K-State Specialist Provides Considerations for Post-Wheat Harvest Weed Management

Now that harvesting season is coming to an end, there are more open areas for weeds to grow and thrive.
Now that harvesting season is coming to an end, there are more open areas for weeds to grow and thrive.

Dallas Peterson, a weed management specialist with Kansas State University Research and Extension, recently shared insights into what Kansas wheat producers have to concern themselves with now that the harvesting season is winding down.

“With all the moisture we’ve gotten in the state this spring and summer, the weeds have come on,” said Peterson. “We need to get on these (weeds) as soon as possible, especially in those areas where weeds were present when we were harvesting wheat. They’re going to be tough to control.”

Peterson emphasized that both previously flooded areas and bare spots are going to be ideal locations for weeds to sprout up. Now that harvesting season is coming to an end, producers also have more open areas for weeds to grow and thrive.

“One thing we do have going for us is we are not limited on moisture; weeds are always more susceptible when they’re actively growing and not stressed, so that’s a good thing,” said Peterson. “But they are at an advanced stage of growth, and that does make them difficult to control.”

Although glyphosate has been a go-to herbicide to control weeds in past years, many species – including marestail, kochia and Palmer amaranth – have become resistant to it as of late. Alternatives, such as paraquat or flumioxazin, may need to be considered.

“The advantage to using the flumioxazin is the residual control, especially pigweed control,” Peterson said. “There’s a range of rates we can use, but probably 2-3 ounces per acre is the best. The main difference you’re going to see is the amount of residual control it provides.”

Farmers can get updated recommendations from the K-State annual publication, “Chemical Weed Control for Field Crops,” which is available online.