Pink Rot Potato Disease

Pink Rot (Phytophthora erythroseptica), sometimes known as ‘Water Rot’ is a potato disease normally associated with high soil moisture at the time when tubers are approaching maturity.

Common Signs and Symptoms of Pink Rot

Plants affected with Pink Rot disease are often show signs of stunting or wilting during the later stages of the growing season.

Wilting starts from the base of the plant’s stem and progresses up causing a yellowing of the leaves, and the roots of affected plants may turn brown to black.

Tuber symptoms are much easier to spot, and include:

Rubbery (but not discoloured) tissue in the early stages with a tough, leathery surface on affected tubers.

Cutting rotten tubers open will initially reveal odourless, cream coloured tissue which, when left exposed to air for around 20-30 minutes, changes to pink.  After around an hour the tissue colour changes to brown, before finally going black.

Tubers infected with pink rot often have a characteristic smell of vinegar.

Common Causes and Conditions of Pink Rot

Pink Rot is caused by infected soil and is most prevalent in dry, hot weather.

Vulnerable / Immune Varieties

There are no particular potato varieties have a high resistance to pink rot.

Controlling Pink Rot

Cultural and Methods:
Pink rot can be controlled by applying the following cultural methods:

Allow tubers to establish a good skin set before harvesting.

Take care not to wound or damage tubers during the harvest.

Avoid harvesting tubers from very wet or poorly drained field areas.

Identify and discard any infected potatoes during harvest and before storage.

Chemicals:
There are no effective chemical products currently available in the UK to control pink rot.