What is in this article?:
- Resistant Palmer amaranth hits Midwest, changes control programs
- Integrated weed kill
- Stick with the plan
- A game changer for Midwest farmers?
Glyphosate-resistant Palmer amaranth is a predicament that could have been avoided “if we hadn’t used only glyphosate year after year after year,” says Evansville, Ind., farmer Joe Steinkamp, a director of the Indiana Soybean Alliance.
Steinkamp is battling the resistant weed on his farm, where it arrived with floodwaters. To stay ahead of this aggressive species, he’s spending three times as much money on soybean weed control as he did three years ago.
He says adopting an integrated weed management program that deploys multiple effective modes of action “is our duty, not only to protect our livelihood today, but for the future.”
A game changer for Midwest farmers?
What makes Palmer amaranth so competitive, even in the Midwest, far north of its historic range?
Very rapid growth — 1 inch or more per day in ideal weather, a very long germination period, prolific seed production, and genetic diversity, which favors rapid adaptation and development of herbicide resistance, says Aaron Hager, University of Illinois weed scientist. The tiny seeds spread easily, too.
Upper Midwest scientists are studying the weed’s germination and growth patterns in northern environments. However, Palmer amaranth “appears to be just as aggressive here as in the South,” says Travis Legleiter, Purdue University weed specialist.
“Farmers had better take this one seriously,” Hager adds. “Those who don’t will find out the hard way that it’s very capable of significantly reducing corn and soybean yields.” Unchecked, Palmer pigweeds can slash yields by 11% – 91% in corn and 17% - 79% in soybeans, says Legleiter, citing research from Colorado, Georgia and Tennessee.
For more photos and scouting guides, go to: http://bit.ly/PalmerID.