Application method and effectiveness of Bee-propolis in reducing grain damage and weight loss in cowpea

Abstract

Cowpea (Vigna unguiculata L. Walp) is a crop adapted to Savannah and drier regions of the tropics like Nigeria where other legumes don’t thrive well. Cowpea is highly vulnerable to infestation by Callosobruchus maculatus across all developmental stages. This pest-induced damage results in substantial quantitative and qualitative losses, characterized by seed perforation, decreased seed weight, reduced germination potential, and diminished market value. This study aimed to evaluate the efficacy of bee propolis in inhibiting cowpea damage and weight loss during storage. Propolis was processed into concentrated solutions for seed coating using ethanol as a solvent. A 100 g sample of cowpea was coated with bee propolis solutions (10%, 20%, 30% w/v) by mixing them in a separating funnel, shaking for thorough coating, and then air-dried for 24 hours. The coated grains were thereafter infested with 20 unsexed adult C. maculatus, covered with muslin cloth, and replicated four times. Controls were uncoated grains and ethanol-treated grains. The results show that propolis is effective in reducing grain damage and weight loss of cowpea. The highest concentration of propolis at 30% reduced both grain damage and weight loss compared to both positive and negative controls. This approach offers a solid framework for evaluating the protective efficacy of bee propolis against Callosobruchus maculatus on stored cowpea, suggesting its potential integration as a biopesticide.