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

Reading Time: 3 minutes 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

Reading Time: < 1 minute 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

Reading Time: 2 minutes 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

Reading Time: 2 minutes 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

Reading Time: 2 minutes 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

Reading Time: 2 minutes 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

Reading Time: 3 minutes 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

Reading Time: 2 minutes 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


Figure 2: Berries were sorted out of the oat sample and weighed, revealing that the nightshade berries comprised one per cent of the total sample weight.

Pest Patrol: Can I feed eastern black nightshade berries to my beef cows?

#PestPatrol with Mike Cowbrough, OMAFRA

Reading Time: 3 minutes [Question]: Find enclosed a sample of oats that I harvested with a considerable amount of eastern black nightshade berries. Is it all right to feed this to my beef cows? [Answer]: If your desire is to have no risk of negative health impacts on your livestock, then do not feed the contaminated oats to your […] Read more

Figure 1. Canada fleabane plants the following spring after surviving fall tillage. Note the plants have multiple branches at the base and were often 10 to15 cm taller than plants not exposed to fall tillage.

Pest Patrol: What have we learned in 2017 for managing glyphosate-resistant Canada fleabane?

#PestPatrol with Mike Cowbrough, OMAFRA, Dr. Clarence Swanton, Dr. François Tardif and Peter Smith, University of Guelph

Reading Time: 2 minutes Multiple strategies are needed to control glyphosate-resistant Canada fleabane. Experience has taught agronomists and farmers that simply tank mixing another mode of action won’t be a good enough long-term approach. Since 2016, we have evaluated different management tactics for Canada fleabane. The following are the results at our Oxford and Norfolk county field locations. Tillage […] Read more