[J 0~4 Cover: 1. Sweet potatoes for sale at a New Guinea Mar ket. 3. Hand-emascu lation of potato flowers for TPS production, Ch il e. 2. CIP staff member studying specimen box with farmers in Ollantaytambo, Peru , for identification of local pests. 4. Testing for the presence of viruses , using nucleic acid spot hybridization. 1 jl 1 - International Potato Center Annual Report 1989 Worldwide Potato and Sweet Potato Improvement International Potato Center Apartado 5969, Lima, Peru 1989 The International Potato Center (CIP) is a nonprofi t , autonomous scientific institution established in 1972 by agreement with the Government of Peru . The Center develops and di sseminates knowledge to facilitate use of the potato and sweet potato as basic foods in the developing world. CIP is one of 13 nonprofit international research 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 Inter- national Bank fo r Reconstruction and Development (World Bank) , and comprises more than 45 countries , international and regional organizations, and private foundations. In 1988, through the CGIAR , CIP received funding from the fo llowing donors: the governments of Australia , Austria , Belgium , Finland , France , Germany, India, Italy, Japan , Mexico, Netherlands, Norway, People 's Republic of China, Philippines , Spain , and Switzerland ; the Canadian International Development Agency (CIDA); the Danish Interna- tional Development Agency (DANIDA); the Euro- pean Economic Community (EEC); the Inter-Ame- rican Development Bank (IDB); the International Fund for Agricultural Development (IFAD); the Swedish Agency fo r Research Cooperation with Developing Coun tries (SAREC) ; the United Kingdom Overseas Development Administration (UKODA); the United States Agency for Interna- tional Development (USAID); the OPEC Fund for International Development ; the United Nations Development Programme; the World Bank (IBRD); and the Consultative Group Secreta ri at. The 1989 A nnual Report is published in English and Spanish by the International Potato Center (CIP). This report covers the period from 1 November 1987 to 31 October 1988. Mention of specific prod ucts by trade name does not imply endorsement of or dis- crimination against such products by· CIP. Citation: International Potato Center. 1989 . Annual Report CIP 1989. Lima, Peru . 194 p . Printed by the International Potato Center , Apartado 5969, Lima, Peru , July 1989. Copies printed: 3100. ' Contents ._ Foreword II Board of Trustees IV CIP Self-Study VI Agroecological Zones and CIP Regions/Thrusts XIV Summary of Research Programs 1 RESEARCH TIIRUSTS Collection, Maintenance, and Utilization of Unexploited Genetic Resources 13 II Production and Distribution of Advanced Breeding Material 25 III Control of Bacterial and Fungal Diseases 37 IV Control of Virus and Virus-Like Diseases 51 ·• v Integrated Pest Management 65 VI Warm-Climate Potato and Sweet Potato Production 77 VII Cool-Climate Potato and Sweet Potato Production 91 VIII Postharvest Technology 97 IX Seed Technology 105 x Food Systems Research 121 Human Resource Development 137 List of Abbreviations and Acronyms 142 Papers Published in Scientific Journals 146 Recent CIP Publications 153 Articles Published in CIP Planning Conferences 155 Research and Consultancy Contracts and Special Projects 159 ~ CIP Staff 163 Financial Statements 169 ! CGIAR Information 178 I Foreword 0 ur host country for CIP's headquarters has suffered especially severe~security and economic problems in recent months, prompting widespread speculation in the international press . Local papers reported that we were leaving the country, and this informa- tion eventually found its way into the global mass media. As a result , then~ has been increased concern among the families of international staff back home , along with donor preoccupation about the safety of both our staff and their investments in CIP facilities . CIP is facing these local problems squarely, and our report this year reflects some of the ways we have adapted our programs and shifted resources to surmount these constraints . In the process, we have been hard pressed to maintain CIP's low-profile approach that has been established over the past two decades. Over the past months , we have curtailed on-farm research and road transportation to CIP experiment stations in many parts of the country . After the security leader at CIP's Huancayo station was killed in late 1988 , all of the scientific staff posted at this principal highland station were moved to other sites and security measures were tightened at all CIP locations . Despite these tragic setbacks , however, CIP harvested a normal crop from well-cared-for research plots in Huancayo in March and April of 1989. Even though deeply shocked by the killing of their colleague, more than 80 workers stayed on the job-loyally caring for CIP research plots and following their customary schedules . Although none of CIP's professional staff remained at Huancayo , many of the local workers have been on the job for more than 15 years , and they have repeatedly proven themselves to be top professionals in their own right. In related efforts, CIP is establishing an experiment station in nearby Quito, Ecuador for our scientists working on problems of highland-potato production who must monitor their plots on a dafiy basis . CIP also upgraded its aircraft in i988' so that sdentists' can better service all experiment stations in Peru and Ecuador, from a Lima base . We will transfer a team of five scientists from CIP headquarters to the Ecuador station , thus providing a backup facility for maintaining the world potato and sweet potato collections. II Although CIP's diversification of program activities from head- quarters to regional programs and into country networks has been accelerated by our host-country's problems, we continue to maintain substantial investments in staff and facilities at the Peruvian locations. We have built a tremendously capable work force of well trained loyal staff of over 500 Peruvians, and it would take years to estab- lish a similar capability at another location. Our experience this past year has clearly demonstrated the responsibility and loyalty of these veteran workers during difficult times. We will continue to decentralize, bringing our programs closer to the more than 80 countries with which we are collaborating. And, as long as lives are not endangered, we also will continue to work in Peru, which probably provides a better climate for improving potato and sweet potato germplasm than does almost any other country. In the coming months, our decisions will be governed to a great extent by the following priorities, which were affirmed in recent discussions with the CIP Board of Trustees. First, the lives of our people cannot be replaced, thus we must ensure adequate personal security. Second, much of CIP's germplasm cannot be replaced and thus must be protected for use by both present and future generations. Third, bricks and mortar can be replaced, so we must make sure that our facilities are adequately designed for optimum flexibility and adaptation. Thus, under adverse conditions, CIP's operations could be modified or moved with minimum effect on staff or budget. As we chart our course for the next decade, which is outlined in the following section on CIP's self-study and plan for change, I would like to pay personal tribute to all CIP staff for their excellent support during this very difficult year. I would also like to offer special acknowledgement for the dedicated work of the Peruvian staff and our host-country colleagues. Our successful collaboration will continue through good planning. Director General III Board of Trustees Executive Committee Program Committee DR. DAVID CALL, Chairperson Dean College of Agriculture and Life Sciences Cornell University Ithaca, New York 14853 U.S.A. DR. DELY GAPASIN, Chairperson Deputy Director Philippine Council for Agriculture and Resources Research and Development (PCARRD) Los Banos , Laguna Philippines DR. AURELIANO BRANDOLINI Diiector General Istituto Agronomico per l'Oltremare (IAO) Via Cocchi 4 Firenze V Italy DR. STACHYS N. MUTURI Director of Research Development Ministry of Research, Science & Technology P.O. Box 30568 Nairobi, Kenya '° I ff .,, I I ... "" • " ' g i I I ' I . I • 's f t r~ ' I DR . JOHN M EAGH ER, Secretary 3 Kingfield Court Burwood, Victoria 3125 Australia DR. LANDER PACORA Executive Director FUNDEAGRO Av. Javier Prado Oeste 1894 San Borj a Lima, Peru DR. LINDS EY INN ES Scottish Crop Research Inst. Invergowrie, Dundee DD2 5DA Great Britain DR. RI CHARD L. SA WY ER . Director General International Potato Center Apartado 5969 Lima, Peru DR. SHEN JINPU Deputy Director Chinese Academy of Agricultu ra l Sciences Bai Shi Qiao Ju No. 30 West Suburb of Beijing Beijing, People's Republic of China *DR. KLAUS RAV EN National Agrarian University Apartado 456 La Molina , Lima , Peru ''' Term ended 1988 ------------1, _________ _ IV v Board of Trustees Executive Committee Program Committee IV DR. DAVID CALL, Chairperson Dean College of Agriculture and Life Sciences Cornell University Ithaca, New York 14853 U.S.A. DR. DELY GAPASIN, Chairperson Deputy Director Philippine Council for Agriculture and Resources Research and Development (PCARRD) Los Banos, Laguna Philippines DR. AURELIANO BRANDOLINI Diiector General Istituto Agronomico per l'Oltremare (IAO) Via Cocchi 4 Firenze V Italy DR. STACHYS N. MUTURI Director of Research Development Ministry of Research, Science & Technology P.O. Box 30568 Nairobi, Kenya DR. JOHN MEAGHER, Secretary 3 Kingfield Court Burwood, Victoria 3125 Australia DR. LANDER PACORA Executive Director FUNDEAGRO Av . Javier Prado Oeste 1894 San Borja Lima, Peru DR . LINDSEY INNES Scottish Crop Research Inst. lnvergowrie, Dundee DD2 5DA Great Britain DR. RICHARD L. SA WYER . Director General International Potato Center Apartado 5969 Lima, Peru DR. SHEN JINPU Deputy Director Chinese Academy of Agricultural Sciences Bai Shi Qiao Ju No. 30 West Suburb of Beijing Beijing, People 's Republic of China *DR. KLAUS RAVEN National Agrari an Un iversity Apartado 456 La Molina, Lima , Peru •:• Term e nded 1988 v CIP's Self-Study and Change Plan VI C IP is well into a process of self-evaluation and change . In 1988, we launched a full-scale analysis of our organizational and management practices that we hope will give rise to many improvements over the next decade. Working from within the institution, we've now entered the implementation stage of our plan-for-change. This brief summary documents the progress to date and outlines some considerations for the future. I Our Rationale While a self-study can be useful for most institutions, such analysis is now particularly valuable for CIP in addressing some fundamental administrative and operational concerns . First, our administrative leadership will soon change. In its 20-year history , CIP has had only one director general and he has strongly influ- enced the strategies and direction of the institution. The intent of the seJf-study process is to provide a constructive atmosphere for the change in management and to encourage all staff to contrib- ute to the planning proc~ss . · Second, CIP has grown rapidly with a philosophy based on user needs, and our programs have diversified through operations in more than 80 ' countries. Thus, a self-study has served as an internal review to ensure that our organizational changes keep pace with growth , that our servicing capabilities are appropriate for research-project requirements , and that our facilities meet operational needs. For example , most of CIP's management staff have attended specialized management courses. The self-study has provided an opportunity to put their collective training to use in - improving the institution . Staff functions and strategies that have served. the institution well during the growing years are being examined and revised, · based on current conditions and on input from all operational levels. Perhaps most importantly , the self- study has provided an environment and a basis for continuing dis- cussion of needed improvements and for identification of alternative approaches. And , in the process, staff have worked together to contribute ne'w insights. Third, CIP will be involved in 1989 in external program and management reviews, which are part of the monitoring process for the programs and management of all CGIAR centers. Our self- sttidy has helped to mirror CIP's activities, thereby providing a framework for preparing for these reviews . Fourth , the process can help generate the flexibility and respon- siveness needed to plan effectively during the current period of economic and social turmoil in CIP's host country (see Foreword). The Plan-For-Change Process Our self-study is the first phase in a Jong-term planning process that began with the Board of Trustees' approval. External manage- ment consultants then were chosen to guide CIP staff through the process , and we se lected a working group from within our st?ff to critically evaluate CIP's total organization , with input from all departments of the Center. Their findings were presented to man- agement as a base for continued discussion and decision~making. Next, CIP's management committee developed a preliminary Plan- tar-Change document, building upon the findings of the working group. The Plan is now being implemented and monitored, with periodic updating scheduled to include feedback from all CIP operations. For (our months , our self-study committee interviewed CIP staff at all levels and stimulated constructive criticism on all phases of CIP work. Management practices were analyzed at all levels and constructive feedb ack provided to all managers . The findings of -. our study committee were presented to staff and the Board prior to the 1988 annual review . They have also provided the base for the next step of the process - the development of a change plan by the management committee. Our management committee is composed of all management- level staff, plus the controller , the executive officer , the head of the information sciences department , and the head of the social sciences department. For six weeks , the management committee , VII Training Department VIII Assistant to the Director General Director of Regional Programs Associate Director for Regional Research Region I Region If Region Ill Region IV Region V Region Vl Region VII Region VIII Board of Trustees Director General Deputy Director General Country Networks H Seed Systems H Visitor Services Director of Research ~ Breeding & Genetics Department I-I Nematology & Entomology Department Pathology Department Physiology Department Genetic LJ Resources Dept. ~ Social Sciences Department Internal Auditor ., Quito I Experiment Station 'i' ~ / CIP Organizational Chart j Information Sciences Department Information Unit Communication Unit Computer Unit Statistics Unit Public Awareness Unit Controller Assistant Controller Treasury Unit Budgeting Unit Accounting Unit Executive Officer Assistant Executive Officer Logistical Services Unit Personnel Unit Maintenance Unit Motor Pool Unit Travel Office Unit Security Unit Lodging and Food Services Unit Foreign Affairs Liaison Officer IX Training Department VIII Assistant to the Director General Director of Regional Programs Associate Director for Regional Research Region I Region II Region Ill Region IV Region V Region VI Region VII Region VIII Board of Trustees Director General Deputy Director General Country Networks Seed Systems Internal Auditor Visttor Services Director of Research Breeding & Genetics Research Support Department Department Nematotogy & Entomology La Molina Department Experiment Station Pathology Department Huancayo Experiment Station Physiology Department San Ramon Ex riment Station Genetic UI 0 Resources Dept. Experiment Station Social Sciences Department CIP Organizational Chart Information Sciences Department Information Unit Communication Unit Computer Unit Statistics Unit Public Awareness Unit Controller Assistant Controller Treasury Unit Budgeting Unit Accounting Unit Executive Officer Assistant Executive Officer Logistical Services Unit Personnel Unit Maintenance Unit Motor Pool Unit Travel Office Unit Security Unit Lodging and Food Services Unit Foreign Affairs Liaison Officer IX x in a consensus approach, addressed the major problem areas that had been identified by the study committee, as well as other pres- sing concerns. The result is a plan-for-change that designates responsibilities and proposes a time schedule for implementing the changes. The plan document was given to all our staff and the Board of Trustees for final revision before being distributed out- side the CIP family. Most of the changes will be implemented prior to the external reviews in late 1989. Our Initial Findings Our -study was designed to identify both the strengths and weak- nesses of the present CIP structure, so that changes could be built around our strong points. We are proud of our many accomplish- ments. CIP is recognized as an exceptionally productive, cost- effective institution , with a dedicated work force of both local and international staff. The change plan goal is to guide our "A" class institution into "A+" performance over the next decade . The preliminary findings clearly indicated that the organizational chart needed updating, with some changes in lines of responsibility. All of the research thrusts and departments named in the new chart are now the responsibility of the director of research . The research program has been restructured as a single unified program with a continuum of research activities . Thrust managers lead this research at headquarters. They also work on collaborative research projects with the regional and national programs. In recent years, CIP's expanding research activities in all regions have generated many excellent collaborative projects with national scientists . Our- plan-for-change helps bring the programs at headquarters and in the regions together into an integrated program . Our findings indicated that the executive office has not been able to expand its supportive capabilities fast enough to keep pace with the increase in research programs in recent years . Con- sequently, there was a need to reorganize the executive office and to add staff so that services could be streamlined. Personnel and purchasing. formerly headed by one person, has now been divided into two positions, with the addition of a local professional personnel officer. Another staff member was assigned to work directly under the executive officer to implement administrative decisions. The department of communications and training also has been divided into two departments: the director of regional research will now be responsible for training and the director general's office will be in charge of the information sciences department. Previously, CIP staff had noted the need to have the monthly responsibility reports coincide with the departmental budget pre- sentations. Our' Change Plan complements this recommendation and provides a budgetary structure whereby costs can be properly identified by either department or thrust. This change will provide management with quicker and more comprehensive information about potential adjustments in funding. Another measure taken as a result of our self-study was the hiring of a team of research-communications computer consultants to develop a plan that will bring CIP up-to-date with computer hardware and software for our institution's many research and information needs. This plan will be implemented as soon as the necessary funds become available. The many databases that were being developed throughout CIP are now being integrated so that computers and software will be more compatible. With the diver- sity of CIP's program, these improvements could well be some of the most valuable changes generated by our self-study. While our study findings recognized the value of CIP's low-profile approach and modest facilities that have produced excellent research, a better working environment was recommended . Space and facilities are needed for the greatly expanded staff. To respond to this need, two new buildings are under construction and staff will be redistributed there when they are completed . As our plan moves rapidly into the implementation phase, the Plan-for-Change document has been published and is available for use by others. A sister center has already followed CIP's lead with a self-study of its own, and others are considering the possibility. Although our study required more time than originally anticipated, the consensus is that the effort has been highly productive. We rec- ommend the self-study process as an effective tool for monitoring the operations of international centers and other agricultural research institutions and for building change into their programs. Richard L. Sawyer Director General XI •· XII ~I ~; •' I) CIP Collaborative Regional Bridges C IP manages its global research and development program within a regional network through which CIP and national program scientists sys- tematically evaluate technologies under a range of local conditions. This approach takes into account the farmer, consumer, and agribusiness commu- nity at all research levels, from the moment a problem is identified, through experiment station and on-farm testing and adaptation, until an effective solu- tion is accepted by local potato and sweet potato producers. Rapid and continuing feedback from these evaluations plays a key role in guiding CIP's overall research program at headquarters in Lima, Peru . (see overview, next page) CIP's capabilities are enhanced by numerous research and consultancy con- tracts that take advantage of the expertise and facilities available at other institutions , often in collaborative research in developed countries. Through contracts with developing-country institutions, we share specialized human and physical resources to focus on high priority local research. PRECODEP~, \ " \/I~ ,, 11•~ t ,, PRAtjl~~~·· I I \ \ \ \ \ \ \ \ \ ' ' ' ' -------------- I • Region I Region II Region Ill • , Region IV • ,Region V • 1 Region VI • Region VII • . Region VIII South America ~ Central America and he Caribbean East and Southern A rica North Africa and the , iddle East West and Central Africa South Asia Southeast Asia China Country Networks C IP has helped to develop five unique collaborative research networks. In these networks , several countries in a geographical area pool their resources to solve common production problems. Once priorities have been assessed, each country undertakes the projects for which it has a compara- tive advantage, sharing its results with the others. CIP participates in the networks as an equal partner, providing technical assistance in its areas of expertise, as well as administrative guidance. The distribution of efforts allows CIP and the member countries to utilize their resources efficiently. This system of shared responsibility and active interchange differs funda- mentally from other agricultural networks that are designed primarily to aid in germplasm distribution . The members benefit from a wide range of research results , and at the same time their interests are consolidated and their self-reliance is strengthened. -----~--------------- ~ CIP Headquarters - Lima l!l Regional Headquarters · · · · · o Department Staff in Regions - - - • Collaborative Research and Contracts - Collaborative Country Research Networks • j> XIII Agroecological Zones and Related Thrust Research in 8 CIP Regions C IP has four experiment stations in Peru, one in each of the major agro-ecological regions of the country. Our headquarters is located at a coastal desert site near Lima (240 m altitude), where faci lities include general research and administrative offices, as well as laboratories , greenhouses , refrigerated and diffused-light stores, growth chambers, and experiment fields. A second station , in the cool Andean highlands near Huancayo (3 ,260 m), is the home of CIP's World Potato Collection. The remaining two stations are in the Amazon region: one in the mid-elevation jungle of San Ramon on the eastern slopes of the Andes (800 m), and the other in the hot, low jungle of Yurimaguas (180 m). CIP research sites in Peru and the potato-growing seasons, with meteorological data for 1988 crop year. Site: -¥- Lima-La Molina e Huancayo • San Ramon • Yurimaguas Latitude: 12°05 'S 12°01·s 11°08'S 5°4l 'S Altitude: 240 m 3280 m 800 m 180 m Growing season: Jan-Mar May-Nov Nov-May Nov-Mar May-Aug May-Aug 88 88 87 88 87 88 88 88 88 88 Air max (0 C) 28.62 23.16 20.80 31.07 29.03 31.58 Air min(° C) 19.31 13.27 6.74 14.54 11.13 19.20 Evaporation (total mm) 452.00 568.90 1001.84 1372.98 534.18 220.10 Rainfall (total mm) 0.90 4.80 661.90 1474.20 222.80 334.30 Solar radiation (daily MJ/m2) 17.32 12.05 19.89 17.84 18.29 no data XIV CIP's international staff includes nearly 100 scientists , administrators , and other experts from over 20 countries. Many of our international staff members are stationed at CIP regional headquarters located throughout the developing world (next page) , where they collaborate directly with the national programs . In Lima, Center operations are supported by more that 500 supporting scien- tists, technicians , administrative personnel, secretarial and clerical support staff, and specialized workers . CIP's six research departments-Breeding and Genetics , Genetic Resources, Nematology and Entomology, and Social Sciences-are staffed and headed by international experts from developed and developing countries. Our interdisciplinary research is concentrated within ten "Thrusts", which combine the work of specialists from several disciplines to improve potato and sweet potato production and use. I II III IV v VI VII VIII IX x CIP's Thrusts Collection, Maintenance, and Utilization of Unexploited Genetic Resources Production and Distribution of Advanced Breeding Material Control of Bacterial and Fungal Diseases Control of Virus and Virus-Like Diseases Integrated Pest Management Warm-Climate Potato and Sweet Potato Production Cool-Climate Potato and Sweet Potato Production Postharvest Technology Seed Technology Potato and Sweet Potato in Food Systems .... I - I "' .. •• ~.- ~ PRACIPA PRAPAC PRECODEPA PROCIPA SAPPRAD Program a Programme Programa Programa Southeast Andino Regional Regional Cooperativo de Asian Program Cooperativo de d'Amelioration Cooperativo In vestigaciones for Potato In vestigaci6n de la Culture de Papa en Papa Research and en Papa de Pomme Costa Rica , Argentina , Development Bolivia, de Terre Cuba, Brazil , Indonesia , Colombia, en Afrique Dominican Chile, Papua New Ecuador, Centrale Republic, Uruguay , Guinea, Peru, Burundi , El Salvador, Paraguay Philippines, Venezuela Rwanda, Guatemala, Sri Lanka, Uganda, Haiti , Thailand , Zaire Honduras , Malaysia Mexico, Nicaragua, Panama Global Regional Contact Points Main Headquarters Peru International Potato Center Apartado Postal 5969 Lima 100, Peru Phone: (51)(14) 36-6920 (51)(14) 35-4283 FAX: (51)(14) 35-1570 Telex: 25672 PE Cable: CIP AP A, Lima E-Mail: 157:CGI801 157:CGI043 Region I Office South America Colombia CIP Region I Office Apartado Aereo 92654 Bogota 8, D.E., Colombia Phone: (57)(1) 286-4019 (Ext. 454) (57)(1) 281-3088 (Ext. 454) (57) (1) 281-3399 FAX: (57)(1) 281-9468 Telex: 42368 ICA TI 45366 CIID CO c/oCIPAPA Cable: CIP AP A Bogota Paraguay CIP Region I Office c/o Sen·icio de Extension Agricola y Ganadera (SEAG) SL Lorenzo, Paraguay Phone: (021) 50-0377 (022) SO- 2526 Telex: 218PY UNDP Oil. Cable: UNDEVPRO Mail: c/o UNDP - C.C. 1107 Asuncion, Paraguay Region II Office Central America & Caribbean Dominican Republic CIP Region II Office Av. Sarasota esquina Nuiiez de Caceres Apartamento 202, Edificio Ambar Plaza 11 Santo Domingo, Rep. Dominicana Phone: (1)(809) 535-4887 (1)(809) 535-6230 FA.'<: (1)(809) 535-6554 Telex: 3464112 HCA RD xv Region III Office East & Southern Africa Kenya CIP Region III Office P.O. Box 25171 Nairobi, Kenya Phone: (254)(2) 59-2206 (254)(2) 59-2054 FAX: (254)(2)59-3499 Telex: 22040 ILRAD Cable: CIPAPA, Nairobi E-Mail: ILRAD 10074:CGU005 Ethiopia CIP Region III Office c\o Institute of Agricultural Research Holetta Research Center P.O. Box 2003 Addis Ababa, Ethiopia Phone: 160055-59 PBX Telex: 21548 IAREf Rwanda CIP Region III Office c\o P.N.A.P. Section de l'SAR B.P.73 Ruhengerl, Rwanda Phone: (250) 332 Cable: (use above address) Burundi CIP Region III Office B.P. 75 Bujumbura, Burundi Phone: (257) 22-4074 Telex through: Hotel Source du Nil No. 5030BDI Telex via FAO 5092 FOODAGBDI XVI Region IV Office North Africa & Middle East Tunisia CIP Region IV Office 11 rue des Orangers 2080 Arlana, Tunis Tunisia Phone: (216)(1) 71-6047 (216)(1) 53-9092 FAX: (216)(1) 71-8431 Telex: 14965 CIP TN E-Mall:C.Martln Egypt CIP Region IV Office P.O. Boxl7 Kafr El Zayat, Egypt Phone: (20)(40) 58-6720 Telex: 23605 PBTNA UN Region V Office West & Central Africa Cameroon CIP Region IV Office P.O. Box279 Bamenda, Cameroon Phone: (237) 36-3285 FAX: (237) 36-3284 c\o Sky Line Hotel Telex: 5110 KN CIP CAM Nigeria CIP Region V Office c\o IITA Oyo Road, P.M.B. 5320 Ibadan, Nigeria Phone: (234) 41-3440 Telex: 31417 TROPIB NG or 2031 TDS IBA NG, c\o IITA BOX 015 Region VI Office South Asia India CIP Region VI Office IARICampus New Delhi 110012, India Phone: (91)(11) 58-8055 Telex: 31-73140 FI IN 31-73168 EiC IN Cable: CIPAPA, New Delhi E-Mail: 157:CGl114 Region VII Office South East Asia Philippines CIP Region VII Office c\oIRRI P.O. Box933 Manila, Philippines Phone: (63)(94) 50015-19 Telex: 40890 RICE PM, 40860 P ARRS PM, 22456 IRI PH (via RCA) 63786 PNRICE E-Mail:IRRI 157:CGI401 Indonesia CIP Region VII Office c\o Lembang Hort. Res. Inst. P.O. Box587 Bandung, Indonesia Phone: (Lembang) (62)6025 FAX: (62) (22)43-1583 Telex: 28276 PHEGARIA Thailand CIP Region VII Office P.O. Box 9-159 Bangkheng Bangkok 10900, Thailand Phone: (62)(2) 579-5586 FAX: (66)(2) 541-1087 Telex: 84478 INTERAG TH Region VIII Office China CIP Region VIII Office c\o The Chinese Academy or Agricultural Sciences Bai Shi Qiao Rd. No. 30 West Suburbs of Beijing Beijing, People's Republic of China Phone: (86) 831-6536 (86) 831-5326 FAX: (86)(1) 831-6545 Telex: 222362 FHBJ CN 222443 FHBJ CN 22233 MAAF CN Cable: AGRIACA Summary of Research Programs CIP has markedly increased workloads ~£Thrust research within the regions of Latin America, Africa, and Asia. An emerging priority within this con- tinuing emphasis · on global regionalization is for collaborative teams to create improved varieties by crossing local potato varieties with materials from CIP. These teams are comprised of NARS and CIP scientists, and the CIP contributions provide combinations of resistances and tolerances to biotic and abiotic stresses. Materials from selected sources other than the Center's breeding program are also being promoted. For example, clone B71-240.2 (bred in Argentina), and cultivar Mariva (from Peru), show wide adaptability· and are being used in several tropical countries around the world. The strong trend towards regionalization extends throughout our Thrust research activities. CIP's scientists and NARS counterparts are increasingly working together in the regions to improve integrated pest and disease control methods, to develop potato seed production schemes that produce clean planting materials (considered by many countries to be as important as the development of new varieties), and to develop new postharvest methodologies. Similarly, CIP is emphasizing the regional approach in sweet potato re- search, where we have centered initial.attention on the collection, distribu- tion, and pathogen cleanup of germplasm. This expanding program also includes socioeconomic studies on production, utilization, production and marketing patterns, as well as research on breeding, integrated pest and disease management, and postharvest methodologies. fo this suinmary, we have highlighted results of some major activities in each of CIP's research Thrusts. The findings represent the work of CIP's head- quarters and regional research teams in collaboration with NARS and others. · 1 Gennplasm and Breeding New accessions for the World Potato Collection continue to be identified, and we are focusing on geographical areas that are not well represented. In 1988, we obtained 156 new accessions from Guatemala, Mexico and Ecuador, and our Collection now maintains a total of more than 4,200 non-duplicate potato clones. The wild species collection con- tains over 1,450 taxonomically classified accessions, with about 200 yet to be clas- sified. CIP's sweet potato collection, already the world's largest, is expanding rapidly: 13 sweet potato collecting expeditions gathered 620 accessions from 240 sites worldwide in 1988. This collection now holds 4,326 cultivated accessions and 1,160 wild accessions. Introduction of clonal accessions to in vitro culture is progressing well, as is the evaluation of agronomic and nutritional charac- teristics. In biosystematic research on the potato, we are emphasizing the use of the endosperm balance number (EBN) to help understand and predict the cros- sability of wild potato species with each other and with cultivated potatoes. This work has included analysis of several wild Peruvian coastal and highland potato species. In addition to facilitating the more effective use of the species, the EBN data also help explain past failures to cross some species belonging to the same taxonomic series. Utilization studies concentrated on Solanum acaule, a wild species that provides a source of resistance to PLRV, and we now have experiments under way to determine the basis of this resistance. Solanum acaule also has been shown to be a reliable source of resistance to PSTV, and our initial findings suggest 2 that PSTV resistance can be successfully transferred from S. acaule to cultivated genetic populations. These findings are especially important in the worldwide application of TPS technology, because PSTV is transmitted through sexual reproduction. In recent years, CIP has developed a large population of diploid potato clones that have resistances to cyst nematodes, root-knot nematodes, bacterial wilt, early blight, late blight, PVY, and PLRV. We are adding to our comprehensive database to document the parental value of such material for tuber yield. The genetic base of the 2x potato population was broadened by the intro- duction of new wild species that show promise for improving the earliness of the 2n pollen producers. We expect that the diploid clones will play an increasing- ly important role in the overall breeding program. In sweet potato breeding, we have only begun to use the wild Ipomoea species, because of cytological and genetic com- plications with this species. However, wild Ipomoea germ plasm has an array of resistances that are not found in cul- tivated germplasm. The wild germplasm, for example, shows resistance to the sweet potato weevil, an insect that is a major, global constraint on production. In a major cytological discovery, our CIP-based research has demonstrated that wild germplasm, especially that from the taxonomic series Batatas, can be manipulated successfully for use by com- mercial breeding programs. Using this new technology, we have crossed syn- thetic hexaploid plants and 3x clones (that produce 2n pollen) with sweet potato cultivars, and some of these cros- ses have produced plump seed. These seed represent 6x hybrids that contain three genomes from the cultivated sweet potato and three genomes from the wild species, Ipomoea trifida. We are now evaluating these hybrids in the field. Genetic engineering experiments using DNA constructs have opened up new possibilities for development of genetic resistance to bacterial-wilt dis- ease caused by Pseudomonas solanacear- um. We transformed several potato clones that are normally susceptible to bacterial-wilt disease, using Agrobac- terium tumefaciens carrying DNA se- quences that code for the production of the highly bactericidal compounds, cecropin and attacin. Some promising plants, obtained from susceptible mother plants, have survived soil inoculation that would normally cause wilt. Tests are under way to determine whether these plants have been definitely transformed. This approach has an advantage over conventional methods because the resis- tance obtained is more likely to be useful against most, if not all, strains of Pseudo- monas solanacearum. We obtained the DNA constructs through a CIP contract with Louisiana State University. In developing potato populations for widespread use in tropical regions, re- search continued to focus on technology that would allow resistances or toleran- ces to pest diseases and stresses to be combined with attributes for high yield, good tuber characteristics, and process- ing quality. Selection emphasized the general combining ability of the progenitors. In Peru and· Brazil, advancements in- cluded selection of high-yielding, early- maturing clones with heat tolerance, immunity to PVY and PYX, and resis- tance to late blight. In addition, clones were identified that have resistance to PLRY, immunity to PVY and PYX, high dry-matter content, and excellent processing quality for potato chips and french fries. Other advances included the sys- tematic introduction of combined im- munities to PYY and PYX into populations oriented to either variety selection or use of TPS for seed and ware potato production. To widen the genetic base of resistant materials, we have intro- duced PVY- and PYX-immune clones through contracts with Cornell Univer- sity (New York, USA) and the Agricul- tural University (Wageningen, The Netherlands). In genetic studies of a lowland tropical potato population with early blight resis- tance, our findings suggest that several important traits can be combined suc- cessfully. Attributes of this population include resistance to bacterial wilt and to early and late blight, immunity to PVY and PYX, earliness, heat tolerance, and good agronomic traits. The heritability estimates confirmed earlier findings and helped explain our rapid progress in combining early blight resistance with at- tributes for earliness. Other genetic 3 studies of potato processing quality indi- cate good potential for selection based on attributes such as tuber yield, specific gravity, and reducing-sugar content. Programs for germplasm evaluation and selection of superior clones are now under way in Brazil, Uruguay, Tunisia, Cameroon, Bangladesh, the Philippines, and Vietnam. We have distributed a potato population carrying a combina- tion of several resistances, tolerances, and other attributes to CIP regions and national programs in 56 developing countries and 14 developed countries. Integrated Control of Diseases and Pests Latent infection is a major problem in controlling bacterial wilt disease. In 1988, we identified two high-yielding clones that are highly resistant to bacterial wilt infection and latent infection within the tetraploid material. These clones are being considered for incorporation into CIP's pathogen-tested collection, and also are being evaluated for their paren- tal values. In contract research with the Univer- sity of Wisconsin, we are identifying stable new sources of resistance to bac- terial wilt disease. The highest levels of resistance to three different strains of Pseudomonas solanacearum (including a highly virulent Mexican strain) were found in accessions of S. acaule, S. com- mersonii, and S. demissum. We are now using these accessions as sources of resis- tance in protoplast fusion experiments with S. tuberosum for incorporation into agronomically acceptable genotypes. Seven clones from the pathogen- tested list were found to be resistant to Verticillium wilt and five were rated as resistant to powdery scab. We are following up on some of our earlier research that identified multi-fac- torial components in potato resistance to PLRV, by examining antibiosis and an- tixenosis as components of resistance to aphid vectors. This technology makes use of an electronic feeding monitor to ex- amine clones from CIP's pathogen- tested list. Several clones showed antixenosis; however, antibiosis was not 4 detected, except in S. neocardinasii. These data are vitally important to the further development of tropical potato genotypes with high resistance to PLRV. In studies ·of the variability of PLRV, in collaboration with the Scottish Crops Research Institute in Great Britain, we identified serologically different isolates of PLR V that might require the develop- ment of strain-specific antiserum for routine detection of PLRV on a global scale. We are now analyzing the sig- nificance of this data with respect to stability of resistance to PLR V. Our genetic studies on resistance to PVY using subspecies andigena and S. stolonifemm show that two non-allelic genes ar~ involved in resistance. The results also showed that environmental conditions modified the expression of the gene for hypersensitivity. These findings provide a better understanding of the deviations from expected ratios that were found in screening for resistance to PVY: The information will also help to improve inheritance of PVY immunity at the diploid level. ELISA tests were used to examine the variability of PYX and PYY and to monitor the stability of resistance in germplasm being evaluated in the regions. Our data reveal no problems re- lated to variability in PVY strains that are found in North, Central, and South America, and in Bangladesh, China, Europe, and Africa. PYX isolates detected in different parts of the world were classified into four serogroups and two serotypes. Serotype PYXo was found in North, Central, and South America, and in Europe, Bangladesh, and India. The PYXA type was detected only in Peru and Bolivia, occurring mainly in the Lake Titicaca plateau. Fortunately, the strain PYXHB that breaks the immunity to PYX found in potato is included in the highly localized PYXA type. The stability of immunity to PYX appears to be estab- lished, unless PYXHB is dispersed from its local area. We have found that NCM ELISA is slightly more sensitive and less suscep- tible to background reactions than is DAS ELISA. The NCM ELISA kits are also easier to prepare and to transport, and the technique can be used for detec- tion of PYX, PYY, PYS, P.VT, APL Y, and APMY. The proven practical useful- ness ofNCM ELISA tests has stimulated the production of test kits and protocol manuals that are now being tested under field conditions in selected CIP Regions. We have introduced and tested the NCM ELISA technique in China, for ex- ample, in a joint project with Inner Mon- golia University. This technique may replace DAS ELISA, which is routinely used by national programs to detect potato viruses in the main cultivars and for quality control of seed potatoes. Because some polyclonal or mono- clonal antibodies for virus detection are difficult to produce, we are developing a simple, rapid, and less-expensive proce- dure that uses a selected antiserum to multiply idiotypic antibodies that are virus-specific. In this approach, rabbits are injected with selected idiotypic an- tibodies. The resultant antibodies (an- tiidiotypic) are used to reproduce the idiotypic antibodies ( anti-antiidiotypic ); We have used similar methodology suc- cessfully in production of anti-anti- monoclonal antibodies for detection of PLRY. We are also developing virus-specific nucleic acid probes to search for more sensitive and efficient methods of virus detection. New probes have now been developed for detection of the potato viruses PYX, PYY, PLRY, and APLY, and the sweet potato virus SPFMY. In sweet potato research, we are con- tinuing intensive work to identify sweet potato viruses. Four sweet potato viruses that had not been described previously are being identified and fully charac- terized. SPFMY isolates that showed minimum serological variation were found to differ substantially in some char- acter is ti cs, such as infectivity and symptom production. Collaborating with the Yolcani Cen- ter, Israel, we began a search in CIP's germplasm collection for accessions with immunity: Of a total of 1,641 accessions, 30 were shown to be resistant, even after grafting to infected sweet potato scions. Some of the more resistant accessions may carry genes for immunity, and we are using aphids and grafting techniques to reinoculate these accessions. 