APHIS Posts Weed Risk Assessment for Palmer’s Amaranth

USDA Animal and Plant Health Inspection Service (APHIS) Plant Protection and Quarantine has posted a new Weed Risk Assessment (WRA) for Palmer’s amaranth. The purpose of a WRA is to evaluate the likelihood that a weed species will escape, naturalize, and spread in the United States, and harm U.S. natural and agricultural resources. Stakeholders can use WRAs to support their own management or policy decisions as needed. This WRA notes that populations across the global range for Palmer’s Amaranth have developed resistance to eight different herbicidal modes of action, with some populations being reported as resistant to two or more of these modes of action. The plant is present outside its native range in 19 states and has caused yield losses ranging from 6% to 94% in corn, cotton, peanut, sorghum, soybean, and sweet potato.