Waterhemp has evolved resistance to 4 herbicide sites of action
When a waterhemp biotype in eastern Nebraska survived a post-emergent application of the PPO inhibitor fomesafen, a team of university scientists decided to take a close look. They discovered the population was resistant to four distinct herbicide sites of action, including PPO inhibitors, ALS inhibitors, EPSPS inhibitors and PS II inhibitors.
Among their findings:
“Our study showed there simply are no effective post-emergent herbicide choices for the control of resistant waterhemp in either glyphosate-resistant or conventional crops,” said Debalin Sarangi, a postdoctoral researcher at the University of Nebraska-Lincoln. “Growers will need to diversify their approaches to weed management and complement the use of chemicals with cultural and mechanical controls.”