Candida guillermondii

Candida guillermondii is a yeast-like fungus recognized as a significant phytopathogen that causes spoilage in various fruits and vegetables. It acts as an opportunistic pathogen, often exploiting surface wounds or weakened plant tissues to establish infection and initiate decay processes during both pre-harvest and post-harvest stages.

The pathogen primarily affects succulent horticultural crops, including tomatoes, apples, pears, citrus fruits, and melons. Because it is highly adaptable, it frequently causes significant post-harvest losses in commercial storage facilities where large quantities of produce are kept in confined, humid environments.

The symptoms of the disease are characterized by the appearance of soft, water-soaked lesions on the surface of the affected produce. Over time, these areas become depressed and are typically covered with a white to cream-colored slimy coating, which constitutes the yeast biomass. Infected fruits often exhibit a distinct fermented or sour odor due to the biochemical breakdown of sugars.

Favorable conditions for the development of the disease include high relative humidity and moderate ambient temperatures, which promote the rapid multiplication of yeast cells. The presence of surface moisture, commonly referred to as condensation, creates a bridge for the pathogen to colonize the healthy tissues adjacent to initial infection sites.

Effective management and prevention strategies must focus on sanitation and physical handling to minimize the spread:

• Maintaining strict hygiene protocols in storage facilities to eliminate inoculum sources.
• Ensuring proper ventilation to prevent condensation buildup on fruits.
• Implementing careful harvesting techniques to reduce skin abrasions and physical damage.
• Applying recommended post-harvest treatments, such as controlled cold storage, to inhibit pathogen growth.