Most all of the soybean acres in Nebraska have been harvested and while some folks are still working on corn, others are done and are focusing on fieldwork. One thing soybean producers might want to consider at this point is sampling for soybean cyst nematode (SCN).
This pest can be quite yield limiting if not managed properly. New research indicates that 47% of fields tested for SCN in Nebraska now have populations above desirable levels when using a specific resistance package in soybeans, PI88788. This package is very common in soybeans and has been quite effective at managing SCN in the past.
However, several other states are seeing this same pattern of higher SCN populations in fields where PI88788 was successfully used in the past. To determine if this might be an issue in your field, you might want to consider taking soil samples. While sampling can be done any time during the year, fall is usually desirable because yield maps are available to show you spots in the field where yield was low and you can’t explain why.
Another great thing about fall sampling is that in no-till situations, you can see the rows, which makes sampling through the root zone much easier. It is best to test for SCN about every six years. Take samples around the same time and follow the same crop (i.e. soybeans) as you did the last time to compare sample results. If fall samples following a soybean crop yield SCN populations of 16,000 eggs/100cc’s of soil (about half a cup), it is best to rotate out of soybeans. Also, if samples are pulled following corn and yield SCN populations of 12,000 eggs/100cc’s of soil, don’t plant soybeans the following spring. Managing SCN can be difficult, but options are still available. Farmers can consider using varieties that have Peking or Hartwig resistance packages.
These packages are not used as frequently as PI88788; but it might help to switch to those varieties if your SCN populations are increasing where PI88788 is used routinely. Rotating to a non-host crop like corn, milo, wheat, or even alfalfa may help in reducing SCN populations over time.
If SCN resistance could be an issue in your field, talk to your seed dealer this fall/winter about variety selection and what your next steps could be.