Research on bean rust in East and Central Africa: status and future directions

Abstract

Introduction Bean rast, caused by Uromyces appendiculatus is an important constraint to bean productivity in many countries of East, Central and Southern Africa. Among the major diseases, rast is ranked as the fifth most important constraint. Annual yield losses due to this disease are estimated at 191,4001 /year in Africa; 119, 0001 (Wortmann et al, 1998). Rust is of high importance (losses of 200 kg/ha) in Madagascar, Ethiopia, Mozambique, Malawi, Zimbabwe and South Africa; and of moderate importance ( losses of 100 kg /ha) in Kenya, Uganda, Tanzania, Zambia, Lesotho, Swaziland, Rwanda, Burundi and DR Congo and Sudan. Rust management methods used by farmers include cultural practices especially sanitation and intercropping, fimgicides and tolerant varieties. Use of resistant varieties is regarded as the most effective and economically viable strategy for rast management. The objective of national and regional breeding programs is to develop rast resistant cultivars. However, the achievement of this objective is constrained by lack of good sources of resistance, limited information on pathogen diversity, human and operational resources. Our objective is to describe the progress made in realizing these objectives and suggest directions for fiiture research.