302 MANUAL OF AMERICAN GRAPE-GROWING 



Species of grapes have very characteristic vines. A glance 

 at a vine enables one to tell the European grape from any of 

 the American grapes ; so, also, one is able to distinguish most of 

 the American species by the aspect of the vine. Many varieties 

 of any species of grape are readily told by the size and habits 

 of the plant. Size of vine is rather more variable than other 

 gross characters because of the influence of environment, such 

 as food, moisture, light, isolation and pests ; yet, size in a 

 plant or the parts of a plant is a very reliable character when 

 proper allowances are made for environment. 



The degree of hardiness is a very important diagnostic char- 

 acter in determining both species and varieties of grapes and 

 very largely indicates their value for the vineyard. Thus, the 

 varieties of the European grape are less hardy than the peach, 

 while our American Labruscas and Vulpinas are as hardy as 

 the apple. The range of varieties as to hardiness falls within 

 that of the species, and cultivated varieties hardier than the 

 wild grape are not found. Grapes are designated in descrip- 

 tions of varieties and species as hardy, half-hardy and tender. 



Habit of growth varies but little with changing conditions 

 and is thus an important means of distinguishing species and 

 varieties and not infrequently stamps the variety as fit or unfit 

 for the vineyard. Habit of growth gives aspect to the vine. 

 Thus, a vine may be upright, drooping, horizontal, stocky, 

 straggling, spreading, dense or open. The vine may grow 

 rapidly or slowly and may be long-lived or short-lived; the 

 trunk may be short and stocky or long and slender. These 

 several characters largely determine whether a vine is man- 

 ageable in the vineyard. Productiveness, age of bearing and 

 regularity of bearing are distinctive characters with cultivated 

 grapes. The care given the vine influences these characters; 

 yet all are helpful in identifying species and varieties and all 

 must be considered by the grape-grower. 



Immunity and susceptibility to diseases and insects are 



