must play in dealing with problems of population, agriculture, and environment over the next two decades. Both of CIP's present commodities are basic staple foods in some parts of the world, but are classified and utilized as vegetables in many areas, particularly where they have most recently been introduced. Both commodities produce more calories per unit area per unit of time than almost any of the other major food crops, including the cereals. Sweet potato production has been decreasing in many parts of the world, where economic conditions allow the consumer to choose foods other than those that have traditionally been considered subsistence foods, with a perceived lower status. In Summary CIP's two major commodities are ideally suited to meet the challen- ges facing agriculture. Both potato and sweet potato fit well within cereal-based farming systems, and can boost food production per unit area per year. They are fast-growing, and produce good ground cover to prevent erosion. Also, they are mainly grown in ridge-type planting to protect the tubers, a practice that also prevents erosion when used in contour plantings. Over the next 20 years, CIP's challenge in fulfilling global agricultural needs is to fit potatoes and sweet potatoes into cereal and agroforestry farming systems that will: • Increase productivity of quality food per unit area per unit of time; • Increase the efficiency of inputs such as fertilizer and water; and • Sustain the increases in productivity with practices that are friendly to the environment. This challenge is based on the assumption that (1) cereals will continue to be the world's mainstay for food security, while other, more productive, foods will play a role of mounting importance; (2) most of the increased production needs in the coming years will be grown on good land now under cultivation; and (3) fragile soils of the highland and lowland tropics, where agroforestry has a comparative advantage, will become increasingly important for food production. Each of these components is being programmed into CIP's global effort to improve potato and sweet potato for the 1990s. Richard L. Sawyer Director General XIII Sola11um acaule Bitter. Sola11um bombyci11wn Ochoa. Sola11um i11fw1dib11lifon11e Philippi. Solanum vidaurrei Cardenas. Painted by Franz f'rcy. Reproduced from The Potatoes of South America: Bolivia, by Carlos M. Ochoa. Published by Cambridge University Press in collaboration with the International Pota to Center, 1990. XIV .. CIP Collaborative Regional Bridges C IP manages its global research and development program within a regional network through which CIP and national program scientists sys- tematically evaluate technologies under a range of local conditions. This approach takes into account the farmer , consumer, and agribusiness commu- nity at all research levels, from the moment a problem is identified, through experiment station and on-farm testing and adaptation, until an effective solu- tion is accepted by local potato and sweet potato producers. Rapid and continuing feedback from these evaluations plays a key role in guiding CIP's overall research program at headquarters in Lima, Peru. (see overview, next page) CIP's capabilities are enhanced by numerous research and consultancy con- tracts that take advantage of the expertise and facilities available at other institutions, often in collaborative research in developed countries. Through contracts with developing-country institutions, we share specialized human and physical resources to focus on high priority local research. PRECODEP~1 I .; \ / I \I t ,, I ', PRAGIPA" I I I I \ \ \ --------------- Country Networks C IP has helped to develop five unique collaborative research networks. In these networks, several countries in a geographical area pool their resources to solve common production problems . Once prio rities have been assessed, each country undertakes the projects for which it has a compara- tive advantage, sharing its results with the others. CIP participates in the networks as an equal partner , providing technical assistance in its areas of expertise, as well as administrative guidance. The distribution of effo rts allows CIP and the member countries to utilize their resources efficiently. This system of shared responsibility and active interchange differs funda- mentally from other agricultural networks that are designed primarily to aid in germplasm distribution. The members benefit from a wide range of research results, and at the same t ime their interests are consolidated and their self-reliance is strengthened. ~~:)~ \ \ \ \ ' -----------·--------------- ' ' ' • Region I South America I. Region II Central America an~the Caribbean Region Ill East and Southern frica I Region IV North Africa and the Middle East Region V West and Central Af ica • Region VI South Asia • Region VII Southeast Asia • Region VIII China ~ CIP Headquarters - Lima l!l Regional Headquarters · · · · · o Department Staff in Regions - - - • Collaborative Research and Contracts - Collaborative Country Research Networks j> xv Agroecological Zones and Related Thrust Research in 8 CIP Regions C IP has four experiment stations in Peru , one in each of the majo r agro-ecological regions of the country. Our headquarters is located at a coastal desert site near Lima (240 m altitude), where facilities include general research and administrative offices, as well as laboratories, greenhouses, refrigerated and diffused-light stores, growth chambers, and experiment fields. A second sta tion , in the cool Andean highlands near Huancayo (3,260 m), is the home of CIP's World Potato Collection . The remaining two stations are in the Amazon region : o ne in the mid-elevation jungle of San Ramon o n the eastern slopes of the Andes (800 m) , and the other in the hot, low jungle of Yurimaguas (180 m). CIP research sites in Peru and the potato-growing seasons, with meteorological data for 1989 crop year. Site: ¥ Lima-La Molina • Huancayo Latitude: 12°05'S 12°01·s Altitude: 240 m 3280 m Growing season: Jan-Mar May-Nov Nov-May 89 89 88 89 Air max (0 C) 27.49 19.92 18.50 Air min (0 C) 19.06 14.15 4.70 Evaporation (total mm) 569.78 540.95 809.73 Rainfall (total mm) 1.50 9.10 706.30 Solar radiat ion (daily MJ/m2) . no data 11.70 no data • Data from weather booth. Ecuado r Colom bia XVI -<> .. ,,. ~ "' 9. c:.., B razil Mid-elevation tropics • -----' Low, humid tropics • ------' Chile • San Ramon .&. Yurimaguas l 1°08'S 5°41 'S 800 m 180 m Nov-Mar May-Aug May-Aug 88 89 89 89 89 89 31.10 30.87 30.88 19.25 16.19 19.29 1042.99 533.05 *236.60 1300.43 289.70 540.04 19.78 18.85 no data C IP's international staff includes nearly 100 scientists , administrators, and other experts from over 20 countries. Many of our interna tional staff members are statio ned at CIP regional headquarters located througho ut the developing world (next page) , where they collaborate directly with the national programs. In Lima , Center operations a re supported by more than 500 supporting scien- tists, technicians, administrative personne l, secretaria l and clerical support staff , and specialized workers. C IP's six research departments- Breeding and Genetics, Genetic Resources, Nematology and E ntomology, and Socia l Sciences- are staffed and headed by international experts from developed and developing countries. Our interdisciplinary research is concentrated within ten "Thrusts ," which combine the work of specialists from several d isciplines to improve pota to and sweet potato product io n and use . CIP's Thrusts I II Collection , Maintenance, and Utilization of Unexploited Genetic Rcsoun:es Production and Distribution of Advanced Breeding Material Ill Control of Bacterial and Fungal Diseltses IV Control of Virus and Virus-Like Diseases v Integrated Pest Management VI VII VIII Warm-Climate Potato and Sweet Potato Production Cool-Climate Potato and Sweet Potato Production Postharvest Technology IX Seed Technology x Potato and Sweet Potato in Food Systems PRACIPA PRAPAC PR ECO DEPA PROCrPA Programa Programme Program a Programa Andino Regional Regional Cooperativo de Cooperativo de d'Amelioration Cooperativo lnvestigaciones lnvestigaci6n de la Culture de Papa en Papa en Papa qe Pomme Costa Rica, Argentina, Bolivia, de Terre Cuba, Brazil, Colombia, en Afrique Dominican Chile, &uador, Centrale Republic, Uruguay, Peru, Burundi, El Salvador , Paraguay Venezuela Rwanda~ Guatemala, Uganda, Haiti , Zaire Honduras, Mexico, Nicaragua, Panama SAPPRAD Southeast Asian Program for Potato Research and Development Indonesia, Papua New Guinea, Philippines, Sri Lanka, Thailand, Malaysia I I .. .. • .. • Global Regional Contact Points Main Headquarters Paraguay Rwanda Peru CIP Region I Office CIP Region Ill Office International Potato Center c/o Servicio de Extension c\o P.N.A.P. Apa rtado Postal 5969 Agricola y Ganadcra (SEAG) Section de l'SAR Lima 100, Peru St. Lorenzo, Paraguay B.P. 73 Phone: (51 )(14) 354354 Phone: (021) 50-0377 Ruhengeri, Rwanda (51)(14) 36-6920 (022) 50- 2526 Phone: (250) 332 & 46616 (51) (14) 35-4283 Telex: 218PY UNDP Off. FAX: (51)(14) 35-1570 Cable: UNDEVPRO Burundi Telex: 25672PE Mail: c/o UNDP - C.C. 1107 CIP Region Ill Office Cable: CIPAPA, Lima Asuncion, Paraguay B.P. 75 Bujumbura, Burundi E-mail: 157:CGI801; CIP Region II Office 157:CGI043; CIP-ISD Phone: (257) 22-4074 Central America FAX: (257) 22-4074 Region I Office Telex: 5030 DOI through: & Caribbean Hotel Source du Nil South America Dominican Republic Telex: (via FAO FOODAG BDI) 5092 Colombia CIP Region II Office CIP Region I Office Av. Sarasota Region IV Office Apartado Aereo 151664 esquina Nunez de Caceres North Africa Bogota 8, D.E., Colombia Apartamento 202, Phone: (57)(1) 286-0182 Edificio Ambar Plaza 11 & Middle East (57)(1) 281-3088 Sto. Domingo, Rep. Dominicana Tunisia (57)(1) 281-3399 Phone: (1 )(809) 535-4887 PAX: (57)(1) 281-9468 (1)(809) 535-6443 CIP Region IV Office (57)(1) 282-0203 FAX: (1)(809) 535-6554 11 rue des Orangers Telex: 42368 ICA Tl CO Telex: 3264112 CODETELEX 2080 Ariana 45366 CIID CO DR CIPAPA Tunis, Tunisia c/o CIPAPA E-mail: CGl112 Phone: (216)(1) 71-6047 Cable: CIPAPA Bogota (216)(1) 53-9092 Bolivia Region III Office FAX: (216)(1) 71-8431 Telex: 14965 CIPTN CIP Regio n I Office East & Southern Africa Egypt Casilla Postal 4285 Kenya Cochabamba, Bolivia CIP Region IV Office Phone: (591)(42) 40668 CIP Region Ill Office P.O. Dox 17 (591)(42) 40929 P.O. Dox 25171 Kafr El Zayat, Egypt Telex: 6445 PRONAPA DV Nairobi, Kenya Pho ne: (20)( 40) 58-6720 Phone: (254)(2) 59-2206 Telex: 23605 PDTNA UN Ecuador PAX: (254)(2)59-3499 CIP Region I Office Telex: 22040 ILRAD Region V Office Moreno Bellido s/n y Amazonas Cable: CIPAPA, Nairobi Apa rtado 16-129-CEQ E-mail: ILRAD West & Central Africa Q uito, Ecuador Ethiopia Cameroon Pho ne: (593)(2) 540600 (593)(2) 500297 CIP Region Ill Office CIP Region V Office (593)(2) 554287 c\o Institu te of Agricult ural P.O. Dox279 FAX: (593)(2) 503243 Research Damenda, Cameroon E-mail: CGl136 Holetta Research Center Phone: (237) 36-3285 P.O. Dox 2003 PAX: (237) 36-2732 Add is Ababa, E thiopia Telex: 5110 KN CIP CAM Pho ne: 160055-59 PDX Telex: 21548 IARET E-mail: c/o ILCA XVII Region VI Office FAX: (63)(2) 817-8470 Telex: 84478 INfERAG TH Telex: 40890 RICE PM, Cable: RICEFOUND South Asia 40860 P ARRS PM, BANGKOK India 63786 RICEPN E-mail: CGI405; IRRI E-mail: IRRI CGI401 Bangkok Office CIP Region VI Office Indonesia CIMMYT CGI205 c/o IARI Campus New Delhi 110012, India CIP Region VII Office Region VIII Office Phone: (91)(11) 58-8055 c\o Lembang Hort. Telex: 31-73140 FI IN Res. Inst. China 31-73168 EiC IN P.O. Box 587 CIP Region VIII Office Cable: CIP AP A, New Delhi Bandung, Indonesia c\ o The Chinese Academy E-mail: CGI114 Phone: (Lembang) (62) 6025 of Agricultural Sciences FAX: (62) (22) 43-1583 Bai Shi Qiao Rd. No. 30 Region VII Office Telex: 28276 PHEGAR IA West Suburbs of Beijing Southeast Asia & The E-mail: CGI120 or Beijing, People's Rep ublic of M.POITS.TESf57 China Pacific Thailand Phone: (86) 831-5329 Philippines CIP Region VII Office FAX: (86) 831-6536 (86)(1) 831-{)545 CIP Region VII Office P.O. Box 9-159 Telex: 222362 FHBJ CN c\ o IRRI Bangkheng 222443 FHBJ CN P.O. Box933 Bangkok 10900, Thailand Cable: AG RIA CA Manila, Philippines Phone: ( 62)(2) 579-5586 Phone: (63)(94) 50015-19) FAX: (66)(2) 541-1087 REGIONAL RESEARCH PROGRAM PREC..ODEPA ----io9ot1 ~;1rrmia ,' Lim.a ; Peru ' PRACIPA ,, \, _____ ,,. ,,,.,. XVIIl v ..... -- ... ' ' ' ' ' ' ' ' --:/ _,, INTERNATIONAL POTATO CENTER (CIP) REGIONS AND COUNTRY NElWORKS Regional (to) and Subregional(•) Headquarters Regional Feature Argentine Husband/Wife Team Com bin es Business and Virology Tests Traditionally, we have used the words of CIP scientists and administrators in our Annual Report. In this article, however, we focus on some practical applica- tions of the scientific research and training being done at CIP headquarters and in the regions. This account is drawn from Tito Alberto Brovelli's interview with Ana Maria Escarra and Juan Barrenechea, owners of Diagn6sticos Vegetales, a private firm devoted to potato virus detection. In future Annual Reports, we will publish similar accounts of c.ollaborative efforts of potato and sweet potato enterprizes in the private-sector and national program institutions in the regions. Their words express, better than ours, the usefulness and developmental impact of CIP's global program. (See CIP Circular Vol. 17(1), 1989 for additional background information on CIJP's virology research and training related to ELISA and Latex tests.) A gricultural e ngineers Ana Ma rfa Escarra and Juan Lorenzo Barrenechea, a husband-and-wife team, are the owners of Diagn6sticos Vegetales, a company that offers virus-detection services and produces pathogen-free potato seed. During the 1980s, they equipped the foremost Argentine laboratory for the identification of potato viruses using enyzme-linked immunosorbent assay (ELISA) tests. After the laboratory was well estab- lished, they began to develop a produc- tion process for completely healthy seed that would supply the internal market. Today, they export seed, as well as virus- detection technology. Their rapidly growing business repre- sents a trend in Latin America. The accomplishments of this couple have proven that it is possible, with a minimum of capital and financial credit, to launch a commercial potato-virus analysis sys- tem to complement government activi- ties, such as Argentina's National Seed Program. To get their business started, Ana Marfa went for training to the potato seed laboratory at the experiment station ofINTA-Balcarce (Instituto Nacional de Tecnologfa Agropecuaria), where she received instruction from virologist, Dr. Ivan Butzonitch. XIX Ana Marla examining plantlets in the final stage of micropropagation. With this new knowledge, and a great deal of determination, she and Juan managed to build two greenhouses in Otamendi, a small potato-producing community south of Mar del Plata. She explained that, "there we were able to reproduce what I had been doing at the INTA laboratory." She was fortunate in being able to learn from an INTA investigator, the late agricultural engineer Atilio Calderoni, about the new diagnostic method, ELISA. This method involves an im- muno-enzyme system that had recently been developed for vegetables, and which CIP had begun to put into practice. To learn more about ELISA, Ana Marfa immediately set about making contacts with international centers. Through them she learned about a virol- ogy course offered at CIP, where this diagnostic technique would be taught. Luis Salazar, who was assisted by his team from the CIP Virology Program. "That training experience," she said, "brought me much closer to a practical and academic understanding of potato virology, and at the same time I made many good friends." After receiving authorization to use the new technique in Argentina and ac- quiring the necessary space and equip- ment, the couple met with producers to work out costs and make agreements. Traditionally, the importation of seed potatoes had been an annual event in Argentina, because new seed tended to become highly infested. But with know- ledge gained from ELISA and research on aphid populations, there were real I She signed up for the course to be held in Dispensing antibody solutions into plates for the October 1981 that was directed by Dr. ELISA test. xx The couple discusses business at the Diagn6sticos Vegetales headquarters. possibilities of keeping seeds healthy for a longer time. In December, Ana Marfa took part in the "First International Course on the Production and Storage of Seed Potato," organized by CIP in Osorno, Chile. Dr. Fernando Ezeta, a scientist at CIP and coordinator of the Program fo r the Production of Basic Potato Seed in Peru, described his experiences in the area. A method was discussed for supplying nothing less than completely healthy seed. Ana Marfa recalls that "this concept was a revelation for me. I saw that if it were possible to transfer this methodol- ogy to my own country, we would be able to move towards seed self-sufficiency and eliminate imports." Juan added that "the idea of beginning healthy-seed production in our country also represented the challenge of more work for us." The couple made arrange- ments to study the new technique. In March 1984, they set off for Peru, for a short but intensive training period at CIP. Assessing the quality of mini-tubers grown from in vitro plantets. XXI After they returned to Argentina, they installed a greenhouse in the Sierra de los Padres area, and started a small tissue culture laboratory at their main office. CIP supplied healthy seed of the varieties used in Argentina. In 1986, producers in all of Argen- tina's potato-growing areas planted trials with this disease-free seed; then national authorities took note and urged other producers to do the same. As a result of these experiments, Diagn6sticos Vegetales was recognized as a leader in this area and their contracts increased. For the first time, profits began to justify the years of study and work. In 1987, other teams of private-sector professionals decided to produce healthy seed, and new business partnerships were formed. In the particular case of Diagn6sticos Vegetales, the opportunity was ideal for establishing contacts with businesses and producers in other Latin American countries interested in finding similar solutions. With training from the Diag- n6sticos Vegetales team, Mexican tech- nicians have set up a virus-detection laboratory in La Junta, Mexico. Tech- nicians from Chile and Uruguay have also received training to set up similar laboratories in their countries. Ana Marfa and Juan Lorenzo con- tinue to look for new ways to combine their scientific and business interests with Argentine institutions and professionals, and with CIP and other research orga- nizations. And the combination promises to pay off with better crops and addition- al oportunities for economic develop- ment in Argentina. Participants in a GIP Virology course practicing the ELISA test for the detection of potato and sweet potato viruses. XXII Summary of Research Programs Our Thrust activities continue. to build within a stronger regional framework of NARS and CIP scientists in Latin America, Africa, and Asia. The individual Thrust reports reflect substantial achievements of this combined team approach, particularly in the development of im- proved CIP potato materials that provide combinations of resistances and tolerances to biotic and abiotic stresses, either alone or in crosses with locally adapted material. We have also helped in the successful integration of selected sources other than the Center's breeding program. Other Thrust research payoffs include integrated pest and disease control methods, potato seed production schemes that yield clean planting materials, and new postharvest methodologies. Our research on sweet potato has progressed rapidly and CIP's sweet potato genebank is now the largest and best documented in the world, ·with duplicates obtained from national collections in Latin America, the Caribbean, China, Japan, and the United States. Simultaneously, we have mounted an intensive CIP/IBPGR collection effort to systematically ex- plore Latin American and Caribbean countries where good genetic diver- sity is found in sweet potatoes. The IITA collection has been placed in vitro and duplicated for transfer to the CIP collection and AVRDC has recently agreed to the transfer of a complete duplicate of its collection to CIP. In a systematic evaluation of CIP's sweet potato collection, we have found resistances to some important pests, tolerance to several abiotic stresses, and other quality factors that will help better serve needs identified by developing countries. As in our collaborative work with potatoes, we are seeking ways to eliminate pathogens and to confirm their elimination. This difficult and labor-intensive work is designed specifically to yield technology for use by developing countries. Rapid progress in improvement of sweet potato flowering and seed set has facilitated new wide crosses. The continuing needs of developing countries are being assessed by surveys of sweet potato workers in those countries, and by CIP social scientists working alongside local scientists and farmers. Similarly, they are recording the successful technologies and their adaptations for J urther improvement and diffusion. XX III Germplasm and Breeding Potato Our genetic resources potato research concentrated on biosystematic studies, germplasm maintenance and utilization, and germplasm enhancement. In the biosyste matic studies, we described three new potato species, S. amayanum and S. bi/1-hookerii of the taxonomic series Tuberosa , and S. salasanium of the series Conicibaccata. All three are from the central Andes of Peru and have a chromosome number of 2n = 2x = 24. In addition, we identified a new form of the important tetraploid wild species S. acaule, which appears to have good potential in the development of improved resistance to PLR V and to mechanical inoculation of PSTVd. Studies of various herbaria in the USA, in Europe, and in Peru at CIP have shown that S. bukasovii has enormous genetic variability, to the extent that four species, S. canasense, S. multidissectum, S. pwzoense, and S. pumilum Hawkes, are all synonyms of S. bukasovii. This is an important taxonomic clarification, be- cause it means thatS. bukasovii can be used in breeding, without major problems. We are making good progress in determining the end0sperm balance number (EBN) of wild potato species. This work helps us understand and predict the crossability of wild potato species with each other and with · cul- tivated potatoes; it also helps us obtain a better understanding of the evolutionary processes in species formation. We continue to identify new cultivars, and the CIP field-planted collection now consists of 3,439 Andean cultivars, with XXIV 99% of these cultivars also maintained in vitro. After electrophoretic verification, 603 duplicates were eliminated from material obtained from Argentina, Bolivia, and Peru. To conserve potato diversity in the fields of Andean farmers, we are testing a novel approach that in- volves training farmers to select segregat- ing TPS materials according to their local needs and preferences. Farmers in three localities are now using TPS of about 20 native cultivars that are popular in tradi- tion a I agricultural areas such as Cajamarca, Cuzco, and Puno, Peru. Of 200 Andean cul ti vars screening for resista nce to the potato tuber moth Phthorimaea operculella, 15 were found to be resistant and 35 moderately resist- ant. Pathogen-tested Andean cultivars were distributed to 14 countries as tuber samples, in vitro plantlets, or seeds. For increased security, CIP has dupli- cated a set of tubers of Peruvian cultivars in · a high-altitude field genebank in central Peru, which is maintained by the National Agrarian University. This ma- terial has been fully duplicated outside of Peru through a collaborative agreement with INIAP in Ecuador. We have completed the transfer of the world potato collection to in vitro cul- ture. Computerization of maintenance procedures of the collection is complete and all labelling is now done by com- puter. In utilization studies, our work focused on use of Solanum acaule, and 124 clones of Sola11w11 acaule that had been found (by mechanical inoculation) to be resis- tant to PSTV d were further tested by Agrobacterium-mediated PSTVd cDNA inoculation. In these tests, 21 clones were shown to be resistant to this mode of inoculation. An additional 4 clones were identifie d as apparently resistant to PLRV, based on their resistance to aphid infestatio n and multiplication of the virus. The 25 clones have been trans- ferred to in vitro and are ready for utiliza- tion in germplasm enhancement and breeding. From this S. acaule material (which may also carry resistance to PVY and PYX) F2 and backcross populations have been generated that will be used in RFLP mapping projects. This project will help to map genes that determine resistance to PSTVd and to some viruses. We have furth er developed several schemes for the effective utilization of the S. acaule material, including a cross com- bination between S. acaule and tetraploid cultivated potato clones. Previously, this combination had fa iled , due to the operation of the tr iploid block or the EBN barrier. O ur germplasm enhancement work included the identification of high levels of resistance to root knot nematodes in 5 new diploid clones, using a newly developed in vitro method that has eliminated temperature problems en- countered in the traditional testing en- vironment. This source of resistance represents a broadening of the base for root-knot-nematode resistance at CIP, since the only previous effective and usable wild sources of resistance were clones of S. sparsipi/um. The newoiploid mate ri a l has S. mu/tidissectum, S. bukasovii, S. canasense, and S. gourlayi in its background. These wild species had been crossed with dihaploid S. tuberosum and ssp. tuberosum clones that were produced under a research contract with the University of Wisconsin. Some of these clones have good 2n pollen produc- tion and are now in use in a 4x x 2x crossing program. They have excellent tuber appearance. Resistance to bacterial wilt was found in selected 2x clones that have the clone MI49.10 in their pedigree; this clone had previously been selected for bacterial wilt resistance and 2n pollen production. Among other clones showing resistance to bacterial wilt, one clone showed a root knot-nematode resistance that can be transmitted to progenies from 4x x 2x crosses. Thus, this clone combines both bacterial-wilt and root knot-nematode resistance. Excellent progress was made in trans- fe rring potato tuber moth resistance from the wild species Sola11um spar- sip ilum to 2x cultivated germplasm. The fmdings indicated that the presence of S. sparsipilum is desirable, but not essential, for the expression of resistance. We have also shown that resistance to root-knot nematodes, bacte rial wilt, and potato tuber wilt, as well as 2n pollen produc- tion, can be combine d in individual xxv diploid genotypes that will transmit these characteristics to their 4x offspring. We are making rapid advances in use of Agrobacterium plasmid gene con- structs to transform potato clones. A range of new promoter (control) sequen- ces was obtained and tested, thus helping us to regulate the amount and site of a particular gene product. Collaborative work with institutions in Florence, Naples, Rome, and Yitervo, Italy, have lead to transformation for resistance to several pests and diseases, and to the use of in vitro methods to select for resistance to biotic and abiotic stresses. A new research contract with Cornell University has been designed to help produce a more detailed RFLP linkage map of potato. The map is based on tomato probes, and has already been used effectively by plant breeders as they begin to elucidate the phyllogeny of tuber-bearingSo/anums. The next step is population development and identifica- tion of useful traits. In potato breeding, our research focuses on population development and true potato seed (TPS) studies. We have made extensive selections for parental lines to be used for variety selection and for TPS utilization. At La Molina, 30 clones from CIP's program and 12 clones fro m the University of Maine were evaluated for their parental value, using a tester that showed combined immunity to both PYY and PYX. Clones C83.383, Maine-37, Cl-137, C84.081, and C84.707 showed good parental value for yield and tuber uniformity, and had medium maturity rates. Based on these findings, we are selecting the progenitors for the next crossing block. At San Ramon, we evaluated a sample of 25 clones for XXVI general combining ability ( GCA), using a line-by-tester design. This sample in- cluded clones with immunity to PVY (simplexes and duplexes) and PYX, with combined immunity to PYX and PVY. Yields were acceptable, with many of the progenies showing high yields, good tuber uniformity, and earliness. All progenies segregated for either PVY or PYX immunity, and clones XY.15 and C84.705 were found to have a high GCA for yield, tuber uniformity, and earliness. At La Molina, we also evaluated a sample of 286 clones introduced from Uruguay to assess their agronomic attributes. The sample was generated from TPS prog- enies segregating for processing at- tributes and virus resistances (PYX, PVY, and PLRY), and 23 clones were selected. They are now being tested for immunity to several viruses. To evaluate drought tolerance, 800 potato clones (selected at San Ramon and La Molina) were tested at Tacna. We found high yields and good levels of ear- liness in several clones and this popula- tion contains many combinations of resistances to virus and other diseases that can be useful in developing parental clones. We also evaluated populations bred for adaptation to warm tropical en- vironments and for TPS parental line development. Ten clones evaluated at La Molina and 2 clones at San Ramon, were selected for making chips and french fries because they had good processing characteristics: good tuber shape, color, and uniformity. The national programs of Burundi, Ethiopia, Rwanda, Tanzania, Uganda, and Zaire participated in a regional trial in which we evaluated a set of the best clones from the national programs and CIP under a broad range of environments in eastern and southern African countries. Clones considered for release as new varieties include: CIP clones 381295.1, 381293.3, and PLAP 8201.12 in Rwanda; and CIP clones 374080.5, 380606.6, and 380602.22 in Zaire. These clones have gone through several cycles of selection including mul- tilocational national yield trials. We have selected promising new clones in experi- ments to assess cultivars of diverse genetic types for yield and other qualities in New Caledonia, Thailand, Fiji, Tonga, and French Polynesia, as well as the Solomon Islands and the Cook Islands. Clone 377850.1 was selected in Fiji and has shown good bacterial wilt and virus resistance, along with heat tolerance and good storability. In China, more than 200 CIP cultivars have been evaluated. In Enshi Hubei Province in southern China, CIP clones 386221.7, 386081, and 386198 outyielded the local cultivar and are being further evaluated. At San Ramon, several clones showed excellent agronomic and reproductive characteristics under rainy- and dry- season conditions. These clones come from 1987 and 1988 TPS populations and have now been put in crossing blocks to assess their parental value. In China, the area grown from TPS transplants increased from 80.5 ha in 1987, to 110 ha in 1988, to 150 ha in 1989. This increase extended over 20 provinces in southwest China and in northern China, and can be attributed to improved logistics, availability of high quality TPS, the establishment of TPS collection dis- tribution procedures, and CIP input in personnel training. Sweet potato Sweet potato studies primarily empha- sized collection, taxonomic identifica- tion, germplasm maintenance, duplicate identification, evaluation, distribution, and enhancement. Six collecting expedi- tions were made (one each in Guatemala and Panama, and four in Peru) with a total of 299 accessions collected at 130 sites. Of the accessions, 155 were I. batatas; nine represented two Ipomoea species from section Batatas, 12 re- presented seven species from other sections, and 123 have not been clas- sified. We began duplication of the IITA sweet potato germplasm collection at CIP with a transfer of 210 accessions maintained in vitro. This genetic material includes 34 advanced selections and 176 breeding lines. The 1,202 IIT A acces- sions have been more thoroughly docu- mented, and a computerized database now contains all of the available data. A total of 3,520 sweet potato accessions were planted at La Molina, with 1,868 Peruvian cultivars and 338 breeding lines grown in the field. Another 966 sweet potato cultivars from other countries were grown in pots in the quarantine screenhouse and 348 accessions have been maintained as in vitro culture. We are transferring materials to in vitro cul- ture as rapidly as possible, and a total of 2,430 sweet potato accessions are now being maintained in vitro under slow- growth conditions. Some of these acces- sions are being duplicated outside of Peru under an agreement with IDEAS in Venezuela. Duplicate verifications by electrophoretic analyses were made at the Institute of Biochemistry in Braunschweig, West Germany, where studies were made of 252 Peruvian cul- XX VII tivated accessions from 60 groups with identical morphological characters. The results and the groupings based on mor- phological data were found to be in agreement for about 85% of the ac- cessions. A VRDC analyzed nutritional com- ponents of storage roots from 897 Peru- vian cultivars. Of these cultivars, 35 had dry-matter content levels greater than 40% ; 13 had starch-content levels greater than 70%; 4 had combined levels of more than 35% dry-matter content with more than 10% of total protein; 4 had less than 2% total sugar content, and 26 had less than 2% fiber content. Significant nega- tive correlations were found between dry-matter content and total protein con- tent, and between dry-matter and fiber content. Positive correlations were found between dry-matter and starch contents. Eighteen cultivars of I . batatas were rated as resistant, and another 12 as moderate- ly resistant to Euscepes postfasciatus weevil. In the People's Republic of China (Xuzhou and Guangdong), scientists are characterizing the Chinese national sweet potato collection, computerizing the data, and introducing the clones to in vitro culture. In sweet potato germplasm enhance- ment research, we are combining both innovative and traditional cytogenetic methods. Studies of wild 2x and 4x I. trifida species have shown exceptional promise for future sweet potato work. Within the section Batatas, only I. trifida has been used in our sweet potato germplasm research; however, we have begun a crossability study to determine the feasibility of using the rest of this taxonomic section. In this work, 2n pollen was formed in 6 of the 11 species studied, and of 70 inte rspecific combinations examined, 28 were successful, while parents of the same ploidy level were shown to be highly crossable. All 11 species studied have become genetical- ly accessible, either directly or indi- rectly. Thus this section shows promise for future sweet potato enhancement work. In our sweet potato population breed- ing work, in the coastal desert and the Amazon Basin in Peru, we have made good progress in selecting material with high and early yields, broad adaptation, and a range of characteristics important to con- sumers. We have emphasiz.ed studies of the newly collected Peruvian germplasm. CIP distributed genetic materials to cooperato rs in 88 NARS. Materials now available from the pathogen-tested list include 245 advanced cultivars of varieties, 35 cultivars in the clean-up process, 172 accessions from native and wild germplasm, plus 56 in the clean-up process. Six sweet potato cultivars are now on the pathogen-tested list and 62 are in the clean-up process. Integrated Control of Diseases and Pests In bacterial-wilt research, our collabora- tion with NARS in several developing countries continues to concentrate on the selection of tetraploid populations with resistance to Pseudomonas solanacea- XXVIll mm inherited from cultivated diploid Solanum species. We have substantially increased our tests and development of potentially useful breeding materials in locations within Peru and worldwide, I . thus intensifying the selection for resist- ance to localized strains of the bacterium. Our combined efforts have produced a new population from a series of crosses between the best bacterial wilt-resistant clones, and a late blight-resistant popula- tion (including some clones that were free from R-genes). A wide range of materials was selected for acceptable yield potential, and further progress has been made in the selection of clones that show no la tent infe ction by P. so/anaceanun at harvest. Some of this work has been done in association with the Peruvian National Potato Program INIAA. We have selected intensively for bacterial-wilt resistance, combined with adaptation and agronomic quality, in several parts of the world, including the Philippines, Indonesia, China , and Brazil. Additionally, we have developed a more precise and severe screening method to enhance levels of resistance to bacterial wilt. This method uses rooted cuttings immersed in the inoculum sus- pension, and is uniform and reproducible for segregating individual plants resist- ance to bacterial wilt. Taxonomic studies were made on Pseudomonas using biochemical tests in multiple-well microtiter plates. These resulted in the subdivision of Biovar 2 P. solanacearum into two distinct pheno- types related to their geographic dis- tribution. This finding will help focus the breeding strategy. Collaborative work between CIP and NARS on the integrated control of bac- terial wilt is designed to provide low-cost control of bacterial wilt by small farmers in developing countries. The philosophy is to complement the performance of tolerant cultivars. In collaboration with the Department of Plant Protection of ISABU, Burundi, a survey to evaluate the occurrence of bacterial wilt in farmers' fields provided valuable findings to help develop integrated control stra tegies. Wilt incidence was shown to be affected by the previous rotation, with the lowest level of carry-over shown after rotation with cassava during the September-to- J anuary season, and after banana, during the following season. The bacterial wilt- tolerant variety Ndinamagara (CIP ac- cession number 720118) was grown on 77% of the total land planted with potato. On average, our varieties showed less wilt than did other varieties; however, bac- terial-wilt incidence was found to be low in susceptible varieties, when the seed was obtained from the ISABU seed farm and the crop was grown in a two-year crop rotation. Increased extension ef- for ts to prevent planting of potato as a monoculture have helped considerably, but volunteer potato plants are still recognized as a major source of bacterial wilt. In Bukidnon, Philippines, the in- oculum potential of P . solanaceam m XXIX (race 1) in the soil was highest following a potato crop, and lowest following maize, although the potential remained sufficiently high to cause disease. Rota- tion with maize or beans reduced bac- terial-wilt incidence and increased yield in a subsequent potato crop, whereas potato monoculture increased wilt and reduced yield. At San Ramon, bacterial- wilt incidence increased when the crop followed rotation with cowpea or beans, whereas the incidence decreased when following maize or a herbicide-treated fallow. These incidences were correlated with the level of rootknot-nematode damage. In our screenhouse tests, the pre- and post-emergence application of the her- bicide Metribuyin effectively con- trolled weed hosts of P. solanacearum and Me/oidogyne spp. Soil amendments also retarded the development of bac- terial wilt. The incidence of bacterial wilt in screenhouse tests could be lowered substantially by application of calcium oxide or urea, or combinations of the two. Field-soil amendment with calcium oxide, urea, and composted sugarcane bagasse also retarded the development of bacterial wilt in the field. We are making follow-up studies of these find- ings in cooperation with INIA in Cajamarca, Peru, with LEHRI in In- donesia, and with CIP staff in Kenya. Alternative screening methods were evaluated to support breeding for resis- tance to Erwinia soft rot and black leg, and we have developed a new method that involves placing cuttings in infested perlite, thus permitting the selection of several resistant genotypes. Our research showed a synergistic interaction between Erwinia caratovora ssp. caratovora and two fusarium spp. inoculated to tubers, xxx which suggests the need to consider a breeding strategy that takes both dis- eases into account simultaneously. In our late-blight work, breeding for resistance to Phytophthora infestans con- tinues to involve two populations: 1) ad- vanced materials containing dominant genes for vertical resistance (R genes), as well as horizontal-resistance genes; and 2) materials free of R genes that are agronomically less advanced. Our aim is to increasingly emphasize the R gene- free population. In both populations, however, our objectives are to increase levels of horizontal resistance to add suitable agronomic characters, as well as to select high levels of late-blight resistance. We selected 166 new clonesin screen- ing at Rionegro, Colombia and Toluca, Mexico and 39 clones were selected after a second testing and have been added to the international late-blight resistance trial collection. This collection now con- tains 170 clones that are available for testing by NARS. New sources o f resis t ance were tapped for population B. A sample of 123 accessions from three wild diploid species is being tested in Peru, and we are planning to cross haploids and andigena- resistant clones. The aim is to introduce resistance into cultivated forms ex- tracted to make crosses with wild diploid species. Progenies with characteris tics for early-blight resistance combined with earliness, were selected in the field at San Ramon, and similar proge nies were found to show early-blight resistance in tests in Israel. Our findings provide addi- tional evidence of the potential for con- trolling this disease through selection for resistance. Our survey of sweet potato diseases continued at La Molina, and we began screening for tuber-rot resistance with emphasis on Java black rot and Fusarium root rot. In experiments at San Ramon, foot rot and soft rot caused severe losses in storage. Chlorotic leaf distortion was shown to be caused by th e fungus Fusarium lateritium. In our virus research, we are em- phasizing the breeding for resistance to potato leaf roll virus (PLR V) alone, or in combination with potato virus X (PYX) and potato virus Y (PVY) immunities. Because the resistance to PLR V is known to have multiple components, the search for parental genotypes within in- dividual resistance components should facilitate efforts to combine them in later stages. One of these components, aphid antixenosis, was identified in four clones maintained at CIP. Resistance to infection is another im- portant component of the resistance to PLRV. This resistance can be broken down by growing resistant clones under high-temperature conditions. For ex- ample, of 62 advanced clones that resisted PLRV infection after 5 field ex- posures during the winter at lea, Peru, only 16 showed moderate to high re- sistance to PLRV in the summer sea- son. These findings indicate that final selections for resistance to PLR V should be done in locations having condi- tions similar to summer conditions at lea. Our studies show that resistance to virus multiplication is another important resistance mechanism. Although is very uncommon in cultivated potato, this mechanism has two important ad- vantages: 1) It reduces the severity of the leafroll disease, and 2) It reduces the inoculate potential in plants having this type of resistance. In a collaborative re- search project with the Scottish Crops Research Institute, we have developed two clones with resistance to virus multi- plication. These clones are G7461.1 and G7445.1. We found wide variability of PLR V among eight PLR V isolates, in studies that used monoclonal antibodies to examine the antigenic determinants (epitopes) on the protein coat of the PLR V particle. Knowledge of such variability is crucial in our strategy for resistance breeding. We continue our search for additional inexpensive and simple methods of virus detection for NARS; production of basic stocks free of viruses is crucial to seed programs. For example, we are studying ways to lower the costs of antisera that are the most expensive reagents used in ELISA, a sensitive, simple, and inexpen- sive method for virus detection. In one method being studied, virus antibodi~s (anti-idiotypes) are produced from a small supply of previously produced an- XXXI tibodies, rather than from purified virus. Complementary nucleic-acid sequences were developed for eight viroids and six viruses to increase the pool of virus and viroid detection methods at CIP. In sweet potato virus research, we continued studies to detect and identify viruses, while also searching for resist- ance genes to sweet potato feathery mottle virus (SPFMV), which is the most important virus of the crop. Antisera and kits for detection of major viruses are now available for distribution to NARS. A previously unknown, mechani- cally transmitted virus (code-named C2) was found in the germplasm collection, and has been identified and partially characterized. Thirteen accessions in the CIP germplasm collection have been found to provide the best available re- sistance to SPFMV through graft in- oculations. Integrated pest management research continues to focus on the identification and use of resistant germplasm, biologi- cal control agents, and other non-pes- ticidal methods. In potato cyst-nematode research, 20 advanced clones were iden- tified as resistant. Two clones, J 16.10 and G.16, have been selected for release in Ecuador where 52 clones also were selected for further evaluation. Resist- ance to potato cyst nematode identified in Solanwn andige11a .Oas been trans- ferred to other adapted material. We also have selected clones with combined resistances to potato-cyst nematode, and late blight viruses. Root knot-nematode resistance was identified in several potato progenies at the diploid and tetraploid level, and additional sources were iden- tified in S. multidissectum, S. bukasovii, S. canase11se, and S.gourlayi. An effective cropping sequence to control root-knot XXXII nematode was identified in Burundi. Several new sources of resistance to root- knot nematode in sweet potatoes were identified. Resistance to potato tuber moth was reconfirmed in 7 potato clones with high densities of glandular trichomes type A and B. This work holds special promise because glandular trichomes provide re- sistance to many kinds of insects and to other pests, and even reduce incidence of late blight. Our studies have confirmed the effec- tiveness of granulosis virus, talc, and the biological insecticide Bacillus thuringien- sis in controlling potato tuber moth. In Egypt and Tunisia, the use of granulosis virus and Bacillus thuri11gie11sis was found to be highly effective in storage. These components are now being used in in- tegrated pest management. Seasonal occurrence of potato tuber moth was studied using pheromone traps in Co lombia , Peru , Burundi, and Ethiopia. The findings provide a basis for more efficient application of control measures and 11 clones have been selected for resistance to leafminer fly. We also have identified clones with re- sistance to Andean weevil, Premnotrypes suturicallus, Thrips palmi, and to the mites Tetra11iclws urticae an d Polyphagotar- sonemus latus. The fungus Beauveria was effective in controlling Andean weevil. Natural enemies in the host range of thrips and mites attacking potatoes were identified in the lowland Philippines. Good progress was made in selecting for resistance to the West Indian sweet potato weevil Euscepes postfasciatus. Beauveria also seems to be effective in controlling the larval, pupal, and adult stages of this pest. Production and Postharvest Technology Our studies continue to show gains in improving the sustainability of yields of potato following continuous production and diffused-light storage cycles. In the Philippines, clones 384515.9, 385131.52, 385130.8, and 385152.44 were found to be especially promising. In screening for yield capability of sweet potato clones, we obtained acceptable tuber-root yields at each of CIP's stations in Peru, as well as at the salty-environment site at Tacna. Unacceptable tuber-root yields were ob- tained only during the hot rainy season at Yurimaguas. A new line of research has begun to examine the physiology of tol- erance to water logging. In sweet potato drought research, our studies have dem- onstrated the importance of maintaining a good foliage cover over the soil and of an early storage-root form ation. Our studies of potato under drought conditions have identified clones that can avoid drought (large root systems, e.g. clones P-3 and P-7) or escape drought (early tuber izing clones, e .g . cv. Berolina). Drought resistance was con- firmed for cultivars Huinkul, LT-7, and MS-3527 R. In Egypt, sunnower was identified as a good alternative crop to maize to shade the early autumn potato crop. Shade-tolerant cultivars also were identified for strip cropping in China. The advantages of pest control through intercropping practices have now been quantified in Southeast Asia. Our recent research has demonstrated the potential for use of the sweet potato germplasm collection in selection for shade tolerance. Thus we anticipate fu- ture selection of clones specifically for intercropping. In our work on improvement of potato and sweet potato production in cool en- vironments of developing countries, we have emphasized multidisciplinary ap- proaches. In field testing and selection for potato tolerance to frost at Puno (3,850), we selected clones for tolerance to frost, earliness, desirable agronomic characters, and high yields despite severe drought and incidence of frost. The out- standing clones were chosen for multi- plication and potential variety releases in collaboration with INIA, Chile. The clones selected for long-day adaptation from CIP 's improved ge rmpl as m produced tuber yields up to 30% greater than did locally grown cultivars. In con- tract research with INIA, Chile, the early sprouting CIP clone DT0-33 showed the most promising performance under sub- optimal temperatures. The most impor- tant characteristics of such performance appeared lo involve shorter dormancy and early tuber initiations, along with a rapid bulking rate. Studies in Cameroon indicated that poultry manure at an ap- plication rate of 5 t/ha produced the best XXXIII results, as compared with yields obtained with locally available fertilizers. Reports from Ethiopia and Cameroon on the use of TPS for potato production indicated that the threshold for resistance to late blight in the segregating progenies is necessary for the success of this technol- ogy. Good progress was made in screen- ing sweet potato clones for adaptation to cool environments at two coastal loca- tions in Peru. In potato storage research, our studies have emphasized consumer potato storage. Evaporative cooling techniques were studied in Peru, Kenya, and India, and forced-air techniques were studied in Pakistan. Simple rustic stores were tested in India. Household storage in bamboo baskets and sacks was analyzed in Burundi. In Peru, clones were evaluated for storage characteristics. Seed storage under rustic versus refrigerator conditions was studied in Egypt. Rustic storage of seed was evaluated in Cameroon. Storage in sand of tubers produced from TPS was ex- amined in India. A storage workshop was held in Malaysia. In potato processing research, our focus · was on clonal evaluation (Peru, Thailand), continued testing and evalua- tion (including costs and returns) for rus- tic processing techniques (India), and marketing and demand for processed products in selected countries (India and Thailand). We also surveyed postharvest practices (China) and backstopping of ongoing CIP-relate d research and processing (Colombia, Guatemala, Peru, and Zaire) and in thesis work (Kenya). Sweet potato studies have also examined village-level rustic processing techniques in India. At Lima, thesis research con- tinued to evaluate the nutritional and XXXIV chemical characteristics of CIP's sweet potato germplasm collection, and a similar evaluation is now underway in Thailand. Sweet potato storage research using rustic stores has begun in India and Kenya. Worldwide collaborative research continues to improve the agronomic characteristics of selected TPS progenies intended for seed production and use in warm-climate areas. Several parental clones were identified with acceptable berry-setting capacity to produce TPS with tolerance to bacterial wilt infection, and for transplanting stock with tuber uniformity and quality, and high-yield stability. Techniques for increasing the production of hybrid TPS were tested in Chile, India, Italy, and Peru. We have intensified our research in postharvest handling of TPS. Seed-vigor losses following harvesting of TPS were shown to occur at a slower rate during storage, when the seed bad been pro- duced with high N rates. A dry environ- ment during storage was found to be important. Seedling-vigor testing of se- lected TPS progenies at various periods of storage demonstrated that the seed must be after-ripened at about 5% to 7% moisture content (dry-weight basis) and under moderate-temperature (20C) con- ditions for at least 12 months, before the seed can be effectively stored in high- temperature environments. Pre-sowing TPS in a solution of KN03 plus KJP04, followed by seed priming, was an effec- tive treatment for enhancing seed vigor at sub-optimal temperatures. In India and Peru, further improve- ments were made in the efficiency of seed- ling-tuber production techniques. The collaborative approach continues to in- vestigate the technical problems and modifications needed at each site for op- timal use of TPS !n a seedling tuber production syste m. Paraguay, Vene- zuela, Cameroon, and Indonesia are more recent partners in this research. Collaboration also has continued in strengthening or developing seed-tuber propagation systems in Bolivia, Burundi, Colombia, Venezuela, Kenya, Myanmar, the Philippines, and Peru. These projects seek to analyze the factors limiting potato production in traditional seed-tuber dis- tribution systems. Their objectives also include the transfer of technology such as simple positive selection of healthy plants, advanced rapid multiplication Food Systems Research In our needs and impact assessment re- search, we focu~ed on food systems char- acterizations, marketing, demand and utilization studies, and impact assess- ment. Food-systems characterization studies were greatly expanded as we analyzed the surveys completed by na- tional scientists on constraints to potato and sweet potato production. Potato seed