Persistence Behaviour of Endosulfan in Fodder Maize

Initial deposition and dissipation of endosulfan residues in maize grown as fodder crop and in cropped soil was studied at two doses (490 and 980 g a.i. ha−1) and two sprays for each dose. It was observed that about 93–95% of initial deposits disappeared from the foliage within 15 days. The a isomer of endosulfan degraded faster than β isomer in both foliage and soil. The toxic metabolite endosulfan sulfate started appearing from 3rd d onwards after first application. The rate of dissipation with time was found to follow first order reaction kinetics. Statistically calculated half-life of residue disappearance and safe waiting period values ranged from 3–4 d and 11–14 d, respectively.