Absorption, Translocation, and Metabolism of Foliage-Applied Chloramben in Velvetleaf (Abutilon theophrasti) and Soybean (Glycine max)

Abstract

A quantitative assay using14C-chloramben (3-amino-2,5-dichlorobenzoic acid) revealed that velvetleaf (Abutilon theophrastiMedic. # ABUTH) leaves absorbed a greater amount of chloramben formulated as an acid than as a sodium salt. A surfactant increased14C-chloramben absorption 5 days, but not 1 day, after application. Translocation of14C-label out of treated leaves was greater in velvetleaf than in soybean [Glycine max(L.) Merr.]. Differences in the amount of14C-label as unmetabolized chloramben in ethyl acetate extracts of treated leaves were not detected between velvetleaf and soybean. The amount of unmetabolized chloramben was greater in the shoot above the treated leaf in velvetleaf (58% of total label recovered) than in soybean (35% of recovered label). The amount of recovered14C-label in unextractable form was greater in treated leaves of soybean compared to velvetleaf.