Potato pink rot is a water mold or oomycete disease of potato tubers caused by Phytophthora erythroseptica. The soil-borne pathogen causes darkened, water-soaked lesions with defined margins near the stem-end of the tuber, and is often identified by the characteristic pink/salmon color and ammonia-like odor of a potato cut and exposed to air after 20-30 minutes. The pathogen survives in infested soil, and infects tubers in the field either through direct contact with soil or swimming zoospores during wet conditions.
During harvest and in storage, disease can spread between tubers through bruises and wounds. Favorable conditions include high temperatures, high moisture, and poorly draining soils. Cultural management involves removing plant debris and volunteer potatoes post-harvest, managing soil moisture, scouting poorly-draining areas for pink rot pre-harvest, avoiding harvesting in hot temperatures and storing tubers in cool, well-ventilated facilities. Pre-harvest chemical management can also prevent disease development.