DISEASES. 211 



on bearing vines are much injured by sun scald the fruit 

 does not mature, and usually it is the largest leaves and 

 those nearest the fruit that are affected the most. The 

 month of August here is very trying upon all varieties that 

 do not possess strong and healthy leaves. The more 

 glossy and shining the surface of the leaves, apparently the 

 less liable are they to sun scald, though there are some va- 

 rieties with a dull rough surface that I have never known 

 to be affected. Sun scald and mildew often go together, 

 and vines affected by the one are very likely to be attacked 

 by the other. 



There is another species of fungus called rust that is 

 sometimes found upon the vines ; the young shoots are the 

 part usually attacked. This, however, is not very prevalent, 

 and seldom found upon bearing vines, but confined chiefly 

 to the nursery. It is probably caused by some mismanage- 

 ment or unsuitable soils. 



The foregoing are the principal diseases that prevail to 

 any extent in this country, all of which, with perhaps 

 the single exception of the rot, may be avoided by simply 

 giving the vines a dry soil, and strictly following some 

 judicious method of training. It may be necessary to dis- 

 card a few of the varieties now in cultivation for particular 

 localities, and this would probably be a gain instead of a 

 loss. And perhaps the rot, which is now so prevalent at 

 the West, may be entirely avoided by the introduction of 

 other varieties. 



