How can I manage the soybean cyst nematode?
Fig. 11. SCN-susceptible (left) and resistant (right) varieties in plots infested with high SCN egg population densities (17,400 eggs/100cc of soil left, 10,500 right).
Fig. 12. Guideline for SCN management based on SCN egg population density, and a soybean-nonhost annual rotation system, which is a common practice in Minnesota. For most fields, 5 years of SCN-resistant soybean and nonhost are needed to reduce the SCN egg population density to low enough (< 200 eggs/100cc of soil) for an SCN-susceptible soybean. In some fields, 3 years of SCN-resistant soybean and nonhost (brown arrow) may be sufficient.
There is no way to eliminate SCN once it is present in a field. Instead, the goals of SCN management are to:
- minimize yield losses
- reduce SCN population density
- maintain yield potential of resistant varieties with an integrated approach
Currently, the most effective SCN management practices are:
- use of resistant varieties (Fig. 11)
- rotation to nonhost crops (Fig. 12)
You can take these steps, which provide the information necessary for making SCN management decisions:
- monitor yield yearly
- scout for symptoms
- take soil samples to determine SCN egg densities