Published online by Cambridge University Press: 12 June 2017
The penetration, translocation, and metabolism of acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} in ivyleaf morningglory [Ipomoea hederacea (L.) Jacq. ♯3 IPOHE], velvetleaf (Abutilon theophrasti Medic. ♯ ABUTH), common cocklebur (Xanthium pensylvanicum Wallr. ♯ XANPE), and soybean [Glycine max (L.) Merr.] were studied. An application to plants of 0.3 kg ai/ha mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl] amino] phenyl] acetamide} 0, 3, 5, or 7 days prior to treatment with 14C-acifluorfen often altered one or more of the physiological processes under study. Pretreatment of ivyleaf morningglory with mefluidide 3, 5, or 7 days prior to application of 14C-acifluorfen increased penetration of 14C and decreased metabolism of acifluorfen, while translocation was unaffected. All mefluidide treatments increased penetration of 14C-acifluorfen into velvetleaf, while the 3-, 5-, and 7-day pretreatments decreased acifluorfen metabolism. Penetration of acifluorfen into common cocklebur was unaffected by pretreatment with mefluidide. However, the 7-day mefluidide pretreatment of common cocklebur increased translocation of 14C into the upper leaves and decreased acifluorfen metabolism. Penetration and translocation of the radiolabel from 14C-acifluorfen in soybean was unaffected by pretreatment with mefluidide. Metabolism of acifluorfen by soybean was decreased by the 0-day mefluidide treatment but was unaffected by the 3-, 5-, or 7-day mefluidide pretreatment.