Managing Glyphosate Resistant Canada Fleabane with Cover Crops and Tillage

Nov 20, 2018

My colleague Dr. Clarence Swanton (University of Guelph) used to say that based on research he did in the 1980’s, one should not expect to control weeds with cover crops. Their utility was in preventing soil erosion and improving soil health but not in significantly reducing weed populations. However, Dr. Swanton has had to re-think his long-held position on cover crops and weed control is given recent observations from on-farm research trials where fall-seeded cereal rye has reduced glyphosate-resistant Canada fleabane populations.

University of Guelph graduate student Ted Vanhie, under the supervision of both Swanton and Dr. François Tardif, are looking at an integrated approach to the control of glyphosate-resistant Canada fleabane using tillage, herbicides and fall seeded cereal rye. The concept being that frost seeding fall rye ahead of soybeans could significantly reduce populations of this weed and improve herbicide control. Below are observations Mr. Vanhie has made during the spring of 2018.

Fall tillage followed by planting cereal rye resulted in the best control of glyphosate-resistant Canada fleabane in the absence of herbicides. (Figure 1)

Although glyphosate-resistant Canada fleabane was still found in no-till fall-seeded cereal rye, there were fewer and smaller plants compared to where no cereal rye was established and no fall tillage operation performed. (Figure 2 and 3).

Control of Canada fleabane with herbicides was improved in no-till plots where cereal rye was established (Figure 4 – preliminary data from Ted Vanhie)

Cereal rye at 50-60 lbs/acre provides little ground cover and shading. It is speculated that there is allelopathy inhibiting recruitment of glyphosate-resistant Canada fleabane (Figure 5). Further experiments will test this hypothesis.

Source : OMAFRA

Video: Evolution of Beef Cattle Farming

The Clear Conversations podcast took to the road for a special episode recorded in Nashville during CattleCon, bringing listeners straight into the heart of the cattle industry. Host Tracy Sellers welcomed rancher Steve Wooten of Beatty Canyon Ranch in Colorado for a wide-ranging discussion that blended family history and sustainability, particularly as it relates to the future of beef production.

Sustainability emerged as a central theme of the conversation, a word that Wooten acknowledges can mean very different things depending on who you ask. For him, sustainability starts with the soil. Healthy soil produces healthy grass, which supports efficient cattle capable of producing year after year with minimal external inputs. It’s an approach that equally considers vegetation, animal efficiency, and long-term profitability.

That philosophy aligned naturally with Wooten’s involvement in the U.S. Roundtable for Sustainable Beef, where he served as a representative for the Colorado Cattlemen’s Association. The roundtable brings together the entire beef supply chain—from producers to retailers—along with universities, NGOs, and allied industries. Its goal is not regulation, Wooten emphasized, but collaboration, shared learning, and continuous improvement.