Incorporation Depths of Imazaquin, Metribuzin, and Chlorimuron for Common Cocklebur (Xanthium strumarium) Control in Soybeans (Glycine max)

Field experiments were conducted in 1986 and 1987 to evaluate the effect of herbicide incorporation to various depths on common cocklebur control with imazaquin, a tank mix of imazaquin and metribuzin, and a preformulated mixture of chlorimuron and metribuzin in soybeans. Herbicide rates included were two-thirds and the full registered rate. All treatments, except chlorimuron plus metribuzin (50 plus 320 g ai/ha, respectively), controlled more common cocklebur when incorporated to depths of 2.5 to 7.6 cm than when left unincorporated. Also, imazaquin at 90 g ai/ha and the tank mix of imazaquin plus metribuzin at 90 plus 280 g ai/ha, when incorporated, controlled more common cocklebur than higher rates of the same combination when not incorporated. Common cocklebur control was similar with 2.5-, 5.0-, and 7.6-cm soil incorporation depths.