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fechar este livroRoots and Tubers for the 21st Century - Trends, Projections, and Policy Options. 2020 Vision for Food, Agriculture, and the Environment. Discussion Paper 31 (IFPRI, 2000, 72 p.)
Ver o documento(introduction...)
Ver o documentoForeword
Ver o documentoAcknowledgments
Ver o documento1. Introduction
Ver o documento2. Trends in the Use of Roots and Tubers
Ver o documento3. Trends in the Supply of Roots and Tubers
Ver o documento4. Baseline Projections of Production and Use
Ver o documento5. High Demand and Production Growth Scenario
Ver o documento6. Roots, Tubers, and the Environment
Ver o documento7. Conclusions and Recommendations
Ver o documentoAppendix: Supplementary Tables
Ver o documentoReferences

7. Conclusions and Recommendations

This paper has analyzed supply and demand trends and future projections for R&T in order to provide a clearer vision of the contribution that these crops can make to the food systems of developing countries over the next two decades. The paper has also stressed the important differences among these crops and the multiple roles they play in today's food systems. The analysis has shown that R&T will continue to play a significant role in developing-country food systems because 1) they contribute to the energy and nutrition requirements of over 2 billion people in developing countries today and will continue to do so over the next two decades; 2) they are produced and consumed by many of the world's poorest and most food insecure households; 3) they are an important source of employment and income in rural, often marginal areas, including for women; and 4) they adapt to a wide range of specific uses, from food security crop to cash crop, from food crop to feed crop, from the latter to raw material for industrial uses, and from fresh food to high-end processed product. To realize R&T potential in these areas, a combination of new technologies and improvements in the institutional and policy environment will be required.

With the foregoing in mind, the key questions addressed in this study can be reconsidered: 1) How have R&T contributed to the food systems of developing countries? 2) What role(s) will R&T play in the next two decades? And 3) What are the factors that have influenced and will influence the supply of and demand for these commodities?

The Changing Roles of R&T in Developing-Country Food Systems

The supply of and demand for R&T began to change significantly in the 1960s and 1970s. These changes - surging potato production in WANA, South Asia, and China, for example - accelerated over the next two decades, particularly during the 1990s. With a few noteworthy exceptions, the trend throughout has been toward greater diversification in use and greater specialization in production by crop and region.

In much of Asia and WANA, rising incomes, growing urbanization, and a desire by consumers to diversify away from strictly cereal-based diets have increased demand for potato as food in fresh and, more recently, in processed form. The same forces have influenced cassava and sweetpotato use in different ways. Growers, traders, and entrepreneurs capitalized on the raw material characteristics of these crops by shifting use toward starch, feed, and processed food products. In Sub-Saharan Africa, population growth, low and stagnant per capita incomes, and rapid urbanization have generated tremendous demand for a cheap, starchy staple to feed poor rural and urban consumers alike. Political instability and highly variable climatic conditions favor cassava as a low-cost, reliable source of carbohydrates, particularly in Central and West Africa. Yam continues to be consumed as a food crop in fresh form, but on a more modest scale compared to cassava.

In Latin America, changing diets in some countries (for example Colombia and Mexico) and the emergence of the fast food and snacks subsector in others (for example Argentina, Brazil, and Peru) have increased potato consumption. Many small producers have been driven out of production by rising costs per hectare and, most recently, by falling tariffs for imports of fresh potatoes and processed potato products. Cassava demand stagnated, with declines in fresh consumption offset by increases in feed use and processing for food and industry uses. Sweetpotato consumption stagnated as well due to weak demand. Growers had little incentive to adopt yield-increasing technology, except where they had access to markets. Increases in yam output were confined largely to Haiti and Jamaica.

Small farmers produce most of the potatoes in Asia and WANA. In most developing countries small farmers produce potatoes primarily for cash, though they have increasingly turned to sales of other R&T as a supplemental source of cash income. These farmers capitalize on the income-generating potential of potato, including its short vegetative cycle and broad adaptability. Relatively abundant labor supplies, new production technologies, improvements in infrastructure and input supply systems, and expansion of postharvest facilities, particularly cold storage, further facilitate their efforts to increase production and improve productivity. The lucrative export market to Europe provides an added incentive in North Africa. The principal policies that helped generate the rise in potato output and productivity includes limited intervention in output markets, credit and tax schemes to build and equip storage facilities, and programs to expand production and marketing infrastructure.