5 In selections for good agronomic characteristics in combination with resis- tance to the cyst nematode ( Globodera pallida ), yields of many selected clones exceeded those of local check cultivars, and some clones also showed resistances to late blight and viruses. We sent ad- vanced clones to the National Potato Re- search Program of Peru, and tuber families were delivered to Ecuador, Colombia, Panama, and Pakistan to in- itiate selection cycles. Wild and cultivated diploid potatoes and pathogen-tested clones were screened for resistance to the root-knot nematode Meloidogyne incognita. Tests also were performed on TPS materials, and useful levels of resistance were iden- tified in both types. We identified clones with high levels of resistance to root-knot nematode within cultivated sweet potato germplasm collected from Peru. Inter- estingly, the largest number of highly resistant clones came from the Depart- ment of Lima, indicating the effective- ness of selection pressures applied by farmers in their sweet potato cultivation practices. 6 Potato clones were selected that showed high levels of resistance to the potato tuber moth under storage condi- tions. The clones included tetraploids, diploids, and pathogen-tested genotypes. In Colombia, potato families with S. berthaultii ancestors were tested for adaptation and for resistance to potato tuber moth. The promising results ob- tained are probably due to glandular trichomes on the foliage of these materials. Excellent levels of control were ob- tained by use of granulosis virus formula- tions against potato tuber moth under field and storage conditions in Peru. A parasitoid, Copidosoma desantisi, was in- troduced from Peru to several areas in Colombia, and substantial parasitism was recorded. In studies of sex pheromones, we have focused on methods that can lower costs of formulations and some of the findings suggest good economic potential. To provide guidance in control measures, pheromone traps were used to study the seasonal counts of the potato tuber moth in Ethiopia and Burundi. In Egypt, sev- eral studies examined the control of potato tuber moth in stores and evaluated the degree of susceptibility to this pest in commercial cultivars and other genotypes. Integrated control measures included use of insecticides, granulosis virus, Bacillus thuringiensis, as well as wire-screened stores, light traps, pheromone traps, and Lantana camara. Several combinations of control methods provided excellent protection. Production and Postharvest Technology The role of nitrogen fertilization in adap- tation of the potato to the warm tropics was examined in a series of experiments that we completed in Peru in 1988. Clone LT-7 was the top-yielding entry, showing a greater ability to utilize nitrogen fer- tilizer, with less reduction in partitioning of dry matter to tubers at high nitrogen levels. As part of an increasing effort to de- velop potatoes for production under hot, arid conditions, studies were made of methodologies to identify drought- tolerant parental material. Findings indi- cated that tuber yield of potato under drought stress is related to the force re- quired to pull plants out of the soil. We are further developing this methodology, along with complementary measurement approaches related to root growth, leaf- water potential, stomatal conductance, and leaf appearance. Drought studies of storage-root yield of sweet potato showed a lack of interac- tion between clones and irrigation treat- ments. This finding suggests that selection for vigor and high yield under suitable irrigation conditions could facilitate simultaneous selection of clones able to yield well under drought conditions. A range of potato cultivars, breeding lines, and species was subjected to periods of heat stress in controlled growth chambers at the Nova Scotia Agriculture College, Canada. The ex- periment made substantial progress in determining the genetic and physiologi- cal basis of heat tolerance. For relay cropping or intercropping potato with annual or perennial crops, CIP has advocated a system that features avoidance of competition for solar ir- radiance. However, in analyzing inter- cropping combinations with potato, we have found that some shade tolerance may be desirable. At Nova Scotia Agriculture College, potato clones and species were screened for shade tolerance, and related work explored physiological parameters associated ~th shade tolerance. We are now assessing the importance of interactions between levels of irradiance and growth tempera- tures, as compared with the effects on growth and photosynthesis. Collaboration with national programs to analyze field performance of relay cropping and intercropping systems is yielding results that now are being trans- fered to farmers' fields. For example, in 7 Egypt, relay cropping of potato into an existing maize crop is an experimental practice gaining favor among farmers who wish to plant in the hot-season period before the traditional planting date. Higher maize crop ,yields are an additional benefit from this relay system. CIP contract research on intercrop- ping continues at the Southern China Potato Research Center at Enshi, Hubei Province. This work demonstrated the yield advantage of alternating double potato rows with double rows of maize, a practice that was particularly effective at higher altitudes. Other cropping patterns are being analyzed for use at different elevations. At the Yunnan Academy of Agricul- tural Science, CIP contract research has examined the benefits of strip-cropping of maize and potato, on factors in addi- tion to yield, such as incidence of soil- borne diseases and the reduction of water, soil, and nutrient losses on sloping soils. Intercropping, and contour plow- ing (instead of surface tilling) proved to be effective in reducing runoff from slop- ing fields. In western Hubei, China, two clones (bred in China) were selected that are well adapted to intercropping with maize. The Bangladesh Agriculture Re- search Institute and the Sugarcane Training and Research Institute, Bangladesh are also working with CIP under contract to collect additional data on the technical and economic feasibility of intercropping potato with sugarcane. In these studies, cane yields were not reduced when the traditional single-row system for planting sugarcane was changed to a double-row system in which more space was available for the potato intercrop. However, sugarcane bene- fitted from residual effects of potassium 8 and phosphorus, as well as from nitrogen applied to, but not used by, the potato crop. Other intercropping studies are under way in Burundi, the Philippine lowlands, and Indonesia. The combined findings suggest that continued work on genetic improvement of potato for use in intercropping- fully complemented by agronomic and physiological studies - will likely yield substantial payoffs at many tropical loca- tions. fa related efforts, participants from eight Asian countries attended a work- shop held in China to discuss the status and future priorities of agronomic re- search that can establish potato as a major crop in hot climates. The needs cited included improved cultivars and development of appropriate methods for managing planting material. Agronomic research priorities included studies on production under suboptimal conditions, including drought. In collaboration with the national potato program in southern Chile, non- Andean populations were developed for frost tolerance in combination with earli- ness and immunity to viruses X and Y. Advanced selections were made with high yield potentials and high specific gravities. In the research to adapt the cool-environment potato population to long-day environments, yields as much as 35% higher were obtained. We selected several outstanding clones with resistance to frost and late blight in collaborative work with the na- tional potato program of Peru, and some clones show promise as varieties. A second recombination cycle is under way to increase the frequency of genes for horizontal resistance to late blight from using sources of resistance free of R genes (Population B). Our preliminary assessments of heritability suggest that rapid progress can be made and that some selected seedlings now have high levels of horizontal resistance. Studies of potato storage technology concentrated on storage of consumer potatoes in warm-dry and warm-humid conditions. Methods to control posthar- vest losses were studied in storage experi- ments in Peru, Kenya, India, Pakistan, Thailand, and the Philippines. Special study interests included storage pests and diseases, water loss, and sprouting. Our research is stressing use of in- tegrated storage methodologies that are appropriate to local conditions. For ex- ample, in cooperative work with the Hor- ticulture Research Institute and the Agriculture Engineering Division of the Department of Agriculture in Thailand, a farmer survey identified specific post- h ar vest problems in the northern lowlands. On average, about half of the potato growers reported yields of less than four tons of potatoes per farm. The potatoes are commonly stored for up to three months in heaps covered with straw or dry grass. Potato tuber moth was the most important storage problem. The survey showed that 75% of the farmers would choose to improve their present storage systems, if the required invest- ment cost would not exceed $13 per ton of potatoes. Based on these needs assess- ments, on-farm research tests were made to improve storage methods. Bamboo storage boxes lined with rice husks were assembled and then filled with tubers and covered with the rice husks for protection against the potato tuber moth. The boxes reduced total tuber weight loss and af- forded complete protection against potato tuber moth damage. During the storage period, potato prices increased by 50%. The returns on the capital invest- ment (storage structure and potatoes) were negative for the control and plus 27% for the boxes. This study illustrates the approach that CIP and collaborators will be establishing in the warm tropics. In Peru, our potato-processing ac- tivities concentrated on transfer of processing technology and related train- ing. Several small processing units are under construction in the highlands of Peru, with technical support from CIP. We are also providing technical support for the processing work of Centro Ideas, whose processing plant at Huancayo is using the technology developed at CIP's pilot plant. The Huancayo plant is now processing several Andean root and tuber crops and operates throughout the year. Products are dehydrated using a combination of solar and artificial drying. CIP, in cooperation with ENEA, Italy, has begun designing solar dryers equipped with additional artificial drying systems, in response to a need for low- cost drying systems that are more effi- cient than solar drying alone. We are testing these systems at CIP's experiment station in Huancayo. In Thailand, evaluation of clones for processing quality has been a high priority in collaborative work with the Agricultural Chemistry Division of the Department of Agriculture. All ad- vanced clones are now routinely tested for processing quality and for domestic cooking quality. In cooperation with Kasetsart Univer- sity, Bangkok and with the Horticulture Research Institute, CIP completed a study on the demand for potatoes and potato products in Bangkok. About one- third of the total potato production there is consumed as processed products. The study predicted an increase in demand for consumer potatoes, and recommen- 9 dations were made for the establishment of production and postharvest programs that will gradually reduce potato retail prices (a major limiting factor for potato consumption) while increasing quality of consumer potatoes. We have found these studies especially valuable in helping to identify leverage points for improvement in the food system, and we are promoting further studies involving scientists within NARS. The International TPS progeny evaluation trials continue to produce new high-performing progenies and this work is being greatly facilitated by our high- volume production unit in Lima. In 1988, 35 new hybrid combinations were distributed to countries participating in the international trials. Studies continued on TPS germina- tion and early seedling emergence responses, as well as on parental effects on rooting capacity and early field estab- lishment of potato seedlings. Factors such as location, seed maturity and sup- plemental nitrogen were shown to be im- portant in effective selection of more vigorous TPS crosses during early seed- ling emergence and development. It was also shown that high levels of supplemen- tal nitrogen during seed production and proper seed development at harvest are essential for enhancing seed vigor and for preserving vigor during long-term storage. The performance of planting mate- rials from comparable genetic back- grounds was evaluated for effects of tuber origin, single sprout seedling tubers, stem cuttings, and apical cuttings. The results suggested that differences in tuber number and size distribution were more clearly related to the physiological origins of the plant materials than to dif- ferences in their genetic backgrounds. 10 To help sweet potato breeders plan effective crossing blocks, studies were made of flowering induction. Accessions from CIP's sweet potato germplasm col- lection were grouped into three catego- ries, high, moderate, and low, to indicate flowering capacity. Only 3% of the acces- sions were rated as high capacity, 88% were moderate, and 9% were low. A case study of the seed potato system in Ecuador was completed as part of the series designed to identify strengths and weaknesses of seed systems. The series includes similar reports on the Philip- pines (CIP Annual Report, 1988), Kenya (in progress), and a combined report on Canada, the Netherlands, and the United Kingdom (CIP Annual Review, 1988). In Ecuador, the findings indicated that in- stitutional and coordination problems, rather than technical problems, are limit- ing the effectiveness of the seed program. Training in seed production con- tinued in South America, Africa, and Asia. An international seed production course organized by CIP-UNA in Lima, Peru, was attended by participants from 10 South American countries. In other training activities in Peru, more than 40 scientists from around the world visited CIP-Lima to gain practical experience with in vitro and rapid multiplication techniques. Huancayo had 30 visiting scientists from outside Peru, who were involved in seed production technology, seed program development, and on-farm research. A formal seed production course was held at Cuzco for 68 Peruvian scientists, workshops on basic seed dis- tribution were held in Cuzco and Huan- cayo, and a short course on basic seed production was held in Lima. A seed production course in Rwanda focused on TPS as an alternative to traditional seed schemes. In Bangladesh, 99 participants .. ! attended a course at BARI on use ofTPS transplants, seedling tubers and tuber- lets. In Santa Lucia (the Philippines), trainees from the Philippines, Vietnam, and Bhutan studied innovative, low-cost Food Systems Research A survey of National Program Leaders indicated that the principal constraints to production and use of potatoes and sweet potatoes are found in the postharvest phase of the food system. Marketing work emphasized the im- portance of backstopping studies con- ducted by NARS scientists. Surveys of National Leaders indicated that CIP had contributed significantly to national pro- gram capacity for training, seed produc- tion, storage, and breeding. Benefits at the farm level had been achieved prin- cipally through improvement in seed quality, and also through the supply of better varieties. Studies in Kenya and Peru revealed that farmers' criteria for evaluating new potato varieties often cliff er sharply from the criteria used by breeders and agronomists. Future Challenges The above findings reflect substantial progress in both potato research and in the relatively new area of sweet potato research. We must now meet the chal- lenge of more precisely assessing the im- pact of CIP work on NARS and on the farmers they serve. We are seeking a deeper and clearer understanding of where our research fits within the priorities of both the national programs and the farm families in developing countries. We are finding that adoption and local adaptation of the new varieties and technologies are difficult to quantify because this kind of data is seldom appropriate technology on rapid propagation techniques for TPS. In China, farmers and scientists worked together in a course to demonstrate new seed technologies. Farmers generally look for varieties that meet several minimum criteria rather than varieties that fulfill only one or a few criteria. An on-farm research study in Indonesia provided a mechanism for farmers to contribute directly to the development of TPS technology. reflected in official statistics. In countries where surveys have been made or where official statistics have been available, CIP's impact has been clearly illustrated in seed scheme improvement and in several other areas. More complete in- formation is needed, however, and we are exploring new methodologies for impact assessment, with the NARS expected to play a large role in the process. We an- ticipate enormous benefits from this col- laborative feedback process, which is designed to evaluate our progress and to focus on how to better serve the NARS. 11 12 Thrust I Collection, Maintenance, and Utilization of Unexploited Genetic Resources Thrust Profile: 1989 In biosystematic research, the Endosperm Balance Number (EBN) was determined for several wild Peruvian coastal and highland species. An EBN provides a measure for predicting the crossability of these wild species with each other and with cultivated potatoes. The Peruvian coastal potato species S. mochicense was found to be an ideal test species for determining the EBN of wild South American potato species. U tiliza- tion studies concentrated on identifying resistance to PLR V and to PSTV in the wild species S. acaule. Low frequencies of usable resistance to both pathogens were identified, and studies are under way to investigate the genetic basis of these resistan- ces and their utilization in breeding. The W arid Potato Collection received a total of 156 new accessions from Guatemala, Mexico and Ecuador, areas which are not yet well represented in the collection. Duplicate accessions continued to be identified and were eliminated from clonal maintenance after sufficient true seeds for long-term storage were obtained from these accessions. The transfer of the World Potato Collection to in vitro culture is virtually complete, with 3,340 accessions maintained in vitro. Tests on CIP's clonal potato collection indicated that it is free of PSTV. A population of diploid potato clones with useful traits was evaluated for its breeding value, and new wild species accessions have entered this diploid breeding program. CIP's first set of clonal transformation experiments for resistance to bacterial diseases usingAgrobacterium tumefaciens as vector, yielded positive preliminary results. In 1988, 13 sweet potato collecting expeditions gathered a total of 620 accessions in 240 localities. About 2,000 cultivated sweet potato accessions from Peru were field- evaluated in 1988, and evaluation of agronomic and nutritional characteristics con- tinues. The introduction of clonal accessions to in vitro culture is now a routine procedure. Following approximately 35,000 controlled pollinations, cytogenetic re- search yielded a series of unexpected positive results that will permit the utilization of some wild Ipomoea species in breeding. CIP scientists selecting potato culti vars. 13 Biosystematic Studies of Potatoes In 1988, biosystematic research studies focused on determining the EBN of several Peruvian coastal and highland species. The EBN concept has been de- veloped in the last decade and is extreme- ly useful in understanding and predicting the crossability of wild potato species with each other and with cultivated potatoes. The evolutionary origin that ac- counts for the EBN is not yet completely understood. Results have shown, how- ever, that the EBN is an indicator for an effective biological isolation mechanism that enables a species to maintain its specific integrity after it has colonized ecological niches within hostile ynviron- ments. This concept has led to research that makes it possible to determine the EBN of coastal Peruvian species found in a hostile desert environment. In these studies, hundreds of crosses were made between diploid coastal and highland species from the taxonomic series Conicibaccata and Tuberosa. Two species were each found to have an EBN of 2: S. chomatophilum from series Con- icibaccata, an Andean species with resis- tance to Phytophthora infestans and to frost; and S. bukasovii, an Andean spe- cies from series Tuberosa with resistance to Globodera pallida and to frost. The identical EBN of the two species indi- cated that they should easily cross, and crosses between these two species were Utilization Studies in Potatoes Screening of accessions of the wild species S. acaule was continued to deter- mine resistance to PLRV and to PSTV. In tests for resistance to PLR V, the ac- cessions of S. acaule to be screened were infested with PLR V-carrying green peach aphids, the natural vector of this virus. In the first tests of resistance levels 14 made without difficulty, although they belong to different taxonomic series. Identification of the EBN of wild po- tato species will allow utilization of these species in more predictable and effective ways. The two diploid coastal species from series Tuberosa, S. wittmackii and S. medians, were found to be reproduc- tively isolated from each other. S. wit- tmackii was found to have an EBN of 1, whereas S. medians had an EBN of 2, thus, this difference accounts for the failure of past attempts to cross these two species. Such biological isolation would be necessary in the harsh coastal environ- ments in which hybridization would quickly erode any specialized advantage the different species might have had in coastal ecological niches. The diploid Peruvian coastal species S. mochicense from the taxonomic series Tuberosa has been shown to be an excel- lent test species for determining the EBN of other species, because it has an EBN of 1 and because it flowers abundantly under both short- and long-day condi- tions. With S. mochicense serving as tester, 11 species were found or con- firmed to have an EBN of 2. Two other species with an EBN of 1 have also served as test species: S. chacoense and S. com- mersonii, which belong to the series Commersoniana, from eastern South America. to PLR V within this population, levels varied from 0% to 100% per accession. Of the 61 accessions tested, 13.1% were highly resistant, 26.2% moderately resis- tant, and 60.7% were susceptible. An ad- ditional series of tests identified four genotypes that are apparently resistant to the replication of the virus, and five genotypes with resistance to the green peach aphid. These nine resistant genotypes represent a low percentage (0.54%) of the tested population. How- ever, this wild species has now been posi- tively identified as an additional source of resistance to PLRV, and studies are under way to determine the genetic basis of this resistance. The same population was tested for resistance to PSTV, and 9.7% of the tested accessions were found to be highly resistant, 18% moderately resistant, and 72% susceptible. These percentages in- dicate that genes for resistance to PSTV are fairly widespread in populations of S. acaule, although at a relatively low level. Resistance to PSTV was determined successfully by mechanical inoculation and by the much more severe test of in- oculation with transformed strains of Agrobacterium tumefaciens carrying either a monomer or a dimer full-length PSTV-cDNA insert in their genomes. The most severe screening tests for PSTV are graft inoculation and inocula- tion with a transformed strain of A. tumefaciens carrying a trimer full-length PSTV-cDNA insert in its genome. These more severe tests broke the resistance of all the genotypes that had previously withstood infection by tests using mechanical inoculation or inoculation with A. tumef aciens carrying a monomer or a dimer full-length PSTV-cDNA in- sert. Graft testing and challenges with transformed strains of A. tumefaciens, which do not occur in nature, were made to study the resistance mechanisms that protect S. acaule from PSTV. Mechani- cal transmission is the only mechanism of A dyad found in a 3X plant, demonstrating 2n pollen production in the plant. 15 transmission known in nature, and ample useful resistance to such transmission has been clearly identified. Tests were also made of the effect of temperature on the infectivity of two PSTV-carrying strains of A. tumefaciens. Eight genotypes of S. acaule, which ap- parently were resistant when challenged at W° C, showed no resistance at 30° C. This finding suggest~ that temperature influences infection, translocation, and replication of the pathogen. This might be one explanation for the absence of PSTV in the high Andes, where tempera- tures never reach 30° C. Transfer of the identified resistances to cultivated material and studies of the Potato Gennplasm Collection Collecting Activities The World Potato Collection received new accessions from areas that had not been well represented. Thirty-two new accessions were collected in collabora- tion with ICT A, the national agricultural research organization in Guatemala. Another 51 native accessions were col- lected in Mexico in collaboration with INIF AP, the national agricultural re- search organization of that country. A donation of 73 accessions was received from INIAP, the national agricultural re- search institute of Ecuador, as a part of an ongoing project of collection and col- laboration between IB~GR and CIP. Elimination of Duplicates A total of 250 new duplicate accessions that were found to be morphologically and electrophoretically identical to other Andean potato cultivars in CIP's collec- tion have now been included in the group of clones to be converted to TPS. A total of '387 previously identified duplicate ac- cessions have produced sufficient TPS for long-term storage, thus this group has 16 genetic basis of the resistances are now under way, and first indications are that resistance to PSTV can be successfully transferred from S. acaule to cultivated genetic populations. S. acau/e is the only known species with resistance to PSTV, and the utilization of S. acaule in breed- ing is well understood, although the use of bridging species and various steps of ploidy manipulation are involved. Reli- able sources of resistance to PSTV will become especially important in the worldwide application of TPS technol- ogy, because this viroid is also trans- mitted through sexual reproduction, which normally eliminates most kinds of viruses. now been eliminated from clonal main- tenance. In recent years, 671 accessions that were received as donations or collected have been found to be morphologically identical to 280 cultivars already main- tained in the collection. After their dupli- cate status has been electrophoreticaliy confirmed, and after obtaining a suffi- cient amount of TPS for long-term storage, these duplicates will be elimi- nated from clonal maintenance. Data on plant and floral characters of 651 accessions were obtained from Ar- gentina, enabling CIP workers to refine the groupings made the previous year on the basis of tuber characters. Electro- phoretic analysis of '383 of these acces- sions indicated that they represented only W different cultivars. More than 4,219 cultivated potato ac- cessions are now clonally maintained at CIP. The wild species collection contains a total of 1,450 taxonomically classified accessions and about 200 accessions yet to be classified. In Vitro Collection of Germplasm The transfer of the World Potato Collec- tion to in vitro culture is nearing comple- tion, with 3,340 accessions now maintained in vitro. In accordance with CIP's own security procedures and IBPGR guidelines, the in vitro collection is being duplicated outside Peru, and over half of the collection has now been duplicated in vitro in Ecuador. By April of 1989, the complete in vitro collection will have been duplicated in Ecuador, under an agreement with INIAP. INIAP recently received funds from the Andean Development Corporation (CAF) to build cold-storage facilities for the col- lection. With these facilities, CIP will not need to renew the collections so fre- quently. Since these renewals are still done in Lima, they require frequent cost- ly shipments of in vitro material from Lima to Ecuador. PSTV Monitoring of the Collection PSTV tests were made on 3,398 acces- sions maintained in the field and on 1,020 accessions maintained in vitro. None of the accessions tested with the NASH test showed any infection with PSTV, indicat- ing that CIP's clonally-maintained potato collection is free of PSTV. Distribution of Potato Germplasm Pathogen-tested Andean cultivars from the World Potato Collection were dis- tributed to 12 countries in the form of 778 tubers, 748 in vitro plantlets, 150 in vitro tubers and 1,650 seeds. Potato Gennplasm Enhancement Diploid Germplasm At Huancayo, 445 2x potato clones were evaluated for pollen stainability, 2n pol- len production, tuber traits, and specific gravity. The genetic background of these clones included haploids from S. tube- rosum, ssp. tuberosum and ssp. andigena; diploid cultivated species; and the wild species S. stolonifernm, S. chacoense, S. sparsipilum, S. microdontum, and S. ver- nei. A total of 119 clones was selected, based on 2n pollen production and known resistances to cyst nematodes, root-knot nematodes, bacterial wilt, early blight, late blight, PVY, and PLRV. In- formation from this selection and related data are being used to develop a database on parental value for tuber yield. New accessions of the wild species S. benhaultii, S. bukasovii, S. canasense, S. chacoense, S. microdontum and S. tari- jense were introduced into the diploid breeding program and were screened for 2n pollen production. Of these, 21 genotypes were found to produce 2n pol- len: 16 from S. berlhaultii, 1 from S. bukasovii, 1 from S. chacoense, and 3 from S. tarijense. Hybrids obtained from crosses of early-maturing haploids with selected wild accessions also were check- ed for 2n pollen production. Of these hybrids, 1,168 genotypes were tested, and 174 produced 2n pollen. At harvest, 34 clones were selected for 2n pollen production and superior tuber traits. This new material will help to widen the genetic base of CIP's 2x potato popula- tion and to improve earliness of the 2n pollen producers. At San Ramon, yield trials were con- ducted during the dry and rainy seasons to evaluate the parental value of the 2x progenitors for 4x x 2x crosses. In these trials, 20 of the 4x x 2x crosses yielded better than did the best 4x x 4x check (an Atzimba x Katahdin cross that yielded 17 396 glplant, on average), when harvested 90 days after transplanting during the rainy season. The best-yielding family was 78.13.13F2 x 84.101.1, which yielded almost 700 glplant. Two families, ND 860.2 x P-127.3 (which yielded · 532 glplant) and Atlantic x P-127.3 (which yielded 516 glplant) had a higher degree of tuber uniformity and vine earliness than did the 4x x 4x check. This research on 2n gametes and ploidy manipulation is undertaken to take advantage of the relative ease with which genetic characters can be com- bined at the diploid level in comparison to recombinations at the tetraploid level. This type of diploid breeding program permits the ready utilization in modern plant breeding of the vast genepool of diploid wild potato species. Diploid genotypes that are found to be of supe- rior parental value will be freed of virus and pathogen-tested as soon as possible. They will then be made available to breeding programs at CIP centers and national breeding programs around the world. The results obtained in 1988 clearly indicate that steady progress has been made over the past decade in this area of long-term research. Many TPS families from the 4x x 2x material with a series of known resistan- ces have already been widely distributed to CIP researchers for tests in San Ramon, Huancayo, Burundi, Kenya, India, Indonesia, and the Philippines. Protoplast Culture and Fusion A special project on asymmetric proto- plast fusion for the transfer of cytoplas- mic male sterility (CMS), funded by the Agency for International Development (AID), was completed at the Weizmann Institute of Science in Israel, and the first set of material has been passed on to CIP scientists for field evaluation. 18 Genetic Engineering Preliminary results on CIP's first set of clonal-transformation tests for resistance to bacterial diseases were obtained in 1988 using constructs of Agrobacterium tumefaciens. These constructs, which were obtained through a research con- tract with Louisiana State University, have DNA sequences that code for the production of the highly bactericidal compounds cecropin and attacin in their genomes. Several potato clones that are normally highly susceptible to the bac- terial wilt caused by Pseudomonas solanacearnm, were used in these trans- formation experiments. In addition to the code for bacterial resistance, a sequence coding for resis- tance to the antibiotic kanamycin was also incorporated into theAgrobacterium genome. If transferred into the potato genome, plantlets regenerated from a co- cul ture of Agrobacterium tumefaciens with potato cells should exhibit resis- tance to kanamycin, in media containing this antibiotic. The first selections for kanamycin resistance were made, and then the resistant material was multiplied and tested for resistance to the bacterial- wilt pathogen under strictly controlled laboratory conditions. Some promising plants obtained from susceptible mother plants have survived heavy soil inocula- tion that normally would cause wilt in the mother plants. Further tests are being made to determine whether these sur- vivors are truly transformed. Louisiana State University has sup- plied 55 new constructs, all coding for resistance to bacterial diseases, which will be incorporated into potato clones, singly or in combination, to study the transformed genotypes' potential resis- tance against bacterial diseases. Because sweet potato crops in China have been observed to be affected by bacterial wilt, transformation work on sweet potatoes has been initiated using Sweet Potato Genetic Resources Sweet Potato Germplasm Collection Collecting activities and taxonomic identification. During 1988, 13 expedi- tions were made: nine inside Peru, and one each in Argentina, Bolivia, Paraguay, and Jamaica. A total of 620 accessions were collected in 240 different localities. Of these 620 accessions, 490 belong to Ipomoea batatas, the cultivated sweet potato. Other Ipomoea species were identified in the remaining 130 acces- sions. These accessions were taxonomi- cally identified by Dr. F. Austin of the University of Florida at Boca Raton. In this classification, 33 accessions were found to belong to six species of the sec- tion Batatas - the taxonomic section of the cultivated sweet potato. Of these 33 accessions, 31 were found to belong to five known species of section Batatas, and two accessions were identified as I. umbraticola, a species new to section Batatas. Some accessions were found to belong to species that are not included in section Batatas, and one of these is new to science. Several others in this group of 29 accessions, although known species, had never before been found in South America (Table 1-1). Articles about these discoveries will be published in the appropriate scientific journals. Sweet potato germplasm donations. Donations of 280 cultivated accessions were received from Argentina, Vene- zuela, Guatemala, and Cuba. These in- cluded 42 accessions from the Argentine collections maintained by INT A at San Pedro and at the University of Tucuman; constructs of Agrobacterium rhizogenes coding for resistance to bacterial dis- eases. Five Chinese sweet potato cul- tivars have been included. 21 accessions from the University of Maracay in Venezuela; 112 accessions from the collection maintained by San Carlos University and ICT A of Gua- temala; and 105 accessions from the col- lection maintained by the National Institute for Research in Tropical Roots and Tubers (INIVIT) at Santo Domingo of Villa Clara in Cuba. With these dona- tions, CIP's sweet potato germplasm col- lection now contains a total of 4,326 cultivated and i,160 wild species acces- sions. Germplasm maintenance. A large- scale experiment was conducted to determine the feasibility of maintaining stem cuttings under slow-growth condi- Table 1-1 . Taxonomic identification and geo- graphic distribution of wild lpomoea species col- lected in 1988. Distribution" Species ARG BOL JAM PAR PER Total Section Batatas /. cordatotriloba 9 0 0 0 0 9 I. grandifolia 0 0 0 0 /. x leucantha 4 0 0 0 0 4 I. ramosissima 0 5 0 0 1 6 I. tiliacea 0 0 11 0 0 11 New species Section Batatas I. umbraticola 0 2 0 0 0 2 Other species 0 2 2 24 29 Undetermined 0 0 2 46 21 68 130 " ARG = Argentina, BOL = Bolivia, JAM = Jamaica, PAR = Paraguay, PER = Peru. 19 tions in the screenhouse. Stem cuttings of approximately 1,000 cultivated acces- sions were maintained for six months in bottles containing water or were planted in peat-moss pots. These basic treat- ments were modified by foliar fertiliza- tion and by pruning the apical shoots after three months. Cuttings maintained in bottles had low percentages of survival, and greater losses were observed in the accessions with thin stems. The cuttings in the peat-moss pots generally had high survival rates. When the surviving stem cuttings were transplanted to the field, those grown in bottles showed a survival rate ranging from 50% to 70%, whereas those grown in peat-moss pots had a survival rate of 80% to 100%. Storage-root yields were about the same for plants obtained from the two treatments and from plants that had been grown from cuttings obtained from field- grown plants. Future maintenance of sweet potato stem cuttings will be done under slow- growth conditions in the screenhouse, using peat-moss pots. Germplasm evaluation and distribu- tion. Data on 7 storage-root characters of approximately 2,000 accessions from Peru have been recorded at harvest, using the descriptor list developed at CIP. Living material from the collection was distributed for use in research projects at CIP, including storage roots from 672 accessions, stem cuttings from 431 accessions, and seeds from 171 ac- cessions. Results of analyses carried out in Peru showed a total carotene content in fresh storage-root samples that ranged from 0.03 mg/100 g to 9.14 mg/100 g fresh weight in 50 accessions that had different fl esh colors. 