HERBICIDE RESISTANT WEEDS IN OKLAHOMA CROPPING SYSTEMS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1019627
• Project Start Date: Oct 1, 2019
• Project End Date: Sep 30, 2024
• Program Code: [(N/A)]- (N/A)

Recipient Organization
OKLAHOMA STATE UNIVERSITY
(N/A)
STILLWATER,OK 74078

Performing Department
Plant & Soil Sciences

Non Technical Summary
Herbicide resistance is one of the biggest threats to Oklahoma crop production and the economic viability to Oklahoma producers. Over 7 million acres of annual crops are harvested each year in Oklahoma, adding over 1.5 billion dollars to the state economy. Therefore, any risk to this industry ultimately puts the state at risk economically. Jussaume and Ervin (2016) stated that escalating weed resistance to herbicides is bringing significant social, environmental, and economic risk and challenges to the entire agricultural industry. Additionally, growers are experiencing higher production cost and/or lower yields reduced yields.The International Survey of Herbicide Resistant Weeds lists over 250 weed species in over 90 crops occurring in 70 countries. This has affected over 150 different herbicides from 23 of the 26 known herbicide sites of action. These issues along with the development of new herbicides and herbicide technologies make weed research a vital need for producers across the United States. The need for weed science research is important to both Oklahoma producers and the Oklahoma economy. With agriculture being a major component of the Oklahoma economy research that can protect this industry and assist it from both an economic as well as a sustainable need should be a concern and important to citizens of both Oklahoma and the United States. This project will look to enhance the knowledge base regarding weed management and the prevention or management of herbicide-resistant weeds to better assist weed practitioners.

Animal Health Component

100%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
213	2410	1140	100%

Knowledge Area
213 - Weeds Affecting Plants;

Subject Of Investigation
2410 - Cross-commodity research--multiple crops;

Field Of Science
1140 - Weed science;

Keywords

weed managment

herbicide

herbicide resistance

cotton

soybean

summer crops

Goals / Objectives
1. Development of effective weed management programs for soybean production systems.2. Development of effective weed management programs for cotton production systems.3. Evaluate weed management options in other summer crops in Oklahoma.

Project Methods
Objective 1: Research will be established near Bixby, Chickasha, Lane, and Haskell to evaluate weed management systems that most effectively control problem weeds in soybean. These locations represent different environments based on both soil type and climatic conditions.1. Roundup Ready Xtend Soybean is currently becoming the most widely adapted soybean technology in Oklahoma as well as the rest of the United States. Herbicide programs will be evaluated that investigate other herbicide modes-of-action applied preemergence and postemergence either alone or in combination with dicamba. 2. Other soybean technologies will be evaluated to determine their fit and effectiveness as overall weed management programs. These technologies will also be evaluated with other herbicide mode-of-action to help battle resistance development to these technologies.Objective 2:Research will be established near Altus and Fort Cobb to evaluate herbicide programs that most effectively control problem weeds in cotton. There are differences in soil type and irrigation methods that can be investigated as part of a weed management system at these locations.1. Roundup Ready Xtend Cotton is the number one most widely used herbicide-tolerant trait in the southwest. This technology will be evaluated to determine overall herbicide programs that can most effectively be used to not only control weeds but help sustain these systems for long term use.2. Enlist Cotton is being adapted by many growers in Oklahoma as a weed management tool. Herbicides programs will be investigated to determine an effective weed management approach with this technology. Objective 3:Research will be conducted near Bixby, Chickasha, Fort Cobb, and Lane to evaluate herbicide performance and programs in various summer crops. This research will be based on new herbicides or technologies that are developed in these crops.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The target audience that was reached by our efforts included: producers, consultants, and agricultural industry representatives. Each of these individual audiences was provided information to assist in understanding and managing herbicide-resistant weeds in Oklahoma. Changes/Problems:We typically have in-person training and field days in which we allow various segments of agriculture to view our research. We did not have any in-person showcases this year. We did participate in two virtual field days this year. What opportunities for training and professional development has the project provided?We are currently training one Ph.D. graduate student as part of the project. 2020 has been an exception, but we also typically have training for consultants and industry representatives showcasing our research work. How have the results been disseminated to communities of interest?We make our results available to commodity groups, producers, consultants, and industry representatives through personal contact and through extension meetings. We did not have any actual face to face meetings this summer. What do you plan to do during the next reporting period to accomplish the goals?We will continue to develop programs that evaluate herbicide programs to best control pernicious weeds in Oklahoma summer cropping systems.

Impacts
What was accomplished under these goals? 1. We continue to evaluate weed management programs for soybean production systems. We have shown that the Xtend and the Liberty-Link soybean systems can be effectively used to manage weeds in Oklahoma. We have also conducted research that has indicated how important a residual herbicide program is important to both these systems. We are also currently investigating the XtendFlex system which allows the use of three over-the-top herbicides in soybean (dicamba, glyphosate, and glufosinate). 2. We have evaluated tank-mix combinations for residual weed management in cotton production systems. These have been very effective tools in both the Xtend and Enlist Cotton weed management programs. The most effective of these have been those that include fomesafen alone or in combination with other residual herbicides. 3. We also continue to evaluate residual and postemergence weed management programs in peanut, grain sorghum, and corn. This research has shown that a program approach is critical for weed management in these systems especially in peanut and grain sorghum.

Publications