116 



POPULAR FRUIT GROWING. 



spots with bright borders and is called bird's-eye rot. The dis- 

 eased wood should be removed. When vines are sprayed with 

 Bordeaux mixture for other diseases, this is held in check, and 

 it is seldom abundant enough to warrant spraying for it alone. 

 Black Rot (Guignardia Udwellii) One of the most com- 

 mon of injurious diseases affecting the 

 grape. It sometimes attacks the leaves, 

 but is most common on the fruit, which 

 causes it to rot, turn black, and finally 

 dry up. The disease breeds in the 

 mummified fruits and in the diseased 

 leaves of the Ampelopsis as well as of 

 the grape. 



Remedies. The dried grapes should 

 be removed and burned. Spraying with 

 Bordeaux mixture is probably the most 

 certain remedy and if persistently fol- 

 lowed up year after year will be found 

 quite effective. The fruit should be 

 kept covered with it until it begins to 

 color, after which ammoniacal carbon- 

 ate of copp-er should be used. If Bor- 

 deaux mixture was used up to ripening 

 time the fruit would look dirty. Bag- 

 ging the fruit is commonly a satisfactory 

 remedy, provided the bags are put out as 

 soon as the fruit is set. To spray effectively with Bordeaux 

 mixture will generally take three or four applications, accord- 

 ing to the weather. It is sometimes washed off before it is dry, 

 when it should be applied again. Some vineyardists are get- 

 ting good results by using a solution of copper sulfate (1 Ib. 

 to 25 gals, of water) just before growth starts. 



Downy Mildew (Plasmopara viticola). This fungus may 

 attack the young wood, flowers or fruit, or all these at the same 

 time. When it attacks the foliage it appears as greenish yel- 

 low, or brownish, irregular spots on the upper surface, with 

 corresponding spots of whitish, frost-like mildew on the under 

 side. The effect of this is to have the leaves dry up and fall 



Fig. 51. Black rot of 

 the grape, showing 

 infested fruit rotted 

 and dried. 



