Development and testing of a control package for Striga hermonthica on small‐scale holdings in the Gambia

Abstract

Studies were carried out on farms to evaluate potential control practices which could be constituted into a package of recommendations for the control of Striga hermonthica in the Gambia. ICSV 1002, a variety of sorghum, was identified as being relatively more tolerant to Striga and to the common insect pests of sorghum. Spot treatment of emerged Striga shoots with 2% solution of product paraquat using a pistol-grip hand sprayer was found to control Striga without stimulating regrowth, improved yields and was more acceptable and cost-effective than handpulling of the shoots in early millet and sorghum. Where there might be objections to the use of paraquat because of its toxicity hazards, a mixture of 2,4-D (1 % soln.) plus glyphosate (1% soln.) or 2,4-D (2% soln.) was a useful substitute. A tentative control package consisting of ICSV 1002, spot spraying of Striga shoots with paraquat, and side dressing of urea fertilizer at 30 kg N/ha at 4 w.a.p. was tested at two sites against farmers' practice on pilot scale. Infestation of Striga was reduced and yields were increased by 119% and 37% by the package at the two sites