CASSAVA IN LATIN AMERICA AND THE CARIBBEAN^[1]: RESOURCES FOR GLOBAL DEVELOPMENT

Clair Hershey^[2]
Guy Henry^[3]
Rupert Best^[4]
Carlos Iglesias^[5]

EXECUTIVE SUMMARY

Cassava as a Catalyst for Development

Cassava was fundamental to the birth and nurture of lowland tropical cultures in the New World, much like maize and potatoes sustained people in the highlands. Long before the arrival of Europeans in the 15th century, cassava was widespread throughout both the dry and humid tropics of the western hemisphere.

The crop's success in its evolutionary homeland leaves a rich legacy for modern agriculture and food systems:

• broad genetic diversity in the form of several thousands of landrace varieties and about 100 related wild species

• an array of biocontrol agents with potential to limit the losses from pests and pathogens

• finely tuned crop management practices that optimize economic output from a range of environmental and cultural variations

• a diversity of processing methods and utilization systems to achieve specific management, income, or nutrition goals.

These same resources underpin continued progress in the cassava sector. Research and development activities in Latin America and the Caribbean have a special dual status - as a catalyst for regional development, and as a resource for contributing to cassava's development role in Asia and Africa.

The cassava sector is at a crossroads in the Americas. Traditional processing and markets continue to dominate in the region. While these are best suited to largely rural societies, where on-farm or community-based processing and local consumption prevail, three-quarters of Latin Americans now live in cities. Income growth and changes in dietary preferences are leading to reduced cassava consumption. Yet the crop retains the basic features that reinforce its role as an appropriate vehicle for development:

• a crop of small, resource-poor farmers

• adaptation to marginal environments where other crops are far more risky

• high potential energy production per unit land area

• high flexibility in management

• ability to enter diverse markets.

With focused and sustained research and development support, this crop can make substantial contributions to the broad goals of food security, poverty alleviation, equity, and protection of the environment.

Trends in Production, Trade, and Utilization

Like nearly everywhere else in the world, cassava in the Americas is usually relegated to the more marginal environments, especially areas with uncertain rainfall, acid soils, low native soil fertility, and difficult terrain. On average, growers apply few inputs, and yields are well below potential levels. The inherent nature of cassava husbandry, especially the labor inputs required, makes it a generally small farmer crop. By the mid-1990s there were indications of significant shifts toward more input-sensitive and larger scale production in some regions, especially in Brazil, Colombia, and Venezuela. Nonetheless, technology, when designed for the majority of cassava growers and consumers, still generally benefits the poor.

Aggregate cassava production in Latin America and the Caribbean, 1961-1999

The highest concentrations of cultivation are in northern and eastern coastal Brazil; southern Brazil and eastern Paraguay; northern Colombia; and on the island of Hispaniola shared by Haiti and the Dominican Republic. In the Amazon basin, density of agricultural exploitation is very low, but cassava is the principal crop in areas of traditional agriculture. In all these regions, cassava contributes significantly to dietary calorie intake and to farmer income. Elsewhere the crop is less highly concentrated, but is nonetheless widely cultivated. It covers the latitudinal range from the northern Caribbean to northern Argentina, and in altitude from sea level to almost 2000 meters above sea level (masl) in the Andean zone.

In the 1960s, area planted to cassava expanded rapidly from 1.8 to 2.6 million hectares, in direct response to demand from population increase. Since the mid-1970s aggregate production has been remarkably stable, varying only between 28 and 33 million metric tonnes. In contrast, production doubled in both Asia and Africa since 1970. Latin America went from producing 35% of the world's cassava in 1970 to 19% in 1999.

Brazil has dominated production in this century, and currently accounts for two-thirds of the total for the Americas. Brazil, Paraguay, Colombia, Cuba, Haiti, Peru and Venezuela account for 97% of production. Although Central America has a comparatively small production area, Costa Rica, El Salvador and Nicaragua have had some of the highest production growth rates anywhere - a six-fold increase between 1970 and 1996.

