It’s not just pigweed, it’s Palmer amaranth pigweed, and it was all over the Bayer CropScience Respect the Rotation plot tour in Collinsville, Illinois – towering over corn and soybeans and most other weeds.

Waterhemp is also a member of the pigweed family that might be more familiar to growers in the Midwest and both are developing resistance to glyphosate. Southern Illinois University weed specialist Bryan Young says resistant waterhemp in the region has been doubling every year for the past three years. “At one point we had ten percent of retailers surveyed said it was a problem in their territory, the next year it was 20%,” he said. “This past fall it was 40% and this fall I’m expecting that will be even higher.”

The Palmer pigweed is more aggressive than waterhemp and has already taken over fields in the south, starting just from one little weed. The Respect the Rotation message for farmers in the Midwest is to keep that from happening by rotating modes of action for herbicides, as well as crops themselves.

Listen to my interview with Bryan from the Bayer field day and watch the video below where he explains how to identify Palmer amaranth. Bryan Young interview

See pictures from the field day in Collinsville in the Bayer CropScience Respect the Rotation photo album.