Some Grape Troubles of Western New York. 441 



B. Powdery Mildew. 

 (^Uncintila spiralis.) 



The appearance of this mildew has been described on page 423. 

 The fungus begins to attack the grape early in June and then con- 

 t'nues to spread with greater or less severity throughout the grow- 

 ing season. Dry weather seems to assist in holding it in check, 

 and warm rains are sometimes followed by very severe attacks. 



The early applications which were formerly recommended in the 

 treatment of most of the diseases of the grape are not now so 

 strongly insisted upon. For the treatment of the powdery mildew, 

 the following applications should be sufficient. The Bordeaux 

 mixture or the ammoniacal carbonate of copper may be used (see 

 page 450, 451). It is perhaps better to use the Bordeaux early in 

 the season, and later the ammoniacal solution. 



First application, about a week before the blossoms open. 



Second application, about a week after the blossoms fall. 



Third application, about two weeks after the second treatment. 



Fourth application ; in many cases this can be omitted entirely. 

 The time for making it cannot be definitely stated, but it may be 

 required some time within two to four weeks after the third. 



Mr. J. A. H. Skinner, of Brocton, has been very successful in con- 

 trolling this mildew by the use of the ammoniacal solution alone. 

 As this is much more easily applied, it may be safe to use it exclu- 

 sively. In making the applications care should be taken to strike 

 the dusters as well as the foliage, for where there is none of the 

 fungicide there the mildew has a chance. Later in the season the 

 application should be directed more to the foliage, for fear of stain- 

 ing the fruit . 



As yet, the Chautauqua vineyards have been apparently almost 

 free from other fungous diseases and the advisability of spraying 

 is an open question. During the past season the powdery 

 mildew does not seem to have been sufficiently severe to warrant 

 spraying beyond exceptional cases. What the conditions ^will 

 be next year it is impossible to say. 



