Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 12, 1997
Publication Date: N/A
Technical Abstract: Weeds have a significant impact on agricultural production and environmental quality. The economic costs and environmental consequences of current control practices have led many weed scientists and crop producers to seek alternate management strategies. A goal for weed science should be to develop systems that give producers more options for weed control. Weed populations respond to all cropping practices. Therefore, even within an annual cropping cycle, weed pressures can be reduced through alteration of agronomic practices. Fall-seeded cover crops have reduced winter-annual weed populations the following spring. Likewise, early spring-seeded cover crops have been shown to reduce summer-annual weed biomass 40 days after planting corn. Use of smother plants, a type of weed-competitive cover crop grown concurrently with corn and soybean early in the season, has produced variable results among locations, years, smother plant species, and weed pressure. In some instances, grain yields of smother plant treatments were equal to weed-free crops, while at other times yields were as low as the weedy crop. Although smother plants have demonstrated their potential to control weeds, practices that reduce weed pressure before crop planting could enhance the reliability of this tactic, and ensure the maintenance of primary crop yields. Greater understanding of the interactions among cover crops, smother crops, and weeds may help in the development of modern, competition-based weed management systems. The added knowledge of weed biology and ecology from this type of research will provide information and practices that farmers can use to develop more effective and diverse weed management systems.