Interactions Between Selected Herbicides and Protectants on Corn (<i>Zea mays</i>)

Abstract

Greenhouse studies were initiated to determine the efficacy of four herbicide antidotes as protectants of corn ( Zea mays L., ‘DeKalb XL72AA’ and ‘DeKalb XL67′) against injury from preemergence or early postemergence applications of the herbicides chlorsulfuron {2-chloro- N -[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide}, fluazifop-butyl {butyl-2-[4-[5-(trifluoromethyl-2-pyridinyl)oxy] phenoxy] propanoate}, or BAS 9052 OH {2-[1-(ethoxyimino)-butyl]-5-[2-(ethylthio)-propyl]-3-hydroxy-2-cyclohexene-1-one}. NA (1,8-naphthalic anhydride) was the most effective of the four antidotes in protecting corn against injury from preemergence applications of chlorsulfuron. CGA-43089 [α-(cyanomethoxy)-imino-benzeneacetonitrile] and CGA-92194 [α-(1,3-dioxolan-2-yl-methoxy)-imino-benzeneacetonitrile] partially protected corn from chlorsulfuron injury, whereas R-25788 ( N,N -diallyl-2,2-dichloroacetamide] was the least effective. R-25788 offered partial to good protection to corn against injury from preemergence applications of fluazifop-butyl and BAS 9052 OH. NA, or CGA-43089, and CGA-92194 partially protected corn from fluazifop-butyl injury but their efficacy against BAS 9052 OH injury to corn was limited. In general, all four antidotes offered better protection to the thiocarbamate-tolerant ‘XL72AA’ hybrid than to the thiocarbamate-susceptible ‘XL67’ hybrid. With the exception of NA, which partially protected corn from postemergence-applied chlorsulfuron, none of the four herbicide antidotes was effective in protecting corn against injury from postemergence applications of any of the three herbicides.