Palmer amaranth is an aggressive, herbicide-resistant weed that has plagued growers in the southern United States. Two Purdue Extension weed specialist have released a publication to help Indiana farmers fight against the weed’s continued spread.
Travis Legleiter says they need to use the knowledge obtained from their southern counterparts to their advantage. “Knowing the battles they’ve fought with this weed in glyphosate resistance in Palmer Amaranth in the south give us some guidance on the aggressiveness of this weed, taking over fields, and causing high yield losses,” he says.
Palmer was first confirmed in the Evansville area in 2011 and then in northwest Indiana last fall.
Legleiter says this is arguably the biggest weed problem to hit agronomic crops in the last 10 years. “What we’ve seen in northwestern Indiana this fall, we know it is aggressive,” he says. “We saw fields that were taken over by Palmer, had significant yield losses due to Palmer, we also saw Palmer plants that were 10 feet tall.”
The publication covers management options like crop rotation, tillage, and hand weeding as well as tips and tables using specific herbicides for pre- and post-emergence control.
It is available online HERE and will be handed out this winter during herbicide-resistant weed meetings around the state.