Field experiments were conducted to compare large crabgrass control by clethodim or sethoxydim applied alone and with selected fungicides registered for use in peanut. Fluazinam, propiconazole plus trifloxystrobin, or tebuconazole did not affect efficacy of clethodim or sethoxydim. Azoxystrobin, boscalid, chlorothalonil, and pyraclostrobin reduced efficacy of clethodim and sethoxydim in some experiments. Increasing the herbicide rate increased large crabgrass control regardless of the addition of chlorothalonil. In laboratory experiments, 14C absorption was less when 14C-clethodim or 14C-sethoxydim was applied with chlorothalonil. Pyraclostrobin and tebuconazole did not affect absorption of 14C-clethodim or 14C-sethoxydim.
Nomenclature: Azoxystrobin, methyl (E)-2-[2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl]-3-methoxyacrylate; boscalid, 3-pyridinecarboxamide,2-chloro-N-[4′-chloro(1,1′-biphenyl)-2-yl]; chlorothalonil, tetrachloroisophthalonitrile; clethodim; fluazinam, 3-chloro-N-[3-chloro-2,6-dinitro-4-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-2-pyridinamine; propiconazole, 1-[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl-methyl]-1H-1,2,4triazole; pyraclostrobin, carbamic acid,[2-[[[1-(4-chlorophenyl)-1H-pyrazol-3yl]oxy]methyl]phenyl]methoxy-,methyl ester; sethoxydim; tebuconazole, α-[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol; trifloxystrobin, benzeneacetic acid, α-(methoxyimino)-2-[[[(E)-[1-[3-(trifluoromethyl)phenyl]ethylidene]amino]oxy]methyl]-,methylester (E,E); large crabgrass, Digitaria sanguinalis (L.) Scop. #3 DIGSA; peanut, Arachis hypogaea L.
Additional index words: Herbicide absorption, pesticide interaction.
Abbreviation: LSS, liquid scintillation spectrometry.