Contrôle des glossines dans le bassin de la Kagéra

Control of the tsetse flies in the Kagera basin. The climate of the African region around the "Great Lakes" induces a strong process of soil weathering which eventually leads to a strong aluminium saturation of the absorption complex, as expressed by the "m" index of Kamprath. The response to aluminium toxicity of the common bean cv. Diacol Calima, a widely grown variety in Burundi, has been studied in pot trials in two ways : (1) Using superficial soil samples of "humiferous high elevation kaolisols" whose "m" index varied between 4 and 92 ; (2) On culture condition consisting of an inert substrate complemented with a nutritional solution to which a serie of soluble aluminium concentrations were added. Under soil condition, biomass produced after a period of 25 days of growth, decreased as from "m" = 33. The number of Rhizobium nodules decreased drastically with aluminium toxicity becoming negligible at "m" - 33. On culture media, rising concentration of aluminium affected growth adversely as well, although root growth inhibition was less pronounced than under soil condition.