Alternaria Fruit Rot
Alternaria spp
12 host plants
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Brown, sunken lesions develop on fruit with concentric rings and dark spore masses in center. Remove infected fruit and improve air circulation. Avoid overhead watering and handle fruit gently.
Harvest promptly to prevent overripe fruit. Do not pick or handle fruit when it is wet. Improve drainage around susceptible plants and avoid overwatering. Remove affected material and dispose of it away from the garden. When replanting, choose resistant varieties and amend the soil for better drainage if waterlogging was part of the problem.
Quick Reference
Management
Late bloom through fruit maturity (May-August in Puget Sound region). Fruit most susceptible during ripening phase. Harvest period and post-harvest storage critical for symptom development and disease progression.
Latent infections establish during cool, wet late-spring and summer bloom periods (no specific temperature optimum documented). Symptom development and fungal activation occur during fruit ripening, particularly in warm harvest conditions. Mechanical damage to fruit during harvest increases infection rates and symptom severity. Storage rot accelerates in warm conditions. # Source: PNW Plant Disease Management Handbook
Cultural Controls
- Harvest promptly to prevent overripe fruit.
- Do not pick or handle fruit when it is wet.
- Hand harvesting results in less rot than machine harvesting.
- Avoid wounding or bruising fruit during harvest.
- Cool berries rapidly after harvest.
- Clean plant debris from picking buckets, packing lines and inspection belts frequently.