2022
Utility of an Oat Cover Crop for Iron Deficiency Chlorosis and Waterhemp Management
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
AgricultureCrop protectionHerbicide
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Joseph Ikley, North Dakota State University
Co-Principal Investigators:
Project Code:
QSSB
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
Herbicide-resistant waterhemp is problematic for many North Dakota soybean farmers as it can germinate throughout the growing season. Obtaining a crop canopy is an important part of waterhemp management. Iron deficiency chlorosis (IDC) can delay canopy closure and prolong the waterhemp germination window in fields with IDC issues. Oats can be inter-seeded into soybeans to help alleviate IDC symptoms and fall-seeded cereal rye can suppress early-season flushes of waterhemp. This project will look at the early-season companion crop suppression capabilities of spring-seeded oats, and the role oats play in late-season waterhemp management.
Key Beneficiaries:
#agronomists, #cover crop applicators, #extension specialists, #farmers
Unique Keywords:
#cover crops, #iron deficiency chlorosis, #weed control, #weed management
Information And Results
Project Summary

Herbicide-resistant waterhemp continues to spread and is problematic for many North Dakota soybean farmers. Waterhemp will germinate throughout the growing season, which means obtaining a crop canopy is an important part of waterhemp management. Iron deficiency chlorosis (IDC) is an agronomic problem that can delay canopy closure in many soybean fields in North Dakota, which can also prolong the window for waterhemp germination in fields that have IDC issues. Oats can be inter-seeded into soybeans to help alleviate IDC symptoms. Fall seeded cereal rye can suppress early-season flushes of waterhemp, but spring-seeded oats have not been evaluated for waterhemp suppression. This project will look at the early-season companion crop suppression capabilities of a spring-seeded oat cover crop, as well as the role the oat companion crop can play in late season waterhemp management due to quicker canopy closure of soybeans not stressed by IDC.

Project Objectives

1) Evaluate oat suppression of waterhemp in soybean.
2) Evaluate the time from planting to canopy closure of IDC-sensitive soybean with and without an oat cover crop, and the effect of earlier canopy closure on late-season waterhemp management.
3) Evaluate the optimal termination timing of an oat cover crop to alleviate IDC symptoms and reduce yield loss due to direct competition of the cover crop with soybean

Project Deliverables

Extension bulletin addressing the use of barley or oats in a systems-approach to alleviate IDC in soybean with the overall goal of waterhemp management.
-Results will be shared at Extension meetings and Scientific meetings.
-Trials will be on display at Weed Science Field Days that are open to the public.

Progress Of Work

Updated December 1, 2021:

View uploaded report Word file

Final Project Results
Benefit To Soybean Farmers

This project will evaluate additional options for waterhemp control beyond sole reliance on herbicides. This will be important moving forward since resistance to most commercially available herbicides has been found in waterhemp across the US, and there is no new mode of actions coming to market in the near future. We currently do not have 2,4-D or dicamba resistance in waterhemp in North Dakota. If successful, the research will also help preserve new soybean technologies by offering additional waterhemp management tools that can also alleviate negative effects of IDC in soybean.

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.