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Monday, November 2, 2009
Convention Center, Exhibit Hall BC, Second Floor
Abstract:
Conservation tillage practices and herbicide tolerant corn and soybean have been widely adopted by US agricultural producers. These systems have reduced the potential for soil and nutrient losses, but have relied heavily on herbicides for weed management. Increase dependence on herbicides can lead to herbicide resistant weeds including ALS and glyphosate resistant horseweed, common and giant ragweed, and other weeds across the corn and soybean belt. Increased concerns about preventing and controlling herbicide resistant weeds has created the need to integrate nonchemical management tactics, while maintaining key soil conservation practices in corn and soybean.
The objective of this study was to evaluate mechanical tillage implements for their incorporation into an integrated weed management system in high-residue corn and soybean. Ten individual treatments were included that evaluated a vertical coulter implement, a rotary harrow, a high residue rotary hoe, and a high residue row cultivator in combination with pre-plant broadcast, pre-plant band, or post emerge herbicides. Conventional no-till treatments completely reliant on herbicides and a weedy check were included for comparison.
Similar results were observed in both corn and soybean studies. The vertical coulter combined with the rotary harrow controlled weeds similar to the glyphosate burndown application. Three passes with a rotary hoe was not as effective as the broadcast pre-emergence herbicides, but did reduce weed density by about 40%. The inter-row cultivator had significantly higher weed biomass compared to the post herbicide, but there was no difference between the cultivator plus a banded pre-emergence and a post herbicide treatment.
Overall, mechanical tillage implements in an integrated weed management system in high-residue corn and soybean systems have the potential to reduce herbicide use while maintaining weed control and reducing the potential for evolution of herbicide resistant weeds.
The objective of this study was to evaluate mechanical tillage implements for their incorporation into an integrated weed management system in high-residue corn and soybean. Ten individual treatments were included that evaluated a vertical coulter implement, a rotary harrow, a high residue rotary hoe, and a high residue row cultivator in combination with pre-plant broadcast, pre-plant band, or post emerge herbicides. Conventional no-till treatments completely reliant on herbicides and a weedy check were included for comparison.
Similar results were observed in both corn and soybean studies. The vertical coulter combined with the rotary harrow controlled weeds similar to the glyphosate burndown application. Three passes with a rotary hoe was not as effective as the broadcast pre-emergence herbicides, but did reduce weed density by about 40%. The inter-row cultivator had significantly higher weed biomass compared to the post herbicide, but there was no difference between the cultivator plus a banded pre-emergence and a post herbicide treatment.
Overall, mechanical tillage implements in an integrated weed management system in high-residue corn and soybean systems have the potential to reduce herbicide use while maintaining weed control and reducing the potential for evolution of herbicide resistant weeds.