20 In Vitro Collection of Sweet Potato Germ plasm A successful protocol that avoids the for- mation of callus has been developed for the introduction of clonal accessions into in vitro culture, and this method is now considered routine. Experiments to restrict growth of in vitro plantlets have been conducted in collaboration with the Peruvian National Agrarian University (UNA) at La Molina, and cultures can now be stored for approximately one year without subcultures. More than 1,000 clonal accessions are now maintained in vitro. Material con- tinues to be received from outside Peru as part of an IBPGR-financed project designed to assist national programs in maintaining sweet potato collections in vitro. The Venezuelan International In- stitute of Higher Studies (IDEAS) in Caracas has agreed to maintain a dupli- cate of CIP's sweet potato in vitro collec- tion. Utilization of Sweet Potato Germplasm Ploidy of hybrids between 6x sweet potato cultivars and 2x wild species I. trifida. Utilization of wild Ipomoea species in sweet potato breeding began relatively recently. Cytological and genetic complications connected with the use of wild species in sweet potato breeding have stymied research in this area. Nevertheless, wild Ipomoea germ- plasm has an array of resistances that are not found in cultivated germplasm, par- ticularly to some species of the highly damaging sweet potato weevil, which is found worldwide. The following research results repre- sent a cytological breakthrough in the utilization of wild Ipomoea germplasm, and they demonstrate conclusively that i wild germplasm, particularly from the taxonomic series Batatas, can be success- fully manipulated for eventual use in commercial breeding programs. Preliminary results indicate that, after the wild germplasm has been sufficiently manipulated for use in breeding, its utilization will become relatively easy. More than 22,000 controlled pollina- tions resulted in a total of 730 seeds. Due to the poor germinability of these seeds, only 250 seedlings were transplanted to the field. Counts of chromosome num- bers of 242 plants identified plants with unexpected ploidy levels. As expected, 187 plants were tetraploid. Four of these hybrid plants were found to be pen- taploid, indicating the functioning of 2n pollen of the 2x male parent used in this cross. Forty-one plants were hexaploid, which could be due to incomplete expres- sion of self-incompatibility of three sweet potato female parents, or the result of parthenogenetic development of2n eggs. Two plants had 105 chromosomes,which makes them 7x, and this result probably was due to the fertilization of 2n eggs ( 6x) with normal pollen (x) (Table 1-2). In field studies at Lima and San Ramon, the tetraploid plants are being evaluated for the potential development of tetraploid sweet potato cultivars and for the use of such 4x clones as testers of 2x and 4x wild germplasm. The production of synthetic 6x clones. A total of 812 axillary buds of 120 dif- ferent I. trifida hybrids were treated with a colchicine solution to double the chromosome number. These hybrids had been derived from crosses between 4x and 2x I. triftda accessions. Studies of pollen samples revealed 55 shoots that were producing pollen with a high degree of stainability. Meiosis studies have indi- cated that 23 shoots are true hexaploids (6x), and 32 are triploids (3x) with 2n pollen production. A total of 1,963 controlled pollinations among the plants that produced pollen with a high degree of stainability resulted in 220 seeds. These seeds represent a valuable 6xl. triftda population that com- bines germplasm of many 2x and 4x I. trifida accessions from diffe rent geographic regions. The synthetic hexaploid plants and the 3x clones producing 2~ pollen were crossed with sweet potato cultivars in 7,651 controlled pollinations, and 1,126 plump seeds were obtained. These seeds represent 6x hybrids that contain three genomes from the cultivated sweet potato and three from wild I. trifida. These hybrids will be field-evaluated during 1989. Table 1-2. Number of progenies with different ploidy levels from 6x x 2x crosses of lpomoea species. Ploidy No. of level progenies Possible origin 4x 187 expected hybrids (3x + x) 5x 4 functioning of 2n pollen (3x + 2x) 6x 51 parthenogenesis of 2n eggs (6x) 21 Regional and National Programs Paraguay. A collecting expedition for wild species of Ipomoea batatas was or- ganized in six regions of Paraguay, and 47 accessions were collected and botanical seed harvested. The national program collected 25 distinct varieties, and samples were sent to Lima. Uganda. The Uganda project to im- prove the technological support to sweet potato production has just started, with major activities to begin in 1989. Uganda is the largest producer of sweet potatoes in East Africa, growing an estimated 450,000 ha. Objectives are to collect, classify, and distribute the best of the existing varieties to farmers. Introduc- tions will be made from sources with good characteristics for countrywide evaluation, selection, multiplication, and distribution. The Philippines. Germplasm was col- lected in the Philippines to develop a collection for breeding purposes. The germplasm was collected in the central and northern Philippines, and more than 100 accessions were maintained and evaluated for biotic and abiotic con- straints. Indonesia. Plans were initiated at the request of the Indonesian government to collect sweet potato germplasm in Irian Jaya, which is an important center of genetic diversity. This will be a collabora- tive effort involving the Indonesian government, A VRDC, IBPGR, CIP, and possibly IDRC. China. A total of 209 local sweet potato cultivars was collected in 1988, and total accessions now equal 990. Two surveys of sweet potato distribution and production were made in northeast and southwest China. Woman selling baked sweet potato in a street of Xuzhou, China. 22 >.. " r ~ .:l: . Collection of sweet potato germplasm in a native market in Concepcion, Paraguay. 23 24 Production and Distribution of Advanced Genetic Material Thrust Profile: 1989 Thrust II Attributes for resistances or tolerances to pests, diseases,and stresses were combined with those for yield, tuber characteristics, and processing quality. Some of these attributes are polygenic and others are oligogenic. Progenitors were systematically evaluated and selected for high general-combining-ability effects for the polygenic characters. High-yielding, early-maturing clones with heat tolerance, immunity to PVY and PVX, and resistance to early blight have been selected in Peru and Brazil. Also, clones have been identified with resistance to PLRV, immunity to PVY and PVX, high dry-matter content, and excellent processing quality (potato chips and french fries). The selections of 18 clones duplex at the PVY locus, i.e. (YYyyxx:xx), plus a group of20 new clones simplex at the PVY and PVX locus, i.e. (YyyyXxxx), have facilitated the systematic introduction of these two immunities into the populations oriented to either variety selection or utilization ofTPS for seed and consumer potato production. When intercrossed, the PVY-immune duplex clones produce progeny having 97.2% immune individuals. When these clones are outcrossed to a susceptible clone, the resultant progeny have 83% immune progeny. When the PVY and PVX simplex clones are intercrossed, 56.25% of individuals within their progeny are immune to both viruses. When these clones are outcrossed to a susceptible clone, 25% of the individual progenies are immune to both viruses. To widen the genetic base of the virus-resistant materials, PVY- and PYX-immune clones have been introduced from Thrust II research contracts with Cornell University (New York, USA) and the Agricultural University (Wageningen, Netherlands). PLRV-resistant clones have been introduced from the Instituto Nacional de Tecnologia Agropecuaria (INTA, Balcarce, Argentina). These clones are currently utilized in the breeding program. Two genetic experiments, using a diallel mating design and a NC design I mating design, were conducted at both La Molina and San Ramon to determine parameters of genetic variation for early-blight resistance in a lowland tropical population. This population has attributes that include resistance to bacterial wilt and to early and late blight; immunity to PVY and PVX, earliness, heat tolerance, and good agronomical traits. Average narrow-sense heritability estimates were h2 = 0.50 for yield and h2 = 0.80 for earliness. For early-blfit resistance, an estimate of h2 = 0:80 was ob- tained 55 days after transplanting, h = 0.72 after 65 days, and h2 = 0.77 after 75 days. Farm -level productio n of seedli ngs from TPS in Paraguay 25 These results confirmed similar estimates obtained in previous years and help explain the significant progress made in combining early-blight resistance with earli- ness. An 8 x 8 diallel mating design was utilized to investigate genetic parameters for quantitative variation in processing quality. Narrow-sense heritability estimates of h2 = 0.47, h2 = 0.70, h2 = 0.25, and h2 = 0.41 were obtained for tuber yield, specific gravity, and reducing-sugar content at 10 and 60 days after harvest. These estimates indicated that consistent progress can be expected as a result of selection, particularly if progenitors are chosen by progeny testing. The population carrying a combination of several attributes, including resistance and tolerance, has been widely distributed to CIP regions and national programs in the form of tubers or TPS or both. In 1988, 14 developed countries and 56 developing nations received these materials. Programs of germplasm evaluation and selection of superior clones are in progress in several national programs and in CIP regions in Brazil, Uruguay, Tunisia, Cameroon, Bangladesh, the Philippines, and Vietnam. Potato Population Development Major research objectives were to com- bine resistances to diseases and stresses with good agronomical performance, earliness, and tuber quality. Progenitors were selected for their resistance traits and general combining ability (GCA) for tuber yield, tuber quality, heat tolerance, and earliness. The previous year's selections of 18 PVY-immune duplex genotypes (i.e. YYyyxxxx), as well as a group of 20 new clones -simplex for both PVY and PYX immunities (i.e. YyyyXxxx), facilitated the introduction of these two immunities into advanced populations. These im- munities were combined with existing at- tributes, including resistances. Simplex genotypes for both PVY and PYX im- munities, combined with heat tolerance and earliness (i.e. YyyyXxxx x Yyyy- Xxxx), were mated in a group of200 cros- ses. Future selection within the progenies of these crosses will permit the identifica- tion of genotypes duplex at both loci (i.e. YYyyXXxx). Crosses of the PVY duplex genotypes to the PVY and PYX simplex genotypes will help identify PVY-triplex 26 genotypes (i.e. YYYy) that will produce progenies that are 100% immune to PVY. These new progenitors should be available by early 1990. (Figure 2-1) Hybrids obtained in the 1988 summer- season crossing block at the Huancayo Experiment Station (1,280 combina- tions) combined several attribut es (Table 2-1). All groups in Table 2- l were assembled using mating designs that per- mit a constant monitoring of the parental Table 2-1 . Combination of traits including yield. disease and stress resistances or tolerances. Traits" No. of progenies Increased gene freq . fo r Y + X 169 Yield, Earl. , Y + X 149 Yield , Earl. , LB, Y + X 108 Yield, Earl. , BW, Y + X 50 Yield, Earl. , LB, EB, Y + X 62 Yield , Earl. , LB , BW, PLRV, y + x 65 Total 603 " HT = Heat tolerance, Earl. = Earliness, Y + X = Immunity to PVY and PVX , LB = Late blight, EB = Early blight, BW = Bacterial wilt, PLRV = Potato . leaf ro ll virus. Frequency in % 100 80 60 40 20 0 Year Figure 2-1. Increase in phenotypic frequency for PVX & PVY immunities at the population level. value of the progenitors, and of the rela- tive magnitude of the genetic variability and its components. This information is also important for evaluating the efficien- cy of the breeding methods and for making adjustments. Evaluations and selections of these materials are made at CIP headquarters in Peru, and within CIP regions where regional breeders have been posted. Tables 2-2 and 2-3 show top-perform- ing clones in which traits for heat tolerance and virus resistance and/or im- munity have been combined with medium to early maturity and high yield, with good tuber characteristics. Advanced clones yielding up to 24 t/ha in a growing period of75 days, have been selected in other experiments with similar materials further selected for ear- liness. Genetic experiments at San Ramon, Peru examined parameters of genetic variation in two populations. One experi- ment used a 9 x 9 diallel mating design to combine resistance to bacterial wilt, late blight and early blight; immunity to PVY Table 2-2. Top-performing, heat-tolerant and PVY + PVX-immune clones selected at San Ramon . Summer 1988 (growing period: 90 days) Clone Yield (t/ha) Earliness" (Atlantic x Y84.007).5 39. 3 7 (Y84.007 x Atlantic).4 30.5 7 (LT-8 x 575049).19 24.9 5 (L T-8 x Y84 001 ).9 24.6 7 (LT-8 x C83. 119) .15 23.9 5 "Earli ness: 1 = very late 5 = medium 9 very early Table 2-3. Top-performing , heat-tolerant, PLRV- resistant and PVY + PVX- immune clones grown at La Molina. Summer 1988 (g rowi ng period: 90 days) . Clone Yield (t/ha) Earliness" (Pirola x LT-9) .13 40.3 (Utatlan 69. 1 x 7XY.1 ).9 35.7 (Serrana x 7XY. 1 ).2 35.3 (L T-8 x At lantic).9 24.6 (L T-8 x Katahdin) .7 21 .7 "Earliness : 1 = very late 5 = medium 9 early 5 7 3 7 7 very 27 and PYX, earliness, heat tolerance; and good agronomical traits. The second population was assembled in a North Carolina mating design I (10 male clones each mated to a random sample of 5 females). In both experiments, narrow- sense heritability estimates were high for yield (h2 = .50)and for earliness (h2 = .80). For early-blight resistance, an estimate of h2 = 0.80 was obtained 55 days after planting, h2 = 0.72 after 65 days, and h = 0.77 after 75 days. These medium- to high-heritability estimates have permitted the rapid introduction of early-blight resistance into the early- maturing population adapted to the warm and hot tropics. This population also carries a medium level of resistance to late blight and immunity to PVY and PYX, and has good agronomical traits. These materials also have been success- fully used in other developing countries. (Uruguay, Brazil, and the Philippines). Of 1,437 clones tested for late-blight resistance in the field at Rio Negro, Colombia, 128 were selected at harvest. The same set of 1,437 clones was tested in Toluca, Mexico, and the data are being analyzed. Trials to study the stability of resis- tance to late blight are under way in some CIP regions. However, the selected materials contain major genes in addition to horizontal resistance. In some regions, horizontal resistance may be difficult to assess if compatible races are not present to overcome the resistance of R genes. Results of a trial conducted in Huanuco, Peru are underscoring this problem, showing that the highest-yielding clones, including one of the controls (Atzimba), were not infected by late blight. This in- dicates that the local isolates do not have the complex races to overcome the resis- tance provided by R genes in some clones (including the control Atzimba). How- 28 ever, the local control Revolucion was severely attacked early in the growing season. Research in tropical countries has made substantial progress in developing populations and clones with good processing characteristics for the fast- food industry (french fries and chips). Clones with adequate specific gravity and low reducing-sugar content were selected at both San Ramon and La Molina during the summer season. The yield of these selected clones ranged from 25 t/ha to 30 t/ha. An 8 x 8 diallel mating design, includ- ing reciprocal crosses, permitted the study of quantitative variation for processing characteristics, i.e. specific gravity and reducing-sugar content. In one evaluation at La Molina, narrow- s ens e heritability estimates were h2 =0.47 for tuber yield, h2 =0.70 for specific gravity, and h2 = 0.25 for reduc- ing-sugar content 10 days after harvest. The estimate obtained for reducing- sugar content 60 days after harvest was h2 = 0.41 (storing the tubers at room temperature, ±25° C). These estimates indicate that additive genetic variability is medium to high for all these traits and that selection should provide consistent progress. In the diallel experiment, no recipro- cal effects were found. This suggests that the direction of the hybridization would not alter the mean progeny performance. In addition, among the 8 progenitors uti- lized in this experiment, the CIP clones LT-7 and TS-2 showed an ability to trans- mit to their progenies the traits of high yield, adequate specific gravity, and low reducing-sugar content at 10 and 60 days after harvest. This finding is important because, normally, in hot environments the specific gravity is drastically reduced. In contrast, for example, the variety ~ Table 2-4. Top-selected clon~s for processing attributes from an early-maturing, heat-tolerant and PLRV-, PVY and PVX'-resistant population. Clone DM SG RS Attribute (B-71-240.2 x 7XY.1).026 23.1 1.085 1.66 Chips (Serrana x LT-9) .041 23.5 1.093 2.20 Chips (Serrana x LT-9).052 24.0 1.096 2.33 Chips (Serrana x L T-9).057 20.9 1.084 2.00 French fries (BR-63.15 x 7XY.1 ).102 . 22.9 1.090 1.00 Chips (Bzura x L T-9).105 25.7 1.106 1.66 Chips · (Bzura x L T-9).109 25.8 1.100 2.00 French fries OM = Dry matter SG = Specific gravity RS = Reducing sugars 1 = 0%, 2 = .1°/o, 3 = .25%, 4 = .5%, 5 = 2% or more Less than 3 is adequate. Katahdin from the USA transmitted low yield, low specific gravity and very low reducing sugars. In 1988, a sample of 110 heat-tolerant, early-maturing, PLR V-resistant, and PVY- and PYX-immune clones was evaluated for processing attributes and for french-frying and chipping abilities. These clones had been exposed to virus infection during four seasons. In a field trial at lea (300 km south of Lima), 43 clones were selected as potentially good for processing (Table 2-4). They also had excellent agronomical attributes and virus resistance. A sample of CIP's pathogen-tested clones was evaluated for processing True-Potato-Seed Research Two experiments were conducted at San Ramon and Huancayo to study early growth characteristics: root length, hypocotyl length, length of first inter- no de, and number of internodes. Measures of these characteristics were analyzed with those for reproductive and agronomical traits (obtained during the growing period and at harvest). Multiple correlation analysis showed low associa- tions. This finding suggests that selection of superior progenies should not be quality at San Ramon. The clone 720091 (Mex-32) was found to be excellent for making french fries, while the clones 800943 (Saturna), 676014 (CFC-69.1), 720111 (Aracy), 720119 (Esperanza), and 800956 (Shuang Feng) showed good qualities for making chips. In evaluations of selected clones at La Molina and San Ramon (summer season), excellent results were obtained from clones from the progenies of the CIP progenitors LT-7 and TS-1, crossed to the European varieties Cleopatra, Aphrodite, Bernlef, and Altema and the CIP BL-2.5 and BL-2.9. based solely on evaluations of their per- formance at the early stages of growth. These two experiments, which used a North Carolina mating design II (20 males and 20 females distributed in 5 sets of 4 x 4 progenitors), also obtained es- timates for some reproductive and agronomical traits (Table 2-5). Some of these traits have high heritability, which accounts for the rapid progress in im- proving them. 29 Experiments utilizing 4x-2x crosses conducted at San Ramon and Huancayo evaluated the parental value of diploid clones producing 2n pollen in their hybrid combinations with tetraploid clones. The results of the experiments indicated that diploid clones will produce later-maturing progenies that perform better under favorable condi- tions (Huancayo). Furthermore, the progeny performance of the 4x-2x matings depends heavily on which tetraploid female progenitor is used. The stress conditions at San Ramon strongly affected the agronomical and r~productive characteristics. These results suggest that selection of the diploid populations should focus on adaptation and agronomical traits to enable selection of better progenitors. This emphasis would maximize the theoretical potential of the 4x-2x breed- ing approach. At San Ramon and La Molina, studies were made of the cytoplasmic effects on reproductive and agronomical charac- teristics ofTPS progenies. In a sample of 24 progenies, 12 reciprocal pairs were compared for 14 characteristics. Perfor- mances among the 12 reciprocal pairs clearly differed, indicating that certain combinations of progenies are sig- Table 2-5 . Heritabili ty estimates for TPS traits from the NC Design II experiment evaluated at San Ramon and Huancayo (1988). Trails h2 Plants at harvest 0.12 Yield/plant 0.55 No. of tubers/plant 0.44 Earliness 0.23 Days to flowering 0.63 Flowering intensity 0.30 Style length 0.51 Pollen production 0.43 30 nificantly superior to others, regardless of the direction of the cross. However, there were no differences within each individual pair of reciprocal crosses, in- dicating that reciprocal effects were in- significant in the population that was analyzed. Maintenance, Multiplication and Distribution of Pathogen-Tested Materials The following materials are now avail- able from the CIP pathogen-tested list: 227 advanced cultivars and varieties, plus 22 in the cleanup process; and 139 acces- sions from native and wild germplasm, plus 6 in the cleanup process. Ten sweet potato cultivars are now in the process of thermotherapy, the first stage of cleanup for this crop. TPS production in Chile during 1987 and 1988 produced the highest yields to date, approximately 31 kg of usable seed from 6 progenies. Potato genetic materials in various forms were distributed to 14 developed countries and 56 developing countries. (Table 2-6). Regional Germplasm Evaluation Brazil. In May, 1987, a sample of 37 progenies, some of which combined A/- ternaria solani and virus resistance, were introduced from CIP-Lima. Seedlings were transplanted to pots in the green- house and the tubers obtained were used during the following season for a prelimi- nary field evaluation. The best progenies were Atlantic x NDD 277.2, Atlantic x TS-2, Maine-28 x TS-2, Maine-47 x TS-2, Y-84.004 x NDD 277.2, and LT-9 x NDD 277.2. The average percentage of selec- tion in these progenies was extremely high at 49%. Both TS-2 and NDD 277.2 are excellent progenitors. Seventy-three clones selected the pre- vious year were evaluated in 1988 for Table 2-6. Distribution of germplasm, 1988. Clones In Vitro In Vitro Plantlets Region Units Aces. Units Aces. Units Aces. - (14) 583 69 589 284 0 0 I (10) 3731 565 517 108 235 4 II (12) 3453 402 275 114 485 12 Ill (11) 4000 394 402 153 550 19 IV (5) 3205 208 0 0 0 0 v (3) 1527 178 0 0 0 0 VI (6) 1194 47 317 156 0 0 VII (8) 2233 152 74 37 0 0 VIII (1) 0 0 48 24 0 0 Total 70 19926 2015 2222 876 1270 35 yield performance, tuber characteristics, and resistance toA. solani. Twelve clones showed early maturity, good yield and tuber characteristics and 25% foliar damage or less caused by the fungus. The progenitors of most of these clones were Serrana and NDD 277.2. Thirty-four progenies combining PVY immunity with other resistances (LB and EB) were inoculated at the seed- ling stage with the pyyn and pyyO strains. On average, the segregation ratio was near to the expected, 1 susceptible to 1 immune. The immune-selected geno- types will be further tested for yield and tuber characteristics. Uruguay. Seventy virus-resistant clones from several germplasm introduc- tions of the 1982 to 1984 seasons were evaluated at the CIAAB experiment sta- tion at Las Brujas for virus symptoms and at the Saito station for yield. Twenty-four clones revealed neither mosaic nor leaf roll symptoms and their yields ranged from 0.5 kg/plant to 1.5 kg/plant. Many of the selected clones had the clone 7XY.1 as progenitor. Tunisia. During 1985-1986, evalua- tion and selection of germplasm with virus resistance permitted the selection Tuber TPS TPS Tuberlets Family Progeny Units Aces. Units Aces. Units Aces. 3366 29 19082 245 17435 35 10963 345 71120 361 257700 164 1109 42 0 0 44000 13 7791 362 29995 189 39200 26 8877 227 14200 71 124600 105 2058 71 0 0 166000 54 2425 41 6600 51 3791500 102 2072 65 42545 254 613800 137 0 0 0 0 0 0 38661 1182 183542 1171 5211150 636 of8 clones which were planted in 100-hill plots for the 1988 Tunisian variety trial. Yields of these virus-resistant clones ranged from 428 g/plant to 721 g/plant while the check Spunta yielded 772 g/plant. These clones will be introduced to the Tunisian variety trials in 1989 in 100-hill plots with 4 replications. From the virus-resistant tuber families introduced in early 1988, 45 clones were selected for further evaluation. The CIP clone LT-8 is progenitor of 60% of the selected clones. This clone is early- maturing, heat-tolerant, and PVY- and PYX-immune. This confirms the evidence of the good parental value of the clone, as indicated in earlier results from Peru, Uruguay, and Bangladesh. Cameroon. Ninety-five late blight- resistant clones from CIP-Lima were planted at the Upper Farm (2,000 m) for multiplication and evaluation. The pl.ants were not protected and the late-blight epiphytotics were very severe. Seventy- eight clones had a final late blight-resis- tance score of 4 (25% foliar damage or less), and 14 clones had yields of more than 1 kg/plant. Thirty-three heat-tolerant, early- maturing, virus-resistant tuber families 31 (with a total of 834 genotypes) received from Lima, were planted at Upper Farm. Selection was for yield, tuber charac- teristics, and maturity, and 144 clones were retained. Progenies from the paren- tal clone 7XY.1 had the highest yields. Bangladesh. A sample of 3,822 gen- otypes (belonging to 21 tuber families) received from CIP-Lima, were tested for performance against locally-cultivated commercial varieties used as checks. These materials were selected for high yield, earliness, heat tolerance, resistan- ces to PLR V, bacterial wilt, and late blight, and immunity to PVY and PVX. In all but two progenies, the percentage of selection at. harvest was high (up to 45% ). The best progenies were Serrana x LT-7, B71-240.2 x 5750492, B79.636.1 x LT-9, and B79.636.1 x575049. Another set of 38 tuber families, con- sisting of 2,425 genotypes, immune to PVY or PVY + PVX, were planted late in the season to expose them to the peak aphid season in order to provide an ade- quate selection pressure against PLR V and other viruses. In spite of the late planting, a number of genotypes gave yields of 500 g/plant. Evaluation of Ft C2 clones: These materials were selected from single hills in 1987. A total of 602 clones grouped into 24 progenies were field-evaluated against the local varieties Cardinal, Patrones, and Diamant. At harvest, 208 clones were retained for yield and tuber characteristics. Table 2-7 shows the yielding ability of these clones. Heat tolerance, earliness, and disease resis- tance are also major attributes of these clones. Analysis of the field data showed that Serrana, B71-240.2, LT-8, LT-9, 377%4.5, Maine-28, and Maine-47 were good progenitors, as indicated by the 32 high percentage of selected genotypes from their progenies. Evaluation of Ft C3 clones: This ma- terial, consisting of 91 clones, has been studied for the last three years. From these clones, 37 were selected for their consistent good performance and other economic characteristics. Eleven of the 37 clones were considered to be out- standing in comparisons made with European varieties (Table 2-8). Evaluation of Ft C6 clones: These genotypes introduced as tuber families from CIP-Lima in 1981-1982 are in the final phase of selection. Fifteen of these clones were planted in Bangladesh in Table 2-7. Range of yielding ability of F1 C2 se- lected clones. Munshiganj, Bangladesh , Feb. 1988. Range of yield No. of Mean yield (glplant) genotypes (gl plant) Above 1000 5 1140 800-900 27 840 500-799 120 598 Below 500 56 373 four locations that represent distinct ecological zones: J oydebpur, Chittagong, Bogra, and Munshiganj. These clones were compared with the Cardinal variety; the seed stocks of the clones were in clonal generation 6, whereas Cardinal was grown in Bangladesh only once after certified seed was introduced (Table 2- 9). The clones had a very low degenera- tion rate, maintaining a yield comparable to or higher than the check. Therefore, these clones do not need their seed stocks changed as often as do the costly European cultivars that usually degen- erate at a faster rate. Additionally, CIP hybrids have very early to medium matu- rity rates, for example, 379673.150 ma- Table 2-8. Performance of top F1 C3 clones. Clone Pedigree Yield (t/ha) 384068.55 CH 103209 x Atlantic 57.8 384109.264 C83.155 x 377888.7 55.2 384084.315 LT-7 x TS-2 51.2 384077.184 C83.258 x Katahdin 45.8 384078.217 C83.119 x Sto. Amor 44.1 384093.844 (378015.17 x 377904.1 ).2 x Katahdin 38.1 384081.275 377959.9 x LT-9 42.0 384077.193 C83.258 x Katahdin 38.1 Cardinal (main crop check) Patrones (early maturity check) tures in 70-80 days; 379667.501, in 80 days; and 379688.230, in 90 days. The Philippines. From August 1987 to August 1988, the Regional Redistribu- tion & Training Center at Santa Lucia distributed the following pathogen- tested germplasm to nine countries in CIP regions VI, VII and VIII: in vitro plantlets (102 units), tuberlets (8,380 units), stem cuttings (600 units), and TPS (633,300 units). Fifteen tuber families with earliness, heat tolerance, early-blight resistance, and some with PVY and/or PVX im- munity, were field-tested at Canlubang (150 m). There was little early-blight in- fection. The best-adapted families were 385380 (378676.6 x A VRDC 1287.19), 32.3 21 .1 386466 (Maine-47 x C83.119) and 386180 (Maine-47 x 7XY.1). The selected materials will be evaluated for early- blight resistance in a trial including the appropriate checks. In the Philippine highlands, several trials with advanced genetic materials as clones and tuber families were con- ducted to evaluate late-blight resistance. A group of clones previously selected for late-blight resistance at Sayangan, Atok was tested at La Trinidad. Yields were variable, but the resistance to late blight was usually higher than that of the well- adapted varieties used as checks. A set of 16 tuber families originating from CIP-Lima was tested under severe, late-blight attack at La Trinidad. Some of Table 2-9. Advanced regional trials at four locations in Bangladesh, February 1988. Yield (t/ha) and Location Clone Joydebpur Chittagong Bogra Munshiganj 379673.151 17.6 19.1 12.7 379667.501 17.4 14.2 30.0 14.4 379688.230 15.3 11 .6 29.8 17.5 Cardinal 15.7 18.9 28.6 15.1 379667.421 16.9 28.4 19.7 379673.150 12.8 11 .1 28.1 16.0 871 .240.2 (GIP 720088) 14.4 8.4 23.3 9.4 33 these families are early maturing and, in spite of being almost as susceptible as the check, their yields were better or equal. This was probably due to an earlier and faster bulking taking place before the foliage had been drastically damaged by the fungus. A set of 25 clones was tested for late- b light resistance against two well- adapted varieties used as checks. Both the yields and the resistance levels of CIP clones were superior to Cosima and Granola. A sample of 26 advanced clones from the CIP breeding program and check varieties was tested at Canlubang for yield, earliness, and early-blight resis- tance. Although the damage caused by early blight was severe in the three highest-yielding clones, their respective yields were higher and their size larger than those of the check Cosima. This suggests that a rapid tuber bulking took place, which permitted the attainment of high yields in spite of the foliar damage by Altemaria. After two seasons of field testing for yield and tuber characteristics, a set of 317 field-selected clones was evaluated for tuber-seed quality, following 9 months in diffused-light storage (DLS). The DLS had minimum temperatures ranging from 21.S° C to 21.9° C and max- imum temperatures ranging from 28.3° C to 31.8° C. After the DLS storage, 155 of the 317 clones were retained for field testing. At harvest, 53 clones (34%) were selected for yield and tuber charac- teristics (Table 2-10) . The performance of the best-yielding clones is remarkable, considering that the tuber seed had been stored at high temperatures. The ability to maintain high tuber-seed quality after extended storage is an important at- tribute that significantly facilitates potato production in the hot lowlands. Table 2-10. Tuber yields of the best 10 clones out of 155 advanced clones and cultivars at Canlubang (150 m) Laguna, December 31 , 1987 to April 8, 1988. Average Clones/ tuber wt. Yield Cultivars Pedigree (g) (t/ha Earliness 384081 .2 377959.1 x LT-7 83 36.7 5 384065.4 378015.25 x 3780 bulk 57 31 .7 5 384091.11 377887x(377887.17xL T- 7)21 68 30.9 7 384068.6 CH103209 x At lant ic 66 29 .2 6 384069 .11 378676.6 x Atlantic 51 27.9 5 2-482 Serrana x DT0-33 66 27.3 5 384104.13 ZPC-72-F96 x 377904.10 112 24.7 7 2-447 Serrana x DT0-33 52 24.1 6 3847071.9 Atzimba x NDD-277.2 35 22.9 7 417.3 65-ZA-5 x 378015.18 42 22 .9 5 Serrana (check) 86 18.5 7 Berolina (check) 55 17.3 7 Cosima (check) 50 14.4 8 Grand mean 56 18.7 6 LSD (.05) 15 3.0 NS Earliness: 1 = very late; 5 = medium ; 9 = very early 34 ' - A second set of 199 clones from CIP- Lima TPS progenies was field-selected at Canlubang and segregated for resistan- ces to late and early blight, bacterial wilt, PLR V, PVY, and PVX. This set was tested after 9 months ofDLS storage, and 155 clones were retained and planted in the field. The five highest-yielding clones were 385389.5 (Mex 750815 x A VRDC 1287.19), 50.4 t/ha; 385306.5 (BzuraxLT- 9), 42.5 t/ha; 385306.2 (Bzura x LT-9), 41.5 t/ha; 385376.9 (C83.119 x A VRDC 1287.19), 41.2 t/ha; and 384556.6 (Atzim- ba x A VRDC 1287.19), 40.7 t/ha. Check yields were low: B-71-240.2, 20 t/ha; Ser- rana, 16.3 t/ha; and Desiree, 14.7 t/ha. A set of 666 PVY-immune clones from CIP-Lima tuber families was selected at Canlubang for heat tolerance, earliness and tuber characteristics. These clones were stored in DLS for 9 months and 417 of them were evaluated under field con- ditions. The yields of these clones were very high (32.4 t/ha-39.6 t/ha) in spite of their early maturity, and all clones had higher yields than did checks B71-240.2 and Serrana, but not higher than CIP clone LT. The pedigrees of the top-performing clones presented in Table 2-10 include the progenitors LT-7, Serrana, Atlantic, and 378015.16 (TS-2), which are charac- terized by a high general combining ability for yield, heat tolerance, and good tuber characteristics. The clone LT-7 is also capable of maintaining good tuber- seed quality after 9 months in DLS. The clone apparently transmits this desirable attribute to its progenies. A set of promising clones and cultivars was tested at Canlubang and Santa Lucia for tuber yield, dry-matter content, and chipping and frying quality. The CIP clonesLT-7,378597.1; Mex-32, 380584.3; and the cultivar Atlantic received the highest ratings. The two clones with the highest yields were LT-7 and Atlantic. The results indicate that it is possible to produce good quality raw materials for both french frying and chipping, even under hot conditions. This can be achieved either by testing existing cul- tivars or, better still, by selecting clones that, in addition to good adaptation and tuber quality, carry resistan'Ce or tolerance to some of the most important biotic or abiotic stresses. 35 36 Thrust ID Control of Bacterial and Fungal Diseases Thrust Profile: 1989 Research advances included higher levels of resistance to bacterial wilt (Pseudo- monas solanacearnm ), reduced incidence of latent infection, greater frequency of resistance in the potato breeding population, and higher yields. Breeding work has begun to develop some levels of resistance in TPS families. In China, two CIP clones were selected for breeding for wilt resistance, and extensive trials were begun for two other clones. The University of Wisconsin research contract continued to identify new, stable sources of resistance by exposing 60 previously selected accessions to three P. solanacearnm strains. The highest levels of resistance to these strains were found in Solanum acaule (PI 498183, 498178, 498081); S. commersoni (PI 320267); and S. demissum (PI 175423). Studies of resistance to P. so/anacearnm, using a tissue culture system, demonstrated that virulence and hypersensitive response genes are located in the same DNA region and are closely linked. Bacterial soft rot of tubers (Erwinia spp.) at harvest was significantly lower in plots where calcium sulphate was applied prior to transplanting of TPS families, and the harvested tubers were more resistant toE. chrysanthemi in inoculation tests. Plantings with seed tubers demonstrated that potato-clone effects had more influence than did calcium application effects on soft rot induced on tubers after harvest. Resistance to soft rot was confirmed in two of the six clones selected the previous year, and screening for resistance to both soft rot and blackleg was initiated with 64 clones. Interactions of Erwinia and fungal pathogens were also noted. Race 0 of Phytophthora infestans was used to screen for horizontal late-blight resistance, and a complex race was used to screen for horizontal resistance in the presence of R genes for vertical resistance. Field screening was done in Huanuco, Peru, in collaboration with staff of the National Potato Program (INIAA). At Huancayo, Peru, 16 selected late-blight-resistant clones were progeny-tested to determine the general combining ability for tuber yield and the best parents were selected to continue the crossing program. Establi shment of Beauveria in the central Andean area of Peru . 37 Early-maturing, early-blight resistant clones were identified at La Molina and San Ramon. Seedling screening for early blight will continue in the field at San Ramon using artificial inoculation. PVY immunity has been incorporated into the breeding population. Of 113 clones from the pathogen-tested list, 30 were shown to be resistant to early blight at San Ramon. Seven of 77 clones from the pathogen-tested list were found to be resistant to Verticillium wilt. In another screening experiment, five of 72 clones showed resistance to powdery scab. Among seven treatments for chemical control of soilborne pathogens at San Ramon, the two providing the best control were Busan 1020 + APCA and Methyl bromide. Bacterial Wiit Disease of Potato Breeding for Resistance to Bacterial Wilt Peru. The large, highly variable popula- tion of tetraploid bacterial wilt-resistant material continued to be evaluated and field-tested under different environmen- tal conditions, and in the greenhouse at Lima. Greenhouse tests concentrated on the detection of resistance to Pseudo- monas solanaceamm. Two high-yielding clones, BWL-87.105 and BWH-87.446, were highly resistant to infection and did not show latent infection when tested in warm environments (30° C to 32° C). Their average yields were 0.84 kg/plant for clone BWL-87.105 and 0.74 kg/plant for clone BWH-87.446. These clones are being evaluated for their parental value and are being considered for incorpora- tion into CIP's pathogen-tested collec- tion for distribution. In another trial, 43 selected clones with a yield average of approximately 1 kg/plant were evaluated for wilting in the field and for latent tuber infection after harvest (Table 3-1). Eight clones showed neither field symptoms nor latent infec- tion, whereas the remaining 35 clones Adult Andean weevil infected by Beauveria sp . under lab conditions. 