Most people are aware that the first confirmed Palmer amaranth infestations were found in Iowa late in 2013. Infestations have been found in five Iowa counties, but we suspect there are more unknown infestations than known. Virgil Schmitt, Iowa State University (ISU) Extension and Outreach field agronomist, and I visited an infestation in Muscatine County on May 9. There was an abundance of Amaranthus seedlings present in the area infested with Palmer amaranth last fall. We are fairly confident that these seedlings were Palmer amaranth because there was little or no waterhemp, or other pigweed species, present in the field last fall. However, I am not convinced that it is possible to distinguish the two species while they are in the seedling stage.
Iowa State University
Hartzler, Robert G., "Palmer Amaranth is Up and Growing" (2014). Integrated Crop Management News. 839.
The Iowa State University Digital Repository provides access to Integrated Crop Management News for historical purposes only. Users are hereby notified that the content may be inaccurate, out of date, incomplete and/or may not meet the needs and requirements of the user. Users should make their own assessment of the information and whether it is suitable for their intended purpose. For current information on integrated crop management from Iowa State University Extension and Outreach, please visit https://crops.extension.iastate.edu/.