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.

glyphosate-resistance increases in midwest in Palmer amaranth

 

For more photos and scouting guides, go to: http://bit.ly/PalmerID.