38 showed both, at levels ranging between Table 3-1. Newly developed potato clones se- 1%and50%. Within this group, 5 yielded lected for their yield and high levels of resistance nearly 1 kg per plant. Controls ( cv. Yun- to bacterial wilta. This material was grown under gay) had bacterial wilt and latent infec- conditions of natural infestation in a farmer's field at Obraje, Carhuaz, Ancash Department, ·- tion levels varying between 20% and Peru at 2,810 mb. 100%. Further trials are being conducted Total yield Number Yield/ to confirm these results. Clone of 3 repeti- of plants plant number tions in kg harvested in kg '!. Greenhouse screening of seedling populations showed that a new popula- 1 BWS-87.2 16.4 15 1.09 2 BWS-87.21 16.2 15 1.08 tion screened last year produced be- 3 BWS-87.23 10.5 9 1.16 tween 38% and 65% of resistant 4 BWL-87.10 10.6 10 1.06 genotypes per progeny for race 1, and 5 BWH-87.38 15.4 15 1.02 6 BWH-87.105 12.0 12 1.00 between 30% and 70% of resistant 7 BWH-87.134 14.7 12 1.22 genotypes for race 3. Survivors of this 8 BWH-87.172 11 .6 10 1.16 9 BWH-87.203 15.0 15 1.00 evaluation were intercrossed and 72 10 BWH-87.211 7.8 6 1.30 families from the resulting progenies 11 BWH-87.233 12.0 11 1.09 12 BWH-87.236 9.2 9 1.02 were tested in 1988. As a result of the 13 BWH-87.247 14.6 12 1.21 intercrossing, resistance frequencies in- 14 BWH-87.250 8.0 8 1.00 creased to between 75% and 95% per 15 BWH-87.257 10.5 10 1.05 16 BWH-87.271 16.0 15 1.06 progeny for race 1, and to between 30% 17 BWH-87.289 17.5 15 1.16 and 84% for race 3. A second screening 18 BWH-87.291 15.2 15 1.01 19 BWH-87.296 12.3 12 1.02 test will check these results. 20 BWH-87.305 14.4 12 1.20 Of256 clones tested in the greenhouse 21 BWH-87.315 11.0 9 1.22 22 BWH-87.332 13.4 12 1.11 for resistance to strain 204 of race 3, 48 23 BWH-87.354 9.9 9 1.10 (18.8%) were resistant. Between 60% 24 BWH-87.364 10.8 8 1.35 25 BWH-87.365 9.0 9 1.00 .. ~ and 100% of bacterial wilt was observed 26 BWH-87.366 10.0 8 1.25 after inoculation of these resistant 27 BWH-87.368 13.7 12 1.14 clones, three of which were totally unaf- 28 BWH-87.383 12.0 11 1.09 29 BWH-87.389 17.7 15 1.18 fected. Of 230 different clones screened 30 BWH-87.432 16.0 15 1.06 against strain 235 of race 1, 84 (36.5%) 31 BWH-87.446 14.0 12 1.16 32 BWH-87.464 15.0 15 1.00 had levels of resistance ranging from 60% 33 BWH-87.466 10.2 9 1.13 to 100% of wilt-free plants per clone. 34 BWH-87.473 9.9 9 1.10 35 BWH-87.487 8.1 8 1.01 Eight of these clones remained 100% 36 BWH-87.489 10.9 9 1.21 wilt-free. 37 BWH-87.511 12.0 10 1.20 38 BWH-87.515 10.2 9 1.13 A new group of 353 clones has been 39 BWH-87.517 13.8 12 1.15 highly selected for yield and agronomic 40 BWH-87.534 9.3 8 1.16 41 BWH-87.535 11.0 10 1.10 characteristics and will now begin field 42 BWH-87.541 13.3 12 1.15 and greenhouse selections for resistance 43 382296.1 06 14.0 12 1.16 to wilt and latent infection. In a yield trial a Percentage of wilting in the field : at La Molina, 285 clones with a yield of - In resistant test clones: 0-40% - In susceptible check: 20-100% between 0.8 kg and 2.5 kg per plant were b Five tubers per clone were interplanted with five ~ selected for further trials from among 627 tubers of the susceptible check, the Peruvian variety "Yungay". clones with proven resistance, excellent Number of repetitions = 3 in Randomized Com- agronomic characteristics, and strong plete Block design. These selected clones are now being further evalu- heterosis. However, only 4.2% of 5,880 ated for latent infection or resistance to wilt. 39 seedlings from recent crosses were selected for further trials, since climatic factors had severely retarded seedling growth and vigor. From a total of 373 clones selected from a TPS population during the 1986/87 growing season at Huancayo, 315 clones (84.4%) were selected for their yield (ranging from 1 kg to 2.53 kg per plant) and their excellent agronomic characteristics. High levels of resistance to bacterial wilt, regardless of the race of P. solanacearnm, were demonstrated in 106 of the selected clones during a severe greenhouse test. The resistance levels ob- served against race 3 (strain 204) ranged from 70% to 100% of wilt-free in- dividuals in 28 clones ( 5 clones remaining 100% wilt-free). In the other 78 clones, the same resistance levels (70% to 100% of wilt-free individuals) were observed in tests against strain 235 of race 1 (10 resis- tant clones remaining 100% of wilt-free). In San Ramon, 27 clones (35%) were selected for BW resistance in combina- tion with earliness (90 days), from a total of 76 clones. During the rainy season of 1987/88, 54 TPS families were evaluated and 320 clones selected with yields rang- ing from 0.43 kg to 1.25 kg per plant. When these clones were tested for latent infection, two families were found to be completely free, 14 families showed latent infection in between 1 % and 5% of harvested tubers, and 38 families had ranges of up to 30%. Integrated Control of Bacterial Wilt Peru. As part of a new project to identify components for integrated control of bacterial wilt, screenhouse experiments were conducted at San Ramon to study the effect of soil amendments on the the incidence of the disease. Amendment mixtures containg urea, quick-lime, and composts of coffee pulp and sugar cane 40 bagasse, were incorporated into steril- ized soil that was then inoculated with P. solanacearum (Biovar 1, race 1). The rate of incorporation was 1 % (by weight). When potato seedlings of a susceptible family (Atzimba x R 128.6) were transplanted into the soil one month later, the incidence of bacterial wilt was 19%, compared with 95% in amended soil. Field experiments are in progress to study the practical value of these find- mgs. To study the effect of crop rotation on the survival of soilborne P. so/an ace arum (race 1), experiments were conducted under field conditions in San Ramon. Different rotation crops were planted in heavily infested soil in five replicated blocks. The population of P. solanacearum in samples of rhizosphere soil was estimated monthly by dilution plating on Granada's selective medium. Two months after planting, P. solanacearum could not be detected with this method in the rhizosphere of maize, field bean, cowpea, and sorghum, but it was detected in soils from the crotalaria, sweet potato, weed-fallow, and bare-fal- low plots. After three months, the bac- teria could be detected in only one plot of sweet potato, thus the rhizospheres of these crops do not appear to promote growth of the potato pathogen that would contribute to its maintenance in soil. Resistance to P. solanacearum bred into TPS Families. Peru. The feasibility of conducting seed- ling screening tests to determine resis- tance to bacterial wilt in TPS families was studied under screenhouse conditions in San Ramon. Standard methodology was used. For each progeny, 3 trays contain- ing approximately 50 seedlings each were inoculated with a locally-isolated virulent strain of Pseudomonas solanacearum "-- (Biovar 1, race 1). A total of 3 separate tests was made on 28 progenies from 14 crosses and their reciprocals from the TPS breeding program. When the progenies were evaluated 28 days after inoculation, the percentage of wilting did not differ among replicates of the same progenies. Progenies from reciprocal crosses between the same two progenitors did not differ in percentage of wilting, except in one case during the third evaluation. However, significant differences in wilting incidence were detected among different progenies. The total disease incidence varied among the 3 evaluations, with mean percentages of wilting measured at 33%, 49%, and 54%, respectively. When progenies were ranked accord- ing to frequency of susceptible genotypes, no correlation was observed between the relative behavior of each progeny on different evaluation dates. Genetic variation among seed lots of the same progeny did not explain this phenomenon, because results from repli- cate lots of each progeny were similar for each evaluation. It was assumed that dif- ferences in screenhouse environmental conditions between evaluations were responsible for the differences in wilting incidence and disease intensities. Similar results were observed when an additional 12 families were tested at each of the evaluation periods. Since effective screening is essential to a successful im- provement program, future research will examine factors affecting this process, both in the greenhouse and in the field. New Sources of Resistance To identify new, stable sources of resis- tance to bacterial wilt, more than 60 ac- cessions, previously rated as highly resistant, were retested at the University of Wisconsin by stem inoculation with three strains of P. solanacearum. Because one of the isolates used was the highly virulent Mexican strain S276, survival rates were lower than in the previous tests. The highest levels of resistance to the three strains were found in Solanum acaule PI 498183, 498178, and 498081; S. commersoni PI 320267; and S. demissum PI 175423. Survivors are now being used as sources of resistance in protoplast fusion experiments with S. tuberosum subsp. tuberosum cultivars. Studies of Resistance to Bacterial Wilt At the University of Wisconsin, a tissue- culture system is being used to study bac- terial wilt resistance. The research focuses on the physiology and genetics of the hypersensitive response induced in tissue cultures of S. phureja. Progress has been made in cloning genes of the strain Bl that control the production of a 60 kd protein. This protein, produced by the bacterium when it comes into contact with plant cells, appears to cause the browning and death of potato cells. Two Tn 5 mutants have been used (BJA34 from strain Bl and KD688 from strain K60), which do not cause the hypersensi- tive response in callus tissues or intact plants and which do not produce the 60 Kd protein. In these two mutants, Tn 5 is inserted in the same EcoRl DNA frag- ment (7.0 kb). When the cloned fragment from BJA34, pT34, was transformed into strain K60, all of the Km-resistant and Amp-sensitive transformants carried the fragment containing the Tn 5 instead of the wild-type fragment. The fragment ex- hibited the same DNA hybridization pat- tern as does BJA34. With pT34 as a probe, the corresponding wild-type frag- ment was identified in a K60 genomic library, and was then subcloned and con- jugated into K60 transformants. All of the 41 transconjugants restored the virulence and positive hypersensitive response phenotype of K60. These results suggest that the virulence and hypersensitive response genes are located in the same DNA region (hrp) and are closely linked. Next, saturation mutagenesis was con- ducted on the 7 .0 kb fragment, using Tn 5-lac, which contains a promoter-less lac gene that enables it to be used as a reporter for induction of DNA transcrip- tion. When the mutants were tested for hypersensitive response and virulence, two separate regions were evident: one ( 1.5 kb) controls both virulence and HR; the other (1 kb) affects only virulence. The direction of transcription in these two regions has been established. In ad- dition, it was found that plant extracts induce the 1.5 hrp region at levels two to three times higher than background levels. This region is of particular interest because it appears to control production of the 60 kb protein that also is induced by plant tissues. The 1.5 kb region is now being studied to see if it contains the gene that codes for the 60 kb protein. lf this is determined, the next steps will be to: 1) establish the limits of the gene by further Tn 5 mutagenesis and 2) obtain the nucleotide sequence of the gene. Studies of this type, which provide the plant pathologist with specific informa- tion on host-pathogen interactions, will potentially lead to the development of alternative strategies for plant breeding, biological contro~ and pathogen iden- tification. Burundi. Control of bacterial wilt continues to be the major research em- phasis. The symptomless carriers with latent infection are of special interest. Four apparently tolerant clones are being stored in diffused light at 28° C - 32° C to test for latent infection. Seed crop studies have shown that removal of a diseased plant and its two adjacent neighbors reduces both the in- cidence of bacterial wilt during the season and the percentage of rotten tubers at harvest. Efforts will be made to introduce this type of roguing in all seed- production units. China. For the last three years, clones 800928 (MS42.3) and 800935 (MS-IC.2) have been found to be resistant to race 3 Establishment and multiplication of Beauveria under field conditions. 42 of P. solanacearum at stations at Penxian, Sichuan Province and at Enshi, Hubei Province. These two clones are being used as parents crossed with local cul- tivars at the Potato Center, southern China and at the CAAS Institute of Plant Protection. Two other clones, 377852.2 and 381064.8, have proven moderately resistant to wilt at the Penxian and Enshi stations and have produced high yields of 1,390 g and 1,965 g per hill in Zhangbei County, Hubei Province. After further adaptation trials, these clones will be proposed for introduction into the local potato production. The Philippines. A large scale breed- ing and evaluation program continues in Mindanao in collaboration with the Philippine Department of Agriculture. A total of 64 advanced clones were evaluated for bacterial wilt and Erwinia resistance, adaptation, and yield. Six of these clones have now been sent to PRI for clean up. Clones with a combined resistance from four wild species continue to be evaluated with promising results. Follow- ing selection for adaptation under hot lowland conditions, the clones are now being screened for BW resistance. Promising clones also were selected from local crosses. Erwinia spp. is becoming an increasingly important problem. A cross between 381064.7 and 378597.1 {Erwinia- resistant parent) has given several promising clones with both bacterial wilt and Erwinia resistance. Bacterial Soft Rot and Blackleg of Potato Effect of Calcium Peru. The effect of calcium nutrition on the incidence of Erwinia diseases during production and storage of potatoes from TPS was further studied in San Ramon. Calcium sulphate was applied in the row before transplanting and incorporated together with the compound fertilizer used. When potato seedlings {Atzimba x R 128.6 and Atzimba x DT033) were transplanted in a randomized block design with four different levels of cal- cium application, the number of plants with above-ground symptoms did not vary significantly with the calcium treat- ment. Table 3-2 shows the causal agents of stem diseases in the field, where 31.6% of post-transplant losses were due to non- pathogenic causes such as insect damage and environmental stress. At harvest, the number of plants with soft-rotting progeny tubers and the total percentage of rotting tubers were significantly lower in plots with higher calcium applications {Table 3-3). Healthy tuber yield average increased to 19.56 t/ha with the highest application Table 3-2. Pathogens isolated from wilting po- tato transplants from the field in San Ramon dur- ing the wet season, 1988. Pathogen Erwinia chrysanthemi (Echr) Erwinia carotovora ssp. carotovora (Ecc) Fusarium oxysporum Fusarium so/ani Pythium sp. Rhizoctonia so/ani Sclerotium rolfsii Ecc + F. oxysporum Ecc + R. solani Ecc + F. oxysporum + S. rolfsii Echr + Fusarium sp. Echr + F. oxysporum Other causes Frequency of isolation. 25.5 12.8 8.5 2.1 4.2 2.1 2.1 2.1 2.1 2.1 2.1 2.1 31 .6 43 rate of 2,240 kg/ha of calcium sulphate. Application of 1,493 kg/ha resulted in a yield of 17.05 kg/ha; an application of747 kg/ha resulted in a yield of 15.85 kg/ha. Soft rot then was induced in harvested tubers by inoculation through submer- sion in a suspension of Erwinia chrysan- themi and anaerobic incubation at 25° C for four days. These results confirmed earlier findings that tubers treated with the highest levels of calcium in the field Table 3-3. Effect of calcium sulphate nutrition on the incidence of Erwinia diseases in crops produced from true potato seed in San Ramon during the rainy season 1988.* Calcium sulphate rate kg/ha Diseases 0 747 1,493 2,240 % Plants with soft· rotted tubers 14.88 15.25 13.50 9.38 at harvest a a b c % Soft rot by weight 5.27 4.06 3.63 3.01 at harvest a b be c • Combined means for 2 TPS families (Atzimba .x R128.6 and Atzimba x DT0-33). Numbers followed by the same letter are not sig- nificantly different, according to Duncan's multiple range test (P = 0.05) . Table 3-4. Percentage weight of soft-rotted tissue from harvested tubers, 4 days after soft-rot in- duction (mean of 30 tubers) , when harvested from plots with different rates of fertilization with CaS04." TPS family Application rate of CaS04 (kg/ha) 0 747 1,493 2,240 Atzimba x OTO 33 46.79 39.37 33.19 26.38 Atzimba x R128.6 55.87 55.39 40.72 32.03 Average 51 .33a 47.38a 36.95b 29.20c • Numbers followed by the same letters are not sig- nificantly different, according to Duncan's multiple range test (P = 0.05). 44 were significantly more resistant to soft rot (Table 3-4). Studies also were made of the effect of calcium nutrition during potato produc- tion from seed tubers. Calcium sulphate was broadcast over the field and incor- porated at a rate of 18 t/ha prior to plant- ing of seed tubers of several cultivars. Susceptibility to soft rot was found to be influenced more by the cultivar variety than by calcium treatment. Only for the cultivar Desiree did calcium treatment significantly increase tuber resistance during the dry season. The use of calcium has been shown to increase Erwinia resis- tance in both tropical (San Ramon) and cool (Wisconsin) climates. Future studies should take place at other loca- tions with an added socioeconomic com- ponent. Resistance Selection Peru. Recent reports suggest that Er- winia is increasing in importance in several regions. Thus studies have been made of the range of susceptibility among the germplasm distributed from CIP. Screening of 106 potato clones from the pathogen-tested list was done to deter- mine their relative susceptibility to bac- terial soft rot caused by Erwinia chrysanthemi. Test tubers were field- grown and stored in diffused light in Huancayo and then screened four months later using the vacuum infiltra- tion method (see Annual Report, 1988). After 5 days of incubation at 25° C and 100% RH, the relative susceptibility of each clone was rated according to the mean incidence of rotting in replicated tuber samples. Of 6 clones that showed resistance in tests during the previous year, only 2 (Up-to-date and DGY-73) again showed resistance. Of 21 clones that showed susceptibility the previous year, 20 were again rated as susceptible. ·- Inconsistencies are probably due to dif- ferences in the water potential of tubers, which are least variable immediately after harvest. Sprouted tubers of 64 potato clones were latently infected artificially by vacuum infiltration in a suspension of E. chrysanthemi containing 106 colony- forming units ( CFU) per ml and then air-dried for 48 hours at 25° C. Inocu- lated tubers were planted in sterilized soil in pots in the screenhouse, under more natural conditions than the pre- viously described testing, and monitored over a 90-day growing period. The rela- tive susceptibility of each clone was then rated according to the mean number of plants in replicated samples that deve- loped symptoms of either soft rot or blackleg. Clones showing a low relative susceptibility to blackleg or soft rot will be retested to confirm their resistance. Interaction of Fungal and Bacterial Diseases in Potatoes At San Ramon, short rotations have resulted in severe losses of potato plants in the pre- and post-emergence stages. A wide range of fungi and bacteria have been isolated from wilting plants and rot- ting tubers (Fusarium solani, Fusarium oxysporum, Pythium splendens, Macro- phomina phaseoli, Rhiwctonia solani, Pseudomonas solanacearum, Erwinia carotovora spp. carotovora and Erwinia chrysanthemi), although their relative im- portance was not clear. Thus, the pathogens were tested in the screen- house to determine their pathogenicity and, in some combinations, their in- creased potency as a result of interaction. Sterile compost was infested by adding the homogenate of an agar culture of each fungal pathogen. Bacterial pathogens were added directly to the compost in aqueous suspensions contain- ing 1a5 CFU per ml at a rate of 20 ml per kg of compost, and 35-day-old potato seedlings (Atzimba x DT0-33) were then transplanted directly into the inoculated soil in pots. Wilting was monitored in three samples of 10 transplants per pathogen and the proportion of rotten progeny tubers was determined after 12 weeks. Only P. solanacearum, R. solani, and Pythium sp. induced wilting. Fungal wilt- ing was induced within 1 week after transplanting, whereas bacterial wilt was not observed until several weeks later. P. solanacearum and R. solani were most frequently isolated in the field. At harvest, all pathogens had induced tuber rotting and could be recovered from infected tubers. By far the most damaging pathogen was P. solanacearum, which was isolated from 71.4% of tubers. Other damaging pathogens included Pythium splendens (38.0% ); Fusarium spp. (26.2% ); Macro- phomina phaseoli (24.6%) and Erwinia spp. (13%). Wounding of stored, well-cured, potato tubers was essential for in vitro infection by Pythium splendens and Fusarium spp., and it significantly in- creased the amount of infection by M. phaseoli. Bacterial soft rot was not in- duced when tubers with latent Erwinia infection were incubated at 5° C and 85% RH for 7 days. However, interaction with fungal pathogens was demonstrated and soft-rot symptoms were particularly severe when P. splendens and M. phaseoli were inoculated into tubers following ar- tificial latent infection with Erwinia chrysanthemi. Fungal Diseases of Potato Late Blight In 1988, 51,676 seedlings were screened against simple race 0 and an isolate of 45 complex race 1, 2, 3, 4, 5, 6, 7, 10, 11 of Phytophthora infestans. Approximately 3,000 seedlings survived the test against each race. Race 0 was used to identify individual plants from these populations that had no R genes for resistance, but that showed some level of horizontal resistance. These plants will be screened against the complex race and also will be tested under field conditions in Colom- bia and Mexico, where there are high levels of inoculum pressure. Clones screened with the complex race will follow the International Testing Scheme for clonal selection, in combina- tion with screening for earliness and other desirable agronomic characters. This scheme is now being improved to provide a more reliable test. The effects of R genes in the genetic material will be neutralized by inoculation with the com- plex race to allow for selection of true horizontal resistance. Field Testing for Late-Blight Resistance under Local Conditions Testing under local conditions at Huanuco is being done in collaboration with the National Potato Program to pro- vide advanced genetic material for variety development in Peru. Evaluations were made of a total of 375 clones, of which 10 were arranged in a simple 10 x 10 lattice. The more resistant clones were infected only slightly. The frequency dis- tribution of clones clearly shows that the majority have R genes that are not com- patible with local isolates of P. infestans, thus limiting the evaluation of horizontal resistance. Progeny Testing for Tuber Yield of Late-Blight Resistant Clones Sixteen clones selected through the In- ternational Testing Scheme were progeny-tested for tuber yield at Huan- cayo, using a line x tester design. Some 46 clones showed good ability to transmit their yield potential. Similar progenies were sent for late-blight testing in Mexico, however, findings have not yet been reported. Selection of parents based on combin- ing ability for yield and resistance to late- blight is becoming a routine procedure in CIP's breeding schemes. The Philippines. Breeding and selec- tion efforts for late-blight resistance con- tinue in a collaborative effort between CIP and the Northern Philippine Root- Crop Research and Training Center at La Trinidad. Recurrent selection work on populations initially received from Lima has provided improved yields and adaptation while maintaining LB resis- tance. The next set of advanced clones is now ready for on-farm, multi-locational trials. Two outstanding clones, 1-1085 ( CIP 676089) variety Sita in Sri Lanka, and 1-1039 (CIP 676008), have been en- thusiastically adopted by farmers. U nfor- tunately, the Sita variety lost its resistance two years after introduction. Because its resistance was mainly due to vulnerable major genes, it was overcome by changes in the pathogen. The same vulnerability could occur with both of these "I-" clones in the Philippines. Early blight Peru. A sample of 31 progenies was evaluated for resistance to A/ternaria so/ani during the summer of 1988. In- dividual genotypes were evaluated under greenhouse conditions at La Molina. Cuttings were taken from the same genotypes and evaluated at the adult- plant stage in the field at San Ramon. Although estimated correlations be- tween seedlings and adult plants based Qn individual readings for each progeny were not significant, they did show a ·- negative trend. The mechanisms for resistance in seedlings and adult plants may differ and probably involve a com- plex interaction between growth stage and pathogen. Clones LT-8 x 378676.6, LT-8x575049, India 1039x378867.6, and PW.49 x BL-2.9 were consistently resis- tant toA. solani and were early-maturing at La Molina and San Ramon. Two field trials for chemical control of early blight in the early-maturing cultivar DT0-33 were conducted at San Ramon, Peru. During the winter season, the best control was achieved with Euparen + Dithane M45. During the summer season, Euparen + Dithane M45 and Dyrene + Dithane M45 reduced foliar infection and increased yields. At San Ramon, 113 cultivars from the pathogen-tested list were evaluated Powdery Scab, Spongospora subterranea. under field conditions. Of these, 30 cul- tivars were evaluated as resistant, 24 as moderately resistant, and 59 as suscep- tible 80 days after planting. In most of the cultivars, resistance was correlated with lateness. Uruguay. The 12 clones remaining from the 47 introduced from CIP in 1985 were planted in two regions in late 1988. Two clones were selected and have been included in regional trials; one is being grown in vitro. From the 225 clones intro- duced in 1987, approximately 13% have been selected. These were exposed to early blight in northeast Uruguay in early 1988. True seed of the best progenies were received from CIP in 1988, and tuber families are being produced in greenhouses for field planting in late 1989. 47 Soilbome Pathogens Verticillium Wilt (Verticillium dahaliae) Clones from the CIP pathogen-tested list were evaluated for resistance to V. dah- liae under greenhouse conditions at La Molina. Procedures were reported in the 1988 Annual Report. Of77 clones, 7 were rated as resistant, 19 as moderately resis- tant, and 51 as susceptible. The resistant cultivars were CGN-69.1, Seseni, P7, Chata Blanca, CUP 199, 703279, and MEX750658. Powdery Scab (Spongospora subte"anea) In collaboration with The National Potato Program of Peru (PIPA) and the University of Cuzco, a field trial was es- tablished in naturally infested soil to evaluate 72 clones from the pathogen- tested list. Based on percentages of in- fected tubers and severity of infection, the clones Gabriela, Puebla, G-8142.6, Albina, and G-80041.7 were rated as resistant. During the second season the No. plants surviving per plot 50 40 30 20 10 March 9 March 23 April 5 clone Gabriela showed resistance under field conditions at Cuzco. Chemical Control of Soilborne Pathogens A chemical trial to control soilborne pathogens (Rhizoctonia solani, Pythium spp., Fusarium spp., Macrophomina phaseoli, ElWinia spp. and Pseudomonas solanacearnm) was conducted at San Ramon in naturally infested soil where potatoes had been planted for three con- secutive seasons. Of the seven treatments tested, the two providing the best control were Busan 1020 + APCA and Methyl bromide. Only 2.8% of the plants in the control plots survived (Fig. 3-1). Bac- terial wilt (P. solanacearnm) was the most damaging disease, killing 70% of the plants. Incidence of Wilt and Fungal Pathogens on Roots of Potato in the Central Highlands of Peru A total of 683 stem samples with varying amounts of wilt and 582 tubers with April 21 Busan 1020 • APCA Methyl bromide Basamid Busan 1020 Ditrapex Calcium hypochlorite May 10 March 16 March 30 April 14 April 28 48 Evaluation date Figure 3-1. Survival of transplants (Atzimba x R 128.6) in plots trea led with various fumigants to control soilborne pathogens in San Ramon (1988). ... ...... various symptoms of rot were collected from three important potato-producing zones in the central highlands: Comas, Huasahuasi, and the Mantaro Valley. The pathogens isolated from stem samples were Fusarium sp. (18.74%), Verticillium sp. (13.03%), Phytophthora erythroseptica (2.04%) and Rhizoctonia sp. (1.17%). Fusarium sp . was the pathogen most frequently isolated in Comas and the Mantaro Valley, whereas the most common pathogen in Huasa- huasi was Verticillium sp~ The pathogens isolated from tubers were Fusarium sp.(23.53%), P. infestans (17.18%),P. erythroseptica (14.43%), and Pythium sp. (1.54%). Healthy tubers were collected from each field immediately after harvest to determine levels of latent infection. Fusarium sp. was the fungus most fre- quently isolated ( 6.6%) from 823 tubers, followed by P. erythroseptica (0.72%), Verticillium sp.(0.24% ), and Pythium sp.(0.12%). In all three zones studied, Fusarium sp. was the most commonly isolated, from either wilt, rot, or latent infection; thus it is the most widespread pathogen in the Peruvian Andes. The study also showed that Pythium sp. was found in various areas of the central Peruvian highlands. Inoculation with this organism caused watery rot in tubers . Field screening for resistance to bacterial wilt. Susceptible cv. Rosita (Jeff), resistant clone BR69.84 (righQ , San Ramon. 49 50 Thrust IV Control of Virus and Virus-Like Diseases Thrust Profile: 1989 In studies of the multifactorial resistance to PLRY in potato, antibiosis and an- tixenosis were examined as components of the resistance to aphid vectors. The feeding behavior of aphids was analyzed using an electronic feeding monitor on selected cultivars. Myzus persicae exhibited antixenosis in clones Pirola, MEX 32, B71.240.2, CFK 69.1, Montsama, and DT0-33, whereas antibiosis was detected only in acces- sions of Solanum neocardenasii. In tests of cv. Mariva, for example, all aphids tested found the phloem rapidly, and fed at length. However, on cv. Tomasa Condemayta, only a few M. persicae and Macrosiphum euphorbiae aphids found and fed on the phloem. The genetic resistance to PVY was studied in haploids from resistant clones derived from ssp. andigena and fromS. stoloniferum . Progenies of their crosses with FDR 2n pollen from clones susceptible to PVY also were studied. Both sources of resistance were shown to have two non-allelic genes involved in the resistance. Results also indicated that environmental conditions modified the expression of the gene for hypersensitivity. These findings provide a better understanding of the deviations from expected ratios, observed in screening for resistance to PVY. Two PLR Y isolates from the Andean region did not react with 10 monoclonal antibodies produced against a PLR Y isolate developed in Britain, whereas other CIP isolates showed a varied range of reaction intensities in the ELISA tests. The discovery of a broad-spectrum, anti-PVY monoclonal antibody (MA C-9) suggested that PVY strains having the common epitope recognized by MA C-9 are widespread in potatoes. By using MA against PYX, the PYX isolates from different countries could be classified into two serogroups and two serotypes. Serotype PYX0 is common in North, Central and South America, and in Europe, Bangladesh and India. Serotype PYXA has been detected only in Peru and Bolivia. Polyvalent or simultaneous detection of potato viruses can be done easily with NCM-ELISA. Both DAS-ELISA and NCM-ELISA are being used successfully in several cooperative institutions in China to detect potato viruses in seed-production and quality-control programs. Production of anti-anti-idiotypes was investigated as a way to facilitate production of selected virus antisera. Probes have been developed for detection of SPFMY, PYX, PVY, PLRY, and APL Y, and a non-radioactive kit has been developed for detection ofPSTY. Trainees in virology preparing sucrose density gradients fo r virus purification. 51 Fourteen isolates of SPFMV in CIP's germplasm collection have been compared with strains reported elsewhere. Four previously undescribed sweet potato viruses are being identified and characterized. In greenhouse experiments, PSTV was found to infect sweet potato cv. Paramonguino by sap inoculation. Methods have been developed to search for resistance to sweet potato viruses and some accessions in CIP's germplasm collection have remained free of SPFMV after several attempts to infect them. Resistance to Vll1lses The development of cultivars that resist or are immune to viral infections should provide farmers in developing countries with the most effective method for con- trolling virus diseases. Substantial progress has been made in recent years on the development of cultivars immune to PVX and/or PVY. This success was possible because the immunities are con- trolled by a single dominant gene for each virus. Current studies on resistance to these two viruses are directed to finding better parental lines, to understanding the basic genetic characteristics of the genes for immunity, and to determining the stability of resistant genotypes under field conditions. Even though a relatively high degree of resistance to PLRV has been found in a few cultivars, more studies are needed Feeding behavior of Macrosiphum euphorbiae in resistant cv. Tomasa Condemayta (left photo) and in susceptible cv. LT-1 (right photo). Note stylet (arrow) in the phloem bundle in LT-1 and across the leaf in Tomasa Condemayta. 52 . ,, ~- to understand the general mechanisms of the resistance to PLR V and especially to the aphid vectors. Components of the Resistance to PLRV Previous research has identified multi- factorial components in the resistance to PLR V in potato, and some of these fac- tors have been identified in potato genotypes. Resistance to virus multi- plication seems to occur, for example, in Solanum acaule OCH 13823, where the virus exhibits limited replication and ac- cumulation in the plant tissue. The resis- tance to infection can be identified by the ability of a particular genotype to escape infection under conditions of high in- ocul um pressure. Such resistance is found, for example, in the clone Mariva, where it is overcome by previous infec- tion with PYX or PVY (see Annual Report, 1988). Tolerance to PLRV can be observed in LT-1, which does not show severe symptoms even though it carries a relatively high concentration of PLRV . Studies in 1988 examined resistance in the form of antibiosis and antixenosis to the aphid vectors. Table 4-1 lists the results of the experiments to identify clones from the CIP pathogen-tested list with these components. These results in- dicated that Myzus persicae shows no preference (antixenosis) for clones Pirola, MEX 32, B71.240.2, CFK 69.1, Montsama and DT0-33. However, an- tibiosis could not be detected in any of the clones, except S. neocardenasii. The methodology commonly used for demonstrating resistance to PLR V infec- tion is based on inoculation using PLR V- carrying aphids. Thus it becomes difficult Table 4-1 . Survival and multiplication of M. persicae in some selected potato clones. Number of aphids after (hours) 0 CIP number Clone 24 72 240 72011 A racy 10.0 11 .6 22.6 800953 Bzura 9.9 7.10 16.0 379706.27 LT-9 9.9 3.1 24.1 S. neocardenasii 9.7 4.7 1.9 575049 CFK-69.1 10.0 13.7 28.9 800969 Lemni russet 10.0 14.0 37.5 676025 AGB 69.1 5.1 3.3 54.9 800957 Piro la 2.5 2.0 37.3 720091 MEX-32 3.3 2.10 34.5 720088 B71.240.2 2.3 2.6 32.0 800310 Cosima 4.3 2.9 34.9 720084 CFK 69.1 4.4 1.9 26.9 720049 Montsama 1.7 1.7 26.6 800174 DT0-33 4.9 2.9 26.4 800944 65-346-19 3.8 2.4 23.9 800101 Superior 4.2 3.1 24.9 800290 GLKS-58-1642.4 3.4 3.2 30.8 703243 lmilla blanca 3.7 2.8 38.2 720142 Ballenera 4.4 4.4 38.0 0 average of 10 replicates. 53 to distinguish between the host's resis- tance to the virus and the indirect resis- tance to PLR V through resistance to aphids. An electronic feeding monitor was used to differentiate between these two types of resistance. Glasshouse observations showed that cv. Tomasa Condemayta is not attractive to aphids. Field observations also indi- cated that this cultivar is rarely found to be infected with PLRV. Experiments were conducted to study the feeding be- havior of aphids on this cultivar, and of the 14 M. euphorbiae aphids observed on Tomasa Condemayta, only 2 reached the phloem. Of the 19 M. persicae aphids tested, 4 reached the phloem. On the susceptible clone LT-9, all aphids from Effect of virus resistance on stability of potato clones : (upper photo) cv. Rosita, susceptible ; and (lower photo) cv. Bzura, immune to PVX and PVY. Letters indicate number of fie ld expo- sures (A) = 1 exposure at La Molina; (B) = 2 exposures at La Molina; (C) = 3 exposures, 1 at lea and 2 at La Molina; D = 2 exposures, 1 each at Huancayo and La Molina; (E) = 3 exposures, 1 each at lea, Huancayo, and La Molina; (F) = 2 exposures, 1 each at lea and La Molina. 