MYCOLOGIOAL SECTION. 115 



clusters which still remained at the time of treatment took a normal 

 development, and in autumn the vines were finer than they had ever 

 been." He had often used sulphate of iron for the treatment of the 

 same disease, but never with such a result. 



It is greatly to be hoped tliat those having vines subject to this 

 disease will give these remedies a thorough trial, both to determine 

 their value and quickness of action. 



Distribution and severity of the Grape Mildews and Black- 

 Rot IN THE United States. 



With the Circular on Remedies for Mildew and Rot, given in full 

 on page OU, there was sent out a circular of inquiry, having for its 

 object the obtaining of a more definite knowledge as to the distribu- 

 tion of, and losses occasioned by, Grape-vine Mildews and Black-Rot 

 of the grape. 



Nearly 400 of these circulars were returned filled out, in the ma- 

 jority of cases with evident care; and the information thiis acquired 

 forms an important chapter in my special report on the Fungus Dis- 

 eases of the Grape-vine, from which I extract the following: 



THE MILDEWS. 



Of all who reported, 203 had neither observed nor heard of the 

 Mildews in their county, or did not know them, or did not state. 

 One hundred and eighty persons, in nearly as many localities, stated 

 the presence of Uncinula spiralis ov'^Feronospora viticola, or both, 

 with varying degrees of injury to the vineyards. The reported loss, 

 depending upon the locality and the season, ranges from ''slight" to 

 "total." Nearly one-third of all who reported stated the loss in the 

 vineyards of their section to be in bad years from 25 to 60 per cent, 

 of the crop, and in some instances, in particular vinej^ards or upon 

 certain varieties, the entire crop. If the reports received can be 

 taken as fairly indicative of the loss from Mildews throughout the 

 gi^ape-growing regions of the United States, then it may be positively 

 stated that during the past ten years this has been as much as 10 or 

 15 per cent, annually. 



Almost without exception, Uncinula spiralis is reported to do 

 serious injury only in dry districts or during severe drought, and 

 chiefly to foreign grapes and a few natives, such as the Delaware. 

 In a few cases a loss of from 10 to 50 per cent, or more is ascribed 

 solely to Uncinula. This fungus is widely distributed in the United 

 States, ranging from Massachusetts to Georgia, and westward across 

 the continent to the Pacific; but the losses occasioned thereby in the 

 country as a whole appear to be trifling. 



Peronospora viticola occurs in nearly all parts of the United 

 States, on wild as well as cultivated sorts. Even the Pacific coast, 

 which long enjoyed perfect immunity, is not now free from it. During 

 the last year at least 8 different counties in California reported its 

 presence, with losses on certain varities ranging from 5 to 100 per 

 cent. It is found also in Utah, and probably occurs in Oregon. It is 

 relatively most prevalent from the mid Atlantic coast district west to 

 the Mississippi and southwest into Texas. Thia fungus everywhci^e 

 injures the vineyards, often attacking fruit as well as leaves. It 

 occurs on the vines throughout the growing season, but is usually 

 worse from June to August. All report its growth to be favored by 

 warm and wet weather, particularly by hot weather following pro- 



