Breeding Cassava for Underprivileged

Abstract

SUMMARY Cassava (Manihot esculenta Crantz), an important crop in the poorer rural uplands of the tropics, was an obvious target for international research attention in 1970 and the Centro Internacional de Agricultura Tropical (CIAT, headquartered in Colombia) established a cassava-breeding program. Assisted by many ancillary disciplines, the program defined its mission as breeding for low input conditions in less favorable environments to alleviate the poverty of small farmers through income generation. From its initiation, CIAT worked in a partnership with national programs. The breeding effort depended on the free exchange of germplasm, based on the understanding that CIAT would collect, evaluate, and maintain cassava germplasm and that this and any advanced materials derived from it would be freely available to any public organization. A key decision was to transfer the major applied breeding effort to Asia, while maintaining a basic breeding scheme in Colombia, with the understanding that a crop is usually more successful outside the center of crop origin and diversification than at the center. Fresh root yield of populations was improved by more than 100% and root dry matter content by more than 20%. The national program collaborators used these populations to develop many improved cultivars in many countries. The biological factors considered as critical for this successful breeding effort were: inclusion of a broad base of genetic variability obtained in the center of crop origin and diversification; evaluation of breeding materials under diverse environmental conditions; and a clear understanding of the different operational principles at different stages of breeding advancement. By 2002, Asian national programs had released more than 50 CIAT-related cassava cultivars in nine countries and farmers grew these new cultivars on more than one million ha. The economic benefits resulting from the increased productivity are well beyond one billion US$. The target population of small farmers in the poorer rural areas of the tropics captured a large proportion of these economic benefits. The understanding of crop germplasm being a common human heritage and the determination of agricultural scientists to use this for the welfare of the neediest people were the social factors for the overall success.