GFM Network News


Figure 1. An overhead look at the level of control that cereal rye has provided when it was seeded the previous fall (mid- November) at 60 lbs./ac. (left) compared to no cereal rye planted (right).

PHOTOS: Pest Patrol: Cover crops versus glyphosate-resistant weeds

#PestPatrol with Mike Cowbrough, OMAFRA

Q: Can cover crops be an effective tool to manage glyphosate-resistant weeds? A: My colleague Dr. Clarence Swanton (University of Guelph) used to say that based on research he did in the 1980s, one should not expect to control weeds with cover crops. Their utility was in preventing soil erosion and improving soil health but […] Read more

An infestation along an old rail line and a field border.

PHOTOS: Pest Patrol: Reining in dog strangling vine

#PestPatrol with Mike Cowbrough, OMAFRA

Q: I’m seeing a weed called dog strangling vine along roadsides, in woodlots and creeping into agricultural fields. It seems quite invasive. How do I get rid of it? A: Your suspicions are correct. Dog strangling vine is invasive and is listed as a noxious weed under the Ontario Weed Control Act, and regulated as […] Read more


Figure 1. A robotic weeder being tested as part of an engineering design project at the University of Guelph.

Pest Patrol: New herbicide names may not mean new chemistry

#PestPatrol with Mike Cowbrough, OMAFRA

Q: Do I have new opportunities in weed control in 2018? A: This is the question I’ve been asked a lot this past winter meeting season, and one I always struggle to answer. There are some legitimately promising concepts being tested such as robotic weeders (Figure 1 at top) and weed seed destruction tools, but […] Read more

Hemp dogbane in Roundup Ready soybean prior to the spot application of glyphosate.

PHOTOS: Pest Patrol: Dealing with hemp dogbane

#PestPatrol with Mike Cowbrough, OMAFRA

Q: I’ve been battling hemp dogbane in my soybean fields. It produces a milky juice that can stain my beans. What can I do to knock back the top growth so it won’t affect crop quality? A: It’s good that your expectations are for top growth control of hemp dogbane (see figure 1), since it’s […] Read more


A relatively small seedling plant found in corn during mid-June but beyond the labelled stage of growth.

Pest Patrol: Tackling prostrate knotweed on today’s farms

#PestPatrol with Mike Cowbrough, OMAFRA

Q: How do I get rid of prostrate knotweed in each of my major crops? A: In Ontario, prostrate knotweed is more frequently found in Huron County and on Brookston clay-loam soils under no-till or minimum-till production systems (Frick, 1990). It can thrive in compacted soils where other plants will struggle to grow well. Below […] Read more

A patch of willowherb in soybean that had escaped an application of glyphosate.

Pest Patrol: Dealing with willowherb

#PestPatrol with Mike Cowbrough, OMAFRA

Q: I’ve noticed small patches of a plant that was identified as “northern willowherb” in some of my fields. It seems tolerant to glyphosate. How do I control this before it becomes a bigger problem? A: This perennial weed has traditionally been found along roadsides and waste areas. In the last five years, more farmers […] Read more


A young plant in winter wheat during early May.

Pest Patrol: Dealing with cleavers

#PestPatrol with Mike Cowbrough, OMAFRA

Q: I had a field of winter wheat with cleavers in it and it was a pain. What is the best way to get rid of this weed in winter wheat? A: I can’t think of a redeeming quality for cleavers, although apparently the fruit is considered one of the best substitutes for coffee (Malik […] Read more

Pre-plant applications of dicamba at the high rate and to emerged fleabane rosettes have provided the most effective control of glyphosate-resistant Canada fleabane (left) compared to an unsprayed strip (right) when planting Xtend soybean varieties. A followup, post-emergence application of dicamba may be necessary when new seedlings have germinated following crop emergence.

Pest Patrol: Control of Canada fleabane

#PestPatrol with Mike Cowbrough, OMAFRA

Q: Canada fleabane has shown up in various places on our farm this year. I assume it is glyphosate resistant. Do I have any other options for soybeans other than Xtend beans? A: Yes, research conducted by the University of Guelph (Ridgetown Campus) has shown that the addition of Eragon LQ (30 ml/acre) + Sencor […] Read more


Figure 1. A September germinated seedling with its three main divided segments.

Pest Patrol: Controlling wild carrot in no till

#PestPatrol with Mike Cowbrough, OMAFRA

Q: I am a long-time no tiller. I have a problem with increasing populations of wild carrot, mostly in my (conventional) soybean fields. This year in Roundup Ready corn, I have applied up to three litres of Transorb 540 and still have green carrot at harvest-time. What is the solution? Do I need to do […] Read more

Figure 1: Jimsonweed in a corn crop during October.

Pest Patrol: Dealing with jimsonweed

#PestPatrol with Mike Cowbrough, OMAFRA

Q: What weed is this, and how do I get rid of it? A: The weed in the picture (Figure 1 above) is jimsonweed (i.e. Datura stamonium), a member of the nightshade family. According to the Canadian Poisonous Plants Information System, jimsonweed “contains toxic tropane alkaloids, which have caused poisoning and death in humans and […] Read more