2020
Waterhemp Control from Soil Residual Herbicides in Micro-Rate Combinations
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Contributor/Checkoff:
Minnesota Soybean Research and Promotion Council
Category:
Sustainable Production
Keywords:
AgricultureCrop protectionHerbicide
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Andrew Lueck, Next Gen Ag, LLC
Co-Principal Investigators:
Project Code:
10-15-44-20227
Contributing Organization (Checkoff):
Minnesota Soybean Research and Promotion Council
$12,150
Institution Funded:
Next Gen Ag, LLC
$12,150
Brief Project Summary:

Soybean growers continue to look for ways to decrease input costs, and herbicide resistant weeds continue to affect yield while new resistant biotypes continue to evolve due to limited post-emergent herbicide options. 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. A micro-rate soil applied residual herbicide program could significantly reduce cost and soybean injury while providing effective waterhemp control. Increased sites of action in soil residual herbicide use will decrease selection pressure...

Unique Keywords:
#weed control
Information And Results
Project Deliverables

A protocol will be created and results analyzed utilizing ARM data management software (randomization program that allows building of treatments and data entry). A known ALS, PPO, and EPSP resistant waterhemp population will be tested near Renville (Lueck 2019). Soybean will be seeded at 140,000 plants per acre on 30” row spacings with plant dates that align with grower timelines. Trial will be 30 treatments (see table below) and four replications in a randomized complete block design. Plots are 10 feet wide (4 rows) by 40 feet in length. Trial area is 1.4 acres (300L x 200W) with alleys. Pre-emergence herbicide applications will be done utilizing a bike sprayer with a six nozzle 20-inch spaced boom. Treatments will be applied through 110002 AIXR nozzles at 15 GPA volume pressurized by CO2 to the middle 2 rows. Section 3 (Clethodim) will be broadcasted at 4 fl oz/A plus 1.5 pt/A oil adjuvant to control volunteer corn and other biologically similar weeds if necessary. Waterhemp control and soybean injury will be visually rated in comparison to the running checks (untreated rows between plots) at 15, 30, 45, and 60 days after application as a qualitative metric. Soybean yield will be taken as pod counts. The trial will occur near Renville, MN. Project timeline is one year.
Treatments will be structured as one of three categories: 1) evaluated herbicides with a standard curve equation at 50% waterhemp control and application rate of 65% or less, as compared to the 1X rate, were built into 3 and 4 combination treatments (1-14); 2) evaluated herbicides with a standard curve equation at 75% waterhemp control and application rate of 75% or less, as compared to the 1X rate, were built into 2 and 3 combination treatments (15-22); or 3) evaluated herbicides with a standard curve equation at 100% waterhemp control and application rate of 100% or less, as compared to the 1X rate, were built into 2 combination treatments (23-26). Remaining treatments (27-30) are the least expensive treatments from 1 thru 26 that include a single EPOST application of Flexstar at V2.

Final Project Results

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.