Evaluation of Fungal Diseases Affecting Soybean Varieties (Glycine max (L.) Merr.) Considered Disease-Resistant in Central Burkina Faso

Abstract

Soybean (Glycine max) is a cash crop of economic and agronomic importance in Sahelian countries due to its ability to fix atmospheric nitrogen. Researchers have developed several disease-resistant varieties, but yields remain suboptimal. This situation motivates this study, which aims to evaluate the diseases that attack resistant varieties, causing damage, in order to identify them and propose control methods. Identification was carried out at several levels: first, symptomatology, then macroscopic identification, and finally, microscopic analysis. Following these analyses, four (4) pathogens responsible for fungal diseases were identified. These fungi are Peronospora manshurica, Phomopsis sojae, Sclerotinia sclerotiorum, and Phialophora gregata, responsible respectively for downy mildew, soybean blight, sclerotinia leaf spot, and brown stem rot. Unfortunately, resistant varieties are no longer resistant to fungal diseases. Since resistance is not an indefinite process, the responsible genes will need to be re-evaluated, and environmental factors taken into account, to develop new, more resistant varieties.