Cranberry (Vaccinium macrocarpon)-Red Shoot


Cause This rare disease is caused by the fungus Exobasidium perenne. It has not been an important disease economically but has been found in beds in both Oregon and Washington.

Symptoms Current-season uprights have spindly stems and bright red leaves that enlarge but are not greatly thickened. These stems are most noticeable in spring, before bloom, when the bright red contrasts with the green of healthy stems. Infected leaves may cup down. Stems may be in clusters or appear singly in the bed. The lower leaf surface is covered with a whitish mass of spores. Diseased leaves wither and drop prematurely.

Cultural control None recommended in the Pacific Northwest.

Reference Nickerson, N. L. 1984. A previously unreported disease of cranberries caused by Exobasidium perenne sp. nov. Canadian Journal of Plant Pathology 6:218-220.