50 ; Farmers’ Bulletin 1220. 
they germinate and produce a slender germ-tube, which penetrates 
the tissue and may destroy it. 
This disease attacks the leaves and shoots, as well as the fruit. 
It usually makes its first appearance on the leaves and young shoots, 
producing reddish-brown dead spots. The fungus may attack the 
blossoms, as shown in figure 55, or young fruit, this being especially 
true in case of the Scuppernong grapes, but usually the disease does 
not attract much attention until the berries are half grown or more. 
Livid or brownish, soft spots first appear; these spread and soon in- 
volve the whole berry, which later becomes black and shriveled or 
mummied, as shown in the accompanying illustration (fig. 56). 
Fic. 55.—A, Two bunches of grape blossoms from an unsprayed check plat almost 
entirely destroyed by black-rot before blossoming. B, A sprayed bunch from the 
same yineyard showing no damage from rot. Natural size. 
These diseased berries remain attached to the bunch and their surface 
becomes covered with minute black pustules, which contain the sum- 
mer spores of the fungus. During the winter and spring another 
form, called the! winter or resting spore, is produced upon these old, 
shriveled berries (fig. 54, c,d). These spores help to carry the dis- 
ease over from one season to another. It is, therefore, desirable to 
destroy by burning or plowing under all diseased fruit and leaves as 
early in the spring as possible. 
TREATMENT. 
This disease can be effectually controlled by thorough spraying 
with Bordeaux mixture, as has been demonstrated by the Bureau of 
Plant Industry. (See spray schedule, p. 74.) 
