Combination of Herbicides for Winter and Summer Weed Control in Turf1

Abstract

AbstractIt is usually necessary to apply herbicides to control both winter and summer weeds in bermudagrass [Cynodon dactylon (L.) Pers. ‘Common’] turf. A study was conducted on a Cecil (Typic Hapludult) loam or sandy clay loam at Griffin, Ga. to determine whether combinations of preemergence type herbicides for summer weeds and postemergence type herbicides for winter weeds would control both type weeds as effectively as when each herbicide was applied singly.Tank mixture of paraquat (l,l′‐dimethyl‐4,4′‐bipyridinium ion) at 0.3 kg/ha with preemergence herbicide treatments generally controlled a higher percentage of winter annual broadleaf weeds than when paraquat was applied alone at the same rate. In contrast, glyphosate [N(phosphonomethyl)glycine] mixtures were less effective than glyphosate alone. Control of corn speedwell (Veronica arvensis L.) was significantly improved from tank mixture of 2,4‐D [(2,4‐dichlorophenoxy)acetic acid] + mecoprop {2[(4‐chloro‐o‐tolyl)oxy]propionic acid} + dicamba (3,6‐dichloro‐o‐anisic acid) with preemergence treatments than with postemergence treatment alone. Bensulide [O‐O‐diisopropyl phosphorodithioate S‐ester with N‐(2‐mercaptoethyl)benzenesulfonamid] and prosulfalin {N‐[[4‐(dipropylamino)‐3,5‐dinitrophenyl]sulfonyl]‐S,S‐dimethylsulfilimine} controlled large crabgrass [Digitaria sanguinalis (L.) Scop.] as effectively when applied as tank mixtures with postemergence herbicide treatments as when applied alone. However, combination of DCPA (dimethyl tetrachloroterephthalate) with the same postemergence treatments reduced large crabgrass control in 1 or more years. Control of goosegrass [Eleusine indica (L.) Gaertn.] from tank mixtures of preemergence treatments with postemergence treatments was just as effective as with preemergence treatments alone.