Watery soft rot (Sclerotinia sclerotiorum)

Symptoms

• The disease is present in soil or storage and often shows up after the crop has been harvested.
• Symptoms can be identified in the field as characteristic white mold with black sclerotia present on the crown of infected carrots.
• Symptoms on foliage are water soaked, dark olive-green lesions associated with collapsed tissues.
• Lesions expand rapidly over the entire leaf, petiole, and rosette with infected tissues
• Covered by abundant cottony, white mycelium.
• Only a small percentage of the roots may be initially infected but the fungus mycelium can move very rapidly from carrot to carrot.
• In storage, a soft, watery rot with white mold and black sclerotia characterizes the disease.
• In a matter of weeks the whole storage container may become a mass of white mold and black sclerotia surrounding each and every carrot.

Management

• Crop rotation.
• Weed control (to improve air circulation)
• Planting on raised beds
• Rapid cooling prior to storage and meticulous sanitation of all storage components
• Frequent inspection in storage