498 T^^ Mildew and the Rot in the Grape. [November, 



THE MILDEW AND THE ROT IX THE GRAPE. 



The partial failure of tlie grape crop in this vicinity for the last few 

 years, has created considerable alarm in the minds of some perspns 

 who have invested large capital in the culture of the vine, for the 

 production of wine. Many are beginning to be distrustful that it is 

 not going to prove a remunerative crop. So great were the appre- 

 hensions entertained, that the subject was brought up before the 

 Horticultural Society of Cincinnati, and a committee appointed to 

 investigate the causes of failure, and if possible, to point out rem- 

 edies, and to report upon the feasibility of the culture of the grape 

 in this vicininty as a remunerative investment of capital and labor. 



As a member of that committee, who have not yet made a final 

 report, I have taken great pains to investigate the subject during the 

 past unfavorable season, and have come to the knowledge of some 

 facts which will serve to dispel the mystery which has heretofore in- 

 volved the two most destructive diseases to which the grape is liable, 

 the mildew and the rot. 



Like all other productions of Agriculture, the grape is liable to 

 many casualties, some of which being dependent upon the season, as 

 untimely frosts, hail storms, etc., are without remedy, while for others 

 also dependent upon the character of the season, as these above nam- 

 ed, we may yet hope for a remedy. 



The mildew makes its appearance under peculiar conditions of 

 the atmosphere sometimes very suddenly in the form of a white 

 mealy powder, covering the young and tender berries, and frequently 

 the growing short leaves and stems of the grape. It has been de- 

 monstrated by a careful microscopic examinator, that these consist 

 of a white organized fungus growing upon the yet unhardened 

 surface of the Epidermal cells forming the cuticle, and in some undis- 

 covered way destroyins: the organization of the parts to which it is 

 attached, as the grapes in all cases, cease to grow, turn black and 

 full off. In no instance have we seen a single berry come to per- 

 fection where this fungus was attached in any considerable quantity. 

 This fungus when viewed through a lens, the focus of which is a 

 quarter of an inch, appears in the form of a most beautiful prema- 

 ture forest growing upon the surface of the grapes, each tree being 

 separate and distinct, with trunk and branches similar in shape to 



