Glufosinate-Resistant Palmer Amaranth Found in Missouri


University of Missouri Extension researchers have confirmed the state’s first case of glufosinate-resistant Palmer Amaranth in the Bootheel Region of Missouri. Palmer Amaranth spreads and adapts quickly to herbicides. Each weed produces up to one million seeds, which heightens the spread of resistance. The confirmation of Glufosinate resistance is a big concern for the state’s farmers because that resistance seems to be evolving at a quicker pace. Extension researcher Jim Heiser says, “Every mode of action that Palmer becomes resistant to seems to come at a quicker pace than the previous one.” He also warns farmers not to solely rely on herbicides to control weeds. He says to consider cultural practices for weed control, such as narrow row spacing for crops, the use of cover crops, and harvest weed seed management techniques. Palmer’s spread likely comes from used farm equipment like combines, custom harvesting crews, and feed and seed from other regions of the country.