Effect of crude extracts of mixtures of different plant species in the control of Megalurothrips sjostedti Trybom. and pod setting of cowpea plants

Abstract

The effect of crude aqueous extracts of orange, Citrus sinensis L., peel and chilli pepper, Capsicum annum L. in mixtures with extracts of other plant species on Megalurothrips sjostedti (Thysanoptera: Thripidae) in cowpea flowers and pod setting ability of the treated plants was evaluated in two years of field studies. Compared with the other treatments, crude extract mixtures of chilli pepper with neem leaf, orange peel with African curry (Ocimum gratissimum L.) leaf and orange peel with Gmelina arborea L. leaf (in that order) were superior in reducing the numbers of thrips (<0.5 thrips/flower) in cowpea flowers and subsequently ensuring higher pod load per plant on treated plots. The mixture of chilli pepper with neem leaf extract was the most effective and compared favourably with the synthetic insecticide check (Uppercott) both on thrips suppression as well as on pod setting per plant. This result indicates the potential of using extract mixtures of different plant species with varying insecticidal attributes for protection of cowpea flowers in low input agriculture practised by limited resource farmers in developing countries.