The Effect of Giant Foxtail (Setaria faberi) Plant Height on Control with Six Postemergence Herbicides

Abstract

Field experiments were conducted from 1986 to 1988 to evaluate giant foxtail control at four plant heights by six POST grass herbicides. Clethodim, fenoxaprop, fluazifop-P, haloxyfop, quizalofop, and sethoxydim controlled 95% or more of 60-cm giant foxtail all three years at the labeled herbicide application rates. Control of 7-, 15-, and 30-cm giant foxtail with fenoxaprop, fluazifop-P, quizalofop, and sethoxydim was dependent upon soil moisture conditions at application. Clethodim and haloxyfop provided the greatest control (89 to 99%) regardless of plant height or soil moisture conditions. No herbicide injured soybean. Soybean seed yield with POST grass herbicides was equal to or greater than yield in the hand-weeded plots.