problems appear to be important in all countries, but are particularly serious in tropical rainy and dry areas. For sweet potato, the importance of the weevil as a production constraint is limited to tropi- cal rainy zones. In other climatic zones, lack of planting material, moisture, and soil fertility were found to be production problems. And postharvest - especially marketing - problems were severe in all zones studied. We made case studies of potato and sweet potato food systems in Asia, Africa, and Latin America. In China, we deepened our knowledge of and diffused-light storage techniques, and the development of simple flush-out methods for basic seed systems. This work strongly emphasizes the participa- tion of farmers. In Kenya, an exceptional case study was completed as part of a series aiming to explore the strengths and weaknesses of local seed systems. Sweet potato propagation techniques were studied under a wide range of environ- ments, and agronomic and climatic fac- tors affecting flowering and seed production were identified. The use of in vitro-propagated plantlets, larger un- rooted cuttings and rooted cuttings, were shown to .result in faster establishment and growth, and increased flowering. utilization patterns in different provin- ces . Our studies und e rlin e d the variability of the production and utiliza- tion systems between the two crops and be tween provinces. Intra-provincial variability trends also were studied. The principal marketing research involved a project to synthesize the six potato marketing case studies completed over xx xv the past six years. Preliminary findings highlight the geographical concentration of potato production in Asia and the im- portance of rural marketing and rural consumption in South Asia and sub- Saharan Africa, as compared with urban marketing in Latin America. The 1984 impact study "Potatoes for the Developing World" was updated, using a new questionnaire prepared for national program leaders and CIP senior headquarters staff and regional leaders. The results indicated growth in national program research in areas related to CIP's research, thus reflecting a strong correlation in priorities. CIP training ac- tivities were felt to have the greatest im- pact on NARS, followed by a number of production technologies especially re- lated to seed. A much lower level of benefit was perceived for non-technical Future Challenges Our Thrusts reports reflect strong pro- gres.s in potato and sweet potato research, with the basic strategies used for potato now paying off rapidly for sweet pota- toes. Now we must find new ways to quantify and index the progress we have made. What has been our impact? CIP and the NARS are inextricably linked in our efforts to improve global potato and sweet potato agriculture and we have no intention of changing our team approach. Nor do we intend to claim credit for all progress reported here. However, we do need to know which of our efforts are providing the best results for the NARS and their client farm families. To make best use of our combined resources we must understand the results that can be XX XVI and non-production activities, perhaps due in part to the strong production orientation of most program leaders. Our work in strengthening NARS is closely involved with two food systems- orie n ted networks. The PRACIPA marketing network completed two years of activities in 1989, and backstopping continues via workshops and annual meetings. The Users' Perspective with Agricultural Research and Development Project (UPWARD) began activities in Southeast Asia, with 12 projects focused on production, postharvest or consump- tion issues within a food-systems context. In addition to participation in informal courses or workshops, strengthening of NARS capacity has also been achieved through diagnostic studies of sweet potato food systems completed or being planned in Latin America or Africa. attributed to CIP efforts versus those of NARS. We have begun to identify and describe such indicators of CIP's progress in all Thrust components: re- search, training, and communications. And consistent with one of CIP's basic principles we will continue to use our own expertise, and we will explore new ways to interact with other institutions that can help us through contracts and international planning conferences to be held in 1991. XX XVII In CIP's germplasm enhancement projec t, an alternative path has been developed to screen wild 2x and 4x accessions for desirable characteristics. Thrust I Collection, Maintenance, and Utilization of Unexploited Genetic Resources Thrust Profile: 1990 Excellent progress has been made in the utilization and enhancement of diploid and tetraploid wild and cultivated potato germplasm, using traditional and newly- developed methods and their combinations. Three diploid potato species new to science and a new form of the tetraploid species S. acaule were described and reported, and the biosystematic position was clarified for several species with excellent potential for germplasm enhancement. The field-maintained cultivated potato collection planted in 1989 contained a total of 3,439 Andean cultivars, and about 99% of this material is now also maintained in vitro. More than 1,500 newly obtained accessions are being studied to eliminate duplication and to be added to the world collection. Security procedures have provided for further duplication of important potato germplasm outside CIP. A new approach is being tested to help in the conservation of genetic diversity in the potato fields of Andean farmers. The genetic transformation of potato clones using Agrobacterium sp. plasmid vectors has also progressed rapidly. A computerized database for the collection has been developed using all the available data. A total of 299 Ipomoea accessions were collected in 130 localities in Guatemala, Panama, and Peru and added to CIP's collection, and additional acces- sions were received as donations from Brazil and Australia. The UTA sweet potato germplasm collection is being transferred to CIP. A total of 3,520 sweet potato accessions of various provenances were planted, either in the field or in the quarantine screenhouse of CIP headquarters in La Molina, on the outskirts of Lima. In vitro introduction and duplication of this collection continued outside Peru. Additional emphasis was given to the use of electrophoresis to identify duplicates. CIP dis- tributed 20,572 stem cuttings from 1,810 accessions, 3,810 storage roots from 561 accessions, and 2,345 seeds from 281 wild Ipomoea accessions for evaluation and utilization. Sweet potato germplasm enhancement continued successfully, combining both innovative and traditional cytogenetic methods. Studies of wild 2x and 4x /. trifida species have shown exceptional promise for use in future sweet potato breeding work. 1 Biosystematic Studies on Potato CIP researchers described three potato species new to science in 1989: S. ama- yanum and S. bill hookerii of the taxono- mic series Tuberosa, and S. salasanium of the series Conicibaccata. All 3 have a chromosome number of 2n = 2x = 24 and are from the central Andes of Peru (2,700 m to 3,700 m). A new form of the important tetraploid wild species S. acaule was also identified and named F. incuyanum. Preliminary tests of F. in- cuyanum have shown apparent resis- tance to multiplication of the PLR V virus and to mechanical inoculation of PSTV d. Taxonomic research on one of the puta- tive ancestors of S. acaule, the diploid, highly frost-resistant species S. buka- sovii, has greatly clarified the taxonomic position of this species. Comparative studies at various herbaria in the U.S.A., Europe, and at CIP have shown that the species S. canasense, S. multidissectum, S. punoense, and S. pumilum Hawkes (but not S. pumilum Dun. or S. pumilum Rojas) are all synonyms of S. bukasovii. This taxonomic clarification has under- lined the enormous genetic variability present in S. bukasovii, a species that can be used in breeding without major problems. Accessions from the species S. bukasovii, S. acaule, S. lepthophyes, S. marinasense, and S. chiquidenum have been tested for resistance to Globodera pa/Iida. In all of these species, the tests showed resistance to pathotype P4A and P SA, and S. marinasense and S. chi- quidenum showed combined high resis- tance to both pathotypes. Current systematic screening for 2n pollen production in CIP's wild germ- plasm collection has two objectives: 1) to better understand evolutionary proces- ses in species formation and 2) to find new ways to utilize wild germplasm in breeding. Unreduced pollen was iden- tified in the hexaploid Mexican species S. fendleri. In Peruvian coastal material, S. medians was found to have a high fre- quency of 2n pollen production (30%), which helps to explain the high frequency of the triploid cytotypes of this species. Hundreds of intra- and interspecific crosses were made to determine the En- dosperm Balance Number (EBN) of species for which the EBN was not known or needed to be confirmed. The results of crosses between lEBN and 2EBN species are being analyzed to as- sess the effects of this specific crossability barrier. Several hybrids with progenitors having different types of resistance genes have been obtained within the wild species genepool, and hybrid materials with potential for combined resistances will be evaluated for these resistances. Potato Germplasm Collection Potato Germplasm Maintenance The total cultivated potato collection planted in the field in 1989 consisted of 3,439 Andean cultivars. About 99 per- cent of these cultivars are also main- tained in vitro. Another 1,600 accessions from recent introductions are being 2 Thrust I studied to identify new cultivars that are not represented in the world collection. As a security measure for the potato collection, CIP has duplicated a set of tubers of Peruvian cultivars at the Na- tional Agrarian University in Peru. This university maintains a national potato collection in a high-altitude field gene- bank in central Peru. In collaboration with the SEINP A project in Peru, a new approach is being tested to conserve potato genetic diversity in the fields of Andean farmers. This project helps train farmers in the true-potato-seed (TPS) technology as applied to native Andean cultivars. Selection of segregating virus- free plants is made by the farmers ac- cording to the ir local needs and preferences. Farmers in three localities are now using TPS of about 20 native cultivars that are most popular in those geographical areas with traditional agriculture, such as Cajamarca, Cuzco, and Puno. A new cold room (-15C) for long-term storage of seeds has been added to the Genetic Resources Laboratory and suffi- cient space is now available to house duplicate sets of seeds from other potato genebanks. Elimination or Duplicates Duplicate identification is continuing within 1,600 potato accessions from recent introductions. After electro- phoretic verification, 603 duplicates were eliminated in material obtained from Ar- gentina, Bolivia, and Peru. Evaluation and Distribution or Potato Germ plasm Of 200 Andean cultivars screened for resistance to the potato tuber moth, Phthorimaea opercu/e/la (PTM), 15 were found to be resistant and 35 moderately resistant. Pathogen-tested Andean cul- tivars were distributed to 14 countries as 215 tuber samples, 357 in vitro plantlets, and 7,090 seeds. In Vitro Collection or Potato Gennplasm The transfer of the world potato collec- tion to in vitro culture is now complete. The material is fully duplicated outside of Peru through a collaborative agree- ment with INIAP, the national agricul- tural research organization of Ecuador. In vitro introduction of clonal material of odd ploidy and wild species was begun during the year. Computerization of maintenance procedures of the collec- tion is now complete, and all labelling is prepared by computer. Utilization Studies on Potato The Utilization or S. acau/e In selection, maintenance, and utilization of clones resistant to PLR V and PSTV d, 124 clones of S. acaule that had been found to be resistant to PSTVd by mechanical inocula tion were further tested by Agrobacterium-mediated PSTVd cDNA inoculation (strain p160a) for resistance to the same pathogen. Twenty-one clones from this material were found to be resistant to Agrobac- terium-mediated PSTVd inoculation, and an additional 4 were identified with apparent resistance to PLRV. The PLR V resistance is based on resistance to aphid infestation and multiplication of the virus. The 25 clones thus identified have been transferred to in vitro and are ready for utilization in germ plasm enhan- cement and breeding. Preliminary screening results indicate that some of this material also might carry resistance to PVY and PYX. From this S. acaule material, Fz and backcross populations have been generated that will be used in RFLP mapping projects for the iden- Thrust I 3 tification of genes that determine resis- tance to PSTV d and to some viruses. Several systematic schemes for the ef- fective utilization of this S. acau/e material have been developed, including a cross combination between S. acaule and tetraploid-cultivated potato clones, a combination that always failed in the past, due to the operation of the triploid block or the EBN barrier. An innovative ap- proach using counterfeit pollination with the.haploid inducer lvP 35 and embryo rescue resulted in six 4x S. acau/e x tuberosum/andigena hybrids. This ma- terial was further crossed with 2x breed- ing material, and the resulting tetraploid hybrid clone AA-3 is resistant to PSTVd, is immune to PVY, and is hypersensitive to PVX. All of these resistances were obtained from the S. acau/e source. Some of the sibs of AA-3 are aneuploid and will th us provide excellent material for RFLP gene-marker studies. Potato Germplasm Enhancement Diploid and 4x x 2x Potato Germplasm Screening f or resistance to root-knot nematode (RKN). Findings confirmed that CIP's 2x progenitors with resistance to RKN transmit that resistance to their 4x progenies which result from 4x x 2x crosses. About 18% of the 4x progenies thus obtained were resistant to RKN. These results also indicated that male x female interaction determines the levels of resistance expressed in the 4x hybrid material. An average increase of 5C in the testing environment caused by a change of roofing material, further demonstrated that higher temperatures might eliminate resistance reactions ob- served in the same material in previous seasons. Because of the temperature problem encountered in the customary testing en- vironment, an in vitro method was used to test newly developed diploid clones for RKN resistance. High levels of resistance were identified in 5 new diploid clones. This material broadens the specific genetic base of RKN resistance at CIP, since the only previous effective and usable wild sources of RKN resistance were clones of S. sparsipilum. The new 4 Thrust I diploid material has S. multidissectum, S. bukasovii, S. canasense, and S. gorlayi in its background. These wild species were crossed with dihaploid S. tubero- sum ssp. tuberosum clones that were produced under a research contract with the University of Wisconsin. Some of these clones have good 2n pollen produc- tion and are now in use in a 4x x 2x crossing program. Their excellent tuber appearance had been confirmed in a pre- vious growing season. Resistance to bacteria/ wilt in selected 2x clones. A total of 40 diploid clones were evaluated by inoculation with iso- late 204 of Pseudomonas solanacearnm. Each clone was represented by 10 plants that were evaluated for wilt symptoms after 12, 25, and 32 days. The scale used in this evaluation ranked from 1 (no wilt- ing) to 5 (completely wilted plant). Three clon es fr om this group (84.193.30, 85.37.38, and 85.123.8) had a score of2 at 25 days after inoculation, whereas the completely susceptible check, th e Peruvian variety "Yungay," had a score of 3.4. All of the resistant genotypes have clone MI.49.10 in their pedigrees. This clone had previously been selected for bacterial wilt resistance and 2n pollen production. Similarly, 84.193.30 and 85.123.8 had previously demonstrated resistance to BW. Clone 85.37.38 is known to transmit RKN resistance to its 4x progenies resulting from 4x x 2x cros- ses; thus this clone combines BW and RKN resistance, and it has been used as a pollen parent in seventeen 4x x 2x com- binations to obtain more than 12,000 seeds. Resistance to the Potato Tuber Moth (PTM). Excellent progress has been made in transferring PTM resistance from the wild species S. sparsipilum to 2x cultivated germplasm, with findings in- dicating that the presence of S. spar- sipilum is desirable, but not essential, for the expression of resistance. A total of 466 clones from nineteen 2x families were evaluated for their resistance to PTM, under storage conditions at San Ramon. F ive replications per genotype were used, and the material was evaluated 150 days after it had entered storage, using a scale ranking from 1 (resistant) to 4 (completely susceptible). High levels of resistance were identified in family 2x- TS-2 x PTMl.33, which had tuberosum cytoplasm. The average resistance score of this family was 2.28, and 4 clones had a score of 1. Doubling of the chromosome number of these clones is now under way. Parental 2x clone MI.49.10 appears to transmit PTM resistance as two families with this progenitor, which had been crossed with susceptible females, showed good levels of resistance to PTM. Initial- ly, MI.49.10 had been selected for resis- tance to bacterial wilt and for its ability to produce 2n pollen. Since its wild pro- genitor is a clone of S. sparsipilum, this result might be expected. In comparing progenies derived from 2x x 4x crosses with MI.49.10 and FH122 (PTM suscep- tible clones of S. stenotomum) as pollen parents, the progenies with MI.49.10 in their pedigrees showed considerably higher levels of resistance than did those derived from FH122. The 116 seedlings from 5 families with Ml.49.10 as male parent had an average score of 2.86 after 150 days of storage, whereas 93 seedlings from 4 families with FH122 as their male parent scored as high as 3.31 after the same length of time in storage. These findings are the more remarkable be- cause Ml.49.10, which is clearly the source of .this resistance, was not specifi- cally selected for this characteristic. These results support the idea that RKN, BW, and PTM resistance, as well as 2n pollen production, can be combined in individual diploid genotypes that will transmit these characteristics to their 4x offspring. From material identified as PTM resistant in previous experiments under conditions of natural infestation in San Ramon, 152 clones were further studied with a laboratory non-choice test, and three groups were identified in the 2x material according to their levels of resis- tance. The first group is from crosses between S. tuberosum haploids and PTM-resistant diploid clones (S x R). Of 89 clones studied, 7 were classified as resistant (R) and 29 as moderately resis- tant (MR). The identification of7 clones with a clear-cut resistance reaction sup- ports the conclusion that PTM-resistant clones can be developed without the S. sparsipilum cytoplasm. The second group was a reciprocal cross of the first (R x S). Only 5 clones were tested, and none were resistan t. The third group rep- resented a cross between resistant clones (Rx R). Of the 17 clones tested from this Thrust I 5 group, only one was susceptible, whereas 9 were resistant and 7 moderately resis- tant. Previous results had indicated that clone MI.49.10 transmitted some PTM resistance to its 4x progenies in 4x x 2x crosses. However, when thirty-eight 4x clones that had MI.49.10 as a male pro- genitor were tested by the laboratory method, none was resistant. It appears that all clones identified as moderately resistant under San Ramon conditions turned out to be susceptible when tested by the laboratory method. Yield trials of 4x x a progenies. Tetra- ploid progenies obtained from 4x x 2x crosses were field tested to ascertain whether the 2x progenitors, which were often derived from wild species, would transmit their resistance to their 4x progenies. The agronomic performance of the 4x material was evaluated at the same time. The 4x material derived from wild species often produced high-yield- ing clones with excellent agronomic char7 acteristics and the desired resistances, but this material was usually late-matur- ing. Use of early-maturing 4x females in 4x x 2x crosses was suggested to correct this deficiency. To assess the relative im- portance of 4x female parents in the ex- pression of maturity in their 4x offspring following a 4x x 2x cross, two groups of genetic material were produced. The first group consisted of families derived from crosses between five 4x female parents (P-3, LT-8, Atzimba, 1-1035, and 781313F2) and 11 male parents, of which seven were 2x and four 4x. Of 55 cross combinations, 49 hybrid TPS families were produced. Use of the wide range of maturity types within the group of female parents is expected to provide a clear understanding of locally adapted, early- maturing females that could be con- 6 Thrust I sidered for this type of 4x x 2x cross. The second group was produced by crossing early-maturing females (AtlantiC, Katah- d in, A VRDC 1287.19, LT-1, and HP278.22) with five male parents (of which four were 2x and one, 7XY-1, 4x). This group was generated to assess whether known early-maturing females can correct the late maturity derived from 2x males with specific resistances. Collaborative research is under way in a doctoral thesis study at the University of Wisconsin. Distribution of seeds from 4x x a cros- ses to CIP breeders. Critical evaluation of progenies derived from 4x x 2x crosses in breeding programs is essential to assess the parental value of the resistant 2x progenitors. Therefore, a list of 158 TPS families derived from 2x x 4x crosses was distributed to CIP breeders to enable them to make use of this material in their advanced breeding programs, as well as to assess the parental value of the 2x progenitors that are 2n pollen producers with specific resistances to BW and RKN. Application of molecular methods for potato germplasm enhancem ent. Sig- nificant advances were made in the use of Agrobacterium plasmid gene constructs to transform potato clones. A range of new promoter (control) sequences was obtained and tested, and it is now pos- sible to regulate the amount and site of a particular gene product. Such control al- lowed direct production of synthetic proteins high in essential amino acids and specifically directed to potato tubers. A relatively new marker gene, known as GUS, was added to all gene construc- tions. GUS, which codes for the produc- tion of an enzyme that reacts when the plant is given a particular substratum, -~. ~ '// ' _/ . - _.,, figure 1-1. Isolated roots in test for GUS activity. This test indicates preliminary evidence for gene insertion. GUS-positive reaction is indicated by blue-stain reaction . represents a simple colorimetric test to ascertain the presence or absence of this gene product. Figure 1-1 shows the results of a GUS assay. A wide range of transformation ex- periments was performed in 1989 using both A. rhizogenes and A. tumefaciens. The transformation products from these experiments have been tested using both kanamycin resistance and GUS reaction. New, more potent genes that show ac- tivity against Pseudomonas solanacea- rnm, the causal agent of bacterial wilt, have been synthesized under contract with Louisiana State University in the U.S.A. These genes code for antibac- terial proteins such as attacin and ce- cropm. However, synthetic modifications known as SB-1 and Shiva show a substan- tially higher level of antibacterial activity than does the natural component. Plant- lets transformed with Shiva have already been tested with kanamycin and GUS and have been through early screening trials conducted by CIP's pathologists. Cuttings from the survivors of the early screening are being re-tested. Collaborating with institutions in Florence, Naples, Rome, and Viterbo, CIP assisted in studies on transformation for pest and disease resistance and the use of in vitro methods to select for resis- tance to biotic and abiotic stresses. Restriction Fragment Length Polymor- phism (RFLP) Analysis. During 1989, CIP established a new research contract with Cornell University in the U.S.A. to further develop the already existing RFLP linkage map of potato (shown in Fig. 1-2). The map has advanced sig- nificantly and is based on tomato probes. On the basis of this map, a collaborative Cornell University-CIP project was car- Thrust I 7 2 3 4 5 6 IUSS TGS6 7 C•b3, TG40, TG1 .lS CD3t COil Rbcst 2 CDt,C0308.TG1 gmt,TG130 16 10 TGl25 TGl38 TG21 abl. TGl4,Prx2 G74 CD64 ' CD67 TG29 CD43 YI' 3 4 6Pgdh3 5 TG25 TG70 035 TG129 CD41 ' CD25 CD9 30 16 fiG5' 3 Gt318,Rbcs3 CD38B 10 Gl19 11 Tc.SO fli£J3.TG32 CD42 TG4~ CD3id from trehalose Utilization of L-tryptophane Utilization of L (+) tartrate 100 100 100 95 0 4 0 0 8 Isolates from warm climates (including 7 from Yurimaguas, Peru; 3 from La Chincana, San Ramon, Peru; and 9 from Brazil). b Isolates from 28 countries: Argentina, Australia, Brazil, Burundi, Chile, China, Colombia, Costa Rica, Egypt, Greece, India, Indonesia, Iran, Israel, Kenya, Malaysia, Mexico, Nepal, Nigeria, Panama, Peru, the Philippines, Puerto Rico, Rwanda, Sri Lanka, Sweden, Uruguay, and Venezuela. At IPP-CAAS, in Beijing, China, monoclonal antibodies against P. solana- cearnm have been produced by im- muni z ing BALB / c mic e wit h glycoprotein extracts from potato strains Po41 (race.-3) and Pol (race 1). Five sub- cloned hybrido ma-cell lines stably secreted monoclonal antibodies that were specific to P. sola11acearn111, but not Lo the bacteria that cause ring rot or soft rot. Antibodies from one cell line (HPS3) were specific to all strains of P. sola11a- cearn111 tested and were successfully used in an ELISA test Lo detect BW infection of potato plants and tubers. In response to wide demand, further research will emphasize the development of this tech- nique lo produce a reliable and inexpen- sive method to detect latent infection in potato seed tubers. Less specific mono- clonal antibodies are being used to group di s tinct s train s o f P. sola11acearnm. Meanwhile, at CIP headquarters, 3 new polyclonal antisera were produced (one against race 1 and two against race 3) and their specificity is now being evaluated. Integrated control of bacterial wilt. Col- laborative research between CIP and NARS continues to focus on the selec- tion of cropping systems that reduce the 36 Thrust III incidence ofBW. Integrated control stra- tegies are needed by farmers to reduce losses in the field. Such control measures a re also required to complement the levels of bacterial wilt (BW) resistance in newly developed potato cultivars that are not completely resistant in adverse, high- tem perat ure environme nts or under heavy inoculum pressure. In collaboration with the Department of Plant Protection ofISABU, Burundi a survey to evaluate the occurrence of BW in farmers' fields provided valuable find- ings for helping to develop integrated control strategies. Wilt incidence was shown lo be affected by the previous rota- tion, with the lowest levels occurring after cassava (during th e September to January season) and after banana, during the following season. The BW-tolcrant variety Ndinamagara (CIP germplasm accession No. 720118) occupied 77% of the total land planted with potato and, on aver age, wilted less than did o ther varieties. However, BW incidence also was notably low in susceptible varieties such as Muziranzara, when the seed had bee n obtained from the ISABU seed farm and a 2-year crop rotation had been practiced. Increased extension efforts have successfully prevented the planting of potato as a monoculture; however, volunteer potato plants were recognized as a major source of P. solanaceamm in the field. R esults from a 3-year study of crop- ping systems in Bukidnon, Philippines, conducted in cooperation with the Philippine Department of Agriculture, also showed the effect of crop rotation on BW incidence in 3 locations over 6 seasons. The inoculum potential of P. so/a11aceamm (race 1) in the soil was highest following a potato crop, and lowest following maize, a lthough the potential remained sufficiently high to cause disease in all cases. Rotation with maize or beans reduced BW incidence and increased yield in a subsequent potato crop, whereas potato monocul- ture increased wilt and reduced yield. The incidence of BW was not influenced by the slope of the land or by terracing or contour-cropping. In San Ramon, Peru, studies of poten- tial components for integrated control of P. sola11acean11n (race 1) showed that BW incidence (in field-grown tomatoes) increased following rotation with cowpea or beans, whereas incidence decreased following maize or a herbicide-treated fallow. These incidences were correlated with the level of root-knot nematode damage (r = 0.75, P < .05). A direct ef- fec;t-of the herbicide mctribuzin on soil- borne populations of P. so/anaceanmz was demonstrated in the screenhouse. When field soil in pots had been pre- viously inoculated with a suspension of the bacte rium (containing 108 viable cells per ml), an application rate equivalent to 4.8 Vha was sufficient to reduce the bac- terial population to < .01. Both pre- and post-emergence appl icat io ns of this product in pot a to c ro ps effectively controlled weed hosts of both P. solana- ceanmz andMeloidogy11e spp. Soil amend- ments also retarded the development of BW. In screenhouse tests, BW incidence in potato seedlings was reduced from 97% at 90 days after sowing, to only 10.7%, when the inoculated soil was pre- viously amended with calcium oxide (0.5% by weight); to 2.7% when amended with urea (0.1 % by weight); and to 0% when amended with a mixture of the two. Field soil amendment with calcium oxide (2 t/ha), urea (200 kg N/ha) and com- posted sugar cane bagasse (10 t/ha), also retarded the development of BW in the field (Fig. 3-2). Previous rotation with Crotalaria spectabilis o r Tagetes erect a resulted in increased wilt in the sub- sequent potato crops, because even though the crops reduced root-knot nematode incidence, they tended to in- c rease the inocu lum potential of P. sola11aceamm . At San Ramon, in race 1-infested soils, tests evaluated the rela- tive resistance of adapted potato cul- t i vars. A s ubs tantial site-sp ecific variability was observed (Fig. 3-3), and 2 cultivars (Yungay and Mariva) per- formed much the same as the resistant check clone BR-69.84. Im plementation of the above in- tegrated cont rol measures to comple- ment the performance of tolera nt cultivars can provide low-cost control of BW for immediate improvement of con- s um er potato produc tion by sma ll farmers in developing countries. In Peru, the effect of integrating the various con- trol components has been studied in San Ramon, and, in association with INIAA, in Carhuaz. Results show a substantial decrease in BW incidence, wi th an as- sociat ed increase in fi nal yield most Thrust III 37 r • % bacterial willt 30 I 25 20 15 10 5 0 Crotolaria • Soil amendment No soil amendment I LSD (0.05) Weeded-fallow Previous cropping Soil amendment = Bagasse (10 t/ha) + Cao (2 t/ha) + Urea (200 kg N/ha) Figure 3-2. Effect of soil amendment and previous cropping practices on bacterial wilt incidence in a Pseudomonas solanacearum (race 1) infested field in San Ramon, Peru. Cultlvar 800258 (K. Jyoti) 377258.1 (LT-2) 720045 (Atzimba) 720087 (Serrana) 800174 (DT0-33) 575003 (1-931) 720088 (B71-240.2) 720050 (CGN-09. 1) 720084 (CFK-09. 1) 377957.5 (LT-5) 720044 (Rosita) 379706.27 (LT -8) ("377257. 1 (LT-1) r ..., 720025 (Mariva) 720064 (Yungay) - 800226 (BR 69.84) y -• I I 0 20 LSD (0.05) t'? I I ~--=- I I I 40 60 80 100 % Bacterial wilt Figure 3-3. Relative resistance to Pseudomonas solanacearum (race 1) in adapted potato cultivars under field conditions in San Ramon, Peru. noted in cultivars adapted to the warm growing conditions. In San Ramon the combined effects of crop rotation with maize, pre-emergence herbicide applica- tion (metribuziun), soil amendment with composted bagasse (10 t/ ha), CaO (5 t/ha) and urea (200 kg/ha), and the use of adapted potato cultivars, were com- pared with the effects on a non-treated control, under highly-infested field con- 38 T hr ust III ditions. Further studies are planned in cooperation with INIAA in Cajamarca, Peru, with LEHRI in Indonesia, and with a CIP pathologist recently stationed in Kenya. Soft Rot and Blackleg Selection for resistance. In breeding work for resistance to Erwinias, there have been few reliable screening methods to ide ntify res is ta nt a nd s uscept ible genotypes, particularly among popula- tions at the early stages of development. Thus, 2 methods were compared during the evaluation of 2 populations (A and B) . Tubers of 1,368 genotypes were in- ocula ted with Erwinia chrysanthemi (Echr) by 1) vacuum infiltration with an aqueous suspension containing 106 c.f.u. per ml, and 2) injection of 0.05 ml of a suspension containing 1a5 c.f.u. per ml, 5 mm deep, avoiding lenticels. In both methods, the tubers were incubated under anaerobic conditions at 26C. Population A (approximately 30% of the genotypes tested) consisted of selections of proge- nies of cullivars of So/a11um tuberosum ssp. andige11a that showed resistance to soft rot. Population B contained selec- tions o f progenies from crosses among tropically adapted clones (mainly ssp. tuberosum). In population A, 4% were resistant (R) and 25% moderately resist- ant (MR) to inoculation by injection, whereas when inoculated by vacuum in- filtration, the percentages were 10% R and 27% MR. In population B, after in- jection, selection percentages were 2% R and 18% MR; whereas they were 1 % R and 4% MR after infiltration. Correla- tion between the results from the 2 methods was low (r = 0.14), however, 26% of the resistant (R + MR) geno- types were selected by both methods. Popula tion B had been previously selected from 96 hybrid families after seedling screening for blackleg resis- tance using a method in which TPS families were sown in sterilized compost and grown for 21 days. Apical cuttings were made, and then treated with rooting hormone. These cuttings were planted in trays containing sterilized ~erlite in · which a suspension ofEchr (10 c.f.u. per ml) had been evenly distributed. Typical blackleg symptoms did not develop in 47% of these cuttings, which were transplanted to the field, where addition- al selection reduced the population to 10% of the original. Eleven genotypes did not develop blackleg after 3 re- inocul atio ns, using 5 cuttings per genotype per test. Five of these geno- types produced tubers that were modera- tely resistant to soft rot after inoculation by injection. Over 300 pathogen-tested cultivars have been tested in preliminary selec- tions for resistance to blackleg and soft rot caused by Echr, using the vacuum infiltration method (CIP Annual Report 1988) . Nine primitive cultivars dem- onstrated high levels of both stem and tuber resistance (Table 3-4), of which 5 were S. ste11otomum, 2 were S. chaucha, and 2 were S. phureja and S. goniocalyx. The incidences of blackleg and soft rot during testing of these clones were highly correlated (r = 0.72, p < .01). /11teractio11 with Fusarium. To improve understanding of the interactions be- tween potato seed storage pathogens, which account for serious production damage on a worldwide scale, the inter- action between Erwinia carotovora ssp. carotovora (Ecc) , Fusarium oxysporum, and F. sola11i was studied by a student at the Agrarian University, in Lima. Four Thrust III 39 Table 3-4. Potential resistance to potato blackleg and soft rot in primitive cultivars from the CIP pathogen-tested collection. Solanum Tubers rotting Blackleg plants CIPNo. Cultivar sp." per sample of 5 per sample of 1 O 700318 SS-135 STN O.Oc 0.7 cd 702547 Espanol Papa STN 0.3 c 0.3d 703244 Zapallo GON 0.3 c 1.3 cd 703279 Unknown PHU 0.3 c 1.3 cd 703299 Papa Pina CHA 0.3 c 1.7 bed 701088 Juana Blanca CHA 0.7 c 0.0 d 703151 Senorita STN 0.7 c .0 cd 70332-1 Yana Ppuna STN 0.7c 1.0 cd 703197 Yana Sucre STN 1.0 c 1.7 bed Check• 800034 Pentland Crown TBR 1.3 c 5.7 a 800085 Ultimus TBR 2.7 b 3.0 b 800048 Desiree TBR 3.7 b 2.3 be 800959 Granola TBR 5.0 a 6.0a Duncan (P < 0.05). " STN = Solanum stenotomum; GON = S . goniocalyx, PHU = S. phureja; CHA = S. chaucha; TBA = S. tuberosum ssp. tuberosum. cultivars were inoculated by stabbing with needles carrying suspensions con- taining 3.3 x 10 7 c.f.u./ml of Ecc and 2 x 1a5 conidia/ml of Fusarium sp., and the amount of rotted tissue was calculated by volume in cm3. Synergism between the bacterium and each of the fungi was par- ticularly pronounced in the cultivar Revoluci6n, but was not observed in the cultivar Desiree. The degree of syner- gism may be related to the cultivar's sus- ceptibility to each pathogen alone. Tests were made of70 clones of S. tu- berosum ssp. a11dige11a, that had been previously selected for combined resist- ance to Ecc, F. oxyspomm, and F. sola11i. Two inoculation procedures confirmed resistance to F. oxyspomm in 88% to 93% of the clones, and to F. sola11i in 72% to 74% of the clones. Resistance to the com~ 40 Thrust III bination of fungal and bacterial patho- gens is now being studied. Detectio11 of late11t i11fectio11. A simple, accurate method to detect and quantify the presence of Erwi11ia spp. in latently infected seed potato tubers is needed for the development of both quarantine and seed certification regulations in both deve loping and developed countries. In Tunisia, collaborative studies at ESH at Chott-Meriem indicated that 50%-100% of seed tubers commonly imported from Europe were latently infected by E . caro- tovora ssp. atroseptica (Eca) as well as Ecc and Echr. However, the level of in- fection tended to decrease during local multiplication under dry field conditions. At CIP, Lima, a student from the UNA used laboratory rabbits to produce polyclonal antisera to 6 Peruvian Erwinia isolates. Antisera against two Ecc strains and two Eca strains (either separately or in combination) reacted positively with a wide range of strains from the CIP collec- tion, including 40 serotypes collected in- ternationally (Fig. 3-4). Antisera against Echr were specific for Echr isolates from several countries. None of the antisera detected isolates of Escherichia coli, P. solanacearum, or Agrobacterium tumefa- ciens. Greater sensitivity and a wider range of detection were observed when 108 3 • 107 13 .. .. 11 .. "' 30 108 • • • 107 • 3t .. 41 ) Susceptible Ind. host + discard (34) ELISA Tolerance (129) (-) Graft with infected .w ... '°J'o ~,00 ----i_ c.i discard (25) ELISA Res. to infection or escapes? (104) (- ) Graft with infected I. nil scions~ i (+)discard (74) Res. to infection or escapes? (30) (- ) Germplasm symptom oboor tioo ~ (>) discard (1 0) (20) (- ) Graft large No. plants with infected I. nil scions and aphid inJulations ----i_ (+) discard (5) ELISA Res. to infection (15) (- ) or escapes? Graft large No. plants with infected I. nil scion with other two isolates + ~(+) discard (2) ELISA Susceptible to (13) (- ) different isolates IMMUNITY? Test with ind. host and determine segregation for resistance and stability of resistance in field and to pre-infection with other viruses. Figure 4-4. Search for genetic resistance (immunity) to SPFMV in CIP germplasm accessions. 60 Thrust IV thin sections analyzed by electron microscopy (Fig. 4-5). The C-7 isolate induces yellowing; necrosis and dropping of basal 1eaves; and dwarfing on / . nil. This virus also infects Nicotiana clevelan- dii and Gomphrena globosa, causing leaf deformation and dwarfing of infected plants. C-7 was experimentally trans- mitted by whiteflies (Bemisia tabaci) and also through the botanical seed of in- fected/. nil. Figure 4-5. Ultra-thin section of phloem companion cell of /. nil infected with C-4 isolate. Isometric particles are seen between the chloroplast membranes. C = chloroplast; S = starch grain; V = virus particles. Bar represents 500 nm. Thrust IV 61 Glandular trichome exudate accumu lated on the body, setae. and tarsi of red spider mite (Tetranychus urticae), as observed under scanning electron microscope (X 442). ThrustV Integrated Pest Management Thrust profile: 1990 Thrust V research focuses on the identification and use of resistant germplasm, biological control agents, and other non-pesticidal methods to develop the ap- propriate components for integrated control of potato and sweet potato pests. The potato cyst nematode (PCN) breeding program identified 20 advanced clones, includ- ing clone G86056.8, which yielded 2.86 kg/plant, and clone G86147.9, which yielded 2.70 kg/plant. Several advanced clones, tuber families, and true seed with resistance to PCN have been sent to Pakistan, Ecuador, Bolivia, Mexico, Colombia, the Nether- lands, Germany, France, and New Zealand for field evaluation and use in breeding. In Ecuador two clones, J 16-10 and G 1-6, have been selected for release. A total of 52 clones have been selected by the national potato program in Ecuador for further evaluations. Resistance to PCN identified in Solanum andigena has been transferred to other adapted material. Clones with combined resistances to PCN, late blight, and viruses have been selected. Metabolites extracted from the bark of Uncaria tomentosa and foliage of Lonchocarpus sp. were toxic to PCN under laboratory conditions. Root-knot nematode (RKN) resistance was identified in several potato progenies at the diploid and tetraploid level, and additional sources were identified in S. multi- dissectum, S. bukasovii, S. canasense, and S . gourlayi. The fungus Paecilomyces /i/a- ci11us had a residual effect for RKN control on the sweet potato crop and in the Philippines, this fungus was effective in controlling PCN and RKN. Crop rotation experiments in Burundi identified the most effective cropping sequence to control RKN. In Peru the economic importance of root-lesion nematode, Pratylenchus spp, was studied andP. flakkensis was identified as the most important. Several new sources of resistance to RKN in sweet potatoes also have been identified. Protein patterns of the false root-knot nematode, Naccobus aberrans, have been studied to aid in iden- tification of populations. This technique is useful for identifying races of this nematode. The occurrence of a new nematode damaging to potatoes was studied and its nature of damage on root tissues has been documented. Further research to determine the significance in terms of impact of this nematode on potatoes is under way. Seven resistant clones with high densities of glandular trichomes type A and B were selected for Potato Tuber Moth (PTM) resistance, and this resistance was reconfirmed in material selected earlier. The granulosis virus was effective after 6 months when stored at room temperatures of 21C ± 2.5C; however, treatment with talc alone was also effective. The biological insecticide Bacillus thuringiensis (BT) applied as dust provided good protection in stored tubers. In Colombia improved techiqucs were 63 developed for mass rearing of the PTM parasitoid Che/onus phthorimaea. In Egypt and Tunisia, the use of granulosis virus (GV) and BT was found effective in storage. These components are now being used in integrated pest management. Seasonal occurrence of PTM using pheromone traps was studied in Colombia, Peru, Burundi, and Ethiopia. Highest trap captures of PTM were identified to enable the timely application of control measures. For leafminer fly, 11 additional clones have been selected. In other studies, clones resistant to Andean weevil, Premnotrypes suturica/lus, thrips, Thrips pa/mi, and mites, Tetranychus urticae and Polyphagotarsonemus /atus have been identified . The fungus Beauveria spp. was effective in controlling Andean weevil. Natural enemies and a host range of thrips and mites attacking potatoes were identified in the lowlands of the Philippines. Sweet potato clones were selected for resistance to the West Indian sweet potato weevil Euscepes postf asciatus. In greenhouse tests, the fungus Beauveria was effective in controlling the larval, pupal, and adult stages of this pest. Potato Cyst Nematode Thrust objectives for potato cyst nematode (PCN) studies are to 1) develop ad- vanced material for varietal selection and parental material with resistance to potato cyst nematode (PCN) Globodera pa/Iida, with primary emphasis on Andean countries and secondarily on adaptation to no n-traditional tropical highlands, 2) b roaden the base of r es istance through utilization of cultivated and wild species, and 3) combine resistance to PCN with resista nce to virus, frost !olerance, and late blight. Screening and Breeding for Resistance One hundred and fifty advanced clones developed by breeders from G 86 and G 85B populations were tested in infested fields at Huancayo, and 62 were selected and sent for regional trials at Huama- chuco, Cuzco, and Puno in Peru. Of these clones, 20 outyielded the two check cul- tivars, and the best clones were G86056.8, with 2.86 kg/plant and G86147.9, with 2. 70 kg/plant. Checks were Maria Huanca (1.94 kg) and Tomasa Condemayta (1.54 64 Thrust V kg/plant) . Yields improved markedly, but there was a decline in resistance to races P4A and PSA, indicating the need to study these races and choose the most appropriate ones to use in screening for the breeding program. High frequencies of PCN races P4A and PSA were identified. R esistance to race P4A was evaluated in clones G86 and G85B, using pot, petri-plate, and field tests. Results from pot and field tests correlated well. However, numer- ous clones found resistant in pots rated as susceptible in the petri-plate test. This finding suggests the need for study of a possible second mechanism for resis- tance related to the hatching and in- vasion be ing selected for in the pot test. Advanced clones, tuber progenies, and true seed were sent to national programs of Pakistan, Ecuador, Bolivia, M exico, Colombia, the Netherlands, Germany, France, and New Zealand. In Ecuador, 5 clones have been recom- mended for release, with clone 13-34 (CIP 279023.3) among the best for yield and resistance. However, clone 116-10, which isofCIP origin (377744.2xBulk LB), and clone Gl-6 are also being considered for release as cultivars. There are 17 selec- tions from the 1988 shipment in yield trials and 35 from the early shipment of 1989. Most genotypes have been rejected because of their susceptibility to late blight. To solve this problem, present breeding efforts are attempting to combine PCN resistance with late blight resistance. Broadening the Genetic Base In Huancayo, more than 400 crosses were made using previously identified PCN- resistant material. A total of 200 pro- genies were tested in the mass seedling screening with 149 rated as resistant to both races of G/obodera pa/Iida. Ten new S. andigena clones rated as resistant were selfed, intercrossed, and outcrossed with I-1039, I-1035, and G3 to evaluate the inheritance of resistance in these poten- tial sources of resistance. The average yield was 1.64 kg/plant, and 1,349 genotype clones (10.8% ) were selected as resistant. Of these, 20 genotypes were selected for resistance evaluations to es- timate the frequency of resistance. In- breeding depression was most evident in self crosses of accessions 703990, CCC 4382, 702426, and 703284, whereas the least inbreeding depression was ob- served in 703430, HJT-15, and CCC 4641. Clone 703430 was also the best parent for yield in this group. The diploid 2n pollen PCN-resistant clone 84-28-58, was used to develop 28 progenies, which were eval- uated for resistance to both races; how- ever, this clone contributed little toward resistance. From this population, 476 clones were planted in the field, with 52 selected for further yield trials (mean yields were 1.1 kg/plant at Huancayo and 0.7 kg/plant at Cajamarca). However, of all selected clones, only one originated from the diploid clone as the male parent; thus this clone did not contribute to improved resistance or yield. In other studies conducted at Cornell University, four clones which combine resistance to PCN races RIA with P4A and P5A have been developed. These are lines L114-1, L115-l, L123-1, and L127-2. Combining PCN Resistance with Virus and Late-Blight Resistance In studies of PCN/virus resistance, 66 clones with an average yield of 1.6 kg/plant were selected at Huancayo and 9 clones with an average yield of 0.78 kg/plant were selected at Cajamar- ca. At Huancayo, 60 clones were selected for PCN and late-blight resistance, and 9 clones were selected at Cajamarca. Of the clones at Huancayo, 21 were found susceptible to race P4A, but resistant to P5A; 17 were resistant to P4A, but sus- ceptible to P5A; and 22 were resistant to both races. This finding indicates that the existing genes accumulated for resis- tance to P4A and P5A can be used eff ec- tively to combine PCN resistance with other traits, because the inheritance of ·double resistance is relatively high. The best strategy to combine these resistan- ces is being investigated. Studies were made of PCN in relation to the nema- ticidal activity of metabolites extracted from the bark of Uncaria tomentosa and from the leaves and stem of Nerium oleander from Peru, and from the foliage of Lonchocarpus sp. from the Philip- pines. Diluted aqueous and ethanol ex- tracts of U. tomentosa became toxic to G. pa/Iida within 24 hours, whereas the aqueous and chloroform extracts of Lon- chocarpus sp. became toxic to nematodes Thrust V 65 48 hours after exposure. Nerium oleander extracts were not toxic. Further experi- ments are planned in the field. If effec- tive, the use of this approach would sig- nificantly reduce the need for toxic nematicides. Root-Knot Nematode (RKN) The main objectives of our root-knot nematode research are 1) to screen for and utilize resistance to Me/oidogyne incognita, and 2) to identify the compo- nents of integrated root-knot nematode management and interrelationships of th.is nematode with other organisms. Screening for and Utilization of Resistance to RKN in Potato A total of 2,670 seedlings were tested representing 33 progenies produced by crossing 5 Meloidogyne susceptible females with 4 resistant 2x clones, 2 sus- ceptible 2x clones and 1 susceptible 4x clone. Few resistant progenies were found. Other tests of resistance were made of 2,580 seedlings representing 35 progenies of 4x-2x crosses, and 1,990 see- dlings representing 9 progenies of 4x crosses, which were developed by cross- ing previously selected resistant material with those developed for adaptation to warm tropics. The frequency of resistant segregating genotypes in these crosses also was lower than expected. However, in other studies involving progeny of 4x- 2x crosses, a high level of resistance to RKN has been identified. In retesting the reaction of 743 pre- viously selected clones (97 from 2x cros- ses, 213 from 4x-2x crosses, and 433 clones from 4x crosses to M. incognita) the lowest incidence of resistance was noted in the clones of 2x crosses. Although clones of 4x-2x crosses retained their high degree of resistance, many clones from the 4x crosses also showed a good degree of resistance. 