Efficacy of the Seed Powder and Oil of Jatropha Curcas in the Control of Acanthoscelides obtectus in Stored Cowpea

Abstract

A study was carried out to evaluate the efficacy of seed powder and oil of Jatropha curcas in controlling post-harvest losses caused by cowpea weevil, Acanthoscelides obtectus (Say) on cowpea. 100 g of J. curcas powder were put in 300 ml of n- hexane used as the solvent. The Jatropha seed powder was tested at dosages of 0.1g, 0.2g and 0.3g and Jatropha seeds oil at the rate of 0.05ml, 0.1ml and 0.2ml were applied to 20g cowpea seeds in petri dishes. The different rates of treatment recorded significant differences (P=0.05) in causing adult mortality compared to the untreated control. The different rates of treatment also recorded significant differences (P=0.05) in oviposition of each treatment compared to the control. The percentage weight loss and seed damage were also suppressed as a result of treatment with the plant material compared to the untreated control. However, among the treatments Jatropha seeds oil at 0.2ml/20g cowpea recorded the highest adult mortality rate and lowest oviposition while control had the lowest mortality rate and highest oviposition. The study shows that Jatropha had bio pesticides effect in controlling A. obtectus