GFM Network News


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


Although it has yet to be confirmed in Ontario, Palmer amaranth is capable of rapid spread and should be treated as glyphosate resistant.

Recognize the threat of these invasive weeds

How big a problem can waterhemp and Palmer amaranth really be? Let’s not find out

Reading Time: 7 minutes Has everyone been crying wolf about waterhemp? After all, haven’t we been hearing warnings in southern Ontario about the weed for the past 15 years, and who has lost a bushel? Well, it was actually 17 years ago — 2002 — when the species was first confirmed in Lambton County, and the good news is […] Read more

Bayer to invest $7.5 billion in new herbicides

Reading Time: < 1 minute Berlin | Reuters — Bayer said it would invest five billion euros (C$7.5 billion) in developing new weedkillers and reducing its environmental impact by 30 per cent by 2030, as it seeks to address the fallout from U.S. class-action litigation over glyphosate. “While glyphosate will continue to play an important role in agriculture and in […] Read more


Volunteer corn.

Pest Patrol: Manage volunteer corn in your 2019 soybeans

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes Q: Due to a challenging 2018 corn harvest, I’ll likely be looking at more volunteer corn in my 2019 soybean crop. What suggestions do you have for managing this weed? A: The only option to control volunteer corn in soybeans is to use one of the post-emergence herbicides from the Group 1 mode of action. […] Read more

Drought stress symptoms in corn leaves where no soil-applied herbicides had been applied and weed control was done with a late post-emergence application.

Pest Patrol: Don’t be cheap with weed control

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes “Weed control is an investment into the current and future crops on every field.” The above quote was parting advice from Norfolk and Oxford County farmer Ann Vermeersch at the 2019 FarmSmart Conference in Guelph. In front of 80 farmers and agronomists, I moderated a session with Vermeersch and Steph Kowalski, a certified crop advisor […] Read more