Interconversion of stereoisomers of endosulfan on chickpea crop under field conditions

Abstract The pure individual stereoisomers of endosulfan, alpha‐endosulfan and beta‐endosulfan, were applied as emulsifiable concentrates to chickpea crop at the rate of 175 g a.i. ha −1 and 50 g a.i. ha −1, respectively. The dissipation rate of these isomers revealed that alpha‐endosulfan interconverted to beta‐endosulfan in minor quantities, while it was converted into endosulfan sulfate on chickpea leaves in significant amounts. On application, beta‐endosulfan was converted to endosulfan sulfate and alpha‐endosulfan in relatively smaller amounts. The study indicates that the beta stereoisomer of endosulfan is more persistent because it is resistant to interconversion and metabolic change.