Pink rot

Phytophthora erythroseptica

Symptoms

• Starts from the stem-end
• Infected tubers feel rubbery
• Sliced tubers leak when they are pinched and smell like solvent
• Tubers discolour to pink/red and eventually blacken (some minutes after cutting)
• Diseased tubers rapidly infect healthy tubers in storage
• Pink rot in storage allows development of bacterial wet rot

Infection and spread

• Long-term survival in the soil as oospores
• Contaminated seed potatoes
• Wet, anaerobic soils after a hot and dry period encourage development
• Motile spores are released in large numbers and infect roots
• Tubers can also be infected via lenticels, eyes and mechanical damage

Possible confusion with

• Rubbery rot (Geotrichum candidum)
• Water rot (Pythium spp.)