Ravinder Singh
A laboratory experiment was conducted to investigate the insecticidal activities of seven plant materials namely: citrus leaf powder (CLP), Acacia leaf powder (ALP), Occimum leaf powder (OLP), mahogany bark powder (MBP), hot pepper powder (HPP), ginger powder (GP) and mahogany wood ash (MWA); and a synthetic insecticide, pirimiphos-methyl dust (PMD) as check. The objective of the study was to investigate the comparative efficacy of the plant materials and PMD in the suppression of Callosobruchus chinensis. developmental durations and damage in cowpea seeds. Plant materials were evaluated at 1 g/20 g cowpea seeds (0.1 g PMD/20 g cowpea seeds). The experiment was laid out in a completely randomized design replicated four times. The results showed that MWA was more effective in causing adult C. chinensis s mortality, but CLP was significantly (P<0.05) more effective in reducing adult emergence, percentage hatching inhibition rate and per cent holed cowpea seeds. There were no significant differences among treatments on number of eggs lai d and developmental durations of C. chinensis s. Application of CLP at the rate of 50 g/kg of cowpea seeds is therefore be recommended for the control of C. chinensis development and damage to cowpea seeds while in storage.
