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SCN is important in Indiana because:

  • Indiana grows 5.9 million acres of soybean annually.
  • SCN has been reported in at least 89 of the 91 Indiana counties with an estimated of 45% of the fields infested.
  • A 50% yield loss is possible in highly infested fields. root-illustration.png

SCN Management Recommendations

There are multiple tactics for managing SCN:

  • SCN symptoms can easily be confused with other problems such as nutrient deficiencies, herbicide injury, other diseases, poor drainage, etc.
  • Oblong areas of stunted, yellowed plants is suggestive of SCN damage.
  • Infected plants generally have poorly developed roots and few nodules.
  • Scout/sample field to determine those that are infested with SCN and population number.
  • Rotation with non-host crop is the simplest and least expensive method to reduce SCN population.
  • SCN resistant varieties are available and should be used in a management program.

What you should know about soil testing for SCN:

  • Where in the field: Collect soil samples from high-risk areas or problem areas such as low yielding, prone to flooding, low area, high traffic. If you do not have a problem area collect soil from the entire field using a zigzag pattern
  • When: Fall in non-host crop or soybean stubble, spring before a soybean crop, during season in the soybean crop root zone
  • How often: At least before planting a second crop of soybean
  • Where should soil test samples be sent? Samples will need to be sent to the lab of your choice, unfortunately the Purdue University Nematology Laboratory closed as of June 2018

What to know about rotating different resistant varieties:

  • Different soybean varieties with the same sources of resistance will vary in yield and SCN control
  • Look for high yield and strong SCN nematode suppression

What to know about rotating different sources of resistance:

  • Grow soybean varieties with different sources of SCN resistance to help minimize buildup of nematodes with resistance
  • Rotate resistant sources just like you would rotate herbicide and/or fungicide mode of action

What to know about rotating to non-host crops:

  • Rotating to non-host crop is the simplest and least expensive method to reduce the SCN population
  • Non-host crops include alfalfa, barley, corn, crown vetch, Ladino clover, oat, pea, sorghum, and wheat
  • Purple deadnettle, henbit, and common mullen are hosts to SCN – a weed-free non-host crop can reduce the SCN population as much as 55%
  • It may take three or more years to reduce sub-economic levels depending on the initial population

What you should know about nematode-protectant seed treatments:

  • There are a number of seed treatments available from many companies.
  • Seed treatments may provide early season protection but should be used in conjunction with SCN resistance.

Purdue University Experts

Darcy Telenko | Plant Pathologist

Purdue University

765-496-5168