🍄Fungal diseasesModerate
Leaf Mold
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Temperature
18–27°C
Humidity
≥85%
Leaf wetness
Required
Season
Spring, Summer, Autumn
About
Leaf mold (Passalora fulva) is a major greenhouse and high-tunnel tomato disease driven by high humidity and poor ventilation, rarely serious outdoors but devastating under cover.
Symptoms
Pale green to yellow blotches on the upper leaf surface with olive-green to brown velvety mould on the underside; leaves curl, brown and drop, starting low in the canopy.
Organic Treatment
Drop humidity below 85%, increase ventilation and spacing, remove infected leaves, and spray copper or Bacillus subtilis.
Chemical Treatment
Chlorothalonil or mancozeb, alternated with difenoconazole in protected culture.
Prevention
Ventilate and heat greenhouses to avoid condensation, space plants, prune lower leaves, and grow resistant varieties.