Spray Burn
A common symptom that is misdiagnosed is damage from spray burn. Some pesticides will cause damage naturally or if not used properly. Rubigan (Recommended for use as a foliar spray. Do not apply through any type of irrigation system). Daconil (Cannot be shipped to some states. If you don’t see it on the shelf at your local garden supply store, it most likely is banned in your area. It is listed as Danger/Poison) is known to cause spray damage.