You know the agronomic headaches weeds cause. Do you know how they hit your bottom line?
Uncontrolled weeds repopulate seed banks, leading to more problems the following season. Bill Johnson, Purdue University Extension weed scientist, says weed seed buildup averages $10 per acre per year for easy-to-control grasses and some broadleaf weeds, and $20 per acre per year for more troublesome weeds such as waterhemp in weed control costs.
In addition, just one broadleaf weed in every 3' of row can reduce corn yield by up to 30%, according to the Weed Science Society of America.
“Start clean and stay clean,” Johnson advises.
TAKE OUT VOLUNTEERS
Volunteer corn is another highly competitive weed farmers, especially those in parts of Iowa and Illinois affected by the 2020 derecho, will want to pay attention to this year, says Bob Hartzler, Extension weed specialist at Iowa State University.
“We have some volunteer corn most years, but usually not a high enough density to impact yields,” he says. “This year, because of the derecho, some fields could see their yields decimated if the farmer is not proactive.”
Here are a few tips to help you address weed issues:
- Be proactive. Prevent weed emergence if at all possible. If not, kill weeds before they reach 4" tall.
- Use multiple modes of action. That can help you stave off the buildup of resistant weeds.
- Evaluate escapes. If weeds seem to take herbicide applications in stride this season, you might be seeing the start of a resistance problem.
