A field study was conducted in 1984 and 1985 to determine residues of ethylenebisdithiocarbamate (EBDC) and ethylenethiourea (ETU) on flue cured tobacco after application of mancozeb or maneb. Residues of EBDC and ETU decreased as the time between application and harvest increased. On plots sprayed at 7-day intervals in 1984 with the 1.92 g/L dilution rate of mancozeb, residues declined from 23.0 ppm for the first harvest to <0.05 ppm for the fourth harvest. ETU residues of 0.07 ppm were detected in fourth harvest samples but not in others. In 1985, EBDC residues from the 1.92 g/L dilution rate applied at 5-day intervals averaged 129.6 ppm on first harvest samples taken 1-day after application and dropped to 16.4 ppm for the last harvest. For the same treatment ETUC residues were 0.29 ppm first harvest samples taken one day after application and dropped to 16.4 ppm for the last harvest. For the same treatment ETU residues were 0.29 ppm were attributed to drift during application.

(Full article published with kind permission from "Tobacco International")