Sweetpotato production in China fell rapidly from the late 1970s to the late 1980s, primarily because the consumption of sweetpotato roots in fresh form declined. As cereal production increased and the overall economy grew rapidly, incomes improved and consumers switched from fresh sweetpotato to more preferred foods. But continued economic growth, diversification of diets, and the demand for meat and processed products led to a rapid increase in demand for sweet-potato as animal feed and starch. Growth rates for sweetpotato production began rising again in the early 1990s. New production technology (such as improved sweetpotato varieties and cleaner planting material) also contributed to increased yields and improved profitability, offering postproduction employment opportunities to poor farm households in the process.

In the past, growth in cassava output in Sub-Saharan Africa has been driven primarily by subsistence demand for food in low-income households. In recent years, cash sales have assumed near equal importance. Cassava production - particularly in West Africa - has increased due to a combination of additional factors, including the crop's ability to do well even on poor soils, with minimal rainfall and little or no purchased inputs; better production technologies (high-yielding varieties and integrated pest management techniques); improvements in postharvest practices; and policy measures intended to promote development of the local cassava processing industry.

The Roles for Roots and Tubers by 2020

IMPACT simulations indicate that R&T will play economically important and increasingly diversified roles in developing-country food systems over the next two decades.

In Asia, potato will serve as a complementary vegetable, occasional seasonal staple in parts of South Asia and China, and, increasingly, as raw material for processed food products. These multiple uses will reflect the continuing segmentation of the market into city versus countryside and low-income versus high-income. Increases in output and productivity for potato will translate into considerably higher levels of total production. But the rise in annual per capita intake will be much more modest, reaching only a third of the consumption levels in Europe or North America by 2020. Potato will not be traded in appreciable quantities. Nevertheless, higher potato production and consumption will help sustain food self-sufficiency, reduce the need for imports of cereal substitutes, and save foreign exchange in the process.

Sweetpotato in China and to a lesser extent in Vietnam will serve a much more diversified role in response to location-specific market requirements. In maize-deficit areas, such as Sichuan province, sweetpotato will be used for feed. In other locations like Shandong province, sweetpotato will be processed into starch for food products such as noodles. Improvements in sweetpotato productivity (yields and quality), processing (economic and technical efficiency), and product development (new uses for starch) will propel the evolution in sweetpotato use. The associated growth in employment and improvements in incomes will help alleviate rural poverty. Growth in sweetpotato feed use will reduce the need for and cost of imports. Its role as a food security crop will be limited to the most isolated, resource-poor, and least-developed food systems in Asia. In Indonesia, Thailand, and Vietnam cassava will follow a development path similar to that of sweetpotato in China.

In Sub-Saharan Africa cassava and yam will continue to be used overwhelmingly as food. Processed food products made from cassava will remain important in rural diets, particularly in West and Central Africa, where they will serve as a basic staple. Continued high rates of population growth and urbanization, combined with comparatively low levels of per capita income and limited economic growth, will promote growth in the use of cassava as food and catalyze its sustained penetration into urban markets. In East and Southern Africa, cassava will be used more as a supplementary staple and as a food security crop. The gradual emergence of processed food products from cassava in urban areas will open up new commercial outlets in cities and towns. Growth rates in cassava area planted and yields will be driven by the introduction of new, high-yielding, disease-resistant varieties; low-cost methods of pest control; and the spread of improved processing techniques to East and Southern Africa. Yam in West Africa as well as sweetpotato and potato in East and Southern Africa will also witness steady increases in consumption, but more modest in volume terms than for cassava. This consumption trend will be reinforced by market niches among higher-income consumers for processed food products and snacks made from yam and potato and among lower-income consumers for processed food and snacks made from sweetpotato. Improved production and postharvest technologies as well as institutional and policy innovations will facilitate the increases in output and productivity that match the increases in consumption.

Cassava and potato will dominate R&T use in Latin America. Cassava will be used in processed form (both for food and industry) and as feed. In contrast potatoes will continue to be used in fresh form, though the use of potato in processed and snack form will also continue to increase. Better varieties will increase yields and, for cassava in particular, the strengthening of small agro-enterprises will increase production further.

Prices of all R&T commodities are projected to decline by 2020, by 14-23 percent, depending on the commodity. The global impact of increased production and lower prices on R&T trade will be minimal. The decline in the economic value of R&T in developing countries, in relation to cereals, meat, and soybean, will be modest; the rise in importance of potato and yam will compensate for the fall in importance of cassava and sweetpotato.