66 Thrust V A total of 81 RKN-resistant clones developed by 4x-2x crossing of suscep- tible female and resistant male pro- genitors were retested to confirm resistance. Temperatures were 4C to 6C higher than previously and most of the genotypes became susceptible when retested at this higher temperature. This finding suggests the need for stand- ardization of the temperature regimes dur ing the screening process (see Table 5-1 for temperature conditions and plant reactions) . Additional sources of resis- tance were found in five 2x clones with Solanum multidissectum, S . bukasovii, S. canasense, and S. gourlayi, thus widen- ing the gene base of the 2x population used in the breeding program. Components of Integrated RKN Management In isolated field plots of potatoes planted as a first crop at lea, Peru, studies were made of the effects on M. incognita of one preplant application of Paecilomyces lilacinus at 2 x 1014 spores/ha; of organic matter (chicken manure) at 6 t/ha; and of Aldicarb at 1.5 kg a.i./ha and 3 kg a.i./ha, when used alone and in combination. The study also investigated the residual effect of these treatments on sweet potatoes planted as the second crop. Although the yields of potatoes in treated plots were higher than in those of control plots, the differences were not significant. For most treatments on sweet potatoes, the yie lds of Meloidogyne-resistant sweet potato cv. Nemaiiete were generally sig- Table 5-1. Reaction of some clones selected as resistant to root-knot nematode, Meloidogyne incognita, during 1988 and retested in 1989. La Molina , Peru. No. o f clones 44 3 1 7 1988 evaluation (Av. temp. = 26C) Root galling indexn 1 2 3 Total= 81 2 12 20 11 12 31 1989 evaluation (Av. temp. = 31 C) 3 4 8 4 17 1 2 3 27 8 5 2 3 6 07 0 0 0 n 1 = highly resis tant, 2 = resistant , 3 = moderately resistant, 4 = mode ra tely susceptible, 5 = sus - ceptible, 6 = very susceptible. nificantly higher than those from the con- trol plots. No differences were noted in the nematode populations for all treat- ments when measured immediately after harvest of each crop; howe ver, the nematode population at sweet potato harvest was significantly lower than that of the init ial p opulation and of that measured after potato harvest. When used in an integrated RKN-management program, the resistant sweet potato cul- tivars, in combination with other treat- ments used in this study, wi ll further reduce nematode populations. A single application of any of these components at the beginning of the first crop resulted in a residual effect that contributed to the yield increase of the second crop. Observations of the effect of these treatments on the third crop (potatoes) indicated a general pattern of decreasing ne matode population, which in part may be att ributed to the use of a highly resis- ta nt rotation crop (sweet potato cv. Nemaiiete). Evaluations were made of the effect of 50 isolates of plant growth-promoting Rhizobacteria on deve lopm e nt of the potato plant and control of RKN. Al- though the metabolites of all these iso- lates were toxic to M. incognito under laboratory conditions, they were not e f- fective when applied to the soil. All the bacterial isolates (in the greenhouse) in- creased plant growth, despite nematode infection, and a few showed some degree of nematode control. Most bacterial iso- lates showed some residual effect as they persisted in the soil ; they promoted a better growth of the next crop than did the non-inoculated control. Nematicidal activity of 16 fungal species isolated from cysts of PCN was evaluated on M. incog- nito, G. pallida, and Naccobus aberrans. These metabolites were very effective in killing the G. pa/Iida juveniles; however, they were not effective in controlling RKN, and the metabolites of only 3 fungi killed 90% of N. aberrans. The data sug- gest some specificity in the biocontrol activity of fungi isolated from G. pallida cysts. Further studies should be made to identify organisms that produce metabo- lites with broad-spectrum activity against several genera of nematodes. Crop rotation influences on RKN con- trol were studied at Gisozi, Burundi. Best results were obtained with Panicum max- imum as the preceding crop, followed by Sorghum sp. and finally Setaria sp. and Tn"ticwn sp. These crops reduced RKN populations in soil. Thrust V 67 Sweet Potato Root-knot nematode (RK.N), M. incog- nita, is a major pest of sweet potato in many areas of the warm tropics. A total of 54 clones from the sweet potato germ- plasm collection were evaluated for resis- tance to M. incognita, and 8 resistant and 4 moderately-resistant clones were iden- tified. At San Ramon, 140 second-genera- tion clones were tested: one clone was found to be highly resistant and 29 were resistant. Seedlings of l,113 genotypes repre- senting 11 progenies were tested, and 76 were found to be highly resistant and 106 were resistant. Root-Lesion Nematode Assessment was made of the distribution of Pratyle11chus spp. in Peru, and methods for management were studied. A total of 174 root and soil samples were collected from La Libertad, Ancash, Lima, lea, Cerro de Pasco, Junin, Huanuco, Ayacu- cho, Cuzco, and Puno. They were analyzed to detect Pratylenchus spp., and the fol- lowing percentages were found: P. flak- ke11sis (46 %), P. penetrans (20%), P. brachycurus (12% ), P. scribneri (2% ), P. zeae (8 %) , P. coffeae (15%), and P. crenatus (3.5%). Small percentages of P. a11dinus, P. macrostylus, P. neglectus, and P. vu/11us also were found. Of 50 plant species tested, all Chenopodiaceae, Liliaceae, Trop ae/aceae, and Um- beliferaceae were resistant. Plant species Chenopodium ambrosioides, Tagetes minuta, and Tagetes patu/a were resistant and antagonistic to P. flakkensis. On the Peruvian coast, sweet potato, cotton, peas, and beans were effective in crop rotation studies and in the Andean high- lands, oats, barley, lupine, and wheat were 68 Thrust V In a retest of the material previously selected in a seedling screening test, 22 out of 32 clones tested retained their high degree of resistance, while 7 out of 14 were rated as resistant in the retest. Higher greenhouse temperature during the retest, ( 4C to 6C higher than that of the initial test) may account for this loss of resistance. Nevertheless, results of the above two studies indicate that the seed- ling screening method is efficient. The resistance of 131 clones of Ipomoea tri- fida was tested in another screening test and 57 highly resistant and 43 resistant clones were identified. identified as useful crops for rotation to reduce populations of this nematode. The protein patterns of false root- knot nematode, Nacobbus abe"ans, were studied to identify races. Electrophoretic studies indicated no differences in protein patterns of these nematodes when grown on roots of potato or tomato plants. However, the protein patterns differed among populations collected from different regions of Peru. Extrac- tion and inoculation methods for this nematode have been developed. The taxonomy of a new plant-parasitic nema- tode attacking potatoes in Peru also is being studied. Examinations of root sec- tions revealed that these ne matodes penetrated and moved inter- and intra- cellularly along the root axis in the corti- cal tissue parallel to the stelar region. Necrosis was usually limited to the cells adjace nt to the nematode. Further studies to identify this new nematode are in progress. Insect and Mite Pests This research identifies useful control components for an integrated pest management (IPM) strategy to reduce Potato Tuber Moth (PTM) Screening for Resistance In an initial test, tubers of 65 advanced clones with high densities of glandular trichomes types A ( 4-lobed) and B (long- stalked with sticky droplets) were tested using the closed container test, and seven of these clones were selected as resistant. Of these seven, clones T86H735.8, T86H748.3, and TA14.6 had high levels of antibiosis. In a second test, laboratory and storage tests were conducted to reconfirm resistance in 190 clones from injury caused by major insect and mite pests that infest potato and sweet potato. populations P82, P83, P85, OCH6579, in hybrids selected for resistance to Australian PTM population, P87, in clones selected for the Colombian PTM population, and in clones with high den- sities of glandular trichomes. Emphasis centered on identifying clones with high densities of glandular trichomes and tuber resistance to PTM. In laboratory tests, 32 clones were selected as resistant. In storage tests, 79 clones were selected as moderately resistant (Table 5-2). Table 5-2. Reconfirmation of resistance to potato tuber moth, Phthorimaea operculella, for clones selected between 1982-1987. La Molina and San Ramon, Peru. Laboratory test Storage test Potato Moderately Moderately popula- No. No. Resistant resistant No. No. resistant tions8 evaluated selected (R) (MR) evaluated selected (MR) P 82 5 1 5 0 P83 8 6 2 4 8 8 8 P85 6 5 1 4 6 5 5 P87 61 19 3 16 61 21 21 OCH 6579 11 3 3 11 2 2 PALM 31 15 5 10 29 16 16 PASR 27 15 4 11 27 1 1 PA 34 26 14 12 37 22 22 PC 3 3 2 3 3 3 PT 3 2 3 Total 189 95 32 63 190 79 79 8 Acronyms used by breeders. P82-87: PTM population developed in 1982, 1983, 1985, and 1987. PA LM: Hybrids with resistance to Australian PTM selected in La Molina. PA SR: Selected in San Ramon. PA: Hybrids with resistance to Australian PTM. PC: Clones resistant to Colombian PTM. PT: Hybrids developed for glandular trichomes resistant to PTM. Thrust V 69 This population has a broad-based resistance to PTM populations from Australia, Colombia, and Peru. In a third test, 401 clones selected in the field from the second clonal generation P87 were evaluated in storage at San Ramon and 75% of the clones were selected for resis- tance. This high level of segregation for resistance reflects substantial progress in the breeding program. Resistance has now been increased through careful selection, and most of the selected clones are high-yielding, averaging more than l kg/plant. Siblings P85072.3 and P85072.4 showed the greatest ability to transmit resistance. Resistance at the diploid level was studied in 111 clones, and a total of 16 were selected as resistant. In Colombia, tests were made of potato clones obtain- ed from Cornell University and CIP breeders. Pupation in some of these clones was substantially reduced (Fig. 5-1) and a total of 120 clones have been selected an~ are being screened for resis- tance to other insect pests. At Cornell University, additional trichome clones have been developed from callus culture: clones 4001, 4029, 4038, and 4040. These clones show promise for transmitting B droplets in backcrosses. Biological Control Further evaluations have been made of the granulosis virus (GV), the bacteria Bacillus tlmringiensis (BT), and the parasitoid Copidosoma sp. The formula- tion of GV plus talc stored at lOC for 6 months was compared with the formula- tion stored for the same period at 21C ± 2.5C (room temperature), and with the freshly prepared GV formulation. All 3 formulations were effective, indicating that G V does not lose its effectiveness when stored at room temperature. The effect of talc alone was investigated at levels of 1 gm/kg, 3 gm/kg, and 5 gm/kg of stored potatoes. Levels of talc at 3 gm/kg and 5 gm/kg affected larval development and damage; pupation was reduced by No. of pupae .--~~~~~~~~~~~~~~~~~~~~--:::::::-~. 20 15 10 5 a a a a 0 87-11 -10 L-237-58 87- 11-3 TM-2 L-237-52 87-1 1-4 TM-1 Crlclla Improved clones Figure 5-1. Results of a test using the closed container test for resistance against the PTM . All the new clones behav ed as resistant when compared with the check Criolla cv. Duncan's Multiple Range Test (P <.05). 70 Thrust V 59%, and the number of holes in tubers was reduced by 76%. PTM larvae on talc- treatcd tubers fell off or showed coated blocked spiracles and mouth parts. In tests of formulations of BT and GV in solulion and powder form, the most ef- fective were BT applied as dust, BT plus talc, GV plus talc, and talc alone. For all treatments, PTM damage and pupation was substantially less than that of the un- treated tubers (Table 5-3). In studies of the interaction between PTM, the parasitoid Copidosoma sp., and G V larvae of PTM emerging from parasitized PTM eggs were placed on GV-treated and untreated tubers. The pupation percentages were: 29.3% for PTM from parasitized larvae, 5.2% for GV alone and 0.4% for both GV and the parasitoid. In storage, GV plus talc and talc alone were tested at rates of 1 gm/kg to 5 gm/kg of potatoes. In comparison with untreated tubers, the 5 gm/kg dose reduced tuber damage by 72%, sprout damage by 59%, and PTM population by 78%, whereas talc alone reduced tuber damage by 49% and sprout damage by 46%. In San Ramon stores, GV and the in- secticide Deltamethrin (Decis) were tested as liquid and dust formulations, and both reduced tuber damage by over 90%, as compared to the check. Del- tamethrin E.C. was not effective. In the field, GV was compared with the biologi- cal insecticide BT (Bactospeine W.P. 0.2%) and the carbamate insecticide Methomyl (Lannate 0.4%). Both GV and BT were as effective as Mcthomyl in reducing PTM larval infestation. In com- parisons with untreated plants, the reductions were: GV, 61 %; BT, 71 %; Mcthomyl, 100%; and GV plus BT, 74%. Table 5-3. Effect of different formulations containing Bacillus thuringiensis (BT) and Granulosis virus (GV) on potato tu ber moth damage and development. La Molina, Peru. x Holes8 -x Pupae8 per per Damage8 Treatments tuber tuber index Bacillus thuringiensis (BT) Bactospeine 0.2% W.P. 2 .50 de 0.40 a 1.00 a Bactospeine 0.2% W.P. (as dust) Oa Oa 1.00 a Bactospeine +talc 0.50 ab Oa 1.00 a Granulosis virus (GV) +talc 1.40 be 0.10 a 1.00 a GV with water 3.40 e Oa 1.30 a Talc alone 1.60 cd 0.70 a 1.10 a Check 4.40 f 6.80 b 2.50 b SD 0.35 0.27 0.12 CV% 17.76 9.44 25.47 8 Means followed by diffe rent letters are significantly different using Duncan's Multiple Range Test (DMRT) P < 0.05. Thrust V 71 Methods to mass rear GV-infected larvae were studied by spraying GV in three concentrations (1,10, and 20 GV- infected larvae/liter of water) in potato plants infested with PTM and maintained in 3m x2m field cages. The optimum dose for obtaining maximum GV-infected lar- vae was 10 larvae/liter of water. At this dosage, 91 % of larvae in foliage were infected. An average yield of 35 infected larvae per plant was obtained. In Co!ombia, laboratory facilities have been established for mass rearing of PTM parasitoids Copidosoma desantisi and Chelottus phthorimeae. Other para- sitoids of Trichogramma spp. are also under study. At Kafr El Zayat, Egypt, GV and BT were tested in storage, and tuber damage with the G V +BT+ talc treat- ment was less than 10%, whereas damage in untreated tubers exceeded 60%. In Tunisia, integrated control studies continued with the evaluation and refine- ment of control components and techni- ques and examination of the population dynamics to optimize IPM strategy in storage. The efficacy of GV (Tunisian isolate) and BT (Bactospeine) separately and in combination was studied, using selected dry carriers (talc or lime) at preestablished initial rates of infestation in potato heaps of 200 kgs, which were surrounded by thick straw. Regression analysis indicated that the treatment ef- fects on populations of PTM differed (P < .05) at one month after storage. At 3 months, the PTM population stabilized without further increase. Only a slight increase in infestation occurred in the control treatment after the first month. The general lack of infestation was at- tributed to both good isolation provided by straw and to high populations of predatory mites, beetles, and spiders in 72 Thrust V the heaps. All treatments provided good control (less than 10% damage com- pared to 25% to 60% for untreated tubers). Seven treatments were found to be equally or more effective than the chemical insecticide K-Othrine. Of these, the combinations of BT-talc, BT- lime, GV-BT-talc, and GV-BT-lime were the most effective. Both GV and BT were obtained from Tunisian sources: the BT from a commercial producer of Bactospeine ($2.89/kg), and the GV from rearing facilities at INRA T (produced at a cost of $0.03 per diseased larva). The G V-producing facilities at this center are non-commercial. The costs for one-ton storage were: GV-talc, $4.67; GV-lime, $2.17; Bactospeine, $8.67, and the insec- ticide K-Othrine, $18.33. The production of GV is very economical in relation to the cost of commercially available insec- ticides. Sex Pheromone When 2 formulations of sex pheromone (PTMl, 0.4 mg + PTM2, 0.6 mg; and PTMl, 0.9 mg + PTM2, 0.1 mg) were compared in water traps at La Molina, Peru, no significant differences were ob- served in trap captures during the first 8 months. However, the PTMl, 0.4 mg + 0.6 mg formulation captured more PTM after 8 months. In Tibaitata, Colombia, the triene component of this pheromone attracted more male moths than did the diene (P < .01). No differences were ob- served in trap capture when diene and triene were blended in proportions of 10:40; 20:30; 30:20; and 40:10. However, lower levels of triene resulted in lower trap captures. Such data are useful in identifying the optimum pheromone blend for monitoring PTM. In Burundi, PTM populations were monitored using sex pherome traps at Gisozi, Nyakararo, Munanira, Mwokora, and Mahwa from September 1988 to August 1989. The highest captures of 10 to 14 moths/trap/week were observed be- tween November and December in the fields and stores at Nykararo. In fields at Mahwa, the PTM population was high during M ay-July (8-20 moths/ trap/ week). In Ethiopia, trapping counts were made at the Holetta Research Center, where the moth populations were low (month/trap/week). These data help in developing recommendations for timely application of insecticides to control this pest and for adjusting planting and har- vesting dates to coincide with low PTM populations. In Egypt, wire-screened stores with pheromone and light traps gave the best protection. Leafminer Fly In field evaluations of 137 clones at La Molina, Peru, 11 were selected as mod- erately resistant to leafminer fly with clones 282 and 220 yielding more than 1.2 kg/plant. In a second test, 10 clones pre- viously selected from the TPS breeding program were reevaluated, and 7 were se- lected (136, 662, 731, 661, 28, 25, and 33). Clones 136, 661, and 28 yielded more than 900 gms/plant. The clones Monserrate, Kinigi, and Mariva, which had been selec- ted earlier for resistance, were reeval- uated and their resistance reconfirmed. Andean Potato Weevil In Peru, a total of 26 clones from the population developed for high altitudes was tested for resistance, using the closed-container test, and 15 clones were selected, some of which are resistant to Left: Andean weevil Premnotrypes spp. larvae and pre-pupae found in a potato store. Right: Tubers showing Andean weevil damage. Thrust V 73 frost and late blight. Of these clones, 85 F 46.J, 8 5F108 .3, 380495. 1, a nd 85LB70.5 yielded more than 2 kg/plant. A storage trial was cond ucted a t Chin- chero, Cuzco, P eru using the fung us Beauveria s p . as a b io logical control agent. This fungus was effective in con- trolling all stages of the weevils, emerging from the stored tubers. Nine isola tes of Beauveria sp. have been collected fro m different locations in Peru and are now being identified . Mass rear ing methods for this fungus have been improved, and barley husks have been shown to be the best and cheapest substrate . In Colombia, physical barrie rs (use of plastic bands 50-cm h igh) to p revent ac- cess to adults was effect ive in reducing infes tation. Of the insectic ides tested , Carbofuran (Furadan) was the most ef- fective as a folia r spray when applied at 60 and 67 days afte r planting. Spider Mites and Thrips C lones segr ega ting fo r g la n d ul a r trichome type A and B were evaluated for resistance to Tetranyclws urticae and Polyphagotarsonemus Latus in field cages at La Molina, Peru. From the b reeding p ro- g ram of Corne ll U nive r sity, c lo nes 1108.1, J115.1, 1115.2, and S. 11eocarde- 11asii were selected for resistance to T ur- ticae. (See thrust photo for glandular tricho me exudate accumulated o n bod y of T. urticae). These clones were suscep- tible when tested for P. lotus, indicating that resistance to one species of mite may not be correla ted to other species. Seven families from Cornell U niversity were eval- uated visually and several clones have been selected. A total of 367 clones have been selected from CIP breeding materia l. In the Philippines, 30 T PS families from the T88 po pulat ion were tested for 74 Thrust V resistance to thrips and mites, and clones T 88719, T88764, T 88766, T888770, T88810, a nd T88814 were selected. Several families also were tested in Pu no, Peru and 17 were selected for resistance. The host range and natural enemies of Thrips p a/mi and P. latus we re stud ied in the Philippines. These two pests have commo n host plants: 13 for T. pa/mi and 17 for P. latus. Nine natural enemies were identified for T pa/mi and 8 for P. latus. Sweet Potato Weevil In Peru, previously selected clones and a ddit io na l ger mplasm were screened under laborato ry and field cond it io ns, and clones RCB 17IN, DLP2173, and DLP2274 were shown to be less damaged in lab and field tests. Scanning electron microscopy (SEM) was used for male and fe male d ifferentia tion of Euscepes postfasciatus adult weevils. In the female, the posterior vent ral segment was ob- served to be nearly flat, while in the male it curves upward. For b io logical contro l, the fungus Beauveria sp. has been iso- la ted from infected adults and mass reared. In greenhouse tests, all treatments with Beauveria sp. resulted in higher mo r- tality ra tes and fewer la rvae and pupae. In the Do minican R epublic, 3 trap designs using sex pheromo ne were field evaluated fo r Cy/as fomzicarius. The water trap was found to be the most ef- fect ive, and a total o f 4,908 C. f omzicarius males were caught in a 40-day period . In collaboration with CARDI (Caribbean Agricultural Develo pment Research In- stitute) , an integrated management pro- gram for this pest has been initiated in J amaica, St. Vincent, and Barbados. Research Contracts Research contracts with the Universidad Nacional Agraria, La Molina, Lima, Peru focused on the control of major potato and sweet potato p ests. Population dynamics of L. huidobrensis have been studied in potatoes, and high infestations were found in September, with para- sitism varying from 3.3% to 13.6%. In the laboratory, selective insecticides are being identified through bioassay with leafminer fly parasitoids. In sweet potato studies, the popula- tion dynamics of the sweet potato white- fly Bemisia tabaci and its parasitoids have been collected for identification. Seasonal occurrence of other sweet potato pests also has been studied. The Centro de Introduccion y Cria de Insectos Utiles (CICIU) of Peru has collaborated in im- proving the mass rearing methods for the polyembryonic parasitoid Copidosoma desantisi of PTM. In the Philippines, collaborative studies with UPLB have evaluated the fungus P. lilacinus for con- trol of potato nematodes. Several isolates were tested and the isolate from Peru at a 2-million spore level gave 68.6% con- trol of G. rostochiensis. At the 4-million spore level, this control increased to 73.4%, and at the 8-million spore level, to 78.4%. This fungus was also effective in controlling root-knot nematode infesta- tion in tomatoes at the 4-million spore level. Ultraviolet light and gamma ir- radiation are being used to enhance the biocontrol efficacy of P. lilacinus and Metarhizium anisoplae. Left: Sweet potato root showing damage caused by the sweet potato weevil Euscepes postfasciatus. Right: Sweet potato weevil pupa lodged in the flesh of the root. Thrust V 75 Sweet potato harvest in alley-cropping e xperim ent with legume trees. Yurimaguas, Peru. Thrust VI Warm-Climate Potato and Sweet Potato Production Thrust Profile: 1990 P otato clones that yield well under warm climates continue to be selected, and now improvements in sustainability of yields following continuous production and diffused light storage (DLS) cycles have also been achieved in some clones. In the Philippines, clones 384515.9, 385131.52, 385130.8, and 385152.44 have excelled for these charac- ters·. Sweet potato clones were screened for yield capability al all CIP stations, and at salty-environment locations at Tacna, Peru. With the exception of results obtained during the hot rainy season at Yurimaguas, early clones produced acceptable tuberous root yields. To improve sweet potato yields under hot, waterlogged conditions, a new line of research has begun to examine the physiology of tolerance to waterlogging. Results from the sweet potato drought program have illustrated the importance of maintain- ing a good foliage cover over the soil and of an early storage-root formation. D rought studies in potato have identified clones that can avoid drought (large root systems, e.g. clones P-3 and P-7) or escape drought (early tuberizing clones, e .g. cv. Berolina). U nder conditions of increasing drought, resistance has now been confirmed for the cultivars Huinkul, LT-7, and MS-35.27.R. The relationship between lethal and sub- Iethal relative water contents of leaves and chlorophyll fluorescence and the ability of clones to withstand drought is now being studied, to rapidly screen genotypes for drought tolerance. Problems with salinity are oft en confounded with those of insuffi- cient water supply, especially in marginal desert regions. A series of experiments with the cultivars Atica, Alpha, and Nicola have show.n them lo be relatively tolerant to saline irrigation water. Alternative crops to maize (e.g. sunflower) were successfully used to shade the early autumn potato crop in Egypt; shade-tolerant cultivars were identified for strip cropping in China. Additionally, advantages of pest control through intercropping practices have been quantified in Southeast Asia. Studies of sweet potato clonal response to a range of artificial shade levels have illustrated the shade tolerance present in sweet potato germplasm, and have sug- gested the possibility of selecting clones specifically for intercropping. 77 Agronomic and Physiological Research Drought and Salt Tolerance Potato. Drought limits potato production in at least 20 of the 44 countries included in the constraints survey (Thrust X), and therefore merits intense research atten- tion. In particular, drought is a serious limitation to winter production of potato in the lowland tropics, where the crop coi~cides with the dry season. In addition to field selection for yield done in col- laboration with national programs, which often takes into account exposure to drought, specific studies have been made of physiological and genotypic responses to drought in Peru and the Philippines, as well as in contract research at the Scot- tish Crops Research Institute (SCRI), and in collaboration with the Volcani Center in Israel. Data collected will assist CIP and national programs to decide on 1) screening strategies that can confi- dently identify drought - tolerant genotypes, and 2) irrigation strategies suitable for localized production condi- tions. Drought-resistance evaluations based on yield and root-pull resistance (RPR) continued in Peru. Physiological age of the tubers at planting was a major con- tributor to the location, season, and year effects. Five traits (foliage dry weight, number of nodes and stolons, and root and stolon dry weight) were closely re- lated lo RPR (r2 = 0.765). Additionally, tuber weight was related to RPR in early clones. In these trials, under conditions of increasing drought, resistance was confirmed for the cultivars Huinkul, LT- 7 and MS-35.27.R, whereas BR-65.15, Cruza-27, Haille, and MEX-21 were rated as moderately resistant. In a field trial comparing the influence of two sub- 78 Thrust VI surface irrigation systems under varying degrees of drought stress, abaxial stoma- ta! resistance increased with stress, while adaxial resistance increased to an even greater extent. Stomatal resistance and stomata! density increased, suggesting a reduction in water loss and a capacity for efficient water use. Measured over time, leaf water potential became more nega- tive, suggesting an increase in the level of tissue stress. In the lowland Philippines, four clones subjected to drought stress, by withhold- ing irrigation for 30 to 50 days after plant- ing (DAP), showed uniform responses of reduced height, branching, canopy cover, and rooting (weight, length, and num- ber). The two clones with S. andigena in their ancestry (P-3 and P-7) produced the most roots, which grew down to 60 cm. However, Berolina, the earliest maturing cultivar (which had a root num- ber similar to that of P-3 and P-7) showed concentrated root growth in the top 15 cm, especially in the drought-stress treatment. This finding suggests that P-3 has drought-avoidance characteristics, whereas Berolina is characterized by drought-escape features. The response of apical cuttings taken from 10 potato clones and subjected to control and stressed moisture regimes in raised field beds was closely related to field response. This finding suggescs that this approach might represent an economy in field space for genotype screening. Reduction in dry matter accumulation was evident at 30 DAP, and tuber yield differences between treatments was evi- dent at 50 DAP. The clones DT0-28 and 380584.3 showed the least tuber yield reduction. Genetic studies must now fol- low in order to determine the heritability of drought tolerant related characters, before the development of various drought tolerant populations can be implemented. Related studies continued under con- tract at the Scottish Crops Research In- stitute to determine the combination of characters that will improve the exploita- tion of soil-water resources over the cropping season. Genotypes were grown in vertical pipes, either well-watered or with terminal drought. Yield and dry matter partitioning to tubers varied be- tween genotypes, and rates of leaf growth were related to available soil-water contents. The differences in genotypic response to drought were not associated with differen- ces in osmotic adjustment. Further experi- ments will determine whether the drought effect can be attributed to water supply due to rooting differences, or to other factors, such as cell-wall exten- sibility. Minimum leaf conductance (i.e. epidermal conductance to measure min- imum water loss) and lethal and sub- lethal relative water content (RWC) values were studied in subsidiary experiments. Genotypes did not differ markedly in RWC; however, they differed in the leaf number at which lethal RWC values oc- curred. Chlorophyll fluorescence shows promise in rapid screening for drought tolerance, whereas the use of rooted cut- tings in a polyethylene glycol-graded os- motica was disappointing, due to its uptake and toxic effect on the plants. In Israel, the decreasing availability of good quality irrigation water, plus the extension of potato production to mar- ginal (often saline) soils, has focused in- tense research attention on genotypic responses to salinity and irrigation methods. This research, funded by the Ministry of Foreign Affairs of the Netherlands, has been under way since 1986. Comparisons of differing levels of irrigation water 2 salinity (1dS/m2,35 dS/m2, and 6.6 dS/m ), have shown that yield reduction is less with short (2- to 3-day) irrigation intervals than with longer (7- to 12-day) irrigation intervals, when the same total amount of irrigation water is supplied over the season. Flexibility of the potato root system to search for water appears to be limited, thus subsurface irrigation close to the plant axis seems desirable. Potato genotypes showed dif- fering yield responses to various water salini~ies (1.4 dS/m2, 4.3 dS/m2, and 6.8 dS/m ). When the potato crop was estab- lished with nonsaline, sprinkler-irriga- tion water and then subjected to a saline drip-irrigation system, the cultivars Atica, Alpha, and Nicola, and the clone L T-4, were shown to be relatively tolerant to salinity, while Baronessa, DT0-28, DT0-33, LT-7, Superior, Desiree, and Cara were susceptible to salinity. Sprinkler irrigation with differ- ing treatments of saline water (1 4 2 . dS/m , 3.8 dS/m2, 5.6 dS/m2, and 9.3 dS/m2) did not significantly reduce tuber yield of potted plants, whether grown in saline or nonsaline nutrient solution. However, in another experiment, the amount of foliage covered with necrotic lesions of Alternaria solani was found to increase with an increase in salt con- centration in the sprinkler-applied ir- rigation water. It appears that this disease, in combination with Vefticillium dahliae, can enhance the salinity-induced decline in plant survival, and therefore emphasizes the need to incorporate resistance to these diseases in genotypes adapted to North African and Mediter- ranean conditions. Thrust VI 79 Results from an additional experi- ment indicated that the physiological age of seed tubers at planting could influence genotypicresponse to salinity. Manipula- tion of the physiological age of seed tubers could minimize the effect of salinity on growth and yield, and this will be studied in future experiments. Results, to date, on the use of saline ir- rigation water illustrate the potential that the potato crop has to adapt to marginal desert lands where supplies of nonsaline irrigation water are not available. Sweet potato. Line-source and drip-ir- rigation systems were used during the summer in Lima to effect varied irriga- tion levels, applied at similar frequencies, once the crop had been established under favorable water conditions. Under the line source system, in which irrigation ranged from 260 mm to 363 mm during the 4-month season, significant yield reductions were noted with less irrigation water (Table 6-1). It was also found that clones producing high yields generally had higher leaf-water potentials. Water use efficiency (WUE, weight of storage root per unit volume of water received by the crop) and storage root dry-matter contents were greater in drier treat- ments. As in the previous year, there was no clone with irrigation treatment inter- action for storage-root yield, or for WUE; therefore, selection for high yield under well-watered conditions would permit simultaneous selection of drought- tolerant cultivars. Table 6-1. Effects of a line·source irrigation system on root yield (kg/m2) of 14 sweet potato clones. La Molina, summer 1989. Clone code Water application rate (mm) Clone name (RCS-) 363 317 283 260 Mean Chiappe 94·1T 1.29 0.86 1.08 0.92 1.04 Paramutai 24-IT 1.07 0.95 0.79 0.87 0.92 De Armero 125-IT 0.88 0.84 0.95 0.79 0.86 Centennial 20-IF 0.74 0.88 0.53 0.49 0.66 Guiador 12Q-IT 0.93 0.50 0.40 0.65 0.62 Paramonguino 276-IN 0.78 0.77 0.10 0.59 0.56 Super Star 38-IT 0.68 0.48 0.30 0.26 0.43 Buen Pobre 72-IN 0.50 0.43 0.36 0.21 0.37 Maleno 44·1N 0.39 0.33 0.33 0.28 0.33 San Pedrano 28-IN 0.12 0.40 0.00 0.04 0.14 Morado 3·1N 0.08 0.14 0.04 0.13 0.10 Japones Portugues 64·1N 0.07 0.05 0.08 0.15 0.09 De Sal 6-IN 0.11 0.09 0.03 0.03 0.07 Amarillo de Quillabamba 173-IN 0.06 0.05 0.01 0.06 0.04 Mean 0.55 0.48 0.36 0.39 SEO clone mean 0.14 p =<0.001 Treatment mean 0.05 p = < 0.05 Clone x treatment 0.18 ns 80 Thrust VI Table 6-2. Storage root yield, yield components, foliage yield, and expansion rate of leaves and petioles (mid-season), for six sweet potato cultivars in four irrigation treatments: 1 = 100% (477 mm), 2 = 80% (405 mm), 3 = 60% (325 mm), 4 = 40% (249 mm) of estimated evapotranspiration. Total evaporation during season = 871 mm. Fresh Fresh Total storage foliage dry weight Expansion rate (cm d'1) root yield yield (foliage+ Clone Treatment (kg m·2) (kg m·2) root g; m"2) Petiole Lamina RCV31 IT 1.36 Nematode 2 1.12 3 0.63 4 0.92 RCB 120 IN 1 0.39 Guiador 2 0.38 3 0.16 4 0.17 RC 146 IN 1.39 Negrito 2 0.87 de Huanco 3 0.83 4 0.52 RCB 146 IN 1 1.30 2 1.32 3 0.67 4 0.35 With the drip system, amounts of water varying from 250 mm to 477 mm were applied to 6 cultivars during the 5-month season. The well-watered treat- ment did not invariably produce the greatest fresh storage-root yield, but it did produce the greatest total dry-matter (foliage plus roots) yield (Table 6-2). Petiole and leaf laminae extension rates were sensitive to water deficit; however, for all clones, the average reduction in extension rate for well- and poorly- watered plots (25%) was proportionally less than the reduction rate for the plots with applied irrigation (48%). Irrigation levels of 160 mm, 360 mm, and 580 mm were applied to plots of 5 3.14 941 1.13 0.89 3.55 859 1.05 0.91 3.41 705 0.86 0.79 1.91 669 0.80 0.69 6.24 1035 1.39 1.12 6.02 975 1.17 0.97 3.12 563 0.76 0.69 3.43 563 0.90 0.80 8.82 1312 5.39 950 1.60 0.84 4.67 833 1.30 0.56 2.83 616 1.31 0.68 3.00 872 1.32 1.01 2.77 819 1.09 0.88 1.79 516 1.03 0.82 2.28 619 0.83 0.75 sweet potato cultivars in the lowland Philippines. Drought sensitivity was ob- served only during the early vegetative stage, and storage-root yield was sig- nificantly reduced only at extreme mois- ture stress. As at Lima, Peru, irrigation greater than 400 mm seemed to be detrimental to root yield. The results from the Philippine study indicate that genotypic ability to tolerate water stress depends more on the earliness of storage-root formation and bulking rate than on crop cover and root growth at- tributes. Data generated in contrasting en- vironments on the physiological response of sweet potato genotypes to drought are Thrus t VI 81 unique, and provide a base upon which to develop breeding and screening strategies to improve and exploit drought tolerance in the sweet potato. The greater ability of the sweet potato over that of other crops to prosper under drought conditions will favor its exten- sion to marginal lands. In vitro screening of sweet potato germplasm for salt tolerance has con- tinued, but several anomalies remain for study. For example, the clone with best fresh and dry weight production under mildly saline conditions (174 mg NaCVl) was characterized by the lowest number of roots, and of nodes with roots. Heat and Shade Tolerance Potato. Additional data have been analyzed from controlled environment studies at Nova Scotia Agricultural Col- lege (NSAC), Canada, and from contract research at Cornell University, U.S.A. At NSAC, combinations of low ir- radiance (250280/mol/m2/s) and high temperature (33C/25C day/night) - as found in shaded intercrops of potato - significantly reduced net assimilation rates for the two clones studied, as shown by comparable rates obtained under high irradiance, cool-temperature conditions ( 430-450 mol/m2/ s and 20C/ 10C). Respiration following 16 h at 30C was greater in plants grown under high-light and low-temperature conditions, sug- gesting a greater pool of assimilates under the more favorable conditions. Data on rates of carbon fixation suggest that leaves adapt to higher temperatures: the net photos~thetic rate at 30C was 9.19 mol C02fm2/s for leaves produced under hot conditions, compared to 7.25 mol for leaves produced under cool con- ditions. Terminal and variable (peak- 82 Thrust VI minus-initial) fluorescence values were closely related to total dry weight production and growth parameters, and may act as indicators for tolerance to high temperature and low irradiance. At the relatively higher temperatures tested at Cornell University (40C/30C), heat sen- sitivity was associated with a complex of responses: increased senescence, a greater chlorophyll a:b ratio, inhibition of dark reactions in photosynthesis, and reduced stomata! conductance. These data support the hypothesis of a causal link between photosynthesis and shoot growth at high temperature, while countering the evidence of a relationship between heat tolerance and dark respira- tion. Incorporation of a high photosyn- thetic rate appears to be the next step in the implementation of these results to improve productivity under high-temperature conditions. This incorporation might be estimated by measuring non-photo- chemical quenching of fluorescence, which correlated closely with C02-satu- rated rates of 0 2 evaluation at 25C and 40C in heat-tolerant and heat-sensitive accessions. Research continued on intercropping as a technique to reduce heat stress for potato, particularly at planting and/or close to harvest. In Egypt, follow-up studies built upon previous successes with relay cropping of an early autumn potato crop into an existing maize crop. This work includes use of sunflower as the shade crop and earlier (July 12) potato planting dates. Relay cropping of potato into either the maize or sunflower crops (established 45 days earlier) resulted in significant improvement in percentage emergence measured at 45 DAP, as well as 6.1 t/ha of maize grain or 2.1 t/ha of sunflower seed. The widespread practice of strip crop- ping potato with maize is important in southern and central China. Research on this topic continues under contract with CIP at the Southern China Potato Re- se arch Center, at Ens hi in H ubei Province. Studies involving variations in spatial distribution and population of both crops confirmed the advantages of 2:2 and 2:1 row ratios of maize:potato, as compared to results obtained with 3- or 4-row strips. In comparisons of maize planting dates, the mid-April planting proved best in terms of total yield (potato plus maize dry yields). Total yield was not influenced by nitrogen rates of 160 kg urea/ha when applied to each crop grown at three altitudes ( 460 m, 1,180 m, and 1,700 m). In measurements of the response of 16 potato clones to strip cropping (1:1 rows at 3.6 plants/m2 for each crop) , clones 694-11, 684-1, and Xinyu 4 produced yields greater than that of the control cultivar, Mira. Maize yield was significantly reduced by a delay in Y = maize yield (kg/mu) 1 mu = 0.0667 ha 400 • • 300 200 A • • potato maturity (Fig. 6-1), which was as- sociated with greater potato plant height and increased competition with maize for light. New potato and maize genotypes must minimize interspecific competi- tion. Further research is necessary to determine whether competition is solely for light, or whether root competition for water and nutrients also exists. Other trials conducted at Kunming, Yunnan Province, compared potato yields as a strip or sole crop in a 2:2 arrangement. Of 20 clones, seven (Serrana, Achirana Into, 381064-7, MEX-32, Kufri Jyoti, Primicia INT A, and Yunnan Purple) pro- duced greater potato yields when strip cropped. Several medicinal and vegetable crops were stuclied to deter- mine their suitability as crops with which potato can be intercropped. Intercrop- ping potato and spinach increased net returns by 8% to 48% above those ob- tained with potato alone, with the variation in returns dependent upon the pol a lo cul- tivar. Potato yields were low when grown • y = 395.8876 - 6.0535 x 0 -1-1- 1- 1- 1- 1- 1-1-1-1-1 - 1- 1- 1-1-1-1- 1-1-1-1-1 - 1-1-1-1-1-1- 1-1-1- 1- 1-1 - 1- 1- 1-1 6/25 6/30 7/5 7/10 7/15 7/20 7/25 7/28 X = potato maturity stage (month/date) Figure 6-1. The relationship between maize yie ld and potato maturity date for 16 potato cultivars when planted as a 1: 1 strip crop, Enshi, China. Thrust VI 83 with the other crops (rhubarb, figwort, tobacco, duhuo, and rue). In a rotation trial, the findings (5.1 t/ha vs 4.1 t/ha, LSD= 0.8 t/ha) indicated the benefits of reversing the strip rotation (i.e. planting maize in the second year, where potato had been planted previously, and potato where maize had been planted). However, yields were not as high as those obtained when the strip cropping followed a lone maize crop (8.3 t/ha) or an autumn vegetable crop (8.2 t!ha). New varieties and agronomic proce- dures introduced to existing intercrop- pi ng practices could have important compensatory consequences for overall yield and stability of the crop associa- tions. However, the research under con- tra ct in China has introdu ced new innovations in isolation (e.g. changing pla nting dates , varieties) without detrimental effects, and these must now be fully tested by farmers. To take into account the difficulties of acquiring adequate supplies of seed potatoes in Maharashtra State in India, collaborative work with the National Agricultural Research Project in Auran- gabad has recently focused on the use of seedling tubers as planting material in the intercropping of potato and preseasonal sugarcane. Intercropping treatments tested four hybrid populations of seed- ling tubers, three tuberlet sizes (5 g-10 g, 10 g-20 g, and 20 g), and two intra-row spacings (7.5 cm and 15 cm). None of the treatments significantly influenced cane growth characters and sugar production, and tuber yields (10.2 t/ha to 12.1 t/ha) were similar to those of the cultivar Kufri Chandramuki (12.3 t/ha). During the two years of experiments, the best monetary returns were obtained with the largest seed tubers and closest intra-row spac- 84 Thrust VI ing. Approximately 16 g of TPS was necessary to produce 550 kg of seedling tubers on 156 m2 of nursery beds, which is sufficient for planting a 1-ha field of sugarcane. In the Philippine lowlands, variable planting dates of sweet corn after potato (0 to 30 days~, at a constant population of 5.6 plants/m for each, did not influence early potato growth or reduce tuberiza- tion. However, the resultant severe shad- ing of up to 70% during the later part of the crop significantly reduced potato yields. The square plot planting arrange- ments for maize planted simultaneously with potato ~5.6 plants/m2 of fotato and 2.8 plants/m to 8.5 plants/m of maize) increased shading and reduced tuber yields compared with yields from plant- ings arranged in rectangular plots. Data from various experiments in which maize was the shade crop indicated that daily radiation levels of MJ/m2 in shaded potato plots were insufficient to sustain rapid tuber bulking. Sweet potato. Sweet po tato is fre- quently intercropped in tropical farming systems, often with low populations of maize. An experiment in the Philippines investigated varietal suitability for inter- cropping with maize. A sharp yie ld decline of tuberous roots was not evident within the sweet corn populations tested (8:1 and 4:1 ratio of sweet potato:maize plant populations) which suggests that sweet potato genotypes are uniformly tolerant to low shade levels. Sweet corn yields ( < 1 ears per plant) were low, how- ever, which may be due to severe competi- tion by the sweet potato, and to the lack of adequate nitrogen. At Yurimaguas, Peru, in intercrop- ping trials of sweet potato and maize that maintained the single-crop sweet potato population, while planting maize at populations ranging from 0.62/m2 to 1.85 plants/m2, a significantly greater dry yield of tuberous roots was obtained, as com- pared with that obtained with sweet potato grown alone. Of the 30 clones tested under these varied shade inten- sities, few outyielded the control clone Jewel. Relay cropping of a full-popula- tion maize crop into a full-population sweet potato crop ( 45 days after planting sweet potato) reduced tuberous root yield of 30 clones by an average of 35%, mainly due to reduced individual storage root weights. Dry weight of foliage was reduced to agreater extent (47%). How- ever, some clones suffered less yield reduction than did the control clone Jewel, and might represent potential sources for shade tolerance. In an exp eriment in the lowland Philippines, with artificial shade applied from date of planting, an interaction was noted between shade treatments (0% to 70% reduction in solar radiation) and genotypes, suggesting that clones may be specifically selected for their perfor- mance as shaded intercrops. Experi- ments are under way to determine the feasibility of field and laboratory screen- ing for shade tolerance, and of the poten- tial for sweet potato as an agroforestry cover crop. Agronomic Practices to Alleviate Other Stresses Potato. In Southeast Asia, the production of good quality seed in the highlands is limited by the presence of soil borne pests and diseases. Opportunities to exploit new highland areas are limited. Thus re- search is emphasizing the production of seed tubers in rice paddies, despite the contingent production proble ms . Restricted root growth has been al- leviated by turning under the rice stubble before forming the traditional beds for potato production: yields were 1.26 kg/m2 as compared with 0.85 kg/m2 ob- tained without stubble incorporation. Plant population densities influenced yield significantly, with yields ranging from 1.17 kg/m2 at 4.6 flants/m2 to 1.53 kg/m2 at 6.4 plants/m . High rates of nitrogen fertilizer application (120 kg/ha to 480 kg/ha) are being studied as a fol- low-up to findings that dosages (600 kg/ha) typically applied to shallots (Al- lium cepa) can vastly improve foliage growth and crop cover. Pests and diseases seriously limit ware potato production in the warm-climate cropping systems of Southeast Asia. The stabilizing effect of inter cropping on pest incidence has been recommended to reduce pesticide usage. Intercropping in close proximity with shallots reduced in- sect populations (particularly aphids) in the potato crop in both 1988 and 1989, but also led to an increase in the popula- tion of thrips. Combinations of intercrop- ping and pesticide usage are now being studied to provide better control of per- sistent pests. Pests, in particular white fly (Bemisa sp.) and tbrips (Thrips tabaci), are also important in the lowland s of the Dominican Republic, where potato is a newly introduced crop. Intercropping is being studied as part of an integrated control program. Where pests are not a problem, yields with readily available cul- ti vars (e.g . R ed Pontiac, Desiree, Achirana INT A) reached a maximum of 24 t/ha, with average yields ranging from 9 t/ha to 20 t/ha. Interest in development of a chipping industry prompted experi- Thrust VI 85 meats financed by Frito Lay (FL), using the clone Atlantic and two FL clones. The yields obtained were equal to, or better than, those of the control cultivar Kennebec, and were unaffected by fer- tilizer composition (15:15:15 vs 12:30:12 N:P:K) or within-row spacing (31 cm vs. 23 cm). This finding suggests that tradi- tional farmer practices do not have to be greatly adapted to accommodate the new cul ti vars. In India, studies were made of poten- tial for use of plant-growth hormones to improve tuber yields and stress tolerance of potato. During 1987-1988, sprouted tubers of Kufri Bahar were treated with two concentrations of GA3, CCC, S3307, and Triadimefon (TFN). Yields from tubers treated with CCC (25 ppm) and TFN (5 ppm) outperformed the control yield (20.5 t/ha) by 3 t/ha to 5 t/ha. The yields from seed tubers retained and stored after harvest also benefited from applications made in the previous seasons. In 1988-89, direct application of TFN to sprouted tubers did increase tuber yield; however, the application stimulated an increase in tuber number per unit area. Further studies are being made of the interaction between environ- ment and seed treatment. Sweet potato. Sweet potato is often grown on marginal soils and the crop is subject to stresses other than drought. Inorganic fertilizer is seldom applied to sweet potato. In Peru, a free-living, nitrogen-fixing bacteria, Azospirillum, was shown to significantly increase tuberous root yields of sweet potato (by up to 200% ), when grown in pots contain- ing 3 kg of sterile coastal soil. In a field experiment at San Ramon, the effects of inoculant Azospirillum were compared, using two cultivars at three N fertilizer 86 Thrust VI rates (0 kg, 80 kg, 160 kg N/ha). The cultivars differed in their N require- ments, and even at high inorganic N ap- plication rates, yield benefits from Azospirillum were still evident. Inorganic N fertilizer applications, much of which pollutes the environment, could be reduced through leaching or utilization. Further research is under way to quantify the N contribution of variousAzospirillum accessions. Twelve experiments were run in coas- tal Peru, under contract with the Nation- al Agrarian University, to study the nutrient requirement for sweet potato. Coefficients of variability were high, ranging from 15% to 30%, as is common in sweet potato experiments. On the slightly alkaline loamy soils (which have low levels of organic matter and total N, high levels of P and K, and no salinity problems) application of 5 t/ha of farm- yard ma nure provided suffici ent nutrients to sustain yields of 20 t/ha to 30 t/ha. Responses to formulation or dosage ofN (0 Kg to 120 kg N/ha), P20s (O kg/ha to 180 kg/ha), or K20 (0 kg/ha to 200 kg/ha) did not differ significantly. At the lowland Amazon site of Yurimaguas, sweet potato yields on limed soil did not respond to N application rates of greater than 30 kg/ha. These results on contrast- ing soils confirm the efficient nature of the sweet potato crop in exploiting the soil for nutrients, and the need for mini- mum inorganic fertilizer application. The role of Azospirillum, or other non-as- sociative N-fixing rhizobacte ria in providing N to the sweet potato crop, cannot be discarded. During the tropical rainy season, sweet potato is often subjected to water- logging, a stress for which it is poorly adapted. This characteristic limits the year-round availability of sweet potato and other tuberous root crops in many tropical areas. Therefore, research is under way to assess the physiological response of young sweet potato plants to waterlogging, and to develop suitable techniques to help identify tolerant genotypes. These studies show that leaf abscission was enhanced after longer periods of waterlogging (up to 6 days), while stem extension was promoted, and foliage dry matter content(%), and tuber dry weight were reduced. Response trei:ids for other variables (e.g. shoot dry weight) measured on the five genotypes were not well expressed, and genotypes did not differ significantly among them- selves. CIP's aim is to identify tolerant genotypes within the germplasm collec- tion that can be used for crop improve- ment or for immediate field production under waterlogged conditions. Clonal Selection For potato and sweet potato, earliness is an important character that gives both crops the flexibility to adapt to the range of cropping systems found in the tropics. This character, in combination with the maintenance of high cooking quality, has received much attention in the past in potato selection. Intensive selection pressure for this character is being ap- plied in the sweet potato program. Potato Pern. Bacterial wilt at San Ramon seriously affected survival and yield of a set of clones (20 tubers/clone) planted during the rainy season of 1989. As in previous years, some clones (e.g. CFK- 69.1, 377250.7, LT-7, and Atlantic) were Although the sweet potato crop is robust at the time of planting, un- favorable conditions (e.g. lack of soil moisture) at planting can seriously delay establishment and reduce plant stand. A series of short-term experiments (ter- minated 30 days after transplanting), sug- gested the following recommendations. When drought-stressed, a stem length of 30 cm (vs. 15 cm, 20 cm, or 25 cm), with 10 cm to 15 cm covered by soil, produces the most vigorous growth, an important asset in combating early-season weed competition. Advantages of dipping cut- tings in a dissolved root hormone (NAA and IBA) were cultivar-dependent, but use of prerooted cuttings was of no benefit to any cultivar when planted under stem water conditions. Drought during establishment significantly reduced stem weight, and leaf weight and area. Root number and weight showed similar, but non-significant, trends. prevalent among the parents of selected clones. Favorable temperatures (31.8C day/16.8C night, average) and planting on clean soil promoted high yields for clones of CIP's pathogen-tested list during the dry season at San Ramon. The data for the past 5 years' testing of pathogen-tested clones have been sum- marized, and clones adapted to the mid- elevation tropics have been designated on the pathogen-tested list. Some of the clones adapted to San Ramon were tested at Yurimaguas during the dry season. Bacterial wilt was found at 40 DAP and later, leading to yield reduction in some clones. However, some clones (e.g. 1-822, CFS-69.1, and 379686.3) produced yields in excess of 1,000 g/m2, and all 30 clones evaluated are being retested in 1990. Thrust VI 87 At Tacna, in southern Peru, salinity is a stress additional to that of high tempera- tures. Of 350 PYY + PYX-resistant clones screened, 5 gave yields of 1,000 g/m2. During the winter season in Lima, PVY + PYX-resistant clones produced high and early yields (with resistance mostly in the duplex condition). These clones will be used as parents for further breeding efforts. The Philippines. All germplasm evaluations in the lowlands were con- ducted -at Canlubang Sugar Estate, Laguna, and were intercropped with sugarcane. In the third field evaluation of clones that had been repeatedly pro- duced and DLS-stored, clones 384515.9, 385131.52, 385130.8, and 385152.44 showed 50% survival rate at harvest, a per-plant yield of 500 g, and an absence of virus symptoms. These clones show potential as cultivars that could sustain lowland tropical po tat o production, without frequent recourse to multiplica- tion in traditional seed areas. Screening for tolerance to early blight was ineffec- tive, because only a slight infection was observed during the )alter part of the growing season. Gray mold disease (Botrytis cineria) was prevalent following one week of continuous rain, and sig- nificantly lowered yields. Nineteen tuber families from local crosses were tested in the field, but they did not out- perform clone LT-7, or the local check clones. Clone LT-7 yields surpassed those of a group of clones planted to evaluate their processing quality, and it showed equal quality. Vietnam and the South Pacific. Fur- ther evaluation is under way for promis- ing clones in Fiji (377850.1) and in Vietnam (Achirana INTA and 1-1039). Good storage characteristics and virus 88 Thrust VI resistance are emphasized in selection to avoid dependence upon sources of im- ported seed tubers. Burnndi. Promising results were ob- tained from exploratory evaluations to determine whether available clones would adapt to lowland (800 m) condi- tions. During the dry season (following maize), irrigated and mulched plots of potato clones yielded from 8.9 t/ha to 18.2 t/ha in a region close to the capital, Bujumbura. Pest and disease incidence was minimal. Sweet Potato Peru . Harvests were made at 90 DAP in Yurimaguas, or 120 DAP at other sites in Peru, to select early-bulking genotypes. Of a total of 60 clones, 5 second- and third -generation clones yielded 1,500 g/m2 during the summer season at Lima. Similarly, 7 second-generation and 10 third-generation selections produced yields of 1,500 g/m2 in an autumn crop at Tacna. Yields were equal to or greater than those of advanced clones from other breeding programs, which had been grown under the same conditions in Tacna. Yields at Yurimaguas were low ( < 1,000 g/m2, with the exception of one clone), which may reflect the lack of ear- liness and/or the poor adaptation to the ambient stresses (flooding, low radiation, acid soils, etc.) encountered there. Be- cause these adverse conditions are typi- cal of areas where sweet potato is not yet exploited as a low-input crop, an intense effort is now being made through the population breeding approach, to raise actual sweet potato yields under these conditions. Egypt. Traditional sweet potato cul- tivars in Egypt are low-yielding, in part due to heavy virus incidence. Two virus- free cultivars were received from NCSU in 1988 along with true seed of 5 hybrids. The cultivars (925 and 1135) outyielded local cultivars by 200% to 300%, but it is unclear from the findings to what extent this yield advantage was due to lack of virus infection. Nevertheless, this exer- cise has shown a potential improvement in yield, and healthy cuttings have been distributed to growers in areas important for sweet potato production. Three- month storage of roots in improved nawalla (rustic, dried mud-brick- adobe - structures with thick straw roofs) resulted in a 20% total weight loss (rotiage plus respiration) for the more A healthy nursery of sweet potato in India. storage-tolerant cultivar 925, whereas in unimproved nawalla, storage losses reached 55% for the cultivar 1135. India. Comparative agronomic eva- luations of · selected sweet potato varieties were initiated by CIP in 1989. Monthly plantings are being made to determine optimum planting dates, along with studies on spacing, fertilization, and planting techniques to provide agro- nomic recommendations. Similar experi- ments are also in progress in other important sweet potato production areas worldwide. Thrust VI 89 Researcher from INIA . Ch ile evalua1in9 luber produclion of clones grown under subop11mal 1emperatu1e cond111ons . Thrust VII Cool-Climate Potato and Sweet Potato Production Thrust Profile: 1990 A mullidisciplinary approach is used to develop technology to improve potato and sweet potato production in cool environments of developing countries. Improvement of potato breeding populations to provide potential cullivars for these environments focuses on limiting stress factors, on major disease and pest resistances, and on developing agronomic characters to meet farmer and consumer needs. The two main target areas for such improved germplasrn are 1) the Andean region, covering mainly the South American highlands and, 2) the non-Andean region, including cool-environment lowlands and highlands of tropical and subtropi- cal latitudes. During crop growth frost, suboptimal temperatures, and drought are the major abiotic stresses that limit potato production in these regions. Reduction of the effects of these stresses increases the potential for potato production in cool environments both by raising productivity and by expanding the area available for cultivation. Agronomic and physiological studies are focusing on cultural practices to improve potato production and lo develop methods to screen genotypes for their efficiency in the use of nitrogen where there is poor nitrogen content in the soil. The sweet potato crop in cool environments of developing countries is playing an increasingly important role in both human and animal diets, with plantings gradually expanding lo wider environments because of the crop's great plasticity for adaptation to unfavorable conditions. Improved germplasm is better adapted and fitted to farmer and consumer needs. Potato research last year included: field testing and selection for frost tolerance in collaboration with the National Potato Program of Peru INIAA, at Illpa, Puno (3,850 m). One-fifth of all clones tested were selected for their tolerance to frost, earliness, desirable agronomic characters, and high yields despite severe drought and incidence of frost. The outstanding clones were chosen by the station for multiplica- tion and potential variety releases. Collaborative projects with the Potato Program of !NIA, Chile. Clones selected for long-day adaptation from CIP's improved germplasm produced up to 30% greater tuber yields than did locally grown cultivars. A second project developed simple technology for potato prod uction that is easily adaptable for use by farmers. 