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A GLOBAL RESEARCH AGENDA FOR HORTICULTURAL CROPS:
CIP AND THE ROLE OF ROOTS AND TUBERS

Hubert Zandstra and Gregory J. Scott
Director General and Senior EcoSTRONG>
Director General and Senior Economist

Introduction

Potato, sweetpotato, and minor Andean roots and tubers together constitute a significant share of the total volume and value of horticultural crops world-wide. These commodities are particularly important as a source of food, employment, and income in developing countries where the bulk of the world's producers, processors, and consumers reside. As we enter the new millennium, roots and tubers will play an increasingly important role in meeting the food requirements, feed uses, and income needs of the world's food system.

In this paper, we briefly describe recent global trends in production and utilization for roots and tubers, and then present CIP's collaborative research program. The central themes of this paper are the growing importance of these commodities in the world's food system, and the integrated nature of CIP's research efforts that are intended to help producers and consumers exploit their full potential. After separate reviews of trends, projects, and research activities for potato, sweetpotato, and Andean roots and tubers, the paper summarizes principal findings and draws attention to what we perceive to be the shifting global research agenda for these horticultural crops in the future.

Potato

Potato (Solanum tuberosum) production worldwide has Potato (Solanum tuberosum) production worldwide has witnessed four major developments over the last three decades:

• The share of global output produced in developing countries has risen from 11% in 1961-63 to 36% in 1994-96 (Figure 1). Not one other of the 15 major food crops has seen such a shift in the location of production. Developing countries in Asia, including China, the world's largest producer, now account for nearly one-quarter of global production and almost 80% of the potatoes produced in developing countries (Scott et al., 1998).

Figure 1. Location of potato production, 1961-63 to 1994-96. (Source: Scott et al., 1998.)

• Processing has emerged as the most dynamic sector in the world potato economy. Processing now absorbs some 60% of production in the United States and 50% in the Netherlands, for example. Processing is also emerging as the growth sector in developing countries, particularly in Latin America, North Africa, and East Asia (FAO, 1995; Scott et al., 1997).
• Trade in potatoes and potato products has assumed multi-billion dollar proportions with traditional commerce in table stock and seed now being rivaled, if not eclipsed, by shipments of frozen french fries, chips, starch, flakes, and other processed products (Scott, 1994; Scott et al., 1997).
• The threat of late blight is menacing with new strains of the pathogen being spotted in variouwith new strains of the pathogen being spotted in various locations and the danger of devastating mutations becoming an increasing concern. These new pests-combined with old nemeses such as bacterial wilt, potato tuber moth, and other insects and the increasing demand for good planting material have all influenced CIP's current collaborative research agenda for potato.

With the launching of the Global Initiative on Late Blight (GILB) in 1996 (Gregory, 1996), CIP renewed and expanded its efforts to address the threat of a global potato famine from late blight. Work on late blight consists of three principal thrusts. The first is biotechnological and aims to identify disease resistance genes and explore the potential for their insertion into advanced materials having other desirable traits (e.g., earliness, high yield, processing quality). The second uses traditional breeding techniques that involve working with the populations of late blight resistant and tolerant clones that CIP has either developed or has access to with a goal toward incorporating these in its program of crosses. The third thrust involves integrated disease management activities that include GIS (geographic information systems) work to identify late blight-vulnerable production zones, the areas designated as the "sexual frontier" or where mutations in the pathogen population suggest the greatest potential for identifying late blight resistant materials, asdentifying late blight resistant materials, as well as a package of proven effective cultural practices to limit the spread of and damage from late blight in producers' fields.

Collaborative research on late blight involves CIP scientists at headquarters in Lima and through regional offices in Latin America (e.g., Ecuador), Africa (Kenya, Uganda), and Asia (China, India, and Indonesia). CIP scientists' research in turn contributes to the global consortium that includes activities with national potato programs in Argentina, Colombia, Ecuador, Peru, Kenya, Uganda, India, and China, to name a few. Advanced research institutes which CIP works include universities and centers of excellence in industrialized countries in North America, Asia, and Europe, together with those in the developing countries.
Other important research includes achievements in biotechnology, virus detection, seed systems, and in trade and processing.

