Phyllosticta Leaf Spot Of maple

Disease Information

Phyllosticta Leaf Spot

 Symptoms and damage

This disease, also known as purple eye, is caused by the fungusPhyllosticta spp. On the leaves, spots appear with pale yellow centers and purple borders. The spots are irregularly round and ΒΌ inch in diameter. Black fruiting bodies of the fungus develop in a circle in the centers of the spots. These fruiting bodies occur in greater numbers on the upper leaf surface. Severe infection can result in partial defoliation of the tree. Often the disease goes unnoticed until leaf accumulation occurs under the tree.


 The fungus survives the winter in fallen leaves. In the spring spores are produced and dispersed to the new leaves of susceptible trees. Rake up all fallen leaves. Fertilization and watering may help to reduce the disease. `Autumn Flame`, `Tilford` and `Gerling` red maple varieties are relatively resistant to leaf spot. Spraying three times at two-week intervals with a copper-based fungicide, mancozeb, chlorothalonil, thiophanate methyl, or triadimefon starting when the leaves begin to unfurl in spring will provide control .

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