91 Contract research with !NIA , Chile. In selection of potatoes for suboptimal temperatures, the early sprouting CIP clone DT0-33 showed the most promising performance. Short tuber dormancy, early tuber initiations, and a fast bulking rate appear to be the most important characters for successful adaptation to suboptimal conditions. A collaborative project in Burnndi. Timing of fungicide applications was shown to be of critical importance in helping to control late blight in varieties with different degrees of horizontal resistance. The resistant variety Sangema was severely infected when fungicide spraying was delayed until 8 weeks after plant emergence. Apparently, the level of horizontal resistance in this variety is not sufficient to withstand the effects of this fungus at this stage, without previous spraying. Improved agronomic practices for potato production in Cameroon . Findings indi- cated that poultry manure applied at a rate of 5 t/ha gave the best results when compared with other locally available fertilizers. Reports on the use ofTPS for potato production from Ethiopia and Cameroon indicated that a threshold for resistance to late blight in the segregating progenies is necessary for the success of this technology. In potato production for human consumption, seedling tubers de rived from TPS offer greater advantages for plant survival and growth. Collaborative project in Paraguay on the use of TPS for commercial potato produc- tion. Seedling-tubers of cross Serrana x LT-7 showed better performance than transplants of this cross. Tuber production of this cross (in both seed beds and the field) was the highest among those tested. Field screening of 400 sweet potato clones for adaptation to cool en vironments in two coastal locations in Pern . In research conducted during the winter, approximately90% of all clones had large roots and 69% yielded more than 0.5 kg/plant. Selected clones are being tested in mid-elevation cool environments (2,000 m - 2,500 m) for perfor- mance and adaptation. Potato Populations in Cool Environments Pota to Improvement of potato populations by selecting cultivars for cool environments has concentrated on limiting stress fac- tors such as frost tolerance, production under suboptimal temperatures, and (more recently) drought tolerance. Agronomic characters suitable lo meet farmer and consumer needs in a wider range of environments are also being considered . 92 Thrust VII Breeding for Stress Tolerance Frost. Two parallel potato breeding populations are under improvement for frost tolerance as the primary crop protection character and the gradual ad- dition of resistances to diseases and pests important in cool environments, such as viruses, late blight, and cyst nematodes. One population is targeted for the An- dean highlands, where frost incidence is a major limiting factor and cyst nema- todes are causing increasing damage. The required crop characteristics are similar to those of the native primitive cultivars that are highly appreciated by farmers and consumers. A second population is being im- proved for use in the non-Andean cool environments (highlands and lowlands) of tropical and subtropical latitudes, where early- and late-season frosts are limiting. This population will eventually have resistance to late blight, and will be adapted to long days. Crop charac- teristics required in this area are similar to those of S. Tuberosum cultivars, which have been long adapted by farmers and accepted by consumers. Testing and selection of clones was done in collaboration with the Peruvian National Potato Program, at their Southern Altiplano Experiment Station at Illpa, Puno (3,850 m). Frost damage is the most limiting factor in this area, which is the largest potato-production region in Peru. Periodic droughts are the second limiting factor. Of the 600 clones tested at this loca- tion during the year, 110 were selected for their tolerance to frost and for yield and other agronomic characters (Table 7-1). Despite the four-week drought that followed planting, and the incidence of frost 87 days after plant emergence, average yields were high. The outstand- ing clones were chosen by the local sta- tion for multiplication of clean seed stocks and for further evaluation in regional trials. Potential variety releases are planned by the national program to help overcome frost damage. Under non-frost conditions (CIP's Huancayo Station), replicated trials of the most advanced frost-tolerant clones from both populations produced tuber yields as high as 2.6 kg. per plant at a plant density of 44,444 plants/ha (Fig. 7-1), indicating their high yield potential under optimum field management. Table 7-1. Tuber yields of top-performing clones with tolerance to frost at lllpa Station, Puno (3,850 m). Frost damage after planting 8 Clone Yield 87 days 112 days number kg/10 hills -1.8 c -2.5 c 87 F172.9 19.8 4 85 F124.1 19.4 3 3 361126.5 18.9 4 3 384025.1 17.9 4 5 85 F65.4 17.9 2 2 64 FF111.2 17.2 3 Local checks Andina 14.5 2 2 Rukii 4.6 a GIP scale derived from % of foliar damage: 1 = 1%-10%, 9 = 81 %-90%. Plant density: 33,333 plants/ha. 125 days -4.5 c 6 9 7 8 9 4 8 Thrust VII 93 1.5-2.0 --- --\ (34.4%) 1.5-2.0 kg --- --\ (29.0%) a b --- ---1.0-1.5 kg (40.6%) <0.5 kg (3.1%) - --- > 2.0kg (6.3%) ;;£...-- -----0.s-1 .o kg (15.6%) --- ---1.0-1 .5 kg (43.0%) - - -- > 2.0 kg (8.0%) --- --- 0.5-1 .0kg (20.0%) Figure 7-1. Tuber yields in kg/plant of frost- tolerant clones at CIP-Huancayo Station, 1989. a) clones for Andean region; b) clones for non-Andean region. Long-day adaptation. The Potato Pro- gram of INIA (Osorno, lat. 40° S) tested 30 selected clones from lhe non-Andean potalo population previously introduced in Chile for adaptation and tuber yield performance under long days. Total tuber yields were reported to be as much as 30% over the local checks (Table 7-2). There has been prog ess in adapting cool-environmenl p0pulalions to long days for selection of potential cultivars. Suboptimal temperatures. Contract re- search was begun with the Potato Pro- gram of INIA, Chile to breed and select potatoes adapted to suboptimal tem- peratures (low-temperature profil e). Two distinct seasons were chosen for screening and selection o f po tato germplasm: 1) a fall-winter season with 94 Thrust VII mild low temperatures and short days (Santiago Valley, lat. 30° S), and 2) a winter-spring season with low tempera- tur es thro ugh most o f the growing season, and increasing day-length (Osor- no, lat. 40° S). Findings from a preliminary trial of a sample of locally available clones planted at the end of August (a month earlie r than the normal season) indicated that early tuber sprouting may be one of the key requirements for fast plant emer- gence and rapid plant growth under these conditions. Of all the clones tested, the early-sprouting clone DT0-33 (from CIP origins) was lhe first to emerge from the soil and develop a larger canopy. Similarly, when clones were harvested 90 days after planting, DT0-33 had the Table 7-2. Tuber yields of top-performing clones selected for adaptation to long days (Osorno, Chile, lat. 40° S). Yields (I/ha) Clone number Marketable Total 383125.82 60.6 61.1 aa 383151.57 37.5 59.6a 383136.47 55.9 57.7 ab 383142.62 52.2 54.2 b 383144.67 52.2 54.2 b 383144.49 51.9 54.2 b local checks Ultimus 40.6 43.1 c Desiree 41 .2 41.6c a Means followed by the same letter are no t significantly different (P < .05) . Specific gravity 1.1 02 1.103 1.106 1.109 1.106 1.109 1.106 1.100 highest yield (Fig. 7-2). However, when harvested at 114 days, yields of other clones were similar or higher, Ultimus and Remehue-10 being particularly out- standing. Further experiments are under way at other locations to examine tuber sprouting, plant emergence, tuber initia- tion, and tuber bulking rate, and to con- firm the value of characters needed to select materials for this type of environ- ment. Successful results of this research will have two direct benefits for clients in sub-tropical latitudes, where there is an increasing expansion of potato produc- tion during mild winters and where low temperatures arc a limiting factor. First, the research will select cultivars DT0-33 ;:::::;~~~~~~ Remehue 8 Urgenta -. Mirka ~=====~IL~\i''~ ·~~~~~k:=:::::i Ultimus . ., '" ~ R128.6 l~=====~=~=:i"'~==::::i Desiree )I Ya~~~: ~===~iiljiiili!iiili::::~wlli:\¥£::@:®:$¥:,;1;,m~::::::J Cardinal ••••1mtmc::::zi::mm Piratini l••••1[:::t·· !llm:i::. a:=m Sebago •••c:=:::m;m:::t Remehue1o l-::::e~;·1 :1 ::t*:':t:b::~zc:i:lilTJZC:i:liliii:liliii:liliii:lilii:I Romano iii 0.0 0.3 Tuber yield (kg/plant) Figure 7 -2. Tuber yields of cu ltivars planted under suboptimal tempe ratures in southern Chile. Experiment Station at Remehue (INIA), 1988. Thrus t VII 95 best suited to suboptimal conditions and to low-temperature profiles in particular. Secondly, because when conditions are favorable, the incidence of major dis- eases and pests is negligible, and the potatoes produced under these condi- tions are healthy and of high quality for use as seed and for human consumption. Agronomic and Physiologic Research Peru. No field studies were made of the efficient use of nitrogen (N) during the 1988-1989 season. H owever, data from previous field, greenhouse, and labora- tory experiments were further analyzed in the search for simple root morphologi- cal characters that would predict 1) yield abi lity on soils with low N, and 2) the ability to respond to added N as inor- ganic fertilizer. In tests of clones grown under low N in the field, both the fresh weight of the root system (averaged over values measured on in vitro plants, rooted cuttings, and rooted sprouts) and the average length of secondary roots were significantly and inversely related to the yielding ability. The ability to increase tuber yield in response to added N was inve rsely related to the diameter of secondary roots (measured either at the basal or apical extremes) and positively related to the apical diameter of the root hairs. These relationships were main- tained in all vegetable material evaluated and will be verified in tests of another set of potato clones. Invest igations are under way to assess non-l inear relationships be- tween tuber yield and yield increase due to added N, and root morphological characters. Bunmdi. A series of agronomic ex- periments during two growing seasons in the Crete region of Burundi investigated liming and fertilization to improve potato 96 Thrust VII production and application of fungicides to control late blight. Tuber yield responses to liming and NPK fertilization were not statistically significant. Acidic soils (pH: 4.7) and low solubility of the source of liming, as well as it s applicatio n r ate, may have prevented the response to the treatments studied. Further studies on application rates of lime as well as other sources of NPK are planned within the context of limited-resource farming systems. During two consecutive seasons, the experiments were conducted on the ef- fect of fungicide applications in control- ling late blight in three varieties with different degrees of resis ta nce. The results indicated that when spraying started 8 weeks after plant emergence, Sangema varie ty had the highest rate of foliar in fection, as compared with Uganda-11 and Ndinamagara. Yields were significantly reduced in Sangema and less affected in the other two. The resistance in Sangema apparently could not withstand the high infection pressure of the fungus when additional protection was delayed; however, the other two varieties showed higher levels of resist- ance. As an additio nal protection measure, further experiments wilJ at- tempt to determine optimal frequency and timing of fungicide applications. To control late blight under high in- oculum pressure, a more integrated ap- proach earlier in the season may be necessary. No horizontal resistance to late blight alone would stand such a pres- sure without adequate additional protec- tion measures. Cameroon. Preliminary fertilization trials in Cameroon to determine sources and applications of ferti lizer to improve Advanced clones selected in the high hills of Rwanda from CIP's genetic material. potato yield s, indicated that poultry manure applied at a rate of 5 t/ha gave the best result. The manure is locally available and cheaper than chemical fertilizers. Other agronomic practices for crop improvement, such as intercropping potato with corn and chemical control of late blight, are being studied. Chile. A collaborat ive project with the Potato Program of INTA, Chile (Osorno, lat. 40° S) reported that when comparing applications of technology between the experiment station and the farmers' fields under both irrigation and rainfall conditions, there is a significant yield gap in favor of the technology as applied by the station. This gap can be narrowed by identifying the factors involved and cor- recting measures developed for an easy adoption by the farmers. Ethiopia TPS. Reports from Ethiopia indicated that trials conducted during the rainy season at Holetta Research Center, which in clud ed the inte rn a tional, regional, East African, and open-pol- linated TPS trials, were almost complete- ly lost to late blight. Future TPS trials during the rainy season will include progenies of late blight-resistant parental clones, known to transmit high levels of resistance to their offspring. Seedling tubers from selected pedigrees also will be considered for testing the feasibility of using TPS as an a ilernative potato production method. Cameroon TPS. Previous experiences have shown that seedling tubers rather than TPS transplants may be the most appropriate technology for seed-tuber production. S ixteen progenies were evaluated in nursery beds th is year for seedling tuber production at Mfonta (1,300 m). The highest yielding progenies for tuberlet production included the pedigrees CIP 98004 (CFK 69.1 x DTO- Thrust VII 97 Large (89.4%) <0.5 kg - --- -\ '" (30.7%) Small (0.0%) No roots (5 .3%) 'I----- Intermediate (5.3%) --- - - 0.5-1.0 kg (44.3%) ----1.5to > kg (4.8%) '--- --- 1.0-1 .5 kg (20.2%) Figure 7-3. Performance of a sample of sweet potato clones from germplasm in cool winter season , Lima, 1989. a) root enlargement; b) root yield kg/plant. 28) at 6.0 kglm2 and CIP 978001 (Atzim- ba x R128.6), at 4.3 kglm2. Seedling-tuber performance for consumer pot ato production was compared with that of commercial Dutch varieties in trials (at 2,000 m) in which plants were sprayed once against late brght. Six of the progenies outyielded the three commer- cial varieties and showed resistance to late blight. Paraguay. Tuber production from see- dling tubers of pedigree Serrana x LT-7, in both seed beds and the field, was sig- nificantly higher than the three other pedigrees evaluated during March-June 1989 at the IAN-Caacupe Experiment Station. 98 T hrust VII Shortly after being harvested the Ser- rana x LT-7 tubers were treated for spr outing a nd planted in selected farmers' fields during July-November of the same year. H owever, yields were rather low as a result of poor emergence and overall plant stand. The short period between planting seasons may result in a serious limiting factor if short dormancy is not bred into segregating progenies; however, if cycles are reversed so that tuber multiplication is done during July-November and con- sumer potatoes are produced during March-June, a solution may be found to the tuber-sprouting problem at planting time. Additional studies are under way. Sweet Potato Evaluation in Cool Environments Evaluations were made of 400 sweet potato clones from the germplasm bank maintained at CIP to examine their per- formance in cool environments during the winter season at two coastal locations in Peru. Preliminary data on plant growth, root enlargement, and yield at harvest (150 days after planting) indicate that much of the material performed well and showed some ability to adapt for pro- duction under cool temperatures. Yields were as high as 2 kg/plant at a plant den- sity of 35,000 plants/ha (Fig. 7-3). These clones will l;>e further evaluated to deter- mine their range of adaptation in cool environments, and at higher altitudes. Thrust VII 99 Thrust VIII P ostharvest Technology Thrust Profile: 1990 A recent survey of national program leaders identified constraints in the postharvest phase as among the most important in production and use of potatoes and sweet potatoes. Interdisciplinary research and training activities in Thrust VIII help develop and d eliver storage and processing technology in collaboration with national programs. During 1989, this work included 20 projects, 4 contracts, and 4 theses under way in more than a dozen countries in Latin America, Africa, and Asia. Past work has emphasized potatoes, but sweet potatoes are now receiving increased research attention. Building on the successful extension of diffused-light storage for seed potatoes, recent storage research has focused on consumer potatoes. Evaporative cooling techniques were studied in Peru, Kenya, and India, and forced-air techniques were studied in Pakistan. Simple rustic stores were tested in India and Thailand. Household storage in bamboo baskets and sacks was analyzed in Burundi. In Peru, clones were evaluated for storage characteristics. Seed storage under rustic versus refrigerated conditions was studied in Egypt. Rustic storage of seed was evaluated in Cameroon. Storage in sand of tubers produced from true potato seed was examined in India. A storage workshop was held in Malaysia. Successful storage trials for consumer potatoes in several countries suggest that interdisciplinary research on adoption of these techniques would now be useful. Potato processing research has focused on clonal evaluation (Peru, Thailand); on continued testing and evaluation - including costs and returns - of rustic processing techniques (India); and on marketing and demand for processed products in selected countries (India, Thail!lnd). Additional activities included a survey of postharvest practices (China), backstopping of ongoing research involving simple processing in selected countries (Colombia, Guatemala, Peru, and Zai're) and thesis work (Kenya) . Sweet potato research has drawn upon baseline surveys of postharvest practices and constraints carried out as part of a diagnosis of sweet potato food systems (see also Thrust X). This work is being conducted in Peru, China, Vietnam, and the Philippines; similar research is under way in Indonesia, Thailand, Taiwan, Argentina, and Uruguay. Results of these surveys emphasize the importance of interdisciplinary research involving biological and social scientists to identify, evaluate, and improve existing technologies. Thrust VIII 101 Sweet potato studies have been included in the experiments using village-level, rustic processing techniques in India. Clonal evaluation for processing has begun in Lima, with thesis work on the nutritional and chemical characteristics of CIP's sweet potato germplasm collection. Similar work is now under way in Thailand. Sweet potato storage research using rustic stores has begun in India and Kenya. Potatoes Consumer Potato Storage Technology continues to be developed for short-term storage of both consumer and seed. potatoes in warm-dry and warm-humid climates, with experiments in Peru, Kenya, Burundi, Cameroon, Egypt, India, Pakistan, and Thailand. These and other activities seek to develop low-cost alternatives to estab- lished marketing and utilization patterns. Successful trials · in several countries point to the need for interdisciplinary research on factors that influence adop- tion of improved storage practices for consumer potatoes. Peru. A total of 18 clones were tested for storability under rustic storage condi- tions at ambient temperatures in Huan- cayo and San Ramon. A cold store set at 4C was used as a control. Total tuber weight losses after 6 months of storage ranged from 6.5% to 20.1 % at Huancayo, from 12.9% to 41.9% at San Ramon, and from 5.1 % to 11.8% in the cold store. Clones Capiro, Yungay, CEW-69.1, and 69-56-52 (Table 8-1) showed excellent storability or keeping quality for con- sumer potatoes. Results of these experi- ments indicate that clones with a long dormancy period do not necessarily have good keeping quality. Boxes with ventilation ducts for storage of consumer potatoes in Thailand. 102 Thrust VIII Table 8-1. Observations on storability for seed and consumer potatoes in a range of clones at Huancayo and San Ramon, Peru. Storability Tuber weight loss (%) Dormancy Incubation indexc 6 months (days) .. periodb 6 months. Clone 4C Hyo SR Hyo SR (days) Hyo SR DT0-33 10.2 18.6 31.8 48 34 354d 0.95 0.78 DT0-28 11.0 20.1 29.0 76 41 357d 0.83 0.65 LT-2 11.8 9.2 41.9 111 48 317 0.90 0.55 871-240-2 7.0 13.3 27.2 97 62 327 0.96 0.86 LT-5 8.8 11 .8 26.0 11 8 76 31 7 0.98 0.83 Serrana 8.9 11.4 21.2 139 62 337 0.95 0.92 Revolucion 9.0 11 .0 23.3 111 43 337 1.04 · 1.09 Rosita 9. 1 15.3 26.0 97 69 327 0.99 0.88 Saturn a 9.3 14.3 23.3 139 62 31 7 0.98 0.75 1-822 8.3 13.2 31.5 84 35 330 0.90 0.68 CEX-69.1 7.1 11 .1 21 .1 70 28 360 1.08 1.00 1-931 9.1 13.4 25.8 63 28 350 1.05 0.92 69-56-52 6.6 9.2 12.9 133 78 310 0.95 1.00 MEX-32 7.4 10.0 18.2 119 55 360 1.16 1.16 CEW-69.1 5.5 7.9 16.5 91 48 370 1.08 0.96 Huancayo 5. 1 6.5 17.9 105 62 330 1.21 1.46 Yungay 7.2 9.0 15.9 98 55 340 1.08 1.37 Capiro 8.7 11 .7 14.1 133 83 330 0.88 0.97 Mean 8.3 12. 1 23:5 102 54 0.99 0.94 Mean 14.6 LSD 0.05 2.2 CV% 7.6 8 Days between harvest and sprouting. b Days between harvest and tuber formation on sprouts. c Storability index: yield from DLS stored tubers (Huancayo and San Ramon) as a proportion of yield from seed tuber stored at 4C. d No tuber formation on sprouts. At San Ramon, research on integrated control of storage losses of potatoes in the warm tropics has shown consistent results over several storage seasons (see Annual Reports 1988 and 1989). Low- cost storage oflocally produced potatoes over a 4-month period is clearly feasible under warm (20C to 30C), rustic condi- tions, without significant loss of quantity or quality. Two storage treatments were highly effective: 1) a single selection of the most suitabie proportion of the crop (undamaged, healthy tubers) for storage, following a 2-week holding period after harvest, effectively reduced losses, and 2) soaking the charcoal store walls with water twice daily to induce evaporative cooling reduced tuber weight loss and infestation by the pocato tuber moth. Ap- plication of CIPC effectively inhibited T hrust VIII 103 sprouting, as did use of thiabendazole or sodium hypochlorite dipping treatments to control pathogens causing rotting (Fusarium and Erwinia spp. ). Neither sprouting nor rotting caused serious los- ses, until after the 4-month storage period. At North Carolina State University, a Ph.D. thesis confirmed previous findings that repeated selection during the storage period increased storage losses, due to thfl higher levels of mechanical damage caused by additional handling (see Annual Report 1989). During 4 months of rustic storage at San Ramon, losses in 14 cultivars adapted to the warm tropics were associated with their rela- tive susceptibilities to the pathogens Erwinia carotovora ssp. carotovora, E. chrysanthemi, Fusarium solani, and F. oxyspornm. Kenya. Research continued to develop low-cost consum er potato storage for low altitudes. Storage experi- ments on the Kenyan coast used the variety Roslin Eburu, harvested at medium altitude. Different types of naturally ventilated stores were com- pared during a storage period of33 days. Preliminary results showed that total weight losses ranged from 21.8% to 51.9%, with lower losses for the naturally ventilated store without evaporative cooling. High losses were mainly due to soft rot caused by Erwinia carotovora, wh ich in turn was induced by skin damage from harvesting immediately after crop maturity. A thesis summariz- ing this research is being prepared for the Cr anfield Institute of Technology. Storage technologies developed for cool highland areas in previous years continue to be evaluated with farmers, in coopera- tion with an F AO project. 104 Thrust VIII Burnndi. Prices for consumer pota- toes increase by 30% to 50% between the ha rvest in January and the seasonal shortage in May. Storage of consumer potatoes was tested with 4 varieties using 3 types of naturally ventilated storage techniques. Storage capacity ranged from 500 kg to 1,000 kg. The maximum possible storage period was defined as the period without significant sprout development, since sprouted tubers can only be sold as seed. Bamboo baskets, positioned on stones so as to allow ven- tilation from below, provided the longest storage period: 31 days for cv. Ndinama- gara, 71 days for cv. Muruta, 61 days for cv. Kinigi, and 101 days for cv. Uganda. India. Storage trials using consumer potatoes were conducted at Athgara in collaboration with the ·central Potato Research Institute. Tubers were stored in sand for 80 days, with losses of 10% by weight and 5% by number; these results impressed local farmers unfamiliar with this traditional procedure. 17iailand. In cooperation with the Horticultural Research Institute and the Agricultural Engineering Division of the D epartment of Agriculture a t Fang (northern Thailand), 4 different types of low-cost, naturally ventilated stores were tested at the experiment station using two commercial cultivars, Fang-60 and Spun- ta. After 7 weeks of storage, total weight loss ranged from 13.8% to 18.9%. During s torage, average outside minimum temperature was 21.4C and average max- imum temperature 34.6C; temperatures in the potato pile ranged from 23.2C to 26.5C. Farm-gate prices for potatoes rose from 5.5 to 7 baht per kg over the storage period. This increase was suffi. cient to generate posi tive economic returns as a result of potato storage in each of the e>..-perimental stores. Need for Adoption Research Recent experiments in warm climates in several countries have identified suitable methods to store consumer potatoes for periods up to 2 months. These methods include appropriate designs for stores, as well as integrated methods to control storage diseases and pests. Interdiscipli- nary research is now needed to evaluate the user's perspective of these storage technologies and to identify factors that ·influence adoption (e.g. availability of credit). Seed Potato Storage Cameroon. Two diffused-light seed storage trials were conducted at mid- elevation sites (1,300 m and 2,000 m) using the local varieties Ki jam and Tibati. One treatment was with sodium hypochlorite, another with CIPC. The controls were tubers that had not been chemically treated. Each trial had sub- treatments with and without Lantana, and lasted for 240 days. Initial findings indicate that potatoes can be stored suc- cessfully for the 240-day period, but the physiological condition of the tubers is better after 180 days (Table 8-2). Al- though the CIPC sprout inhibitor prolonged dormancy, it became less effec- tive after 90 days. Sodium hypochlorite had a negligible effect, perhaps because soils in the region are relatively clean. At lower elevations, rotting was more pronounced for tubers stored after the rainy season than after the dry season. The percentage of rotted tubers, the sprout lengths, and the weight losses were greater at lower than at higher alti- tudes. Tubers from each of the treatments have been planted to evaluate their yields. Egypt. Four hybrids and 4 commercial varieties from certified seed imported from Europe were placed in storage (in early June) for 3 to 5 months inside a cold store at 4C to 5C, and in a non-refri- gerated store (Nawalla). Tubers from the two stores were presprouted under dif- fused light for 2 weeks, then planted at the end of September 1988. The experi- Table 8-2. Percentage rotted sprout lengths and percent weight losses of tubers stored under diffused- light rustic stores at Mfonta, Cameroon, in 1989 (1,300 m.a.s.I.). % Rotted tubers Sprout length (mm) % Weight loss 90 180 240 90 180 240 90 180 240 Treatments days days days days days days days days days 1.4 4.3 6.8 12.3 20.1 20.2 10 29 39.7 2 1.8 2.8 5.4 11.4 20.5 19.9 9 27 38.3 3 2 .2 6.9 11.1 13.4 21 .8 24.3 10 30 41.7 4 1.6 4.2 6.5 13.1 21.6 21 .9 12 29 39.3 5 0.4 4.1 6.1 8.4 20.9 24.0 9 27 36.3 6 1.6 3.6 4.5 9.0 18.8 22.4 9 27 37.5 a Treatments: 1 = Lantana but no chemical treatment. 4 = 0.5% Hypochlorite but no Lantana. 2 = No Lantana, no chemical treatment. 5 = CIPC (20 ppm) and Lantana. 3 = Lantana and 0.5% Sodium Hypochlorite. 6 = CIPC (20 ppm) no Lantana. Thrust VIII 105 Table 8-3. Comparison between varieties of different sources and seedling tubers from TPS in cold store and non-refrigerated store (Nawalla), Egypt. Nawalla Cold store Germ.% Germ.% 30 45 Stem Harv. 30 45 Stem Harv. Mari<. Variety/progeny days days No. (tlha) days days No. (tlha) % Alpha 74 49 2.9 23.4 86 89 3.2 32.4 85 Serrana x DT0-28 75 93 1.9 31 .2 83 96 2.4 33.0 80 Claudia 88 91 2.6 24.7 77 95 2.1 27.1 70 CFK 69.1 x DT0-33 85 97 2 .8 29.1 89 95 2.9 36.8 80 Spunta 95 97 2.8 28.5 89 91 1.9 30.0 90 Atzx DT0-28 80 98 2.9 30.3 86 99 3.0 33.9 80 Drag a 84 96 2.8 27.9 48 88 2.0 29.0 85 Atzx DT0-33 81 95 2.7 30.8 91 99 3.2 36.5 75 Planting date: Sep. 18, 1988. Harvesting date: Feb 1, 1989. Plot size: 9.4 m2• Reps.: 3. ment was harvested in early 1989. Com- parable yields for the hybrids and com- mercial varieties kept in a rustic store indicate that expensive refrigeration is not necessary for seed potatoes under Egyptian conditions (Table 8-3). India. A previous storage design for consumer potatoes was modified to ac- commodate seed potatoes. During the first 3 months after harvest, consumer potatoes were stored in darkness. They were subsequently exposed to diffused light by opening the windows and placing the tubers in thin layers on shelves. After 70 days, total weight losses were 11.5% for cv. Kufri Bahar and 4.4% for cv. Kufri Jyoti. Tubers of 13 different genotypes - including 9 TPS families - also were stored in sand, which is a traditional storage method used by farmers. After 6 months of storage, average weight losses were 52.5% and average loss of tubers due to rotting was 38.6%. No significant differences were found in storability be- tween genotypes. 106 Thrust VIII The Philippines. Non-chemical me- thods to control sprouting of potato tubers are being developed in a col- laborative project with the University of the Philippines at Los Banos. In prelimi- nary experiments, plants of the Liabiatae family were screened to identify natural sprout inhibitors. Species presently being evaluated are Coleus amboinicus Lour., Mentha cordifolia Opiz, Ocimum basili- cum L. and Ocimum sanctum L. Potato Processing Thailand. The demand for processed potato products is growing rapidly in many Southeast Asian countries. In Thailand, about 5,000 t/yr of potatoes (about 30% to 50% of national produc- tion), are processed into snacks and con- venience foods. Most processing is carried out by local companies. Research has emphasized evaluation of clones for processing quality. In cooperation with the Agro-Ind us try Section of the Agricul- tural Chemistry Division of the Depart- Low-cost store for consumer potatoes in Thailand . ment of Agriculture, 40 clones and cul- tivars were evaluated for use in process- ing into chips and fre nch fries. In addition, clones are being evaluated for domestic cooking quality. Results of a joint study of marketing, consumption, and demand for potatoes and potato products in Bangkok have been published by the Department of Agricultural Economics of Kasetsart University, the Horticultural Research Institute of the Department of Agricul- ture, and CIP. These findings highlight the potential for increased consumption of fresh and processed potatoes, as population growth and rising incomes generate greater demand. The metho- dology developed for this study should be useful for similar research in other countries. India. Low-cost, village-level techni- ques for processing of potatoes are being developed by CIP and SOTEC, a non- profit development organization based in Bareilly. Seven village processing units are currently operating under the super- vision ofSOTEC. These units process an average of 550 kg of potatoes per day. The main products made are dehydrated strips and chips, part of which are ground into flour. Conversion rates for strips and chips (raw material to processed product) range from 14% to 16% for medium- sized to large tubers. Product quality, in- cluding moisture content and uniform size and color of the chips, is being stressed, and guidelines are being de- veloped to standardize product quality. Processing equipment has been further improved, as well as the economic ef- ficiency of the processing methods. Raised slatted floor. India. Thrust VIII 107 SOTEC assists the processing units in securing funds for initial investment and in marketing of the processed products. Numerous recipes have been developed and are being demonstrated to rural and urban consumers. The processing units have generated substantial employment opportunities for rural women. Socioeconomic backstopping of the processing research at SOTEC included 1) estimates of the cost of production based on technical coefficients and es- timated prices for inputs and outputs (Table 8-4), and 2) contract research by an economist at the Agro-Economic Re- search Centre, Himachael Pradesh University, who studied the marketing of processed potato products in New Delhi. The cost estimates include various simulations of prices for fresh potatoes as well as processed products (Table 8-5). These calculations indicate that process- ing of more than 500 kg of raw product per day was barely profitable; they also demonstrate the importance of the price of potatoes and labor in determining unit production costs. Although more detailed information is needed on con- version rates, these findings provide an economic justification for combining rus- tic storage with simple processing and for Table 8-4. Variable costs of simple potato processing in India. Variable cosV Amount of fresh potatoes processed/day (kg) 200 400 600 1 ,000 packet (US$) .099 .086 .079 .074 beginning with the former to eventually finance the latter. Studies of the marketing of processed potato products in New Delhi found a much wider variety of products than had been supposed. A total of 15 products are currently available, differentiated on the basis of form, package, weight, and price. Solar-dried chips produced with rustic techniques represent half the volume sold. Most sales are to middle-income consumers. The majority of.the retailers contacted (82.6%) felt that demand for processed products could be increased by reducing the price and introducing more attractive packaging (see Thrust X for additional details). Peru.. Since 1987, CIP-Lima scientists have been evaluating clones to em- phasize processing potential for chips and french fries, using CIP's germplasm Table 8-5. Economic feasibility of producing dried potato chips in India (90 work days, 3 and 5 years credit). Amount of fresh potatoes processed/day 200 kg 400 kg 600 kg 1.000 kg 3rd 5th 3rd 5th 3rd 5th 3rd 5th year year year year Total annual cost/packet .18 .18 .17 .16 .16 .15 .15 .15 Annual net revenues/packet (US$) (.12) (.02) .14 .21 .21 .30 .33 .40 108 Thrus t VIII Table 8-6. Yield and processing attributes of eight advanced clones. Yield Clone Pedigree (kg/pt) 3772 19.18 N568.7 x DT0-28 1.19 377838.2 BR63.65 x N522.22 1.30 E86.011 (377835.9 x Pl/PS BK) x 378015BK 0.84 E86.692 CFS69.1 x Atlantic 1.20 E86.695 CFS69.1 x Atlantic 0.72 86LM 235 Aphrodite x L T-7 1.25 86LM 320 CEX69.1 x Atlantic 1.05 86LM 614 BL2.9 x 378015 .3 1.10 with multiple resistance or tolerance to different biotic and abiotic stresses. Eight clones have been identified as good chip and/or french fry producers (Table 8-6), following experiments with some 400 clones in different environments (La Sweet Potato Baseline surveys to document and analyze existing forms of sweet potato utilization for human consumption and animal feed are under way in China, Viet- nam, Indonesia, Thailand, and Peru. These studies are in response to national program leaders' opinions about con- straints and opportunities for expanding sweet potato production (see Thrust X) . Field studies on these issues also are under way in Argentina, Uruguay, and the Dominican Republic, as part of a broader diagnosis of the food system for sweet potatoes in those countries. Other research is designed to upgrade and in- crease the economic efficiency of tradi- tional processing. New processed sweet potato food products are being de- veloped, using a consumer-oriented ap- proach. SG RS Use Observations 1.081 low Ch LT parent 1.080 low Ch LT parent 1.084 low Ch Warm, cool climates 1.078 low Ch/ff Warm, cool climates 1.088 low Ch Warm, cool climates 1.083 low Ch TPS parent 1.097 low Ch TPS parent 1.094 med. Ch TPS parent Molina, San Ramon, and Huancayo), with testing for yield, specific gravity, and reducing sugar content. Future studies will test an additional 1,000 clones for yield and processing attributes, to iden- tify progenies for processing quality. Sweet Potato Processing The Philippines. Processed sweet potato food products for low- and middle-in- come urban groups are being developed by scientists at Visayas State College of Agriculture (VISCA) at Leyte. Con- sumer surveys indicate that research should focus on chips, noodles, and cubes for traditional food dishes, and flour for hot cakes and baby food. Experi- ments on the standardization of process- ing techniques for sweet potato chips showed that a slice thickness of 1.5 mm to 2 mm was most suitable for producing a crispy (when fried) final product. Va- rious pre-frying treatments also were tried with sweet potato cultivars having white, yellow, and orange flesh colors. However, sensory scores were about the same for the fried chips and for the control. Thrust VIII 109 Sweet potato flour has the potential to be used as a substitute for wheat flour in the preparation of popular noodles in Philippine markets - without affecting the texture and general acceptability of the noodles. An acceptable level of sub- stitution was found to be 25% for odong noodles (dried type) and 50% for canton noodles (fried type). In the formulation of miki noodles (fresh type), 25% sweet potato flour produced an unsatisfactory product. Qf the sweet potato varieties screened for use in noodle processing, Miracle, Karingkit, VSP-3, VSP-6, and UPLSP-5 w<;re the best performers. China. With 6 million ha of sweet potatoes, China has a rich tradition of village-level processing. CIP is working with the Food Science .Laboratory of the Sichuan Academy of Agricultural Scien- ces at Chendu, Sichuan Province, to document and improve established pro- cessing techniques for sweet potatoes in China and other countries. Sichuan is the largest sweet potato producing province in China, and local farmers and rural entrepreneurs have considerable ex- perience in sweet potato processing utilizing labor-intensive techniques. The principal products are starch, noodles, and dried chips. Major constraints iden- tified in a recent baseline survey included low starch recovery rates due to ineffi- cient processing equipment and non- availability of high-starch cultivars. Research to increase the economic ef- ficiency of processing methods is under way to increase income from sweet potato processing. Semi-mechanized processing is being developed and evaluated at the village level. Thailand. In collaboration with the Department of Agricultural Extension, a baseline survey is being carried out on production and utilization of sweet potatoes. Preliminary findings indicate Products made from sweet potatoes are highly nutritious. In the developing world, sweet potato flour is being used as a substitute for cereal flour in bread making. 110 Thrust VIII that sweet potatoes are used pre- dominantly for fresh consumption, with only a small proportion being processed into sweets and snacks. Processing for starch also has potential, if prices for fresh roots can be reduced. Indonesia. A baseline survey carried out by the Central Research Institute for Food Crops identified a total of 10 dif- ferent sweet potato products in various retail outlets in West Java. However, these products account for only a very small proportion of total sweet potato production. Most sweet potatoes are consumed when fresh or are used for animal feed. Existing processing methods are being documented and evaluated. Future research will identify additional market opportunities for sweet potato products used for human consumption, as well as for animal feed. Peru. A pilot survey of sweet potato consumption and processing at Lima found that processed products for human consumption included flour, starch, chips, and bread, with the foliage being used for animal feed. Preliminary results of the consumer interviews indi- cate a limited use of these products (e.g. starch is used only as an ingredient in a traditional dessert). The available infor- mation is meager, however, and other recent studies suggest considerable potential for substituting sweet potatoes for imported wheat flour in bread making (see Thrust X). As higher-income con- sumers use sweet potato products more frequently, a lower price might well e:?C- pand the market for both fresh and pro- cessed products. More information is needed regarding the influence of government policies, in the form of sub- sidies for wheat-based products, and how this may hamper the development of sweet potato products in Peru and else- where (e.g. the Philippines). At the Universidad Nacional Agraria- La Molina, in a Master's thesis project, the chemical and nutritional characteris- tics of sweet potato cultivars in CIP's germ- plasm collection are being evaluated for possible use in bakery products. Of 150 cultivars evaluated, only 15 were iden- tified as having low values of reducing sugars. Flour of suitable cultivars will be used to evaluate nutritional quality of bakery products, particularly bread, when 30% of the wheat flour is replaced by sweet potato flour. Thrust VIII 111 Pollinated inflorescences in the field, identified for TPS production experiments. Thrust IX Seed Technology Thrust Profile: 1990 Worldwide collaborative research focused on improving agronomic characteristics of selected TPS progenies intended for seed production and use in warm climates. Several parental clones were identified with acceptable berry-setting capacity that produced TPS with tolerance to bacterial wilt infection and transplant shock, tuber uniformity and quality, and high yield stability. Techniques for increasing the efficiency of hybrid TPS production were tested in Chile, India, Italy, and Peru. Supplemental N applications were found to increase the production of TPS, but may reduce tuber production of the mother plant. In soils of medium P and high K content, additional doses of up to 160 ppm (P) and 240 ppm (K), were found to be optimal for increasing flowering and TPS weight. Berry weight was increased by preplanting incorporation of farmyard manure, and by the addition of foliar fertilizers. The transformation of fertile clones into cytoplasmic male sterile lines to increase the efficiency of hybrid TPS production was success( ul in six clones and their crossing ability is being tested. Additional research emphasized postharvest handling of TPS. Seed-vigor losses following harvest of the TPS were shown to progress at a slower rate during storage, when the seed had been produced with high N. The storability of TPS was better maintained in a dry environment, as compared to when exposed to ambient air. Seedling-vigor testing of selected TPS progenies at various periods of storage demonstrated that the seed must be after-ripened al about 5% to 7% moisture content (dry-weight basis) and under moderate temperature (20C) conditions for at least 12 months, before the seed can be sown effectively in high-temperature environments. Presowing of TPS in a solution of KN03 + K3P04 followed by seed drying (osmotic priming) was an effective treatment for enhancing seed vigor at supraoptimal (30C) temperatures. The efficiency of seedling-tuber production techniques was further improved in extensive studies conducted in India and Peru. Collaborative projects continue to expand successfully in Paraguay, Venezuela, Cameroon, and Indonesia. The studies investigate the technical problems and develop modifications needed at each site for optimal use of TPS in a seedling-tuber production system. 113 CIP has increased the extent of its collaboration towards strengthening or develop- ing seed-tuber propagation systems in Bolivia, Burundi, Colombia, Venezuela, Kenya, Myanmar, the Philippines, and Peru. The objectives of these projects include: the analyses of limiting factors of potato production and of traditional seed-tuber dis- tribution systems; the transferring of information such as simple positive selection of healthy plants and advanced rapid multiplication and diffused-light storage techni- ques; and the development of simple flush-out basic seed systems. Farmer participa- tion is an integral part of the process in all projects. A case study exploring the strengths and weaknesses oflocal seed systems was completed in Kenya. Research on the improvement of sweet potato propagation techniques was con- ducted under a wide range of environments. Agronomic and climatic factors affecting flowering and seed production were identified. The use of in vitro-propagated plantlets, larger unrooted cuttings, and rooted cuttings was shown to result in a faster establishment and growth, and increased flowering. Increased plant N uptake and root yields were obtained by the incorporation into the soil of various Azospirillum strains. TPS Progeny Evaluation The International Progeny Evaluation Trials were conducted at 14 locations representing a wide range of environ- ments worldwide. In Peru, progeny per- formances in these trials generally differed at San Ramon and Lima, which represent a humid and a dry tropical en- vironment, respectively, and for the two seasons of evaluation. Some progenies, however, showe d relatively stable production in all environments. These in- clude Maine x C83.119, Serrana x LT7, C83.174 x C83.119, C83. 119 x A VRDC1287.19, and C83.119 x Y87.013. In these trials, the parent C83.119 trans- mitted high yields and stability levels to its progenies. In evaluations of advanced progenies in Lima, the treatments included two ir- rigation systems and two transplanting methods. The plants of progenies Y84.027 x 377964, L T-9 x A VRDC- 1287.19, and YY-7 x LT-7 showed high tolerance to transplant shock, as the vigor and potato yields were unaffected in 114 Thrust IX those treatments in which bare-rooted seedlings were transplanted to the field. Sixty selected progenies from new parental lines of improved agronomic and reproductive characteristics were evaluated under cool (Huancayo) and warm (San Ramon) conditions. Most of the progenies outperformed the controls for most of the agronomic traits evaluated (which included tuber characteristics). At San Ramon, 15 progenies selected from a population adapted to warm climates were evaluated during the hot, rainy season, under conditions of severe bacterial wilt infection . Sever a l progenies yielded well, confirming their potential for use in those conditions. A sample of 45 families was evaluated at San Ramon (dry season) and La Molina (winter season) to determine the genetic parameters for this population. The North Carolina design I used a sample of 15 male clones and 3 female clones per male in 3 sets. Parental clones that transmit their good agronomic and reproductive characters to their progenies have been identified and will be used as TPS parental lines. At San Ramon, 220 clones previously selected for adaptation to warm climates were evaluated for their flowering and fruit-setting capacity during both the dry and rainy seasons. Several clones were identified as having suitable reproductive characters (Table 9-1) and will be used in the TPS program as parents to further assess their potential. Protoplast fusion was used to trans- form clones for cytoplasmic male sterility (CMS). Using pollen of known TPS male parents, such as 7XY.l, LT-7 and Atzim- ba, these clones were crossed to assess their efficiency as progenitors and the segregation of their progenies. Two of these clones produced tetrad CMS pol- l en, but only Y245.7 showed good agronomic performance and potential for use as a parental line in TPS produc- tion. Over 300 genotypes were evaluated as potential TPS parents and screened for tetrad CMS at Huancayo, San Ramon, and La Molina. Of the population, six clones were identified as having tetrad CMS pollen: C386LM87-B, C116LM87- B, C137LM87-B, 382301.1, 382302.2, and 382291.1. Tests of their crossing ability are under way. A general scheme for agronomically evaluating TPS progenies was tested for a second year at two locations in Peru. In this approach, evaluations are made of a set of advanced progenies from the TPS breeding program at CIP, using 2 me- thodologies: 1) direct production of con- s umplion tubers by transplanting seedlings lo the field, and 2) use of seed- ling tubers. The seedling tubers are produced in beds under controlled ir- rigation in the highlands. Tubers 3.5 cm to 5.0 cm in diameter are planted at Lima and San Ramon the following season, along with transplants of the same progenies. New improved TPS progenies are being incorporated into this evalua- tion scheme each year. In India, locally developed hybrid progenies were evaluated in Modipuram and Tripura. In Modipuram, 13 hybrid Table 9-1. Evaluation of advanced TPS parents for various reproductive characters in warm environments. San Ramon, Peru, rainy season. Characters Clones Yield/pt Earliness DFI Fl FD F/I SL AT BA pp Clone 42 LM88 B 1.24 5 40 7 6 5 5 2 2 3 Clone 43 LM88-B 1.08 5 45 7 6 5 5 2 2 5 Clone 152 LM88-B 1.00 7 38 5 6 5 4 2 2 5 Clone 61 LM88-B 1.00 7 45 7 7 7 4 2 2 5 Clone 44 LM88-B 0.94 5 38 7 7 5 5 2 2 5 Clone 18 LM88-B 0.90 6 38 5 5 5 4 2 2 5 Clone 45 LM88-B 0.90 5 39 6 5 5 4 2 2 5 Clone 517 LM88-B 0.71 6 39 7 6 5 5 2 2 5 Clone 339 LM88-B 0.70 7 39 7 7 5 7 1 5 Clone 39 LM88-B 0.70 5 46 3 3 5 4 2 2 5 Thrust IX ll5 families: HPS-I/III, HPS-1/13, HPS-1/67, HPS-2/67, HPS-2/111, H PS-2/13, HPS- 7/ III, HPS-7/PPS, HPS-24/ III, HPS- 25/30, HPS-27/111, H PS-26/PPS and HPS-(II x I) were evaluated for seedling- tuber production in nursery beds. One to two seeds were sown at depths of 1/2 cm to 1 cm, with 10 cm x 10 cm spacing. After 2 weeks of germination, the seed- lings were thinned down to a desired level of 100 plants/m2• All populations bad an optimu m plant density, except HPS- 26/PPS, which had approximate ly 50 plants/m2. The crop was dehaulmed after 90 days of seed sowing and at harvest, observations were recorded on total tuber yield; number of different sizes of seedling tubers, and segregation. At the same location, the field perfor- mance of 17 hybrid families transplanted to the field was evaluated for consumer or seed production. Also evaluated were 11 families of which different sizes of seedling tubers bad been used for plant- ing. In the trial of the 17 hybrid families, percentage of seedling survival recorded 45 days afte r transplanting was above 75% in all progenies (T able 9-2) . Except for H PS-2/13 and HPS-10/111, the tuber yield produced byTPS families was more than 20 t/ha. HPS-12/13 gave the highest tuber yield, but it showed poor tuber uniformity. TPS families HPS-7/111 and HPS-25/13 gave 31.7 t/ha and 33.2 t/ha tube r yields, respectively, which is as good as or better than the best cultivars being used by the farmers. Percentage of marketable sized tubers of TPS families ranged from 55.1% to88.7%. Some of the hybrids had over 80% marketable yields. In genera~ the number of tubers produced per unit area by TPS families was much higher compared to that of the cultivars. Table 9-2. Evaluation of TPS families as transplants at CPRS, Modipuram, India (1988-89). TPS Survival Yield Marketable Tubers Av. tuber Tuber family % (t/ha) yield(%) (no./m 2) wt. (g) uniformity HPS-1/111 85.8 ab 26.7 Cd 84.7 ab 114.3 Cd 23.7 be 5.0 HPS-1/ 13 86.3 ab 25.3 d 88.6 a 98.7 Cd 27.3 ab 5.0 PS-1/67 95.9 a 23.3 cd 79.5 abc 139.7 abc 20.0 cde 5.0 HPS-2/111 92.1 ab 23.8 de 83.7 ab 110.0 cd 21.7 bed 5.0 HPS-2/13 85.4 ab 19.1 ef 85.6 ab 76.7 d 24.7 be 4.7 HPS-11/ 111 90.0 ab 28.3 bed 87.6 a 109.0 Cd 26.0 be 4.5 HPS-7/ 111 91 .3 ab 31.7 abc 75.1 abc 173.3 ab 20.7 cde 5.0 HPS-7/67 92.9 ab 25.2 d 63.9 Cd 145.0 abc 16.7 def 4.0 HPS-7/ PPS 84.6 b 23.9 de 68.4 bed 190.7 a 12.7 f 3.0 HPS-8/PPS 85.4 ab 23.6 de 55.1 d 169.3 ab 15.0 ef 2.0 HPS-1 0/111 86.7 ab 15.6 f 70.9 abed 112.0 cd 14.0 f 3.3 HPS-12/111 90.0 ab 22.5 de 73.0 abc 107.3 cd 21 .3 cd 3.0 HPS-12/13 90.0 ab 37.5 a 87.1 a 111 .3 cd 32.3 3.0 HPS-25/ 111 75.0c 26.0 cd 86.4 a 10 1.0 cd 25.3 be 4.0 HPS-25/13 88.8 ab 33.2 ab 87.3 a 123.3 bed 27.3 ab 5.0 HPS-26/PPS 89.2 ab 27.1 Cd 75.2 abc 138.3 abc 20.3 cde 3.0 HPS-27/ 111 87. 