Integrating host plant resistance and chemical control in the management of Cowpea pests

Studies were conducted at Manga in the Sudan Savanna zone of Ghana to evaluate the potential of integrating host plant resistance with chemical control in the management of key insect pests of cowpea, Vigna unguiculata. None of the improved varieties tested showed significant and consistent resistance to the key pests and there were no significant interaction effects between varieties and spray regime. The local varieties, Omondaw and Bengsogla however supported relatively fewer Megalurothrips sjostedti and pod sucking bug (PSB) populations and thus suffered significantly lower damage (shriveled pods) and produced better yields under no insecticide protection than the improved varieties. This was particularly evident in 2005 when the pest population was very high. Spraying the crop with Karate during the reproductive phase produced better results than with neem extracts. Nevertheless, applying neem seed extracts twice and four times increased grain yield by 45 - 54% and 126 - 144 % respectively over the control, confirming their potential in cowpea Integrated Pest Management.