54 ~· both test species reached the phloem and fed longer than on the other cultivars. This feeding behavior also indicates that Mariva is resistant to the virus and not to the aphid, because the aphid vec- tors (Myzus persicae and Macrosiphum euphorbiae) are both capable of feeding on the phloem sap. Studies on Resistance to PVX and PVY Haploids from resistant clones and progenies of their crosses with FDR 2n pollen 2x clones susceptible to PVY, were evaluated for resistance to PVY. All haploids from the cv. Serrana were hypersensitive to PVY. Progenies segregated into hypersensitive and sus- ceptible genotypes. Haploids from the clone XY 13.15 (V2 or CIP 375335.1) with immunity to PVY from S. tuberosum ssp. andigena were either hypersensitive or immune. Of their progenies, only hy- persensitive haploids were susceptible. The immune haploids segregated into immune, hypersensitive, and susceptible phenotypes. The segregated proportions indicate that two non-allelic genes were involved in resistance: one responsible for the immune phenotypes, and the other for the hypersensitive phenotypes. Haploids from 78C 11.5 (V3 or CIP 378650.1) with immunity to PVY from S. stoloniferum were immune, low-degree hypersensitive, and susceptible. Their immune haploid progenies were immune or susceptible. The hypersensitive haploids were highly susceptible. These results indicate that this clone carries a gene for immunity, along with another gene for a low degree of hypersensitivity that is modified to yield a susceptible phenotype. This again indicates that two non-allelic genes are involved with the immune and hypersensitive genotypes. Based on these findings, the proper genotypes can be selected to improve the inheritance of PVY immunity at the diploid level. Such selection can also determine the relationship among the genes for immunity to PVY, as obtained fromS. andigena andS. stoloniferum. The findings also indicate modifications in the expression of the gene for hypersen- sitivity and they clarify the causes of deviations from expected ratios observed in the screening for resistance to PVY. Studies also were made of the ap- propriate environmental conditions for the expression of the gene for hypersen- sitivity. Resistance to the PVXHB strain is being confirmed in cultivars Bzura ( CIP 800953) and Atlantic (CIP 800827) as an additional attribute to their immunity to the common strains of PVX. Preliminary results indicate a similar level of resis- tance in Serrana. Mechanically-inocu- lated plants were symptomless, and the ELISA test detected only slow virus mul- tiplication in the few plants infected. Development of Virus Resistance Peru. Nearly 400 advanced breeding clones underwent a PLR V field-ex- posure trial in lea. Observations for virus symptoms were made in the field 65 days after planting, and selection for tuber shape was done at harvest. A few clones from these selections with good tuber shape for processing were tested for their reducing-sugar con- tent, dry-matter content, and specific gravity (Table 4-2). These materials (selections from 1986, 1987, 1988) and another 5,000 seedlings with resistance to PVX and PVY from different families, were submitted to a PLRV field-ex- posure trial at lea in October 1988. How- ever, the aphid-population data obtained in lea for 1987 and 1988 indicated higher populations of Aphis gossipii and 55 Table 4-2. Specific gravity, reducing-sugar content, dry-matter content, and tuber shape of some se- lected clones resistant to PVX, PVY and PLRV. Specific dry Reducing Tuber Pedigree Clone gravity matter sugar Shape 871 .240.2 X7XY.1 86004 1.087 21.84 4.00 round 86006 1.074 19.81 2.66 oval 86010 1.083 21.17 2.00 round 86026 1.085 23.10 1.66 round 86066 1.086 21.91 1.00 oval SERRANA X LT-9 86041 1.093 23.48 2.20 round 86051 1.087 22.15 1.33 oblong 86052 1.096 24.02 2.33 round 871 .240.2 x 86076 1.086 22.18 1.33 round 575049 86084 1.090 22.81 1.00 round MARIVA X7XY.1 86090 1.080 22.37 3.60 round 86092 1.081 20.72 2.00 round 8R63.15 X 7XY.1 86102 1.089 22.87 1.00 round 86103 1.083 21.08 2.00 oblong 8ZURA X LT-9 86105 1.106 25.72 1.66 round 86109 1.077 20.33 2.00 oblong Rophalosiphum sp. than of Macrosiphum euphorbiae and Myzus persicae. Thus the efficiency of the former aphid species as vectors of PLR Y must be determined. With lea as a testing site, CIP can select for heat tolerance during the second half of the year. A breeding strategy to obtain PLR Y resistance also was developed as shown in Fig. 4-1. Of the two populations in Fig. 4-1, the population consisting mostly of S. tuberosum (List A) shows promise for adaptation to hot, tropical, long-day environments. This population contains immunity to PYX and PVY, as well as resistance to PLRY. Two experiments were conducted to optimize the screening method for PLR Y resistance in seedlings. The first experiment compared two aphid popula- tions to determine the optimum number of aphids needed for inoculating seed- lings during screening. The second ex- periment compared glasshouse and field-exposure effects in screening for 56 PLR Y resistance. In the first glasshouse experiment, three families with different numbers of aphids per seedling were evaluated for infection with PLRY, using a split-plot experimental design. The tested progenies differed significantly and B72.233.5 x 7XY.1 showed the most resistance to PLRY. The number of plants infected was not correlated with the number of aphids used for infection. Therefore, a population of 15 viruliferous aphids per seedling was as effective as a population of 50 aphids per plant in test- ing for resistance. These findings confirm the results obtained last year. Uruguay. Two clones selected by CAAB from the 1986 introductions con- tinue to show excellent resistance to PLRY, PVY, and PYX, as well as good agronomic characteristics. These have been freed of virus and are now available in CIP's pathogen-tested genebank. Several crosses were made, and the parents (the two clones mentioned) and the seeds of six crosses were sent to CIP. From introductions in 1985 and 1986, 14 clones were selected and the 2 most promising were included in regional replicated trials and maintained with in vitro culture. Of the introductions made in 1987, 228 (11.7%) were retained in the winter crop in the north of the country. The full set of 228 was planted for virus- resistance trials in the spring of 1988 at the Las Brujas Experiment Station. A selection of 21 clonal cultivars from CIP was evaluated for virus resistance under field conditions. B71-240.2, Pirola, and BR63-76 showed high levels of com- bined resistance to PLR V, PVY and PVX. Variability of Potato Viruses Variability of PLRV. The variability of some PLRV isolates available at CIP was studied in collaboration with the Scottish Crops Research Institute, Dundee, Scot- land (SCRI). Isolates were tested for Populations CIP Regions (List A) - Mainly S. tuberosum - Hot tropics, long days B71 .74.49.12 B77.861.11 B79.638.1 B71.240.2 Serrana Pampeana Katahdin Pentland Crown A racy Bzura 104.12.LB BL 1.5 Mex 32 Santo Amor (Already done) - - [LR x (X + Y) ] -- [LR x LR] Progenitors x with (X + Y) immunity [LR x (X + Y)] -- [LR x (X + Y) ] x LR -- [LR x (X + Y) x LR x (X + Y) ] Figure 4-1. Breeding strategy for PLRV resistance. GIP-Lima (List B) - Mainly S. andigena phureja, tuberosum BR63.5 BR63.15 BR63.65 CUP-199 1-1124 CFC 69.1 Mariva lea Nevada x List A (LR x LR) Combine X, Y & LR resistance Increase level of LR resistance if the level of resistance to PLRV is low Backcross lntercross 57 their serological reactions to 10 monoclonal antibodies produced against a British isolate of PLR V. PLR V isolates China and 29 reacted well with the monoclonal antibodies tested, but iso- lates Korea and Uruguay reacted less strongly, probably because of the low virus concentrations in the plant tissues. Isolates 10 and 01 from the Andean region did not react at all, probably be- cause they belong to a distantly related antigenic PLRV. These results suggest the existence of serologically different isolates of the PLRV that might require the development of strain-specific an- tisera for routine detection of PLRV. Fu- ture experiments will examine the significance of these isolates on the stability of resistance to PLR V so far obtained. Variability of PVX and PVY NCM-ELISA tests are in progress to study the variability of PVX and PVY, and to monitor the stability of the resis- tance in the germplasm being evaluated in the regions. The epitope recognized by the broad-spectrum, anti-PVY mono- clonal antibody (MA) C-9 was detected in 40 samples from a test plot in Florida, U.SA.; in 57 samples of 17 old cultivars grown in Bangladesh; and in Bolivia (10 from Cochabamba, 12 from Toralapa, and 18 from the Lake Titicaca Plateau). PVY strains having the epitope recog- nized by MA C9 have now been found in North, Central, and South America, and in Bangladesh, China, Europe, and Africa. Using anti-PVX MA 58, 59, and 67, the PVX isolates detected in different parts of the world can be classified into four serogroups and two serotypes (Table 4-3). PVX strains with epitopes recognized by MA 58 and 59 are found in North, Central, and South America, and in Europe, Bangladesh, and India. PVX isolates with these epitopes were clas- Table 4-3. PVX serogroups (according to Torrance et al.) and serotypes, as determined by mono- clonal antibodies 58, 59, and 67, detected in potato by ELISA on nitrocellulose membranes (NCM- ELISA). Number of isolates Area Serogroup Serotype 2 Bangladesh I or II PVX0 India IV pvyo 4 USA IV PVX0 1 Guatemala IV PVX0 3 Chile IV PVX0 27 Peru IV PVX0 3 Peru I or II PVX0 Peru Ill PVXA 13 Bolivia (Lake Titicaca Plateau) I or II PVX0 8 Bolivia (Lake Titicaca Plateau) Ill PVXA 3 Bolivia (Lake Titicaca Plateau) IV PVX0 15 Bolivia (Cochabamba) I or II PVX0 8 Bolivia (Cochabamba) IV Pvx0 Bolivia (Cochabamba) Ill PVXA 19 Bolivia (Toralapa) I or II PVX0 10 Bolivia (Toralapa) IV PVX0 58 - 10 78.0 48 63. 1 107 Three male parents (7XY.1, R128.6, and A VRDC 1287.19) were evaluated to determine the effect of post-storage temperatures on their pollen viability. Seed-setting in flowers pollinated at six different developmental stages is being analyzed to define the best pollinating time and to minimize the probabilities of selfing. Improved devices and methods were developed and tested with promis- ing results for pollen extraction, storage, and pollination suitable for large-scale hyb~id TPS production. South America To meet the strong local demand for reducing costly imports of seed, trials were begun in Paraguay to investigate the potential for a TPS, tuber-based seed sys- tem. Annual seeding of botanical seed during the winter season (June-July) is thought to be capable of providing heal- thy planting material that can be stored during the summer (December- February). This material then could be utilized the following year in several plantings. Fourteen progenies were sown in a nursery in July 1987 and later transplanted to seedbeds (total trans- planted area: 50 m2). The seedling tubers were harvested in December, then graded and stored under diffused-light conditions. High summer temperatures promoted fast sprouting. In related trials: • Seedling tubers of 9 g , to 20 g were planted in seedbeds in March to study th~ p0tential of a second multiplication for the 1988 planting season. • Seedling tubers larger than 20 g also were planted in the field in March to evaluate the produc- tion of consumer potatoes and healthy seed for the planting season. Seed emergence was uneven in these trials, except in sections of the field that were occasionally shaded by nearby plants. Later in the season, all progenies grew well with fast canopy development and satisfactory yield performance. For the fourth consecutive year, large quantities of TPS were produced in the south of Chile as a part of the collabora- tive project between !NIA and CIP (Table 9-2). So far, a total of 56.7 kg of hybrid seed has been produced and dis- tributed worldwide. The conditions for TPS production during 1988 were by far the best in four years. Table 9-2. Summary of TPS produced in Osorno (Chile) during four seasons (1984-88) under the Collaborative Project ININ CIP. INIA, Osorno, 1988. Net areaa Total fresh Total dry Number of plants fruit weight seed weight Season (m2) Female Male (kg) (kg) 1984/1985 698 781 383 372.4 5.39 1985/1986 2341 2411 1420 1140.3 13.16 1986/1987 2266 2414 1215 481 .2 5.78 1987/1988 3131 2870 2610 2635.2 32.40 Total 8436 8476 5628 4628.8 56.70 a Net area: Does not include borders, areas to separate block progenies, or blocks of males or females. 108 .. .. . /' ! Africa In April, 1988, potatoes were produced from TPS at three locations in Cameroon. The main constraints in test- ing this technology were insect damage (cut worms mostly) after transplant, and climatological factors, especially heavy rains (up to 700 mm in one week). TPS from 22 progenies were sown in early April in a large seed nursery (10 m2). Soil was not sterilized and only Furadan was applied two days before sowing. Germination was 80% for most progenies although two progenies had germination rates lower than 25%. After 40 days, seedlings were transplanted to nurseries and fields for seedling tuber production. Asia Approximately 735,000 seeds have been produced from 152 hybrid combinations at the Canlubang and Santa Lucia sta- tions in the Philippines. An extended day length (18 hrs) and heavy (800 kg/ha) fer- TPS Physiology Seed Density Low-density TPS from ten crosses produced seedlings that had lower per- centages of emergence and/or dry weight than did seedlings of medium- or high- density seed, except for TPS of Atzimba x R128.6. The differences between high- a n d medium-density seed effects generally were less important than the differences when they were compared with effects of low-density seed. The female-parent genotype had a stronger effect on seedling performance than did the pollen source genotypes (Atzimba vs CFK69.1 crosses). However, the results also may suggest that the specific com- bining effect of the pollen parent could tilizer applications (split, applied week- ly) resulted in profuse flowering for most of the parents, especially for 381064.3, 381064.7, 381064.10, and 381064.12. Research focuses on identification of TPS progenies (hybrids and open pol- linated) with high-yield potential as transplants, as well as on tuber genera- tions with resistance to bacterial wilt and viruses. China Improved TPS progenies are being developed for various environments of China. During 1988, 25 kg of high-quality OP seed was collected at Wumeny and 5 kg of hybrid seed was collected at Humeny for distribution to farmers in southwest China. Improved coordination between research and extension, high- quality seed, and establishment of TPS collection procedures helped boost the area planted with TPS transplants from 33 ha in 1987 to 110 ha in 1988. influence early seedling performances (Serrana x LT7 vs other crosses x LT7). Radical Elongation The effects ofTPS crosses on early radi- cal development were studied in 23 dif- ferent crosses, and mother-plant influences were found to be significant. The most vigorous cross, Atlantic x L T7, was used to demonstrate the importance in TPS production of location, seed maturity, and supplemental N for effec- tive selection of more vigorous crosses during early seedling emergence and development. Two other selected crosses (Atzimba x R1286.6 or Atzimba x DT028) were used to show that high levels of supplemental N during seed 109 production and proper seed develop- ment at harvest are both essential for enhancing seed vigor and preserving vigor during long-term storage. Supplemental Nitrogen Supplemental N applied at regular inter- vals ( 10 days) during seed development has been shown to increase seedling vigor of TPS, when seed is tested after storage of more than 12 months. This improve- ment was clearly shown in TPS tested under high (>ZS' C) temperatures after 20 months of storage. However, sup- plemental- N has also been shown to lower seedling performance in tests of newly-harvested TPS. Thus, supplemen- tal N effects are associated with both increased seed vigor and increased seed dormancy. Under favorable temperatures (20° C to 2S' C), supplemental N, applied at the rate of 540 kg/h and divided into 6 ap- plications, produced TPS that emerged at a much faster rate than did the control or other N treatments. The N treatments had similar effects on the percentage of emergence and seedling dry weight. However, emergence under favorable temperatures was 90% for all treatments, and dry weights varied by a maximum of only 0.7 mg/plant. Thus, supplemental N influences on TPS vigor are more evident under supra-optimal temperatures. Early Vigor Studies were made of TPS germination, early seedling vigor, and finalizing paren- tal effects on the rooting capacity and early-field establishment of potato seed- lings. The TPS vigor studies used seed of six selected hybrid combinations produced at Huancayo. The seed was obtained by pollinating flowers of only one influorescence per plant on the same day for each hybrid, leaving only four berries to develop per plant. The seed was harvested 50 days after pollination. Standard procedures were used for seed extraction, drying, and storage. The seed was germinated under light or dark con- ditions at 2 to 6 months after extraction Screening for resistance to transplant shock, GIP-Lima. 110 and the corresponding rates for each progeny and environment were calcu- lated for a germinating period of 15 days. Although the experiment is still at a preliminary stage, progenies were shown to differ in response. Pollen Selection Previous studies of seedling charac- teristics suggested that pollen-selection techniques may be an effective tool for increasing the uniformity of progeny per- formance in some TPS crosses. Findings indicated that the tolerance of pollen grains to high-temperature exposure may not be associated with a higher adapta- tion in the clonal pollen parents for producing tubers under tropical condi- tions. Similarly, such tolerance may not influence the performance of the result- ing TPS cross during emergence at supra-optimal temperature. These ex- TPS Agronomy South America In Peru, advanced TPS progenies from CIP's breeding program, included in the international TPS trials, were evaluated for performance as transplanted seed- lings or as seedling tubers. The seedling tubers were produced during the off- season in protected nursery beds. Be- cause the region is a basic seed-producing area, virus build-up is important; therefore, the seed-sized tubers (3.5 cm) are being evaluated for virus contamination over three succes- sive generations. At San Ramon, another experiment evaluated a TPS utilization system for small farms in hot-humid areas. Use of TPS to grow table potatoes in beds might offer an attractive production alternative, especially in subsistence- level farming areas. In San Ramon, a low- periments were repeated and expanded in 1988 to include a wider variety of genotypes. The study findings also suggest that pollen grains of different sizes may produce TPS progenies that differ in sporophytic characteristics, at the seed- ling stage. That is, the proportion of pol- len sizes and their viability may differ among clones, which suggests that such differences also may occur in pollen lots of a given clone when harvested at dif- ferent stages of plant maturity. In preliminary experiments, several new crosses were produced using pollen of various sizes. The TPS will be tested for the effects of pollen size on the resulting seedling and tuber characters. The work on pollen selection is ex- pected to produce results that can be applied to large-scale TPS production. cost method using locally available sub- strates has shown promise. The sub- strates are solarized to control soil-borne pathogens, and a simple irrigation system is used to apply water from streams, which are commonly found on tropical farms. The usefulness of this system for household production will be assessed under farmer-management conditions on three different farms in the San Ramon area. Four TPS progenies of Atlantic x LT- 7, Serrana x LT7, CFK69.1 x DT0-33, and Atzimba x 7XY.1 were evaluated in Paraguay. In cooperation with national institutions, 200 m2 of seedlings were grown in seedbeds and 100 m2 in farmers' fields. Agronomic performance was evaluated and both groups of col- laborators agreed that Atlantic x L T7 and Serrana x LT7 showed fewer problems 111 during transplanting and produced fewer and larger tubers. Africa Spring- and fall-season experiments in Egypt examined the feasibility of using seedling tubers as an alternative source of planting materials. Different sizes and generations of seedling tuber progenies were used, with imported and local varieties used as checks. Some of the findings are listed below. Imported seed and physiologically- old seedling tubers had better emergence rates and more stems per hill than did local physiologically-young tubers. Imported varieties and seedling tubers from the spring crop had higher yields than did those from the fall crop. For the spring crops, the amount of consumer tubers produced from seed ob- tained from imported seed and from seedling tubers was greater than that produced from the fall-crop seedling tubers. Seven tons of first- and second- generation seedling tubers produced at CIP-Kafr El-Zayat Experimental Station in the spring were distributed to 40 farmers. The performance of these farmers' plots (100 m2 to 200 m2) during the fall was evaluated and compared with farmers' plots sown with seed of European varieties. The seedling tuber yields were generally higher than those of farmers' seed, and farmers' responses were positive about the prospect of using seedling tubers. In Cameroon, TPS feasibility trials ex- amined the use of TPS to produce potatoes. They were planted in three locations in unsterilized field soil; yield and numbers of tubers were only average, although some progeny Rroduced more than 250 mini-tubers/m2. Transplants were unsuccessful because of severe at- tacks by crickets and large ants. Asia Multilocational trials of the All-India Coordinated Potato Improvement Project over two seasons confirmed that hybrid TPS-family yields equaled or sur- passed those of standard cultivars when used as transplants or fust-generation tuberlets (Table 9-3). In other com- parisons with local cultivars in India and Sri Lanka, trials over two seasons showed that selected TPS hybrid progenies main- tained better yield potential for at least two generations of tuber production. The best-yielding hybrid progenies have been Table 9-3. Evaluation of TPS families: on-farm trials with F1 C 1 tubers in Meerut District (U.P.) India during 1987-88 season Families Site I HPS-11111 20.8 HPS -2/111 19.8 HPS-11111 20.4 PS-11/111 25.0 Kufri Badshah (cv) 21 .9 NPK fertilizer applied : 150:80:100 kg/ha Crop duration: 90-11 O days 11 2 Yield (t/ha) Site II Site Ill Site IV Mean 26.3 28.0 28.3 25.9 25.3 20.2 21 .8 27.3 27.8 27.9 25.8 29.3 31.6 28.5 28.6 25.6 25.3 25.4 24.5 distributed to Bangladesh, Nepal, Sri Lanka, and the Philippines. In Vietnam, 20 kg of OP TPS of CFK69.1 and Atzimba was collected from farmers in Dalat. This seed was dis- tributed to 45 cooperators, who har- vested 48 ha of transplants in 1988. Propagation To validate previous experiments, ran- dom comparisons were made among single-sprout seedling tubers, stem cut- tings (mother plants from seedling tubers), apical cuttings (from seedlings) and seedlings. These materials were all from the same progenies and were com- pared in nursery beds and in the field (San Ramon and Lima) at constant main- stem densities. The seedlings had the lowest survival rate in nursery beds (Table 9-4). Yields from stem cuttings were significantly bet- ter than those from either seedlings or apical cuttings. Seedlings had the highest tuber number per plant and percentages of small tubers (10 g) whereas these In China, two CIP TPS progenies (CFK69.1 x 7XY.1 and 379303.37 x 7XY.1) have yielded 40 t/ha in the seed- ling tuber generation. One of these progenies will be selected for potato production of seedling tubers in south- west China using hybrid seed produced in China. measures were intermediate in seedling tubers and apical cuttings, and lowest in stem cuttings. As a result of these find- ings, more emphasis will be placed on seedling tuber production and use. At Lima, seedling survival rates in the field were lower than those for seedling tubers and stem cuttings. At San Ramon, field survival rates among planting materials did not differ statistically (Table 9-5). Yields among propagation methods for each progeny did not differ, except for Atzimba x R-128.6 at Lima, where the difference between seedling tubers and stem cuttings was significant. As in the findings with nursery beds, tuber numbers per plant were highest in Table 9-4. Yield and yield components of planting materials from TPS progenies in nursery beds (Means of Lima winter and San Ramon dry season experiments, 1988). Plants harvested Tuber number Yield % Per plant %< 10 g kg per m2 CEX-69.1 x DT0-28 Seedling tubers 84 6.2 63 5.5 Stem cuttings 87 2.4 30 5.7 Apical cuttings 83 5.8 66 3.9 Seedlings 62 12.0 87 4.0 Atzimba x DT0-28 Seedling tubers 79 3.6 60 3.4 Stem cuttings 80 2.9 35 6.0 Apical cuttings 78 5.1 56 4.7 Seedlings 54 11.3 80 4.1 LSD 5% 11 1.0 12 1.2 113 Table 9-5. Yield and yield components of single-stem planting materials from TPS proge- nies in the field (San Ramon dry season, 1988). Harvested CFX-69.1 x DT0-28 Seedling tubers Stem cuttings Apical cuttings Seedlings Atzimba x DT0-28 Seedling tubers Stem cuttings Apical cuttings Seedlings LSD 5% Plants tubers Yield (%) per hill 64 73 80 75 62 75 76 66 ns 8.1 5.7 12.2 15.8 7.5 7.4 11 .7 12.9 3.3 I/ha 11 .2 12.4 11 .7 13.4 13.4 17.5 18.9 14.5 5.6 seedlings and lowest in stem cuttings. In comparisons between seedlings and api- cal cuttings, and between seedling tubers and stem cuttings, the differences in tuber numbers recorded in the field were less than those in nursery beds. In previous studies of the effects of tuber origin on seed production, seed tubers from warm climates have yielded significantly less than their counterparts from cool climates, irrespective of the production method used. Table 9-6 shows the results when mother plants were raised from seed tubers of wann- and cool-climate origins. Stem cuttings were then compared under warm- climate field conditions. Tuber-origin ef- fects were not reflected in cutting and survival rates or in total and marketable yield (Table 9-6). Thus, seed tubers produced in warm climates may be a suitable source of mother plants in potato-production systems based on cut- tings. South America In vitro propagation techniques have been improved and approximately 6,000 mini-tubers are being produced twice a year in greenhouses in Uruguay. Results from the fall of 1988 showed that these mini-tubers had a multiplication rate of 20 t/ha. Three locally selected clones are being multiplied with this method, to be used as substitutes for some imported seed. Africa At Nairobi, in work with the National Potato Research Program in Tigoni, spe- cial- project funding was used to rehabilitate the facilities and reorganize the basic seed program. The production cycle was begun with carefully selected tubers of five standard Kenyan varieties produced at ADC Molo. Five tubers of each variety were sent to Lima to under- Table 9-6. Effect of tuber origin to produce mother plants on performance of cuttings in the field (Lima, summer 1988). Climate during Survival Yield Variety seed production % Total g/m2 Marketable (%) Desiree warm 87 1670 91 cool 90 1630 93 LT-5 warm 86 1570 92 cool 85 1470 89 ns ns ns 114 go virus clean up. The number of cuttings harvested per mother plant was low, ex- cept for Kenya Baraka, which yielded 36 cuttings/plant. The low rates were at- tributed to high soil and air temperatures in the screenhouses. A new, larger screenhouse is now under construction, with a capacity of 10,000 tuberlets per season. Asia On-farm trials in the Philippines have shown the feasibility of growing potatoes from apical cuttings. In 64 trials, cuttings from 1-1085, 1-1039, P-7, and 1-1035 yielded over 21 t/ha and produced higher economic returns than did the control grown from tuber seed, although overall yields of the cuttings were lower. Evaluation of CIP germplasm for suitability as cuttings for consumer potato production has revealed several areas for exploitation. In Vietnam, farmers continue to use sprouts to rapid- ly multiply limited amounts of seed tubers. Again, major genetic differences have been detected. The clone CIP 380584.3 is an outstanding performer for sprout utilization. China In vitro tuber production experiments were extremely successful in using stand- ard procedures for growing shoots in shallow M.S. substrate media for 2 to 3 weeks; then tuber-inducing regulators were used or else the flasks were put in the dark. Micro-tubers were harvested at 3 to 4 weeks. This technique will now be incorporated into the pre-basic seed- production program. ~ / Case Studies on Seed - Tuber Systems A case study of the seed-potato system in Ecuador was completed as part of a series designed to identify strengths and weaknesses of the seed systems. The series includes similar reports on the Philippines (Annual Report, 1988), Kenya (upcoming) and a combined report on Canada, the Netherlands and the United Kingdom (Annual Report 1988:157). In Ecuador, where potatoes have been cultivated for thousands of years, small highland farmers produce most of the crop. The government has been involved officially in potato research and exten- sion for 25 years, and in potato-seed production and promotion for 15 years. However, seed production in the official program remains at a relatively low level. Apart from the introduction of new varieties, the basic technology of seed production, selection, storage, manage- ment, and marketing in the informal small-farm sector has changed little in recent decades. Among the major technical innova- tions in potato production, modern seed production appears to have had less of an impact than have other innovations. New varieties have made the greatest impact on the seed potato system, and most of these have been diffused and adopted within informal systems. This finding highlights an important weakness in the formal seed system: the lack of an effective seed distribution model. The potato-growing areas of Ecuador have distinct large- and small-farm sectors, with separate seed-potato systems. Generally, these two systems have little contact. A principal conclusion of the study is that institutional and coordination problems - rather than technical pro- 115 blems - are limiting the effectiveness of the seed program in Ecuador. The seed program is part of the broader task of Sweet Potato To help breeders make better crossing blocks for sweet potato and to improve seed production, studies were made to categorize or regroup sweet potato germplasm available at CIP. Based on the number of flower buds and flowers on vines, 1,460 accessions of sweet potato were grouped into State Pat. 1 Flower (F) Bud (B) 7 No bud (N.B.) Pat. 2 F B - NB - 10 11 12 F - Pat. 6 B - N.B. - 10 11 12 2 extending research results to the appro- priate users. categories of high-, moderate- and low- flowering capacity. Of the total acces- sions, 3% were in the high-flowering category, 88% in the moderate, and 9% in the low. The selected accessions of the three categories have shown eight patterns of flowering habit. Patterns designated 1, 2, 3 4 5 6 7 8 2 3 4 5 6 7 8 Months Remarks: Plants were grown in open field at GIP-Lima. Planting date, July 20, 1986. Figure 9-1 . Flowering pattern of sweet potato. 116 and 6 are shown in Fig. 9-1. The majority of accessions with high-flowering capacity follow pattern 1. Patterns 1 and 2 described the habits of most of the moderate-flowering accessions, while pattern 6 included 30% of the low- flowering accessions. The flowering pat- tern seems to be determined by the juvenile period of an accession and by its response to photoperiod and tempera- ture. A study of short-day treatment and grafting effects on flower induction indi- cated that the high- and moderate- Flower/30 days/plant 100 50 0 '--~-"'"- 1/a SN ND LD 21 SD 3/ SD SD ND LD LD SD flowering accessions are easily induced to flower by grafting and/or a short-day treatment (9 hr). The findings on short-day treatment effects on flower induction of scion and root stock in grafted plants clarified the principles of flower-induction capacity of a stock. Figure 9-2 shows the effects of photoperiodic pretreatment on scions and root stocks. The flower-induction capacity of the stocks (I. nil, purpurea, and setosa) were studied and varietal differences were determined for flower-induction SD (9 hr) - ND (13-11.5 hr) E LD (15 hr) SD ND LD SD ND SD ND LD SD ND Root stock, c. c. j. (/. purpurea). SD, ND, and LD stand for short, natural, and long day. a 1 = photoperiodic pretreatment on root stock; 2 = photoperiodic pretreatment on scion; 3 = photoperiodic during growing period; 4 = var. RCB 195 of Cat. II. Figure 9-2 Effect of pretreatment of scion and root stock on flowering under different day lengths. 117 capacity of the stocks, positive effects of short-day treatment of the stock (I. nil), and for the effects of age of the stock (I.nil) on flower induction of the grafted plant. The techniques useful for improv- ing flower induction in sweet potato in- cluded selection of competent stock of high compatibility, conditioning of stock by short-day treatment, taking of scions from mature mother plants, and growing of the grafted plant under short-day con- ditions (Fig 9-2). I. purpur.ea with white flowers is recommended as an elite root stock for open-field growing, and for its high com- patibility for grafting with scions, adap- tability to rather heavy soil, tolerance to nematodes, and high-flowering induction capacity. I. nil also is recommended as elite stock, especially when grown in pots. It has a high flowering capacity and its root system is adapted to porous soil. To facilitate short-day treatments and seed collection, grafted and non-grafted plants were trained to a single vine and tied stakes were posted around the plants. The findings indicate that the traditional biannual harvesting of sweet potatoes was also associated with an ap- proximate 2-month interval without flowers. In further studies in 1988, sweet potatoes were grown continuously for 12 months without an intervening harvest. Thlining South America The International Seed Production Course was organized by CIP-UNA in Lima, Peru and attended by 18 par- ticipants from Bolivia, Brazil, Colombia, Ecuador, Guatemala, Honduras, Para- guay, Peru, Uruguay, and Venezuela. Beginning in 1989, the course will be held in Chile. 118 This research provided an uninterrupted record of the developmental responses of 150 varieties under a wide diversity of environmental conditions throughout Peru at locations including coastal desert, cool highlands, and mid- and low- elevation humid tropics (from latitudes .s°S to 17°S). Preliminary analysis of selected varieties indicates that the flowering of a given variety of sweet potato can vary considerably from one location to another. Thus, environmental requirements for the various develop- mental responses may differ widely among sweet potatoes and other Ipomoea species. After experiments in 1986-87 and 1987-88, 14 varieties were selected that perform well in cool environments. Three of the 14 varieties proved to be exceptionally resistant to cold weather, showed no damage from numerous hail storms, and produced the best harvest weight in tubers. Following extensive tests of cultivation methods, a CIP research guide is being prepared to help in training and demons- tration of a system of reliable, efficient regimens for propagation and post- planting maintenance of sweet potato plants. It also includes information on the handling of post-in-vitro-propagated plantlets. In other training activities in Peru, more than 40 visitors and trainees from all over the world visited CIP facilities in Lima to gain practical experience in in vitro and rapid multiplication techni- ques. Huancayo had 30 visitors from out- side Peru. They were given information on seed-production technology, seed- program development, and on-farm re- search. A formal seed production course at Cuzco was attended by 68 participants from the national program and various rural development projects. In January, workshops on basic seed distribution were organized in the southern region (Cuzco), and in the central region (Huancayo). In September, at Lima, 22 seed specialists attended a two-day meeting on basic seed production. Africa A two-week seed production course in Rwanda focused on use of TPS as an alternative to traditional seed schemes. A CIP regional scientist participated in a seed-production course held in Holetta, Ethiopia in August, presenting a lecture on rapid multiplication technique~ and their integration into a seed program. Asia In Bangladesh, 99 participants at- tended a one-week course at BARI on use of TPS as transplants, seedling tubers, and tuberlets. In CIP Region VII, innovative and low-cost appropriate technology was a major topic for training farmers and scientists. The emphasis was on rapid propaga- tion techniques, including in vitro propagation; establishment and main- tenance of mother plants; and transplant- ing and management of cuttings in the field as well as TPS. Trainees at Sta. Lucia represented Bhutan (1), the Philippines (4), and Vietnam (3). In China, farmers and scientists worked together in a course to demonstrate new technologies. Seedling tuber production at CIP station, KAFR, El Zayat, Egypt. 119 .. ThrustX Food-Systems Research Thrust Profile: 1989 Food-systems research analyzes patterns and trends of potato and sweet potato production, and assesses the needs of potato producers, market agents, and con- sumers. An overall aim is to evaluate the process of technological change and the impact of crop-improvement programs in developing countries. In 1988, research focused on constraints to potato and sweet potato production and use, farmer experimentation and technological change, marketing and demand, impact of potato improvement programs, prospects for Andean crops, and patterns and trends in root-crop production and use. A survey of national program leaders indicated that the principal constraints to production and use of potatoes and sweet potatoes were concentrated in the post- harvest phase of food production. Studies in Kenya and Peru revealed that farmers' criteria for evaluating new potato varieties often differ sharply from breeders' and agronomists' criteria. Farmers generally look for varieties that meet several broad ~ criteria, rather than varieties that meet only one or a few criteria, such as yield or disease resistance. On-farm research in Indonesia provided a mechanism for farmers to contribute ~ directly to the development of TPS technology. A study in Peru's southern highlands revealed that the potato is the only native Andean food that is eaten frequently in both rural and urban areas. These studies suggest that the future of Andean food crops will depend on the extent to which agricultural research and development activities address the needs of these crops and of their producers. Other major considerations include future economic policies, which in the past have favored the subsidized importation of wheat and rice to the detriment of domestic food production. Marketing work emphasized backstopping studies conducted by NARS scientists. Surveys of national leaders indicated that CIP has contributed significantly to increas- ing the national programs' capacity for training, seed production, storage, and breeding. Benefits at the farm level had been achieved principally through improve- ments in seed quality, and also through the supply of better varieties. Farmer weighing seed for potato tuber moth evaluation trials, Bangladesh. 121 Assessment of Production and Use Constraints To help set research priorities, CIP has begun to systematically assess the needs of the National Agricultural Research Systems (NARS) and of potato and sweet potato farmers, market agents, and con- sumers. Workshops In Argentina and Uruguay, special workshops were organized in 1988 to bring together sweet potato researchers, extension agents, processors, and farmers. After formal presentations and discussion, working groups formulated conclusions and recommendations for future sweet potato research and development. Diagnostic surveys and marketing studies figure prominently in the re- search activities recommended by the working groups. Varieties Planting material Virus Bacteria & fungi Environment Nematodes Insects Consumer storage Seed storage Marketing Demand 2.5 Sweet potato 1.5 NARS Survey In 1987 and 1988, questionnaires were mailed to a total of 117 potato and sweet potato researchers in developing countries, requesting detailed informa- tion on pre-planting, field-production, and postharvest problems. Figure 10-1 shows that for both crops, constraints to production and use were concentrated principally in the postharvest phase, while constraints in the pre-planting phase ranked next. For sweet potatoes, postharvest problems of storage, marketing, and limited demand were considered to be particularly important. In the pre-plant- ing phase, two problems were high- lighted: the lack of early varieties that meet consumers' and processors' re- quirements, and scarcity of planting material. The principal field-production Potato I 0.5 0 0.5 Score: 0: Not present 1 : Little practical importance 2: Somewhat important 3 : Very important 1.5 2 2.5 Source : CIP 1987 constraints survey. Figure 10-1. Scores indicating relative importance of constraints to production and use of potato (121 regions in 38 countries) and sweet potatoes (34 regions in 14 countries). 122 problems were caused by the sweet potato weevil (Cy/as formicarius), drought, poor soils, and weeds. For potatoes, the most important con- straints cited were unstable supplies and prices, and high marketing margins. The scarcity and high cost of planting material also were noted. In the field-production phase, late blight, potato leaf roll virus (PLRV), and tuber moth were the most frequently noted problems. Responses from an expanded survey are being analyzed to determine the main constraints reported by researchers in different agro-ecological zones. A survey report will be published in late 1989. In-depth studies of crop production, marketing, and use are needed to com- plement survey findings and to provide reliable information. These studies would serve as a basis for setting research priorities at CIP and NARS. Field Studies Peru. A multidisciplinary team from CIP and Peru's National Research Institute (INIAA), conducted a field survey in the coastal valley of Canete, which produces about one-quarter of the country's sweet potatoes. Sweet potato was found to be prin- cipally a commercial, dual-purpose crop: most roots are sold for human consump- tion and the foliage is commonly used for feeding dairy cows. Although many varieties are grown, only a few have desirable agronomic traits and good market acceptance. Hence, farmers are eager to obtain early-maturing, dual-pur- pose varieties. Most sweet potato farmers have relatively little management experience with sweet potato. Generally, these farmers have been laborers on cooperatives that only recently have been divided into individual parcels. Thus, ap- plied on-farm research and extension methods show promise for increasing yields and farm incomes. China. Approximately 80% of the world's sweet potatoes are grown in China and extensive biological research has been conducted on the crop here. However, socioeconomic data is scarce, particularly that related to marketing and utilization. CIP contracted the Interna- tional Food Policy Research Institute (IFPRI) to conduct an extensive review of available publications, unpublished reports, and statistical data. This literature review produced little information on potato or sweet potato marketing and utilization; therefore, the IFPRI is now conducting field studies that focus on these topics. Total root-crop production in China has fallen about 20% during the last decade. Three major factors account for this decrease: 1) in recent years, the government has sharply reduced pur- chases of root crops throughout the country, 2) a poor transport and com- munications infrastructure retards private-market integration and dis- courages market agents from handling perishable root crops, and 3) a decentral- ized fertilizer-allocation system provides little incentive for farmers to apply fer- tilizer to root crops. These findings high- light the important roles played by policies and infrastructure in determin- ing sweet potato production trends. Fanner Experimentation and Technological Change Involving farmers more effectively in the formal, science-based research and development system offers great paten- tial for improving the generation and dif- fusion of new technologies that will be used on a large scale. In 1988, field 123 studies were conducted in Kenya, Peru, and Indonesia. Evaluation and Choice of New Varieties Kenya. Potatoes are attractive to many highland farmers because of their dual use as both a food and cash crop. This double purpose gives farmers, most of whom are women, flexibility in the dis- posal of their harvest. The distribution of potato varieties varies greatly because farmers change varieties rapidly. When production levels fall,they often use new varieties to recover previous yield levels, instead of renovating seed of the same variety. Because of the proximity, con- venience, and low cost of local seed tubers, the farmers' own communities are usually the primary source of seed when they decide to renovate or change varieties. Because the gene pool is delineated at this local level, the com- munity serves as a seed bank for in- dividual farmers. This customary Sweet potato farmer, China. 