Photo Gallery: Photos - Suspected glyphosate resistance to pigweed in Arizona cotton

Oct. 9, 2012

This cotton field in Buckeye, Ariz., with a high population of the weed Palmer amaranth (pigweed) has suspected resistance to glyphosate-based herbicides.
This Buckeye cotton field is a complete loss due to uncontrolled pigweed.
The second suspected glyphosate-resistant field in Buckeye.
Bill McCloskey discusses suspected glyphosate resistance to pigweed during an Arizona cotton field day.
A female Palmer amaranth can produce 600,000 to 1.6 million seeds. Seeds can spread several hundred feet in a gentle breeze or several miles during a storm event.

Tests under way by UA weed specialist Bill McCloskey, Tucson, will prove whether Arizona pigweed is resistant to glyphosate, and if so whether the resistance level is moderate or high.