Recherche sur l`efficacite d`enrobage des semences avant la semis contre les maladies transmis par semence, les maladies racinaires et la mouche du haricot

Several chemicals were tested at both the on-farm and exptl. levels to control major seed-transmitted root diseases in the Great Lakes region of Africa. Seed treatments to control the beanfly in Burundi were combined to assess the efficiency of combined treatments against fungi and insects. Individual systemic products, such as benomyl, carbendazim, and methyl thiophanate plus mancozeb, were particularly efficient against anthracnose. Thiram was less efficient when used alone, and effective when combined with other systemic products. Athough captan was not tested alone, it seems more efficient than thiram as overall fungicide and merits additional assessment. No chemical reduced root rot severity uniformly. Endosulfan was effective against the beanfly in all treatments. Yield increases obtained with benomyl plus thiram and benomyl plus thiram and endosulfan were between 250 and 350 kg/ha (20-40 percent) in northern Rwanda, and between 100-230 kg/ha (36- 86 percent in the poor highland soils of Zaire-Nilo. Endosulfan alone increased yields by 100 kg/ha in the central plateau area. (AS-CIAT)