Tamboti wood ash and burnt goat dropping ash, safe alternatives to control cowpea weevils, Callosobruchus maculatus (Fabr.) (Coleoptera: Bruchidae) during storage for subsistence farming.

Abstract

This study determined the effect of tamboti wood ash and burnt goat dropping ash along with a chemical insecticide (avi-klorpirifos) on the reproduction, egg hatchability, damage, and mortality of cowpea weevil (Callosobruchus maculatus Fabr.). The germination potential of treated cowpea seeds was also determined using a susceptible variety-Blackeye. Two hundred grams of clean cowpea seeds were mixed with 25 g of tamboti wood ash and goat dropping ash. These seeds were then infested with 5 pairs of newly emerged adults of C. maculatus under controlled laboratory conditions. The experiment revealed that both tamboti wood ash and goat dropping ash had negative effects on the efficiency of C. maculatus and significantly reduced the extent of damage. In germination test, these ashes showed a significant improvement in germinability of treated cowpea seeds. However, in all instances, tamboti wood ash proved to be much more effective than goat dropping ash. The study observed that these natural products have the potential to protect cowpea seeds from the damage caused by C. maculatus during storage and can, therefore, be used as an alternative pest management method against cowpea weevils.