2018
Control of Pigweed with an Integrated Systems Approach in Soybean
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Contributor/Checkoff:
Kansas Soybean Commission
Category:
Sustainable Production
Keywords:
AgricultureCrop protectionHerbicide
Parent Project:
Control of Pigweed with an Integrated Systems Approach in Soybean.
Lead Principal Investigator:
Anita Dille, Kansas State University
Co-Principal Investigators:
Project Code:
1880
Contributing Organization (Checkoff):
Kansas Soybean Commission
$35,578
Institution Funded:
Kansas State University
$35,578
Brief Project Summary:

Pigweed emergence and growth coincides closely with soybean emergence, creating an immediate situation for crop and weed competition. Uncontrolled pigweed can produce an abundance of seed, greatly impacting weed control effectiveness for many years. And pigweed resistance ALS-inhibitor and glyphosate herbicides has developed. The objective of this project is to evaluate an integrated systems approach of using row-crop cultivation, reduced row width, cover crops, and glufosinate with residual herbicides to build a means for farmers to implement sustainable pigweed control.

Key Benefactors:
farmers, applicators, ag retailers, extension specialists

Information And Results
Project Deliverables

Expected outcomes from this research project:
1. Understand the effects an integrated systems approach to manage pigweed in Liberty-Link soybean to facilitate sustainability for soybean growers.

2. Make confident recommendations about the use of narrow soybean row width and cover crops to decrease pigweed emergence and growth.

3. Generate applicable extension presentations to communicate the findings of this experiment to soybean producers and agronomy professionals to facilitate pigweed control and thereby increase soybean yield and Kansas grower profitability.

Final Project Results

Update:
All field trials have been completed. See attached report for details. One Extension publication is near final publication and is attached (MF3448 Pigweed).

View uploaded report Word file

View uploaded report 2 PDF file

All treatments containing the herbicide program component resulted in excellent (> 97%) pigweed control which demonstrates the importance of using overlapping residual herbicides with multiple effective sites of action. Treatments containing row-crop cultivation (RC) tended to reduce pigweed density and biomass at 3 and 8 weeks after planting (WAP) in all locations compared to the 30-inch row width no cover crop treatment. Mixed results were observed when the effect of winter wheat cover crop (CC) was considered: in about half of the site-years, CC provided approximately 50% reductions in pigweed density and biomass whereas in the remainder CC provided no change to an increase in pigweed density. Decreased row widths achieved the most consistent results by reducing pigweed biomass at 8 WAP when data were pooled across location: decreasing row widths from 30-inches to 15-inches resulted in a 23% reduction whereas decreasing from 15-inches to 7.5-inches achieved a 15% reduction. In conclusion, RC should be incorporated where possible as a mechanical option to manage pigweed, and decreased row widths should be used when economically feasible to suppress late season pigweed growth. CC achieved inconsistent pigweed control in this research and should be given special consideration prior to implementation. The integral use of these components with an herbicide program as a system should be recommended to achieve the best pigweed control as well as reduce the risk of resistance.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.