Assessment of Striga hermonthica infestation and effectiveness of current management strategies in maize-based cropping systems in eastern Uganda

Abstract

Striga is a major constraint to cereal production in the tropics, particularly on soils of low fertility. Striga causes 30 to 80% cereal crop losses in sub-Saharan Africa. The objective of this study was to assess farmers’ perception of level of infestation and efficacy of current management options of Striga (Striga hermonthica (Delile) Benth) in maize-based cropping systems in eastern Uganda. A survey was conducted in Iganga district in eastern Uganda, involving 360 households. On the basis of the survey outputs, on-farm trials were conducted to assess the efficacy of a herbicide seed-coating technology, imazapyr herbicide resistant maize (IR-maize) variety, either as a sole crop or intercropped with soybean (Glycine max) or common beans (Phaseolus vulgaris L). The study revealed that S. hermonthica caused more than 50% maize (Zea mays) yield loss and farmers were dissatisfied with the existing control practices. Farmers’ knowledge about Striga was mainly sourced from agricultural extension service providers. The on-farm trials revealed that IR-maize provided effective protection against S. hermonthica infestation. Also, intercropping Longe 6H maize variety with either soybean or common beans significantly reduced Striga infestation in farmers’ fields. Longe 6H-soybean intercropping reduced Striga infestation by 32%; while Longe 6H-common bean intercropping reduced Striga infestation by 14%. Intercropping either IR-maize or Longe 6H hybrid (farmer-preferred) with the aforementioned legumes, reduced S. hermonthica infestation (30–50%) and improved maize yield parameters (20-30%). For effective management of S. hermonthica in the maize-based cropping systems in eastern Uganda, farmers should be encouraged to adopt the improved IR-maize and intercrop farmer-preferred maize varieties with legumes in order to improve maize yields.