Published online by Cambridge University Press: 12 June 2017
A quantitative assay using 14C-chloramben (3-amino-2,5-dichlorobenzoic acid) revealed that velvetleaf (Abutilon theophrasti Medic. # ABUTH) leaves absorbed a greater amount of chloramben formulated as an acid than as a sodium salt. A surfactant increased 14C-chloramben absorption 5 days, but not 1 day, after application. Translocation of 14C-label out of treated leaves was greater in velvetleaf than in soybean [Glycine max (L.) Merr.]. Differences in the amount of 14C-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 recovered 14C-label in unextractable form was greater in treated leaves of soybean compared to velvetleaf.