The Looming Threat of Palmer Amaranth
Palmer Amaranth, the great unknown, continues to be a threat as it makes its northern trek. Our best advice for managing Palmer is don’t let it get established. Start your field clean through tillage or herbicide application and keep them clean throughout the growing season. This means make sure your fields are always protected by residual herbicide.
If you don’t believe Palmer is a real threat to our area, think again. Young Palmer plants are up and growing in the state of Iowa. According to Iowa State University’s Extension and Outreach Integrated Crop Management News, Palmer seedlings have been found at the site of the 2013 Muscatine County infestation. The troubling factor is, it is nearly impossible to distinguish Palmer Amaranth versus waterhemp during the vegetative stage. Although noted in the ISU’s Crop Management News, Palmer leaves are frequently wider in relation to their length when compared to waterhemp. Palmer also grows much faster and has a denser canopy.
On top of Palmer’s resistance to chemical herbicides and its ability to produce a massive number of seeds, the most concerning factor is its impact on yields. While waterhemp can cause yield losses of 30% when present in soybeans, it doesn’t hold a candle to Palmer Amaranth, which can cause up to 80% yield losses.
If you have any unusual pigweed activity in your fields, scout them frequently until they can be identified as either waterhemp or Palmer Amaranth. For help with scouting, identification and plans of action, contact your Stutsman Representative!