Field evaluation of foliar and soil insecticides for the control of Aphis gossypii Glover (Homoptera: Aphididae) on potatoes in Kenya

Abstract

Field evaluation showed oxydemeton methyl 25% E.C. at 0.6 kg a.i./ha and dimethoate 40% E.C. at 0.74 kg a.i./ha to be more effective than cypermethrin 40% E.C. at 0.25 kg a.i./ha, decamethrin 2.5% E.C. at 0.03 kg a.i./ha, endosulphan 35% E.C. at 0.8 kg a.i./ha and profenofos 50% E.C. at 0.74 a.i./ha in the control of apterae on potatoes. Disulfoton 10G at 1.6 k0g a.i./ha and carbofuran 10G at 5.2 kg a.i./ha were superior to oxamyl 10G at 5.2 kg a.i./ha and terbufos 5G at 2.6 kg a.i./ha applied in the furrow at planting for the control of aphids. Although these insecticides gave good control of apterae, the alate population in the treated plots varied from significant reduction to no reduction. All the insecticides tested did not significantly increase potato yield, although mean yields were increased.