Efficacy of Neem Leaf (Azardirachta indica), Bitter Leaf (Vernonia amygdalina) and Pawpaw Leaf (Carica papaya) Powder in the Control of Callosobruchus maculatus in Stored Cowpea

Abstract

A laboratory experiment was carried out to investigate the insecticidal properties of Azadirachta indica (Neem), Vernonia amygdalina (Bitter Leaf) and Carica papaya (Pawpaw) leaf powders against Callosobruchus maculatus in stored cowpea. The experiment was carried out using a completely randomized design. The treatments were applied as single and mixed applications at the following rates-3g, 6g and 9g. Each treatment were replicated 4 times making a total of 92 experimental units. Each treatment was applied to 100g. Data collected include adult mortality, number of eggs, larval development, percentage grain damage, percentage weight loss and percentage germination. The data collected were subjected to analysis of variance (AVONA) at 5% probability level. The result indicated that, there were significantly differences between plant products treatments and the synthetic treatment over the control throughout the period of the experiment (1 to 8 weeks). However, the various treatment of the plant products used for the experiment proved to be effective in controlling C. maculatus of stored cowpea. However, Cypermethrin dust at 0.6g/100g was the most effective in controlling grain damage while pawpaw leaf powder and Bitter Leaf powder proved to be most effective in controlling grain damage among the natural botanicals, adult mortality and number of eggs laid by C. maculatus on the stored grains. The result clearly indicated the potential values of using plants extracts as complimentary to chemicals pesticides in controlling C. maculatus on cowpea grains.