Glufosinate-resistant Palmer Amaranth Confirmed in Arkansas

Glufosinate tolerance is a growing trait in a lot of soybean and cotton varieties in the last two decades, with tolerant acres ballooning — largely in the southeast and mid-South — to more than 15 million acres. But a new risk to the efficacy of the popular herbicide arises with the discovery of glufosinate-resistant Palmer amaranth, or pigweed, in two northeastern Arkansas counties. The samples tested were collected in 2019 and 2020, but the level of the resistance made it a troubling find; one sample was found to be 3 1/2 times more resistant to the herbicide than normal susceptible weeds. Though weed scientists say they have every reason to believe the discoveries are fairly isolated, it’s a call for growers to take a close look at their weed control strategies to ensure they’re not opening the door for that resistance to spread to other acres or crops. See more on the situation.