124 reliance on neighbors for seed often leads to communities of farmers who grow much the same varieties. Certified seed is used by iess than 5% of Kenyan farmers. There is little correla- tion between the varieties provided by the seed certification program and those that farmers grow. For example, the popular local variety Nyayo is grown by half the farmers, but no certified seed is produced. Little or no certified seed is produced for several of the more popular varieties. Study findings reflect the high price of certified seed, lack of timely dis- tribution, and farmers' skepticism about its value. These findings also suggest that public officials and farmers differ widely in ·their perceptions of farmers' needs. Cost -benefit analysis of certified seed use on small farms is needed to assess the economic merit of using local seed as compared with certified seed. A possible source of confusion about variety preferences may stem from the different processes of evaluation and choice of varieties. Potato breeders and farmers often concur on the relative agronomic merits of a variety. However, additional considerations such as trader preferences, availability of seed, infor- mation flows, and local environment, in- fluence a farmer's choice of variety. Special concerns are that varieties be resistant to late blight and that they yield well. Farmers who produce primarily for home consumption are concerned that a variety taste good; commercially- oriented farmers are more concerned with a variety's marketability. Because some communities or localities develop reputations among traders as sources of particular varieties, trader demand may effectively limit the choice of variety for commercially-oriented farmers. Peru. Andean farmers are hardwork- ing and pragmatic plant breeders. The farmers' careful evaluation and selection of naturally occurring crosses account for hundreds of native Andean potato varieties with a wide range of agronomic and culinary characteristics. Field studies in the Andes indicate that farmers seldom seek to grow a single ideal potato variety, preferring instead to choose a range of varieties that can fulfill broader needs. Moreover, when farmers are evaluating potential new varieties, they tend to select a variety that meets several needs, rather than a variety that may be excellent for a single or limited purpose. Thus, Andean farmers manage a range of varieties that fulfills their total food system's needs. Individual variety selections are based on their fit within diverse ecological conditions and are generally evaluated in terms of their value as both a cash crop and as a household food. Farmers look for "friendly varieties" that offer the farmer flexibility in use for sale as well as for household consumption. In the 1987/88 season, 17 potential new varieties were evaluated in five central-highland locations in Peru. Farmer group evaluations resulted in the selection of two "friendly potato" can- didates. One selection was based mainly on the potato's ability to meet market requirements. Although it was relatively late-emerging, it performed well in the area. Hail storms did not seriously affect it, and it produced a reasonable number of large tubers and several smaller tubers for seed. It had an attractive color and shape, and was better for use in soups than for boiling. The farmers' second potato selection was based on its ability to meet household needs. It matured quickly, and emerged rapidly in a strong stand with many stems. It withstood light frost, but was somewhat susceptible to hail. It produced plenty of good-sized tubers that were nicely shaped, white-skinned, and similar in ap- pearance to a native variety. This variety cooked quickly and tasted good. Although the farmers appreciated these clones, they were not ready to en- dorse their release as varieties. The farmers take a long-term view of variety selection based on a detailed knowledge of ecological and climatic variations, and they wanted to see how the clones per- formed in different soils under diverse weather conditions. Although Andean farmers do not lay out experiments with several side-by-side replications, they do replicate their "trials" over a period of time in different seasons. The complexity of the local ecology and of household needs is reflected in the farmers' use of 39 criteria to evaluate the varieties. Although breeders using statis- 125 tical models cannot manage such diverse criteria, the farmers' perspectives could be incorporated into the breeders' selec- tion process by involving farmers directly in the evaluation of potential new varieties. These studies on potato varieties are continuing in the highlands, and similar work on sweet potato varieties is begin- ning on the Peruvian coast. Experiments in a Non-traditional Environment Research in San Ramon and Oxapampa, on the eastern slopes of the Peruvian Andes, has shown that many in-migrant farmers experiment extensively with potato cultivation practices. These experiments are primarily "adaptive" in the sense that they 1) seek to adapt previous cultivation practices to new environments, and 2) address varie- tal testing, planting dates, agro-chemical application, and plant shading. Such ex- periments differ from the farmers' "problem-solving" experiments that ad- dress a specific difficulty, such as a new disease arising in a relatively stable en- vironment. They also differ from the "curiosity'' experiments that may stem from the farmers' interest in potential agronomic relationships. Although the methods used in such experiments are not as rigorous as those of formal science, this farm-level re- search presents clear evidence of the farmers' acute observation of the en- vironment, of their ability to respond to changes, and of their crucial role in the process of technological change. Farmer experimentation provides both a human resource and a body of knowledge; thus, it should be stimulated to foster local adaptations of techno- logies and to provide insights for more formal research. 126 Farmer Experimentation with TPS in Indonesia On-farm research is often preceived and planned as an adjunct to experiment sta- tion research that will facilitate technol- ogy transfer. In Indonesia, however, an entirely different approach is being used to involve farmers closely in all stages of the TPS experiments. The purpose is to enlist farmers' active collaboration in the development of systems for producing seed and consumer potatoes from TPS, which potentially may be used throughout Southeast Asia. Farmers and researchers interacted during informal group meetings held every 15 days. The use of TPS under Indonesian conditions was clearly defined as a "learning experience" for everyone, with all farmers and scientists involved as equal partners. No "recipes," "blueprints," or "packages" were specified or sought. Rather, the re- searchers contributed their previous ex- perience, and the farmers contributed their knowledge of local vegetable production and conditions. The farmers received no financial assistance, other than the provision of TPS. As this ap- proach became understood, and as farmers and researchers became familiar with one another, discussions became frank and mutually productive. At the initial meeting in February 1988, researchers outlined several methods for growing TPS and the merits of each method were discussed. The farmers readily understood the topics under discussion and several important considerations were identified. They were more concerned about agronomic characteristics, such as maturity or dis- ease resistance, than about yield per se. They preferred to transplant seedlings directly to the field, as they do for cab- bage or tomato, rather than to produce tuberlets. They indicated a preference for producing consumer potatoes from TPS, as they were not accustomed to pro- ducing and storing seed tubers. The farmers also were concerned about hav- ing a reliable supply of TPS. The 11 farmers attending the first meeting insisted that a packet of (old) TPS used for demonstration be left with them. This seed was sown in a nursery bed and served as a useful point of dis- cussion. In the first season (February-July 1988), farmers were encouraged to produce tuberlets and to learn about the technique. It was feared that this techni- que would be neglected, because of the farmers' professed preference for transplanting. In the second season, (Oc- tober 1988-January 1989), several pos- sible experiments were discussed and 20 farmers were asked to participate. All farmers elected to test the performance of TPS as a source of direct transplants. Eleven of the 20 farmers were given approximately 500 seeds of one of three progenies: Atzimba x DT0-28, Atzimba x R 128.6, or Serrana x DT0-28. As a group, they prepared one demonstration plot, generally following CIP's recom- mendations. Discussions continued, however, and farmers clearly had their own ideas. The other nine farmers then sowed their beds according to their own ideas. No two beds were prepared the same: there were variations in sub- stratum media, shading, watering, and in the use of mulch and pesticides. Emer- gence and vigor varied considerably due to the age of the seed (too old) and the media used. Farmers having poor results were given more seed and several new farmers joined the group. When fresh seed was received from Lima, some farmers requested samples. By this time, farmers were more confi- dent and the group was more adept at informal interaction. Feeling more at liberty to experiment, they radically changed nursery management. During a visit to the Lembang Horticultural Re- search Institute (LEHRI), some farmers were impressed by the use of stem cut- tings: one even began his own program of cuttings. Yields and the number of tubers per m 2 varied considerably but progeny per- formances did not differ widely. Yields increased with later plantings, pre- sumably as a result of improved seed quality and farmer techniques. Analysis and discussion are still required to iden- tify factors that may have contributed consistently to yield differences. The continuing discussions revealed these important considerations: • Farmers still prefer to transplant seedlings to the field rather than to produce tuberlets. • They prefer to produce seedlings in small trays and to transplant to nursery beds for tuberlet produc- tion or to banana-leaf pots for direct transplanting to the field. • They were unconcerned with shape, size and color of tubers dunng this early stage. • All farmers said that they would keep their produce from the next season as seed, and they showed concern about seed storage. The potential for introducing rapid multiplication techniques has been ex- plored, and five farmers have requested mother plants and training in this area. 127 Marketing and Demand Thrust X has two marketing goals: to develop an information base that other institutions and researchers can draw upon, and to help strengthen NARS' capabilities in conducting marketing and demand studies. Backstopping NARS Research. To help backstop marketing studies con- ducted by NARS, support was provided in planning, reviewing, and financing col- laborative projects and research con- tracts. A study in Thailand examined marketing, consumption, and demand for potato products. Draft reports of potato marketing studies were prepared by researchers from Indonesia, Zaire, the Dominican Republic, and Bangladesh. A central finding of the Thailand Study was that potato consumption is dis- couraged by high potato prices and the low income of many urban consumers. The Indonesian Study revealed that potatoes produced in mid-elevation areas of this country were of relatively poor quality and were difficult to market. The Zaire Study concluded that potato marketing in Zaire's capital, Kinshasa, was both risky and costly because of the irregularity of supply and the perish- ability of potatoes produced in the Kivu area. Exploration of the economic feasibility of simple processing was sug- gested as a step toward lower marketing costs and risks. The Dominican Republic Study indicated that many commonly held beliefs about the "exploitative" practices of middlemen may overlook the essential functions that marketing agents perform, such as assembly, transporta- tion and bulk breaking. The Bangladesh marketing Study found that, despite peri- odic market surpluses and price declines, potato production is still profitable for most farmers, irrespective of the size of 128 their farms. The study found that, con- trary to popular belief, large growers who sell their harvest on the farm received lower prices than do growers who sell their potatoes in the marketplace. The findings also indicated that in some parts of the country, traditional potato storage is more profitable than is cold storage. This helps explain why cold-storage facilities are seldom used in areas such as Tongibari. PRACIPA - Commercialization Thrust X activities also backstop mar- keting studies conducted by national col- laborators in the Andean Cooperative Potato Research Program (PRACIPA). Under this program, which completed its first year of activities in March 1988, marketing studies have been conducted by local researchers in five Andean countries: Bolivia, institutional market- ing of seed potatoes; Colombia, market- ing of processed potatoes; Ecuador, marketing of seed potatoes; Peru, developing a market information system for consumer potatoes; and Venezuela, marketing of consumer potatoes in the western highlands. Bolivia. PRACIPA-Bolivia surveyed more than 15 institutions (public, private, and combined) that distribute seed potatoes in the Cochabamba region. In 1986 and 1987, two of these organizations handled over 75% of the seed in the country. Most of the seed consisted of Dutch varieties such as Alpha, Cardinal, and Diamant. The survey results and other findings were presented in a workshop organized by the Instituto Boliviano de Technologia Apropecuaria (IBT A) in September 1988; a second sur- vey is under way to assess farmers' par- ticipation in, and opinions of, the various seed-potato distribution programs. Colombia. Colombia has few tradi- tional potato processing facilities. To as- sess the economic feasibility of village-level processing, surveys were made of 81 growers, 133 urban con- sumers, and operators of 20 eating estab- lishments in the Pamplona region in 1987 and 1988. Nearly all of the farmers were interested in simple potato processing facilities, preferably in cooperative units. Consumers and restaurant owners ex- pressed an interest in the various products processed from potato flour they were shown, but disliked their color (grey) and hardness. In addition to con- tinued backstopping of the technical work in the Pamplona area, PRACIPA- Colombia is now conducting an informal survey in the Pasto-Ipiales region to as- sess the feasibility of using processed potatoes to feed guinea pigs. Eeuador. The national potato pro- gram in Ecuador has recently upgraded its technical capability to produce im- proved seed. To determine the demand for this seed, surveys were made of mul- tipliers, users, and non-users of improved seed in central Ecuador. The results show that, contrary to the widely-held belief, most multipliers do not sell seed to Impact As.sessment NARS Survey In 1987, a questionnaire was mailed to the leaders of national potato programs in Africa, Asia, and Latin America to assess the status of national potato programs, their research problems, and the impact of CIP and NARS activities to date. Responses were received from 41 nation- al leaders. Status of National Programs. The data indicate that three-quarters of the countries surveyed now have potato- breeding programs. Thirteen countries other producers. Instead, they keep most of it for their own use. Preliminary results of a survey in northern Ecuador show a similar pattern. Peru. Work during 1987 and 1988 in- cluded helping prepare a regular market bulletin for potatoes in central Peru; set- ting up a computerized database cover- ing monthly market statistics for the past 25 years; and surveying government per- sonnel and growers in the central high- 1 ands who receive the bulletin. Government personnel felt the bulletin was useful and requested that it appear bimonthly. The National Farmers Or- ganization has expressed an interest in reproducing copies of the bulletin for dis- tribution through its local chapters. INIAA has initiated new research on the marketing of seed and processed potato products. Venezuela. More than 100 potato growers were surveyed in the Tachira region of Venezuela. Findings emphasize the highly commercial orientation of producers, the predominance of tradi- tional sources of market information, and the need for improved availability of seed and access to transportation from farm to marketplace. have comprehensive breeding programs and gene banks. Their activities include crossing, screening, clonal evaluations, and varietal releases. Eight countries have intermediate-level breeding programs that utilize germplasm popula- tions bred elsewhere. Ten countries have variety-testing programs that depend on imported advanced clones or varieties. All of the countries polled can receive and utilize tubers, 32 can handle TPS, and 28 can handle in vitro materials. 129 More than half of the countries have selected and released new varieties from genetic materials provided by CIP. Three-quarters of the countries are cur- rently conducting research on TPS and diffused-light seed storage (DLS). The new D LS technology has reached more countries than the other storage techni- ques. Impact of Collaboration. National leaders indicate that collaboration with CIP has had a positive impact in several areas, most notably in improving links with other programs; expanding training; improving planning, coordination, and management; and, in releasing of new varieties. Most respondents felt that col- laboration with CIP had helped the pro- gram to increase its staff and budget. The survey findings suggest that na- tional program/CIP collaboration has helped farmers obtain better quality seed,improve seed storage and obtain better varieties. Impact of CIP Research Contracts. CIP contracts research on priority topics at institutions around the world. A ques- tionnaire was mailed to the leaders of all such contracts, requesting their views on the benefits of their contract in terms of improvements in training (amount, quality), research facilities, theses, publi- cations, and varieties released. The ques- tionnaire also solicited information on the use of new research techniques or methods in seed production, in exten- sion, and by farmers. Benefits. The survey respondents in- dicated that the principal benefits had come through expanded training and publications (Table 10-1). In developed countries, significant benefits of research contracts accrued to developing-country nationals who prepared theses or worked as research assistants. In both developed and developing countries, most breeding contracts helped support student thesis work. In developing countries, many re- search contracts helped to improve re- search facilities. Use of New Techniques. Most research contracts have led to the development of Table 10-1 . Principal benefits of research contracts and users of new techniques and methods (% respondents indicating each answer). Developed countries Developing countries Breeding Other Breeding Other contracts contracts contracts contracts Principal benefits: Number of people trained 9 5 7 7 Quality of training 8 3 6 7 Research facilities 5 3 6 5 Number of theses 9 2 5 4 Number of publications 10 4 6 6 New varieties released 4 2 4 Principal users: Researchers 10 4 7 6 Seed programs 5 2 3 4 Extension 2 2 3 5 Farmers 2 2 3 4 No. observations 10 5 7 7 Source : GIP survey of research contracts 1986-87. 130 .. new methodologies; fewer have resulted in new production methods. In developed countries, relatively few new technologies have been used by seed programs, in agricultural extension ac- tivities, or by farmers. In contrast, in developing countries, new techniques have been used more fre- quently in seed programs, and by exten- sion agents and farmers. Research contracts have improved ties between CIP and research institutes around the world; they also have pro- moted an information and technology ex- change among countries. For example, Argentina's National Research Institute (INT A), under contract with CIP, Prospects for Andean Crops Over 40 food crops were domesticated in the Andes of South America in pre- Columbian times. These include the potato, as well as: • oca (Oxalis tuberosa) • mashua (Tropaeolum tuberosum) • quinoa ( Chenopodium quinoa) • caiiihua (Chenopodium pal- lidicaule) • kiwicha (Amaranthus caudatus) • lupines (Lupinus mutabilis) These crops are potentially valuable food resources, but with the exception of the potato, production and consumption of these crops are declining in the Andean regions. The Peruvian government and many non-governmental organizations have in- itiated programs to promote the produc- tion and consumption of these crops. To provide a solid knowledge base to help in the planning of improvement programs, a study was conducted in the department released a new potato variety, "Serrana." It has been distributed to many other countries, and is now grown in Argentina, Brazil, the Republic of Korea, Peru, the Philippines, Thailand, and Vietnam. The Plant Research Institute in Aus- tralia has a contract with CIP to provide pathogen-free germplasm for regional trials in Southeast Asia. In addition to benefiting developing countries in the region, the experience has allowed the Institute to become the center for impor- tation of potato germplasm into Aus- tralia. A similar project with sweet potatoes is now under way. Study objectives were to identify 1) the role these crops play in local farming systems, and in rural and urban diets, and 2) the principal constraints to greater production and utilization. Native An- Table 10-2. Crops grown in two communities of Cuzco Department, Peru. Average area % of farmers planted with growing the in the crop Crop crop (m2) Potato 100 9,354 Olluco 76 1,943 Barley 63 3,203 Broad bean 59 1,340 Mashua 43 1,163 Oca 27 1,321 Oat 25 4,505 Lupine 24 1,008 Quinoa 20 745 Oca/Olluco 12 2,000 Broad bean/quinoa 4 1,300 Others 12 136 of Cuzco, in the Peruvian highlands. Source: Cuzco farm survey 1987. 131 dean crops generally were found to grow at between 3,500 and 4,000 m, usually in complex farming systems that include both crops and livestock. In the five com- munities surveyed in the districts of Ccatcca and Colquepata, potato is the most commonly grown crop, followed by olluco, barley, and broad bean (Table 10-2). Rotations generally include rela- tively long periods of fallow (up to 7 years) and the total cultivated area averages between 1 and 2 ha per family. Rural respondents indicated that low yield and the scarcity of good crop land are two principal barriers to expanding the production of native Andean crops. Table 10-3. Farmers' perceptions of the principal factors limiting production of Andean crops in the two communities of Cuzco Department, Peru (% farmers reporting each factor) . Quinoaa Lupinesb Ollucac Ocac Mashuac Low yield 61 22 11 16 17 Scarcity of good land 21 38 48 32 28 Climate problems 12 37 11 4 8 Scarcity of seed 7 4 8 17 Pests and diseases 15 20 Storage problems 6 4 8 Other problems 4 4 16 28 Total 100 100 100 100 100 a A cereal. b A pulse. c Root crops. Source: Cuzco farm survey 1987. Rural areas (N = 51) City of Cuzco (N 100) I Root Crops Potatoes Churio Olluco -; Mashua Oca Cereal-based foods 132 Bread Barley Wheat Rice Noodles Quinoa ~ Cariihuaco Kiwi cha Pulses Dried broad beans Fresh broad beans Lupines I I I I I I I I 100 80 60 40 20 0 20 40 60 80 100 Figure 10-2. Consumption of selected foods: percentage of respondents reporting "frequent" consumption in the Department of Cuzco, Peru. " (Table 10-3). Climatic problems were also noted, particularly for quinoa and lupines. Seed scarcity, insects, diseases, and storage were also mentioned as problems for root crops. Consumption patterns in rural areas reflect production patterns. Rural diets are heavily dependent on tubers (Fig. 10- 2). Because of the relatively good storage High Low properties of potatoes, and particularly those of chuiio (dried potatoes), the crop plays a particularly significant role in the rural food system. Virtually all rural families eat potatoes frequently; three- quarters eat chuiio, and approximately half eat olluco. Bread is the only cereal- based food that is eaten frequently in rural areas. Medium Pulses Rural Cereal- based food Figure 10-3. Foods consumed at lunchtime in rural areas and in the city of Cuzco, by socioeconomic strata (% respondents). 133 Aside from the technical constraints, cropping patterns reflect the increasing degree of commercialization of agricul- ture. When farmers require more money, for example, to pay for school fees and consumer goods, they plant a larger proportion of their land with cash crops, principally potatoes, barley, and oats. The survey revealed that diets in the city of Cuzco are much more diverse than those in rural areas, and are closely linked to socioeconomic status. Con- sumption of tubers and cereal-based foods tends to decline sharply as incomes rise, whereas consumption of meat and vegetables increases significantly. Consumption of wheat-based pro- ducts, e.g., bread and noodles, and of rice is increasing in both rural and urban areas (Figure 10-3). This can be at- tributed to long-term governmental sub- sidies for the importation of wheat and rice. Other factors influencing consump- tion patterns in the city of Cuzco are price and availability. Some tubers, such as ol- luco, oca, and mashua, are available in city markets for only a short time each year after harvest. Cereals such as kiwi- cha and caiiihua are scarce and costly Analysis of Patterns and Thends Worldwide, there is little systematic in- formation on potato and sweet potato production and use and on the needs of producers and consumers. Thrust X ac- tivities help generate and disseminate needed information. Statistical Database CIP maintains a computerized database that contains country-level estimates of root-crop production and use, as well as major economic and demographic indi- cators. This information is used to generate comprehensive statistical publi- cations and to provide an information 134 throughout the year. The high prices of chuiio and quinoa sometimes discourage use by urban residents. Few agricultural research and exten- sion activities have addressed the needs of farmers who grow native Andean crops. As rotations have intensified and as new pests, diseases, and fertility problems have developed, the national agricultural research systems have not been able to offer farmers adequate solu- tions. Consequently, both production and consumption of native Andean crops have declined in rural areas. In urban areas, the decreasing availability of An- dean crops has increased their price and discouraged consumption. Additionally, for several years, economic policies have tended to raise the relative price of native Andean crops by subsidizing the impor- tation of cereals, particularly rice and wheat. Future production and use of Andean crops will depend largely on government price and trade policies and on the de- gree of commitment to crop research and extension built around the needs of An- dean farm families. service for personnel at CIP and collabo- rating institutions. The database is up- dated annually by incorporating recent FAO and World Bank estimates. Publications The book Underground Crops (Winrock International, 1988) represents the first comprehensive use of the entire database to produce a reference book on global root-crop production and use. An initial narrative section outlines the salient characteristics of root crops, discusses accuracy of available statistics, and sum- marizes the highlights of the book's 31 ·-· tables. A special commentary is included on African root-crop data. The tables list national statistics for the years 1961 to 1985, including information on total pro- duction, area, and yields of cassava, edible aroids, potato, sweet potato, yam, and unspecified root crops. Recent es- timates also are provided for per capita root-crop production; availability for consumption; supply of dietary energy and protein; root-crop trading, and farm- gate prices. A volume titled World Geography of the Potato (in progress) will :;ynthesize the mass of country-specific data avail- able at CIP and in NARS. The book in- cludes country and world maps of potato production zones. It identifies, describes, and classifies farming systems in develop- ing countries where the potato plays, or potentially could play, an important role. It also describes the ecology, climate, po- pulation patterns, and cropping systems of each production zone. Potato storage in Egypt. Country-level Research A graduate student at the Universidad Nacional Federico Villareal has mapped out Peru's principal agro-ecological zones of potato production. This map significantly contributes to under- standing potato production patterns in the extremely diverse ecology of the Andes, where the potato originated. Peru's national potato program will use the map in planning and targeting potato- improvement efforts. The government of Indonesia, via CRIFC, is expanding its research on both potatoes and sweet potatoes. As a con- tribution to the decision-making process, provincial- and district-level data on potato and sweet potato production from the Central Bureau of Statistics, the Of- fice of Statistics, and district offices in Java were compiled in 1988. These data were assembled in a com- puterized database, and a report contain- ing statistical tables, figures, and maps is scheduled for publication in 1989. 135 136 •. Human Resources Development Profile: 1989 The Training and Communications Department coordinated CIP's human resource development efforts in 1988, providing backup assistance for research administrative programs at headquarters, in all CIP regions, and in collaborative NARS projects. The closely associated units of Training, Communications Support, and Information Services provided technical and professional support that ranged from field demonstrations and evaluations with farm families to electronic, machine-to-machine communications. A total of 302 national research and education collaborators from 57 countries participated in 16 specialized activities. The 16 production activities involved 353 national researchers, extension, and education collaborators and farmers from 55 countries. CIP scientists at headquarters worked alongside 57 visiting scientists from 29 countries, for a total of 221 weeks. And 94 graduate students and national collaborators from 14 countries did their research at headquarters, regional sites, or universities overseas. CIP was also host to the workshop "Human Resource Develop- ment Through Training," with participants from 13 CGIAR centers and 4 non-as- sociated centers. CIP's administrative and research staff were assisted in designing and planning print, photographic, and electronic media. Media production in support of ad- ministration included the annual report, self-study, budget documents, a public- awareness brochure, and an audio-visual presentation for visitors. CIP's research-based publications include 9 works in Spanish, 18 in English, and 7 in French. Co-publishing efforts included contracts to translate CIP technical media into French and Chinese. To enhance skills in applied communications technology and related training skills in human resource development, the Department provided informal learning sessions and on-the-job experiences for visiting scientists at head- quarters, as well as in regional and in-country settings including Chile, Ecuador, and Colombia. Media developed for this work included technical information bulletins and complementary slide sets, plus research guides and course lecture materials and handouts. In addition, advisory support was provided to national programs and networks, and included assistance to PROCIANDINO. RICA, COTESU, SEINPA, and ALAP. Collaboration was begun with other Centers to exchange information on policies and to share experiences and tools. These included sharing a bibliography of reference documents used at CIP for translation. CIAT was contacted for collaboration on machine-assisted language translations from English into Spanish. Hands-on practice for trainees at an internati onal production course , Shimla, India. 137 The Information Services unit developed a CIP Bibliographic Database of more than 25,000 references for conventional and non-conventional literature in CIP's library. Other new services include access to potato and sweet potato references from CABI and AGRIS magnetic tapes, via a computer at CIP headquarters. Databases such as AGRIS in Vienna and DIALOG also can be accessed via satellite. A specialized bibliography on TPS has been prepared. Other activities to encourage exchange among the Centers include a database on publishing procedures, training in scientific writing and consultancy support to the Latin American Potato Journal. Developing Human Resources CIP's global human resource develop- ment program builds upon a regional and national network of farmers, agricultural researchers, extensionists, educators, and businessmen. The Training and Communication Department coordinates these efforts within three closely associated units: Training, Communication Support, and Information Services. Communication roles are central to this process, and CIP staff activities range from traditional field work with farm families to electronic, machine-to-machine communication. They provide both direct technical ser- vices and professional consultancies to support research and administrative programs at headquarters, in all CIP regions, and in collaborative NARS projects. Training The training support strategy for human resource development is based on the premise that communication skills should be learned in conjunction with crop-improvement skills. CIP training objectives are classified as 1) produc- tion-oriented, to help participants respond to farm-level problems, and 2) specialized, to enhance research capabilities (Table 11-1). 138 Highlights of 1988 activities include: • 302 national research and education collaborators from 57 countries participated in 16 specialized group training activities. • 353 national researchers, ex- tension agents, education collaborators and farmers from 55 countries par- ticipated in 16 production group training activities. • 57 visiting scientists from 29 countries worked with CIP scientists at headquarters in Peru for a total of 221 weeks. • 94 students and national col- laborators from 14 countries carried out their thesis re- search at headquarters, regional sites, or at col- laborating universities. Other training included informal ses- sions and on-the-job experiences at headquarters in Peru to help visiting scientists communicate their research findings more effectively; training of selected national scientists and com- •· Table 11-1. Training activities of GIP and the collaborative research networks, 1988. No. of No. of Region Activity participants countries Headquarters-Peru ·•' Production with special a emphasis on seed production 18 10 Workshop on marketing (PRACIPA) 12 7 Visiting scientists 57 29 Scholarships 24 10 Student assistantships 17 1 Preprofessional practiceb 53 5 Region I Argentina Workshop on advancements in potato breeding 29 6 Colombia Workshop on field-level diagnostic skills (CIP/CIAT) 16 10 Colombia Potato tuber moth 19 6 Region II Mexico Potato germplasm management (PRECODEPA) 13 8 Region Ill Zimbabwe Workshop on improvement in seed production and distribution 15 10 Kenya Postharvest technology 16 10 Rwanda Seed production 6 2 Ethiopia Seed production 35 1 Rwanda Workshop on late blight (PRAPAC) 34 5 Zaire Production 31 Region IV e- Egypt Production 27 Morocco Production 15 Turkey Production 12 Tunisia Seed production and storage 18 ~ Region V Cameroon Workshop on potato production and constraints in West and Central Africa 11 10 Cameroon Production a 16 Nigeria Vegetative seed productiona 27 14 Region VI India Modern methods in potato production 23 4 India Sweet potato production 16 4 India Workshop on sweet potato improvement 32 15 India Workshop on marketing and processing 18 9 Sri Lanka Workshop on TPS, extension and on-farm technology transfer 18 6 Region VII Burma Production 24 1 Fiji Production 16 9 Philippines Production a 17 Region VIII - China Workshop on potato production 33 11 China True potato seed 12 1 China Workshop on postharvest 37 14 China Sweet potato virology 8 China English language 9 China Sweet potato in vitro germplasm management 12 a United Nations Development Program (UNDP) b 45 trainees from Peru, 8 from developed countries 139 municators on course organization, management, and evaluation (e.g., na- tional staff from Chile); development of communications-related learning ex- periences in regional and in-country courses, e.g., Ecuador and Colombia; and preparation of training materials, in- cluding technical information bulletins and complementary slide sets, and other media such as research guides, lecture materials and handouts. CIP was host to a workshop for all international agricultural research centers on "Human Resource Develop- ment Through Training." Participants from 13 CGIAR centers and 4 non-as- sociated centers made recommendations that were subsequently approved by the Center directors. A working group was named to further evaluate the recom- mendations and prepare viable plans of action, and joint efforts began immedi- ately following the workshop. ministrative programs. The media products ranged from photos of field and laboratory experiments to editorial help with journal articles and co-published books (Table 11-1). Technical and professional communications services in- cluded writing and editing, audience analysis, language translation, graphics and illustration, printing and audiovisual production, and distribution. CIP's pub- lications and learning materials now in- clude co-publishing efforts and other contracts to translate CIP technical media and the CIP circular into the the French and Chinese languages. Media production in support of ad- ministration included the annual report, a self-study and budget documents, a public-awareness brochure, and an audio-visual presentation for visitors to CIP. Support to National Programs and Networks Communication Support National program collaborators, mainly Unit functions included planning and in Latin America, were assisted in iden- design for print, photographic, and tifying communications problems and in electronic media for research and ad- seeking solutions. Accessing database, Information Service Unit. 140 This assistance included support to: • PROCIANDINO to help develop communication strategies for transfer of tech- nology to their audiences. • Red Interamericana de Com- unicadores Agricolas (RICA) to help generate an informal flow of information among com- municators in agricultural re- search institutions in Latin America. • Country-level projects in Peru, e.g., COTESU and SEINP A, as well as ALAP. Information Services Development of Databases. A CIP Bibli- ographic Database has been developed, containing conventional and non-con- ventional literature from CIP's library that is related to potatoes and sweet potatoes. The database now has more than 25,000 references; it includes bibli- ographical data, keywords, and abstracts in the English, Spanish, and French lan- guages, if available in the original docu- ment. Potato and sweet potato references are accessed from CABI and AGRIS magnetic tapes maintained by a com- puter at CIP headquarters in Lima. Other databases (for example, A GRIS in Vienna and DIALOG in the USA) are accessed via satellite. A database on publishing procedures has also been designed and procedures are available that provide instructions for submission of articles to more than 100 journals. Services. ISU services directly sup- port CIP headquarters and regional staff and are free-of-charge to qualified users in national and regional programs, in- cluding researchers, university profes- sors, and students. Retrospective Searches. A total of 1,260 retrospective searches have been conducted for 152 CIP staff and 329 na- tional researchers. Selective Dissemination of Informa- tion. This quarterly service is available to recommended users who have a continu- ing need for up-to-date information on specific topics. Over 200 profiles have been developed and 114 users are being serviced. Specialized Bibliographies. Users other than CIP staff may require special- ized bibliographies prepared from CIP's priority research areas; three such bibli- ographies have been prepared from the CIP database. Training demonstrations: All visiting scientists at headquarters in Lima were given an orientation on how to use the CIP information services. Participants in group training exercises received instruc- tion on how to access information, and a slide set was prepared for use by regional staff in in-country and regional activities. Cooperation International Agricul- tural Research Centers: As a result of the first CGIAR Documentation and In- formation Services Meeting held at CIP in 1985 and a subsequent meeting was held at ICRISAT. ISU staff have been instrumental in developing action plans for inter-center collaboration. 