Soybean cyst nematode (SCN) is the number one yield-reducing pest of soybean crops globally and in the US. This pest causes twice the domestic soybean yield loss of any other disease, and since 1996 has caused an average annual loss of $1.5 billion in the US alone. Yield losses of up to 60% have been reported, though losses of up to 30% can occur with no above-ground symptoms. This is a pernicious pest with often subtle or unremarkable above-ground symptoms when they do manifest, so growers may assume that either SCN is not in their fields or that it isn’t a problem until they see widespread symptoms or severe yield reduction.
Extensive collaborative sampling for this pest from 2014-2019 was coordinated by Cornell University and Cornell Cooperative Extension programs and was supported by the NY Corn and Soybean Growers Association (NYCSGA), NYS Dept. of Agriculture and Markets (NYSDAM) and Northern NY Agricultural Development Program. Over the six years of these soybean disease surveys, SCN was positively identified in 7 of 24 sampled counties.
Funding through NYCSGA and NYSDAM allowed for testing of an additional 104 fields across the state in 2020. Of these fields, 51 tested positive for SCN (49.04%), and positive samples were collected from 29 of 41 total counties tested (70.73%). In 2021, surveys supported by NYCSGA and the NY Dry Bean Industry identified SCN infestations in another 6 counties where it had not previously been detected. Since it was first identified in NY in 2016, SCN has been confirmed in 36 of the 46 counties sampled.
Continued surveillance testing for this pest is critical toward management, as NY soybean growers need to be aware if they have SCN in their fields (and at what severity) so they can stay ahead of the infestation and make integrated management decisions. By utilizing our network of field crops extension specialists and a reliable testing facility that specializes in this pest, we can cast a broad net for sampling and receive dependable results for our efforts.

1. Collaborators will sample a total of up to 75 soybean fields around NY state for SCN.
2. Samples will be submitted to a lab dedicated to SCN identification at the University of Missouri (SCN Diagnostics) for proper analysis.
3: Results from the testing facility will be shared with growers and summarized for sharing via websites, extension meetings, reports, and articles. Positive test results will be shared with participating growers and will include extensive educational information and resources on best integrated management practices to minimize losses to this pest.

The specific objective of this proposal is to encourage statewide monitoring for SCN by providing funding to offer this service to soybean farmers across NY.

Updated July 28, 2023:
Once again this year, NYCSGA is the only funding source for this type of soybean cyst nematode soil sampling in NY soybean fields. We have at least 7 extension agents who have signed on to this project so far, and we are working toward identifying fields that we plan to sample this fall. In addition, the USDA-ARS (Ithaca) will conduct in-depth SCN identification assays on fields sampled in this study. Fields identified as having high SCN populations will be sampled more intensively in order to potentially identify SCN race, that is, whether that given SCN population may be more or less injurious toward certain soybean varieties.
Soybeans have recently begun flowering in NY, so many conventional growers are applying protective fungicides in order to limit damage by white mold and other pathogens. Several popular fungicides also have activity on SCN, so the effect on our samples remains to be seen.
Last year's SCN populations showed an increase from previous growing seasons. We're eager to continue monitoring known populations to identify populations increases as they happen, and to identify new or previously undetected populations.

Updated October 30, 2023:
Soybean harvest is underway, and so far we've submitted 45 samples to the testing lab, and we're expecting to submit more as harvest activities continue. Soybean crops suffered from a number of fungal pathogens this year. SCN infestation is associated with fungal disease, so we may see some significant SCN pressure this year.

Now that we have confirmation that SCN has spread throughout the state, not only do we need to identify outbreaks in previously unaffected or untested fields, but we also need to monitor population levels on an ongoing basis to provide relevant and reasonable management recommendations to growers, whether they be specific crop rotations, genetic resistance, nematode protectant seed treatments, or a combination of all three. While populations of SCN in NY have shown thus far to be primarily low to moderate, we have a better chance of managing yield and financial losses by continuing to monitor population levels to keep them in check before they become unmanageable.
Compounding the issue are the many other agronomically important soybean diseases that have been identified as new or expanding in soy production areas across NYS in recent years, including sudden death syndrome, brown stem rot, and northern stem canker. These soilborne diseases, especially sudden death syndrome, are often highly correlated with SCN infestations. Given the potential impact this pest could have on NY soybean production, especially as the associated diseases expand, we feel it is important to continue our monitoring efforts to stay ahead of this pest in NYS, to continue to raise awareness of its threat to crops, and to arm NY soybean growers with information about the SCN populations that may be in their fields.
New York is fortunate compared to other states who have been dealing with SCN for decades, in that we have the opportunity to track this pest as it expands through our state, allowing us to implement integrated management strategies before populations get out of control and yields are severely impacted.