(c:llO J.1::10d31::1 1YnNNY Z66ldIJ On the Cover Tomasa Quispe is a farmer and self- educaled plant breeder who uses true potato seed (TPS) for potato propagation in the tiny community of C lones. In the province o f Cusco, Peru. She originally learned to produce TPS from an elderly peasant visiting from a more remote community In the highlands. Today Quispe is one o f a handful o f farmers in the Andean agroecosystem who use the TPS technique and recognize the value of the high-quality planting material it produces. Quispe hos several types of potatoes In her germ plasm collection. Having grown seed tubers from TPS over many seasons, she shares some of her potato selections with fam ily and community members who do not know how to produce TPS themselves. In using TPS. Quispe is carrying on a centuries-old Andean tradition of protecting the genetic diversity of the potato. one of the International Potato Center's mandate crops and a fundamental source of sustenance in this complex agroecosystem. Photograph by Yolanda Kodelja. during an interview In 1991 by the International Potato Center's Gisella Orjeda for the IBPGR publication Geneflow. CIP is grateful to Minka and Jorge Leon for granting permission to use their drawings of the Andean crops which appear on our cover. These drawings originally appeared in Lost Crops of the Incas. National Ac ademy Press. Washington D.C .• 1989. Cover design: Cecilia Lafosse ·. I International Potato Center Annual Report 1992 International Potato Center Apartado 5969, Lima, Peru 1992 The International Potato Center (CIP) Is a not-for-profit, autonomous scientific institution established in 1971 by agreement with the government of Peru. The Center develops and disseminates knowledge to facilitate us~ of the potato and sweetpotato as basic foods in the developing world. CIP is one of 16 international research and training centers supported 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 International Bank for Reconstruction and Development (World Bank), and comprises more than 45 countries, international and regional organizations, and private foundations. In 1991. through the CGIAR, CIP received funding from the following donors: the Australian Development Assistance Bureau; the Canadian International Development Agency; the CGIAR Secretariat Stabilization Fund; the Chemical and Mining Society of Chile; the Danish International Development Agency; the European Economic Community: the German Agency for Technical Cooperation; the Inter-American Development Bank: the International Development Research Centre, Canada; the Japan Economic Cooperation Bureau; the Kellogg Foundation; the OPEC (Organization of Petroleum Exporting Countries) Fund for International Development; the Rockefeller Foundation; the Scottish Crop Research Institute; the Swedish Agency for Research Cooperation; the Swiss Development Cooperation and Humanitarian Aid; the UNDP; the Overseas Development Administration, United Kingdom; the United States Agency for International Development; the World Bank; and the governments of Austria, Belgium, Brazil, Finland, France, Germany, India, Italy, Korea, Mexico, the Netherlands, Norway, the People's Republic of China, the Philippines, and Spain. The Annual Report C/P 1992 is published in English and Spanish by the international Potato Center; It covers the period from January l, 1991toDecember31,1991. Mention of specific products by trade names does not Imply endorsement of or discrimination against such products by CIP. Citation: international Potato Center, 1992. Annual Report CIP 1992. Lima, Peru. 254 p. Printed by the international Potato Center Apartado 5969, Lima, Peru, August 1992. Copies printed: 3,800. Managing editor Christine Graves Editors Melissa Anderson Princess Ferguson · Process support Ximena Ganoza Emma Martinez Hernan Rincon Photography Jesus Chang Maglorio Espinoza Raymundo Medina Abel Mondragon Text processing/layout Pilar Bernui Fernando Jurado Alda Nagata Marla del Carmen Prieto Rosario Reyes Marco Sheen Ivonne Valdizan Art Cecilia Lafosse Victor Madrid Anselmo Morales Christy Zevallos Photomechanlcs Rufino Failoo Printing Victor Ayme Ram6n Barrientos Pedro Chavez Godofredo Lagos Hector Rojas Reiser Ruiz 1 1 Foreword Board of Trustees Approaching Sustainability CIP's Decentralized, Collaborative Research Structure Global Contact Points The CGIAR: A Global Agricultural Research System CIP in the News: Debut for the Hairy Potato A Research Overview The Research Programs 1. Production Systems 2. Germplasm Management and Enhancement 3. Disease Management 4. Insect and Nematode Management 5. Propagation and Crop Management 6. Postharvest Management, Marketing Training Information CIP Publications Research Projects and Contracts CIP Staff Financial Statement Abbreviations and Acronyms Contents ii iv vi x xvi xviii xx xxv 1 27 51 81 103 125 151 157 A-1 A-23 A-39 A-47 A-56 Foreword I n our annual report of 1972, Dr. Richard L. Sawyer, CIP'sfounder and first Director General, spoke of establishing a center that would bring the potato to a hungry world. Dr. Sawyer retired in May 1991 following 20 years of distinguished service. It was my privilege to succeed him and to join a center with an excellent scientific record, an outstanding research staff, and a unique client orientation. During these past 20 years, international centers have benefitted greatly from the development ---+-----I 2,000 t-----+----f 1,000 t------t--7:- o ...... _._ ........ ~------------~'"""'~~~~"""- LA MOLINA - Arid HUANCA YO - Highlands QUITO - Highlands CIP Headquarters Experiment Stations x SAN RAMON - Subtropical Lowlands YURIMAGUAS - Humid Tropics • ' " " • .. •· The Research Programs The 1990s CIP strategy also includes the focusing of research, and the strengthening of its integration. The previous ten research Thrusts have been concentrated in six Programs to ensure greater cohesiveness. Breeding and social science activities have been distributed across the Programs, and training and information functions have been included as project components. PREVIOUS THRUSTS CURRENT PROGRAMS 1. Production Systems 2. Germplasm Management & Enhancement 3. Disease Management 4. Insect & Nematode Management 5. Propagation, Crop Management 6. Posthatvest Management, Marketing Thrust Restructuring and Redistribution of Activities The shaded areas indicate the distribution of previous Thrust activities within the current Programs. xi New CIP Regions C lose to 30 internationally recruited scientists work at CIP locations throughout the world. CIP's decentralized, collaborative operational structure helps ensure the relevance of research in its client countries worldwide. The global research program allows CIP and national program scientists to work together to develop and evaluate technologies under a range of local conditions. CIP's research approach takes into account the farmer as well as the consumer and the agribusiness community, seeking the user perspective at all levels of the food chain. xii I I I I I PRAG/PA ----, ' \ I \ I \ ! I I I I I I I PROCIPA I / / I I I D Sub-Saharan Africa I I CIP REGIONS * Regional Office Middle East and North Africa • " " As part of its strategy for the 1990s, CIP will capitalize on these strengths by streamli- ning the management of its growing number of regional activities. This includes a reduction in the number of CIP regions from eight to five, corresponding to the major continental areas. This consolidation, along with increased agroeceological analysis in CIP's research, will provide more effective transfer of technology across and within ecoregions. At the same time, it will promote the establishment of multidisciplinary expertise in each major geographical area, the sharing of skills within and among regions, and the more efficient use of local expertise. AND NETWORKS • Country Liaison Office [71 South and West LJAsia r:;i • East and Southeast Asia and the Pacific xiii Networks CIP has helped develop six unique collaborative networks that are fundamental vehicles for implementing cost-efficient research and disseminating its results among the center's clients. In these networks, countries within a geographical area share responsibilities for certain priority research, according to comparative ad- vantage. CIP participates in the networks as an equal partner, providing technical assistance in its areas of expertise as well as administrative guidance. The Networks and Their Members Special Country Projects Parallel to CIP's core collaborative research with national programs in client countries, special country projects are sometimes initiated when a country has a well developed program in one or more of CIP's mandate areas. In these cases, CIP helps the country in question to seek complementary funding for a fixed time period to strengthen national capabilities in priority concerns. These projects, co-directed by CIP and national program staff members, are important mechanisms for the achievement of sustainable results at the national level. CIP's current special country projects in South America include PROINPA in Bolivia, FORTIPAPA in Ecuador, and SEINP A in Peru; there is also one special country project in Africa, in Burundi. xiv J " Agroecologies T o prioritize research and better evaluate the potential of its commodities, CIP has determined the principal agroecologies for potato and sweetpotato in its client countries. This classification is based on climatic and geographical criteria. While the major constraints of CIP's mandate crops cut across ecoregions, agro- ecological analysis is a tool for better research decision-making, bringing environmen- tal considerations to bear on priority setting and resource allocation. Classification Criteria Used to Define CIP's Agroecologies Is the temperature Is the region Are there more lOC (501') or I than 3 cm of above more than less than 1,500 . yes summer rainfall 8 months Yes meters above sea level? in the driest of the year? month? No CIP's Agroecologies The Andean Ecoregion Yes Is the temperature above lOC (50F) all 12 months of the year? No Subtropical Lowlalnds Yes Yes Are there more than two dry months in the year? No [--- -Humid Tropics CIP's has conducted ample research in the Andean highlands, an ecoregion of special interest. Andean farmers have domesticated some 25 species of edible roots and tubers, ranging from the potato-one of CIP's CGIAR-mandated com- modities-to species about which very little is known. Because of the proven need, the Center's comparative advantage, and the outstanding support shown by donors and partners, CIP is investigating opportunities to do more research on this agroecosystem. This will involve preserving and managing the region's threatened natural resources, as well as investigation of the potential of the lesser known Andean tuber and root crops, both here and in other agroecologies. xv Global Contact Points Latin America and the Caribbean Peru C/P Regional Office International Potato Center Apartado 5969 Lima 100, Peru Phone: (51-14) 35-4354 (51-14) 36-6920 Fax: (51-14) 35-1570 Telex: 25672 PE Cable: CIPAPA, Lima . E-mail: 157:CGl801 or CIP 157:CGI043 or CIP-ISD C/P-SEINPAJINIAA Special Project (same address as above) Ecuador CIP-INIAP/FORTIPAPA Special Project Apartado 17-16-129-CEQ Quito, Ecuador Phone: (593-2) 554-721 (593-2) 554-726 Fax: (593-2) 562-286 E-Mail: TODOS@CIP.EC Bolivia CIP-IBTA/PROINPA Special Project Casilla Postal 4285 Cochabamba, Bolivia Phone: (591-42) 42-925 (591-42) 40-929 Fax: (591-42) 45-708 Telex: 6445 PRONAPA BV E-mail: CGI272 xvi Chile CIP-Chile Liaison Office Casilla 16487 Santiago 9, Chile Phone: (56-2) 225-2118 Fax: (56-2) 225-8773 Telex: 242207 INIA CL Colombia CJP-ColombiaLiaison Office c/o ICA (La Selva) Apartado Aereo 128 742 Rionegro, Antioqufa Colombia Phone: (57-4) 537-0161 (57-4) 537-0079 Su -Saharan Africa Kenya CIP Regi01ui/ Office P.O. Box 25171 Nairobi, Kenya Phone: (254-2) 63-2054 (254-2) 63-2151 (254-2) 63-2206 Fax: (254-2) 63-1499 Telex: 22040 ILRAD Cable: CIPAPA, Nairobi E-mail: CGI265 Burundi CIP-ISABU Special Projecr B.P. 75 Bujumbura, Burundi Phone/Fax: (257-22) 4074 (Bujumbura) (257-44) 2103 (GS021) Telex: 5030 BDI through Hotel Source du Nil Telex: (via FAO FOODAG BDI) 5092 Cameroon CJP-C ameroon Liaison Office P.O. Box 279 Bamenda, Cameroon Phone: (237) 36-3285 Fax : (237) 36-3921 Telex: 5892 KN & 842 KN E-mail: C.MARTIN or CGI238 Middle East & North Africa Tunisia CJP Regional Office 11 rue des Orangers 2080 Ariana, Tunis, Tunisia Phone: (216-1) 71-6047 (216-1) 53-9092 Fax: (216-1) 71-8431 Telex: 14965 CIP TN E-Mail: CGI019 Egypt CIP-Egypt Liaison Office P.O. Box 17 Kafr El Zayat, Egypt Phone: (20-40) 58-6720 Telex: 23605 PBTNA UN South & West Asia India CIP Regi01uil Office IARI Campus New Delhi 110012, India Phone: (91-11) 573-1481 (91-11) 574-8055 Telex: 3173140 Fl IN 3173168 EIC IN Cable: CIPAPA, New Delhi E-mail: CGI046 East and Southeast Asia & the Pacific Indonesia CIP Regfonal Office c/oCRIFC Jalan Merdeka 147 Bogor, Indonesia Phone/Fax: (62-251) 31-3687 & 31-7951 Home: (62-251) 32-3801 E-Mail: CGI193 China CIP-China Liaison Office c/o The Chinese Academy of Agricultural Sciences Bai Shi Qiao Rd. No. 30 West Suburbs of Beijing Beijing, People's Republic of China Phone: (86-1) 831-6536 Fax: (86-1) 831-6545 Telex: 222720 CAAS CN or 22233 E-Mail: CGI030 Cable: AGRIACA Philippines CIP-Philippines Liaison Office c/olRRI P.O. Box933 Manila, Philippines Phone: (63-94) 50-015/19 Ext. 248 Fax: (63-2)817-8470 (63-2) 818-2087 Telex: 40890 RICE PM, 40860 P ARRS PM, 63786 RICE PN E-mail: CGI401 or IRRI Network Coordination Offices PRACIPA (same address as PROINPA, Bolivia) PRAPACE B.P.1218 Kigali, Rwanda Phone: (250) 84761 Telex: 22510 TRAKIG Rwanda Cable: (use above address) PRECODEPA c/o Programa Nacional de Papa IDIAP Cerro Punta, Chiriqui Panama Phone: (507) 71-2036 Fax: (507) 71-2084 (PRECODEPA) Telex: 3679 IDIAP PG PROCIPA (same address as CIP) SAPP RAD (same address as CIP-Philippines Liaison Office) UPWARD (same address as CIP-Philippines Liaison Office) xvii The CGIAR: A Global Agricultural Research System xviii CIAT CIMMYT CIP IBPGR I CARDA ICRAF ICRISAT IFPRI IIMI IITA ILCA ILRAD INIBAP IRRI ISNAR WARDA International Center for Tropical Agriculture Cali, Colombia International Maize and Wheat Improvement Center Mexico City, Mexico International Potato Center Lima, Peru International Board for Plant Genetic Resources Rome, Italy International Center for Agricultural Research in Dry Areas Aleppo, Syria International Center for Research inAgroforestry Nairobi, Kenya International Crops Research Institute for the Semi-Arid Tropics Hyderabad, India International Food Policy Research Institute Washington, DC, USA International Irrigation Management Institute Colombo, Sri Lanka International Institute of Tropical Agriculture Ibadan, Nigeria International Livestock Center for Africa Addis Ababa, Ethiopia International Laboratory for Research on Animal Diseases Nairobi, Kenya International Network for the Improvement of Banana and Plantain Montferrier-sur-Lez, France International Rice Research Institute Manila, Philippines International Service for National Agricultural Research The Hague, the Netherlands West Africa Rice Development Association Bouake, Ivory Coast xix xx Beyond the domains of scientiflC research and agriculture, C/P's activities become known to the general public through media coverage. Every year, journalists from many countries visit CIP locations and report on our work. The following article appeared in the USA, on page one of the Los Angeles Times, December 25, 1991. It is reprinted here (in a slightly abridged version) with the publisher's permission. xxi xx ii • .. xxiii • xxiv A Research Overview A social scientist seeks farmers' opinions on a new late-blight-resistant variety, as part of the cultivar selection process in Huanuco, Peru. xxv CIP has become an internationally acknowledged center of excellence through more than 20 years of work to improve the production and utilization of potato and sweetpotato as basic foods in the developing world. This year's programmatic overview concentrates on the recent structural reorganization that has been carried out to enhance the Center's effectiveness. CIP will build on its experience and expertise to catalyze the translation of research results into products and services that will have practical impact in farmers' fields. For administrative and programmatic effectiveness, CIP's ten Thrusts have been regrouped into six Programs and our eight regions consolidated into five, by major continental area. We are also strengthening collaboration with development-oriented institutions, and assisting them in the use of CIP's products. Our present strong collaboration with national programs will be complemented by closer ties to non-governmental organizations (NGO's) and private industries that have comparative advantage in specific aspects of the development process. In formulating our research agenda, we recognize that it is impossible to meet all the needs that may arise in CIP's client countries with relation to the diverse aspects of potato and sweetpotato production and utilization. We are using a simple philosophical framework to help us in making pragmatic choices that will maximize our practical output. The guidelines are focus, integration, balance, and impact. The following are some examples of how CIP's revised framework for the research program is operating. Focus To facilitate the revision of CIP's research agenda, a formal priority setting exercise was conducted last year in collaboration with the International Service for National Agricultural Research (ISNAR). The process involved the evaluation of all research projects based on factors such as the importance of the constraint being studied, the likelihood of research success, and the probability of adoption of the technological product as compared with the research costs involved. The whole of CIP's scientific community participated in the process, and in most cases decisions reflected a consensus. This exercise translated CIP's collective institutional knowledge into quantitative data, which is being used as a valuable tool in resource allocation. Our new project-based budgeting system strengthens the xx vi correlation between priority setting and resource allocation. This system replaces the previous mode of budgeting by Department and/or by Regional Office. With resources allocated on the basis of programmatic priorities, Program Leaders now play the central role. This year's Production Systems Program report includes a simulation study done in collaboration with CABO--DLO in Wageningen. This study has enabled us to sharpen the agroecological characterization of the world's potato growing zones. It will ultimately help us to quantify the potential impact of our work, as well as to improve technology design, thus contributing to the focusing of resources. Integration Tue six new Programs address global concerns as well as specific regional and national needs in a holistic way. Research, training, and information activities at headquarters and in the regions have been integrated within the Programs, facilitating better management both at the technical and the administrative levels. This increased integration will help us maximize the practical effect of our research results. For example, the Insect and Nematode Management Program report shows significant progress in control of potato tuber moth and Andean potato weevil. Non-chemical methods identified for the management of these pests have the potential to reduce the financial and environmental costs of potato production by counteracting dependence on harmful and costly chemicals. Training and information activities will help translate these research results into practical alternatives for farmers. Another aspect of integration that will receive careful attention is the area of inter-Program management. For example, since potato and sweetpotato breeding are important components of several Programs, strategy papers on these subjects are being conceptualized on a cross-Program basis. A strategy paper is also being developed on the propagation dissemination, evaluation, and release of the breeding products emerging from the Programs. Balance Tue balance between short-term and long-term goals is one of our primary concerns. We are committing resources now to strategic work that may not fully pay off in practical terms for many years. Thus, this research investment is balanced by allocating resources for translating existing xx vii knowledge and technology into immediate practical impact. The following examples illustrate how we are approaching this question. The Propagation and Crop Management Program report shows that true potato seed (TPS) technology is already being adopted on a large scale throughout the world, particularly in India, Bangladesh, Indonesia, Egypt, Nicaragua, and Paraguay. Vital elements in this success story include breeding for improved germ plasm, and research on TPS production methods. An additional factor is the development of more efficient dormancy management to provide faster and more uniform seedling emergence and growth. In the short term, emphasis must be placed on widespread use of the existing genetic materials and technology. In the longer term, however, we will emphasize the development of improved progenitors for the production of hybrid TPS. Feedback from farmers in Indonesia, for example, indicates the need to improve earliness, as well as resistance to bacterial wilt. Rapid advances in sweetpotato virus detection are shown in the Disease Management Program report. Much of this success is based on the application of NCM-ELISA procedures to sweetpotato. In the short term, the emphasis is on distribution of NCM-ELISA kits and antisera to our regional personnel and to national program scientists. In the longer term, we will complement this with the development of improved virus resistance. The Postharvest Management and Marketing Program report contains substantial new information on analyses of sweetpotato market opportunities and requirements, processing techniques for human and animal consumption, and germplasm characteristics for specific processed products. Initial emphasis will be on applying the available information to catalyze horizontal transfer of existing techniques, especially for greater use of sweetpotatoes for animal feed. In the longer term, we will concentrate more on the development of new processing technologies, as well as on germplasm improvement. Impact This year's Germplasm Management and Enhancement report shows that we have continued to progress in the identification of valuable genes from the potato and sweetpotato germ plasm collections. We have also advanced significantly in our ability to utilize these genes in our breeding programs. For ex-ample, new diploid potato families were generated by using 2n gametes, producing 2x potatoes with improved agronomic characteristics xx viii and resistance to bacterial wilt, potato tuber moth, potato leafroll virus, potato virus Y, and root-knot nematode. The genetic constitution of these families facilitates more efficient transmission of quantitatively segregating resistance to several of the pests from the diploid to the tetraploid level. This provides us with a valuable tool for accelerating the development of improved resistance in advanced potato materials. The report also shows that we are complementing conventional enhancement approaches with biotechnological techniques. Through genetic engineering at CIP we can now transform potato clones by inserting antibacterial genes, as well as the coat-protein gene against potato leafroll virus. We have also made progress in restriction fragment length polymorphism (RFLP) mapping for potato trichome characteristics, and in the use of polymerase chain reactions to amplify RFLP markers. All of this will facilitate germplasm enhancement. There is little doubt that such advances can ultimately translate into improved potato varieties. As we have mentioned, CIP is fine-tuning its potato breeding strategy to attain maximum impact in farmers' fields. Perhaps an even greater challenge, however, than increasing our impact is that of documenting it. In this and other areas the emphasis will be on illustrative case studies. Better documentation of the value of CIP's products will encourage their expanded use by our clients and beneficiaries and foster the continued support of donors. In Conclusion All of our activities will continue to be based on strong, extensive collaboration with colleagues in our partner countries. Other concerns that will be given special attention are environmental protection, gender and equity issues, the role of biotechnology, and the sustainability of agriculture. More specifically, CIP will augment its activities in the Andes to contribute more broadly to equity, environmental protection, and sustainable agriculture in this fragile agroecosystem. The focus will be on biodiversity of Andean root and tuber crops and the management of natural resources. In this work, coordination with national organizations, other international centers, and NGO's will be especially important. CIP is well poised to move ever more strongly into a focused, integrated, balanced mode to produce practical impact. The result will be improved welfare for the people we serve. The progress achieved during 1991 is documented in the following pages. xxix A farmer evaluating potato clones at flowering in Cochabamba, Bolivia. Of the 20 farmers participating in this PROINPA trial, seven were women. Scientist-farmer collaboration from planning through evaluation encouraged community advancement. Program 1 Production Systems 1991 In Review T he Production Systems program is a consolidation and refocusing of activities reported in previous CIP Annual Reports in the Thrusts on production and distribu- tion of advanced breeding material, warm climate potato and sweetpotato production, cool climate potato and sweetpotato production, and potato and sweetpotato in the food systems of developing countries. An important aspect of the refocusing was the addition of a more transparent and specific agroecological perspective to CIP's research. The principal agroecologies for potato and sweetpotato in CIP's client countries are based on climatic and geographic criteria. Potatoes are important in the Temperate, Highlands, Arid-Mediterranean, and Subtropical Lowlands agroecologies; sweetpotatoes are important in Temperate, High- lands, Subtropical Lowlands, Semiarid Tropics, and Humid Tropics agroecologies. In November 1990, a definitive synthesis of research on potato intercropping was published in Field Crops Research. The potential for potato to follow rice in the swamps in the East African highlands was again confirmed by yields reaching 30 t per hectare in farmers' fields in Burundi. Preliminary results on farmer participation in clonal selection in the Bolivian Andes show that women farmers, men farmers, and scientists shared the same notions of plant health and vigor for most characteristics. Differences in varietal preferences among production zones or between men and women farmers were not marked. Several methods were developed and intensively tested in the Dominican Republic to assess the economic and agronomic importance of the sweetpotato weevil, Cylas formicarius elegantulus. Weevil damage was estimated at US$88 per hectare. Ex- trapolating these results to the greater Caribbean Region, effective weevil control would generate about US$15 million in benefits. A group of 40 highly selected potato clones and progenitors for yield, tuber quality, and resistances were cleaned-up from diseases for use in CIP and national program breeding activities. Of these clones, two are immune to potato virus Y (PVY), two to potato virus X (PYX), 18 to both PVY and PYX, three are resistant to leaf roll and six have high dry matter and low reducing sugar contents and are good for processing as chips and french fries. In the Philippines, 22 clones selected for long storability in diffuse light in the lowland tropics and high yield were evaluated in farmers fields at three sites. Farmers selected several of these clones, and we are multiplying them for further on-farm trials. Program 1 1 In Taiwan, after six years of testing, two PVY immune clones are being multiplied for dissemination to farmers. To date, sweetpotato see.d families comprising a total of about 2,500 individuals from a wide variety of sources and different agroecologies have been evaluated at Yurimaguas in Peru. High yields and general adaptation of members of these seed populations to the lowland humid tropical conditions ofYurimaguas suggest that very specific physiological adaptations to agroecological conditions (such as photoperiod sensitivity) either do not exist in sweetpotato, or may be easily overcome through selection among segregating progenies. A new sweetpotato variety named Alto Urubamba (CIP clone ME12) was released in Peru. Clones NCSU 925 and NCSU 1135-introduced from North Carolina State University-continue to find good acceptance among farmers and consumers in Egypt. In 1990, we began an in-depth interdisciplinary study to assess the impact of pesticides in an intensive, year-round, commercial potato-producing area in northern Ecuador. Preliminary results of modelling the potential for such intensive pesticide use to result in groundwater contamination show that only very low levels of pesticides accumulate at the bottom of the root zone and could possibly be delivered to groundwater. High organic matter content of the soil, which increases its sorption capacity, and the short persistence of the chemicals appear to be responsible for these findings. Occupational safety in the application of pesticides appears to be a more important environmental problem than groundwater leaching. In November, CIP conducted a priority setting exercise of its restructured research portfolio. The presumed importance of controlling late blight and finding low-cost propagation methods for clonal planting materials in potatoes was confirmed. The importance of the Subtropical Lowlands for both potato and sweetpotato was also highlighted. Research, training, and information activities in Production Systems are organized around the following areas of emphasis: • characterization of potato production constraints and opportunities • characterization of sweetpotato production constraints and opportunities • adaptation and integration of potato production technologies • adaptation and integration of sweetpotato production technologies • evaluation of the impact and sustainability of potato production technologies 2 Program 1 Characterization of Potato Production Constraints and Opportunities Specific objectives of this project arc to: • establish informational benchmarks for impact evaluation, • quantify the potential for potato cxpan- sio n in developing countries by agroccology, • measure yield gaps in representative benchmark locations, as well as the scope for economically bridging such gaps, • assess the scope for cost savings and the effects of input policies in different pro- duction systems, and • develop and update varietal trait and technology profiles consistent with pro- ducer circumstances. • The major output is better quantitative and qualitative information to guide de- cision-making on technology design and resource allocation within and across potato production systems in developing-country agriculture. Agroecological Characterization for Potato Production The Centre for Agrobiological Research (CABO-DLO) at Wagcningen in the Netherlands conducted a simulation study for CIP on the crop potential of potato under irrigated and rain-fed conditions in different agroccological zones. Agroecological characterization was ex- plored with a crop model with local data on the production environment. The weather data were obtained from the Mi.iller database, which contains a global set of long-term monthly average values of weather variables for 978 J>rogram I meteorological stations. Information on soils came from a world soil data file from NASA. This data base consists of 15,413 records with information extracted from the FAQ/UNESCO soil map. Identification of potential growing sea- sons, assuming that water was non- limiting, was the first step in the characterization process. The length of potential growing season was determined from daily temperature data. Temperature constraints for growing the crop were as- sum cd to be: daily minimum temperature above s·c, daily maximum temperature below 28°C, a minimum temperature re- quirement of 1,250°Cd (Cd = duration of season expressed as temperature sum), and a maximum temperature requirement of 2,000°Cd. The minimum crop require- ment of 1,250°Cd matches the require- ment of a short growing season crop for production of seed-potatoes in temperate regions or that of an early maturing crop in tropical regions. Based on these assumptions, it was possible to find a growing season for potatoes in the many temperate and sub- tropical regions of the world. In particular, there is productivity potential in terms of temperature in the northern subtropical zone stretching from Mexico to North Africa and on into the lndo-Gangetic Plain of South Asia and South China. In con- trast, temperature constraints to potato production are binding in much of the lowland tropics. The simulation of potential yield (maxi- mum tuber dry matter production that can be achieved given planting and harvesting dates) from a simple crop growth model 3 gave a sharper agroecological characteri- zation. For a specific variety, potential yields are dependent only on Solar radia- tion and temperature. All other conditions such as water and nutrient supply and pest and disease control are assumed to be op- timal. Assuming temperature limits of 5 · and 28°C and a light use efficiency of 2.9 g Mf 1, potential yields (in tons of dry matter) for climatic by soils zones are shown in Map 1-1 for the highest yielding season. The highest potential yields are found in the temperate zones at latitudes between 40° and 50° latitude in the north- ern as well as in the southern hemisphere. At higher latitudes, yields are lower because low spring and autumn tempera- tures reduce the length of the growing season. Closer to the equator, high sum- mer temperatures reduce the growing season and lead to low harvest indices. Areas with high potential yields are the tropical highlands with suitable tempera- tures year-round. On an annual basis, po- tential yields in a Mediterranean climate are higher because at least two (spring and autumn) crops can be grown. This modelling effort could be ex- tended in several directions to improve technology design and to quantify poten- tial impact. Such extensions range from a global assessment of enhanced frost, heat, or drought tolerance to a scenario analysis of the effects of climatic change. The cal- culation of potential yields not only out- lines the boundaries of technically feasible potato cultivation but also provides the basis for estimating and sub- sequently explaining productivity gaps in well-defined potato growing regions. }>otato Intercropping Systems Intercropping potato with other crop species is a prevalent practice in the 4 tropics, but it is largely based upon non- documented farmer experience. Improve- ment of indigenous systems and the creation of systems appropriate to future potato-production zones in hot areas re- quire a clear understanding of their physi- cal and biological interactions. In November 1990, a definitive syn- thesis of research on potato intercropping was published in Field Crops Research (Vol. 25 (1,2), 1990). The papers in that issue were the result of a symposium on intercropping with potatoes in the tropics, held in Kunming, China, and cosponsored by the Asian Potato Association, CIP, FAO, the Chinese Academy of Agricul- tural Sciences, and other institutions in China. The authors provided basic infor- mation on the present status of intercrop- ping with potato, giving specific examples from contrasting agroecological zones. Their results help to unravel, in part, the complexities of intercropping systems in- volving the potato, and assist in progress towards increased food production from land already under cultivation. Four intercropping systems suitable for the potato that minimize the influence of interspecific competition, while maximiz- ing the use of wasted resources by one or other component crops, were identified: I relay-cropping potato into an existing annual shade crop; II intercropping with perennials; III intercropping with annuals; and IV relay-cropping an annual shade crop into an existing potato crop. The specific cooling effect of shaded soil on crop emergence under conditions of high soil temperature in system I, and on the detrimental effect of high tempera- ture late in the potato cycle in system IV, were noted. In addition, utilization of available solar energy is enhanced. Inter- cropping with perennials (system II) and Program 1 .. .. . . . ~ ~ / Ii i - - - - < 50 00 k g dm > 50 00 k g dm > 85 00 k g dm > 12 00 0 kg d m > 15 50 0 kg d m > 19 00 0 kg d m ° ' M ap 1 -1 . A gr oe co lo gi ca l z o n in g fo r p ot en tia l y ie ld s (dr y m a tte r i s a bo ut 2 0% ) o f S ola nu m sp p. fo r c lim at e- by -s oi ls z o n e s ba se d o n h ig he st yi el di ng s e a so n . annuals (system III) represent systems with possibilities for manipulation of crop cultural practices in the dominant crop. These range from limited·(e.g., in planta- tion tree crops) to almost limitless pos- sibilities (e.g., in pruned alley crops) with a concomitant range of management deci- sions. A potato crop in the tropics may with- stand reductions in the receipt of irradi- ance of up to 25 % for extended periods with negligible yield decline. Selection of clones adapted to this level of reduction may be made under sole-crop conditions. With further reduction in irradiance, dif- ferences in genotypic ability to tolerate shade are expressed. Therefore, it was suggested that, to increase total produc- tivity beyond that attributable to temporal complementarity and efficient use of photosynthetically active radiation, incor- poration of shade tolerance will be neces- sary. Farmer Preferences for Clonal '!raits in the Bolivian Andes Farmers in the BoUvian Altiplano (gener- ally 3,000 m) tend to own less than 5 ha of land (cultivated on a rotational basis), have an integrated crop-animal ecosys- tem, seasonal migration, low incomes, and little or no access to inputs or credit. Quechua-and Aymara-speaking com- munities in most of the highlands organize the use of grazing, farm and irrigated lands, social policy, and political partici- pation through group meetings and con- sensus. Men predominate at these meetings. Under such conditions, special efforts have to be made to incorporate fanners' preferences, particularly those of women, in technology design. This study focused on farmer participation in clonal selection 6 of potatoes, primarily with resistance to late blight. Farmers evaluated this ad- vanced clonal material in a locational (field) trial carried out by the Breeding and Phytopathology Departments of PROINPA in 1990-1991. Participating fanners came from two potato-producing zones in Cochabamba province with high incidence of late blight. The participants (13 men and 7 women) were selected by consensus dur- ing meetings among members of seven communities. Scientists requested that at least one participant from each communi- ty be a woman fanner. The communities were also requested to select fanners known for their agricultural ability in po- tato production, their demonstrated will- ingness to share their knowledge with other farmers, and the ability to participate for three days in the field investigation. Farmers evaluated tubers from differ- ent clones before and during flowering as well as at harvest. Prior to and in full flowering, thick stems, lack of leaf dis- ease, plant height, growth habit, color of leaves (darker preferred) color of existing flowers (associated with known varieties), high stem count, and leaf width were the most cited characteristics in descending order. Fanners' and scientists' notions of plant health and vigor converged for most characteristics. At harvest, the 20 farmers selected a total of 39 clones of the 138 originally planted, while scientists' final selection totaled 43. Of these, 23 clones were the same for both groups (X mean yield (X) = 937 g/plant), including the 10 clones most frequently chosen by farmers at harvest (x = 993 g/plant). Overlapping selections were generally higher yielding and free of evident disease or insect problems. Where farmer and scientist selections diverged, Program 1 farmer selection (x = 706 g/plant) most was tallied with that at harvest. Prelimi- often relied on skin color, form, size and nary results are presented in Table 1-1. Of • number of eyes in relation to market char- the 10 clones, perhaps 5 have good poten- acteristics, while scientist selections (x = tial for multiplication in farmers fields. 664 g/plant) were more dependent on re- Clones 382146.15 and 386105.8 require sistance to Phytophthora infestans or too much cooking time (56 and 57 min), other desirable morphological qualities particularly in the fuel-scarce highlands. for future breeding. Clone 381403.30 has an unacceptably bit- ter flavor. Ratona's yield is too low. The Postharvest evaluations of culinary two clones selected most for their plant quality, cooking time, dry matter and other characteristics, 79-918- lx282-ll-1 and sugar content were carried out on the 10 84-75-16 are watery, good flavored with clones most often selected by farmers at moderate cooking time. These two show harvest. Frequency of farmer choice of most promise for initial on-farm, these clones before and during flowering farmer-led trials. Table 1-1. Characteristics of the ten clones most frequently selected by farmers at harvest in a clonal trial for resistance to Phytophthora infestans, Cochabamba, Bolivia, 1990-91. Kg/plant Cooking time Dry Clone No. (No. plants Culinary Color (3500 m) matter of 10) characteristics Skin Flesh minutes % 375333.1 1.06 (7) Watery Purple White 39 19.2 Flavorless Regular 79-918-1x 0.97 (10) Watery White White 39 20.2 282-11-1 Good 381382.34 0.78 (8) Floury White White 36 18.1 Good flavor Very good 382146.15 0.99 (9) Watery White White 56 20.2 Good 84-75-16 1.06 (10) Watery Purple/ Cream 43 23.4 Good white 386105.8 1.28 (8) Watery White Cream 57 19.2 Regular 676008 1.10 (9) Excellent Rose Yellow/ 25 25.4 Floury purple The best of 10 371379.121 0.83 (9) Floury Rose Cream 44 22.2 Very good Ratona 0.25 (10) Floury Purple Cream 35 20.2 Very good 381403.30 0.87 (8) Watery White White 35 19.2 Flavorless Bitter Progi;am 1 7 The attendance rate of participants dur- ing the investigation was over 95%. There appeared to be no significant difference between production zones, or men and women in terms of characterization of plants or potato tubers, either in relation to characteristics cited or to overall number of observations. However, women's atten- dance at meetings to discuss research pro- cedures and results was much higher than at initial meetings, indicating that the dif- fusion of information to women and their interest in participation increased. Hun- dreds of farmers attended a slide presenta- tion about this study. In 1992, research will continue with farmers in the two zones being provided with 10 or more tubers of the promising or moderately acceptable clones, as well as a few new frost-resistant clones. Concurrent trials are being carried out by the Breeding Department of PROINPA in conjunction with experimental stations and other in- stitutions in various areas of Bolivia. Characterization of Sweetpotato Production Constraints and Opportunities The primary objective of this project is to review, generate, and synthesize informa- tion on important sweetpotato production systems in Asia, Africa, and Latin America. Such information aids in decid- ing in which disciplines to invest, on which problems to work, to which regions to allOC:·:.:·:·:·:·:·:·:·:·:·:·:-:-:·:·:·:::·:·:::::::::·:·:::::;:;:;:::;:;:;:::::::::::::·:·:·: ..... ·.•••• Sorting llillllilllllllf======== Washing •'''''1''''''1'''' 1''''''1''''''1'''''''1''''''1'''''r''''='''''''=''· = .... = ... = .. ·=· ......= ...... =:.:.:::=-:-:.:.=·.-.-.=·.,.,.,=.,.,.,=:·:·:·:=··-·.·=· . ·=· ===""""= Transport •••••••••••••••••••••Ill Harvesting •••••••••••••••••••••Ill Weeding •••••••••••••••••••••Ill Planting .mz:illlll''''''I·,, ••••••••••••••••••• Land preparation •••••••••••BlllllllllllB••lllllllllll••••llll 0 10 20 30 40 50 60 70 80 90 1 00 Figure 1-1. Gender division of labor(%) for sweetpotato activities in two sites in the Philippines. financed in Burundi by the East and Southern African Root Crops Regional Network (ESARRN). CIP has been assist- ing with the design and analysis of the sweetpotato questionnaire. A similar sur- vey in Kenya, based on group interviews in 30 villages, was carried out in collab- oration with COSCA. It will complement data collected by CIP and KARI in 1989 (see CIP Annual Report 1990). Field work was completed in 1991. 12 Economic Loss Assessment of Sweetpotato Weevil Globally, the sweetpotato weevil (SPW) is the most important pest of the crop. Weevil infestation results in quality and weight losses to damaged roots. In spite of the widely recognized importance of the pest, reliable estimates of the size of quality and weight losses are not readily available. Program 1 .. • • The Dominican Republic. From March through December 1991, several methods were developed and intensively tested to assess the economic and agronomic im- portance of the SPW, Cylas formicarius elegantulus. Sweetpotato farmers in two major producing regions were visited twice, immediately before harvest and several weeks later after the production was sold. The first visit permitted damage measurement in a randomly selected sample of plots; and information was elicited on the production system and its cost. During the return visit, information on sales was gathered. Two innovative features of this eco- nomic loss assessment were the detailed treatment of partial damage and the ex- plicit consideration of the weight loss in damaged roots. The results showed that assessment of the size of economic loss was sensitive to information on these two aspects. In the Dominican Republic, sweet- potato is marketed as Grade A export, Grade A domestic, Grade B domestic, and animal feed. This market classification is affected by weevil damage, as well as by damage from other pests and disease. The size, shape, and appearance of the root also affect quality. As a result of information gathered dur- ing the pretests, 21 different categories were defined to capture different levels of partial and total economic loss (Table 1-2). It was also assumed that roots with severe weevil damage could not be sold as animal feed, due to their bitterness. The need to adjust the estimates for weight loss reflecting larva tunneling Table 1-2. Economic categories used to assess sweetpotato weevil damage in the Dominican Republic . Grade A export marketable Grade A export sold as Grade A domestic, due to superficial SWP damage Grade A export sold as Grade A domestic, due to superficial damage from other pests or disease Grade A export sold as Grade B, due to mild to moderate SPW damage Grade A export sold as Grade B, due to mild to moderate damage from other pests or disease Grade A export sold as Grade B, due to severe damage from other pests or disease Grade A export not marketable due to severe to total SPW damage Grade A export not marketable due to severe or total damage from other pests or disease Grade A domestic marketable Grade A domestic sold as Grade B, due to mild to moderate SPW damage Grade A domestic sold as Grade B, due to mild to moderate damage from other pests or disease Grade A domestic sold as animal feed, due to severe damage from other pests or disease Grade A domestic not marketable due to severe or total SPW damage Grade A domestic not marketable due to severe or total damage form other pests or disease Grade B marketable Grade B as animal feed, due to severe damage from other pests or disease Grade B not marketable due to severe or total SPW damage Grade B not marketable due to severe or total damage from other pests or disease Animal feed marketable Animal feed not marketable due to severe or total SPW damage Animal feed not marketable due to severe or total damage from other pests or disease Program 1 13 through damaged roots also became ap- parent during data collection. Damaged roots weighed significantly less than un- damaged roots of the same Size and shape. Estimates from the San Juan Valley, the second largest sweetpotato producing region in the Dominican Republic, are ,suggestive of the size of economic losses and of the importance of including infor- mation on partial quality losses and on weight reduction of damaged roots. Incor- porating both corrections gave an estimate of weevil damage of US$88 per hectare. Production destined for animal feed sold at only 14% of the Grade A-export price. Production Grade B-domestic market fetched 27% and production Grade A- domestic market was 82% of the Grade A-export price. The use of a more aggregate quality classification (marketable, not marketable due to weevil damage, and not marketable due to other damage) led to overestimates approaching 65%. In contrast, failure to include weight loss reductions from dam- aged roots resulted in a 29% underes- timate of weevil damage. Economic losses were highest in months when prices were higher and growing conditions drier. Economic los- ses were highly and positively correlated with yields. On average, 39% of produc- tion was damaged by the weevil. This level of damage translated into a 40% decrease in producers' income. Extrapolating these average losses suf- fered by the 31 farmers in the sample from the San Juan Valley to the country as a whole, the weevil annually costs the Dominican Republic about US$600,oo0. The weevil is widespread in the Caribbean and Central America. If the results from this case study are representative for the region, the total economic benefits from effective weevil control would amount to about US$15 million. Adaptation and Integration of Potato Production Technologies Four agroecologies (Subtropical Low- lands, Temperate, Highlands, and Arid- Mediterranean) account for 98% of potato production in the developing world. By breeding for multiple traits in its advanced populations, CIP provides a broad range of durable protection against biotic and abiotic stresses that often interact to re- duce the impact of single-factor resistance and desirable agronomic traits. To date, potato breeding populations combine: re- sistance to potato leafroll virus (PLR V), PVX, and PVY with heat tolerance, for the warm Subtropical Lowlands and the Arid- Mediterranean region; resistance to late 14 blight, PVX, and PVY, for use across all potato growing agroecologies; resistance to late blight and cyst nematode, for the Temperate and Highland areas; and resist- ance to Alternaria, PVX, and PVY with heat tolerance, for the Subtropical Low- lands. The integration of these multiple resist- ances with IPM and agronomic practices will also receive attention. Over the me- dium term, attention will shift from potato intercropping to novel multiple and relay- cropping systems, which often stretch the limits of crop adaptation. Program 1 • I· • The overall objectives are to generate and monitor advanced potato materials adapted to specific agroecologies, and to integrate component research into im- proved cropping systems for verification in well-defined production environments. Advanced Potato Materials Adapted to Specific AgroecoJogies Peru. During 1991, two potato popula- tions were evaluated at La Molina and San Ramon to identify: superior progenitors with high general combining ability (GCA) for yield, earliness, tuber quality, and adaptation to warm and hot environ- ments combined with resistance to the most important diseases (i.e., PVX; PVY, PLRV, bacterial wilt, late blight, and early blight); and, to identify superior progenies to be used by NARS for variety selection. The first population was assembled as 17x4 line by tester mating design, where the lines were duplex PVY-immune and the testers carried other resistances. The best line for heat tolerance, yield and ear- liness at both locations was YY-13. YY-3 and YY-11 were excellent at San Ramon and YY-16 at La Molina. The second pop- ulation was assembled in a 12x3 line by tester mating design where the lines were PLRV-resistant and the testers PVY- and PYX-immune. The best lines for GCA at both locations were 88018 and 88146. The tester XY.9 proved to be excellent. The highest-yielding, earliest-maturing and most heat tolerant progenies also combin- ing resistance to two or three diseases were, at San Ramon, YY-3 x XY-9, 88052 x XY-9, and 87031 x XY.4. At La Molina, the best wasl'Y.13 x AVRDC-1287.19. As a result of this project, a group of 40 clones and progenitors selected for yield, tuber quality, and resistances have been cleaned-up from diseases for use in CIP Program 1 breeding activities and NARS. Of these clones, two are immune to PVY, two to PVX, 18 to both PVY and PVX, three are resistant to PLRV, and six have high dry matter and low reducing sugar contents and are good for processing as chips and french fries. A set of 46 tuber families from the CIP-INRA (Institute National de la Recherche Agronomique) cooperation project were field-evaluated during the hot summer of 1991 under arid conditions at La Molina and compared to five European cultivars used as controls. At 90 days after planting, the 12 top tuber fam- ilies yielded from 15 to 20 t/ha, while controls Desiree, Claustar, Spunta, Acker- segen, and Fanette, yielded from 6.6 to 12 t/ha. An important activity within this project is the breeding for tolerance to frost, early maturity, wide adaptability and other major constraints of the highlands as late blight, cyst nematodes and viruses. Testing and selection of clones with frost tolerance and good agronomic characters is conducted year-round at high altitude locations in Peru. Crosses of frost tolerant clones and sources of resistance to the potato cyst nematode are also routinely made. Of the 135 frost-tolerant clones passed to the Peruvian potato program, seven were selected with yields over 2 kg/plant and are now undergoing multi- plication for use in regional trials. The Philippines. Yields of CIP clones LT- 7 and 378597.1 have been consistently as high as those of Sequoia, Cosima, Katah- din, and Red Pontiac cultivars, as is at- tested to by evaluations made at Canlunbang (150 m ). Diffuse light storage (DLS) of 229 tuber families for nine months, resulted in yields of over 30 t/ha in 28 cases, while yields of over 40 t/ha 15 were obtained from 4 families: 385145.1 x 385152.32 (48.2 t/ha), 385110.59 x 384071.17 (48 t/ha), 385080.3 x TPS 13 (44.5 t/ha), and 385110.59 x LT-7 (43.6 t/ha). The cultivar Cosima (from cold stor- age) used as control yielded only 18.2 t/ha. A total of 39 advanced clones selected at Canlunbang and Cagayan were tested for yield and long storability in DLS, using rooted cuttings and 16 of them yielded over 20 t/ha. The highest yielders were the CIP clones 385130.11 (29.4 t/ha), 385132.10 (25.4 t/ha) and 385114.31 (25 t/ha) while Cosima (from cold storage) yielded 20.7 t/ha. Twenty-two clones selected for long storability in DLS and high yield in Can- lunbang and Cagayan were evaluated in farmers' fields in three sites at the Cagayan Valley. The top yielders were 385144.31 (B-71-240.2 x Y84.005) with 30.6 t/ha and 385130.llA (Y84.025 x 378015.16) with 29.3 t/ha. Farmers selec- ted several of these clones and we are multiplying them for further on-farm trials. Also several clones were provided toSAPPRAD. Fiji. In trials conducted with the col- laboration of the Sigatoka Research Sta- tion, the potato clones 384071.3 (Atzimba x NDD-277.2), originally selected in Viet- nam; 377850.1 (BR-63.74 x DT0-28), local selection; and 384558.10 (A4.17 x LT-7), selected in Philippines, were found to be the best yielders. The clone 377850.1 may be released as a new cultivar and seed production is underway. New Caledonia. Oones 24.16 (B-71-240.2 x DTO-bulk), 379667.421 (377831.5 x M.Tr,opical), and 378597.1(TD38.8 OP) had consistently high yields at two loca- tions. 16 Taiwan. There are two very good PVY- immune clones selected from CIP mate- rials. After six years of testing these two clones are now in multiplication. Bolivia. The Bolivian national program is benefitting from enhanced frost-tolerant cultivars. This year the Bolivian program received 50 progenies with 10,000 seeds for evaluation and selection of frost- tolerant clones. Potato in Rice-based Cropping Systems in East Africa The traditional center for potato produc- tion in East Africa is the higher altitude zone of the Zaire/Nile divide. Agroeco- logical conditions such as cooler temper- atures and abundant rainfall are especially favorable for potato cultivation. In response to increasing population density, potato production has gradually gained importance in rice-based cropping systems in the swamps. Heavy land at the bottom of the toposequence is reclaimed in a very labor-intensive mode of production. Farmers plant rice during the rainy season, and beans, corn, and sweetpotato in the dry season. Farmers want a more profitable dry-season crop, with a short cycle of 3-4 months. Since 1987, the Burundi potato pro- gram has conducted trials in swamps with selected existing varieties. 