Weed management is a significant investment for farmers. Weed experts say it’s not uncommon for corn and soybean operations to spend $100 per acre for herbicides and adjuvants used in a broad-spectrum weed-control program. James Rose, a weed management specialist with CHS, offers tips to make the most of that investment. 

Manage troublesome weeds in 2023

The main weed enemies this year are not new, but that doesn’t make them any easier to control. Palmer amaranth continues its northern march into the Corn Belt from the mid-South, says Rose, while waterhemp remains one of the most problematic weeds in the upper Midwest and eastern Corn Belt. “Giant ragweed and kochia are also troublesome weeds in the Midwest.”

Fight herbicide resistance

Herbicide resistance makes it harder to effectively control weeds and management costs, says Rose. “We’ve documented cases of Liberty and dicamba resistance in Palmer amaranth recently. That means farmers have to be more thoughtful about the herbicides they use to get effective control. If you know you have resistant weed populations, choose products with effective sites of action against those resistant weeds.”

Making timely herbicide applications while weeds are small and using residual products can improve control success, Rose says. “As input costs rise, it can be tempting to cut application rates. I encourage farmers to follow labeled rates to get the most effective weed control and reduce the risk of herbicide resistance developing in their fields.”

Protect yield potential

Rose encourages farmers to work closely with trusted agronomic advisors to build a solid weed management plan that spans the entire season. “Use best management practices to start, stay and finish clean. Don’t let weeds get away from you later in the year, as that can cause issues for subsequent growing seasons.”

He also recommends using effective adjuvants in the herbicide tank mix to enhance spray performance. “Water conditioners that contain AMS can reduce herbicide tie-up in the tank and increase efficacy for glyphosate and glufosinate applications,” Rose says.

If all else fails, consider using tillage to get troublesome weeds under control. “If you have an area that’s tough, maybe go in with a disk to reduce that weed pressure,” Rose recommends.