GFM Network News


Soybean planting showing leaf injury symptoms caused by a “bleaching” herbicide.

Pest Patrol: Crop injury from herbicide residues more common in 2020

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 4 minutes In 2020, a few farmers observed leaf injury in their soybean crops. The injury caused parts of the leaf to turn white, then yellow (see photo at top). This injury is typically caused by “bleaching” herbicides. It was odd, though, because the bleaching herbicide had been applied to the previous year’s corn crop, and it […] Read more

Figure 1. Dog strangling vine along a roadside in York Region where it is creeping into the fenceline and bordering corn field.

Pest Patrol: Dog strangling vine control with herbicides

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes An invasive perennial weed from the milkweed family, dog strangling vine is extremely difficult to control once it gets established (Figure 1 at top). Progress has been made on biological control of this weed in Ontario through the release of Hypena opulenta, a leaf-feeding caterpillar. However, integrated strategies that include both biological and chemical methods […] Read more


A sight no one wants to see in soybeans: cupping of the leaves caused by dicamba.

U.S. legal system helps weeds win

Luckily, Canadian producers are still outside the reach of the Ninth Circuit Court ruling on dicamba-based herbicides

Reading Time: 5 minutes In farming circles, the term “less-forgiving” has become more than a cliché. It’s now a mirror on reality. Farmers are already dealing with an incredible list of challenges and complexities, including everything from new seed technologies, concerns about land costs, equipment decisions, commodity markets, trade issues… you name it. Now growers in the U.S. must […] Read more

Figure 1: The untreated control plot.

Pest Patrol: The latest word on nipplewort in cereals

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes Here’s a question in my in-box. “I have a customer with a no-till rotation that has nipplewort — a lot of it. We found some pretty decent options for most crops in the rotation to clean it up before planting, but he’s got some in his wheat this year too. “What would be our best […] Read more


Bayer puts Roundup future claims settlement on hold

Judge questions proposal for third-party scientists to rule on chemical's carcinogenicity

Reading Time: 2 minutes Frankfurt | Reuters — Bayer was forced on Wednesday to delay part of a proposed settlement of allegations that its widely used herbicide Roundup caused cancer after a U.S. judge questioned its plan to deal with future claims. The German company said that lawyers representing those preparing a class action had withdrawn a request for […] Read more

Split-rate applications of fungicide to control fusarium and leaf diseases are no longer recommended as a half dose increases the chance of resistance.

Stay calm and spray on

A field guide to fungicide resistance management

Reading Time: 6 minutes Do you have questions about fungicide resistance? Have you ever wondered if that fungicide you used before is still working as it should? Are you worried about losing fungicide tools? Well, you’re not alone. “There have been a lot more questions about fungicide resistance in the last two years than in the last 10,” says […] Read more


Weed control with Authority Supreme (Groups 14 and 15), notice that overall weed control is good with the exception of Canada fleabane.

Pest Patrol: Weed control in IP soybeans

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes For more than a decade now, the University of Guelph and OMAFRA have been comparing the level of weed control, crop safety and grain yield associated with different herbicide programs in food grade, non-GMO soybeans, otherwise known as IP (identity preserved) soybeans. Table 1 (see below) summarizes the weed control and crop injury achieved with […] Read more

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