Evaluation of selected indigenous pesticidal plant powders against stored maize and cowpeas insect pests.

Abstract

The insecticidal properties of powders of Lippia javanica dried leaves, and wood of the Spirostachys africana wood were evaluated on-station to determine the efficacy and optimise their use in reducing maize grain storage losses at concentrations of 2% and 5% w/w compared to Actellic Super dust (ASD) at 0.05% w/w and an untreated control. On maize, L. javanica 5% provided the best control among the pesticidal plants and showed potential to control grain damage to between 21% 33% compared to about 40% in the untreated control by week 24. On cowpeas (Vigna unguiculata), the same treatments were applied, and an additional treatment of Combretum imberbe wood ashes at 2% and 5% w/w was included. The C. imberbe 5% treatment was equally effective as ASD in reducing grain damage in cowpeas over a 16 week storage period. The results are discussed in the context of sustainable use of the plants by resource poor farmers.