Dissipation study of thiophanate methyl residue in/on grapes (Vitis vinifera L.) in India.

A multi-location field trial was conducted in India during 2006-2008 to evaluate the dissipation pattern of thiophanate methyl (75% WP) in/on grapes at two application rates (500 and 1,000 g a.i. ha(-1)). The quantitative analysis of the fungicide residues as carbendazim was performed using a UV/VIS spectrophotometer at the maximum absorption band of 281 nm. The average recovery was found 87% and the relative standard deviations (RSD) were below 3.8%. Following the first order kinetics the fungicide dissipates in grapes with a half-life (t(1/2)) value of 4.74-6.52 days irrespective of locations and doses.