Fungal Diseases: Humidity, Airflow and Timing

Fungi spread when leaves stay wet. Change the conditions and you change the disease.

Cultural controls first

• Wider spacing and pruning for airflow.
• Drip rather than overhead irrigation, and water in the morning so leaves dry quickly.
• Remove infected residue and rotate crops to break the cycle.
• Resistant varieties where available.
• Clean tools and seed.

Fungicides

Protectants work before infection; curatives only partly after. Spray by forecast or at the first symptoms, rotate groups and follow label intervals.

Know the pattern

Powdery mildew likes warm, dry days with humid nights; downy mildew and blight prefer cool, wet weather. Match the action to the weather.