GFM Network News


Figure 1. Attempted mixing of Dual II Magnum with ATS as the carrier (left) compared to successful mixing with water (right).

Pest Patrol: The importance of doing a ‘jar test’ with fertilizers and herbicides

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 4 minutes Each year I get more questions about mixing the liquid fertilizer, ammonium thiosulphate (ATS), with herbicides. With reductions in atmospheric sulphur deposits, Ontario research has shown positive yield responses in some crops when sulphur fertilizers are applied, so it makes sense that farmers are looking at ways to add sulphur to their crop in an […] 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


Figure 1: A weed seed’s perspective of having to germinate in the spring under a thick winter wheat canopy, which reduces the amount and quality of two key components for that weed to germinate: sunlight and heat.

Pest Patrol: Why growing cereals is bad for weeds

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes The benefits of growing winter wheat in a crop rotation have been well established. Long-term research at the University of Guelph has shown a 10 bu./ac. increase in corn yields and a five bu./ac. increase in soybean yields when winter wheat is grown. Other benefits, such as increased soil organic matter when cereals are grown, […] 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

What can potato chips teach you about weed control? You might be surprised.

Pest Patrol: Dealing with bias in pest management research trials

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes I have biases. Perhaps that’s a surprising statement coming from someone who is supposed to be impartial, but experiences lead to biases. It’s human nature. The bigger question is how does one account for and neutralize those biases when evaluating something such as a weed control program? That’s the topic that I wanted to tackle […] 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

Figure 1. Hairy galinsoga seedling.

Pest Patrol: More and more hairy galinsoga

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes Q: I’m seeing more of a weed called hairy galinsoga, and I’m struggling to control it. Any suggestions? A: Historically, we have found this annual plant mainly in horticultural crops throughout the southern portion of the province, but in the last five years, there have been more inquiries on managing hairy galinsoga in field crops. […] 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

Figure 4: Waterhemp in soybean.

Pest Patrol: Dealing with waterhemp and Canada fleabane

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes In last month’s #PestPatrol, we discussed options for the control of glyphosate-resistant waterhemp. However, across the province, there appears to be a more immediate threat for the 2020 season from glyphosate-resistant Canada fleabane. This article will focus on management strategies to control both species at the same time. It is true that glyphosate-resistant Canada fleabane […] Read more