Soybean Cyst Nematode Found in Williams County
The soybean pest, confirmed in western North Dakota fields, can cut yields by up to 30 percent even when plants look healthy.
Updated on Nov. 3, 2026 in Agriculture
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Soybean cyst nematode, Heterodera glycines, was confirmed in soybean fields in Williams County, North Dakota. The finding shows the pest is not confined to eastern parts of the state.
Why it matters
Soybean cyst nematode is the most damaging soybean pest in the United States and continues to spread across North Dakota mainly through movement of infested soil. Because western North Dakota remains under-sampled, additional infestations may be found in the region.
Soybean cyst nematode can reduce yields by up to 30 percent even when plants appear healthy. The source does not state how many acres in Williams County are affected.
The players
NDSU Extension
The extension service of North Dakota State University, which provides research-based agricultural education and runs the free SCN Soil Sampling Program for producers.
North Dakota Soybean Council
A state checkoff organization that funds soybean research and promotion and partners with NDSU Extension on the free SCN Soil Sampling Program.
The details
NDSU Extension and the North Dakota Soybean Council offer a free SCN Soil Sampling Program that producers can use after harvest by sampling around soybean roots. Producers are also advised to limit soil movement on equipment between fields to slow the pest's spread.
Timeline
Article reporting the Williams County confirmation was published on November 3, 2026.
Market Landscape
The discovery in Williams County shows soybean cyst nematode has moved beyond eastern North Dakota, where it was previously concentrated. This expansion underscores why the free NDSU Extension SCN Soil Sampling Program is pushing testing into under-sampled western counties.
Producers can use the free SCN Soil Sampling Program to test fields after harvest. Limiting soil movement on equipment between fields helps slow the spread of the nematode.
The takeaway
Because soybean cyst nematode can cost yield even when plants look healthy, testing fields is the only reliable way to know whether it is present. Producers in western North Dakota should consider sampling even if no symptoms have appeared.
Further reading
For more on crop pests and farm practices across the state, see Agriculture in North Dakota coverage.
Source note: This article includes information reported by The Roundup.
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