The main disease of apples everywhere. Symptoms are
scabby fruit, premature fruit drop and leaf infection,
followed by early defoliation. The following year, you’ll
find reduced fruit bud development and general weakening
of the tree. The fungus which causes apple scab overwinters
in leaf litter. Spring winds blow spores into the tree
canopy, resulting in lesions on leaves. Warm rainy weather
favors scab development. New infections are produced
through the summer as rains wash the fungus onto other
leaves and fruit.
Solution: Collect and remove fallen leaves. Use Sulfur Guard™ before blossom time to prevent initial springtime infection. (Repeat weekly in rainy, warm weather.) Reapply after blossoms fall and again 12 days later. Sulfur can be used up to day of harvest to retard the spread of scab. Other recommended products to control Apple Scab are Serenade Solutions, Green Guard, and Compost Tea.