Abstract

This research reported the effect of four plant powders including Azadirachta india, Alstonia boonei, Garcina kola and Moringa oleifera on the mortality adults and emergence of maize weevil (Sitophilus zeamais) on stored wheat grains. The powders were incorporated into 20 g of wheat grains at 0.0% (control) 2.5, 5.0, 12.5 and 25.5% (w/w). The ability of the plants powders to protect wheat grains were assessed in terms of mortality rates after 24 to 96 h of post treatment, percentage grain weight loss and damage after the first filial generation (F1). The results indicated that A. indica and A. boonei provide the highest protection of the treated grains. G. kola and M. oleifera were not good enough protectants at the concentrations tested. These plants powders did not adversely affect seed viability after three months of storage, suggesting that seeds treated with A. indica, A. boonei, G. kola and M. oleifera are suitable for consumption and planting stock. Seed powders of A. boonei can be used as a good alternative to pesticides against S. zeamais in addition with that of A. indica which effects are well established by many former works.

Key words: Sitophilus zeamais, Azadirachta indica, Alstonia boonei, Garcina kola, Moringa oleifera,wheat storage.