Abstract
Cotton (Gossypium hirsutum L.) response was evaluated when propanil (3′,4′-dichloropropionanilide), thiobencarb {S-[(4-chlorophenyl)methyl] diethylcarbamothioate}, butachlor [N-(butoxymethyl)-2-chloro-2′,6′-diethylacetanilide], oxadiazon [2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-δ2-1,3,4-oxadiazolin-5-one], bifenox [methyl-5-(2,4-dichlorophenoxy)-2-nitrobenzoate], acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid}, and metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] were applied over-the-top at simulated drift rates at two growth stages during 1975 to 1979. No rate of butachlor or thiobencarb injured cotton. The order of phytotoxicity for the herbicides applied to cotyledonary cotton was propanil > metribuzin > bifenox > oxadiazon > acifluorfen > butachlor = thiobencarb. Herbicides injured cotton less at the five- or eight-node stage than at the cotyledonary stage. Injury was more severe in seasons of wet or cold weather during early plant development.