Grape > Leaves > Malformed or distorted leaves
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- Distorted and twisted leaves, margins of the leaf are often cupped upward
- Stunted or unusual growth of vines
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- Galls are formed on the undersides of leaves from phylloxera feeding
- Leaves become cupped upward
- Present throughout the growing season
- More information on Grape Phylloxera...
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Phomopsis Cane and Leaf Spot
- Leaves may be puckered along the veins or the margins may be turned under
- Dark brown spots with yellow edges can also appear along leaf veins and petioles, the lower leaves are most commonly affected
- Fruit will turn light brown and shrivel, small raised black pimple like structures may be visible on the fruit surface
- Symptoms on berries are most obvious close to harvest on maturing fruit
- More information on Phomopsis Cane and Leaf Spot...
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Anthracnose (Bird’s Eye Rot)
- Leaves develop circular lesions with gray centers and brown or black margins, the center of the leaf spot may fall out resulting in small ragged holes in the leaf
- Infected shoots develop spots that become sunken lesions with gray centers and dark reddish-brown raised edges
- Infected shoots may be confused with hail damage; but unlike hail damage, the edges of the lesions are raised and black
- Berries develop small, reddish circular spots that average 1/4 inch in diameter that may become sunken with a dark brown to black margin, resembling a “bird’s eye”
- Berries are susceptible from bloom to veraison
- Infection is more prevalent in rainy years
- More information on Anthracnose (Bird’s Eye Rot)...
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- Leaves have large, red-brown patches; a gray mold may or may not be observed on the leaf
- Berries become soft and watery, and may be covered in a fuzzy white-gray mold
- White grapes will start to turn brown while purple grapes turn reddish in color
- Berries that have been infected for several days will shrivel and drop to the ground as hard mummies
- Multiple berries in a cluster can be infected
- More information on Botrytis...
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- Young leaves will appear smaller, cupped and chlorotic
- Shoots are stunted (shortened internodes)
- Shoots growing on infected canes will appear deformed and discolored
- A canker that is flat in appearance develops on older woody vines, often around old pruning wounds
- Symptoms usually only seen in vines >6 years old
- More information on Eutypa Dieback...
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Tomato/Tobacco Ringspot Virus Decline
- Leaves exhibit a random pattern of yellows and greens or leaf yellowing in first year of infection
- Smaller leaves, shorter internodes, and reduced yield are evident in second year
- Growth is severely stunted in the third year
- Fruit clusters are sparse with uneven ripening
- More information on Tomato/Tobacco Ringspot Virus Decline...
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Grapevine Fanleaf Virus
- Leaves are fan-shaped (resembling 2,4-d injury)
- Leaves may develop a bright yellow mosaic pattern or yellow vein banding
- More information on Fanleaf Degeneration...