The molecular search for durable late blight resistance genes progressed with the identification of several molecular markers associated with resistance in Solanum phureja that will be tested for their capacity to predict resistance in new crosses. In addition, a marker database has been established including more than 1,000 pathogen isolates. Significant progress is predicted in 1998 for identifying usable genes. Continued evaluation of CIP's Population B for late blight resistance has resulted ition B for late blight resistance has resulted in the identification of resistant clones in several countries, including China, where the disease is severe and potatoes are increasingly important. (See CIP, 1997.)
Breakthrough bacterial wilt research in 1997 resulted in dramatically increased sensitivity in detection methods of the bacteria that will significantly reduce the time needed for verification of the pathogen in seed stocks. Potato clones with combined resistance to bacterial wilt and two potato viruses were also identified in 1997.
Potato seed systems research in the Philippines, China, and Africa increased the range and impact of informal seed systems and thus the impact of new varieties. Technology developed in the Philippines has been adapted in several countries such as Thailand, Vietnam, and Samoa. Farmer Field chools increased farmer participation directly. Broader adaptation of these technologies is anticipated in 1998.
Research on trade and potato processing has highlighted the tremendous growth in the volume and value of the potato trade as well as strong outlook for rapid growth in the future especially in Latin American and Asia. In the trade area, in particular, successive collaborations have contributed to this work, first by thesis students from Wageningen Agricultural University in the Netherlands, followed by linkages to work by a number of organizations that are members of the Programa Regionalions that are members of the Programa Regional Cooperativo de Papa (PRECODEPA) (Scott, 1996), and collaborative trends analysis and projections both with FAO and IFPRI.
Factors contributing to these trends include rapid urbanization, growing participation by women in the formal work force, rising tourism, rising incomes combined with growth in production, falling tariff and non-tariff barriers, and declines in containerized shipping costs (Scott, 1994). One major challenge to developing country producers in the years ahead will be to better integrate local supply with agro-industry, both for domestic consumption and export. Considerable opportunities exist for closer collaboration with the private sector in these areas (see, e.g., ICA, 1992).

Sweetpotato

Global sweetpotato production fluctuated with the aggregate effect being a decline in area planted, less than offset by an increase in yields (Table 1), whereas output remains heavily concentrated in China (Figure 2). Recent indications from China are that the fall in area planted has stabilized and production has begun to rebound accordingly (Gitomer, 1996).

Trends in sweetpotato area planted and production have been highly uneven in other locations. Indonesia, the philippines, and Brazil, for example, experienced declining output and area planted since the mid-1970s. preliminary indications are that the very recent sharp dpreliminary indications are that the very recent sharp declines in exchange rates in East Asia and the steep rise in the trade deficit in Brazil may slow or even reverse these trends (see, e.g., peters and Wheatley, 1997). On the other hand, sweetpotato production expanded rapidly in recent years in much of Sub-Saharan Africa because the crop has the ability to do well on marginal soils with minimal production (input) costs (Von Braun et al., 1991; Scott and Ewell, 1992).

Increasingly in China, sweetpotato is used for animal feed due to the expanding livestock industry that supports the surge in demand for meat (Rosegrant et al., 1997). In fact, sweetpotato is used in some form for some animals in virtually every country where it is produced (Scott, 1992). Recent projections merely confirm that this utilization pattern for sweetpotatoes will intensify in the decades ahead not only in Asia, but also in those parts of Africa and Latin America where feed grains are in short supply, foreign exchange expenditures limited, demand for meat and dairy products strong, and growers as well as policy makers are in search of alternatives to complement more conventional, large-scale, feedlot livestock production systems (Scott et al., 1998).

In light of these trends and after more than five years of diagnostic work in Asia, Africa, and Latin America, CIP researchers have formulated a new sweetpotato research agenda. This integrated approach includeearch agenda. This integrated approach includes:

• Development of more locally adapted clones with high dry matter content.
• Integrated pest management aimed principally at reducing damage and losses from sweetpotato weevil.
• Improved processes and products to satisfy the latest demand for starch, flour, and animal feed in developing countries.

Increasing dry matter (DM) content is the primary objective for sweetpotato breeding at CIP. Recent evidence from Southeast Asia and East Africa suggests that progress in this area is being made much more rapidly than previously believed possible. In Indonesia, for example, performance of the four best clones recently accelerated based on CIP's collaborative work with CRIFC. Results show that root yield, dry matter content, and starch content are well above the local average (see Il-Gin Mok, 1997) in these new clones. It is particularly noteworthy that preliminary economic estimates suggest that starch production from these clones would be competitive with other raw material sources in the starch industry in Southeast Asia. Recent results from Kenya also show a number of clones with a combination of high yields, dry matter content, and total dry matter yield (see Carey et al., 1997). Collaboration with Kenya Agricultural Research Institute in Kenya and NAARI in Uganda proceeds apace in light of these highly promising findings.

