Leafy Spurge Invasion
Camp Gilbert C. Grafton, the home of the North Dakota Army National Guard's engineers,
is regularly invaded by troops with tracked vehicles, bulldozers, graders, scrapers and other
heavy equipment. But there's another invader there too: leafy spurge.
This noxious weed is a problem across North Dakota and the camp's nearly 10,000 acres
near McHenry. It causes deterioration of native vegetation, wildlife habitat and cattle grazing value.
"Our soil is a very sandy loam, and if we're not good stewards of the land, it could soon
look like a desert," says Lt. Col. Rick Moszer, plans and operations officer at the camp. "With
NDSU we've been working to find how best to manage the land so that we may continue to have its use."
Collaboration with NDSU on leafy spurge control began in 1985 when the camp was
expanded by nearly 8,000 acres. Researchers released about 100 flea beetles at several
sites, including Camp Grafton, hoping the insects would kill the leafy spurge.
The beetles multiplied and thrived across the state, and millions of them were captured
and moved to other spurge-infested land in North Dakota and surrounding states in cooperation
with the N.D. Department of Agriculture, the USDA and county weed boards. In some areas,
the beetles nearly eliminated leafy spurge, but not at Camp Grafton.
"We've learned that the beetles don't do very well in sandy soil," says entomologist
Denise Olson. The camp is one site where she's testing long-horn beetles, another pest that preys on
leafy spurge.
Researchers also used cattle and angora goats to combat leafy spurge at the camp. The latex
in leafy spurge irritates the mouths and throats of cattle. Sheep and goats, however, relish the plants.
"Camp Grafton was our first significant opportunity to study this problem," says range
scientist Bill Barker. After three years, the researchers achieved 70 percent control. "But we didn't know
how to manage the goats and we suffered up to 40 percent mortality."
That prompted a shift to sheep. After three years of grazing with sheep and cattle, control
was back to 70 percent. After four years, control was at 80 to 90 percent. The grazing helped
bring the weed under control and cut herbicide costs at the camp by $20,000 or more.
Now the camp hosts training for producers, land managers and Extension staff. NDSU
graduate students who worked on Camp Grafton projects now direct control efforts around the region.
One student, Kevin Sedivec, is now NDSU's extension rangeland management specialist.
He works with Tim Faller, director of NDSU's Hettinger Research Extension Center, on
related projects near Bismarck and Sentinel Butte and cooperates in work at Camp Grafton. Additional
work is under way at NDSU's Ekre Ranch near Walcott. Those studies expand on earlier lessons and
tailor treatments to local conditions.
Much of the work is part of Team Leafy Spurge, a USDA-funded effort in North and
South Dakota, Montana and Wyoming directed by former student Chad Prosser, now with the USDA.
As part of that effort, NDSU researchers studied the economics of control methods. Next, they'll look
at the impact of research so far. "Where land managers have stopped leafy spurge from spreading
and are reclaiming land, we want to assess the economic impact," says economist Dean Bangsund.
Thanks to the efforts of weed scientist Rod Lym, Plateau is the latest herbicide to be labeled
for use on leafy spurge. Like most herbicides used on leafy spurge, fall-applied Plateau was tested
at Camp Grafton. Traditional treatments of Tordon plus 2,4-D applied in June didn't work at
Camp Grafton because that's when most training occurred.
Manufacturers don't test their products on leafy spurge because the market is too small.
Plateau was developed for use on peanuts. Lym helps determine the proper rate and timing
for applications and must show that no harmful residues remain.
Lym was one of the earliest cooperators at Camp Grafton. He's now studying grasses
that compete with leafy spurge. "We try to use everything that's available and find out what
combinations work. Herbicides, grazing or insects might not work on their own, but maybe they can weaken
leafy spurge so that well-managed grasses can compete or herbicides are more effective."
For more information: Bill Barker, 701-231-7222, william.barker@ndsu.nodak.edu
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