The two largest producers, Brazil and Paraguay, channel significant production to animal feed.^[6] In all other major producing countries, most is used directly or indirectly for human food, with only 10-20% utilized to feed animals. There are three main types of food products, and a wide range of minor ones. Roots are consumed fresh in most of Colombia and Paraguay, and sporadically elsewhere. In the Caribbean and North-eastern South America, roots are ground into a mash, which is partially dried and formed into large flat breads called casabe. These are toasted on a griddle and may be stored for several weeks. In Northeast Brazil and throughout much of the Amazon basin, roots are rasped and toasted to make coarse flour (farinha). For reasons still unclear, most forms of processing prefer roots with high cyanogenic potential (bitter varieties).

Small-scale and medium-scale factories produce either native or modified starch from cassava in pockets throughout the region. Brazil produces by far the largest volume - about 30 000 metric tonnes (MT) in 1996. This is a growing market and several countries, especially Colombia, Paraguay, Venezuela and Brazil are increasing their capacity to produce and use cassava starch.

Leaves are high in protein, and supplement diets as a vegetable in Northeast Brazil. Farmers commonly dry leaves and use them on-farm in animal feeding.

Little cassava is traded internationally to or from the Americas. Curiously, most of the current trade is based on export of fresh roots from Costa Rica, overall a minor cassava producer in the region. The market for fresh cassava in North America has grown steadily parallel with rapid increase in populations of Latin American origin. Costa Rica exported 45 000 tonnes in 1995, nearly triple the volume of 1990. There are nascent industries for producing and exporting frozen and processed-frozen cassava, especially to Latin populations in the U.S.

Constraints and Opportunities for System Improvement

Cassava has attained its current level of production and utilization as a consequence of many forces that ultimately impact farmers' decisions of how much to grow. Development based on cassava is tied to an array of constraints and opportunities, both internal and external to the cassava system. Among the most influential of these are agriculture and trade policies, urbanization, income and related changes in food demand, characteristics of the resource base for production, trends in commodities that compete with cassava as an energy source, institutional resources for crop and market development, and technology for production and post-harvest management.

By the 1970s, urbanization and overall economic development had substantially changed the social, economic and political landscape in the Americas. Food preferences shifted in favour of more convenient foods, away from basic staples, and toward more diversified diets. The perishability of fresh cassava adds a high margin to urban market prices, and makes it a comparatively expensive food.

In the 1970s and 80s, attempts to constrain the rise in food prices for an increasingly urbanized society led to subsidies, especially on wheat imports and locally-produced coarse grains. These actions were eventually a disincentive to internal production of other food energy sources, including cassava. A notable example was the huge negative impact on farinha consumption in Brazil brought on by wheat subsidies. Per capita consumption of farinha slid from 26 kg in 1960 to 12 kg in 1980, as the ratio of farinha to wheat prices rose from 0.61 to 2.95 (Lynam, 1987).

The debt crisis of the 80s that broadly affected Latin America catalyzed a turnaround of these policies. By the 1990s, major market reforms were underway throughout the region, moving both internal production and trade toward free-market dynamics. In this scenario, cassava has the potential to compete with coarse grains in animal feed rations, as a partial substitute for wheat in bakery products, and as a source of industrial starch. The interchangeability of raw materials for food and industry will tend to stabilize and set floors on some commodity prices in a free-trade environment. Further, continuing advances in technology will provide relatively plentiful supplies of competing carbohydrate sources, with the caveat that there will be inevitable occasional shortfalls. Cassava's comparative advantages as an efficient carbohydrate producer are tempered by a lower historical investment in research and development compared to its competing alternatives. In order to take full advantage of cassava's potential contributions to development, the evolving trade policies need to be accompanied by research investment that gives balanced treatment to different crops.

