|Buhler, Douglas - Doug
|GUNSOLUS, JEFFERY - UNIVERSITY OF MINNESOTA
Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/1995
Publication Date: N/A
Interpretive Summary: Chemical weed control has been a dominant component of weed management in soybean over the past 25 years. Recent environmental and economic concerns have increased interest in mechanical weed control systems. Little research has been conducted on the interactions of crop cultural practices and mechanical weed control techniques in current soybean production systems. Our goal was to determine the effects of soybean planting date on weed populations and the weed control effectiveness and soybean response to mechanical weed control systems Delaying soybean planting from mid-May to early-June reduced weed densities and yield losses from weeds. Weed control with a herbicide treatment was not affected by planting date, but control with mechanical systems was often increased by delaying soybean planting. When soybean was planted early, mechanical weed control usually did not result in soybean yields as great as the herbicide treatment. However, when planting was delayed, weed densities were reduced and mechanical weed control resulted in soybean yields similar to the herbicide treatment. Initial weed pressures, date of planting, and climatic conditions interacted to determine weed control levels and soybean yields. Delaying planting reduced weed densities, yield losses from weeds, and improved the effectiveness of mechanical weed control operations. Effective mechanical weed control systems combine the art and science of weed control to create the management skills necessary for a successful weed management program.
Technical Abstract: Additional information on mechanical weed management systems is needed so that producers can develop systems that meet their production and weed control goals without sacrificing profitability of crop production. Field research was conducted in 1989, 1990, and 1991 to determine the effect of preplant tillage and soybean planting date on weed populations and the effectiveness of mechanical weed control operations. Delaying soybean planting from mid-May to early-June reduced weed densities and yield losses from weeds. Weed control with a herbicide treatment was not affected by planting date, but control with rotary hoeing and cultivation was often increased by delayed soybean planting. Early-planted soybean usually yielded better following herbicide treatment than mechanical control. However, when preplant tillage and planting were delayed, weed densities were reduced and mechanical weed control operations usually resulted in soybean yield similar to the herbicide treatment.