Bioefficacy of plant extract mixtures for the protection of cowpea flowers against megalurothrips sjostedti trybom (Thripidae)

Abstract

The present study was conducted to conrol Megcdrothrips sjostedti thrips, infestation on cowpea flowers. Aqueous extract mixtures of different plant species were applied on cowpea plants at 10: 10 % w/w on weekly basis in two years of field studies in Samaru, northern Guinea savanna of Nigeria. The result indicates that the extract mixtures of Gmelina arborea and Eucalyptus tree barks, African mangold (Tagetes erecta L.) and G. arborea leaves as well as mixtures of G. arborea and Azadirachta indica were effective in protecting cowpea flowers from damage and consequently increased pod density of plants under field conditions compared with the untreated control. The performance of aqueous bark extracts of G. arborea + Eucalyptus citriodora was not inferior to the synthetic insecticide treatment on the parameters tested. These findings would generate further interest in the application of plant extract mixtures as a pest management strategy on cowpeas grown by limited resource farmers in third world countries and possibly other crops with similar pests complex problems. © 2010 Academic Journals Inc.