132 OPEN AIR GEAPE CULTURE. 



the sap, to effect which, they must be supplied with 

 air and light. Now, if the leaves on the laterals are 

 allowed to grow, they crowd the foliage at the base 

 of the plant, so that many of the leaves are partially 

 shaded, while if these laterals are prevented from 

 growing, the sap which would be absorbed by them 

 goes to the elongation and enlargement of the main 

 stem, by which the leaves are disposed over a greater 

 surface and consequently maintain a more vigorous 

 action. And, as during the first two years at least, 

 the production of canes well ripened in their whole 

 length, is no object, seeing that they are all to be cut 

 away at the winter pruning, the vines should not be 

 stopped, but should be allowed to grow to the end of 

 the season. For as the roots require a certain degree 

 of warmth to enable them to grow, and as the earth 

 as in the best condition as regards temperature, just 

 :at the close of the growing season, it is best to main- 

 itain a vigorous action in the roots at that time a 

 .time when they can make the most of it. 



The second reason is, that the sap, as before stated, 

 flows most vigorously through stout, free-growing 

 shoots. Now, by removing the laterals, we increase 

 the vigor of the main stem as well as its size, and 

 hence not only obtain an enlarged, but a more 

 suitable channel for the sap to flow in. The conse 

 quence is, that a well trained shoot will far exceed the 



