Abstract

The toxicity of Jatropha seed oil to maize weevil, Sitophilus zeamais Motsch. in stored grains was tested in the laboratory. The cost analysis of seed oil extraction was estimated. The rates of seed oil treatment at 0.2, 0.5 and 1.0 ml and the untreated control for storage of 100 g grains were replicated four times. Each experimental unit contained five pairs of freshly emerged adult S. zeamais. Results showed disproportionate increase in adult mortality with increase in rate of treatment. There was significant difference (P<0.05) in the treatments compared to the oil-free control. At the end of four months storage period, the weevil perforation index (WPI) ranges between 17.91 and 26.315% in the treatments compared to the control. Application of the seed oil to the grains was simple and the results determined the possibility of including the seed oil in pest management programme.

Key words: Jatropha curcas, Sitophilus zeamais, costs analysis, toxicity.