Water-soaked lesion turning dark brown or beige with white sporulating growth in wet weather:
- Late blight | See factsheet for more information
Symptoms: large water-soaked lesions that become black with white sporulation on the margin. Usually on the lower leaf surface but occasionally on the upper surface. Appear beige once lesions dry out in hot weather
Lesion with gray fungal sporulation:
- Gray mold | See factsheet for more information (LIHREC)
Symptoms: light brown spots that often start at a wound or dead tissue. Fuzzy gray fungal growth develops in moist conditions. Common in greenhouse production, especially with poor ventilation.
Zonate shaped lesions during wet weather:
- Zonate spot (Cristulariella)
Symptoms: light tan lesions with distinct concentric rings. Occurs during wet weather and can be confused with late blight. Associated with nearby infected box elder and black walnut trees.
More information/prepared by:
- For more information, please contact:
Meg McGrath – mtm3@cornell.edu & Chris Smart – cds14@cornell.edu - Originally prepared for Vegetable MD Online by Thomas A. Zitter.