Effect of Organic Fertilizers on the Susceptibility of Tomato Lycopersicon esculentum: Solanaceae to Helicoverpa armigera Lepidoptera: Noctuidae in the Niayes Area Senegal.

The aim of this study is to compare the effects of organic manures on tomato (Lycopersicon esculentum var. Mongal) by analyzing their impact on the yield, dry-matter, and the susceptibility of tomato to Helicoverpa armigera Hubner (Lepidoptera, Noctuidae) in Niayes area (Senegal) Under pesticide free condition. The experimental design was set in complete random block with 7 treatments. The overall yield varied between 30.4t/ha with the horse dung treatment and 24.5t/ha with the untreated. The Poultry and Groundnut manures recorded the highest losses due to damages by H. armigera respectively 13.3 and 13.2t/ha. The Horse and Fish manures were the least affected by the pest (9.7 and 10.1t/ha) and therefore recorded the highest net yields respectively 20.7 and 17.7 t/ha. However the Cow and Sheep manures showed more dry-matter to tomato fruit conferring them a longer shelf-life. The horse dung based-fertilizer is highly recommended in tomato farming in the sahelian agroecosystems. The chemistry of the manures in relation to the plant performance is discussed in this paper. A combination of the organic manure is suggested to improve the sustainability of soil fertility and crop productivity.