The Influence of Technology, Institutions, and Policy

By 2020, we envision that the environmentally sound production of a diversified range of high-quality, competitive products for food, feed, and industry will integrate R&T into emerging markets. R&T adaptation to marginal environments, their contribution to household food security, and their great flexibility in mixed farming systems make them an important component of a targeted strategy for improving the welfare of the rural poor and linking smallholder farmers to emerging markets (Scott et al. 2000).

Although the projections for future production and use of roots and tubers in developing countries are realistic, they are by no means guaranteed. The continuous generation and diffusion of improved production and postharvest technology is essential if the root and tuber sectors in Asia, Africa, and Latin America are to flourish. Additional socio-economic research on the most effective and efficient ways to facilitate development and adoption of this improved technology will also be required. These efforts will only prove successful provided there are substantial levels of public and private investment in agricultural research at both the national and international levels in the decades ahead. Past analysis of such investments has shown that they can offer high rates of return (see, for example, Norgaard 1988; Johnson 1999; Walker and Crissman 1996).

Emerging from this review of the production and use patterns for the major R&T is a dichotomous vision for capitalizing on the emerging opportunities for these crops. Potato and yam primarily face supply-side constraints; cassava and sweetpotato face mainly demand-side constraints. Given the linkages between production and post-harvest activities, however, efforts to improve R&T should use a systems approach.

The removal or reduction of barriers to increased output of potato and yam - for example, through the development of disease- or drought-tolerant varieties, better pest management, improved systems for diffusing planting material, and policies and procedures aimed at stabilizing the within-year and year-to-year flow of supply onto the market - can enable producers to find outlets for their increased production of these commodities more easily. Producers can also identify and exploit the latent demand for feed and processed food products made from cassava and sweetpotato by lowering costs, raising quality, and improving availability. To minimize or overcome these constraints will require improved germplasm, more technically and economically efficient procedures for producing raw material and finished products, strengthened grower-to-processor linkages, and small-to-medium-scale enterprises for producing and marketing the products.

In addition to these concerns, a recent review of current research on R&T in the CGIAR identified the following commodity-specific priorities (Scott et al. 2000).

Research and Policy Priorities

· Cassava. Research priorities involve market appraisals and identification of linkages between producers, processors, and policymakers that capitalize on cassava's potential for expanded use in processed form. Such market-driven initiatives should be bolstered by germplasm research - including biotechnology research - on specific end uses (such as starch), tissue culture, rapid multiplication of planting material, pest and disease resistance (most notably cassava bacterial blight and cassava green mite), and appropriate technologies and procedures to ensure that cassava production and processing have a benign impact on the environment, with particular regard to soil erosion and water quality.

· Potato. Research priorities include enhancing resistance to prevalent diseases such as late blight by combining conventional plant breeding techniques and biotechnology; improving informal seed systems; and developing effective integrated crop management. Research on risk assessment for biotechnology and the impact of potato improvement on poverty, the environment, and human health also merit high priority, as does research on the demand and use of processed products.

· Sweetpotato. Concerted international efforts are under way to increase dry matter content and yield, exploit national and international germplasm for appropriate postharvest characteristics, including starch quality and pre-beta carotene content, and systematically support national efforts to foster greater product development for sweetpotato by small- and medium-scale farmers and entrepreneurs. Because sweetpotato cultivation is often concentrated in the poorest growing areas and among farmers with limited-resources, an evaluation of the impact of sweetpotato research on the food consumption and income-earning activities of the poorest countries is warranted.

· Yam. Areas of concentration for yam research include genetic improvement through more efficient germplasm screening; breeding for host-plant resistance to pests such as nematodes; reducing the high cost of planting material and labor-intensive field operations; and exploiting the crop's potential to be used in processed form.

While each of the major R&T has its commodity-specific priorities, recent appraisals of international agricultural research have stressed the need for and potential benefits from closer collaboration among IARCs (Strong et al. 1998). The recent TAC review of R&T highlighted the potential gains from capturing the synergies among the interested organizations involved with these commodities (TAC 1997b). At present, areas of potential gain include phytosanitary regulations, which affect the international exchange and transfer of germplasm and the speed of varietal improvement; biotechnology, which, among other things, involves the sharing of information and techniques for cryopreservation of germplasm (the storage of plant cuttings at -190° C) so as to reduce the cost and improve the quality of the preserved R&T; and postharvest technology and marketing. The latter area entails collaborative assessments of the market for R&T and related products (Ferris et al. 1999; Prain et al. 1999); joint capacity building through methodology development in the area of market analysis (Scott 1995) and product development (Wheatley et al. 1995); the exchange of information about procedures, processes, and products; and mobilization of regional interaction between scientists and their respective organizations (Scott, Ferguson, and Herrera 1992; Scott, Wiersema, and Ferguson 1992; Scott et al. 1992). These collaborative efforts can produce gains from synergy. But equally if not more important, these efforts would help fill the gap left by the absence of the private sector in R&T development.17