Overall, national programs built substantial research capacity during the 1970s, but many were forced to make cutbacks in the mid- to late 80s in response to national economic crises. Current capacity is concentrated in just a few countries (Brazil and Cuba) with many producing countries largely dependent on outside resources, such as from international centers. Several regional and global networks function in the Americas, but activities are limited by inadequate funding. The continuing broad interest in international cooperation among participants indicates a high potential to make these networks fully functional.

In 1999 cassava-producing countries took a significant step toward regaining momentum by formalizing a consortium (known by the Spanish acronym CLAYUCA) to support research and development. This is especially significant because of strong participation and leadership of the private sector.

Research and development investment in the region should be targeted at a broad range of constraints and opportunities in both production and post-harvest areas. The principal constraints to production are soil erosion, low soil fertility, inherent low yield potential of landrace varieties, weeds, and a complex of pests and diseases. Alleviating these constraints through management and genetic options suitable for most cassava growers could nearly double current yields.

Post-harvest constraints are acute in Latin America. Market options are usually limited, often to a single form of traditional utilization. If farmers increase production by adopting new technology, they find a corresponding depression of market prices, for no net gain. Diversifying market opportunities and developing processes and production systems that conform to these needs, are the major challenges of the cassava sector in Latin America.

Priorities and Strategies for Meeting Development Goals: The Way Ahead

The main opportunities for capturing the potential development benefits of cassava in Latin America depend on linking more efficient and cost-effective small-scale production to dynamic growth markets. The starch and animal feed industries appear to present the best medium-term opportunities. Cassava's competitive position in comparison to alternative energy sources depends on a multi-pronged approach to market development, processing innovations, and improving production efficiency. In contrast to Africa and much of Asia, where demand is buoyant, the Latin American situation calls for interventions with a greater demand-side focus.

On the supply side, there is a need both for taking advantage of existing technologies for improving yield and quality, as well as for further investment in production technology. The production systems of the future will continue to be strongly biased toward more stressful environments, especially areas that are drought-prone, and with acid, infertile soils. There are, on the other hand, examples where cassava is moving into more fertile areas, such as former soybean areas of Paraná, Brazil. Here, starch market demand and technology for high yields make cassava the most profitable option.

The genetic base available in Latin America, especially in collections in Colombia (CIAT) and Brazil (EMBRAPA), is a vital resource for meeting goals of genetic improvement. These collections will only be optimally useful if safely preserved in situ or ex situ, evaluated for an array of traits, and made broadly available to research programs.

The movement toward more commercial markets will affect criteria pertaining to root quality. Where the markets evolve from human food to industrial consumption, quality criteria may become more relaxed, but focused on traits not previously a priority. Starch quantity, on the other hand, gains importance in industrial markets. Root form and peel characteristics will be more of an issue as processing is mechanized. Controlling the flow between supply and demand will require new management approaches to planting and harvest periods, and post-harvest handling. Extending the shelf life beyond the few days normally available would add a highly beneficial flexibility to industrial systems, and to fresh roots for urban markets or for export. The possibilities of genetic modification of key steps in the deterioration pathway need to be pursued.

There is already considerable experience demonstrating the need for parallel development of market opportunities, increased production capacity, and processing methodology. Several countries have implemented integrated cassava research and development projects as a means of bringing together all the elements of cassava-based development. Research strategies increasingly involve producers and consumers in the full range of design and implementation through participatory methods. Cassava's contributions to rural development are a reality in these project areas. The potential to realize much broader benefits lies in expanded and collaborative public and private investment in this sector of the agricultural economy so closely associated with the poorest producers and consumers.

Scenarios for Successful Cassava-based Development

Demand for starch for industry and dried cassava for animal feed will grow and create a demand for low-cost, high-quality energy sources. In urban markets, the very lowest income families apply additional income to higher consumption of staples such as farinha. Cassava producers will respond by adopting new varieties and basic yield-increasing agronomic practices, especially fertilizer and mechanical/chemical weed control. They will obtain higher and more uniform quality by managing production and harvesting practices. The principal beneficiaries of the increased income will be the rural poor who occupy the marginal lands, and the urban poor who will have access to food at lower cost.

