Bean improvement for low fertility soils in Africa

Bean ( Phaseolus vulgaris check for this species in other resources L.) production in Africa is constrained by edaphic stresses. A pan-African effort, Bean Improvement for Low Fertility in Africa (BILFA), was initiated in 1990 to screen beans for tolerance to several edaphic stresses. In the first cycle, 280 entries consisting primarily of promising or released materials from African bean breeding programmes, were evaluated for tolerance to low availabilities of soil N, P, and K, and toxicities of Al and Mn. Several entries were identified as tolerant for each of the stresses but especially promising are: RWR 382, RAO 55, ACC433, XAN 76 and MMS 224 for low P tolerance; ICA Pijao and EMP 84 for low K tolerance; Muhinga, Ntekerabsilimu and 7/4 ACC for tolerance to Al toxicity; and MCM 5001 and XAN 76 for tolerance to Mn toxicity. Several varieties, including XAN 76, RAO55, and OBA 1 have performed well under a number of edaphic stresses. The Rwanda breeding programme appears to be a relatively better source of low P tolerance materials. The Great Lakes Region is apparently the best source of tolerance to Al toxicity. Problems encountered during implementation of the BILFA are discussed.