Control of Spurred Anoda in Cotton

Abstract

Control of spurred anoda [Anoda cristata (L.) Schlecht.] in the greenhouse was less than 75% after 28 days with preplant incorporated herbicides except dinitramine [N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine] which gave 88 to 94% control. In greenhouse and field studies with cotton (Gossypium hirsutum L. ‘Coker 210′) preemergence applications of norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone] controlled 93 to 100% of the spurred anoda 4 weeks after application. Control with postemergence applications of fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-toly)urea] was 46.0 to 92.5%; 90.7 to 100% with prometryn [2,4-bis(isopropylamino)-6-(methylthio-s-triazine]; and 100% with methazole, [2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione]. Preemergence applications of norflurazon plus fluometuron, prometryn, or methazole applied postemergence controlled 93, 97, and 100% of spurred anoda, respectively. Fluometuron plus the same three postemergence treatments controlled 63, 95, and 88% of spurred anoda, respectively. Results of our tests suggest that the best control of spurred anoda can be obtained in cotton by a combination of norflurazon applied preemergence at 1.68 kg/ha followed by two postemergence applications of either fluometuron at a rate of 2.24 kg/ha, prometryn at a rate of 1.68 kg/ha, or methazole at a rate of 1.68 kg/ha.