Effectiveness of plant based insecticides as a sustainable means of control of cucumber mosaic virus

Abstract

Cucumber (Cucumis sativus) is an important crop in Pakistan. It is affected by many biotic and abiotic factors. Among these, Cucumber mosaic virus is the important disease with economic losses. The purpose of this study was to evaluate the effectiveness of plant based insecticides as a sustainable means to control the Cucumber Mosaic Virus. Sustainable means are economical, environmental friendly and socially acceptable. For this purpose, cucumber varieties /lines were evaluated against cucumber mosaic virus (CMV) under natural field conditions conducive for development of disease and aphid population. All varieties/lines were in the range of moderately susceptible to susceptible except Beet alpha and Nandini-732 which were moderately resistant with 16.26% disease incidence and highly susceptible with 50.11% disease incidence respectively. Relative humidity and rainfall had a positive relationship with the disease (CMV) development while temperature had a negative relation with disease development. Aphid population increased with the increase of relative humidity and rainfall and decreased as the humidity and rainfall decreased. With the increase in temperature, there was a gradual decrease in aphid population build up. For economical and environmentally safe management of the disease, one pesticide and different bio-pesticides were evaluated under natural field conditions against insect vector and disease. In order to manage CMV and aphid population, the pesticide Imidacloprid and three plant extracts of neem (Azadirachta indica), garlic (Calotropis gigantea) and aak (Allium sativum) were used. All the applied treatments gave significant results. Among them, imidacloprid was proved the best in reduction of disease incidence/severity and aphid population. It was followed by neem, garlic and aak extract respectively. Aak was found to be the least effective treatment even though it led to a significant reduction in disease incidence and aphid population compared to the untreated control where maximum plant infection and aphid population was found on plants.