Evaluation of Herbicides for Use in Zero and Minimized Tilled Corn and Sorghum1

Abstract Adequate weed control has been one of the principal problems associated with developing minimized tillage systems. Recent herbicide releases appear promising for solving the weed control problem. We evaluated ten different preemergence herbicide treatments and one postemergence treatment for 3 years for weed control in till‐planted corn (Zea mays L.) and sorghum (Sorghum bicolor, L. Moench). All herbicide treatments were compared on plots that were either disked or nondisked to see if reduction of plant residues improved weed control. All herbicide treatments reduced weed populations and resulted in increased yields compared to the cultivated check. Plots that were disked as opposed to those nondisked were significantly lower in weed yields for 2 years, but were significantly better in crop yields only 1 year. Most of the herbicides gave excellent weed control even though residues of the previous year's crop averaged 5,218 kg/ha and covered 73% of the ground.