GENERAL PRACTICE. STOCKS AND THEIR INFLUENCE. 107 



STOCKS AND THEIR INFLUENCE. 



Where the soil and climate are suitable for the growth and maturity of the fruit of 

 any tree, there the organs naturally provided for the supply of sap may afford it of the 

 proper quality and in sufficient quantity for every want. Trees, however, succeed 

 better, are more productive and not more susceptible of disease when supplied with 

 sap from roots and passing through a stem of another suitable species or variety. The 

 universal method of establishing trees by budding and grafting testifies to the sound- 

 ness of those practices, and the finest fruit and fullest crops are not produced by trees 

 on their own roots. 



Stocks are employed first, for the increase of a particular variety of fruit ; second, to fit 

 varieties for some particular soil ; third, to produce some alteration in the habit of the tree, 

 for adapting it to the desired cultural requirements. The advantages of stocks for the 

 preservation of remarkable varieties which could not be reproduced from seed, and the 

 more rapid increase of particular kinds, cannot be over-estimated, for by no other means 

 are fruit trees increased so beneficially to the grower. Seedling fruit trees seldom afford 

 such fine fruit as the same varieties do when established on appropriate stocks. The 

 cultivated apple affords the finest fruit when grown on the paradise stock ; cultivated pears 

 are improved in size, colour, and quality on the quince, and cultivated apricots, nectarines, 

 and peaches are more productive on the plum than when on their own roots. In fact, 

 whatever tends to arrest luxuriant growth causes the tree to become more productive. 

 Mr. Knight states : " When the course of the descending current is intercepted, that 

 necessarily stagnates and accumulates about the decorticated part, whence it passes 

 into the alburnum, is carried upwards, and is expended in an increased production of 

 blossom and fruit." Budding and grafting act beneficially by arresting the downward 

 flow of the sap, for there is always a decortication at the junction of the scion with the 

 stock when the former is of a different kind to the latter, and the fruit resulting is larger, 

 higher coloured and better flavoured. When a stock is of slower growth than the 

 variety of fruit it supports, the vigour of this is modified, the sap concentrated, acquiring 

 greater specific gravity, and is therefore richer ; the tree arrives at a fruiting state earlier, 

 blossoms are more profuse and set better, the wood and fruit ripen sooner through the 

 more abundant deposition of cambium. Thus restraining growth to a proper degree 

 by the influence of the stock is attended with the best results to the planter, but the 

 restriction must not be so severe as to impair the health of the tree. Luxuriance of 

 growth is no criterion of health. All fruit trees are liable to disease. Stone fruits are 



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