Department of Zoology, University of Delhi, Delhi, 110 007, India
Online published on 15 December, 2011.
Both mancozeb and radiolabelled maneb dissipated rapidly from brinjal plants under subtropical conditions. The half life of mancozeb on brinjal plants was 15 days, whereas the half life of radiolabelled maneb was 10 days under similar conditions. Both these compounds were found to be most persistent on leaves and least on fruits. Besides the parent fungicide, three compounds namely ethylene thiuram disulphide (ETD), ethylene thiuram monosulphide and ethylene thiourea (ETU) were detected in the brinjal fruits as metabolites or degradation products. The amount of ETU was 0.032 ppm on zero day which increased to 0.51 ppm 20 days after treatment, however, a gradual decline was observed thereafter. The amount of ETU was found to be only 0.003 ppm 42 days after treatment. This suggests the formation of ETU from ethylene bis dithiocarbamates (EBDCs) and then its breakdown to certain other compounds.
