Absorption, Accumulation, and Metabolism of Benefin, Diphenamid, and Pebulate by Tobacco Seedlings

Abstract

Benefin accumulated rapidly in the roots of tobacco (Nicotiana tabacumL. ‘Kentucky 14′) seedlings incubated in nutrient solution containing14C-labeled benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine) and remained in the roots unaltered. Very low levels of radioactivity were detected in the shoots. Diphenamid (N,N-dimethyl-2,2-diphenylacetamide) accumulated in the shoots of treated plants throughout the treatment period but remained at low levels in the roots. Diphenamid was extensively metabolized in the shoots but only to a slight extent in the roots. The carbon-14 of pebulate (S-propyl butylethylthiocarbamate) accumulated in moderate amounts in both the roots and shoots of the tobacco seedlings, but attempts to recover pebulate failed.