Soybean Cyst Nematode
To determine if nematodes are a problem, soil samples should be retrieved from the field and the soil analyzed through state plant diagnostic clinic or nematology labs. The type of nematode common in the southern US will be identified with soil test results. Varietal resistance is available for Soybean Cyst Nematode (SCN), Root Knot Nematode (RKN), and Columbia Lance Nematode. Resistance source should be matched to the type of nematodes present. Crop rotation to non-host species is a viable management option, and should be applied whenever possible. Tillage has not been clearly identified as a management option. Tillage equipment can spread nematodes from one field to another.
The best sampling time depends on the purpose of the sampling. If detection is the purpose, soybean cyst nematodes (SCN) can be sampled throughout the year. The ideal time would be following harvest when nematode levels are likely to be highest. Concentrate on areas of the field where yields were less than expected and sample directly within the row since SCN is most likely to be in the root zone. If the purpose of the sampling is to determine current levels in known infested fields for management purposes, late fall or spring would be optimal times. In northern climates, fall or early spring is ideal since nematode levels decline very slowly through the winter. In more southern climates, spring time, just prior to planting is best since nematode numbers often fall dramatically through the winter in the warmer southern soils. The following link gives more detail on sampling for SCN. Plant Health Initiative www.planthealth.info/scn_scout_nextyear.htm
“For more information on this or other topics related to soybean production, contact your state extension specialist or your local extension educator/agent.”
The following is the link to the soybean extension specialists: state extension soybean specialist