n June, 1917.] Apple Culture in Victoria. 333 



APPLE CULTURE IN VICTORIA. 



By J. Farrell, Orchard Supervisor. 



(Coiitiimcd from page 294.) 



Nature's Method of Building the Tree. 



"When the apple tree is allowed to commence life through being 

 enabled to germinate from the pip or seed, or when propagated from a 

 root-graft or layer it is developed by the annual multiplicatiou and 

 extensions of its roots and branches. While these develoj)ments arc 

 taking place the wood of the root system, the stem, and that of the tree's 

 superstructure becomes thickened by the addition of corresponding rings 

 of new wood which are formed during the successive periods of vege- 

 tation. 



The clusters of leaf scars on the bark of the branches of unpruned 

 trees between the wood growth of the various ages denote the positions 

 of the original terminal buds, while the marks on the leaders of annually- 

 j)rnned trees, as well as the concentric circles which circumscribe the 

 wood rings, and which may be observed in transverse sections of the 

 stem and branches, likewise indicate the periods of rest. 



Following each dormant period which is caused mostly by the pre- 

 valence of low temperatures during the lull of winter comes the regular, 

 familiar, but nevertheless remarkable, phenomenon of the bare branches 

 of the tree gradually bursting apart the scales of their leaf buds, and 

 revealing the delicate forms of the rudimentary leaves which soon 

 expand into a rich gannent of green foliage. 



This wondrous change is brought about by the genial return of spring 

 and the accompanying rise of temjx'rature which acts upon the invigorat- 

 ing materials stored up in the tree causing them to vigorously renew 

 their activities. 



The warmer conditions also sweeten the soil, and, to some extent, 

 prepare the plant food which the feeding roots of the tree absorb in the 

 form of crude sap, made up of mineral nitrates in solution. 



How the raw saj) is absorbed by the points of the feeding roots, the 

 manner in which it travels to the leaves in which it is assimilated and 

 converted into elaborated sap, and subsequently distributed to the various 

 parts of the tree and to the fruit, are problems which have long puzzled 

 physicists. The old theory that capillary attraction is the agency by 

 which the raw sap is carried up the trunk and branches of the tree like 

 oil through the wick of a lamp seemed a totally inadequate explana- 

 tion. The general consensus of opinion among modem physicists, how- 

 ever, is, as they explain, that the sap in the tree moves in the various 

 directions simultaneously by a process which they term osmosis. 



The high, but practically incalculable pressure, exerted in some of the 

 internal tissues of the stem, and also distributed more or less irregularly 

 through the tissues of other parts of the tree, forces the cap to the grow- 

 ing points of the leaders, laterals, and to the other buds. This causes 

 the leaves to expand, and the process continues while the building up 

 of new structures is going on during the currency of the period of vege- 

 tation. 



