Key points to know about SCN
Many farmers don't know their fields are infested with SCN - you often can't tell SCN is there from looking at the field.
The effect of SCN on soybean yield is directly related to the numbers of nematodes feeding on the root system.
Observation of adult females and cysts on the roots of soybean plants is the most accurate way to diagnose SCN infestation in the field.
Once present in the soil, SCN can never be eliminated. However, the nematode can be managed to minimize SCN reproduction and maximize crop yields.
Crop rotation coupled with planting SCN-resistant varieties are the cornerstones for the management of SCN. Non-host crops, such as corn, sorghum, sunflower, and alfalfa can reduce SCN population densities each year a non-host crop is planted.
Anything that moves even small amounts of infested soil is capable of spreading SCN, including farm machinery, vehicles and tools, wind, water, animals, and farm workers.
How to choose SCN-resistant soybean varieties
Look for varieties that yield consistently well in SCN-infested fields on multiple sites. Yield data from noninfested fields are not useful.
Look for varieties that consistently decrease SCN population densities or keep the SCN numbers in check in multiple fields. It is very difficult to reduce SCN numbers in a field once they develop to high levels, so it is important to consider how well SCN-resistant varieties control SCN numbers in order to maintain the productivity of fields for years to come.
Look for data from as many different reliable sources as possible, including university variety trials and strip trials conducted by co-ops, grain elevators, and seed companies.
Wise selection of varieties will ensure that soybeans can be grown profitably in SCN-infested fields for many years to come.