Studies with Manganese [14C]Ethylenebis(dithiocarbamate) ([14C]maneb) Fungicide and [14C]Ethylenethiourea ([14C]ETU) in Plants, Soil, and Water

Abstract

Total radiochemical residues on tomato and bean plants decreased rapidly with time following foliar field applications of either [14C]maneb or [14C]ETU (ethylenethiourea). No accumulation or persistence of intact ETU residues was observed from either treatment. In soil treated with [14C]ETU or with [14C]maneb, the half-life of total radiochemical 14C-labeled residues under field conditions was less than 4 weeks for ETU and between 4 and 8 weeks for maneb, whereas the half-life for intact ETU itself was less than 1 week. In plant uptake tests, only trace amounts of total radiochemical residues were taken up by tomato plants grown in field soil treated with [14C]maneb or. [14C]ETU. No intact ETU residues were detected in plants from these treatments, and ripe tomatoes from these plants contained no detectable 14C-labeled residues (<0.01 ppm). In water, glycine was confirmed as the major photodegradation product of [14C]ETU. Ethyleneurea, hydantoin, and Jaffe's base were also identified by mass spectrometry. Overall, these 14C data indicate very little likelihood for the appearance of significant amounts of ETU in the environment or on maneb-treated crops. © 1977, American Chemical Society. All rights reserved.