Mefluidide and Acifluorfen Interactions on Ivyleaf Morningglory (Ipomoea hederacea), Velvetleaf (Abutilon theophrasti), and Common Cocklebur (Xanthium pensylvanicum)

Abstract

In greenhouse studies, postemergence applications of 0.1 or 0.3 kg ai/ha mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl] amino] phenyl] acetamide} as a tank mixture with 0.3, 0.4, or 0.6 kg ai/ha acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid}, or as a pretreatment 3, 5, or 7 days prior to acifluorfen treatment, often increased injury to ivyleaf morningglory [Ipomoea hederacea(L.) Jacq. ♯3IPOHE], velvetleaf (Abutilon theophrastiMedic. ♯ ABUTH), and common cocklebur (Xanthium pensylvanicumWallr. ♯ XANPE), compared to the injury from either herbicide alone. All sequential treatments with 0.1 kg ai/ha mefluidide and 0.3 kg ai/ha acifluorfen increased injury and decreased dry weight of ivyleaf morningglory and velvetleaf when compared with 0.6 kg/ha acifluorfen alone.

Effect of Herbicides on Soybean Thrips (Sericothrips variabilis) in Soybeans (Glycine max)

“…Production of field crops normally involves controll ing a variety of pests which include weeds and insects. An important tool in weed control is the use of herbi cides (3,4,5,6,7,13,14). The effects of herbicides on both predator and pest insects and injury resulting from the combination of insect injury and herbicides also have been reported (1,9,10,11,12).…”

Penetration, Translocation, and Metabolism of Acifluorfen Following Pretreatment with Mefluidide

“…Penetration and translocation of 14 C in ivyleaf morningglory, velvetleaf, common cocklebur, and soybean 7 days after treatment with 14 C-mefluidide or after treatment with 14 C-acifluorfen applied alone or 0, 3, 5, or 7 days following application of 0.3 kg/ha mefluidide. suppresses growth of common cocklebur (6, 11) but has little effect on ivyleaf morningglory (6). Ivyleaf morningglory, however, absorbed 9.8% more 14 C than common cocklebur.…”

“…The 3-, 5-, and 7-day mefluidide pretreatments did not alter the translocation of radiolabel. Hook and Glenn (6) reported that applying mefluidide 3 or 7 days prior to application of acifluorfen injured ivyleaf morningglory more than either herbicide alone. This increased herbicidal activity from sequential treatments with mefluidide and acifluorfen may be explained partially by increased penetration of acifluorfen.…”

“…TLC plates were developed in a solvent system of ethyl acetate:isopropyl alcohol:distilled water (65:25:10, v/v/v). The plates were exposed to X-ray film 6 for 28 days. The Rf values were recorded, and plates were scraped at the site of each major metabolite.…”

“…Combinations of mefluidide with 2,4-DB [4-(2,4-dichlorophenoxy)butyric acid], dinoseb (2-s^c-butyl-4,6-dinitrophenol), dinoseb plus naptalam (N-l-naphthylph thalamic acid), or glyph osate [JV-(phosphonomethyl) glycine] increased control of hemp sesbania and common cocklebur (11). Hook and Glenn (6) reported that tank mixtures and sequential applications of mefluidide and aci fluorfen increased the control of ivyleaf morningglory, velvetleaf, and common cocklebur compared to either chemical alone. How mefluidide enhances the activity of acifluorfen is unknown.…”