Spot Anthracnose Of dogwood

Disease Information

Spot Anthracnose

Symptoms and damage

 This disease is caused by the fungus Elsinoecorni, one of the most common leaf diseases of flowering dogwoods. The flower bracts are usually attacked first and then the leaves, young shoots and fruit of dogwoods, primarily during wet spring weather. Symptoms are small (? inch), tan spots with reddish-purple borders. When infection is severe, these spots can cause flower bracts and leaves to become wrinkled and distorted. As further infections occur, individual spots eventually merge to form larger spots. The centers may drop out. This fungus survives from year to year on infected twigs, fruits and other tissues.

COMMENTS on disease

Frequent rains or extended periods of high humidity are needed for disease development. When dry weather follows bud swell and bloom, the symptoms are rarely seen on the flower bracts. If spotting does not appear on the bracts, the disease may not be severe on the leaves.

Management

In most cases this disease doesnt result in significant damage, but severe and repeat infections each year can significantly weaken a tree. Thin the canopy to increase air movement. Planting species and cultivars with some degree of disease resistance is an excellent option for managing this problem in the landscape.

If spotting becomes severe, fungicides can be used in the spring starting at bud break and continuing until leaves are fully expanded. Fungicides available for use include chlorothalonil, mancozeb, propiconazole, thiophanate-methyl or copper fungicides .

 

 



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