Avaliação de produtos alternativos no controle de pragas e doenças em feijão-caupi

Abstract

Cowpea is a crop of great importance due to its nutritional and socioeconomic value. In addition, cowpea has drought tolerance, an important characteristic for cultivation in semiarid regions. During the production cycle, cowpea is affected by and insects that can decrease its production. The objective of this study was to evaluate the effect of alternative products on the incidence and severity of diseases and on the population of cowpea insects grown in the field. The following products were evaluated: neem extract, neem oil, ash and lime, kaolin, raw cow's milk, garlic extract and Bordeaux mixture, by spraying on the Creole cultivar Sempre Verde. The experimental design was randomized in blocks, with eight treatments and four replications. The evaluation of insects and diseases was carried out throughout the crop cycle. The diseases that affected the plants were: cercosporiosis, rust, powdery mildew and anthracnose. The insects that reached the largest population were the leafhopper and the leaf beetle. The application of Bordeaux mixture, neem extract and oil, lime and ash, garlic extract, cow's milk and kaolin did not increase height, number of pods per plant, number of seeds per plant, weight of seeds per plant and cowpea productivity. The application of alternative products did not influence the germinative percentage in cowpea seeds. Spraying with cow's milk decreased the incidence of A. flavus; and the spraying of neem extract decreased the incidence of Penicillium sp. in cowpea seeds. For the leaf beetle, spraying with the alternative products did not decrease the defoliation of the plants. Spraying with ash and lime reduced the occurrence of leafhoppers on cowpea leaves. Garlic extract, neem extract and cow's milk syrup reduced the severity of the rust. The Bordeaux mixture controlled powdery mildew. The lime and ash reduced the severity of anthracnose. It is concluded that garlic extract, neem extract, cow's milk, Bordeaux mixture and lime and ash can be used for the alternative management of pests and diseases in cowpea.