Evaluating Neem Extracts, Neemsol, and Cypermethrin for Sustainable Insect Pest Control in Cowpea (Vigna unguiculata)

Abstract

Cowpea (Vigna unguiculata) is a valuable crop widely cultivated for its ecosystem services and contribution to carbon credit schemes. It is an important legume crop in sub-Saharan Africa, serving as a major source of plant-based protein, essential amino acids, vitamins, and minerals. However, its production is significantly constrained by susceptibility to insect pests across all growth stages. This study evaluated the efficacy of neem-based treatments: neem extract (Azadirachta indica) at concentrations of 5%, 10%, and 20%, neemsol (GA), and cypermethrin in controlling cowpea insect pests under field conditions. The experiment was arranged in a randomized complete block design with three replications per treatment, including an untreated control. All data collected were subjected to analysis of variance (ANOVA) using software IBM-SPSS 2020 and means separated using Duncan’s Test of Significance. All neem-based treatments demonstrated pest control efficacy comparable to cypermethrin. Although cypermethrin-treated plots yielded the highest number of pods (103.67), neemsol (76.00) and neem at 20% concentration (76.33) also produced substantial pod numbers. Notably, neem-treated plots produced the highest seed weight (79.72 g), surpassing both cypermethrin (74.03 g) and neem at 20% concentration (58.22 g). Given its minimal cost and comparable performance, neem extract at 20% concentration presents a promising, low-input alternative to synthetic pesticides. The efficacy of cypermethrin was not significantly different from neemsol (GA), and neem leaves extract at 20% concentration. This suggests that neem-based products could be a viable alternative to synthetic insecticides for managing insect pests on cowpea. These findings underscore the potential of neem-based biopesticides for sustainable insect pest management in cowpea cultivation.