Beneath healthy-looking soybean fields across the U.S., a microscopic thief quietly steals bushels—and billions of dollars—without farmers ever knowing it’s there. Soybean cyst nematode (SCN) has become the nation’s most destructive soybean pest, inflicting an estimated $1.5 billion in yield losses annually while typically leaving no obvious signs of distress above ground.
That was Michael and Dennis Gallagher’s experience with SCN on their west-central Iowa farm some years ago, after getting their first yield monitor in 1998. During harvest, Dennis saw soybean yields registering 55 to 60 bushels across the field on the monitor. Then, in one area of the same field, yield suddenly dropped into the mid‑30s — with no visible difference in the crop.
“Dad wasn’t surprised to see a few drops here and there, but not a 20-bushel one,” Michael recalls.
The unexplained drop pushed Dennis to pull soil samples. The test came back showing very high SCN egg counts — a " huge number,” Mike recalls, confirming soybean cyst nematode as the cause of the hidden loss.
“That was our aha moment,” Michael recalls. “I was only 7 years old at the time, but that made a big impression on me.”
A Fundamental Shift in SCN Management
Since that SCN discovery, the Gallaghers have incorporated the use of native traits — PI 88788 and Peking — in their soybean crops to counter the pest, along with rotating to corn.
Michael adds that they look forward to using a new solution for SCN on the way from BASF Agricultural Solutions, Nemasphere. It is the first-ever biotech trait designed specifically to address SCN and prevent soybean yield loss.
Nemasphere represents a fundamental industry shift in the battle against SCN, unlike traditional native resistance found in PI 88788 and Peking. Nemasphere is based on a transgenic trait—a Cry14 protein engineered directly into the soybean, says Hugo Borsari, BASF vice president of business management for seeds in North America.
The protein targets SCN the moment the pest feeds on developing roots, delivering up to a 60% reduction in SCN populations. The transgenic trait helps farmers capture significantly higher soybean yields compared to traditional varieties relying solely on native traits.
“We’re not just adding yield; we’re giving farmers access to the yield potential SCN has taken away,” says Borsari.
Yield Protection as a Game Changer
SCN often skims up to 30% of the soybean yield potential in infected fields. When considering what that loss represents in dollars, the impact is staggering, reports Greg Tylka, Iowa State University nematologist and professor.
“You want to make the most return on investment from your input costs, and then you got this microscopic, some people think imaginary, little critter that lives in the soil that’s kind of holding back your yield,” he says. “So the better you can manage SCN, the more you’re going to get out of your seed, your fertilizer, your herbicides, and so forth.”
Importantly, Nemasphere controls SCN before egg development. Female SCN remove roughly 30 times more nutrients from the plant than males due to the energy required for egg production. Blocking that production provides a direct hit on future SCN populations and an immediate protection of plant resources.
Because the new trait is expressed by the plant itself, the protection follows the roots as they grow, rather than staying confined to the seed zone.
“You’ll get season-long control all the way out to the growing tips of the root, which is extremely important, because we know SCN always wants to infest the growing parts of the root system,” says Mike McCarville, trait technology lead for BASF.
Do You Have SCN In Your Soybean Fields?
For farmers who don’t know whether they have SCN, Tylka recommends soil testing for them.
Another option to consider, he adds, is to think about whether your soybean yields are not increasing while your corn yields are.
“If you’re seeing your corn yields go steadily up while your soybeans are not, that’s often a key sign you have SCN,” Tylka notes.
More Than a Nematicide: A Comprehensive Package
While stopping SCN is the primary focus, Nemasphere is being developed as part of a broader yield protection package. The trait will be stacked with the Enlist E3 herbicide system and adds tolerance to mesotrione (HPPD chemistry), providing a residual pre-emergence herbicide option in soybeans.
McCarville sees the package as a way to tackle multiple yield-limiting factors simultaneously. “All of this is driving at growers being able to harvest more of the yield potential that our breeders deliver every year and get out of that stagnating yield position in soybeans,” he says.
USDA estimates the genetic gain in soybean varieties is roughly 1 bushel per acre per year, but SCN and other environmental stresses mean farmers often only see a fraction of that progress in their bins. “What’s actually harvested is somewhere between a quarter and a half of that potential that the breeders are delivering,” McCarville notes.
Along with helping farmers “recapture” existing soybean yield potential, the new trait helps shut down additional disease issues that can develop from the damage SCN causes. McCarville estimates that roughly a third of all soybean disease losses are tied to SCN in some way. Issues like seedling blights, Sudden Death Syndrome (SDS), and brown stem rot can all become more frequent or more severe when SCN is present.
“SCN doesn’t just cause harm by itself,” he says. “It’s like the instigator at a party, encouraging everybody else to misbehave and cause problems. Both the incidence and severity of these other diseases are increased by SCN.”
Looking Ahead To 2028
With Nemasphere slated for a 2028 commercial release, the industry is looking toward a future where SCN is finally held in check.
McCarville says farmers interested in giving the new technology a hard look will have the opportunity in extensive field plots this year and will be testing the product in 2027.
For more information on the technology and where to see it at work, reach out to your local BASF representative or retailer.
