Bioefficacy of moringa oleifera and anacardium occidentale against insect pests of watermelon (citrullus lanatus thumb) and their effects on fatty acid profile

This experiment was carried out at Ladoke Akintola University of Technology, Teaching and Research farm during the late and early planting seasons of 2011 and 2012 to determine the efficacy of Moringa oleifera(L) and Anacardium occidentales(L) extracts on major insect pests of pests of watermelon and their effects on fatty acid compound of watermelon. This experiment was arranged in a randomized complete block design and each treatment was replicated three times. Each of the plant extracts was applied at three different concentrations (5, 10 and 20%). Gas chromatography was used to determine the level of fatty acid composition.The results clearly showed that the applied plant extracts exhibited insecticidal action against the Aulocophora africana (Weise) and Dacus cucurbitae(Coquillet). Meanwhile, M. oleifera proved to be more effective than cashew nut extracts in the control of the observed insects. Although, none of these plant extracts significantly(P<0.05) performed better than synthetic insecticide (Lambdacyhalothrin) against the studied insects during the raining season but plant extracts treated fruits had higher number of fatty acid compounds than that of synthetic insecticide. Therefore, the use of plant extracts in the management of insect pests of watermelon in organic farming improved the nutritional contents of watermelon fruit.