Dormant Spraying for Alfalfa Weeds

Mar 06, 2018

By Bruce Anderson

Treating weeds like pennycress (shown here), downy brome, mustards, cheatgrass, and shepherd's purse in dormant alfalfa can help protect yields of your first-cut alfalfa.

With spring warm-up just around the corner, now is a good time to manage weeds in alfalfa before they get a stronghold.

Weeds like pennycress, downy brome, mustards, cheatgrass, and shepherd's purse are common in first-cut alfalfa. They lower yields, reduce quality, lessen palatability, and slow hay drydown. If you walk over your fields during the next few weeks when snow is gone, you should be able to see their small, green, over-wintering growth.

If your alfalfa variety is Roundup Ready, you can spray almost any time without hurting your alfalfa. However, once conventional alfalfa starts growing, you can't control these weeds very well without also hurting your alfalfa. Fortunately, if you treat your alfalfa as soon as possible during upcoming spring-like weather, you can have cleaner, healthier alfalfa at first cutting.

Before spraying these weeds, be sure they are causing economic damage to your alfalfa. Spraying will give you more pure alfalfa but may cost some in total tonnage.

Several herbicides can help control winter annual grasses and weeds in conventional alfalfa. They include metribuzin, Velpar, Sinbar, Pursuit, Raptor, and Karmex. They all control mustards and pennycress, but Karmex and Pursuit do not control downy brome very well.

To be most successful, you must apply most of these herbicides before alfalfa shoots green up this spring to avoid much injury to your alfalfa. If alfalfa shoots are green when you spray, growth may be set back a couple weeks. If it does get late, use either Raptor or Pursuit because they tend to cause less injury to your alfalfa.

Timing is crucial when controlling winter annual weeds before alfalfa starts to green up. Take advantage of the nice weather when it occurs.

Source: unl.edu

Video: From Conventional to Regenerative: Will Groeneveld’s Journey Back to the Land

"You realize you've got a pretty finite number of years to do this. If you ever want to try something new, you better do it."

That mindset helped Will Groeneveld take a bold turn on his Alberta grain farm. A lifelong farmer, Will had never heard of regenerative agriculture until 2018, when he attended a seminar by Kevin Elmy that shifted his worldview. What began as curiosity quickly turned into a deep exploration of how biology—not just chemistry—shapes the health of our soils, crops and ecosystems.

In this video, Will candidly reflects on his family’s farming history, how the operation evolved from a traditional mixed farm to grain-only, and how the desire to improve the land pushed him to invite livestock back into the rotation—without owning a single cow.

Today, through creative partnerships and a commitment to the five principles of regenerative agriculture, Will is reintroducing diversity, building soil health and extending living roots in the ground for as much of the year as possible. Whether it’s through intercropping, zero tillage (which he’s practiced since the 1980s) or managing forage for visiting cattle, Will’s approach is a testament to continuous learning and a willingness to challenge old norms.

Will is a participant in the Regenerative Agriculture Lab (RAL), a social innovation process bringing together producers, researchers, retailers and others to co-create a resilient regenerative agriculture system in Alberta. His story highlights both the potential and humility required to farm with nature, not against it.