In Latin America there is an increasing entrepreneurial entry into the cassava sector by small to medium growers and investors. Processing will move to larger, more efficient plants, which will help make cassava products more competitive with alternative energy sources. The move toward larger scale production and processing in some regions will challenge cassava's traditional ability to preferentially benefit the poorest producers. There is a need for processes and varietal traits that can add value at the farm level. Women's employment in the cassava sector will shift from the more menial cultivation and processing functions to include management and factory labour.

Cassava R&D will be driven by partnerships between private and public sector institutions, as well as NGOs. Nonetheless, given the relatively limited economic and political power base of most cassava growers and consumers, continued strength of public sector support is essential.

CASSAVA AS A CATALYST FOR DEVELOPMENT

Overview

Latin America^[7] is home to cassava and all its wild relatives. The crop was vital to the development of lowland tropical cultures throughout the New World. The Carib and Arawak Indians of the Caribbean and northern South America were probably some of the earliest cultivators, and many of their customs of cultivation and processing remain virtually intact today in that region and throughout the Amazon basin. Every tropical country of the region produces cassava, but it is most highly concentrated in four areas: northern and eastern coastal Brazil, southern Brazil and eastern Paraguay; North-Western South America (especially the Caribbean coast of Colombia); and in the Greater Antilles (Cuba, Haiti, and Dominican Republic) (Figure 1). The Americas gave cassava to the rest of the world after arrival of early European explorers. Along with the crop itself, these explorers introduced cultivation and processing techniques from cassava's homelands. This history has profound influence on current status of the crop, and its potential for further development.

Cassava has numerous traits that confer comparative advantages in marginal environments, where farmers often lack the resources to improve the income-generating capacity of their land through purchased inputs. The species tolerates acid soils, periodic and extended drought, and defoliation by pests. It is highly compatible with many types of intercrops, and flexible in time of harvest. These traits have combined to make cassava a significant sustaining force benefiting the poor in the tropics.

Despite the historical importance of cassava, in recent years it has lagged behind other crops in growth rates for production and utilization. The reasons are many, with vital implications for projections of future crop development. Among the main factors, government policies, and trends in food demand resulting from urbanization tipped the balance in favour of alternative food energy sources since the 1970s. Investment in cassava, to keep it competitive in the agricultural and commercial worlds, has not been adequate. As a crop predominantly grown and utilized by the poor, it has generally been relegated to a lower status by both private and public research.

Cassava can be an ideal focus for a development-oriented research where goals concern food security, poverty alleviation, equity, and protecting natural resources^[8]. The future of cassava in Latin America and the Caribbean is most defined by its potential as a vehicle for linking the rural poor to growth markets. This potential follows from the complex and interacting effects related to urbanization, rising incomes, evolving trade policy, and trends in other food and feed crops.

Development Goals

Because of successes in improving the efficiencies of food production, processing and marketing, acquiring food to provide a basic diet requires an ever-decreasing share of labour and income in much of the world. Agriculture is increasingly a means of earning disposable income, in addition to meeting basic nutritional needs. Yet, for the most disadvantaged, adequate nutrition continues to be elusive. A substantial sector of the rural economy appears to have few prospects for participation in these trends of economic development in the near future. Unfavourable economic or land tenure policies, lack of access to education, difficult environments, and high population density can combine to prevent social and economic advance.

Figure 1. - Edapho-Climatic classification of Cassava production for Latin America

Some will argue that in a global economy spurred by technology and service sectors, that agriculture will become increasingly less effective as a vehicle for achieving broad development goals. In real terms, prices for agricultural commodities in world markets have been falling for decades, as technology introduces new production and processing efficiencies. But few countries have developed economically and socially without the underlying support of a strong agricultural sector. Further, Latin America has shown in the past decade that broad economic development can be based as much, or more, on agriculture as on manufacturing.

