How to Manage Pests

Pests in Gardens and Landscapes

Apple mosaic

Leaves with apple mosaic turn pale yellow or white along the veins and develop large yellow spots that later turn brown. Leaves fall prematurely. Small yellow spots develop on the leaves of less sensitive varieties or varieties infected with mild strains of the virus. Tree growth and yield is reduced.


All varieties of apple are susceptible to apple mosaic but some, such as 'Jonathan', 'Golden Delicious', and 'Granny Smith', exhibit more conspicuous symptoms. Besides varietal difference, mosaic symptoms vary with the strain of the virus and are more pronounced in a cool spring. Apple mosaic is transmitted by budding, grafting, and root grafts of healthy trees with infected trees. Its occurrence can be minimized by using virus-free propagation sources. You cannot eliminate the virus without removing the tree. Fruit yields may be reduced 25 to 50%.

Leaf symptoms of apple mosaic
Leaf symptoms of apple mosaic

Statewide IPM Program, Agriculture and Natural Resources, University of California
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