Persistence and metabolism of imidacloprid in different soils of West Bengal

A laboratory experiment was performed to study the persistence of imidaclop rid from two formulations (Confidor 200 g litre(-1) SL and Gaucho 700 g kg( -1) WS), and its metabolism in three different soils (Gangetic alluvial soi l of Kalyani, lateritic soil of Jhargram and coastal alkaline soil of Canni ng) of West Bengal following application at 0.5 kg and 1.0 kg AIha (-1). Di ssipation of imidacloprid in soil followed first-order kinetics and DT50 va lues ranged from 28.7 to 47.8 days. The shortest half-lives (28.7 and 35.8 days) were observed in the lateritic soil of Jhargram for both liquid and p owder formulations. The formation of two metabolites of imidacloprid, imida cloprid-urea and imidacloprid-olefin, was first detected on day 30 of degra dation at 28 (+/-1) degreesC in all three soils. (C) 2001 Society of Chemical Industry.