Tree and Shrub Disease

Scab is a common disease on apples, crabapples, hawthorn, mountain-ash, cotoneaster, firethorn and pears. Apple scab lives on infected leaves and fruit of the plant and can spread with the spring rains to infect again. The first signs of apple scab is lesions on the leaf or fruit that look like mold spots, though as the disease progresses and the lesion grows, a thick scab is formed. After infection, the tree may begin to lose leaves and fruit prematurely, ensure that the debris is raked and destroyed to prevent the spread of apple scab. Homeowners may also apply a fungicide to susceptible trees in early spring before it blooms, followed by 2 more sprays about 15-20 days apart.

Pear scab affects pears much in the same way apple scab affects apples. Lesions will begin to form on the leaf and fruit of the plant becoming larger and darker as time passes. Twigs can also be infected by pear scab (unlike apple scab) allowing another host for the disease to overwinter on. Taking care to rake and destroy fallen leaves and fruit will reduce the risk of re infection. Fungicides may also be applied in the same time fashion as apple scab.

Disease Development Favored by: Humid weather Warm weather Corrective Measures: Rake and destroy fallen leaves and fruit Apply fungicides if needed in early spring or late fall following the infection
Lesions on apple and leaf	Apple scab on a Crabapple