Sour Rot
Geotrichum candidum
2 host plants
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
This disease affects California grape (Vitis californica) but limited information about symptoms, management, or economic impact is available. Minimal data exists on how to identify or control this condition. Further research is needed to understand its significance in cool temperate regions.
Reduce moisture around affected tissue by improving drainage and air circulation. Remove rotted material cleanly and dispose of it away from the planting area. Avoid wounding healthy tissue during cleanup, as fresh wounds create new entry points. If the problem keeps returning, evaluate whether the site is too wet or poorly drained for the species you are growing.
Quick Reference
Management
Primarily post-harvest storage period, especially in cool, moist storage facilities. Field infections less common but occur on mechanically damaged fruit near harvest. Extended wet periods during harvest increase risk.
Growth optimum 68-77°F (20-25°C), but tolerates cool temperatures (50-75°F range). Requires wound or damage sites for infection; cannot penetrate uninjured fruit skin. High humidity and free moisture favor mycelial growth and sporulation. Mechanical injury during harvest is primary risk factor. # Source: Geotrichum candidum general plant pathology
Cultural Controls
- Avoid mechanical injury to fruit during harvest and handling.
- Handle fruit gently; use padding in harvest containers and conveyor systems.
- Cool fruit rapidly after harvest to slow fungal growth and sporulation.
- Maintain cool storage temperatures (32-40°F) to suppress fungal growth.
- Ensure good air circulation in storage to reduce humidity and condensation.
- Remove and discard any fruit showing symptoms to prevent spread to adjacent fruit.