COMPARATIVE EFFECT OF NEEM POWDER, WOOD ASH AND CHILI PEPPER ON THE CONTROL OF CALLOSOBRUCHUS MACULATUS ON STORED BEANS

ABSTRACT Cowpea (Vigna unguiculata) is a vital source of protein and income in sub-Saharan Africa, yet post-harvest losses caused by the cowpea weevil (Callosobruchus maculatus) pose a significant challenge to food security and farmer livelihoods. This study investigated the efficacy of three locally available botanical powders—neem leaf powder (Azadirachta indica), chili pepper powder (Capsicum spp.), and wood ash—in controlling C. maculatus infestation in stored cowpea grains under laboratory conditions. A completely randomized design with four treatments and three replications was employed, assessing adult weevil mortality, survival rate, seed damage, weight loss, and oviposition over seven days. Results demonstrated that all three botanicals significantly reduced weevil survival, seed damage, weight loss, and egg-laying compared to the untreated control, with neem leaf powder being the most effective, followed by chili pepper and wood ash. The study confirmed that botanical powders act through chemical toxicity, repellency, and physical barriers, offering environmentally safe, affordable, and practical alternatives to synthetic insecticides. These findings provide actionable insights for farmers, extension workers, and policymakers, highlighting the potential of neem and chili powders for sustainable post-harvest pest management and emphasizing the need for further research on optimal preparation, dosage, and storage conditions to enhance efficacy. Overall, the study contributes to reducing storage losses, preserving grain quality, and promoting eco-friendly pest control practices.