Infection occurs in the spring. The new spores formed on the surface of the galls are dispersed but do not cause more galls to form during that same season. They remain dormant until the following spring. Exobasidium vaccinii Remove and destroy all galls before they become white with new spores. If many plants had the disease in previous years and galls were too numerous to pick, apply a fungicide to protect new foliage and flowers as they emerge.
Applications can cease when the leaves reached their full size.
Ovulinia Petal Blight Pale white to rust-colored spots from on petals. Spots enlarge rapidly. Petals become slimy and fall apart easily. Ovulinia azalea Remove crop debris. Apply chlorothalonil, myclobutanil, PCNB, triadimefon, ziram, or triforine as blossoms open.