Prunus necrotic ringspot
Prunus Necrotic Ringspot Virus (PNRSV)
Individual branches or the entire tree shows delayed budbreak or foliation, stunted wavy leaves, and shortened blossom pedicels in spring. Leaves develop chlorotic spots, lines, or rings as they emerge (A). In severe cases, chlorotic areas become necrotic and fall out, leaving the leaves "shot-holed" or tattered (B). Fruit maturity may be delayed, and fruit may be marked (C). In other cases, trees may develop symptoms as described one year and then remain symptomless in subsequent years ("shock" symptoms).
Common to all fruit-growing regions in eastern North America.
Any disease or disorder that causes shot hole symptoms, such as bacterial spot, bacterial canker, and sour cherry yellows may be confused with PNRSV infection. Generally, identification of the pathogen is needed to confirm diagnosis.
PNRSV can be transmitted to healthy trees during pollination by bees or during propagation. PNRSV is managed through nursery-based virus certification programs and, in the orchard, by roguing affected trees.
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