Soybean Cyst Nematodes: A pest that is becoming more common on Eastern Canadian farms

This article was written for our soybean export buyers by the Sevita International Export Team. For grower-related questions, please contact your local Sevita representative.

What are Soybean Cyst Nematodes?

Soybean Cyst Nematodes (SCN) are a parasitic worm that infects soybean roots and is a growing issue in soybean production in North America. It also infects a number of other legume crops and weed species. It is the number 1 soybean pest in North America creating significant economic losses every year. Yield reductions from SCN can exceed 50% in severe field conditions.

Where does SCN come from and what does it do?

SCN was first identified in North Carolina, USA in 1954. Since it was first identified, SCN has spread widely across North American soybean production areas. It can live in the soil for many years and spreads by moving with soil on farm equipment and when water moves soil during heavier rain events. 

SCN can reproduce multiple generations in a year (every 2-4 weeks) and can increase soil populations very quickly in a single season. Once a field is infested with SCN, it is impossible to eradicate it. The pest moves from the soil and feeds on the soybean roots.

Soybean Cyst Nematodes can be more damaging in drier weather conditions. The root damage can also create entry points for other fungal diseases and is often associated with an increase in Sudden Death Syndrome, a disease that can cause premature leaf loss and reduced yields.

In recent years, the pest has moved into Canadian growing regions, predominately Southern Ontario. Click the video below to see the spread of the pest across North America:

What can be done to help combat SCN?

Resistance to SCN has been bred into new soybean varieties to help reduce yield losses. Soybean breeders have successfully used two primary sources of resistance: "PI88788" and "Peking", to help reduce damage from SCN.

Most varieties use the PI88788 source. Unfortunately, the PI88788 resistance has been used frequently in many varieties over a long period of time and the resistance is starting to break down and growers are experiencing yield losses again. The Peking resistance remains fairly stable and effective at this time. Other sources of resistance to SCN exist but they have not been widely deployed.

What can farmers do?

SCN is not highly mobile and only moves short distances on its own. Growers can reduce the impact of SCN by preventing the introduction on their farms and reducing the spread of the organism in their fields.

Growers can reduce SCN by rotating other crops for two or three seasons between soybean crops. They can also reduce the spread of SCN by managing soil erosion and by using reduced tillage methods. Growers can also select varieties with SCN resistance that is effective in their conditions.

What Can Sevita International do to Help Prevent Soybean Cyst Nematode Issues?

• Sevita currently offers 7 different food-grade soybean varieties with SCN resistance.
• In fields with heavy pressure, Sevita offers seed treatments to help combat the pest. 
• Sevita Genetics is working on adding different sources of resistance to new varieties to prevent the overuse of the PI88788 source. 

For additional information or questions, please contact the Sevita Export team