CIP's other recent research acsing findings.

CIP's other recent research achievements with sweetpotato included:

• Sweetpotato clones from various sources(including local farmer varieties, regionally bred varieties and exotic introductions) showed an impact at the farm level in 1997 in a number of countries. Especially important was the identification in Eastern and Southern Africa of acceptable, orange-fleshed varieties with the potential to contribute to improved vitamin A intake, one of the most serious nutritional deficiencies in Africa (see Low et al., 1997). Increased adoption of these new varieties by farmers is predicted for 1998.
• IPM studies in Uganda provided significant practical and theoretical information on the possibility of controlling sweetpotato weevil (the most devastating constraint to global production) by pheromone trapping (Smit and Odongo, 1997).
• Specialized training and follow-up research in sweetpotato virology catalyzed the adaptation of a successful propagation system that has produced enough virus-free material to plant more than a million hectares in Shandong, Henan, and Northern Jiangsu provinces in China. Virus detection efficiency has tripled. Preliminary calculations suggest that the internal rate of return on this investment is 120% and that the net present value is about 250 million dollars (Walker, 1997).
• Production research in postharvest utilization of sweetpotato in 1997 verified the potential for this cro in 1997 verified the potential for this crop in starch-based industries and animal feeding, particularly in China and other parts of Southeast Asia.

Studies of national and provincial statistics in China, in collaboration with the Chinese Academy of Agricultural Sciences, documented the spread of sweetpotato processing primarily for feed and starch (Wheatley et al., 1997). Processing has income- and employment-generating potential for small farmers in the poorer parts of the country. The potential for the expanded use of sweetpotato as a substitute for imported maize in pig feed is a heretofore overlooked way for China to avoid the massive feed imports predicted by some observers.

Regional surveys conducted in Vietnam indicate an upswing in the use of sweetpotato for animal feed and sweetpotato starch for making noodles, with prospects of even more expansion. The surveys and analysis were done by the National Institute of Agricultural Sciences, the Postharvest Technology Institute, and the Animal Husbandry Research Institute, with assistance from CIP, Users' Perspective with Agricultural Research and Development (UPWARD), and Centro Internacional de Agricultura Tropical (CIAT) staff (Prain, 1997).

These macro-studies document the importance of and potential for sweetpotato processing, lay out a set of collaboratively forged research priorities and policies, and provide a common framework for the variouolicies, and provide a common framework for the various institutions engaged in sweetpotato postharvest research.

Table 1. Sweetpotato production, area and yield in developing countries.

	1994-96			Average annual growth rate comparing 1977-79 with 1994-96
	Production1	Area2	Yield3	Production	Area	Yield
Africa4	6,824	1,458	4.7	1.3	1.6	-0.3
Sub-Saharan5	6,680	1,452	4.6	1.3	1.6	-0.3
Uganda	1,967	494	4.0	1.5	1.3	0.0
Rwanda	950	145	TH=109>950	145	6.5	1.2	2.3	-1.2
Burundi	648	107	6.1	1.8	2.1	-0.3
Kenya	632	64	9.8	4.3	3.3	1.0
Madagascar	503	89	5.7	2.0	1.1	0.9
Congo	408	100	4.2	1.6	2.7	-1.0
Tanzania	362	243	1.5	-3.0	1.6	-4.5
Asia6	116,195	7,235	16.1	-0.9	-2.3	1.4
China	108,482	6,159	17.6	-0.8	-2.3	1.6
	1.6
Indonesia	2,147	225	9.5	-0.3	-1.8	1.5
Vietnam	1,764	318	5.6	-0.3	-0.7	0.4
India	1,159	140	8.3	-1.8	-2.9	1.1
Philippines	589	136	4.3	-3.2	-3.0	-0.1
Korea DPR	460	33	13.8	1.4	1.5	-0.1
Papua New Guinea	447	105	4.2	0.4	0.7	-0.4
Bangladesh	432	45	9.6	-3.4	-2.7	-0.7
Korea Rep.	259	15	17.0	-9.9	-8.6	-1.4
Latin- America7	1,836	244	7.5	-1.5	-2.0	0.5
Brazil	655	58	11.3	-2.0	-3.3	1.3
Total	124,855	8,937	14.0	-0.8	-1.8	1.0

1 Thousands of tons.
2 Thousands of hectares.
3 Tons per hectare.
4 Africa not including South Africa
5 Africa less Morocco, Algeria, Tunisia, Egypt, Libya, and South Africa.
6 Asia, less Israel and Japan, plus Oceania, except Australia and New Zealand.
7 South, Central, and North America, except Canada and the USA.
Source: FAOSTAT, updated 3 october 1997.

