CONTROL Good drainage is very important in avoiding fungal diseases as well as good air circulation to reduce humidity levels. Irrigation in the early morning instead of at night reduces the length of wet time and breaks up large droplets of dew that would dry up slowly. Pruning of trees and shrubs can increase sunlight and air flow. Too much thatch will keep humidity levels higher. During periods of high heat and humidity it is a good idea to avoid excessive nitrogen application as it supplies the disease with a tender, lush host. Always look for resistant varieties when seeding. Fungicides are available.