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 that 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.
Collect and remove fallen leaves. To build health of trees, spray a harpin proteinbased product, which promotes growth and aids in resistance of disease, or Gardener's Gold™ Compost Tea before blossom time, especially if scab has been a problem in the past. Repeat every 7-10 days. For broad spectrum disease control, use a biofungicide that harnesses the disease-fighting powers of the bacterium Bacillus subtilis. Use the biofungicide as a preventive or curative foliar spray when symptoms are first noticed. Apply at 7- to 10-day intervals. We recommend Green Guard™ Plant Growth Enhancer and Plant Guardian™ Biofungicide Wettable Powder.