THE GRAPES OF NEW YORK. 69 



The chief natural factors which govern the distribution of varieties 

 of grapes are: Latitude and altitude; temperature of air and soil; water 

 supply; the chemical and physical properties of the soil; air currents; and 

 insects and fungi. 



Latitude and altitude very largely determine the annual temperature, 

 the amount and intensity of sunlight, and the length of the growing season — 

 all very important factors in growing grapes. Species and varieties of 

 grapes are usually adapted to regions having about the same latitude; 

 northern types do not succeed in the South nor the reverse. Length of 

 season has more to do with the adaptation of grapes than the degree of heat 

 or cold, for some southern sorts are hardy in vine in the North but the 

 seasons in the northern latitude are not sufificiently long for the fruit to 

 mature. On the other hand, northern varieties mature too quickly in the 

 South and pass through maturity to decay with too great rapidity. The 

 metes and bounds of latitude are often set aside in grape-growing by local 

 modifications. Thus it often happens that valleys in regions not generally 

 adapted to viticulture are so protected from cold winds, so open to sunshine, 

 or are so free from fogs or frosts as to furnish ideal conditions for grape- 

 growing. 



Probably the chief factor in determining the adaptability of a region 

 to grape culture is temperature. Each of the different species and varieties 

 of grapes requires a certain amount of warmth for its best development 

 and can endure but a certain degree of cold. The temperature of a region 

 is chiefly determined Ijy latitude, altitude and proximity to large bodies of 

 water, though variations in the surface of the country are often important 

 modifying agents of temperature and especially influence spring and fall 

 frosts. 



The grape does best in an equable temperature and does not thrive in 

 regions where there is a great daily range. Regions and seasons in which the 

 temperature is comparatively low in the growing months of May, June and 

 July and high, with much sunshine, in the maturing months of August, 

 September and October, produce the best grapes in the latitude of New York. 

 An average of from 55° to 65° for the first named period and of from 65° 

 to 75° for the second are ideal temperature conditions for the grape. 



This fruit is very sensitive to moisture conditions. Not only must the 



