Canada fleabane is an aggressive winter and summer annual that can wreak havoc on farmer’s yields if not properly managed. To top it off, this weed has developed resistance to several herbicides over the past decade including Group 2, 9, and 22. In Ontario,  Group 2- and glyphosate-resistant biotypes have been confirmed. This adaptive and aggressive weed can reduce yields by over 90% if left untreated.

Size matters

Fall and early spring are the best times to control Canada fleabane. Applying herbicides on plants that are 10 cm or smaller will deliver the best control. In Nufarm small plot research trials, applying herbicides when the fleabane was 30 cm tall resulted in a 27% decrease in efficacy compared to trials that received herbicide applications when the weeds were only 10 cm tall.

The four herbicide applications in the trials were BlackHawk® and Bifecta®, Eragon® and metribuzin, Elevore™ and metribuzin, and lastly Bifecta plus Roundup Xtend®. There’s no question that it’s important to watch staging of Canada fleabane, and spray earlier to get the best results in soybeans.

Managing Canada fleabane

Bifecta is an excellent pre-emergent herbicide for controlling Canada fleabane including Group 2- and glyphosate-resistant biotypes. It features two active ingredients (Group 5 and 14) for stronger resistance management and up to five weeks of residual control. This proven combination controls the toughest resistant broadleaf weeds with bonus activity on hard-to-control annual grasses.

Below is a chart that shows Bifecta working in the field compared to other herbicides on glyphosate-resistant fleabane. The ratings were taken 28 days-after-application. Bifecta is very consistent when it comes to managing Canada fleabane compared to other competitors.

If you are looking for a convenient and flexible pre-plant or pre-emergent herbicide look no further than Bifecta. The easy-to-use co-pack does not require a surfactant and it can be tank mixed with other burndown and pre-emergent herbicides (i.e. glyphosate and BlackHawk).


Always read and follow label directions.
BlackHawk® and Bifecta® are registered trademarks of Nufarm Agriculture Inc. All other products are trademarks of their respective companies.