GFM Network News


A field sample of wild oat screened with three chemical families within the Group 1 mode of action by the Tardif lab. Note there is resistance observed when Puma (a “fop”) was applied, moderate resistance when Achieve (a “dim”) was applied and moderate susceptibility when Axial (a “den”) was applied.

Pest Patrol: Herbicide-resistant wild oats in spring cereals

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 4 minutes Q. Are there any solutions to control herbicide resistant wild oats in spring cereals? A. Wild oats have been an undesirable weed in spring cereal crops for many years, and its control has been limited to a handful of herbicides within the same mode of action (specifically, WSSA herbicide Group 1). Until recently, there have […] Read more

Figure 1. The white fluffy growth on Canada fleabane rosettes following several weeks in the cool and wet environment of the vernalization chamber.

Pest Patrol: White mould and Canada fleabane

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes I could barely contain my excitement. What was this fluffy white stuff that had taken down large fleabane rosettes? Had I accidentally stumbled upon an effective biocontrol option for glyphosate-resistant Canada fleabane? I wondered, what would it take to reproduce this potent material so we could inoculate plants throughout Ontario? I quickly took a sample […] Read more


Figure 1. Canada fleabane leaf injury caused by 28 per cent UAN.

Pest Patrol: Using 28 per cent to manage Canada fleabane

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes I’m thankful that farmers and agronomists share their ideas, experiences and questions with me as it relates to killing weeds. During the winter months I’ll test out ideas in the greenhouse to see if they’re worth taking to the field. I’m fortunate that we have some great public-sector researchers (such as Dr. Page, Dr. Sikkema […] Read more

Corteva to accelerate Enlist E3 soybean rollout

Reading Time: 2 minutes Chicago | Reuters — U.S. seed and crop chemical maker Corteva said Thursday it will accelerate production of its next-generation biotech soybean seeds and complementary herbicides in Canada and the U.S. over the next five years. The move heightens the competition for sales to farmers with rivals Bayer and BASF. Up to 20 per cent […] Read more


Figure 1: Unsprayed control.

Controlling scentless chamomile with herbicides

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes Several herbicide treatments were evaluated in a 2019 on-farm research trial to determine best management options for scentless chamomile, a weed with a reputation for being difficult to control. Although 10 treatments provided greater than 80 per cent visual control of emerged plants, new seedlings continued to emerge several weeks after application, resulting in a […] Read more

The trouble with identifying waterhemp in the field is that growers often dismiss it as one of the other pigweed species.

The latest on waterhemp

Incredibly, the weed is already resistant to four modes of action in Ontario, with more in danger

Reading Time: 6 minutes In U.S. farm media circles, it seems that every week there’s another report, another bulletin, another research paper about waterhemp. Often it’s a confirmation of another find in a midwest county or state. More recently, reports indicate the weed is resistant to seven different modes of action with the latest — Group 15 herbicides — […] Read more


As much as companies have been communicating on stewardship, there are still issues in using newer technologies.

Are crop trait technologies simplifying your life, or complicating it?

Deciding how to use the technologies can turn into more of a challenge than deciding which of them to use

Reading Time: 6 minutes The arrival of a new herbicide-resistant technology is often greeted as an opportunity for growers and the industry. That isn’t really new. Roughly 30 years ago, Group 2 herbicides solved the problem of atrazine resistance, then LibertyLink and Roundup Ready technologies enabled growers to push beyond Group 2 resistance. Now that Xtend and Enlist systems […] Read more

Figure 1: Light green waterhemp plants approaching the top of the soybean canopy after two applications of glyphosate that proved ineffective. At this stage, no herbicide will adequately control waterhemp.

Pest Patrol: Plan to manage waterhemp in 2020

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes Waterhemp has spread further across Ontario during the 2019 season and can now be found in eight counties (Bruce, Chatham-Kent, Essex, Haldimand, Lambton, Middlesex, Norfolk and Northumberland). A close relative of pigweed, waterhemp is a competitive annual broadleaf weed that has been found resistant in the province to four different herbicide groups (Group 9: Roundup, […] Read more


Contrast in control of Roundup Ready alfalfa with herbicides applied in early fall (foreground) compared to late fall (background).

Pest Patrol: Killing off Roundup Ready alfalfa

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes Six tank-mix partners are recommended for the removal of Roundup Ready alfalfa, and since they vary significantly in cost (Table 1 below), their effectiveness was evaluated in a trial conducted at the Elora Research Station in 2018-19. Growing degree day accumulation after herbicide application appeared to have the greatest effect on the control of Roundup […] Read more

A cereal rye cover crop established after corn silage in the fall of 2018.

Pest Patrol: Planning for cover crops

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes Q: I want to plant cover crops after harvest. Should I be concerned about any herbicide residues that would make it harder to get them established? A: Two important factors influence the potential for herbicide carryover that could negatively affect establishment of a desired cover crop: The sensitivity of the cover crop to herbicide residues. […] Read more