Not every fall gives you a hard stop after harvest. When warm weather holds and moisture sticks around, weeds don’t slow down just because the combine has come through. That open window is one of the most overlooked herbicide application opportunities in the calendar, and for growers who want to get more out of their crop protection solutions heading into next season, a post-harvest burndown pass is a move that can alleviate weed pressure into next season.. Applying BlackHawk EVO with a glyphosate herbicide is an effective way to clean up whatever is still growing before freeze-up closes out the season.
Why an Open Fall Changes the Equation
After harvest, there’s often more weed growth happening in a field than growers realize. There can be annual weeds that survive the season, winter annuals and perennials pushing new growth before freeze-up; all of them can actively build root mass and set seed if they’re left alone. In a short fall, freeze-up naturally challenges some of the growth cycle, but in a long, open fall, those weeds get weeks of growing time they wouldn’t otherwise have.
The problem is it’s not just about this season. Weeds that set seed in the fall add to next year’s seedbank. Perennials that bulk up root reserves over a long fall come back stronger in the spring. The work you do or don’t do after harvest shows up the following year.
Where BlackHawk EVO Fits In
BlackHawk EVO is powered by Duplosan technology and features three active ingredients – Group 14 (pyraflufen-ethyl) and two Group 4‘s (dichlorprop-p and 2,4-D ester). It makes a great tank-mix partner for glyphosate, to deliver fast, complete control of a broad range of tough broadleaf weeds, including:
- Kochia, including Group 2-, 4- and 9-resistant biotypes
- Cleavers, including Group 2- and 9-resistant biotypes
- Narrow-leaved hawk’s-beard, including Group 2-resistant biotypes
- Volunteer canola, including all herbicide-tolerant biotypes
- Wild mustard, including Group 2-resistant biotypes
If any of those have been a recurring problem in your fields, a post-harvest pass with BlackHawk EVO and glyphosate is an efficient way to knock them back before the next season.
The Advantage of No Residual
One of the reasons BlackHawk EVO is a great option for a fall burndown is that it keeps seeding options open for the following spring. For crop rotations in western Canada, that flexibility is valuable. Growers who seed fall rye or winter wheat can make a burndown pass with BlackHawk EVO pre-seed or pre-emergence in western Canada.
Reading the Fall to Know When to Move
Not every fall warrants a post-harvest burndown. The decision comes down to what the season looks like after the combine rolls through. A few things that make a strong case for going out:
- Weeds are actively growing taking moisture and nutrients from your fields
- Winter annuals like shepherd’s-purse or stinkweed have germinated and are establishing across the field
- Perennial weeds like dandelions or Canada thistle are still green and building root reserves
- Fields with a known history of resistant weed populations that set seed prolifically
- A dry in-crop season that kept in-crop applications from working as well as expected
A Low-Risk Move With a Long Payoff
The role of glyphosate herbicide in Canada has shifted considerably over the years. Where it once handled most burndown work on its own, the spread of resistant weed populations has made a tank-mix partner standard practice. Post-harvest timing in the fall is a great time to get a jump on next season. The benefits of BlackHawk EVO make it a great option for post-harvest burndown applications in western Canada.
Reach out to your local Nufarm representative to talk through your post-harvest burndown program.
