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SCN is important in Nebraska because:

  • SCN has been found in 59 Nebraska counties producing 93% of the state’s soybeans.
  • Originally found along the Missouri River, SCN has been identified as far west as Dawson, Phelps, and Red Willow counties in the past few years.
  • Yield reduction from SCN can be 5 to 10 bushels per acre or more.
  • Over 136,000 eggs per 100 cc (3.4 oz) of soil have been recorded during surveys of some Nebraska fields.
  • In Nebraska fields, there is an increased reproduction of SCN populations on PI 88788, the resistance found in about 98% of all SCN-resistant varieties commercially available to Nebraska farmers. 

SCN Distribution

SCN Management Recommendations

There are multiple tactics for managing SCN:

  • Scout / sample fields to know which field are infested with SCN and what the population densities (numbers) are 
  • Rotate SCN-resistant soybean varieties
  • Rotate to nonhost crops
  • Maintain optimum growing conditions and avoid plant stress

Soil testing tips:

  • The Nebraska Soybean Board is sponsoring soybean cyst nematode sample analysis through the University of Nebraska Plant and Pest Diagnostic Lab. Contact your local Extension Office for a sample bag and form. 
  • Submit samples to:
    • UNL Plant & Pest Diagnostic Clinic
      Plant Sciences Hall
      P.O. Box 830722
      Lincoln, NE 68583-0722
  • Testing should be repeated approximately every six years after initial confirmation of SCN to assess management and possible development of resistance.
  • It is important to sample at the same time of year and with the same crop in the field or following the same crop to get an accurate comparison.

What to know about rotating different resistant varieties:

  • Resistance to SCN has been identified and is available in many soybean varieties.
  • A rotation of resistance sources is recommended for SCN infested fields.
  • When different SCN resistance sources cannot be identified (PI88788 is the most common), a change in resistant soybean variety should be substituted.
  • All varieties with PI88788 are not the same as to their effect on SCN.

What to know about rotating to non-host crops:

  • Anytime SCN is confirmed in a field, the following rotation should be used: non-host crop – resistant soybean – non-host crop – resistant soybean.
  • Additional years of the non-host crop will reduce the SCN population (number of eggs) further.

Favorable environmental conditions: 

  • Weather conditions which favor maximum soybean yields are those which favor maximum SCN reproduction.
  • In years with drier conditions, especially in sandy soils, yield losses are higher.
  • In a regional survey, higher SCN populations have been associated with sandier, well-drained soils.
  • Fields in no-till with high clay content soils tend to have lower SCN populations.
  • High soil pH is also associated with high SCN populations.

University of Nebraska Experts