'The results are very promising, indicating that about 40% of Burundi's potato production could be grown in the swamps during dry season. In 1990 and 1991, more on-farm verifi- cation trials were carried out in rice fields in several swamps at three locations in Burundi. The varieties Muruta Program 1 (380506.10), Kinigi (378699.2), P .3 (374080.5), and the advanced clone BU 85058 were planted in each swamp after the June-July rice harvest. Potatoes were harvested in September-October. Chemi- cal fertilizer (60-90-60 NPK) was applied at a rate of350 kg/ha to a standard 100 m2 plot. Phytosanitary control was used only for insects, such as leafhoppers and cutworms. High yields in these trials confirmed earlier results. In the highest-yielding location at Ngozi, the average yield on the four farmers' fields included in the trials was 31 t/ha in 1990 and 30 t/ha in 1991 (for nine participating farmers). In the two other locations, average yields ranged from 12 to 17 t/ha per year. More applied and adaptive research, particularly soil fertility research and agroclimatic base data analysis, is needed before these systems can be reliably trans- ferred to other heavy wetlands of the East African highlands. Nonetheless, the 1990 and 1991 trials amply confirm the poten- tial for potatoes to contribute to food pro- duction in response to population pressure. Adaptation and Integration of Sweetpotato Production Technologies This project has two main objectives. The first is to comprehensively analyze and report the results of international testing of elite germplasm so as to gain an under- standing of the value of germ plasm selec- ted in certain environments (agroeco- logies) to varietal selection programs elsewhere. This information should make sweetpotato breeding more efficient at the regionally, nationally, and globally. The second objective is to promote, assist in, and report on the selection and dissemination of new varieties by partners in the developing world. Activities in- clude the identification of important selec- tion criteria, and regional- and on-farm testing. To increase efficiencies, a par- ticipatory approach involving farmers is encouraged. Overview and Analysis of International Germplasm Testing During 1991, a significant amount of pathogen-tested, advanced germplasm Program 1 from diverse sources, either as clones or as seed populations, was distributed for test- ing to national programs and CIP regional breeders from CIP headquarters, the CIP regional redistribution center in the Philip- pines, and North Carolina State Univer- sity, under a CIP research contract. Additionally, the SAPPRAD cooperators are participating in an international germplasm exchange, using clones cleaned up by the Plant Research Institute, Australia. Because germplasm is being trans- ferred both as seed populations and as clones, a comparison can be made of the efficiency of the two methods for transfer of elite germ plasm. Clean-up of clones is a lengthy and expensive process. Further- more, shipment of clones in vitro is expen- sive, and losses may be high during shipping, or during transfer from in vitro to in vivo. In contrast, seed presents few quarantine problems, and large numbers of genotypes can be distributed at a low cost. 17 Information about the performance of internationally distributed elite germplasm is still very incomplete. Through sys- tematic monitoring, we expect to make a much more comprehensive evaluation of the performance of internationally distrib- uted germplasm in the coming years. Peru. The performance of seed introduc- tions from various sources at Yurimaguas (humid tropics, with low base status soils) has been reported in previous Annual Reports. Evaluations of seed introductions continued during 1991. To date, seed families comprising a total of about 2,500 individuals from A VRDC (Subtropical Lowlands), IITA (Semiarid Tropics), two Chinese programs (Subtropical Lowlands and Temperate), Vietnam (Humid Tropics), Japan (Temperate), USA (Tem- perate), Puerto Rico (Semiarid Tropics), Rwanda (Highlands), Tonga (Humid Tropics), and South Africa (Subtropical Lowlands) have been evaluated. In- dividuals with high, early yields of attrac- tive roots were selected from each of these sources for varietal selection, and for con- tribution to broad-based breeding popula- tions. Evaluation of pathogen-tested elite clones and varieties has begun at sites in Peru, but results obtained so far do not permit a comprehensive analysis with re- spect to the adaptation of clones from dif- ferent origins to different agroecologies, nor to the relative efficiency of seed versus clonal distribution of germplasm. , The adequate performance at Yurima- guas of seed populations from various agroecologies (including temperate re- gions where photoperiods vary markedly during the growing season), may indicate th~t very specific physiological adapta- tions to agroecological conditions (such as 18 photoperiod sensitivity) either do not exist in sweetpotato, or may be easily overcome through selection among segregating progenies. More analysis will be neces- sary before conclusions can be reached. The Philippines. Thirty-six elite intro- duced clones were evaluated at Canlun- bang, a Humid Lowlands site. Nine of the clones came from Papua New Guinea, four from Taiwan, one from the USA, one from Korea, 10 from Vietnam, and 11 from the Philippines). The trial was har- vested at 90 and 120 days after planting. Two Vietnamese clones (B007, BOOS), three clones from Papua New Guinea (PNG 6, PNG 135, and PNG 295), and one from the Philippines (L002) had early, high yields. In SAPPRAD-sponsored multiloca- tional trials, which compared introduced and indigenous cultivars at five lowland locations during the wet and dry seasons, clones from A VRDC, Papua New Guinea, and Puerto Rico were among the top per- formers at each location. Yields of clones L383 and L390 (CN 1038-16 and CN 1108-13) were outstanding. Clones selec- ted for superior quality as food were" from Puerto Rico (Papota) and Papua New Guinea (L318 from the lowlands, and Gonime from the highlands). East Africa. Over the years, high yielding, elite clones from IIT A have been evaluated by national programs in both highland (e.g., Rwanda and Uganda) and semiarid (e.g., Tanzania) agroecologies in this region. In general, initial evaluations identified introduced clones with high yields, but over subsequent years, these were progressively infected by viruses, and yields declined. Furthermore, lack of desirable taste characteristics has impeded the release and adoption of these clones as Program 1 varieties. The introduced germplasm has nevertheless been used to contribute sour- ces of high yields and earliness to national breeding programs. Under the auspices of ESARRN, true seed populations produced by the Rwan- dan (Highlands) national program were evaluated at Ukiriguru, Tanzania (Semi- arid Tropics), and several promising clones were selected for further evalua- tion. The results in East Africa tend to sup- port the conclusion that, especially in the case of germplasm transfer as seed popu- lations, adaptations to climatic and edaphic (agroecological) conditions may not be as limiting to breeding success, as resistances to diseases and pests, and quality characteristics related to consumer acceptance. Selection and Dissemination of New Sweetpotato Varieties Peru. A new variety named Alto Urubam- ba (CIP clone ME12) was jointly released by the National University of San Antonio Abad of Cusco, and the Upper Urubamba Agricultural Production Cooperative. The variety is highly resistant to root-knot nematode, and matures in 3-4 months, in oontrast to 7-8 months required by the local varieties. In addition to high yields, Alto Urubamba has taste quality charac" teristics preferred by the regions' farmers and consumers, and is thus in high demand. The variety Jewel, introduced from the USA, will probably be released soon by INIAA. This variety produces high, early yields at important production locations on the Pacific coast, and in the Amazon basin. Program 1 Egypt. Clones NCSU 925 and NCSU 1135, introduced from North Carolina State University, USA, and which out- yield local varieties, continue to find good acceptance among farmers and con- sumers. NCSU 925 has been released as a variety, and seed multiplication by the public and private sectors is underway. In 1991, about 40 ha were planted to these new materials; the area projected for 1992 is 200 ha. Indonesia. A small set of advanced clones entered regional trials at five locations on the island of Java under varying climatic conditions. BIS 183, the most promising clone from previous years' trials, was evaluated in farmers' fields in two com- mercial production areas: Kuningan, west Java, and Magelang, central Java. The clone performed well in both locations. As well, a marketing and preference study assessed its market potential in Magelang. BIS 183 was judged by traders to have good skin, flesh, and shape characteristics similar to those of Magelangan, one of the most popular local varieties. Consumers were asked to rate both boiled and fried roots. The clone found higher aeceptance among higher income urban consumers than among rural consumers. India. Work is conducted in collaboration with the Central Tuber Crops Research Institute (CTCRI), and feeds into the All India Coordinated Root Crop Improve- ment Program. Adoption of two varieties selected by CTCRI, Sri Vardhini and Kal- m egh, was accelerated this year at Sonepat near Delhi, and in Ganwa-Badaun in central India. Sri Vardhini outyielded local varieties by 100-150%, and was ready to harvest 20-25 days earlier. High farmer demand for planting material could not be satisfied, and multiplication efforts have been stepped up. 19 The Philippines. Researchers and farmers from six provinces of Luzon participated in a two-day workshop to study farmers' selection criteria. Farmers evaluated 37 cultivars based on root and foliage charac- teristics. Taste tests were· also carried out. Preferred varieties had broad, purplish un- damaged leaves, and high yields of smooth, uniform, red-skinned, yellow- fleshed, medium to large (250-500 g), ovate roots. Preferred cooked roots were sweet, with a dry, fine texture. Sri Lanka. Under a SAPPRAD project, three improved Central Agricultural Re- search Institute (CARI) varieties (CARI- 426, CARI-9, CARl-273) and a commonly grown local variety (Wariyapola) were evaluated in multilocational trials during the northeast and southwest monsoon seasons. The CARI varieties showed wide adaptability under a range of production systems, including rice-fallows stand with coconut, open-land upland, river valley basins, and home gardens. CARI-426 outyielded all other varie- ties at all locations and seasons. It produces attractive pinkish-orange roots, with deep orange flesh color. However, because of its f!1Q,i~t te~tgr_e, the variety is unacceptable to some consumer groups. Evaluation of the Impact and Sustainability of Potato Production Technologies The objectives are: to quantify the agro- nomic, economic, social, and environ- mental effects of improved potato technologies; to document the rate of return to CIP's research; and, to determine the climatic, edaphic, economic, and social conditions leading to large off-site environmental effects threatening to the sustainability of improved potato technologies. Environmental Effects of Intensive Pesticide Use Among major field crops, potato cultiva- tion uses the most pesticides. Interdiscipli- nary study was started in 1990 to assess the impact of the use of these pesticides in Carchi, an intensive, year-round, commer- cial potato-producing area in northern Ecuador. Three types of impact were defined: production, environmental, and health. The use of pesticides has an ob- vious positive effect on potato yields, but 20 their use is also widely assumed to pollute the environment and cause health problems. The project includes economic, physi- cal and health-related aspects. The eco- nomic component features the monitoring of field-level production practices of a sample of farmers. Information is gath- ered on the types, rates, and timing of pesticide use. In northern Ecuador, late blight (Phytophthora infestans) is the most im- portant disease, and the study recorded the use of 34 different fungicides for its con- trol. However, the farmers overwhelming- ly select products with mancozeb as the control agent of choice (Figure 1-2). The larvae of the Andean weevil (Premnotrypes vorax) and flea beetles (Epitrix spp.) are the major soil and foliage insect pests. The study documented the use of 25 insecticides for their control. Prod- ucts with methamidophos are commonly Program 1 t used for the leaf insects, and carbofuran for the Andean weevil (Figure 1-2). The data from the 196 potato fields monitored in 1990 and 1991 reveal that farmers spent on average about US$120/ha on fungicides and about US$60/ha on in- secticides at 1991 prices. These expendi- tures correspond to about 10% and 5% of the total costs of production, respectively. The effectiveness and efficiency of pesticide use will be examined after data collection is completed. The data are used by as a starting point for physical and medical research. The former is well ad- vanced while the latter is just starting. The medical research will focus on farm worker safety during pesticide handling and application, rather than on the long term effects of consuming contaminated food or water. The pesticides that are applied to farm fields become an environmental problem once they leave the field. After considera- tion of all possible pathways for off-site effects of pesticides, work in the physical component has concentrated on leaching to groundwater as the most important. A limited number of field samples was obtained and simulation modeling used to estimate the fate of pesticides in a variety of unstudied conditions. Preliminary results of the modeling exercise show that only very low levels of pesticides accumu- late at the bottom of the root zone and could be possibly delivered to ground- water. Environmental contamination by leaching of pesticides to groundwater is A view of the watersheds being studied for pesticide use, Carchi, Ecuador. Program 1 21 FUNGICIDES Percent of total kilograms applied 111111 Mancozeb 80 - Maneb7 m Sulfurs h::::;::J Cooper 3 f;:;:;:;:;:;:;I Propineb 2 D Others2 INSECTICIDES Percent of total kilograms applied 111111 Metamidophos 48 - Carbofuran 42 m Profenophos 3 !::;::::::;::} Malathion 3 mm:~ Dimethoate 2 D Others2 Source: Unpubfished data, monitoring of 196 parcels in 1990 and 1991. Figure 1-2. Active ingredients of chemicals applied in potato production in Carchi, Ecuador (monitoring of 196 parcels in 1990 and 1991). apparently unimportant. Key factors for this result are the high organic matter con- tent of the soil which increases its sorption capacity and the short persistence of the Priority Setting In November, CIP conducted a priority- setting exercise of its restructured portfolio of research projects, with the guidance of an economist from ISNAR. The exercise confirmed the relative im- portance of some projects and the relative unimportance of others. For example, the presumed importance of controlling late 22 chemicals. In other intensive, commercial potato-producing regions with different pesticides and soils, leaching of pesticides to groundwater may be important. blight and finding low-cost propagation methods for clonal planting materials in potato was confirmed (Table 1-3). Like- wise, earlier thinking that a relatively low priority should be attached to work on field-storage diseases in potato and bac- teriaVfungal diseases in sweetpotato was supported. Program 1 j • However, some projects, such as in- tegrated control of bacterial wilt in potato, received a lower than expected score be- cause of a low probability of research suc- cess. Others, such as IPM for nematodes in sweetpotato, received a higher than Table 1-3. Priority-setting exercise: project score by commodity. Project POTATO Control of late blight Low-cost propagation of clonal planting materials Integration and adaptation of technology Germplasm enhancement & molecular techniques Combining resistances to viruses/fungi Integrated control of bacterial wilt Collection and characterization Improvement of sexual propagation Detection and control of viruses Integrated management of potato tuber moth Expanding utilization for developing countries Characterization of production systems ') Molecular approach to detect/control of pathogens ; ~esistance to insects/mites Abiotic stresses and crop management Integrated management of Andean weevil Management of cyst nematode Control of field-storage diseases SWEETPOTATO 0 Collection and~ Product development for developing countries Characterization of production systems Integration and adaptation of technology Improved planting materials and management techniques Integrated management of weevil Germ plasm enhancement & molecular techniques Integrated management of nematodes Identification control of viruses Control of bacterial/fungal diseases Score 259 900 ~ ,,, ,,,,_<_...,.- 174,100 100,900 99,200 95,100 92,100 76,300 75,800 64,900 59,000 51,200 37,200 36,500 31,900 14,200 5,200 4,900 154,700 132,600 85,800 80,300 45,200 38,700 30,400 21,100 20,700 2,200 Note: The projects were ranked by the following scoring method: 01; x P1i x P2; x P3; x P4; x P5; x E) where: V = net value of potential increase in production available to consum.ers for agroecological zone i (AEZ;) (in monetary units); P1 =importance of solving the constraint to achieve the potential in AEZ; (in%); P2 =extent of technology adoption in AEZ; (in%); P3 =probability of research success for AEZ; (in%); P4 = importance of the project for the regions (between 0-1 ); E = adjustment for environmental impact. The project score is then obtained by summing across each agroecological zone. Program 1 23 expected priority because of extremely bright prospects of technical success. For each research project listed in Table 1-3, scores were estimated by each of the important potato and sweetpotato agroecologies described earlier in this report. Combining these project scores within each agroecology gives a compara- tive picture of the expected economic im- portance of each agroecology to CIP's research. The importance of the subtropi- cal lowlands for, both potato and sweet- potato stands out in Table 1-4. About 97% of the subtropical lowlands for both potato and sweetpotato is in Asia. Training At UPW ARD's annual conference, held during Apr 2-5 at the University of the Philippines at Los Banos, experienced re- searchers on sweetpotato and young UPWARD researchers presented results of their investigation on sweetpotato farm- ing households, merchants and con- sumers. Discussions at the working groups and the final business meeting permitted to identify the research areas and as- sociated goals which UPWARD should pursue. The proceedings were recently published. The Philippines. An Asia-wide training course on consumption and nutrition re- sear~h was held November 1991. Rapid methods for evaluating nutritional status 24 Table 1-4. Comparison of expected benefits from research investments by commodity and agroecological zone. POTATO Subtropical Lowlands 24.5 Temperate 12.5 Arid-Mediterranean 7.8 Highlands 5.3 SWEETPOTATO Subtropical Lowlands 29.0 Temperate 8.8 Humid Tropics 5.3 Highlands 2.8 Semiarid Tropics 4.0 Total 100.0 and studying the consumption habits of households were presented. Trainers came from UPWARD and from the Department of Nutrition of the University of the Philippines at· Los Banos, where UP- WARD is funding a number of research projects. CIP economists participated in a train- ing workshop hosted by CIAT for strengthening the disciplinary skills of social scientists working in NARS. Brazil. In Recife, CIP social scientists co- hosted with CIAT staff a workshop on farmer participation in problem diagnosis and constraint identification. Researchers from several NARS in Latin America at- tended the workshop. Program 1 JI!' "*I It .. The germplasm collection is maintained in in vitro tissue culture, carefully stored under controlled light and temperature conditions. Cl P's extensive germplasm collection has grown in 1991 with the addition of a substantial number of Andean root and tuber cultivars. ll • Program 2 Germplasm Management and Enhancement 1991 In Review This Program constitutes the activities formerly included in Thrust II, Production and Distribution of Advanced Breeding Material. Work continued 0n collecting, managing, and improving the germ plasm collection. The collection of Andean potatoes was reduced by eliminating 607 accessions that were duplicates. There are 639 pathogen-tested potato accessions in the in vitro collection available for worldwide distribution. Highly efficient pathogen elimination in several advanced and native Andean cultivars was accomplished by the Austrian Research Center Seibersdorf in collaborative research. A core collection within group S. tuberosum ssp. andigena, the largest and genetically most variable group within the World Collection at CIP, is being established. During 1990 and 1991 closer collaboration among potato genebanks around the world was achieved, and top priority was assigned to publishing a catalogue of wild potato species maintained in many countries. More wild species were investigated for their reproductive characteristics with respect to pollen-stylar interactions and their breeding potential. Other wild species accessions have been evaluated for resistance to bacterial wilt (BW), and the identified resistance will be transferred to cultivated potatoes. New diploid potato families with resistance to BW, root-knot nematode (RKN), potato tuber moth (PTM), potato leafroll virus (PLRV), and potato virus Y (PVY) were generated. The effect of glandular trichomes on Phytophthora inf es tans infection was examined in 15 hybrids derived from haploid S. tuberosum x S. berthaultii crosses. Some potato genotypes were irradiated with gamma-rays to induce somatic mutations for improving agronomic characters of successful BW-resistant material. Genetic transformation through the insertion into potato clones of antibacterial protein genes, coat-protein genes, lytic peptide genes, and bacillus thuringiensis (Bt) genes for PLRV can now be done at CIP. A new Restriction Fragment Length Polymorphism (RFLP) map for potato has been generated, mapping a total of 220 markers. Randomly Amplified Polymorphic DNA (RAPD) markers, generated by the polymerase chain reaction (PCR), have been adapted to analyze DNA variation in tuber-bearing Solanum, demonstrating that RAPD markers are suitable for large-scale assessment of genetic diversity of potato populations. CIP's in vitro sweetpotato collection has been increased by 1072 accessions with materials received from the Asian Vegetable Research and Development Center (AVRDC). Experiments to assay long-term storage conditions for sweetpotato are Program 2 27 underway. International distribution of in vitro sweetpotato accessions can now draw on a stock of 90 pathogen-tested accessions. Seven collecting expeditions for sweetpotato genetic resources were undertaken in six Latin American countries, yielding 870 accessions of cultivated and wild material from 513 locations. Peruvian cultivated germplasm has been evaluated for its ability to perform at high altitudes and under mid-elevation jungle conditions. Sweetpotato germplasm collected in Cuba was duplicated at CIP, and 97 in vitro accessions were received. A revised version of sweetpotato descriptors has been submitted to IBPGR for publication, and guidelines for duplicate identification in sweetpotato collections have been produced. The identification of sources of resistance to race 3 of Meloidogyne incognita has continued, evaluating accessions from Bolivia, Brazil, China, Colombia, The Domini- can Republic, and Ecuador. Twelve accessions were found to be resistant, and 13 moderately resistant. Screening was also carried out for resistance to Fusarium oxyspo- rum and the fungus Diplodia gossypina. Resistance to both pathogens was found. In Peru, local and imported sweetpotato germplasm is being used to develop advanced populations with adaptation to various agroecologies. Priority traits are high yield, earliness, and high root dry matter content, to be combined with resistances and tolerances to principal abiotic and biotic constraints. Work on selection of clones with high yield, scab resistance, and good plant survival rate is being conducted in cooperation with the Central Research Institute for Food Crops (CRIFC) and other Indonesian institutions. Research on germplasm enhancement has focused on developing tetraploid (4x) storage-root producing interspecific hybrids between cultivated 6x /. batatas and wild 2x /. trifuia. These hybrids are to be used as testers for the evaluation of wild species germplasm and as bridges for the transfer of selected wild species germplasm to the cultivated genepool. Optimum conditions for plant regeneration via organogenesis from internodes, roots, and leaves of sweetpotato clones were established, and the research results are now being tested usingAgrobacterium-transformed plants (varieties Jewel and Huachano). These plants are to be transformed with the cowpea trypsin inhibitor to engineer resistance to the weevil. In crossability studies, it has been established that/. trifida and /. x leucantha acts as rr bridge species. Additionally, it has been put forward that self-incompatibility in species of sweetpotato section Batatas is explained in the light of the stigmatic papillas. Priorities for research on Andean root and tuber crops (ARTC) will be defined in 1992. However, a preliminary strategy for the systematic collection of these crops and thefr wild rel~tives has been formulated and several collecting missions undertaken with the participation of national partners. Collected material was deposited at national herbaria in La Paz, Quito, and Lima. As well, donations of oca germplasm from Peru and ulluoo germplasm of Bolivian origin were received from the non-governmental organization SAPHA (Servicios Agrarios, Puno) and the University of Turku in Finland. 28 Program 2 • .. The identification of duplicates by means of morphological and biochemical charac- terization is a major objective for ARTC. With the exception of maca, ARTC's are propagated by vegetative means. However, CIP research has demonstrated that all can produce botanical seed at different rates. Four viruses were identified in ulluco, and antisera for the detection of these viruses are now available. Attempts to eliminate virus from ulluco started in 1991on15 Peruvian commercial clones. Work in this Program was divided into five primary projects. These were: • Potato germplasm collection and characterization • Potato germplasm enhancement and molecular techniques • Sweetpotato germplasm collection and characterization • Sweetpotato germplasm enhancement and molecular techniques • Collection and characterization of Andean root and tuber crops Potato Germplasm Collection and Characterization In order to identify new sources of resist- ance, characterization of wild species is an important objective. Special emphasis is being placed on the overall improvement of screening methods. As well, collabora- tion with national programs for germ- plasm maintenance and characterization is a continuing priority. The CIP World Potato Germplasm Collection A total of 607 Andean potato accessions were found to be duplicates of other culti- vars already maintained in the World Potato Collection at CIP. Of these, 455 accessions were duplicates from national or institutional collections donated to CIP in recent years. As well, 152 new dupli- cates were identified within the main collection that is conserved in the field as well as in vitro. The in vitro collection now comprises 639 pathogen-tested accessions available for worldwide distribution. For a long-term Program 2 storage assay, in vitro microtubers have been produced from 350 potato genotypes. Pathogen elimination in several ad- vanced and native Andean cultivars was accomplished by the Austrian Research Center Seibersdorf in a collaborative re- search project. In vitro cultures obtained from these cultivars were returned to CIP after virus indexing (comparative ELISA +test plants). Virus eradication was very efficient resulting in surplus mericlones for most accessions. For in vitro acces- sions received in 1991, the process has been adapted and mericlone production was started. With the goal to select a Core Collec- tion within S. tuberosum ssp. andigena, which represents the largest portion of accessions in the collection, isoenzyme analyses were undertaken. So far, about 1,000 accessions have been analyzed for six isoenzymes, utilizing tips from young leaflets of 3-4 week-old plants. Although the data obtained are being computerized 29 for further analyses, the following poten- tially new allozymes not previously re- ported in tuber-bearing Solanum species have been identified: in the isoenzyme IDH, allozyme 4; in locus PGMI, allo- zyme 3; and, in locus PGM2, allozyme 4. Sources of resistance to the Andean potato weevil (Premnotrypes vorax Ilustache) present in the fields at Porcon in the Cajamarca region of Peru have been identified in the potato collection. A total of 18 potato cultivars from several Andean countries, mainly from the taxonomic group of S. tuberosum ssp. andigena, showed no weevil damage in their tubers for three consecutive years. However, four susceptible check cultivars grown in the same fields had 45-75% of their tubers damaged by the weevil. A donation of about 800 Peruvian po- tato cultivars was made to the National University of Cajamarca in Peru. Provid- ing duplicate sets of material to interested NARS in the countries where these ge- netic resources were collected is an im- portant way of insuring the maintenance of the World Potato Collection. Inter-genebank Collaboration A closer collaboration among potato gene- banks around the world is becoming a reality. At an October 1990 meeting in Washington, DC, USA, representatives of the Braunschweig Genetic Resources Center, Germany; the Inter-Regional Potato Introduction Project, USA; and CIP, agreed that a joint data base of acces- sions maintained in these genebanks should be produced. A second meeting, held in Sturgeon Bay, Wisconsin, USA, in August, also included representatives from genebanks in Scotland, the former USSR, Germany, Argentina, Ecuador, and Peru. A data base structure and some standards to 30 develop a joint data base were proposed by CIP on the basis of input received from other genebanks. This structure was ac- cepted and the group agreed to formally create the lntergenebank Potato Database (IPD). Publishing a detailed catalog of the wild potato species has top priority. Bolivia. The health status of the Bolivian Potato Collection maintained at Toralapa by IBTA-PROINPAhas been substantially improved. The morphological character- ization of this collection is in progress for the identification of duplicates. A system- atic evaluation has been started to select the best accessions for tolerance to nema- todes (Nacobbus spp. and Globodera spp.), frost damages, wart disease (Syn- chytrium endobioticum ), and drought. Argentina. A collection of S. tuberosum ssp. andigena maintained by INTA at Balcarce, Argentina, is being studied to determine its degree of genetic variation. Some cultivars of the triploid Andean po- tato species S. x chaucha have also been identified in this collection. Wild as well as primitive cultivated germplasm has been utilized in the Argentinean potato breed- ing program. Clones with high yields and excellent quality characteristics have been identified among S. tuberosum ssp. tube- rosum, ssp. andigena, and S. x chaucha. The wild potato species, S. gourlayi, S. acaule ssp. acaule, S. acaule ssp. aemu- lans, S. commersonii ssp. commersonii, S. commersonii ssp. malmeanum, and S. cha- coense, were found to be alternative sources of resistance to Fusarium spp., Meloidogyne spp., and PLRV. Subspecies acaule, aemulans, commersonii, and mal- neanum have also been used for a success- ful, extensive genetic analysis at the level of individual loci by means of isoenzyme electrophoresis. Program 2 Potato Germplasm Enhancement and Molecular Techniques Germplasm enhancement is achieved through the introduction into breeding material of traits from wild species; through the use of innovative tissue cul- ture methods; through the production of true seed; and through the use of molecu- lar techniques such as genetic engineer- ing, gene mapping, and the development of PCR markers. Germplasm Enhancement U si,ng various wild species as new sources of germplasm enhancement. Several wild species previously not utilized in pro- grams of germplasm enhancement were investigated to study their breeding poten- tial. Accessions unique to CIP's wild po- tato collection from the taxonomic series Conicibaccata and Piurana were inten- sively evaluated. Their reproductive char- acteristics, particularly with respect to pollen-stylar interactions, were studied in order to investigate interspecific crossa- bility of these species with cultivated po- tatoes. Hybrid seeds were generated in crosses with haploids of tetraploid breeding lines, and the characterization of their reproduc- tive traits are underway. Simultaneously, screening for resistance to late blight and PTM was conducted. Other wild species accessions, whose taxonomic identity is to be confirmed, have been evaluated for resistances to BW. Some genotypes were selected for crosses with diploid breeding lines to transfer the identified BW resistance to the genepool of the cultivated potato, following a suc- cessful breeding scheme established at Program 2 CIP several years ago for this resistance at the diploid level. Hybrids were probably obtained in crosses of 2x potato breeding lines with the 2x non-tuber-bearing Sola- num species S. brevidens, S. etuberosum, and S. fernandezianum which have a high potential of resistance to PLRV and bacte- rial diseases, such as Erwinia. The verifi- cation of the true hybrid nature of this material is underway by means of isozyme and RFLP markyrs. Generating new breeding materials by enhancement with traits obtained from wild species. New diploid potato families were generated by using 2n gamete pro- ducing 2x potatoes with some resistance to RKN, BW, PTM, PLRV, and PVY. Pre- liminary evaluation indicated that some clones could have a combination of virus resistance with any of the other three pests or diseases as well as 2n pollen and im- proved agronomic characters. Among these families are some that will be selec- ted for adaptation to long day conditions for the southern cone of South America, China, and the southern part of Africa. Quantitatively segregating resistance to the PTM can be transmitted more effi- ciently in 4x x 2x crosses by 2n pollen produced through first division restitution (FDR) than in 4x x 4x crosses (Table 2-1). It appears that levels of transmission of these quantitatively inherited resistances depend on female (4x) - male (2x) inter- actions, as observed previously in trans- mission of RKN and BW resistances from the diploid to the tetraploid level. Introgression of virus resistance genes derived from S. acaule was attempted by crossing tetraploid Fl hybrids of S. acaule 31 Table 2-1. Transmission of resistance to PTM from 2x (MR) and 4x (S) potatoes via FDR 2n pollen. Number of progenies Females (4x) Males (2x) Total Resistance (%)8 Atzimba 84.38.12 28 1 (R) + 2(MR) (10.7) Atzimba 87HW13.7 34 3(R) + 3(MR) (17.6) P-3 87HW13.7 34 2(R) + 4(MR) (17.6) V-2 Ml49.10 13 1 (MR) (17.7) a Laboratory and storage tests. MR = moderate resistance; R = resistant. and tetraploid cultivated potatoes with 2x potato breeding lines. Different levels of ploidy, aneuploidy, and significant im- provement of agronomic characters were observed in the resulting introgression lines (Figure 2-1). Virus resistance was found to segregate in this material, and resistance to potato virus Y (PVY), Potato Virus X (PYX), and Potato Leaf Roll Virus (PLRV) was identified. RFLP charac- terization has been initiated to understand the mechanism of introgression and thus to identify the transfer of the chromosome segments which carry the genes that con- fer virus resistance. Figure 2-1. Tuber yield from an S. acaule intro- gression line (left) and a diploid progenitor of the introgression line (right). 32 The effect of glandular trichomes on Phytophthora infestans infection was ex- amined in 15 hybrids derived from haploid S. tuberosum x S. berthaultii crosses. The race of the fungus used in this experiment was 1-3-4-5-7-8-10-11. A wide range of variability in the reactions of potato geno- types to the late blight pathogen was ob- served. It appears that the trichome prop- erties confer some resistance to late blight and insects. S. acaule, S. commersoni~ andS. gourlayi are being characterized for their reproduc- tive biology and ploidy manipulation as part of research designed to widen the base for genetic variability in tetraploid potato populations, and to incorporate resistance to viruses, Fusarium wilt, and aphids from these species into CIP's tetraploid breed- ing material. In order to achieve this goal, several hundred new dihaploids were generated from long day-adapted 4x tuberosum cultivars with virus resistance and processing quality, or both. These dihaploids are to serve as crossing partners with mainly diploid wild species repre- senting a new source of a diverse pool of genes for further germ plasm enhancement. The methods used to accomplish such germplasm transfer from the wild to the cultivated genepool of potatoes represent a varying combination of generation and use of haploids, utilization of 2n gametes, ploidy manipulation, recurrent selection, Program2 ' " in vitro and in vivo screening, and electro- phoretic characterization. Innovative tissue culture methods for germplasm enhancement. The concept that tissue culture may, through the gener- ation of somaclonal variants, aid in the development of useful agronomic traits or resistances, such as insect resistance in potato, was supported by positive results obtained with glandular trichome mate- rial. Cultures of second and third genera- tion backcrosses of this material yielded plants with greatly improved glandular tri- chome characteristics. A total of 134 plants regenerated from 5 diploid Fl hy- brids of 2x cultivated potato and 2x S. berthaultii were evaluated for their tri- chome traits as well as agronomic and reproductive characters. Thirty-seven clones were selected for further use in breeding. Somaclonal variants with im- proved tuber resistance to PTM were also obtained from other sources of material. Evaluation of the improved tuber resist- ance as well as of the agronomic characters of this material is underway. Some potato genotypes with good re- sistance to BW but relatively inferior ag- ronomic characteristics, sµch as the Burundi clone Cruza 148, were also irra- diated with gamma-rays to investigate the possibility of inducing somatic mutations that would improve some agronomic char- acters. For this purpose, either protoplasts or in vitro plantlets were irradiated, and plantlets were regenerated after irradia- tion for evaluation of their insect resis- tance and agronomic characters. True seed production and virus cleanup of 2x progenitors for international dis- tribution to NARS. Botanical seeds on 4x x 2x and 2x x 2x crosses were produced and exported to CIP scientists in the re- gions and to NARS scientists worldwide Program 2 to aid national efforts to increase genetic variability in breeding stocks. Some of the progenies derived from 4x x 2x crosses can be directly selected and evaluated in variety testing programs. Twenty diploid potato genotypes that confer resistances to RKN, PVY, PLRV, BW, and PTM or a combination of these and which produce 2n pollen are being cleaned up from virus and soon will be- come available for international distribu- tion. Applying Molecular Technology Genetic engineering. The identification and analysis of large samples of transgenic plants through dot blotting requires tech- niques of rapid DNA extraction and pre- paration of probes. CIP now has in-house facilities and capabilities to do this type of analysis. Transformation through the insertion of antibacterial protein genes and the coat- protein gene for PLRV into potato clones can now be carried out at CIP. Two geno- types, Desiree and 86007, were used for transformation with A. tumefaciens and A. rhizogenes as vectors for gene coding for antibacterial proteins. Nearly 400 GUS (B-glucuronidase gene)-positive lines were obtained with the A. rhizogenes vector and 50 were obtained using A. tumefaciens. Preliminary dot hybridiza- tion indicated the presence of the antibac- terial genes in these transgenic plants, but confirmation of the first set of results is underway using Southern Blot in an at- tempt to identify position effects and to determine whether the number of inserts corresponds to levels of observed resis- tance. For this purpose, GUS-positive plants were inoculated with Pseudomonas solanacearum, and these plants showed a wide range of responses to the pathogen. 33 Some transgenic plants appeared to be re- sistant to it while others were aS suscep- tible as the original non-transformed genotypes. Studies were carried out to demonstrate the effects of ploidy and inbreeding on the efficiency of regeneration after genetic transformation employing A. tumefaciens as vector. These effects were studied using a set of haploids and their original tetra- ploid progenitors as well as clone 7XY.1, and a set of diploid S. phureja and their somatically-doubled tetraploid deriva- tives. It appears that there are clear effects of inbreeding and ploidy on this trait, and that increased levels of inbreeding signif- icantly reduce the efficiency of transfor- mation. Genotypic differences in the response of wild, cultivated and advanced hybrid breeding material to the efficiency of re- generation, following transformation with Agrobacterium sp., were also observed and determined by the GUS reporter gene. The antibacterial protein gene con- structs are at present inserted into the ge- nomes of popular Peruvian potato varie- ties such as Yungay to improve their resistance to BW caused by Psewlomonas solanacearum. A. tumefaciens, containing the se- quence coding for the coat protein of PLRV, was used to insert this gene into cultivars Desiree and 7XY.1. Reporter genes and Elisa testing permitted identifi- cation of 54 plants as transformed. Further testing, both by Southern Blot and infec- tion with PLRV is underway. Several collaborative projects on ge- nefa~. transformation in the area of basic and applied research are being carried out. Lytic peptide genes, using A. tumefaciens as vector, are also employed to transform 34 potato genotypes for resistance to Phy- tophthora infestans. DNA hybridization analysis has demonstrated the presence of the cecropin gene which confers late blight resistance in transgenic plants. The transformed material was selected using the GUS reporter gene. Bacillus thuringiensis (Bt) genes, which confer resistance to insects, have also been employed to transform some common Eu- ropean cultivars such as Desiree. Prelimi- nary results have permitted identification of the presence of the gene in transformed genotypes as well as some actual insect resistance. This work is being carried out at the laboratories of ENEA in Italy. Potato Gene mapping. In collaborative research with the Department of Plant Breeding and Biometry at Cornell Univer- sity, USA, one progeny of a dihaploid of S. tuberosum (tbr) x S. berthaultii (ber) cross (N263) was used to generate a new RFLP map. The population used for this purpose consisted of 150 clones derived from a backcross between an Fl of a tbr x ber cross and ber, and about 220 markers were mapped. The mapping population is kept virus free. Along with some well- known genes, the new markers denomi- nated as CD, CT, and TG from Cornell University and CP and GP from the Max Planck Institute in Germany were used to construct a new map, which is more com- plete than the original one constructed at · Cornell University, this map seeks to tag properties related to both types of tri- chomes, A and B. They have already been tentatively mapped on specific chromo- somes, and further efforts to obtain more conclusive results are underway. Several other resistance genes have been targeted for mapping at CIP and in collaborative research with Cornell Uni- versity. Resistance to RKN, race 3 of Program 2 .. Pseudomonas solanacearum, and the PTM is segregating in one and the same diploid population in Peru, simultaneous mapping for these characteristics is under- way at CIP. Mapping of a resistance gene to the nematode Globodera rostochiensis is being carried out in a haploid population derived from the USA cultivar Atlantic at Cornell University. Development of PCR markers. RAPD markers generated py PCR have been adapted to disclose DNA variation in tuber-bearing Solanum. Some factors af- fecting the reproducibility of the obtained results were investigated in collaborative research with Cornell University, Kobe University in Japan, and the University of Washington, USA. Factors such as quality and quantity of DNA samples were found to influence the reproducibility of results, and reliable and repeatable results were obtained through proper control of these factors and thus of PCR (Figure 2-2). It was demonstrated that RAPD mark- ers are suitable for large scale assessment of genetic diversity in potato populations due to the simplicity of this method. PCR is also used to amplify RFLP markers to avoid the use of plasmids which might still raise questions of biosafety. PCR ampli- fied RFLP markers are also more easily labelled and provide clearer signals in Southern Blot hybridization compared to those amplified by using plasmid. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 2.0 0.564- Figure 2-2. PCR markers for 17 potato clones. Sweetpotato Germplasm Collection and Characterization CIP's germplasm collection for sweet- potato is the world's largest. Objectives of this project include making the collection more comprehensive and eliminating du- plicates. Future collecting work will focus on Central America, an underexplored area within the primary center of diversity. Characterization of accessions are being Program 2 done in situ in collaboration with the national programs of the countries of origin, to avoid quarantine restrictions. Maintenance of the gennplasm collection. For 141 accessions from 11 species, seed stocks were increased to a total of 11,514. In intraspecific crosses involving four spe- cies, 441 seeds were generated; and from 35 interspecific hybrid populations, involv- ing 7 species, 1,299 seeds were harvested (Table 2-2). In a set of four poly-crosses for four traits of interest to breeders, 17,528 seeds were obtained (Table 2-3). In vitro collection and international dis- tribution. The sweetpotato in vitro collec- tion has been increased by 1072 accessions with materials received from AVRDC. Ex- periments to assay the possibility for long term storage so far have revealed differing growth patterns within the clones tested, and these experiments need to be con- tinued. International distribution of in vitro sweetpotato plantlets has been increased Table 2-2. Intra- and interspecific hybrid populations generated in this work. Number of Number of Number of Number of Total Number of Female accessions genotypes Male accessions genotypse seed produced lnt~aspecific lea 3 4 lea 2 3 33 tic 5 12 tic 6 13 362 trf 1 trf 3 3 20 trl 4 6 trl 3 6 26 I nterspecific cdt 3 3 lea 2 2 100 cdt 2 2 trf 2 3 19 cdt 4 6 trl 5 11 251 cyf cdt 4 5 19 gdf cdt 4 5 84 lea 2 3 cdt 4 6 203 lea 2 2 trl 4 7 31 rms cdt 25 trf 1 cdt 2 2 3 trl 5 11 cdt 4 6 559 trl 2 lea 2 2 5 Total 36 56 48 75 1740 * lea = I. xleucantha, tic = /. tiliacea, trf = I. trifida, trl = I. triloba, cdt = I. cordato-triloba, cyf = I. cynanchifo/ia, gdf = /, grandifolia, rms = I. ramosissima. Table 2-3. Generation of seed-pools using material of I. batatas (L) Lam. Number of Number of seeds parents obtained High starch and dry matter content 15 4,864 Heavy pubescence and abundant latex in vine 19 11,967 White flesh color 12 116 Mostly pigmented with anthocyanine in flesh 11 581 Total 57 17,528 36 Program 2 ~ ~ since there are now 90 pathogen~tested accessions available. Collecting sweetpotato genetic resources. Seven collecting expeditions were under- taken during 1991, and the following countries were visited: Mexico, Honduras (visited twice), Nicaragua, Argentina, Bolivia, and Peru. On these trips, 870 ac- cessions of cultivated and wild material were collected in 513 locations. Cultivated material (I. batatas (L.) Lam.) is repre- sented by 622 accessions (71.5%) and 248 accesions (28.5%) are wild material. Of the wild accessions, 163 (65.7%) have al- ready been identified taxonomically, and of these, 119 (73%) are six Ipomoea spe- cies of section Batatas (Table 2-4). Evaluating sweetpotato genetic resour- ces. A part of the Peruvian cultivated germplasm has been evaluated for its yielding potential and for its ability to perform at high altitude (2,500 m ). Germ- plasm with low sugar content, or so-called "camote papa", was evaluated for mid- elevation jungle conditions, and the effect of flowering on tuber root production was also determined. Screening accessions from the germ- plasm bank for adaptation to cool en- vironments. More material from CIP's sweetpotato collection was screened this year for adaptation to cool conditions. From 379 clones, 51 were selected for their relatively good performance under cool conditions at approximately 2,000 m in the highlands of Cajamarca, Peru. The selected material has already been planted in the field for further testing in replicated trials. In previous tests, 16 clones were iden- tified that had shown some degree of adap- tation to cool environments after several replicated trials. Although these clones were the most adapted, they did not exhibit Program 2 their full yield 'potential and were rather late maturing (Figures 2-3, 2-4). They are currently being used in poly-crosses with other improved breeding material to com- bine additional desirable traits such as earliness, high yield, and better root ap- pearance. Table 2-4. The taxonomic identification's given to newly collected wild species. Number of accessions Countries Specie(s) collected explored I. trifida 73 Honduras (5), Nicaragua (56), Mexico (12) I. tiliacea 21 Honduras (8), Nicaragua (10), Mexico (3) I. triloba 8 Mexico (8) I. ramosissima 4 Nicaragua (4) I. umbratico/a 11 Honduras (3), Nicaragua (4), Mexico (4) I. tabascana Mexico (1) I. peruviana 2 Peru (2) Other lpomoeas 28 Nicaragua (6), Mexico (22) lpomoea spp. 16 Nicaragua (1 ), Honduras (11) Mexico (4) TOTAL 164 Maintenance, Evaluation, Documentation, and Distribution of Sweetpotato Genetic Resources A revised list of sweetpotato descriptors has been submitted to IBPGR for publica- tion. Guidelines for duplicate identifica- tion in sweetpotato collections comprising a few key morphological descriptors have also been produced. A color chart for the characterization of storage root skin and flesh color is also included. 37 Yield Kg/plant 0.5 0.4 0.3 0.2 0.1 DLP2398 ARB610 Clones DLP1934 k I Rainy lllJllllOry DLP933 Figure 2-3. Yield performance by season of a sample of sweetpotato clones evaluated in Jesus, Cajamarca, Peru, 1991. Yield Kg/plant 0.7 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 0.6 0.5 0.4 0.3 0.2 0.1 ARB174 INGLES ARB452 ARB567 ARB320 RCB1061N RCB1431N RCB361N DLP1995 ARB350 Clones Figure 2-4. Yield performance of a sample of sweetpotato clones evaluated in Llacanora, Cajamarca, Peru, 1991. 38 Program 2 Morphological data of key sweetpotato descriptors from 1,929 Peruvian acces- sions in CIP's collection have been vali- dated in the field according to the new descriptor list. Cluster analyses of the data obtained sorted out 1,027 accessions within 212 morphologically identical groups. A total of 518 of these accessions comprising 168 groups was verified, and about 400 Peruvian cultivated accessions with identical morphology and electro- phoretic patterns will be eliminated from clonal maintenance after obtaining seeds. Yield trials with 340 accessions of Peruvian breeding lines were conducted by breeders at four sites in Peru. A total of 228 of the lines tested were not selected at any of the testing sites. A follow-up on sweetpotato characterization of national collections in collaboration with NARS was made in Jamaica (75 accessions) and in the Dominican Republic (215 acces- sions). Based on recorded data, new groups will be planted on the basis of morphological similarities. A similar ap- proach has also been implemented in Mexico (260 accessions) and Argentina. However, in the latter two countries, na- tional collaborators had already recorded morphological data and sent them to CIP for processing and to receive suggestions for a new planting order aimed at duplicate identification. Cuba. Sweetpotato germplasm collected in Cuba with IBPGR funding during the past year by the national Cuban institution INIVITwas duplicated at CIP, and 97 cul- tivated in vitro culture accessions were received. Bangladesh. Starting in January 1991, 46 accessions of native sweetpotato germ- Program 2 plasm have been collected. Nine of these yielded 21-33 t/ha, considerably higher than the Bangladeshi national average of 11 t/ha. Genotypes SP-078 and SP-088 yielded 33.33 t/ha of tubers, SP-093 yield- ed 25 t/ha, SP-069, SP-080, SP-085, SP- 089, SP-137 all yielded 22.22 t/ha, and SP-360 yielded 21.11 t/ha. Seed treatment for storage. A simple method to dry sweetpotato seeds to about 5% moisture content for long term storage has been developed. It consists of placing the seeds in open Petri dishes, in trays together with a container filled with silica gel to 2-3 times the total weight of all seeds in the tray. After sealing the trays with transparent plastic, they are stored in an incubator at 15-17°C for about 14 days. During this time, the silica gel is replaced when its blue color changes (about three to four times). Viability and seedling vigor were not affected by this treatment, in contrast to viability and vigor lost in seeds stored with a 10% moisture content. Evaluation of various resistances to bi- otic stresses. The identification of sources of resistance to race 3 of Meloidogyne incognita has continued as 273 accessions from Bolivia, Brazil, Colombia, the Dom- inican Republic, Ecuador, and China have been evaluated. Of these, 12 were found to be resistant and 13 moderately resistant. Screening for resistance to Fusarium o.xy- sporum, carried out on 29 native Peruvian cultivars with high yield, showed that three of them might have some resistance; these will be reevaluated. Of 196 Peruvian accessions screened for resistance to Di- plodia gossypina, 84 showed resistant re- actions which need to be confirmed in future tests. 