Bot canker
Identification tip: Bot canker causes death of arms, cordons,
and vines. The wedge-shaped, darkened cankers that develop in the
woody vascular tissue are indistinguishable from Eutypa dieback.
Unlike Eutypa dieback, there are no foliar symptoms.
|
Eutypa dieback
Identification tip: Symptoms in the wood are characterized by
darkened cankers that develop in the vascular tissue.
|
Leafroll virus
Identification tip: Leaves with leafroll virus symptoms
are cholorotic with rolled edges. Leaves of red fruit varieties
have reddened leaf tissue.
|
Measles
Identification tip: On berries, small, round, dark spots, each bordered
by a brown-purple ring, may occur.
|
Phylloxera
Identification tip: Damaged vines in field showing dead, dried up branches
and foliage due to root feeding by phylloxera.
|
Pierce’s
disease
Identification tip: Advanced late-summer or fall symptoms of Pierce's
disease on foliage of a white grape variety shows concentric rings
of drying from the outer edge toward the center.
|
