Dissipation of carbendazim and mancozeb following application of combination product on soybean and cotton

Dissipation and harvest time residues of carbendazim and mancozeb were studied in cotton and soybean following application of combination product (carbendazim 12% + mancozeb 63%). The residues of carbendazim and mancozeb persisited till 30^th (harvest) and 50^th (harvest) day in cotton leaf sample. Half-life of carbendazim in soybean was 13.1 and 16.7 days and in cotton was14.3 and 15.8 days, respectively, at recommended and double dose. The half-life of mancozeb at recommended and double dose was 3.5 and 4.1 days and 4.1 and 4.7 days, respectively, in soybean and cotton.The harvest time residues of carbendazim and mancozeb were below LOQ (< 0.05 mg kg⁻¹) in all the soybean and cotton samples. The residues persisted till 30^th day with levels of 0.3 and 0.5 mg kg⁻¹ at different doses in the soybean pod samples from Anand location. A preharvest interval of 30 and 50 days is proposed in soybean and cotton, respectively.