Some Grape Troubles of Western New York. 445 



appear some days or even a week or two before the berries are 

 attacked. On the young shoots and leaf stalks it effects char- 

 acteristic changes in the form of elongated, very dark brown or 

 black spots, which are slightly depressed owing to the absorption 

 of the juices from the cells composing the underlying tissues, 



Fig. 5. 

 Not sprayed. 



-Catawba clusters and black rot. 



Sprayed. 



over the surface of which the characteristic pimples or pustules 

 are more or less thickly scattered."* 



The treatments for the black rot are very similar to those men- 

 tioned on page 441. One fact should, however, be kept constantly 

 in mind : the black rot is a very energetic disease and a berry 

 afifected with it is ruined. The fungus does not appear until 

 rather late in the season, generally not until the fruit is fully two- 

 thirds grown. This makes later applications dangerous on ac- 

 count of the necessary staining of the fruit. It is therefore 



* h'cribner. Fungous Diseases of the Grape and Other Plants, p. lo. 



