Eutypa dieback is a fungal disease appearing as cankers on
trunks and arms of infected grapevines. It is one of the most
destructive diseases on the woody tissue of grapes. The fungus
causing this disease has a wide host range, which includes at
least 80 species in 27 botanical families. Most of its hosts are
tree species that are common in natural forests. The earliest
symptoms of the disease are cankers formed around pruning
wounds. The cankers are hard to detect since they are concealed
by old, dead bark, which can become somewhat flattened. A cross-
section of the infected area might show a wedge-shaped area of
darkened wood coming to a point in the center of the trunk.
Symptoms of Eutypa dieback are apparent after the canker has
become well established, perhaps 2 to 4 years after the
infection of the pruning wound. As new shoots develop on the
trunk or arms above the cankered area, vine growth appears
stunted and the internodes become shortened. Symptoms are not
readily visible until late spring because a