Florida Agricultural Experiment Station


 These diseases are controlled by the sprays applied after
blooming time. Apparently best control is obtained with bor-
deaux, but due to the residue which it leaves this mixture can-
not be used late in the season and some less staining spray
must be employed. Copper acetate has been the material most
widely used but recent investigations indicate that basic copper
chloride or copper sulfate may be used to good advantage.
 Downy mildew, caused by the fungus Plasmopara viticola
 (B. & C.) Berl. and De Toni, attacks all the young growing
parts of the plant. It is first noticed on the leaves where yellow-
green spots are seen on the upper surface. These spots soon
become reddish-brown, are irregular in shape and the under-
surface is covered with a white downy growth of the fungus
which is very conspicuous as a dense matted cottony mass.
When the young fruit is attacked, brownish spots appear which
later become covered with the gray downy growth of the fungus.
This gray covering of the lesions has caused rot at this stage
to be called the "gray rot". If the fruits are half grown or
larger before the disease appears they take on a brown or
brownish-purple color, become soft and wrinkled and fall to
the ground. When the disease appears at this stage it is called
"brown rot".
 This disease has not been prevalent in Florida for some time.
Control may be obtained by exercising care to cover the under-


Fig. 12.-A sprayed Florida Beacon vine showing abundance of foliage and fruit well
 protected from sunburning. (Photo taken June 10.)