Figure 2. Location of sweetpotato production, 1961-63 to 1994-96.

Source: Scott et al., 1998.

Detailed evaluations of existing technology focused on starch, flour, and feed in China, Kenya, Peru, and Uganda. Work with Sichuan Agricultural Academy of Science (SAAS) on small-scale starch production in Sichuan Province, China, was the most promising of all. It identified several areas for immediate improvement. Operational analysis in Peru quantified the raw material costs and conversion rates needed to achieve profitability at an existing starch plant (Meerdink, 1995). The necessary higher yields with more extractable starch seem well within reach. Sweetpotato flour appears more problematic in Peru for a variety of reasons (see Espinola et al., 1997). However, in Uganda, and to a lesser extent in Kenya, prospects are brighter for flour. Markets are emerging in the wake of declining supplies of cassava flour. Economic analysis of farm-level use of roots for pig feed in China is extremely encouraging. Modest changes can improve the prospects for even more widespread use. In Peru, dual purpose varieties with balanced production of vines for fodder and roots for human consumption show considerable potential to improve the lot of small-scale dairy farmers (León-Velarde, 1997).

In addition to research results and policy recommendations, a major effort has been made to improve local research capacity by preparing postharvee local research capacity by preparing postharvest methodologies appropriate to conditions in Africa, Asia, and Latin America. "Adding Value to Root and Tuber Crops", the manual on product development, co-published with the CGIAR centers which specialize in tropical agriculture in Latin America (CIAT) and in Africa (IITA), provides operational guidelines and a common framework for sweetpotato postharvest researchers worldwide (Wheatley et al., 1995). "Prices, Products, and People", a compendium of methods for analyzing agricultural marketing in developing countries, prepared with several IARC social scientists, is intended to serve a similar purpose (Scott, 1996).

Impact

Recent demand for a better documentation of impact in the CGIAR, has led CIP to conduct and sponsor nine impact studies covering research on varieties, seed, and integrated pest management (IPM) in Africa, Asia, and Latin America (Walker and Crissman, 1996). Return on investments in research projects ranged from 25% to more than 100%. In 1993 prices, net profits per hectare (discounting research and implementation costs) varied from $100 to more than $1,300 per hectare. These benefits do not include environmental ones associated with reduced use of pesticides.

The nine studies were by necessity only a partial selection of technological impact of CIP associated research. They probably represent abof CIP associated research. They probably represent about a third of all potential cases, ignoring major successes with bacterial wilt control (Costa Rica, East Africa) and diffused light storage (Central America and other regions), as well as several other activities such as true potato seed, IPM, and varietal change. Despite this, if you take the total investment in CIP since its inception and compare it with its actual and projected impact of only these nine technologies studied, the annual return in 1994 dollars will be approximately $230 million, or more than ten times CIP's annual budget (CIP, 1995).

Clearly, these achievements cannot be attributed solely to CIP staff. As in all CIP's activities, the work is conducted by a wide range of institutions in client locations and backed by contract research in industrialized countries. In that sense, the results confirm the wisdom of CIP's creators to develop a Center that conducts its work in a highly decentralized and participatory fashion.

Andean Roots and Tubers

CIP's work to conserve, characterize and utilize minor Andean root and tuber crops such as oca, ulluco, mashua, arracacha, and achira became formally part of the Center's mandate in 1992 (CIP, 1992). Many, if not all, of these roots and tubers are in danger of extinction for a variety of reasons. That fact, plus what is widely believed to be their untapped potential, has led to theelieved to be their untapped potential, has led to the formulation of a collaborative research agenda focusing on, among other things, genetic conservation and characterization, disease management, and postharvest technology and marketing. CIP includes these efforts as a key component of its natural resources initiative aimed at preserving the natural resource base, i.e., plants, animals, soil, and water, in the highlands of South and Central America, East Africa, and South Asia. Recent achievements for CIP's progress in Andean roots and tubers (ARTC) include the following:

• Recently, an important collection of accessions including oca, ulluco, mashua, Yacón, and arracacha was placed in CIP's trust by the University of Cerro de pasco, Peru;
• The publication of a minimum descriptor list for oca, ulluco, and arracacha is underway to help Andean NARS to reduce the size of their collections and to handle them more efficiently.
• Preliminary morphological and molecular characterizations have identified duplicated and reduced the size of CIP's ARTC collections (Arbizu, 1997).
• Seed of the highly self-incompatible oca (Oxalis tuberosa) were successfully produced; genetic field studies completed in 1998 will be directly relevant to the design of oca seed gene banks.
• Producers and production systems were characterized and principal production problems identified for ARTC.
• Urban markets with consumption p for ARTC.
• Urban markets with consumption potential for artc were identified, and studies showed that consumers in primary and secondary market cities preferred oca and ulluco (Espinoza and Crissman, 1997).
  
