Abstract

Cowpea (Vigna unguiulata) is attacked by a wide spectrum of insect pests that ravages the crop in the field at different growing stages sometimes resulting in complete crop failure. In order to reduce insect pest damage, increase cowpea seed yield and reduce the indiscriminate use of insecticide, it was necessary to conduct an experiment geared towards integrating cowpea cultivar with date of planting alongside minimal application of insecticide in the management of cowpea insect pests across two major agro-ecological zones. The experiment was laid out in a randomized complete block design with three replications at three locations; Sumbuya, Serabu and Nguala. Five improved cowpea cultivars with varying maturity dates and one local check, two planting dates and two spraying regimes were compared. The study reveals that flower thrips (Megalurothrips sjostedti) and legume pod borers (Maruca vitrata) were the major insect pests limiting cowpea production in the country. Planting improve cowpea cultivars such as IT99k-573-1-1, IT99k-573-2-1, IT89KD-391 and IT97K-277-2 in mid-September coupled with three spraying regimes at budding, 50% flowering and 50% podding will improve grain quality and lead to an increase grain yield of between 60 and 62%.

Key words: Planting date, legume pod borer, flower thrips, grain yield, management.