44 
three-quarters or even all of the bunch is absolutely ruined, lu 
such circumstances there is very little of the crop that is worth 
harvesting. 
The disease is carried over winter in the black shriveled berries 
which are usually left on the vines. It is wise to remove and burn 
all such berries to reduce the chances of attack for another year. 
Fig. 15 shows the condition of bunches ruined by black rot at time 
of harvesting. 
Remedy. — The best treatment for this disease is to spray the vines 
carefully with Bordeaux mixture, using the 4-4 formula. That is, 
4 pounds sulphate of copper. 
4 pounds quick-lime. 
50 gallons water. 
DIRECTIONS FOR SPRAYING GRAPES. 
*"In view of the fact that spores are very abundant where the 
disease has prevailed it is well if all primings and weeds are removed 
from among the vines and burned. Before vegetation or sprouting 
of the buds takes place in early May the vines should be sprayed 
with a fungicide to catch the spores that are awaiting the oppor- 
tunity to germinate and effect an entrance into new tissue. 
"It is important to remember that nd fungicide can kill the Black Rot 
fang us when it has effected an entrance into the tissue of the plant or 
berry. The value of the remedy is wholly as a preventive. 
"Before the grapes come into blossom the vines should again be 
sprayed to protect the new growth and foliage against attack. The 
blossoming period extends over ten days or two weeks and no spray- 
ing should be done at this time. A film of fungicide on plants 
cannot be considered effectual for more than two weeks and if dash- 
ing rains intervene the period is correspondingly reduced. 
"After the blossoming period is completed the vines should again 
be sprayed, being particular to moisten all the foliage above and 
below as perfectly as mechanical devices and reasonable care will 
permit. 
"// is important to remember that a spore of the Black Rot fungus is 
exceedingly minute and if arty portion of the vine is not protected by a 
film of the fungicide, a spore alighting on that portion may enter the 
tissue as easily as if no .praying had been done. 
"Subsequent spraying should be made at intervals of two weeks 
until the last of July. If no rot appears by that date it is not prob- 
able that it will come, but if it is known to be present in the neigh- 
borhood, it will be wise to spray once more about the middle of Au- 
gust." 
•Bull. No. IC Exp. Ktallon. State Collet*. P*. 
