Comparative Efficacy of Plant Extracts in Managing Whitefly (Bemisia tabaci Gen) and Leaf curl Disease in Okra (Abelmoschus esculentus L)

Abstract

Abstract Okra leaf curl disease (OLCD) is an important disease responsible for yield losses in okra in all okra growing regions in the world. Effective management of the OLCD is very important in order to improve yield. The study was conducted to evaluate the effectiveness of different botanicals in the management of the OLCD. The treatments applied were 10% (w/v) crude extract each of neem leaf, garlic, mahogany bark, chili pepper fruit, pawpaw dried leaf, bougainvillea leaf and the control (water), in a randomised complete block design with four replications. The plant extracts significantly reduced the population of whitefly vector, as well as the incidences and severities of OLCD infections and increased fruit yield compared to the control (P< 0.05). Neem leaf extract followed by garlic extract significantly (P< 0.05) reduced the populations of whitefly and the incidences and severities of OLCD but significantly increased ((P < 0.05) fruit yield compared to crude extracts of mahogany, bougainvillea, chili pepper, and pawpaw leaves. The population of whitefly was positively correlated with severity of OLCD (r = 0.679; P> 0.05). Fruit yield was also negatively correlated with the severity of OLCD (r = -0.857; P< 0.05) and whitefly population (r = -0.750; P< 0.05). Farmers can manage OLCD in their okra fields by spraying with neem leaf or garlic extracts in order to improve fruit yields