PROTECTIVE BIOACTIVITY OF BIONIMBECIDINE BOTANICAL AND JATROPHA LEAF POWDER (JATROPHA CURCUS L.) IN THE MANAGEMENT OF CALLOSOBRUCHUS MACULATUS (F.) INFESTATION IN STORED COWPEA (VIGNA UNGUICULATA L. WALP.)

Abstract

Synthetic insecticides have been the main tool used for the control of cowpea bruchid in storage, but the indiscriminate use of the insecticides with their negative effect on man and the environment has been a serious problem to their use. Hence, the practice shifts to the use of alternative eco-friendly relatively cost effective control measures. Laboratory experiments were conducted under ambient conditions of temperature 32-35o c and 55-65% relative humidity to determine the bioactivity of Jatropha (Jatropha curcus L.) leaf powder on C. maculatus (F) infestation on stored cowpea grains (Janwake, Danmalaysia and Iron beans). Ten grams of cowpea grains was weighed into a 200 ml bottle in three replicates for untreated and 3 levels of treatment with Jatropha leaf powder (1.0 g, 2.0 g, and 3.0 g respectively). Grain treatments with these dosages were afterward carried out before infestation with three pairs males and females of adult C. maculatus. Number of eggs laid and adults emerged were counted and recorded throughout the first filial generation. Experiments were arranged in completely randomized designed (CRD). Data obtained were computed and subjected to analysis of variance (ANOVA). Significantly different means were determined using least significant difference (LSD) at 5% level of probability. Results showed no significant differences in all the parameters tested for treated and untreated grains. This indicated that Jatropha leaf powder treatment was ineffective in suppressing infestation, and damage caused by the cowpea bruchid. This may partly be due to difference in the dose used for Jatropha leaf powder and aging of bionimbecidine botanical powder. Similarly, varietal differences did not appear to have had effect on the level of infestation by C. maculatus.