Laboratory Evaluation of Insecticidal Potentials of Kane Plant (Anogeissus leiocarpus Guil and Perr) for the Control of Bambara Groundnut Weevil (Callosobruchus subinnotatus Pic.) on Stored Bambara Groundnut ( Vigna subterranean (L.)Verdcourt)

Abstract

Laboratory experiment was conducted during the year 2010 to evaluate the insecticidal potentials of different parts of Kane plant, Anogeissus leiocaipus Guil and Perri (leaves, stem and root barks), compare their efficacy with conventional insecticide (pirimiphos-methyl) and determine the concentration/rate that is effective in the control of damage caused by Bambara groundnut weevil, Callosobruchus subinnotatus Pic. on stored grains of Barn bar a ground nut (Vigna subterranae (L.) Verd.). The different parts of the plant materials were tested in powdered form at three different concentrations viz: 1, 3 and 5g/100g grain while the synthetic insecticide was applied at the recommended rate of 0.25g/100gseed. The experiment was laid out in a completely randomized design with each treatment replicated three times. The result shows that root bark at 1g/100g grain was the most effective in reducing oviposition (10.78) thereby bringing about a significant reduction in adult emergence (4.72), number of emergence holes (4.72), mortality (4.69) at 3 days after treatment (DAT) and grain damage (3 .07) while it competed favorably with the synthetic insecticide (pirimiphos-methyl). A significantly higher mortality of 2.89 and 2.89 in the first generation progeny was recorded in the leaf treated grains at 60 and 90 DAT, respectively. All the three different plant parts did not exhibit any significant negative effect on viability of the seeds tested. The stem bark and the leaves proved equal in efficacy to the root lark only at the highest rate/concentrations of 5g/100g grain. Based on the results of the experiments conducted, applications of the root bark of A. lelocarpus at the rate of 1- 5g/100g grain is recommended for an effective, cheap and safe protection of V. subterranean grains against damage caused by C. subinnotatus in storage.