39 Sweetpotato Germplasm Enhancement and Molecular Techniques The major objective of enhancement re- search is to combat the sweetpotato weevil (SPW), the crop's mejor pest. One ap- proach is to cross lpomoea Batatas with other Ipomoea species to allow access to a new genepool. Molecular techniques in- clude developing innovative methods for germplasm multiplication. Research on germplasm enhancement and population improvement is focusing on developing and improving breeding populations for priority characteristics at key regional locations, selected with a focus on agroecologies and biotic con- straints. This project is a principal source of new materials for international testing, both as seed and as clones. These activities also serve as a training ground for sweet- potato breeders from national programs, and as a laboratory for the development of sweetpotato breeding methodology. Per- formance of materials developed under this project in each location, will be im- portant in determining the future level and locations of work. During the last year, work has been ongoing at headquarters, and at regional locations in the Philip- pines, Indonesia, and China. Peru. Local and imported germplasm is being used to develop advanced popula- tions with adaptation to the agroecologies available at experiment sites in CIP's host country. Work is conducted at locations in the Amazon basin (humid tropics), in the higl).lands, and on the Pacific coast (arid and meditel'ranean). Materials are eval- uated at different sites within and across agroecologies to select for yield stability. Priority traits are high yields, earliness, and high root dry matter content, com- 40 bined with resistances and tolerances to the principal abioticand biotic constraints. These constraints at the humid tropical sites (Yurimaguas and San Ram6n) in- clude excess moisture, low soil fertility, high temperatures, and the fungus Di- plodia. In the highlands of Cajamarca at about 2,500 m, the principal constraint is low temperatures. At the Pacific coast lo- cations of Vitarte, Canete, and Tacna, con- straints include RKN, cool winters, soil salinity, and drought. In collaboration with the Universidad Nacional Jorge Basadre Grobmann-Tacna, selection has been conducted under saline soils since 1985. This program, which in- cludes hybridization and seedling selec- tion, has developed a number of advanced clones with tolerance to salinity (5 to 10 mmho/cm), high boron concentrations (more than 4 ppm), and some tolerance to drought. These clones produce yields of over 20 t/ha (root dry matter content ranges from 20 to 40%) in 100 to 120 days, and have a range of root skin and flesh colors. During the last year, selection of high yielding early maturing clones, some of them also combining high dry matter con- tent and resistance to RKN, was made in the Amazon Basin and at coastal locations. These clones are being cleaned up from pathogens for international distribution, and are also being used as parents in a new cycle of selection. Root yields and dry matter contents of some selected clones evaluated at San Ram6n are presented in Table 2-5. These and other results indicate the tendency in sweetpotato for dry matter content to Program 2 Table 2-5. Evaluation of advanced sweetpotato clones planted (density 37,037 plants/ha) at San Ramon, Peru, rainy season and dry season, 1991. Rainy season Yield/plant(g) Clone 120 days 90d SR88.050 613 650 SR88.075 763 LM 88.113 513 LM 88.082 432 LM 88.014 1106 468 LM 88.040 545 372 increase during the growing season, but some clones produce and maintain a high root dry matter content from a relatively early harvest date. Crossability studies have enhanced knowledge about sweetpotato section Batatas. In interspecific crosses, it was shown that/. trifida and I. x leucantha act as "bridge species" during geneflow from wild to cultivated species (Figure 2-5). In the first research stage, self-compatability was determined in /. tribola (2x ), x Leu- cantha (2x ), I. lacunosa (2x ), I. tenuissima (2x), I. cynanchifolia (2x), I. grandifolia (2x ), /. ramosissima (2x ), and /. cordato- triloba (2x), as well as self-incompatibility in I. trifida (2x ), /. tiliacea ( 4x ), and /. batatas (4x, 6x). Sexual compatibility is related to a multiallelic sporophytic in- compatibility system which is expressed in the stigmatic papillas. In the second stage, 4162 cross pollinations were per- formed between 11 species at two loca- tions. Seventy-six interspecific combina- tions from 110 theoretically possible combinations in a diallelic 11 x 11 design were obtained. Of the 76, 37 succeeded with a crossability rate ranging from 0.01 to 1.00 in one location. In the other, 11 of 17 combinations were successful when es- timating crossability by seed production. Program 2 Dry season Yield/plant(g) Dry matter(%) 105d 120d 90d 105d 120d 867 1054 25 26 35 803 1002 23 26 27 610 938 31 32 36 658 760 28 33 35 511 733 34 35 35 496 490 35 35 34 Considering the factors affecting cross- ability, it was found that latitude is one of the factors explaining flowering synchro- ny in progenitors; whereas seed germina- tion of the progeny and the early death of seedlings is explained in the light of the unbalanced genome (embryo/endosperm) relationship. The evaluation of crossabil- ity of interploidy crosses of diploid with tetraploid progenitors and the correspond- ing reciprocals-generated diploid and tri- ploid progenies and maternal effects were observed. In crosses between hexaploid and diploid progenitors, hexaploid proge- nies were generated, a maternal effect pre- vailing. When /. trifida is hybridized reciprocally with/. batatas, I. x leucantha, I. tenuissima, and I. ramosissima, the cros- sability range is from 0.01 to 1.00. In crosses between/. trifida, as male progen- itor, with /. cordata-triloba, I. cynanchi- f olia, . I. grandifolia, I. lacunosa, and /. triloba, crossability varies from 0.06 to 0.23. Reciprocal crosses of I. x leucantha with I. grandifolia, I. trifida, and/. triloba, had a crossability range from 0.01 to 0.95. In crosses between I. x leucantha, as fe- male progenitor, with/. cordato-triloba, I. cynanchifolia, I. lacunosa, and /. tenuis- sima, crossability ranged from 0.27 to 1.00. The cross of/. x leucantha, as male 41 BAT = /. batatas (4x, 6x) CDT = I. cordato-triloba (2x) CYF = I. cynanchifolia (2x) GDF = /. grandifofia (2x) LAC = I. lacunosa (2x) RMS= I. ramosissima (2x) TEN = I. tenuissima (2x} TLC = I. tiliacea (4x) Gene flow male -----+ female Grade of crossability ----low TRF = I. trifida (2x} TRL = I. triloba (2x) ----medium LCA = I. x leucantha (2x} ----high Figure 2-5. Polygon of crossability between eleven lpomoea species, section batatas (convolvulaceae). progenitor, with I. batatas and/. ramosisi- sima gave a crossability rnnge of 0.03 to 0.52. The morphological characterization of some progenies and progenitors shows that the nectary color is the main distinc- tive trait. Indonesia (Humid Tropics). Work is con- ducted in cooperation with the Central Re- search Irn,>titute for Food Crops (CRIFC) at Bogor, and other national institutions in Indonesia. Germplasm has been collected from various parts of the country. About 42 540 clones are now under preliminary characterization, and some have been screened for weevil and scab resistance. Evaluation of storability of harvested roots was measured by observing root quality and weight loss for 40 days after harvest. A few accessions showed good storability. Clones with high yield potential, scab resistance, and good plant survival rate were selected for use as parents in a recur- rent selection program. Materials from Program 2 this project will feed into Indonesian vari- ety selection programs, and be made avail- able for international distribution and testing. The Philippines (Highlands and Humid Tropics). Research continued with na- , tional program cooperators on the evalua- tion of local and introduced sweetpotato germplasm for yield, earliness, root dry matter, shade tolerance, and for SPW and RKN resistance. Superior clones were identified for each trait and will be used in advanced breeding programs. Heritabilities for root yield, root size, number of roots per plant, and dry matter content were estimated by parent-offspring regression during dry and rainy season trials (fable 2-6). Sixty open-pollinated seedlings per parent were evaluated using an RCBD with three replications. Root dry matter heritabilities in two rainy season trials were moderate, indicating that prog- ress can be expected in selection for this trait. China (Subtropical Lowlands). The prin- cipal aim of the project, carried out under contract with the Guandong Academy of Agricultural Sciences (GAAS), is to assist in the evaluation of the Chinese germ- plasm collection for a number of traits such as resistances to BW, Fusarium wilt, and weevil infestation. Tolerance to drought and humidity and storability of roots are also evaluated, as are quality components such as dry matter content and culinary quality. Promising clones from these evaluations have been included in a crossing nursery, and seed has been used in the selection of improved clones. GermpJasm Enhancement Using Wild Sweetpotato Species The objectives in this area of research are to develop methods for the evaluation and utilization in breeding of the closer rela- tives of the cultivated sweetpotato for traits of high interest, including weevil resistance, high root dry matter content, and hybrid vigor. Utilization of the Wild Species Ipomoea trifula. So far, research on germplasm en- hancement has focused on developing tet- raploid ( 4x) storage-root producing interspecific hybrids between cultivated 6x I. batatas and wild 2x I. trifula. These hybrids, which induce storage root forma- tion in interspecific progenies, are to be used as testers for the evaluation of wild species germplasm. They may also serve as bridges for the transfer of selected wild species germplasm to the cultivated genepool if their ploidy can be manipu- lated through the use of 2n pollen or colchicine doubling. Table 2-6. Heritability estimates in sweetpotato, Canlubang, the Philippines, 1989-1991. Yield Root per plant Root size (length) Dry matter(kg) Number of parents Program 2 Rainy season 0.11 ± 0.24 0.42 ± 0.19 0.07 ± 0.19 0.47 ± 0.17 24 1989 Dry season 0.38 ± 0.12 0.02 ± 0.14 0.81 ± 0.32 18 Rainy season 0.17 ± 0.18 0.25 ± 0.26 0.15 ± 0.20 0.38 ± 0.12 22 1991 Dry season 0.34 ± 0.42 0.40 ± 0.37 0.44 ± 0.35 38 43 Collecting sweetpotato, I. trifida, in the wild. During the past year, research was con- ducted to improve the storage root charac- teristics of the 4x tester population. This was done through intermating the best yielding 4x interspecific hybrids from work of previous years. New testers will be selected from among seedlings for high root production, reduced dry matter con- tent, earliness, and attractive appearance. Progenies from the interspecific tester population were sent to cooperators in the Jiangsu Academy of Agricultural Science in China, and to Indonesia. Work was also conducted on the eval- uation of germplasm atcessions of/. leu- cantha, /. triloba, I. ramosissima, /. tenuissima, '2x and 4x I. trifida, by cross- ing them reciprocally with the 4x testers. Except for I. trifida, the wild species used produced seed only when used as females. 44 The nature of this unilateral interspecific incompatibility, which has important im- plications for wild species utilization, is under investigation. Progeny evaluations of the interspecific crosses will permit the evaluation of the wild species accessions. Applying Molecular Techniques to Sweetpotato Breeding Transformation and regeneration of sweetpotato cultivars. The objectives in this area are to develop and use molecular techniques for the transformation and re- generation of selected varieties to improve some high priority traits. Although work in this area is just beginning, strong col- laboration with institutions having a com- parative advantage in the area of DNA technology is anticipated. Program 2 During the past year, optimum condi- tions for plant regeneration using organo- genesis from intemodes, roots, and leaves of nine sweetpotato cultivars were estab- lished through the testing of different growth regulators and culture condi- tions. The cultivars Jewel and Huacha- no were found to have high organogenic potential. The results of last year's research are now being tested using Agrobacterium- transformed plants of Jewel and Huachano as model cultivars, with the intention of using cowpea trypsin inhibitor constructs to engineer resistance to weevil. This work is being conducted in collaboration with Agriculture Genetic Center, a private UK company. Collection and Characterization of Andean Root and Tuber Crops Although priorities for research on An- dean root and tuber crops (ARTC) will be defined in a planning conference in early 1992, a preliminary strategy for the sys- tematic collection of these crops and their wild relatives has been formulated and collections are underway. Collecting missions and germplasm donations. Several collecting missions were undertaken with INIAP, the national agricultural research institute of Ecuador, IBTA, the national agricultural research institute of Bolivia, and CICA, the center for the study of Andean crops in Cusco, Peru. National scientists nominated by their respective national program accom- panied CIP researchers on their collecting missions. Duplicates of collected accessions were left with collaborating institutions. A considerable amount of herbarium mate- rial was deposited at the national herbaria in La Paz and Quito, as well as at UNALM in Peru. A collecting mission in Bolivia, jointly undertaken with IBTA, resulted in the collection of 93 accessions. Another small expedition carried out in Peru A donation of about 80 accessions of oca germplasm from the Department of Puno in Peru was received from the non- governmental organization SAPHA yielded 40 samples. Showing a sample of one of the ARTC, mashua. Program 2 45 (Servicios Agrarios, Puno). Another im- portant donation of about 120 accessions of ulluco, mainly of Bolivian origin, came from the University of Turku in Finland. This material had been collected by Finn- ish researchers studying the reproductive biology and variability of ulluco. A dupli- cate set of this material had been left in Bolivia, but could not be maintained there. CIP will ther6fore now return an identical set to Bolivia for utilization in breeding programs. By November, collections carried out by CIP and donations received from NARS accounted for CIP's ARTC germ- plasm holdings (Table 2-7). Experience with potato and sweet- potato collections would indicate that ARTC collections are highly duplicated and not representative in terms of geo- graphic coverage. Therefore, 1992 collec- tion activities will concentrate on northern Argentina, northern Chile, and possibly Colombia, in order to fill identified geo- graphic gaps. Efforts will also concen- trate on identifying duplicates by means of morphological and biochemical characterization. Conservation of ARTC germp/asm. Some duplicates of the accessions listed above are maintained either as field collections or in vitro by the NARS of the material's country of origin, such as INIAP (Quito, Ecuador, field collection and in vitro), CICA (Cusco, Peru, field collection) and IBTA (Cochabamba, Bolivia, field collec- tion). A complete set of ulluco, oca, mashua, and yacon accessions is being duplicated in vitro at CIP Quito and CIP La Molina, and arracacha and achira are maintained as potted plants in an insect- proof greenhouse at CIP La Molina. Maca, which displays orthodox seed storage be- havior, is maintained as botanical seeds at -1s·c. With the exception of maca, ARTCs are exclusively propagated by vegetative means. However, practically all have re- tained their ability to set botanical seed at different rates as is the case with mashua, arracacha, yacon, mauka and achira. It had appeared that sexual seeds of yacon were unknown and probably not produced at all. However, CIP's collecting activities, yielded the discovery and collection yacon seeds. Furthermore, seed produc- tion was achieved in La Molina (on the dry Pacific coast of Peru), under very different Table 2-7. ARTC ger'mplasm held in CIP's collection. Common Number of Species name accessions Origin Oxalis tuberosa oca 212 Peru, Bolivia, Ecuador Ul/ucus tuberosus ulluco 134 Peru, Bolivia, Ecuador Tropaeol11m tuberosum mashua 15 Peru, Bolivia Polymnia sonchifolia yacon 12 Peru, Bolivia Arracacia xanthorrhiza arracacha 11 Peru, Bolivia Canna edu/is achira 9 Peru, Bolivia Mirabi/is expansa mauka Peru LeRjdium meyenii ma ca 33 Peru 46 Program 2 .. conditions from those of the warm Andean CIP and in research collaboration with San valleys, where the ARTCs originate. Thus, the possibility of maintaining germplasm of these crops through sexual seed is under investigation. Characterization and documentation. In collaborative research between CICAand CIP, a collection of 480 oca accessions from the southern Andes was morphologi- cally characterized. Procedures for a computerized compi- lation of passport and morphological data have been developed. The documentation of ARTC germplasm includes photo- graphing the underground parts of each plant accession, the preparation ofherbar- ium specimens collected during the vari- ous collectingmissions, and the field planting of material at Quito, Ecuador. All of these data and materials are organized for easy cross-reference. A research contract with INIAP's plant nutrition department determined the raw protein (using the Kjeldahl methods) and dry matter content of around 400 acces- sions of oca, ulluco, and mashua from the Ecuadorian INIAP collection. Preliminary analysis of the data obtained suggests that the nutritional variation of these species in Ecuador is very limited. Virological studies. Serological virus de- termination and partial characterization of four viruses previously found in ulluco at Training Training on Germplasm Management Zaire. A germplasm management course, held in Bukavu, June 9-13, was organized by PRAPAC with participation of 16 Program 2 Marcos University of Llma, Peru, con- firmed previous results by Brunt et al. in 1982 which identified ullucus mosaic virus, ullucus virus C, papaya mosaic virus strain ullucus, .and ullucus mild mosaic virus. Antisera for the detection of these viruses were produced and are now available. Attempts to reduce the cost of the DAS-ELISA test have demonstrated that penicillinase enzyme was as sensitive as alkaline phosphatase in the detection of ulluco viruses. This is a much cheaper test than DAS-ELISA, and is now routinely used in the detection of ulluco viruses. Kits for the PCN-ELISA test are available and have been sent to CIP's Highland sta- tion at Quito, and to the biotechnology laboratory of San Marcos University. Vims elimination. Attempts to eliminate ulluco virus began in 1991. Plants of 15 Peruvian commercial ulluco clones, main- tained at CIP's germplasm bank in Peru, were selected for virus elimination by heat treatment. The stem tips of 20 cm high plants were clipped off and placed in a rustic thermotherapy chamber under con- tinuous light and temperatures from 29- 330C. These conditions induced rapid growth of new shoots from the axillary buds. Meristemes were cultured after two weeks of heat treatment. This work is still in progress. trainees from Burundi, Rwanda, Uganda, and Zaire. Mexico. An international course on the evaluation and selection of potato germ- plasm was held at the National Potato 47 Program in Toluca, August 9-11. It was organized by PRECODEPAand funded by CIP Region II. Participants were from Guatemala (1 ), ·El Salvador (1 ), Honduras (1), Nicaragua (1), Panama (1), the Dom- inican Republic (1 ), Haiti (1 ), Cuba (1 ), and Mexico (2). 'fraining in Potato Breeding Peru. A workshop on advances in potato breeding in Andean countries, was held in Lima, February 4-7. It was jointly organ- ized by CIP Region I and PRACIPA, with funding from IDRC. Participants from Bolivia (4), Colombia (4), Ecuador (3), 48 Venezuela (3), and Peru (13) attended the workshop. Breeding topics discussed in- cluded fungal and viral diseases, insect and nematode resistance, earliness, frost resistance, genetic engineering, quaran- tine regulations and exchange of genetic materials. Colombia. The PRACIPAnetwork organ- ized a breeding projects coordination meeting in Rio Negro and Bogota, June 24-28. The meeting was hosted by ICA and the CIP Region I office in Bogota. Nine participants from Bolivia (2), Ecuador (1), Peru (1), Venezuela (1), and Colombia (3) attended the meeting. Program 2 • Electron microscope view of sweetpotato virus C-4. Many destructive sweetpotato viruses remain unknown. The challenging task of identifying them and determining their relative importance remains to be done. Program3 Disease Management 1991 In Review Through the process of restructuring CIP's research efforts, Program 3 incorporates the activities of former Thrusts III (Control of Bacterial and Fungal Diseases) and IV (Control of Virus and Virus-Like Diseases). Disease management continues to be an important and necessary part of CIP's research agenda. Diseases of potato and sweetpotato caused by fungi, viruses, bacteria, and viroids can drastically reduce the production of these crops in developing countries unless methods of integrated control are utilized. CIP collaborates with other institutions worldwide to develop the components for disease control, especially screening for resistance in germplasm and its utilization by NARS and in breeding programs. Field resistance to potato late blight has been further improved using both a major-gene containing and a major-gene free population, combined with resistance to potato viruses X and Y. In Peru, the recently released Canchan-INIAA variety is gaining popularity and two more cultivars are being considered for varietal release. Three varieties were released in Uganda and many promising selections are soon to be named in several other countries. The potato bacterial wilt (BW) resistance program has undergone significant changes. Screening in Peru has been expanded from San Ram6n (race 1) into Cajamarca (race 3) and Piura (races 1 and 3). Fundamental heritability studies were begun with numerous sources of resistance and a new breeding scheme was initiated emphasizing race 3, which was found to be more homogeneous than race 1 and the principal cause of the disease. Further, because potato plants become more susceptible to wilt in the presence of the root-knot nematode (RKN), renewed emphasis has been placed in combining these resistances. A monoclonal antibody developed in China was effective in detecting most strains of Pseudomonas solanacearum. At Wisconsin, USA, RFLP taxonomic studies of the bacterium using over 200 strains and several probes has permitted a tentative new classification scheme based on natural groupings. The Erwinia resistance program was expanded to include screening for resistance to blackleg after the initial selection for soft rot resistance. In Tunisia differences in resistance to soft rot were found among varieties, and interaction to cause greater disease incidence of Erwinia with Verticillium wilt fungus was shown. Screening for virus resistance in wild potato species has yielded new accessions for resistance to PLRV, PVXc, PVX-HB, PVX-GUA, PVY, PVS, PVT, and PSTVd. Breeding for resistance to PLRV has produced eight highly resistant clones. Four Program3 51 varieties from Poland were reconfirmed as highly resistant to PLRV and to the aphid Myzus persicae. It was shown that immunity to PVX and PVY can be transferred by protoplast fusion. Combination of resistances to PVX, PVY, and early blight (Alternaria solam) has been achieved. The virus detection program continues to provide antisera to the major potato viruses and a new PLRV antiserum is being prepared. Nitrocellulose membrane ELISA and nucleic acid spot hybridization procedures have begun to be employed to monitor the stability of immunity to PVX and PVY worldwide. Two probes were selected and compared for their ability to detect different PVX strains, both being highly specific for the strain used for its preparation, but a recombined probe detects all strains and isolates so far tested. A unique recombinant probe, for both true seed transmitted pathogens PVT and PSTV d, was prepared and proved to be effective. Sweetpotato chlorotic leaf distortion disease, originally described in the USA, was found in Peru and Kenya. True seed from Brazil, Ghana, Kenya, Ni~eria, Papua New Guinea, the Philippines, Peru, and the USA also was found to carry this disease. Laboratory methods to test for resistance to fungi that cause rots of sweetpotato storage roots were developed and screening conducted on about 300 accessions of CIP's germ plasm for Rhizopus, Diplodia and Fusarium rots. In three accessions resistance to Fusarium oxysporum only was found. Screening for resistance to scab in the field in Indonesia resulted in 20% of 130 clones reacting as highly resistant. Surveys in sub-Saharan Africa revealed an incidence of previously described diseases, as well as two unknown diseases whose etiology is being investigated. The unidentified sweetpotato virus C-4 was characterized as to symptomatology under greenhouse conditions. It was shown to be transmitted by an aphid to lpomoea nil, and the virus particles shown to be isometric of about30 nm diameter. The C-2 virus was named sweetpotato chlorotic flecks virus (SPCFV). It was found to be widespread in China, Japan, and Peru and was isolated from plants from Bolivia, Brazil, Colombia, Cuba, and Panama. It infected several cultivars, but not Im by 3102. Work is progressing on C-3 and C-6. Virus detection kits for potato viruses are a well used CIP product. Antisera, Das-ELISA, and NCM-ELISAkits were distributed to evaluate more than 750,000 virus samples. Disease management activities are divided into projects centered around particular diseases or general categories. Project objectives are the control of potato late blight, soft rot and blackleg, and powdery scab; detection of viruses and of plant resistance to viruses combined with resistance to fungi; and integrated control of bacterial wilt in potato. In sweetpotato, the objectives are to control fungal and bacterial diseases; identify viruses and resistances to viruses, and to develop detection methods. 52 Program 3 Potato Control of Late Blight The control of potato late blight (Phy- tophthora infestans) focuses mainly on developing host resistance as the major component of integrated control. Horizon- tal resistance is less vulnerable and thus preferred in breeding. To this end, two sources of resistance are being used, one that contains major genes (R-genes) in addition to horizontal resistance (Popula- tion A) and the second containing only horizontal resistance genes (Population B). Until now, following a multilocation testing scheme that includes key locations where late blight is endemic and severe (Rionegro, Colombia; Ruhengeri, Rwan- da; and Toluca, Mexico), many late blight resistant clones have been developed for Yield Kg/plant distribution to NARS for utilization as potential varieties. Emphasis is now being placed on the use of Population B as the major future source of resistant cultivars. Breeding activities with Population A this year concentrated on field testing of clones from the ninth and tenth generation or group (G-9 and G-10) for horizontal resistance to late blight, in Rionegro, Ruhengeri and Toluca. Selected clones showed late blight resistance, wide adapt- ability, and good agronomic attributes. The test at Toluca, that includes clones of G-9 previously selected in both Rionegro and Ruhengeri, led to the selec- tion of an additional 42 resistant clones to be distributed to NARS. Six of these yield- ed around 2.5 kg per plant (Figure 3-1 ). 387224.11 387052.36 388714.6 388764.26 387297.6 Clones Figure 3-1. Potato yield response under late blight conditions in a sample of clones selected from G-9, tested at Toluca, Mexico, 1991. Program 3 53 Field testing of about 3,000 G-10 clones for the first time at both Rionegro and Ruhengeri, resulted in the selection of 544 and 203 late blight resistant clones, respectively. Of these clones; 92 were con- firmed to combine resistance to late blight and immunities to PVY and/or PVX. Im- munities to PVY and PVX are being grad- ually introduced into Population A A frequency-distribution histogram of the apparent infection rates r calculated for all G-10 clones at Rionegro and Ruhengeri confirmed that the different de- grees of infection expressed by a popula- tion of clones in the field follow a normal distribution curve. This demonstrates that resistance to late blight is of a quantitative nature and subject to improvement by in- creasing its frequency (Figure 3-2). It is also evident that the screening locations Number of clones are suitable, although some unknown R-genes for vertical resistance exist that could interfere with the selection process. Breeding with Population B for hori- zontal resistance to late blight in the ab- sence of R-genes included: • Successful crossing of the 31 most ad- vanced putative R-gene free clones, with varying degrees of horizontal re- sistance, that were selected by screen- ing Population A Progenies obtained through appropriate mating designs will permit researchers t? estimate clone heritability of late blight resistance, ver- ify the absence of R-genes, and deter- mine the stability of resistance and their parental value for breeding. • Identification of a new set of 25 clones derived from Population A, quite probably soo~~~~~~~~~~~~~~~~~~~~~~~~~--. 700 600 500 400 300 200 100 0.03- 0.05 0.08 - 0.10 0.14- 0.16 0.20 - 0.22 Apparent infection rate (r) Figure 3-2. The number of G-1 O clones infected at varying rates indicated that LB infection follows a normal distribution curve (Rwanda, 1991 ). 54 Program3 free of R-genes and having different degrees of horizontal resistance. Simul- taneous inoculation of detached single leaves of a large sample of clones was done with a race zero strain and a com- plex race that included virulence to the weak genes R2, R4, RlO, and Rll. These tests were carried out under con- trolled environmental conditions in Lima. Positive leaf infection with both races followed by lesion growth and a high sporulation rate (Figure 3-3) indi- cated the absence of R-genes. Subse- quent progeny tests of selected clones will be conducted to confirm their free- dom from R-genes and to use them in breeding. • Initial selection of 2,730 single-hill clones that are potentially resistant, from among a population of 60,000 Percent of leaf area infected seedlings transplanted and exposed to natural infection in the field at Quito, Ecuador. This mid-term breeding popu- lation for horizontal resistance to late blight originated from native R-gene free Andigena and Tuberosum germ- plas m. Trials in larger plots are scheduled for the following season to reconfirm resistance and to select for agronomic attributes. Results of these efforts should speed up progress to achieve high levels of horizon- tal resistance to late blight in cultivars free ofR-genes. Peru. The Peruvian national program re- ceives most of the advanced late blight resistant germplasm developed at CIP as direct support. During the last five years, 14 clones in regional trials have shown high yields and stable resistance to late Check Iii) Complex race 100 80 60 40 20 3871709 387214.9 387291.4 387334.5 Atzimba 387170.6 387181.7 387231.7 387291.12 387341.1 Tomasa Clones Figure 3-3. Sample of clones free of R genes extracted from Population A by inoculating detached single leaves with either race "O" or a complex race. Program3 55 blight. Clones 377744.1and380474.6 are soon to be released as varieties. Likewise, the recently released late blight resistant variety CANCHAN-INIAAdeveloped by INIAAand CIP with farmers participation is rapidly gaining popularity as a result of efforts by individual farmers and some nongovernmental organizations. Burundi. Regional trials in Burundi were carried out during the two potato growing seasons in 1991. Four CIP clones showed high resistance to late blight, good adapt- ability, and outstanding yields, 382147.18, 382195.21, 381381.26, and 381381.9. CIP clone 382147.18 had the highest tuber yield with and without fungicide treatment for late blight control. Clone 381381.26 had a short period of tuber dormancy, a highly desirable character because it per- mits two consecutive planting seasons. Check varieties Muruta and Kinigi pro- duced poorly when not sprayed. Other A late blight test in Santa Catalina, Ecuador. 56 clones and varieties were slightly affected by late blight, indicating their high levels of horizontal resistance. Cameroon. Five promising advanced late blight resistant clones have been selected over a four-year period at four experimen- tal stations in Cameroon. Clone 720055 (of Mexican origin) and CIP clone 382121.27 were selected for variety re- lease, and are in the seed production stage. CIP clone 382381.20 is on standby to re- place 720055 if the latter fails to show stable horizontal resistance to late blight. So far, this last clone has only shown hy- persensitive reaction to late blight infec- tion. This result shows that local races in Cameroon were not able to overcome un- known R-genes present in this clone. It was therefore impossible to assess the clone's true level of horizontal resistance. Ecuador. For about eight years the Ecuadorian potato program (INIAP) has Program3 "' received CIP materials bred with empha- sis on resistance to late blight and cyst nematode. One late blight resistant variety, Santa Rita, has already been released. Other promising clones are undergoing advanced trials for final selection as resis- tant varieties. Some of these clones show tuber yields comparable to or greater than those of local cultivars (fable 3-1). Mexico. Five OP-selected clones (382143.17, 380026.12, 382245.20, 381381.9, and 380018.21) from the international testing scheme for late blight resistance carried out at Toluca Valley, were in regional trials throughout the country and had good adaptation, high yields, and good late blight resistance. Aftenegional trials, ad- vanced clone 380024.6 was rated as excel- lent by the INIFAP.Potato Program. The Philippines; After several years of in-country regional trials of the most ad- vanced clones selected for resistance to late blight and adaptability, four of seven clones showed excellent yield perform- ance and outyielded the local susceptible checks Granola and I-1035 (Table 3-2). P-6 (CIP 380496.2) was the highest yield- er, at 22.2 t/ha, double the yield of check I-1035 (11.4 t/ha). However, it was not selected because of its purple splashed skin color. Further studies on farmers' ac- ceptance of new varieties with obvious advantages are needed to help capitalize on available technology and satisfy farmers' requirements. Uganda. After three years of testing and selection of late blight resistant clones in- troduced from CIP, three new varieties were released in 1991 with their original CIP numbers. Results of 13 on-station and 16 on-farm trials conducted at five loca- tions from 1989 to 1991 indicate that va- rieties 381381.20, 381379.9, and 374080.5 had good adaptation, resistance to late blight, and high tuber yields. After approval by the Uganda Variety Release Committee, these clones are undergoing multiplication as basic seed stocks for dis- semination throughout potato growing areas. Venezuela. The Venezuelan potato pro- gram reported that most advanced clones Table 3-1. Yield performance of advanced late blight resistant potato clones tested over several locations in Ecuador, 1991 (reported by INIAP, Ecuador). Pichincha Carchi Quito Chimborazo CIP Number Vha Vha kg/plant kg/plant 384163. 80.0 47.9 2.8 1.6 382119.17 73.2 54.7 2.6 1.8 382172.3 72.9 384375.3 65.2 51.9 2.2 1.8 384292. 61.0 30.7 2.3 2.~ 384343. 56.6 384304. 52.2 37.5 1.9 1.8 Local checks Cecilia 72.3 6.3 0.5 Esperanza 65.0 30.6 1.7 1.1 Catalina 50.2 1.2 Gabriela 39.9 19.4 1.1 1.1 Program3 57 Table 3-2. Tuber yields of seven late blight resistant potato clones grown in farmers' fields in three locations in the Philippines, 1991 . Sayangan Sinipsip Sinto (2,300 m) (2,700 m) (2,500 m) Mean t}ha marketable t/ha marketable t}ha marketable tlha Clone (%) (%) (%) P-6 23.0 95 22.0 93 20.8 87 22.2 LBR-5 17.8 95 15.0 88 19.3 90 17.4 1-1085 14.8 90 15.0 90 16.8 88 15.5 LBR-13 13.6 90 13.0 70 9.5 78 12.0 LBA-9 9.7 92 10.0 77 15.0 88 9.7 LBA-3 7.6 70 13.7 70 10.8 92 10.7 1-1039 6.4 90 9.0 83 8.8 95 8.1 Checks 1-1035 11.0 90 10.0 90 12.3 85 11.4 Granola 10.2 82 4.3 20 6.5 82 8.9 Mean 12.8 88 12.6 81 13.3 87 12.9 CV(%) 21.8 8 25.0 12 23.0 8 LSD (0.05) 4.1 10 previously introduced from CIP were un- dergoing regional trials for variety release. Tuber yields of the most promising late blight resistant clones (382147.18, 382147.17, 382157.22, 382121.25, and 382140.14) were two to five times higher than those of popular susceptible cultivar Granola. International distribution. During 1991, 21 countries received late blight resistant materials as clones and/or segregating progenies for resistance to late blight (Table 3-3). Integrated control of bacterial wilt (BW) Peru. An in vitro technique was investi- gated as a possible alternative to the mass screening technique currently used for screening of genettcally transformed plants. Sap from transformed plants was dtracted, filtered, and spotted at the cen- ter of petri plates uniformly inoculated with Pseudomonas solanacearum. A zone 58 5.4 16 4.5 11 free of bacterial growth occurred where spotted with the sap of transformed plants, but not when the sap was from control plants, suggesting that only transformed plants produce a bactericide. The three polyclonal antisera produced in 1990 were compared using DAS- ELISAand NCM-ELISAtechniques. The one prepared against strain CIP-204 was best. It was tested for detection of latent infection in tubers, compared with plating on Kelman's agar medium. Samples con- sisted of 2-5 tubers sliced 2 mm thick from the stolon end and macerated in 15 ml of PBS. The three techniques detected the presence of P. solanacearum in most sam- ples (Table 3-4). Therefore, because it is easier to use and interpret, NCM-ELISA should be recommended for use by NARS to detect latent infection in seed programs (membranes can be spotted and mailed to CIP for completion of the tests). NCM- ELISA kits were prepared and sent to NARS of Chile, Egypt, Indonesia, Kenya, Program3 "' Table 3-3. Distribution of late blight resistant material from the International Late Blight Project during 1991. Country Number of clones Bolivia8 99 Burundi 122 Colombia8 34 Ecuador Ethiopia 104 Ghana 110 Guatemala 69 India 49 Kenya 41 Madagascar 79 Malaysia Nepal 20 Netherlands Nigeria 75 Panama 10 Philippines 128 Rwanda8 113 Sri Lanka 16 Uganda8 102 Venezuela Vietnam Total 1,171 a These countries received 2 shipments. Mauritius, Nepal, Nigeria, the Philip- pines, and Uruguay. In an attempt to further minimize the variation that occurs in screening tests for resistance, cuttings from up to six different nodes of given plants were tested, using resistant variety Molinera and susceptible varieties Ticahuasi, Yungay, and Revolu- ci6n. Inoculum consisted of 5 x 10 7 cfu/ml of isolate CIP 204. There were significant differences between different sets of cut- tings for a given variety. The younger, more apical cuttings were more resistant than more basal ones. The nodes were numbered from 1 to 6 from the base to the apex. Significant differences per variety, starting with the most resistant, were: Program3 Clones from tuber families 885 320 426 614 4,363 True seed/ families 6,000/30 3,750/25 11,500/23 3,000/15 4,600/23 4,000/20 1000/10 4,000/20 27,500/166 Ticahuasi 5-2, Yungay 6-4, Revoluci6n 5-4, and Molinera 4-3. Therefore, using multiple cuttings from one plant causes greater variability than if only one apical cutting per seedling is used. Close to 9000 plants of 363 genotypes were screened for resistance under green- house conditions for five different breed- ing programs (results reported elsewhere). Because the Huaraz field screening site cannot continue to be used, new sites are being explored. At San Juan, Cajamarca, the uniformity of soil infestation with the bacterium is being established. In Piura near the equator, two field sites (Huan- cabamba, 2,080 m, and Frias, 1,810 m) were utilized to screen 175 genotypes that 59 Table 3-4. Detection of latent infection of potato tubers harvested from field grown plants that showed bacterial wilt symptoms, by plating on Kelman 's agar or by two serological tests. Sample Culture medium a Number Kelman+ TZC DAS·ELISAb NCM-ELISAc T#1 0.142 T#2 0.196 T#3 +++ 0.392 ++++ T#4 +++ 0.605 ++ T#5 +++ 0.573 ++++ T#6 ++ 0.458 T#7 +++ 0.201 T#8 + 0.192 T#9 0.231 T#10 +++ 0.625 ++ T#11 +++ 0.580 +++ T#12 0.299 T#13 +++ 0.692 ++ T#14 +++ 0.665 ++ T#15 0.222 T#16 0.173 T#17 0.201 T#18 ++ 0.215 ± T#19 0.214 T#20 +++ 0.300 T#21 +++ 0.266 T#22 ++ 0.443 + T#23 0.335 +++ Buffer ,0.146 a(-)= No typical colony was observed(-),(+)= 2-5 colony/plate, (++) = 5-10 colonies,(+++)= more than 10 colonies/plate. bMean of absorbance at (405 nm) of four wells per sample, read after 20 min. 0 (-) = No reaction, (+, ++, +++, ++++) =represent a low, medium, high, and very intense purple color 20 min after adding the conjugated enzyme. include the best resistance available from numerous sources. The low latitude and relatively low altitude for potato growing, are very favorable conditions for BW de- velopment. Twelve clones yielded over 1 kg/plant and had no foliar wilt, but latent infection. occurred in the symptomless tubers. This relative resistance should prove useful, provided the most tolerant clones are the most resistant ones under less adverse conditions. 60 A genetic study of the general and spe- cific combining abilities for resistance to P. solanacearum was conducted in a pop- ulation developed to include inmunity to PVX and PVY. The 120 clones selected at San Ram6n in a heavily infested field were evaluated under greenhouse conditions in La Molina and their narrow-sense herita- bility for resistance to BWwas found to be low (0.18). Clones (382291.3 x XY-16).82 and (381050.1 x XY-13).23 were resistant Program3 "' ,, to strains of races 1 and 3 and showed good yield and medium earliness. When 100 clones were arranged in a 10 x 10 lattice for evaluation for resistance at San Ram6n, the most resistant, medium earliness clones were (381077.1 x XY- 13).73, (382291.1 x XY-13).68, and (381077.1 x XY-16).28. Tubers of the 30 resistant clones from the previous evalua- tion were assayed for latent infection. Only clones (381077.1 x XY-16).28, (382302.2 x XY-9).55, and (382291.l x XY-16).68 failed to show latent infection. The search for new genetic resources and the use of RFLP to monitor the intro- gression of genes conferring resistance followed by the mapping of genes of a 2x population has begun by screening a group of 34 Fl plants with race 3 isolate 204. Results are pending, as are those of screen- ing for re8istance to RKN. Attempts were made to transform po- tato genotoypes to combine natural resis- tance with synthetic resistant-gene constructs by inoculation with Agrobac- terium tumefaciens containing antibacte- rial genes. It was initially shown that regeneration without infection was possi- ble. However, when plants were infected with the gene construct, regeneration did not take place. Thus, different media were tried. Diploid Solanum phureja clones CCC1386.26 and PI123050.2, and the tet- raploid obtained by endomitosis in callus culture of the first of these, CCC1386.26.82, were tested for their re- generation ability in three different media using leaves, leaves with petiole, and stem segments as explants. Desiree, a cultivar with well-known regeneration capacity was used as a control. Regeneration occurred in the three tested genotypes, with a higher rate of success with stem segments. The Program3 less inbred genotypes had greater regener- ation ability. Because potato plants become more susceptible to P. solanacearum when at- tacked by RKN, resistance to this parasite is of great interest for integrated control. An evaluation was made of the reaction to Meloidogyne incognita of224 diploid po- tato clones developed by intermating 24 2x clones (having either single or com- bined resistance or tolerance to Meloido- gyne incognita, Globodera pallida, Phthorimaea operculella, Pseudomonas solanacearum, early blight, and soft rot) with three 2x clones having resistance to PVY and PLRV. The genetic background of these clones includes various potato cultivars and breeding lines (Solanum tu- berosum ssp. tuberosum and S. tuberosum spp. andigena, S. bokasovi~ S. gourlay~ S. chacoense, S. multidissectum, S. phureja, S. sparsipilum, S. yungaenses, and S. ste- notumum). Approximately 60% of the clones were found to have varying degrees of resistance to M. incognita. Only one clone was found to be highly resistant while 78 were resistant and 54 moderately resistant. Some clones showed resistance to both M. incognita and P. operculella. Since over 50% of these clones produce functional 2n pollen and some produce 2n eggs, there appears to be a good possibility of transferring the resistance traits by 2x - 4x crosses. A total of 5 clones having resistance to either M. incognita and P. solanacearum, or M. incognita and PLRV are presently included in the pathogen tested list or are being cleaned up for dis- tribution. The possibility that M. incognita is im- plicated in the dissemination of potato spindle tuber viroid (PSTVd) was investi- gated. Data suggest that PSTVd may be carried on the surface of the female 61 M. incognito, on the cuticle of juveniles, inside the egg mass, and on the surface of eggs extracted from PSTVd-infected plants. This is of particular interest since the egg masses left in the 'soil from one season to the next can become a focal source of PSTV d infection. This is the first report of possible involvement of a tylenchoid nematode in the dissemination of a viroid. The role of M. incognito on the inci- dence of some tuber diseases under stor- age conditions was investigated. Data in- dicate 59% of the tubers infected with M. incognito at the time of storage rotted after 60 days storage as compared to 13% of uninfected tubers. After 4 months of stor- age, the rate of rotting increased to 68% for infected and 16% for uninfected tu- bers. Erwinio spp., P. solanocearum, and Fusarium spp. were the organisms prima- rily isolated from the rotted tubers. The total weight losses due to rotting of tubers were 60% and 17% for infected, and 89% and 26% for uninfected tubers after 60 and 120 days of storage. China. The effectiveness of four mono- clonal antibodies (McAb) produced by es- tablished hybridoma cell lines was deter- mined by testing them against 45 strains of P. solanoceorum from potato of various geographical origins, including Beijing, Hebei, Hubei, Huang, and Hunan prov- inces. Determinations were made by indi- rect ELISA. Bacterial suspensions were sonicated and diluted to 50 mg/ml. Mono- clonal antibodies were harvested from as- citic fluid and diluted to 1:100 in 0.01 M PBS (pH7.4). Reactions were generally considered positive when the absorbance value was two times greater than the neg- ative control. Results indicated that the McAb3 reacted strongly with all 45 strains of P. Solanacearum tested, whereas McAb2 62 reacted moderately with all strains. McAb 1 and McAb4 showed positive reaction with all strains except Po 2 and Po 10. A modified immunofluorescent test with McAbs was used for detecting BW latent infection of potatoes. The tissue ex- tract was prepared from samples of tuber seeds by homogenizing and centrifuging at 1500 rpm for 5 min. The supernatant was then centrifuged at 8000 rpm for 10 min. The pellet containing bacteria was resuspended, incubated with McAbs for 1 hr, then centrifuged and resuspended in FITC conjugated antimouse immunoglob- ulin for another hour. Bacteria were pel- leted, then resuspended in 0.5 ml PBS and collected on the surface of a polycarbonate membrane filter (0.2 micrometer pore size, 13 mm diameter) by filtration. The stained polycarbonate membrane was mounted on microslides with glycerol PBS (9:1) and coverslips. All bacteria extracted from each sample were intercepted and cap- tured on the surfaces of the membrane filters. This method could enhance the de- tection rate of BW latent infection. How- ever, it requires more McAb and FITC conjugated antimouse immunoglobulin than the normal IFA method. Indonesia. Potato germ plasm was screened for resistance to Pseudomonos solanoceo- rum. True potato seed from the CIP breed- ing population were germinated and mul- tiplied at Tangkuban Prahu, West Java, in 1990-91. Clones were selected based on adaptability and tuber shape using cultivar Granola as a check. Screening was done at the Horticultural Research Institute Sub- station (at 1,100 m), Segunung, West Java. Before screening, the field was planted with seedlings of tomato cv. Gon- dola, a local variety. By 25 days after planting, 28% of plants were wilting. 1be distribution of wilted plants was uniform Program 3 throughout the field. One month after planting, the field was plowed to incorpo- rate the plants into the soil. The clones were planted in a 5-hill plot with 35 cm between hills and 80 cm between rows. A completely randomized design was used with each hill representing a different clone. Of the 151 clones tested, 9 were se- lected based on the percentage of infested tubers. Only 3 clones (S60, S89, and Sl02) did not show any symptoms on either stems or tubers, and S78 had no tuber symptoms, but stems wilted. A highly sig- nificant correlation coefficient was ob- tained (r = 0.627) between the percentage of stem wilting and the percentage of tuber infection. Although further studies are re- quired, the degree of stem wilting could be used as a marker for the selection of resis- tant clones in this environment. Next year selected clones will be tested for resis- tance in two locations and during two sea- sons. Adaptability of the clones will be monitored and the level of latent infection will be evaluated after harvest. Kenya. In collaboration with the National Agricultural Laboratories (NAL), 68 clones from CIP's BW resistance program were planted for evaluation during the rainy season (April), in a plot that has been continuously planted to potatoes and is heavily infested with the pathogen. The following 18 clones were rated as resis- tant: 900927, 376999.6, 800935, 387973.12, 800977, 387067.2, 800942, 800959, 387973.7, 386295.1, 720025, 386191.21, 678009, 387968.5, 378015.16, 800949, 386295.8, and 800937. The Philippines. A search began for a biological control agent to be used in the integrated control of BW. Eighteen potato root samples were collected at Lantapan, Program 3 Intavas, Dalwangan, and Canlubang. A total of 341 rhizobacteria were isolated and maintained for in vitro screening against P. solanacearum. Three strains-Al, Bl and B2-of P. solanacearum were used in screening of the rhizobacteria isolates. A total of 144 isolates inhibited the growth of P. solana- cearum in vitro, indicating their antago- nistic capabilities. Among them, 75% were against strain Al, 55% against strain Bl, and 60% against strain B2. Some an- tagonistic rhizobacteria were effective against all strains of P. solanacearum, whereas others were effective against only some. Ten antagonistic rhizobacteria isolates were selected for a greenhouse test. Strains T2, N3, and C4 of P. solanacearum and two potato varieties 38.6 and Cosima were used in experiments at Los Banos. Disease control by rhizobacteria isolates was more effective using variety Cosima, than with 38.6. Some antagonistic rhizo- bacteria isolates controlled strain C4 when it was inoculated to the potato plant. How- ever, no treatment proved effective against strains T2 and N3. No antagonistic rhizo- bacteria isolate could consistently control the disease, especially when the different strains of P. solanacearum were used as inoculum. Uganda.. In collaboration with the Ministry of Agriculture, field experimentation was initiated to determine the best rotation to manage BW by integrated control prac- tices, including the use of resistant culti- vars. Initial results were a low incidence of wilt with susceptible varieties but none with resistant Cruza 148 (720118). United Kingdom. Research conducted for CIP at Rothamsted Agricultural Research Station was initiated this year. Studies began with tomato plants, which can be 63 more easily managed under controlled conditions. The pathogenicity of diverse strains of Pseudomonas solanacearum was investigated using in vitro cultured axenic tomato plants inoculated and incu- bated under strictly controlled environ- mental conditions. Strains representing a range of biovars, races, and RFLP groups differed in pathogenicity and aggressive- ness.Host-pathogen interactions were sig- nificantly affected by temperature, nutri- ent medium, pathogen strain, and inocula- tion technique. However, the method was too severe to detect specific differences in resistance or tolerance of cultivars to dif- ferent strains. Instead, both susceptible and resistant cultivars showed rapid and high mortality. In future, host-pathogen interactions will be studied by infectivity titration (using several levels of inocu- lum), at different temperatures, and will involve susceptible and resistant cultivars of potato, tomato, eggplant, pepper, and groundnut. United States. A comprehensive study of the taxonomy and genetic diversity in P. solanacearum by means ofRFLP analysis has been completed at the University of Wisconsin with more than 200 strains, based on the use of seven different probes. The data are being analyzed, including calcu- lations of similarity coefficients to develop a new taxonomy of the species based on natural groupings that reflect its evolution. Race 3-specific DNA sequences were isolated to develop a DNA probe for rapid identification of P. solanacearum by means of subtractive hybridization. Dur- ing the past year, efforts continued to de- velop a diagnostic kit based on the use of nonradioactive probes for hybridization with sample DNA. Extensive studies with two different nonradioactive detection systems included FMC Chemiprobe, 64 which sulfonates cytosine in the DNA probe and then detects the hybridized DNA with a mouse monoclonal antibody, and Boehringer's Genius system, which labels the probe by incorporating digoxigenin-labeled dUTP, which is rec- ognized by an antibody-alkaline phospha- tase conjugate. Both systems are effective in detecting race 3 bacteria from pure cul- ture, but are subject to high background problems when used to detect bacteria squeezed from potato tubers, as would have to be done in the field. The nature of the signalling system that results in induction of the hypersensitive reaction in plants to certain P. solanacea- rum strains, appears to involve cytoplas- mic membranes that exhibit tyrosine kinase activity. Phosphorylation of this protein on tyrosine residues, which is unusual for prokaryotes, was demonstrated by phos- phoaminoacid analysis of base hydrolysis products and by immunoanalysis. Mem- branes isolated from a polygalacturonase- defective regulatory mutant with reduced pathogenicity also exhibited reduced in vitro phosphorylation. Since PG is in- duced in planta, the results suggest that the tyrosine kinase plays a role in recognizing environmental signals that are important in pathogenesis. Control of Soft Rot and Blackleg (Envinia) Peru. At CIP headquarters 318 clones, mostly S. tuberosum ssp. andigena (ADG), selected up to 1990 as resistant to soft rot with isolate CIP 004 of Erwinia chrysanthemi (Ech), were re-evaluated. Ten tubers per clone were injected with 0.01 ml of a suspension of about 5 x 104 bacteria/ml of isolate CIP 367 of Ech. Tubers were then maintained for 72 hours in an incubation misting chamber with Program3 controlled temperature (27-30°C). From the 318, none had rot diameters less than 0.9 mm (HR), 12 had from 1.0 to 3.9 mm (R), 104 from 4.0 to 6.9 mm (MR), 137 from 7 .0 to 9.9 mm (S), and 65 had rot diameters of more than 100 mm (HS). Tubers of a new population of 2,750 potato clones from the first generation of crosses involving 56 ADG cultivars and 13 tuberosum x andigena hybrids were also evaluated with the injection method in the misting chamber, with 465 being HR, 132 R, 213 MR, 207 S, and 1,733 HS. Selections with HR soft rot reactions are being multiplied for re-evaluations using 10 tubers each. Furthermore, remaining tubers of those clones selected as HR, R, or MR to soft rot were evaluated for resist- ance to blackleg caused by Ech. Of 566 clones, 259 showed no blackleg when their stem cuttings were transplanted into a perlite substrate infested with a suspen- sion of 1 x 105 bacteria/ml. Moreover, 73 of the 259 clones survived a re-evaluation with a suspension of 1 x 106 bacteria/ml. The 73 clones combining resistance to both soft rot and blackleg are being prop- agated for further tests. Two line by tester (5 x 3 end 4 x 3) experiments were made including 14 clones selected from progenies of ADG cultivars with several degrees of resist- ance to soft rot. A total of27 progenies was planted at La Molina in a completely ran- domized block design with 3 replicates of 30 genotypes each. From 2,430 genotypes planted, 930 were selected at harvest 110 days after transplanting. The ANOVA of these two experiments showed no signifi- cant differences between the lines in both experiments, which indicates a General Combining Ability (GCA) effect. However, the line by tester interactions of both experiments did not yield significant dif- Program3 ferences thus indicating the absence of Specific Combining Ability. Lines CIP 700031.3 and ERW 376.2 and tester CIP 700726. 