17 Potato is perhaps the exception, albeit on a limited basis (Qaim 1999).

The private sector has underinvested in R&T for three key reasons: (1) These crops are produced and consumed in developing countries, with the exception of potato (and, in the case of sweet-potato, Japan and the United States), hence there are few spillover benefits for industrialized countries. (2) While some R&T commodities have export potential, their commercial prospects abroad are generally more modest than for other agricultural products. As a result, the outlook for foreign exchange earnings is less attractive. And (3) R&T are cultivated and used by low-income households with limited means to purchase new technology. Moreover, most R&T producers are rarely organized into effective national organizations. These circumstances and the limited resources national agricultural research institutes have for R&T research (TAC 1997b), call for the creation of an advocacy group on behalf of these commodities in addition to closer collaboration. In individual countries such a body would serve as the rough equivalent to a growers' association or industry representative. It would seek to promote the needs of producers, traders, processors, and consumers of R&T in domestic policy deliberations, public resource allocation, private investment decisions, and trade negotiations. In that spirit, and in the case of cassava, Plucknett, Phillips, and Kagbo (1998, 12) have called for R&T supporters to “keep the needs of industry before the public and decision makers ... [and] ... for research and development, provision of infrastructure and investments, and changes in policies to grasp the new [commercial] opportunit[ies].” In a similar vein, a focal point is needed at the international level for gathering support and capturing the synergies of all those organizations working on R&T for the benefit of developing countries (Scott et al. 2000).

Policymakers should take increased cognizance of the growth prospects for particular R&T, and for particular uses in particular regions. Policymakers can do so by ensuring that the national and international databases for these crops are improved, particularly for R&T production and use in Sub-Saharan Africa (see, for example Minde, Ewell, and Teri 1999). More disaggregated and continuously updated projections at the regional and subregional levels for particular R&T can also be useful to prospective investors, multilateral agencies, and bi-lateral donors. Policy-makers in developing countries should eliminate measures like overvalued exchange rates or subsidies on imported food, in order to benefit from the full potential of R&T (see, for example, Byerlee and Sain 1991).

Policymakers can also foster R&T development by removing policy distortions that promote artificial economies of scale in livestock production (Delgado et al. 1999). Policies that promote only large-scale, feed-lot hog production in China offer a prime example of the constraints placed on sweetpotato production for household- and village-level processing into pig feed. Policymakers can include R&T in national five-year plans in order to give research on these crops more legitimacy and public support. They can also encourage efforts to seek more nontraditional funding for research and development of R&T (Spencer and Associates 1997).18 Policymakers can also facilitate the use of R&T as a means of alleviating poverty among the poor and most vulnerable groups in a variety of ways. For example, innovations and their benefits should be made available to all groups, including women. Credit schemes would enable women entrepreneurs to purchase improved cassava-processing equipment in Sub-Saharan Africa (Spencer and Associates 1997). Policymakers in developing countries must also be more vigilant in negotiations over tariff and nontariff barriers for R&T and their substitutes because these mechanisms can affect resource-poor households (Scott, Basay, and Maldonado 1997). Policymakers also need to be more sensitive to the allocation of resources within national R&T programs in order to ensure that postproduction activities - often most closely linked to income generation - are not underfunded in relation to production research.

18 In one practical example, financially consistent measures have been developed to cost and sell planting materials for potato (Espinosa, Crissman, and Hibon 1996). Revenues can then be recycled to support potato research and development, which are often entirely dependent on annual government appropriations and/or donor financial support.

In the environmental arena, policymakers can promote conservation of the natural resource base by making sure that research and extension efforts provide small farmers with viable technical alternatives to resource-depleting practices for soil, water, and forest resources, and by fostering farmer-based organizations to help disseminate the alternative technologies. Policies that discourage the improper use of pesticides and fertilizers should complement these efforts.

Policymakers in industrialized countries can also help improve the growth prospects for R&T in developing countries in a variety of ways. These include abandoning trade arrangements that limit import demand for R&T (see, for example, Henry 1998), eliminating subsidies on exports of competing food products (Spencer and Badiane 1995), and facilitating technology transfer (small- to intermediate-scale processing equipment, for example) to strengthen production and use of R&T in developing countries. Finally, access to developed-country markets can also help maintain genetic diversity for R&T in developing countries (Fano et al. 1998).