Incidence and Control of Insect Pests of Vegetable Crops on Jos Plateau, Northern Nigeria

Abstract

A study on the insects associated with green beans, okra, peas and cabbages was carried out at Vom and Riyom Agricultural Stations in Jos, Nigeria from October, 1980 to April; 1984. During the study period, a wide range of insects were found in association with green beans and okra plants. Sericothrips occipitalis, Empoasca spp., Aphis craccivora, Zonocerus variegatus and Bemisia tabaci were found on pea, green beans and okra plants while Myzus persicae and Brevicoryne brassicae were common on cabbage plants. Early infestation of okra and cabbage by Podagrica spp. and Brevicoryne brassicae respectively within the first three weeks after sowing, resulted in poor plant performance and low yield. Insecticide treatments reduced insect population on the treated plants and enhanced yield. In this study, insecticide treatments and the treatment of using ordinary water to hand wash aphids from cabbage plants bi-weekly, reduced aphid population on plants and increased crop yield. The number of insects on different experimental plants treated with Dichlorvos at 500, 750 and 1000g a.i/ha; pennethrin at 12.5g a.i/ha; deltamethrin at 7.5, 10.5, 12.5 and 17.5g a.i/ha, cypennethrin at 12.5g a.i/ha; carbofuran 3g at 100g a.i/ha was less than those on untreated plants.