Look for Palmer Amaranth This Harvest
As reports of Palmer amaranth continue to sweep across the country, nearly everyone has heard about this formidable weed. Now's the time for you to pay closer attention and look for infestations.
“The only refuge where this weed has not been reported is Minnesota and North Dakota,” says Rich Zollinger, North Dakota State University Extension weed specialist. "It appears that once established, eradication is impossible – at least no state or area has been able to return the land to ‘weed-free’ status."
“Correct Palmer amaranth identification and prevention in North Dakota has been a key Extension message this year,” adds Zollinger.
Once the combine starts rolling, it’s important to be on the lookout for this weed. From the truck drivers to combine operators, make sure everyone knows how to identify this weed. If you do spot an infestation, properly clean your equipment before moving to the next field to avoid weed seed dissemination.
“I encourage everyone to keep keen observation,” says Zollinger. “A good refresher on how plants would look at this time of the year is in page 137 of the North Dakota Weed Control Guide.”
Bob Hartzler, Iowa State University Extension weed specialist, recommends looking for infestations on roadsides, around grain bins and storage areas, and near field edges. He recommends the following when you find Palmer amaranth:
- Properly eradicate small infestations. This weed can produce 1 million seeds per plant, and pulled plants can reroot and produce seed if not properly disposed.
- Don’t underestimate the number of plants present. Palmer amaranth emerges from mid-May through August.
- Don’t confuse the identification of water hemp with Palmer amaranth.
“The majority of waterhemp and Palmer amaranth plants have the same general shape and growth habit,” says Hartzler. “This reinforces the need to closely examine the floral characteristics of the two pigweeds – the large bracts of female Palmer amaranth make it simple to differentiate Palmer from waterhemp.”
- Have an attitude of prevention.
“High seed production and the efficiency of field equipment at disseminating seeds will facilitate the movement of Palmer amaranth across Iowa,” says Hartzler. “However, individual farmers can prevent it from becoming established in their field with a combination of vigilance and diverse weed management.”