141 List of Abbreviations and Acronyms A GRIS AID ALAP AMV ANOVA APLV APMV ARARI AVRDC a.i. avg BARI BPI BW CAAS CABI CDH CGA CGIAR CIAAB CIAT CIP CIPC CMS CNPH COTESU CPRA CPRI cm CV CV. DLS DMRT DNA d EB EBN EDTA ELISA 142 International Information System for Agricultural Sciences and Technology (Italy) Agency for International Development Asociacion Latinoamericana de Papa alfalfa mosaic virus analysis of variance Andean potato latent virus Andean potato mottle virus Aegean Regional Research Institute (Turkey) Asian Vegetable Research & Development Center (Taiwan) active ingredient average Bangladesh Agricultural Research Institute Bureau of Plant Industries (Philippines) bacterial wilt Chinese Academy for Agricultural Sciences Commonwealth Agricultural Bureau International (CAB In- ternational) Centre pour le Developpment de l'Horticulture (Senegal) general combining ability Consultative Group on International Agricultural Research Centro de Investigaciones Agricolas "A-Boerger" (Uruguay) Centro Internacional de Agricultura Tropical (Colombia) Centro Internacional de la Papa (Peru) isopropyl-N-3-chlorophenyl-carbamate cytoplasmic male sterility Centro Nacional de Pesquisa de Hortali~s (Brazil) Cooperacion Tecnica Suiza Centre de Perfectionnement et de Recyclage de Pratiques Agricoles de Saida (Tunisia) Central Potato Research Institute (India) centimeter coefficient of variation cul ti var diffused-light store Duncan's multiple range test deoxyribonucleic acid day early blight endosperm balance number ethylenediaminetetraacetic acid enzyme-linked immunosorbent assay EMBRAPA ENEA ERSO FAQ FDR FONAIAP GA GAAS g h ha hrp IAO IBPGR IBTA ICA ICAR ICRISAT ICTA IDEAS IDRC IFPRI UTA INIA INIAA INIAP INIFAP INIPA INIVIT INPT INRA INRAT INTA IPO ISABU kb L LAR LB LEHR I LER Empresa Brasileira de Pesquisa Agropecuaria (Brazil) Energia Nucleare e delle Energie Alternative (Italy) Consorzio "Mario Neri" (Imola, Italy) Food and Agriculture Organization of the United Nations first division restitution Fondo Nacional de Investigaciones Agropecuarias (Venezuela) gibberellic acid Guandong Academy of Agricultural Sciences gram hour hectare hypersensitive response Istituto Agronomico per l'Oltremase, Italy International Board for Plant Genetic Resources Instituto Boliviano de Tecnologia Agropecuaria Instituto Colombiano Agropecuario (Colombia) Indian Council for Agricultural Research International Crop Research Institute for Semi-Arid Tropics Instituto de Ciencia y Tecnologia Agricolas (Guatemala) The Venezuelan International Institute of Higher Studies International Development Research Centre (Canada) International Food Policy Research Institute International Institute of Tropical Agriculture (Nigeria) Instituto Nacional de Investigaciones Agropecuarias (Chile) Instituto Nacional de Investigacion Agraria y Agroindustrial (Peru) Instituto Nacional de Investigacior.es Agropecuarias (Ecuador) Instituto Nacional de Investigaciones Forestales y Agropecuarias (Mexico) Instituto Nacional de Investigacion y Promocion Agropecuaria (Peru) National Institute for Research in Tropical Roots and Tubers (Cuba) Institut National de la Pomme de Terre (Togo) Institut National de la Recherche Agricole (Senegal) Institut National de la Recherche Agronomique de la Tunisie Instituto Nacional de Tecnologia Agropecuaria (Argentina) Research Institute for Plant Protection (Netherlands) Institut des Sciences Agronomiques du Burundi kilobar liter leaf area ratio late blight Lembang Horticultural Research Institute, Indonesia land equivalent ratio 143 LSD LUE lat. long. MA MBN MJ m meq min ml mm mo NAR NARS NASH ND NS NSAC nm ns OP PBI PCARRD PCN PIPA PLRV PNAP PRACIPA PRAPAC PRECODEPA PRI PROCIANDINO PROCIPA PSTV PTM PTV PVA 144 least significant difference light use efficiency latitude longitude monoclonal antibody Meloidogyne bacterial wilt nematode resistant material mega joule meter miliequivalent minute milliliter millimeter month net assimilation rate National Agricultural Research Systems nucleic acid spot hybridization test not determined not studied Nova Scotia Agricultural College nanometer not significant open-pollinated Plant Breeding Institute (Cambridge, UK) Philippine Council for Agriculture and Resources Research and Development potato cyst nematode Programa de Investigacion en Papa (Peru) potato leafroll virus Programme National de l'Amelioration de la Pomme de Terre (Rwanda) Programa Andino Cooperativo de Investigacion en Papa (An- dean region) Programme Regional d'Amelioration de la Culture de Pomme de Terre en Afrique Centrale (Central Africa) Programa Regional Cooperativo de Papa (Central America- Caribbean) Plant Research Institute Programa Cooperativo de Investigacion Agricola para la Sub- region Andina Programa Cooperativo de Investigaciones en Papa (southeast region of South America) potato spindle tuber viroid potato tuber moth Peru tomato virus potato virus A PVM PVS PVV PVX .. PVY ppm RCB RGR RH RICA RLER RNA SAPP RAD SCRI SD SED SEINPA SLA SPCV SPFMV SPLV SPMMV sec TPS t UNA UNDP US AID var. vol vs. WUE wk wt yr •' potato virus M potato virus S potato virus V potato virus X potato virus Y parts per million randomized complete block design relative growth rate relative humidity Red Interamericana de Comunicadores Agricolas relative leaf expansion rate ribonucleic acid Southeast Asian Program for Potato Research and Develop- ment Scottish Crops Research Institute (Scotland) standard deviation standard error or difference Semilla e Investigacion en Papa (Peru) special leaf area sweet potato caulimo-like virus sweet potato feathery mottle virus sweet potato latent virus sweet potato mild mottle virus second true potato seed ton Universidad Nacional Agraria - La Molina (Peru) United Nations Development Programme United States Agency for International Development variety volume versus water use efficiency week weight year 145 Papers Published in Scientific Journals Aley, P., and E. R. French. 1987. Capacidad de biovares I y II de Pseu- domonas solanacearum para causar infeccion latente en tuberculos de papa. Fitopatologia 22(2):48. (Abstr.) Antle, J. M., and C. C. Crissman. 1988. The market for innovations and short run technological change: evidence from Egypt. Economic Development and Cultural Change 36(4):669-690. Atlin, G. N., and S. G. Wiersema. 1988. Selection against inbred seedlings in mixtures of inbred and hybrid true potato seed. Potato Research 31:105- 112. Bartolini, I., and P. J atala. 1988. Separacion de componentes del medio de cultivo de bongos y nema- toxinas producidas por bongos con tres tipos de Sephadex. [Separation of components of fungal media and nematoxins produced by fungi with three types of Sephadex.] Nematropica 18(1):2. (Abstr.) Baulcombe, D. C., and E. N. Fernandez- Northcote. 1988. Detection of strains of potato virus X and of a broad spectrum of potato virus Y isolates by nucleic acid spot hybridization (NASH). Plant Disease 72:307-309. Bryan, J. E. 1988. Implementation of rapid multiplication and tissue cul- ture methods in third world countries. Am. Potato J. 65:199-207. Canto-Saenz, M., R. Anguiz, and H. Tor- res. 1988. Interaccion entre Verticil- lium dahliae y Pratylenchus flakkensis in Potato. [Interaction between Ver- ticillium dahliae a n d Pratylenchus flakkensis.] Fitopatologia 22:64. (Abstr.) Canto-Saenz, M., N. Chacon, and P. Jatala. 1988. Damage threshold den- 146 sity of Globodera pallida on potatoes in Pomamanta, Peru. In Abstracts of the E.S.N. XIXth International Nematology Symposium, Uppsala, Sweden. August 7-13. p. 20. Caringal, E. M., and P. Vander Zaag. 1987. On-farm evaluation of rapid multiplication of potatoes (Solanum spp.) in Benguet. Phil. Agr. 70:101- 107. Chandra, R., J. H. Dodds, and P. Tovar. 1988. In vitro tuberization in potato. IAPTC Newsletter 55:10-20. Chavez, G. L., and K. V. Raman. 1987. Evaluation of trapping and trap types to reduce damage to potatoes by the leaf miner Liriomyza huidobrensis (Diptera: Agromyzidae) Insect Sci. Applic. 8(3):369-372. Chavez, R., C . R. Brown, and M. Iwanaga. 1988. Transfer of resistance to PLR V titer buildup from Solanum tuberosum to a tuber-bearing Sola- num gene pool. Theor. Appl. Genet. 76:129-135. Chavez, R ., M. T. Jackson, P. E. Schmiediche, and J. Franco. 1988. The importance of wild potato species resistant to the potato cyst nematode, G/obodera pa/Iida, Patho- types P4A and PsA, in potato breed- ing. I. Resistance studies. Euphytica 37:9-14. Chavez, R., M. T. Jackson, P. E. Schmiediche, and J. Franco. 1988. The importance of wild potato species resistant to the potato cyst nematode, G/obodera pa/Iida, Patho- types P4A and PsA, in potato breed- ing. II. The crossability of resistant species. Euphytica 37:15-22. Chavez, R., P. E. Schmiediche, M.T. Jackson, and K.V. Raman.1988. The breeding potential of wild potato species resistant to the potato tuber mo t h , Phthorimaea operculella (Zeller) Euphytica. 39:123-132. Delgado de la Flor, R., P. Jatala, and A. Gonzalez. 1988. Distribucion del nematodo quiste de la papa (Globodera spp.) en Cuzco, Peru. [Distribution of the potato cyst nematode (Globodera spp.) in Cuzco, Peru.] Nematropica 18(1):4. (Abstr.) Delgado de la Flor, R., P. Jatala, and A. Gonzalez. 1988. Efectos de algunos extractos de plantas sabre la actividad de Caenorhabditis elegans. [Effects of some plant extracts on the activity of Caenorhabditis elegans.] N ematro- pica 28(2):4. (Abstr.) Demagante, A. L., and P. V ander Zaag. 1988. Potato (Solanum spp.) growth and yield under isohyperthermic con- ditions as influenced by weed control treatment. Phil. Agr. 70(1-2):91-99. Demagante, A. L., and P. Vander Zaag. 1988. The response of potato (Sola- num spp.) to photoperiod and light intensity under high temperatures. Potato Res. 31:73-83. Dodds. J. H. 1988. Tissue culture tech- nology. Practical application of sophisticated methods. Amer. Pot. J. 65:167-180. Dodds, J. H., and J. M. Jaynes. 1987. Crop plant genetic engineering. Science fiction to science fact. Out- look on Agriculture 16:11-115. Ekanayake, I. J., S. K. De Datta, and P. L. Steponkus. 1989. Spikelet sterility and flowering response of rice to water stress at anthesis. Annals of Botany 63:257-264. Ekanayake, I. J ., P. Malagamba, and D. Midmore. 1988. Effect of water stress on yield indices of sweet potatoes. In Abstracts of Eighth Symposium ofln- ternational Society for Tropical Root Crops. pp. 31-32. (Abstr.) Ekanayake, I. J., and D. J. Midmore. 1988. Drought response of potatoes in warm tropical areas. In Abstracts of International Conference on Dry Land Farming, Amarillo/Bushland, Texas, U.S.A., August 15-19. 1988. p. 8. (Abstr.) Ekanayake, I. J ., and P. L. Steponkus. 1988. Water stress induced female floral defects anthesis, and grain sterility in upland rice. Plant Physiol- ogy 84( 4):141. Escobar, V., and P. Vander Zaag. 1988. Field performance of potato (Solanum spp.) cuttings in the warm tropics: influence of planting system, hilling, density and pruning. Am. Potato J. 65:1-10. Estrada, N., and L. Valencia. 1988. Desarrollo de cultivares de papa resistentes a la palomillaPhthorimaea opercu/ella (Zeller) en Colombia. Revista Latinoamericana de Papa 1 (1):64-73. Fabian, 0., and E. N. Fernandez- Northcote. 1988. Evaluacion de ger- moplasma de Lycopersicon spp. y Capsicum spp. para resistencia al virus peruano del tomate. Fitopa- tologia 23:32-36. Fernandez-Northcote, E. N., and Char- lotte Lizarraga. 1988. Detection of potato viruses X and Y serotypes in potato leaf extracts by enzyme-linked immunosorbent assay on nitrocel- lulose membranes (NCM-ELISA).In Fifth International Congress of Plant Pathology, Kyoto, Japan, 1988, p. 48. (Abstr.) 147 Fernandez-Northcote, E. N., J. Sal- damando, B. Casana, and 0. Fabian. 1987. Contact transmission and syner- gism of Peru tomato virus (PTV) and tobacco mosaic virus in tomato. Evaluation of Lycopersicon spp. and Capsicum spp. germplasm for resis- tance to PTV. Fitopatologia 22:42-43. (Abstr.) Franco, J., and A. Matos. 1987. Effect of sodium hypochlorite treatment on Globodera pallida. Nematropica Vol. 18 (in press, Abstr.) Franco, J., A. Matos, and A. Gonzalez. 1987. La fertilizacion inorganica en el manejo integrado del nematodo del quiste de la papa. Fitopatologia (Peru) 22:64. (Abstr.) Franco, J., A. Matos, and A. Gonzalez. 1987. La fertilizacion inorganica en el manejo integrado del nematodo del quiste de la papa. Nematropica Vol. 18. (in press, Abstr.) Franco J ., A. Gonzalez, A. Matos, and R. Salas.1987. Efecto de clones resisten- tes a la multiplicacion de G/obodera pallida. Fitopatologia (Peru) 22:62- 63. (Abstr.) Golmirzaie, A. M. 1988. Comparison of hybrids with different open-pol- linated (OP) generations of true potato seeds (TPS) for agronomical characters. Amer. Potato J. 65:480. (Abstr.) Gonzalez, A., J. Franco, and A. Matos. 1987. Metodos para la evaluacion de resistencia a G/obodera pa/Iida en plantulas individuales de papa. Fito- patologia (Peru) 22:64. (Abstr.) Gonzalez,, A., J. Franco, and A. Matos. 1987. Metodos para la evaluacion de resistencia a Globodera pa/Iida en plantulas individuales de papa. Nematropica Vol. 18. (in press, Abstr.) 148 Hidalgo, 0. A. 1988. Progresos en la produccion de tuberculos semilla de papa en Latinoamerica. Revista Latinoamericana de la Papa, 2:(1), 1989. Hidalgo, 0. A., A. A. Fedalto, and J. A. M. Telles. 1988. Comportamento em campo de batata-semente ar- mazenadas sob luz difusa e/ou frio no Distrito Federal. Hort. Bras. 6(1):58. (Abstr.) Ho, T. V., N. T. Hoa, T. T. Loan, L. T. Tuyet, and P. Vander Zaag. 1988. Techniques for using sprouts for potato production in the tropics. Potato Res. 31:379-383. Ho, T. V., and P. Vander Zaag. 1987. Sweet potato in Vietnam. Agriculture International 39(7-8):221-223. Horton, D. E. 1988. Las papas en los paises en desarrollo. Revista Latino- americana de la Papa 1(1):9-17. Horton, D. E. 1988. Potatoes: truly a world crop. Span. 30(3):116-118. Horton, D. E. 1988. The nutritional and economic value of potatoes in de- veloping countries. LIFE Newsletter 20(4):2. Horton, D. E. 1988. World patterns and trends in sweet potato production. Tropical Agriculture 65(3):268-270. Horton, D., and G. Prain. 1988. The In- ternational Potato Center's experien- ces with farmer participation in on-farm research. Culture and Agriculture 34:1-4. Horton D., and R. L. Sawyer. 1988. On- farm research: experiences with potatoes. Entwicklung + Landlicher Raum 3:19-21. Huaman, Z., A. Baltazar, and J. Espinoza. 1988. Studies on the effect of stigma exertion in true potato seed production. Am. Potato J. 65(8):484. (Abstr.) .. Iwanaga, M., and R. Ortiz. 1988. Com- parison of the parental value of FDR 2x and of 4x progenitors in two loca- tions. Amer. PotatoJ.65:491. (Abstr.) Jatala, P ., I. Bartolini, and M. Zegarra. 1988. Determinacion selectiva de car- bohidratos y minerales en las extrac- ciones de nematoxinas exogenas de bongos. [Selective determination of carbohydrates and minerals in ex- ogenous nematoxin extractions of fungi.] N ematropica 18( 1): 11. (Abstr.) Jatala, P., and A. Gonzalez. 1988. Un nuevo nematodo que ataca la papa en Peru [A new nematode attacking potato in Peru.] Nematropica 18(1):11. (Abstr.) Jatala, P ., and E. Guevara. 1988. Efecto de varias poblaciones deMeloidogyne incognito sobre la expresion de resis- t en cia y susceptibilidad de papa generado de semilla botanica. 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Detection of potato viruses X and Y in sap extracts by enzyme-linked immunosorbent assay on nitrocellulose membranes (NCM- ELISA). Fitopatologia 22:43. (Abstr.) Llerena, R., L. Mattos, and E. French. 1987. La punta morada en papa. Fitopatologia 22:49. (Abstr.) 149 Llontop, J., and J. Franco. 1988. El nematodo del quiste de la papa (Globodera spp.) en la region andina de La Libertad, Peru. I. Distribucion e identificacion de especies. Fito- patologia 23(2):49-58. Llontop, J., and J. Franco, 1988. El nematodo del quiste de la papa ( Globodera spp.) en la region andina de La Libertad, Peru. II. Razas de Globodera pallida. Fitopatologia 23(2):59-64. Llontop, J.·A., J. Franco, and M. Scurrah. 1987. Identificacion de especies y razas del nematodo quiste de la papa Globodera spp. en la zona papera de La Libertad, Peru. Fitopatologia (Peru) 22:63. (Abstr.) Llontop, J. A., J. Franco, and M. Scurrah. 1987. Identificacion de especies y razas del nematodo quiste de la papa Globodera spp. en la zona papera de La Libertad, Peru. Nematropica Vol. 18. (in press, Abstr.) Llontop, J. A., M. Scurrah, and J. Franco. 1987. Maria Huanca, new potato variety resistant to potato cyst nematode. Nematropica Vol. 18. (in press, Abstr.) Lopes, C.A., J. A. Buso, and 0. Hidalgo. 1988. Comportamento de genotipos de batata para resistencia a murcha bacteriana causada por Pseudo- monas solanacearum. Fitopatol. Bras. 13(2):97. (Abstr.) Malagamba, P. 1988. Potato production from true seed in tropical climates. HortScience 23(3):495-500. Martin, C., and H. Torres. 1987. Control de tizon temprano de la papa (Alter- naria solani) en condiciones de selva alta en Peru [Control of early potato blight (Altemaria solani) under high- land jungle conditions in Peru.] Fitopatologia 22:58. (Abstr.) 150 Mendoza, H. A., C. Martin, and A. Bran- dolini. 1987. Miglioramento della patata per resistenza ad Altemaria solani in ambiente tropicale. Revista di Agricoltura Subtropicale e Tropi- cale. Firenze LXXXI (1-2):53-71. Midmore, D. J. 1988. Potato (Solanum spp.) in the hot tropics. VI. Plant population effects on soil tempera- ture, plant development and tuber yield. Field Crops Res. 19:183-200. Midmore, D. J., D. Berrios, and J. Roca. 1988. Potato (Solanum spp.) in the hot tropics. V. Intercropping with maize and the influence of shade on tuber yields. Field Crops Res. 18:159- 176. Midmore,D.J., andR. E.Rhoades.1987. Applications of agrometeorology to the production of potato in the warm tropics. In C.J. Stigter (ed.), Agrometeorology of the Potato. Sym- posium held in Wageningen, April 9- 10, 1987. Actae Horticulturae 215:103-136. Midmore, D. J., J. Roca, and D. Berrios. 1988. Potato (Solanum spp.) in the hot tropics. IV. Intercropping with maize and the influence of shade on potato microenvironment and crop growth. Field Crops Res. 18:141-157. Nakashima, J., and E. N. Fernandez- N orthcote. 1987. Purification of potato virus A (PV A) and its serological detection. Fitopatologia 22:42-43. (Abstr.) Ochoa, C. 1988. New Bolivian taxa of Solanum (Sect. Petota). Phytologia 65(2):103-113. Ochoa, C. 1989. Solanum amayanum: a new wild Peruvian potato species. Amer. Potato J. 66(1):1-4. Ochoa, C. 1988. So/anum bil/-hookeri: new wild potato species from Peru. Amer. Potato J. 65(12):737-740. Ochoa, C. 1989. Solanum salasianum: new wild tuber-bearing species from Peru. Amer. Potato J. (in press). Ochoa, C. 1989. Solanum ser. Simplicis- sima, nueva serie tuberifera de la Sect. Petota (Solanaceae). Revista Academia Colombiana de Ciencias Exactas, Fisicas y Naturales, Bogota, Colombia (in press). Pallais, N., and N. Fong. 1988. Influence of dormancy on the effectiveness of priming true potato seed. In Abstracts of 85th Annual Meeting of the Amer. Soc. of Hort. Sci. and 33rd Annual Meeting of Canad. Soc. Hort. Sci., Michigan State Univ. Hort- Science 23:796. (Abstr. # 552). Pizarro, A., M. Canto-Saenz, and J. Cepeda. 1988. Cost-benefit relation of aldicarb 15G on potatoes in Huasahuasi, Peru. In Abstracts of the XX Congreso Anual de Nematologia de la ONT A, San Jose, Costa Rica, November 7-11. p. 8. Potts, M. J.1987. Dialogue underlies suc- cess of potato in Burundi. Interna- tional Agricultural Development 7(5):9-10. Potts, M. J., and E. Biranguza.1989. The evaluation of alternative fodder crops under African highland conditions. Expl. Agric. 25:99-107. Potts, M. J ., E. Biranguza, and C. Bweyo. 1989. Evaluation of alternative legumes for green manure and grain under African highland conditions. Expl. Agric. 25:109-118. Potts, M. J ., and S. Nikura. Developing a seed potato farm spurs introduction of new ideas. Agriculture Internation- al 39(9/10):266-270. Quispe, C., and J. Franco. 1987. Efecto de tres densidades de inoculo, tres metodos de desarrollo radicular y tres criterios de evaluacion en la deter- minacion de resistencia de papa a G. pallida. Fitopatologia (Peru) 22:61. (Abstr.) Quispe, C., and J. Franco. 1987. Three inoculum densities, three methods of root propagation and three criteria to evaluate potato resistance to Globodera pallida. Matropica Vol. 18. (in press, Abstr.) Raman, K. V., R. H. Booth, and M. Palacios. 1987. Control of potato tuber moth Phthorimaea operculella (Zeller) in rustic potato stores. Trop. Sci. 27:175-194. Raman, K. V. 1988. Control of potato tuber moth with sex pheromones in Peru. Agric. Ecosystems Environ. 21:85-99. Raman, K. V.1988. Insecticide toxicity to three strains of green peach aphid (Myzus persicae Sulzer) reared on resistant and susceptible potato cul- tivars. Crop Protection 7:62-65. Rhoades, R. E. 1988. Thinking like a mountain. ILEIA 4(1):3-5. Rhoades, R. E. 1988. When the honeymoon is over: managerial reality after technology generation and acceptance. In David Groenfeldt and Joyce Moock (eds.), Social Science Perspectives on Managing Agricultural Technology. pp. 169- 178. Romero, J., and K. V. Raman. 1988. Evaluation of ten solanum potato cul- tivars for major insect pests, natural enemies, and pest resistance in the highlands of Peru. Trop. Agric. 65(1):34-36. Salazar, L. F. 1988. The plant viruses. In R. G. Milde (ed.), The Filamentous Plant Viruses. Vol. IV, South America. New York and London, Plenum Press, p. 343-347. Salazar, L. F., I. Balbo, and R. A. Owens. 1988. Comparison of four radioactive probes for the diagnosis of potato 151 spindle tuber viroid by nucleic acid spot hybridization. Potato Research 31:431-442. Salazar, L. F., R. W. Hammond, T. W. Diener, and R. A. Owens. 1988. Analysis of viroid replication follow- ing agrobacterium-mediated inocula- tion of non-host species with potato spindle tuber viroid cDNA. J. Gen. Virol. 69:879-889. Santos, A. B. de los, 0. K. Bautista, and M. J. Potts. 1986. Table potato storage in the Philippine highlands: a survey of current practices. Philip- pine Agriculturist, 69:365-384. Scott, G. J. 1988. Improving peasant marketing practices: the case of potato producers in Peru. Culture and Agriculture 34:4-8. Scott, G. J., and C. Gutierrez. 1987. La comercializacion de alimentos y los campesinos: el caso de la papa en la sierra central del Peru. Cuadernos de Agro-Industria y Economia Rural. Bogota: Pontificia Universidad Javeriana. 18:9-19. Scurrah, M., and J. Franco. 1987. Con- tribution of S. andigenum and S. ver- nei-S. tuberosum in potato cyst nematode resistance for the Andean region. American Potato J. 64:456- 457. Scurrah, M., and J. Franco. 1987. Fourth cycle of selection for resistance to two pathotypes of Globodera pallida. In 10th Triennial Conference of the European Association for Potato Re- search, Aalbory, Denmark. p. 259. (Abstr.) Scurrah, M., J. Franco, and M. Lazaro. 1987. Seleccion de clones resistentes a Globodera pallida en dos ambien- tes. Fitopatologia (Peru) 22:61-62. Scurrah, M., J. Franco, and M. Lazaro. 1987. Selection of resistant clones to Globodera pallida in two environ- 152 ments. Nematropica Vol. 18 (in press, Abstr.) Song,BoFu,QuDongYu,andP. Vander Zaag. 1987. True potato seed in China: past, present and future. Am. Potato J. 64:321-327. Stegemann, H., S. Majino, and P.E. Schmiediche. 1988. Biochemical dif- ferentiation of clones of oca ( Oxalis tuberosa, Oxalidaceae) by their tuber proteins and the properties of these proteins. Economic Botany 42(1):37- 44. Tivoli, B., H. Torres, and E. R. French. 1988. Inventaire, distribution et agressivite des especes ou varietes de Fusarium rencontrees sur la pomme de terre ou dans son environnement dans differentes zones agroeco- logiques du Perou. Potato Research 31:681-690. Torres, H., and D. Gamarra. 1988. Iden- tificacion y control de microorganis- m o s contaminantes de semilla botanica de papa. Fitopatologia 23:26-31. Vander Zaag, P., and A. L. Demagante. 1987. The potato (Solanum spp.) in an isohyperthermic environment. I. Agronomic Management. Field Crops Res. 17:199-217. Vu Tuyen Hoang, Pham Xuan Liem, Vu Bich Dan, Ngo Doam Dam, Nguyen Xuan Linh, Nguyen van Viet, Pham Xuan Tung, and P. Vander Zaag. 1988. True potato seed research and development in Vietnam. American Potato J. 65:295-300. Wiersema, S. G., and R. Cabello. 1987. A comparison of variability in storage behaviour of seed tubers from true potato seed and clonal tubers. Potato Research 30:485-489. 'r Wiersema, S. G., R. Cabello, P. Tovar, and J. H. Dodds. 1987. Rapid seed multiplication by planting into beds micro tubers and in vitro plants. Potato Research 30:117-120. Recent CIP Publications Von Arx, P. T. Ewell et al. Management on the potato tuber moth by Tunisian farmers: a report of on-farm monitor- ing and a socioeconomic survey. 1988. 30p. Aguilar, J., and C. Vittorelli. Disinfest planting substrate using methyl bromide to produce basic potato seed tubers in greenhouses. 1988. 11 p. Bebbington, A. Farmer strategies in regional agricultural change. The case of commercial potato produc- tion in Oxapampa. Working Paper 1988-1. 1988. 17 p. CIP and ICAR. Potato Research in India. Report of the 1988 External Review 1989. 69 p. CIP Informe Anual, 1986-87. 1988. 232 p. CIP. Annual Report 1988.1988. 210 p. CIP. Bacterial diseases of the potato. Planning Conference Report 1987- 1988. 233p. CIP. Catalogo de publicaciones y mate- riales visuales. 1988. 64 p. CIP. Exploration, maintenance, and utilization of sweet potato genetic resources. Report of the First Sweet Potato Planning Conference 1987. 1988. 369 p. CIP. Informe Anual 1988. 226 p. CIP. International Potato Center 1988. 24 p. Illus. CIP. Mejoramiento de la batata (Ipomoea batatas) 0n Latinoamerica. 1988. 277 p. CIP. Publications Catalog. 1988. 59 p. CIP. Publications of the Social Science Department and its Staff. 1988. 22 p. Xinagling, G ., C. Tianqing, Z. Mingkai, S. Bo Fu, and W. Shaoyan. 1988. Potato Anther Culture. Bulletin of Agricultural Science and Technology 7:18-19. CIP. Strategies for the conservation of potato genetic resources IV. Report of the Planning Conference, February 9-13, 1987. CIP. The social sciences at CIP. Report of the Third Social Science Planning Conference, September 7-10, 1987. 1988. 72p. Cortbaoui, R. and R. Booth. Evaluation en champs d.'agriculteurs des entrepots pour la conservation de la semence. 1988. 10 p. Cortbaoui, R. Siembra de papa. 1988. 17 p. 20 ed. revisada. Cortbaoui, R. Optimisation de la pro- ductivite de la pomme de terre eva- luation et utilisation des resultats des essais en champs d'agriculteurs. 1988. 13p. Cortbaoui, R. Recherche en champs d'agriculteurs en vue de l'optimisa- tion de la productivite de la pomme de terre 1988. 9 p. Cortbaoui, R. Optimisation de la pro- ductivite de la pomme de terre plani- fication et mise en oeuvre des essais en champs d'agriculteurs. 1988. 15 p. Cortbaoui, R. Optimisation de la produc- tivite de la pomme de terre evaluation et utilisation des resultats des essais en champs d'agriculteurs. 1988. 13 p. Ezeta, F. N. Collaborative country re- search networks. 1988. 12 p. Franco, J., and Rincon, H. (eds) Inves- tigaciones nematologicas en programas latinoamericanos de papa. Reimpresion 1988. 2 volumenes, p. 189 153 Gregory J. Scott. La pomme de terre en Afrique Centrale; Une etude sur le Burundi, le Rwanda et le Zaire.1988. 248p. Horton, D. Analyse de budget partiel pour les essais de pommes de terre en champ d'agriculteurs. 1988. 12 p. Horton, D. Underground crops: long- term trends in production of roots and tubers 1988 Lizarraga, R., P. Tovar, U. Jayasinghe, and J. Dodds. Cultivo de tejidos para la eliminacion de patogenos 1988. 23 p. (Guia de Investigacion CIP 3) Malagamba, P., and A. Monares. True Potato Seed: Past and present uses. 1988. 40 p. Midmore, D. J. Fisiologia de la planta de papa bajo condiciones de clima calido. Guia de Investigacion CIP 24. 1988.15 p. Monares, A., et al. Economia de la in- dustria de semillas en el Peru con enfasis en los cultivos de papa y hor- talizas. 1988. 72 p. Monares, A. La papa en Chile: tuber- culos-semilla de categoria certificada 1988. 85 p. Monares, A., and A. Achata. Costos de produccion de la semilla (Sexual) hibrida de papa. Metodo agro- economico de estimacion basado en 154 muestreos. Serie de Evaluacion de Tecnologia No. 8. 1988. 25 p. Monares, A., and Achata, A. Produccion de semilla (Sexual) hibrida de papa en Chile: Factibilidad economica. 1988. 37p. Rhoades, R. and Bidegaray, P. Los agricultures de Yurimaguas; uso de la tierra y estrategias de cultivo en la selva peruana. 1988. 136 p. Rhoades, R., M. Benavides, J. Recharte, E. Schmidt, and R. Booth. Tradition- al potato storage in Peru: Farmers' knowledge and practices. Food Sys- tems Research Series No. 4. 1988. 67 p. Rhoades, R. E. Comprendre les petits agriculteurs: perspectives sociocul- turales des essais en champ d'agri- culteurs. 1988. 9 p. Scott, G. Marketing Bangladesh's potatoes: present patterns and future prospects. 1988. 107 p. Scott, G. Potatoes in Central Africa: A study of Burundi, Rwanda and Zaire. 1988. p.159. The American Phytopathological So- ciety. Compendium of sweet potato diseases. 1988. 74 p. Wissar, R., and R. Ortiz. Mejoramiento de papa en el CIP por adaptacion a climas calidos tropicales. Guia de In- vestigacion CIP 22. 1988. 51 p. Articles Published in CIP Planning Conferences Accatino, P. 1988. The role of the social sciences in meeting farmer and na- tional program needs. In Proceedings of the Third Social Sciences Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, September 7-10, 1987. pp. 95-101. Beaufort-Murphy, H. 1988. A review of strategies for overcoming sterility and incompatibilities of sweet potatoes. In Proceedings of the First Sweet Potato Planning Conference on Exploration, Maintenance and Utilization of Sweet Potato Genetic Resources, Interna- tional Potato Center, Lima, Peru, February 23-27, 1987. pp. 175-184. Crissman, C. 1988. Identifying strengths and weaknesses in seed programs. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber, 7-10, 1987. pp. 262-272. De la Puente, F. 1988. Progress in ex- plorations and collections of sweet potato genetic resources, the IBPGR/CIP Project. In Proceedings of the First Sweet Potato Planning Conference on Exploration, Main- tenance and Utilization of Sweet Potato Genetic Resources, Interna- tional Potato Center, Lima, Peru, February 23-27, 1987. pp.75-100. Dodds, J. H . 1988. Review of in vitro propagation and maintenance of sweet potato germplasm. In Proceed- ings of the First Sweet Potato Plan- ning Conference on Exploration, Maintenance and Utilization of Sweet Potato Genetic Resources, Interna- tional Potato Center, Lima, Peru, February 23-27, 1987. pp. 185-192. Dodds, J. H. 1988. Status of the in vitro potato collection at CIP and new ap- proaches for long term conservation. In Proceedings of the XXIX Planning Conference on Strategies for the Conservation of Potato Genetic Resources IV, International Potato Center, Lima, Peru, February 9-13, 1987. pp. 75-87. Dodds, J. H. and S. Y. C. Ng. 1988. In vitro methods for pathogen elimina- tion and international distribution of sweet potato germplasm. In Proceed- ings of the First Sweet Potato Plan- ning Conference on Exploration, Maintenance and Utilization of Sweet Potato Genetic Resources, In- ternational Potato Center, Lima, Peru, February 23-27, 1987. pp. 323- 329. Elphinstone, J. 1988. Methods of control of Erwinia diseases of the potato. In Proceedings of the Planning Con- ference on Bacterial Diseases of the Potato, International Potato Center, Lima, Peru, March 16-20, 1987. pp. 187-192. Elphinstone, J ., L. de Lindo, and E. R. French. 1988. Control of Erwinia dis- eases in San Ramon. In Proceedings of the Planning Conference on Bac- terial Diseases of the Potato, Interna- tional Potato Center, Lima, Peru, March 16-20, 1987. pp. 193-201. French, E. R. 1988. Field evaluation of clones bred for resistance to Pseudo- monas solanacearum.In Proceedings of the Planning Conference on Bac- terial Diseases of the Potato, Interna- tional Potato Center, Lima, Peru, March 16-20, 1987. pp. 109-112. French, E.R., and L. Sequeira. 1988. Ad- ditional sources of resistance to bac- terial wilt. In Proceedings of the 155 Planning Conference on Bacterial Diseases of the Potato, International Potato Center, Lima, Peru, March 16- 20, 1987. pp. 29-33. French, E. R., and U. Nydegger. 1988. Mass screening procedures for resis- tance toPseudomonas solanacearum. In Proceedings of the Planning Con- ference on Bacterial Diseases of the Potato, International Potato Center, Lima, Peru, March 16-20, 1987. pp. 15-17. Gregory, P. 1988. Sweet potato research at CIP. In Proceedings of the First Sweet Potato Planning Conference on Exploration, Maintenance and Utilization of Sweet Potato Genetic Resources, International Potato Cen- ter, Lima, Peru. February23-27, 1987. pp.11-16. Hidalgo, 0. 1988. Soft rot and blackleg (Erwinia spp.) in warm climates. In Proceedings of the Planning Con- ference on Bacterial Diseases of the Potato, International Potato Center Lima, Peru, March 16-20, 1987. pp. 179-186. Horton, D. E. 1988. Assessing impact: the general framework. In Proceed- ings of the Third Social Sciences Plan- ning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, September 7-10, 1987. pp. 231-246. Horton, D. E. 1988. The Social Sciences at CIP. In Proceedings of the Third Social Sciences Planning Conference on The Social Sciences at CIP, Inter- national Potato Center, Lima, Peru, September 7-10, 1987. pp. 31-79. Horton, D. E. 1988. World patterns and trends in sweet potato production and use. In Proceedings of the First Sweet Potato Planning Conference on Ex- ploration, Maintenance and Utiliza- 156 tion of Sweet Potato Genetic Resour- ces, International Potato Center, Lima, Peru, February23-27, 1987. pp. 17-25. Horton, D. E., W. Collings, M. Iwanaga, H. Mendoza, and M. Collins. 1988. Constraints to production and utiliza- tion of potatoes and sweet potatoes. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp. 129-133. Horton, D. E., N. Puican, and R. Rhoades. 1988. Root crop database. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp. 111-117. Huaman, Z. 1988. CIP's role in the development of an Inter-Gene Bank Cooperation for potato genetic resources conservation. In Proceed- ings of the XXIX Planning Con- ference on Strategies for the Conservation of Potato Genetic Resources IV, International Potato Center, Lima, Peru, February 9-13, 1987. pp. 97-100. Huaman, Z. 1988. Current status on the maintenance of sweet potato genetic resources at CIP. In Proceedings of the First Sweet Potato Planning Con- ference on Exploration, Main- tenance, and Utilization of Sweet Potato Genetic Resources, Interna- tional Potato Center, Lima, Peru, February 23-27, 1987. pp. 101-120. Huaman, Z. 1988. Descriptors for the characterization and evaluation of sweet potato genetic resources. In Proceedings of the First Sweet Potato Planning Conference on Exploration, Maintenance and Utilization of Sweet Potato Genetic Resources, In- ternational Potato Center, Lima, Peru, February 23-27, 1987. pp. 331- 355. Huaman, Z. 1988. Status of the native Andean cultivated potato collection maintained at CIP. In Proceedings of the XXIX Planning Conference on Strategies for the Conservation of Potato Genetic Resources IV, Inter- national Potato Center, Lima, Peru, February9-13, 1987. pp. 27-44. Huaman, Z., L. de Lindo, and J. El- phinstone. 1988. Resistance to black- leg and soft rot and its potential use in breeding. In Proceedings of the Plan- ning Conference on Bacterial Dis- eases of the Potato, International Potato Center, Lima, Peru, March 16- 20, 1987. pp. 215-228. Iwanaga, M. 1988. Use of wild germ plasm for sweet potato breeding. In Proceedings of the First Planning Conference on Exploration, Main- tenance and Utilization of Sweet Potato Genetic Resources, Interna- tional Potato Center, Lima, Peru, February 23-27, 1987. pp. 199-210. Jatala, P ., C. Martin, and H. A. Mendoza. 1988. Role of nematodes in disease expression by Pseudomonas sola- naceamm and strategies for screening and breeding for combined resis- tance. In Proceedings of the Planning Conference on Bacterial Diseases of the Potato, International Potato Cen- ter, Lima, Peru, March 16-20, 1987. pp. 35-37. Jatala, P., and K. V. Raman.1988. Major insect and nematode pests of sweet potatoes and recommendations for transfer of pest free germplasm. In Proceedings of the First Sweet Potato Planning Conference on Exploration, Maintenance and Utilization of Sweet Potato Genetic Resources, Interna~ tional Potato Center, Lima, Peru, February 23-27, 1987. pp. 319-321. Mendoza, H. A. 1988. Progress in resis- tance breeding in potatoes as a func- tion of efficiency of screening procedures. In Proceedings of the Planning Conference on Bacterial Diseases of the Potato, International Potato Center, Lima, Peru, March 16- 20, 1987. pp. 39-64. Monares, A. 1988. Analytical framework for design and assessment of potato seed programs in developing countries. In Proceedings of the Third Social Science Planning Con- ference on The Social Sciences at CIP, International Potato Center, Lima, Peru, September 7-10, 1987. pp. 247-261. Monares, A., and P. Malagamba. 1988. Design of a client-oriented technol- ogy: the case of true potato seed. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp. 173-181. Ochoa, C. and P. Schmiediche. 1988. Status of the collection at CIP: wild species. In Proceedings of the XXIX Planning Conference on Strategies for the Conservation of Potato Genetic Resources IV, International Potato Center, Lima, Peru, February 9-13, 1987. pp. 19-26. Otazu, V., J. Elphinstone, and H. Torres. 1988. Erwinias and other pathogens and pests: possible interactions in the warm climate of San Ramon. In Proceedings of the Planning Con- ference on Bacterial Diseases of the Potato, International Potato Center, Lima, Peru, March 16-20, 1987. pp. 203-214. 157 Piiia, M. 1988. Assessing results of train- ing and communication. In Proceed- ings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, September 7-10, 1987. pp. 273-286. Prain, G., and U. Scheidegger. 1988. User friendly seed program. In Proceedings of the Third Social Science Planning Conference on the Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp.182-203. Rhoades, R. 1988. CIP's philosophy on farmer participatory research. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp. 159-172. Rhoades, R. 1988, Food systems re- search. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, Inter- national Potato Center, Lima, Peru, September 7-10, 1987. pp. 80-94. Rhoades, R. 1988. The reference file method: an eclectic approach for im- proving agro-ecological and crop data of developing countries. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp. 118-128. Scott, G. 1988. Potato marketing and demand in developing countries. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International 158 Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp. 134-153. Scott, G. 1988. Training through market- ing research: the CIP experience. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, Septem- ber 7-10, 1987. pp. 317-333. Schmiediche, P. 1988. Breeding for Resistance to Pseudomonas solana- cearum. Proceedings of the Planning Conference on Bacterial Diseases of the Potato, International Potato Cen- ter, 16-20 March, 1987, Lima, Peru. pp.19-27. Schmiediche, P. 1988. The utilization of wild potato species in breeding. In Proceedings of the XXIX Planning Conference on Strategies for the Conservation of Potato Genetic Resources IV, International Potato Center, Lima, Peru, February 9-13, 1987. pp. 135-149. Schmiediche, P., J. Jaynes, and J. H. Dodds. 1988. Genetic engineering for bacterial disease resistance in potatoes. In Proceedings of the Plan- ning Conference on Bacterial Dis- eases of the Potato, International Potato Center, Lima, Peru, March 16- 20, 1987. pp.123-132. Zachmann, R. and G. Robertson. 