Due to rapid evolution and spread of herbicide resistance in Palmer amaranth and gradual decrease in the number of effective herbicides in soybean to control this problem weed, results of this study will help growers to make a robust herbicide program in Roundup Ready and Liberty Link soybeans, as well as in the new herbicide-tolerant cultivar such as Roundup Ready 2 Xtend, Enlist, and Balance GT.

1. Compare weed control, crop safety, soybean yield, and gross profit-margins of different herbicide programs in Liberty Link, Roundup Ready 2 Xtend, Balance GT, and conventional soybeans. Field experiments will be conducted at Clay Center, Concord, Lincoln, North Platte, and Scottsbluff.

2. Determine the effect of soybean production practices and herbicide programs for control of glyphosate-resistant Palmer amaranth in Roundup Ready 2 Xtend, Balance GT, and Enlist soybeans. Field experiments will be conducted at grower's field infested with glyphosate-resistant Palmer amaranth at Carleton, Thayer County.

3. Determine critical period of weed removal in soybean affected by pre-emergence soil applied herbicide. Field experiments will be conducted at Clay Center, Concord, and Scottsbluff.

• An Extension Field Day will be organized at glyphosate-resistant Palmer amaranth research site near Carleton, Thayer County for on-site demonstration of research results to growers, extension educators, and other interested stakeholders.
• This study will be conducted not only to find out the management solution for glyphosate-resistant Palmer amaranth in Nebraska, but also to create state-wide awareness about this troublesome weed species as well as best management practices for management.
• An Extension Field Day will be organized at South Central Ag Lab near Clay Center for on-site demonstration of research results to the growers, extension educators, and other interested stakeholders.
• Four NebGuide publications will be prepared on variety of topics including ‘control of glyphosate-resistant Palmer amaranth in soybean’, ‘Economics of weed control in Xtend, Balance GT, and Enlist soybean’ based on the results of this project, etc.
• Four papers will be published in peer-reviewed journals (Weed Science and Weed Technology) from the results of this project.
• A number of oral presentations will be made to disseminate information from the results of this project to growers, extension educators, and other interested stakeholders during the Crop Production Clinics, Field Days and by writing articles for the CropWatch, Corn & Soybean Digest, Nebraska Farmer, and Nebraska Soybean.
• Time lapse videos will be prepared to emphasize “importance of residual herbicides for weed control in soybean” and “critical period of weed removal in soybean affected by residual herbicide.” The videos will be presented during extension meetings and will be made available on YouTube.

Updated February 12, 2021:

View uploaded report

This is a novel research project. This project will have a direct impact on Nebraska soybean growers. Due to rapid evolution and spread of glyphosate-resistant weeds, results of this study will help growers to make a robust herbicide programs in Roundup Ready and Liberty Link soybeans, as well as in the new herbicide-tolerant cultivars such as Roundup Ready 2 Xtend, Enlist, and Balance GT soybean.
• An Extension Field Day will be organized at glyphosate-resistant Palmer amaranth research site near Carleton, Thayer County for on-site demonstration of research results to the growers, extension educators, and other interested clientele.
• An Extension Field Day will be organized at South Central Ag Lab for on-site demonstration of research results to the growers, extension educators, and other interested stakeholders.
• Four NebGuide publications will be prepared on variety of topics including ‘control of glyphosate-resistant Palmer amaranth in soybean’, ‘Economics of weed control in Xtend, Balance GT, and Enlist soybean’, etc. based on the results of this project.
• Four papers will be published in peer-reviewed journals (Weed Science and Weed Technology) from the results of this project.
• A number of oral presentations will be made to disseminate information from the results of this project to growers, extension educators, and other interested stakeholders during the Crop Production Clinics, Field Days and by writing articles for the CropWatch, Corn & Soybean Digest, Nebraska Farmer, and Nebraska Soybean.
• Time lapse videos will be prepared to emphasize “importance of residual herbicides for weed control in soybean” and “critical period of weed removal in soybean affected by residual herbicide”. The videos will be presented during extension meetings and will be made available on YouTube.