Effectiveness Of Neem (Azadira Chta Indica) As An Organic Pesticide In Vegetable Production

Neem trees offer the potential of a locally available biological insecticide and the possibility of improving agricultural in the Virgin Islands. Neem is a hardy tree with rapid growth whose leaves and fruits can be made into a variety of products with insecticidal properties. Producing and utilizing such products would not only reduce farmers' expenses through decreased dependence on costly imported chemicals, but would also be more environmentally sound. Agricultural run-off and non point source pollution are quickly becoming major concerns in the Virgin Islands. This project directly addresses these concerns by testing two environmentally sound methods of organic insect control on a widely grown crop, sweet potato.Four treatments (traditional spraying, commercially available neem extract, neem mulch treatment and no input) were compared for their effect on crop yield and incidence of pest damage. Sweet potato weevil (SPW) is the primary pest problem with this crop. Data was collected in accordance with previous SPW studies in the Virgin Islands (Crossman et al. 1993). Additional measurements were taken on the height and spread of vegetative material, crop canopy closure and incidence of foliar pests. Harvested storage roots were divided into three size categories (below market, medium and jumbo), weighed and percent infestation and damage of SPW recorded. Traditional spraying produced the greatest number of marketable storage roots. Neem mulch treatment had the highest average weight/storage root and greatest total yield. The Neem spray was the most effected by SPW, however results may have been influenced by the minimal infestation of