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The study was conducted to evaluate yield response of five cowpea (Vigna unguiculata (L.) Walp.) varieties to field infestation and damage by major insect pests of cowpea. Three local varieties of cowpea, namely, Sokoto, Oloyin and Drum, and two International Institute of Tropical Agriculture (IITA) varieties, IT 90K-277-2 and IT90K-76, were planted on the Teaching and Research Farm of University of Agriculture, Abeokuta (UNAAB), Ogun State, Nigeria in September, 2006 and repeated in September, 2007. The experiment was laid out in Randomised Complete Block Design in split plots arrangement. Insecticidal spray constitutes the main plot while variety was the sub-plot. The main plot size was 19.4 m × 19 m and each of the sub-plot was 2.4 m × 3 m. The space between sub-plots was 1 m. Data from the sprayed plots were significantly (P < 0.05) higher than the unsprayed ones in the two seasons. Irrespective of season, the unsprayed plot of IT 90K-277-2 has a significantly (P < 0.05) high incidence of Ootheca mutabilis. The local variety, “Drum” has the highest incidence of flower thrip – Megalurothrips sjostedti in the two planting seasons. The highest mean number of peduncles/plant and pods/plant was in “IT 90K-277-2”. In both seasons, “IT90K-76” has a significantly (P < 0.05) lower number of damaged seeds and pods and “Oloyin” a significantly (P < 0.05) higher mean number of total pod sucking bugs. The grain yield was in the order IT90K-76 > Oloyin > IT 90K-277-2 > Sokoto > Drum. [ABSTRACT FROM PUBLISHER]

The efficacy of aqueous extracts of cashew, Anacardium occidentale L. products was tested on Legume flower bud thrips on field cowpea in the 1999 and 2000 seasons using nutseed and nutshell at 10% w/v, bark and leaf at 20% w/v. Aqueous extract of cashew nutshell was superior to other cashew products in reducing thrip populations in cowpea flowers and compared favourably with cypermethrin + dimethoate. Pod density per plant was significantly enhanced on cowpea plants sprayed with aqueous extract of cashew nutshell compared to other extracts. Cashew extract contains cardole (a caustic substance) and anacardic acid, which may have been responsible for its insecticidal effect on thrips. This result indicates the potential of cashew products especially the nutshell for integrated management of thrips in legume crops. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]