1 ab 23.1 de 84.0 ab 95.3 cd 24.3 be 4.0 Duncan's Multiple Range Test at P < 0.05. Tuber uniformity (shape, size, and color). 11 6 T hrust IX Seedling tuber production In nursery beds, India. Average tuber weight of all TPS progenies was between 12.7 g and 32.3 g; however, some of the TPS families had poor tuber uniformity (a score of 3 or lower). In the seedling-tuber evaluation, tubers of 2-5 g, 5-10 g, 10-20 g, and > 20 g of 11 TPS families were evaluated for their field performance at Modipuram during 1988-89. The same-sized seed tubers of cultivar Kufri Bahar were also planted for comparison. The crop was dehaulmed after 90 days of maturity. Tuber yield (t/ha), marketable yield(% ), tuber number of tubers/m2, and average tuber weight (g) were recorded at har- vesting. Hybrid HPS-I/13 produced higher tuber yield than did cv. Kufri Bahar. But the marketable yield produced by Kufri Bahar was higher than that of all other TPS families. TPS famili es produced more tubers per unit area than did the cultivars. Average tuber weight of cv. Kufri Bahar was superior to that of all other TPS hybrids. In comparative field trials using second- and third-generation seed tubers of TPS families, the yield potentials of seed tubers of both generations were similar. After 90 days of maturation in the field, the crop was dehaulmed and the yields of both generations of plants were compared to that of locally grown cul- tivars. Thus, the farmer could use part of the produce from each generation to plant his next crop without substantial loss of yield. In Tripura, completely op- posite findings were obtained in a trial using 5 hybrids, 1 OP, and the cv. Kufri Jyoti as control. Similar-sized seedling tubers were used, after 1 or 2 field pro- pagations. The results showed significant yield differences for both generations. Seedlings of 11 hybrid and two open- pollinated (OP) TPS families were transplanted to the field at a spacing of 60 cm x 15 cm, and survival percentages of all families ranged from 74% to 92%. HPS-I/67 had the highest survival rate. Hybrid HPS-7/111 produced the highest tuber yield, and OP TPS-2 was the poorest yielder. Tuber yield of some of the TPS families equalled that of cv. Kufri Jyoti, but the average tuber weight in all TPS families was much lower. In a comparative field trial using seed- ling tubers graded as 5 g, 10 g, and 20 g, that were produced in beds in the pre- vious season, HPS-7/13 was the highest yielder and TPS-2 (OP) was the lowest. The crop was dehaulmed after 96 days of planting. Plants from seedling tubers of the three sizes had statistically similar Thrust IX 11 7 yields. Seedling tubers of 5 g and 10 g produced maximum number of tubers per unit area and had the lowest average weight. In another experiment, using 20 g, 40 g, and 60 g seedling tubers produced from transplants during the previous season, and dehaulrning the crop 96 days after planting, the different sizes did not differ in yields or number of tubers/m2. This finding suggests that the farmer could sell those tubers larger than 20 g for consumption and use the non- marketable produce as seed for his next season's crop, without loss in yield. One of the best performing progenies in several Asian countries, HPS-1/13, was compared for three consecutive seasons to the locally grown cultivars (Fig. 9-1) at three locations (Modipuram, Deesa, and Agartala). The marketable yields for HPS-1/13 were generally lower as com- pared to those of cultivars. But the proportion of market-sized tubers in this progeny was higher than 60% at all three Yield (Vha) 50 40 30 20 10 0 locations during the three seasons. Be- cause seedling tubers from transplants of this progeny normally have produced higher yields, the finding that they have approximately 40% non-marketable tubers (ranging from 10 g to 20 g) can be considered as an advantage, because this fraction could be ideal for use as seed in the next season. Furthermore, an eco- nomic analysis of the data indicated that the cost of production of this fraction for HPS-1/13 was about US$38 per ton, as compared to regular market prices of approximately US$152 per ton of seed tubers. Also, instead of the 2.5 t of com- mercial seed tuber normally used to plant one hectare, the farmer would require only 1.7 t of seedling tubers obtained from the 10 g-20 g portion. Generally, the average weight of tubers from HPS-1/13 transplants is lower than that of the cultivars. Further hybrid progenies are being screened to improve this characteristic. p::({:I Deesa cv r::::::J Agartala 1/13 C=:J Agartala cv 1986-87 1987-88 Year 1988-89 Figure 9-1 . Comparative yield (Vha) of seedling transplants of HPS 1/ 13 and locally grown cultivars. 118 Thrust IX In the Philippines at Canlubang, new progenies of locally selected parents were evaluated for yield and other desirable characteristics. The hybrid LT- 7 x LBB is a promising progeny, having high yields, tubers of uniform shape and color, and large size. At two locations in Italy, Marigliano, near Naples, and Camigliatello, in the Calabrian region, seedlings of 28 hybrid TPS families were transplanted at both locations, using 2 seedlings per hill and 10 hills per plot. Best results were achieved by the progeny UP 88201 x AVRDC-1287.19, with total tuber production of 51.6 t/ha. Chiquita x A VRDC-1287.19 had the best tuber uniformity and excellent tuber quality, as well as good yields. At Camigliatello, hybrid families producing encouraging results included: UP 88.201 x A VRDC 1287.19, UP 88.201 x W 842, Spunta x CFK69.1, W842 x Production of Hybrid TPS Seed Production of Selected Hybrids In Lima, 9 female and 11 male pro- genitors were crossed to produce TPS for distribution and regional evaluation of38 new hybrids and 2 OP progenies. All parental material came from transplanted in vitro plants. Sufficient quantity of seeds was obtained, except when pollen of TS-1 and TS-2 was used. Crosses made with those two male parents were affected by the low viability and rapid loss of germinability of the pol- len after short periods of storage. Similarly, little or no flowering was ob- served in L T-9 and Atlantic female progenitors. The plants were drip ir- A VRDC 1287.19, W 842 x R 128.6, UP 88.202 x A VRDC 1287.19, UP 88.203 x A VRDC 1287.19. They produced excel- lent yields and high tuber quality that compared very well with results obtained from commercial varieties used in the region. CFK69.1 and AVRDC 1287.19 were the best male parents for transmitting good traits for tuber yield quality to their progenies. The best female parental lines were UP 88-201, UP 88-202, UP 88-203, UP 88-204, and UP 88-205. At Marigliano, the best results for yield and quality were achieved by Morene x BR-63.15. Progenies OP of the CIP clone LT-5 produced excellent yields, with a total tuber yield of 57.1 t/ha. At Camigliatello, Morene x BR-66.15 provided the best combination for yield and quality, and LT-5 OP again per- formed well. rigated, fertilized with supplementary nitrogen, and treated with a 3-hour night break. In Italy, a diallelic crossing block in- volving 7 progenitors (V-2, R-128.6, LT- 5, 1-931, I-1062, CFK 69.1, and AVRDC 1287.19) was used lo produce hybrid TPS for local testing and for distribution in CIP Region IV. The TPS was produced on 2-stem plants grown under screen- house conditions with high rates of N fertilization applied at weekly intervals. The fruits were left to mature on the plant for about 10 weeks before extracting the seed. ThrustIX 119 Eight kilograms of seed of advanced CIP hybrids were produced under con- tract with INIA in Osorno, Chile. Vari- able amounts of hybrid seed have been produced through this contract in the last five years (Table 9-3). Production in Chile highlighted the importance of maintaining high pollen viability, using plants of high sanitary condition, and using efficient hybridization methods. In Kothi, India, attempts were made to produce substantial quantities of TPS of 8 hybrids for large-scale on-farm evaluation. The8 hybrids were HPS-1/13, HPS-1/67, HPS-7/13, HPS-7/67, HPS- 2/13, HPS-2/67, HPS-25/13, and HPS- 25/67, chosen on the basis of their performance in the previous years at dif- ferent locations. In total, 4.58 kg of hybrid TPS wa; obtained from these hybrids. In addition, approximately 1 kg of TPS was obtained from 54 different test crosses, when 27 new hybrids developed as female lines were crossed with two elite male testers (TPS-13 and TPS-67). These newly generated TPS families are being analyzed for TPS quality, germination, field establishment, yield potential, and plant and tuber characteristics. A stan- dard procedure for extracting and processing TPS developed in CIP Region VI was followed for extracting the seed of this year's production. Soil Nutrients and Flowering Several experiments on fertilizer applica- tion and rates were conducted on dif- ferent soils from various regions of Peru. Higher doses (240 ppm) ofN significant- ly increased flowering and TPS setting, but reduced tuber production on Atzim- ba potatoes in a sandy loam soil, with neutral pH, low in organic matter and N content with medium levels of available P and K. The sources of N urea, ammonium nitrate, and ammonium sulfate did not differ in their effects on flowering and fruit production. In soils with medium content of avail- able P (6 ppm to 8 ppm by Olsen), doses of 80 ppm to 160 ppm of P205 increased TPS production significantly, but higher rates affected TPS weight. The use of simple and triple super- phosphate, and of ammonium phos- phate, had a similar effect; rock phosphate (30% of P205) was shown to be a good source of P for soils that had a pH level of less than 6.5 and little available phosphorous. In alluvial soils from the Peruvian coastal valleys of Canete and Chincha, characterized by a high content of avail- able K, the addition of fertilizers in- creased flowering and berry formation; Table 9-3. Area, number of female and male plants, berries, and hybrid TPS produced in Osor- no, Chile, over 5 seasons. Area Number of plants Berries Seed wt. Year (m2) M F (kg) (kg) 1984/85 818 781 383 372.4 5.4 1985/86 2,743 2,411 1,420 1,140.34 13.2 1986/P.7 2,655 2,414 1,215 481.20 5.8 1987/88 3,669 2,870 2,610 2,835.15 32.4 1988/89 2,766 2,158 2,294 687.36 8.0 120 Thrust IX Hybrid TPS production at the La Pampa Station (INIA), Osorno, Chile, 1988-89. however 240 ppm of K20 reduced berry set and 100-TPS weight. A formulated fertilizer mix of K2S04 and MgS04 per- formed better than did formulas contain- ing onlyK. Applied at weekly intervals before flowering, 2 foliar applications of fertili- zer containing macro- and micro- nutrients increased the number and size of berries and the 100-TPS weight; how- ever, there was no improvement in the rate of TPS germination and vigor of potato seedlings during the first 20 days. Light Duration In Lima, Peru clones DT0-28 and LT-7 were studied under greenhouse condi- tions to determine the effects of daylength on flowering. The daylength treatments were increasing, constant (15 hours), and d ecreasing. Decreasing daylengths caused a significant increase in pollen production on the DT0-28 clones but not in LT-7. Flowers produced on LT-7 in plants subjected to the con- stant daylength treatment had pollen of lower viability. Neither clone produced flowers on control plants grown under 12 hours of light. TPS Physiology TPS handling. The performance of seed when sown has been demonstrated to be strongly affected by general conditions during the seed development phase, and after harvest. Periodic high applications of N following pollination improve per- formance and this practice is routinely used in TPS production. To investigate the effects of moisture conditions in storage on seed germina- tion and seedling vigor, TPS of the cross Thrust IX 121 Table 9-4. Effects of N applied during seed production and moisture conditions during seed storage on the coefficient of velocity (CoV) and percentage of germination, after 7, 11 , and 14 months of storage. Storage Coefficient of velocity Percent of germination period Nitrogen: Low High Low High (months) Moisture: Amb Dry Amb Dry Amb Dry Amb Dry 7 14.0 16.0 13.4 11 17.8 29.3 16.7 14 2 15.0 31.6 15.0 Linear R ns •• ns Quadrattc R .98** .99** .97** Atzimba x DT0-28 was grown with high and low nitrogen fertilizer applications. The TPS was stored at room temperature in ambient air (9% to 12% seed mois- ture) and dry (5%) condit ions. Germina- tion tests we r e performed un de r favorable conditions after 7, 11, and 14 months of storage (Table 9-4), and see- dling vigor was tested after 14, 20, and 23 months. The rate and percentage of ger- mination (0 to 8 days after sowing) were more strongly influenced by the moisture conditions during storage than by fer- tilizer application: dry seed germinated more quickly and at higher rates than did TPS stored in ambient air. The rate of germination showed a linear association with time in storage and the percentage 18.9 80 75 68 95 25.2 100 99 98 95 30.2 57 99 99 99 .98° ns ** ns ns ** . 90** .80** .89** ns was high (~95%) in dry seed produced with high N (Table 9-5). The responses for other treatments were curvilinear; germination potential began to decrease by the 14th month in storage. Seedling vigor parameters were shown to be in- fluenced more strongly by N treatments during seed production. High-N seed had much higher rates and percentages (0 to 10 days) of emergence and seedling dry-weight (17 days) levels than did low- N seed, particularly when stored dry. In s torage, low-N seedling emergence parameters decreased linearly with time, whereas high-N seed showed linear in- creases in rate of emergence and the per- ce n tages we re hi gh (95 % ). These findings suggest that TPS should be Table 9-5. Effects of nitrogen applied during seed production and moisture conditions during seed storage on the coefficient of velocity (CoV) and percentage of emergence, after 14, 20, and 23 months of storage. Storage Nitrogen: Low High period Moisture: Amb Dry Amb Dry (months) CoV % CoV % CoV % CoV % 14 10.8 68 10.g 71 13.1 97 14.1 100 20 3.8 2 0.0 0 13.0 78 14.7 95 23 0.0 0 2.5 14.3 96 14.9 98 Linear 2 -.74 -.90 -.52 -.88 .29 .04 .55 .14 Signifi. (R) ** ** ns ** ns 122 Thrust IX produced with high N and stored dry for sowing under favorable conditions. Pres owing TPS treatments. Presowing treatments were compared for seedling- stand establishment under screenhouse conditions with old ( > 18 mo) and new ( < 6 mo) seed for 3 potato crosses. The treatments consisted of soaking the seed in solutions of KN03m + KJP04 at 1.0 MPa (priming) and gibberellic acid at l ,500 ppm (GA1500). Evaluations of emergence and seedling growth para- meters were performed within the first 17 days after sowing under mean (max.) air temperatures of 29C and 34C. Seedling vigor levels were lower in the second test (34C) than in the first (29C). In both tests, overall seedling performance was highest in seed of the cross Atlantic x LT-7. Old seed was more vigorous than new seed, particularly when the crosses Atzimba x R128.6 and Serrana x LT-7 were tested at 34C. Priming increased early emergence over the other treatments at 34C and in- creased seedling dry weight in both tests Dry wt (mg/plant) 10 6 6 4 2 0 - A First test {29° C) I LSD (5%) - B TPS cross 0 Priming ITJ GA 1500 11111 Rinsing - c Figure g-2. Mean seedling dry weight as affected by presowing treatments. (Figs. 9-2 and 9-3). GA1500 generally increased final emergence in Serrana x LT-7. It was concluded that for sowing TPS at high temperature a) the genotype is a crucial factor, b) sufficient seed Dry wt/ plant (mg) 6 Second Test {34° C) 6 4 t 2 0 IB New 1111 Old GA Cross A RIN PAI I LSD (5%) I GA RIN PAI GA RIN Cross B Cross C Figure 9-3. Ettect of presowing treatments and seed age on seedling dry weight. (PRl1 = Priming ; GA = GA 1500; RIN = Rinsing.) Thrust IX 123 storage ( > 18 mo) may be essential, and c) seed priming is more effective than the standard GAlSOO treatment. Storage of treated TPS. The preserva- tion of the effects of various seed treat- ments during storage at two temperatures was evaluated, using TPS of Atlantic x LT-7, Atzimba x R128.6, and Serrana x LT-7 that were produced in 1987 and 1988 in Chile. The TPS treat- ments were a priming solution (KN03 + KJP04 at 1.0 MPa), gibberellic acid (1,500 ppm), and rinsing (water for S min). The treated seed was stored for 4 months at 2 temperatures: SC and 22C. The priming effects were preserved bet- ter at SC than at 22C. Seedlings produced with the priming treatments showed a higher coefficient of velocity and greater dry weight than did those with the rinsing TPS Agronomy TPS in Seed-Tuber Programs South America. A collaborative project between the Ministry of Agriculture (MAG) and CIP was initiated in Paraguay to produce large volumes of seed tubers of 2 selected TPS progenies: Atlantic x LT-7 and Serrana x LT-7. These seed tubers will be used as the basis of a system to supply local farmers with high quality seed tubers. The tubers were produced by transplanting seed- lings into 600 m2 field beds, at a rate of about SO per m2, at 2 different experi- ment stations. The plants were harvested 3 months after transplanting and the tubers stored for 3 months, before plant- ing in February for further multiplica- tion. The tubers of 4 progenies produced last year also were planted in plots at both stations to assess the best adapted 124 Thrust IX treatment. Priming of seed stored at SC produced the highest seedling vigor and dry weight/plant. In general, the priming treatment produced better performance than did the standard gibberellic acid and presowing rinsing treatments. In India, studies using freshly ex- tracted seed of 4 sizes showed that a solution of 10% HCl can be safely used to soak seed for up to 80 min. to remove the mucilage and to clean fungus or bac- teria from the seed coat. The effects of seed size were also studied in another experiment to determine the proportion of different embryotypes and their relationship to seedling vigor. Seedlings from large seed with embryotype A, i.e. fully developed embryos, were shown to be more vigorous than those from seed with embryotype B. progenies. They were also planted in a large production field at the experiment station. In addition, some of the tubers were distributed to farmers to obtain their help in identifying potential problems that may need further research. In four farmers' fields in Venezuela (states of Trujillo and Merida), seedling tubers were produce d in beds and planted in the field after the regular storage period. (One of these farmers has been growing potatoes from seed tubers that originated from true seed sown in beds on his farm about S years ago. He obtained 20 t/ha last season). Due to the potential for adoption of this method of potato production in those regions, two methods of seedling-tuber production in seedbeds were evaluated by the national scientists: direct sowing and transplant- ing seedlings into the seedbeds. The transplanting me thod showed better plant establishment, higher yields, and improved tuber-size distribution. Of the different progenies tested, Atzimba x 104.12 LB showed the most promising results, with yields of more than 9 kg per m 2 of seedbed. Africa. In Cameroon, preliminary evaluations have indicated that seedling- tuber production in nurseries can be an appropriate method for providing quality-protein planting materials to farmers at low cost. When seedlings are transplanted to the field under the high- stress conditions of the production sites, they traditionally have shown poor field establishment; however, this limitation can be overcome by nursery production of seedling tubers. In Mfonta (1,300 m) 16 progenies were evaluated in nurse? beds, at a plant density of 100 plants/m . Seedling tubers were harvested 90 days after transplanting and the highest yield- ing progenies were CFK69.l x DT028, Atzimba x R128.6, Atzimba x 104.12-LB, and I-931 x A VRDC 1287.19. On the Upper Farm, crop production from seed- ling tubers of 13 progenies was compared with that of three commercial varieties. Six of the progenies out yielded the three varieties and had greater resistance to late blight. The three highest yielding progenies were CFK 69.1 x 104.12LB, CFK 69.1 x DT028, and Atzimba x 104.12LB. In Sri Lanka, progenies are being adapted to the local conditions. Im- proved TPS parents were identified from locally-selected clones and large quan- tities of hybrid TPS are being produced to replace the less productive progenies used in the past. Trials for agroeconomic evaluation of the use of TPS continued at a number of locations in India. Economic studies have demonstrated clear advantages of TPS use in many areas; thus, TPS is attracting increasing inte rest by farmers (see Thrust X). A very active TPS agronomy program is under way in the Patna region, under CPRS supervision . Seed of the best progenies have been selected through systematic evaluation in India and have been distributed to Bangladesh, Nepal, Sri Lanka, and the Philippines. TPS progenies th at have shown promising results at specific growing locations were distributed to farmers to be tried on-farm. TPS technology was introduced at 2 isolated growing areas of the Philippines (Canlaon, Negros and Lantapan, Bukid- non). In Canlaon, farmers have success- fully sustained TPS production 3 years after its introduction, with most TPS now grown with seedling tubers. In Lantapan, where bacterial wilt is a limiting factor for potato production, TPS was introduced to provide clean seed. Twenty interested farmers were provided with TPS, and instruction on production; the~ are now obtaining 1. 7 kg-3.8 kg per m from their beds. Seed- ling tubers of the first generation were planted in June 1989. In September 1989, TPS was distributed (sold) to various farmers in Mindanao along with careful instructions on how to grow the crop from TPS. True seed production continues m Dalat, Vietnam, where hybrid TPS production was initiated in 1989 at the Potato Research Station and 200 g of Thrust IX 125 hybrid seed were produced. Generally, plants were staked and allowed to main- tain 5 flowers resulting in 3 fruits per stem. On average, 100 seeds were ob- tained per berry. The female parent was CFK69.1, while male parents included LT-7, 38.6, 7XY.1, 88.14, 88.8, and I- 1039. Production is expanding for 1990. In the Red River Delta (RRD) area, during the 1988-89 season, only 10 kg of TPS (OP) were utilized for transplanting in 6 cooi>eratives (Haihung 2, Langson 2, Seed-Tuber Propagation Bolivia. A 12-year research project funded by the Swiss Development Agen- cy has been started by the Bolivian Agricultural Research Institute (IBT A) and CIP to analyze the limiting factors of potato production and to strengthen the national program by developing and transferring appropriate technologies. An intensive workshop was conducted with key organizations participating to define the objectives and activities to be implemented by the project. Burundi. CIP is collaborating with the Burundi National Potato Seed Project to produce large quantities of prebasic seed for wide distribution and to develop tech- nical information aimed at promoting on- farm seed reproduction systems. A greenhouse and an in vitro laboratory were completed and equipped, with as- sistance from Belgium. In vitro-derived tubers produced in Gisozi were planted on 1 ha at Mwokora, and on 18 ha at Munanira. The seed tubers harvested will be distributed to rural projects and farmers. At Mwokora, seed quality has been further improved through an in- 126 Thrust IX and Hasonbinh 2). Approximately700 ha of potatoes were grown from the tuber- lets during the 1988-89 season. Extensive adoption has been limited by technical problems: too wet or dry conditions in the seedbed and after transplanting, and poor adaptation of existing progenies to short-day conditions. In the RRD, the breeding work is now focusing on the selection of TPS parental lines that will produce tuber yields of good quality and large siz.e under cool short-day conditions. novative integrated approach for bac- terial wilt control. Thirty farmers have participated in these trials, and 15 have replanted the seed produced in their own fields. Colombia. In collaboration with CIP scientists, a project was started by ICA in Boyaca and Cundinamarca to 1) produce large amounts of prebasic seed using ad- vanced rapid multiplication techniques, and 2) diffuse the technology among farmers. An aphidproof screenhouse (120 m2) was completed in April at the San Jorge Station. CIP has provided crude antisera against PVY, PVX, PVS, APMV, and APLV for processing and distribution to PRACIP A members. A study of the adoption of appropriate dif- fused-light stores for small farmers (pre- viously promoted by ICA/CIP) has indicated that these stores are well ac- cepted by the farmers. Peru. The third phase of CIP's col- laborative project with the Peruvian Na- tional Potato Program is designed to strengthen the capacity for self-sus- . tainability of four major facilities for basic-seed production. The La Molina facilities continued prebasic-seed production and distribution to the other units and basic-seed revenues from the year's sales have generated a reserve fund in addition to covering the opera- tional costs of 1990. The traditional seed-tuber distribu- tion systems of Peru were analyzed to develop an effective decentralized strategy for distributing basic seed to widely dispersed communities of small farmers . Basic-seed dissemination through rural development projects has continued in Cuzco, Huancayo, Caja- marca, and Puno. Information also was gathered to help increase the efficiency of distribution of high quality seed to small farmers, focusing on the Cajamar- ca, Cuzco, and Puno areas. In Cuzco, a survey dealing with principal potato dis- eases covered approximately 20% of the crop production area. In Cajamarca, 500 small farmers were surveyed and 250 seed producers were identified. Survey findings show that this broad-based traditional seed system handles 80 varieties of potatoes that are in daily use: 25 are improved varieties and 55 arena- tive. The farmers identified bacterial wilt as the principal production problem, which is of increasing concern. Tests were made of new approaches for a basic-seed distribution with farmer par- ticipation. Community assemblies selec- ted the individual farmers who would receive 50 kg of basic seed, on condition that at harvest each would give 12.5 kg to four other farmers. Thus, with 500 kg of basic seed, 400 farmers obtained high quality seed. The demand for such small quantities of high quality seed far ex- ceeded the supply. Other strategies to increase the ef- ficiency of basic-seed distribution to the informal markets of small farmers also were investigated. The most promising strategies were: • Selling allotments of 20 kg of basic seed at the weekly community fairs. • Selling allotments of 100 kg to 500 kg to communities. • Selling larger quantities to rural development projects. At Puno, a similar survey involved 419 small ·potato producers and 30 units of peasant cooperatives. In the Puno area, farmers reported that they grew 109 varieties, of which only 19 were improved varieties. Their preferences for varieties do not differ, for production intended for home consumption or for market. Only 9% of the Puno farmers were seed producers. Although potato growing is widely diffused in Puno, individual plots are small and the average farmer uses 147 kg of seed tubers. Venezuela. Socioeconomic studies are being conducted to assess the impor- tance of prebasic seed-tuber production in Venezuela and the efficiency by which the technical information is developed and diffused. Research to assess the im- portance of vectors of virus and viroid diseases is also under way. In the potato growing area of the Caragua state, aphid vectors of the species Myzus persicae were more prevalent than were Brevicoryne brassicae, and populations increased near the end of the season, when rainfall decreased. At Trujillo, both species were important. At Monagas, A. citricola was predominant, and a fourth species, M. euphorbiae, was found. New materials for seed production have been introduced from CIP, and a popular Thrust IX 127 variety (Andinita) was cleaned and returned to Venezuela to be propagated using in vitro techniques. The viroid PSTVd was not detected. A similar proj ect will start next year in the Dominican R epublic. Kenya. A new basic seed production approach proposed in 1987-88, has been impleme nt e d. The Agricultural Development Cooperation will produce clean in vitro plant materials at the Plant Quarantine Station at Muguga; mother plants and prebasic seed at the National Potato Research Center in Tigoni; basic seed at Marindas; and certified seed at Molo. Research at Tigoni has focused on increasing the efficiency of mother-plant use for producing cuttings, tuberlets, and tubers. The Philippines . In Benguet Province, a survey was conducted as a follow-up to the 1987-88 on-farm trials that intro- duced new cultivars through apical cut- tings. This study assessed the potential for use of apical cuttings, as well as the farmer's acceptance of C IP clones. Of 64 farmer cooperators, 50 grew CIP clones and shared with neighbors. The clones 1-1035, P-7, and P-3 were the most popular. The area planted to these clones increased substantially over that planted last year. The clone B71-240.2 (locally named Dalisay) also was widely grown, while the clones 1-1035 (released as Mon- tanosa) and 1-1039 are becoming important. The study findings indicate that cut- tings are a viable tool for potato produc- tion, as demonstrated by high potential yield in farmers' fields. This practice can boost seed production by providing a so urce of clean pla nting materia ls. Tubers produced from these materials can then be used for large-scale production. 128 Thrust IX Myanmar. Since the variety Up-to- date was introduced in 1914, only a few small quantities of imported seed have been received (all before 1935); UTD continues to b e grown from locally produced seed. Studies were begun in 1984 to evaluate the need for a seed pro- gram. Using simple selection (positive selection of healthy plants), farme rs started to improve their seed stocks. CIP also arranged to import seed tubers from the United Kingdom, and to have the local UTD cleaned of all pathogens at the Plant Research Institute in Australia. Results of trials conducted during the summer season using seed from the UK, from Australian (positively selected), and from local unselected seed, showed that yields did no t differ among crops. Yields during that season were less than 20 t/ha for all seed used. For the spring crop, irrigated local seed produced slightly lower yields than did the o ther seed. In virus testing with ELISA, all seed stocks (including the local seed) were shown to have been positively selected, and imported seed, even after 4 genera- tions, are still totally virus free. Local unselected seed showed low levels of PYX, PVY, and PLRV. These findings indicate that the Shan Hills of Myanmar are we ll suited for seed-potato production, and that virus levels remain low and can be eliminated by simple selection techniques. Case Studies on Seed-Tuber Systems T he Kenya seed-potato system case study was completed as a part of a series that includes the Philippines (Annual Report 1988), E cuador (Annual Report 1989), Canada, the Netherlands, and the United Kingdom (Annual Report 1988). A com- parat ive report is being prepared. Major findings of the Kenya case are described below. Potato production in Kenya is dom- inated by small-holder production dis- persed in highland areas that grow a large and ·changing mix of varieties. Production is mostly market-oriented, and the seed- potato system is dominated by farmers who grow their own supplies. Govern- ment participation in certified seed production has received a low level of funding and has been ineffective, provid- ing less than 1 % of the total seed needs. Seed production and distribution acti- vities are dispersed among institutions associated with the National Potato Re- Sweet Potato Environmental Effects on Flowering Experiments were conducted at several locations to determine the basic environ- mental conditions that promote flower- ing and seed production of sweet potato. search Station, which initially assumed responsibility for the seed program. The study conclusions note that the research stations are fundamentally service in- stitutions, whose research objectives are to develop and disseminate technical in- formation that can be used in producing potato seed. Thus, this research carries no direct responsibility for efficiently producing potato seed according to farmers' needs. A private firm has now become inter- ested in producing potato seed efficient- ly, according to farmer demand, and is planning to promote the use of certified seed. The studies were based on the develop- mental responses of 150 sweet potato cul- tivars selected as representative of the CIP germplasm, which included cultivars that flower prolifically, as well as those that had not flowered previously. A wide Potato seed in market at Mwokora, Burundi. Thrust IX 129 range of environments was studied over a 12-month period. The basic field-study findings indicate that the flowering and seed production of a sweet potato cultivar can vary consider- ably from one location to another or ac- cording to the method of cultivation utilized (Fig. 9-4). The response differen- ces suggest that the developmental stages of sweet potato may have a wide range of envir.onmental requirements. The flowering and seed production of sweet potato has also been observed to be af- fected by an unidentified species of fruit fly that feeds on the anthers, causing up to 100% of the buds to abort. This pest has been found in Lima, Chincha, Canete, and Tacna, but not at other ex- perimental locations in Peru. Cultivation Procedures and Flowering Several cultivation procedures were tested to further define the factors that A. On-trellis F B NB 2 3 4 5 6 B. On the ground control the developmental stages of sweet potato. In addition, the develop- mental responses of standard unrooted sweet potato cuttings were compared with those of potted rooted cuttings, as well as with responses of in vitro-pro- pagated plant material. Procedures were compared for train- ing the plants onto individual stakes and trellis supports, and for plants growing on the ground, without support. Flower- ing responses ranged widely among the cultivars compared. For example, train- ing individual plants onto a single stake did not induce non-flowering cultivars to flower; nor did this method increase the flowering of a cultivar, when compared with that of the same cultivar growing on the ground without support. When plants were grown on individual stakes, the entire bulk of a plant was tied onto one stake, thus limiting light and ventilation in the center of the plant mass. 7 8 9 10 11 12 B 7°'6 F NB dr72 94 ~r22· 82 2 3 4 5 6 7 8 9 10 11 12 Figure 9-4. Effect of cultivation methods, A) on-trellis; B) on the ground, on flowers (F), buds (B), and no-bud (NB) formation in the sweet potato clones 72, 94, 226, and 82. 130 Thrust IX On the other hand, training plants onto a trellis (5 plants per 3-meter trellis) induced some non-flowering cultivars to flower and se t seed. This method in- creased the flowering of all flowering cul- tivars in all of the locations in which the trellis system was tested. Some non- flowering cultivars showed an extreme sensitivity to light quality and quantity, beyond the photoperiod requirement. For instance, cultivar 226 produced flowers only on the portion of the branches along the top of the trellis, where as no buds or fl owers were produced on the portions of branches between the top of the trellis and the ground. In the Philippines, 12 sweet potato cultivars were grown on stakes or on the ground without s upport and we re evaluated for flowering and fruit set. The cultivars VSP-3, Miracle, and G ll3.2b were the most prolific in flowering and seed production. The cultivars showed different responses to the two planting methods. In general, the use of stakes enhanced fruit and seed production; however, the degree of influence varied among the cultivars. Cultivars such as Miracle and VSP-3 were slightly affected by the cultivation method, whereas cul- tivars such as Tipipay, Sinuksuk, and VSP-4 never flowered when grown on the ground. Sweet Potato Planting Materials Trials were conducted throughout Peru to compare the growth and development of standard unrooted cuttings, of potted rooted cuttings, and of in vitro- propagated plant material. Plants grown from potted rooted cuttings established more quickly, and grew and flowered more rapidly than those grown from standard unrooted cuttings. However, in general, plants grown from in vitro- propagated plantlets outperformed both standard unrooted cuttings and potted rooted cuttings, in establishment, vigor, rate of growth, flowering, and storage- root yield. In Kenya, a collaborative project with the Kenyan Agricultural Research In- stitute (KARI) has begun to develop suitable propagation methods that could increase a multiplication rate that favors the rapid establishment of high-quality, locally-grown sweet potatoes. Initial ef- forts are primarily at the Katumani Na- tional Dryland Farming Research Center. Research will later be expanded to Mtwapa on the coast and Embu in the central region of the country, where sweet potato has shown potential as a crop with tolerance to drought. In arid areas, sweet potato production con- straints include the lack of vines to plant at the beginning of the rainy season, thus slowing plant establishment. Experiments in the Philippines have examined several factors influencing rooting and growth of sweet potato cut- tings. Data collected at 30, 60, and 90 days after planting (DAP), indicated that plant survival and growth was enhanced by planting bigger cuttings including apex + 4-nodes, and 4-node cuttings (Table 9-6); storage-root formation was faster and better with these materials. The number of nodes (which is corre- lated with plant age) also influenced growth. Survival and growth rates were lowest, when the youngest node was used for planting. In single-node cuttings SNC excised from different segments of5- to 6-month- old plants, nodes from the middle por- T hrust IX 131 Table H . The influence of size and origin of sweet potato cuttings on growth on a per-plant basis, at 30 days after planting. Survival Length Size of cuttings (%) (cm) Apex + 2 nodes 50 11 Apex + 4 nodes 81 19 1 node (mid-portion) 88 12 2 nodes (mid-portion) 91 21 4 nodes (mid-portion) 100 19 LSD (0.05) NS tion showed the fastest shoot and root development, and produced vigorous plants. Shoot tips showed poor initial growth, but had the highest rate of shoot growth at 90 DAP. Nodes from the mid- dle and basal portion produced more storage roots. Depth of planting did not influence the growth of cuttings; however, at any depth, nodal cuttings grew better than did apical cuttings (Table 9-7) . In another experiment, the potential of SNC as planting material was com- pared with that of the vine. Single node cuttings were taken from the pathogen- tested mother plants and rooted for 3 Shoot Root Weight Length Weight (g) (cm) # (mg) 6.5 10.4 5.3 344 12.1 8.9 3.6 1463 6.0 9.9 3.4 358 9.5 9.9 5.5 716 15.7 10.4 6.9 616 2.7 ns ns 456 weeks prior to planting. The vines were from 5-month-old plants grown in the field, but were initially from single-node plantings. Survival was excellent for both SNC and vines, and yields ranged from 705 g to 970 glplant for the SNC and 715 g to 925 g/plant for the vines. Single node cuttings produced larger (60 mm) but misshapen roots, whereas vines produced medium-sized roots of normal appearance. Slightly higher yields were obtained with SNCs of all cultivars, espe- cially those ofTN-57. In Peru, samples of sweet potato roots obtained from farmers' fields in two ir- rigated growing regions on the Coast Table 9-7. The effect of depth of planting of apical and nodal cuttings on growth, as measured at 30 and 60 days after planting. Shoot Root Length Weitt Length Weight Survival (cm) (g (cm) Number (mg) Type of cutting/ (%) Depth at planting Planting 60 30 60 30 60 30 60 30 60 30 60 Apical Bud exposed 16 6.2 25 2.7 14.2 7.9 22.5 3.5 3.1 22 1912 Bud buried 19 4.0 10 2.4 6.6 6.0 14.8 2.4 2.7 17 115 Nodal Bud exposed 84 14.0 28 5.8 10.8 10.9 18.8 6.2 4.7 437 1598 Bud buried 84 14.5 28 7.6 11.9 11 .5 19.0 8.2 4.5 464 1165 LSD (0.05) ns 7 ns ns 2.4 ns 2.4 ns 260 ns 132 Thrust IX (H uaral and Caiiete) and from the rainfed area of San Ramon were used for screening Azospiri//um populations. A total of 26 strains were isolated, 3 having a high nitrogen-fixing capacity as shown in the corresponding laboratory tests. When these selected strains were used in controlled inoculation of potted sweet potato plants of cultivars Jonathan and Paramutai, a two-fold increase in foliage fr e sh weight was observed in the Jonathan cultivar, when fertilized with 80 ppm N, without inoculant, whereas Paramutai showed a three-fold increase with the same fertilizer application, but was inoculated with the bacteria. The N content of the Paramutai plants in- creased four-fold when inoculated. The addition ofAzospiri/lum was favorable to root yields in both cultivars grown in San Ramon, producing double the yields of those of the control pots. Sweet potato germplasm collection at VISCA, Leyte, Philippines. Thrust IX 133 National program and CIP researc hers discuss sweet potato consumption with a farm family in Peru. ThrustX Food Systems Research Thrust Profile: 1990 The client's or user's perspective is a fundamental concept built into Thrust X food-system work to help guide both national and international research. This perspective helps 1) assess the concrete needs and demands of the final "users" of technology: small farmers, low-income consumers, processors, and other participants in the food systems of developing countries and 2) provide field-based information for decision-makers and researchers in national potato and sweet potato programs and in other public and/or private institutions. It is a demand-driven, bottom-up alternative to the top-down, supply-driven model of conventional " technology transfer." In the words of the formal goal statement, the approach is designed to "expand the knowledge of agricultural programs and policies and the production, marketing, and use of potatoes and sweet potatoes." The objectives are to aid in the identification of clients' needs and priorities, the generation and diffusion of appropriate tech- nologies, and the assessment of program results and policies. The "expansion of knowledge" referred to in this formal goal statement is achieved through hands-on needs and impact assessment and through strengthening the research capacity of National Agricultural Research Systems (NARS). Research on needs and impact assessment is being conducted within three impor- tant fields of research: food-system characterizations; marketing, demand, and utilization studies; and impact assessment. Work on food-system characterization progressed well during 1989, as national scientists completed surveys and analyses of constraints to potato and sweet potato production and use for five major agroecological zones. Potato-seed problems appear to cut across the different zones, but are particularly serious in tropical rainy and dry areas. The importance of the weevil as a constraint in sweet potato production is limited to tropical rainy zones. In other zones, planting material, lack of moisture, and soil fertility figure as production problems. In all zones, postharvest constraints are severe, especially in marketing. Case studies of potato and sweet potato in food systems were completed in Asia, Africa, and Latin America. Continuing studies in China helped to deepen knowledge of the diverse utilization patterns in different provinces. This knowledge will be used to broaden the use of the crops in other countries. In India, a survey of sweet potato researchers identified the sweet potato weevil as the major production problem, but postharvest issues were of most concern. Informal interviewing in Kenya, Uganda, 135 and Rwanda laid the groundwork for priority-setting by national programs, and for the organization of a formal survey in Kenya. Early results of structured informal surveys in four countries of Latin America point to distribution patterns as the key variable differentiating sweet potato systems. The principal research on marketing was developed through a sabbatical leave project that synthesized six potato-marketing case studies completed over the past six years. Preliminary conclusions note the geographic concentration of potato production in Asia and the importance of rural marketing and rural consumption in south Asia and sub-Saharan Africa, versus urban marketing in Latin America. Two studies of sweet potato marketing were conducted in Latin American cities; the findings highlight the importance of root and flesh color, and other aspects of presentation for urban markets. In preparation for CIP's Third External Review, the 1984 impact study Potatoes for the Developing World was updated using responses to new questionnaires from national program leaders and CIP senior headquarter staff and regional leaders. Results showed the growth in national program research in areas related to CIP research. Training was felt to have bad the greatest impact on NARS, followed by a number of production technologies, especially related to seed. There was a much lower level of perceived benefit from non-technical and non-production activities, perhaps due, in part, to the solid production orientation of most program leaders. As part of interdisciplinary technology development, social scientists were in- volved in the study of TPS in farmers' fields in India and Indonesia. Results from India show that seedling tubers have lower net costs than seed tubers. In research involving farmer evaluation ofTPS in Indonesia, farmers identified a few appropriate methods for using TPS and are now assessing them. Thrust activities are closely associated with two food-system networks. The PRACIPA marketing network completed two years of activities in March 1989, and backstopping continues via workshops and annual meetings. In Southeast Asia, the Users' Perspective with Agricultural Research and Development (UPWARD) began activities with 12 projects focused on production, postharvest, or consumption issues, within a food-system context. In addition to participation in formal courses and workshops, strengthening of NARS' capacity also has been achieved through collaborative research activities with a strong "training with research" component; these include the diagnostic studies of sweet potato in food systems completed or being planned in Latin America and Africa. Food Systems Characterization Assessment of Production and Use Constraints, by Climatic Region Knowledge of the constraints to potato and sweet potato production and use in 136 Thrust X major production zones and food sys- tems is essential in helping set ap- propriate research priorities, target regional efforts, and extrapolate loca- tion-specific research results. National researchers answered ques- tionnaires on the relative importance of several potential constraints to potato and sweet potato production and use at different sites in their own countries. The potential constraints ranged from pre- planting and field-production problems, to marketing costs and limited demand. Because constraints are generally re- lated to ecological conditions that cut across political or administrative units, averaged findings for countries or CIP regions can be misleading. Thus, the data have been analyzed for major world climates using Koppen's classification of five major climatic zones on the basis of temperature and moisture combinations. Constraints are also influenced by other variables apart from climate, but in the absence of detailed global information on these variables, Koppen's classifica- tion of climates provides a useful prelimi- nary scheme. Results are presented for five major climate zones: • Tropical rainy climates with no cool season (A climates in the Koppen system) • Dry climates (B climates) • Mid-latitude rainy climates with mild winters (C climates) • Mid-latitude rainy climates with severe winters (D climates) • Cold climates with no warm season (E climates) A more refined analysis of constraints is in progress to define 12 climatic types, including altitude as one of the criteria. Potato and sweet potato production areas. For both potato and sweet potato about one-half of the sites for which na- tional researchers provided information have mid-latitude, rainy climates with mild winters (C climates). Consequently, Boxes of potatoes ready for export. Guangdong Province, China. Thrust X 137 given the large number and expertise of the survey respondents, it seems likely that C climates are the most typical for both potato and sweet potato production in developing countries. The tropical rainy (A) climate was the second-ranked for both crops; accounting for about two- fifths of the sweet potato sites and one- third of the potato sites covered by the survey. Between 10% and 15% of the sites for both crops have dry (B) climates, and less than 10% have climates with severe winters or no warm season (D or E climates) (Table 10-1). According to national researchers, potatoes usually are produced for sale to urban areas, and are usually eaten by people with relatively high incomes. In contrast, sweet potatoes generally are grown for household use in rural areas, and in urban areas, are usually eaten by lower-income families (Table 10-2). There are important exceptions for both crops, however. In most dry areas (B climates) and in the cooler northern areas (D climates) of China, sweet potatoes are grown primarily for sale. And in many cool, rainy areas (C di- mates), particularly in the mountains, potatoes are grown primarily for home consumption (Table 10-3). Potato constraints by zones. In tropical rainy zones (A climates), the principal constraints are considered to be the high cost and poor quality of seed, high production costs, transport problems, handling losses, unstable prices, late blight, and drought. In dry zones, scarcities and poor quality of seed are considered to be serious constraints, particularly as re- lated to storage. Insects and late blight cause important losses in the field, and consumer potato storage also is a major problem in the dry zones. Many mid-latitude rainy zones (C climates) are traditional potato-growing areas. Perhaps because potatoes have been grown for such a long time, many pests and diseases attack the crop. Re- searchers consider fungal and virus dis- eases and several seed-related problems to be especially critical. Sweet potato constraints by zones. The sweet potato weevil (Cylasfom1icarius) is Table 10-1. Number of production sites• by climate and altitude. Potato Sweet potato Below Above Below Above Climatesb 1,000m 1,000 m 1,000 m 1,000 m Tropical rainy (A) 19 22 53 14 Dry (B) 7 11 14 3 Moderate rainy, cool winters (C) 25 35 69 18 Moderate rainy, cold winters (D) 2 5 0 Cold (E) 1 4 0 0 All sites 54 73 141 35 11 Numbers of sites with information vary among tables. b Based on Koppen 's classification of climates, presented in Trewartgam G.L. and L.H. Horn. An Introduction to Climate. McGraw-Hill: New York , 1980. 