By Jennifer Jones, CCA, ISA Research Agronomist

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When was the last time you tested for soybean cyst nematode (SCN)? We know SCN is considered the most damaging pathogen to soybeans and is found across Illinois. Populations are increasing, and common sources of plant resistance like PI 88788 are losing effectiveness at controlling SCN. Testing and understanding the SCN egg count in your fields is a crucial piece of the battle to protect your yield and sources of resistance.

The Illinois Soybean Association and University of Illinois are partnering for the fourth year to offer free SCN egg testing to Illinois growers, funded by the Illinois Soybean Checkoff Program. Contact freeSCNtesting@illinois.edu for a free testing kit or download the SCN submission form found on the Free SCN Testing page. The submission form provides detailed instructions on how to collect the soil samples and submit them to University of Illinois for analysis. Nathan Schroeder, a Professor in the Department of Crop Sciences at University of Illinois, runs the program. Check out this recent article where Schroeder explains the sampling process and how to understand the results. Typically, results and recommendations are returned to you in about two weeks, though it may take a bit longer if you submit samples during the busiest sampling period after harvest.

Last year, Schroeder created a list of over 400 commercial soybean varieties with relative maturities of 2.5 to 5, and their advertised source of resistance. The SCN Coalition worked with Schroeder to develop a PDF version of the list, which you can find here. Recently, Schroeder did the same thing for 2027 offerings. Because the free SCN egg testing submission form asks for the most recent soybean variety used in the field where the samples were collected, Schroeder was able to include brands that are used by farmers around Illinois. You can find the 2027 list on the Free SCN Testing page here. The SCN Coalition is currently developing this list into a PDF version like 2026’s.

Another resource developed by The SCN Coalition is the SCN Profit Checker. After receiving your SCN egg count results, you can enter them into the Profit Checker tool to understand how SCN might be impacting your bottom line. It is a good tool to reference and easy to use. The information from this tool should be considered alongside the recommendations you receive from the University of Illinois, not in place of them.

While harvest is likely at the top of your mind right now, remember that this is also a great time to take soil samples to test for SCN before the ground freezes. Don’t miss an opportunity to protect next year’s crop by knowing your SCN numbers.