AMES — The status of weed control across the state and the most effective herbicides for tackling weeds are outlined in a recently released Iowa State University Extension and Outreach publication.
The "2016 Herbicide Guide for Iowa Corn and Soybean Production" was written by ISU Extension and Outreach weed specialists Bob Hartzler and Mike Owen and is now available online at the Extension Store, store.extension.iastate.edu.
Hartzler and Owen note the many weed issues from the past continue to plague Iowa’s farmers, particularly the weed, water hemp, in soybean fields.
“There has not been a notable increase across the state in major weed management failures,” Hartzler said. “However, random surveys suggest that a high percentage of fields with weeds visible above the soybean canopy have evolved resistance to one or more herbicides.”
The 24-page guide provides industry updates and gives instructions on how to design resilient herbicide programs to manage herbicide resistance. The resilient herbicide programs rely on multiple herbicide groups to manage weeds and the new publication details successful approaches. Non-herbicidal strategies also are included.
It also lists the effectiveness of different herbicides for controlling grass, broadleaf and perennial weeds in corn and soybeans, grazing and haying restrictions for herbicides used in grass pastures and the active ingredients in herbicide prepackage mixes.