138 Thrust X Table 10-2. Income level of potato and sweet potato consumers. Potato consumers Sweet potato consumers Low Middle & Low Middle & Climates income high income income high income A 7 30 B 17 c 16 51 D 0 0 A ll sites 24 98 considered to be the most important con- straint to sweet potato production and use in tropical rainy areas, where lack of processed products, price instability, transport problems, drought, and low- fertility soil are also major constraints. In dry areas, the major problems are unstable supplies and prices, handling losses, weeds, and the poor quality of planting material. In mid- latitude rainy zones, re- searchers have found the principal con- straints to be low-fertility soil, lack of moisture, s torage diseases, unstable prices, and lack of processed products. In the cool, rainy zones of northern Chjna, the principal problems cited are lack of moistur e, low-fe rtility so il, salinity, marketing problems, and the 47 17 9 6 60 29 4 120 53 lack of a variety with good qualities for fresh consumption. Agroecological Studies of Potato During 1989, country profiles were com- pleted for all developing countries and maps of zones are being refined. To more precisely identify the climate charac- teristics of each production zone, the Koppen classification is being overlayed on these maps. The potato zones are being refined by a geographer at Clark University (USA) and details of the spa- tial distribution are being reviewed care- fully. The European Potato R esearch Association has agreed to provide sum- maries on potato production and utiliza- tion in Europe in the form of a book, entitled World Geography of the Potato , which is now being prepared and will be submjtted for publication in 1990. Table 10-3. Principal final destinations of potatoes and sweet potatoes (number of sites). Potatoes Urban Rural Climates areas areas8 A 30 11 B 16 2 c 25 42 D 0 0 All sites 71 55 a Includes both rural and urban areas. Urban areas 9 7 16 2 34 Sweet potatoes Thrust X Rural areas8 50 10 66 3 129 139 Asian Food Systems China. Of total developing-country production, China grows over 50% of the potatoes and over 80% of the sweet potatoes. Because of the importance of this production, an agreement was made with the International Food Policy Re- search Institute (IFPRI) to study both crops in Chinese food systems, to identify Chinese research needs, and to explore the opportunities for horizontal transfer of technologies to other developing countries. P"rovincial and local investiga- tions of potato and sweet potato utiliza- tion patterns begun in late 1988 were completed in' Hebei, Shanxi, Shaanxi, Heilongjiang, and Inner Mongolia. Data are now being collected in Henan, Anhui, Hubei, Hunan, Guizhou, and Sichuan and these findings should complete the description of all major potato- and sweet potato-cultivating provinces in China. A key initial observation is that pro- duction practices and uses of both potatoes and sweet potatoes are widely diverse, and potentials vary substantially among the regions and sub-regions of China. Further studies are needed to un- derstand the different roles these crops can play, especially the industrial use of sweet potato, so as to determine the potential for use in other developing countries. Similarly, China might benefit from international experience with food processing of potatoes. Both potatoes and·sweet potatoes are important staple foods for millions of Chinese and are likely to remain so for decades. In some localities, production accounts for more than 80% of direct staple-crop consumption. But use of the 2 crops as staples varies considerably, from less than 1 % in some localities to 140 Thrust X almost 100% in others. Potato and sweet potato use as animal feed (especially sweet potatoes), and as processed food, industrial material, and export product is expanding in several areas in China, with growth potential for both crops. A special study was made in Yunnan Province, where roughly 80% of the potatoes are of the East German variety Mira, which was introduced into Yunnan in the early 1960s. This variety originally had some late-blight resistance, but was very susceptible to virus. White potatoes in northwest Yunnan, which is one of the poorest areas of China, are generally of low quality and of small size. A high- altitude potato improvement base in the region might be an attractive project to increase the nutritional and income levels of the population. Observations in northwest Yunnan also provide strong evidence, matching that gained from local investigations in north China, that the traditional statisti- cal reporting system may be substantially underestimating white-potato cultivation in China's mountainous areas. India. Official statistics provide little information on sweet potato; thus there is a strong need to collect primary data. A survey conducted by scientists and technicians working at experimental sta- tions in sweet potato areas indicated that sweet potato is grown as a minor crop throughout India, usually on plots of less than one quarter ha. In general, the crop is rainfed, with only rare supplemental irrigation. The main planting season coincides with the onset of the monsoons, and rice-sweet potato seems to be the most common rotation. Most roots are consumed boiled or fried as snack foods or vegetables, and in some areas the leaves are also eaten as greens. Most of the vines and some culled roots are fed to livestock. Local markets are the main commer- cial outlets and farmers generally bring their produce directly from the fields. In major producing areas, agents also are involved in crop marketing. According to the scientists, the prin- cipal constraints to production and use of sweet potato are related to marketing problems and limited demand. They cited the instability of supplies and prices, unacceptability of varieties, poor presentation of the merchandise, lack of adequate transportation, and use of late- maturing varieties as the major market- ing limitations. Lack of diversification of the product and the lack of a tradition of sweet potato in the diet were the major demand factors identified. The sweet potato weevil (Cy/as) was considered to be a serious production problem. Of the abiotic stresses, drought was considered the most serious problem. In some areas, scarcity of planting material is a major constraint. Nematodes, viruses, fungi, and bacteria were not considered to be important problems. Indonesia. Potato and sweet potato are important crops for Indonesia, where the potato is generally grown as a cash crop and has high export potential; sweet potato is one of the most important In- donesian subsistence crops, and is sold as a low-cost carbohydrate food throughout the country. Until recently, national re- search focused on potato cultivation in cooler, upland areas, while the role of the sweet potato was generally overlooked. A special project was begun in 1987 to characterize the food system and develop technology, working primarily with the Agency for Agricultural Research and Development (AARD). Indonesian and CIP scientists col- laborated on two interdisciplinary, rapid- appraisal rural research projects in Java and in West Sumatra, in the areas of highest commercial production. Three shorter surveys were conducted throughout Java to examine the existing market for sweet potato and to collect sweet potato germplasm and identify farmer-based characterization of sweet potato cultivars. Provincial time-series data were collected on sweet potato yields and production areas in Indonesia. The rapid-appraisal surveys in rural Java show that farmers seek new sweet potato cultivars that mature quickly, can be intercropped, grow well in the wet season, are high-yielding, and whose color and taste qualities make them easily marketable. Deterioration during trans- port is a problem. Insects, diseases, pe- riod of home storage, weeds, flavor, quality, and marketability of local cultivars were not considered to be major constraints. Yields in fields ranged from 10 t/ha (with no fertilizers, weeding or care) to 22 t/ha (with fertilizers and weed control). In West Sumatra, the farmers' primary problem is growing sweet potato in the wet season, when yields are said to be lower and sweet potato skins darken, making them unattractive, and prices for lower quality roots are reduced by as much as 50%. The sample yields in March were very high, and 3 villages had yields of over 30 t/ha. Farmers have developed methods to use animal labor for harvesting, and they now grow cul- tivars that mature in 4 months at 700 masl, which may be adaptable to conditions in Java. The Central Research Institute for Thrust X 141 Food Crops ( CRIFC) is preparing to publish these results, as well as the find- ings of the marketing, cultivar, and col- lection surveys. These surveys help to identify new directions for CRIFC Bagor Research Institute for Food Crops (BORIF) re- search as Indonesian sweet potato breed- ing in the past has tended to emphasize high yields with little consideration given to other factors, and previous introduc- tions of improved varieties have met with little success. The database on sweet potato cultivar selection, production, marketing, con- sumption/sale, and processing in Java is quite extensive, providing an example and a framework for further studies in Indonesia. Food Systems of East and Central Africa Initial work has focused on defining the scope and priorities for research, through collaborative links with national researchers and with The International Institute of Tropical Agriculture (IIT A) personnel. Workshops and training activities conducted as part of the development of a research program in Kenya have helped tighten the dispersed sweet potato re- search of the Kenyan Agricultural Re- search Institute (KARI) into a more user-oriented program. Farmers in the major production zones were surveyed informally and available statistics and the results of pre- vious research were reviewed. Several production regions are now being formally surveyed and these find- ings will provide a cross-section of the 142 Thrust X roles of sweet potato in different rural food systems. A fundamental reorganization of re- search is under way in Uganda, the most important sweet potato-producing country in Africa. Based on preliminary interviews with users and pooling of local technical knowledge, priorities were set and a potential work plan developed, in- cluding interdisciplinary socioeconomic surveys. The team has surveyed one dis- trict, and results are being analyzed. Food Systems of Latin America and the Caribbean Work on sweet potato in food systems of Latin America began in 1988 with a diag- nostic survey of sweet potato production and use in the Canete Valley in Peru. The full report has now been extensively revised and the final publication is in press. During 1989, diagnostic surveys were conducted in Argentina, Uruguay, and in northern Peru. All were prepared via small inte rdisciplinary, collaborative workshops involving national research and extension personnel and CIP scien- tists. The early stages of field work in Argentina and Uruguay involved social science support from CIP, but national program staff did the bulk of the inter- viewing. In Peru, personnel from CIP and INIAA took part in all field work and a joint workshop was held shortly after completion of fieldwork to analyze results and to define the framework for the reports. These reports are now being processed. Pero. Two initial studies have reported different roles for sweet potato in dif- ferent food systems. Production on the dry irrigated coast is highly commercial- ized and largely determined by the metropolitan market of Lima. In con- trast, production in the northern hills is largely subsistence-oriented, with sys- tems including kitchen gardens, inter- cro pp ing, border and short-cycle rotation; marketing in the hill area is local, sporadic, and small-scale. Sweet potato is eaten as a regular co-staple. The differences in the two areas are reflected in variety use. On the coast, only a few varieties are acceptable in Lima, so there is great uniformity in the varieties grown at any given time in the Canete Valley, which supplies the Lima market. Many varieties are tested as farmers look for the most commercial types, but few are selected. On the other hand, in the northern hills, many varieties are grown at any given time, because no single market imposes characteristics. There is also less change in varieties over time, Sweet potato market in Kampala, Uganda. because there is less pressure to select or reject. Argentina and Urnguay. In Argentina, most production is highly commercial and extensive, especially in Buenos Aires and Cordoba, where average area planted to sweet potato is 21 ha and 32 ha, respectively. Innovative locally designed machinery and a well-devel- oped marketing system are used in the washing and special sacking of the roots. One of the major problems identified for future work is the narrow genetic base available to commercial regions, despite a wealth of genetic material in the north of the country. This situation is similar to that of Peru, and raises the issue of how to exploit national germplasm resources. Other problems identified include the special technical requirements and as- sociated problems of the temperate zone, especially the need for seedbeds, with their high costs and phytopathological Thrust X 143 problems, as well as the need to store the crop. Smaller-scale, subsistence production is found in the northe rn region of Tucuman, however, with some selling to local fairs and markets. The situation is similar to that in northern Uruguay, where the foliage also is used for animals. Although less sophisticated than the Buenos Aires system, the Southern Uruguay system is also a metropolitan system in which many small farmers supply fresh roots to intermediaries of the Montevideo wholesale market. Paraguay. A survey was conducted to characterize the production stages, com- mercialization, and industrialization of the sweet potato in Paraguay. The socio- economic importance of the sweet potato in relation to other crops was analyzed both for commercial farmers and an in- digenous group in the southern region. Interviews conducted with farmers, com- mercial agents, agronomists, and proces- sors of sweet potato and the findings of a bibliographic review indicated a limited expansion of sweet potato cultivation in comparison with other crops, as well as diminishing yield trends. Problems en- countered include low levels of produc- tion technology, lack of quality varieties, limited commercial access to the market, the displacement of sweet potato by foreign products in the diet, and limited processing of the roots into alternative food products. The study indicated the need to activate programs to improve the technical and financial assistance cur- rently available to sweet potato pro- ducers and processors. Educational programs also are needed to promote the consumption of this underexploited source of nutrition. These preliminary results from Latin America depict a crop that, on the one hand, is commercially produced to satisfy a clear demand niche in major popula- tion centers and, on the other hand, is a co-staple or special-use subsistence crop, with small-scale marketing potential. Marketing, Demand, and Utilization Potato Marketing A substantive synthesis and analysis was developed based on case studies of potato marketing already conducted and published in Bangladesh, Bhutan, Burun- d~ Rwanda, Zaire, Madagascar, Peru, and Thailand. Preliminary results of this synthesis emphasize: • the geographic concentration of potato production in Asia, and the dis- parate evolution of output and yields in Latin America, Africa, and Asia. • the shifting importance of potato production by agroecological zones, e.g. rising output in the lowlands of 144 Thrust X southern Asia due to changes in pro- duction and postharvest technology, demographic trends, and shifts in rela- tive prices. • the importance of rural marketing and consumption in sub-Saharan Africa and southern Asia versus urban mar- kets in Latin America. A study of demand for processed potato products in New Delhi showed that 15 different processed potato pro- ducts are sold at a wide range of outlets, from confectionery shops to street venders. Products are differentiated on the basis of form (chip, crisp, strip), packaging (fancy, plain, none), weight (25 gr to 250 gr) and price. The most expensive products were potato crisps in "fancy'' packages, but most sales consist of dried chips (nearly 50%) and potato chips (16%). Most processed products were sold at confectionery, general, and provision stores. Venders as well as juice and tea shops also sell processed potatoes. The major buyers of all types of processed products come from middle- income groups (57%), with high-income groups purchasing exclusive, "fancy" products (23% ). Just 4% of retailers sold only to low-income groups. Females and children are more frequent customers than are men. From the retailer's point of view, the principal constraints to expanded sale of processed products are price, packaging and the need for greater advertising. Sweet Potato Marketing At Lima, Peru, a Master's thesis on the wholesale demand for sweet potatoes showed that, although national sweet potato production fell from 167 thousand tons in 1971 to about 123 thousand tons in 1987, sweet potato shipments to Lima almost doubled, from 47 thousand tons in 1971 to nearly 74 thousand tons in the first 10 months of 1988. About 70% of this total consists of yellow-flesh varieties, while 30% have purple flesh; however, shipments of purple-flesh varieties have increased much more rapidly since 1972. The largest concentration of output has shifted from the northern coast and high- lands (which had 45% of annual output in 1944 versus 18% today) to the central coast, in particular the Canete Valley. The demand has been met through in- creasing area, doubling yields (through a small but successful breeding program), and the break-up of the cooperatives that favored small-scale, intensive agricul- tural production. The bulk of production in Canete is sold through local as- semblers, who are in charge of grading, bagging, loading, and transport to the wholesale market in Lima. Estimates of sweet potato consump- tion, based on household surveys, indi- cated a range between 6.5 kg/yr in 1971-72 and 13.6 kgtyr (for low-income families) in 1979. Consumption (and availability) of sweet potatoes, as reflec- ted in marketing data, is much higher: about 20% of the sweet potatoes shipped to Lima are re-shipped to northern loca- tions, and an apparently substantial, but unknown, percentage of the total quan- tity is used in Lima to feed household pets. Sweet potatoes represent about 4% of the total calories consumed in Lima on an average daily basis (1977-1980). Sweet potatoes are now also used for processing. One researcher's thesis sug- gests that if 5% of the wheat flour used to make bread were to be replaced by a sweet potato product, the total demand would require doubling of current na- tional sweet potato production. A study of sweet potato marketing in the central market of Buenos Aires, Ar- gentina indicated that 86% of sweet potato supplies to the market now come from the provinces of Buenos Aires and Cordoba. Santiago del Estero, which was previously an important supplier to the capital, now accounts for only 11 %. The first phase of this two-stage study describes a highly sophisticated market- ing system involving the machine washing and special sacking of sweet potatoes. Thrust X 145 The findings highlight the importance of color and presentation of the product in the market, and show wide fluctuations in prices depending on the time of market- ing. These factors underline the need for breeding efforts to take careful note of marketing requirements and consumer preference. Sweet Potato Utilization A book on sweet potato consumption and nutrition is nearing completion, which will serve as a comprehensive review of secondary sources on the nutri- tive components of both the fleshy storage roots and the green tops. This review examines current worldwide uses of the crop, including uses as a tropical spinach or salad green, staple food, animal feed, starch source, industrial raw material, dessert, processed convenience product, fast food, snack, multipurpose flour, and alcoholic or non-alcoholic drink. The Impact of CIP Technology The 1984 impact study Potatoes for the developing world was updated in pre- paration for CIP 's Third External Review. Sources of information for the update included results of an "impact questionnaire" filled out by CIP regional leaders in 1984, with an updated version filled out in 1989; a similar questionnaire completed by national program leaders between 1987 and 1989, and written responses of thrust managers, depart- ment heads and regional leaders to five open-ended questions about the major achievements, impacts, and constraints of their programs. Figure 10-1 shows the growth in na- tional-program research related to CIP Postharvest technology ~~;;;::~~--- Diffused-light storage ~---a••• Meristem culture Simple processing Biological control ..I of nematodes Recombinant DNA • 1983 . 1989 L--~--L~~-'-~~-'-~~~~~~~~ 0 20 40 60 80 100 120 Number of countries Source: GIP regional leaders surveys 1983, 1989 Figure 10-1 . NARS research in progress. 146 Thrust X research, which can be used to analyze effectiveness of the way research priori- ties are identified through collaboration between CIP and national programs. The rapid growth in the number of countries screening materials for adaptation to warm conditions probably reflects both CIP's increasing adapted populations and the growing interest of national programs in cultivating potatoes in warm and hot areas. A similar analysis can be made of the increase in use of sex pheromones and TPS. The lower levels of activities for the other research areas might indicate e ithe r a problem of regional rather than global importance (nematodes), or a relatively new area of research activity for CIP (consumer potato storage). National program leaders were asked how their institutional or research ac- tivities have benefited as a result of col- laboration with CIP (Figs.10-2and10-3). Training Plan., coor. & manage. Facilities Variety releases Seed production Farm-level impact Links with extension Staff Institutional benefits that were con- sidered especially valuable included training, links with other programs, im- proved capacity for planning, and management of research. These im- proved capacities stem from regional courses in which scientists from various countries are brought together and asked to prepare research plans as a routine part of course activities. The responses of program leaders to questions relating to increased capacity to conduct certain activities (Fig. 10-3) indicated that CIP's train-the-trainer philosophy, using experienced former students as instructors for CIP courses, has paid great dividends. Seed tech- nologies, ranging from seed storage to rapid-multiplication techniques, also were rated as highly beneficial. Several important factors may be reflected in the low level of perceived benefits in a range of non-technical and non-production ac- Foreign budget ,====r•• Domestic budget I 0 10 20 30 Number of countries Source: NARS survey 1987 40 50 Figure 10-2. Number of countries reporting specific institutional benefits due to collaboration with CIP. Thrust X 147 Training , llllllllllllr••• Seed storage ~ General agronomy Seed supply Breeding genetics Disease control Rapid-multiplication techniques TPS research Pest management On-farm research Tissue culture Communications Lowland production Crop system research Extension methods Consumer-potato storage -;;;;: Social sciences ~ Marketing Potato processing 0 10 20 30 40 50 Number of countries ·source: NAAS survey 1987 Figure 10-3. Number of countries reporting increased capacity in specific areas due to collaboration with CIP. t1v1t1es. For example, program leaders are drawn from the ranks of biological scientists and are trained primarily to identify and resolve p roblems in these disciplines. The social sciences usually are not represented in national agricul- tural programs, but often are located in other sectors of the ministry or in univer- s i tics; therefore, the questionnaire respondents may be less awar e of achievements in these areas. Figure 10-4 depicts the greater national program capacity to improve the welfare of farme rs. Given the mixed view of outsiders' opinions on whethe r national programs have improved links with ex- tension services (Fig. 10-2), and the im- provement in ext ension methods as perceived within the national programs, (Fig. 10-3), it is not surprising that nation- al program leaders fee l that most of the benefits to farmers have been in the form of technologies (e.g. improved seed) that are delivered directly to the farmers by the research program. These are tentative results, as CIP is now placing a top priority on the review of impact assessment methodologies to establish a fully institut ionalized impact- assessment process. Socioeconomic Aspects of Technology Development: Cost of Potato Production Using TPS India. An evaluation was made of agro- ecological characteristics and socioeco- nomic conditions of the three areas in 148 Thrust X India where TPS work is under way, and an assessment was made of the participa- tion of farmers in TPS trials. Virus control Physiological condition (seed) Less virus in seed Storage in seed program Better varieties Agronomic management Insect control Seed supply On-farm seed storage Control of funQi Control of bacteria Timely supply of seed Nematode control True potato seed Consumer potato storage Processing Marketing 0 10 20 30 40 50 Number of countries Source: NARS survey 1987 Figure 10-4. Number of countries reporting benefits to farmers in specific areas due to collaboration with CIP. Producers, with medium to large farms, who cultivate wheat, sugar cane, and potato in Modipuram in the northern plains, successfully tested TPS for seed- ling tuber production. In Deesa, in the arid western plains, where the cooperators are large-scale farmers and almost exclusively potato producers, the trials generally were not successful, as the cooperators were un- happy managing the sma ll trial plots. These findings suggest that the experi- me nts s ho uld co ntinu e with small farmers in this area. Farmers in Tripura, in the humid northeast, have major problems obtain- ing seed tubers. Thus, TPS should have grea t potential. Farmers are mostly small-scale, and many have only rudi- mentary irrigation facilities. Potatoes are th eir maj o r c r op, a nd th ey are not familiar with transplanting techniques. These factors combined with heavy rains after one or two days of sowing created problems in some of the experiments. In both on-station and on-farm trials, costs were calculated for use of Fl Cl seedling tubers of HPS-1/13 as compared to costs of using seed tube rs of a local cultivar (Kufri Baha r or Kufri Jyoti) . In all trials, net costs were less for the seedling tubers. However, in furthe r trials at Modipuram, F1C2 and F1C3 seedling tubers showed higher costs per Lon than did seed tubers, due to reduced yields. However, these comparisons were of large-size seed; thus further research should be made of the cost of small-sized F1C2 and F1 C3 see- dling tubers. Indonesia. An interdisciplinary team of national (LEH RI) and CIP scientists has been working in collaboration with farmers to develop and refine techniques for the production of ware potatoes and seed tubers from true potato seed (TPS). Farmers formulate their own research, assess results, refine techniques, and Thrust X 149 proceed with new experiments. LEHRI- CIP researchers primarily document and discuss farmer-formulated trials and their results with the farmers, using an unstructured group format. Whether farmers carry out research as individuals or as a family "team" within a larger group, they constantly compare, assess, and experiment with their own techniques for TPS cultivation, tuber production, and sale. They reformulate their trials based on their own findings, as well as those of their fellow farmers. With a new technology such as TPS, farmers experiment with techniques used successfully for other crops, modifying them to fit TPS and their agronomic re - quirements. In early trials, farmers nar- rowed their choice of techniques to a few promising methods, and experiments in following seasons served to refine these techniques. Farmers' TPS yields have equaled or surpassed yields from seed tubers. This project has been expanded to a second area in Majalengka, West Java, where the Indonesian agricultural re- search and extension service (Dinas Per- tanian) is actively participating in CIP-LEHRI visits to farmers and their fields. The extension service also is in the process of introducing TPS to one large farmer and an additional cooperative group of small farmers. LEHR! plans to host a training session for extensionists, farmers, and scientists on flexible TPS technology transfer. Strengthening Capacity of NARS UPWARD Project UPWARD (Users' Perspective with Agricultural Research and Develop- ment) was established in 1989 and is the first research network to stress the role of food systems in the development of ap- p ropr iat e potato and sweet potato production in Southeast Asia. The net- work will focus on the " users" of agricul- tural technology and knowledge, with a specific emphasis on the role of the household as a unit for production, con- sumption, distribution, and use. One of the key objectives is to train young devel- oping-country researchers from the so- cial sciences and no n-traditional agricultural sciences (nutrition, market- ing, home economics) as members of na- tional program teams, which in the past have usually emphasized only technical aspects of production. Twelve project s we re s t a rted or launched during th e year in three 150 Thrust X countries: Thailand, Indonesia, and the Philippines. 171ailand. Proj ects concentrated on sweet potato production and household utilization. Sweet potato, like potato, is a supplemental vegetable and little re- search information is available on its production and use. Since concentra- tions of production vary greatly, a decision was made to study 13 areas rep- resentative of high and low production zones. Examples are Ratchaburi, near Bangkok, with over 800 ha of production, and Chiang Mai, with less than 160 ha. In initial research, Thai food habits were shown to vary widely in consumption of sweet potato. Popular sweet potato preparations include steamed sweet potato, sweet potato in coconut syrup, sliced sweet potato sweets (Mun Rang Nok), fr ied sweet potato balls (Kai Nok Krata), sweet potato with ginger in syrup, and fried sweet potato. Sweet potato also is used in many curries. Preparation and simple processing of sweet potatoes are household activities. Thailand's projects are conducted by the Field Crop Section, Crop Promotion Division, Department of Agricultural Extension, Bangkok, and the Department of Agricultural Exten- sion, Farm Home Improvement Sub- division. Indonesia. The projects in this country are more diverse. One project led by LEHRI conducted a follow-up of the technologies that had been developed by the experiment station. The study was highly interdisciplinary and focused on the main technical areas: varieties, pos- tharvest, seed, and agronomy. The team spent a week to 10 days in different areas looking at how the "end-user" had util- ized the results of the experiment station. Findings indicated major constraints in the flow of information from experiment station to farmers, because of the large number of agencies that handle the infor- mation. This slower flow was in contrast to the more direct flow of information from private companies. Visits were made to commercial and household processing units in another In- donesian study that investigated the processing of sweet potato in Java, which has received little research attention. A project to assess farmers' knowledge and to collect germplasm of sweet potato in Irian Java was formulated, but no re- search has been initiated. The Philippines. UPWARD co-spon- sored the first national socioeconomic seminar and workshop on rootcrops ("Enhancing Social Relevance in Root- Crop R&D"). Research on sweet potato progressed well in the mountain provin- ces, as well as in the lowlands. Sweet Sweet potato, rice , banana, and other crops being grown on rice terraces in Indonesia. Thrust X 151 potato is known to be the most widely cultivated root crop in the Philippines, with over 7,000 hectares planted. In the highlands, it is a staple food crop, par- ticularly among the tribal groups. Cul- tivation practices and varieties differ among ethnic tribes. Detailed reports on this research are now being prepared. Other studies will concentrate on marketing in Baguio and household gar- dens. PRACIPA Project The marketing project of PRACIPA (Programa Andino Cooperativo de Investi- gaci6n en Papa) completed its second year of activities in 1989; some of the research results are listed below. Bolivia. The survey of the "formal" distribution of seed by 12 institutions continued in the Cochabamba region, where two institutions now handle 70% of such seed. Assessment of farmers' opinions of the existing seed is also con- tinuing. A preliminary report has been prepared, which described the "infor- mal" distribution system through local fairs. The IBT A/ CIP special project added another scientist who has con- tinued his seed research from within the project. The results of this work are being used by the special IBT A/CIP project and a sister project to design an adequate seed distribution system. Colombia. In the second year of this project, work on simple potato process- ing has focused on the feasibility of using dehydrated potatoes or potato flour as feed for guinea pigs. Continued good prices for fresh potatoes in the Pasto- Ipiales region have suggested further study of the viability of this alternative, to supplement the limited amount of infor- mation available on the technical aspects 152 Thrust X of this type of processing and its economic returns. Estimates of the cost of production for simple processing in Pamplona have been made, but must be adjusted to account for the actual time and resources spent. Ecuador. In a stratified sample multi- pliers, users, and non-users of improved seed, were interviewed in the northern and southern regions of the country. The results indicate that 1) seed multipliers in the north produce seed for their own use and for sale; there are no seed multipliers located in the southern region; and 2) in the northern region, 53% of the non- users reported that they did not know where to buy improved seed, whereas in the south, over half of those interviewed had no knowledge that such seed existed. These results confirm the previous year's findings that suggested the need to reas- sess the distribution system used for im- proved seed. The problem of the lack of information available to growers regard- ing types, local price, and timing of availability of seed, deserves special at- tention. A collaborative project is plan- ning an extension of the information system for seed. Peru. The preparation and dissemina- tion of bulletins about potato production and marketing have continued in the central region, and a total of 27 bulletins have been printed and distributed over the last two years. The format of the bul- letin has been expanded to include infor- mation about production and marketing, as well as credit, costs of production, and fertilizer prices. The database set up as part of this project also has been utilized to generate projections for potato prices in Lima. Work on marketing of seed potatoes and processed potato products Family sorting seedling tubers, Indonesia. in the central highlands is nearing com- pletion. Venezuela. Marketing research in the Merida region of the country consisted primarily of a formal survey administered to potato producers. Key survey findings reflect the highly commercial production orientation (76% of the harvest is sold), the useof"white"varieties for the market and "black" varieties for on-farm con- sumption, and the tendency to sell to local rural assemblers and at the farm gate. Farmers generally reported that they had to accept the prices that they were offered because they lacked the in- formation, financial resources (or credit), storage facilities, and access to the services of a producer organization to market them directly. Training An increasing number of general pro- duction courses for both potato and sweet potato include a socioeconomic or food-system component. This type of for- mal training was given in courses in Chile, Argentina, Kenya, the Philippines, and Indonesia. In addition, specialized training in on- farm diagnostic skills, which is part of a larger UNDP-funded project, has been integrated into the collaborative survey work in countries of Latin America. Training associated with the joint development and execution of the in- dividual country projects is a major com- ponent of both the UPWARD and the PRACIPA marketing networks. Thrust X 153 154 Participants in a recent workshop learned about sweet potato germplasm utilization in Los Barios, Phi lippines. Highlights of Information Sciences and Thaining Activities Information Sciences Department The Department of Information Scien- ces was created in 1989 to integrate infor- mation functions and resources at CIP, and to respond to the emerging com- munication challenges of the Center's progressive decentralization. CIP's in- formation generation, processing, and relay functions are be ing reorganized within an organizati onal structur e designed to meet Center-wide research and administrative needs. It includes the Information and Communication Units from the former Training and Com- munication Departm ent, and incor- porates the Computer, Statistics, and Public Awareness Units. The concep- tualization of the information function has received a positive review from the External Review panels. The goals of the new Department are to assess information and communica- tion needs; design information and com- m uni cation strategies ; provide the structure and mechanisms for informa- tion exchange and management within CIP and with NARS, donors, and the general public; and facilitate the exchange of information among national programs. Communication Unit CI P 's Communication Unit supports CIP in the development and implementation of communication strategies through the generation, d esign, production, and delivery of communication services and products. These include simplified pub- lications, photographs, audiovisual aids, and editing/writing, translation, and communication training. Working with CIP scientists to diagnose user needs, the Communication Unit helps program and deliver optimum quality products and services for the Thrust activities. CIP re- search, administration, and training are assisted in the exchange of research- based information among CIP's regional operations and main headquarters, as well as among national scientists. Net- works, professional associations, and mass media all play a role in this process. Over the past year, the Unit's achieve- ments included the following: •The Communication Unit has pro- vided the facilities and technical ex- pertise for in-house processing and publishing of a wide range of publica- tions including th e C IP Annual Report , CIP Circular, training ma- terials, research reports, books, and other print media. Jn total, 32 publica- tions were produced including the translation of several titles into a second language. Nearly 90,000 copies of CIP publications are distributed each year to clients and subscribers worldwide. • The Unit produced new slide collec- tions (slide sets to accompany the Technical Information Bulletins , TIBs). Of these, five were produced in 155 English, Spanish, and French, and four in English and Spanish. In addition, the Unit has processed more than 30,000 slides and color prints for reports and presentations, as well as graphics for papers that CIP scientists regularly submit to journals. The slide collection ( 4,000) and black and white negatives and contacts are managed by the Unit, and a new inventory of the collection was initiated. • Training materials were developed or translated for courses at headquarters and regional courses, as well as for in-country courses. Thirty-one transla- tions were coordinated and 7 training guides were published in Spanish, in addition to a large number of un- published documents produced for use in training. • A global mailing list of nearly 6,000 entries, in operation since 1985, has been restructured and integrated with training data into the Potato Network Database. • New electronic technologies were in- troduced in text processing and layout for the CIP Annual Report, CIP Cir- cular, and other publications. Text processing has largely been trans- ferred from the minicomputers to microcomputers. Center publications are produced almost completely within CIP. Equipment has been or- dered for further development of graphic and layout capabilities. • Copublishing ventures in English have been reassessed and new working ar- rangements established for commercial publishing and other translation/edit- ing functions. Revamping of CIP-wide publications and media procedures also was begun within the Publications Committee. Copublishing agreements 156 exist between CIP and the "Editorial Hemisferio Sur" for 20 Technical In- formation Bulletins in Spanish. These copublication agreements also in- cluded the translation and publication of the book Potatoes by D. Horton, as well as of the book Principios de Al- macenamiento de la Papa by R. Booth and R. Shaw. New contractual ar- rangements were made with Cam- bridge University Press, Cambridge, England. Computer Unit Building on the computer system existing at headquarters and in the regions, the newly formed Unit evaluates CIP's com- puter needs and resources, helping up- date and develop technology in the computer and telecommunications fields. The unit assesses alternatives for the development of information systems, using appropriate technologies. The unit provides the scientific and administrative staff with the orientation, training, and computer facilities neces- sary for performing their activities. It also assists in the diffusion of computer tech- nologies for use in national programs. The Computer Unit acts as an interface between computer users and CIP's management, providing technical re- sources for the Computer Committee to propose guidelines and define standards for computer systems at CIP. Several staff members were trans- ferred from the Information Unit to the Computer Unit, and functions were redefined. An assessment of computer and com- munication needs was conducted in coor- dination with the Communication Unit, as well as an assessment of present and projected information systems at CIP. Databases have been developed with this information. In May, three consultants assisted CIP in determining priority changes required for bette r support of ongoing and projected operations. The Computer Committee and the management have analyzed their recommendations and priority recommendations are being im- plemented. Use of PCs has increased substantially, and CIP has received over 50 additional compatibles to support basic research and administrative infor- mation processing and management. T elecommunications through electronic mail has increased significantly during this year, both for headquarters and regional offices. T elexes and FAXs are now sent regularly through electronic mail, thereby increasing efficiency, and achieving a reduction of cost. Successful trials have been conducted to communi- cate through BITNET with selected universities. Information Unit The special proj ect funding provided by IDRC to establish an information service for potato researchers at CIP has con- cluded this year. These services have been successfully incorporated into CIP's regular operations. Among the achievements of the Information Unit are the following: • Implementation and maintenance of CIP's Bibliographic Database, in which has been included the input of the complete library collection of 34,000 references on potato and sweet potato. • Retrospective searches CIP Staff and national programs are provided regularly. This year, special emphasis was placed on providing regular ser- vices to new users from Asia and Africa. From June 1989 to June 1990, 822 retrospective computer searches were made. The SDI service includes tailor-made searci1es offered three times a year with the objective of keeping national scientists updated in their specific areas of research. Over 300 SDI sub- scriptions are provided to users from CIP and NARS. The individual nature of the SDI service has been highly valued by researchers receiving this type of service, as can be found in the evaluations conducted periodically. •Bibliographies. This year, CIP has produced two comprehensive bibliog- raphies: True Potato Seed and In- tegrated Pest Management of Potatoes that have been distributed to all na- t ional potato programs and key libraries. • Accession Lists. These publications list on a monthly basis all new documents received by the CIP library, and are distributed to all potato programs. • Photocopies and Publications Sup- plied. Based on specific items iden- tified in the searches or SD Is, users of these information services can request from CIP, for each search or SDI, up to 30 free photocopies or two articles. This service is utilized widely by re- searchers from all over the world, who can find information not easily avail- able in local libraries. One of the objectives of CIP's infor- mation and communication services is to support and strengthen the exchange of information among potato and sweet potato research ers from d eveloping countries. Several activities have been 157 undertaken leading towards the achieve- ment of this objective, among which is the database on Publishing Procedures of Agricultural Journals. The Potato Network Database has been designed to integrate all informa- tion on individuals and institutions work- ing with potato or sweet potato around the world. This information system in- cludes the Center's mailing list, as well as all training data. Statistics Unit With the reorganization of the Depart- ment, a Statistics Unit was created this year to provide statistical advice and training for the appropriate design, analysis, organization, and presentation of research projects. The Unit assists scientists, both at headqu arters and regional offices, in the application of the most advanced statistical methods for re- search processes, using modern comput- ing and communication software and 158 hardware. It collaborates in the statistical design and analysis of data managed by CIP's Administration and Management. Furthermore, it assesses the specific statistical needs of CIP's scientific work in general. The Unit promotes the utiliza- tion of statistical methodologies and software by national programs and net- works. Public Awareness Unit This newly formed Unit has been created within the Department, although no staff were contracted during 1989, and the public awareness function is being as- sessed by the Public Awareness Commit- tee, which was formed at mid-year. The Committee has developed a short-term operational plan to respond to the com- munication needs of CIP's publics, in- cluding CIP employees, and specific external audiences including NARS, donors, and the international scientific community. Training Department CIP training is developed jointly with na- tional and regional programs to help im- prove research and technology, and respond to farmers' problems in potato and sweet potato production and use. The annual work plan consists of group and individual participation in both short-term and specialized training (see Table 1). CIP also supports graduate training for students from NARS that have potato and sweet potato improve- me.nt projects. R egional and head- quarters staff assist as resource scientists in courses organized by national and in- ternational organizations, presenting lec- tures and seminars when required. Jointly with CIAT and IITA (the other international centers whose research and development mandates include root and tuber crops), CIP began the second year of a three-year project on Human Resour- ces Development. This project focuses on the generation and transfer of root- and tuber-crop technology in national agricultural research systems of Africa, Asia, Latin America, and the Caribbean. The three centers have developed and integrated concepts and methodologies to cover six areas of special need: or- ganization and management of vegeta- ti ve seed producti o n pr og r a ms; Table 1. CIP training activities for 1989. No. of No. of countries No. of Training activity participants represented courses Specialized group 399 47 21 Group 188 24 16 Training at CIP headquarters 47 22 119 Thesis 94 14 integrated pest management (IPM); training in farm-level diagnostic skills; product development; training and com- munications; and formative and summa- tive evaluation. This project began in 1988 as a follow-up to earlier projects. Training on Collection, Maintenance and Use of Unexploited Genetic Resources CIP's central goal of improving potato and sweet potato production builds upon the wide genetic base represented by the world collection of these two crops now maintained at CIP headquarters. Effec- tive use of this genetic wealth depends largely on the capabilities of national scien tis ts who do their research on breeding, selection, and adaptation in diverse environments. The required ex- pertise for breeding work is not always available or sufficient at the NARS, thus CIP training is selective ly directed toward improving national scientists' capabilities in this area. Several co ur ses on Germplasm Management were offered during 1989. A course on Potato Germ plasm Manage- ment was held in Colombia and Ecuador, with participants from a ll 5 Andea n countries: Bolivia (1), Colombia (1 ), Ecuador (2), Pe ru (8), and Venezuela (2). The course was initiated in Bogota where the students received lectures and "pract ica ls" on principles of potato breeding, selection of progenitors, and breeding methods. Emphasis was given to breeding for resistance to late blight and bacte rial wilt. The trainees par- ticipated in the harvest and selection process of an International Late- Blight Project Trial in Rionegro, Colombia. In 159 Quito, Ecuador, the students learned about breeding for resistance to the potato cyst nematode. A two-week regional training course on potato germplasm management in Nairobi, Kenya was attended by 17 trainees representing 11 National Potato Programs from countries in east, central, and southern Africa. This course em- phasized screening techniques for biotic and abiotic factors. Summary analysis and aiscussioil by th e participants covered four major areas: (1) mechanisms of communication in potato germplasm utilization; (2) methods and efficiency of acquisition of potato germplasm; (3) potato germplasm screening methods, procedures and strategies, and ( 4) TPS research and the use of seedling tubers as an alternative propagatio n method. Recommendations were made to im- prove the germ plasm utilization program in the regions. A Workshop on Sweet Potato Germ- plasm in Kenya was co-sponsored by the Kenyan Agriculture Research Institute (KARI) and CJP at Nairobi and Katumani. A total of 22 participants attended: 12 from the sweet potato programs at six of KARi's stations, 3 from other Kenyan institutions, 2 from IBPGR, and 5 from CIP. Topics included collaborative re- search and sweet potato germplasm col- lection and utilization. In addition, Kenyan researchers were trained on the use of the morphological descriptions developed by Dr. Z6simo Huaman, of CIP. A regional course for Asia - Potato Germplasm Management, Breeding, and Evaluat ion - was held at PCARRD, Los Baiios, Philippines, sponsored by CIP, SAPPRAD and PCARRD. Participant.s 160 came from China (4), Fiji (1), Indonesia (1), Malaya (1), Pakistan (1), the Philip- pines (8), Thailand (2), Vanuatu (1) and Vietna m (3). The participants were potato scien ti s ts now in vo lved in germplasm management and evaluation. Course topics included; basic genetics; crop taxonomy; tissue culture as a means of maintaining germplasm; virology in- volving the identification and detection of viruses; and breeding strategies and evaluation methods. 'Jraining on Integrated Management of Pests and Diseases Developing countries generally have few scientists with experience in integrated methods for disease and pest manage- ment. Thus, CIP works in collaboration with other international institutions in putting together comprehensive training programs. Over the p ast year, IPM workshops and conferences were held in regions II, VI, and VIII. In Guatemala, in September, trainees prepared a master plan to initiate and conduct IPM work in their respective countries. The course was attended by 14 participants from Guatemala (9), Panama (1), Honduras (1), Costa Rica (1) and Nicaragua (1), all in the PRECODEP A network. Entomologists from CIP and from the countries of PRECODEPA are backstopping and monitoring IPM ac- tivities in the region. An International Conference on Sweet Potato Pest Management was sponsored by the University of Florida and CIP in Miami, Florida. Researchers studying in- sect pests of sweet potatoes worldwide exchanged information about insect problems and management approaches. Special emphasis was placed on topics concerned with the sweet potato weevil, including the use of sex pheromones, biological controls, and weevil/host plant interactions. The sweet potato weevil is the most serious pest affecting production and utilization of the sweet potato in Asia. To support Asian researchers, the Interna- tional Training Course on Integrated Control of Sweet Potato Weevil was held at the Central Tuber Crops Research In- stitute (CTCRI), Trivandrum, India, in August. Attending the course were par- ticipants from Bangladesh (2), the Philip- pines (2), Thailand (1), Indonesia (1), and India (5). Key topics included taxonomy, biology, and evaluation of genetic resistance and other control methods for the sweet potato weevil. Toward the end of the course, work plans on integrated control of sweet potato were prepared by the trainees with the assistance of CIP and CTCRI scientists. A related seminar on diseases and pests of sweet potato was also held in August at CTCRI, and was attended by participants from India (6), Bangladesh (2), the Philippines (2), Thailand (1), and Indonesia (1) . A training course on potato bacterial wilt was sponsored by the Institute of Plant Protection of CAAS and CIP at Beijing, China, in May. The course was designed for scientists from China and included discussion of: 1) the principles and applications required for breeding for resistance to bacterial wilt, (2) germ- plasm evaluation for bacterial-wilt resis- tance, and (3) bacterial-wilt management and serological techniques. Twelve trainees from different provinces of China at tended the course. 'fraining on Communication and 'fraining Methods Training on communication and training methods is an integral part of the relay and exchange of technology developed within CIP's research Thrusts through departmental and collaborative research projects. In May, a workshop on Training and Communication skills was held in Lima, Peru, with participants from Colombia (6); Ecuador (6), and Peru (5). Course instructors were from CIAT (1) and CIP (3). During the course, each national team developed a plan to sup- port future training and communication activities in their countries. In a related activity, CIP and CIA T have screened and compiled nearly 100 documents on communication, training, and evaluation in an Inventory of Train- ing Materials. The materials, in both the Spanish and English languages, were shared with participants in the workshop. Documents in English are being further screened and classified, and several documents in Spanish are being trans- lated into English for use in the Asian and African workshops to be held in 1990 and 1991. Seed-Technology Training Although excellent potential varieties have been produced by CIP breeding programs and by breeders in the national programs through collaborative research projects, recent CIP studies of global use of improved potato varieties have shown that new genetically improved materials have not been reaching farmers' fields. Thus, upward trends in potato produc- tion in developing countries apparently stem from higher yields obtained from traditional varieties and/or expansion of the areas growing such varieties. 