Effectiveness of aqueous extracts of neem seeds and deltamethrin in protection of cowpea (Vigna unguiculata): case of Megalurothrips sjöstedti (Trybom)

Abstract

Cowpea, is a popular seed legume in Chad. It is experiencing production losses due to insect pest attacks. The thrips of flower buds Megalurothrips sjostedti is one of these pests, whose economic importance is well established. This study aims in promoting the use of neem extract as an alternative to chemical pesticides in the management of thrips. The trial was conducted at the agricultural research station in Chad. The experimental design was a Complete Randomized Block with four treatments and four replicates, including Control (no treatment), deltamethrin at normal dose (1L/ha), aqueous extract of neem seeds alone (140 g) and its combination with a low dose of the chemical insecticide (1/10 of the normal dose). The results showed that deltamethrin reduced thrips density by 79.41 % at the third application. The botanical insecticide indicated a reduction in thrips density of 44.11% at the third. Deltamethrin showed a yield increase of 463.875 kg. ha−1 compared to the control (P