Throughout soybean harvest, Syngenta has been asking growers across the Midwest about their soybean crop and the types of pest pressure they faced this season. Many growers spoke about the weather, insects and diseases, but they named one pest above all others as a consistent problem: soybean cyst nematode (SCN).

SCN, the No. 1 pest in U.S. soybeans, affects the crop every year. The 2015 season was no exception. Once SCN presence is confirmed in a field, it cannot be removed, only managed.

SCN infects soybeans at the roots. Nematodes penetrate into the root tissue and leave behind unprotected wounds, which can lead to dwarfed or stunted plants in severe cases. These compromised root systems damage the plant’s ability to take up moisture and nutrients, and can reduce yield. In most cases, no aboveground symptoms are visible from SCN presence. This makes SCN one of the hardest pests to diagnose without sampling. University extension services, such as Iowa State University, are urging growers to sample soil for SCN and, if found, to plant resistant seed varieties treated with nematicide seed treatments.

Like the nematode’s pervasive presence, acceptance of the severe threat that SCN poses is beginning to spread.

“We have a big issue with nematodes that people don’t realize,” said Steve Boever, a grower in Readlyn, Iowa.

Boever has dealt with SCN pressure in the past, but this year he planted seed treated with Clariva® Complete Beans seed treatment, a combination of separately registered products, to fight SCN. A more robust root system is one of the biggest changes that Boever noticed this season.

“Big roots mean big yields,” Boever said. “These have been my best beans in 30 years.”

Boever is not alone in fighting SCN. Growers across the U.S. are now giving the pest more attention. Grower reports across the Midwest in 2015 have confirmed its presence in all major soybean-producing states. With the spread of this pest, there is also a proliferation of soybean diseases. When SCN infects soybeans, wounds to the roots can lead to increased damage from SCN-related diseases, such as sudden death syndrome (SDS).

With new growers confirming SCN presence in their fields every year, the best way to protect soybeans is to rotate with non-host crops like corn, alfalfa and cereals, and to plant SCN-resistant varieties treated with Clariva Complete Beans. For additional activity against SDS, growers can add Mertect® 340-F fungicide to Clariva Complete Beans. Mertect 340-F adds proven, effective SDS protection and, in combination with Clariva Complete Beans, rounds out a powerful seed treatment program to protect soybeans.

To learn more about the spread of SCN and related diseases and how to best protect soybeans, visit the Tools to Grow More Soybeans resource page. Join the conversation online – connect with us at