STOCKS AND RESISTANT VINES 69 



for better or worse in characters of vine and fruit by the stock 

 upon which it is grafted. A plant is a delicate mechanism, 

 easily thrown out of gear, and all plants, the grape not the 

 least, are more or less changed in the adjustments of stock and 

 cion. One could fill a large volume on the supposed reciprocal 

 influence of stock and cion in fruits. Space suffices, here, 

 however, to mention only those proved and those having to do 

 with the influence of the stock on the cion when the grape is 

 grafted. 



Influence of stocks on European grapes summarized. 



Common experience in Europe and California indicates that 

 varieties of Vinifera grapes grafted on resistant stocks which 

 are perfectly adapted to soil and climate produce not only 

 larger crops but sweeter or sourer grapes ; that the crop ripens 

 earlier or later ; that the vine is often more vigorous ; and that 

 there are some minor differences depending on the stock used. 

 Winemakers assert that the character of their product may be 

 affected for better or worse by the stock. Often vines are so 

 improved by grafting that the extra expense of the operation 

 and of the stock is paid for; although, to be sure, about as 

 often the effects are deleterious. The successes and failures of 

 vineyards on resistant stocks make plain that the vine-grower 

 must study the many problems which stocks present and exer- 

 cise utmost intelligence in the selection of the proper stock. 



Influence of stocks on American grapes. 



No doubt American species of grapes may be as profoundly 

 modified by stocks as the European specfes, but there is but 

 little evidence on this phase of grape-growing to be drawn from 

 the experience of vineyardists. One rather conclusive experi- 

 ment, however, shows that American grapes may be improved 

 by growing them on stocks which give them better adaptations 

 to their environment. The experiment was tried in the Chau- 



