A simpler way to stay ahead of SCN

August 20, 2026 | Kriss Nelson

Soybean cyst nematode remains the No. 1 yield-robbing pest of soybeans, yet many Iowa farmers don't know it's affecting their fields until significant yield has already been lost.

For Michael Grob, a soybean farmer and chief operations officer of Minnesota Valley Testing Laboratories, that needed to change.

“As a farmer myself, it sounded like it'd be kind of handy to have something that was a little more useful and could be part of our normal fertility sampling without having to take the extra sample,” Grob says.

That idea led MVTL and Freyr Diagnostics to develop NEMAGENE™, a DNA-based soybean cyst nematode test that uses polymerase chain reaction technology to detect SCN from the same soil sample already collected for routine fertility testing. Growers simply request the test with their fertility analysis, receiving SCN results alongside fertility recommendations in 24 to 72 hours.

Research in action

The Iowa Soybean Association is also evaluating the technology through its ongoing soybean cyst nematode seed treatment trials, comparing Syngenta’s new Victrato treatment with ILEVO, Saltro or untreated soybeans, depending on the location. Most trials compare Victrato directly with ILEVO.

Soil samples collected from those research sites will be analyzed using NEMAGENE™ to measure SCN egg counts and to determine how populations change throughout the growing season.

Alex Schaffer, ISA research agronomy lead, says the technology's greatest value may be making routine SCN monitoring easier for farmers.

“What we think will be valuable for farmers is that they can take a subsample from the regular fertility sample they're already collecting,” Schaffer says. “That eliminates the need to collect a separate SCN sample and makes it much easier to monitor fields on a regular basis.”

From reactive to proactive

As both a farmer and laboratory leader, Grob says the biggest advantage isn't simply receiving results more quickly; it's changing how farmers think about SCN.

“Up to this point, SCN testing has been very reactive,” Grob says. “You'd notice yellowing in the field, wonder what was wrong, and then pull samples to see if it was nematodes. Now, by working it into the normal fertility sample, you can make management decisions before the problem costs you yield.”

Instead of collecting a separate SCN sample, growers can simply request the NEMAGENE ™ test when submitting routine fertility samples. The test is performed on the same soil sample, allowing SCN results to be delivered alongside fertility recommendations.

Knowing where SCN populations exist allows farmers to make informed decisions about crop rotation, resistant soybean varieties, seed treatments and nematicide applications. Rather than treating an entire field, management practices can be targeted to areas with the highest SCN populations.

Grob has already used the technology on his own farm.

Field maps showed SCN wasn't evenly distributed across his fields but concentrated in smaller areas. Those maps now help guide management decisions much like fertility or yield maps.

“It just gives you a lot more information about what you've got throughout the field so you can make better management decisions,” Grob says.

Don't wait for symptoms

Dr. Lisa Miller, principal scientist at MVTL, says one of the biggest misconceptions about SCN is believing growers will see it before it affects yield.

Research has shown soybean fields can lose as much as 30% of their yield before visible symptoms appear. During one field visit, Miller found a small area that looked only slightly shorter and lighter green than the surrounding soybeans. Testing revealed approximately 8,000 SCN eggs.

“You don't know that you have a problem there,” Miller says. “This area is going to look terrible in two years when you come back to soybeans, and you don't know that yet.”

She says that's why broad, routine testing is so important. Testing allows growers to establish a baseline across their fields and monitor trends before populations become economically damaging.

“It's much easier to keep soybean cyst nematode populations low than it is to bring high populations back down,” Miller says.

Because SCN populations vary dramatically across a field, even moving a soil probe a few inches can produce very different egg counts. Sampling across the field provides a much more accurate picture of where populations exist and where management changes may be needed.

Testing made easy

Testing for soybean cyst nematode no longer requires an extra trip through the field or a separate soil sample. With NEMAGENE ™, growers can add SCN testing to their routine fertility analysis, making it easier to detect problems early and make informed management decisions before yield losses occur.

Sample Once – SCN testing with NEMAGENE ™ uses the same sample collected for your soil nutrient analysis – no additional sampling required.

Request SCN Testing – Simply include “SCN” on your submittal form to request SCN testing.

Result Delivery – SCN results are delivered alongside your soil nutrient results, typically within two business days.

Familiar Metrics – SCN levels are reported eggs/100 cc soil, using the same metric as the traditional method.

<subhead> Proactive management

For Grob, the investment is easy to justify.

At roughly $2.50 per acre on 10-acre grids, he says the information pays for itself if it helps recover even modest yield losses.

“Would you spend $2.50 an acre to gain another 10 bushels of soybeans?” Grob says. “I would do that all day long.”

He believes the new testing approach gives farmers something they've never had before - a practical way to make SCN management proactive rather than reactive.

“We've always managed fertility with information,” Grob says. “Now we can manage SCN the same way.”

For more information about NEMAGENE™ or soybean cyst nematode testing, contact Ben Carlson, Iowa agricultural services representative with Minnesota Valley Testing Laboratories, at bcarlson@mvtl.com or (515) 382-5486. You may also contact Derek Swanson-Cullen, agricultural services representative with Minnesota Valley Testing Laboratories, at dswansoncullen@mvtl.com or (507) 276-7114.

Written by Kriss Nelson.

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