7 showed the highest GCA to transmit their soft rot resistance to their progenies. In general, these experiments showed the percentage of soft rot resistant (HR, R, and MR) genotypes in all proge- nies to be relatively high. In the 5 x 3 experiment, the percentage of resistant genotypes ranged from 37% (obtained in. the cross CIP 700031.3 x CIP 702734.1) to 17% (cross CIP 703855.5 x ERW 88- 056.02). In the 4 x 3 experiment the range varied from 44% resistant genotypes (crossERW376.2x CIP700726.07) to4% (cross CIP 703660.2 x ERW 399). Additional research established better methods to reduce variability in screening for resistance to soft rot and blackleg. Two storage conditions for tubers after a 20-day suberization or curing period were 5°C and 22°C, with evaluations by micro- injection inoculation at 10-day intervals (up to 100 days) with Erwinia chrysanthemi at three concentrations. Incubation was partially anaerobic at 28°C. Susceptibility decreased rapidly with time in storage and was also lower with cold storage (Table 3-5). The following inoculation methods to test for blackleg were evaluated: • Plants obtained from tuber sprouts were transplanted to plastic containers con- taining perlite inoculated with bacterial suspension (1 x 105 cfu/ml). The con- tainers were placed under greenhouse conditions at 26-29°C for 8 days. • Potato tubers were inoculated with bac- terial suspensions (1 x 107 cfu/ml) by vacuum infiltration prior to planting in pots containing sterile soil. The pots 65 Table 3-5. Effect of time and temperature on the susceptibility of stored potato tubers inoculated with Erwinia chrysanthemi using the microinjec- tion method. Storage Diameter of rotted tissue in mm (days) 22·c 5·c mean 10 17.10 a 13.70 bed 15.40 a 20 15.77 ab 11.68 de 13.73 a 30 14.57 be 7.90 ghi 11.07 b 40 12.62 cd 8.38 gh 15.50 be 50 13.37 bed 7.55 hij 10.46 be 60 13.55 bed 6.50 ijk 10.02 cd 70 11.45 def 6.05 jkl 8.75 d 80 9.10 gh 5.40 kl 7.25 e 90 10.07 'efg 4.85 I 7.46 e 100 9.65 fgh 5.27 kl 7.46 e Means followed by the same letter are not sig- nificantly different at P = 0.01 by Tukey's test. were placed under greenhouse condi- tions at 26-29°C. • Using vacuum infiltration, potato tubers were inoculated with bacterial suspen- sions (1 x 107 cfu/ml), prior to planting under field conditions at San Ram6n Experiment Station. When the tubers were inoculated by vacuum infiltration to produce blackleg, all clones showed a higher percentage of plants with blackleg symptoms under greenhouse conditions than under field conditions. The most significant differ- ences in susceptibility to blackleg among clones occurred 45 days after planting, both in the field and the greenhouse. Santa Catalina, Yana Puna, and Juana Blanca clones showed more resistance under both conditions. (Table 3-6). In another test, plants of all clones obtained from tuber sprouts and transplanted to infested per lite showed more susceptibility to blackleg than those obtained from tubers inoculated by vacuum infiltration. The differences in susceptibility among clones occurred 72 66 hours after transplanting to infested per- lite. Santa Catalina was significantly more resistant than Revoluci6n, Serrana, and Granola but did not differ significantly in susceptibility from the other 12 cultivars. In a comparison of the susceptibility of 16 clones to blackleg using the three inocula- tion methods, some clones such as Santa Catalina (resistant) showed consistent sus- ceptibility across methods. Other clones showed varying degrees of susceptibility depending on the inoculation method. For example, Jatun Huanca was among the more resistant clones when inoculated by the first and third methods but it was one of the most susceptible with the second method. Tunisia. Research was conducted at 5 locations by the Tunisian Potato Seed Table 3-6. Incidence of blackleg in 16 potato cultivars under field and greenhouse conditions after inoculation with Erwinia chrysanthemi by vacuum infiltration. Blackleg(%) Clones Field Greenhouse Revoluci6n 15.83 cde 80.00 a UP to date 27.50 be 77.50 ab Granola 30.83 be 75.00 abc Desiree 49.17 a 75.00 abc Rosita 13.33 cde 67.50 abc Ms-1 c-2 35.83 ab 67.50 abc Achirana inta 23.33 bed 62.50 abed Jatun huanca 5.832 de 62.50 abed Mariva 15.00 cde 60.00 bcde Serrana inta 23.33 bed 57.50 cdef Yungay 8.33 de 57.50 cdef Seiiorita 19.17 bcde 45.00 def Pirola 19.16 bcde 45.00 def Juana blanca 15.00 cde 42.00 ef Yana puna 3.33 e 40.00 fg Santa Catalina 1.66 e 25.00 g Means followed by the same letter are not sig- nificantly different at P = 0.01 by Duncan's Mui- tiple Range Test. Program3 .. • • • Program on the susceptibility of different varieties to Erwinia soft rot. Cultivar reac- tion varied with location, with symptoms or latent infection being more pronounced in the heavy soils at Saida and Ghar El Melh. The cultivar Atica was most suscep- tible, whereas Cardinal was the most tol- erant. There was no direct relation be- tween dry matter content or total sugars and disease incidence. The interaction between Erwinia car- otovora subsp. atroseptica and the fungi Verticillium dahliae and Colletotrichum coccodes was studied in the greenhouse. Each pathogen produced damage, but when combined the damage increased. Control of Powdery Scab The Philippines. At Benguet State Uni- versity, screening of potato cultivars and clones for powdery scab (Spongospora subterranea) resistance and evaluation of different fungicides and three methods of fungicide application to contro~ powdery scab were evaluated in the greenhouse and in the field. Of the 30 potato clones and cultivars evaluated, BW-5 was· rated as highly resistant; Yungay, P-2, Huaycha Pacefia, P-6, Cosima, Poos-590, and G-5 as resistant, while all others-including Baraka were very susceptible (Table 3-7). Soil treatment with most fungicides used was found to be more effective in controlling the disease compared to dip- ping and dusting of seed tubers. Among the fungicides tested, Curzate (a.i. = 465 g/kg Mancozeb and 40 g/kg Cymoxanil) and Erosal (a.i. = 800 g/kg Elemental sulfur) were the most effective. Future activities include screening of additional cultivars and a breeding program for resistance and adaptation. Program3 Resistance to Viruses Peru. Wild Solanum species are the most valuable reservoir of genes resistant to pathogens. In 1991 further accessions with resistance to some potato viruses were identified in limited evaluation trials. Fifty-three accessions including eleven different species were evaluated for resis- tance to PVX, PLRV, PVY, APMV, APLV, and PSTVd. Solanum sucrense, pre- viously reported as immune to PVXc and hypersensitive to PVX-HB, demonstrated a differential hypersensitive reaction to these two viruses. Plants grafted with PVX-HB or PVX-GUA suffered severe apical necrosis while plants grafted with PVXc reacted with only small necrotic lesions. Virus infection could not be de- tected in grafted plants. However, both viruses could be detected in mixed infec- tions (PVXc and PVY), suggesting that co-infection with. PVY breaks the resis- tance of this accession to PVXC. To date, Tab.le 3-7. Disease reaction8 of1Oof30 potato cult1vars and clones field tested for resistance to powdery scab. Buguias, the Philippines, De- cember 1990 to April 1991. Infection Disease Cultivar/Clone rate(%) index BW-5 0.00 a 0.00 a Yungay 2.10 ab 0.70 ab P-2 2.50 ab 1.00 b Huaycha Paceiia 4.80 ab 1.25 b P-6 8.70 ab 1.33 b Cosima 9.30 ab 1.38 b Poos-590 9.60 ab 1.20 b G-5 11.00 ab 0.95 b P-3 11.80 ab 1.00 b Baraka (check) 46.80 e 3.10 de 8 Average of five replications. Any two means having a common letter are not significantly different at the 5% level. 67 70% of the 17 accessions evaluated as resistant to PYX are from Bolivia. Two Solanum candolleanum acces- sions have been found with resistance to PYXc, PYX-HB, PYX-GUA, PVY and PSTYd. An accession of Solanum raphanif olium with a high level of resis- tance to PLRY was identified. No virus was detected in graft-inoculated plants. This accession is also resistant to mechan- ical inoculation with PYS and PVT. Resistance to PLRY infection in clones .,. .,. • ;!~ • .t G-1, G-5, ICA Guaptiva, Chacay'"INTA, Berol'ina? Santanfalea, SC-2559f and HuaychaPacefia has been confirmed. Five new sources of resistance to this virus from the CIP pathogen-tested collection were identified. Crosses by CIP breeders created eight clones with high levels of resistance to PLRY. They did not show any infection after seven years of exposure to PLRY in trials conducted at two locations in Peru (lea and Tacna) with high vector and inoculum pressure. From 60 families with combined resistance to PLRY, PVY, and PYX, 550 clones were selected for future evaluations and selection. Polish cultivars Bogna, Irga, Orlik, Brda, Lotos, and Fregata, which were re- ported as highly resistant to PLRY, were tested under greenhouse conditions against ten PLRY isolates available at CIP. The results obtained confirmed that, ex- cept for Orlik and Fregata, these cultivars were resistant to PLRY. The resistant cul- tivars also showed resistance to the aphid Myzus persicae. A diploid Polish accession DW84- 1457 was graft-inoculated with various PLRY isolates. Results showed that this cloQe is highly resistant to both infection with and multiplication of PLRY. Analysis of Fl progenies of S. acaule (OCH-13824 and OCH-13823) showed that in these 68 clones resistance to aphids (antixenosis), resistance to PLRY infection, and resis- tance to translocation to tubers are herita- ble characters. Different aphid species (Myzus persi- cae, Aphis gossypii, Macrosiphum eu- phorbiae, and Rhopalosiphum padi) collected from different regions in Peru were evaluated for their efficiency to transmit PLRY isolates from Peru, South Korea, and China: Evaluations were made on acquisition and inoculation thresholds, transovarial transmission of the virus to their progenies, and the aphids' feeding behavior on host plants. M. persicae was the most efficient vec- tor for the acquisition and transmission of PLRY. M. persicae clones collected from warmer climatic regions were more effi- cient vectors than the clones collected from cooler areas of Peru. However, PLRY isolates from Peru were transmitted more efficiently than the foreign isolates by allM. persicae clones tested. The short- est acquisition period of Peruvian and Ko- rean isolates of PLRY by M. persicae clone San Ram6n was 2 minutes. For the Chinese PLRY isolate it was 3 minutes. Transovarial transmission of PLRY iso- lates to the progenies of aphids was nega- tive. These results suggest that PLRY and its vector have adapted to each other in their particular environment. Therefore, breed- ing and testing for resistance to PLRY should be site-specific. Experimental results also indicate that immunity to PYX and PYY is transmitted through protoplast hybridization. The dip- loid parents immune to PYX and PVY were extracted from the tetraploid clone Y3 (CIP 378650.1), a tuberosum hybrid with immunity to PYX derived from S. acaule, and to PVY from S. stoloniferum. Program 3 The Y3 clone flowers scarcely and it is male sterile. However, the somatic hy- brids flowered profusely and showed im- proved male fertility under CIP headquar- ters conditions. These results illustrate the good prospects of breeding at the diploid level and of somatic hybridization to ac- celerate the breeding for immunity to PYX andPVY. Combining Resistances to Viruses and Fungi Studies on the variability of PYX and PVY allowed the selection of tetraploid and diploid sources of heritable immunity to PYX and PYY, which are being used by several breeders at CIP. Efficient and reli- able seedling screening for immunity to PYX and PVY has been established and is used to test 30,000-60,000 seedlings/year. The technique is being implemented in some regions. The stability of immunity to PYX and PVY has been confirmed under field conditions at headquarters and in Uruguay. Advanced clones or cultivars from the CIP pathogen-tested seed program were evaluated for their reaction to PYXcp (55 entries) and PYY° (20 entries). Nine clones reacted as immune to PYX. Of these, Huayro (CIP 703304, S. chaucha), Yurac Wana (CIP 703351, ssp. andigena) and Camera (CIP 703482, ssp. andigena), are native cultivars; the S. vernei back- cross hybrid (VfN) 62,;:3~-3 is nematode resistant; TS-4 (frltr3~Qo~ is a TPS progenitor an ¥'agana INIA (Cif)20139) is a Chilean cultiv with high resistance to PLR rostochiensis. Three clon~~~~.t6 resistant to late blight reac mmune to PVY: CIP 386011.5, CIP 3 7026.13, and CIP 383081.27. Program3 During summer at San Rarn6n, 50 pro- genies were evaluated for resistance to Alternaria. The best progenies for yield and earliness and resistant to EB were: 380587.21 x XY-16, LT-7 x YY-9, CGN- 69-1 x YY-9, Tollocan x YY-9 and C85.003 x YY-9. A flush-out system has been established to avoid latent infection of P. solanacearum. The 105 previously selected clones were reevaluated for agro- nomical characters at La Molina and for resistance to Alternaria at San Ram6n. Seventy-six clones were tested at La Molina for earliness, yield and tuber qual- ity, the best clones being (EB85.008 x XY-16).72, (EB87.007 x XY-9).11 and (EB87.001 x XY-20).72. In greenhouse trials, 60 progenies (EB x XY and EB x Y), were evaluated for resistance to PVY or both PVY and PYX. From these, 46 progenies were evaluated in the field at La Molina (July-October) for agronomical characters, selection, and introduction into the flush-out system. At EMBRAPA (Brazil), CIP progenies segregating for PYY or PVY + PVY im- munities have been screened at the seed- ling stage. This process has become a routine first step in the evaluation process. Since 1989, virus resistant materials were evaluated for early blight resistance and 22 resistant clones were selected. Their vegetative period fluctuated between 70 and 95 days. In another evaluation of 60 virus resistant clones, 36 showed a high level of resistance to early blight and yields of up to 49 t/ha with vegetative periods of from 72 to 95 days. Colombia. A total of 112 progenies de- rived from crosses using PYX- and PVY- immune as female parent and P. infestans- resistant clones as male parent were screened for immunity to these viruses in Colombia at Tibaitata (greenhouse) or 69 La Selva (screenhouse). Procedures were tested to determine the possibility of se- lecting for combined immunity to PVX and PVY and resistance to late blight under these conditions. The surviving mother plants have provided.the basic pro- genitors for the Colombian National Po- tato Program to breed for combined im- munity to PVX and PVY and resistance to late blight. Virus Detection Peru. Serological detection of viruses continues with high efficiency, except for PLRV because of the recent depletion of CIP's antiserum stock. A polyclonal antiserum for PLRV is being improved by the elimination of non- specific reactions. Production of a new PLRV antiserum has ben initiated. Changes in the virus purification method included the use of affinity chromatogra- phy, enzyme treatments using two differ- ent enzymes, and use of lgG against normal proteins in order to remove con- taminants in the final preparations. Im- munoprecipitation of IgG with healthy sap, removal of contaminants using ELISA plates previously coated with IgG against normal proteins, and affinity chro- matography using Protein A and gel agarose reduced the non-specific reaction of the antiserum produced. The antiserum obtained in NCM had higher virus- specific reactions and lower non-specific reactions with healthy sap. However, the same IgG in DAS-ELISA was suitable only for coating but not for conjugation, because of its remaining non-specific re- action with healthy sap. An antiserum to PVX-8 Pe (serotype PVX0 ) was produced which simulta- neously detects different PVX isolates (Andean and non-Andean). 70 ELISA on nitrocellulose membranes (NCM-ELISA) and NASH procedures have been established to monitor the sta- bility of immunity to PVX and PVY worldwide, especially in regions where there are no laboratory facilities. NARS have considerably increased their use of serological techniques for virus detection. Kits for DAS-ELISA and NCM-ELISA, and reagents commonly used in serology are supplied on request. Antisera, DAS-ELISA, and NCM-ELISA kits were distributed to national and re- gional programs to evaluate more than 750,000 samples for 'important potato viruses. Detection of viruses using recombinant molecular probes continues with the aim of increasing the range of probes and im- proving existing ones. A recombinant plasmid with a frag- ment of hop stunt viroid (HSVd) cDNA 151 base pairs (bp) and a fragment of PSTVd cDNA 220bp-long has been con- structed. Probes prepared from this plas- mid indistinctively detect HSVd, PSTVd, and Citrus exocortis viroid (CEVd). This wide-spectrum probe has potential use for the identification and detection of viroids in Andean tuber and root crops, potatoes, and sweetpotatoes. The possibility of sweetpotato being a host for PSTVd was reported last year. However, until now no naturally infected sweetpotato plants have been found. Pre- liminary data indicate that the nematode Meloidogyne sp. can transmit PSTVd to potatoes. This transmission seems to occur only when egg masses from Meloidogyne females that have developed in PSTVd- infected plants are transferred to healthy plants. Because sweetpotato crops are often used as a rotation, the transmission Program3 of PSTVd to sweetpotato seems possible and requires continuous monitoring. A wide selection of PVX isolates grou- ped into two serotypes, the Andean PVXA and the common PVX0 , has been evalu- ated by NASH. Two probes, pX61 (prepared from PVXcp, serotype PVXA) and pPVX19 (from European PVX isolate from group 3, serotype PVx°), were selected and compared in relation to their ability to detect different PVX isolates (Figure 3-4). Probe specificity greatly influences the detectability of the different strains or iso- lates. Especially at low virus concentra- tions, both probes revealed high specificity in detecting PVX isolates from the serotype group of the strain used for their preparation. The exact localization of the pX61 cDNA within the viral genome has been identified by sequencing both strands 'of the clone. Probe pX61 corresponds to the HindIII fragment between nucleotides 3008 and 4107 (1099bp) of the genomic PVXcp RNA. The RNA sequence of PVXcp RNA reveals approximately 77% homology with the sequence reported for the European strains. Probe pPVXl 9 rep- resents the region between nucleotides 2893 and 3865 in the PVX genome of the European strain. The two probes overlap significantly (around 60%) and both came from the 3' end of the ORFl which is known to be highly conserved. A recombinant clone (pX6119) con- taining cDNA sequences from both pX61 and pPVX19 has been constructed in an effort to overcome the specificity found in probes prepared from a specific strain. A radioactive nick-translated pX6119 probe detected all PVX strains and isolates test- ed so far. These results indicate that probes Figure 3-4. Specific detection of potato virus X isolates by NASH using probes pX61 and pPVX19. Program3 71 with predetermined specificity can be con- structed by a combination of highly spe- cific viral sequences. The preparation of a unique recombi- nant probe for both PSTVd and PVf has been undertaken. This should allow simul- taneous detection of both pathogens in seed lots. Botanical seed transmission of PSTVd makes it necessary to test large amounts of seed, and the NASH test using a probe is the method of choice for viroid detection. Recently, the need to simplify the testing procedure and to increase the reliability of tests for viruses that are dif- ficult to detect, led to the preparation of a cDNA probe for NASH detection of po- Sweetpotato Control of fungal and bacterial diseases Peru. Monitoring of disease incidence continued in Peru. As a result, Fusarium lateritium and Fusarium spp. were identi- fied as causing the symptoms described for chlorotic leaf distortion. F. lateritium was isolated from apical buds, folded and unfolded leaves, open and closed flowers, anthers, pistils, and ovaries of samples collected in San Ram6n, Yurimaguas, Vitarte, Canete, and Tacna. In the field, symptomatic plants show a mycelial growth, white to salmon colored in the entire blade of folded leaves. Once the leaves are unfolded, the mycelial mat is primarily on the margins of the upper sur- face. Sweetpotato varieties differed in their reaction, chlorotic patches occurring on the young leaves of some, necrosis and distortion in others, while still others had no symptoms. 72 tato virus T (PVI), the only potato virus known to be transmitted through botanical seed. Seeds infected with both PSTV d and PVT have been tested by NASH with a combination of both the PSTVd and PVf probes. No interference in the detection of both pathogens occurred. Recent experiments in collaboration with the Department of Fruit Crops of INIAA (Ministry of Agriculture, Peru) have shown that avocado (Persea ameri- cana L.) trees are affected by a PSTVd- like viroid. Preliminary results indicate that this disease is fairly widespread in Peru. Until now PSTVd has not been de- tected in field-grown potato plants in Peru. Research continued on soft rot (Rhizo- pus stolonifer), one of the most important postharvest pathogens. Since the fungus penetrates the storage roots through the wounds caused during harvest, a variety of inoculation methods using nails, cutting implements, and cork borers were tested. For each treatment 20 storage roots were used. Roots were washed with run- ning water and surface disinfected with sodium hipochlorite 2.5% for 5 min. Inoc- ulated roots were placed in plastic trays. Evaluations were made from 2 days after inoculation up to 15 days. The best method was when small blocks of the fungus were placed on wounds made with a cork borer. No resistance to Rhizopus soft rot was found in the 80 entries of CIP's germ plasm that were screened. Another common disease in harvested sweetpotato storage roots is java black rot (Diplodia gossypina). Very often roots coming from the field are already infected. Program3 After a few days in storage, they become Indonesia. Screening for resistance to rotted. Tue proportion of rotted tissue de- scab (Elsinoe batatas) was done in the pends on the variety. sweetpotato growing area in Java where scab is prevalent during the wet season. Several methods have been tested to Landraces collected in West Java were produce symptoms on artificially inocu- used for preliminary evaluation of resis- lated roots. The most effective was when tance. At the Muara Experiment Farm in roots were thoroughly washed with run- Bogor, 130 clones were planted in a lattice ning water, surface disinfected for 5 min~ design with 2 replications. Disease was utes (then allowed to dry overnight), and scored twice, 65 and 72 days after plant- inoculated with disks removed from the ing. Of the clones tested, 20.0 and 26.2% edge of five-day old colonies of D. gossy- were highly resistant or resistant; 26.9 pina growing on PDA (cut with a Smm were moderately resistant, 20.0 suscepti- cork borer and placed on the surface of ble, and 6.9% highly susceptible. fresh wounds made with a scalpel). Inoc- Tue list of selected clones from 130 ulated roots were put in trays and incu- accessions is presented in Table 3-8. Se- bated at 27°C for 30 days. lection was based on yield ( 7 kg/6 m2), Resistance to D. gossypina was evalu- harvest rate (80% or greater) and scab ated for 196 CIP germplasm entries. A rating ( 1.0 being most resistant). Many second evaluation will be done in 1992. clones collected in farmers' fields had The same entries were screened for resist- higher yield than Southern Queen (SQ) 27, ance to F. solani. Fusarium spp. cause a leading variety. Some of these clones could be released as varieties after multi- surface rot and dry rot of stored roots. location trials. These fungi also enter the roots through wounds. A second evaluation of those en- Highly significant correlation coeffi- tries that did not show symptoms ¥1"ill be cients were obtained between scab rating conducted in order to determin~.~pes; •. and yield, and yield related characters. Additionally, a. ·g/ roup of 29 sei~ted ·· Together with the variable storage root · number, scab rating provided an equation entries were~ sere. eqed against F. ox .. y- . which could help predict yield very accu- spotum. Oneoft~em, DLP144, wa~Jo~nd rately. These results clearly demonstrate to be highly/ re.S{stant and t~,<( others that scab resistance is an important factor (DLPl 139 a~d RCB95) were;fe$3.stant. affecting sweetpotato yield during the wet f' ' ,,,,,,/"'""':,.'"'"/ Argentina. ~!~e::'.sl.lt"Vey of nursery season. material was made in Buenos Aires Prov- ince with a group of sweetpotato growers. The etiology of each disease was deter- mined. A collection of sweetpotato lines was evaluated for susceptibility to foot rot caused by Plenodomus destruens in an infected area at EEA-INTA, San Pedro, under field conditions. Preliminary results showed the number of rotted seedlings ranged from 0-2 out of up to 10. Program3 In experiments on screening for stor- ability, storage roots were stored at ambi- ent conditions immediately after harvest. Approximate temperature range was 25- 320C, and RH 89-90%. Clones used as material for this experiment were selected based on performance in the preliminary evaluation, i.e., average yield higher than 1 kg/m2. Weighed sweetpotato samples of around 1 kg were prepared and placed on 73 Table 3-8. Sweetpotato germplasm resistant to scab (Elsinoe batatas) in preliminary screening, Bogor, Indonesia. Yield Clone N9 Name (kg) B0034 Setempat 12.1 B00079 Bulhok 11.6 80047 Genjah Rantai 11.4 80088 unknown 11.4 80129 Tarico Kunir 10.6 B0010 unknown 10.2 B0051 BIS 175 9.5 B0097 ~iru 9.4 B0098 Putih 9.0 B0076 Cereu Putih 8.9 80071 unknown 8.8 B0052 Pa pol a 8.6 B0063 No.5 8.4 B0127 unknown 8.4 B0054 BIS 173 7.7 BOOS? No. 9 7.7 B0103 unknown 7.2 B0033 P.B. 7.1 B0069 Rambo 7.1 Checks B0053 BIS 183 10.0 B0053 BIS 183 10.0 B0068 SQ27 8.9 B0068 SQ27 8.0 Mean of unselected clones 3.9 wooden shelves in a storehouse with nat- ural ventilation. Storability of harvested roots was measured in terms of weight loss and by observing root quality. Samples were weighed at 14, 28, and 41 days. Weight loss of local varieties Brol merah, Genjah rantai, and B0089 was extremely low after 41 days storage. All samples were cut in half to observe storage root quality on the final day. Scores for root qµality were based on the percentage of rotten root tissue. Kenya. The nationwide survey of sweetpotato diseases, begun August 1990, 74 Scab Number of Average Harvest score roots weight(g) rate(%) (0-4) 98 124.6 87.5 0.8 95 123.3 95.0 0.0 63 180.2 97.5 0.3 94 125.4 97.5 0.3 57 186.8 92.5 0.3 52 197.7 87.5 0.3 64 159.6 97.5 0.3 73 131.6 92.5 0.8 46 212.8 80.0 0.0 42 224.3 90.0 0.0 59 155.1 97.5 0.0 40 215.6 80.0 0.0 46 187.8 97.5 0.0 44 196.3 97.5 0.0 47 175.4 82.5 0.0 68 113.7 87.5 0.8 54 138.7 90.0 0.0 45 158.6 87.5 0.8 40 180.9 100.0 0.5 70 138.0 100.0 0.0 51 198.7 95.1 0.0 51 188.3 90.0 0.0 48 167.6 100.0 0.0 31 126.4 80.6 1.8 continued. Six more districts were sur- veyed. Some patterns of disease distribu- tion and incidence are beginning to emerge. Though present in all districts, Alternaria spp. occur most frequently in the cool, wet highlands. Fusarium lateri- tium occurs at lower elevations, especially where it is hot and dry. Erinose also de- creases in frequency at higher altitudes which are associated with cooler temper- atures and higher moisture. This is not surprising for a mite-related disorder. Phomopsis ipomoeae-batatas was wide- spread. It is interesting to note that Al- ternaria blight was the only problem Program3 .. .. found in Kericho district, a high altitude, tea-growing area. Unknown B, a scab-like condition pre- viously found in other districts, continued to be a problem. Its etiology remains un- determined. Unknown A, a bacterial blight-like condition that was prevalent on the coast, was again found. Cultures of the Fusarium sp. were sent to Pennsylvania State University, for identification and comparison with isolates from the USA. True sweetpotato seed (TSPS) from farmers' fields were sent to Louisiana State University, for isolation. F. laterit- ium was isolated from 42% of seeds in one seed lot, but not in any of the four other seed lots. United States. At Louisiana, isolations were attempted from TSPS collected from several countries. Fusarium lateritium was isolated from seed from Brazil, Ghana, Kenya, Nigeria, Papua New Guinea, the Philippines, Peru, USA (in- cluding Puerto Rico), Rwanda, and Zam- bia, but not from Australia, China, Japan, or Taiwan (Table 3-9). A collection of 98 isolates has been obtained from sources in the USA and other countries. Pathogenicity and other tests have separated these isolates into three groups: nonpathogenic; systemic colonizers with epiphytic mycelial growth that do not cause chlorosis; and isolates which reproduce the whole CLD syn- drome. Isolates obtained during Fall 1991 have not yet been tested. All three types were isolated from USA and African sam- ples. No CLD isolates from Asia, Aus- tralia, or South America have been isolated. However, failure to isolate the fungus from seed cannot be taken as evi- dence of its absence; some seed lots from areas known to be infected did not yield the fungus. Thus, there also is a need to Program 3 examine sweetpotato plants growing in these areas. The production of nitrate-nonutilizing variant strains of each of the isolates of F. lateritium proved useful in determininig the ability of isolates to form heteroka- ryons when paired on minimal medium. Formation of heterokaryons in this system is an indication of vegetative compatibil- ity and indicates that two isolates have a common allele at the genetic locus which controls compatibility. This approach is being used widely to determine vegetative compatibility groups (VCGs) for different taxons of fungi and is an important tool in determining phylogeny and relatedness. Often, geographically isolated popula- tions of fungi are in different VCGs. To date, variants from 42 isolates have been produced and VCGs determined for 35 of these. Thirty-three of these 35 isolates are from the USA and fall into four, or possi- bly five, VCGs. There appears to be an indication that VCGs differ in prevalence in different geographic locations within the USA: isolates from North Carolina were grouped in VCG-2 (9 isolates) or VCG-3 (2); isolates from Louisiana in VCG-1 (3), VCG-2 (5), VCG-3 (1), or VCG-4 (2); isolates from South Carolina were grouped in VCG-1 (1), VCG-2 (2), VCG-3 (4), and VCG-4 (2); and isolates from Puerto Rico were one each in VCG-2 and VCG-4. Isolates from Kenya and Ni- geria have not yet been assigned to VCGs but they arc not in the same VCGs as USA isolates. Virus Identification Peru. Sweetpotato or Ipomoea setosa sci- ons infected with a new virus named C-4, were grafted onto virus-free cultivars of sweetpotato. Cultivars Jewel, Georgia Red, and DLP1541 showed clear whitish 75 Table 3-9. Germination of seed and isolation of Fusarium lateritium and other fungi in sweetpotato . seed obtained from one or two sites in each country. No Number of Seed Total lots seed Genn ination • Isolation•(%) (%)0t ,.,,,..h-er""'fu_n....,gi,..--..,F.-;.-/a"°"te'"""rit,,..iu-m S8ef1. Isolate type c Country lots CLO EMG Non TBT North America United States Louisiana & South Carolina Puerto Rico 18 1,115 31(62)80 0(2.5)14 0(17.0)58 15 8 0 3 2 97 25(48)71 0(1.0)2 15(18.5)22 2 2 3 0 0 South America Brazil Peru Africa Ghana Kenya Nigeria Rwanda Zambia Austral-Asia Australia 12 3 7 6 10 5 China (PR) 3 Indonesia Japan 6 Papua New Guinea 1 Philippines 6 Taiwan (AOC) 96 39 594 51 (88)100 113 223 301 297 239 72(83)95 0(52)100 14(71)94 52(82)100 31 (41)56 25 88 148 24(73)100 47 81 354 27(72)100 98 55 344 21 (31)47 89 37 1 0(1.2)8 5(19.7)32 0(3.0)15 0(1.0)4 0(1.2)3 0 0 0(1)2 2 0 0 2(2.3)4 0 1-3 0(0.3)2 7(13.7)21 0(6.3)42 0(6.7)20 0(1.2)9 0(2.0)6 0 0 2 0 1 0(0.5)3 0 1 2 3 2 4 2 3 0 0 0 0 0 0 0 4 3 0 0 0 0 0 3 2 0 1 5 0 0 0 1 3 0 0 0 0 2 0 0 0 0 0 0 0 6 0 4 6 0 0 a Percentages are given as "minimum (mean) maximum" for seed lots tested. b Number of seed lots from which F. lateritium was isolated. . c The number of isolates obtained which either: induced all symptoms of chlorotic leaf distortion (CLD); induced epiphytic mycelial growth only (EMG); did not induce any symptoms or signs (non); or are still to be tested (TBT) in greenhouse pathogenicity tests on susceptible CLO-free mericlones of NC-845 sweetpotato. flecks on leaves one month after grafting, under greenhouse conditions. Occasion- ally necrosis at the center of the flecks appeared. Symptoms on sweetpotato cul- tivar Jewel became less defined with time, .but persisted in cultivars Georgia Red and DLP1541. Latent infection occurred in cultivars Paramonguino and S-24. The yield of storag~ roots of C-4 infected Jewel was about 20% less than that of virus-free plants in preliminary pot exper- iments under greenhouse conditions. 76 Macrosiphum euphorbiae transmitted the C-4 virus in a persistent manner from sweetpotato to I. nil. It did not transmit the virus from sweetpotato to /. setosa nor from I.setosa to I. nil. Myzus persicae and Aphis gossypii were not vectors of this virus. M. euphorbiae was viruliferous for more than a week after acquisition and feeding for 2 days. Negatively stained dip preparations and partial purifications of infected sweet- potato and partially purified preparations Program3 show C-4 to h ve isometric particles of about 30 nm d' meter (See the photo in- troducing this section). Observations of ultrathin secti ns of infected sweetpotato tissue reveal the presence of virus-like particles int e phloem companion cells. Data collect d recently indicate that this virus is wide y distributed in Peru. Sweetpo to chlorotic flecks virus (SPCFV), a elongated virus formerly code named C-2, was found to be wide- spread in Peru, Japan, and China. The virus infected the sweetpotato clones Nemafiete, Jewel, Luby 3074, and UTA Tis 2498, but not Imby 3102. SPCFV was detected in 8 sweetpotato plants from Cuba (INVT-59, INVT-67), Panama (DLP 3873, DLP 3850), Bolivia (DLP 1626), Colombia (DLP 2165, DLP 2108), and Brazil (DPW 2680). The virus code-named C-3 infected Paramonguino and Georgia Red causing mottle .and interveinal · mottle, respec- tively. Symptoms were more severe in stem cuttings of cultivars maintained for a long time. Isometric particles were ob- served in these plants by electron micros- copy. In preliminary purification tests from I. setosa, plants infected with C-3, isometric, and sometimes, bacilliform par- ticles were observed. I. nil grafted with C-3-infected /. setosa scions did not show symptoms. An elongated virus code-named C-6 was isolated from sweetpotato cv. Sosa 29 (Dominican Republic) with chlorotic spot symptoms. Mechanical transmission was not successful. It was transmitted by graft- ing to/. setosa, /. nil, and I. batatas, but not to D. mete/, D. stramonium, L. es- culentum, and P. floridana. /. nil and I. setosa infected with C-6 (Figure 3-5) showed symptoms of fine chlorotic spots and vein clearing on the Program3 leaves. I. batatas ( cv. Pararrionguino) in- fected with C-6 showed chlorotic spots initially, and then mottling followed by yellowing and leaf drop. Figure 3-5. lpomea setosa infected with sweetpotato virus C-6, showing fine chlorotic spots and vein clearing. Virus Resistance Peru. Thirteen accessions from the CIP germplasm collection evaluated last year as resistant when tested with four SPFMV Peruvian isolates were challenge- inoculated with three other SPFMV strains (C, YV, and RC). SPFMV strains were detected in four of the accessions tested by grafting onto the indicator plant /. setosa, but they were not detected by NCM-ELISA directly from sweetpotato. These 13 resistant accessions were ex- posed to field conditions in lea, Peru, in a completely randomized block design to 77 determine stability of the resistance. Only four accessions maintained their resist- ance in the field. Virus isolates infecting these resistant clones, which are not sero- logically related to SPFMV, SPMMV, SPLV, SPCV or SPCFY, have been ob- tained from different sweetpotato plants by grafting to I. setosa and I. nil. Five sweetpotato clones (Nemafiete, Jewel, Luby 3074, Imby 3102, and IITA Tis 2498) from the pathogen-tested list were tested for resistance to SPFMV (C and C-1 strains), SPLV and SPMMY. All clones showed resistance to SPLV. ~emafiete, Jewel, and IITA Tis 2498 were resistant to both SPFMV strains. Only IITA Ti~ ~8 was resistant to SPMMV. Detection Methods Peru. A modification of the NCM-ELISA procedure previously reported involved spotting samples onto dry nitrocelullose membranes rather than wet ones. This change prevented contamination between samples and allowed simplification of the procedure while preserving test sensi- tivity. Sweetpotato plants from Mexico and the Dominican Republic were tested by NCM-ELISA for sweetpotato viruses SPFMV, SPMMV, SPLV, SPCV and SPCFV. Using membranes spotted in the two countries, it was shown that only SPFMV was present in both, suggesting that SPMMY, SPLV, SPCV and SPCFV are not common in either. This year 54 NCM-ELISA kits and 45ml of antisera were distributed among regional and national program scientists. More than 100,000 samples were evalu- ated for SPFMV, SPMMV, SPLV, SPCFV infection. 78 Molecular clones prepared from dif- ferent regions of the viral genome of SPFMV Cl. were transcribed in vitro into 32P-RNA molecules and used as probes against several strains and isolates of SPFMV available at CIP. The degree of hybridization reflects the concentration of the virus present in the infected plant but it is also greatly influenced by probe spec- ificity, especially in the detection of non- homologous combinations at low virus concentration. Sensitivity in detecting strain Cl and the common strain C was satisfactory with a minimum detection level of 24 pg of purified virus and less than 1 pg of viral RNA. However, the probes analyzed did not detect (or detected with low signal) other SPFMV strains. This indicates a high strain specificity of the prepared probes. Because of the need to have probes that detect a wide range of virus strains, anal- ysis of hybridization reaction was per- formed using cDNA clones from other SPFMV strains. Double stranded cDNA clones produced from a Nigerian isolate of SPFMV (SPV-I) which infects Nicotiana benthamiana were labeled by nick- translation. The cDNA probes were tested against several isolates of SPFMV. All clones reacted with a high hybridization signal to strains RC, YV, SPll, SP14, SP33, SP35, SP37, and SP43 (CIP collec- tion ). Three of the probes revealed a wider detection range and reacted also to strain C and other isolates, including Cl, which also infects Nicotiana benthamiana. The cDNA clones were also transferred into plasmid pGEM7Zf( +),containing specific promoters for SP6 and T7 RNA polymer- ases, and used as RNA probes. Results obtained with RNA probes were similar to those obtained with DNA nick-translated probes. Non-radioactively labelled probes, which can be effective in detecting viruses Program3 1 and viroids in potato and other hosts, could not be used for sweetpotato due to a high level of background or nonspecific reac- Training Training on Disease Control A training video entitled Detection of po- tato viruses with ELISA was produced. A manual describing all the techniques used in virology is under preparation. Individual training on detection and characterization of P. solanacearum was provided at Rothamsted to two partici- pants from the Philippines and the Nether- lands from May 28-June 1 in collaboration with the Philippines potato program and Agrico Research. Asimilar course was run from October 13-17 for a participant from CENARGEN, EMBRAPA, Brazil who will produce polyclonal antisera against P. solanacearum for use in the plant quaran- tine service in Brazil. Peru. A course on the pathology of potato seed-tuber production for Andean coun- tries was held in Lima at CIP headquarters, February 11-27. The objectives were to exchange and update knowledge related to pathology in potato seed-tuber produc- tion. Participants were from Bolivia (2), Colombia (2), Ecuador (2), Venezuela (2), and Peru (3). The third advanced virology course, held in Lima May 6-June 8, covered virus purification, identification, and prepara- tion of antisera for virus detection and ELISA and NASH techniques. Trainees Program 3 tions caused by the high content of latex and other interfering substances in the plant tissue. from Brazil (2), Chile (1 ), and Guatemala (1) attended. Costa Rica. A workshop on bacterial wilt, held May 27-29, was organized by PRE- CODEPA and CIP Region II. Participants from Costa Rica (2), El Salvador (1) Mex- ico (1), and CIP (1) attended the work- shop. Panama. CIP virologists met with their colleagues from Guatemala, Mexico, Costa Rica, and Panama to evaluate antisera pre- pared at CIP's virology laboratory and to fine tune methodological procedures for serological detection of important viruses. The meeting was held June 30-July 7. It was hosted by IDIAP and organized by PRECODEPA. Kenya. A workshop on integrated control of bacterial wilt of potato, was held at ILRAD in Nairobi, November 10-15. Funding came from ODA, PRAPAC and CIP. The 12 participants came from nine countries: Rwanda, Burundi, Egypt, Mauritius, Swaziland, Malawi, Zaire, Uganda (2), and Kenya (3). Also attending the workshop were CIP staff from Burundi and Rwanda. The topic was detection and identification of Pseudomonas solana- cearum, including ecology and taxonomy, breeding and screening for resistance, and integrated control methods. 79 Weighing his catch of Andean potato weevils, this farmer participates in a field day competition in which farmers learned about the pest's habits while collecting them. 1 Program 4 Insect and Nematode Management 1991 In Review I nsect and nematode pests are among the most variable and complex problems facing potato and sweetpotato farmers in developing countries. Of the world's food crops, the potato is the largest single user of pesticides. The results of a recent priority study conducted at CIP indicated that an estimated $1.5 billion worth of insecticides, fungi- cides, and nematicides were used by developing country farmers to protect their potato crops. The same study projected that this amount could rise to $4.8 billion by the year 2000. Unlike potato, pesticide use on sweetpotato is neglible, but evidence suggests that it is now increasing in many locations, possibly because of im!}alances created by the overuse of pesticides in other crops. At CIP, components for the integrated management of potato and sweetpotato insect and nematode pests are developed, combined, tested, and transferred to national programs, according to the specific needs of ecoregions in which they operate. These components include improved, resistant germplasm, as well as biological and agronomic measures. The integration and evaluation of component technologies for specific agroecologies will be accomplished in Program 1 (Production Systems), in close collaboration with farmers and partners in CIP's client countries. These technolo- gies should make it possible to substantially reduce the amount of harmful insecticides, acaricides, and nematicides in use. In work this year, significant advances have been made in the development of insect and nematode resistant varieties. After nearly 12 years of extensive research, a potato clone with the glandular trichome type Aand resistance to Colorado potato beetle (CPB) has been developed at Cornell University under a long-term research contract. This clone (NYL 235-4) has now been released as a CPB-resistant cultivar. Countries with severe CPB problems, such as Cyprus, Iran, and Turkey-as well as the USA, and the countries of the former Soviet Union, and Western and Eastern Europe--could signif- icantly reduce the use of insecticides by growing this cultivar. Several of CIP's hybrids have been tested and promising selections made in the glandular trichome progeny with resistance to many insect and mite pests. Some progeny also express resistance to late blight (Phytophthora infestans). A sweetpotato variety soon to be released in southeast Peru is a cultivar highly resistant to root-knot nematode (RKN). Local materials mature in 7 to 8 months, whereas the CIP clones are early maturing and can be harvested in 3 to 4 months. They are in high demand among members of the 5000-family Alto Urubamba Cooperative. These farmers normally grow coffee, but are hard pressed by low prices. In contrast, Program 4 81 they import sweetpotatoes from long distances at a high cost. The availability of the CIP clones should help to partially fill the income gap caused by the reduced price of coffee. Advanced hybrids with resistance to potato cyst nematode (PCN) and false root-knot nematode (FRKN) have been identified. Some of these materials are now in the final stages of evaluation. In another 3-4 years, more releases from this material are expected to occur in Peru, Bolivia, and Ecuador. Significant progress has been made in the integrated pest management of potato tuber moth (YIM) and Andean potato weevil (APW). In North Africa and the Middle East, a significant reduction has occurred in field use of insecticide for P1M control because of the adoption of cultural practices. As a result of extensive research to identify non-chemical methods of PTM control, the insecticide Parathion, previously used in Tunisia on consumption and seed potatoes, is now prohibited. The use of biological methods including Bacillus thuringiensis (Bt) and granulosis virus (GV) is gaining importance in. this region. The sex pheromone of PTM has been accepted by several NARS worldwide to monitor P1M populations. In Central America, farmers have been able to significantly reduce their insecticide application on potato crops through the use of monitoring data obtained from sex pheromone traps. The parasitoids of P1M have been effective in Peru and Colombia. In these countries mass rearing facilities have been established for producing these beneficial insects to control P1M. Good progress has also been made on the use of G V to control this pest in Peru, Bolivia, Egypt, and Tunisia. Work on integrated pest management (IPM) of Andean potato weevil has now been widely accepted by farmers of Chincheros, Cusco, Peru. Village authorities have passed a law mandating the use of a native fungus introduced by CIP for control of this pest. The fungus, Beauveria brogniartii, is replacing the mixture of dangerous insecticides used previously. Other IPM strategies used by these farmers include natural predators- 1 in this case domestic chickens-as well as better storage and cultural practices. This program is particularly timely because there is evidence that the weevil is forcing a great many Andean farmers to abandon large tracts of their land. Evidence of this can be found in virtually every potato growing area in the Andes above 2,500 m. In Central America and the Caribbean, the use of pheromone traps to monitor and mass trap the sweetpotato weevil Cylas formicarius has been adopted by farmers. There is a great demand for this technology in all countries with severe sweetpotato weevil (SPW) problems. Progress in the development of resistant cultivars to this pest has been slow. The recent discovery of Bt strains effective in controlling this pest has opened up new avenues for genetically engineering sweetpotatoes with the Bt-toxin gene. In the near future transgenic sweetpotatoes with resistance to SPW may become available. Progress has been good on biological control of this pest through the use of parasitoids and insect-killing fungi. The use of these approaches needs to be extended through ct:>llaboration with farmer cooperatives and the private sector. Six main projects have been identified within CIP's Insect and Nematode Manage- ment Program for the successful development of integrated pest management, four on potato and two on sweetpotato: • Potatoes with resistance to major insect and mite pests • Integrated pest management for the control of potato tuber moth 82 Program 4 • Integrated pest management for the control of Andean potato weevil • Management of potato cyst nematode and false root-knot nematode • Integrated pest management for the control of sweetpotato weevil • Integrated pest management for the control of sweetpotato nematodes Potatoes with Resistance to Major Insect and Mite Pests The primary objective of this project is to develop and improve resistance in existing and new potato clones for major insect and mite pests such as CPB, P1M, leafminer fly (LMF), thrips, CPB, and mites. The secondary objective is to test these mate- rials in regions where these pests are im- portant. Both conventional and non-conventional methods of breeding are emphasized. Several institutions are collaborating in screening and breeding for resistance to potato pests. They include Universidad Nacional Agraria La Molina (UNALM) in Peru, lnstituto Colombiano Agropecuario (ICA) in Colombia, the University of the Philippines Los Banos (UPLB) in the Phil- ippines, ENEA in Italy, Plant Genetic Systems (PGS) in Belgium, aod Cornell University, Michigan State University (MSU), and the University of Wisconsin in the USA. Resistance to Potato Tuber Moth Peru. Five clones were identified with high level of antibiosis to the first instar of PTM. These were clones 83693.15, 85112.1, 85136.1, 83639.15, and 85115.1. In another study 300 diploid (2x) clones were screened for resistance to PTM dam- age in storage. Only clone 90.250 was selected as moderately resistant. In order to increase the genetic base, 149 acces- sions of wild potato obtained from the Program 4 University of Wisconsin were screened under greenhouse conditions for resist- ance to the green peach aphid (GPA), Myzus persicae, and PTM, Phthorimaea opercu/ella. Six species--S. cardiophyl- lum (PI 283062), S. hjertingii (PI 498019), S. lignicua/e (PI 310993), S. megistacro- /obum (PI 265879), S. pinnatisectum (PI 275230), and S. sanctae-rosae (Pl 498392)- were selected as resistant to both these pests. Colombia. Resistance identified for PTM in S. berthaultii was transferred to the cultivated level by crossing this species with the diploid potato (S. phureja) culti- var Criolla or Yema de Huevo. The Fl hybrid was resistant to PTM which indi- cated that resistance was a dominant char- acter. The widely grown (in Colombia) cultivar Parda Pastusa was moderately re- sistant to this pest. Screening methods to identify resistance have been improved by burying 25% of tuber surface into sand placed in plastic containers. Resistance to Leaf miner Fly Peru. Liriomyza huidobrensis was studied under greenhouse and field conditions. In greenhouse tests cultivars Kinigi, Mariva, and Monserrate exhibited high levels of antibiosis to the larva of this pest (mortal- ity of 35-53% ). In field tests, 80 clones from the CIP pathogen-tested list and 16 clones developed in the TPS breeding 83 program selected from two-year tests were challenged by natural LMF populations in the field. Clones P7 and F8 from the CIP pathogen-tested list were significantly less damaged (50% vs 85% for susceptible cv. Revoluci6n). Other clones selected in- cluded the vadety Tahuaquena and 1Ml. From the TPS population five clones 86.662, 86.136, 87.282, 86.641, and 86.040 have been selected. Of these, the first three clones had good resistance and yield (mean 0.5 kg/plant) (Figure 4-1). Several developmental parameters of this pest (oviposition, time from egg to adult, mortality of larva and pupa) were studied on clones 86.136 and 86.662. Understand- ing of such resistance mechanisms is es- sential to the success of breeding for pest resistance. In other field trials conducted by UNALM with 48 clones, five (C-65, C- 350, C-112, C-64, and C-30) were selected as promising. Clones 86.136 (Resistant) 87.282 (Resistant) Revoluci6n (Suceptible) 43.3 50.67 100 Glandular Trichomes Tdchome types A and B confer resistance to a wide range of insect and mite pests. Progress has been made in combining glandular tdchomes in plants with good horticultural traits. A total of 432 clones (89 from Cornell University and 343 gen- erated by CIP breeders) were evaluated using the red spider mite (RSM), Tetranychus urticae. Of these, 24 clones were selected for resistance to damage by and multiplication of RSM. For LMF, 48 clones with high densities of glandular tdchomes were field evaluated and 35 were selected as resistant. In other mate- dal received from Cornell University, the mechanisms of resistance provided by these tdchomes to PTM, LMF, RSM, two- spotted mite (TSM), Polyphagotarsone- mus latus, and GPA, as well as natural enemies of GPA and PTM, were studied. Resistance in clone K419.8 to GPA was highly related to the presence of both tdchome types A and B. Exudate from 0.762 :::::·:·:-:.·,.'.'.'···. ·:<·:·:·:-:·::;:>:·:·:········· .. 120 100 80 60 40 20 0 0.2 0.4 0.6 0.8 1.2 l!lllll % LMF damage !? j Yield kg/plant Figure 4-1. LMF damage and plant yield in one susceptible and two resistant potato clones, La Molina, Peru, 1991. 84 Program 4 Green peach aphid (GPA) stuck on potato glandular trichomes. these trichomes accumulated on the body and proboscis of these insects leading to high mortality (60% nymphal mortality) (Figure 4-2). The birth-rate of GPA nymphs was reduced by 95%. ·Clones K421.2, K432.5, and K434.l exhibited a high level of antixenosis to egg laying by P1M. In clones K421.2 and 434.1, high P1M larval mortality were observed (18% more than in a susceptible clone) indicat- ing antibiosis. LMF oviposition and lon- gevity were reduced in clones K434.1, K419.8, and K432.5. RSM studies reveal- ed that clone K432.5 significantly reduced RSM populations. A mortality of 26% oc- curred in larval stages. Oviposition was reduced by 75% and a high proportion of RSM was trapped on the glandular tri- chomes. Longevity of RSM was reduced by 29%. In other studies with TSM the clone K434.1 reduced oviposition by 50% and longevity by 29%. The effect of glandular Program 4 trichomes on parasitoids,Aphidius sp. and Copidosoma koehleri, was studied. No ad- verse effect was observed. United States. At Cornell University, stud- ies concentrated on genetic mapping of trichome-mediated insect resistance from S.berthaultii and on breeding for resist- ance to CPB. A genetic map has been developed for one of the progenies that segregates for trichome density, sucrose ester production, and the enzymatic brow- ning reaction associated with resistance to aphids and CPB. RFLP markers used in this study have identified the parental source of alleles at 100 loci at regular intervals along the chromosomes. The goal is to map the responsible genes by corre- lating RFLP variation at mapped loci with trichome phenotypes. Genetic markers for these traits will be useful for introgression of the effective wild chromosomal seg- ments into cultivated material. 85 % Mortality fiij Revoluci6n t§jl K Clones 100 80 60 40 20 GPA RSM PTM LMF Figure 4-2. Effects of glandular trichomes in Revoluci6n and K clones at immature stages of four major potato pests, La Molina, Peru, 1991. After nearly 12 years of intercrosses and backcrosses following hybridization to produce tetraploid offspring of S. ber- thaultii and S. tuberosum clones, promis- ing new clone NYL235-4 resistant to CPB feeding has been selected. Tuber yield, maturity, and glycoalkaloid content of NYL235-4 approach those of tuberosum clones. Field resistance to CPB has been evaluated for several years at both re- search and commercial farms by Cornell University. Results indicate at least 50% reduction in first generation densities of CPB larvae compared to commercial cul- tivars. In comparison to plots protected against insect attack by use of insecticides, NYL235-4showeda10-15% yield reduc- tion, in contrast to 50-70% for standard commercial cultivars. Moreover, this clone 86 and others like it currently in development can produce commercial-scale yields without significant insecticide input. Therefore, this resistance is almost equiv- alent to one soil application of Aldicarb or three or more applications of foliar insec- ticide. Cornell has now released this clone. Italy. At ENEA, 28 CIP cross combina- tions (3916 progenies) with glandular tri- chomes were field tested near Bologna for resistance to CPB feeding damage. CPB injury was less than 50% in 28 clones; and 2 genotypes had a yield comparable with the susceptible controls. In other studies at ENEA, some CIP-developed glandular trichome clones reduced infection by late blight. The Philippines. Five screening tech- niques were tested for identifying Program4 resistance to TSM in glandular trichome progenies provided by CIP. Artificial infestation of a terminal shoot of one month-old potato plants using a leaflet containing 5-10 adult TSM was the most appropriate, and several susceptible geno- types were discarded prior to field trials. The three best clones selected for TSM resistance were 394A, 312.1, and 656. Out of the 21 clones with glandular trichomes, seven showed resistance to this pest. Combined Resistance In order to combine resistance to PTM, LMF, and GPA with good agronomic traits, 230 different crosses were made in Peru. Seed from these 230 families is being tested to obtain tuber families for distribution to NARS. Most of the clones selected for resistance to PTM exhibited lateness and poor tuber shape. These clones are now being crossed with a pop- ulation developed for resistance to LMF to improve yield. Material from diverse sources used in this program include ad- vanced PTM resistant genotypes, glandu- lar trichome progeny, and LMF resistant populations. Genetic Engineering for Pest Resistance CIP is collaborating with ENEA, MSU, and PGS through special project funding on the development of transgenic potatoes with resistance to PTM. Work at ENEA focused on the development of two DNA sequences similar to other known Bt se- quences. These were then used for trans- forming potato plants by Agrobacterium infection. MSU developed a transgenic potato (RO) expressing the Btk gene with resistance to PTM in the laboratory. PGS has engineered three different potato cul- tivars, Berolina, Bintje, and Kennebec using the cryIA (b) truncated gene for re- sistance to PTM. Several CIP advanced clones have now been selected for engi- neering Bt genes with resistance to PTM. Other genes of interest for transformation include the Cowpea trypsin inhibitor gene (CPTI). Integrated Pest Management for the Control of Potato Tuber Moth This project aims to adapt proven inte- grated pest management (IPM) control components to specific agroecological conditions and assist client countries in promoting IPM. Another objective is to increase the level of PTM control through better biological control and cultural prac- tices. Several NARS have cooperated in this global project. These include: UNALM; Centro de Crfa de Insectos Utiles (CICIU); INIAA and SEINPA from Peru; ICA in Program 4 Colombia; PROINPA in Bolivia; PRE- CODEPAin Central America and the Car- ibbean; the Ministry of Agriculture in Egypt; INRATin Tunisia; the Kenyan Ag- ricultural Research Institute (KARI) in Kenya; and the International Centre for Insect Physiology and Ecology (ICIPE). Peru. Efforts concentrated on the use of biological control with granulosis virus (GV) and the parasitoid Copidosoma koehleri. The effect of GV on PTM dam- age to foliage of potato plants in the field 87 was investigated by comparing GV with the application of biological insecticide Bt and chemical insecticide (Methomyl). Only one application was made at 30 days after plant emergence. A high pro- portion of PTM larvae in GV treated plants was infected. Highest disease de- velopment (98%) occurred at 15 days after application of GV. At 60 days, infection in PTM larvae dropped to 70% indicat- ing virus persistance of over two months. This virus was also tested in stores in Cusco, Cajamarca, and Huancayo, at a dosage of 5 kg of talc mixed with 100 GV-infected larvae per ton of stored po- tatoes. A total of 103,817 kg of basic seed (14 commercial and 3 native varieties) pro- duced by SEINPA and other programs in Peru was used. Four months after storage a 95% reduction in damage was observed in tubers treated with GV (0.45% vs 10.72% for untreated tubers). In all stores two PTM species were found, P. oper- culella and Symmetrischema plaesiosema. In the Cajamarca experimental station the variety Mariva was 100% damaged, while GV-treated tubers had very low damage(%). The effect of talc (a carrier in the GV formulation) on GPA on potato sprouts was investigated. Tubers were treated with 5 kg of talc/t. At 60 days when sprouting began, the tubers were exposed to GPA. In the first week after infestation, the GPA population was reduced by 43% (0.2 vs 2.68 GPAs in untreated tubers). Similar results were observed at four months after storage. Talc hinders GPA movement and blocks mouth parts during feeding. A sim- ilar effect of talc was observed for PTM where spiracles and mouth parts of a larva are totally covered by talc particle.