Thus far, the HG type for 11 fields has been determined, and they were all HG type 0. Testing populations from the other fields is still in progress. Some of these fields have been infested with SCN for 8 to 10 years and have been in production with SCN-resistant soybean cultivars. Thus far, we have not found evidence for a virulence shift in the fields tested, however, more fields need to be tested for a more accurate examination of virulence changes. Additional infested fields were sampled in 2014.
This information will be useful to soybean growers who use host resistance as the primary management tool for SCN. Evidence about a shift in virulence will alert growers that different sources of host resistance may be needed to manage SCN in the area.