Studies on insect podborer infestations on Cajanus cajan (L.) Millsp. (pigeon pea) under different insecticidal spraying regimes in the Kenya Highlands

Abstract

Three insecticides were tested in sprays in the field in Kenya in 1976 for the control of podboring insects, especially the noctuids Pardasena virgulana (Mab.) and Heliothis armigera (Hb.) and the agromyzid Melanagromyza obtusa (Mall.), on pigeon pea (Cajanus cajan). DDT was applied twice at a concentration of 25% diluted to 180 ml/10 litres water, 40% dimethoate was applied at 30 ml/18 litres, and 35% endosulfan at 102 ml/18 litres water; these quantities were applied to 450 m2. The percentage pod damage and (in brackets) percentage seed damage totalled 30.4 (18.3) for DDT, 24.7 (13.5) for dimethoate, and 32.4 (17.3) for endosulfan, as compared with 47.9 (24.4) for no treatment.