Seed powder extract of physic nut (Jatropha curcas) as a biopesticide for weevils (Callosobruchus maculatus) in stored cowpea (Vigna unguiculata)

Abstract

The study explored the effectiveness of physic nut (Jatropha curcas) in the control of cowpea weevils (Callosobruchus maculatus). The repellence, mortality rates and progeny emergence of weevils were observed, as well as germination viability of the treated cowpea seeds. The study adopted experimental research, using complete randomized block design. The results showed that seed powder extract of physic nut is effective in disrupting the normal activities of the weevils. However, the repellence and mortality rates of the weevils depended on the dosage administered and the duration of exposure to the treatment. The treatment was found to be most effective at 20 g, where repellence and mortality rates were 53.3% and 60.0%, respectively, while 0 progeny emergence occurred during the experimental period. The treated seeds were also found to be viable for planting as there was 100% seed germination. The study adds to the literature on innovative, sustainable and indigenous pest control measures in post-harvest storage of edible seeds in Africa.