Pink eye of potato

Pink eye of potato is a bacterial infection primarily caused by the soil-borne bacterium Pseudomonas fluorescens. While this bacterium is commonly found in the environment, it acts as an opportunistic pathogen under specific physiological stress conditions, affecting the periderm and internal tissues of potato tubers.

The primary crop affected by this pathogen is the potato. Infection typically occurs during the tuber bulking and maturation stages. The bacterium gains entry into the tuber through the eyes, lenticels, or any mechanical wounds present on the surface of the skin, leading to localized tissue degradation.

Symptoms of the disease are characterized by distinct pink to pale red blotches surrounding the potato eyes. In advanced stages, these areas may become water-soaked, necrotic, or depressed. Because the infection can compromise the tuber's barrier, secondary opportunistic soft rot bacteria often invade the damaged tissue.

The development of Pink eye is heavily dependent on environmental conditions, particularly soil moisture and aeration. Excessive water that creates anaerobic conditions in the soil leads to tuber suffocation. When the tubers cannot respire properly, their natural defense mechanisms are weakened, allowing Pseudomonas fluorescens to colonize the periderm.

Management strategies focus on cultural practices rather than chemical control. Key actions include improving soil drainage to prevent waterlogging, ensuring proper soil aeration, and avoiding harvesting in wet conditions to reduce tuber wounding. Selecting well-drained fields and maintaining optimal crop health are essential for minimizing the impact of this bacterial disorder.