CHAPTER XIII 



DISEASES. 



Mildew. — Nearly all attempts to cultivate the exotic 

 grape-vine in the open air, in the United States, have 

 ended in total failure and disappointment. In a few soli- 

 tary instances, and under peculiar circumstances, where 

 the excessive changes have been counteracted by shelter 

 or otherwise, a partial success has been obtained, but the 

 climate of the whole eastern and middle parts of the Union, 

 is too vajiable for its easily checked, though vigorous 

 constitution, and by which the vital energy is impaired at 

 the time of greatest activity — when mildew in its various 

 forms completes the works of destruction. This mildew 

 is the growth of fungoid vegetation, the seeds of which 

 aie so small in many kinds as to be invisible to tbe naked 

 eye. Tbere are two kinds which are most troublesome to 

 the grape-vine — one, which we presume to be the Oldium 

 Tuikeri, that is at present devastating the vineyards of 

 Europe ; and the other a Bolry/is, or some analogous 

 genus. The first indication of the former is shown by 

 the leaves having brown spots* upon them, and which 

 "permeate quite through the tissue. Afterwards, are seen 

 Bmall white patches of tlie soft and delicate fungus at- 

 tached to tlie under side of the leaf, and which, if not 

 speedily destroyed, will soon extend to the fruit stalks, 

 penetrate to the berries by the rhizoma or spawn, and 

 make them in appearance like a diseased potato in the 

 tirst stage of infection, stopping their growth, and reuder- 



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