s recommended for black-rot,
except that the first application should be made before the
blossom-buds appear.

_Powdery-mildew._

Less troublesome than downy-mildew in the East, powdery-mildew
(_Uncinula necator_), unless checked, is capable of destroying the
entire crop of European grapes on the Pacific slope. In the East it
sometimes causes great loss on the several varieties known as "Rogers
hybrids" and, curiously enough, is often a rather serious disease of
the Concord. The disease is caused by a superficial fungus which
passes the winter on fallen leaves and also on the canes. The spores
begin to germinate a few weeks after the grape blossoms, but the
disease is not often found until the grapes are nearly half grown. The
fine white filaments of the fungus, which constitute the vegetative
portion of the parasite, then attack the leaves, shoots and fruit,
sending up short irregular branches on which great numbers of spores
are borne. These give the upper surface of the leaf a gray, powdery
appearance, hence the name. Eventually the diseased leaves become
light brown and if the disease is severe, soon fall. Infected berries
take on a gray, scurfy appearance, speckled with brown, are checked in
growth and often burst on one side, exposing the seeds. The berries,
however, do not become soft and shrunken as when attacked by the
downy-mildew. The disease passes the winter in resting-spores produced
late in the growing season. Powdery-mildew differs from other fungous
diseases of the grape in being more prevalent in hot, dry seasons than
in cold, wet ones.

In eastern America powdery-mildew is controlled by the treatment
recommended for black-rot. When black-rot is not prevalent, two sprays
with bordeaux mixture are recommended; the first in early July and the
second about two weeks later. On the Pacific coast, however,
powdery-mildew or "oidium" as it is often called there, the name
coming from Europe, is more cheaply and more successfully combated by
dusting with flowers of sulfur. Dusting is often done by hand or with
perforated cans but this is wasteful and uncertain, and any one of
several sulfur-sprayers may be used which does the work better.

_Anthracnose._

Another widespread disease is anthracnose (_Sphaceloma ampelinum_),
called "birds-eye-rot" because of the peculiar spots produced on the
affected fruits, which attacks leaves, shoots and fruits of the vine.
It first appears on the leaves in small, irreg