This plant disease is caused by a fungus (Venturia pyrina) that commonly infects pears. The fungus spends the winter in infected plant debris and twig lesions. In the spring, spores are produced and discharged into the air. They are blown to the developing leaves, flowers, twigs, and young pears. If the leaves and fruit are wet, the fungus infects them, and spots develop. The infected tissues produce more spores, which further spread the fungus. As temperatures increase in the summer, the fungus becomes less active.
Unless they are severely infected, the pears are edible if the scabby areas are removed. To prevent recurrence of the disease next year, remove and destroy leaf debris and infected fruit in the fall. Next spring, spray with a fungicide containing captan.
Plant Care for Pear