Asgrow test plot

Asgrow’s Chancellor, S.D., test plot sits across the road from the Poet Biorefinery. It is home to dozens of field tests in both corn and soybeans.

Nematodes are one of the most ubiquitous insects on the planet, and they have adapted to nearly every environment, including farm fields.

Discovered over 260 years ago, nematodes have been known as a crop pest for longer than most farmers can remember and managed for just as long. However, as traditional treatments are becoming less effective, new tools are going to be needed to treat the sneaky insect.

One company’s answer is NemaStrike, a seed treatment that is part of Monsanto’s Acceleron Seed Treatment system. It is in its final stages of test plot sampling and will hit the open market starting next year.

Testing has been conducted throughout the Midwest, but for Asgrow agronomist Jeff Spieler, the NemaStrike test plot in Chancellor, South Dakota, is where he sees results.

With a yield boost averaging just about a six bushels per acre for corn and a two bpa on beans, the NemaStrike system has proven to help yield in even the mildest of nematode pressure areas, he said.

“Controlling them will certainly be a benefit for producers,” Spieler said.

The reason for the treatment and testing was because of the recently studied impact nematodes have in corn. Soybean cyst nematodes, have been spreading in eastern South Dakota in recent years, but nematodes in corn – a completely different species – have gone relatively unmonitored.

“We’ve been studying what their pressure is in terms of how much economic damage they can cause,” Spieler said.

NemaStrike targets nematodes that attack both beans and corn.

While little is known about nematode’s impact in corn as of yet, researchers believe the studies on soybean cyst will help treat other species of nematodes.

“(Soybean cyst is) a very serious nematode,” said South Dakota State University Extension plant pathologist, Emmanuel Byamukama. “We could have as high as 30 percent yield loss with just a moderate population of nematodes.”

During Byamukama’s time studying nematodes, it has been determined that a high pressure of nematodes occurs once around 10,000 eggs are discovered in 100 cubic centimeters of soil during testing.

Byamukama has seen dozens of fields at that level or beyond it and believes nematodes are present in over 30 counties in South Dakota, although most of those are on the eastern side of the state due to the prevalence of soybean growing in the eastern half of the state.

Throughout his studies, Byamukama has discovered several key things to help control nematode populations that he believes could be applied to any species of nematodes. Firstly, crop rotation is the best way to minimize nematode’s impact in your soil, he said.

“One year out of soybeans is not enough,” he added.

For high-pressure areas, Byamukama recommends that three or more years be taken between soybean or corn rotations to help minimize the impact they’ll have. In addition to a standard rotation, he also recommended farmers take soil samples every two to three years to make sure whatever method they are using is working.

Surprisingly, the most ignored aspect of nematode management is weed control, Byamukama said.

During his studies, he has noticed that several prominent weeds in South Dakota also host nematodes. He urged every producer to check with their agronomist to make sure that their treatments are targeting weeds, the crop and the ground itself.

For producers in high pressure zones, Byamukama urged them to look at seed treatments such as NemaStrike as a way to add to their portfolio of attacks against the insect. He said adding a seed treatment can help manage them as to not overuse standard treatments and create resistance issues.

Like most situations, Spieler said that the use of NemaStrike depends heavily on the history of the ground you’re working with. Both Byamukama and Spieler agreed that rotations are the easiest way to minimize risk, but ultimately tests will help determine if its working.

“Unfortunately, you can see the damage in beans but you can’t see the damage in corn,” Spieler said.

The Chancellor test plot for Nemastrike will wrap up its findings in November, but Spieler said they have a good feeling the seed treatment will follow the trend of increasing yield by roughly 15 percent compared to non-treated seeds.

Reach Reporter Jager Robinson at 605-335-7300, email or follow on Twitter @Jager_Robinson.


Jager is a repoter for Tri-State Neighbor, covering South Dakota, southwestern Minnsota, northwestern Iowa and northeastern Nebraska.