Dissipation of chlorothalonil in leafy vegetables accelerated by use of bio- fertilizer

Abstract

Persistence of the fungicide, chlorothalonil, in spinach and green onions was studied following application of the fungicide along with or without co-application of a bio fertilizer viz Arka microbial consortium. Samples of these leafy vegetables drawn periodically at 0 (1h), 1, 3, 5, 7, 10,15 and 20 days after application of chlorothalonil were analysed by GC-ECD. The residues of chlorothalonil in spinach as well as green onions persisted longer in bio fertilizer untreated crop than in treated crop, following application of the fungicide at recommended as well as double the recommended doses. Increase in biomass by 11 to 15 per cent in spinach and green onions resulting from application of the bio fertilizer seemed to have resulted in faster dissipation of chlorothalonil in the produce. The waiting period recommended for safe harvest of these leafy vegetables were reduced by 0.1 to 2.6 days in bio fertilizer treated produce. Waiting period reduced significantly in case of spinach following both treatments mentioned above but following only the higher dose treatment in green onion. The bio fertilizer used in this study increased the yield without harming the environment, thereby, also, accelerating the reduction in chlorothalonil residues in the produce.