One of the primary lessons emerging from global development experiences in the last quarter of this century is that agriculture has as much potential as industrialization to contribute to economic growth. While the Asian model for emerging economies clearly highlighted industrial growth, in Latin America manufacturing actually declined as a percent of GDP from 1980 to 1995 (World Bank). Agriculture has been a more important engine of growth in countries such as Brazil, Colombia, Argentina and Chile. Sustaining this agriculture-based growth, and introducing greater attention to equity and environmental issues, are challenges for this generation of research and development initiatives.

Food Security

Latin America is a land-rich continent. There is little doubt that the region as a whole has adequate land resources to comfortably produce enough food to be self-reliant. Except for Haiti and the Dominican Republic, population density is low (Table 1). For most of the region, per capita food production has been climbing steadily. These averages, however, hide some serious trouble-spots. Not coincidentally, cassava is a basic staple in these regions. Haiti is probably the most pronounced case of food security concerns. Cassava has a moderate role in the diets, but rice is the preferred staple. Pressure to cultivate more marginal lands, and lack of resources for purchased inputs, have made cassava a continually more popular crop. Area planted has doubled in the past 30 years.

The Northeast of Brazil, and especially the semi-arid interior, is another area where dietary calories are frequently deficient. This region is subject to periodic extended droughts, and even in normal years, growing most grain crops is risky. Here, cassava is not only a famine reserve crop but is the preferred staple and an integral part of the culture. Annual per capita consumption here is 43.7 kg, compared to 17.6 kg in the country as a whole (Pires de Matos, et al., 1997).

The Northwest coast of South America is a sub-humid and semi-arid region where cassava has a moderately important food security role. This area, mainly in Colombia but also including parts of Venezuela, has a six- to eight-month dry season and erratic rainfall during the rainy season. Cassava is commonly intercropped with maize and legumes, and will almost always yield something even when the intercrops fail.

For the most part, the Amazon basin is sparsely populated and characterised by shifting agriculture. Cassava is the principal calorie source in much of this region. It fits well in a system that complements farming with hunting and fishing to provide protein sources. These systems have been in relative harmony with the surrounding ecosystems for centuries, but are under increasing pressure to intensify because of deforestation, migration, and rising lifestyle expectations.

Paraguay has the highest per capita consumption in the region and one of the highest in the world, at more than 300 kg/year in rural areas. The national importance of the crop is due in part to its good adaptation in marginal soils, but even more to a long and strongly held tradition among Paraguayans for eating cassava. The crop is important for food security, but not necessarily because of the lack of possible alternatives.

Apart from the regional differences in consumption, there are strong differences between rural and urban population, a phenomenon we discuss at greater length in a later section. Rural populations typically obtain two to three times more of their calorie intake from cassava as compared to urban dwellers (Table 2).

Poverty Alleviation and Equity

As in most of the world, cassava in Latin America is increasingly a commercial crop, a source of income for purchasing the basics of life. Also similar to other continents, cassava is a crop of the poor, and for the most part, a food of the poor. These characteristics confer a high potential to cassava as a vehicle to alleviate poverty and address equity concerns in some areas.

Cassava generates income to farmers mainly through sale of fresh or processed roots, but also indirectly through sale of animals fed on cassava. Various strategies can increase that income-generating potential: more efficient production (lower cost per unit of production through higher volume at the same cost, the same volume at lower cost, or both); a higher market price, or adding value to products prior to sale.

The opportunities for income generation from cassava vary widely. The poorest areas may have inadequate infrastructure and poorly developed markets. There is often little possibility to sell surplus production beyond household needs. This is especially true for most of the Amazon region where villages are very isolated. Cassava technology could contribute indirectly to income generation in these remote areas by product substitution. By improving cassava's productivity, the area and labour inputs to produce adequate supplies for household use, could be reduced. This would free resources for producing higher value products, such as spices, herbs, or speciality rainforest products that are more easily marketed.

