Publication

Palmer amaranth (Amaranthus palmeri S. Watson) is an emerging pest issue in South Dakota. To date, it has mainly been traced as moving into the state by mechanical means, primarily through grass and cover crop seed and is found more frequently in central South Dakota than in other parts of the state. This “new” weed is a concern as it can grow 2-3 inches per day and has very prolific seed production. It can easily become resistant to multiple herbicide modes of action and is very competitive in many crops. Being from the pigweed family, to the untrained eye, it can resemble other common South Dakota weeds such as common waterhemp (A. rudis) or red root pigweed (A. retroflexus). In order to raise awareness about Palmer amaranth and help producers learn to identify it, we created a pocket-sized “Identification and Management of Palmer amaranth in South Dakota farmers” guide. The pamphlet focuses on basic physical identification characteristics of the weed, the reason for concern in South Dakota, and ideal management tactics. We initially printed 800 copies in December of 2019 which were quickly disseminated to farmers across the state at extension meetings, farm shows, pesticide applicator training meetings, through Extension, NRCS, and NGO agency offices, and from farmer to farmer. A second printing of 800 is set to arrive in March 2020 for further distribution. New weed species that come as herbicide resistance seed, or quickly develop resistance and spread quickly are of great threat to our cropping systems. We hope to raise awareness and understanding of the threats Palmer amaranth brings to South Dakota through this ‘pocket guide’ publication. Gared Shaffer, Sara Bauder, and Ruth Beck generated the content, took or procured all photos, and edited this publication. It can be found online at https://extension.sdstate.edu/sites/default/files/2020-01/P-00142.pdf.