<;, caus- ing to asphyxia and death. 88 The parasitoid Copidosoma koehleri was used for biological control of P1M at La Molina and Ancash. In La Molina, 3,685 mummies (165,825 adult wasps) were released over 2.3 ha. Pheromone traps (45/2.5 ha) were placed for mass trapping adult male PTMs. By harvest, 270,073 male PTMs were captured in pheromone traps and damage to tubers was less than 15%. Later attempts to re- cover the parasitoid were unsuccesful, possibly because of indiscriminate insec- ticide use in Some plots. In Ancash, 22,500 mummies were re- leased in potato stores and fields at several locations. A 78-95% parasitism rate was observed at harvest. PTM-parasitized mummies have now been recovered from several localities in this region indicating good establishment. Mass rearing mod- ules for this parasitoid are now being set up in this region to cover 3,432 ha in this region. Colombia. Two parasitoids, C. koehleri and Che/onus phthorimaeae, have been mass reared.and used in biological control of PTM. The first was released in Tibaitata and Boyaca for the control of P. oper- culella and the second in Fam plona for the control of Tecia solanivora, a PTM spe- cies which has spread from Venezuela to Colombia. CIP has assisted this program by building a laboratory for the mass pro- duction of this beneficial insect. Insects produced here are now being used by both Colombia and Venezuela to control PTM. Bolivia. Surveys were conducted in the Mizque valley. In farmers' stores more than 50% of seed tubers were infested by PTM. Inadequate use of insecticides in this region prevents effective pest con- trol. Various non-chemical alternatives developed by CIP in Peru were tried, in- cluding repellent plants such as mufia Program 4 (Minthostachys sp.) and Eucalyptus sp., and GV. All these reduced PTM infesta- tions in stores. A local strain of G V and the parasitoid Copidosoma sp. were identified in this region. Tunisia. On-farm and basic research on PTM was emphasized. On-farm research concentrated on the development of PTM infestation in relation to the growth of the potato crop. The beginning of foliage in- festation by PTM coincided with the end of foliage growth and did not depend on PTM caught in pheromone traps. Tuber infestations began one week after the fall of the lower leaves. This coincided with the beginning ofunfavorable climatic con- ditions for the crop (temperatures > 20°q which cause senescence of the plant, and migration of PTM to tubers. Studies of the circadian rhythms of this pest indicated that flight activity begins approximately two hours before sunset, reaches its max- imum four hours after sunset and stops close after midnight. In storage trials, pre- dators played an important role in control- ling the number of PTM eggs. In other studies, methods were devel- oped to assess the market value of PTM- damaged potatoes. Damaged potatoes fall into three categories: potatoes with low infestation (only one gallery) sold at full market price; potatoes with moderate in- festation (two or three galleries) sold at about 50% of full market price; and pota- toes with high infestation (four or more galleries) which are discarded. The evalu- ation was simplified by establishing the relationship between the level of infesta- tion in a potato lot and the distribution of damage. Thus, the economic significance of the damage can be assessed by deter- mining the total level of infestation. Using this method, 40 farmers were interviewed and tubers were evaluated for PTM Program 4 infestation. The highest level of infesta- tion in any sample of ware potatoes was 19%. Some farmers (8%) reported that they sold their potatoes at reduced prices when they observed growing PTM infes- tation in their storage heaps. Thus, PTM infestation was thought to be a significant determinant of market price. Potatoes with two or more galleries per tuber typically sold at 30-50% less than clean tubers. However, potatoes with only one gallery per tuber were not price discounted. In- creased farmer adoption of IPM in potato fields between 1986 and 1990 is docu- mented by farm surveys. Results indicate that harvesting before mid-June is thought to be the best way to avoid PTM infesta- tion. Other important control methods used by farmers include irrigation and hill- ing-up. Generally, farmers have avoided using insecticides for PTM control. Figure 4-3 shows the change over time of cultural practices and insecticide use. Farmer adoption of new insecticides in rustic potato stores was documented by storage surveys. Results indicate that at the beginning of the decade, Parathion and DDT were the predominant insecticides used against PTM. Since new government regulations imposed in 1984, farmers in Tunisia have favored the use of synthetic pyrethroids. In 1990, some farmers also tried a biological insecticide (Bactospein, a formulation of Bt) for the first time. On-farm trials with a new formulation of biological insecticide G V were con- ducted. This biological insecticide was ef- fective in controlling PTM infestation over four months of storage. Egypt. PTM monitoring studies revealed that the male moth population increased in July-August and then declined. The use of light and pheromone traps in wire mesh- screened stores resulted in a decrease of 89 Adoption of cultural practices Insecticide use %of farmers o/o of farmers 100 25 !mm! 1986 ra 1986 -1990 -1990 80 20 60 15 40 10 20 5 0 0 Irrigation Timely harvest Hiling Soil Foliar Both Pest Management Practice Figure 4-3. Changes in PTM management practices in potato fields in Tunisia between 1986 and 1990. PTM infestation (8.4% damaged tubers vs 21 % in non-screened stores without light and pheromone traps). The use of biolog- ical insecticides Bt and GV was effective in the control of this pest in stores. Kenya. A naturally occurring GV that in- fects P1M was identified and mass rearing started for use in biological control. Low- cost pyrethrum dust will be tried as a G V carrier. Integrated Pest Management for the Control of Andean Potato Weevil This project aims to adapt proven IPM control components to specific agro- ecological conditions in Peru, Bolivia, CO- iombia, and Ecuador and assist these countries in promoting the use of IPM. Another objective is to increase the level of ~ntrol of APW through improved bio- logical control. On-farm and storage research focused on the control of widespread APW species 90 Premnotrypes latithorax in Peru, and P. vorax in Colombia. Peru. In collaboration with the INIAA Andenes Experiment Station and small farmers, experiments were conducted at Huatata (3,760 m) in Cusco; including the use of Beauveria brogniartii as the most important component of an integrated APW management program. B. brongni- artii isolated from infected APW adults Program4 •• has been propagated in floating barley subtract. A small laboratory to manage the fungus and mass rear it has been equip- ped at the INIAA Andenes Experiment Station. Farmers in this area traditionally store healthy and damaged tubers near their houses. Potatoes are usually covered with mulch for 6 to 7 months to avoid frost and greening. During the first 80 days in stor- age, the larvae leave the damaged tubers and enter the soil to pupate. Beauveria propagated in floating barley was applied in the soil before storage of infested tu- bers. When APW larvae enter the soil, they become infected by the fungus through contact. Mortality at three months after inoculum application reached 97%. A total of 62 potato stores (3m2 each) was treated with the fungus. Three months after Beauveria application, mortality of APW larvae in many potato stores reached 99% (Figure 4-4). Other methods of con- trol tried with 10 farmers were: putting trenches around the store, manually col- lecting adult APW, planting barrier crops such as Lupinus mutabilis, using plastic sheets for sorting harvested tubers and preventing entry of APW larvae into soil, and using domestic chickens. APW dam- age at harvest in fields using IPM tech- niques was below 17%, as compared with 50% in fields with no IPM. Volunteer po- tatoes were demonstrated to be an im- portant source of APW infestation. On average, 54 APW were found in those plants. APW infestation levels in stores were quantified by soil sampling of vari- ous farmer stores. An average 3,072 APW/m2 were found. Effective cultural practices used to eliminate the pest include Program 4 plowing after harvest to expose APW to solar radiation. A 53% reduction of APW population was observed in fields plowed after harvest. A total of 72 farmers partic- ipated in this large-scale cultural trial with good results. Colombia. Three different weevil species were identified, Premnotrypes vorax, Amphideritus vilis, and Bothynodontes sp. 1be relative proportion of these three pests at Sote Panelas was determined by making collections from the cultivar Criolla. The dominant pest was A. villis (58%) fol- lowed by P. vorax (32%) and Bothyno- dontes sp. (10% ). Esterase activity was determined after treating fields with Car- bofuran. Higher esterase activity in A. villis indicates that the pest may have de- veloped resistance to this insecticide. Mortality (%) 100 80 60 40 20 0 '---'---- Check One Two Three Substrate B. brongniartii kg/m2 Figure 4-4. Mortality of APW larvae after one to three monthly storage treatments using B. brogniartii at Huatata, Cusco, Peru, 1991. 91 Management of Potato Cyst and False Root-knot Nematode The primary objective of this project is to produce potato clones with resistance to all known races of potato cyst nematode (PCN). The secondary objective is to de- velop location specific IPM programs in collaboration with NARS. Peru. Some 18,000 seedlings from 198 progenies were tested for resistance to PCN in the greenhouse using pot tests and in the lab using petri dish tests, and finally in PCN-infested fields. The most ad- vanced clones selected for tolerance in the field were 377740.2, 276724.1, 377744.3, and 380426.1, yielding 43, 40, 36, and 34 t/ha, respectively. In Huancayo, 372 clones were selected for resistance to PCN races P4, PS, and P6. In Puna, 44 clones were evaluated. The cultivar Marfa Huan- ca (released in 1989) continued to be the most resistant potato to this pest. Five new clones selected in this region for PCN resistance were G87555.2, G87381.2, G87554.8, G87154.10, and G874344.2. IPM trials were conducted in Cajamar- ca. Resistant, tolerant and susceptible po- tato cultivars were integrated with the use of non-host crops (wheat, barley, lupine, ulluco, faba beans, peas, oats, quinoa, and maize), cultural methods (organic amend- ments with chicken and cow manure), and biological control using Bauveria brog- niartii. Cultivar Yun gay outyielded ( 45 t/ha) other cultivars. Chicken and cow ma- nure at 10 t/ha increased yields and re- duced PCN populations by 50% as compared to the controls. Manure applica- tion did not increase yield of Marfa Huanca (Table 4-1 ). A reduction of 40- 90% in PCN population was observed in all trials where potatoes were rotated with non-hosts. .Electrophoretic studies of protein pat- terns of Globodera pallida and G. rosto- chiensis eggs were conducted to deter- mine the feasibility of using this technique for the identification of nematode species and races. There were differences in pro- Table 4-1. Effects of several integrated management components on the G/obodera pa/Iida population and on the yield (t/ha) of three Peruvian potato cultivars. Potato cultivars Revoluci6n Yungay Maria Huanca Pf/Pia Tuber Pf/Pia Tuber Pf/Pia Tuber Treatments yield yield yield Chicken manure (1 0 Vha) 6 19.6 a 3 44.2 a 1.3 38.6 a Control 20 12.8 b 4 29.5 b 1.3 38.7 a Aldicarb 15G (25 p.c. k/ha) 4 14.1 b 3 36.1 b 1.3 33.1 a Beauveria brogniartii (0.5 t/ha) 8 12.4 b 5 29.7 b 1.3 32.3 a Cow manure (10 Vha) 7 16.9 ab 8 36.9 ab 1.7 36.3 a NPK (160-180-100) 11 14.0 b 5 29.1 b 1.3 34.0 a a Ratios of final population/initial population. Same letter within each column indicates non-significant differences, Duncan Test (0.05). 92 Program 4 ' , .. tein patterns between the races within each nematode species at isoelectric focusing points corresponding to a pH gradient of 5.0-5.9. A protein band at isoelectric fo- cusing point 5.7 was found in a G. rosto- chiensis population from Bolivia. This is in contrary to previous reports establish- ing the absence of such protein band in G. rostochinesis (Figure 4-5). Such discrep- ancy may be due to the difference in meth- odology in using eggs versus cysts. Clean eggs may be more valuable than the entire cysts in electrophoretic studies for the de- termination of races and species of the PCN using protein patterns. Studies were conducted to determine the presence of physiological races of the false root-knot nematode (FRKN) Nacco- bus aberrans and to establish an interna- tional race classification scheme. Fifteen N. aberrans populations collected from Argentina, Ecuador, Bolivia, Mexico, Peru, and the USA were inoculated on 10 different plant species. Preliminary find- ings based on the root galling caused by G.pallida this nematode indicate that there may be at least 6 races and 2 variants of 2 races of FRKN. This classification scheme re- quires the use of 5 differential hosts and is the first universal classification scheme that includes nematode populations from several countries. Sequential histopathological changes caused by in vitro infection ofN. aberrans in susceptible potato roots were examined. Data indicate that the juveniles penetrate and move inter- and intracellularly in the cortical tissue. One or more juveniles were found in the large cavities formed in the cortical tissue 7 days after infection. Cell walls surrounding these cavities were thickened. Their cytoplasm, in addition to becoming dense, contains starch granules, hypertrophied nuclei, and many vacuoles. The immature vermiform females were formed 25 days after infection. They caused more extensive cellular necrosis as compared with that caused by the infec- tion of juveniles. In roots inoculated with immature females, galling occurred within G. rostochiensis lsoelectric focusing point England Panama Ecuador Peru Bolivia 5.0 - 5.1 - 5.2 5.3 5.4 5.5 - 5.6 - 5.7 5.8 - 5.9 6.0 - -~-- _J__ -=-=----'------ P2A P3A P4A P3B P3A P2B P2C P4B P5A P6 P6 P6 R1B A2A R3A = - == - - == = Figure 4-5. Electrophoretic differentiation of species and races of G. paflida and G. rostochiensis from various countries, as demonstrated by the presence of protein bands at isoelectric focusing points corresponding to pH gradients of 5.0 to 5.9. Program 4 93 2-3 days and gradually caused deforma- tion of the vascular system. Hypertrophy was oriented on the lateral side of the root and at the infection site, giving rise to typically lateral formation of galls on roots. In other studies in Puno, the clones G.877443.8 and G.877434.2 were identi- fied as resistant to FRKN. Bolivia. Fifty-two clones were identified as resistant to PCN. Of them, 13 clones had no cyst associated with their roots. Cultivars Sakampayas, Wacalajra, Palis, Sutamari, and Choqueluky were the most tolerant. The distribution of FRKN was deter- mined by surveys in the main potato grow- ing areas of Cochabamba, Chuquisaca, and Potosi. FRKN was more widely dis- tributed than PCN. In resistance studies, 94 clones showed good tolerance to FRKN. Root galling did not take place in 48 clones. The most tolerant clones have been used successfully in crosses with ad- vanced clones with high yield and resist- ance to late blight. Hybrids between culti- vated diploids (S. phureja, S. stenotomum) and several wild species with resistance to FRKN have been obtained and will be evaluated in future. Commercial cultivars Palis, Sakampaya, Pituwaycas, Wacalaj- ras, Chejchis, Tarackos, Jankos, Sutmaris, and Yaris showed tolerance to this nema- tode. Yield loss studies conducted under greenhouse and field conditions indicated that losses vary from 36-43%. Resistance of Gendarme, a native cultivar with good yield and adaptation, was confirmed. Screening methods have been improved and modified. The most effective methods appear to be pot tests and the mass-seed- ling tray technique. Crop rotation trials with beans and lupine were effective in increasing potato yields but had no effect on nematode population. The role of weeds in harboring FRKN populations is now being investigated. Proinpa (Bolivia) is now involved in the further testing of these IPM strategies. Integrated Pest Management for the Control of Sweetpotato Weevil This project aims to adapt proven IPM control components to specific agroeco- logical conditions in Asia, Africa, and Central and South America. A secondary objective is to increase the level of control by biological methods and by producing clones with resistance to this pest. Work in this project was done in collab- oration with the NARS of Peru, the Do- minican Republic, Cuba, the Philippines, India, Sri Lanka, Thailand, China, Bangla- desh, Indonesia, Kenya, Burundi, and the Universities of Florida and Mississippi in USA. 94 Peru. Work was concentrated on develop- ing IPM strategies for the West Indian sweetpotato weevil, Euscepes postfascia- tus. Eighty clones identified in earlier tri- als were field evaluated for both stem and root damage using a 1-5 visual scale (l=no damage, 5=severe damage) and eight clones were selected. Yield loss in these clones varied 0-26%. Two clones, ARB 562 and DLP 103, showed no yield loss when infested with weevils. Another four clones selected in 1990 trials (ARB 539, DLP 1959, ARB 320, and RCB4911) were evaluated in farmers' fields located at Program 4 Limon and Llanguat in Cajamarca. At har- vest these clones were again evaluated as moderately resistant to this pest. Crossing of /. trifida and/. batatas yielded 11 hy- brid progeny that were screened in the field using clip-on cages. Only the clone HH 38.4 was rated as susceptible. Of the 40 clones tested from the CIP pathogen tested list, one clone CIP 440001 was rated as resistant. Clone 440002 (Regal), re- ported as resistant to Cy/as formicarius, was rated as susceptible to E. postfas- ciatus. Biological control of this pest was at- tempted by making 11 liberations of the parasitoid Eurydinoteloides /ongiventris. A total of 11,000 adults were released in farmers' fields at Carabayllo, Lima. Root damage was diminished by 25%. Another parasitoid, Heterospilus sp., has been col- lected from Limon, Cajamarca. This is the first report regarding the occurrence of this beneficial insect. The prospects for mass rearing them is now being studied. Africa. In Kenya and Burundi surveys and field trials were conducted for the control of locally present sweetpotato weevil (SPW). Two SPW species of major im- portance identified in this region were Cy/as puncticollis and C. brunneus. Egg- laying behavior of these two pests indi- cates that at the end of their life cycles, C. puncticollis laid more eggs than C. brunneus. Neither species reacted to the synthetic sex pheromone of C. formica- rius. Females of these two species appear to release a species-specific pheromone which attracts male weevils. A simple pro- cedure was developed for collecting pher- omones from these two species. After confining 200-500 virgin females in a glass jar, air was drawn over these insects and the volatiles emanating from the unit were trapped using a glass absorption trap Program 4 containing Porapak Q. The pheromone was collected at 48 hour intervals by elut- ing the trapped volatiles with methylene chloride. These volatiles have been bioas- sayed using glass rods. C. brunneus re- acted instantly to the test extract of C. brunneus virgin females. The insects first lifted their antennae, then moved about quickly, ocassionally flying and jumping on the test rod. The reaction of C. punc- ticollis males to the female extract of the same species was variable. Only 20 to 30% of the test males reacted wildly to the test extract. The identification of the ac- tive component of the pheromone is now being studied at the Insect Attractants and Behavior Laboratory of the US Depart- ment of Agriculture in Florida, USA. A field and laboratory test has been devel- oped for evaluating resistance in sweet- potato cultivars grown in this region. Central America. In the Dominican Re- public, five producers in the major sweet- potato production areas (San Juan and Cibao) were selected. Current producer practices for controlling SPW were docu- mented. Some practices, for example the use of insecticide to treat cuttings, were applied incorrectly, while other recom- mended techniques such as the removal of alternate hosts, hilling-up, and early har- vest were not practiced by all farmers. High plant-to-plant variability was ob- served in all fields, indicating a possible constraint to using random sampling to determine levels of yield and weevil dam- age. Resistance tests were conducted using six cultivars widely grown in this region: Cano Morada, Manicera, La Loca, Copela, Haitianita, and Tiffey. The variety Tiffey was the most non-preferred variety to adult SPW damage. Sex pheromone studies emphasized the development of a low-cost, efficient pheromone trapping 95 system. A trap made with a plastic jug, about a gallon in volume, tha.t contained water to which a few drops of cooking oil or any household detergent was added, proved most effective in trapping male weevils. The trap costs less than US$0.25 and can be made using locally available materials. A dose of 10 mg per rubber septa was placed inside these traps for trapping male weevils. This dose re- mained effective for over 5 months. These pheromone traps, when placed in the field, were effective in the continuous trapping of male weev'ils, thereby lowering the damage rate at the time of harvest. The traps were particularly effective in nurs- eries for growing planting material. Such plots are generally small and can be pro- tected with only a few traps. In Cuba, the use of sex pheromone traps, Beauveria bassiana and a predatory ant, Pheidole sp., were demonstrated as effective IPM strategies for the control of SPW. On a single night each of the phero- mone baited traps captured approximately 24,000 male weevils. Asia. In the Philippines, the fungus B. bassiana was grown on residues of corn stalks and then applied to SPW-infested plants under greenhouse and field condi- tions. Root damage by C. formicarius on treated plants was significantly reduced (5% vs 46% for untreated plants). In other trials, a total of 23 strains of Bacillus thu- ringiensis (Bt) were isolated from SPW and were then identified into 5 crystal pr.oteins. Efficacy tests of Bt strains against SPW revealed that six representa- tive strains showed some level of toxicity to both the larval and adult stages of this pest. Samples with cr)'INcryIB gave the highest per~nt mortality (70-90% ). Other control methods identified as effective for this pest include hilling-up and the use of 96 sex pheromone traps. The clones Bang- kasi, DC-1, and LO II, id No. 10, were classified as moderately resistant in a field trial. In Bangladesh, sex pheromone traps were used for determining the population dynamics of SPW. Highest catches (100- 150 male weevils/week/trap) occurred during January and February. In India, the sex pheromone has been synthesized using local facilities. This pheromone is as effective as the one produced in Europe or the USA. In China, a total of 114 clones obtained in South China and the Xuzhou Sweet- potato Research Institute were screened for resistance to C. formicarius at the sweetpotato laboratory located at Guang- dong, Guangzhou. Resistant clones were ZS 684, ZS 687, ZS 915 and GN 888. In Indonesia, 274 sweetpotato acces- sions were tested under field conditions. Of these, four were free of any weevil damage (B0046, B0059, B0067 and B0226). Further tests are now underway to confirm resistance in these accessions. IPM trials to compare packages of wee- vil control measures were conducted by SAPPRAD cooperators in Sri Lanka and Thailand. In Sri Lanka, trials included in- secticide dip of cuttings, mulching, and hilling-up at six weeks. In Thailand, trials included chemical control, sex pheromone traps, and hilling-up. Effective IPM pack- ages in both countries included insecticide dips of vine cuttings and hilling-up. In Thailand, sex pheromone traps were also components in the most effective control packages. In both countries, IPM pack- ages reduced weevil damage, and in- creased storage root yields in comparison to untreated check plots. Program 4 t ' United States. In contract research with the University of Florida, the sex phero- mone of C. formicarius was efficacious at reducing weevil populations on plants and protecting roots from weevil damage. Ef- ficacy of sex pheromone improved when combined with monthly applications of chemical insecticiqes. Several entomopathogenic nematodes were isolated from collections made in the Caribbean. Some of these may represent a new species of Heterorhabditis. These nematodes varied in their infectivity to and reproduction in C. formicarius. Re- sults from such studies indicated that en- demic entomopathogenic nematodes from the Caribbean may be more suitable as biological control agents of this weevil than commercial, temperate-climate nem- atodes. In other studies conducted at Mis- sissippi State University, additive genetic variability was found in a sweetpotato breeding population for resistance to C. formicarius. Progress was made in devel- oping and refining techniques to measure genetic differences in resistance levels. These accomplishments provide a scien- tific basis for sweetpotato improvement by developing genotypes with resistance to the weevil. Integrated Pest Management for the Control of Sweetpotato Nematodes The main objective is to develop clones with resistance to the root-knot and rot nematodes. Other objectives include de- termining the economic importance of these nematodes in major sweetpotato growing areas and developing IPM strate- gies for use in countries with severe nem- atode problems. Root-knot Nematode Peru. A total of 1062 clones of the germ- plasm collection (originating from several countries) and 1f82 clones developed by CIP's breeding program were tested for their reaction to root-knot nematode (RKN), Meloidogyne incognita. The most numerous resistant clones came from CIP's breeding program followed by those originating from China, USA, Japan, and Peru (Table 4-2). In separate tests, 3102 genotypes rep- resenting 16 progenies developed as the Program 4 first generation polycross of previously selected clones from the germplasm col- lection with tolerance to salinity were evaluated for resistance to RKN. Signifi- cant numbers of highly resistant segregat- ing genotypes originated from five progenies. Progeny ST-15 had the highest number of highly resistant segregating ge- notypes (31.9% ). The first generation polycross of susceptible cultivar Tambefio had 99% of its genotypes segregating as susceptible. The highly resistant geno- types selected in this test are being retested and those with confirmed resistance will be field tested for their agronomic charac- teristics and included in the breeding pro- gram. In Canete and Cusco, 35 clones (ME-1 to ME-35) previously selected for resist- ance to M. incognita and/or M. javanica were field tested. With the exception of six clones, all the ME clones significantly 97 Table 4-2. Reactions of sweetpotato breeding materials to the root-knot nematode Meloidogyne incognita. Root necrosis indexb Final designated Root galling index8 host reaction° Origin 2 3 4 5 2 3 4 5 HR R MR s Total Bolivia 0 5 5 11 2 0 15 5 2 1 0 4 18 23 Brazil 0 4 13 9 3 0 18 9 2 0 0 2 26 29 China 7 50 54 14 3 0 97 30 0 6 45 6 71 128 Colombia 0 8 40 63 12 0 81 26 16 0 0 3 5 115 123 Dom. Rep. 0 7 29 26 4 0 46 19 1 0 0 2 5 59 66 Ecuador 0 6 15 8 0 16 9 3 2 0 0 1 29 30 Japan 6 39 67 11 92 30 0 6 34 7 77 124 Peru 0 88 123 216 25 0 52 90 167 14~ 0 25 25 402 452 USA 6 47 22 3 0 0 63 15 0 0 5 40 9 24 78 Other Countries 0 5 3 0 0 4 2 3 0 0 0 8 9 Cl P's breeding material 41 591 522 27 4 726 322 122 8 32 355 190 605 1182 Total 60 841 885 398 59 5 1210 557 318 154 49 511 250 1434 2244 • 1 = no root galling and/or nematode reproduction; 5 =very severe root galling and/or very high nematode reproduction. b 1 = no root necrosis; 5 = very severe and generalized root necrosis. c Host reaction based on the combined root galling and root necrosis responses (HR= highly resistant, R =resistant, MR= moderately resistant, S =susceptible). outyielded the local cultivars Marfa Angola in Canete and Maria Angola, Jewel, and Inca in Cusco in addition to being resistant to M. incognita and M. javanica. Of these clones, 16 have been selected for use in future polycrosses. Clones ME3 and ME16 were selected for excellent processing qualities as chips. Clone ME 12 was selected by the farmers in the province of la Convenci6n, Cusco, for its resistance to M. incognita, high yield, and good chipping quality. This clone is now being considered for release as a new cultivar by the University of Cusco in collaboration with the Col- onizadores del Alto Urubamba Agrarian Cooperative. Rot Nematode China. Rot nematode Ditylenchus des- tructor is an important nematode of sweet- 98 potato in China. Infected storage roots of susceptible cultivars became completely destroyed after a month of storage (Figure 4-6). In other trials, 234 clones of the germplasm collection originating from Peru were evaluated for their resistance to Ditylenchus destructor. Fifty-eight clones were identified as resistant (Table 4-3). These clones can either be used in the breeding program for developing new populations or sent out for testing under field conditions in China. At the Xuzhou Sweetpotato Research Center, 164 sweetpotato accessions were evaluated for resistance to rot nematode. Out of 13 accessions identified as resis- tant, 3 accessions (LU 78066, Qianshu-1, and Zhezhouhong) were highly resistant. LU 78066 is being used in the Chinese breeding program due to its high yield and resistance to this nematode. Program 4 Figure 4-6. Typical symptoms in sweetpotato storage roots infected with Ditylenchus destructor. (A) Sunken lesions and crinkled periderm. (B) Discolored and corky textured internal. Table 4-3. Reaction to rot nematode Ditylenchus destructorof some sweetpotato clones originating in Peru. Rot index (lab & storage test)8 1 2 3 4 5 Total Tested clones per category 0 58 97 42 37 234 Damaged clones(%) 0 24.8 41.5 17.9 15.8 100 a 1 = No discoloration of flesh and/or evidence of nematode presence at or around the point of inoculation; 5 = complete and generalized discoloration and browning of the entire storage root accompanied by the presence of a very high nematode population. The Philippines. A total of 143 accessions and cultivars was screened for resistance to M. incognita. At a 5,000 nematode egg innoculum level, 10 were found' resistant in the first trial and 11 in the second. The clones which consistently manifested re- sistance included Bangkas, CM-3, DC-9, and L-52. These clones were resistant under both greenhouse and field condi- tions. Identification of Other Major Pests and Natural Enemies Work in this area contributes to potato and sweetpotato research in general. At CIP headquarters in Peru, an insect identifica- tion unit has been established. Fifty-one insect species have been identified in ship- ments received from Argentina, Bolivia, Colombia, Ecuador, Paraguay, Kenya, Peru, and the USA. q.rowing whitefly infestation in devel- oping countries was reported by several Program 4 CIP regional scientists during the Center's annual review. Whiteflies are proving to be a problem in experiments and in farm- ers' fields in Egypt, China, India, Colom - bia, Peru, and the Dominican Republic. The problem is closely linked to overuse of pesticides. Whitefly infestation causes physical damage to plants and is a vector for virus diseases. The population dy- namics of whitefly, Bemeisia tabaci, and 99 its natural enemies in sweetpotato crops were determined in contract.research with the Universidad Nacional Agraria in Peru. The life cycle of this pest is completed in 26days. Other important pests of sweetpotato identified in this project include the aphid, Training Training on Pest Management A seminar/workshop on progress in potato pest control in the Andean zone, spon- sored by PRACIPA and CIP, was held at CIP headquarters in Lima, November 17- 22. The objectives were to analyze the current research on control of main potato pests in Andean countries and to plan pro- jects on IPM for the 1992-1994 period. The participants were from Bolivia (2), Ecuador (2), Venezuela (2), Colombia (2), Peru (3), CIP-Colombia (2), CIP-Lima (7), and PRACIPA (1). As part of this workshop, the participants visited Cusco to see an IPM project on Andean potato weevil being conducted by CIP and INIAA in Huatata. Kenya. A course on integrated pest and disease management for sweetpotato, was held in Nairobi and Mbita Point, August 12-23. It was organized by ILRAD and the International Centre for Insect Physiology and Ecology, and sponsored by CIP Re- . gion III. The 12 participants came from Burundi, Mauritius, Rwanda, Malawi, Tanzania (2), Uganda (2), and Kenya (4). 100 Macrosiphum euphorbiae, leafhopper, Empoasca fabalis, leafminer, Pebobs sp., and a new pest species, Hypena sp. The biology of all these pests has been studied. In Kenya, the sweetpotato butterfly was identified as a sporadic, seasonal pest. The life cycle of this pest at 25°C is completed in 42-56 days. Tunisia. A workshop about on-farm re- search techniques for IPM of the potato tuber moth was held at SAIDA, September 2-6. Participants were 14 scientists from the national programs in Region IV. They came from Tunisia, Egypt, Yemen, Mo- rocco, Lebanon, Turkey, and Syria. United States. CIP, in collaboration with Virginia Polytechnic Institute and State University, the University of Florida, and Oregon State University, organized an in- ternational conference on potato pest man- agement October 12-17 in Jackson Hole, Wyoming. The conference addressed all current knowledge related to management of potato insects, diseases, and nematodes. Particular attention was given to advances in potato pest biology and management, applications of biotechnology in potato pest management, pesticide resistance and resistance management strategies, and al- ternative management approaches for po- tato pests. A total of 180 scientists participated. Selected papers from the meeting will be published as a book by the American Phytopathological Society (APS). Program 4 • Farmers in Nicaragua are already able to produce commercial quantities of potaoes from true seed. These sell well in local markets and are often preferred to potatoes grown from traditional cultivars. Programs Propagation and Crop Management 1991 In Review The restructuring process coalesced propagation and crop management work into Program 5 which encompasses activities in former Thrusts VI (Warm-Climate Potato and Sweetpotato Production), VII (Cool-Climate Potato and Sweetpotato Pro- duction), and IX (Seed Technology). Propagation research and seed production capabilities strenghtened worldwide as national seed schemes incorporated more efficient techniques developed through col- laborative research projects. This resulted in higher quality and a lower cost for producing seed. Meanwhile, socio-economic research played an important role in the faster and more accurate identification of propagation practices suitable for adoption by seed schemes under specific farming conditions. Most significant progress was made by collaborative projects in China, Uganda, Burundi, Cameroon, Kenya, Tunisia, Venezuela, Bolivia, and Peru, among others. Extensive adoption of True Potato Seed (TPS) seemed likely in India, Bangladesh, Indonesia, Egypt, Nicaragua, and Paraguay, while interest in the potential use of this technology continues to grow in many other countries. This higher adoption potential was based on rapid progress made by breeding for improved progenies and by devel- opment of more efficient parents and hybrid TPS production methods. Research on post-harvest handling of TPS has made important advances toward efficient manage- ment of dormancy for faster and more uniform seedling emergence and early growth. In India, official release of hybrid progeny HPS-I/13 has made commercial production of potatoes via TPS feasible. This progeny has shown superior agronomic characteristics and outyielded the local crop in many trials in countries such as Indonesia, Bangladesh, Uganda, Cameroon, and Peru, where it has been tested. In Nicaragua, results obtained by the growing number of farms using the adapted techniques-about 140 farms this year -will lead to a significant increase in the area cultivated to potatoes from TPS in the near future. TPS technology as adopted in Nicaragua is being transferred to other Central American countries. Other successful efforts are underway in Paraguay, Indone- sia, and Bangladesh. In Egypt, two TPS nationally registered varieties (Serrana x DT0-28 and Serrana x LT-7) are now distributed commercially, supplying farmers with quality seedling tubers for planting. In Paraguay, the latter progeny was officially named "Villa Serrana". Potato germplasm was distributed to 77 countries and sweetpotato to 33, for evalua- tion or use as breeding material. Three potato varieties were released in Uganda, four in Cameroon, and four will soon be released in Burundi and two in Zaire. Program 5 103 Several collaborative projects extensively evaluated sweetpotato germplasm for tolerance to various stresses, thus selecting improved genotypes. In China, evaluation included tolerance to shade to identify improved types for intercropping, a popular practice in extensive areas of the country. Activities in Program 5 have been divided into six main research subjects designed to respond to the research, maintenance, distribution, and monitoring needs of germ- plasm of CIP's mandate crops as well as to develop information on alternative propa- gation systems and crop management practices. These are propagation of healthy clonal potato planting materials in diverse agricultural systems, sexual potato propagation, sweetpotato production through improved planting materials and management tech- niques, abiotic stresses and potato crop management, and maintenance, distribution, and monitoring of advanced potato and sweetpotato germplasm. Propagation of Healthy Clonal Potato Planting Materials in Diverse Agricultural Systems Potato clonal propagation Venezuela and Colombia. Application of experimental results on improved man- agement practices established a more effi- cient scheme for pre-basic seed production in Venezuela. In Colombia, studies com- pared performance of crops grown from farmers' seeds and from certified seed. Productivity advantages of using higher quality seed tubers and factors influencing farmers' decisions on renewing their seed stocks were more clearly identified. Also, production of antisera for local use in- creased significantly. Burundi. To help overcome bacterial wilt (BW) latent infection, the Burundi Na- -tional Program produces and distributes about 400 t of seed per year. The Gisozi- ISABU Station produces pre-basic seed which is sent to Munanira to reduce the risk of BW infection in the field. About 36 t of pre-basic seed were produced with an average BW infection of 0.2% and 0.5%, and yields of 22.1 and 25.8 t/ha in the first and second seasons, respectively. 104 For basic seed production, 10 ha were planted per season with pre-basic seed tuber material from the Munanira Seed Farm and from positive selection. Produc- tion of about 165 t for the first season and 200 t for the second were obtained, with BW infection values of 0.3% in the first season and 0.2% in the second. In 1986 and 1987, BW infection in Mwokora exceeded 60%. Introduction of an integrated control approach in the seed production program has progressively re- duced BW infection to 0.7%. A production system whereby pre-basic seed tubers mul- tiplied at Munanira are only planted once at Mwokora appears a more suitable practice for the production of high quality seed tubers free from bacterial infection. Quality seed tubers of varieties Ndinamagara, Uganda 11, Muruta, and Sangema are being distrib- uted in increasing numbers for wider use. (Figure 5-1) Results obtained through col- laborative research activities conducted with the Belgium Cooperation Agency in Burun- di, indicate that this seed tuber production Program 5 II Table 5-1. Evolution of potato seed production and bacterial wilt infection in seed farms, Burundi, 1985-1991. Munanira Year Production Infection (t) (%) 1985 33.3 0.2 1986 48.2 1.2 1987 50.2 3.1 1988 47.6 2.9 1989 49.9 1.2 1990 68.8 0.7 1991 68.6 0.5 method has proved to be practical and aceptable to resource-poor farmers. In Mwokora, research focused on cul- tural practices for reducing soil borne pathogens and for developing methods for improved seed tuber storage. Manage- ment problems of harvesting, storage, and timely distribution to farmers are among the project priorities. Critical components of the integrated approach for BW control in seed tuber production: - a seed tuber production scheme - 2 1 /2-yr rotations with wheat and setaria, including weed-free fallow & cultivation during the dry season - a rouging system to elim- inate diseased & neigh- boring plants to restrict disease dissemination - other field sanitation practices Host resistance Mwokora Production Infection (t) (%) 105.2 191.2 64.1 150.1 65.8 160.2 14.5 266.9 0.8 295.6 0.9 377.5 0.7 Kenya. Micropropagation for producing high-quality seed tubers is now fully im- plemented at Tigoni-NPRC. In vitro plants are transplanted at high density in wooden boxes to produce apical cuttings under extended day length conditions (16 hours), thus maintaining mother plant juvenility for 4-6 months. Yield performance of api- cal cuttings taken from in vitro plants has Seed scheme - a simple seed-quality control method for la- tent infection detection - training of personnel and farmers Others Training Figure 5-1. Critical components for the production of high quality seed tubers under bacterial wilt conditions. Source: Ph. D. thesis, J. L. Rueda, University of Reading, England. Program S 105 varied from 2.6 (Roslin Eburu/B53) to 9.8 (Kenya Dhamana) tubers per plant. In the field at Marindas (2,900 m ), yields of 58.2 t/ha with 80% of seed size tubers were obtained. Experiments conducted in that location have shown that highest yields are obtained when tuberlets are used for propagation. On-farm research was initiated on the use of rooted cuttings supplied by the NPRC involving farmers near Tigoni. Yields higher than 25 t/ha were obtained at several farms. Trials at Tigone using seed tubers pro- duced in Marindas (2,900 m) from rooted cuttings, and in Njabini (2,400 m) pro- duced by using a traditional clonal selec- tion scheme, did not reveal significant differences in plant growth and yield. Uganda. At HCRS, Kalengyere (2,500 m), a program of development and production of basic seed is being implemented by adopting appropriate seed production methods as a phased program (Flush-out system) during the vector-free period. In this respect, preliminary studies indicate that aphid populations appear from late April to mid-May as rains stop and tem- peratures rise. Populations peak by the end of August and then decline sharply. Sep- tember to March is practically aphid-free. The two seed production schemes under study use locally adapted varieties Cruza, Sangema, Rutuku, and Marirahin- da for producing basic seed. The first scheme is based on conventional clonal propagation and the second uses rooted cuttings for faster multiplication. Table 5-2 (A) shows production levels of basic seed through this program, while 5-2 (B) shows the volume of pre-basic seed pro- duced. Part of the approximately 50 t of basic seed supplied for multiplication was mul- tiplied as foundation seed. The rest was Table 5-2. Seed production of several varieties in Uganda, 1991. A Basic seed (t) Variety Cruza Sangema Rutuku Marirahinda Total B Pre-basic seed (t) Variety Cruza Sangema 106 Stage 1 (Clonal A) 4 3 3 0.5 10.5 No. of tubers ex-stem cuttings 10,000 4,000 Stage 2 (Clonal B) 12 10 10 1 33 Area planted m2 1,000 400 Stage 3 (Basic Seed) 36 30 30 2 98 Total producticn (kg) 3,000 1,300 Program 5 Tissue culture capabilities are becoming more advanced in African laboratories. supplied to farmers through District Agri- cultural Officers. Cameroon. A tissue culture unit with virus indexing capabilities and a screenhouse with 40 beds for rapid multiplication were developed at IRA-Bambui. Rapid multi- plication in screenhouse was intensified by using rooted cuttings which provide high quality basic seed tubers for subse- quent variety release. The first lot of basic seed tubers will be produced during the dry season (December to February) and then planted at the seed farm for field increase by mid-April. Studies on aphid populations at four locations of the main potato producing regions, and virus surveys in the Western highlands, indicated that PVS is by far the most common virus in farmers' fields. Up Program 5 to 94% PVS infection was recorded in the local cultivar Tuh-Nso in one location. Low percentages of PYX- and PLRV-in- fected plants were recorded at all loca- tions. Results of surveys for PSTV detection were negative, suggesting that PSTV may be absent from local materials. Social science studies examined the formal and informal seed systems in the most important potato producing areas of Cameroon. Preliminary analysis of a survey made in the northern province of Adamauoa showed that a marked decline in the area grown to potatoes followed the closing of a seed multiplication center that for- merly organized potato marketing for local farmers. 107 Studies of formal seed systems ana- lyzed the cost incidence of improved tech- niques for breaking dormancy to reduce the production period, and of producing and multiplying basic seed locally. Results point to 20% savings on. tuber costs through the use of chemicals to break dor- mancy which in tum improves seed qual- ity. A proposal has been made to further reduce production costs by 80% through one-time, on-station multiplication of basic seed. The Philippines. Planting materials other than costly seed tubers are needed in de- veloping countries. Seed tubers alone ac- count for about 50% of the total produc- tion cost in the Philippines. Use of sprout cuttings appeared to be a feasible, low- cost alternative for the lowlands in a study that included a large number of clones. With yields of 30 t/ha of seed tubers, clones such as 2k-75, P-6, and 32k-289 yielded significantly more than the tuber propagated control. Several clones showed survival rates higher than 60%, considered acceptable under lowland con- ditions. China. The scale of seed tuber production of promising potato cultivars in the Yunnan Province has expanded consider- ably. Cuttings from in v~tro plantlets and microtubers provided by Yunnan Normal University (YNU) and Yunnan Agricul- tural University (YAU) have greatly in- creased the amount of basic seed tubers available to meet the needs of different regions. Production at Zhanoshan City, Guang- dong Province, reached approximately three million mini-tubers during the win- ter/spring season. In Sichuan, Fujian, and Hubei, promising cultivars are being mul- tiplied by different propagation tech- niques. 108 Mira and Purple Skin, important local varieties, were cleaned-up from viruses by combining thermotherapy with meristem culture at YNU. Research on the influence of photoperiod, light intensity, and growth regulators on in vitro tuberization showed, under adequate daylength conditions, that an intensive light treatment benefitted in- vitro tuberization. No effect was found with the use of growth regulators. Studies at YNU have shown that biochemical and physiological changes occur during seed tuber storage, pointing to the relationship between endogenous hormones and sprouting. Changes in endogenous ABA, GA, IAA, and ZT were quantitatively measured during storage. Peru. Various institutions integrating the national basic seed production system pro- duced approximately 1,200 t of basic seed. Also, the program has continued active involvement in research and training at locations that produce basic seed. Grow- ers of improved breeding materials evalu- ated and selected several promising genotypes. Agronomic research focused on en- hancing efficiency and reducing costs at the pre-basic stages and on developing management practices specific to the cul- tivars and the ecologies where the seed is produced. At the pre-basic seed stage, use of 500-1000 ppm of the growth regulating compound CCC in the in vitro tuberization media gave best results. Combined with low-cost modifications of the MS propa- gation media, production cost of tuberlets larger than 45 mg was cut to US$0.08. Modified substrates and cultivation meth- ods in greenhouse seedbeds helped im- prove management and productivity of individual program cultivars. Virus detec- tion techniques were also improved. Program 5 Socio-economic work continued on traditional seed distribution systems in the Peruvian highlands and the identification of alternative systems appropriate for low income farming areas. A model was de- signed and implemented in small farmers' communities based on multiplying and- Sexual Potato Propagation TPS Adoption Significant progress was made in the adoption rate of TPS technology. True po- tato seed (TPS) technology is expanding rapidly in India, Indonesia, Bangladesh, Egypt, Nicaragua, and Paraguay. In China, seedling tubers continue to be used to plant about 20,000 ha of potatoes. Im- proved genetic materials and seed produc- tion and handling techniques have increased the diffusion of TPS technology as well as the success rate obtained when tested in farmers' fields. TPS is increas- ingly regarded by the public and private sectors as a viable commercial alternative to expensive high-quality seed which lim- its potato production by small farmers of developing countries. Advances were also made in the areas of progeny testing effi- ciency, improved genetic materials, virus transmission mechanisms, seed dor- mancy, and post-harvest handling. TPS Diffusion Asia. Selected TPS progenies are being increasingly used for large-scale commer- cial seed production. In India, farmers have increased their demand for seed. Commercial production of TPS is now possible in India following the official re- lease of TPS variety HPS-1/13. This Program S distributing high quality seed from farm- ers who specialize in producing seed within the highly fragmented farming sec- tor of seed users. Local committees fonned by seed multipliers are part of higher-level organizational units of the various produc- ing regions of Perµ. progeny has outyielded the crop from seed tubers of local cultivars in Bangladesh, Cameroon, Uganda, and other countries. The superior adaptation of HPS-1/13 was confirmed by experiments in Peru. The most advanced TPS genotypes from vari- ous CIP Regional Programs were com- pared for transplanting and seedling tuber yields and rated for various agronomic characteristics. Interest in TPS is also in- creasing rapidly in Morocco, Tunisia, Kenya, and Ghana. Indonesia. Growing numbers of inter- ested farmers from potato growing regions are now adopting CIP's selected TPS progenies. Among the most popular prog- enies in use are Serrana x DT0-28 and HPS-7/13. About 100 small farmers cur- rently use TPS in Indonesia. Egypt. Seed of TPS registered varieties Serrana x DT0-28 and Serrana x LT-7 is being used in by private interests to pro- duce seedling tubers to sell to farmers. An increasing number of small farmers are also using TPS to produce their own seed- ling tubers. Nicaragua. TPS was used in planting ap- proximately 140 ha of potatoes in different types of farming units, ranging from fam- ily farms to large agricultural coopera- tives. About 40% of farmers used TPS for transplanting seedlings and 60% used it to 109 produce seedling tubers. The Ministry of Agriculture plans to use TPS for 30% of the national potato production. In Para- _guay, the Ministry of Agriculture is sup- porting a seedling tuber production scheme developed by the national pro- gram. Farmers are buying ~edling tubers at about half the price of imported seed tubers. Following results obtained in Ni- caragua and Paraguay, national programs of Guatemala, Cuba, Jamaica, St. Kitts, Dominica, Venezuela, and Peru have initi- ated efforts to investigate the possibility of usingTPS. Genetic Improvements The establishment of a systematic method of evaluation allowed for fast progress in selecting superior TPS progenies with wide adaptation. Newly selected TPS pro- genies.from CIP's breeding program were evaluated for transplant and seedling tuber production under a wide variety of envi- ronments at several locations this year. A number of progenies were advanced to large-scale seed production for extensive on-farm testing next year. These new pro- genies showed good potential in tests con- ducted in several countries. In Egypt, LT-9 x 104.12LB and LT-8 x 104.12LB stood out among a large number of different TPS progenies. In Peru, transplanting and using seedling tubers of LT-9 x TS-3 pro- duced superior tuber uniformity and yields. In China, CFK-69.2 x 7XY.1 and 379697.153 x TS-2 showed good poten- tial. Serrana x TS-3 was well accepted by farmers for double cropping and the clone TS-3 is considered a superior parent for crossing with local cultivars. In Bangla- desh, HPS-7 /67 transplants outyielded Kufri Joti, a widely used cultivar. In China, the selection of TPS progenies for late blight and bacterial wilt resistance 110 is continuing in Huize, Yunnan, Penxian, Sichuan, and Enshi, Hubei. Virus and Viroid Transmission in TPS Studies conducted in CIP-Peru on the pos- sible mechanisms for PS1Vd and PVT transmission showed important variations among parental clones with respect to transmission rate when pollen from in- fected plants was used for pollinating ei- ther infected or non-infected plants. In PS1Vd, 57% of the plants became in- fected when pollinated from infected plants. Non-infected plants pollinated from PVT-infected plants remained non- infected. Advances in TPS Postharvest Management All orthodox (resistant to desiccation) seeds, such as TPS, have a critical seed moisture content (SMC) above which seeds in storage deteriorate at a logarith- mic rate. The critical moisture point is not affected by the storage temperature; though seeds do deteriorate faster when stored at higher temperature. To determine the critical point for stor- ing TPS, seeds of Atzimba x 104.12LB were stored for two years at increasing SMC levels from 3.9 to 10.9% and under a constant temperature of 30°C. Seed quality was evaluated at 4month intervals using the coefficient of velocity and the percentage of germination under high temperature conditions (27/40°C) at 7 days in petri dishes. The results in Figure 5-2 show that TPS stored at above 6% SMC deteriorated more rapidly after 1 year of storage. Therefore, TPS should always be stored hermetically sealed at below the critical point of about 6% SMC. Programs I Coefficient of velocity of germplasm (0-7 days) Percentage of germination (7 days) 30 Quadratic 20 R2 =0.92 p <0.001 10 0 3 4 5 6 7 8 9 10 11 Seed moisture content(% d.w) 100 80 60 40 20 0 12 13 3 Quadratic R =0.93 p <0.001 4 5 6 7 8 9 10 11 12· 13 Seed moisture content(% d.w.) Figure 5-2. Velocity and percentage of germination under high temperatures (27/40.C) in TPS of Atzimba x 104.12LB as affected by seed moisture during 16 months of storage. This is of particularly importance for maintaining seed quality in warm climates. TPS Dormancy TPS are usually considered to be "dor- mant" (difficult to germinate) for some time after the seeds are harvested. A TPS seed lot may be defined as being dormant if the favorable temperature for germina- tion falls within a temporarily restricted range, which is commonly found between 10 and 20°C. As TPS afterripen in storage, seed dormancy progressively decreases until most of the seeds in a given lot be- come non-dormant, and are thus able to germinate freely at 27/40°C (21/3 h/day) in less than 7 days. The effect of storage temperature (5, 15, 30°C) on the rate of dormancy loss was examined at increasing periods of storage using TPS of Atzimba x 104.12LB stored at 5% SMC. The results in Table 5-3 show that TPS germinated faster and more completely when stored Table 5-3. Effects of storage temperature on the velocity and percentage of germination of TPS at 7 days under 27/4o·c (21/4 h) tested after increasing periods of storage. Velocity coefficient Germination % Months in storage 3o•c 15•c 5•c 3o•c 15•c 5•c 4 23.3 19.2 18.3 95 72 75 8 25.4 20.5 18.8 99 96 91 12 28.7 24.6 23.0 96 93 79 16 29.3 22.8 20.5 100 88 80 20 31.8 25.1 19.9 100 93 93 24 31.0 26.8 22.8 99 96 91 Linear 0.80** 0.72*" 0.27*" 0.21* 0.32** 0.18* Quadratic 0.86** 0.73tt 0.29* 0.25* 0.45tt n.s. tt, *, n.s. denote P< 0.01, P < 0.05, and non-significant, respectively. Program S 111 Atzimba x DT0-33 100 80 60 40 20 Percentage of germination 2 months 0-"--~---'------' Dry (4%) Moist (6%) Seed moisture content 100 80 60 40 20 Percentage of germination 3 months .0 ~-----'-----~ Dry (4%) Moist (6%) Seed moisture content 43°C Serrana x DT0-33 Percentage of germination Percentage of germination 2 months 100 80 60 40 20 100 80 60 43oc 40 20 O.<.