How to Manage Pests
Pests in Gardens and Landscapes
Apple measles occurs in California's coastal areas, most frequently on 'Red Delicious'. Measles first
appears as small, red pustules on the smooth bark on young twigs. Tissue in the centers of the pustules
is dead, and the lesion extends into the cortex or to the phloem tissue on the inside of the bark. Surface
tissue of the bark may thicken, crack, and slough off over a large area, resulting in scurfy cankers.
Slicing into the roughened bark reveals brown flecking or streaking of internal bark tissue. Cracking
and sloughing of the bark surface may continue for several years.
Apple measles symptoms are an expression of manganese toxicity, caused by acid soil. Applying lime may
alleviate measles symptoms, but it is usually difficult for trees to recover.
red pustules on young twigs
apple measles lesions