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Fanleaf
degeneration - Grapevine fanleaf virus
Annemiek
Schilder, MSU Plant Pathology |
| Home > Scouting guide> fanleaf degeneration |
| Fanleaf
degeneration affects vinifera cultivars. It is characterized by fan-shaped
leaves with toothed margins, proliferation of shoots, short internodes and
zigzag growth. Foliar symptoms appear early in the spring and persist through
the growing season. Sometimes leaves show a bright yellow mosaic or yellow
vein banding with little or no malformation. Fruit clusters are small with
poor fruit set, irregular ripening and shot berries. The causal virus is
spread by dagger nematodes and planting material. The virus is not transmitted
through seeds and has no natural weed hosts. Roots from infected vines can
be a source of infection even after the mother plant has been removed. |
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| Leaf with fanleaf symptoms (left) compared with a healthy leaf (right). |
| Fanleaf degeneration on fruit cluster. |
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