Recent reports from Bayer and Corteva indicate the emergence of suspected herbicide-resistant waterhemp populations in Iowa.
Bayer reported dicamba-resistant waterhemp, while Corteva identified a suspected 2, 4-D-resistant population. An Extension Field Specialist with Iowa State University Extension and Outreach emphasized the need for further studies to confirm that.
“Well, suspected population. So that’s always— it’s kind of an intensive process to go through to prove that a population is surviving 2,4-D at an unexpectedly high rate compared with like what a natural population out in the environment might do. And so they— I believe they’ve gone through one round of testing and they’ll do one more this spring. And so, if it survives like they think it has been. Right. If it’s proven to be resistant, then they should be able to do that yet this summer,” according to Meaghan Anderson.
She highlighted the significance of these findings, cautioning against over-reliance on herbicides like 2, 4-D. She stresses the importance of implementing comprehensive weed management programs to slow the evolution of resistance while effectively controlling waterhemp.