-----~-----' Dry (4%) Moist (6%) 0 -"'--------<-------' Dry (4%) Moist (6%) Seed moisture content Seed moisture conterit Figure 5-3. High percentages of germination show that storing TPS under high temperatures breaks dormancy. under higher temperature conditions. Dor- mancy was completely lost only after 20 months of storage at under 30°C. This suggests that TPS dormancy might be "broken" in a shorter period of time if sufficiently dry TPS could resist storage at a higher temperature than 30°C. TPS of Atzimba x DT0-33 (moderate dormancy) and Serrana x DT0-33 (high dormancy) were used to study the effect of high tt:mperature (30 vs. 43°C) during storage, on the rate and effectiveness of dormancy loss. At each temperature, the TPS were stored "dry" (3-4% SMC) and "moist" (6% ), according to the critical SMC p~nt defined above for TPS. The results 112 shown in Figure 5-3 show that moist TPS of Atzimba and Serrana quickly lost dor- mancy and died during the first 3 months of storage, while dry TPS lost dormancy but preserved most of its viability. Dry TPS of Atzimba lost dormancy sooner when stored at 43°C than at 30°C. Dry TPS of Serrana appeared to lose dormancy equally well after 3 months of storage at 30 and 43°C. However, a slight reduction in viability was observed when stored at 43·c. The results indicate that dormant seeds do not begin to deteriorate (lose vigor), as a consequence of high moisture and/or high temperature conditions in storage, Programs 1 until immediately after seed dormancy has been lost and optimum seed vigor has been attained. In order to lower the storage tem- perature and preserve seed quality, it is important to determine precisely when under high temperature conditions, each TPS lot has sufficiently lost its seed dor- mancy. The results also suggest the need to study individual progenies to determine their specific storage requirements for breaking dormancy as soon as possible after the TPS is harvested. Abiotic Stresses and Potato Crop Management Evaluation of Improved GermpJasm East Africa. Potato germplasm evalua- tions in almost all countries of Region III, with the exceptions of Angola, Namibia, and Somalia, have resulted in the release of new varieties from germplasm supplied by CIP. However, the lack of appropiate seed production programs hampers the distribution and widespread use of these varieties among farmers. An expanded Coordinated Regional Trial will be im- plemented including germplasm adapted to either highland or lowland environ- ments. China. Research on adaptability of potato genotypes focused on improved perfor- mance when intercropped with m·aize, a popular practice in Southwest China. Re- sults with clones evaluated for adaptabil- ity to intercropping with maize indicated adaptability relates not only to high yields but also to disease resistance, earliness, plant type, and the conversion efficiency of intercepted radiation to plant dry mat- ter. Creeping plants favor early light inter- ception, but cause weak growth and low yield of maize. A prolonged growing pe- riod increases the amount of intercepted radiation but enhances competition be- tween crops. Clone 87P48-64 was better Program 5 than other cultivars for intercropping with maize. Several advanced CIP clones were evaluated under winter cropping condi- tions at the Yuxi location (1,655 m) in Yunnan. Yield of clone B-71.240.2 (CIP- 24) was highest at 56.5 t/ha, while the local variety yielded 39.8 t/ha. CIP-24 is a widely adapted cultivar that grows and tuberizes well under both spring/summer and winter/spring conditions. In Yunnan, during the spring/summer planting season, more than 15 farming households planted seed tubers of selected clones in about two hectares along with their own seeds of the local variety. Se- lected clones CIP-24, CFK69.l, I-1085, Huinkul, and I-1039 showed excellent canopy growth and resistance to major diseases. In the early spring, similar re- sults were obtained in Sichuan where CIP clones yielded on average 20 t/ha, a 160% increase over the Chuanyu control variety. Bolivia. Growth-chamber tests were car- ried out on seedling of progenies of paren- tal genotypes with known tolerance to frost. Tuber families of the most tolerant crosses will be tested for frost tolerance next season. Information being developed on the in- heritance of frost tolerance and its quanti- f ica tio n should help increase the 113 frequency of genes for tolerance to frost in native populations and permit the selec- tion of adapted cultivars highly tolerant to frost. Use of Growth Regulators India. Studies were conducted on the ad- vantages of using growth regulators in a better partitioning of dry matter into tu- bers. Higher (18.5 to 26.1 % ) tuber yield and greater tuber weight were obtained by soaking seed tubers for 4 hours in solu- tions of 10 ppm triadimefon and 1 ppm uniconazole. Intercropping and Crop Rotation Studies China. At Enshi, Hubei (1,100 m), potato intercropped with maize using three plant densities for each crop were planted in alternating rows. The number of tubers Maize planted Time (weeks) 0 Maize planting Maize 6 weeks Potato planted 6 produced per unit area and mean tuber weight were closely related to stem den- sity of potatoes, but the effect of maize density was not significant. The treat- ments did not show significant differences in the conversion coefficient of inter- cepted radiation or dry matter partitioning in potatoes. However, the intercepted ra- diation increased with high stem densities, but the amount of assimilates translocated into individual tubers was lower, with a subsequent lower average tuber weight. Egypt. Experiments conducted at Kafr El- Zayat, showed that potatoes intercropped with maize could be planted in August as an early fall crop (Figure 5-4). This will supply potatoes to the market when they are not usually available. lntercropping with maize or sunflower sown six weeks before potato planting increased plant emergence by 30% and yield, by 40%, especially for heat tolerant varieties. Maize 1 O weeks Potato 4 weeks 10 Maize harvested Potato 6 weeks 12 Maize harvesting Potato planting Figure 5-4. lntercropping potato and maize in Egypt led to a 40% yield increase. Sou>'ce: R. El-Bedewy, et al., 1991. 114 Program 5 Soil Fertility and Mineral Nutrition Peru. At various highland sites, experi- ments to evaluate potassium (K) sources showed KN03 was a better source of K than KzS04, and KCl. Potato yield in- creased from 15.3 t/ha (control) to 25.0, 28.6, and 35.7 t/ha after application of 80, 160, and 240 kg/ha of KzO, respectively. Results obtained through the last sev- eral years of soil fertilization experiments have been used to formulate a local NPK- mixed fertilizer, "BAYOMIX 11-22", made with 50% rock phosphate. This fer- tilizer is widely used by potato growers of the Peruvian highlands. Effect of Planting Dates Uganda. Field experiments conducted at Kalengyere (2,500 m) studied the effect of planting dates on tuber yield of two varieties--a main season variety (Cruza) and an early maturing one (Sangema). Experiments were also conducted to study their relationship with the build-up of aphid populations and to identify vector- free periods for quality seed tuber produc- tion. At planting dates later in the year than early September for Cruza and late August for Sangema, yield and tuber number per plant declined lin- early in both varieties. Data recorded on aphid build-up showed that their population attained a critical value during February-March whereas September to January appears to be an aphid-free period, suggesting that crops for seed tuber production should be planted before the end of October in that loca- tion. Maintenance, Distribution, and Monitoring of Advanced Germ plasm Potatoes During 1991, potato germplasm was dis- tributed to 73 countries from CIP Head- quarters and redistribution centers located in Kenya, India, and the Philippines (Table 5-4). Use of true seed families is increasing at the expense of tuber families as CIP's partner countries continue to develop ca- pabilities to handle true seed segregating populations. Excluding the International Late Blight trial (which distributes only tubers) the proportion of tuber export to in vitro export is fairly stable. Egyptian needs are now being met by the private Program 5 sector. CIP continues to rely on the INIA- Chile contract for supplying larger quanti- ties of standard TPS progenies. The contract produced 7.7 kg ofTPS in 1991. CIP Experimental Stations in La Molina and Huancayo, Peru, produced 25-50 g of seed of each of 65 progenies for interna- tional evaluation trials. CIP's collection of pathogen tested potato germplasm in- creased in 1991 (Table 5-5). Varietal Releases A number of new varieties were released this year: 115 Table 5-4. Potato distribution by seed units. Tuber True seed TPS Clones families families (x 1000) L. America 10,115 Africa 14,485 Asia 1,578 S.E. Asia 994· Total 27,580 • TPS variety CIP IP88001, HPS-1/13 was officially released as a variety by the Government of India. • TPS varieties CIP 980001, Serrana x D1D-28; and CIP 985003, Serrana x LT-7 were registered and released by the Egyptian Ministry of Agriculture. • TPS varieties CIP 978001, Atzimba x R-128.6; CIP980003, Atzimba x 7xy.1; and CIP985003, Serrana x LT-7, while not formally released, are being pro- duced and grown in Nicaragua. • TPS varieties CIP IP88001, HPS-1/13; CIP IP88004, HPS-II/67; and CIP IP88006, HPS-7 /67, are being produced in Bangladesh for further trials. CIP 985003, Serrana x LT-7; CIP 978001, Atzimba x R-128.6; and CIP 980001, Serrana x DT0-28, are being used ex- tensively for research trials. Table 5-5. Pathogen-tested potato germplasm. Potato a. Wild and primitive clones b. Advanced clones/varieties c. Differentials/indicator hosts d. International late blight clones e. Research clones/parental lines with restricted distribution 116 10,130 171,770 13,335 10,231 8,380 5,633 4,037 44,250 5,341 3,352 44,300 2,908 27,732 251,180 27,246 • TPS varieties CIP 978004, Atzimba x DID-28; CIP 985003, Serrana x LT-7; and CIP 986001, Atlantic x LT-7, are being grown by many farmers in Indo- nesia. • Three varieties have been released but not named by the Ministry of Agricul- ture in Uganda: CIP 374080.5 (also named in past years in Peru, Bolivia, Burundi, and Guatemala); and CIP 381381.20 and CIP381379.9 both com- ing from the international late blight trials. • Cameroon has named four varieties: CIP 720055, IRA-Bambui, clone of Mexican origin; CIP 382121.27, CIPIRA, from the International late blight trial; CIP 386298.9, IRA Babun- go, from tuber families with virus resis- tance; and CIP 386298.13, IRA88, from tuber families with virus resistance. Pathogen tested 192 288 32 325 106 Being cleaned 77 06 02 64 Program 5 .. • Burundi has four candidates for release and Zaire has two. Sweetpotato Sweetpotato was distributed to 33 coun- tries during the year from CIP Headquar- ters and Regional distribution center in the Philippines, Table 5-6. This is the first year a significant amount of sweetpotato germ plasm has been available for distribu- tion. Distribution of in vitro plantlets has proved difficult. Many countries have been unable to receive and propagate the material. Further training is necessary on receipt and recovery of in vitro plantlets. Pathogen tested advanced clones, vari- eties and breeding lines have increased during the year. A total of 93 clones are pathogen tested and 129 are in the process of cleaning. In addition, about 40 patho- gen-tested clones of the AVRDC collec- tion are being rechecked. Table 5-6. Sweetpotato distribution by planting units. Clonal True seed in vitro families L. America 546 1,219 Africa 871 11,625 Asia 392 3,710 S.E. Asia 391 8,100 Total 2.455 26, 112 Sweetpotato Production Through Improved Planting Materials and Management Techniques The development of new and improved propagation and crop management tech- nologies for sweetpotatoes is an important aspect of CIP research. Program 5 Rapid multiplication of new or im- proved planting materials is an important part of sweetpotato production, especially in areas with high incidence of virus in- fected planting materials or where adverse weather conditions have damaged the ex- isting planting materials. The use of single node cuttings is an extremely efficient method for rapid increase and production of stock plants under nursery conditions. The stock plants can be used to produce stem-tip cuttings for planting in the field. However, nodal cuttings produce lower yields of storage roots than stem-tip cut- tings so they are only recommended for the production of stock plants. Kenya. Trials were conducted to test the use of single node cuttings for rapid mul- tiplication. Cuttings of five cultivars were planted in pots with the node and a portion of the stem buried beneath the surface of the soil. Survival rates ranged from 70 to 100% at 60 days after planting, and (among the cultivars tested) those with unlobed leaves had a higher survival rate than those with lobed leaves. Similar re- sults have been obtained in India with cuttings planted horizontally producing better yields than those planted vertically. Peru. Inexpensive materials for propaga- tion of sweetpotato such as the use of rustic pots made from banana leaves and newsprint have been successfully tested under different conditions in Peru. Planting and Harvesting Dates, Fertilizer Use and Planting Methods India. A series of year round, on-farm and research station trials was conducted to determine optimum planting and harvest- ing dates, fertilizer needs, and planting methods for the western Indo-Gangetic plains. 117 Rustic pots shown in these two pictures are made from banana leaf (top, bottom) and newspaper (bottom). They are used for planting sweetpotato shoot tips which establish and grow more quickly and produce higher yields than nodal cuttings. 118 Program 5 Results demonstrated that highest yields are obtained from July-August plantings and October-November har- vests. Low temperatures from November to February resulted in the absence of stor- age root production in that region, The application of an NPK fertilizer did not increase yields. Spacing 60 cm between rows and 20 cm between plants produced better yields than planting at 60 x 10 cm. Tolerance to Drought China. Some areas in southern China have extended dry seasons without irrigation. A large number of sweetpotato cultivars was evaluated in Guangdong for drought toler- ance. Of those tested, 34 were classified as tolerant to drought, 35 medium tolerant, 29 sensitive, and 3 as highly sensitive. The Philippines. In Los Banos, 50 sweetpotato cultivars were screened for drought tolerance and to determine possi- ble heritable morphological or yield char- acteristics associated to drought. Several of the cultivars, such as L076, VSP2, and N052, are considered highly tolerant to drought since no difference was obtained when grown under both drought stress and non-stressed conditions. Shade Tolerance Sweetpotato has been found to be ex- tremely sensitive to low levels of solar radiation. Trials conducted in Los Banos, Philippines, demonstrated that some culti- vars (Miracle and VSP-5) are shade toler- ant and produce well under 60% transmitted light. Lower levels of trans- mitted radiation restricted yield. The use of shade tolerant cultivars would be an important addition to intercropping sys- tems. Program 5 Adaptation The storage root and plant top yields of 50 sweetpotato cultivars (representing a wide genetic variation within CIP's germ plasm) were evaluated under diverse environ- ments in Peru over two years, to determine a possible correlation with environmental factors and cultivation procedures. Dis- tinct groups of cultivars were identified by growth, yield, and cultivation require- ments under the various conditions. Culti- vars such as RCB IN-172 (Zapallo de Quillabamba) was highly productive in various soils and climates, whereas EEY- 41 (Jewel) had a significantly lower adap- tation range being affected by low temperatures (Figure 5-5). Specific cultivation procedures im- proved survival and growth rates as well as yield in the cool Peruvian highlands. For instance, cool pretreatment of cuttings resulted in up to 98% plant .survival as compared to 40% survival without the pre- treatment. Differences in yields in three coastal desert locations of varying soil pH (5.3, 7.9, and 8.3) confirm reports that soil pH can have a strong influence on yield. In Tumbes, Peru, a high pH (8.3) resulted in very low yields. Flowering For sweetpotato breeding purposes, the use of trellises increased efficiency of pol- linating and seed collection. In Argentina, flowers of plants grown on trellises re- mained dryer and had a lower incidence of fungal infection during rainy periods than those grown flat on the ground. Sweetpotato seedlings grown from seed flowered freely, 16 hours or more, in the long summer days. Several native Argen- tinean cultivars that normally do not 119 Plant top yield Summer Fresh weight (kg/m2) 12,-~~~~~~~~~~~~~ 10 8 6 4 2 0 •EEY4 mRCBIN172 Storage root yield Summer Fresh weight (kg/m2) 14,-~~~~--~E-E-Y4~~-~R-C_B_IN~17-2-, 12 10 8 6 4 2 0 Plant top yield Winter Fresh weight (kg/ni') 10 8 6 4 2 •EEY4 •RCB IN 172 o.i.--..---..---¥m--..-~-J'>l\\'ll-~-l&\l\>l~-.------J Storage root yield Winter Fresh weight (kg/m ) 14,-~------~~~~----~~--, 12 •EEY4 B 10 8 6 4 2 o+-.,__..,__..,__..,_~--1'""-~--f"lll~-,_...! TU = Tumbes; LI = Lima; VI = Vitarte; Cl = Cieneguilla; SP = San Pedro and CH = Chincha; TA-a & TA-b = Tacna; CA= Canyasbamba and Tl= lingua; HU= Huancayo; SR= San Ramon; YU = Yurimaguas. Summer= Oct.-Apr.; Winter= Apr.-Nov. Figure 5-5. Plant top and storage root yield of two sweetpotato cultivars in various agroecologies and seasons, Peru. flower, flowered and produced seeds when the plants were covered to reduce daylength to 12 hours and the ground was mulched with black plastic to raise soil temperatures. Cultivars evaluated in Los Banos (Philippines) also flowered under 12 hour photoperiods. Soil Management, Fertilizers, and Mineral Nutrients eooperative research with national insti- tutes in Peru and China is currently study- ing the yield of sweetpotato plant tops and storage roots in relation to different levels of NKP fertilizers, the residual effect of 120 PK fertilization, liming in highly acidic soils, humid jungle conditions, and the use of organic fertilizers under various crop rotation systems. Results showed applica- tions of various levels of nitrogen fertiliz- ers do not increase production of storage roots over that of the control. However, the application of PK increased storage root yield. The lack of effect of nitrogen on the yield of storage roots was confirmed by results of another on-farm trial which used cow manure. In this trial, not only was the storage root yield low compared to plant top yield, but the individual storage roots of all cultivars were extremely small com- pared to the size of storage roots usually Programs produced in the area. Use of organic ma- nure or NPK fertilizer increased the yield of plant tops over storage roots. Therefore, Training Propagation and Crop Management Peru. With CIP's cooperation, 4 to 5 short courses are organized every year to be held in the principal Peruvian cities (Cusco, Puno, Huancayo, Iquitos). Course programs are related to fertilizer use and soil management with an emphasis on po- tato. The courses are offered for local uni- versity professors, researchers, and extension agronomists of government and non-government agricultural institutions. During the development of the training courses, results of our sub-projects are presented and discussed. Potato Breeding Peru. A workshop on advances in potato breeding in Andean countries was held in Lima, February 4-7. It was jointly organ- ized by CIP Region I and PRACIPA, with funding from IDRC. Participants from Bolivia ( 4), Colombia ( 4), Ecuador (3), Venezuela (3), and Peru (13) attended the workshop. Discussion topics included fungal and viral diseases, insect and nem- atode resistance, earliness, frost resis- tance, genetic engineering, quarantine regulations, and exchange of genetic ma- terials. Colombia. The PRACIPA network organ- ized a breeding project's coordination meeting in Rio Negro and Bogota, June 24-28. The meeting was hosted by ICA and the CIP Region I office in Bogota. Program 5 selecting the most effective type of fertil- izer is important if plant tops, rather than storage roots, are needed for animal forage. Nine participants from Bolivia (2), Ecu- ador (1), Peru (1), Venezuela (1), and Co- lombia (3) attended the meeting. Potato Production Peru. This UNDP-funded course on na- tional potato production was held January 20-February 2 at the Agricultural Experi- ment Station in Andenes, Cusco. It was organized by the Universidad Nacional Agraria La Molina and the Instituto Nacional de Investigaciones Agropecua- rias y Agroindustriales (INIAA), and sponsored by CIP. Twenty participants from Peru and one from Bolivia attended. This course covered agronomy; soil, fertilizer and water requirements and their management; breeding techniques; viral, fungal, bacterial diseases and pests; phys- iology of growth and development, dor- mancy and storage; seed production, certification and inspection; postharvest technology and visits to potato production fields. A contract with the Universidad Nacio- nal Agraria La Molina for training Peru- vian agronomists from government and private institutions was carried on from previous years. The objective was to imp- art knowledge about agronomical factors of potato production with emphasis on fertilization. Under this contract, 222 par- ticipants attended courses in Huancayo, Arequipa, Ayacucho, and Puna. 121 Ghana. An in-country potato production course took place in Ho, July 15-20. It was jointly organized by the Ministry of Agri- culture, Department of Crop Services and CIP Region V. The 21 participants were all from Ghana. Uganda. A UNDP-funded course on veg- etative propagation, was held in Kampala, September 24-27. It was organized by CIP Region III. Participants came from Uganda, Tanzania, Kenya, Ethiopia, Mad- agascar, Burundi, Mozambique, and Malawi. Sweetpotato Production Jamaica. A workshop on production and pest management of sweetpotato was held in Kingston, January 23-25. It was jointly organized and financed by the Caribbean Agricultural Research and Development Institute (CARDI) and CIP. Additional sponsors included the Canadian aluminum company Alcan and the Jamaican Ministry of Agriculture. The objectives of the work- shop were to assess the market potential of swcetpotato, identify current production constraints, and review appropriate inte- grated pest management strategics for cur- rent production systems. Participants came from: Jamaica (23), the Dominican Republic (2), Montserrat (1), Saint Vin- cent (1), and the USA(l). Saint Vincent. A regional training course on improved technologies for swcetpotato production was held in Kingstown, Febru- ary 18-23. It was sponsored by the Univer- sity of the West Indies in collaboration with CARDI, CIP and the Ministry of Agriculture, Industry and Labour. Objectives of the course were to in- crease the understanding of factors affect- ing the performance of the swcetpotato crop, identify factors affecting sweet- 122 potato production for specific markets, in- crease the knowledge of effective pest and disease management, and review produc- tion and postharvest technology. The 24 course participants came from: Saint Vin- cent (7), Barbados (1), Dominica (3), Gre- nada (2), Montserrat (3), Saint Kitts-Nevis (4), Saint Lucia (3), and Trinidad (1). China. An in-country sweetpotato germ- plasm management workshop was held in Wandong, February 26-March 2. It was co-sponsored by IBPGR and CIP. Partici- pants came from China, India, the Philip- pines, Vietnam, and Fiji. Egypt. An in-country sweetpotato course, was held in Kafr El-Zayat, September 22- 25. The four-day course was attended by 20 participants from several Egyptian pro- vinces. Chile. "Sweetpotato: a new agricultural alternative for Chile" was the name of a seminar/workshop organized by the In- stituto de Investigaciones Agropecuarias (INIA) and CIP. It was held at La Platina Experimental Station, Santiago de Chile on October 3. Participants from Chile (41), Argentina (2), and Uruguay (1) at- tended the event. Seed Production Technology and Related Disciplines Bangladesh. A regional workshop on TPS production prospects and problems, jointly organized by the Tuber Crop Re- search Center (BARI) and CIP Region VI, was held at the Bangladesh Agricultural Research Institute in Joydebpur, Gazipur, January 20-25. The 18 participants came from India (7), the Philippines (2), Viet- nam (3), Indonesia (1), Malaysia (1), Nepal (1 ), Bhutan (1 ), and Bangladesh (2). Kenya. A workshop on seed potato tech- nology and distribution systems in East Program 5 and Central Africa, was held in Nairobi, May 27-31. The 20 participants were seed specialists with management responsibil- ity for national seed production programs. They came from Kenya (6), Rwanda (2), Burundi (3), Uganda (5), Zaire (2), Tanza- nia (1), and Madagascar (1). Participants were required to submit review papers to assess current seed tech- nology in the region. Working groups developed recommendations for im- plementing sustainable seed production schemes at the end of the meeting. The workshop covered topics related to prop- agation methods and quality control, orga- nization and management of seed pro- grams, policy issues, and developing sustainable seed production schemes for each country. Chile. The first course/workshop on meth- odologies to improve the use, production, and storage of potato seed-tubers was held at the Carillanca Experiment Station, Sep- tember 24-25, and Quilamapu Experiment Station, September 26-27. Jointly organ- ized by INIA (Chile) and CIP Region I South Cone, the course/workshop was at- tended by 95 partiGipants. Objectives were to train extensionists in methods to improve the use, production Program 5 and conservation of seed-tubers and de- sign a strategy with potato seed producers for implementing seed quality improve- ment programs. Peru. A TPS Latin American workshop, organized by CIP, was held in Lima, Sep- tember 5-7. Its objectives were to review current knowledge on TPS technology at CIP, discuss and exchange experiences among countries presently using TPS (Chile, Nicaragua, Paraguay and Peru), identify limiting factors in large scale pro- duction, and establish a collaborative re- search network with countries interested in this technology. The workshop was attended by 34 par- ticipants from Bolivia, Colombia, Costa Rica, Cuba, Ecuador, Guatemala, Jamai- ca, Mexico, Venezuela, and the USA(one participant each), Chile (3), Italy (2), Nic- aragua (2), Paraguay (2), the Dominican Republic (3), Peru (2), and CIP (10). Uganda and Ghana. Two workshops on the organization and management of veg- etative seed production programs were held in Uganda (October) and Ghana (De- cember). CIP regional personnel and IITA collaborated in organizing them. 123 China produces about 90% of the world's sweetpotatoes. Over the last 10 to 15 years sweetpotato production has become dramatically more market-oriented, both for fresh and processed uses. • ,._, Program6 Postharvest Management, Marketing 1991 In Review Postharvest activities at CIP focus largely on storage, processing-including breeding for processing, and marketing as well as related work on nutrition and consumption. During 1991, research, training, and information in these fields previously located in Thrusts II, VI, VII, VIII, and X have been consolidated to constitute Program 6. Leadership of Program 6 was also transferred back from the regions to CIP headquarters to facilitate closer collaboration with other Lima-based staff. A review of research projects, contracts, and theses in Program 6 led to the clustering of activities into two major projects: one each for potato and sweetpotato. The reduced number of projects aims to assure that a critical mass of human and financial resources is available in each project to foster more interdisciplinary work at the operational level, to encourage prioritization of activities within the projects, to minimize administrative requirements, and to promote greater transparency, hence accountability, in the Program. As stated in the Strategic Plan, resource allocation across commodities in Program 6 will be 25% for potato and 75% in sweetpotato. This reflects as much the needs and opportunities for postharvest work in sweetpotato as the fact that past accomplishments with potato will require less core support· to sustain. In the years ahead, Program 6 activities will focus more on Asia and sub-Saharan Africa with Latin America declining in relative importance. Consumer potato storage research continues to explore the potential of alternative, low-cost storage methods. In India, experiments on both rustic storage and storage media showed promising results. Varietal evaluation in Burundi and Cameroon included testing materials for dormancy and storability. In Egypt, tubers and TPS progenies kept in cold storage and a traditional non-refrigerated store demonstrated great variability in their reaction to these different conditions. Seed storage tests in Cameroon, Uganda, and Egypt also documented differences in varietal reaction to length and type of storage. Research on natural sprout inhibitors in the Philippines found promising treatments for two different types of tubers. Village-level potato processing research in India developed operational guidelines for specific processing activities through trials involving both labor and equipment. A Ph.D. thesis at the University of Nairobi examined the feasibility of small-scale production of solar-dried potato flour and its potential uses. A case study on improved village-level processing in Peru documented the knowledge acquired and lessons learned. A manual on processing, marketing, and use of root and tuber crops in developing countries was prepared in collaboration with CIAT and IITA and is being reviewed. Program6 125 The growing importance of the fast food and snack industry for potato use in Central and parts of South America, Southeast Asia, and the potential for such processing in countries like India were documented at symposia organized by CIP. Through breeding research at CIP headquarters, clones from CIP's pathogen tested list as well as from CIP's own breeding program have been identified as having good processing charac- teristics (for chips and/or french fries) and adaptability to tropical growing conditions. In addition, a segregating population has been assembled that can be used by NARS interested in selecting new varieties for processing. The marketing component of the PRACIPA project completed its first phase during 1991. This project answered specific questions about marketing problems in Bolivia, Colombia, Ecuador, Peru, and Venezuela and documented research methods and expe- riences that were previously unavailable. Marketing and demand research in Tunisia helped explain why average per capita consumption of potatoes rose from 10.5 to over 20 kg/yr between 196Q and 1990. Urbanization, changing tastes and preferences, and increases in incomes have all contributed to this phenomenon. Comparative analysis of potato production, marketing, and consumption trends in Latin America point out the sharp increase in per capita potato consumption in countries such as Colombia where it rose from 30.0 to 60.8 kg/yr between 1961 and 1988. CIP published a manual on methods for agricultural marketing research in conjuction with the Inter-American Institute for Cooperacion in Agriculture (IICA). Jennifer A. Woolfe's thorough review of sweetpotato postharvest literature was also completed during 1991. Among its principal findings, the author notes the untapped potential of the crop to improve diets for low-income consumers and expand market opportunities for resource-poor farmers. In her view, low yields and low recovery rates for sweetpotato are among the most significant constraints to an expansion in process- ing. Sweetpotato breeding for processing will give major emphasis in the years ahead to testing promising elite materials in selected countries. CIP's current list of pathogen tested clones contains materials from a number of countries as well as AVRDC and IITA. Breeding work conducted in Peru, United States, China, Thailand, and Colombia continued to evaluate sweetpotato clones, varieties, and breeding populations for processing characteristics. Collaborative research projects on sweetpotato processing in China and Vietnam focused on converting sweetpotato starch into noodles. Efforts at the Crop Research -Institute at the Sichuan Academy of Agricultural Sciences were devoted to keeping both wet and dried starch a white color. A Master's student at the Asian Institute of Technology, supported in part by UPWARD, analyzed noodle making in Vietnam and developed a series of procedures to produce a higher quality, more transparent final product. Experiments in Burundi and Cameroon using raw, grated sweetpotato as a partial substitute for imported wheat flour have generated promising results and con- siderable interest on the part of local bakeries. Several bakeries are already producing sweetpotato bread commercially. Comparative analysis of FAQ time-series data on utilization patterns for root and tuber crops in developing countries over the last 25 years found that sweetpotato 126 Program6 •' exhibited the greatest dynamism. Now 30% to 50% of national output in countries such as China and Brazil goes to animal feed. A Ph.D. thesis at Cornell University on sweetpotato marketing in Rwanda found that the crop's future as a principal staple in rural areas is secure. The capacity of the marketing system to reduce costs will largely determine sweetpotato's future role in urban diets. The thesis notes that research into storage and processing is the single most useful contribution that can be made. A consumer survey on sweetpotato bread in Lima served as the basis of a master's thesis at Wageningen Agricultural University. Results indicate the bread has promising com- mercial potential provided certain characteristics can be improved. Root and tuber crop processing, marketing, and utilization was the theme of a series of workshops organized in Guatemala (Latin America), Philippines (Asia), and Nigeria (Africa) in collaboration with CIAT and UTA as part of a UNDP project on human resource development. The objectives included documenting recent trends in processing and utilization, presenting and analyzing research methods, and discussing mechanisms for addressing priority needs in this field. Active collaboration with other centers such as CIAT and UTA as well as with networks like UPWARD, SAPPRAD, PRACIPA, PRECODEPA, and PRAPAC will continue to be a key component of the Program's global strategy in the year ahead. Expanding Utilization of Potatoes in Developing Countries Consumer Potato Storage India. India produces over 15 million t of potatoes a year, more than 20% of all potatoes produced in developing coun- tries. Village-level storage of potatoes is a major problem in almost all potato pro- ducing areas of the country. The lack of inexpensive storage methods leads to ex- cessive physiological weight loss, rottage, and sprouting. Research in India continues to explore low-cost alternatives to cold storage, including rustic stores and storage media. Rustic storage experiments in India showed considerable promise. After sort- ing and grading, tubers were placed in a rustic store for 2 months beginning in April 1991. Each month, three replications weighing 565 kg each were removed from the store. Physiological weight loss after one and two months storage was approxi- Program6 mately 4% and 9%. Average rottage after one and two months of storage was 1 % and 6%. Potatoes are traditionally stored in sand in many parts of India. Yet, lack of dry sand can be a serious constraint to this type of storage in certain places. Therefore, trials were conducted evaluating potato storage in five different locally available media: sand, brick kiln soil, wood ash, soil, and rice husks. Three replications of 10 kg each were stored in the five media. Storage began in April 1991 and lasted two months. Much less physiological weight loss was observed for tubers stored in brick kiln soil (Table 6-1 ). Least rottage occurred for potatoes stored in wood ash though it was not much different from those in dried soil a11d brick kiln soil. Tubers stored in sand had the most sprouts and those stored in husks had the least but the differences were not significant. 127 Table 6-1. Storage attributes of five media. Physiological Rottage Number of Sprout Media Loss(%) Loss(%) Sprouts Length (cm) Sand 15.4 b 20.0 a 1.7 a 1.0 b Brick kiln soil 8.7 c 8.6 b 2.7 a 1.5 ab Dried soil 12.7 b 9.8 b 3.0 a 1.4 ab Wood ash 19.8 a 6.2 b 3.0 a 2.3 a Rice husks 20.7 a 18.0 a 4.0 a 1.7 ab Means followed by the same letter are not significantly different at p = 0.05 using the Duncan's Multiple Range test (DMRT). Sprout length, significantly different in the two media, was shortest in sand and longest in wood asq. Burundi. Research at two locations stud- ied the effect of potato storage on weight loss and sprout length. The variety Uganda 11 was put in storage in early July at Gisozi (2,090 m), after being harvested at Mwokora (2,350 m) in late June, and on July 8 at Mwokora immediately after har- vest. The tubers were placed in baskets surrounded by straw with 6 replications in Gisozi and 9 in Mwokora. Each basket contained 20 tubers (5 kg) and was in- stalled in a dark, naturally ventilated wooden store (15 m x 1.5 m and 1.0 m ground clearance) with ~n 800 kg capac- ity. Ventilation from below was restricted during the day by closing air vents. At night, the cooler air was allowed to enter and circulate. The tubers were removed after 120 days. Average weight loss at Gisozi and Mwokora was 7% and 7.1 %; sprout length was 14.3 mm at Gisozi and 45.9 mm at Mwokora. Cameroon. Evaluation of clones for selec- tion of improved varieties also involves testing under storage conditions for dorm- ancy ·and length of storability. In Cam- eroon, clones selected from late blight resistant materials (LBT-88A and LBT- 89A) and virus resistant materials (VIF- 128 88A) were evaluated. Tubers were stored in a diffused light store at Upper Farm (2,000 m ). More than 150 tubers per clone were evaluated. Data were collected on number of rotted tubers, sprout length, and dormancy. Results indicate that for up to 90 days no tubers rotted. After 180 days, tubers from CIP 720122 had the highest percentage of rotted tubers (35.3%). Tu- bers from the virus resistant clones had, in general, the longest sprouts and a dorm- ancy peljod of less than 90 days. Egypt. Tubers of 13 commercial varieties and seedling tubers of two TPS progenies were stored for 3 months inside a cold store at 4°C and in a traditional non-re- frigerated store (nawalla) at ambient tem- perature. All tuber lots were cured under rice straw for about 2 weeks then sorted to discard pest-infected or decayed tubers prior to storage. Each treatment consisted of 5 kg of tubers packed inside a jute sack and replicated three times. Results indi- cate that, in general, nawalla storage re- sulted in more decayed tubers and greater weight loss than cold storage (fable 6-2). However, the different varieties exhibited great variability under these conditions. Varieties Nicola, Draga, and Diamant showed lower losses than other varieties under nawalla storage conditions. Varie- ties Timate, Oblix, Ailsa, and King Program6 Table 6-2. Effect of storage conditions on tuber losses of 13 potato varieties and two hybrid (TPS) progenies. Nawalla8 Cold Store Progeny/ Loss Total Loss Total Sprout Variety % weight Sprout condition % weight Condition " loss% loss% Barak a 2.0 14.0 Long & weak 0.0 2.0 Free Nicola 2.2 10.6 Short & strong 0.0 4.0 Free Cara 1.0 14.0 Long &weak 0.0 4.6 Free Draga 1.6 11.6 Short & strong 0.0 5.0 Free Alpha 1.2 15.1 Short & strong 0.0 6.2 Short Diamant 1.5 12.8 Short & strong 1.0 5.1 Short Spunta 1.3 13.0 Short & strong 0.0 5.1 Short Timate 3.4 23.7 Long, weak, branched 0.0 7.0 Long Lise ta 1.3 15.8 Long & weak 1.5 5.5 Long Oblix 3.2 25.0 Long, weak, branched 2.3 7.0 Long Mondi al 1.0 11.7 Long & weak 0.0 1.5 Short King Edward 2.0 17.6 Long, weak, branched 0.0 2.0 Short Ails a 1.8 21.3 1.1 5.4 Long Serrana x oro-28 1.5 11.0 Short & strong 1.3 5.4 Free Serrana x LT·7 2.4 11.1 Long & strong 0.0 3.4 Free 8 Nawalla: inspections at three week intervals, with the first sorting after six weeks. b Cold store: one inspection only. Duration of Storage = three months, from 9/6/91 to 9/9/91. Potatoes in Egypt are traditionally stored in diffused-light storage structures called nawal/as. Program 6 129 Edward showed higher losses. Therefore, the latter varieties should be stored under cold storage conditions. The two TPS pro- genies (Serrana x DT0-28 and Serrana x LT-7) showed low losses under nawalla conditions. Seed Potato Storage Cameroon. Research focused on the effect of storage periods on yield and other agronomic characteristics of seed. A trial conducted at Babungo (1,150 m) included tubers from seven advanced clones and two imported varieties. Tubers were stored for 8.5 months in a diffused light store (DLS). Part of the seed was re- planted, and harvested tubers were stored again for 2.5 months. Tubers were planted in a randomized complete block design with three replications, 10 tubers per rep- lication. Plants were harvested at 90 days. Data were collected on number of plants at harvest time, number of tubers, and average tuber yield per plant. Results in- dicate that tuber weight increased when tubers were stored for only 2.5 months. However, average yield per plant in- creased when tubers were stored for 8.5 months. The increase in yield was a result of formation of several, albeit small, tu- bers (Table 6-3). Uganda. Potato varieties Sangema and Cruza were studied for their storage be- havior in a replicated trial involving three grades of seed stock and three stor- age methods. Data for different parame- ters show that rottage 90 days after storage was 1.3-5.3% in different grades of seed stocks of Sangema in DLS as against 13.3- 20.3% in baskets and 9.3-34.0% in bags (dark storage). In Cruza, the rottage was comparatively low. After 240 days of stor- age, the rottage percentage was 10.3- 15.3% in Sangema in DLS, 17.9-34.0% in baskets, and 47.0-51.4% in dark storage. Sprout development, judged by sprout weight per kg, was extensive in bags and baskets, but balanced using DLS. Results suggest that Cruza can be stored three to four months in DLS and Sangema can be stored in DLS up to six months without significant deterioration. Egypt. Tubers from 11 varieties originated from certified seeds imported from Eu- rope and seedling tubers of five hybrids Table 6-3. Plant stand and average tuber weight of clones stored in rustic, diffused-light store for 2.5 and 8.5 months at Babungo (1175 m) in the western highlands of Cameroon, 1991. Average stand Average tuber Average yield count (22 days) weight (g) (g/plt) Clone 2.5mo. 8.5mo. 2.5mo. 8.5mo. 2.5mo. 8.5 mo. 382196.7 7.3 10 44.9 49.3 265 695 385259.5 8.7 10 69.6 46.3 780 1033 382196.1 9.3 10 76.1 53.1 829 855 386295.2 5.7 10 75.1 46.1 758 770 386290.6 10.0 10 52.6 49.9 647 783 386290.5 10.0 10 44.8 37.6 779 887 386294.4 10.0 10 58.8 42.9 682 759 Cardinal 1.0 10 65.4 51.7 301 636 Diamant 1.0 10 54.6 51.8 191 544 Mean 7.0 10 60.2 47.6 581 773 130 Program 6 were stored for about 3.5 mo inside a cold store at 4-4.5°C and an improved nawalla (non-refrigerated store). All seed lots were pre-sprouted for two weeks under diffused light prior to planting in late September 1990 in 4.2 m2 plots. The experiment was harvested in late January 1991. Yields of seedling tuber progenies Serrana x DT0- 33, Serrana x LT-7, and Serrana x DT0-28 stored in traditional stores were as good as those of commercial cultivars. This sug- gests that seedling tubers of those proge- nies can be safely stored at ambient temperature for 3.5 mo instead of expen- sive cold storage. It also shows that nawalla-stored seed ofDraga, Alpha, Dia- mant, Cara, and Spunta have yields com- parable to their respective seeds kept in cold storage. Philippines. Research on natural sprout inhibitors continued at the University of the Philippines in Los Banos (UPLB) with support from CIP. Extracts from various plants were used in experiments including oil from solasi (Ocimum sanetum) and pat- chouli (Pogostemon cablin). For Cosima tubers stored three months, covering with dry mufia leaves followed by dipping in mint crude extract for 10 minutes (Table 6-4) seems to be the best treatment. For Granola tubers, sprouting was best controlled by pot treatment with patchouli oil. Processing Potato processing activities have covered three broad topics: village-level proces- sing, industrial or semi-industrial process- ing in developing countries, and industrial processing in developed countries. Given CIP's mandate and comparative advantage, most research, training, and information has focused on village-level processing. On occasion, CIP provides support to local institutions working to get a better under- standing of the array of processing activi- ties that typically take place in developing countries, including industrial and semi- industrial processing. As an international center, CIP also monitors developments in industrial processing in developed coun- Table 6-4. Effect of dipping potatoes in various plant extracts and oils on disease incidence and sprouting of tubers. Treatments Sprouting Days to Diseased Days to Average % sprouting tubers disease severity % Mint extract (5) 63.3 cd 62.3a 13.3 be 34.7 4.3 bed Mint extract (1 0) 40.7 b 54.0 a 16.7 be 37.0 2.8 be Muria extract (5) 62.3 cd 64.3 a 20.0 c 42.7 4.5 cd Muria extract (10) 63.3 cd 68.7 a 10.3 b 35.3 5.0 d Oregano ext. (5) 67.7 cd 63.0 a 13.3 be 30.0 3.0 bed Oregano ext. (1 0) 73.3 cd 57.3a 20.0 c 48.7 2.7 b Solasi oil (10) 20.0 a 33.0 b 89.7 a 31.3 3.3 bed Oregano oil (10) 13.3 a 54.7 a 70.0 d 30.3 3.8 bed Muria dry leaves 60.0 c 68.3 a 0.0 a 1.0 a Control 76.0 d 58.7 a 17.3 be 25.0 4.3 bed c.v. (%) 11 31 2 64 21 Means followed by the same letter are not significantly different at 5% level using DMRT. Program6 131 tries to identify important trends for devel- oping countries (e.g., exports of processed potato products to Asia). During 1991, research on village-level potato processing involved time-:in-motion studies of operations in India, a Ph.D. the- sis at the University of Nairobi on process- ing potato flour; preparation of a case study on experience to date and lessons learned in Peru; and completion of a draft manual (in English and Spanish) on prod- uct development for root and tuber crops. India. Previous research on village-level potato processing in India had shown re- covery rates to be a key factor influencing profitability. Current research is attempt- ing to examine more closely the individual operations involved in processing to de- velop guidelines in the operational use of resources. Experiments conducted jointly with the Society for the Development of Appropriate Technology (SOTEC) studi- ed influence of lot size, peeling duration, and number of paring laborers on recovery rates for fresh and stored (1 and 2) tubers. Results for fresh potatoes indicate that for the 30 kg lot size, 4 min peeling and 5 paring laborers is the optimal combination in terms of paring time and recovery rate. For potatoes kept for one month in a store the optimum is 30 kg, 7 min peeling, and 2 or 6 laborers; and for those kept two months, 30 kg, 4 min peeling, and 6 labor- ers are optimum. The larger lot size appar- ently reduces excessive abrasion of potato flesh in peeling, thereby raising recovery rates. The same observation applies to peeling time. Economic analysis of these technical guidelines should now be done. Kenya. J. Kabira's thesis on the feasibility of small-scale production of solar dried potato flour and its potential uses in Kenya has three objectives: investigate the pos- sibility of this type of flour production 132 using different pre-processing treatments, carry out preliminary evaluations on the feasibility of incorporating potato flour into common Kenyan foods, and carry out preliminary economic assessment of tech- nology for potato flour production. Among the major findings was that flour from all three products did not differ sig- nificantly in suitability for blending with corn flour (Table 6-5), whereas flour from raw potato slices was much more suitable for blending with wheat flour than flour from blanched slices and shreds. Prelimi- nary economic analysis showed, depend- ing on the market price of potatoes, potato flour could compete favorably with sor- ghum (or millet), cassava, and blended flours, but had difficulty with corn and wheat flours. Kabira concludes that re- search is now needed on the market poten- tial of the flour, both as a convenience food for household use and as a composite flour ingredient for bakeries and related industries. Peru. During the last 15 years, various research and development projects have sought to improve labor-intensive pro- cessing techniques for potatoes in Peru. A recent case study analyzes this experience to document the knowledge acquired. It also identified lessons learned in tech- nology, marketing, and finance and ad- ministration. These include: • Improving existing technologies re- quires time not only to transfer pre- sumed improvements but also to de- velop new processes and products that will respond to changing market condi- tions. • Product characteristics and the target market segment as well as sources of inputs and marketing channels of pro- cessed products must be clearly identi- fied at the outset. Program6 Table 6-5. Sensory properties• of potato flour from uncooked potato slices, blanched potato slices, and cooked potato shreds. Sensory Raw Blanched Cooked parameters slices slices shreds Unmilled product Color (whiteness) 7.8 c 6.7 cd 5.2 d Appearance 6.3 c 6.8 cd 6.3 d Odor 7.3 c 7.0 c 6.3 c Ease of grinding 7.2 c 5.7 d 6.8 c Suitability for packaging in plastic bags 7.0 c 5.2 d 6.8 c overall acceptability 7.3 c 6.2 c 6.2 c Flourb Color (whiteness) 7.3 c 5.5 d 5.2 d Appearance 7.3 c 5.5 d 5.7 d Odor 6.8 c 6.2 c 6.7 c Suitability for blending with wheat flour 8.0 c 5.8 d 5.8 d Suitability for blending with maize flour 6.8 c 7.0 c 6.3 c overall acceptability 7.5 c 6.0 d 6.0 d Source:J. N. Kabira. 1990. Feasibility of Small-Scale Production of Solar Dried Potato Flour and its Potential Uses in Kenya. University of Nairobi. Phd. Nairobi, Kenya. 281 p. a On a hedonic scale of 1 (extremely unacceptable) to 9 (extremely acceptable). Means followed by similar letters are not significantly different at P = 0.05 by Tukey's test. • Heavy investments in plant and equip- ment can generate cash-flow difficul- ties; more realistic cost and cash-flow estimates are needed to overcome this problem. Product Development Manual. In re- sponse to the growing interest in process- ing and new processed products for root and tuber crops by National Programs in Africa, Asia, and Latin America, CIP has collaborated with CIAT and IITA to pre- pare a manual on product development. This document is intended to convey, in user friendly form, the wealth of experi- ence acquired over the last 15 years by center scientists and their developing country counterparts in this field. Sections review each of the four phases successful initiatives frequently go through: assess- ing the potential for new or improved pro- ducts, research in support of new products Program6 and processes, setting-up pilot plants, and expansion into commercial operations. The volume offers various useful guide- lines for addressing the issues that present themselves during each phase of the prod- uct development process. An interdiscipli- nary approach is stressed throughout. LatinAmerica. Urbanization, female par- ticipation in the work force, shortening of lunch hours, rising incomes, advertising, and a desire by consumers to diversify their diets have all contributed to a growth in potato processing in developing coun- tries. At the international workshop on root and tuber crop processing, marketing, and utilization in Latin America organized by CIP in collaboration with CJXI', UTA, and hosted by Guatemala's lnstituto de Ciencia y Tecnologfa Agrfcolas (ICTA), April 8-12, presentations by researchers and entrepreneurs explained the extent 133 and dynamism of this indu8try. In Guate- mala, for example, a single locally-owned restaurant chain with over 25 outlets han- dles some 100 t of fresh potatoes a week. One-third (over 6,000 t) of annual potato production in Panama goes to processing. Recent research by the Instituto Colom- biano Agricola (ICA), backed by CIP so- cial scientists, found that over 12% of potato production in Colombia-more than 300,000 t/yr-is for the processing industry. Local processors in Colombia have ideas stimulatingly different from those of ICA scientists about the appropri- ate characteristics of potato varieties used for processing and, most importantly, are eager to participate in research to improve locally available gennplasm. Asia. Many National Programs in Asia have requested infonnation on interna- tional potato trade from CIP, particularly on imports of processed potato products. Such data are considered useful for pro- jecting the potential for expanding domes- tic potato production to reduce potato imports, calculating foreign exchange savings from import substitution, and per- suading policy makers to provide more support for local potato research and de- velopment activities. FAQ does not pub- lish such statistics. Hence, CIP social scientists have approached other sources to procure such figures. Preliminary analysis of data on exports from U.S.A. to Asia shows that in recent years over 80% of frozen french fry ship- ments go to Japan and, to a much lesser extent, Hong Kong and Singapore. Work on Dutch trade statistics is being done by a CIP thesis student at Wageningen Agri- cultural University, Dept. of Agricultural Marketing. Initial findings from his re- search to be completed next year show that during 1988-90 Dutch processors exported 134 some 700,000 t of processed potatoes per year. All but 40,000 t of these shipments went to other European countries. Still, according to recent research by the Centre for Research and Development of Coarse Grains, Pulses, Roots, and Tuber Crops (CGPR1), Indonesia officially imported US$1 million of processed potato prod- ucts during 1989 and 1990. CIP also supported a symposium on potato processing and storage during the Third Triennial Conference of the Asian Potato Association held June 17-18 at Bandung, Indonesia. This gathering in- cluded presentations on processing trends in Indonesia, India, and Thailand and on developments in the Dutch potato industry relevant to Asia. Of particular interest was the potential for processing in India where currently industrial or semi-industrial pro- cessing still only accounts for some 50,000 t/yr in a country that produces nearly 15 million t of potatoes annually. In contrast, Thailand processes roughly 5,000 tout of 15,000-20,000 t of potatoes harvested annually. Breeding for Processing Peru. Urban consumers in the developing world have increased demand for quality potatoes for a rapidly emerging snack and fast food industry. French fries, preferably long cuts, and chips are of primary inter- est. Potatoes for these purposes should have an oblong or round shape, shallow eyes, good texture, high dry matter, and low reducing sugar. Not all potato varie- ties meet these specifications. Varieties with such attributes have been bred for use in developed countries, e.g., Russet Bur- bank in the USA. However, differences in day length and temperature as well as susceptibility to important diseases and pests severely limit their production in Program6 .• tropical environments. Hence, CIP initi- ated a program to select populations and clones with the appropriate agro-climatic adaptation and agro-industrial character- istics. Two types of genetic materials were used in this project: advanced clonal ma- terial from CIP's pathogen tested list and . breeding programs, and a segregating population. About 200 highly selected clones from the pathogen tested list were evaluated. llie clones adequate for pro- cessing and carrying resistance or toler- ance to at least one pest, disease, or stress are currently distributed to NARS. In ad- dition 500 clones with a wide genetic base from CIP's breeding program were also evaluated for processing attributes. These clones come from a gene pool containing S. tuberosum spps. tuberosum and an- digena, S. phureja, S. stenotumum, and a few wild Solanum species which have contributed resistance factors. Segregating populations for processing consist of true seed progenies or tuber families originating from crosses of se- lected parents. These populations carry re- sistance or tolerance to several pests and diseases and to climatic and soil con- straints in developing countries. They also have a wide genetic base; and, therefore, have been used to determine gene action and heritabilities for processing quality characteristics and to select the best pro- genitors. All materials (clonal and popula- tion) have been tested at CIP's experiment stations at San Ramon and La Molina (summer and winter seasons). Selection criteria for french fries in- clude: medium- to large-sized tubers over 45 mm diameter, shallow eyes, oval to oblong regular shape, cream or white flesh without blemishes, and a specific gravity from 1.079-1.086 (20-22% DM content). Program6 Reducing sugar content should be below than 0.5%. Tuber characteristics for chips are the same as for fries, except that they should be 40 to 60 mm in diameter and be rounq,Jo o!:>long, have a specific gravity frQtn'~l.029\096 (21-24% DM), and re- dudrig sugar content below 0.25%. Whether for french fries or chips, tubers should be free from diseases, cracking, secondary growth, greening, and the ten- dency to tum gray or black after cooking. After 3 seasons of evaluating the patho- gen tested list clones under cool and hot weather conditions, the following were found suitable for proce : 676014 ... (CFC 69.1), 720091 ( ;72oii1 (Aracy), 800827 (Atl 1cy, (Shuang Feng), 800957 (Pfrola). Further evaluations showed that clones 378017 .2 (LT-7), 378015.16 (TS-2), 379706.34 (LT- 9), and 678011 (BL-2.9) were also suit- able. These materials have been widely distributed to CIP's regional offices and NARS and could be tested by national programs interested in this type of potato use. After testing, a large number of clones from CIP's br~eding program have been found very adequate for processing as french fries or chips, or both. These clones have other very important characteristics (Table 6-6). Six advanced clones with high dry matter, low reducing sugars, good yield, and wide adaptation have been iden- tified as potential processing varieties. These clones have been introduced into the pathogen-tested program for clean up and future distribution to NARS. After 5 years of breeding for processing research and the selection of good progenitors, a segregating population of more than 150 clones has been assembled for use by NARS to select new varieties for processing. 