59 Farmers’ Bulletin 1220. 
spores, which penetrate the tissues, and continue their destructive 
work. The young shoots are sometimes attacked and killed. 
The fruit, if attacked when young or only partly grown, shows 
first a brownish spot, and later becomes covered with the gray, downy 
Fic. 57.—A grape leaf attacked by the downy mildew, showing the appearance of 
the leaf above and below. 
growth of the fungus. This form of the disease is sometimes called 
“oray-rot ” by vineyardists (fig. 59). When the berries escape the 
disease until they are half grown or more it appears as a brown or 
brownish purple spot which spreads and soon involves the whole 
berry. The affected fruit becomes soft and wrinkled and falls to the 
