PMN Crop News Homepage   

Posted 30 July 2015. PMN Crop News.

Palmer Amaranth Is a Game Changer

Scouting Patrol: Arkansas farmer keeps his fields under constant surveillance to manage weeds

Source: United Soybean Board Press Release.

Chesterfield, Missouri (July 16, 2015)--They didn’t think it was coming. But now it’s here, and it’s changed everything.


Managing herbicide-resistant Palmer amaranth is an all-consuming task for soy checkoff farmer-director Derek Haigwood, from Newport, Arkansas.

“We used to pull spray rigs around with pickup trucks,” says Haigwood. And now? “We had to switch to a full commercial operation with two huge sprayers.”

Haigwood says his weed-management plan is expansive – including crop and herbicide rotation, different seed varieties and other cultural practices – but nothing seems to work.

“It’s absolutely shocking how resistant this weed is,” he says of Palmer amaranth. “I don’t think an atomic blast would get rid of them.”

The best way Haigwood knows how to keep Palmer amaranth under control is kill it when it’s less than 3 inches tall.

“You have to get them when they’re small,” he stresses. “If they get to be knee-high, there’s nothing you can spray on them.”

After planting, Haigwood goes right into spraying pre-emergence herbicides. Then he’ll be sure to keep a close watch on his fields for signs of Palmer amaranth.

“Flooding is a big issue for us,” he says. “If the river backs into my field, it leaves seeds on the ground. Then I have to start all over again.” Haigwood sprays as often as he needs. Otherwise, he says he could lose a whole field. Preventing that loss justifies the added cost.

His fields are scouted, and any weeds that escaped his herbicides, or were in areas that couldn’t be treated, get chopped.

“It feels so archaic to go out and chop weeds, but that’s what we have to do,” he says. “We’re just focused on getting the small weeds before the crop canopy comes in.”

Haigwood urges farmers north of Arkansas to start scouting for Palmer amaranth.

“I think it’s coming with a vengeance, and it will change everything you do,” he cautions. “If it’s not controlled, you’ll go back to plowing beans like they did in the old days.”