135 Table 6-6. Top clones from a breeding population selected for resistance to viruses and favorable processing characteristics .. Pedigree %OM SG %RS Characteristics 871.240.2 x 7XY.1 23.10 1.085 1.66 Chips; resistant to PVY,PLRY Serrana x L T-9 23.48 1.093 2.20 Chips; resistant to PYX, PYYand PLRY Serrana x L T-9 24.02 1.096 2.33 Chips; resistant to PYX, PYYand PLRY Serrana x L T-9 20.95 1.084 2.00 French fries; resistant to PYX, PVY,PLRY 871 .240.2 x 575049 22.18 1.086 1.33 Chips; resistant to PVY,PLRY 871.240.2 x 575049 21.46 1.086 3.3 French frhs; resistanttJ PYY, PLRY 8R63.15 x 7 XY.1 22.87 1.089 1.00 Chips; resistant to PVY,PLRY 8zura x LT-9 25.7 1.106 1.66 Chips; resistant to PYX, PYYand PLRY 8zura x LT-9 25.83 1.100 2.00 French fries; resistant to PYX, PYY and PLRY DM = Dry matter, SG = Specific gravity, and RS = reducing sugars. PLRY= Potato leafroll virus, PVY and PYX = Potato viruses Y and X. Marketing/Demand Work on potato marketing and demand has focused on location specific-studies of seed or table potato marketing systems, inducting research on consumption and demand; comparative analysis of regional or global trends in marketing and demand for potatoes; and the P.reparation and dif- fusion of methods and materials to enable n~honal researchers to do this type of re- search. This year location-specific re- search focused on the Andean region and Tunisia. Comparative analysis of trends in potato production and use examined 136 developments in Latin America. Methods materials were published in Spanish. Amlean Network (PRACIPA). The first phase of the marketing component of the Co- operative Program for Research on Pota- toes in the Andean Region (PRACIPA) was completed. Impact of the project can be summarized as follows. In Bolivia, the project demonstrated the advantages of thinking of market (user) requirements first, then producing seed to satisfy those needs. This involved getting the National Program to produce improved quality seed for native varieties-something it had not Program 6 ,. done before. In Ecuador, project results revealed the need for promotion of im- proved quality seed among small, peasant producers to demonstrate the increases in yields and incomes possible with such planting material. The project in Colom- bia altered National Program thinking on the importance of alternative market out- lets for potatoes. Whereas most observers thought that only 5% or less production went to processing, this research found that 12% or more was used for chips, french fries, and snack foods. Work in Peru showed what could be done with limited resources to procure, analyze, and distribute information on seed and table potato marketing. The study in Venezuela enabled NARS researchers to examine marketing issues (their work had pre- viously been confined to production re- search) and to gather baseline information on potatoes. From the regional perspective, the PRACIPA-Marketing Program project ac- complished three things. First, it answered questions that National Programs leaders and research scientists had about potato marketing problems in their respective countries. Second, it documented local re- search experience and methods· previously unavailable. Third, the project developed an informal network of researchers work- ing on marketing issues. While other potato-related disciplines pave strong pro- fessional peer groups and even disciplin- ary association in Latin America, this was the first attempt to establish the equivalent in the marketing field to sustain such re- search in the future. Tunisia. Between 1960 and 1990, average per capita consumption in Tunisia jumped from 10.5 kg/yr to more than 20 kg. Re- search on potato marketing and demand concluded that this jump stems from Program6 increased consumer purchasing power, ur- banization, and evolving consumer prefer- ences and consumption habits (e.g., for a more diversified, easier to prepare diet). Furthermore, analysis of existing house- hold and marketing survey data, plus an independent consumer survey in Tunis, was used to estimate an average income elasticity of potatoes of 0.45, i.e., a 10% increase in income would result in a 4.5% increase in the quantity of potatoes de- manded (consumed). Potato consumption among low income consumers would increase more in response to changes in income (about 0.60) than high income in- dividuals (roughly 0.30). Strong consumer demand for potatoes would help explain why the long-term trend in retail prices is fairly flat (with recurrent seasonal price movements) even though total consump- tion has grown from 45,000 t to 160,000 t over the last thirty years (Fig. 6-1 ). LatinAmerica. Research on trends in pro- duction, marketing, and consumption in Latin America using FAO time series data found that potato ranks sixth in production (fresh weight) among the major food crops. Average potato yields have risen nearly 70% since 1960, faster than any other major food crop except tomato and sorghum. While area planted was largely unchanged for the region as a whole, this figure masks the impressive growth in area cultivated with potatoes during this period in Colombia (152% ), Mexico ( 45% ), Bolivia (30%), Ecuador (63%), and Cuba (38% ). As a result, estimated per capita consumption in Colombia, for example, more than doubled from 30.0 to 60.8 kg/yr between 1961-63 and 1986-88. In Cuba, it jumped from 15.1 to 23.4 between 1961 and 1988. Marketing Research Methods. As case studies and comparative analysis of potato 137 Dinars/t 600.-..--~~~~~~~~~~~~~~~~~~~~~~ I > I I I ! I I I l I I I I I I I I I ""-----'-----"'-----'-----------'-----.l-----L----...1---- ---.J-----L ____ .J____ --- -'-----L----.J I I I I I• I I I I 1 I I I 0 I 500 I t I I I I ! I l I I I I I t t I I I I I I l I I I ! I I I f I I I I t I I I I J 1 I ! 1 l I I I I I I I 1 I ' ' ' ' ' ' ' ' ' ' ' ' l I I I I I I I t I I I l I I ... -----.----- .. -----.-----,-----.-----;----- ... ----;---- -- _, _____ ,.. ____ _, ____ -- .... ----- .. ---- ... I I I I ! I 400 I I I I I ! t I l I I I I l I I I I I I r I 0 I ' ' ' ' ' ' I I I I 1-----..1-----'- ___ _, _____ - I I I I 300 I I l I ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' 200 100 0'-'-~~~~~~~~~~~~~~~~~~~~~~ 1175 1/77 1/79 1/81 1/83 1/85 1/87 1/89 1/91 Date Figure 6-1. Retail potato prices in Tunis (constant 1983 prices). marketing and demand are completed, ef- forts have increasingly focused on prepa- ration of methods materials. This year CIP published, with Interamerican Institute for Co-operation in Agriculture (HCA), a manual on methods for agricultural mar- keting research. The manual covers pro- ducer-level marketing problems, seed marketing, consumption and demand is- sues, markets for processed food products, prices and market!ng margins, and prob- lems in food marketing systems and their relevance for production-oriented biolog- ical research. A similar publication is planned for English-speaking researchers in Asia and Africa in 1993. Product Development for Sweetpotatoes in Developing Countries Baseline Studies Jennifer A. Woolfe completed her very thorough review of the literature on sweet- potato postharvest research in late 1991. The book has been published by Cam- bridge University Press in collaboration 138 with CIP. Topics covered are: chemical composition of sweetpotato, its nutritional value, postharvest procedures for storage and processing, livestock feeding, and patterns and trends in consumption and use. Each chapter ends with an extensive list of references (the chapter on chemical Program6 composition has over 200). The book finds • low-yields, low product recovery rates, a remarkably high nutritional value in and high root production costs do not •· sweetpotato roots and vines (fable 6-7). allow sweetpotato to compete with The book also notes that, if strategies to other raw materials that yield similar increase sweetpotato production are to end products (highly significant) succeed, efforts to improve the crop's ag- • lack of availability of cultivars with ronomic characteristics must be comple- mented by initiatives to seek new uses for suitable characteristics for processing its roots and vines. In the author's view, purposes (significant) constraints to increased sweetpotato pro- • insufficient or unstable supply of raw cessing may be ranked as follows: material (less significant) Table6-7. Proximate composition of sweetpotato roots and other plant foods (per 100 g). Total carbo- Dietary Moisture Energy Protein Lipid hydrate fiber Ca p Fe Food (%) (kcal) (kJ) (g) (g) (g) (g) (mg) (mg) (mg) Sweetpotato Boiled 71 114 477 1.7 0.4 26.3 2.4 32 47 0.7 Baked 64 141 590 2.1 0.5 32.5 40 58 0.9 Flour 12 336 1406 2.4 0.7 79.2 70 98 3.2 Cassava Flour 13 341 1427 1.5 0.5 83.4 99 92 3.3 Rice Boiled, white 68 135 565 2.3 0.3 28.0 0.8 8 36 0.3 Flour 12 365 1527 6.8 0.7 80.0 17 135 1.6 Noodles, cooked 79 88 368 1.0 20.3 7 7 0.6 Maize Porridge 81 76 318 1.8 0.8 15.6 4 0.6 Tortilla 48 210 879 4.6 1.8 45.3 196 138 2.6 Meal 12 354 1481 9.3 3.9 73.6 19 237 3.3 Wheat Chaphati 46 202 860 7.3 1.0 43.7 3.4 60 2.1 Bread 33 278 1163 8.7 1.6 55.7 2.7 24 98 1.3 Noodles, cooked 75 108 452 2.7 2.1 19.4 21 25 0.8 Pasta, cooked 66 132 552 4.1 0.7 26.7 8 59 0.5 Sorghum Porridge 80 85 356 2.7 0.5 17.0 4 31 1.7 Meal 11 343 1435 9.5 2.8 75.5 28 238 10.0 Beans (Phaseo/us vulgaris) Boiled 69 118 494 7.8 0.5 21.4 7.4 38 140 2.4 Source: Adapted from J. Woo/fe. 1992. Sweetpotato: An Untapped Food Resource. Cambridge University Press. Cambridge, U. K. 643 p. Program6 139 Harvesting sweetpotato vines for livestock feeding in China. This publication will be a valuable ref- erence for a broad group of agricultural professionals in both developed and de- veloping countries. Breeding for Processing Breeding-related research in this program focuses on distribution and testing of elite, high yielding cultivars for processing- related uses. Research is also conducted on improvement of important quality traits and monitoring nutritional quality in elite materials. Sweetpotato can produce high yields of carbohydrates (roots) and protein (foliage) under diverse agroecological conditions in short growing seasons without massive chemical ·inputs. However, demand for sweetpotato for fresh consumption has 140 declined in several developing countries in recent years. The crop can serve as raw material for a wealth of processed food, feed, and industrial products, substituting for imported grains. Needs assessment studies conducted by CIP (including constraints surveys, work- shops, and Jennifer Woolfe's recently- published book) point out that in many countries the lack of high yielding varie- ties with appropriate quality characteris- tics is a constraint to increased use of sweetpotatoes for processing. Some breeding programs (e.g., China, Japan, AVRDC, and IITA) have successfully se- lected high yielding varieties or elite clones with appropriate characteristics for processing (principally high dry matter yields). Table 6-8 presents reported dry Program6 Table 6-8. Reported fresh root yields and root dry matter contents for sweetpotatoes from four different sources, evaluated at source locations and at CIP, Peru.8 Source Location Fresh root Dry matter Dry matter of evaluation yield (t/ha) content(%) yield (t/ha) AVRDC AVRDC 22.S 38.0 8.5 AVRDC CIP 24.6 32.8 8.1 llTA llTA 20.3 37.3 7.6 llTA CIP 42.3 28.3 12.0 Japan Japan 27.2 36.2 9.8 Japan CIP 29.0 35.4 10.3 SAP Sri Lanka 22.9 39.6 9.1 8 At source locations, data are for selected clones. At CIP, Peru, data are means of trials of clones selected from seed introduced from source locations. matter yields of improved clones from various sources. These contrast with re- ported national averages for a number of countries (fable 6-9). Efforts in Program 6, as reflected in CIP's Strategic and Medium-term Plans, attempt to capitalize on gains already made by breeding programs around the world, by testing promising elite materials (distributed as clones or segregating seed progenies) in selected countries. Selection and dissemination of varieties suitable for processing in those countries will comple- ment studies of markets, policies, and technologies for sweetpotato processing which will be conducted at the same time. A subproject is being developed to help certain national programs select high yielding varieties suitable for processing. The subproject will have high priority in future breeding work on sweetpotato in Program 6. CIP breeders in Asia, Africa, and Latin America will work with col- leagues in NARS and regional networks to coordinate and assist with selection and dissemination of varieties for processing. Peru. Work was conducted at CIP experi- mental sites in Peru on improving native and introduced breeding populations for earliness, root dry matter content, and yield (see also Programs 1 and 2). Roots of 200 promising clones were evaluated Table 6-9. National yields and root dry matter content of varieties from five Asian countries. Country Bangladesh China Indonesia P~ilippines Vietnam Program6 National yields (t/ha) 11 18 9 5 5 Dry matter Variety Daulatpuri Xuzhou-18 Various Various Various Yields (%) (t/ha) 30 3.3 28 5.0 28-37 3.3 23-37 1.9 25-34 1.7 141 for fried slice quality. A number of clones . with excellent chip color (non-darkening) were selected. A thesis student from the UN ALM is evaluating the effects of plant- ing and harvest dates on quality of fried slices in a select group of clones. Non-sweet sweetpotatoes may have potential for use in processing. For exam- ple, sugars in dried sweetpotato chips cause problems with storage and handling for composite feed formulation. Several non-sweet clones with good agronomic characteristics were selected from seed in- troduced from Japan (progenies of Satsumahikari, a variety which lacks B- amy lase activity). An MSc. thesis student from the UNALM is investigating the in- fluence of environment, stage of develop- ment, and storage on the sugar content of the selected clones to identify consistently non-sweet genotypes. United States. Improvement in digestibil- ity of sweetpotatoes could improve feed use efficiencies in animals and reduce flat- ulence in humans. Starch digestibility, trypsin inhibitors, and dietary fiber con- stituents have been identified as possible causes of low sweetpotato digestibility relative to grains. Previous work at AVRDC identified elite clones with high in vitro starch digestibility. Theses being conducted at headquarters, and under con- tract with North Carolina State University (NCSU), are evaluating genotypic and en- vironmental effects on starch digestibility and trypsin inhibitor activity (TIA) of raw roots of different breeding populations. Initial results of work at NCSU have iden- tified clones with in vitro digestibility equal to or superior to maize. In vivo feed- ing experiments using sweetpotatoes with varying levels of TIA and starch digest- ibility are planned. 142 United Kingdom. Starch properties influ- ence the potential uses of sweetpotato. Tue Natural Resources Institute and the Uni- versity of Nottingham are assisting in a collaborative investigation of genotypic and environmental influences on starch properties of breeding clones selected from introduced and Peruvian germplasm. Initial results have shown strong environ- mental influences on several starch pa- rameters with some clones less influenced than others. A greater range of variation in starch parameters was found among the Peruvian clones than among the foreign introductions. China. Fresh roots of 104 promising clones from the South China germplasm collection were evaluated for quality com- ponents as part of a contract with the Guangdong Academy of Agricultural Sci- ences. Boiled roots of 59 of the clones were evaluated for eating quality. Tue mean dry matter content was 25%, with a range from 13.8-35.2%. Soluble sugar contents ranged from 1.98-5.65%; Starch from 5.81-27.4%; and Vitamin C from 10.5-41.l mg/100 g (fresh root). Tue relatively low dry matter content of the Chinese clones reconfirms earlier reports and highlights the need for intro- ducing germplasm with higher levels of dry matter. Several clones with excellent eating quality were selected. Root dry matter content was not clearly related to eating quality in the clones evaluated. Thailand. During 1991, thirty-four com- mercial varieties were evaluated for chem- ical composition including protein and starch content as part of a contract with the Institute of Food Research and Product Development in Thailand. Dry matter ranged from 29-43%, protein from 3.2- 12.1 %, and fiber from 5-13% of dry weight. Starch recovery rates, determined Program6 using a pilot plant, ranged 37-62% with a mean of only 52%, highlighting technical problems of sweetpotato starch extraction. Amylase content in the genotypes studied ranged 11-31 % of the total High Amylase varieties could serve as raw materials for edible films. PIUlippines. Masters' thesis research through collaboration with the UPLB de- termined the processing potential of 17 cultivars with good agronomic character- istics and a range of root quality traits. Clones with highest consumer acceptance for fresh consumption were dry textured and moderately sweet. General accept- ability of'snack products (pancakes, sweetpotato/peanut bars) was not neces- sarily related to fresh eating quality. Colombia. A collaborative project with I CA seeks to evaluate the potential oflocal and introduced sources of germplasm for potential use in the cassava-drying indus- try which CIAT helped establish in the At- lantic coast region. During 1991, 30 elite foreign clones were introduced from CIP. Local accessions were also evaluated. Three local cultivars were identified as promising. During 1992, selected clones will be multiplied for agronomic and pro- cessing evaluation. During the coming years work in Pro- gram 6 on the development and dissemi- nation of cultivars with processing characteristics will focus on developing a close association with national variety se- lection programs, utilization specialists, farmers, and processors in key regions of selected countries. Processing China. Sweetpotato processing research in China is headquartered at the Crops Research Institute (CRI), Sichuan Acad- Program6 emy of Agricultural Sciences (SAAS). Sichuan Province produces over 20 mil- lion t of sweetpotato annually, about one- sixth of world output. CIP has had a collaborative project with CRI since 1989 focusing on improving local techniques for bleaching starch and village-level noo- dle processing. Major changes in agricul- tural policy, income levels, and eating habits among Chinese consumers over the last 15 years mean that China now uses roughly 40% of total sweetpotato produc- tion for processing, 34% for feed, 14% for direct human consumption, and 11 % for other uses. Hence the interest in improv- ing upon these achievements. Results to date include: • Development of techniques for keeping both wet and dried starch a white color. Such starch facilitates production of the transparent noodles preferred by con- sumers. • Work on low-cost equipment to reduce labor requirements and costs for noo- dle-making. Such efforts are also in- tended to ensure greater quality control for characteristics such as noodle color and cooking quality. • Establishment of 20 small-scale, semi- mechanized processing units with plans to expand to 100 units in the next 12 months. Vietnam. Thesis research (Master of En- gineering) on the use of sweetpotato in Vietnam was completed at the Asian Insti- tute of Technology with partial support from UPWARD and the Japanese govern- ment. Use of sweetpotato in Hiephoa dis- trict of Habac province in Vietnam was surveyed. Three popular processes for sweetpotato use-chip production, fer- menting of roots for animal feed, and pro- duction of noodles-were identified and 143 existing procedures studied. Transparent noodles had the highest potential as a food product. However, current methods do not produce a noodle of a~ptable quality (i.e., whiteness). This study developed a process to make white starch, previously unused in Vietnam. It includes liming to keep the pH of the starch slurry to about 8.6-9.2 during grating and separation pro- cesses. In addition, mixing gelatinized starch with raw starch in the proportion of 30% and 70% on a dry weight basis pro- duces the best quality noodles. A soaking treatment following strand formation in boiling water is essential for giving a transparent appearance. Burundi. Research on substituting raw, grated sweetpotato for imported flour in breadmaking began in Burundi in 1990 after CIP postharvest scientists demon- strated the use of such techniques, based on experience in Peru. This work is being carried out in collaboration with the Burundi National Institute for Agricul- tural Research and a locally-based FAO project on rustic agroindustrial technolo- gies. Ten different sweetpotato/wheat com- binations have been tried under laboratory conditions. The most widely accepted rec- ipe is one in which sweetpotato constitutes 30% (fresh weight) of the dough. The number of bread pieces obtained with this mixture is only slightly less than when 100% wheat flour is used. The overall savings on this type of bread production is Preparing sweetpotato for bread making at a neighborhood bakery in Bujumbura, Burundi. 144 Program6 15%. A suburban bakery in Bujumbura is now producing sweetpotato bread. Other bakeries have asked for assistance and some are experimenting with the new bread. Cameroon. In late 1991, research was in- itiated with a small, local bakery to study the use of sweetpotato to replace wheat flour in breadmaking. This work is being done in collaboration with the FAO Food Prevention Losses Project at Bamenda. Preliminary trials substituting fresh sweetpotatoes for wheat flour on a 30% basis (fresh weight) have indicated better income for the bakery and a lower price for consumers. Several factors are under observation and a new study will be initi- ated in 1992 with one of the largest baker- ies in Bamenda. As the supply of sweet potatoes during the dry-season (from De- cember to April) could be a future con- straint, the FAO Pilot Processing Plant at Santa is producing dried sweetpotato ma- terials to replace fresh sweetpotato during this period. Marketing/Demand Research by CIP on sweetpotato market- ing and demand has focused on compara- tive analysis of FAO statistics on production, utilization, and consumption; and location-specific case studies focus- ing on particular countries, products, or processes. Global Trends. Sweetpotato has shown the greatest dynamism, in terms of pro- cessing, of all the root and tuber crops in developing countries over the last two de- cades (Table 6-10). Whereas the crop was used largely for human consumption up until the mid- l 970s, from 30-50% of na- tional sweetpotato output in countries such as China and Brazil now goes to make animal feed as well as processed Program6 products for human and industrial use. In fact, some amount of sweetpotato in vari- ous forms is almost always used as animal feed wherever it is produced in developing countries. FAO statistics indicate sweet- potato use for animal feed is 40% of total output in China, 35% in Brazil, 30% in Madagascar, 17% in the Republic of Kf' innovative technologies. (ibid) 7 p. Carli, C. and P.K. Njoroge. 1991. The util- ization of rapid multiplication teer~ niques for potato basic seed productif n , in Kenya. In L.J.C. Autrey et al.(~ Proceedings of the 2nd triennial meet- ing of the African Potato Association. APA, Reduit, Mauritius. pp. 51-58. Castillo, R. and M. Plermann. 1991. An- dean root and tuber crops: a case study. Instituto Nacional de Investigaciones Agropecuarias, Quito, CIP, Ecuador. 8 p. Canedo, V. and K. V. Raman. 1991. Servi- cio de identificaci6n de insectos y aca- ros en el Centro Internacional de la Papa. In Programa y Compendios. 15a. Reuni6n de ALAP, Lima, Peru, Sep. 8-14. ALAP, Lima, Peru. p. 50. Chujoy, E., F. Aquino, L. Duna, and A. Tumapon.1991. Field screening of po- tato genetic material for resistance to Pseudomonas solanacearum in Mind- anao, Philippines. In Proceedings of the 3rd triennial conference: plenary papers and abstracts. Meeting held in Bandung, Indonesia, June 17-22. Asian Potato Association, Bandung, In- donesia. pp. 120-121. Chujoy, E. and K. Hoang. 1991. Sweet potato genetic resources in Vietnam. In Sweet potato cultures of Asia and South Pacific: proceedings. 2nd Annual UPWARD International Conference, Laguna, Philippines, Apr. 2-5. UPWARD, Los Banos, Philippines. pp. 89-96. Collins, W.W. and Mendoza, H.A. 1991. Breeding sweet potato for weevil resist- ance: future outlook. In R.K. Jansson, K.V. Raman (eds.) Sweet potato pest management: a global perspective. Westview Press, Boulder, CO, USA. pp. 399-406. dorzo C, P., O.A. Hidalgo, and L. Lujan. 1991. Analisis de la situaci6n de la pro- ducci6n de tuberculos-semillas en Co- lombia. Bogota, Colombia. 49 p. qorzo, C.P., 0. Hidalgo, and C. sanchez de Luque. 1991. Comparaci6n de mues- tras de tuberculos-semillas certificada y comun del agricultor en Colombia. In Programa y Compendios. 15a. Reuni6n de ALAP, Lima, Peru, Sep. 8-14. ALAP, Lima, Peru. p. 104. Publications Crisci, C., F. Vilaro, and 0. Hidalgo. 1991. Efecto de la infecci6n secundaria de PLRV y PVY sobre el rendimiento del cultivo de la papa en el Uruguay. (ibid) p.89. Crissman, C.C. 1991. Analisis comparati- vo de sistemas de producci6n y distri- buci6n de semilla de papa. In Aspectos tecnol6gicos del cultivo de papa en el Ecuador. Documento Tecnico No. 4. FUNDAGRO, Quito, Ecuador. pp. 27-58. Cruz, P. and M. Hermann. 1991. Manipu- laciones promisorias para una mayor obtenci6n de semilla botanica en ulluco (Ullucus tuberosus). In 7mo. Congreso intemacional sobre cultivos andinos: resumenes, La Paz, Bolivia, Feb. 4-8. Instituto Boliviano de Tecnologia Agro- pecuaria, CUD, La Paz, Bolivia. p. 54. De la Puente, F., A. Boy, M. Lenscak, and M. Elechosa. 1991. Exploraci6n, reco- lecci6n, conservaci6n y evaluaci6n de recursos geneticos de la batata (Ipo- moea batatas (L.) Lam.) en la republica Argentina. INTA, CIP, Mar del Plata, Argentina. 17 p. De la Puente, F., J. Dfaz, and D.F. Austin. 1991. Desarrollo de un banco de germo- plasma de camote o batata [Ipomoea batatas (L.) Lam.] en el CIP. 2do. Sim- posio Latinoamericano sobre Recursos Geneticos de Especies Hortfcolas, Mar del Plata, Argentina, Sep. 22-25. CIP, Lima, Peru. 15 p. Del Rio, A. and M. Hermann. 1991. Poli- morfismo isoenzimatico en oca (Oxalis tuberosa). In 7mo. Congreso intema- cional sabre cultivos andinos: resume- nes, La Paz, Bolivia, Feb. 4-8. Instituto Boliviano de Tecnologfa Agropecuaria, La Paz, Bolivia. p. 58. Demonteverde, V., D. Simongo, G. Opefia, T. Gerpacio, R. Muyco, and E. Publications Chujoy. 1991. Potato germplasm eval- uation using apical cuttings. 7th Scien- tific Meeting of the Federation of the Crop Science Societies of the Philip- pines, Quezon City, Philippines, Nov. 7-9. CIP, Manila, Philippines. 1 p. Destefano Beltran, L., P.G. Nagpala, J. Kim, J.H. Dodds, and J.M. Jaynes. 1991. Use of synthetic genes to en- hance nutritional quality and disease resistance in plants: application to po- tato. In Molecular methods for potato improvement. Application of Molecular Techniques to Potato Germplasm En- hancement, Lima, Peru, Mar. 5-9, 1990. CIP, Lima, Peru. pp. 49-64. Dodds, J.H. 1991. Application of molecu- lar methods at CIP, potato improve- ment through gene identification and gene transfer. In Molecular methods for potato improvement. Application of Molecular Techniques to Potato Germ- plasm Enhancement, Lima, Peru, Mar. 5-9 1990. CIP, Lima, Peru. pp. 45-48. Dodds, J.H., C. Merzdorf, V. Zambrano, and C. Sigilefias, and J.M. Jaynes. 1991. Potential use of Agrobacterium- mediated gene transfer to confer insect resistance in sweet potato. In R.K. Jansson, K.V. Raman (eds.) Sweet potato pest management: a global per- spective. Westview Press, Boulder, CO, USA. pp. 203-219. El-Nashaar, H.M. and L. de Lindo. 1991. Reacci6n de esquejes de papa genera- dos a partir de yemas axilares a la in- fecci6n por Pseudomonas solanacea- rum. In Programa y Compendios. 15a. Reuni6n de ALAP, Lima, Peru, Sep. 8-14. ALAP, Lima, Peru. p. 41. Espinola, N. and N. Pallais. 1991. Hidra- taci6n parcial de la semilla sexual de papa en una soluci6n osm6tica para au- mentar su vigor durante la germinaci6n. A-11 In Programa y Compendios. 15a. Reu- ni6n de AI.AP, Llma, Peru, Sep. 8-14. 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Proceedings of the 2nd trien- nial APA meeting. African Potato As- sociation, R&luit, Mauritius. pp. 71-76. Rueda, J.L., D. Simeya, and P.M. Harris. 1991. Control integrado de la marchi- tez bacteriana en producci6n de semilla de papa en Africa Central.In Programa y Compendios. 15a. Reuni6n de ALAP, Lima, Peru, Sep. 8-14. ALAP, Lima, Peru. p. 107. Sala, F. 1991. Sur les problemes de la diffusion de !'information agricole. Le cas du Centre International de la Pomme de Terre: une evaluation. Uni- versite Paris-Nord. U.F.R. des Sciences de la Communication (France) Memoire (M.S.T., Communication). Paris, France. 81 p. Salazar, L.F. 1991. Detecci6n de viroides y virus con tecnicas de ADN recombi- nante. In W.M. Roca, L.A. Mroginski (eds.) Cultivo de tejidos en la agricul- Publications tura: fundamentos y aplicat:iones. CIAT, Cali, Colombia. pp. 877-885. SAnchez de Luque, C., O.A. Hidalgo, and L.F. Salazar. 1991. 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Results of a survey on non-viral pathogens and disorders of sweet potato in Kenya. 9th Symposium of the ISTRC, Accra, Ghana, Oct. 21- 28. NARL; CIP, Nairobi, Kenya. 6 p. Song, B.F., X. Gong, and G. Wang. 1991. Screening of TPS progenies for virus resistance. In Proceedings of the third triennial conference: Plenary papers and abstracts. Held in Bandung, Indonesia, June 17-22, 1991. Asian Potato Associa- tion, Bandung, Indonesia. pp. 116-117. Song, B.F., H. Yang, M. Fan, Z. Yan, G. Wang, and E. Chujoy. 1991. Evaluation of potato varieties for drought toler- ance in northwest China. (ibid) pp. 113-115. Stegemen, H., A.A. Shah, R. Estrada, M. Galvez, N. Hilschman, L. Schilde, Z. Huaman, P. Schmiediche, S.C.S. Tsou, and R. Wilckens. 1990. 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Held in La Paz, Boli- via, Feb. 4-8. lnstituto Boliviano de Tecnologfa Agropecuaria, .ba Paz, Bo- livia. p. 57. Torres, H. and M.A. Pacheco. 1991. "Ga- briela" y "Esperanza" dos cultivares de papa, resistentes a rofia (Spongospora subterranea). In Programa y Compen- dios. 15a. Reuni6n de AIAP, Lima, Pe- ru, Sep. 8-14. ALAP, Lima, Peru. p. 96. Trinca, S., C. de Pace, R. Caccia, G. Scarascia Mugnozza, J.H. Dodds, and J. Jaynes. 1991. Transformation of po- tato (Solanum tuberosum L.) leaf disc using A. tumefaciens-mediate transfer ofDNAsequences coding for lytic pep- tides. In Molecular methods for potato -improvement. Application of Molecu- lar Techniques to Potato Germplasm Enhancement. Meeting held in Lima, Publications Peru, March 5-9, 1990. CIP, Lima, Peru. pp. 85-95. Tupac Yupanqui, A., J. Elphinstone, and E. French. 1991. Efecto sinergfstico de Erwinia spp. y Fusarium spp. en la pudrici6n de tuberculos. In Programa y Compendios. 15a. Reuni6n de ALAP, Lima, Peru, Sep. 8-14. AIAP, Lima, Peru. p. 94. Tupac Yupanqui, A. and S.G. Wiersema. 1991. Efecto de la selecci6n y trata- mientos quimicos en los tuberculos so- bre las perdidas de almacenamiento. (ibid) p. 98. Valencia, V.L. 1991. Fitomejoramiento a insectos plagas de la papa en la regi6n andina. Avances en el Mejoramiento Genetico de la Papa en los Paises An- dinos. Lima (Peru). Feb. 4-7 CIP. Lima, Peru. 18 p. Wambugu, F.M., A.A. Brunt, and E.M. Fernandez-Northcote. 1991. Viruses and virus disease of sweet potato (Ipomoea batatas) in Kenya and Uganda. In L.J.C. Autrey, et al. (eds.) Proceedings of the 2nd triennial APA meeting. Afri- can Potato Association, Reduit, Mauritius. pp. 91-96. Wang, J., B. Li, and B.F. Song. 1991. Commercial in-vitro tuberlet produc- tion: Meeting the needs of a tropical climate and beyond. In Proceedings of the third triennial conference: plenary papers and abstracts. Meeting held in Bandung, Indonesia, June 17-22. Asian Potato Association, Bandung, Indone- sia. p. 21. Watanabe, K. 1991. Generation of new diploid potato germplasm and simul- taneous selection in agronomic charac- ters, 2n gametes and resistances. In Proceedings of the third triennial con- ference: plenary papers and abstracts. Meeting held in Bandung, Indonesia, A-21 June 17-22. Asian Potato Association, Bandung, Indonesia. pp. 99-100. Watanabe, K. 1991. Present status of germ- plasm enhancement at CIP and applica- tion of biotechnology. In Molecular methods for potato improvement. Appli- cation of Molecular Techniques to Po- tato Germplasm Enhancement, Lima, Peru, March 5-9, 1990. CIP, Lima, Peru. pp. 135-140. Watanabe, K., J.H. Dodds, F. Buitron, A. Panta, R. Salinas, C. Sigiiefias, and V. Zambrano. 1991. Genetic engineering applied to potato for bacterial disease resistance. In Proceedings of the third triennial conference: plenary papers and abstracts. Meeting held in Bandung, In- donesia, June 17-22. Asian Potato Asso- ciation, Bandung, Indonesia. pp. 92-93. Watson, G.A., A. Dimyati, Bahagiawati, A.H. Malian, and J. Wargiono. 1991. Sweet potato production, utilization and marketing in commercial centers of pro- duction in Java, Indonesia. In Sweet potato cultures of Asia and South Pacific: proceedings, 2nd Annual UPWARD Conference. Held in Laguna, Philip- pines, April 2-5, 1991. UPWARD, Los Banos, Philippines. pp. 361-381. Wiersema, S.G., A. de Buck, and M.D. Upadhya, 1991. Low-cost storage of A-22 consumer potatoes in the North Indian plains. In Proceedings: symposium on developments in potato processing and storage in Asia. Held in Bandung, In- donesia, June 17-22. Asian Potato As- sociation, Bandung, Indonesia. pp. 112-117. Zapata, J.L., E.N. Fernandez-Northcote, and H.A. Mendoza. 1991. Combina- ci6n de la inmunidad a los virus X e Y de la papa y la resistencia a Phytopht- hora infestans en clones de papa. In Programa y Compendios. 15a. Reuni6n de AIAP, Lima, Peru, Sep. 8-14. AIAP, Lima, Peru. p. 90. Zapata, J.L., O.A. Hidalgo, J. Landeo, and G. Forbes. 1991. Evaluaci6n de clones de papa por su resistencia a Phytopht- hora infestans en las condiciones de Rionegro (Antioquia) Colombia. (ibid) p. 95. Zhang, H., X. Cao, X. Ma, and B.F. Song, 1991. Incidence of PSTVd infection and strategy of its control in seed potato and TPS production in China. In Pro- ceedings of the third triennial confer- ence: plenary papers and abstracts. Meeting held in Bandung, Indonesia, June 17-22. Asian Potato Association, Bandung, Indonesia. pp. 28-29. Publications ... .. Research Projects and Contracts Program 1. Production Systems Collaborative Agronomic and Physiological Studies on Sweetpotato in Warm Climates: Philip- pines and Vietnam. H. Taja (Institute of Biology, Philippines)/N. Van Uyen (HCMC, Vietnam)/M. Potts. Agronomy of Potato Production in Cameroon and Other Countries with Similar Agroecological Conditions. Dominic Nyualem (IRA, Cameroon)/ T. Gass, C. Martin. Develop Sustainable Cropping Systems on Upland Eroded Soils with Sweetpo- tatoes in S. China. Song Bofu. Development of Cultural Practices for Po- tato Production from Seed Tubers and Seedling Tubers. A. Sharara (Ministry of Agriculture, Egypt)/R. El Bedewy, R. Cortbaoui. Ecophysiology of Potato Production in the South Region of Chile. J.S. Rojas (INIA, Chile)/P. Malagamba, P. Accatino. Evaluation of Sweetpotato Clones in Various Environments in Peru. H. Goyas (INIAA)/E. Carey/ 0. Hidalgo. Fanner Participatoty TPS Research. N. Gumli (LEHRI, lndonesia)/M. Potts. Improvement of Sweetpotato in Egypt. S. Doss (Ministry of Agriculture, Egypt)/R. El-Bedewey. Intercropping Studies on Potato with Maize and other Annual Crops. L. Jiemin (S. China Potato Research Center)/Song Bofu. Introduction, Screening, Multiplication and ·"Redistribution of Potato Germplasm. (The Philippines) E. Badol/E. Chujoy, V. Escobar. Introduction, Screening, Multiplication and Redistribution of Sweetpotato Germplasm. (The Philippines) Chujoy. On Farm Trials to Introduce Cultivars to Improve Potato Production in Burundi and Yield Improvements Through Agro- nomic Practices. Ck Muvira, Z Nzoyihera (ISABU, Burundi)/D. Berrios.* Research on Socio-Agro-Economics, Pro- duction, Varieties, Utilization and Marketing of Sweetpotato in Chile. P. Accatino/C. Covarrubias,J. Kalazich, J. Santos Rojas, H. Lopez (INIA, Chile): Socioeconomic Studies on Sweetpotato in India. T.K. Pal, KR. Lakshmi (CTCRI, TrivandrumyMS. Jairth, MD. Upadhya, T.R. Dayal. Studies on the Effect of Potassium Nitrate on Potato Production and Processing. F. Payton/S. Villagarcia (Sociedad Qufmica y Minera de Chile S.A.). Sustainable Potato Production in Dominican Republic. National Scientists/F. Payton. Use of Plant Growth Substance in Im- proving Quality and Quantity of Potato Yield. National Scientists of CPR/, Jndia/M. Upadhya. Contracts Consultancy on Sweetpotato Production and Utilization. A. Boy. lnstituto Na- cional de Tecnologfa Agropecuaria, Argentina. *denotes projects receiving complementary funding Publications A-23 Development of Potato Varieties for Low- land Tropical Conditions.N. Govinden. Mauritius Sugar Industry Research In- stitute, Nairobi, Kenya; Evaluation of Sweetpotato Germ plasm for Tolerance to Certain Abiotic Stresses Under Arid Conditions. N. Arevalo. Universidad de Tacna, Peru. Selection of Potato Genetic Materials Adapted to Suboptimal Temperatures. J. Santos Rojas. lnstituto de lnvesti- gaciones Agropecuarias, Chile. Soil Management, Fertilizers and Mineral Nutrition of the Potato and Sweetpo- tato Under Adverse Conditions of Soil and Climate. S. Villagarcia. Universi- dad NacionalAgraria, La Molina, Peru. Sweetpotato: An Uptapped Food Resource. J.A. Woolfe. England. World Potato Geography. R. Rhoades. Cooperative Activities Health Effects of Pesticides Use in Ecua- dorian Potato Production. C. Crissman/ J. Antle. Montana State University, USA (Rockefeller Foundation). Departmental Agricultural Chemical Use and Sustaina- bility of Andean Potato Production. C. Crissman/]. Antle, S. Capalbo (Mon- tana State University). Breeding Sweetpotato Populations Having Short Duration and High Stable Yields for Tropical and Sub-Tropical Regions of South Asia. T.R. Dayal. A-24 Global Trends and Constraints to Root Crop Production and Use. G. Scott. Potato Production in the Cropping Sys- tems of the Warm Climate Zone of Asia. M. Potts. Socioeconomics of Germplam Evaluation. G. Prain. Sweetpotato in African Food System. P. Ewell. Sweetpotato in Asian Food Systems. G. Prain. Sweetpotato in Food Systems of Latin America. G. Prain/A. Swindale. Sweetpotato Populations for Hot, Humid Environments. E. Carey. Special Projects Special Project. N. Bezen~on. Swiss De- velopment Cooperative (PROINPA). User's Perspective with Agriculture Re- search and Development. R. Rhoades. Ministry Development Cooperation, The Netherlands. Theses Intercropping with Sweetpotato, Improve- ment of Crop Productivity in Sub-Op- timal Environments. A. Oswald. Irrigation Requirements for Sweetpotato. E. Rios (P. Malagamba). Study of the Inheritance of Frost Tolerance in Native Potato Clones of S. tuberosum ssp. andigena from Bolivia. E. Carrasco. Publications Program 2. Germplasm Management and Enhancement Collaborative Characterization of Sweetpotato Germplasm in Dominican Republic. 0. Malamud, P. Gomez (CESDA)/Z. Huaman. Collection, Characterization and Evalua- tion of Native Sweetpotato Germ plasm. M.A. Mannan, K.R. Bhuiyan (Ban- gladesh Agricultural Research Institute)/ T.R. Dayal. Collection, Otaracterization and Maintenance ofSweetpoato Genetic Resources in Bra- sil I. Sias Costa, J. Cabral de Miranda (EMBRAPA)/P. Accatino/F. De la Puente.. Collection, Characterization and Main- tenance of Sweetpotato Germplasm in Several Regions in Argentina. A. Boy, P. Bianchin4 M. Lenskak (INTA, Ar- gentina)/F. de la Puente/P. Accatino. Conservation, Evaluation and Utilization of Potato Landraces and Wild Species in situ and ex situ. R Ortega (OCA, Peru)/ C. Quiros (UC Davis)/K. Watanabe, J.Dodds. Introduction, Evaluation and Multiplica- tion of Sweetpotato Germplasm. IRA Scientists, Cameroon/C. Martin. Introduction, Maintenance and Dis- tribution of Potato Advanced Genetic Materials. (Kenya) C. Carli/ H.M. Kidane-Mariam/S. N gang a. Production of Materials with Resistance to Erwinia Through Genetic Manipu- lation by Agrobacterium. (P. Oliger/ J. Dodds/P. Accatino (Facultad de Cien- cias Biol6gicas/Agronom.fa, Pontificia Universidad Cat6lica, Chile). Contracts Characterization of Genetic Variation in Tuber-BearingSolanumSpeciesbyUseof Publications RFLP Malkers. K Hosaka/K Watanabe, J.Dodds. Resistance to Potato Insect Pests by Means of Conventional and Innovative Tech- nologies. A. Sonnino. Ente Nazionale de Energie Alternative, Italy. (Italian Government). Evaluation of a Sweetpotato Germplasm for the Warm Tropics. Feng Zu-Xia. Guangdong Academy of Agricultural Sciences, China. Maintenance of the Potato Germ plasm In- Vitro Collection. G. Garcia/J. Dodds. Instituto Nacional de Investigaciones Agropecuarias, Ecuador. The Utilization of Increased Genetic Var- iability in the Potato Breeding Program. M. Huarte/P. Accatino/K. Watanabe/ H. Mendoza. InstitutoNacionaldeTemo- logfa Agropecuaria, Balcarce, Argentina. Maintenance of In-Vitro Sweetpotato Germ- plasm in Venezuela. L. Villegas (IDAE, Venezuela)/J. Dodds. Breeding and Adaptation of Cultivated Di- ploid Potato Species. W. W. Collins. North Carolina State University, USA. Pathogen Elimination of Potato. J. Schmidt, Austria. Use of Genetic Engineering Methods to Confer Fungal Disease Resistance to Potatoes. C. di, Pace. Universita Degli Studi Della Tucsi Viterbo, Italy. (Italian Government). In-Vitro Selection of Potato Mutant Toler- ant toAbioticStress.L. Monti. Univer- sita di Napoli, Italy. (Italian Government). Evaluation of a Sweetpotato Germplasm Collection. Sheng Jialian. Zuzhou In- stitute of Sweetpotato, China. A-25 Departmental Adaptation and Utilization of Potato and Sweetpotato Populations in Breeding. H.Mendoza. Adaptation and Utilization of Potato Pop- ulations in Breeding. H. Mendoza. Biosystematic Studies of Selected Wild Species and Their Utilization in Breed- ing. P. Schmiediche. Collection of the Sw.eetpotato Genetic Re- sources. F. de la Puente/Z. Huaman. Development of Improved Sweetpotato Genn- plasm for Warm and Cool Tropics of S.E. Asia. E. Chujoy, R. Muyco, I. Ona and D. Amalin/L. Tandang, E. Bado!, B.Ansebno, H. Taja, J. Bacusmo, E. Orolfo (Dept. of Agriculture, Philippines, and NPRCRTC). Evaluation and Selection ofSweetpotatoes in Cool Environments. J. Landeo. Exploitation of S. acaule, S. stolo- nif er um and Other Polyploid Species. K. Watanabe. Germplasm Enhancement Through the Use of Haploids and 2n Gametes. K. Watanabe. In Vitro Potato Gennplasm Collection. In- troduction, Maintenance and Analysis. R. Lizarraga/J. Dodds. In Vitro Sweetpotato Germplasm Collec- tion. Introduction, Maintenance and Analysis. R. Lizarraga/J. Dodds. Introduction of Potato Wild Species Germ plasm from the Series Conicibac- cata and Piurana into the Genepool of the Cultivated Potato Generating Tuberosum-Haploid x Wild Species Hy- brids. B. Trognitz. Ploidy Manipulations for Exploitation and Enhancement of Sweetpotato Germplasm. G. 01jeda/P. Schmiediche. A-26 The Maintenance, Documentation, Dis- tribution and Evaluation of Potato Germ- plasm. Z. Huaman. The Maintenance, Documentation, Dis- tribution and Evaluation of Sweetpo- tato Germ plasm. Z. Huaman. Use of Innovative Tissue Culture Tech- niques to Improve Potato Germplasm. J. Dodds. Special Projects Germplasm Exploration, Conservation and Utilization of Several Under-Utilized An- dean Tuber Crops. M. Hermann. GTZ. Breeding Potato for Processing in Tropical Countries. H. Mendoz.a. PEPSICO Food Int., McDonald's. Thesis Comparison of Methods for Selection for General Combining Ability for Yield. UNA, La Molina, Peru. J.L. Marca (H. Mendoza). Crossability Between Ipomoea Species of SectionBatatas. UNA, La Molina, Peru. J. Diaz (F. De la Puente). Estimation of Genetic Variation and De- velopment of Representative Collec- tions in 2x Wild Species of Tuber Bearing Solanum. UNA, La Molina, Peru. J.A. Mont Neyra (J. Dodds, K. Watanabe). Inheritance of Earliness in Auto tetraploid. UNA, La Molina, Peru. L. Cab1a (H. Mendoza). Quantitative Variation in Potato Breeding. UNA, La Molina, Peru. J. Tenorio (A. Golmirzaie). Regulation of Media Components for In Vitro Conservation ofSweetpotato. UNA, La Molina, Peru. A. Baltazar (J. Dodds). Publications Program 3. Disease Management Collaborative Control of Bacterial Wilt on Potatoes. He Liyuan (CAAS, China)/Song Bofu. Development and Utilization of Virus Detection Techniques. Zhang Heling (University of Inner Mongolia, China)/ SongBofu. Efficacy of Binucleated Rhizoctonia for the Biological Control of Pathogenic Rhizoctonia on Potato. (Argentina) A. Escande, H. Torres, P. Accatino. E1Winia Disease in Different Phases of the Tunisian Potato Seed Program. M Mahjoub (ESH, Tunisia)/R. Cortbaoui Etiology and Epidemiology of Bacterial and Fungal Pathogens Affecting Sweetpo- tato in Kenya. R. W. Gatumbi (NAL, Kenya)/L. Skoglund. Evaluation of Advanced CIP's Potato Ge- netic Materials and Four Andean Coun- tries. R Pineda, E. Hernandez (ICA, Colombia)/M. Sola, J. Revelo (INIAP, Ecuador)/R. Egusquiza (UNA, Peru)/ A. Hidalgo (INIAA, Peru)/R. Leon, E. Ortega (FONAIAP, Venezuela)/ 0. Hidalgo, J. Landeo, H. Mendoza, J. Bryan. Evaluation of Advanced Potato Breeding Material in Southern South America. Balcarce breeder (INTA, Argentina), J. Busa (CNPH-EMBRAPA, Brazil), J. Kalazich (INIA, Chile), A. Lopez (Min. Agr., Paraguay), F. Vi1aro (ClAAB, Uruguay)/C/P Breeders. Evaluation of Advanced Potato Genetic Materials for Cameroon and Neighbor- ing Countries with Emphasis of Dis- ease Resistance. National Breeders of China (CAAS, China)/Song Bofu. Publications Evaluation of Advanced Potato Genetic Materials in Egypt. L. Anrity (Min. of Agriculture)/R. El-Bedewy. Evaluation of Advanced Potato Genetic Materials with Emphasis of Virus Re- sistance. M. Fahem (CPRA, Tunisia)/ R. Cortbaoui. Evaluation of Clones for PLRV Resistance Immunity to PVY and PYX and Adap- tation to the Center West Region of Brazil. J A. Buso (CNPH-EMBRAPA, Brasil). Evaluation of Potato Germ plasm for Ear- liness and Resistance to PVY, PYX, PLRV andAlternaria solani. F. VUaro, C. Crisci (INIA, Uruguay)/P. Accatino, H.Mendoza. Genetic Control of False Root-Knot Ne- matode, Frost and Black Wart by the Use of Resistant Varieties in Bolivia. N. Estradn/Bolivian Natwnal Scientists.* Introduction and Utilization of Potato Germ- plasm. National Scientists of China (CAAS, China)/Song Bofa. Management of Bacterial Wilt. AO. Michieka (NAL, Kenya)/L. Skoglund. Managing Bacterial Wilt through Resistant Germ plasm and Appropriate Farming Sys- tem. A Twnopon, L. Duna, N. Balanay (Min. of Agriculture, Philippines)/ Fe Aquino, E. Chujoy. Research on the Control of Bacterial Wilt of Potato in Piura Department of Peru. M. Delgado. Selection of Advanced Clones for Resist- ance to Late Blight, Combined with Earliness. E. Badal (NPRCRTC, Phil- ippines)/£. Chujoy. Selection of Potato Cultivars with Late Blight Resistance, Adaptation and Qual- ity. (Kenya) H.M. Kidane Mariam. A-27 Studies of Potato Yellow Vein in Colom- bia. C. Sanchez de Luque, Grupo Mul- tidisciplinario de Papa (ICA, Colombia). Studies ofYellow Vein Virus. A. Saldarriaga (UNM, Colombia)/0. Hidalgo. Test Application of Modem Technology for Detection of Potato Pathogens. A. M. Escarra (Argentina)/L. Salazar. Virology of Andean Tuber and Root Crops. R. Estrada (Universidad Nacional Mayor de San Marcos)/ U. J ayasinghe, M. Hermann. Contracts Breeding Potatoes Resistant to the Potato Leafroll Virus, PLRV. K.M. SwiezynskL lnstytut Ziemniaka, Institute for Potato Research, Poland. Consultancy on Sweetpotato Breeding. F. Vilaro. Centro de Investigaciones Agdcolas, "A. Boerger". Early Blight of Potatoes: Specialization of Alternaria spp. T. Ames de Icochea. Etiology of Sweetpotato Chloritic Leaf Distortion. C.A. Clark/R.A. Valverde/ D.R. La Bonte. Louisiana State Univer- sity, USA. Evaluation of CIP Advanced Clones for the National Potato Program of Peru. A. Hidalgo. Instituto Nacional de In- vestigaci6n Agraria, Pen'.i. Evaluation of Genetic Material for Resist- ance to PVX, PLRV, Alternaria and Earliness Under Field Conditions. C.Crisci/F.Vilar6. Centro de Investiga- ciones Agdcolas "A. Boerger". Evaluation of p.enetic Material from CIP for Resistance to Late Blight and Bacte- rial Wilt. J.L. Zapata and 0. Trillos/ G.Fori:>es,O.Hidal,goandH.M.El-Nashaar. Instituto Colombiano Agropecuario, Rio- negro, Colombia. A-28 Evaluation of Potato Germplasm for Re- sistance to Alternaria, PVX and PVY in Brazil. F. Reifschneider. Centro Na- cional de Pesquisas de Hortali~s, EMBRAPA, Brazil. Fundamental Research to Develop Con- trol Measures for Bacterial Pathogens of the Potato. L. Sequeira. University of Wisconsin, USA. Potato Germplasm Evaluation for Resist- ance to Bacterial Wilt. C. A. Lopes. Centro Nacional de Pesquisas de Hor- tali~s, Brazil. Germplasm Evaluation with Emphasis on Earliness and Virus Resistance. Aegean Regional Agricultural Research Insti- tute, Turkey. Potato Germ plasm Evaluation and Multipli- cation. N. Kuzman. Aegean Regional Agricultural Research Institute, Turkey. Selection of Resistance to Late Blight of Po- tato. F. Flores. Instituto Nacional de In- vestigaciones Forestales y Agropecua- rias, Mexico. Strategic and Applied Research to Control Erwinia Diseases of Potatoes. Detection of Seed Contamination, and Nature of Disease Resistance. M. Perombelon. Scot- tish Crop Research Institute, Dundee, Scotland. Survey and Control of Diseases of Sweet- potato in Argentina. I. de Mitidieri/ M. Scandiani/P. Aley. Estaci6n Experi- mental Agricola, INTA, San Pedro, Argentina. The Accumulation of Sweetpotato Feathery Mottle Virus, dsRNAand Selected Viral Proteins in Sweetpotatoes; and the De- velopment of Testing Procedures for Sweetpotato Viruses. J. Moyer. North Carolina State University, USA. The Utilization of Solanum tuberosum spp. Andigena Germplasm in Potato Publications Improvement and Adaptation. R.L. Plaisted/H.D. Thurston/ W.M. Tingey/B.B. Brodie/E.E. Ewing. Cornell University, Ithaca, USA. Transformation Methods for Possible Resistance to Bacterial Diseases. A. Brandolini, C. Montanell4 G. Nascari. Virus Diseases of Sweetpotatoes. G. Loebenstein/ H.J. Vetten (Israel/ Germany).* Departmental Antiserum Production and Improvement of Serological Techniques for Virus De- tection. V. Flores/L. Salazar. Breeding and Selection of Potato Clones with Disease Resistances and Other Ap- propriate Horticultural Characteristics. H.M. Kidane Mariam. Breeding for Early Blight Resistance, and the Variation of the NormalAlternaria spp. H. Mendoza and H. Torres. Breeding for Late Blight Resistance with Populations A and B. J. Landeo. Breeding for Resistance.to Bacterial Wilt. R.Anguiz,H.M.El-Nashaar,H.Mendoza, P. J atala, and K. Watanabe. Characteristics of the Transmission of Po- tato Viruses and Viroids Through TPS. P. Malagamba, C. Barrera, L. Salazar, N.Maza. Development of Improved Native Potato Germ plasm. I. Selecting Resistance to Erwinia spp. Z. Huaman, L. de Lindo, and E. French. Development of Potato Germ plasm for Re- sistance to Diseases and Insect Pests in South East Asia. Il Gin Mok. Development of Sweetpotato for Resist- ance to Diseases and Insect Pests in South East Asia. Il Gin Mok. Publications Ecology, Taxonomy and Strategy to Con- trol of Pseudomonas solanacearum. H. M. El-Nashaar. Evaluation for Horizontal Resistance to Phytophthora infestans. L. Skoglund/ P. Tegera. Exploitation in Potato Genetic Resources for Control of Pseudomonas solanacea- rum. K Watanabe/HM. El-Nashaar. Fungal and Bacterial Diseases of Sweet- potato in Peru. P. Aley. Genetic Studies and Breeding for Virus and Viroid Resistance in Sweetpotato. H. Mendoza/L. Salazar. Identification and Characterization of Sweetpotato Viruses. S. Fuentes/ L. Salazar. Identification of Sweetpotato Whitefly- Bome Viruses. M. Nakano. Identification, Physiology, Pathogenicity and Control of Alternaria spp. Assoc- iated with Early Blight. H. Torres. In Vitro Eradication of Sweetpotato Viruses and Viroids. J. Dodds. Mechanism of Resistance and Variabil- ity of Potato Leaf Roll Virus (PLRV). U. Jayasinghe. Molecular Analysis of Genetic Resist- ance of Potato to Viruses and Develop- ment of Molecular Probes. M. Querci/ L. Salazar. Molecular Analysis of Genetic Resistance of Sweetpotato to Viruses and Develop- ment of Molecular Probes. M. Querci/ L. Salazar. Search for Genes for Resistance to Viruses in Wild Solanum tuberiferous Species. C. Lizarraga, A. Salas, L. Salazar. Studies of Potato Virus Y and Potato Virus X. E. Fernandez-Northcote. Study of Phytophthora infestans Isolates in Kenya, Rwanda and Other East A-29 African Countries. L. Skoglund! R. Mibey/ P. Tegera/A. Rubigiri. Special Projects Conferring Resistance to Potato Virus and Viroid by Molecular Interference S e- quences Incorporated into Potato Via Agrobacterium Vectors. J. Jaynes/ J. Dodds. Louisiana State University, USA, USAID. Inheritance of an Screening for Com- ponents of Resistance to Potato Leaf Roll Virus in Potato. H. Baker. Scot- tish Crop Research Institute (ODA Holdback Fund Facility). Technology Development for Control of Bacterial Wilt of the Potato (Pseudo- nwnas solanacearum). J. Elphinstone/ HM. El-Nashaar. Rothamsted Experi- mental Station, U.K. (ODA Holdback Fund Facility). FINNIDA Expert Project. J. Korva. Fin- nish International Development Agency. Theses Application of Immunological Techniques in Electron Microscopy for the Detection of Potato Viruses. UNA, La Molina, Peru. M. T. Trefogli (U. Jayasinghe). Biological Control of Bacterial Wilt. UPLB, Philippines. Hongqi Zeng (E. Chujoy). Characterization; Compatibility and In- compatibility Reaction of Differentials to Phytophthora infestans. UNA, La Molina, Peru. W. Galindez (G. Forbes) Comparison of Methods to Uniformly Infest Fields with Pseudomonas solanacearum. Universidad Nacional del Centro, Huancayo, Peru. E. Ponce Lopez (H.M. El-Nashaar/V. Otazu). A-30 Detection and Quantification of Pectolytic Erwinias in Tuber Seed and its Effect on Disease Incidence in Different En- ,,.. vironments. UNA, La Molina, Peru. A Vdlantoy Palomino (HM El-Nashaar, E. French). Development and Standardization of Ef- fective Screening Procedures to De- termine Resistance to Blackleg and _Soft Rot. UNA, La Molina, Peru. L. Gutarra de Lindo (H.M. El-Nashaar). Development of a Heat Tolerance Potato Population with Resistance to PLRV and Immunity to PVY and PVX. UNA, La Molina, Peru. G. Mendoza/ H. Mendoza, U. Jayasinghe. Efficiency of PLRV Transmission by Dif- ferent Species of Aphids. UNA, La Mo- lina, Peru. G. Brignetti (U. Jayasinghe). Fusarium Species Pathogenic to Sweetpo- tato (Ipomoea batatas) in Peru. UNA, La Molina, Peru. W. Perez Barrera/ E. French, T. Ames. General (GCA) and Specific (SCA) Com- bining 'Abilities for Resistance to Bacte- rial Wilt (Pseudomonas solanacea- rum E. E Smith) in a PVX and PVY Immune Autotetraploid Potato Popula- tion. R. Anguiz (H. Mendoza-Supervisor, H. El-Nashaar). Genome Structure and Expression of Sweetpotato Feathery Mottle Virus. University of Birmingham, U.K. J. Nakashima (R. Wood). Identification of Viroids in Sweetpotatoes. UNA, La Molina, Peru. A. Hurtado (L. Salazar). Inheritance of Horizontal Resistance to Late Blight in Advanced Potato Hy- brids. INIAA, Huanuco, Peru. E. Ronca! (J. Landeo). Publications Pathogenic Variation in Pseudomonas solanacearum. UNA, La Molina, Peru. J. Marin Horna (H.M. El-Nashaar) Potato Powdery Scab (Spongospora sub- terranean): Screening for Resistance and Assessment of Control with Fungi- cides. Benguet State University, The Philippines. Nguyen Due Tri/ P. Vander Zaag, E. Chujoy, M. Potts (UPLB, the Philippines). Races of Phytophthora infestans in the Philippines. Tran Xuan Ai/E. Chujoy, M. Potts (UNDP). Recurrent Selection for Late Blight Re- sistance. Region VII. UPLB, Philip- pines. Dao Huy Chein (E. Chujoy). Studies on the Heredity of the Resist- ance to Sweetpotato Feathery Mottle Virus. E. Mihovilovich (H. Mendoza/ L. Salazar). Studies on the Mechanisms of Resistance of Potatoes to Viruses: Determining the Factor that Confers Extreme Resist- ance to Potato Virus X in Potato. UNA, La Molina, Peru. S. ~ga (M. Querci/ L. Salazar). Program 4. Insect And Nematode Management Collaborative Developing Control Components for In- tegrated Management of False Root Knot Nematode in Puno, Peru. J. Arcos (INIAA), J. Franco (PROINPA), R. Cahuana (INIAA). Economic Consequences of the Potato Tuber Moth in the Tunisian Potato Economy. K. Fuglie/M. Essamet (INRA1). Evaluation of Germplasm and Selection for Cyst Nematode Resistance. R. Eguiguren (INIAP, Ecuador)/ 0. Hidalgo. Evaluation ofSweetpotato Germ plasm for Resistance to Sweetpotato Weevil in Central America and the Caribbean. National Scientists of the Region/ H. Kokubu, E. Carey, 0. Malamud. Integrated Control of Andean Weevil in Venezuela. F. Torres (FONAIAP, Vene- zuela )IL. Valencia. Integrated Control of Root-knot Nema- tode. M. Goethals (ISABU, Burundi)/ D. Berrios.