6 Mildew of the Grafe Vine. 



MILDEW OF THE GRAPE VINE. 



By Edward F. Underhill, Brocton, N. Y. 



The minds of grape-growers have been much exercised in reference 

 to the diseases which, during hiter years, have attacked the grape vine 

 of America. They have, in some localities, and with certain varieties, 

 rendered the profits of grape culture uncertain, and the results even 

 hazardous. Many theories have been propounded to account for the 

 abnormal manifestations on the vine, and each theory has found those 

 who have produced facts to overturn it. The result is, that to-day 

 we are vpry far from being able to explain the causes of the morbid 

 growth. 



The fungus commonly known as " mildew," and the disease called 

 the " brown rot " (which latter has been so especially hurtful to the 

 Catawba vine), have been usually regarded as distinct. But Mr. W. J. 

 Flagg, I believe, regards them only as different phases of the same unnat- 

 ural condition of vegetable growth. I am not prepared to either affirm 

 or deny the correctness of his conclusions. With a commendable and 

 intelligent zeal he is seeking to enforce the necessity of applying rem- 

 edies to check the increasing tendency to disease in our vineyards, and 

 he, more than any other writer, has brought to the knowledge of vine- 

 yard proprietors the facts connected with the appearance of the didium^ 

 or mildew, which for many years was the scourge of the European 

 vine, and the theory and methods of applying sulphur as the most suc- 

 cessful remedy which has been used abroad to stop its ravages. But, 

 from his writings on this suWject, I infer that Mr. Flagg assumes 

 the mildew on the American vine to be identical with didiutn of 

 Europe ; and that view, I believe, has generally been entertained by 

 those who have discussed the subject. With that conclusion I take 

 issue. 



Last year Mr. Flagg, in his delightful work on European vineyards, 

 printed a translation of the Manual for the Sulphuring of Diseased 

 Vines and Results, written by M. Mares, an extensive vineyard propri- 

 etor, of Montpellier, France. In it were included drawings, showing 

 the appearance of the didiian under the microscope, and for the first 

 time the grape growers of this country were furnished with data by 

 which they could determine whether the fungus growth on their vines 

 was the same as that which had brought such disaster upon the vine- 

 yards of Europe. To determine this question to my own satisfaction, 

 I proceeded last season to make a series of microscopic observations 



