Plant Health Initiative

Samples to check for SCN can be taken anytime during the year, but soil samples taken following harvest provide the best population density estimates. Check roots during midseason for the presence of females and cysts.

Click here to view a video with Greg Tylka on how to check roots for SCN (link to Iowa Soybean Association)

Click here to view a video on fall soil sampling for SCN

Soybean Cyst Nematode

The soybean cyst nematode (SCN) is a small plant-parasitic roundworm (Heterodera glycines ) that feeds on the roots of soybeans.  Soybean cyst nematode is one of the most important diseases of soybeans. Yield losses occur because plants are producing fewer pods than they should.

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 can move even small amounts of infested soil is capable of spreading SCN, including farm machinery, vehicles and tools, wind, water, animals, and farm workers.