Common Bean Impacts

Eastern and Southern Africa

In the Great Lakes Region of Eastern and Central Africa, beans are consumed at one of the highest rates in the world, approximately 60 kg per capita per year. Sperling and Munyaneza (1995) and Kalyebara et al. (2008) documented adoption of improved beans at the national level. A study conducted in 2005 across Malawi, DR Congo, Rwanda, Tanzania and Uganda found high adoption of varieties released in the 1980s and 1990s (Kalyebara et al. 2008). Sperling and Munyaneza (1995) used a nationwide household data and estimated adoption rate of 40% and intensity of 10-20% for climbing beans in Rwanda after about 7 years of intervention. High adoption of these varieties was explained not only by their attractive attributes, but also by the farmer-participatory breeding/ selection process utilized, and by investment in seed delivery systems (Odendo at al. 2002; David at al. 2002; David and Sperling 1999).

Largely as a consequence of 25 years of research by CIAT and national partners, Rwanda has gone from hunger-inducing shortages of beans to producing surpluses for export. Climbing bean varieties had been adapted only at high elevations in the country. CIAT introduced germplasm capable of tripling yields in mid-altitude environments. Within a few years, adoption rates reached 90% in the target areas (David et al. 2000). Today the Rwandan research program has matured and is producing its own improved varieties for home consumption and for high-end markets. Farmers are harvesting 2-4 tons per hectare, well above averages for other parts of Africa.

Market-oriented development explains much of the high adoption of improved bean varieties. Farmers with good market access tend to select varieties that are in demand by those markets, and private seed producers tend to invest in multiplying and marketing varieties that are already popular in those markets (Odendo et al. 2004, Rubyogo et al. 2010). Another contributing factor is the high rate of release of new varieties over time; Sperling and Munyaneza (1995) for example described how prolific release and dissemination was able to sustain the adoption of improved varieties after root rot attacked a popular Rwandan variety in 1991. A high rate of varietal release increases farmers’ chances of finding an appropriate match for their conditions. The diversity of types and levels of stress across rained environments as well as diverse socio-economic settings and issues requires farmers to choose from a diverse set of varietal options (Sperling et al. 1993; Katungi et al. 2011).

Latin America and the Caribbean

Drought tolerant beans poised for impact in Nicaragua and Rwanda

In 2000, CIAT plant breeders in Colombia made drought tolerance the centerpiece of their efforts to improve small-seeded Meso-American bean types farmers grow in difficult environments. Many of these lines have now been released in Nicaragua and Rwanda (three are pending release in Malawi, where they demonstrated a yield advantage in excess of 50%). These materials represent the first drought-tolerant bean varieties developed and released for the warm tropics (Beebe et al. 2008). Farmers recognize the difference; in Nicaragua they point out how a new variety uniformly fills its seeds under drought. This highlights the contributions that farmers can make in adapting crops to impending climate change.


Beebe SE, Rao IM, Cajiao C and Grajales M. 2008. Selection for drought resistance in common bean also improves yield in phosphorus limited and favorable environments. Crop Science 48:582-592.

David S, Kirkby R. and Kasozi S. 2000. Assessing the impact of bush bean varieties on poverty reduction in sub-Saharan Africa: Evidence from Uganda. Network on Bean Research in Africa, Occasional Publications Series No. 31. Kampala, Uganda: CIAT. 31 pp.

David S, Mukandala L and Mafuru J. 2002. Seed availability, an ignored factor in crop varietal adoption studies: a case study of beans in Tanzania. Journal of Sustainable Agriculture 21:5-20.

David S and Sperling L. 1999. Improving technology delivery mechanisms: lessons from bean seed systems research in Eastern and Central Africa. Agriculture and Human Values 6:381-388.

Kalyebara R, Andima D, Kirkby R and Buruchara R. 2008. Improved Bean Varieties and Cultivation in East and Central Africa-Economic and Social Benefits. PABRA-CIAT Kampala.

Katungi E, Sperling L, Karanja D, Farrow A, and Beebe S. 2011. Relative importance of common bean attributes and variety demand in the drought areas of Kenya. Journal of Development and Agricultural Economics Vol. 3(8):411-422.

Odendo M, David S and Kalyebara R. 2004. The Key role of beans in poverty alleviation: Lessons from the Impact of Improved bean varieties in Western Kenya, Occasional publications Series, No.43.

Rubyogo JC, Sperling L, Muthoni R and Buruchara R. 2010. Bean seed delivery for small farmers in Sub-Saharan Africa: The power of partnerships. Society and Natural Resources 23(4):1-18.

Sperling L, Loevinsohn ME and Ntabomvura B. 1993. Rethinking the farmer’s role in plant breeding: Local bean experts and on-station selection in Rwanda. Experimental Agriculture 29:509-519.

Sperling L and Muyaneza S. 1995. Intensifying production among smallholder farmers: the impact of improved climbing beans in Rwanda. African Crop Science Journal 3:117-125.

Grain Legumes

Grain Legumes is a partnership among four CGIAR Research Institutes: ICRISAT as lead center, CIAT, ICARDA and IITA, along with several public and private institutes and organizations, governments, and farmers worldwide.

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