Soybean cyst nematode (SCN) is the leading yield-limiting soybean disease in the U.S. and Canada, with estimated losses exceeding 125 million bushels annually. The pest has been detected across 30 U.S. states, three Canadian provinces and Puerto Rico. Yet it often goes unnoticed because aboveground soybean cyst nematode symptoms may not appear until substantial yield loss has already occurred, including irreversible losses of up to 30% in some fields.¹
Early detection and effective soybean cyst nematode control require thorough scouting, soil testing and proactive management, especially in high-risk fields. One of the most overlooked aspects of SCN management is soil health. Healthy soils support more vigorous plants and influence SCN pressure, particularly through soil pH and structure.
Healthier soils equal healthier plants
Healthy soil for soybean production will not eliminate soybean cyst nematode, but it can help plants better tolerate stress. Poor soil structure, compaction, low organic matter, nutrient limitations and poor drainage can restrict root growth. When soybean roots are already struggling, SCN feeding can cause more severe damage.
Cover crops may also support soil health, but species selection matters. Some cover crops, including lupine, field pea and forage pea, can host soybean cyst nematode. Where SCN is a concern, growers should choose non-host cover crops and avoid weeds or volunteer soybeans that can allow nematode populations to persist.²
Soil pH impacts soybean cyst nematode levels
Soil pH can affect soybean cyst nematode reproduction. SCN tends to reproduce more successfully in soils with a pH above 6.5, while slightly acidic to neutral soils around pH 6.0 to 6.5 may be less favorable for population growth. Growers should not manage pH for SCN alone. Still, pH should be part of a complete soybean soil test that also evaluates nutrient availability and other soil factors influencing soybean health.³
Is no-till or reduced tillage effective for soybean cyst nematode control?
No-till and reduced tillage have a complex relationship with soybean cyst nematode. No-till practices can help reduce SCN populations when weeds and volunteer plants are adequately controlled.Many weeds and volunteer soybeans can serve as alternative hosts for plant-parasitic nematodes, allowing populations to persist between soybean crops.
Therefore, successful SCN suppression in conservation tillage systems hinges entirely on rigorous weed management. Without eliminating these opportunistic hosts, the benefits of reduced soil disturbance are quickly undone, leaving fields vulnerable to sustained infestation.
Tools for soybean cyst nematode control
The strongest soybean cyst nematode control program uses multiple tools.
Planting SCN-resistant soybean varieties remains one of the most economical management options. Growers should select varieties resistant to the specific SCN race or type present in the affected field.⁴ However, overreliance on the same resistance source can reduce long-term effectiveness, so growers should rotate resistance sources when possible.
For SCN specifically, rotating with nonhost crops such as corn, cotton, tobacco, wheat, rye, oats or sweet potato is a strong and reliable management tool to reduce population pressure.
Seed treatments can add another layer of protection. ILEVO seed treatment is used in soybeans to help manage sudden death syndrome and has activity against SCN.
Newer trait technologies are also expanding the SCN toolbox.Nemasphere is a biotechnology trait, set to release in 2028, developed for soybean cyst nematode management and is designed to help reduce nematode reproduction from within the plant.
Healthy soil for soybean production can improve plant vigor, but controlling soybean cyst nematode depends on understanding field pressure and using the right combination of tools. Regular soil testing, non-host crop rotation, resistant varieties, seed treatments and sound agronomic practices all work together to reduce soybean cyst nematode yield loss.
Experts are available to help you make your soybean cyst nematode management decisions. Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative.
________________________________________________
Endnotes
- Bissonnette, Kaitlyn, Travis Faske, and Albert Tenuta. “An Overview of Soybean Cyst Nematode.” Crop Protection Network, 23 April 2021, doi:10.31274/cpn-20210423-0, cropprotectionnetwork.org/publications/an-overview-of-soybean-cyst-nematode.
- Strunk, Connie. “Cover Crop Considerations When Dealing With Soybean Cyst Nematode.” SDSU Extension, South Dakota State University, 10 Feb. 2022, https://extension.sdstate.edu/cover-crop-considerations-when-dealing-soybean-cyst-nematode.
- Bissonnette, Kaitlyn, Faske and Tenuta. “An Overview of Soybean Cyst Nematode.”
- North Carolina State Extension. “8. Soybean Nematode Management.” North Carolina Soybean Production Guide, NC State Extension Publications, content.ces.ncsu.edu/north-carolina-soybean-production-guide/8-soybean-nematode-management.
