Best Management Practices for Dickeya in 2017 Potato Crop

Nathan Kleczewski, Extension Specialist – Plant Pathology; and Andy Wyenandt, Specialist in Vegetable Pathology, Rutgers University;

  1. Avoid purchasing varieties (with lot numbers) which are known to have Dickeya from any source.
  2. Do not purchase seed from those growers/brokers with a known history of Dickeya.
  3. Do not rely on Blackleg tolerance levels reported on the North American Seed Health Certificates or the Florida Test results for presence of Dickeya in ANY seed lot from ANY source.
  4. Request PCR testing for Dickeya dianthicola from supplier (directly from grower/or broker) using an independent lab. Reject any load if no Dickeya test results are available or those seed lots that have tested + for Dickeya.
  5. All equipment during seed piece cutting needs to be disinfested on a regular (daily) basis, and/or disinfested between lot numbers and/or varieties. Quaternary ammonium is a good option for this purpose.
  6. Fields with a known history of Dickeya should not be planted back into potato for at least 3 years or longer.
  7. Avoid planting brassicas and onions in potato rotations, especially in fields with history of Dickeya. This includes cover crops containing brassicas.
  8. Wash/dump water needs to be displaced in an area away from packing shed, particularly those sheds near any production field or source of ground water that may be used for irrigation.
  9. Culled potatoes need to be dumped away from any production field, source of ground water, or any area where contamination of equipment may occur.
  10. Rogue or volunteer plants appearing in fields with known Dickeya infestation the previous year or any prior year need to be removed, and/or sampled and tested if “Blackleg” symptoms are present.
  11. There is no chemical control for Dickeya. Copper sprays, etc. will not help with controlling this disease.
  12. All potato growers with fields with Dickeya-suspect symptoms need to be sampled and tested during the growing season.
  13. Any grower which rejects a load of seed for suspect Dickeya should report information to your local Extension Agent, specialist, or Potato Growers Association.
  14. Sample and re-test truckloads of seed potato for Dickeya once delivered. All results should be reported to your local Extension Agent, specialist, and/or Potato Growers Association.
  15. All growers are encouraged to report every variety, lot number (North American Seed Cert), field (general) location, and testing results each spring so Dickeya can be tracked and that this information be publically available to all potato growers in and out of the state.
  16. Growers using surface water (pond or stream) should are encouraged to do monthly water testing for Dickeya, especially if water source is near a field with known Dickeya infestation.