Field bindweed is extremely susceptible to aminocyclopyrachlor compared toother weed species. Laboratory studies were conducted to determine ifabsorption, translocation, and metabolism of aminocyclopyrachlor in fieldbindweed differs from other, less susceptible species. Field bindweed plantswere treated with 3.3 kBq 14C-aminocyclopyrachlor by spotting asingle leaf mid-way up the stem with 10 µl of herbicide solution. Plantswere then harvested at set intervals over 192 h after treatment (HAT).Aminocyclopyrachlor absorption reached a maximum of 48.3% of the appliedradioactivity by 48 HAT. A translocation pattern of herbicide movement fromthe treated leaf into other plant tissues emerged, revealing a nearly equalaminocyclopyrachlor distribution between the treated leaf, abovegroundtissue, and belowground tissue of 13, 14, and 14% of the appliedradioactivity by 192 HAT. Over the time-course, no solubleaminocyclopyrachlor metabolites were observed, but there was an increase inradioactivity recovered bound in the nonsoluble fraction. These resultssuggest that aminocyclopyrachlor has greater translocation to belowgroundplant tissue in field bindweed compared with results from other studies withother herbicides and other weed species, which could explain the increasedlevel of control observed in the field. The lack of soluble metabolites alsosuggests that very little metabolism occurred over the 192 h timecourse.