161 The analysis of the factors that are hampering use of improved breeding products r eadily indicates that the availability of healthy planting material is a first- order constraint. Thus, CIP's Regional Programs and training efforts are directed towards assisting national programs in developing efficie nt seed multiplication program s and in strengthening existing programs. This in- itiative requires specialized training in seed technology, with emphasis on rapid multiplication of healthy vegetative materials, as well as the logistics and ad- m in is tr at io n of a ppropria te seed programs that respond to country needs. Group training activities in seed tech- nology in 1989 included the Third Inter- national Storage and Seed Production Course held in January /February in Osorno, Chile. Developed jointly by INIA and CIP, the course brought together trainees from Chile (7), Brazil (1), Bolivia (1), Ecuador (1), El Salvador (1), Dominican Republic (1), Mexico (1), Honduras (1), Peru (1), and Panama (1). Instructors from INIA, the Univer- sidad Austral, CIP, and the private sector emphasized seed producti on and storage, as well as technology of TPS production. The course is part of a UNDP-funded project oriented toward development of human resources and technical and scientific training. The course consisted of lectures, "practicals," discussions, field visits, and group work. A potato production course was held in Canoinhas, Santa Catarina, Brazil and was organized by the potato program of EMBRAP A-CNPH, in collaborati on with the Basic Seed Production Service, and was funded by CIP. Held in October and November, the course was attended 162 by participants from Brazil (23), Hun- gary (2), Paraguay (1), and Mozambique (1). Emphasis was given to seed produc- tion in collaboration with government and private institutions. In Quito, Ecuador, INIAP and CIP offered a course on Production of Basic Potato Seed in October/November. Major topics included tissue culture, rapid propagation by stem cuttings, and prevention of dissemination of systemic diseases associated with vegetative propagation. Eleven part icipants at- tended the course, with 2 each from Colombia and Ecuador, and 1 each from Chile , Argentina, Uruguay, Peru, Guatemala, Brazil, and Venezuela. Dis- cussion topics included prebasic seed production, in vitro maintenance and multiplication, serological techniques for virus detection, and NASH for viroid detection. As part of CIP headquarters' assis- tance to national programs, a practical course in virology had been programmed as an annual activity for individual trainees interested in the basic techni- ques of virology. This course was held at CIP headquarters in Lima, Peru in February, bringing together participants from Colombia (1), Venezuela (2), the Dominican Republic (1), Costa Rica (2), Ecuador (1), Peru (7), and Bolivia (1). Likewise, a first course in advanced virology was held at CIP-Lima in June. Six trainees participated: one each from Colombia, Brazil, Peru and Austria, and 2 from Mexico. This six-week course is designed for scientists with advanced degrees who are actively engaged in virus research and in identification or prepara- tion of antisera for virus detection. Each week of training is built around learning modules that cover a particular techni- que in detail, with intensive practical ex- perience under the guidance of an expert virologist. In San Jose, Costa Rica, CIP col- laborated with the Ministry of Agricul- ture in holding a training course for the PRECODEPA network. The course, Pathology in Seed Potato Production, was attended by eight participants from Costa Rica and one each from Mexico, El Salvador, Haiti, Panama, Honduras, Guatemala, and the Dominican Re- public. Country reports were presented by participants from each country on completion of the course, providing a two-way exchange of information and enabling assessment of participants' comprehension of the subject matter. An in-country course on Storage of Potatoes was held in February at Gisozi, Burundi, organized by the Institut des Sciences Agronomiques du Burundi (ISABU). The course was attended by 10 trainees from government and private or- ganizations. CIP and IIT A collaborated to offer a course on Organization and Manage- ment of Vegetative Seed Production Programs, which was funded by the UNDP in Nairobi and Kakamega, Kenya, in October. A total of 17 participants attended from Uganda, Zambia , Seychelles, Ethiopia, Mauritius, Sudan, Swaziland, Lesotho, and Rwanda. A training course in virus detection for six regional staff also was held in Nairobi in July, with participants from Kenya, Rwanda, and Ethiopia. Regions III and VI had specialized training courses on TPS as an alternative method of propagating potatoes. During May, in Nairobi, Kenya, a total of six CIP staff rece ive train ing in the software program s needed for their work . 163 trainees representing the national programs of Kenya, Rwanda, Uganda, Mozambique and Ethiopia attended a one-week course on practical aspects of TPS technology. An in-country seed production and storage course was held at CPRA-Saida in Tunisia. Eighteen trainees from several development agencies attended the course, which was organized by Tunisian scientists of CPRA-Saida, INRAT, and CIP. An in-country potato production course was held in Menemem, Turkey, and Bagdad, Iraq and was attended by 12 trainees from private or semi-private seed companies. Al Agadir, Morocco, 15 trainees from state extension, research, and seed production agencies allended an in- country course held at the Instilul Agronomique et Veterinaire. The first Specialized Regional Course - on Germplasm Management and Seed Production for West and Central Africa was held in Bamenda, Cameroon in June. A total of 18 scientists attended from Senegal, Gambia, Nigeria, Ghana, Mali, Cape Verde, C&e d'Ivoire, and Cameroon. The Ninth International Training Course on Potato Seed Production and Certification was sponsored by CIP at CPRS Modipuram, in Novem- ber/December, and was attended by trainees from Nepal (8), Sri Lanka (3), Buthan (4), and India (3). A Regional Workshop on Low-Cost Storage of Ware and Seed Potatoes held in India in May, was attended by par- ticipants from Kenya (1), Nepal (2), Buthan (3) and India (10). The workshop focused on technologies available for 164 transfer to farmers and analysis of their needs. Participants made recommenda- tions for plans and strategies for future research and development activities on storage in cool and warm climates. A total of 28 scientists attended a Regional Workshop for Researchers on True Potato Seed (TPS) held at New Delhi in January. Participants were from Bangladesh (1), Buthan (2), Nepal (2), the Philippines (2), and Vietnam (1). A regional course on Sweet Potato Tissue Culture and Virology was held in the Philippines, under the sponsorship of SAPPRAD, CIP, and PCARRD at VISCA. The course was designed for scientists from the Philippines, In- donesia, Malaysia, Sri Lanka, and Papua New Guinea. Course work covered the basic concepts and techniques of tissue culture and virus erradicatioi:i~ tion, and indexing. Such knowledge is retfulred to develop the procedures for sending germplasm for clean-up and for receiving clean materials from the Plant Research Institute in Victoria, Australia. A training course on utilization of ELISA and dot-ELISA kits was held at Inner Mongolia University in Tukei Province, China in January, with seven trainees from six of the country's potato research or production institutions. A course on Seed Potato Production of improved varieties was held in China in May, and was attended by 20 par- ticipants from provinces of southern China. CIP, in collaboration with the Insti- tute for Agronomic Research (IRA- Bambui ), sponsored an In-Country Potato Production Course in Bamenda, Cameroon. The course was held in two- day sessions, starting in April with plant- ing, and finishinginJulywith harvest. The course was attended by 20 agronomists from government and private organiza- tions of Cameroon. The First In-country Course on Potato Production sponsored by CIP in col- laboration with the National Root Crops Research Institute (NRCRI) was held in Jos, Nigeria in July. Twenty researchers, e:xtensionists, and production specialists from government organizations attended the course, which dealt primarily with ware and seed-potato production. CIP also sponsored the 18th Interna- tional Training Course on Modern Methods of Potato Production held at the Central Potato Research Institute (CPRI) in Shimla, India. A total of 22 researchers, extension specialists, and university teachers from India, Nepal, and Bangladesh participated. The course was coordinated by CPRl's Division of Social Sciences and most of the 40 in- structors were from CPRI. Sweet Potato Training Production technology is the central focus of most of CIP's training related to sweet potatoes (Ipomoea batatas L.). As research projects develop and NARS' in- terest continues to increase, CIP plans to adjust the balance between production and specialized training, according to users' needs. In 1989, CIP sponsored sweet potato production courses, seminars, and workshops in CIP regions I, IV, VI and VII, as indicated in the following summary. The First International Course on Sweet Potato Crop was held in San Pedro, Argentina in March, coordinated by the lnstituto Nacional de Tecnologia Agropecuaria of Argentina and spon- sored by CIP. Course participants came from Paraguay and Brazil (3 each ); Ar- gentina, Colombia, Ecuador, Peru, Uruguay (2 each); and Mexico, the Dominican Republic, Cuba, and Venezuela (1 each). Course objectives were to enable participants to: (1) iden- tify and describe problems and potentials in sweet potato production; (2) explain the scientific basis for sweet potato production, including botany, physiology, agronomy, pathology, economics, etc. and (3) develop research projects oriented to solving problems of sweet potato production and marketing. At the Kafr El Zayat station in Egypt, a one-week Sweet Potato Production course was held for potato growers, re- searchers, horticulturists, and exten- sionists. A Seminar on Sweet Potato in Asia was held in July at CTCRI, Trivandrum, India. The National Sweet Potato Seminar- Workshop was held in Baybay, Leyte, Philippines in collaboration with PRCRTC and VISCA. A total of 47 par- ticipants attended this in-country course. A Regional Sweet Potato Production training course was held at PCARRD, Los Banos, Philippines in January/ February, attended by trainees from the Philippines and Indonesia (6 each); Viet- nam (4); the Solomon Islands, Thailand and Taiwan (2); and Korea, Tonga,and Australia (1). The objectives were to communicate the present state of scien- tific knowledge on major disciplines of sweet potato research; to equip national scientists for teaching general produc- tion courses in their home countries; and to develop research work plans for each participating country. The focus was on 165 farm-level problems, with analysis of the farmers' production constraints. Presen- tations dealt primarily with production, breeding, and postharvest problems. An In-Country Workshop on Sweet Potato Production Utilization and Mar- keting was held in Vietnam, in Septem- ber, with 3 groups of 35, 11, and 22 participants. Postharvest Technology CIP sponsored a course on Village-Level Processing of Root and Tuber Crops at the Society for the Development of Ap- propriate Technology (SOTEC) in Bareilly, India in March. Participants came from India (5), Bangladesh (2), and Nepal and Sri Lanka (1). Potato and Sweet Potato Agronomy In Peru, in close collaboration with the Soil Department of the Universidad Agraria at Lima, training courses were held, emphasizing fertilizers and fer- tilization techniques used in potato and sweet potato production. More than 200 Peruvian researchers and extensionists from government and private institutions from throughout Peru attended these courses. The courses included presenta- 166 tions on plant nutritional requirements; types, dosage, and methods of fertilizer application; and economic analysis of in- puts and returns. Support for Collaborative Research Networks CIP-sponsored research networks are progressively increasing their abilities to conduct training within their regions. The senior network, PRECODEPA, is fully meeting the needs of its country members for training in potato produc- tion technology, along with some special- ized training. The other networks are making similar progress and the in- creased capabilities of the NARS and collaborative networks have released CIP's staff for more specialized training, technical assistance, and development of training materials. The national leaders of the potato programs of the PRECODEPA countries attended a seminar in Lima, Peru in February/March, which provided a scientific update for the participants, while helping strengthen and develop collaborative bridges within the in- dividual countries and PRECODEPA. .· List of Abbreviations and Acronyms A GRIS AID ALAP AMV AN OVA APLV APMV ARARI AVRDC a.1. avg BARI BPI BW CAAS CABI CGA CGIAR CIAAB CIAT CIP CIPC CLO CMS CNPH COTESU CPRI cm CV CV. d DAP DLS DMRT DNA EB EBN EDTA ELISA EMBRAPA International Information System for Agricultural Sciences and Technology (Italy) Agency for International Development Asociaci6n Latinoamericana de Papa alfalfa mosaic virus analysis of variance Andean potato latent virus Andean potato mottle virus Aegean Regional Research Institute (Turkey) Asian Vegetable Research & Development Center (Taiwan) active ingredient average Bangladesh Agricultural Research Institute Bureau of Plant Industries (Philippines) . bacterial wilt Chinese Academy for Agricultural Sciences Commonwealth Agricultural Bureau International (CAB In- ternational) general combining ability Consultative Group on International Agricultural Research Centro de Investigaciones Agricolas "A-Boerger" (Uruguay) Centro Internacional de Agricultura Tropical (Colombia) Centro Internacional de la Papa (Peru) isopropyl-N-3-chlorophenyl-carbamate chlorotic leaf distortion cytoplasmic male sterility Centro Nacional de Pesquisa de Hortalic;as (Brazil) Cooperaci6n Tecnica Suiza Central Potato Research Institute (India) centimeter coefficient of variation cultivar day days after planting diffused-light store Duncan's multiple range test deoxyribonucleic acid early blight endosperm balance number ethylenediaminetetraacetic acid enzyme-linked immunosorbent assay Empresa Brasileira de Pesquisa Agropecuaria (Brazil) A-1 ERSO FAO FDR FONAIAP g GA GAAS h ha hrp IAO IBP GR IBTA ICA ICAR ICRISAT ICTA IDEAS IDRC IFPRI IITA I LB RT INIA INIAA INIAP INIFAP INIPA INlVIT INPT INRA INRAT INTA !PO ISABU kb L LAR LB LEHR I LER A-2 Consorzio "Mario Neri" (Italy) Food and Agriculture Organization of the United Nations first division restitution Fonda Nacional de Investigaciones Agropecuarias (Venezuela) gram gibberellic acid Guandong Academy of Agricultural Sciences hour hectare hypersensitive response Istiluto Agronomico per l'Oltremase, Italy International Board for Plant Genetic Resources Instiluto Boliviano de Tecnologia Agropecuaria Instiluto Colombiano Agropecuario (Colombia) Indian Council for Agricultural Research International Crop Research Institute for Semi-Arid Tropics Instituto de Ciencia y Tecnologia Agricolas (Guatemala) The Venezuelan International Institute of Higher Studies International Development Research Centre (Canada) International Food Policy Research Institute International Institute of Tropical Agriculture (Nigeria) International Late Blight Resistance Trial Instituto Nacional de Investigaciones Agropecuarias (Chile) Instituto Nacional de Investigaci6n Agraria y Agroindustrial (Peru) Instituto Nacional de Investigaciones Agropecuarias (Ecuador) Instituto Nacional de Investigaciones Forestales y Agropecuarias (Mexico) Instituto Nacional de Investigaci6n y Promoci6n Agropecuaria (Peru) National Institute for Research in Tropical Roots and Tubers (Cuba) Institut National de la Pomme de Terre (Togo) Institut National de la Recherche Agricole (Senegal) Institut National de la Recherche Agronomique de la Tunisie Instituto Nacional de Tecnologia Agropecuaria (Argentina) R esearch Institute for Plant Protection (Netherlands) Institut des Sciences Agronomiques du Burundi kilobar liter leaf area ratio late blight Lembang Horticultural Research Institute (Indonesia) land equivalent ratio LSD LUE lat. long. MA MBN MJ m meq mm ml mm mo NAR NARS NASH NCM NCSU ND NS NSAC nm ns OP PBI PCARRD PCN PIPA PLRV PNAP PRACIPA PRAPAC PRECODEPA PRI PROCIANDINO PROCIPA PSTV PTM least significant difference light use efficiency latitude longitude monoclonal antibody Meloidogyne bacterial wilt nematode resistant material megajoule meter milliequivalent minute milliliter millimeter month net assimilation rate National Agricultural Research Systems nucleic acid spot hybridization test nitrocellulose membranes North Carolina State University not determined not studied Nova Scotia Agricultural College nanometer not significant open-pollinated Plant Breeding Institute (UK) Philippine Council for Agriculture and Resources Research and Development potato cyst nematode Programa de Investigaci6n en Papa (Peru) potato leafroll virus Programme National de I' Amelioration de la Pomme de Terre (Rwanda) Programa Andino Cooperativo de Investigaci6n en Papa (An- dean region) Programme Regional d'Amelioration de la Culture de Pomme de Terre en Afrique Centrale (Central Africa) Programa Regional Cooperativo de Papa (Central America- Caribbean) Plant Research Institute Programa Cooperativo de Investigaci6n Agricola para la Sub- region Andina Programa Cooperativo de Investigaciones en Papa (southeast region of South America) potato spindle tuber viroid potato tuber moth A-3 PTV PVA PYM PVS PVV PYX PVY ppm RCB RFLP RGTC RH RICA RKN RLER RNA SAPP RAD SCRI SD SED SEINPA SEM SLA SNC SOTEC SPCV SPFMV SPLV SPMMV sec TPS t UNA UNCP UNDP UPLB UPWARD USAID var. vol vs. WUE wk wt yr A-4 Peru tomato virus potato virus A potato virus M potato virus S potato virus V potato virus X potato virus Y parts per million randomized complete block design Restriction Fragment Length Polymorphism relative growth rate relative humidity Red Interamericana de Comunicadores Agricolas root-knot nematode relative leaf expansion rate ribonucleic acid Southeast Asian Program for Potato Research and Development Scottish Crops Research Institute (Scotland) standard deviation standard error or difference Semilla e Investigacion en Papa (Peru) Scanning Electron Microscopy special leaf area single node Society for the Development of Appropriate Technology sweet potato caulimo-like virus sweet potato feathery mottle virus sweet potato latent virus sweet potato mild mottle virus second true potato seed ton Universidad Nacional Agraria - La Molina (Peru) Universidad Nacional del Centro del Peru United Nations Development Programw" University of the Philippines - Los Banos User's Perspective with Agricultural Research and Development United States Agency for International Development variety volume versus water use efficiency week weight year Papers Published in Scientific Journals Brandolini, A. G. and H. A. Mendoza. 1989. Resistencia aA/temaria solani: habilidad combinatoria general y heredabilidad en una poblaci6n avan- zada. [Resistance toA!temariasolani: general combining ability and heritability in an advanced popula- tion]. (Abstract only). Programme and Abstracts of the XIV Biannual Meeting of the Latin American Potato Association (ALAP). Mar del Plata, Argentina. p. 38. Chandra, R., J. H . Dodds, and P. Tovar. 1988. In vitro tuberization in potato (Solanum tuberosum L.). In Intl. Assoc. for Plant Tissue Culture Newsletter, The Netherlands, July 1988. No. 55. pp. 10-20. Chavez, R., C. R. Brown, and M. Iwanaga. 1988. Application of inter- specific sesquiploidy to introgression of PLR V Resistance from non-tuber- bearing Solanum etuberosum to cul- tivated potato germplasm. Theoretical and Applied Genetics 76:497-500. Dayal, T. R., M. D. Upadhya, and S. M. Chaturvedi. 1988. Heterosis for yield and other traits in potato (Solanum tuberosum L). J. Indian Potato Assoc. 15(3-4):139-147. De la Puente, F., J. Diaz, and C. Aguilar. 1989. Recursos geneticos del camote (I. batatas (L) Lam) en el Peru. In Libro de Resumenes. IX Congreso Latino-Americano de Genetica. Lima, Peru. Demagante, A. L. and P. Vander Zaag. 1988. Potato (Solanum spp.) in an isohyperthermic environment II. Response to planting dates. Field Crops Res. 19:153-166. Dodds, J. H. 1988. Tissue culture tech- nology: practical -application of so- phisticated methods. Am. Potato J . 65:167-180. Ekanayake, I. J. 1989. Efectos de la sequfa sobre las caracteristicas de las raices de la Papa. [Effect of drought on root system characteristics of potatoes]. In Resumen y Programa. XIV Reunion de la Asociaci6n Lati- noamericana de la Papa. Mar del Plata, Republica Argentina. p. 3. (Abstr.). Ekanayake, I. J. and D. J. Midmore. 1989. Root pulling resistance of potatoes in a drought environment. In 73rd An- nual Meeting of the Potato Associa- tion of America. Oregon. U .S.A. (Abstr.). Ekanayake, I. J ., S. K. De Datta, and P. L. Steponkus. 1989. Spikelet sterility and flowering response of rice to water stress at anthesis. Annals of Botany 63:257-264. Ewell, P. T.1989. Linkages between On- Farm Research and Extension in Nine Countries. OFCOR Compara- tive Study No. 4. The Hague: International Service for National Agricultural Research (ISNAR). Franco, J., A . Gonzalez, A. Matos, and H. Torres. 1989. Beauveria bassia11a: promisor biocontrolador del nema- todo de! quiste de la papa ( Globodera pallida). Fitopatologia 24:23-28. Ho, T. V., N. T. Hoa, T. T. Loan, L. T. Tuyet, and P. Vander Zaag. 1988. Techniques for using sprouts for A-5 potato production in the tropics. Potato Res. 31:379-383. Horton, D. 1988. El cultivo de la papa en los Andes peruanos. In Estudios Ru- rales Latinoamericanos. (Sep.-Dec. 1988) Vol. 11(3) pp. 339-354. Horton, D. E. 1988. Las Papas en los paises en desarrollo. Revista Latino- americana de la Papa. Vol.1(1):9-17. Huaman, Z., B. Tivoli, And L. de Lindo. 1989. Screening for resistance to Fusarium dry rot in progenies of cul- tivars of S. tuberosum spp. andigena with resistance to Envinia chrysan- themi. Am. Potato J. 66(6):357-364. Jayasinghe, U., C. Chuquillanqui, and L. F. Salazar.1989. Modified expression of virus resistance in potato in mixed virus infections. Am. PotatoJ. 66:137- 144. Kadian, M. S., P. K. Patel, K. C. Thakur and M. D. Upadhya. 1988. Compara- tive yield potential of seedlings and seedling tuberlets from true potato seed in Deesa. J. Indian Potato Assoc. 15(1-2):68-73. Lizarraga, Ch. and E. N. Fernandez- Northcote. 1989. Detection of potato viruses X and Y in sap extracts by a modified indirect enzyme-linked im- munosorbent assay in nitrocellulose membranes (NCM-ELISA). Plant Disease 73:11-14. Lizarraga, R., Z. Huaman, and J. H. Dodds. 1989. In vitro conservation of potato germplasm at the Internation- al Potato Center. Am. Potato J . 66( 4):253-269. Lopez, P.A., 0. A. Hidalgo, A. Chena. 1989. Comparaci6n de semilla cer- tificada (entera) con semilla comt1n (entera y partida) bajo condiciones de campo de productores del Para- guay. [Comparison of certified seed A-6 (whole) vs. common seed (whole and cut) under farmer conditions of Paraguay] . In Resumenes XIV Reunion de la ALAP. p. 20. (Abstr.). Mayeregger, M., A. L6pez, and 0. A. Hidalgo. 1989. Evaluaci6n de cul- tivares de papa en ensayos regionales y a nivel de finca de productor en el Paraguay. [Evaluation of potato cul- tivars in regional trials and at farmer level in Paraguay]. In Resumenes XIV Reunion de la ALAP. p. 20 (Abstr). Midmore, D. J . 1988. Potato (Solanum spp.) in the Hot Tropics VI. Plant population effect on soil tempera- ture, plant development and tuber yield. Field Crops. Res. 19:183-208. Ortfz, R., M. Iwanaga, and H. A. Men- doza. 1988. Combining ability and parental effects in 4x-2x Crosses for potato breeding. Potato Research 31:643-650. Pallais, N. and N. Fong. 1988. Influence of dormancy on the effectiveness of priming true potato seed. In Proc. 85th Ann. Meet. of the Amer. Soc. of Hort. Sci. and 33rd Ann. Meet. of the Canad. Soc. Hort. Sci., East Lansing, Michigan. Aug 6-11. 1988. Hort- Science 23(3):796. (Abstr.). Pallais, N., H. Asmat, N. Fong, and C. Sandoval. 1988. Factors affecting seed- ling vigor in potatoes: I. Stage of seed development and presowing Treat- ment. In Proc. 72nd Ann. Meet. Potato Assoc. Amer., Fort Collins, USA. Jul. 24-28 1988. Am. Potato J. 65(8):494-495. (Abstr.). Pallais, N., R. Garcia, and N. Fong. 1988. Factors affecting seedling vigor in potatoes: II. Genotype, after-ripen- ing, and seed priming. In Proc. 72nd Ann. Meet. Potato Assoc. Amer., .. .. Fort Collins, USA. Jul. 24-28 1988. Am. Potato J. 65(8):495. (Abstr.). Pande, P. C. and M. S. Kadian. 1988. Evaluation of TPS progenies for potato production in Central Indo- G ange tic Plains. J. Indian Potato Assoc. 15(3-4): 186. (Abstr.). Potts, M. J . and E. Biranguza. 1989. The evaluation of alternative fodder crops under African highland conditions. Experimental Agriculture, 25:99-107. Potts, M. J ., Biranguza, E., and C. Bweyo. 1989. Evaluation of alternative legumes for green manure and grain under African highland conditions. Experimental Agriculture 25:109- 118. Rhoades, R . 1989. The role of farmers in the creation and continuing develop- ment of agricultural technology and systems. In R. Chambers, A. Pacey, and L. A. Thrupp, (eds.). Farmer First. Appropriate Technology. Lon- don. pp. 12-34. Rhoades, R. 1989. Evolution of Agricul- tural Research and Development since 1950: Toward an Integrated Framework. Gatekeeper Series No. SA112. Sustainable Agriculture Programme. International Institute for Environment and Development. 19 pp. Rhoades, R . 1989. Agricultural An- thropology: new disciplinary blood in international agricultural research. Practicing Anthropology. Rhoades, R. and R. Booth. 1989. An at- tempt to improve the storage of con- sumer potatoes on small farms in Peru. Tropical Science 29:1-8. Scott, G. J. 1988. La pomme de terre en Afrique Centrale: une etude sur le Burundi, le Rwanda et le Zaire [Pota- toes in Central Africa: a study of Burundi, Rwanda and Zaire]. Les Cahiers du CEDAF, 1988. Vol. 4-5. Sonnino, A ., M . Iwanaga, and A. Hinostroza. 1988. Chromosome num- ber doubling of 2x potato lines with diverse genetic background through tissue culture. Potato Research. 31:627-631. Sonnino, A., S. Tanaka, M. Iwanaga, and L. Schilde-Rentschler. 1989. Genetic control of embryo formation in another Culture of Diploid Potatoes. Plant Cell Reports 8:105-107. Suni, M., I. J . Ekanayake, and D. J. Mid- more. 1989. Resistencia, densidad estomatica y relaciones hi'dricas de Solanum tuberosum L. como respues- ta a condiciones de deficiencia de agua en el campo. [Stomata] resistance, density, and water potentials of So/a- num tuberosum L. as affected by field water deficits]. In Abstracts lOms Reuni6n de la sociedad de fisiologia vegetal. Puerto Iguazu, Misiones, Republica Argentina. p. 22. (Abstr.). Thakur, K. C., M. D . Upadhya, and M. S. Kadian. 1988. Potato production from TPS tuberlets in Hooghly Dis- trict of West Bengal. J. Indian Potato Assoc. 15(3-4):131-133. Tivoli, B., H. Torres, and E. R. French. 1988. Inventaire, distribution et agressivite des especes ou varietes de Fusarium rencontrees sur la pomme de terre ou dans un environnement clans differents zones agroecologiques du Perou. [Inventory, distribution and aggresiveness of species and varieties of Fusarium found on potato or their surroundings in differe nt agro- ecological zones of Peru]. Potato Re- search 31:681-690. A-7 Torres, H., E. Roman, and J. Vicencio. 1989. Evaluaci6n de resistencia a Ver- tici/lium dahliae en clones avanzados de papa. In Res6menes X Congreso ASCOLFI, V Reuni6n ALF y XXIX Reuni6n APS-Division del Caribe. 9-14 de Julio. p. 25. (Abstr). Torres, H., J. Alcazar, and C. Vittorelli. 1989. Incremento masivo de Beau- veria sp. controlador biol6gico del gorgojo de los Andes. In Resfunenes y Programa. XIV Reuni6n Latino- Americana de Investigadores en Papa (ALAP). Mar del Plata, Argen- tina. 5-11 Marzo. p. 58. (Abstr.). Torres, H. andJ. Vicencio. 1989. Control quimico del tiz6n temprano (Altema- ria solani). In Resumenes y Progra- ma. XIV Reuni6n Latino-Americana de Investigadores en Papa (ALAP). Mar del Plata, Argentina, 5-11 de Marzo. p. 43. (Abstr.). Vander Zaag P., A. L. Demagante, and E . E. Ewing. 1989. Influence of plant spacing on potato growth and yield. Potato Research. (Accepted) . Vander Zaag, P. and A. L. Demagante. 1989. The Potato (Solanum spp.) in an isohyperthermic environment IV. Effects of cutting seed tubers. Field Crops Res. 20:1-12. Vander Zaag, P. and A. L. Demagante. 1988. The Potato (Solanum spp.) in an isohyperthermic environment III. Evaluation of clones. Field Crops Res. 19:167-181. Velupillai, M. and E . R . French. 1986. Diseases and pests of potato in Sri Lanka: 1975-1985. J. Indian Potato Assoc. 13:47-54. Verman, K. D., C. L. Khushu and M. D. Upadhya. 1988. Resistance to green peach aphid, Myzus persicae (Sulzer) in some hybrids of Solanum species. A-8 Newle tts. Aph. Soc. India Vol. 72(2):10-12. Wiersema, S.G. 1989. Comparative per- formance of three small tuber sizes with standard size seed tubers planted at similar stem densities. Potato Research 32:81-89. Wilkins, C. P., H.J. Newbury, and J. H. Dodds. 1988. Tissue culture conser- vation of fruit trees. IBPGR Newslet- ter (73-74):9-20. Yabar, E., H Torres, and C. Vittorelli. 1989. Biocontrol de Premnotrypes latithorax en condiciones de almacen tradicional. In Res6menes y Progra- ma. XIV Reuni6n Latino-Americana de lnvestigadores en Papa (ALAP). Mar de! Plata, Arge ntina, 5-11 Marzo. p. 58. (Abstr.). Papers in Press or Submitted for Publication Anderson, J . L. and D. E. Horton. Potato production in the context of the world and farm economy. In P. Harris (ed.). The Potato Crop (second edition) Chapman and Hall, London (forth- coming). Antle, J . A. and C. C. Crissman. 1989. Production risk and efficiency in technology adoption in the Philip- pines. Economic development and cultural change. (in press, May 1989) Boucaron C., L. Collet, and P. Vander Zaag. 1989. Influence of growing and storage conditions on the subsequent performance of Solanum seed po- tatoes. Trop. Agric. (Trio.) 66 (in press). Brandolini, A. G. 1989. Comparison of two rating methods for Altemaria solani damage in potatoes. Rivista di Agricoltora Subtropicale e Tropicale, .. .. Firenze, Italia. (Submitted June 1989). Chandra, R. and M. D. Upadhya, 1989. Raising plants from non-germinated potato seeds. The National Academy of Sciences, India. Crissman, C. C. 1989. Seed Potato Sys- t ems in The Philippines: A Case Study. (Lima: CIP-PCARRD, 1989) 89pp. Crissman, C. C. and J.E. Uquillas. Seed Potato Systems in Ecuador: A Case Study. (Lima: CIP-FUNDAGRO, 1989) 56 pp. E kanayake, I. J. and D . J . Mid more. 1988. Drought response of potatoes in warm tropical areas. /11 Proc. Interna- tional Conference on Dryland Farm- ing. Bushland, U.S.A. Aug. 15-19, 1988. Ekanayake, I. J. and D. J. Midmore. 1989. Root pulling resistance of potatoes in a drought environment (Abstr.). Am. Potato J. (in press). Ekanayake, I. J., P. Malagamba, and D. J. Midmore. 1989. Effect of water s tress on yield indices of sweet potatoes. E ighth Symposium of the International Society of Tropical Root Crops. Bangkok, Thailand. Oct. 30 - Nov. 5, 1988. (in press). E lphinstone, J. G. 1989. Reducci6n de la marchitez bacteriana por aplicaci6n de varias practicas agron6micas. [Re- duction of bacterial wilt through the application of various agronomic practices]. Abs tr. Fitopatologfa 24(2). (in press). French, E. R. and U. Nydegger. A two- decade epidemic of Pseudomonas solanacearnm o n potato in Peru. Proceedings 7th lnternat. Conf. Plant Pathogenic Bacteria. Budapest-Hun- gary, June 11-17, 1989. 6 pp. (Sub- mitted September 15, 1989). Gregory, P., M. Iwanaga, and D. H orton. 1990. "Sweet potato research: global issues." In Proceedings of the 8th Symposium of the International So- cietyforTropical Root Crops (ISTRC), Oct. 30-Nov. 5, 1988. (forthcoming). Horton, D .1990. Assessing the impact of international research: concepts and challenges. In R. Echevarria (ed.) ISNAR/Rutgers Agricultural Tech- nology Management Workshop on Methods for Assessing R esearch Im- pact and for Diagnosing Research System Constraints, New Brunswick, New Jersey. Jul. 6-8, 1988. (forthcom- ing). H orton, D . "Constraints to sweet potato production and use." Paper Presented at the workshop on sweet potato im- provement in Asia, h eld at Trivandrum, India, October 24-28, 1988. In Improveme nt of Sweet Potato ( Ipom oea batatas) in Asia. ICP (forthcoming). Horton, D. and G. Prain. Beyond FSR: new challenges for social scientists in agricultural R&D. Quarterly Journal of International Agriculture (forth- coming). Horton, D., G. Prain, and P. Ewell. Socioeconomic aspects ofIPM: CIP's experiences. In R. K. J ansson and K. V. Raman (eds.) Sweet Potato Pest Management: A G lobal Perspective. (forthcoming). Huaman, Z. and H. Stegemann. 1989. Use of electrophoretic analyses to verify morpho logica lly ident ical clones in a potato collection. Plant Varieties and Seeds. (Submitted for publication in April 1989). A-9 Iman, S. A., A. H. M. D. Hossain, L. C. Sikka, and D. J . Midmore. 1989. Agronomic Management of Potato- S ugarcane Intercropping and its Economic Implication. Field Crop Res. (in press). lwanaga, M., P. Jatala, R. Ortfz, and E . Guevara.1989. Use of FDR 2n pollen to transfer resistance to root-knot nematodes into cultivated 4x potatoes. J. Amer. Soc. Hort. Sci. (in press). Jieming, L. and DJ. Midmore. 1989. A review of potato intercropping prac- tices. in Western Hubei, China. Field Crops Res. (in press). Kadian, M. S. and M. D. Upadhya. 1989. Field evaluation of seedling vs seed- ling tubers ofTPS Families under dif- ferent agro-climates. J . Indian Potato Assoc. (Abstr.). Khatana, V. S., M. S. Kadian, and M. D. Upadhya. 1989. Socioeconomic studies of potatoes using TPS. J. In- dian Potato Assoc. (Abstr.). Kumagai, T. Y. Umemura, T. Baba, and M. lwanaga. 1989. The inheritance of amylase null in storage roots of sweet potato, Ipomoea batatas (L.) Lam. Theoretical and Applied Genetics. (in press). Llontop, J ., M. Scurrah, and J. Franco. 1989. Maria Huanca una nueva variedad resistente al nematodo de quiste de la papa G. pa/Iida. Revista Latinoamericana de Papa. (in press). Malamud, 0 . and K. V. Raman. 1989. Strategies to develop an integrated pest management program for sweet potato weevil complex in the Carib- bean. In Papers presented in Carib- bean Food Crops Society, 25th Annual Meeting, Guadalupe, July 2- 8, 1989. Proceedings (in press). A -10 Mehra, S. K. and M. D. Upadhya.1989. Village-level processing of tubers produced from TPS families. J. In- dian Potato Assoc. (Abstr.). Merrill-Sands, D., P. T. Ewell, S. Biggs, and J . McAllister. Issues in institu- tionalizing on-farm, client-oriented research: a review of experiences from nine national agricultural re- search systems. Quarterly Journal of International Agriculture. (in press). Midmore, D. J. 1989. Influence of tem- perature and radiation on photosyn- thesis, respiration, and growth parameters of the potato. Potato Re- search. (Abstr.), (in press). Midmore, D. J. 1989. Intercropping of Potatoes in the tropics. Introduction. Field Crops Res. (in press). Midmore, D. J. 1989. Potato and sweet potato research: a worldwide man- date for the International Potato Cen- ter. In Proc. Int. Symp. Prod. Veget. Trop. and Subtrop. T ARC.Japan. (in press). Midmore, D. J. 1989. Potato production in the tropics. In P.M. Harris (ed.). The Potato Crop. The Scientific Basis for Improvement. Chapman and Hall, 2nd Edition. (in press). Midmore, D. J. 1989. Scientific basis and scope for improvement of intercrop- ping with potato (So/anum tuberosum L.) in the Tropics. Field Crops Re- search. (in press). Midmore, D. J. andJ. Roca.1989. Potato (So/anum spp.) in the Hot Tropics VIL The influence of production and storage cycles in hot climates on sub- sequent growth and tuber yield. Field Crops Res. Submitted, August 1989. Orjeda, G., R. Freyre and M. lwanaga. 1989. Production of 2n pollen in diploid Ipomoea trijida, a putative .. wild ancestor of sweet potato. J. Heredity. (Submitted September 15, 1989). Pallais, N. 1989. Osmotic priming true potato seed: I. Effects of seed age. Potato Res. (in press). Pallais, N., H. Asmat, N. Fong, and J. Santos-Rojas. 1988. Factors affecting seedling vigor in potatoes: I. Stage of seed development. Am. Potato J. (in press). Pande, P. C., M. D. Upadhya, and M.S. Kadian. 1989. Evaluation of seedlings of true potato seed (TPS) families as a propagating material (Abstr.). J. In- dian Potato Assoc. Pande, P. C., M. S. Kadian, and M. D. Upadhya. 1989. Field performance of seedling tubers in three successive clonal generations. J. Indian Potato Assoc. Potts, M. J. 1989. Factors affecting the introduction of a new crop in tropical areas: The potato. Research and Development in Agriculture. Potts, M. J. 1989. On-farm potato re- search in Burundi: a historical perspective, present philosophy and practices. In On-farm trials: ex- periences with potatoes in developing countries. (Forthcoming). Potts, M. J. 1989. The influence of inter- cropping on pests and diseases of potato in warm climates with special reference to their control. Field Crops Research. Potts, M. J. and A. B. de los Santos. On-farm trials in the Philippines. In On-farm trials: experiences with potatoes in developing countries. (forthcoming). Potts, M. J. and N. Gunadi. 1989. The influence of intercropping with Al- lium spp. on insect populations in potato (Solanum tuberosum) Annals of Applied Biology. Prange, R. K., K. B. McRae, D. J. Mid- more, and R. Deng. 1989. Reduction in potato growth at high temperature: role of photosynthesis and dark respiration. Am. Potato J. (Submitted June 1989.). Raman, K. V. 1988. Strategies to develop sweet potato with weevil resistance in developing countries. In Report of the Workshop on Sweet Potato Im- provement in Asia, held at ICAR, Trivandrum, India and jointly spon- sored by the International Potato Center (CIP), the Indian Council of Agricultural Research (ICAR), and the Central Tuber Crops Research Institute (CTCRI), October 24-28, 1988. Proceedings (in press). Raman, K. V. and E. M. Alleyne, 1989. Biology and management of West In- dian sweet potato weevil Euscepes postfasciatu (Fairmaire). In R. K. Jansson and K. V. Raman, Sweet Potato Pest Management: A Global Perspective, Westview Press . Sub- mitted October 1989. (in review). Raman, K. V., and E. B. Radcliffe, 1989. Pest aspects of potato production. In- sect and mite Pests. In Harris, P, ed: Potato Crop, 2nd ed. Chapman and Hall Publishers, (in press). Raman, K. V., M. Scurrah, M. Iwanaga, M. Palacios, and J. Alcazar, 1989. Studies on host-plant resistance of potatoes and sweet potatoes to major insect pests occurring in developing countries. Annual Plant resistance to Insects Newsletter. Vol.15. (in press). A-11 Rhoades, R. 1989 Farmers who experi- ment: An untapped resource for agricultural research and develop- ment. In Warren, D.M., D. Broken- sha, and L. J. Slikkerveer. Indigenous Knowledge Systems: The Cultural Dimension of Development. Kegan Paul International (in press). Rhoades, R. and A. Bebbington. Mixing it up: variations in Andean farmers' rationales for intercropping potatoes. Field Crops Research. (in press). Rhoades, R. E. and D. E. Horton. Past civilizations, present world needs, and future potential: root crop agriculture across the ages. In Proceedings of the 8th Symposium of the International Society for Tropical Root Crops. (ISTRC), October 30- November 5, 1988. (Forthcoming). Thakur, K. C. and M. D. Upadhya. 1989. Extraction and Processing of True Potato Seed. Seed Science and Tech- nology. Trebejo, I. and D. J. Midmore.1989. The Effect of drought on potato (Solanum spp.) growth, yield, and water use in a hot and a cool tropical climate. J. Agric. Sci. (Camb.). Submitted after revision Sept. 1989. Tung P. X., E. Rasco, Jr., P. Vander Zaag, and P. Schmiediche. 1989. Resistance to Pseudomonas solana- cearum in the Potato: I. Effects of source of resistance and adaptation. Euphytica. (in press). Tung P. X., E . Rasco, Jr., P. Vander Zaag, and P. Schmiediche. 1989. Resistance to Pseudomonas solana- cearnm in the potato: II. Aspects of A-1 2 host-pathogen-environment inter ac- tion. Euphytica. (in press). Tupac Yupanqui, A. and J. G. El- phinstone. 1989. Susceptibilidad de clones de papa adaptadas a los tr6picos ca.lidos a la pudrici6n blanda causada por Erwinia spp. [Suscep- tibility of potato clones, with adapta- tion to the warm tropics, to tuber soft rot caused by Erwinia spp.]. Fitopa- tologia 24 (2) . (Abstr.) (in press). Uquillas, J . E., C. C. Crissman, K. De- Walt and W. Peterson. 1989. Aspects of the Potato Food System of the Sier- ra of Ecuador. 75 pp. (CIP: In press, 1989). Valencia, L., 1989. El gusano blanco de la papa premnotrypes vorax (Hus- tache) en Colombia: I. Compor- tamiento de adultos en el campo. Revista ALAP 2(1) . Accepted for publication (in press). Valencia, L., 1989. El gusano blanco de la papa premnotrypes vorax (Hus- tache) en Colombia: II. Fluctuaci6n de las poblaciones de larvas en el Campo. R evista ALAP 2(1) . Ac- cepted for publication (in press). Vander Zaag, P. and V. Escobar. 1989. Rapid Multiplication of Potatoes in the Warm Tropics: Rooting and Es- tablishment of Cuttings. Potato Re- search 32. (in press). Yang, M . S., N. 0. Espinoza, P. G. Nag- pala, J. H . Dodds, F. F. White, and J. M. Jaynes. 1989. Expression of a syn- thetic gene for improved protein quality in transformed potato plants. Plant Science, (in press). Conference Papers and CIP Publications Aley, P. and E. R. French.1989. Avances en la detecci6n de pat6genos fungo- sos del camote en el Peru. In Resfune- nes V Congreso Latinoamericano de Fitopatologfa, Cali, Colombia, Jul. 10-14, 1989. p. 11. (Abstr.). Anguiz, R. and H. A. Mendoza. 1989. Significaci6n de la correlaci6n entre la resistencia al tizon temprano (Alter- naria solani) en plantulas y plantas adultas en el mejoramiento por Resis- tencia. In Resumenes del IX Con- greso Latinoamericano de Genetica y II Congreso Peruano de Genetica. Oct. 1-5, 1989. Lima, Peru. Avila, C. A., L. F. Salazar, 0 . A. Hidalgo, J. Nakashima, and A. Dusi. 1989. Boosting tuber-seed production in Brazil: serological techniques and an- tiserum production. CIP Circular (1989). Vol. 17(1):1-6. Brandolini, A. G. and H. A. Mendoza. 1989. Resistencia aA/temaria So/ani: H abilidad combinatoria general y heredabilidad en una poblaci6n avan- zada. Programme and Abstracts of the XIV Biannual Meeting of the Latin American Potato Association (ALAP). Mar del Plata, Argentina. Calua, L. and H . A. Mendoza. 1989. Herencia de precocidad en papas autotetraploides. In Resumenes del IX Congreso Latinoamericano de Genetica y II Congreso Peruano de Genetica. Oct.1-5, 1989. Lima-Peru. Canedo, V. and K. V. Raman, 1989. La Colecci6n Entomol6gica del Centro Internacional de la Papa. XXXII Convenci6n Nacional de Entomolgia "J.E. Wille." Aug. 6-11, Lima, Peru. p.1. De la Puente, F.1989. Recursos fitogene- ticos de Batata (/. batatas (L) LAM) ysu utilizaci6n.In Proceedings-Curso "Uso de Recursos Geneticos en Ame- rica del Sur." FAO/INIAA/UNA. Lima, Peru. Diaz, J., J . Mont, and M. lwanaga. 1989. Frequencia de polen 2n y relaci6n entre diametro del polen con nivel de ploidfa en 8 especies del genera Ipomoea Secci6n Batatas. [2n pollen frequency and relationship between ploidy level and pollen size in 8 species of Section Batatas, genus Ipomoea ]. IX Congreso Latinoameri- cano de Genetica. Oct. 1-5, 1989. Lima, Peru. D iaz, J., M. Iwanaga, and F. de La Puente. 1989. Cruzamientos interes- pecificos en el genero Ipomoea de la Secci6n Batatas. [Interspecific cros- ses in Se ction Bat a tas , g e nus Ipomoea]. IX Congreso Latinoame- ricano de Genetica. Oct. 1-5, 1989. Lima, Peru. Diaz, M. L. and H. A. Mendoza. 1989. Estimados de heredabilidad en el camote (/. batatas ) . In Resumenes del IX Congreso Latinoamericano de Genetica y II Congreso Peruano de Genetica. Oct. 1-5, 1989. Lima, Peru. Diaz, M. L. and H. A. Mendoza. 1989. Parametros de estabilidad fenotfpica en camote (/. bat at as). In Resumenes del IX Congreso Latinoamericano de Genetica y II Congreso Peruano de Genetica. Oct. 1-5, 1989. Lima-Peru. A- 13 Dodds, J. H. 1988. Tissue Culture Tech- nique for Germplasm Improvement and Distribution. Proceedings of Meeting held at CIMMYT, Mexico. August 1988. Dodds, J. H. 1989. Biotechnological methods for conferring insect resis- tance in sweet potatoes. In Proceed- ings Intl. Congress of Sweet Potato. Miami, June 1989. Dodds, J. H. 1989. Biotechnological techniques applied to potato and sweet potato improvement for developing countries. In FAO/CTA Symposium Plant Biotechnologies for Developing Countries. June 1989. Luxembourg. Dodds, J. H. 1989. Biotechnology ap- plied to potato improvement. In Proceedings of 3rd IPBnet Con- ference. Nairobi, January 1989. Univ. Colorado/US-AID. Dodds, J . H . and M. Tejada. 1989. Present and potential impact of potato biotechnology in developing countries. ACIAR/CGIAR Meeting Canberra, Australia. May 1989. C.A.B. Intl. Dodds, J. H., R. Lizarraga, C. Sigueiias, A. Gutierrez, and 0. Malamud, 1988. Tissue culture technique applied to potato and sweet potato improve- ment. Jn Proceedings of First Interna- tional Congress of Plant Tissue Culture: Tropical Species. Bogota, Colombia, 1987. Ekanayake, I. J . 1989. Methods of Study- ing Drought Stress and Irrigation Re- quirements of Potatoes. CIP Research Guide 30. CIP, Lima, Peru. 40 pp. Ekanayake,I.J. andD.J. Midmore.1989. Drought response of potatoes in A-14 warm tropical areas. P. W. Unger (ed.). In Proceedings Intl. Con- ference on Dryland Farming. Amaril- lo/Bushland, Texas, U.S.A. Aug. 15-19, 1988. 8 p. (Published late Spring 1989). Elphinstone, J., L. de Lindo, and E. R. French. 1988. Control of Erwinia dis- eases in San Ramon. In Report of the Planning Conference on Bacterial Diseases of the Potato. Mar. 16-20, 1987. International Potato Center, Lima - Peru. pp. 193-201. Fabian, 0. and K. V. Raman, 1989. Crianza Masai del "Gorgojo de! Camote" Euscepes postf asciatus (Fair- maire ). XXXII Convenci6n Nacional de Entomologia "J.E. Wille." Aug. 6-11, Lima, Peru. 5 pp. French, E. R. 1988. Field evaluation of clones bred for resistance to Pseudo- monas Solanacearum. In Report of the Planning Conference on Bacterial Diseases of the Potato. Mar. 16-20, 1987. International Potato Center, Lima, Peru. pp. 109-112. French, E . R. 1988. Strategies for bac- terial wilt control. In Report of the Planning Conference on Bacterial Diseases of the Potato. Mar. 16-20, 1987. International Potato Center, Lima, Peru. pp. 133-134. French, E. R. and L. Sequeira. 1988. Ad- ditional sources of resistance to bac- terial wilt. In Report of the Planning Conference on Bacterial Diseases of the Potato, Mar. 16-20, 1987. lnterna- tional Potato Center, Lima, Pe?'. pp. 29-33. French, E. R. and U. Nydegger. 1988. Mass screening procedures for resis- tance lo Pseudomonas Solanacea- rum . In Report of the Planning Conference on Bacterial Diseases of the Potato, Mar. 16-20, 1987. Interna- tional Potato Center, Lima, Peru. pp. 15-17. Freyre, R. and M. Iwanaga. 1989. Pro- duction of interspecific sesquiploid hybrids between S. Tihorosun ssp. an- digena and S. acaule through double pollinations and embryo rescue. First International Symposium on the Molecular Biology of the Potato. Aug.13-18, 1989. Bar Harbor, Maine, U.S.A. Galvez, R. and H. A. Mendoza. Incre- mento de la frecuencia genica para inmunidad al virus Y de la papa (PVY). In Resumenes de! IX Con- greso Latinoamericano de Genetica y II Congreso Peruano de Genetica. Oct. 1-5, 1989. Lima-Peru. Golmirzaie, A. M. and H. A. Mendoza. 1988. Breeding strategies for true potato seed production. CIP Circu- lar, Vol. 16:(4). Golmirzaie, A. M., J. Tenorio, and J. Dodds. 1989. Evaluation of cybrids (Tetrad CMS) true potato seed of Solanum tuberosum. In Proceedings of 3rd Cuban and International Semi- nar on Interferon, 2nd Cuban and In- ternational Seminar on Biotechnology and 1st Iberoamerican Congress on Biotechnology. Interna- tional Conference Center, Apr. 17- 22, 1989, La Havana, Cuba. Hernandez E . and H. A. Mendoza. 1989. Herencia de factores de calidad para procesamiento en papas autotetra- ploides. In Resumenes de! IX Con- greso Latinoamericano de Genetica y II Congreso Peruano de Genetica. Oct. 1-5, 1989, Lima-Peru. Hidalgo, 0 . A.1988. A Batata-duce (Ipo- moea batatas) e as perpectivas do Centro Internacional de la Papa (CIP) na sua investigacao e transfe- rencia de tecnologia. [The Sweet Potato (I. batatas) and CIP's perspec- tives on its research and technology transfer.] p. 75-82. In F. Franca, C. A. Lopes and R.E. Jabuoniski (eds.). Seminario sobre a Cultura da Batata- Doce. Brasilia, D.F. 1987. Hidalgo, 0. A. 1988. PRECODEPA y PROCIP A: Dos experiencias de redes regionales de investigaci6n y trans- ferencia de tecnologia en papa en Latinoamerica. [PRECODEPA and PROCIP A, two experiences of re- gional networks for research and technology transfer on potatoes in Latin America.] In Mejoramiento. pp. 257-264. Hidalgo, 0. A. and H. Rincon (eds). 1989. Avances en la produccion de Tuberculo-semilla de Papa en los Pafses del Co no Sur. [Advances on Tuber Seed Production in the South Cone Countries.] CIP, Lima, Peru. 199p. Huaman, Z. and F. De la Puente. 1988. Development of a sweet potato gene bank at CIP. CIP Circular Vol. 16(2):1-6. Jayasinghe, U. and C. Chuquillanqui. 1989. Interacci6n de los virus de papa en la resistencia a la multiplicaci6n de! virus de! enrollamiento de la hoja de papa. In V Congreso ALF, X Con- greso ASCOLFI y XXIX Reunion APS-CD, International Congress. Jul. 10-14, 1989. CIAT, Cali, Colombia. Jayasinghe, U. and C. Chuquillanqui. 1989. Use of Indicator Plants for Detection of Potato Viruses. Re- A-15 search Guide 21. International Potato Center, Lima, Peru. 29 pp. Kadian, M. S. and M. D. Upadhya.1989. Field performance of TPS parental lines for seedling transplants and see- dling tubers, under multilocation tri- als. In Regional Workshop on True Potato Seed (TPS) for Researchers, held in New Delhi, India. Jan. 4-8, 1989. Leal, H., K. V. Raman, and J. Alcazar. 1989. Evaluaci6n de la patogenicidad de 10 Capas de un virus del tipo granulosis que afectan a la polilla de I a pap a, Phthorimaea operculella (Zeller) (Lepidoptyera: Gelechiidae). XXXII Convenci6n Nacional de Entomologia "J.E. Wille." Aug. 6-11, Lima, Peru. p. 35. Martin, and C. and H. Torres. 1989. Con- trol of Rhizoctonia and other soil- borne diseases of TPS. In Fungal Diseases of the Potato. pp. 191-205. Mehra, S. K. and M. D. Upadhya. 1989. Village Level Processing of TPS Families. In Regional Workshop on True Potato Seed for Researchers, held in New Delhi, India. January 4-8, 1989. Mulcahy, D. L., G. B. Mulcahy, R. Popp, N. Fong, N. Pallais, A. Kalinowski, and J. N. Marien. 1988. Pollen selec- tion for stress tolerance or the ad- vantage of selecting before pollination. In Proc. 10th Int. Symp. on Sexual Reproduction in Higher Plants. Cresti, M ., P. Gori, and E. Pacini (eds.). Univ. of Siena, Italy. May 30, June 4. 1988. pp. 43-50. Orjeda, G. and M. lwanaga. 1989. Una alternativa para la evaluaci6n de espe- cies silvestres de Ipomoea: hibridos interespecfficos 4 x entre I. batatas A -16 Lam. (2n=6x=90) I. triftda (H.B.K.) Don (2n = 2x = 30). IX Congreso Latinoamericano de Genetica. Oct. 1-5, 1989. Lima, Peru. Ortiz, R., M. I wanaga, and S. J. Peloquin. 1989. Genetic cytoplasmic male sterility and 2n pollen in 4x x 2x and 4x x 4x progenies. Seventy-Third An- nual Meeting fo the Potato Associa- tion of America at Oregon State University, Corvallis, Oregon. Jul. 30- Aug. 3, 1989. Otazu, V., J. Elphinstone, and H. Torres. 1989. Erwinias and other pathogens and pests: possible interactions inthe warm climate of San Ramon. In Bac- terial Diseases of the Potato. pp. 203- 214. Palacios, M., KV.Raman, and M. Scurrah. 1989. Metodos de selecci6n para re- sistencia a la polilla de la papa Phtho- rimea operculella. In Proceedings of the XIV Meetings of the Latin Ame- rican Potato Association. Mar de Plata, Argentina. (Abst.). p. 65. Pallais, N., D. Mulcahy, N. Fong, R. Fal- con, and P. Schmiediche. 1988. The relationship between potato pollen and true seed: effects of high tem- perature and pollen size. In Cresti, M., P. Gori, and E. Pacini (eds.). Proc. 10th Int. Symp. on Sexual Reproduction in Higher Plants. Univ. of Siena, Italy. May 30 - Jun. 4, 1988. pp. 285-290. Pande, P. C. and M. S. Kadian. 1989. Comparative evaluation of true seed (TPS) Families at CPRS Modipuram during 1985-88. In R egional Work- shop on True Potato Seed (TPS) for Researchers, held in New D elhi, India, January 4-8, 1989. Raman, K. V. 1988. Major sweet potato insect pests and selection for resis- tance to the sweet potato weevil, Eus- cepes postfasciatus (Fairmaire). In Report of the Workshop on "Sweet Potato Improvement in Africa" held at ILRAD, Nairobi, Sep. 28 - Oct. 2, 1987 (UNDP Project CIAT-CIP- IITA). pp. 83-89. Raman, K. V. 1989. The Forgotten Weevil: Euscepes postfasciatus: Pros- pects for IPM. International Con- ference on Sweet Potato Pest Management June 18-23, 1989, Miami Airport-Hilton and Marina, Miami, Florida, U.S.A. (Will be pub- lished as a chapter in book "Sweet Potato Improvement Pest Manage- ment: A Global Perspective" editors R.K. Jansson and K. V. Raman, West View Press.) Raman, K. V. and J. Alcazar. 1989. Efec- tividad y Multiplicaci6n de un Virus Granulosis para el Control de la Polil- la de la Papa, Phthorimaea operculella (Zeller). XIV Reuni6n de la Asocia- ci6n Latinoamericana de la Papa. Mar del Plata. Mar. 5-11, Argentina. p. 55. Tangpinijkul N., V. Thepent, W. Panuampai, and S. G. Wiersema. 1988. Storage of Consumer Potatoes in Thailand: Results of Farmer Survey and On-Farm Research. ISTRC Sym- posium, Oct. 30 - Nov. 5, 1988, Bangkok, Thailand. Thakur, K. C. and M. D. Upadhya.1989. Technology of hybrid true potato seed production in south Asia. In Regional Workshop on True Potato Seed (TPS) for Researchers held in New Delhi, India. Jan. 4-8, 1989. Torres, H. 1989. Soilborne and foliar dis- eases in the highland tropics. In Fun- gal Diseases of the Potato. pp. 169- 179. Upadhya, M. D. 1989. Low-cost multi- purpose storage for ware and seed potatoes. In Regional Workshop on Low-cost Storage of Ware and Seed Potatoes, held in New Delhi, India. May 15-19, 1989. Valencia, L. 1989. Avances de investiga- ci6n entomol6gica en el Convenio ICA-CIP (1989)./n P.L.G6mez (ed.). Aspectos Entomol6gicos del Cultivo de la Papa. Reuni6n PRACIP A. CNI Tibaitata. July 1989. pp. 66-79. Valencia, L. 1989. El Gusano Blanco de la Papa (Premnotrypes vorax (Hus- tache ): II. Control Qufmico. (Abstr.) Congreso SOCOLEN, Medellin. Jul. 25-28, 1989. Valencia, L.1989. Reflexiones acerca del Manejo de Plagas en Sistemas de Pro- ducci6n. Seminario Taller, lnvesti- gaci6n en sistemas de producci6n. CNI Tibaitata. P. L. G6mez (ed.). Jun. 27-29, 198. pp. 118-123. Valencia, L. and C. Le6n. 1989. Factors Influencing the Susceptibility Res- ponse of Some Potato Cultivars to the Damage by the Potato Tuber Moth. (Abst.). 73rd Annual Meeting. The Potato Association of America. Oregon State University. Jul.31-Aug. 3, 1989. Corvallis, Oregon, U.S.A. Valencia, L. and I. Valbuena. 1989. El Gusano Blanco de la Papa (Premno- trypes vora.x (Hustache): I. Control con Barreras Plasticas. (Abstr.). Con- greso SOCOLEN, Medellin. Jul. 25- 28, 1989. Villegas, L. and J. H. Dodds. 1988. Cul- tivo de Tejidos Vegetales Aplicado a la Producci6n Agricola. Corporaci6n Andina de Fomento (CAF). Pro- A-17 grama Andino de Biotecnologia. Course held in Caracas, Venezuela, May 9-20, 1988. Villegas, L. and J. H. Dodds. 1989. T6picos de Ingenieria Genetica y Regeneraci6n de Plantas. Programa Andino de Biotecnologia de la Cor- poraci6n Andina de Fomento (CAF). Course held in Caracas, Venezuela, Oct. 10-21, 1988. Wiersema, S. G.1988. Potato Processing in Developing Countries: Recent Developments and Potential. ISTRC Symposium, Oct. 30 - Nov. 5, 1988, Bangkok, Thailand. Wiersema, S. G. 1989. Introduction to Sweet Potato Processing. Training Course on Sweet Potato Processing and Utilization, Aug. 1-4, 1989, Thailand. A -18 Wiersema, S. G. 1989. Postharvest Re- search on Potato and Sweet Potato in Asia. CIP Planning Workshop for Re- search and Training in Asia at Kuala Lumpur, Malaysia, Sep. 7-9, 1989. Wiersema, S. G.1989. Requirements for Storage of Potato Tubers. SAPP RAD Storage Design Workshop, Kuala Lumpur, Malaysia, September 1989. Wiersema, S. G., J.C. Hesen, and B. F. Song. 1989. Report on a Sweet Potato Postharvest Advisory Visit to the People's Republic of China, Jan. 12- 27, 1989. CIP Internal Report, 21 pp. Zuniga, L. and H. A Mendoza. 