9G BOARD OF AGRICULTURE. 



Our chairman has very truly said that this has been a most 

 unfavorable year for the grape. Mildew has affected varieties 

 in localities where they have never before been affected ; 

 (I think all varieties have been occasionally affected, in certain 

 localities, though generally exempt.) But this year, none were 

 exempt. The season was peculiarly unfavorable. It has been 

 truly said, that some of the circumstances attending the pres- 

 ence of mildew go to upset many of the theories of the text- 

 books in regard to it. Suppose we look at that subject of 

 mildew for a moment. I confess, I have never been able to 

 satisfy myself that there was any peculiar cause for it. I believe 

 there are various causes operating, some at one time and some 

 at another. I am most inclined to accept Dr. Fisher's theory, 

 that it is due to hygrometric changes. He tells me, that up to 

 the 9th of July — and you will remember the season was, up to 

 that time, cool and wet — his grapes had no mildew upon tliem. 

 At that time, we had two or three bright and hot days, which 

 they improved to make their hay, and immediately the mildew 

 appeared. It took the upper leaves on his trellises, and was 

 instantly apparent. Immediately after these two or three days, 

 the cool, moist weather returned, and the mildew stopped. 

 That is a very remarkable fact, for according to the generally 

 received opinion, a wet season makes mildew ; and we have 

 always believed that the spores of this fungus in the air, in 

 continuing wet weather, found favorable circumstances to grow, 

 and establish themselves. My experience was the same ; I had 

 no mildew until that time, and then I found it, as the doctor 

 did, upon the upper leaves. That is one theory. Prof. Silli- 

 man, I think, wrote an article upon mildew, which appeared in 

 the " Horticulturist," in which he expressed his belief that it 

 was a constitutional defect, inherent in the vine. I do not 

 think that can be exactly true. I think I can say, that if there 

 is any constitutional defect, if there is a weakness in the vine, 

 it would be peculiarly predisposed to that disease, and so it 

 might ensue under circumstances of such slight provocation as 

 would not affect healthy vines, without that constitutional 

 defect. I think that view of the case is strengthened by the 

 fact, that our weak-growing vines are generally most subject to 

 mildew. I find it to be the case with some of these slow-grow- 

 ing, tender vines, that they lose their leaves in the summer 



