2023
2023 Continued Evaluation of Waterhemp Control and Crop Injury in Two-Pass Conventional Variable Rate Tank Mix (CVRTM) Herbicide Programs in Soybean
Category:
Sustainable Production
Keywords:
AgricultureCrop protectionHerbicide
Lead Principal Investigator:
Andrew Lueck, Next Gen Ag, LLC
Co-Principal Investigators:
Project Code:
10-15-44-23137
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
Modern soybean genetics, such as glyphosate, dicamba, glufosinate, 2, 4-D, and HPPD-tolerant soybeans, provide herbicide tolerance to increase post-emergence weed control options. Misapplication and overuse of these herbicides has led to selection pressure in waterhemp. Soil-applied residuals are effective as the herbicide is absorbed into the weed at emergence. This project focuses on the continued development of conventional variable rate tank mix programs and objectives achieved through two application studies. The first study will be new as yield has not been taken in the past on these combinations. The second study is repeated to collect multiple year data.
Key Beneficiaries:
#ag retailers, #agronomists, #applicators, #farmers
Unique Keywords:
#herbicides, #weed control, #weed management
Information And Results
Project Summary

Soybean growers continue to look for ways to decrease input costs through herbicide program selection, unfortunately, herbicide resistant weeds continue to affect yield while new resistant biotypes continue to evolve due to limited post-emergent herbicide options. Modern soybean genetics, such as glyphosate (i.e. Roundup), dicamba (i.e. Xtendimax), glufosinate (i.e. Liberty), 2, 4-D, and HPPD (i.e. Callisto) tolerant soybeans, provide herbicide tolerance to increase post-emergence weed control options. However, misapplication and overuse of post-emergent herbicides has led to selection pressure in waterhemp populations. Soil applied residuals are effective as the herbicide is absorbed into the weed at the most vulnerable stage of growth, emergence.
This grant focuses specifically on the continued development of Next Gen Ag conventional variable rate tank mix (CVRTM) programs and objectives achieved through two studies: 1) CVRTM combination soybean injury and yield impact; and, 2) PRE vs. PRE fb EPOST CVRTM combination efficacy. The first study will be new in regards to yield has not been taken in the past on these combinations. The second study is repeated from 2021 and 2022 in an effort to collect data across years and environment and will be conducted at the research farm in Renville, MN, with seed and chemical provided by supporting industry partners.

Project Objectives

1. GOAL : Achieve non-significant yield differences in the crop safety study.
OBJECTIVE #1: Evaluate visual crop injury during growing season.
OBJECTIVE #2: Evaluate CVRTM combinations for yield impact. Achieve non-significant differences.

2. GOAL : Achieve 95% Waterhemp Control at 75 DAA in the efficacy study.
OBJECTIVE #1: Develop a summative treatment list for 95% waterhemp control via CVRTM supported residual herbicide program in soybean. Rate step ups and different application timings for products will be evaluated.
OBJECTIVE #2: Evaluate CVRTM combinations of residual herbicides applied PRE only and maintain 95% waterhemp control 75 DAA.

3. GOAL : Achieve Effective Control at Viable Economic Costs
OBJECTIVE #1: Conduct an estimated cost per treatment evaluation utilizing local elevator price lists combined with the North Dakota Weed Guide product addendum for ball park cost estimates. With such a volatile economic state region, supplier, and availability will create unpredictable price points.

4. GOAL : Provide Multi-Faucet Knowledge Transfer Opportunities

Project Deliverables

Evaluation of success will be determined by 1) objectives achieved; 2) no error application; 3) number of attendees at speaking appointments; 4) feedback from collaborating parties.

Progress Of Work

Update:
See uploaded file below.

View uploaded report Word file

Update:
See attached final data summaries. Ag Expo appearance will conclude grant obligations.

View uploaded report PDF file

Final Project Results

Update:
See attached final data summaries. Ag Expo appearance will conclude grant obligations.

View uploaded report PDF file

View uploaded report 2 PDF file

In 2023, sulfentrazone containing treatments averaged 42.8 bushels of soybean per acre, while non-sulfentrazone containing treatments averaged 46.0 bushels of soybean per acre. However, sulfentrazone containing treatments also tended to have increased weed control compared to non-sulfentrazone containing treatments. This is likely due to sulfentrazones higher solubility characteristics compared to Valor SX(flumioxazin), Warrant (encapsulated acetachlor), or Zidua SC (pyroxasulfone) which means it activates in the soil with less rainfall. Only 2 inches of rain occurred from preemergence application to last evaluation (75 days). In a year with more significant early rainfall, one may have observed increased impact of Valor SX+Warrant preemergence combo injury, however, in 2023 that combination did not appear to have an impact on soybean yield.

After 3 years of data, growers could consider applying the residual CVRTM approach PRE as a potential cost and time saving one-time application in years with average early rainfall. However, in years with below average early rainfall the grower must be prepared to utilize a two-pass approach that includes a contact or systemic product. This conventional program is universal across all soybean genetics minimizing tank cleanout events for operations that grow multiple herbicide tolerant soybean genetics. Next Gen Ag LLC is responsible for conducting and summarizing information, but is not liable for any decisions made on the basis of this study or publication.

This publication and more MSRPC funded research conducted by Next Gen Ag LLC can be found online at www.nxtgenag.com under the “Latest News” tab and “Public Grant Research Studies” page.

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.