Studies on Degradation and Efficacy of Synthetic Pesticides on Okra Crop
The present study was carried out at Institute of Environmental Studies and Department of Agriculture and Agribusiness Management, University of Karachi. The efficacy and degradation studies of different insecticides used against jassid infestation on okra crop were monitored. The insecticide λ-Cyhalothrin, Profenofos and Acephate form organophosphate group and Cartap from carbamate group were studied. For efficacy studies of insecticides, an untreated control plot was kept along with the treated plots. The insecticides were applied four times during the experimental period. Jassid population data were taken before and after 1, 2, 3,4,5,6 and 7 days of insecticices application. Degradation studies were carried out at 1, 7 and 30 days after insecticides application. Cartap was found most effective against jassids by providing 59.9% after first day and 98.0% after 5 , 6 and 7 day of its application. Acephate followed cartap bygiving 75.7 % th th th reduction after 7 day of its application. Profenofos provided minimum reduction of 9.8% after first day and th maximum reduction of 35.1% in jassid population after 7 day. λ-Cyhalothrin was found least effective against jassid but it was better as compared to untreated control plot by providing 5.7%, 16.1%, 9.7% and 3.8% after 1 ,3 and 7 day of application, respectively The degradation studies depicted that λ-Cyhalothrin followed the st rd th first order kinetics and degraded as the fastest by showing 99.89% after first day, 99.93% after 7 day and th 99.96% after 30 day of application. Acephate followed λ-Cyhalothrin by showing 29.11% after 1 day, 94.96% st after 7 day and 99.34% after 30 day of application. Though the initial degradation of profenofos (15.19%) was th th less than the cartap (17.00%) after 1 day, but it degraded faster later on by providing 92.18% after 7 day and st th 99.30% after 30 day of its application. Cartap provided 17.00% degradation after 1 day, 88.02% after 7 day th st th and 92.80% after 30 day of its application.