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How Meaghan Anderson Helped Iowa’s Farmers Deal With Palmer Amaranth

10 Up & Comers: Meaghan Anderson

Palmer amaranth was one of the last things on Meaghan Anderson’s mind last summer. That changed in mid-July 2016, when it surfaced in an unlikely place in Iowa.

A central Iowa chemical company sales representative emailed a photo of a weed that resembled Palmer amaranth to Bob Hartzler, Iowa State University (ISU) Extension weeds specialist.

“I remember looking at the picture that he forwarded to me,” says Anderson, an ISU field agronomist based in Iowa City, Iowa. Palmer amaranth – the Satan of the weed world – had previously infiltrated cropland in five Iowa counties via livestock feed brought up from southern states with huge infestations.

This time, though, something was different. This Palmer amaranth surfaced in a noncrop field planted to a pollinator mix of grasses, flowers, and forbs.

“I thought it was weird that it would show up in a field like that,” says Anderson. “Almost 10 days later, I got a text message on a Sunday from a crop consultant to the east of me. He sent me a picture of Palmer amaranth off the front of his tractor in a CP 33 seed mix, which was a habitat buffer type of seed mix.

“That’s when I started to get worried,” she says.

Tracking a Demon Weed

True to its Satanic nickname, this pugnacious pigweed is demonic. Palmer amaranth can:

  • Produce 250,000 to 500,000 seeds per plant.
  • Germinate nearly the entire growing season.
  • Grow 10 feet tall, with the circumference of a baseball bat.
  • Slice corn and soybean yields by 91% and 78%, respectively, under severe infestations.

What happened is that many Iowa native seed producers were unable to meet high demand for seed used in CRP and pollinator/wildlife habitat seedings. To obtain all required seeds in conservation mixes, some native seed firms shopped seed species in southern states contaminated with Palmer amaranth.

“At that point, we weren’t even thinking about it coming in the seed,” she says. “It wasn’t like it ever happened, because it did happen in Ohio in 2014. But it was not at the forefront of my mind. When you think about all the feed and bedding sold across state lines, it was pretty incredible that it was the native seed industry that really caused a huge (Palmer amaranth) explosion across the state.”

Anderson quickly plunged into pollinator plots and CRP plantings, helping farmers and landowners detect Palmer amaranth infestations. Her findings also fanned a flurry of web-based stories and newsletters dedicated to the infestations and how to manage them.

“My local crop scout knew I had planted a pollinator plot,” recalls Marc Knupp, a Washington, Iowa, farmer. “He was the first person to tell me I should pay attention to all the writings (about Palmer amaranth) that Meaghan Anderson was doing. I gave her a call and she came out to my farm twice, boots on the ground. She wasn’t afraid to go out in the field, scouting for Palmer amaranth. She is very good.”

Meaghan Anderson spends a share of her days helping farmers identify differences between waterhemp (left) and Palmer amaranth (right).

Contagious Enthusiasm

That doesn’t surprise Hartzler, her mentor at ISU. “Meaghan’s enthusiasm and dedication are contagious,” he says.

Anderson’s dedication to Iowa agriculture was honed while growing up on a west-central Iowa corn and soybean farm near Jamaica. Although initially planning to attend Iowa, she switched to Iowa State University and majored in biology.

“The second semester, I switched to agronomy, and then I decided that is where I wanted to be,” she says. “I’m not sure what sparked the change. It probably had something to do with going home in the fall on weekends, riding with my dad or brother in the combine.”

Her interest in agriculture intensified when she pursued her master’s degree at ISU in crop production and physiology, with a weed science emphasis.

“The trigger for me to go to graduate school was Dr. Bob Hartzler,” Anderson says. “He taught a weed identification class that I took, and that got me intrigued about weeds. They always seem to win, no matter what we do.”

Besides serving as a teaching assistant, she also would help Hartzler with Extension presentations.

“It was really cool to have the opportunity to be an authority on subject matter,” she says. “You would have a lot of people from industry come with questions and have high-level conversations with them.”

That’s what prompted Anderson to accept her current positon in 2015.

“It gave me an opportunity to educate so many people,” she says. "It just seemed to catch on with me.”

Tested Tough

Her agronomic mettle was tested last year. At the start of 2016, Palmer amaranth infested fields in five Iowa counties. By year’s end, it grew to 49, leaving many landowners and farmers stunned.

“They (reactions) ranged from being surprised that it could happen to ‘we can’t believe it’ to outright anger in some cases,” she says. “I don’t think we can ever lie back and feel relaxed about Palmer amaranth anymore, especially since it is now in conservation plantings.”

Complicating the situation is that Anderson and Hartzler had no data from which to make recommendations in CRP and pollinator plantings.

“It was a really interesting situation, when you had between 3- and 7-foot-high Palmer in the middle of CRP plantings. I spent a lot of frustrating afternoons. When I came home from work, I’d tell my husband not to talk to me,” she jokes.

The good news is that farmers and landowners are now aware of what happened in 2016. Meanwhile, most conservation planting mixes are produced north of Iowa in Minnesota, North Dakota, and Canada.

“I would not expect to get Palmer amaranth from those states and country,” she says. “Knowing how those mixes will be produced will be important in the future.”

Still, she cautions farmers and landowners to be vigilant. Palmer not only infiltrated conservation plantings in 2016, but also in cropland. Iowa counties with Palmer amaranth infestations in cropland grew from five to 12 last year. Meanwhile, concerns exist that it can migrate from conservation plantings to cropland.

“It is probably in more crop fields than of what we are aware of,” she says.

If it does, Anderson will be ready to inform her region’s farmers about Palmer amaranth and other agronomic topics for farmers in her area.

“I like to have an ability to help farmers be more efficient on their farms,” she says. “I really enjoy it.”

Meaghan Anderson is featured in Successful Farming magazine’s “10 Up & Comers” section on pages 36 and 37 in the June/July 2017 issue.

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