University of Arkansas Partner

SCN is important in Arkansas because:

  • SCN is a yield-limiting pest in soybean.
  • It has been reported in every soybean-producing county of the state.
  • SCN is one of three important plant-parasitic nematodes of soybean in Arkansas.  The others are southern root-knot nematode and reniform nematode. 

SCN Management Recommendations

There are multiple tactics for managing SCN:

  • Crop Rotation
  • Host Plant Resistance
  • Nematicides: Fumigants and Seed-Applied Non-Fumigants
  • Tillage Practices
  • Agronomic Practices

What to know about rotating different resistant varieties:

  • Soybean varieties with resistance to SCN or root-knot nematode are not resistant to all biotypes of SCN or species of root-knot nematode.
  • Soybean varieties are often only resistant to one or two SCN biotypes or species of root-knot nematode, thus resistant varieties should be selected based on biotype or species or root-knot nematode on a field by field basis.
  • Tolerance is not a “type” of resistance and growing tolerant varieties sustains or, with some varieties,  increases nematode population densities.

What to know about rotating different sources of resistance:

  • There are limited sources of resistance to many of the SCN biotypes and to southern root-knot nematode in commercial soybean varieties.
  • Some soybean varieties with the same genetics are marketed with a different variety of names by different seed companies, but all contain the same source of resistance to SCN.

What to know about rotating to non-host crops:

  • Crop rotation with any crop other than soybean is an excellent way to manage populations of SCN.
  • Corn, cotton, soybean, and some grain sorghum hybrids are poor rotation crops for southern root-knot nematode as they can maintain or in some cases increase nematode population density.
  • Rice is an excellent rotation crop for both root-knot and SCN in fields where a flood is maintained for the majority of the cropping season.
  • Peanut is an excellent rotation crop for both southern root-knot and SCN.
  • A rotation sequence of 2 to 3 years out of soybean may be required to reduce SCN population densities below damage threshold.

Nematode-protectant seed treatments:

  • There are several seed-applied nematicides, made up of both chemical and biological active ingredients, marketed for use against soybean nematodes.
  • Seed-applied nematicides may provide some protection of the developing seedling, but do not provide season-long nematode control.
  • Seed treatments are most beneficial when used in areas with a low population density of SCN and when paired with moderately resistant cultivars.

University of Arkansas Experts

Travis Faske | Plant Pathologist/Nematologist

University of Arkansas

501-676-3124

John Rupe | Plant Pathologist

University of Arkansas

479-575-2778