GFM Network News


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


Dr. Clarence Swanton.

Pest Patrol: Thank you, Dr. Clarence Swanton

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes “Matty Cowlick” is indifferent to the recent retirement of Dr. Clarence Swanton, weed scientist in the department of plant agriculture at the University of Guelph. But I’m happy for him. I’m happy that Clarence will continue with his research program and to advise graduate students, and happy that he will have more time to spend […] Read more

Farmers’ friends: bugs, birds and worms can eat weed seeds before they get a chance to germinate.

Weed control with small critters

Insects, birds and worms are a free – and resistance-free – method of controlling weeds before they get a chance to germinate

Reading Time: 4 minutes The dominance of zero- or minimum-tillage practices on the Prairies means lots of weed seeds are left on the soil after harvest, but it turns out that there’s help available to stop them from germinating next spring, and you don’t have to buy it at your local chemical dealer. “Lowering the deposits into the weed […] Read more


The choice is simple: spend an hour cleaning equipment or a more expensive hour in the field spraying.

Hitchhiking pests

Yes, cleaning out equipment takes time, but it’s worth it

Reading Time: 6 minutes When it comes to discussing the scourge of weed management in Eastern Canada, much of the light has shone on herbicide-resistant Canada fleabane and its spread from Essex County to the Quebec border in just five years. The latest weed species that is cause for concern is common waterhemp. It’s been the topic of conversation […] Read more

Some plants along the rail line are glyphosate resistant.

Pest Patrol: Sanitation of weed seed

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes Q: Can we stop the spread of weed seeds? A: “I’ve been thinking a lot about sterility lately.” I knew as soon as the words came out of my mouth that I had slipped up. I was responding to a question in the audience at a local crop conference about ways to stop the movement […] Read more


Figure 1: This unsprayed control treatment consists mainly of common ragweed but with green foxtail, common lamb’s-quarters, witchgrass, crabgrass and red-root and green pigweed.

Pest Patrol: Weed control in identity-preserved, non-GMO soybeans

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes A decade of public research trials evaluating weed control in non-GMO soybeans at the University of Guelph has demonstrated that the key to success is to start with a soil-applied herbicide program that has three or more different modes of action. In Ontario, there are a number of common weeds (e.g. common ragweed, lamb’s-quarters, foxtail […] Read more

Growers in the U.S. are dealing with the spread of Palmer amaranth, which overcame glyphosate as far back as 2010.

Better herbicide tolerance technologies are on the way

Better technologies are coming, but we’ll need patience and shrewd management until they arrive

Reading Time: 4 minutes Count off the many challenges facing a farmer in any growing season and outside of weather conditions, the biggest impediment has to be weed management, particularly as it relates to herbicide tolerance. In spite of the importance of varietal or hybrid selection and fertility, and the potential for yield losses from insect pests and diseases, […] Read more


The U.S. ‘No. 1 weed problem’ heads north

Other weeds are higher priority for now, but be on the lookout for Palmer amaranth

Reading Time: 4 minutes It can grow two to three inches per day and reach eight feet tall. Each plant can produce more than a million seeds that can emerge right through the growing season. It has reduced yield up to 91 per cent in corn and 79 per cent in soybeans. It’s resistant to glyphosate and multiple other […] Read more

Quinoa planted into a stale seedbed and with the use of an experimental herbicide (left) compared to the same herbicide applied but without the use of a stale seedbed (right).

Pest Patrol: Try the stale seedbed approach for weeds in alternative crops

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 2 minutes Q: I’m looking to grow a new crop where there are few herbicides available to control weeds. Are there any non-chemical methods to reduce the number of weeds that could emerge in the crop? A: Since I began with OMAFRA in 2002, I’ve been involved in projects that investigated methods to control weeds in “new” […] Read more