Impact of cashew (Anacardium occidentale L) and moringa (Moringa oleifera Lam) leaves-based biopesticides on major insect pests and predators associated with white-seed melon (Cucumeropsis mannii Naudin)

Abstract

We assessed the impact of cashew (Anacardium occidentale L.) and moringa (Moringa oleifera Lam.) leaves extracts on the insect pests and yield of white-seed melon (Cucumeropsis mannii Naudin) under field conditions in the late season of 2022. Concentrations (50%, 75%, and 100% v/v) of aqueous leaves extracts of A. occidentale and M. oleifera were utilised, with chlorpyriphos 20EC (Perfect killer ® ) and water serving as the positive and negative controls, respectively. Spraying began three weeks after germination and continued weekly for four weeks. Insect sampling was done weekly, six days after each spraying, to assess the effectiveness of each treatment. Pod and seed yields were recorded at harvest. We noted three major insect pests and two predators associated with the crop. The synthetic pesticide highly suppressed the major insect populations (pests and beneficial) by 90.6% to 100%. Plots treated with 100% v/v of A. occidentale (A100) produced the highest pods (5.4 kg/m 2 ) and seed (116.2 g/m 2 ) yields. Plots treated with the synthetic pesticide yielded the lowest seed yield (53.6 g/m 2 ). There was no significant difference (p>0.05) in pod and seed yields among the treatments. The difference in the yields is thus due to random variations.