Published on Mon, 04/28/2014 by BASF Canada

Resistance management techniques for your farm

Growers are becoming more concerned about the spread of resistant weeds on Canadian farms. In fact, a recent poll conducted by Ipsos Reid shows that 86 percent of growers say that resistance is a concern. Almost 90 percent of growers in Canada say they’ll adjust their growing practices in order to delay herbicide resistance on their farms. 

“Applying a pre-seed herbicide will help control weeds that have either germinated last fall or early in the spring and will allow you to start the season with clean fields.” 

The list of glyphosate-resistant species has grown to include four different biotypes found in three provinces and Agriculture and Agri-food Canada continues to test additional sites. Despite the growing problem of resistance, there are steps growers can take to delay the issue on their farms.

Lionel Kaskiw, a Crop Production Adviser at Manitoba Agriculture, believes that the key to delaying resistance is to take a proactive approach and prevent resistant weeds from going to seed. At a recent event he offered a number of ways that growers can take action on their farms.

Tank-mix modes of action

Rotating herbicides from different chemistry groups is a good management technique and helps manage resistance from spreading. However, using products with multiple modes of action or tank-mixing from two different chemistry groups is the most effective way to delay resistance. 

Spray early

Controlling weeds early in the season by using a pre-seed burndown and targeting weeds when they are smaller than four inches is an effective way to stay ahead of problem weeds.

Scout fields and watch for escapes

Scouting fields in the days after applying a herbicide is important for managing escapes. By keeping an eye on any weeds that aren’t controlled, growers can stay ahead of potentially resistant weeds.

Control roadsides and ditches

Weeds are often seen growing on the roadsides and ditches surrounding fields.  If weeds are not controlled before they go to seed they return seeds to the seed bank for future years. Weeds like kochia and dandelion are especially troublesome since their seeds can spread over great distances.

Use full label rates

Always use the full label rate of your chosen herbicide. Label rates are determined to adequately control susceptible species.  By using sub-lethal doses of a chemical, weeds continue to survive, reducing the herbicide effectiveness and it no longer provides the benefit of resistance management.

There are certainly additional strategies growers can implement, but staying ahead of weeds and preventing them from going to seed will make weeds easier to manage.

“Applying a pre-seed herbicide will help control weeds that have either germinated last fall or early in the spring and will allow you to start the season with clean fields,” said Bryce Geisel, Technical Market Specialist at BASF Canada. “Heat herbicide uses an alternative mode of action and is unique with its wide spectrum broadleaf control, to provide multiple modes of action to your glyphosate application to manage resistant weeds.”

As glyphosate-resistance continues to spread, implementing proper weed management techniques are going to become more important to help delay or manage the problem. Considering some or all of these strategies for your operation will help prolong the use of herbicides and manage resistance.

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