Soybean Cyst Nematodes: Most Damaging Pest In Nebraska

Extension educator hands out 'Tode Awards' to the state's counties.

Published on: Apr 4, 2013

John Wilson is well versed in soybean cyst nematodes and their management. He annually gives out what he calls "Tode Awards" to Nebraska counties for their work in sampling for soybean cyst nematodes. SCN, he adds is, the most devastating pest in Nebraska soybeans. Last year SCN losses were estimated at $40 million in Nebraska and over $1 billion nationally.

Losses from SCN can be reduced if a farmer knows it is present, but there's the catch. Farmers can have yield losses of 20-30% with no visible plant symptoms. Often the first indication of an SCN problem is when soybean yields plateau, or even start to drop off, while corn yields continue to increase in the same field.

John Wilson, left, visits with a producer during a 2012 soybean cyst nematode field day.
John Wilson, left, visits with a producer during a 2012 soybean cyst nematode field day.

The best way to determine if SCN is present in a field is to take a soil test. The Nebraska Soybean Board recognizes the seriousness of this pest and has funded a project with UNL to encourage farmers to sample their fields for SCN. The Soybean Board's support covers the cost of analyzing soil samples, normally a $20 per sample cost.

We just completed the eighth year of this sampling project with some staggering results. Since 2005, almost 4,400 samples have been submitted and SCN has been identified in 27 Nebraska counties for the first time. That's twice the number of counties where it had been previously identified, Smith says. Since it was first discovered in Nebraska in 1986, SCN has now been identified in 54 counties that produce over 90% of Nebraska's soybeans.

"Without the Nebraska Soybean Board's support, we would not have been able to reach this many Nebraska farmers," he says.

In 2012, 540 samples were submitted and 219 (40.6%) were positive for SCN.

"From these results, we have identified the 4th Annual 'Tode Award winners," he says.

They are:
Most Samples Submitted
•Winner: Buffalo County (109)
•Honorable Mention: Kearney County (45), Saunders County (40), Platte County (29)

Most Samples Positive for SCN
•Winner: Buffalo County (32)
•Honorable Mention: Saunders County (31), Kearney County (20), Seward County (16)

Highest Percentage of Samples Positive for SCN
•Winner: Douglas County (100%)
|•Honorable Mention: Dodge County (82%), Polk County (80%), Madison County (78%)

Sample with Highest Egg Count (number of eggs/100 cubic centimeters of soil)
•Winner: Pierce County (88,200)
•Honorable Mention: Seward County (45,240), Saunders County (37,560), Platte County (31,360)

"This is the first time in 15 years that we haven't detected SCN in a new county, but that's not surprising given that less than 10% of the state's soybean production comes from counties where it hasn't been identified," Smith says. "Having over 40% of the samples come back positive for SCN was the highest level since we began the sampling program."

Although it often goes undetected, SCN is reducing the profitability of Nebraska's soybean production. To learn more about SCN or to pick up bags for submitting soil samples contact your local UNL Extension office.