Herbicide Systems for Johnsongrass (Sorghum halepense) Control in Soybeans (Glycine max)

Fenoxaprop, fluazifop-P, haloxyfop, quizalofop, and sethoxydim applied postemergence reduced johnsongrass populations in soybeans over a 3-yr period. The selective postemergence herbicides were more effective as split applications than as single, high-rate applications for controlling heavy infestations of johnsongrass. Fluchloralin applied preplant incorporated decreased the number of postemergence applications required to maintain johnsongrass control above 80%, although control depended primarily upon the selective, postemergence herbicides. Glyphosate applied by ropewick reduced johnsongrass populations more when used in conjunction with fluchloralin than when used alone.