GROUNDNUT DISEASES IN NIGER AND BURKINA-FASO

Surveys were undertaken in the major groundnut growing areas of Niger and Burkina Faso to assess the distribution and impact of groundnut diseases. The study covered 37 fields in 1986 and 58 in 1987 in Niger, and 64 fields in Burkina Faso in 1987. Seed and seedling diseases led to heavy reductions in stand densities, hence in yields, in both countries. Rust, late leaf spot and early leaf spot were found in all cropping zones. Rust, late leaf spot and early leaf spot were found in all cropping zones. Rust and late leaf spot caused serious damage when rainfall was high. Rosette is a strong risk in Niger, where it reached high levels in 1987, and in the wetter regions of Burkina Faso. Furthermore, there were considerable fluctuations from one year to the next. Variability in crop growth was one of the main problems in Niger. Clump was present in Niger and in Burkina Faso, but its incidence was only locally serious. Other diseases were widely distributed, though their impact remained negligible: leaf scorch (L. crassiasca), leaf spots due to P. arachidis-hypogaea, anthracnose (C. dematium), leafblight (R. solani), stem rot (S. rolfsii), pod rot, peanut mottle, tomato spotted wilt, witches' broom, etc. Possible control methods against the main diseases are discussed, along with current and future research.