With the weather warming up, you may want to consider getting your fields sampled for soybean cyst nematode (SCN) this spring if you have never sampled them or if it has been a while; especially if yields maybe lower than expected or if you have areas in fields that have spots that yielded poorly. These could be hot spots for SCN. It would be good to definitely sample these areas of the field. Sudden Death Syndrome (SDS), a disease that lives in the soil also showed up in some fields this past year. There is a very close relationship between SDS and SCN. Many times if you have SDS, you also may have SCN. You may want to sample areas in a field where SDS was present for SCN.
We have been emphasizing the importance of sampling your fields for SCN the past several years. Loren Giesler, former UNL Extension Plant Pathologist and John Wilson, Extension Educator have conducted several workshops over the years, about the importance of managing for SCN and that soybean cyst nematode is the most important pest of soybean in the world. It can reduce soybean yields 30% without showing any visible symptoms. It can cause significant yield loss if not kept under control. It has been moving west from the Missouri River. This pest has been identified as a common problem in Missouri and Iowa and it is being identified in more fields each year in Nebraska as well. In Nebraska, 59 counties have confirmed presence of SCN mostly in eastern Nebraska, but in counties that produce over 92% of Nebraska’s soybeans. Every county that borders the Missouri River in Nebraska is infected with SCN. Soybean cyst nematodes live in the soil and once they infest your soil, you will have them forever. Most of the soybean growing regions of the United States are infested with SCN. With all the flooding in recent years, it would be good to soil test fields for SCN this spring, especially if fields will be going into soybeans in 2021.
The University of Nebraska-Lincoln has conducted SCN research in Nemaha County and other locations in southeast Nebraska as well. Nebraska Extension’s On-Farm Research Program had a research trial evaluating the seed treatment ILeVO on a farmers field in Missouri in 2016. Nebraska Extension and the Nebraska Soybean Board continue to have a program that will pay for a soil analysis for SCN. If you are interested in sampling some fields, UNL Extension in Nemaha County has instructions on sampling for SCN, a soil probe available for use, and sample bags in our office. I am also available to sample fields in southeast Nebraska this spring. All the counties in southeast Nebraska have fields that have tested positive for SCN. Feel free to call (402) 274-4755 or stop by our office in the Nemaha County courthouse in Auburn if you are interested in participating in this program. So if you sample your fields, what should you do if you find SCN? Soybean cyst nematodes can be controlled by best management practices and their impact on soybean production will be reduced significantly. If you do have SCN, plant a resistant variety, rotate to non-host crops, such as corn and wheat, and plant soybean varieties with different sources of resistance. This year there is soybean variety that has been released with another source of resistance that can be used to reduce the impact of SCN, PI 89772 (recently available from Golden Harvest). For SCN infested fields, you also may want to consider planting these fields last and/or cleaning any tillage or planting equipment before moving on to a different field. Check with your seed dealer to determine the best soybean varieties to meet the requirements of resistance for SCN. If you have any questions about SCN, feel free to contact me at (402) 274-4755, (402) 274-9639 (cell) or firstname.lastname@example.org.