Agriculture Reference
In-Depth Information
GRAPEVINE DISEASES
Anthracnose
Elsinoe ampelina
In rainy, hot, and humid areas, anthracnose can take hold and cause damage to vine-
yards. The fungus overwinters on infected shoots and then spreads by rain onto new tissues
in spring. Hot weather encourages growth. It affects all parts of the growing vines, but you
can recognize it mainly by the lesions that form on shoots and berries. These start out as
small reddish circles that then grow and become sunken and gray. Darker margins form
around the edges of the lesions, and the tissue may crack. Leaf spots are similarly circular
with gray centers and darker margins.
Finally, the fruit develops the small circular spots, which enlarge and turn whitish grey
with reddish to black edges. (These spots look like bird eyes, and the disease is sometimes
called bird's eye rot.) Eventually the fruit cracks and splits.
CONTROL
Prune out and destroy infected wood. Clean away fallen foliage, fruit, and prunings. Plant
resistant varieties. Manage the canopy to encourage air circulation. Apply a lime sulfur-
based fungicide as a dormant spray in late winter, before bud break, then through the grow-
ing season at two-week intervals.
Black Measles (Esca)
Togninia
spp.
Black measles symptoms show up mainly in midsummer to late summer. Leaves devel-
op dry spots between veins. Leaves can drop off, and tendrils and canes may die back. The
disease enters through pruning wounds. It is most prevalent in areas with hot summers and
where spring rains are heavy.
CONTROL
