448 BUI.LETIN 76. 



The stems when mildewed show the same gray appearance on 

 their surface as is seen on the under side of the leaves. In severe 

 cases the fungus kills the stem outright beyond the diseased por- 

 lion, and a general browning of these parts takes place. 



The downy mildew is not so serious late in the season as is the 

 black rot, and this necessitates particular care in making the early 

 applications. The Bordeaux mixture and the ammoniacal car- 

 bonate of copper are the safest fungicides to use. The appli- 

 cations should be made as already recommended for the pow- 

 dery mildew, but greater thoroughness must again be insisted 

 upon, as the disease is more serious than the powdery mildew. 



F. Ripe Rot. 

 {Glceosporium frudigenum.') 



A disease which to all appearances was the ripe or bitter rot of 

 grapes was seen in some vineyards about Keuka lake. This year 

 the injury done was not serious, but it is evident that the disease 

 exists in this region and it may cause severe losses if the proper 

 conditions for its development are present. 



Affected berries change color in the portion first attacked, and this 

 discoloration gradually spreads over the entire berry changing it 

 to a reddish brown. Here the berry remains and shrivels, often 

 hanging to the stem until quite dry, or sometimes dropping to 

 the ground as soon as the shrivelling begins. Pimples appear on 

 the surface of the shrunken portions, but such berries can be dis- 

 tinguished from those attacked by the black rot by their not being 

 of such a black color. They are generally a clear brown or deep 

 purple.* 



This disease appears to attack grapes later than does the black 

 rot, which makes it rather difficult to control. But the appli- 

 cations designed for black rot, if thoroughly made, will also 

 check the progress of this disease. 



G- Drought. 



In several vineyards on the shores of Canandaigua lake were 

 noticed vines which had lost most of the lower leaves from the 



* Scribner ; Ibid. pp. 38, 39. 



