What started as an outbreak contained to the northwest portion of the state is rapidly growing into a statewide problem.
The Palmer amaranth weed spreads rapidly and is resistant to many pesticides, so Purdue University professor of weed science Bill Johnson farmers who do catch it must act quickly to prevent further damage.
“This weed problem will expand and blow up on people very quickly, and it’s because of the high levels of seed production,” Johnson says. “You can have just one or two escaped plants one year, and really have a train wreck as far as the weed control situation the next year.”
Betsy Bower, an agronomist for the agricultural co-op Ceres Solutions, identified Palmer amaranth in the state’s western counties and has talked to farmers about how they can minimize crop damage.
“They know that we need to be concerned about it, scared about it, that if we identify it it’s going to take a pretty aggressive course of control, and we can’t allow it to get any size at all,” Bower says.
Johnson says if a farmer discovers Palmer amaranth their best option is to clear the weeds by hand in order to limit the weed’s seed exposure.
So far, he says the weeds have not caused significant crop damage, but northwestern counties are most at risk.