Latin America has a long history of land tenure systems that mitigate against equitable development. The gap between landless or small landholders and large landowners is wide, and the political pressure to remedy this has been only sporadically successful. The 20% highest earners typically earn 50-60% of total income (compared to 40-50% in developing Asia). Perhaps more striking is the fact that the lowest quintile earns only about 2-6% of total income in Latin America (compared to 6-9% in developing Asia) (World Bank). It is unreasonable to expect that improvements in the cassava system alone could overcome this inequity. On the other hand, in those areas where cassava has a strong comparative advantage in adaptation, it can have a pivotal role in preferentially raising the income level of the poorest farmers.

System changes are bound to impact gender issues. Participation by women in cassava production, processing, marketing and household use in the region is highly variable. In many of the near-subsistence and traditional systems of the Amazon basin and in the Caribbean, women are the principal cultivators and processors. Elsewhere, women tend to have a greater share of the responsibility for production and processing in smaller-scale systems, managed at the family or community level, both in production and processing. Household food purchasing and preparation is almost exclusively the domain of women. Increasing mechanization and automation tends to reduce the role of women in production and processing.

Protecting Natural Resources

Practices to protect the environment evolved along with cassava itself in Latin America. Traditional systems incorporated numerous practices that sustained them virtually unchanged over centuries. Intercropping stabilized the soil against erosion through extended canopy cover; provided a complex biological environment that probably inhibited pest and disease build-up; and combined species with different nutrient needs, as well as legumes to provide nitrogen. The slash-and-burn systems destroyed small areas of natural habitat, but were stable over time unless population pressure increased. This system leaves considerable residue on the soil surface to impede erosion during the establishment phase. Harvesting over extended times for household use meant that large areas of soil were not exposed to erosion-causing rainfall at any one time. Indigenous and other cultivators throughout the Amazon basin still widely use these practices. Elsewhere, systems have changed to less extensive, more intensive practices, although many of the traditional practices are retained.

Higher productivity and environmental protection are highly compatible when technology design is appropriate, but system intensification typically brings a mix of positive and negative environmental impact. Sedentary agriculture brings risks of soil depletion unless nutrients are efficiently recycled or brought in from outside the system. The shift from intercropping to monocropping, while facilitating management, reduces the potential advantages of pest and disease suppression, and extended soil protection. Mechanical soil preparation tends to leave little surface residue, increasing potential for erosion. Commercialization of the crop leads to harvest of larger areas at any given time, thereby exposing soil to erosion. And in the most intensive systems, agrochemicals can combine both positive and negative effects. Herbicides may eliminate the small amount of vegetative cover that helps stabilize the soil, but also allow more vigorous crop growth. They can facilitate no-till systems that are highly soil-conserving. Pesticides may decrease short-term yield losses, but can also destroy beneficial species and lead to even larger pest populations. Chemicals can contaminate water supplies, or create hazards for applicators if improperly handled.

Soil erosion seems to be the most generalized environmental risk in Latin American cassava systems. This is especially evident in hillside agriculture of the Andean region, but is also a concern on lesser slopes, especially with the light soils that typify much of the cassava environment. There is considerable technical knowledge already about methods to control erosion, and there has been some success in applying these practices at the farm level. Much more needs to be done both at the research and extension levels, and we elaborate on these points in a later section.

One of the unique and invaluable resources of the Americas is the native genetic base of the genus Manihot. The natural habitat of the genus extends throughout most of tropical and subtropical America, with concentrations in Meso-America, and in a large area from north-eastern Brazil south to Paraguay. These landrace varieties and wild species are a vital resource for the continued long-term improvement of the crop, not only in the Americas but worldwide. Already a considerable effort has gone into protecting this diversity, especially the cultivated species, Manihot esculenta. Less attention has been given to collecting and conserving the wild Manihot species, or protecting their native habitat.