National Nematode Day returns on October 6, 2025, and it serves as a timely reminder that the most damaging soybean pathogen in North America is often the one you don’t see. Soybean cyst nematode (SCN) continues to reduce yields in Ohio, even in fields without visible symptoms. The best way to stay ahead of this pest is to know your numbers, and post-harvest is the ideal time to sample.
Why Sample Now?
Once the combine leaves the field, the window is wide open for collecting accurate SCN soil samples. Residue is low, equipment is out of the way, and soil conditions typically allow for easier probing. Fall sampling provides a realistic picture of SCN egg densities after a full growing season and gives you time to plan management strategies before the next soybean crop.
Even fields that appear healthy can experience 5–30% yield loss with no aboveground symptoms. This applies not only to fields coming out of soybeans, but also to those that will be planted to corn next season or were in corn this year and will return to soybeans. Routine testing is the only way to detect shifts in populations, assess the effectiveness of resistance sources, and prevent long-term yield decline.
Free SCN Soil Testing
Thanks to continued support from the Ohio Soybean Council, each Ohio grower can submit two soil samples at no charge for SCN testing. This program is designed to help you monitor SCN pressure without cost being a barrier.
To participate:
- Complete the SCN sample submission form
→ Download and complete the Soil Sample Submission Form
- Collect soil cores following standard guidelines
(10–20 cores per sample, 6–8 inches deep, mixed in a clean bag)
- Send samples and the completed form to:
OSU Soybean Pathology and Nematology Laboratory
Attn: Dr. Horacio Lopez-Nicora
110 Kottman Hall
2021 Coffey Road
Columbus, OH 43210
Samples will be processed for egg counts, and results will be shared directly with the submitter.
Turn Your Results Into Decisions
Once you receive your SCN numbers, take the next step by using the SCN Profit Checker, an online tool from The SCN Coalition. By entering a few field details, you can estimate yield loss and understand the economic return of resistance management, crop rotation, and other practices.
Knowing your SCN levels now can help you select appropriate varieties, evaluate resistance sources like PI 88788 or Peking, assess the need for seed treatments, or make rotation decisions before spring.
Take Action This Fall
National Nematode Day is more than a date, it’s a reminder to protect soybean yield potential through testing and management. Sampling after harvest is quick, inexpensive, and one of the most effective steps you can take to manage SCN long-term. Follow #nematodeday on social!
If you have questions about sampling, reports, or SCN management strategies, contact:
Horacio Lopez-Nicora, Ph.D.
Assistant Professor and Soybean Pathologist/Nematologist
The Ohio State University
lopez-nicora.1@osu.edu