Gilbertella rot

Gilbertella rot is a destructive fungal disease caused by the pathogen Gilbertella persicaria, a member of the Mucorales order. This pathogen is known for causing rapid soft rot in various fleshy fruits and vegetables, presenting a significant challenge both in the field during the growing season and during post-harvest storage and distribution.

The disease affects a wide range of commercially important crops, most notably stone fruits like peaches and nectarines, as well as strawberries, tomatoes, and bell peppers. The fungus typically gains entry into the host tissue through wounds, bruises, or natural openings, exploiting the high sugar content and moisture levels of the fruit to propagate rapidly.

The symptoms of Gilbertella rot typically begin as water-soaked lesions that expand quickly, causing the underlying tissue to collapse into a soft, mushy state. A key diagnostic feature is the development of a dense, white, fluffy mycelium on the surface of the fruit, which eventually turns dark gray or brownish as the fungus produces its characteristic sporangia.

Environmental conditions play a critical role in the development and spread of the disease. High relative humidity (often exceeding 90%) and warm temperatures are ideal for spore germination and mycelial growth. Because the spores are easily airborne, the pathogen can spread rapidly from a single infected fruit to neighboring healthy ones, leading to secondary infection outbreaks in storage environments.

Effective management strategies rely on integrated control measures to limit the presence of inoculum and protect the produce. Essential practices include:

• Minimizing mechanical injury during harvesting and sorting.
• Maintaining strict sanitation protocols in packing houses and storage facilities.
• Using appropriate fungicide treatments pre- and post-harvest where permitted.
• Ensuring proper ventilation and temperature control to keep humidity levels low in storage.