1989. determinaci6n de componentes de variancia genetica en una poblaci6n avanzada de papas autotetraploides. In Resumenes de! IX Congreso Latinoamericano de Genetica y II Congreso Peruano de Genetica. Oct. 1-5, 1989. Lima-Peru. Research and Consultancy Contracts in 1990 Research and consultancy contracts and special projects facilitate research on priority problems and provide funds for potato and sweet potato work in both developing and developed countries. The contracts greatly increase CIP's flexibility to meet changing needs and have proved to be both effective and low cost. In budgetary terms, collaboration with olher institutions through contract research is advantageous because facilities and personnel needed for a specific research activity are already in place. Thus, CIP conserves resources, and such savings are especially important as CIP moves further into biotechnological research with its high-cost implications. The returns on investments have been worldwide, both in terms of research data and in building valuable relations with the contractees who frequently play an important role in CIP's research-planning conferences and other planning and assessment activities. Thrust I Collection, Maintenance, and Utilization of Unexploited Genetic Resources Departmental Projects 1. Biosystematic Studies of Selected Wild Species and their Utilization in Breeding (in preparation - two pre- vious projects merged). Genetic Resources.P. Schmiediche/ C. Ochoa 2. The Maintenance, Documentation, Distribution, and Evaluation of Potato and Sweet Potato Germ- plasm. (In preparation - two pre- vious projects merged). Genetics Resources. Z. Huaman 3. Germplasm Enhancement through the Use of Haploids and 2n Gametes. Genetic Resources. K Watanabe 4. Development of Cytological and In Vitro Techniques to Facilitate Exploitation of Sweet Potato Germplasm. Genetic Resources . P. Schmiediche/G. Orjeda 5. Jn Vitro Potato and Sweet Potato Germplasm Collection. Introduc- tion, Maintenance, and Analysis. Physiology. R. Liza"aga/J. Dodds 6. Use of Innovative Tissue Culture Techniques to Improve Potato Germplasm. Physiology. J. Dodds 7. Collection of the Sweet Potato Ge- netic Resources and Sweet Potato Germplasm Enhancement. Genetic Resources.F. de la Puente/ Z Huaman Contract Projects 8. Institute N acional de Investiga- ciones Agropecuarias (INIAP) Ecuador. "Maintenance of the Potato Germplasm In Vitro Collec- tion". Region I. G. Garcia 9. Ente Nazionale di Energie Alterna- tive (ENEA), Italy. "Development of Potato Project Varieties Resis- tant to Insect Pests by Means of Conventional Innovative Breeding Technologies." Special Project. A. Sonnino, L. Bacchetta 10. Zuzhou Institute of Sweet Potato (XISP), China. "Evaluation of Sweet Potato Germplasm." Genetic Resources. Sheng Jialian 11. Guangdong Academy of Agricul- tural Sciences (GAAS), China. "Sweet Potato Germplasm for the A-19 Tropics." Genetic Resources. Feng Zu-Xia 12. Universita degli Studi della Tuscia Viterbo, Italy. "Use of Genetic En- gineering Methods to Confer Fun- gal Disease Resistance to Potatoes." Special Project. C. Di Pace 13. Universita di Napoli, Italy. "In Vitro Selection of Potato Mutant Tolerant to Abiotic Stress." Special Project. L. Monti 14. Maintenance of In Vitro Sweet Potato Germplasm in Venezuela. L. Villegas (IDAE, Venezuela) Genetic Resources. J. Dodds 15. Louisiana State University (LlU), U.SA. "The Use of Agrobacterium Plasmid Vectors to Insert Anti-bac- terial, Anti-insect and Frost Resis- tance Genes into Potato Plants." Physiology. J.M. Jaynes Thesis Projects 16. The Utilization of Wild Potato Species of the Series acaule and etuberosa as Sources of Resistance to Potato Leaf Roll Virus (PLR V) and Potato Spindle Tuber Viroid ( PSTV d). UNA, PelU. Genetic Resources. C Albizu, (P. Schmiediche) 17. Crossability between Ipomoea species of Section Batatas. UNA, Pero. Genetic Resources. J. Diaz, (F. De la Puente) 18. Production of Synthetic 6x Clones of Ipomoea trifida. UNA, Peru. Genetic Resources. R Freyre, (M Iwanaga) 19. Techniques for the Management and Conservation of Sweet Potato (Ipomoea batatas) Cuttings. UNA, Peru . Genetic Resources.A. Robles, (F. De la Puente) A-20 Thrust II Production and Distribution of Advanced Breeding Material Departmental Projects 20. Adaptation and Utilization of Potato and Sweet Potato Popula- tions in Breeding. Breeding & Genetics. H. Mendoza 21. Breeding of True Potato Seed Populations. BreedJng & Genetics. H. Mendoza 22. Breeding and Selection of Potato Clones with Disease Resistances and Other Appropriate Horticul- tural Characteristics. Breeding & Genetics. H. M. ](jdane-Mariam 23. Breeding, Selection, and Distribu- tion of Appropriate TPS Progenies and/or Parental Lines in East and Southern Africa. Breeding & Genetics. H. M. Kidane-Mariam 24. Breeding Sweet Potato for Low Sugar and Resistance to Weevil. Breeding & Genetics. T. Dayal 25. Evaluation of Potato Clonal and TPS Germplasm for Adaptation to Warm Climates. Breeding & Genetics. E. Chujoy 26. Development of Improved Sweet Potato Germ plasm for Warm and Cool Tropics of Southeast Asia. Breeding & Genetics. E. Chujoy 27. Development of True Potato Seed (TPS) Parental Lines and Progenies for Agronomic and Reproductive Characters. Breeding & Genetics. A. Golmirzaie Collaborative Projects 28. Production, Evaluation, and Utilization of Potato Germplasm in Colombia. Region I. I. Valbuena of East & Southern African (ICA, Colombia)/0. Hidalgo Countries/ H. M. Kidane-Mariam 29. Evaluation of Germplasm and Selec- 39. Introduction, Maintenance, and tion for Cyst Nematode Resistance. Distribution of Advanced Genetic Region I. R. Eguiguren (INIAP, Materials of Potato. Region III. Ecuador)/O. Hidalgo C. Carli/ H.MKidane-M an·a/Sylvester 30. Evaluation of Advanced Potato Nganga Breeding Material in Ecuador. 40. Evaluation of Advanced Genetic Region I. H. Andrade (INIAP, Materials with Resistance to Late Ecuador)/O. Hidalgo Blight, Bacterial Wilt, Storability, 31. Evaluation of Advanced Potato and Adaptation. Special Project. Breeding Material in Venezuela. A. Rubirigi ( I S A B U , Bunmdi)I Region I. R. L. Palencia (FONAIAP, J. Rueda Venezuela )/0. Hidalgo 41. Selection of Potato Cultivars with 32. Evaluation of Advanced Potato Late Blight Resistance, Adaptation, Breeding Material in Peru. Region I. and Quality. Special Project. A. Hidalgo (INIAA, Peru )I 0. Hi- B . Tuku (IAR, Ethiopia )/P. Callejas dalgo 42. Evaluation of Advanced Genetic 33. Evaluation of Advanced Potato Materials of Potato with Emphasis Breeding Material in Chile. Region I. on Virus Resistance. Region IV. J. Kalazich (INIA, Chile)/CJP M. Fahem ( C P R A , Tunisia )I Breeders R. Cortbaoui 34. Evaluation of Advanced Potato 43. Evaluation of Advanced Genetic Breeding Material in Argentina. Materials of Potato in Egypt. Region Region I. A. Mendiburu (INT A, IV. L. Anrity (Min. of Agricul- Chile )!CIP Breeders ture)/R. El-Bedewy 35. Evaluation of Advanced Potato 44. Evaluation of Advanced Genetic Breeding Material in Uruguay. Materials of Potato for Cameroon Region I. F. Vilaro (CIAAB, and Countries with Similar Agro- Uruguay)/CJP Breeders ecological Conditions. Region V. 36. Evaluation of Advanced Potato National Breeders of West and Breeding Material in Paraguay. Central Africa/C. Martin Region I.A. Lopez (Min. of Agricul- 45. Introduction, Evaluation, and Mui- ture, Paraguay)!CIP Breeders tiplication of Sweet Potato Germ- 37. Evaluation of Advanced Potato plasm. Region V. IRA Scientists/ Breeding Material in Brazil. Region I. C. Martin J. Buso (CNPH/EMBRAPA, Brazil)/ 46. Breeding for TPS Parental Lines. CIP Breeders Region VI. CPRI Scientists/M. 38. Collaboration with National Pro- Upadhya grams in the Evaluation and Selection 47. Evaluation, Multiplication, and Dis- of Superior Clones and TPS Pro- tribution of Advanced Genetic genies. Region III. National Breeders Materials of Potato. Region VII. Na- A-21 tional Breeders from Southeast Potato Breeding Program." Breed- Asian Countries/P. Vander Zaag/ ing & Genetics. A. Mendiburu E. Chujoy 56. Agriculture Canada. "The Nutri- 48. Evaluation of TPS Progenies and tional and Chipping Evaluation of Production of Hybrid Seed. Region Selected Parental Clones in Peru, VII. National Scientists (LEHR I, the Philippines, and Canada." Indonesia)/M. Potts Breeding & Genetics. T. R. Tam 49. Introduction and Utilization of 57. University of Tacna, Peru. "Evalua- Potato Germplasm. Region VIII. tion of Sweet Potato Germplasm National Scientists of China for Tolerance to Certain Abiotic (CAAS, China)/S. Bofu Stresses under Arid Conditions." 50. Evaluation of Cultivated Sweet Breeding & Genetics. N. Arevalo Potato Germplasm in Paraguay. 58. Instituto Nacional de Investigaci6n Region I. M. Cardoso (Ministry of Agraria, (INIAA), Peru. "Evalua- Agriculture, Paraguay)/A. Stroh- tion of CIP Advanced Clones for the menger National Potato Program of Peru." 51. Development of Improved TPS Breeding & Genetics. D. Untiveros Progenies for Various Environ- 59. Centro Nacional de Pesquisas de men ts of China. Region III. National Hortali~as (CNPH/EMBRAPA), Scientists of China (CAAS, China)! Brazil. " Evaluation of Potat o S. Bofu Germplasm Evaluation (Solanum Contract Projects tuberosum L.) related to Resistance to Altemaria solani. " Region I. 52. Cornell University, Ithaca, USA. F. J. B. Reifschneider "The Utilization of Solanum tubero- sum spp. andigena. Germplasm in 60. Consorzio "Mario Neri", ERSO, Potato Improvement and Adapta- Imola, Italy "Selection of Potato tion." Breeding & Genetics. R. L. Clones with High Starch Content." Plaisted/H. D. Thurston/W. M. Tin- Special Project. F. Concilio/F. Cioni gey/B. B. Brodie/E. Ewing 61. Centro Nacional de Pesquisas de 53. North Carolina State University, Hortali~as (CNPH/EMBRAPA), USA. "Breeding and Adaptation of Brazil. "Selection of TPS Progenies Cultivated Diploid Potato Species." Adapted to Northeast and West Breeding & Genetics. W. W. Collins Central Brazil." Region I. J. A. Buso 54. University of Wisconsin, Madison, 62. North Carolina State University, USA. "Potato Breeding Methods USA. "Breeding Early-Yielding, with Species, Haploids, and 2n and Disease-Resistant Sweet Gametes." Genetic Resources. S. J. Potatoes with Enhanced Food Peloquin Quality and Nutritional Value." 55. Instituto Nacional de Tecnologfa Breeding & Genetics. W. W. Collins Agropecuaria, (INT A), Balcarce, 63. Aegean Regional Agricultural Re- Argentina. "The Utilization of In- search Institute (ARARI), Turkey. creased Genetic Variability in the "Potato Germplasm Evaluation and A-22 Multi plication." Region IV. N. Kuzman 64. Centro de Investigaciones Agrico- las, "A. Boerger" (CIAAB), Uruguay. Consultancy on Sweet Potato Breeding. Region I. F. Vilaro 17iesis Projects 65. Inheritance of Earliness in Auto- tetraploid Potatoes. UNA, Peru. Breeding & Genetics. L. Calua (H. Mendoza) 66. Inheritance of Earliness, Yield, and Dry-Matter Content in Sweet Potatoes. UNA, Peru. Breeding & Genetics. L. Diaz (H. Mendoza) 67. Inheritance of Quality Factors in Autotetraploid Potatoes. UNA, Peru. Breeding & Genetics. E. Her- nandez (H. Mendoza) 68. Comparison of Methods for Selec- tion of General Combining Ability for Yield. UNA, Peru. Breeding & Genetics./. L. Marca (H. Mendoza) 69. Quantitative Variation in Potato Breeding. UNA, Peru. Breeding & Genetics.!. Tenorio , (A. Golmirzaie) 70. Components of Genetic Variance for Various Traits in Advanced Populations of Autotetraploid Potatoes. UNA, Peru. Breeding & Genetics. N. Zuniga (H. Mendoza) Thrust III Control of Bacterial and Fungal Diseases Departmental Projects 71. Integrated Control of Bacterial Wilt. Pathology./. Elphinstone 72. Procedures which Determine Resis- tances to Bacteri al Diseases in Potato. Pathology./ . Elphinstone 73. Soilborne Diseases. Pathology. H. Torres 74. Breeding for Early-Blight Resistance. Breeding & Genetics. H. Mendoza 75. International Testing of Late Blight- Resis tant Clones. Breeding & Genetics. J. Landeo 76. Breeding for Late-Blight Resis- tance with Populations A and B. Breeding & Genetics./. Landeo 77. Breeding for Resistance to Bac- terial Wilt. Genetic Resources. P. Schmiediche 78. Ecology and Taxonomy of Pseudo- monas solanacearum. Pathology. H. El-Nashaar Collaborative Projects 79. Integrated Control of Bacterial Wilt. Special Project. A. Autrique (ISABU-Burundi)/J. Rueda 80. Management of Late Blight Through Resistant Germplasm. Region VII. E. Bado/ (NPRCRTC, The Philip- pines)/E. Chujoy 81. Managing Bacterial Wilt Through Resistant Germplasm and Appro- priate Farming Systems. Region VII. N. Balanay (Ministry of Agriculture, The Philippines )IP. Vander Zaag 82. Control ofBacterial Wilt on Potatoes. Region VIII. H. Liyuan (CAAS, China )/S. Bofu 83. Erwinia Disease in Different Phases of the Tunisian Potato Seed Pro- gram. Region IV. M Makjoub (ESH, Tunisia)/R. Cortbaoui Contract Projects 84. Centro Nacional de Pesquisas de Hortali~as (CNPH/EMBRAPA), Brazil. "Potato Germplasm Evalua- A-23 tion for Resistance to Bacterial Wilt." Region I. C. A . Lopez 85. lnstituto Colombiano Agrope- cuario, (ICA), Rionegro, Colombia. "Evaluation of Genetic R esistance to Pseudomonas solanacearum and Phytophthora infestans." Pathology. P. L. Gomez 86. Instituto Nacional de Investiga- ciones Agropecuarias (INIAP), Ecuador. "Study and Control of the Potato Diseases, Rosellinia Black Rot (Lanosa) and Common Rust (Roya) in Ecuador." Region I. H. 'Orellana 87. University of Wisconsin, U.SA. "Fundamental Research to Develop Control Measures for Bacterial Pathogens of the Potato." Pathol- ogy. A. Kelman, L. Sequeira 88. Universidad Nacional de Huanuco, Peru. "Development of Potato Varieties with Resistance to Diseases and Adaptation to Ecological Zones of the Department of Huanuco." Pathology. E. To"es Vera 89. National Agricultural Laboratories, Nairobi, Kenya. "The Reaction of Selected Potato Clones to Two Races of Pseudomonas solanacearum in Kenya." Region Ill A. 0. Michieka 90. Cornell University, Ithaca, U.SA. "Population Genetics of Phytoph- thora infestans in its Natural Ecosys- tem at Toluca." Pathology. W. E. Fry 91. Centro de Investigaciones Agricolas "A. Boerger" (CIAAB), Uruguay. "Selection of Clones with Resis- tance to A. solani and Precocity in Materials with Antecedents to Virus Resistance." Region I. F. Vilaro/ C. Crisci A-24 92. Consultative Contract, Universidad Agraria, La Molina, Peru. "Early Blight of Potatoes: Specialization of Altemaria spp." Pathology. T. Ames de Icochea 93. Gilat Regional Experimental Sta- tion, Israel. "Verticillium Wilt and Early-Blight Tolerance of Potato in Hot Climates." Pathology. A. Nach- m ias 94. lnstituto Nacional de Investiga- ciones Forestales y Agropecuarias (INIFAP), Mexico. "Selection of Potato Genetic Material Resistant to Late Blight." Region II. M. Villa- "eal Thesis Projects 95. Serological D etection of Etwinia carotovora. UNA, Peru. Pathology. C. Co"edor, (J. Elphinstone) 96. Selection of in-Laboratory, Green- house, and Field Clones Resistant to Spongospora subte"anea and Path- ogenicity to Different Isolates. UNA, Peru . Pathology. W. Galin- dez, (E. French) 97. Biological Control of Rhizoctonia solani with Antagonistic Organisms. UNA, Peru. Pathology. P. Gutie"ez, (H. To" es) 98. Sources of Resistance to Early Blight in CIP's Germplasm Collec- tion. UNA, Peru. Pathology.A. Paler mino, (V. Otazu) 99. Identification of Native and Intro- duced Hosts of Pseudomonas sola- nacearum in Peru. UNA, Peru. Pathology. B. Paz, (E. French) 100. Incidence of Wilt and Fungous Rots of Potato in Central Highlands of Peru. UNA, Peru. Pathology. W. Perez, (L. de Lindo) 101. Inventory of Pests and Diseases Af- fecting Sweet Potato Production. UNA,Pern. Pathology. 0. Quincho, (J. Elphinstone) 102. Interaction between ETWinia caroto- vora var. caratovora and Fusarium spp. Affecting Potatoes in Peru. UNA, Pern. Pathology. H. Silva, (E. French) 103. Biological Control ofBacterial Wilt. UPLB, The Philippines Region VII. Hongqi Zeng (P. Vander Zaag) 104. Genetics of Bacterial Wilt Resis- tance. UPLB, The Philippines. Region VII. Pham Xuan Tung (E. Chujoy) Thrust IV Control of Virus and Virus-Like Diseases Departmental Projects 105. Antiserum Production and Im- provement of Serological Techni- ques for Virus Detection. Pathology. L. Salazar 106. Identification and Characterization of Sweet Potato Viruses. Pathology. L. Salazar 107. Mechanism of Resistance and Variability of Potato Leaf Roll Virus (PLRV). Pathology. U. Jayasinghe 108. Studies on Potato Viruses X and Y. Pathology. E. N. Fernandez-North- cote 109. In Vitro Eradication of Sweet Potato Viruses and Viroids. Physiology. J. Dodds 110. Genetic Studies and Breeding of Viruses and Viroid Resistance . Breeding & Genetics. H. Mendoza 111. Molecular Analysis of Genetic Resistance to Viruses. Pathology. M. Querci 112. Development of Molecular Probes for the Identification of Pathogens. Pathology. M. Querci 113. Epidemiology of Potato Viruses in Peru. Special Project. L. Bertschinger Collaborative Projects 114. Effect of Potato Virus Son Growth, Yield, and Late Blight. Special Project. M. Goethals (ISABU, Bun.mdi)/J. Rueda 115. EpidemiologyofPVYandPLRVin Potato Seed Fields in Tunisia. Region IV. C. Cheri/ (INRA T, Tunisia)/R. Cortbaoui 116. Development and Utilization of Virus Detection Techniques. Region VIII. Z. Heling (University of Inner Mongolia, China )IS. Bofu. 117. Studies on Yellow Vein Virus. Region I. A. Saldarriaga (UNM, Colombia)/O. Hidalgo Contract Projects 118. Istituto Agronomico per l'Oltre- mare (1.A.0.), Italy. "Production of Antisera Against Major Potato Viruses." Special Project. M. Brog- gio/M. Galanti 119. Scottish Crops Research Institute, Scotland. "Resistance to Potato Leafroll Virus." Pathology. B. D. Harrison 120. North Carolina State University, USA . "The Accumulation of Sweet Potato Feathery Mottle Virus, ds- RNA and Selected Viral Proteins in Sweet Potatoes. Pathology.! Moyer 121. Universidad Nacional Agraria, La Molina.Pern. Consultative Contract A-25 on "Monoclonal Antibodies for Potato Viruses." Pathology. J. Cas- tillo 122. Universidad Nacional Agraria, La Molina, Peru. "Maintenance of Monoclonal Antibodies for Potato Viruses." Pathology. J. Castillo 123. Centro de Investigaciones Agricolas "A. Boerger" (CIAAB) Uruguay. "Evaluation of Genetic Material for Resistance to PVX and PLR V Under Field Conditions." Region I. C. Crisci/F. Vilaro 124. Instytut Ziemniaka, Institute for Potato Research, Poland. "Breed- ing Potatoes Resistant to the Potato Leafroll Virus, PLRV." Pathology. K M. Swiezynski 125. Louisiana State University, USA. "Attempts to Elucidate the Etiology of Sweet Potato Chlorotic Leaf Dis- tortion." Pathology. C. A. Clark 126. North Carolina State University, U.SA. "Development of Virus Test- ing Procedures for Sweet Potatoes." Pathology./. Moyer Thesis Projects 127. Studies on the Mechanisms of Resistance of Potatoes to Viruses: Determining the Factor that Con- fers Extreme Resistance to Potato Virus X in Potato. UNA, Peru. Path- ology. S. Vega, (M. Querci/L Salazar) 128. Combination of PVX and PVY Im- munity with High Resistance to Phytophthora infestans in Potato Clones. UNA, Peru . Pathology./. L. Zapata, (E. N. Femandez-Nonhcote) 129. Efficiency of PLRV Transmission by Different Species of Aphids. UNA, Peru. Pathology. G. Brignetti, ( U. J ayasinghe) A-26 130. Identification and Some Charac- teristics of Sweet Potato Feathery Mottle Virus Isolates from Peru. UNA, Peru. Pathology. C. Cedano, (L. Salazar) 131. Virus Infections in Potato Clones with Different Levels of Resistance to PVX, PVY, and PLRV under Field Conditions and Associated Aphid Species. UNA, Peru. Pathol- ogy.Edgar Garcia, (EN.Femandez- Nonhcote) 132. Studies on Virus and Viroid Se- quences in Chromosomal DNA from Potatoes. UNA, Peru. Pathol- ogy. P. Chimoy, (L. Salazar) 133. Identification of Viroids in Sweet Potatoes. UNA, Peru. Pathology. A . HuTtado, (L. Salazar) 134. Inheritance of Extreme Resistance to PVY in S. tuberosum. UNA, Peru. Pathology.R. Galvez, (H. Mendoza) 135. Breeding for PVY Immunity. UPLB, The Philippines. Region VII/ UNDP Vu Dinh Hoa (E. Chujoy) Thrust V Integrated Pest Management Departmental Projects 136. Screening for and Utilization of Resistance to Root-Knot Nematode Species. Nematology & Entomology. P. Jata/a 137. Components of Integrated Root- Knot Management and Inter- relationships of this Nematode with Other Organisms. Nematology & Entomology. P. J at ala 138. Screening for and Utilization of Re- sistance to Potato Cyst Nematode. Nematology & Entomology. M. Scu"ah/ J. Franco 139. Components of Inttgrated Potato Cyst Nematode Management. Nematology & Entomology.1 Franco 140. Management of Potato and Sweet Potato Insect Pests of Global Im- portance. Nematology & Entomol- ogy. K V. Raman/M. Scu"ah 141. Management of Potato and Sweet Potato Insect Pests oflmportance in Specific Regions. Nematology & Entomology. K V. Raman 142. Management of Potato Insect Pests of Importance in The South Ame- rican Andean Region. Nematology & Entomology. L. Valencia 143. Resistance to Potato Tuber Moth. Nematology & Entomology. L Valencia 144. Integrated Control of Potato Tuber Moth and Other Insect Pests of Potato and Sweet Potato. Nematol- ogy & Entomology. K. V. Raman. Collaborative Projects 145. Ecology and Control of the Andean Weevil. Region I. H. Ca/vache (I CA, Co/ombia)/L. Valencia 146. Biological Control of Potato Tuber Moth. Region I. R. Lopez (ICA, Colombia)/L. Valencia 147. Integrated Control of Potato Tuber Moth in Venezuela. Region I. J. Rincon (FONAIAP, Venezuela)/ L. Valencia 148. Integrated Control of Andeari Weevil in Venezuela. F. To"es Region I. (FONAIAP, Venezuela)/ L. Valencia 149. Integrated Control of Potato Tuber Moth and Aphids in Eastern and Southern African Countries. Spe- cial Project. National Entomol- ogists/B. Parker 150. Integrated Control of Root-Knot Nematode. Special Project. M. Goethals (ISABU, Burundi)! I.Rueda 151. Integrated Management of Tuber Moth in Burundi. Special Project. Z. Nzoyihera (IS ABU, Burundi)! C. Turner 152. Integrated Management of Potato Tuber Moth and Aphids in Ethiopia. Special Project. B. Tuku (IAR, Ethiopia)/P. Callejas 153. Integrated Control of Potato Tuber Moth in Egypt. Region IV. S. Doss (Ministry of Agriculture)/R. E/- Bedewy 154. Integrated Management of Sweet Potato Weevil (Cy/as fonnicarius) Region VII. D. Arna/in (VISCA, The Philippines)/P. Vander Zaag 155. Evaluation of Trap Types with Sexual Pheromones of Cy/as spp. Region II. National Scientists of Cuba, Venezuela/O. Malamud 156. Evaluation of Sweet Potato Germ- p la sm for Resistance to Sweet Potato Weevil in Central America and the Caribbean. Region II. Na- tional Scientists of the Region/ O.Malamud 157. Agronomic Practices to Control Sweet Potato Weevil. Region II. Na- tional Scientists of the Dominican Republic and Haiti/0. Malamud 158. Biological Control of Sweet Potato Weevil in Central America and the Caribbean. Region II. National Scientists of the Region/O. Malamud Contract Projects 159. University of the Philippines, Los Banos (UPLB), The Philippines. A-27 "Integrated Control of Weeds and Nematodes by the Use of Biological Control Agents and Solarization." Nematol~ & Entomology. R Davide 160. North Carolina State University, USA. "Evaluation of Potato Lines for Resistance to the Major Species and Races of Root-Knot Nema- todes (Me/oidogyne spp.)." Nema- tology & Entomology. J. N. Sasser 161. Instituto Nacional de Investiga- ciones Agropecuarias (INIAP), Ecuador. "Evaluation of Clones Resistant to the Root-knot Nema- tode (Globodera spp.) in Ecuador." Region I. R. Eguiguren and J. Revelo 162. Universidad Nacional Agraria, La Molina, Pern. Consultancy on "Pratylenchus spp. as an Important Nematode Pest of Potatoes." Nematology & Entomology. M. Canto 163. Universidad Nacional Agraria, La Molina , Pern. Consultancy on "Biological and Selective Chemical Control of Potato and Sweet Potato Insect Pests." Nematology & Ento- mology. J. Sanniento and Colleagues 164. The Southeast Asian Regional Cen- ter for Graduate Study and Re- search in Agriculture (SEARCA), The Philippines. "Management of Thrips and Mites Attacking Potato in the Lowlands." Region VII. E. N . Bernardo. Thesis Projects 165. Extraction and Inoculation Me- thods of Nacobbus abe"ans and its interaction with Globodera pa/Iida. UNA, Peru. Nematology & Entomo- logy.!. Arcos, (P. Jatala/ M. Canto) 166. Development of IPM Approach to Control the Potato Tuber Moth, A-28 Phthorimaeaopercule/la (Zeller) (Le- pidoptera: Gelechiidae) in Storage. Nematology & Entomology. G. P Das .(K V.Raman/ E. Maga/Iona) 167. Effect of Glandular Trichomes on Leafminer Fly (Liriomyza huido- brensis) Damage in Potatoes. UNA, Peru. Nematology & Entomology. G. Hospina, (K V. Raman) 168. Detection and Evaluation of Granulosis Virus (GV) for Potato Tuber Moth (PTM) Phthorimaea operculella Control. UNA, Peru. Nematology & Entomology. H. Leal, (KV. Raman) 169. Variability of Nacobbus abe"ans. UNA, Peru . Nematology & En- tomology. R. Montecinos, (P. Jatala/ M. Canto) 170. Reaction of Potato Clones to Praty- lenchus spp. from Umari Huanuco. UNA, Peru. Nematology & En- tomology. Z. Nicolas, (P. Jatala/ M. Canto) 171. Determination of Some Compo- nents for an Integrated Control of Pratylenchus flakkensis. UNA, Peru. Nematology & Entomology. J. Sal- divar, (M. Canto) 172. Life Cycle of the Central American Potato Moth, Scrobipalpopsis sola- nivora Povolny and Studies on Moni- toring Field Populations. Nema- tology & Entomology. F. To"es , (L. Valencia) Thrust VI Warm-Climate Potato and Sweet Potato Production Departmental Projects 173. Improving Efficiency of Fertilizer, Water, and Light Use in Non-Tradi- tional Warm Potato-Growing Areas. Physiology. D. Midmore 174. Agronomic Management for Con- trol of Bacterial Wilt. Physiology. D.Midmore 175. Adaptation and Utiliz.ation of Potato Populations for the Hot Tropics. Breeding & Genetics. H. Mendoza 176. Evaluation of the Physiological Response of Potatoes and Sweet Potatoes to High Temperature and Water Use Using In Vitro Techni- ques. Physiology. /. Ekanayake 177. Evaluation of Genotypic Responses to Water Stress and Improvements in Water Use Efficiency by Potatoes and Sweet Potatoes for Warm Climates. Physiology. /. Ekanayake 178. In Vitro Screening of Sweet Potatoes to Saline and Osmotic Stress Condi- tions. Physiology./. Ekanayake 179. In Vitro Tuberization Response of Potatoes at High Temperatures. Physiology./. Ekanayake 180. Soil Fertility and Mineral Nutrition of Potato in Adverse Climate and Soil Conditions. Physiology. S. Vil/a- garcia 181. Potato Production in the Cropping Systems of the Warm Climate Zone of Asia. Physiology. M. Potts. Collaborative Projects 182. Potato Production from True Potato Seed in Paraguay. Region I. T. Mayeregger (I AM, Paraguay). A. Strohmengher 183. Improvement of Sweet Potato in Egypt. Region IV. S. Doss (Ministry of Agriculture, Egypt)/R. El-Bedewy 184. Potato Production from True Potato Seed. Region IV. N. Farag (Ministry of Agriculture, Egypt)/ R. El-Bedewy 185. Potato Production from True Seed in Cameroon and Other Countries of the Region. Region V. S. Nzietchueng (Ministry of Dachang, Cameroon )I C. Martin 186. True Potato Seed Hybrid Families in Different Agroecological Zones oflndia. Region VI. (National Scien- tists of CPRI, India )/M. Upadhya 187. True Potato Seed on Farm Trials in India. Region VI. (National Scien- tists of CPRI,lndia )/M. Upadhya 188. Use of Plant Growth Substances in Improving Quality and Quantity of Potato Yield. Region VI. (National Scientists of CPRI,lndia)/M Upadhya 189. Tuber Seed Production and Storage for Warm Climates in Asia. Region Vil (National Scientists, LEHRI, Indonesia)/M. Potts 190. Agronomic and Physiological Studies on Sweet Potato in Warm Climates: The Philippines and Viet- nam. Region VII. H. Taja (Institute of Biology, The Philippines)/N. Van Uyan (HCMC, Vietnam )IP. Vander Zaag 191. Intercropping Studies on Potato with Maize. and other Annual Crops. Region VIII. L. Jiemin (S. China Potato Research Center)/ S. Bofu Contract Projects 192. U niversidad N acional Agraria, La Molina, Peru. "Soil Management, Fertilizers and Mineral Nutrition of the Potato Under Adverse Condi- tions of Soil and Climate." Physiol- ogy. S. Villagarcia A-29 193. Scottish Crops Research Institute, Scotland. "Drought Tolerance in Potatoes." Physiology. P. Waister 194. Maritius Sugar Industry Research Institute (MSIRI), Nairobi, Kenya. "Development of Potato Varieties for Lowland Tropical Conditions." Region 111. K Wong yen Cheong 195. Instituto Nacional de Tecnologfa Agropecuaria, (INTA), Argentina. Consultancy on Sweet Potato Production and Utilization. Region I . A . Boy Thesis Projects 196. Effect of Nitrogen Fertilizer and In- oculation With Awspirillum on Yield and Nitrogen Content of Two Sweet Potato Varieties. Physiology. (UNA, Peru.) M.Julca, (P. Malagamba) 197. Management of Sweet Potato Plant- ing Material. UNA, Peru. Physiol- ogy. F. Wizman, (P. Malagamba) 198. Irrigation Requirements for Sweet Potato. Physiology. E. Rios, (D. Mid- more) Thrust VII Cool-Climate Potato and Sweet Potato Production Departmental Projects 199. Breeding for Resistance to Frost, Early Maturity, Wide Adaptability and other Major Constraints of the Highlands. Breeding & Genetics. J. Landeo 200. Improving Efficiency of Fertilizer, Water, and Light Use in Traditional Potato Growing Areas. Physiology. D.Midmore 201. Evaluation and Selection of Sweet Potatoes in Cool Environments. (In A-30 revision). Genetic Resources. F. de la Puente 202. Breeding for Highland Adaptation Including Cyst Nematode, Late Blight, and Frost, PYX, and PVY Resistance. Breeding & Genetics. J. Landeo (In revision). Collaborative Projects 203. Ecophysiology of Potato Produc- tion in the Southern Region of Chile. J. S. Rojas (INIA, Chile) . Region I. D. Midmore/P. Malagamba 204. The Production of Sweet Potato Basic Planting Materials in Burundi. Special Project.A Sinduhije (ISABU, Burundi)/!. Rueda 205. On-Farm Trials to Introduce Cul- tivars to Improve Potato Production in Burundi. Special Project. Z. Nzoyihera (IS AB U, Burundi)/ C. Turner 206. Yield Improvements through Agro- nomic Practices. Special Project. Z. Nzoyihera (IS ABU, Burundi)/ C. Turner 207. Potato Production from True Seed: Progenies and Agronomy. Special Project. B. Tuku (IRA, Ethiopia )I P. Callejas 208. Development of Cultural Practices for Potato Production from Seed Tubers and Seedling Tubers . Region IV. A . Sharara (Ministry of Agriculture, Egypt)/R. El-Bedewy 209. Pot a to Production fr o m True Potato Seed. Region IV. N. Farag (Ministry of Agriculture, Egypt)/ R . E/-Bedewy 210. Potato Production from True Seed in Morocco. Region IV. A. Hilali (I.AV., Morocco)/R. Cortbaoui 211. Potato Production from True Potato Seed in Tunisia. Region IV M. Fahem ( C D R A , Tunisia)/ R. Conbaoui 212. Agronomy of Potato Production in Cameroon and Other Countries with Similar Agroecological Condi- tions. Region V. P. Foncho (IRA, Cameroon )IC. Martin Contract Projects 213. Instituto de Investigaciones Agro- pecuarias (INIA), Chile. "Selection of Potato Genetic Materials Adapted to Sub-optimal Temperatures." Region I. J. Rojas Thesis Projects 214. Determination of Type of Gene Ac- tion in the Control of Frost Resis- tance. UNA, Peru. Breeding & Genetic. V. Huanco, (J. Landeo) 215. T echniques for Selecting Potato Genotypes for their Efficient Use of Nutrients and Evaluating Leaf Lon- gevity with Respect to Efficient Use of Nitrogen. UNA, Peru. Physiol- ogy. S. Sarapura, (D. Midmore) Thrust VIII Postharvest Technology Depaltmenta/ Projects 216. Low-cost Storage of Consumer Potatoes. Physiology. S. Wiersema 217. Simple Processing for Low-income Groups. Physiology. S. Wiersema 218. Physiological Aspects of Seed and Ware Potato Storage. Physiology. S. Wiersema 219. Integrated Control of Postharvest Losses D uring T ropical Potato Storage. Pathology. J. Elphinstone 220. Breeding Potatoes for Processing in Tropical Countries. ,Breeding & Genetics. H. Mendoza Collaborative Projects 221. Improvement of Potato Storage Techniques in Burundi. Special Project. Z. Nzoyihera (IS ABU, Burundi)/C. Turner 222. Research and Transfer of Posthar- ve st Technologies to African Countries. Region III. (National Scientists of African Countries)/G. Hunt 223. Swe et Po t a t o St o rage (Post- Maturity Technology). Region III. A. Abubaker (Min. of Agriculture, Kenya )!G. Hunt 224. Low-cost Potato Processing. Region III. J. Kabira (Min. of Agriculture , Kenya )/G. Hunt 225. Assessment of Promising Potato Clones Under Seed Storage Condi- tions. Region III. J. Kabira (Min. of Agriculture, Kenya)/G. Hunt 226. Storage of Ware and Seed Potatoes. Region IV. S. Doss (Min. of Agricul- ture, Egypt)/R. E/-Bedewy 227. Studies on Potato and Sweet Potato Storage. Region V.J. Lekunze (IRA, Cameroon )IC. Martin 228. Rustic Stores for War and Seed Potato and Sweet Potato. Region VI. R. Nave (SOTEC, India )IS. Mehra 229. Table and Seed Potato Storage for Lowlands of Southeast Asia. Region VII. (National Scientists of Southeast Asian Countries)/P. Vander Zaag Contract Projects 230. The Philippine Root Crop Research and Training Center (PRCRTC), The Philippines. "Development of A -31 Simple Processing Technologies for Sweet Potato/Potato-based Pro- ducts for Low-income Groups as Target Consumers." Region VII. T. VanDen 231. Society for Development of Ap- propriate Technology (SOTEC), India. "Village-Level Processing of Potato and Sweet Potato." Region VI. R. Nave Thesis Projects 232. Pre- and Postharvest Factors In- fluencing Consumer Potato Tuber Storability in the Tropics. UNA, Pero. Physiology. A. Tupac, (S. Wier- sema//. Elphinstone/E. French) 233. Production and Utilization of Solar- Dried Potatoes in Kenya. Region III. University of Nairobi, Kenya. J. Kabira ( G. Hunt) Thrust IX Seed Technology Departmental Projects 234. Agronomic Technology for Grow- ing Potatoes from TPS. Physiology. P. Malagamba 235. Physiological Studies on the Production from True Potato Seed (TPS). Physiology. N. Pa/lais 236. Pollen Selection. Physiology. N. Pa/lais 237. Investigation of Environmental Conditions During the Develop- ment of Sexual Reproductive Or- gans of Ipomoea batatas and Other Ipomoea Species. Physiology.H. Beau- fort-Murphy 238. Study on the Feasibility of TPS Production in Warm Tropics. Physiology. C. Almerkinders A-32 239. Soil Fertility and Mineral Nutrition on Flowering and Fruit Production of Potato Clones. Physiology. S. Villa- garcia 240. Potato Seed Programs in Develop- ing Countries. Social Science. C. Crissman Collaborative Projects 241. Production of Basic Potato Seed in Colombia. Region I. P. Corzo (ICA, Colombia )/0. Hidalgo 242. Production of Seed Tubers from True Potato Seed. Region I. E. Or- tega ( F 0 NA I AP, Venezuela)/ 0. Hidalgo 243. Production of Basic Seed in Venezuela. Region I. E. Ortega (FONAIAP, Venezuela )/0. Hidalgo 244. Adaptive Research on TPS Produc- tion. Region I. J. S. Rojas (INIA, Chile )fl. Bryan 245. Basic Seed Production in Peru. Spe- cial Project. A. Hidalgo (INIAA, Peru )f R. Wissar. 246. Client-oriented Seed Program. Spe- cial Project. A. Hidalgo (INIA, Peru)/E. Franco 247. In Vitro and Rapid Multiplication for Basic Potato Seed Production. Region I. J. Rojas (INIA, Chile)! J. Bryan 248. Seed Potato Production in Paraguay. Region l.M. Maye"eger(Ministryof Agriculture, Paraguay)/A. Stroh- menger 249. Basic Seed Production in Kenya. Region III. I Nyoroge (KARI, Kenya) IC. Carli 250. Agronomic Techniques for Potato Seed Production. Region III. Na- tional Scientists of African Countries/ C. Carli 251. Evaluation of Rapid Multiplication Techniques for Potato Basic Seed. Region III. National Scientists of African Countries/C. Carli 252. Multiplication Methods for Sweet Potato Propagation. Region III. Na- tional Scientists of Kenya/C. Carli 253. Potato Basic Seed Production in Burundi. Special Project . A. Sin- duhija (ISABU, Burundi)/!. Rueda 254. On-farm Potato Seed Production. . Special Project.Z. Nwyihera (ISABU, Burundi)!C. Turner 255. Production of Hybrid True Potato Seed. Region VI. National Scientists (CPRI, India) /K Takur 256. Screening of True Potato Seed Families as Transplants, and Seed- ling Tubers as Seedling Materials. Region VI. National Scientists (CPRI, India)/M. Upadhya 257. Physiological Studies on True Potato Seed. Region VI. National Scientists (CPRI, lndia)/M. Upadhya 258. Technology of Using Cuttings for Seed and Table Potato Production in Southeast Asian Countries. Region VII. National Scientists of Southeast Asian Countries/ P. Vander Zaag 259. Hybrid True Potato Seed Produc- tion in Vietnam. Region VII. V. Hoang (Min. of Agriculture, Vietnam)/ P. Vander Zaag 260. Seed Production Systems Using True Potato Seed in The Philippines and Vietnam. Region VII. National Scientists of Vietnam/?. Vander Zaag 261. Development of a Propagation Sys- tem for Potato and Sweet Potato in Cameroon and Other Countries in the Region. Region V. J. Lekunze (IRA, Cameroon), Country Scien- tists/C. Martin Contract Projects 262. Victoria Department of Agricul- ture, Australia. "Production of Pathogen-tested Potato Germplasm for Southeast Asian and Pacific Countries." Region Vil P. T. Jenkins 263. Istituto di Agronomia, Universita di Napoli, Italy. "Selection of TPS Parental Lines in the High Seed Production ." Special Project. L. Monti, L. Politano 264. Instituto de Investigaciones Agro- pecuarias, (INIA), Osorno, Chile. "True Potato Seed Production in Chile." Region I. J. Santos Rojas, A. Cubi/los 265. Universidad Nacional Agraria, La Molina, Peru. "Training and Con- sultancy Research in Effects of Soil Management and Fertilization on Flowering, Fruit Setting, and Seed Quality of the Potato." Physiology. S. Villagarcia Thesis Projects 266. Embryo Culture and Sweet Potato. UNA, Peru. Physiology. R. Salinas, (J. Dodds) 267. An Investigation of the Flowering Responses of Ipomoea purpurea in Lima, from Accessions Collected in Peru, Ecuador, Venezuela, Colom- bia, and Bolivia. UNA, Peru. Physiol- ogy.A. Reyes, (H. Beaufort-Murphy) 268. Promotion of Flower and TPS Production Via Growth Regulations. A-33 UNA, Peru. Physiology. R. Garcfa, (P. Malagamba) 269. Cutting Production and Utilization Under Warm Conditions. UPLB, The Philippines. Region Vll/UNDP. He Wei (P. Vander Zaag) Thrust X Potato and Sweet Potato lo Food Systems Departmental Projects 270. Impact Assessment. Social Science. D. Horton 271. Root Crop Statistics. Formerly "Patterns and Trends in Root Crop Production and Use". Social Science. D.Horton 272. Constraints to Potato and Sweet Potato Production and Use. Social Science. D. Horton 273. User's Perspective on Generation of Appropriate Sweet Potato and Potato Techniques. Social Science. R. Rhoades 274. Marketing and Demand for Potatoes in Deve loping Countries. Social Science. G. Scott 275. Survey of National Seed Programs. Social Science./. Bryan/C. Crissman 276. Cooperative Program of Potato Marketing Research in the Andean Region (PRACIPA-Comerciali- zacion). Special Project. G. Scott 277. Assessing the Feasibility of Potato Agriculture in Mid-Elevations. So- cial Science. G. Watson A -34 278. The Sweet Potato in Food Systems. Social Science. G. Watson 279. Potato Production in Warm Climates oflndonesia. SoclalSdence. G. Watroo Collaborative Projects 280. Farmer's Cultural Practices and Farmer and Consumer Selection of Sweet Potato Varieties. Region VIL G. Watson/M. Potts 281. Farmer Participation in Research to Develop Low-cost Technology. Special Project. V. Lama (INIA, Peru )IE. Franco/G. Prain 282. Collection and Analysis of Data on Potato and Sweet Potato Produc- t ion in Indonesia. Region VII. A. Supriadi (LEHRI, Indonesia)/ G. Watson 283. The On-farm Production of Seed and Ware Potatoes from TPS. Region VIL M. Potts/G. Watson Contract Projects 284. England. Sweet Potato: An Un- tapped Food Resource. Social Science./. A. Woolfe 285. International Food Policy Research Institute (IFPRI), U.SA. "White Potato/Sweet Potato Development in China." Social Science. B. Stone 286. H. P. University, India. "Demand Study for Processed Potatoes." So- cial Science. B. K Sikka 287. Peru. "Demand for Sweet Potato." Social Science. M. Collins Staff SENIOR MANAGEMENT Richard L. Sawyer, Ph.D., Director General Jose Valle-Riestra, Ph.D., Deputy Director General William A. Hamann, B. S., Assistant to the Director General Peter Gregory, Ph.D., Director of Research Kenneth J . Brown, Ph.D ., D irector of Regional Research Primo Accatino, Ph.D., Associate Dir., Transfer of Technology Adrian Fajardo, M. S., Executive Officer Leonardo Hussey, Controller RESEARCH THRUSTS (Manager s and Associate Managers) I. Collection, Maintenance and Utilization of Unexploited Genetic Resources (P. Schmiediche- Z. Huaman) II. Production and Distribution of Advanced Breeding Material (H. Mendoza - M. lwanaga) III. Control of Bacterial and Fungal Diseases (E. French) IV. Control of Virus and Virus-Like Diseases (L. Salazar - U. Jayasinghe) V. Integrated Pest Management (F. Cisneros - P. Jatala) VI. Warm Climate Potato and Sweet Potato Production (D. Midmore - H. Mendoza) VII. Cool Climate Potato and Sweet Potato Production (J. Landeo - D. Midmore) VIII. Postharvest Technology (S. Wiersema) IX. Seed Technology (P. Malagamba - A. Golmirzaie) X. Food Systems (D. Horton - R. Rhoades) RESEARCH DEPARTMENTS Breeding and Genetics Humberto Mendoza, Ph.D., Geneticist, Head of Department. (sabbatical leave from Sept. 3, 1989) Andrea Brandolini, Dot. Agr., Visiting Associate Scientistt Edward Carey, Ph.D., Sweet Potato Breeder Carlo Carli, D ot. Agr., Sweet Potato Breeder (Kenya) Enrique Chujoy, Ph.D., Geneticist (The Philippines) T. R. Dayal, Ph.D., Sweet Potato Breeder (India) Ali Golmirzaie, Ph.D., Geneticist, Acting Head of Department (from Sept. 3, 1989) Haile M. Kidane-Mariam, Ph.D., Breeder (Kenya) Juan Landeo, Ph.D., Breeder II Gin Mok, Ph.D., Sweet Potato Breeder (Nigeria) A-35 Marfa Scurrah, Ph.D., Breeder Genetic Resources Peter Schmiediche, Ph.D., Breeder, Head of Department Fermfn De la Puente, Ph.D., Breeder Z6simo Huaman, Ph.D., Geneticist Masaru Iwanaga, Ph.D., Cytogeneticist* Kazuo Watanabe, Ph.D., Cytogeneticist Nematology and Entomology Parviz Jatala, Ph.D., Nematologist, Head of Department Rolf Aalbu, Ph.D., Entomologist (Tunisia) Javier Franco, Ph.D., Nematologist (until Sept. 9, 1989-transferred to PROINP A-Bolivia) Hirotaka Kokubu, Ph.D., En- tomologist, (Dominican R epublic) K. V. Raman, Ph.D., Entomologist Luis Valencia, Ph.D., Entomologist (Colombia) Pathology Edward R. French, Ph.D., Pathologist, Head of Department Hossien El-Nashaar, Ph.D., Bacteriologist John Elphinstone, Ph.D., Bacteriologist Enrique Fernandez-Northcote, Ph.D., Virologist Gregory A. Forbes, Ph.D., Mycologist Upali Jayasinghe, Ph.D., Virologist Masaaki Nakano, B. S., Virologistt Maddalena Querci, Dot. Agr., Visiting Associate Scientistt Luis Salazar, Ph.D., Virologist Linnea G. Skoglund, Ph.D., Mycologist (Kenya) L. J. Turkensteen, Ph.D., Adjunct Scientist (The Netherlands)t A-36 Physiology Patricio Malagamba, Ph.D., Physiologist, Head of Department (sabbatical leave, part of 1989) Cornelia Almekinders, Ir., Scientific Associatet Helen Beaufort-Murphy, Ph.D., Physiologist John Dodds, Ph.D., Tissue Culture Specialist Indira Ekanayake, Ph.D., Physiologist David Midmore, Ph.D., Physiologist, Acting H ead of Department (part of 1989) Noel Pallais, Ph.D., Physiologist Frederick Payton, Ph.D., Agronomist (Dominican Republic) Michael Potts, Ph.D., Agronomist (Indonesia) Siert Wiersema, Ph.D., Physiologist (Thailand) Social Science Douglas E. Horton, Ph.D., Economist, Head of Department Charles Crissman, Ph.D., Economist (Ecuador) Peter Ewell, Ph.D., Economist (Kenya) Keith Fuglie, Ph.D., Economist (Tunisia) Gordon Prain, Ph.D., Anthropologist Robert E. Rhoades, Ph.D., Coor- dinator, UPWARD (The Philippines) Gregory J. Scott, Ph.D., Economist (sabbatical leave, part of 1989) Greta Watson, Ph.D., Visiting As- sociate Scientist (Indonesia, until May 31, 1989)t Keith Fuglie, Ph.D. Economist (Tunisia)t INFORMATION SCIENCE DEPARTMENT (Previously Training & Communications) Manuel Piiia, Ph.D., H ead of Depart- ment (left June 1989)* Carmen Siri, Ph.D., Head of Depart- ment (from July 1989) James Bemis, Jr., Ph.D., Senior English Writer/Editor Christine Graves, M.A., Writer/Editor Linda W. Peterson, B. F.A., English, Editor* Carmen Podesta, M.A., Librarian/Infor- mation Officer Hernan Rinc6n, Ph.D., Communica- tions Unit Alfredo Garcia, M.S., Statistics Unit Marciano Morales-Bermudez, M.S., Su- pervisor, Communication Unit Training Department Manuel Piiia Jr., Ph.D., Head of Department* Fernando N. Ezeta, Ph.D., Head of Department (from June 1989) George Hunt, Agr. E ng., Training Of- ficer (Kenya) Gary Robertson, M.A., Training Coor- dinator* Rainer Zachmann, Ph.D., Training Materials Specialist* Margarita Villagarcfa, M.S., Training Coordinator Assistant Research Support Fausto H. Cisneros, Ph.D., En- tomologist, Head of Department Lombardo Cetraro, Biologist, Field & Greenhouse Supervisor, San Ramon, Peru Jose Luis M arca, M .S., Field Supervisor, Yurimaguas, Peru. Francisco Munoz, Ph.D., Superinten- dent, Quito, Ecuador Victor Otazu, Ph.D., Superintendent, San Ramon, Peru Mario Pozo, Ing. Agr., Field & Green- house Supervisor, Lima, Peru REGIONAL RESEARCH Headquarters James E. Bryan, M. S., Seed Tech- nologist Fernando Ezeta, Ph.D., Network Specialist (tranferred to Training Department, June 1989) Region I - Andean Latin America Apartado Aereo 92654 Bogota 8, D .E., Colombia Oscar Hidalgo, Ph.D., Regional Repre- sentative Juan Aguilar, Ing. Agr., Seed Produc- tion SEINP A (Peru)t Lukas Bertschinger, Ir., Associate Scientist SEINP A (Peru)t* Efrain Franco, M. S., Economist, Team Leader SEINPA (Peru), from July 1989t Urs Scheidegger, Ph.D., Agronomist, Team Leader SEINPA (Peru), left June 1989 t* Anna Strohmenger, Dot. Agr. Visiting Associate Scientist (Paraguay)t Andre Devaux, Ir., Agronomist, Team Leader PROINP A (Bolivia)t Nicole Bezan\:on, Ir., Anthropologist, PROINP A (Bolivia)t Nelson Estrada, Ph.D., Breeder, PROINP A (Bolivia)t Javier Franco, Ph.D., Nematologist, PROINPA (Bolivia)t Joanne Parker, Ph.D., Pathologist, PROINPA (Bolivia) t A-3 7 Greta Watson, Ph.D., Human Ecologist, PROINP A (Bolivia)t Ricardo Wissar, M.S., Agronomist SEINPA (Peru)t Region II - Central America and Caribbean P.O. Box 711 c/o HCA Santo Domingo, Dominican Republic Oscar Malamud, Ph.D., Regional Representative Region III - East and Southern Africa P.O. Box25171 Nairobi, Kenya Sylvester Nganga, Ph.D., Regional Rep- resentative Patricio Callejas, M. S., Agronomist (Ethiopia)t George Hunt, Agronomist, Training Of- ficer (Kenya) Jeroen Kloos. Ir., Coordinator, PRAPAC (Rwanda)t* Marco Soto Ph.D., Coordinator PRAPAC (Rwanda), from Sept.1989t Jose Luis Rueda, M. S., Agronomist (Burundi)t Lyle Sikka, MSC, Seed Specialist (Uganda), from June 1989t Caroline Turner, M.S., Agronomist (Burundi) t * Region IV - North Africa, Near and Middle East 11 Rue des Orangers 2080 Ariana, Tunis, Tunisia Roger Cortbaoui, Ph.D., Regional Rep- resentative Ramzy E l-Bedewy, Ph.D., Scientific As- sociate (Egypt) Olivier Roux, Ing., Associate Scientist (Tunisia)t A -38 Region V - West and Central Africa c/o IRA Bambui P.80Mankon Bamenda, Cameroon Carlos Martin, Ph.D., Regional Representative Thomas Gass, Eng., Associate Scientistt Region VI - South Asia International Potato Center Indian Agricultural Research Institute Campus, New Delhi, 110012, India Mahesh Upadhya, Ph.D., Regional Representative M. Kadian, Ph.D., Agronomist M.S. Jaikath, Ph.D., Socio Economist K.C. Thakur, Ph.D., Breeder V.S. Khatana, Ph.D., Socio Economist Region VII - Southest Asia c/olRRI P.O. Box933 Manila, Philippines Peter Vander Zaag, Ph.D., Regional Representative Ponciano Batugal, Ph.D., Coordinator- SAPRAD Greta Watson, Ph.D., Visiting Scientist (Indonesia), until May 1989t Region VIII - China Chinese Academy of Agricultural Sciences, Bai Shi Qiao Rd. No. 30 West Suburb of Beijing People's R epublic of China Song Bo Fu, Ph.D., Regional Representative ADMINISTRATION Office of the Director General R osa Rodriguez, Head of Visitor's Office Haydee Zelaya, International Personnel Officer Mary Ellen Mulholland, Consultant Internal Auditor Carlos Nino Neira, C.P.C., Internal Auditor Office of the Executive Officer Cesar Vittorelli, Agr. Eng., Assistant Executive Officer Maritza Benavides, Administrative Assistant Logistics Supervision Llicas Reano, C.P.C., Supervisor Jorge Luque, M.B.A., Warehouse Of- ficer Jose Pizarro, Importations Officer Arturo Alvarez, Local Purchasing Of- ficer Manuel Scollo, B.A., R.R. I.I., General Serv. Officer Personnel & Labor Relations Supervision Guillermo Machado, Lie., Supervisor Ana Dumett, B.S. Soc. Assist., Social Worker German Rossani, M.D., Medical Officer Ada Sessarego, Personnel Assistant Foreign Affairs Liaison Office Marcela -Checa, Liaison Officer 'Iransportation Supervision Carlos Bohl, Supervisor Jacques Vandernotte, Chief Pilot Djordje Velickovich, Pilot Percy Zuzunaga, Co-Pilot Equipment and Maintenance Supervision Gustavo Echecopar, Ing., Supervisor 'Iravel Office Ana Marfa Secada, Travel and Telex Executive Assistant Auxiliary Services Supervision Nancy Oshiro, Supervisor Controller's Office Oscar Gil, C.P.A., Assistant Controller 'Ireasury Unit Sonnia Orellana, Cashier Budget Unit Guillermo Romero, Chief Accountant ACCOUNTING UNIT Miguel Saavedra, Chief Accountant Staff Office of the Controller Edgardo de las Rios, C.P.A., Accountant Blanca Joo, C.P.A., Accountant Eliana Bardales, C.P .A., Accountant SCIENTIFIC ASSOCIATES Adolfo Boy, Ph.D., Sweet Potato Agronomist (Argentina) Manuel Canto, Ph.D., Nematologist (Peru) R6mulo de! Carpio, Ing. Agr., Taxonomist (Peru) Pedro Le6n Gomez, Ph.D., Breeder (Colombia) Ulises Moreno, Ph.D., Physiologist (Peru) Carlos Ochoa, M.S., Taxonomist (Peru) Francisco Vilaro, Ph.D., Sweet Potato Breeder (Uruguay) Sven Villagarcfa, Ph.D., Soil Scientist (Peru) A-39 SCIENTIFIC AND OTHER ASSISTANTS (By Department or Region) Raul Anguiz, M.S., Breeding & Genetics Walter Amor6s, M.S., Breeding & Genetics Miguel Ato, Ing. Ind. Alim., Breeding & Genetics Luis Calua, M.S. Breeding & Genetics Luis.Diaz, M.S., Breeding & Genetics Jorge Espinoza, M.S., Breeding & Genetics Rosario Galvez, M.S., Breeding & Genetics Manuel Gastelo, M.S., Breeding & Genetics Luis Manrique, Ing. Agr., Breeding & Genetics Elisa Mihovilovich, Bio., Breeding & Genetics Daniel Reynoso, M.S., Breeding & Genetics Felix Serquen, M.S., Breeding & Genetics Jorge Tenorio, B.S., Breeding & Genetics Roger Vallejo, M.S., Breeding & Genetics Cesar Aguilar, Ing. Agr., Genetic Resources Jesus Amaya, Tech. Dip!., Genetic Resources Humberto Asmat, Biol., Genetic Resources Anibal Baltazar, Ing. Agr., Genetic Resources Walberto Eslava, Ing. Agr., Genetic Resources Rossana Freyre Sala, B.S., Genetic Resources A-40 Marfa del Rosario Herrera, Biol., Genetic Resources Matilde de Jara Vidal6n, Biol., Genetic Resources Christa Merzdof, M.S., Biol., Genetic Resources Gisella Orjeda, B.S., Genetic Resources Armando Quispe, Ing. Agr., Genetic Resources Alberto Salas, Ing. Agr., Genetic Resources Victor Zambrano, Biol., Genetic Resources Jesus Alcazar, M.S., Nematology & En- tomology Ver6nica Caiiedo, Biol., Nematology & Entomology Oder Fabian, Ing. Agr., Nematology & Entomology Arelis Carmen Garzon Biol ' ., Nematology & Entomology Lily Gavilano, Biol., Nematology & Entomology Alberto Gonzales, M.S., Nematology & Entomology Erwin Guevara, Ing. Agr., Nematology & Entomology Gabriela Manrique, Ing. Ind., Nematology & Entomology Angela Matos, Ing. Agr., Nematology & Entomology Marfa Palacios, Biol., Nematology & Entomology Marina Zegarra, Biol., Nematology & Entomology Pedro Aley, M.S., Pathology Ida Bartolini, M.S., Pathology Ciro Barrera, M.S., Pathology t Miguel Cervantes, Biol., Pathology Carlos Chuquillanqui, B.S., Pathology Christian Delgado, M.S., Pathology Violeta Flores, Biol., Pathology Segundo Fuente:;, Biol., Pathology Wilman Galindez, Ing. Agr., Pathology Liliam G. Lindo, Ing. Agr., Pathology Charlotte Lizarraga, B.S. Pathology Josefina Nakashima, M.S., Pathology Ursula Nydegger, Tech. Dip., Pathology Ricardo Orrego, Ing. Agr., Pathology Hans Pinedo, Ing. Agr., Pathology Hebert Torres, M.S., Pathology Ernesto Velit, Biol., Pathology Jose Luis Zapata, Ing. Agr., Pathology Donald Berrios, Ing. Agr., Physiology Fausto Buitron, Ing. Agr., Physiology Rolando Cabello, Ing. Agr., Physiology Nelson Espinoza, Biol., Physiology Rosario Falc6n, B.S., Physiology Nelly Fong. M.S., Physiology Rolando Lizarraga, B.S. Physiology Norma de Mazza, Q.F., Physiology Ana Panta, Biol., Physiologyt Jorge Roca, B.S., Physiology Roxana Salinas, Ing. Agr., Physiology Carmen Sigueiias, Biol., Physiologyt Daniela Silva, Biol., Physiology Pilar Tovar, Biol., Physiology Adolfo Achata, Economist, Social Science* Marisela Benavides, Sociol., Social Science Hugo Fano, Economist, Social Science Cecilia Gallegos, Economist, Social Science Victor Suarez, B.S., Statiscian, Social Science Fiorella S. Cabrejos, M.S.T., User Services Manager, Information Unit Martha Crosby, B.A., Librarian, Information Unit Cecilia Ferreyra, Circulation & Reference, Information Unit Griselda Lay, B.A., Information Assistant, Information Unit Jorge Vallejo, Ing. Agr., Classification Assistant, Information Unit Ivan Bendezu, Ing. Agr., Database Assistant, Information Unit Myriam Diaz, Proofreader, Informa- tion Unit Fabiola Castilla, B.A., Information Unit* Ana Marfa Ponce, M.S., Electronic Eng. System and Database Manager, Computer Unit Alberto Velez, E lectronic Eng., System Manager, Computer Unit Jorge Apaza, Ing. Econ., Computer Unit Pia Marfa Oliden, Computer Assistant, Computer Unit Beatriz E ldredge, B.S., Biometrician, Statistics Unit Jesus Chang, M.S., Audiovisual Specialist, Communication U nit Emma Martinez, Lie., Production Processes, Communication Unit Jaime Machuca, Ing. Agr., Communica- tion Assistant, Communication Unit Anselmo Morales, Artist, Communica- tion Unit Felix Munoz, M.S . , Communication Assistant, Communication Unit Godofredo Lagos, Print Shop, Communication Unit Marfa del Carmen Prieto, Text Processing, Communication Unit Rufino Failoo, Photomechanics, Com- munication U nit Cesar Sepulveda, Photocopy, Com- munication Unit Carlos Alvarez, M.S., Training* A-41 Nelson Espinoza, Biol., M.S., Training (from August 1989) Jorge Palacios, Dep., Training Lauro G6mez, Tech., Research Support Nelson Melendez, Tech. Dep., Re- search Support Luis Zapata, Ing. Agr. (Reg. I) Jorge Queiroz, Ing. Agr. (Reg. II) Stan Kasule, B.S. (Reg. III) John Kimani, B.S. (Reg. III) M. Shahata, B.S. (Reg. IV) (Egypt) M. Sharkani, B.S. (Reg. IV) (Egypt) S. K. Menra, M.S., Postharvest Assis- tant (Reg. VI) A. Demagante, M.S. (Reg. VII) V. Escobar, M.S. (Reg. VII) B. Fernandez, M .S. (Reg. VII) C. Montierro, M .S. (Reg. VII) B. Susana, B.S. (Reg. VII) Jorge Bautista, B.S., Controller's Office Jose Belli, C.P.A., Controller's Office Luz Correa, C.P.A., Controller's Office Vilma Escudero, B.S., Controller's Office A-42 Alfredo Gonzalez, C.P.A., Controller's Office Alberto Monteblanco, C.P.A., Control- ler's Office *Left during the year. tThese positions are separately funded as Spe- cial Projects by the following donor agencies: Australian Development Assistance Agency Belgium, General Administration for Coopera- tion and Development (AGCD) Canada, International Development Research Centre (IDRC) Food and Agriculture Organization of the United Nations (FAO) Italy, Ministry of Foreign Affairs Japan, International Board for Plant Genetic Resource Japan, Tropical Agriculture Research Center Netherlands, Ministry of Foreign Affairs Rockefeller Foundation Swiss Development Cooperation and Humanitarian Agency United Kingdom, Overseas Development Ad- ministration (ODA) United States, Agency for International Development (USAID) United States, Pepsico Food International United States, McDonald's Corporation World Bank/INIPA Financial Statements Moreno Patino Mo