2024
Do Micronutrient Fertilizers Help Reduce Herbicide Injury and Impact Weed Control?
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
FertilizerField management Herbicide
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Mark VanGessel, University of Delaware
Co-Principal Investigators:
Project Code:
24A01380
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
The goal of this research will be to provide growers with better recommendations for soybean safety; this is research will pertain to both early planting dates as well as traditional planting times.
Key Beneficiaries:
#farmers
Unique Keywords:
#micronutrient, #weedcontrol
Information And Results
Project Summary

As herbicide-resistant weeds continue to develop and spread, farmers struggle to find effective herbicides that maintain a high level of crop safety. Often farmers need to use additional herbicides to achieve good weed control, while sometimes sacrificing crop safety. In recent years, companies have advertised nutritional or microbial products that can be added to postemergence herbicides that might improve crop safety and enhance weed control. These types of products can be used for both agronomic and horticultural crops. Local extension personnel have been asked about them but there is no local data for these types of products. Unfortunately, there is limited university data evaluating these products and thus little we can say to help make informed decisions.

It stands to reason that if an additive improves crop safety, it could impact weed control. If an additive improves the recover rate of a soybean plant, then an injured weed is likely to recover as well. This question has been asked, but there is no information to address it.

To evaluate the utility of these types of products, we propose using herbicide mixtures that represent a range of herbicides for soybean response with different nutrient additives. Benefits to state and regional soybean farmers include information in extension guides and other educational resources on benefits of micronutrient additives to herbicides for weed control and crop safety.

Penn State University will also do this trial, providing us with two locations and allow us to evaluate the consistency of the results across different growing conditions.

Project Objectives

The objectives of this research will be to evaluate:
• the relative crop safety of many of the common soybean herbicides
• potential interactions if herbicides are used in combination with other herbicides
• the effect of planting date on soybean safety

Project Deliverables

Procedures to Achieve Objectives:
Evaluating all herbicides and micronutrient combinations is not practical given the number of products available. We have selected common herbicide tank mixtures that represent multiple herbicide groups for Enlist and conventional soybeans. Discussions with farmers and viewing online resources, the most commonly used nutritional products were primarily macronutrients, primarily micronutrients, or contained both macro- and micro-nutrients. As a result, we will select one product from each of these categories. The specific products often mentioned herbicide recovery in their promotional literature.
Herbicides are selected based on previous UD Weed Science Herbicide Trials and include a mixture of Roundup PowerMax3 plus Liberty plus Enlist One. Herbicide mixture for the conventional soybean scenario is Basgaran plus Reflex plus Select Max.
Adjuvants will be used as recommended.
Nutritional products will be used at rates recommended by the manufacturer for soybean production. These products label do not specify timing so they will be applied at the 4th trifoliate stage of the soybeans which correspond to the optimum timing for postemergence herbicide application for weed control.
Applications will be made at 20 g/A. Plots will be evaluated for crop response and weed control on a weekly basis until 4 weeks after treatment. Further ratings will be made as needed. Plots will be harvested to determine impact of injury on yield.

Data Analysis:
Trial will be conducted as a small-plot replicated trial. Data will be analyzed in a statistically sound procedure, based on the design of each study. Yield and injury for a specific variety will be compared to the untreated plots of the same variety. All trials will be replicated four times.

Dissemination of Results:
Reports of this study will be disseminated through extension presentations and be used to develop weed control recommendations. Research plots will be highlighted on field tours at the Research and Education Center. Information will be included in the Mid-Atlantic Weed Management Guide. An annual report will be available through the UD Weed Science Website (http://extension.udel.edu/ag/weed-science/weed-science-reports/).

Progress Of Work

Updated August 5, 2024:
All research treatments have been applied, plots have been rated on a regular basis. Research has been discussed at the Weed Science Field Day in June 2024.

Final Project Results

Benefit To Soybean Farmers

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.