  
  

Natural Resource management for Mountain Ecologies

In the context of the CGIAR, CIP convenes research for the sustainable management of natural resources in mountain regions. This Global Mountain Program is shared with the International Center for Research in Agroforestry (ICRAF) for the East African Highlands and International Centre for Integrated Mountain Development (ICIMOD) in the Himalayan region of Asia (CIP, 1996). CIP's work in the Andes places emphasis on biodiversity, soil and water management, sustainable production systems, and policies for sustainable resource use. The work is conducted by a wide range of institutions in Venezuela, Ecuador, Colombia, Peru, and Bolivia. They include universities, national research institutes, and non-governmental organizations. These institutions have formed the Consortium for Sustainable Development in the Andes (CONDESAN), and cooperate in planning and implementing research. CONDESAN conducts its fieldwork in six benchmark sites. Recent research achievements include:

• Greater emphasis on post-harvest processing and marketing of unique Andean crops which is required to preserve their presence in regional production systto preserve their presence in regional production systems, increase farmer income, and maintain biodiversity (CONDESAN, 1997).
• Remote sensing and Geographical Information Systems (GIS) were integrated to monitor land use in the arid and semi-arid Andes. Simulation models were developed for predicting the production of native pastures and the consequences of frost. Methods were developed to map frost risk, combining daily temperature data with satellite imagery, and to assess pasture production.
• Surveys of soil and water conservation methods in the Andes showed that intensification and diversification of cropping systems reduce the time between investment on, and returns to, soil conservation. Farm households with more steeply sloping land, younger heads of household, and greater access to urban markets were more likely to adopt conservation practices.
• Improved management of Andean wetlands (bofedales) has been developed using near infrared imagery in cooperation with the Bolivian Association for Tele-detection and Environment (ABTEMA) and Wageningen Agricultural University. Effective estimates of production potentials allow more judicious use of water resources.
• CIP, in collaboration with CONDESAN, is working in six benchmark sites with local municipal governments to develop methodologies involving the use of minimum data sets, crop productivity/climate models, participatory research agendas, and roundtable forums to design ih agendas, and roundtable forums to design integrated micro-watershed development plans.
• Improved management of livestock production systems is being studied in cooperation with the International Livestock Research Institute's System-wide Livestock Program and with universities and National Agricultural Research Systems in the Andean ecoregion. Productivity-enhancing changes in the policy environment are being evaluated in five locations in the region.
• - CIP's pioneering interdisciplinary research on the economic, environmental, and health consequences of intensive pesticide use in Andean potato production was published in book form in 1997 (Crissman et al, 1997).
  
  
  

Conclusion and Recommendations

Potatoes and sweetpotatoes are major horticultural crops worldwide. Their importance in developing countries, particularly in Asia, is especially noteworthy. Analysis of trends and prospects for potatoes and sweetpotatoes in developing countries indicates that growth rates in production have accelerated in recent years, particularly for potatoes. The emerging research agenda for these crops reflects these shifts in the location and growth in production. In addition, as has been stressed throughout this paper, CIP's research agenda focuses on a prioritized set of key constraints and opportunities linked to these crops, namely, late blight, bacterial wilt, seed systems, trade and pre blight, bacterial wilt, seed systems, trade and processing for potatoes; improving dry matter, improved integrated pest management, and product development for sweetpotato. Research institutions in industrialized, as well as developing countries, are actively involved in CIP's collaborative efforts to address these challenges.

CIP's research agenda has broadened in recent years to include work on ARTC and natural resource management for mountain ecologies. CIP sees these activities as a logical extension of earlier efforts on potato and to a lesser extent sweetpotato that focuses often on high altitude environments in the tropics and sub-tropics and increasingly incorporates a concern for issues of environmental protection and sustainability of the natural resource base. These new initiatives involve not only many of CIP's existing collaborators, but also provide an opportunity for new linkages with institutions in industrialized and developing countries with a shared interest in horticultural research as it relates to the challenges of food production, poverty, and bio-diversity in Asia, Africa, and Latin America.

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