How do I Manage Soil-borne Diseases and Nematodes?

Management of nematodes starts with the development of a nematode management plan. A soil sample of the field should be taken first to see if nematodes are present, followed by consulting field histories and crop rotations. When populations are not present, practices should be implemented to prevent introduction. Soil samples that test negative for nematodes do not guarantee that a field is free of nematodes.

After reviewing soil samples, assess nematode management options to design and implement a successful nematode management plan that will meet the needs and goals of your operation. It's important to remember nematode populations are extremely variable. When making a nematode management decision, it's important to review field histories, crop rotations and a current soil sample.

Four items are important for effective nematode management:

  • Use of healthy seed material
  • Crop rotation
  • Chemical control
  • Preventing reinfestation

Use of healthy seed material
Plant only certified potato seed that has originated from a limited generation program. Do not plant year-out or eliminator seed. Growers should obtain a copy of seed certifications with the consent of the seed grower. A document called a plant health certificate is used by certification agencies in the United States and Canada, and can be requested from the responsible agency in the state where the plants, or slips, were grown. It lists information such as summer and winter test results, certification pedigree of seed, certification lot numbers, seed class and farm history. A soil sample also should be taken from seed tare dirt to determine the presence of nematodes.

Crop rotation
Crop rotation and cropping sequence impacts nematode populations and are important considerations for the management of potato nematodes. Crop rotation with unrelated crops is a sound practice for reduction of several soil-borne problems. Growers should consult with a university representative to determine the appropriate rotation pattern for managing nematodes.

Chemical control
Telone® II soil fumigant, or Telone C-17 fungicide and nematicide in some areas, is a preplant soil fumigant for the management of all major species of nematodes and certain nematode-transmitted diseases. As a fumigant, Telone moves throughout the soil profile on its own rather than requiring water or incorporation for movement.

Contact nematicides may appear to be an attractive option, but they may only prove effective under certain weather and field conditions. But in many cases, growers should apply a contact nematicide in conjunction with Telone to provide the best management possible.

The following product bulletins provide further information on the application of Telone II for nematode management in potato production:

  • "Sequential Application of Telone II plus K-PAM HL or Sectagon 42 or Vapam HL for Suppression of Verticillium dahliae, Control of Stubby-root Nematode Vector of Corky Ringspot and Control of Root-knot and Lesion Nematodes in Soils to be Planted to Potatoes, Onions and Carrots"

  • "For Control of Stubby-root Nematode Vector of Corky Ringspot in Soils to be Planted to Potatoes"

  • "Simultaneous Application of Telone II plus K-PAM HL or Sectagon 42 or Vapam HL for Suppression of Verticillium dahliae and Suppression of Root-knot, Lesion Nematodes and Stubby-root Nematode Vector of Corky Ringspot in Soils to be Planted to Potatoes, Onions and Carrots"

Telone® II soil fumigant has received two additional supplemental labels for the management of nematodes in the Pacific Northwest. In California (Modoc and Siskiyou counties), Colorado, Idaho, Nevada, Oregon, Utah and Washington, refer to the supplemental labeling for Telone II titled "For the Control of Nematodes and the Suppression of Wireworms in Soils to be Planted to Potatoes, Onions or Carrots" for directions for use.

Potato growers in Idaho also can refer to the supplemental labeling for Telone II titled "For Treatment of Soils Actively Involved in the USDA/ISDA Potato Cyst Nematode Eradication Program" for directions for use.