Potato Review Group

Contents

Background

Control

Further information:

Ring rot notes

Top of page

 

Background

  1. The disease is caused by Clavibacter michiganensis subsp. sepedonicus.
  2. This is a quarantine disease.
  3. Tuber symptoms
    • a soft cheese-like rotting of the vascular ring, particularly at the stem end
    • a cheese-like ooze from the vascular ring if a cut tuber is squeezed
    • the bacterial ooze is odourless and unlike brown rot does not stream from infected tissues when held in water
    • in severe cased the tuber skin may crack
  4. Foliar symptoms
    • these may be seen late in the season as yellowing and wilting of leaves and stems, particularly if soil is dry and air temperatures are high
    • cool, moist conditions are likely to prevent expression of foliar symptoms
  5. Progeny tubers become infected via stolons of the parent plant and tubers can also become infected through wounds at harvest.
  6. The bacterium can survive in volunteer potatoes and on boxes, machinery, etc which have been in contact with the bacterial ooze.
  7. The disease is favoured by cool climates and could survive in soil in association with volunteer potatoes.

More …

Control

  1. The only control is through use of disease-free seed.
  2. Seed tubers from UK certified Safe Havens are grown from brown rot free sources and to a very high standard of hygiene.
  3. The bacterium is a quarantine organism and an EU Directive requires member states to perform annual surveys for the disease.
  4. However, sampling may not be adequate to identify all seed lots at risk of carrying the disease.

More …

Top of page

 

Bacterial ring rot notes

Ring rot 2004 (Symptoms; biology; control)

 

Top of page