Prevalence of pigeonpea diseases and associated crop losses in Asia, Africa and the Americas∗

Surveys were carried out to determine the prevalence of pigeonpea diseases in the major pigeonpea growing areas of Asia, Africa and the Americas between 1975 and 1980. In India, surveys in eleven states revealed that wilt, sterility mosaic, Phytophthora blight, Macrophomina stem canker and yellow mosaic were economically important diseases. Other diseases were of minor importance. Disease problems in Bangladesh, Malaysia and Nepal were of less importance. In Africa, wilt was a serious disease in Malawi (36.3%), Tanzania (20.4%) and Kenya (15.9%). Leaf spot in Kenya and Malawi, and powdery mildew in Kenya, Tanzania and Zambia were important. Other diseases were not economically important. In the Americas witches’ broom, Phoma stem canker and rust were the important diseases. Annual crop losses due to the combined effect of wilt and sterility mosaic diseases in India were estimated to be worth about US$ 113 millions. In Africa the estimated losses from wilt disease alone were over US$ 5 millions annually.