Effect of weed removal regimes on postflowering insect damage and grain yield of cowpea, Vigna unguiculata (L.) Walp. in a rain forest area of Nigeria

Abstract

The effects of different regimes of weed removal on infestation or damage by four major post-flowering insect pests, Megalurothrips sjostedti (frybom), Maruca testulalis (Geyer), a hemipterous bug complex and Cydia ptychora (Meyrick), and grain yield of cowpea, Vigna ungutculata (L.) Walp., were determined m field plantings during the early and late seasons of 1986 m Akure, Nigeria. In cowpea plots subjected to two, three or four weedings, percentages of flower infestation by M. testulalis, pod damage by hemipterous bugs and seed damage by C. ptychora were significantly lower than in non-weeded plots. Seed yield in all weeded plots was significantly higher than in non-weeded plots. Yield in plots weeded once was also significantly lower than in plots weeded twice, thrice or four times.