* Publications Integrated Control of Sweetpotato Insect Pests in Argentina. H. Bimboni, D. Ruberti (INTA, Argentina)/ K.V. Raman. Integrated Management of Andean potato Weevil in Farmers Fields. FUNDAGRO (Ecuador,Colombia)/Luis Valencin. Integrated Management of False Root- Knot Nematode of Potato. (Bolivia). J. Franco/R. Montecinos/N. Ortuno (PROINPA). * Integrated Management of Sweetpotato Weevil (Cylas formicarius). D. Amalin, E. Vasquez (VISCA, Philippines)/ P. Vander Zaag. Integrated Management of Tuber Moth in Burundi. Z. Nzoyihera (ISABU, Burundi)/D. Berrios.* Integrated Pest Management (IPM) in Po- tato. G.P. Das, M.M. Rashid (Tuber Crops Research Centre, BARI)/ M.D. Upadhya. Integrated Pest Management (IPM) in Sweetpotato. G.P. Das (Tuber Crops Research Centre, BARl)/K. V. Raman. A-31 Integrated Pest Management for Sweet- potato. J. Sakubu (ISABU, Burundi)/ D. Berrios."' IPM for Potato Pests in Kenya. C. Ngaah-Taracha (KARI, Kenya)/ N.Smit. IPM for Sweetpotato Pest in Kenya. 0. Magenya, C. Ngaah-Taracha (KARI, Kenya)/N. Smit. Management of the Andean Weevil. A. L6pez (ICA, Colombia)/£. Valencia. Population Dynamics of the Potato Tuber Moth, Optimizing IPM Strategy in Field and Storage. H. Ben Salah, R. Ben Amor, K. Lebdi (INRAT, Tu- nisia)/0. Roux. Production of Sweetpotato Planting Mate- rials and Management of Sweetpotato Insect Pests. (Paraguay) Bilateral Ital- ian. T. Mayeregger (IAN), M. Cardozo (SEAG)/A. Strohmenger (IAO), K. V. Raman, P. Accatino. The Design and Execution of an Integrated Control Program for Andean Potato Weevil in Huatata, Chincheros, Peru. M. Pacheco (INIAA, Peru)/J. Alcazar. The Integrated Control of the Potato Tuber Moth in Tunisia: Farmers Fields and Storage. H. Ben Salah, K. Lebdi (INRAT,Tunisia )/0. Roux. Contracts Breeding and Screening for Resistance to PCN. R. EgU.squiza, M. Canto-Saenz. UNA, Peru. Consultancy on Biological and Selective Chemical Control of Potatoes and Sweet potatoes Insects Pest.J. Samziento and colleagues. UNA, Peru. Development of Host-Plant Resistance to the Sweetpotato Weevil, Cylas for- A-32 micarius elegantulus. P. Thompson, J. C. Schneider. Use of Sex Pheromone and Entomopatho- genic Nematodes for Control of Sweet- potato Weevil, Cylas formicarius (F ab- ricius). R. Jansson. University of Florida, IFAS, Florida, USA. Departmental Breeding for Resistance to Insect Pests (Potato Tuber Moth, Leaf Miner Flies and Aphids) of Potato. A. Golmirzaie/ K. V.Raman. Components of Integrated Root-Knot Ne- matode Management and Interrelation- ships of the Nematode with other Or- ganisms in Potato. P. Jatala. Components of Integrated Root-Knot Nematode Management and Inter- relationships of the Nematodes with other Organisms in Sweetpotato. P. Jatala. Development of IPM Strategies Against the Sweetpotato Weevil and Its Socio- economical Implications. H. Kokubu/ A. Swindale. Development of Mass Production Methods for Beauveria sp. Parasitic to the An- dean Potato Weevil (APW) and the West India Sweetpotato Weevil. H. Torres. Development of Mass Production Methods for West Indian Sweetpotato Weevil (SPW). H. Torres. Integrated Control of Potato Cyst Nema- tode. M. Canto, J. Landeo. Management of Potato and Sweetpotato Insect Pests of Importance in Region I. L. Valencia. Management of Potato Insect and Mite Pests of Global and Regional Impor- tance. K. V. Raman. Publications Management of Sweetpotato Insect and Mite Pests of Global and Regional Im- portance. KV. Raman. Management of Sweetpotato Insect Pests oflmportance in Region I. L. Valencia. Screening for and Utilization of Resist- ance of Potato to Root-Knot Nema- todes. P. J atala. Screening for and Utilization of Resistance of Sweet potatoes to Root-Knot Nema- todes Meloidogyne Species. P.Jatala. Special Projects Special Project on PTM. 0. Roux. Swiss Development Cooperative. Theses Evaluation of Potato Cyst Nematode Reproduction Globodera pallida (Stone Behrens 175 in the Pot Test). Universidad Nacional de Caja- marca, Cajamarca, Peru. C. Posadas (M. Canto-Saenz). Evaluation of Sweetpotato Resistance to Euscepes postfasciatus FAIRMAIRE. UNA, La Molina, Peru. J.Sarmiento (KV. Raman/M. Palacios). Reaction of 15 Plant Species to 15 American Populations of Nacobbus aberrans. Universidad San Antonio Abad, Cusco, Peru. T. Boluarte (P. Jatala). Screening for Resistance to Sweetpotato Weevil. UNA, La Molina, Peru. A. Decheco (K. V. Raman/J. Sarmiento, UNA). The Inheritance of Resistance to Meloidogyne incognita in Sweetpotato. B. Huerta (P. Jatala). Program 5. Propagation, Crop Management Collaborative Adaptive Research on TPS Production. J.S. Rojas (INIA, Chile)/J. Bryfln. Agronomic Techniques for Potato Seed Pro- duction. National Scientists/C. Carli. Basic Seed Production in Peru. E. Franco (INIAA, Peru).* Client-oriented Seed Program. E. Franco (INIAA, Peru).* Collaboration with National Programs in the Evaluation and Selection of TPS Progenies and Superior Clones. National Breeders/ H.M Kidane-Mariam. Developing Technology for the Use of Cuttings for Seed and Table Potato Production and for Sweetpotato Pro- duction in Southeast Asian Countries. National Scientists/M. Potts. Publications Development of a Propagation System for Potato in Cameroon and other Countries in the Region. National Scientists/ C. Martin. Development of a Propagation System for Sweetpotato in Cameroon and Other Countries in the Region. National Scientists (Africa)/C. Martin. Development of Basic Seed Production in Kenya. /. Nyoroge (KARI, Kenya)/ C. Carli. Development of Improved TPS Progenies for Various Environments of China. Z. Dongyu (CAAS)/National Scientists of China/Song Bofu. Development of Multiplication Methods on Sweetpotato. National Scientists (Kenya)/C. Carli. A-33 Evaluation of Rapid Multiplication Tech- niques for Basic Seed Production in the Region. Region III. National Scientists/ C. Carli. Evaluation of TPS Progenies and Produc- tion of Hybrid Seed. A. Azirin Asandhi (LEHR!, Indonesia)/National Scientists/ M.Potts. In-vitro and Rapid Multiplication for Ba- sic Potato Seed Production. J.S. Rojas (INIA, Chile )/J. Bryan. On-farm Potato Seed Production. C. Muvira (ISABU, BurunchyD. Berrim. * Physiological Studies on True Potato Seed. National Scientists (India)/ M. Upadhya. Potato Basic Seed Production in Burundi. A. Sinduhije (ISABU, Burundi)/ D. Berrios.* Potato Production from True Potato Seed. N. Farag (Ministry of Agriculture, Egypt)/R. El-Bedewy. Potato Production from True Potato Seed in Tunisia. M. Fahem (CDRA, Tuni- sia)/R. Cortbaoui. Potato Production from True Seed in Cameroon and Other Countries in the Region. National Researchers (West African Countries)/C. Martin, C. Ntonifor. Potato Production from True Seed in Morocco. A. Hilali (IAV, Morocco)/ R. Cortbaoui. Production and Evaluation of TPS Fami- lies for Subtropical Areas. (A) Breed- ing for TPS Parental Lines. (India) K.C. Thakur, M.D. Upadhya. Production of Basic Potato Seed in Co- lombia. A. Gonzales, P. Corzo (ICA, Colombia)/0. Hidalgo. Production of Hybrid True Potato Seed. National Scientists (lndia)/K.C. Takur. A-34 Production of Seed Tubers from TPS. E. Ortega (FONAIAP, Venezuela)/ 0. Hidalgo. Production of Seed Tubers from True Po- tato Seed. E. Ortega (FONAIAP, Venezuela)/0. Hidalgo, P. Malagamba. Screening of True Potato Seed Families as Transplants and Planting Tubers as Seed- ling Materials. National Scientists (lndia)/M. Upadhya. Seed Potato Production in Paraguay. A. Strohmenger (IAN, Paraguay)/ M. Mayerreger. Seed Production Systems Using True Po- tato Seed in Philippines and Vietnam. National Scientists (Philippines and Vietnam)/M. Potts. Studies on Potato Hybridization, Pollen Management and Outcrossing Rates. J. Kalazich (INIA, Chile)/P. Malagamba. Studies on TPS Production in Bangladesh. H. Rashid, A. Quasem (TCRC, Ban- gladesh)/M.D. Upadhya. Survey and Virus Loss Estimates on Sweet- potato in Argentina. Socioeconomic Importance. S. Nome (lnstituto de Fi- tovirologfa)/L. Salazar. The Potato and the Utilization of Seed Tubers Derived from True Potato Seed in Paraguay. T. Mayerreger (IAN, Pa- raguay)/A. Strohmenger. True Potato Seed Hybrid Families in Dif- ferent Agroecology Zones oflndia. Na- tional Scientists/M. Upadhya (CPRI, India)/P. Malagamba/K.C. Thakur. True Potato Seed, On-Farm Trials in India. National Scientists/M. Upadhya (CPRI, lndia)/M.S. Kadian/P. Malagamba. Tuber Seed Production and Storage for Warm Climates in Asia. National Scientists/M. Upadhya (CPRI, India). Tuber Seed Production through Rapid Propagation Method. Bilateral Italy. Publications M. Mayeregger(IAN, Paraguay)/A.Lopez (SEAG, Paraguay)/A. Strohmenger, P. Accatino. Use of TPS for Potato Production in Monserrat, Dominica, St. Kitts and Jamaica. R. Fletcher (CARDI, Jamai- ca )/0. Malamud. Use of TPS for Potato Production in Nicaragua and Haiti. F. Torres (Nicaragua), M. Bastiat (Haiti)/ 0. Malamud. Contracts An Investigation to Determine Optimum Environmental and Cultivation Re- quirements for Maximum Flowering, Seed and Storage-Root Production in Argentina, 1988 to 1991. A. Boy/ J. Ploper/H. Beaufort-Murphy. INTA, Argentina. Identification of Suitable Locations for Germplasm Multiplication. AARI, Turkey. Production of Pathogen-tested Potato Germplasm for Southeast Asian and Pacific Countries. P. Smith. Victoria Department of Agriculture, Australia. TPS Production in Turkey for the Needs of the Middle East and North Africa. AARI, Turkey. Training and Consultancy Research in Effects of Soil Management and Fertilization on Flowering, Fruit Set- ting and Seed Quality of the Potato and Sweetpotato. S. Villagarcia. UNA, Peru. Instituto de Investigaciones Agropecua- rias, Chile. True Potato Seed Produc- tion in Chile. J.S. Rojas, A. Cubillos. Publications Departmental Agronomic Technology for Growing Potatoes from TPS. P. Malagamba/ J. Bryan/R. Cabello. Breeding, Selection and Distribution of Appropriate TPS Progenies and/or Parental Lines in the East and Southern Africa. H.M. Kidane-Mariam. Development of True Potato Seed (TPS) Parental Lines and Progenies for Agro- nomical and Reproductive Characters. A. Golmirzaie. Different Breeding Approaches for Hy- brids TPS Production. A. Golmirzaie/ P. Malagamba. Investigation of Environmental Condi- tions During the Development of Sexual Reproductive Organs of Ipo- moea batatas and other Ipomoea Spe- cies. H. Beaufort-Murphy. Maintenance and Multiplication of Patho- gen Free Potato Seed; Production of Low Virus Seed. J. Bryan. Maintenance and Multiplication of Sweetpotato Pathogen-Free Materials. J. Bryan. Physiological Studies on True Potato Seed (TPS) Quality, Storage and Handling. N. Pallais. Sweetpotato Propagation. H. Beaufort- Murphy. TPS Production in Warm Climates. P. Malagamba. Special Projects Supporting Seed Production and Research to Improve Productivity of Potatoes in Peru. E. Franco. Swiss Development Cooperation, SEINPA. A-35 Consultancy on Potato Improvement in Central Africa. L. Sikka. USAID Mis- sion, Kampala, Uganda. Strengthening of Potato Prebasic Seed Research and Production in Bolivia. A. Devaux. Swiss Development Coop- eration, PROINPA. Pilot Project for Potato Seed Production Under Rustic Greenhouses in Puno. E. Franco. Swiss Development Coop- eration, SEINPA. Sweetpotato Program in ISABU. D. Niyongabo/D. Berrios. Ministry des Affaires Entrangers, Belgium. Theses An Investigation of the Flowering Re- sponses of lpomoea purpurea in Lima, from Accessions Collected in Peru, E- cuador, Venezuela, Colombia and Boli- via. UNA, La Molina, Peru. A. Reyes (H. Beaufort-Murphy). Evaluation of Different T}'pes of Proge- nies for TPS Production. UNA, La Mo- lina, Peru. S. Buendia (A. Golmirzaie). Influence of Various Potassium Levels and sources on the Colour of Chips Obtained from Potatoes, cv. Chasqa. (SQM Project). UNA, La Molina, Lima, Peru. L. Linares Garcia/ P. Malagamba, S. Vi.llagarcla,J. Roca. Morphological and Physiological Be- havior of Three Potato Clones Subject to Water Stress Due to Drought. PROINPA-IBTA, ~olivia. P. Mamani (P. Malagamba,J. Roca). Promotion of Flower and TPS Pro- duction Via Growth Regulators. UNA, La Molina, Peru. R. Garcla (P. Malagamba). Program 6. Postharvest Management, Marketing Collaborative Assessment ·of Promising Potato Clones Under Seed and Ware Storage Condi- tions. J. Kabira (Min. Agriculture, Kenya )/H. Kidane-Mariam. Evaluation of Potato Clones for Food Processing and Cooking Quality. SAPPRAD (Thailand). K. Tantidham/ S. Wiersema. Evaluation of Sweetpotato Clones for Food Processing and Cooking Quality. SAPPRAD (Thailand). K. Tantidham/ S. Wrersema. Improved Sweetpotato Processing in Chi- na. Z.F. Tang/Song Bofu. Improvement of Potato Storage Tech- niques in Burundi. Z. Nzoyihera (ISABU, Burundi)/D. Berrios. A-36 Rustic Store for Ware and Seed Potato and Village Level Processing of Potatoes. S. Mehra/J. Singh/V.S. Khatana/ S.K. Roy (IARl)/R. Nave. Storage of Ware and Seed Potatoes. S. Doss (Min. Agriculture, Egypt)/ R. El-Bedewy. Studies on Potato Storage and Processing. J. Lekunze (IRA, Cameroon)/C. Martin. Studies on Sweetpotato Storage and Pro- cessing. J. Lekunze (IRA, Cameroon)/ C. Martin. Studies on Sweetpotato (/. batatas) as an Alternative Component of Cropping Systems on the Lowlands of Ecuador. F. Hinostroza, R. Carillo (INIAP, Ecuador)/J. Korva, 0. Hidalgo, G. Scott. Publications Sweetpotato Germplasm Evaluation, Se- lection and Use of Suitable Materials when Processing for Food. (Colombia) A. Alvarez, J. de la Torre, A. L6pez (ICA)/0. Hidalgo, G. Scott. Sweetpotato Storage (Post Maturity Tech- nology). A. Abubaker (Min. Agricul- ture, Kenya)/S. Nganga. Thai Food Habits and Potential Proces- sing of Sweetpotato. CIP/UPWARD. P. Duluyapach/S. Wtersema/G. Prain. Use of Sweetpotato Starch and Flour in Food Processing. S. Maneepun (Kaset- sart University, Thailand)/S. Wiersema. Contracts Breeding Yielding, Early and Disease Re- sistant Sweetpotatoes with Enhanced Food Quality and Nutritional Value. W.W. Collins. North Carolina State University, USA. Case Study of Village-Level Processing in Vietnam. Q. Nghiem. UNDP Human Resource Development. Development of Simple Processing Tech- nologies for- Sweetpotato/Potato Based Products for Low-Income Groups as Target Consumers. SAPPRAD. T. Van Den. The Philippine Root Crop Research and Training Center, Philippines. Screening for Natural Sprout Inhibitors of Potato Tubers Using Plants of the Labiatae Family. E.G. Quintana, O.K. Bautista. University of the Phil- ippines, Los Banos, Philippines. Sweetpotato Marketing in Argentina: A Study Based on Data from the Central Market of Buenos Aires. C. Maggi. Instituto de Economfa y Sociologfa Rural, Instituto Nacional de Tecnologfa Agropecuaria, Argentina. Publications The Nutritional and Chipping Evaluation of Selected Parental Gones in Peru, The Philippines and Canada. T.R. Tarn. Agriculture Canada. Departmental Low-Cost Storage of Consumer Potatoes. SAPPRAD. S. Wiersema. Marketing and Demand for Potatoes. G. Scott. Marketing and Demand for Sweetpo- tatoes. G. Scott. Potato and Sweetpotato Breeding for Processing in Tropical Countries. H. Mendoza. Socio-Economics of Potato Processing. G. Scott. Socioeconomics of Sweetpotato Proces- sing. G. Scott. Theses Chemical and Nutritional Evaluation of Some Sweetpotato (fpomoea bata- tas) Cultivars with Low Sugar Content for its Possible Use in Bakery. UNA, La Molina, Peru. H. Cardenas (Z. Huaman/N. Fong). Consumer Demand for Sweetpotato Bread in Lima, Peru. University of Wagenin- gen, The Netherlands. H. Denen. * Effect of Growing Conditions and Post- harvest Management on Quality of Po- tatoes for Processing and Fresh Con- sumption. Chiang Mai University Wiwat. W. Panuampai (S. Wiersema). Fruit-flavored Sweetpotato Fresh Roots-based Appetizer Juice by Augmented/Enzymic Means. UPLB, The Philippines. Wang Shengwu/ S. Wiersema. A-37 Processing Potentials of Sweetpo- tato UNDP. UPLB, The Philippines. H. Qindara/S. Wiersema. Production of L-glutamic Acid Using Corynebacterium glutamicin and Glucose Derived from Sweetpotato Tubers. UNDP. UPLB, Philippines. Phung Huu Hao/S. Wiersema. A-38 Relative Prices and the Feasibility of Pro- ducing Sweetpotato Bread in Lima, Peru. University of Wageningen, The Netherlands. A. Overbeek (G. Scott).* Trypsin Inhibitor Activity in Sweetpotato. Contract Project 68. North Carolina State University, USA. Mr. Dapeng (W. Collins). Publications Staff in 1991, listed by Department or Region *Staff who left during the year. +Staff funded by special projects (see note page46). Directors Richard L. Sawyer, Ph.D., Director General (until April, 1991) Hubert Zandstra, Ph.D., Director General (as of April, 1991) Jose Valle-Riestra, Ph.D., Deputy Director General Peter Gregory, Ph.D., Director of Research Kenneth J. Brown, Ph.D., Director of Regional Programs Office of the Director General William A. Hamann, B.S., Assistant to the Director General Edward Sulzberger, M.S., Assistant to the Director General (Public Awareness) Rosa Rodriguez, Head of Visitor's Office Office of the Director of Research Pons Batugal, Ph.D., Assistant to the Director of Research Jose Luis Rueda, Ph.D., Assistant to the Director of Research Staff Staff Research Programs Leaders Production Systems G. Prain (untilApril, 1991) T. Walker (as of April. 1991) Germplasm Management and Enhancement J. Dodds Disease Management E. French Insect and Nematode Management K.V. Raman Propagation, Crop Management P. Malagamba Postharvest Management, Marketing G. Scott Research Departments Breeding and Genetics Humberto Mendoza, Ph.D., Geneticist, Head of Department Ali Golmirzaie, Ph.D., Geneticist (sabbatical, Oct. 1990 - Sept. 1991) Edward Carey, Ph.D., Sweetpotato Breeder Juan Landeo, Ph.D., Breeder Enrique Chujoy, Ph.D., Geneticist (the Philippines) T.R. Dayal, Ph.D., Sweetpotato Breeder (India) A-39 Haile M. Kidane-Mariam, Ph.D., Breeder (Kenya) II Gin Mok, Ph.D., Sweetpotato Breeder (Indonesia) Genetic Resources John Dodds, Ph.D., Tissue Culture Specialist, Head of Department Peter Schmiediche, Ph.D., Geneticist (sabbatical, Oct. 1990-1991) Fermin de la Puente, Ph.D., Germplasm Collector· Z6simo Huaman, Ph.D., Germplasm Curator Kazuo Watanabe, Ph.D., Cytogeneticist Michael Hermann, Ph.D., Andean Crop Specialist, (Ecuador)+ Bodo Trognitz, Ph.D., Geneticist Norio Sato, Ph.D., Tissue Culture Associate Scientist+* Carlos Ochoa, M.S., Consultant Carlos Arbizu, Ph.D., Special Consultant on Andean Root and Tuber Crops+ N ematology and Entomology Parviz Jatala, Ph.D., Nematologist, Head of Department (sabbatical, July 1990 - Aug. 1991) K.V. Raman, Ph.D., Entomologist (Acting Head, July 1990 -Aug. 1991) Rolf Aalbu, Ph.D., Entomologist (Tunisia)* Hirotaka Kokubu, Ph.D., Entomologist (Dominican Republic) Luis Valencia, Ph.D., Entomologist (Colombia) Olivier Roux, Ir., Associate Entomologist Breeder (Tunisia)+ Nicole Smit, M.S., Associate Entomologist (Tunisia)+ A-40 Pathology Edward R. French, Ph.D., Pathologist, Head of Department Luis Salazar, Ph.D., Virologist Hossien El-Nashaar, Ph.D., Bacteriologist Enrique Fernandez-Northcote, Ph.D., Virologist Gregory A. Forbes, Ph.D., Mycologist (Ecuador, as of November 1990) Upali Jayasinghe, Ph.D., Virologist John Elphinstone, Ph.D., Bacteriologist* Maddalena Querci, Dot. Biol., Associate Scientist+ Linnea G. Skoglund, Ph.D., Mycologist (Kenya) L.J. Turkensteen, Ph.D., Adjunct Scientist (The Netherlands)+ Massaki Nakano, B.S., Virologist, Visiting Scientist+ Jari Valkonen, M.S., Virologist, Visiting Scientist+* Physiology Patricio Malagamba, Ph.D., Physiologist, Head of Department Helen Beaufort-Murphy, Ph.D., Physiologist Noel Pallais, Ph.D., Physiologist Frederick Payton, Ph.D., Agronomist (Dominican Republic) Michael Potts, Ph.D., Agronomist (Indonesia) Siert Wiersema, Ph.D., Physiologist (Indonesia) Andreas Oswald, M.S., Physiologist+ Jukka Korva, M.S., Agronomist (Ecuador)+ Carlo Carli, Ing. Agr., Seed Physiologist (Kenya)+ Staff .. Social Science Thomas Walker, Ph.D., Economist, Head of Department (as of April) Gordon Prain, Ph.D., Anthropologist (Acting Head of Department, Dec 1990-April, UPWARD Coordinator, the Philippines, as of Aug. 1991) Charles Crissman, Ph.D., Economist (Ecuador) Peter Ewell, Ph.D., Economist (Kenya) Keith Fuglie, Ph.D., Economist (funisia)+ Robert Rhoades, Ph.D., Anthropologist (Philippines, until April)+ Gregory Scott, Ph.D., Economist Anne Swindale, Ph.D., Agric. Economics (Dominican Republic)+ Adhiambo Odaga, Ph.D., Geographer (Cameroon)+ Alwyn Chilver, M.S., Economist (Indonesia)+ Research Support Fausto Cisneros, Ph.D., Entomologist, Head of Department Mario Pozo, Ing. Agr., Field and Greenhouse Superintendent (Lima) Lombardo Cetraro, Biologist, Field & Greenhouse Supervisor (San Ram6n) Victor Otazu, Ph.D., Superintendent (San Ram6n) Jose Luis Marca, M.S., Supervisor, Seed Production Francisco Munoz, ph.D., Superintendent (Ecuador) Hugo Goyas, Ing.Agr., Supervisor (Yurimaguas) Miguel Quevedo, Ing. Agr., Off-station Field Supervisor (Cajamarca & Canete) Lauro G6mez, Acting Supervisor (Huancayo) Staff Regional Research The regional designations used here are those used during the year 1991. Headquarters James E. Bryan, M.S., Senior Seed Specialist Region I - South America Oscar Hidalgo, Ph.D., Regional Representative • Semilla e Investigacion en Papa, (SEINPA) Peru Efrain Franco, M.S., Economist, Team Leader+ Juan Aguilar, Ing. Agr., Seed Production+ Jorge Recharte, Ph.D., Anthropologist+ Ricardo Wissar, M.S., Agronomist+ • Project for the Investigation of the Potato, (PROINPA) Bolivia Andre Devaux, Ph.D., Seed Specialist, Team Leader+ Greta Watson, Ph.D., Human Ecologist+ Nicole Bezenc;on, LR., Associate Expert+ Nelson Estrada, Ph.D., Breeder+ Javier Franco, Ph.D., Nematologist+ Joanne Parker, Ph.D., Fungi Mycologist+ • Southern Cone (Chile) Primo Accatino, Ph.D., Breeder Region II - Central America and the Carribean Oscar Malamud, Ph.D., Regional Representative A-41 Region III • East and Southern Africa Sylvester Nganga, Ph.D., Regional Representative Donald Berrios, Agronomist (Burundi)+ Lyle Sikka, M.S., Consultant on Seed Technology (Uganda Special Project)+* • Programa Regional d' Amelioration de la Culture de la Pomme de Terre en Afrique Centrale et de L'Est, (PRAPAC) Rwanda Marco Soto, Ph.D., Coordinator+ Region IV • North Africa, Near & Middle East Roger Cortbaoui, Ph.D., Regional Representative Ramzy El-Bedewy, Ph.D., Scientific Associate (Egypt) Region V • West and Central Africa Carlos Martin, Ph.D., Regional Representative Thomas Gass, Eng., Associate Scientist+ (until May 1991) Region VI - South Asia Mahesh Upadhya, Ph.D., Regional Representative M.S. Kadian, Ph.D., Agronomist M.S. Jairth, Ph.D., Socioeconomist K.C. Thakur, Ph.D., Breeder V.S. Khatana, Ph.D., Socioeconomist Region VII • South East Asia and the Pacific Michael Potts, Ph.D., Regional Representative A-42 • User's Perspective with Agricul- tural Research and Development (UPWARD), The Philippines Virginia N. Sandoval, Ph.D., Anthropology, Asst. Coordinator Inge Verdonk, Ir., Nutritionist (Philippines)+ Cherry Bangalanon, M.S., Family Res. Mgmt. Region VIII - China Song Bofu, Ph.D., Regional Representative Training Department Fernando Ezeta, Ph.D. Head of Department George Hunt, Agr. Eng., Training Officer (Region III)* Margarita Villagarcia, M.S., Training Assistant Information Sciences Department Carmen Siri, Ph.D., Head of Department Hernan Rinc6n, Ph.D., Head Communications Unit James Bemis, Ph.D., Senior English Writer /Editor Alfredo Garcia, M.S., Coordinator, Statistics Unit Christine Graves, M.A., Writer/Editor Carmen I. Podesta, M.S., Librarian/Information Officer Marciano Morales-Bermudez, M.S., Supervisor, Communication Unit Fiorella Sala Cabrejos, M.S.T., Coordinator, User Services Manager, Information Unit Staff .. i Administration Controller's Office Carlos Nifio Neira, C.P.C., Internal Auditor (Acting Controller since January 1990) Oscar Gil, C.P.A., Assistant Controller J~ Belli, C.P.A. * Vilma Fscudero, B.S. Jorge Bautista, B.S. Alfredo Gontiilez, C.P .A.* Alberto Monteblanco, C.P.A. • Treasury Unit Lucy Correa, C.P.A., Accountant • Budget Unit Guillermo Romero, Chief Accountant* Alberto Monteblanco, C.P.A., Accountant • Accounting Unit Miguel Saavedra, C.P .A., General Accountant Edgardo de los Rfos, C.P.A., Accountant Blanca Joo, C.P.A., Accountant Eliana Bardales, C .. P .A., Accountant Otrice of the Executive Offi~er ~ Vittorelli, Agr. Eng., Acting Executive Officer (as of Aug. 1991) Adrian Fajardo, M.S., Exective Officer (sabbatical, as of Aug. 1991) Maritza Benavides, Admin. Assistant • Logistics Lucas Reano, C.P.C., Supervisor Jorge Luque, M.B.A., Warehouse Officer Jose Pizarro, Importations Officer Arturo Alvarez, Local Purchasing Officer Staff Manuel Scollo, B.A., R.R.1.1., General Serv. Officer • Personnel and Labor Relations Guillermo Machado, Lie., Supervisor Ana Dllmett, B.S. Soc. Assist., Social Worker* Martha Pierola, B.S., Social Worker German Rossani, M.D., Medical Officer Lucero Schmidt, Nurse • Foreign Affairs Liaison Marcela Checa, Liaison Officer • Transportation Carlos Bohl, Supervisor Jacques Vandemotte, Chief Pilot Djordje Velickovich, Pilot* Percy Zuzunaga, Co-Pilot • Equipment and Maintenance Gustavo Echecopar, Ing. Agr., Supervisor • Security Aldo Tang, Comdt., Security Supervisor • Travel and Telex Ana Marfa Secada, Supervisor • Auxiliary services Nancy Oshiro, Supervisor Scientific Associates Teresa Ames Icochea, Ph.D., Micologist (Peru) Adolfo Boy, Ph.D., Sweetpotato Agronomist (Argentina) Manuel Canto, Ph.D., Nematologist (Peru) R6mulo del Carpio, Ing. Agr., Taxonomist (Peru) A-43 Ulises Moreno, Ph.D., Physiologist . (Peru) Francisco Vilaro, Ph.D., Sweetpotato Breeder (Uruguay) Sven Villagarcia, Ph.D., Soil Scientist (Peru) Scientific and other Assistants Breeding and Genetics Raul Anguiz, M.S., Biol. Walter Amor6s, M.S., Ing. Agr. Miguel Ato, Ing. Ind. Alimentarias Luis Calua, M.S., Ing. Agr. Luis Diaz M.S., Ing. Agr. Jorge Espinoza, M.S., Ing. Agr. Rosario Galvez, M.S. Manuel Gastelo, M.S., Ing. Agr. Luis Manrique, Ing. Agr. Elisa Mihovilovich, M.S. Daniel Reynoso, M.S., Ing. Agr. Felix Serquen, M.S., Ing. Agr. * Jorge Tenorio, B.S., Biol. Genetic Resources Cesar Aguilar, Ing. Agr. Jesus Amaya, Tech. Dipl. Humberto Asmat, Biol. Anfbal Baltazar, Ing. Agr. Jorge Benavides, Biol. Fausto Buitr6n, Ing. Agr. Alfonso Del Rio, Biol.+ Jaime Diaz, M.S. Walberto Eslava, Ing. Agr. Rene G6mez, Ing. Agr. Marfa del Rosario Herrera, Biol. Kurt Manrique, M.S. Gisella Orjeda, M.S. Matilde Orrillo, Biol. A-44 Ana Panta, Biol. Armando Quispe, Ing. Agr. Alberto Salas, Ing. Agr. Roxana Salinas, Ing. Agr. Carmen Sigiiefias, Biol. Judith Toledo, Bio.+ Fanny Vargas, Ing. Agr. Sandra Vega, Biol.+ Victor Zambrano, Biol. Nematology and Entomology Jesus Alcazar, M.S., Ing. Agr. Tatiana Boluarte, Ing. Agr. Ver6nica Canedo, Biol. Roberto Delgado de la Flor, Ing. Agr. Oder Fabian, Ing. Agr. Arelis Carmen Garz6n, Biol.* Lily Gavilano, Biol. Alberto Gonzalez, M.S. Erwin Guevara, Ing. Agr. Rossio Haddad, Biol. Angela Matos, Ing. Agr. Norma Mujica, Ing. Agr. Marfa Palacios, Biol. Marina Zegarra, Biol.* Victor Zambrano, Biol. Pathology Pedro Aley, M.S., Ing. Agr. Ciro Barrera, Ing. Agr. Ida Bartolini, M.S., Biol. Miguel Cervantes, Biol. Carlos Chuquillanqui, B.S., Ing. Agr. Christian Delgado, M.S., Biol. Violeta Flores, Biol. Segundo Fuentes, Biol. Wilman Galindez, Ing. Agr. Josefa Gamboa, Biol. Liliam G. Lindo, Ing. Agr. Charlotte Lizarraga, B.S. Staff Josefina Nakashima, M.S. Ursula Nydegger, Tech. Dipl. Ricardo Orrego, Ing. Agr. Hans Pinedo, Ing. Agr. Judith Toledo, B.S. Hebert Torres, M.S., Ing. Agr. Ernesto Velit, Biol. Physiology Rolando Cabello, Ing. Agr. Rosario Falc6n, B.S., Biol. Nelly Fong, M.S., Nutrition Rolando Lizarraga, B.S. Norma de Mazza, Q.F. Jorge Roca, B.S., Biol. Social Science Marisela Benavides, M.A., Pub. Admin., Social. Miguel Daza, Lie. Social. Hugo Fano, Economist Cristina Fonseca, M.S., Agronomist Jose Herrera, M.A., Economist Victor Suarez, B.S., Statistician Information • Computer Unit Ana Marfa Ponce, M.S., Eng., System & Database Manager Roberto Castro, Ing. Electron., System Design & Development Alberto Velez, Eng., System Manager Pia Marfa Oliden, Computer Operations Jorge Apaza, Ing. Econ., PC Management and Support Jorge Palomino, Accountant, VAX and PC Support Staff • Information Unit Ivan Bende:zU, Ing. Agr., Database Assistant Martha Crosby, B.A., Librarian Griselda Lay, B.A., Information Assistant Jorge Vallejo, Ing. Agr., Classification Assistant Cecilia Ferreyra, Information Services • Communication Unit Jesus Chang, M.S., A.V. Section Coordinator Emma Martinez, Lie., Supervisor of Processes Jaime Machuca, Ing. Agr., A.V. Operations Section Coordinator Felix Munoz, B.C.E., Distribution Section Coordinator Anselmo Morales, Art Section Coordinator Rufino Failoo, Photomechanics Section Coordinator Godofredo Lagos, Print Shop Section Coordinator Marfa del Carmen Prieto, Text Section Coordinator Christy Zevallos, Lie., A.V. Specialist • Statistics Unit Beatriz Eldredge, B.S., Biometrician Training Ivan Boluarte, Agr. Eng. Assistant* Nelson Espinoza, Assistant, (leave of absence, Sept. 1990-1991) Jorge Palacios, Dip., Language Teacher America Valdez, M.S., Ing. Agr. A-45 Research Support Roberto Duarte, Agr. Eng. Ana Marfa Romero, Agr. Eng.* Nelson Melendez, Tech. Dep. * Others Roberto Duarte, Agr. Eng. Luis Navarrete, Ing. Agr. (SEINP A, Puno, Peru) Noemi Zuniga, M.S. Ing. Agr. (SEINP A, Cajamarca, Peru) Region I Jorge Abad, Ing. Agr Carlos Canizares, Ing. Agr. Jorge Carillo, Ing. Agr. Patricio Espinosa, M.S. Diego Estrella, Ing. Agr. Ivan Reinos, M.S. Leonor Romero, Assistant Luis Zapata, Ing. Agr. Region II C. Mejia, Tech. Assist. R. Arbona, Tech. Assist. P. G6mez, Tech. Assist. Jorge Queiroz, Ing. Agr. Region III Stan Kasule, B.S., Assistant* John Kimani, M.S., Technician J. Mutuura, M.S. Research Associate Region IV A. El-Ashker, Technician A. El-Oraby, Technician M. Shahata, B.S. M. Sharkoni, B.S. Region V C. Ntonifor, Tech. Asst. A-46 Region VI S.K. Mehra, M. S., Postharvest Assistant Region VII A. Demagante, M.S., Res. Asst. V. Escobar, M.S., Res Asst. B. Fernandez, M.S., Res Asst. C. Montierro, M.S., Res. Asst. R. Muyco, Res. Asst. F. Aquino, Res. Asst. A. Pangelinan-Ona, Res. Asst. M. Piniero, B.S. Human Ecol. B. Susana, B.S., Res. Asst. G. Opena, Res. Asst. R. Demonteverde, Res. Aide Region VIII Gong Xifeng, Res. Asst. Wang Gui Ling, Res. Asst. + Positions designated with an"+" are separately funded as Special Projects by the following donor agencies: • Australian Development Assistance Agency • Belgium, General Administration for Cooperation 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 • Netherlands, Ministry of Foreign Affairs • Rockefeller Foundation • Swiss Development Cooperation and Humanitarian Agency • United Kingdom, Overseas Development Administration (ODA) • United States, Agency for International Development (USAID) • United States, Pepsico Food International • United States, McDonald's Corporation • World Bank/INIPA • Food Industry Crusada Against Hunger (FICAH) Staff Ji 1lfon•no 11r1tiizo Moreno Pa11rio y Asoc1ados Sociedod Civil no Rosponsabllidad Um1lada F1rrna Miembro de Price Waterhouse REPOllT OF INDEPENDENT ACrolJNT.l\NTS f ebruary 26, 1992 To the Henbers of the Board of Trustees International Potato Center - CIP Financial Statements las Begooias 441 Uma27. Peru Apartado 2869 T etts. · 42-0567 · 42·0555 Tele• 20006 Pnwalr Fax i2s522 \Je have examined the statements of f;nanciel position of International Potato tenter - CIP (a not- for-profit organi zet ion) es of Decerrber 31, 1991 and 1990, end the related statements of operations and changes in unexpended fund balances and changes in financial position for the years then ended. Our examinations were made in accordance with generally accepted auditing standards and, accordingly, included such tests of the accounting records and such other auditing procedures as we considered necessary in the circunstences. Jn our report dated March 14, 1991, our opin;on on the 1990 financial statements was qualified because it was not possible to determine with reasonable accuracy if the core contribution receivable from the Jnteramerican Develo~nt Bank would be col tectible. As explained in Note 3, this donation was received during 1991 with no material effect on the afore-mentioned financial statements. Accordingly, our present opinion on the 1990 financial statements, as presented herein, is different from that expressed in our previous report. Also noted in the afore-mentioned report, our opinion on the 1990 financial statements was qualified because the Center did not record depreciation on its property, pl ant and equi pnent. As explained in Note 6, the Center has restated the 1990 statement of financial position to record the accurulated depreciation at Decent.er 31, 1990 of US$7, 698, 091 and has recorded the depreciation for the year ended Oecenber 31, 1991 with charge to operating expenses in an amount of US$1,536,645. In accordance with generally accepted accounting principles, the Center should restate all the financial statements at Deceni>er 31, 1990. Jn our opinion, except for the effect in 1990 of the matter described in the preceding paragraph, the financial statements examined by us present fairly the financial position of Jnternational Potato Center - CIP as of Oec~r 31, 1991 and 1990 and its operations and changes in its unexpended fund balances and changes in its financial posltion for the years then ended, in conformity with generally accepted accounting principles consistently applied. ~~ ;:J~ ..--:- Countersigned by _c:f) ___ {j;1£tner) Fran~-~ MX':' Peruv1 an Publ l c Accountant Registration No. 155 Financial A-47 INTERNATIONAL POTATO CENTER - CIP STATEMENT OF FINANCIAL POSITION (Notes land 2) as of December 31, 1991 and 1990 (Expressed in U.S. dollars) ASSETS CURRENT ASSETS Cash and short-term deposits Accounts receivable: Donors (Note 3) Advances and current portion of loans to executives and employees (Note 4) Other Inventories of laboratory and other supplies Prepaid expenses (Note 5) Total current assets RESTRICTED FUNDS (Note 7) LOANS TO EXECUTIVES AND EMPLOYEES - NON-CURRENT PORTION (Note 4) FIXED ASSETS (Note 6) Cost Accumulated depreciation LIABILITIES AND FUND BALANCES CURRENT LIABILITIES Bank indebtedness (Note 7) Accounts payable and other liabilities Grants received in advance - donors Other accounts payable and accrued expenses Payable to donors Total current liabilities PROVISION FOR SEVERANCE INDEMNITIES net of advances of US$ 28,058 (US$31,599 in 1990) FUND BALANCES Capital invested in fixed assets Capital fund Unexpended fund balances (Note 8) GRANTS PLEDGED (Note 9) The accompanying notes are part of the financial statements. A-48 1991 1990 l,l 34.799 854,603 4,247,561 6, 163,869 318.787 260,308 254.476 580,300 761.232 832,771 912,134 659,829 7,628,989 9,351.680 218,399 207,767 35,755 49,582 i ~ 19,317,018 18.402.430 ( 9, 1 23,886 ) ( 7,698,091 ) 10, 193, 132 10,704,339 ,. " 18.076,275 20,313,368 217,201 515,960 596.006 884,238 1.000.000 1.600,000 564,162 958,699 136,000 2.513,369 3,958,897 1,288,423 553.204 10, 193, 132 10,704,339 1.536,645 2,544,706 5,096,928 14,274,483 15,801,267 18,076,275 20,313,368 Financial INTERNATIONAL POTATO CENTER - CIP ' STATEMENT OF OPERATIONS AND CHANGES IN UNEXPENDED FUND BALANCES (Notes 1 and 2) asofDecember31, 1991and1990 (Expressed in U.S. dollars) 1991 1990 REVENUE Operating grants: Unrestricted 13,857,384 13,402,659 Restricted 1.805.756 2,229.890 Other restricted core grants 527.176 1.131.085 16.190,316 16,763.634 Special project grants 3,943,561 2,983,216 Grants for fixed asset additions 874,978 1, 103,600 Grants for cooperative activities 521.627 200,331 Working fund grants 210,000 Other income, net 498.463 842,058 22.028.945 22.102.839 EXPENSES Operating costs: Potato and sweetpotato research programs 5,601, 140 5.483,698 Research services 1.944,079 1.743,836 Regional research program and training 3.279,023 4.018,637 ~ Conferences and seminars 22.050 80.278 Information services and library 1.275.400 1.145,563 Administration costs 1.974.344 1.880.156 General operating costs 3,207,872 2.975.305 Depreciation 1.536.645 External program and management review 97,049 18.840,553 17.424.522 Other restricted core expenditures 649,541 919,096 Special projects 3,632.681 3,104,683 Cooperative activities 434,725 190,055 23.557,500 21.638.356 (Deficit) excess of revenue over expenses (1.528,555) 464.483 Transferred to capital invested in fixed assets ( 1,023,667) (1.847.661) Unexpended fund balance, beginning of year 5,096,928 6.480.106 UNEXPENDED FUND BALANCE, END OF YEAR 2.544,706 5.096.926 The accompa11yi11g notes are part of the fi11a11cial stateme11ts. Financial A-49 INTERNATIONAL POTATO CENTER - CIP STATEMENT OF CHANGES IN FINANCIAL POSITION • For the years ended December 31, 1991 and 1990 (Expressed in U.S. dollars) ·liil 1991 1990 SOURCE OF FUNDS (Deficit) excess of revenues over expenses (l,528,555) 464,483 Adjustment to reconcile to net cash provided by operations: Depreciation 1,536,645 Provision for severance indemnities 841,307 554,553 Cash provided by operations 849,397 l,019,036 Decrease in accounts receivable 2, 183,653 Decrease in inventories 71,539 Decrease in loans to executives and employees-non-current portion 13,827 Increase in payable to donors 136,000 Increase in accounts payable and other liabilities 869,771 Increase in grants received in advance 1,542.400 Decrease in restricted funds 117,364 3,254.416 3,548,571 • APPLICATIONS OF FUNDS Purchase and replacement of fixed assets - Core acquisitions 905,604 l,847,661 • ~ - Net cost of replacement 118,063 Payment and advances of severance indemnities and exchange gain in the year l 06,088 740,401 Increase in prepaid expenses 252,305 153,369 Increase In restricted funds 10,632 Decrease in accounts payable and other liabilities 981,528 Decrease in grants received in advance 600,000 Increase in loans to executives and employees-non-current portion 25,330 Increase in accounts receivable 2,311.l 18 Increase in inventories 12.424 2,974,220 5,090,303 Increase (decrease) in cash and short-term deposits 280, 196 (l,541.732) Cash and short-term deposits. beginning of year 854,603 2,396,335 CASH AND SHORT-TERM DEPOSITS, END OF YEAR 1,134.799 854,603 • The accompa11yi11g 11otes are part of the fi11ancial statements. A-50 Financial INTERNATIONAL POTATO CENTER - CIP NOTES TO FINANCIAL STATEMENTS as of December 31, 1991 and 1990 (Expressed in U.S. dollars) l. Operations The International Potato Center (CIP) is a nsot-for-profit organization located in Lima, Peru, with programs throughout Latin America, Central America, and the Carribbean, the Near and Middle East, Asia, and Africa. CIP's principal objective is to contribute to the development of the potato and other tu- berous roots, through scientific research programs, preparation and training of scientists, dissemination of research results in publications, conferences, forums and seminars, and other activities, in accordance with its objectives. CIP was established in 1972 in accordance with an Agreement for Scientific Cooperation with the Government of Peru signed in 1971 and expiring in 2000. The Center is a member of the group of International Agricultural Research Centers which is supported by the Consultative Group for International Agricul- tural Research. In accordance with existing legislation and provisions of the Agreement described above, CIP is exempt from income tax and other taxes. If for any reason the Center's operations are terminated, all of its fixed assets are to be transferred to the Peruvian Ministry of Agriculture. 2. Summary of significant accounting policies The principal accounting poMcies are as follows: a) Foreign currency The books and accounts are maintained in U.S. dollars. Transactions in other currencies are recorded at the rates of exchange ruling on the dates of transactions. Pledges in currencies other than U.S. dollar are recorded at exchange rates prevailing at the time of receipt, or if outstanding at December 31, at the rates of exchange in effect at year end. Monetary assets and liabilities in currencies other than U.S. dollars are translated at market rates of exchange at the end of the year. b) Accruals The financial statements of the Center are presented using the accrual basis of accounting, except for outstanding commitments (d, below). c)Revenue Grant transactions are recorded as revenue on the basis of donor commit- ments. Core unrestricted grants and capital and working fund grants are pledged on an annual basis and as such are recognized as revenue in the year in which the grant is pledged, as long as they are deemed to be probable of Financial A-51 collection. If a pledge is cancelled in a subsequent financial period, it is written-off and charged against revenues in the year it is cancelled. Restricted grants, which may be pledged for more than one year, are recognized as revenue only to the extent that related expenses have been incurred or budgeted. Other income, net. such as interest on investments, proceeds from sales of fixes assets and supplies, and administrative fees on special projects are recognized as earned. d) Expenditures Firm orders for purchases of fixed assets and services are recorded in the year of their commitment. At December 31, 1991, the amount recorded under this practice totalled US$67, 110. Expenditures made by international programs are recorded on the basis of reports received. Expenses related to special projects and cooperative activities are applied, when incurred, against the respective income. e) Investments Short-term investments principally comprise certificates of deposit bearing interest at current bank rates and are valued at cost. f) Inventories of laboratory and other supplies Inventories of laboratory supplies and other materials are valued at es- timated market value which approximates cost. g) Fixed assets Property, plant, and equipment are stated at cost. This includes the pur- chase price plus costs of freight, insurance, and handling charges. Grants used for the acquisition of new or replacement property, plant, and equip- ment are charged to the appropriate fund source as period expense and subsequently capitalized. In 1991, the Centerhas adopted the practice of recording depreciation on its property, plant, and equipment to be in conformity with generally accepted accounting principles. The statement of financial position at December 31, 1990, has been restated to reflect this situation (Note 6). Depreciation is computed using the straight-line method over the term of the useful lives of property, plant, and equipment. The cost of property, plant, and equipment, net of accumulated deprecia- tion, disposed of in a fiscal period are charged directly to the capital invested in fixed assets and the corresponding asset account is reduced by the same amount. Maintenance and repairs are recorded as operating costs in the year incurred. h) Vacations Employees' vacation expenses are charged to operating expenses when they are taken. i) Provision for.severance indemnities A-52 In 1991, new legislation for severance indemnities was established. Accord- ing to the new legislation, the accumulated indemnity from inception up to December 31, 1990, will be deposited in a financial institution progres- Financial j • sively during a period which may not exceed l 0 years and will be made within the first semester of each year. The new legislation has retroactive effects for the calculation of indemnities for .employees engaged after July 11, 1962. Indemnities as of January l, 1991, will be deposited in the months of May and November of each year comprising all the months worked in each semester. CIP has elected to pay accumulated indemnities from inception up to December 31, 1990, over a l 0-year period. CIP paid the first year deposit in May of 1991 in the amount of US$25,266. The retroactive effect for the calculation of indemnities for employees engaged since June, 1972, in- creased ·the liability in the amount of US$841,307. CIP has paid the current year deposit in the amount of US$173,581. 3. Accounts receivable from donors The 1990 agreement with the Inter-American Development Bank for the dollar core contribution of US$1,444,000 at December 31, 1990, had not yet been signed at that date; therefore, there was uncertainty whether the contribution would be received. During 1991, the contribution was received with no material effect on the financial statements. The contribution was reduced to US$l ,230,000, the balance was covered by the International Bank for Reconstruction and Development. 4. Advances and loans to executives and employees The Center offers home and vehicle loans to some employees. These loans are funded with its own funds, and they are repayable in monthly installments. Advances and loan balances with executives and employees at December 31, are as follows: Advances to personnel Loans funded by CIP, repayable over a one-to-three year period, bearing interest (as from 1988) of 11.5% per annum and secured by employees' homes Less current portion 5. Prepaid expenses 1991 1990 274,836 79,706 354,542 (318,787) 35,755 150,765 159,125 309,890 (260,308) 49,582 This balance is comprised of the following at December 31: Advances to organizations tor research work Travel advances Advances to contractors Other Financial 1991 317,596 71.440 159,600 363,498 912,134 1990 241,748 53,642 148,220 216,219 659,829 A-53 6. Property, plant, and equipment For the year ending December 31, 1991, CIP has begun to record deprecia- tion on property, plant, and equipment to be in accordance with generally accepted accounting principles. CIP has restated 1990 year end balances of this account to record accumulated depreciation from inception to December 31, 1990, in the amount of US$7,698,091 with credit to accumu- lated depreciation account and debit to capital invested in fixed assets account. For the year ended December 31, CIP recorded depreciation expense in the amount of US$1,536,645. At December 31, property, plant, and equipment are stated as follows: 1991 1990 De pre- Accumulated Net book Net book elation Cost depreciation value value rate USS USS USS USS years Buildings 5,150,101 l ,030,408 4, 119,693 3,816,366 33 Research equipment 2, l 00,794 l.528.750 572.044 712,652 7 Vehicles 2.249,239 l ,783,902 465,337 566,967 Aircraft 3,019.486 981,319 2,038, 167 2,340, 116 4-10 Furniture and office equipment 941,978 719,639 222,339 226,695 7 Operating farm equipment 662,773 346,054 316,719 362,069 10 Installations 2,352,876 l ,272,404 l ,080.472 l, 159,004 10 Site development 837,638 185,956 651.682 670,625 33 Computer equipment l.315,151 795,608 519,543 593,933 Communication equipment and other 686,982 479,846 207, 136 255,912 7 19,317,018 9, l 23,886 l 0, 193, 132 10,704,339 Vehicles and other fixed assets replaced or retired are transferred from the property, plant, and equipment and related equity account to a memoran- dum account. Fixed assets sold or donated are eliminated from the memoran- dum account. The balance of the memorandum account at December 31, 1991, is US$1,313, 172 (US$5 l 9,967 in 1990). 7. Bank indebtedness The Center has various credit lines and loan arrangements with Citibank N.A .. totalling US$530,000 at December 31, 1991 (US$ 250,000 in 1990), which bear interest at the New York prime rate plus 1.5%. The amounts are guaranteed by a deposit of US$218,400 (US$207, 767 in 1990) in the afore-mentioned financial institution which earns interests at 3.35% per annum (6.6% in 1990). A-54 Financial • • " • 8. Unexpended fund balances t This balance is comprised of the following at December 31: 1991 1990 Operating funds - Unrestricted (3,026,012) ( 347,062) - Restricted 947,836 l,070,201 Working funds l,785,000 l.785,000 Capital funds 148,689 Special projects 2,533,074 2,222, 194 Cooperatives activities 304,808 217,906 2.544,706 5,096,928 9. Grants pledged During 1991, the following donations were pledged to CIP for special projects in 1992 through 1994: 1992 1993 1994 I. Special Projects International Development Research Center 99.700 Swiss Development Cooperation and Humanitarian Aid 2,264.733 l ,902.781 577.230 United States Agency for International Development 317.400 ) Netherlands Government 120,000 ' Inter-American Development Bank 209,000 Belgian Government 694, 125 527,900 German Government Agency for Technical Cooperation - GTZ 260,000 7,944 Finnish Government 64,100 OPEC Fund for International Development 21.000 4,050,058 2.438,625 577.230 II. Cooperative activities Federal German Government Agency for Technical Cooperation - GTZ 24.860 3.270 Kellogg Foundation 10,000 Rockefeller Foundation 96,510 Scottish Crop Research Institute 10,897 15,787 l.925 United Kingdom Overseas Development Administration 190,876 128,294 333, 143 147,351 l.925 The above amounts are not reflected in the accompanying financial statements. Financial A-55 Abbreviations and Acronyms Terminology ABA ADG ANOVA APW ARTC BW Bt Cd CEVd cfu CGA CLD cm CPB CPTI CV d DAP DI..S DNA EB ELISA FRKN g GA ug GCA GPA GV h ha l:JSVd IAA IPM LB LMF -,. m McAb A-56 abscisic acid S. tuberosum ssp. Andigena analysis of variance Andean potato weevil Andeanrootandtubercrops bacterial wilt Bacillus thuringiensis Duration of season expressed as temperature sum citrus exocortis viroid colony forming units general combining ability chlorotic leaf distortion centimeter Colorado potato beetle cowpea trypsin inhibitor gene cultivar day days after planting diffused-light store deoxyribonucleic acid early blight enzyme-linked immunosorbent assay false root-knot nematode gram gibberellic acid microgram, 10-6 general combining ability green peach aphid granulosis virus hour hectare hop stunt viroid indole 3-acetic acid integrated pest management la~ blight leafminer fly meter monoclonal antibodies Abbreviations and Acronyms • min minute mmho/cm millimho per centimeter (a measure of electrical conductivity) , NASH nucleic acid SPQt hybridization test nm nanometer, 10-9 ( NCM nitrocellulose membranes ns not significant PBS phosphate buffer solution PC produccion comercial PCN potato cyst nematode PCR polymerase chain reaction pg picogram, 10-12 PLRV potato leafroll virus PS1Vd potato spindle tuber viroid P1M potato tuber moth PVA potato virus A PVT potato virus T PYX potato virus X PVY potato virus Y ppm parts per million RCBD randomized complete block design RFLP restriction fragment length polymorphism RH relative humidity RKN root-knot nematode .. RSM red spider mite ~ SMC seed moisture content SPCFV sweetpotato chlorotic flecks virus SPCV sweetpotato caulimovirus SPFMV sweetpotato feathery mottle virus SPLV sweetpotato latent virus SPMMV sweetpotato mild mottle virus SPW sweetpotato weevil t metric ton TGA tuber glycoalkaloids TIA trypsin inhibitor activity TPS true potato seed TSM two-spotted mite TSPS true sweetpotato seed VCG vegetative compatibility group ZT Zeatin riboside Abbreviations and Acronyms A-57 Organizations AGRIS AIAP ARARI APA APA APS AVRDC BARI BGRC BPI CAAS CABI CABO-DLO CARDI CARI CGIAR CIAAB CIAT CICA CICIU CIED CIMMYT CIP CNPH CONAPAPA COSCA COTESU CPRI CRI CRIFC CTCRI EEA-INTA EMBRAPA ENEA ESARRN FAQ FONAIAP FORTIPAPA FUND AGRO A-58 International Information System for Agricultural Sciences and Technology_ (Italy) Latin American Potato Association Aegean Regional Research Institute (Turkey) African Potato Association Asian Potato Association American Phytopathlogical Society Asian Vegetable Research and Development Center (Taiwan) Bangladesh Agricultural Research Institute Braunschweig Genetic Resources Center (Germany) Bureau of Plant Industries (Philippines) Chinese Academy for Agricultural Sciences Commonwealth Agricultural Bureau International Centre for Agrobiological Research (Netherlands) Caribbean Agricultural Research and Development Institute Central Agricultural Research Institute (Sri Lanka) Consultative Group on International Agricultural Research Centro e Investigaciones Agricolas- A-Boerger (Uruguay) International Center for Tropical Agriculture (Colombia) Centro de Investigaci6n en Cultivos Andinos (Peru) Centro de Cria de Insectos Utiles Centro de Investigaciones Educaci6n y Desarrollo International Maize and Wheat Improvement Center International Potato Center Centro Nacional de Pesquisa de Hortalicas (Brazil) Comite Nacional de Productos de Papa IIT NCIAT /Rockefeller Foundation Project financed by ESARRN Cooperaci6n Tecnica Suiza Central Potato Research Institute (India) Crops Research Institute (Sichuan, China) Central Research Institute for Food Crops (Indonesia) Central Tuber Crops Research Institute (India) Estaci6n Experimental Agropecuaria-INTA (Argentina) Empresa Brasileira e Pesquisa Agropecuaria (Brazil) Comitate Nazionale per la ricera e per lo sviluppo dell Energia Nucleare e delle Energie Alternative (Italy) East and Southern African Root Crops Regional Network Food and Agricultural Organization of the United Nations Fondo Nacional de Investigaciones Agropecuarias (Venezuela) Fortalecimiento de la Investigaci6n y Producci6n de Papa (Ecuador) Fuodaci6n para el Desarrollo Agropecuario Abbreviations and Acronyms GTZ German Agency for Technical Cooperation ,.:/ IAO Instituto Agronomico per L'Oltremase (Italy) • IBPGR International Board on Plant Genetic Resources IBTA Instituto Boliviano de Technologia Agropecuaria l ICA Insituto Colombiano Agricola (Colombia) ICAR Indian Council for Agricultural Research ICIPE International Centre for Insect Physiology and Ecology ICRISAT International Crops Research Institute for Semi-Arid Tropics ICTA Instituto de Ciencia y Technologia Agricolas (Guatemala) IDB Inter-American Development Bank IDRC International Development Research Centre (Canada) IFPRI International Food Policy Research Institute IICA Interamerican Institute for Cooperation on Agriculture IITA International Institute of Tropical Agriculture (Nigeria) IL RAD International Laboratory for Research on Animal Diseases (Kenya) INIA Instituto Nacional de Investigaciones Agropecuarias (Chile) INIAA Instituto Nacional de Investigaci6n Agraria y Agroindustrial (Peru) INIAP Instituto Nacional de Investigaciones Agropecuarias (Ecuador) INIFAP Instituto Nacional de Investigaciones Forestales y Agropecuarias (Mexico) INIPA Instituto Nacional de Investigacion y Promocion Agropecuaria (Peru) ~ INIVIT National Institute for Research in Tropical Roots and Tubers (Cuba) INPT Institut National de Pomme de Terre (Togo) INRA lnstitut National de la Recherche Agronomique (Senegal) ~ INRAT Institut National de la Recherche Agronomique de la Tunisie (Tunisia) INTA Instituto Nacional de Technologia Agropecuaria (Argentina) IRRI International Rice Research Institute IPD Intergenebank Potato Database IPO Research Institute for Plant Protection (Netherlands) IRA-Bambui Institute of Agronomic Research (Cameroon) IR-I Inter-Regional Potato Introduction Project (USA) IS ABU Institut des Sciences Agronomiques du Burundi ISNAR International Service for National Agricultural Research KARI Kenyan Agricultural Research Institute LEHR I Lembang Horticultural Research Institute (Indonesia) MSU Michigan State University (USA) NAL National Agricultural Laboratories (Kenya) NARS national agricultural research systems NASA National Aeronautical and Space Administration (USA) NCSU North Carolina State University (USA) NPRC National Plant Research Center (Kenya) NSAC Nova Scotia Agricultural College Abbreviations and Acronyms A-59 .. ODA ORSTOM PBI PCARRD PGS PNAP PRACIPA PRAPAC PRAPACE Overseas Development Agency Institut Francais de Recherche Scientifique pour le Developpement en Cooperation Plant Breeding Institute (UK) Philippine Council for Agriculture and Resources Research and Development Plant Genetic Systems (Belgium) Programme National de l' Amelioration de la Pomme de Terre (Rwanda) Programa Andino Cooperativo de Investigaci6n en Papa (CIP regional network) Programme Regional d' Amelioration de la Culture de la Pomme de Terre en Afrique Centrale et de l'Est Programme Regional d' Amelioration de la Culture de la Pomme de Terre et de la Patate Douce en Afrique Centrale et de l'Est (formerly PRAPAC) PRECODEPA Programa Regional Cooperativo de Papa (CIP regional network) PROCIANDINO Programa Cooperativo de Investigaciones en Papa (southeast South PROCIPA PROINPA RICA SAAS SAP HA SAPPRAD SCRI SEINPA SOTEC UN ALM UNCP UNESCO UNDP UPLB UPWARD USAID ViSCA YNU YAU A-60 America) Programa Cooperativo de Investigaciones en Papa (CIP regional network) Project for the Investigation of the Potato (Bolivia) Red Interamericana de Comnicadores Agricolas Sichuan Academy of Agricultural Sciences Servicios Agrarios, Puno (Bolivia) Southeast Asian Program for Potato Research and Development (CIP regional network) Scottish Crops Research Institute Semilla e Investigaci6n en Papa (Peru) Society for the Development of Appropriate Technology Universidad Nacional Agraria La Molina (Peru) Universidad Nacional del Centro del Peru United Nations Educational, Scientific, and Cultural Organization United Nations Development Programmme University of the Philippines Los Banos (the Philippines) User's Perspective with Agricultural Research and Development (CIP regional network) United States Agency for International Development Visayas State College of Agriculture (Philippines) Yunnan Normal University (China) Yunnan Agricultural University (China) Abbreviations and Acronyms 1 t a NTERICIPl '9 INTERNATIONAL POTATO CE -·- ISNN 0256-6311