1988. Social Science training: past ex- perience and needs expressed by na- tional programs. In Proceedings of the Third Social Science Planning Conference on The Social Sciences at CIP, International Potato Center, Lima, Peru, September 7-10, 1987. pp. 334-343. "· Research and Consultancy Contracts in 1988 Research and consultancy contracts and special projects facilitate research on priority problems and provide funds for potato and sweet potato work in both developing and developed countries. The contracts greatly increase CIP's flexibility to meet changing needs and have proved to be both effective and low cost. In budgetary terms, collaboration with other institutions through contract research is advantageous because facilities and personnel needed for a specific research activity are already in place. Thus, CIP conserves resources, and such savings are especially important as CIP moves further into biotechnological research with its high-cost implications. The returns on investments have been worldwide, both in terms of research data and in building valuable relations with the contractees who frequently play an important role in CIP's research-planning conferences and other planning and assessment activities. Thrust I Collection, Maintenance, and Utilization of Unexploited Genetic Resources 1. Guangdong Academy of Agricultural Sciences (GAAS), China - Devel- opment of sweet potato germplasm for the tropics. Feng Zu-Xia 2. Zhuzhou Institue of Sweet Potato (XISP), China - Evaluation of sweet potato germ plasm. Sheng Jia Lian 3. Instituto Nacional di Investigaciones Agropecuarias (INIAP), Ecuador - Maintenance of the potato germ- plasm in vitro collection. F. Munoz 4. Rothamsted Experimental Station, England - Stability/variability of potato in culture and storage. M. G.Klones 5. Ente Nazionale delle Energie Alter- native (ENEA), Italy - Develop- ment of potato varieties resistant to insect pests by means of conventional innovative breeding technologies. A. Sonnino and, L. Bacchetta 6. Universita degli Studi della Tuscia Viterbo, Italy - Use of genetic en- gineering methods to confer fungal disease resistance to potatoes. C. Di Pace Thrust II Production and Distribution of Advanced Breeding Material 7. Instituto Nacional de Tecnologia Agropecuaria (INTA), Balcarce, Ar- gentina - Programa de utilizacion de mayor variabilidad genetica en el plan de mejoramiento de papa. A. Mendiburu 8. Centro Nacional de Pesquisas de Hortalicas (CNPH/EMBRAPA), Brazil - Evaluacion de germoplas- ma de papa (So/anum tuberosum L.) con relac10n a resistencia aA/temaria solani. F. J.B. Reifschneider 9. Centro Nacional de Pesquisas de Hortali~as (CNPH/EMBRAPA), Brazil - Selection of TPS progenies adapted to the northeast and center west of Brazil. Jose A. Buso 10. Agriculture Canada, Canada - Nu- tritional and chipping evaluation of selected parental clones in Peru, the Philippines and Canada. T. R. Tam 11. Consorzio "Mario Neri" (ERSO), Imola, Italy - Selection of potato clones with high starch content. L. Concilio 12. Instituto Nacional de Investigacion Agraria (INIAA), Peru - Evalua- ci6n de clones avanzados del CIP para el Programa Nacional de Papa del Peru. D. Untiveros 159 13. UniversityofTacna, Peru - Evalua- tion of sweet potato germplasm for tolerance to certain abiotic stresses under arid conditions. N. Arevalo 14. Aegean Regional Agricultural Re- search Institute (ARARI), Turkey - Potato germplasm evaluation and multiplication. N. Kuzman 15. Cornell University, Ithaca, New York, U.S.A. - The utilization of Solanum tuberosum s~p. andigena germplasm in potato unprovement and adaptation. R. L. Plaisted, H. D. Thurston, W. M. Tingey, B. B. Brodie, E. E. Ewing ,and D. Ave 16. North Carolina State University, U.S.A. - Breeding and adaptation of cultivated diploid potato species. W. W. Collins 17. North Carolina State University, U.S.A. - Breeding early-yielding, and disease-resistant sweet potatoes with enhanced food quality and nutri- tional value. W. W. Collins 18. University of Wisconsin, Madison, U.S.A. - Potato breeding methods with species, haploids and 2n gametes. S. J. Peloquin Thrust III Control of Bacterial and Fungal Diseases 19. University of Queensland, Brisbane, Australia - Taxonomy of Pseudo- monas solanacearum. A. C. Hayward 20. Centro Nacional de Pesquisas de Hortali~as ( CNPH/EMBRAP A), Brazil.- Potato germplasm evalua- tion for resistance to bacterial wilt. Carlos A. Lopez 21. Instituto Colombiano Agropecuario, (ICA), Rio Negro, Colombia - Eva- luacion de la resistencia de material genetico de papa a Pseudomonas solanacearnm y Phytophthora infes- tans. P. L. Gomez 22. Instituto Nacional de Investigaciones Agropecuarias (INIAP), Ecuador - Estudio y control de las enfer- medades lanosa y roya de la papa en Ecuador. H. Orellana 160 23. L.E.H.R.I. Experimental Station of AARD, Indonesia - Breeding for resistance to bacterial wilt of potato in Indonesia. Sudjako Sahat 24. Gilat Regional Experimental Station, Israel - Verticillium wilt and early- blight tolerance of potato in hot climates.A. Nachmias 25. National Agricultural Laboratories, Nairobi, Kenya - The reaction of selected potato clones to two races of Pseudomonas solanacearnm in Ken- ya. A. 0. Michieka 26. Universidad Nacional Agraria-La Molina, Peru - Consultancy on early blight of potatoes: specialization of Altemaria spp. T. Ames de Icochea 27. Universidad Nacional de Huanuco, Peru - Desarrollo de variedades de papa con resistencia a enfermedades y adaptacion a zonas ecologicas del Departarnento de Huanuco. E. Tor- res Vera 28. Cornell University, Ithaca, New York, U.S.A. - Population genetics of Phytophthora infestans in its natu- ral ecosystem at Toluca. W. E. Fry 29. University of Wisconsin, U.S.A. - Fundamental research to develop control measures for bacterial pathogens of the potato. A. Kelman and L. Sequeira 30. Centro de lnvestigaciones Agricolas "A. Boerger" (CIAAB), Uruguay - Seleccion de clones con resistencia a A. solani y precocidad en materiales con antecedentes de resistencia a virus. F. Vilaro and C. Crisci Thrust IV Control of Virus and Virus-Like Diseases 31. Istituto Agronomico per l'Oltremare (I.AO.), Italy.- Production of an- tisera against major potato viruses. M. Broggio and M. Galanti 32. Universidad Nacional Agraria-La Molina, Peru - Consultative con- tract on maintenance of monoclonal antibodies for potato viruses. J. Cas- tillo 33. Universidad Nacional Agraria-La Molina), Peru - Maintenance of monoclonal antibodies for potato viruses. J. Castillo. 34. Instytut Ziemniaka, (Institute for Potato Research), Poland - Breed- ing potatoes resistant to the potato leafroll virus, PLRV.K M. Swiezynski 35. Scottish Crop ~esearch Institute, Scotland. - Resistance to potato leafroll virus. B. D. Hanison 36. Louisiana State University, U.S.A. - Attempts to elucidate the etiology of sweet potato chlorotic leaf distortion. C.A. Clark. 37. North Carolina State University, U.S.A. - Development of virus test- ing procedures for sweet potatoes. I.Moyer 38. North Carolina State University, U.S.A. - The accumulation of sweet potato feathery mottle virus, dsRNA, and selected viral proteins in sweet potatoes. J. Moyer 39. Centro de Investigaciones Agricolas "A. Boerger" (CIAAB) Uruguay - Evaluation of genetic material for resistance to PVX and PLR V under field conditions. C. Crisci and F. Vilaro Thrust V Integrated Pest Management 40. Instituto Nacional de Investigaciones Agropecuarias (INIAP), Ecuador - Evaluacion de clones resistentes al nematodo del quiste (Globodera spp.) en el Ecuador. R. Eguiguren and J. Revelo 41. Universidad Nacional Agraria-La Molina, Peru - Consultancy on biological and selective chemical control of potato and sweet potato insect pests. J. Sanniento and Co/- leagues 42. Universidad Nacional Agraria-La Molina, Peru - Consultancy on Pra- tylenchus spp. as important nematode pests of potatoes. M. Canto 43. The Southeast Asian Regional Cen- ter for Graduate Study and Research in Agriculture (SEARCA), The Philippines - Management of thrips and mites attacking potato in the lowland. E. N. Bernardo 44. University of the Philippines, Los Baiios (UPLB), The Philippines - Integrated control of nematodes and weeds by the use of biological control agents and solarization. R. Davide 45. Institute of Virology, U. K. - Studies on the potato tuber moth. P. Entwistle. 46. North Carolina State University, U.S.A. - Evaluation of potato lines for resistance to the major species and races of root-knot nematodes (Meloidogyne spp.). J. N. Sasser Thrust VI Warm Climate Potato and Sweet Potato Production 47. Maritius Sugar Industry Research In- stitute (MSIRI), Rednit, Mauritius - Development of potato varieties for lowland tropical conditions. K Wong Yen Cheong 48. Universidad Nacional Agraria-La Molina, Peru - Manejo de suelos, fertilizantes y nutricion mineral de la papa bajo condiciones adversas de suelo y clima. S. Villagarcia 49. Scottish Crop Research Institute, Scotland - Drought tolerance in potatoes. P. Waister Thrust VIII Postharvest Technology 50. The Philippine Root Crop Research and Training Center (PRCRTC), The Philippines - Development of simple processing technologies for sweet potato/potato-based products for low-income groups as target con- sumers. T. van Den 51. Society for Development of Ap- propriate Technology (SOTEC). India - Development of village-level potato processing and utilization of potato in local foods. R. W. Nave 161 Thrust IX Seed Technology 52. Victoria Department of Agriculture, Australia - Production of pathogen- t est e d potato germplasm for Southeast Asian and Pacific Countries. P. T. Jenkins 53. Instituto de Investigaciones Agro- pecuarias (INIA), Osorno, Chile - Produccion de semilla botanica de papa en Chile. J. Santos Rojas and A. Cubi/los 54. Istituto Agronomico per l'Oltremare (IAO), Italy - The use of novel an- tibacterial ~enes to confer bacterial disease resistance to potato plants. D.E.Foard 55. Istituto di Agronomia, Universita di Napoli, Italy - Selection ofTPS pa- rental lines in high seed production. L. Monti and L. Politano 56. Universidad Nacional Agraria-La Molina, Peru - Training and con- sultancy research in effects of soil management and fertilization on flowering, fruit setting and seed quality of the potato. S. Villagarcia 57. Louisiana State University (LSU), U.S.A. - The use of agrobacterium plasmid vectors to insert anti-bac- terial, anti-insect and frost resistance genes into potato plants. J. M. Jaynes 162 Thrust X Potato and Sweet Potato in Food Systems 58. Instituto Nacional de Tecnologia Agropecuaria (INT A), Argentina - Consultancy on sweet potato produc- tion and utilization. A. Boy 59. England - Sweet potato: an un- tapped food resource. J. A. Woolfe 60. H.P. University, India - Demand study for processed potatoes. B. K Sikka 61. Peru - Demand for sweet potato. M. Collins 62. Peru - Study of farmer selection of potato varieties in Kenya. L. Crissman 63. International Food Policy Research Institute (IFPRI), U.S.A. - White potato/sweet potato development in China. B. Stone 64. University of Arizona, U.S.A. - Houseshold gardens. V. Ninez 65. Centro de Investigaciones Agricolas, "A. Boerger" (CIAAB), Uruguay - Consultancy on breeding and propagation of sweet potato . F. Vilaro Support Department 66. Consultancy Contract. La Molina, Peru - Management of light and temperature in CIP greenhouses. U.Moreno 67. Consultancy Contract. Lima, Peru - Management of sweet potato germ- plasm. R. de/ Carpio Regional Research and Training 68. International Agricultural Centre, Wageningen, The Netherlands - Consultancy for regional research and training. H. P. Beukema i •- Staff SENIOR MANAGEMENT Richard L. Sawyer , Ph.D., Director General Jose Valle-Riestra, Ph.D., Deputy Director General William A. Hamann , B.S., Assistant to the Director General Peter Gregory , Ph.D ., Director of Research Kenneth J . Brown, Ph .D ., Director of Regional Research Primo Accatino , Ph.D ., Associate Dir. , Transfer of Technology Adrian Fajardo? M.S. , Executive Officer Leonardo Hussey , Controller RESEARCH THRUSTS (Leaders and Co-Leaders) I. Collection, Maintenance , and Utilization of Unexploited Genetic Resources (P. Schmiediche- Z. Huaman) II. Production and Distribution of Advanced Breeding Material (H. Mendoza-M. lwanaga) III. Control of Bacterial and Fungal Diseases (E. French) IV. Control of Virus and Virus-Like Diseases (L. Salazar-U. Jayasinghe) v . Integrated Pest Management (F. Cisneros-P. Jatala) VI. Warm Climate Potato and Sweet Potato Production (D . Midmore-H. Mendoza) VII. Cool Climate Potato and Sweet Potato Production (J. Landeo-D. Midmore) VIII. Postharvest Technology (S . Wiersema-R. Rhoades) IX. Seed Technology (P. Malagamba-A. Golmirzaie) X. Potato and Sweet Potato in Food Systems (D . Horton-R. Rhoades) RESEARCH DEPARTMENTS Breeding and Genetics Humberto Mendoza, Ph.D ., Geneticist, Head of Department Andrea Brandolini , Dot. Agr. , Visiting Associate Scientistt Edward Carey, Ph.D., Sweet Potato Breeder Enrique Chujoy, Ph .D ., Geneticist (The Philippines) T . R. Dayal, Ph.D ., Sweet Potato Breeder (New Delhi) Ali Golmirzaie, Ph.D., Geneticist Haile M. Kidane-Mariam, Ph.D ., Breeder (Kenya) t Juan Landeo , Ph.D., Breeder II Gin Mok, Ph .D. , Sweet Potato Breeder (Nigeria) Maria Scurrah , Ph.D., Breeder Kazuo Watanabe , Ph.D ., Cytogeneticist Genetic Resources Peter Schmiediche, Ph.D., Breeder, Head of Department Fermin De la Puente, Ph.D ., Breeder Zosimo Huaman, Ph.D., Geneticist Masaru lwanaga, Ph .D ., Cytogeneticist Nematology and Entomology Parviz Jatala, Ph.D ., Nematologist , Head of Department Javier Franco, Ph.D., Nematologist Bruce Parker, Ph.D., Entomologist (Kenya)t 163 K. V. Raman, Ph.D., Entomologist (sabbatical leave) Luis Valencia , Ph.D. , Entomologist (Colombia) Pathology Edward R. French, Ph.D ., Pathologist, Head of Department Hossien El-Nashaar, Ph .D. , Bacteriologist John Elphinstone,. Ph.D ., Bacteriologist Enrique Fernandez-Northcote, Ph .D ., Virologist Gregory A . Forbes, Ph .D ., Mycologist Upali Jayasinghe, Ph.D. , Virologist Maddalena Querci , Dot. Agr., Visiting Associate Scientistt Luis Salazar , Ph.D., Virologist Linnea G . Skoglund, Ph .D. , Mycologist L. J . Turkensteen , Ph.D., Adjunct Scientist (Netherlands) Physiology Patricio Malagamba , Ph.D ., Physiologist , Head of Department (sabbatical, part 1988) Cornelia Almekinders, Ir. , Scientific Associatet Helen Beaufort-Murphy , Ph.D., Physiologist Jurg Benz, Ir. , Scientific Associate (until August 1988)t John Dodds, Ph.D., Tissue Culture Specialist (sabbatical , part 1988) Yoshihiro Eguchi , B.S., Visiting Scientist*t Indira Ekanayake , Ph .D. , Physiologist David J. Midmore, Ph.D. , Physiologist (sabbatical , part 1988), active Head of Department Noel Pallais , Ph .D., Physiologist Frederick Payton, M.S. , Scientific Associatet Michael Potts, Ph .D. , Agronomist (Region VII , Indonesia) Siert Wiersema, Ph.D ., Physiologist (Region VII, Thailand) Social Science Douglas E. Horton , Ph.D. , Economist , Head of Department Charles Crissman , Ph.D. , Economist Peter Ewell, Ph.D., Economist (as of September 1, 1988) 164 Anibal Monares , Ph.D. , Economist (until April, 1988) Gordon Prain, Ph .D ., Anthropologist (as of August 1988) Robert E. Rhoades , Ph .D. , Anthropologist Gregory J. Scott, Ph .D. , Economist (sabbatical leave from Sept. 1988) Greta Watson, Ph.D., Visiting Associate Scientist (Indonesia)t Norio Yamamoto, Ph.D. , Ethnobotanist* t Research Support Fausto H . Cisneros, Ph .D ., Entomologist, Head of Department James E . Bryan, M .S. , Seed Technologist (transferred from Regional Research) Lombardo Cetraro , Biologist, Field & Greenhouse Supervisor , San Ramon Alfredo Garcia, M.S., Biometrician, Lima Victor Otazu, Ph.D. , Superintendent , San Ramon Mario Pozo , Ing. Agr., Field & Greenhouse Supervisor , Lima Miguel Quevedo, Ing. Agr., Field & Greenhouse Supervisor , Huancayo Marco Soto, Ph.D. , Superintendent, Huancayo REGIONAL RESEARCH Headquarters James E . Bryan, M.S., Seed Technologist (until June 1988, transferred to Research Support) Fernando Ezeta , Ph.D ., Network Specialist Region I-Andean Latin America Apartado Aereo 92654 Bogota 8, D .E., Colombia Oscar Hidalgo , Ph .D ., Regional Representative (from July 1988) Oscar Malamud, Ph .D ., Regional Representative (until June 1988) Juan Aguilar, Ing . Agr. , Seed Production (Peru)t Lukas Bertschinger , Tr ., Associate Scientist (Peru) t Efrain Franco, M.S., Economist (Peru)t Gordon Prain , Ph.D., Anthropologist (Peru) (until July 1988)t • • ,fi .. Luis Valencia , Ph.D. , Entomologist (Colombia) - Urs Scheidegger, Ph.D., Agronomist, Team Leader SEINPA (Peru)t Anna Strohmenger, Dot. Agr. , Visiting Associate Scientist (Paraguay)t Cesar Vittorelli , Ing. Agr., Co-Leader National Potato Program (Peru) (until Dec. 1988)t Region 11---Central America and Caribbean P.O. Box 711 c/o IICA Santo Domingo, Dominican Republic Oscar Malamud, Ph.D., Regional Representative Region III-East and Southern Africa P .O . Box 25171 Nairobi, Kenya Sylvester Nganga , Ph.D. , Regional Representative Carlo Carli, Dot . Agr., Seed Specialist (Kenya)t Patricio Callejas, M.S., Agronomist (Ethiopia)t George Hunt, Eng. Agr., Postharvest Specialist (until Oct. 1988)t Jeroen Kloos, Ir., Coordinator PRAPAC (Rwanda) t Jose Luis Rueda , M.S. , Agronomist (Burundi)t Caroline Turner, M.S ., Agronomist (Burundi)t Haile M. Kidane-Mariam , Ph.D., Breeder (Kenya) Bruce Parker, Ph .D., Visiting Scientist (Kenya)t Region IV-North Africa, Near and Middle East 11 Rue des Orangers 2080 Ariana, Tunis , Tunisia Roger Cortbaoui, Ph.D. , Regional Representative Ramzy El-Bedewy, Ph.D ., Scientific Associate (Egypt) Region V-W est and Central Africa c/o IRA Bambui P. 80 Mankon Bamenda, Cameroon Carlos Martin, Ph.D., Regional Representative (as of January 1988) II Gin Mok , Ph.D., Sweet Potato Breeder (Nigeria) Thomas Gass, Eng., Associate Scientisrl Region VI-South Asia International Potato Center Indian Agricultural Research Institute Campus New Delhi, 110012,. India Mahesh Upadhya, Ph.D., Regional Representative Lyle Sikka, M.S., Seed Technologist (Bangladesh, until April 1988t and Consultant until December 1988) T. R. Dayal, Ph.D. , Sweet Potato Breeder (New Delhi) M. Kadian, Ph .D. , Agronomist M.S. Jaikath , Ph.D. , Socio Economist K.C. Thakur, Ph.D. , Breeder V.S. Khatana, Ph.D ., Socio Economist Region VII-Southeast Asia c/o IRRI P.O. Box 933 Manila , Philippines Peter Vander Zaag, Ph .D., Regional Representative Ponciano Batugal, Ph.D., Coordinator- SAPPRAD Enrique Chujoy, Ph.D., Geneticist (The Philippines) Michael Potts , Ph .D., Agronomist (Indonesia) Greta Watson, Ph.D., Visiting Scientist (Indonesia) Siert Wiersema, Ph.D ., Physiologist (Thailand) Region VIII---China Chinese Academy of Agricultural Sciences Bai Shi Qiao Rd. No . 30 West Suburb of Beijing People's Republic of China Song Bo Fu, Dr., Regional Representative Qin Yuti an, B.S., CIP Liaison Officer 165 TRAINING AND COMMUNICATIONS DEPARTMENT Manuel Piiia, Jr. , Ph.D. , Head of Department Christine Graves , M.A., Writer/Editor George Hunt, Agr. Eng. , Training Officer (Region III from Nov . 1988) Linda W. Peterson, B.F.A. , English Editor Carmen Podesta , M.A., Librarian/ Information Officer Hernan Rincon, Ph .D. , Spanish Editor Garry Robertson, M.A. , Training Coordinator Carmen Siri, Ph.D. , Coordinaior, Information Service Unitt Rainer Zachmann, Ph.D., Training Materials Specialist ADMINISTRATION Internal Auditor Carlos Niiio Neira , C.P.C. , Internal Auditor Office of the Executive Officer Adrian Fajardo , Executive Officer Cesar Vittorelli , Agr. Eng., Assistant Executive Officer Maritza Benavides, Administrative Assistant Logistics Supervision Lucas Reaiio , C .P.C., Supervisor Miguel Cabanillas , B.S. Ind. Eng., Chief of Warehouse Jose Pizarro, Importations Officer Jaime Cavallini , Local Purchasing Officer Personnel & Labor Relations Supervision Guillermo Machado , Lie., Supervisor Ana Dumett , B.S. Soc. Assist., Social Worker German Rossani , M.D., Medical Officer Ada Sessarego, Personnel Assistant Foreign Affairs Liaison Office Marcela Checa, Liaison Officer Transportation Supervision Carlos Bohl , Supervisor Jacques Vandernotte , Chief Pilot Djordje Velickovich, Pilot Percy Zuzunaga , Co-Pilot 166 Equipment and Maintenance Supervision Gustavo Echecopar, Agr. Eng., Supervisor Travel Office Ana Maria Secada, Executive Assistant Auxiliary Services Supervision Nancy Oshiro , Supervisor Controller's Office Leonardo G. Hussey , Controller Oscar Gil , C.P.A ., Assistant Controller Treasury Unit Sonnia Orellana , Cashier Budget Unit Guillermo Romero , Chief Accountant Accounting Unit Miguel Saavedra , Chief Accountant Staff Office of the Controller Edgardo de los Rios , C .P.A., Accountant Blanca Joo, C.P.A., Accountant Eliana Bardales , C.P.A. , Accountant SCIENTIFIC ASSOCIATES Adolfo Boy, Ph.D., Sweet Potato Agronomist (Argentina) Manuel Canto , Ph.D., Nematologist (Peru) Romulo del Carpio , Ing. Agr. , Taxonomist (Peru) Pedro Leon Gomez, Ph.D., Breeder (Colombia) Carlos Ochoa , M.S. , Taxonomist (Peru) Francisco Vilaro , Ph.D. , Sweet Potato Breeder (Uruguay) Sven Villagarcia , Ph .D. , Soil Scientist (Peru) SCIENTIFIC AND OTHER ASSIST ANTS (By Department or Region) Raul Anguiz, M.S., Breeding & Genetics Walter Amoros , M.S., Breeding & Genetics Miguel Ato , Ing. Ind . Alimentarias, Breeding & Genetics Luis Calua, M.S. , Breeding & Genetics Luis Diaz , M.S ., Breeding & Genetics Jorge Espinoza , M.S ., Breeding & Genetics Rosario Galvez , M.S., Breeding & Genetics Luis Manrique , Ing. Agr., Breeding & Genetics ,, • .. ... Felix Serquen, M.S., Breeding & Genetics Jorge Tenorio, B.S., Breeding & Genetics Roger Vallejo, M.S., Breeding & Genetics Ricardo Wissar, M.S., Breeding & Genetics Cesar Aguilar, Ing. Agr., Genetic Resources Jesus Amaya, Tech . Dip!. , Genetic Resources Humberto Asmat , Biologist , Genetic Resources Anibal Baltazar, Ing. Agr. , Genetic Resources Walberto Eslava, Ing. Agr. , Genetic Resources Matilde de Jara Vidalon, Biol., Genetic Resources Rossana Freyre Sala, B.S. , Genetic Resources Christa Merzdorf, M.S., Biol., Genetic Resources Gisella Orjeda, B.S., Genetic Resources Armando Quispe, Ing . Agr., Genetic Resources Alberto Salas, Ing. Agr. , Genetic Resources Jesus Alcazar, M.S., Nematology & Entomology Ida Bartolini , M.S., Nematology & Entomology Oder Fabian , Ing. Agr. , Nematology & Entomology Arelis Carmen Garzon , Biol. , Nematology & Entomology Alberto Gonzales, M.S., Nematology & Entomology Erwin Guevara, Ing. Agr. , Nematology & Entomology Angela Matos, Ing. Agr., Nematology & Entomology Raul Salas , Ing. Agr. , Nematology & Entomology Maria Villa, Biol. , Nematology & Entomology Marina Zegarra, Biol. , Nematology & Entomology Pedro Alay, M.S. , Pathology Ilse Balbo , Biol., Pathology* (left 1988) Ciro Barrera, Ing. Agr. , Pathology Lukas Bertschinger, Ing . Agr. ETH, Pathologyt Carlos Chuquillanqui, B.S., Pathology Violeta Flores, Biol., Pathology Segundo Fuentes , Biol., Pathology Wilman Galindez, Ing. Agr. , Pathology Liliam G. Lindo, Ing. Agr. , Pathology Charlotte Lizarraga , B .S., Pathology Josefina Nakashima , Biol. , Pathology* Ursula Nydegger, Tech. Dip ., Pathology Hans Pinedo, Ing. Agr., Pathology Hebert Torres, M.S ., Pathology Ernesto Velit, Biol ., Pathology Jurg Benz, M.S., Agronomist, Physiologyt Donald Berrios, Ing. Agr., Physiology Fausto Buitron, Ing . Agr., Physiology Rolando Cabello , Ing. Agr., Physiology Nelson Espinoza, Biol., Physiology Rosario Falcon , B.S., Physiology Nelly Fong, M.S ., Physiology Rolando Lizarraga , B.S., Physiology Norma de Mazza , Q .F., Physiology Ana Panta , Biol ., Physiologyt Frederick V. Payton , M.S ., Agronomistt Mark Reader, B.S., Physiology* (left 1988) Jorge Roca , B.S., Physiology Roxana Salinas, Ing. Agr., Physiology Carmen Sigiieiias, Biol., Physiologyt Daniela Silva , Biol., Physiology Dora Pilar Tovar, Biol., Physiology Adolfo Achata , Economist, Social Science* Marisela Benavides , Socio! ., Social Science Hugo Fano , Economist , Social Science Cecilia Gallegos , Economist , Social Science Victor Suarez, B.S ., Statistician , Social Science Beatriz Eldredge , B.S., Biometrician, Research Support Segundo Guevara, Electronic Tech., Operator, Research Support Lauro Gomez, Tech., Research Support Jose Jibaja, B.S., Biometrician, Research Support* Jose Luis Marca , M.S., Research Support Nelson Melendez, Tech. Dip ., Research Support Alberto Velez, Electronic Eng., Research Support Luis Zapata , Ing. Agr. (Reg. I) Jorge Queiroz, Ing . Agr. (Reg. II) Stan Kasule, B.S. (Reg. III) John Kimani, B .S. (Reg. III) M. Shahata, B.S . (Reg. IV) (Egypt) 167 M. Sharkani, B.S. (Reg . IV) (Egypt) S. K. Menra, M.S ., Post Harvest Assistant (Reg . VI) A. Demagante, M.S. (Reg. VII) V. Escobar, M.S . (Reg. VII) B. Fernandez, M.S. (Reg. VII) C. Montierro, M.S. (Reg . VII) B. Susana, B.S. (Reg. VII) Jorge Apaza, Ing . Econ ., Training & Communications Fiorella Cabrejos, M.S.T., Training & Communications Fabiola Castillo , B.A., Training & Communications Jesus Chang, M.S. Ed., Training & Communications Martha Crosby, B.A., Training & Communications Cecilia Ferreyra, Training & Communications Marciano Morales-Bermudez, M.S., Training & Communications Jorge Palacios, Dip., Training & Communications Ana Maria Ponce , M.S., Training & Communications Jorge Vallejo , Ing. Agr. , Training & Communications Margarita Villagarcia, M.S., Training & Communications 168 Eliana Bardalez, C.P.A., Controller's Office Jorge Bautista , B.S., Controller's Office Jose Belli, C.P .A, Controller's Office Luz Correa , C.P.A., Controller's Office Vilma Escudero , B .S., Controller's Office Alfredo Gonzalez, C.P.A., Controller's Office Alberto Monteblanco, C.P.A., Controller's Office * Left during the year. t These positions 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 • .. .). • Financial Statements ·Moreno Patino MorenoPatifloyAsociados SociedadCivi1de Aesponsabilidad Umitada Firm a Miembio de Price Waterhouse REPORT OF INDEPENDENT ACCOUNTANTS March 3, 1989 To the Members of the Board of Trustees International Potato Center - CIP las Begonias 441 Uma27,Pen.i. Apai1ado2869 Ms.:42-0555·42-0567 Teklx 20008 Priwalt We have examined the balance sheets of International Potato Center - CIP (a non-profit organization) as of December 31, 1988 and 1987, and the related statements of revenue, expenditures 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 proce- dures as we considered necessary in the circumstances • As described in Note 2-c), and in accordance with guidelines estab- lished by .the Consultative Group for International Agricultural Research for the preparation of financial statements by International Agricultural Research Centers, firm orders for pur- chases of fixed assets and services are recorded in the year of their commitment rather than at the time when the actual liability arises . In our opinion, excep·t for effect of the matter described in the preceding paragraph, the financial statements examined by us present fairly the financial position of International Potato Center - CIP as of December 31, 1988 and 1987 and its revenues, expenditures and changes in its unexpended fund balances and changes in its financial position for the yea rs then ended, in conformity with generally accepted accounting principles consistently applied . ~~;V~ :~~:~~-''""'''"' Franci~~- Moreno Peruvian Public Accountant Registration No. 155 169 INTERNATIONAL POTATO CENTER - CIP BALANCE SHEET (Notes* 1 and 2) as of December 31 , 1988 and 1987 (Expressed in U .S. dollars) 1988 1987 ASSETS • CURRENT ASSETS Cash and short-term deposits 3,352,991 2,716,847 Accounts receivable Donors 1,558,152 3,099,626 Advances to personnel 59,544 18,075 Loans to executives and employees - current portion (Note 3) 118,304 115 ,366 Other (Note 4) 496,096 352,219 Inventories of laboratory and other supplies 720,349 624,473 Prepaid expenses and other current assets 97,222 113,502 Total current assets 6,402,658 7,040 ,108 RESTRICTED FUNDS (Note 3) 203,578 275,000 - LOANS TO EXECUTIVES AND EMPLOYEES - NON-CURRENT PORTION (Note 3) 74,212 176,545 l FIXED ASSETS (Note 5) 15 ,235 ,347 11 ,355 ,942 21,915,795 18,847 ,595 • The accompanying notes are an integral part of ihe fina ncial statements. 170 INTERNATIONAL POTATO CENTER - CIP ' 1988 1987 LIABILITIES AND FUND BALANCES CURRENT LIABILITIES Bank overdrafts and current portion of long-term debt (Notes 3 and 6) 140,200 283,353 Accounts payable and other liabilities 1,424,455 1,040,334 Grants ,received in advance 2,182,245 Other payables and accrued expenses 383,494 229,026 Total current liabilities 1,948,149 3,734,958 LONG-TERM DEBT (Note 3) 55,237 167 ,509 PROVISION FOR SEVERANCE INDEMNITIES, net of advances of 23,012 (61,273 in 1987) 212,919 425,029 °".:J' FUND BALANCES· Funds invested in fixed assets (Note 5) 15,235 ,347 11,355,942 Unexpended funds - Operating funds - Unrestricted 3 ,591 6,195 - Restricted 564,680 88,888 Capital fund 188,000 Working funds 1,575,000 1,317,000 Special projects 2,219,116 1,510,969 Cooperative activities 101,756 53,105 4,464,143 3,164,157 GRANTS PLEDGED (Note 7) 21 ,915 ,795 18,847 ,595 • The accompanying notes are an integral part of the financial statements. 171 INTERNATIONAL POTATO CENTER - CIP STATEMENT OF REVENUE, EXPENDITURES AND CHANGES IN UNEXPENDED FUND BALANCES (Notes 1 and 2) for the years ended December 31, 1988 and 1987 • (Expressed in U.S. dollars) 1988 1987 REVENUE Operating grants: Unrestricted 12,418,294 9,211,096 Restricted 3,081,939 2,194,525 Other restricted core grants 851,549 723 ,860 16,351,782 12,129,481 Special project grants 2,215 ,755 1,840,181 Grants for fixed asset additions 1,188,000 806,547 Grants for cooperative activities 140,562 444,755 Working fund grants 258,000 17,000 Other income, net 560,927 665,991 20 ,715,026 15,903,955 EXPENDITURES Operating costs: l_ Potato and sweet potato research program 3,983 ,190 3,795,862 Research services 1,614,033 1,602,004 Regional research program and training 3,477,441 2,958,629 Conferences and seminars 152,401 103,593 Library and information services 646,616 642,913 Administration costs 1,281,626 1,434,283 Other operating costs, including replacement of an aircraft for 3,019,180 in 1988 4,641 ,182 1,563,061 15 ,796,489 12,100,345 Other restricted core expenditures 604,589 807,615 Special projects 1,503,137 1,963,173 Cooperative activities 91 ,911 403 ,378 Grants returned 4,471 3,432 18,000,597 15,277,943 Additions to fixed assets 1,414,443 618,547 19,415 ,040 15,896,490 Excess of revenue over expenditures 1,299,986 7,465 ~ Unexpended fund balance, beginning of year 3,164,157 3,156,692 UNEXPENDED FUND BALANCE, END OF YEAR 4,464,143 3,164,157 • The accompanying notes are an integral part of the financial statements .· 172 INTERNATIONAL POTATO CENTER - CIP STATEMENT OF CHANGES IN FINANCIAL POSITION for the years ended December 31, 1988 and 1987 i) (Expressed in U.S. dollars) 1988 1987 SOURCE OF FUNDS Excess of revenue over expenditures 1,299,986 7,465 Decrease in accounts receivable 1,353,190 Decrease in prepaid expenses and other assets 16,280 Decrease in restricted funds 71,422 25,000 Decrease in loans to executives and employees - non-current portion 102,333 180,489 Increase in funds invested in fixed assets 3,879,405 868,682 Increase in accounts payable and other liabilities 395 ,436 Increase in grants received in advance 2,182,245 Provision for severance indemnities 216,236 42,651 7,334,288 3,306,532 APPLICATION OF FUNDS Purchase and replacement of fixed assets !, - Core acquisitions 1,414,443 618,547 - Special projects 70,501 207,098 - Net cost of replacement 2,394,461 43,037 Increase in accounts receivable 1,607,313 'Y Increase in inventories 95,876 106,978 Increase in prepaid expenses and other current assets 32,427 Decrease in accounts payable and other liabilities 998,984 Decrease in grants received in advance 2,182,245 Decrease in long-term debt 112,272 116,251 Payment and advances of severance indemnities 428,346 75,033 6,698,144 3,805,668 Increase (decrease) in cash and short-term deposits 636,144 (499 ,136) Cash and short-term deposits, beginning of year 2,716,847 3,215,983 CASH AND SHORT-TERM DEPOSITS , END OF YEAR 3,352,991 2,716,847 The accompanying notes are an integral part of the finan cial statements 173 INTERNATIONAL POTATO CENTER - CIP NOTES TO FINANCIAL STATEMENTS as of December 31, 1988 and 1987 (Expressed in U.S . dollars) 1. Operations The International Potato Center (CIP) is a non-profit organization located in Lima , Peru, with programs throughout Latin America , Central America and the Caribbean , the Near and Middle East, Asia and Africa. CIP's principal objective is to contribute to the development of the potato, sweet potato and other tuberous roots through scien- tific research programs, preparation and training of scientists, dissemination of research results in publications , conferences , forums and seminars, and other activities , in accor- dance with its objectives. CIP was established in 1972, in accordance with an Agreement for Scientific Coopera- tion 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 sup- ported by the Consultative Group for International Agricultural Research (CGIAR) . 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 assets are to be transferred to the Peruvian Min- istry of Agriculture. 2. Summary of significant accounting policies 174 The principal accounting policies are as fo llows: a . Foreign currency - The books and accounts are maintained in U .S. dollars. Transactions are mainly in U.S . dollars. Assets and liabilities denominated in currencies other than the U.S. dollar are expressed at year-end exchange rates. Exchange gains and losses are included in the statement of revenue, expenditures and changes in unexpended fund balances . b . Revenue - Grant transactions are recorded as revenue on the basis of donor commitments. Core unrestricted grants, 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 collection . Restricted operating and special project grants are accounted for in the period stipulated by the donor. Other income net is recorded when earned and is comprised primarily of interest on investments, proceeds from sales of fixed assets and supplies, translation gains and losses, and of administrative costs of special projects. c. Expenditures - Firm orders for purchases of fixed assets and services are recorded in the year of their commitment. At December 31, 1988 the amount recorded under this practice totalled 892,740 (364,100 in 1987) . ( r •1 Expenditures made by international programs are recorded on the basis of advices received . Expenses related to special projects are applied when incurred against the respective income. d. Investments - Short-term investments are principally comprised of certificates of deposit bearing interest at current bank rates and are valued at cost. e . Inventories of laboratory and other supplies - Inventories of laboratory, supplies and other materials are valued at estimated mar- ket value, which approximates cost. f. Fixed assets - Fixed assets are stated at cost. Additions to fixed assets are recorded as grant expenditures and cost of replacements are reported as operating expenses in the statement of revenue, expenditures and changes in fund balances and added to the related equity account. Upon the sale or retirement of fixed assets , their cost is removed from the fixed asset and related equity accounts . Fixed assets are not depreciated . Maintenance and repairs are recorded as operating costs in the year incurred. g. Vacations - Employee vacation expenses are charged to operating expenses when they are taken . h. Provision for severance indemnities - Peruvian employees' severance indemnities are accounted for on an accrual basis ~ and are calculated in accordance with current legal dispositions . The amount accrued represents the amount that would have to be paid to the employees if they were to terminate as of the date of the financial statements. 3. Loans to executives and employees and long-term debt CIP provides loans to certain of its executives for the acquisition of homes and/or vehi- cles. These loans are funded by a term loan from Citibank N.A. - New York and in certain instances with CIP's own funds . At December 31, 1988, outstanding loans obtained from Citibank N.A. amount to 157,409 (265 ,753 in 1987) , and bear interest at the New York prime rate plus 1.5% and are repayable in monthly installments until June 1990. Loan balances with executives and employees at December 31 , are as follows: Loans funded by line of credit of Citibank N.A., secured by related homes and/or vehicles, repay- able under the same conditions as advances under the term loan at no direct cost to CIP 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 1988 157,409 35,107 192,516 (118,304) 74 ,212 1987 265 ,753 26 ,158 291 ,911 (115 ,366) 176,545 175 4. s. In addition, at December 31 , amounts outstanding under the term loan from Citibank N.A. are as follows: Current portion (Note 6) Non-current portion (maturing 1989-1990) 1988 102,172 55,237 157,409 1987 98,244 167,509 265,753 These amounts are guaranteed by a position of a deposit of 203,578 (275,000 in 1987) in the aforementioned financial institution, which earns interest at 8% per annum (6.3% in 1987). Accounts receivable - Other This balance is comprised of the following at December 31: 1988 1987 Advances to organizations for research work 264,150 248,679 Travel advances 72,399 46 ,809 Advances to contractors and other 113,267 8,014 Other 46 ,280 48,717 496,096 352,219 Fixed assets Fixed assets at December 31 , comprise the following: 1988 1987 Buildings and constructions 3,709 ,009 3,001,705 Research equipment 1,779,833 1,567,297 Vehicles and aircraft 4 ,828 ,323 2,313,207 Furniture, fixtures and office equipment 1,330,152 1,220,813 Operating farm equipment 546,887 456,782 Installations 1,654,794 1,373,237 Site development 783,671 776 ,706 Communications equipment and other 581 ,217 561,250 Construction in progress 21,461 84,945 15 ,235 ,347 11 ,355 ,942 Vehicles and other fixed assets replaced or retired are transferred from the fixed asset and related equity accounts to a memorandum account. Fixed assets sold or donated are eliminated from the memorandum account. The balance of the memorandum account at December 31 , 1988 is 817,010 (699,891 in 1987). 6. Bank overdrafts and current portion of long-term debt At December 31, this balance is comprised of the following: 1988 1987 Bank overdrafts 38,028 185 ,109 Current portion of Jong-term debt (Note 3) 102,172 98 ,244 140,200 283,353 176 r CIP has various credit lines and loan arrangements with Citibank N .A . totalling 525,000 (680,000 in 1987), which bear interest at the New York prime rate plus 1.5% . As of December 31 , 1988, unused amounts under these credit facilities totalled 300,000 (400,000 in 1987). '.) 7. Grants pledged --. During 1988 the following donations were pledged · to CIP for special projects in 1989 through 1992: 1989 1990 1991 1992 International Development Research Centre - Canada 146,600 Swiss Development Cooperation and Humanitarian Aid 731,258 660 ,692 653 ,746 528,730 United States Agency for International Development 345,975 404,875 22 ,500 Netherlands Government 71,955 108,556 Pepsico Food International/ McDonald's Corporation 50,000 Belgian Government 435 ,120 German Agency for Technical Cooperation - BBA 17,900 28,200 Food Industry Crusade Against Hunger 90 ,000 ,, 1,888,808 1,202,323 676 ,246 528,730 The above amounts are not reflected in the accompanying finan cial statements. 177 The CGIAR: A Global Agricultural Research System T he Consultative Group on International Agricultural Research (CGIAR) was established in 1971 to bring together coun- tries , public and private institutions , interna- tional and regional organizations, and repre- sentatives from Jeveloping countries m support of a network of international agri- cultural research centers . The basic objec- tive of this effort is to increase the quantity and improve the quality of food production in developing countries. The research sup- ported by the CGIAR concentrates on the critical aspects of food production in developing countries, of global importance, that are not covered adequately by other institutions. Currently, the CGIAR network is involved in research on all of the major food crops and farming systems in the major ecological zones of the developing world. The CGIAR consists of over 40 donor organizations . They meet twice a year to consider program and budget proposals as well as policy issues of the 13 international agricultural research institutes supported by the group. The World Bank provides the CGIAR with its chairman and secretariat, while the Food and Agriculture Organiza- tion (FAO) of the United Nations provides a separate secretariat for the group's Tech- nical Advisory Committee (TAC) . The TAC regularly reviews the scientific and technical aspects of all center programs and advises the CGIAR on needs, priorities, and opportunities for research . Of the thirteen centers , ten have commodity-oriented programs covering a range of crops and livestock , and farming systems that provide three-fourths of the developing world's total food supply. The remaining three centers are concerned with problems of food policy, national agricul- tural research, and plant genetic resources. 178 CIAT International Center for Tropical Agriculture Cali , Colombia CIMMYT International Maize and Wheat Improvement Center Mexico City, Mexico CIP International Potato Center Lima, Peru ICARD A International Center for Agricultural Research in the Dry Areas Aleppo, Syria ICRISAT International Crops Research Institute for the Semi-Arid Tropics Hyderabad, India IITA ·International Institute of Tropical Agriculture Ibadan , Nigeria ILCA International Livestock Center for Africa Addis Ababa, Ethiopia ILRAD International Laboratory for Research on Animal Diseases Nairobi , Kenya IRRI International Rice Research Institute Manila, Philippines WARDA West Africa Rice Development Association Bouake, Ivory Coast IBPGR International Board for Plant Genetic Resources Rome, Italy IFPRI International Food Policy Research Institute Washington , D.C. , U.S.A. ISNAR International Service for National Agricultural Research The Hague , Netherlands \ r