Caron-14-trifluralin residues in soil and carrots

The persistence and movement of 14C-trifluralin and its metabolites were studied in sandy loam soil under outdoor conditions. Uptake by carrots of the herbicide from the treated soil was also investigated. The bulk of the 14C residues was present in the upper 0-7.5 cm layer during the growing period. The non-extractable 14C residues increased with time. Downward movement of the 14C-trifluralin, or its degradation products, was not observed at significant concentrations. After 4 months, 2.7 and 6.1% of the initially applied radioactivity were found in the form of metabolites, designated TR-1 and TR-2, respectively, in the combined soil samples from the three depths. The metabolites TR-4 and TR-1, as well as trace amounts of the metabolite TR-21, were present in the form of soil bound 14C residues. Most of the radioactivity was located in the peel of the carrots. The pulp contained 14C residues of TR-1 and TR-2 (0.010 and 0.004 ppm, respectively). 14 refs, 2 figs, 3 tabs