Comparative antifeedant activities of the epicarp and mesocarp methanolic extracts of the seeds of Balanites aegyptiaca against cowpea bean (Vigna unguiculata) storage pest (Callosobruchus maculatus)
Umar Muhd Sani
Farmers in West Africa including northern Nigeria use various parts of plants to preserve cereals and legumes against damage by storage pest. Phytochemical screening of both the epicarp and mesocarp methanolic extracts of the seeds of Balanites aegyptiaca have been conducted and results indicated the presence of alkaloids, flavonoids, tannins, saponins, carbohydrates and terpenoids. In the present study the antifeedant efficacies of the methanolic extracts on cowpea bean (Vigna unguiculata) against the cowpea weevil storage pest, Callosobruchus maculatus, have been investigated. The test insects were cultured and the first generation progenies that emerged were used for the study. The beans were dressed with different doses (0.05, 0.10, 0.15, 0.20, and 0.25g) of the extracts and the weevil perforation index (WPI) was observed to have decreased as concentration of extracts increased. Compared to the control which has WPI of 50%, both extracts were found to be effective antifeedants with the mesocarp extract being more effective for the period taken for the study. The ability to protect the seeds from damage has been clearly shown by the percent protectant ability (PPA) whose value at 0.25g dose for the mesocarp extract was 100% while for the epicarp extract it was 81.18%. The mesocarp extract was therefore more effective than the epicarp extract at the highest dose used. The results of this study indicated that Balanites aegyptiaca seeds' mesocarp and epicarp extracts possessed antifeedant activity which may be associated with the presence of the secondary metabolites detected by the phytochemical screening.
Umar Muhd Sani. Comparative antifeedant activities of the epicarp and mesocarp methanolic extracts of the seeds of Balanites aegyptiaca against cowpea bean (Vigna unguiculata) storage pest (Callosobruchus maculatus). Journal of Medicinal Plants Studies. 2016; 4(6): 199-203.