The persistence of thiophanate-methyl, dimethyl 4, 4'-o-phenylenebis (3-thioallophanate), and its metabolites on plant leaves and glass plates was examined using a radiolabeled compound. Apple and grape leaves and glass plates treated with thiophanate-methyl-phenyl-14C were kept outdoors, except on rainy days and nights when they were kept in green house.
Half lives of thiophanate-methyl on apple and grape leaves were around 15 and 12 days, respectively. On glass plates half life was around 3 days. The per cent of abundance of the parent compound and a major degraded product, methyl 2-benzimidazolecarbamate, versus applied thiophanate-methyl at 14 days after treatment was as follows; 52.6 and 10.1% on apple leaves, 49.5 and 8.9% on grape leaves, and 5.5 and 24.1% on glass plates, respectively.