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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Research Project #429921

Research Project: Novel Weed Management Solutions: Understanding Weed-Crop Interactions in Northern Climates

Location: Sunflower and Plant Biology Research

Project Number: 3060-21220-029-000-D
Project Type: In-House Appropriated

Start Date: Oct 1, 2015
End Date: Sep 30, 2020

Objective 1: Identify, at the genome and physiological levels, plant-plant interactions that impact plant growth and lead to crop yield losses, especially crop-weed interactions that occur during the critical weed-free period, and interactions that occur between the different crops inter-planted in relay cropping systems, such as corn, soybeans, or sunflowers relayed with camelina, ryegrass, or canola. [NP304, Component 2, Problem Statement 2A3] Sub-objective 1.A: Determine the parameters for evaluating the impacts of winter annual cover crops on corn, sunflower, and Amaranthus spp. productivity. Sub-objective 1.B: Identify physiological and molecular mechanisms that control interactions between cover crops and corn, sunflower, and Amaranthus spp. Sub-objective 1.C: Evaluate impacts of candidate genes on cover crop-relay crop and cover crop-weed interactions. Objective 2: Determine the molecular and physiological mechanisms by which winter annual cover crops suppress weeds in northern temperate agroecosystems, and identify genes that will enhance weed suppression in these crops, such as genes associated with weed-tolerance, cover-crop tolerance, and cold hardiness. [NP304, Component 2, Problem Statement 2A3] Sub-objective 2.A: Identify genetic markers for improving the weed-suppressing trait of winter hardiness in winter canola and/or camelina varieties. Sub-objective 2.B: Evaluate the weed-suppressing traits of winter-hardy canola and camelina in the field.

Weeds are major pests of agro-ecosystems that reduce production of the nation’s food, feed, fiber and fuel crops. The industry-adopted practice of rotating crops with engineered tolerance to a limited set of herbicides continues to put selection pressure on the evolution of herbicide-resistant weeds. As part of a holistic and sustainable approach to managing weeds in temperate agro-ecosystems, we propose to identify cover crop-relay crop interactions to enhance relay crop productivity, cover crop-weed interactions to enhance weed suppression, and identify winter-hardy annual cover crops that suppress weeds in relay cropping systems. In this proposal, winter canola will serve a dual purpose as both a cover crop for evaluating weed suppression, and as a surrogate weed for weed-relay crop interactions. Our model relay cropping system consists of inter-seeding a commodity crop (corn or sunflower) into an established cover crop (winter canola) such that their lifecycles overlap. Currently, no winter-hardy annual broadleaf cover crops are economically suited for weed suppression in relay cropping systems in the upper Midwest (UMW) and Northern Great Plains (NGP). Consequently, the objectives of this project are: (1) elucidating regulatory signals and pathways associated with cover crop-relay crop and cover crop-weed interactions that impact plant productivity, and (2) identifying economically suited winter-hardy broadleaf cover crops that suppress weed establishment in inter-seeded relay crops. These objectives will be accomplished through the use of physiological, molecular, and genomic approaches, with the long-term goals of revolutionizing weed management practices.