As reported earlier, 46 Todd County soybean fields in the fall of 2021 to determine the level of soybean cyst nematode (SCN) activity.  The results of those tests were reported in terms of the number of nematode eggs per 100 cubic centimeters of soil.  Based upon those egg numbers, the fields were evaluated for the odds of SCN related yield reductions.  The 46 fields sampled belonged to 33 different producers.

After the results from the tests were received in January, I personally visited each producer to help them understand their results, and to discuss recommendations for dealing with SCN in their situation.  I also created a one-page fact sheet titled “Understanding Your Soybean Cyst Nematode (SCN) Egg County Numbers” to help producers understand how the samples were collected and the production practices needed to minimize SCN yield losses.  UK soybean disease specialist Dr. Carl Bradley reviewed and approved the factsheet.

Of the 46 fields sampled, 5 were considered at low risk for SCN related yield reductions.  Eighteen fields were considered as moderate risk and 22 fields were considered at high risk for SCN yield reduction.  One field was rated as “Over Threshold” meaning that it was at a very high risk level.

There are 2 basic production practices for dealing with soybean cyst nematode:  crop rotation and use of SCN resistant soybean varieties.  I shared that information with each producer, and also explained to them that there is currently only one source of SCN resistance available in all commercial soybean varieties.  Consequently, we expect that the effectiveness of that resistance will decline over time.  Growers should look for an opportunity to utilize different resistance sources if they become available in high-yielding soybean varieties.