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[Latin America] [sub-Saharan Africa]

The multiple disease resistance of these varieties has helped farm families by reducing crop losses and lowering production costs. Higher productivity has benefited consumers by permitting a steadier supply of beans at lower, more stable prices. Improved varieties have had environmental impacts as well. By decreasing the need for pesticides, the new beans have helped diminish contamination of water and soil. And by permitting more intensive production on land already in production, they have reduced pressure on fragile environments, such as hillsides and forest margins. In the sections that follow, we present some highlights of germplasm impact.

Latin America

Over the last decade or so, total bean production in Latin America has risen 25 percent—from 4.2 million tons in 1983-85 to 5.3 million tons in 1993-95. At the same time, total area has risen by only 2 percent—from 7.9 million to 8.1 million hectares—and the annual rate of growth in area has actually declined to -0.5 percent.

Increased production has thus resulted mainly from higher yields. The annual growth rate in yield is now at about 2.7 percent (compared to 1.9 percent a decade ago), and this is well above Latin America's average rate of growth in population (1.9 percent). With beans more readily available in the marketplace, per capita consumption has started to rise as well.

In some parts of Latin America, the changes have been more pronounced than in the region as a whole. For example, in the Andean zone (Bolivia, Colombia, Ecuador, and Peru), bean production was essentially stagnant until the early 1990s. Rates of growth in yield and production lagged well behind population growth. But by 1995 bean production in these countries as a whole had risen sharply, apparently as a result of higher yields.

A growing body of evidence from field studies suggests that improved varieties have contributed importantly to yield increases. A literature database maintained on CIAT's World Wide Web site contains abstracts of about 40 such studies.

One of the earliest analyses was conducted in Costa Rica. This work cast doubt on the then conventional view that technical change generally bypasses small farmers in Latin America. The study documented widespread adoption of new bean varieties, together with a new and more profitable bean production system.

Central America as a whole (see also Impact in Central America) has benefited from cooperative development in the 1980s of bean varieties resistant to bean golden mosaic virus. This virus had devastated bean crops throughout the region as well as in Mexico and the Caribbean. Within 4 years of release of the first resistant lines, they had been widely adopted in Guatemala and neighboring countries. At present, about 40 percent of Central America's total bean area is planted to varieties of CIAT origin.

In Brazil, a series of surveys conducted during the early 1990s by CIAT and several national organizations found that improved varieties were being planted on 75 percent of the total bean production area in four states (Espírito Santo, Goiás, Minas Gerais, and Rio de Janeiro). Their economic impact, through additional production, was estimated at US$85 million annually.

A 1990 survey carried out by CIAT economists in Peru's northern Cajamarca department documented the success of the variety Gloriabamba, released 3 years earlier by Peruvian bean researchers. Despite the harsh growing conditions of this remote semiarid region, 65 percent of small farmers were growing the variety on about 35 percent of the total bean area, with an average yield increase of 27 percent. The additional production made possible by Gloriabamba was estimated at 3038 tons per year, worth $1.5 million.

In Bolivia's Eastern Plains, where bean production was not even a part of local agricultural tradition, the crop was introduced during the early 1980s for production in the winter season. Previously, a lack of options during that period had forced farmers to seek temporary work elsewhere. But now many of them stay home to produce beans for export, mainly to Brazil, Colombia, and Japan. To increase returns from the enterprise, small farmers belonging to a bean production cooperative added an export arm to their organization, and it now earns $3 million annually.

Sub-Saharan Africa

Improved bean germplasm is spreading in this region and beginning to have an impact according to field studies, but the effects are still not evident in national production figures. In fact, as mentioned previously, growth in the continent's bean output still lags well behind demand.

It is encouraging, though, that progress has been made even under the most trying circumstances, as in Rwanda. The vast majority of the country's farmers grow common beans, and the crop accounts for a third of all calories and two-thirds of all protein consumed by Rwandans. Since the 1980s the national bean program, with CIAT support, has released about 20 new climbing beans of Mexican origin that show marked advantages over bush beans and local climbing varieties, especially in terms of yield and root rot resistance. They are the ideal technology for a country where producing more food on less land is of the utmost urgency.

In 1993 a nationwide survey found that 43 percent of all Rwandan farm families were growing improved climbing beans on about 20 percent of the country's total bean growing area. The new beans raised production by 66,000 tons a year, generating extra income of about US$15 million.

In late 1995 a new survey was conducted to monitor the impact of seed aid following the genocide and civil war that shattered the country in 1994. Remarkably, the study found that, despite the violence and its aftermath, improved climbing beans were being grown by nearly half of the farmers surveyed and accounted for a third of the seed sown.

Since then the climbing bean varieties that appeal to Rwandan farmers have also been spread by means of the regional networks to Kenya, Congo (formerly Zaire), Tanzania, and Zambia. A 1996 study conducted near Kakamega in western Kenya showed that 1,000 farmers had adopted one or more of five climbing varieties within four growing seasons of their introduction. A similar study carried out in central Kenya during 1998 found that 1700 farmers were growing these varieties and selling the seed to neighbors at premium prices.

The impact of new bush bean varieties is evident in northern Tanzania and southeastern Uganda. The higher yields and disease resistance of the varieties have strengthened the food security of farm families and enabled them to produce a surplus for the market. For example, a survey conducted in Uganda's Mbale District showed that two new varieties had increased bean supplies during periods of food shortage, raised adopting farmers' cash income, and reduced the amount of labor women invest in gathering wild vegetables to stretch dwindling food supplies. A popular new variety in northern Tanzania has been shown to have environmental benefits as well. Because of its shorter cooking time, it reduces annual consumption of firewood in rural households by 10 percent.