Soybean cyst nematode is considered the No. 1 pest of soybeans globally, causing yield losses of approximately 100 million bushels a year across the U.S. alone.
It was confirmed for the first time in Cayuga County, N.Y., in 2016.
These high yield losses are due to the pest’s rapid and highly productive lifecycle, but the yield loss estimates don’t relate directly to the current situation in New York.
Still, the best way to avoid these potential losses is to gain a better understanding of SCN populations statewide.
A network of pathologists and nematologists have come together to fight this pest on a unified front through the SCN Coalition. Their website is full of useful information, resources, recommendations and more, including proper sampling techniques, labs you can send soil samples to for testing and best management practices.
Take soil samples now
On top of this, it is highly recommended that New York soybean growers take a proactive approach to identify and manage this pest while populations are low. Right now is the best time to get out and take soil samples.
Once established in a field, SCN is tricky because the pest has been developing races that can overcome the most widely deployed sources of genetic resistance in commercial soybean varieties.
Since SCN populations are low in fields this time of year, it’s important to focus your soil sampling on fields with a long history of soybean production and in areas that are most likely to harbor populations.
The most high-risk areas for finding SCN are compacted areas such as entryways, areas that are frequently flooded, areas where you have found sudden death syndrome, sections with high pH levels and areas of fields that are consistently low-yielding.
Despite your focused soil sampling efforts, you may get zeros as your test results. This doesn’t mean that your fields are SCN-free though because it can be challenging to detect the pest at low population levels due to the way it is distributed in the soil. Zeros are good, but that doesn’t mean you should stop sampling.
Holistic management is best
Although SCN management is getting more challenging, we recommend an integrated management approach. This involves annual testing of fields to know your numbers, rotating SCN-resistant sources in your soybean varieties, rotating with non-host crops such as corn or wheat and utilizing nematicidal seed treatments.
Find a good testing lab
For soil sampling, focus on high-risk areas and collect 15 to 20 1-inch-diameter core samples at 8 inches deep from within soybean rows near the roots. Mix the cores and send them to an SCN testing lab. Follow specific packaging instructions from individual facilities.
Many options are available for SCN testing facilities, including public and private labs. Testing, on average, costs between $25 and $28 per sample at most testing labs.
The Cornell University Plant Disease Diagnostic Clinic offers this service, or you may consider some highly recommended facilities that focus entirely on SCN, such as Midwest Laboratories, SCN Diagnostics or the University of Illinois Plant Clinic.
Most private and public testing facilities accept out-of-state samples.
For anyone interested in further, in-depth information on SCN, check out this hourlong webinar on the biology and management of SCN from Iowa State nematologist Greg Tylka.Cummings is the field crops and livestock IPM coordinator for the New York State Integrated Pest Management.