Note: You can listen to my conversation with Greg Kruger by clicking on the audio link above.
In the last year alone, Palmer amaranth has seen a significant spread across Nebraska — particularly in parts of southern Nebraska, from North Platte to Lincoln down to the Nebraska-Kansas border.
"If we look back across time, the first report of Palmer amaranth was back in the 1800s in Nebraska," says Greg Kruger, Nebraska Extension weed science specialist. "It's not a new species, but it's certainly become very front and center for us in terms of weed management, particularly in the south-central part of Nebraska and up in the Panhandle."
"We've kind of always had it in the background. But because of our management practices, it's become very problematic for us, particularly this summer it seems to have blown up on us," Kruger adds.
In the latest episode of Down in the Weeds, we visited with Kruger on the growth of Palmer amaranth in the state in recent years, and discuss some strategies for control.
Part of the reason for the increase in the glyphosate-resistant Palmer population in the last several years has been due to overreliance on glyphosate to control weeds in corn and soybean rotations. However, Kruger notes even in some cases where growers are working to take every necessary step possible, Palmer has still gained the upper hand.
Some of the steps for control may sound like a broken record at this point, but they’re worth repeating. Most notably, using multiple effective modes of action and using overlapping residuals. Also worth consideration is diversifying the rotation with a cool-season cereal crop like winter wheat, which not only opens a door for additional chemistries, but also helps crowd out weeds during a different time of year, and leaves behind a thick stand of residue that continues to suppress weed growth.
Kruger advises if Palmer is ever seen in a field — whether one plant or a million — to use some sort of residual-based product in the tank when going across with a spray application. "There are a plethora of options in different cropping systems,” he says. “I'm not married to one or another, but making sure we have those and we're layering those as we make multiple applications across the field is really important."