PLANTING, PRUNING, AND TRAINING FRUIT-TREES. 197 



stronger branches. Leave all the fruit possible on the strong, and suppress 

 them upon the weaker branches. 



500. A solution of sulphate of iron, in the proportion of one grain to a pint 

 of water, applied after sunset to the green leaves and leaf-buds of weak 

 ■branches, is rapidly absorbed by the leaves, and powerfully stimulates their 

 action upon the ascending root-sap cf fruit-trees. 



501. By detaching weak branches from the wall or espalier to which they 

 are fixed, they receive an increased amount of light ana air on both sides. As 

 Jight is the chief agent employed in the elaboration of the sap, its energy will 

 thus be largely increased. But this must not be done until the end of May 

 when any danger from frosts may be considered as past. The same result is 

 obtained by covering the stronger branches from the light. 



502. The sap develops itself much more vigorously imder short pruning 

 •than under long branches. If, then, it is desired to obtain wood-branches, 

 prune short : when the branches are vigorous they develop few flower-buds. 

 ■On the contrary, if it is desired to develop fruit-bearing branches, prune long ; 

 the less vigorous branches develop abundance of flower-buds. Another appli- 

 cation of this principle, to re-establish the vigour of a tree exhausted by a 

 heavy crop, is to prune it short the following year. This may appear to be a 

 contradiction of a maxim previously laid down, to prune short an over- vigorous 

 branch and leave the weak ones long. The contradiction is only apparent ; 

 the one applies to a whole tree, which is to be treated alike in all its parts ; the 

 other to a tree whose equilibrium is to be restored, — the one to the production 

 •of wood, the other of fruit. 



503. The tendency of sap to flow to the extremity of the branch leads to a 

 TOore vigorous development of the terminal bud than of the lateral buds ; 

 accordingly, where it is desired to obtain an elongation of the branch, it is 

 necessary to prune back to a vigorous wood-bud, and to leave none beyond it 

 which can interfere with the action of the sap. 



504. The more the sap is retarded in its circulation, the smaller is the force 

 with which it acts in developing branches, and the greater its action in pro- 

 ducing /owe'/*-i«f?s. Trees only begin to develop flower-buds when they have 

 reached some maturity ; for their production it is necessary that the sap should 

 have attained some consistency, and circulate slowlj'. This elaboration is 

 Assisted by the extended course it has to run in the lengthened branches ; it 

 is also assisted by broken and interrupted lines. This well-known principle 

 has been taken advantage of to check the sap by pinching and torsion, 

 and even partially breaking over-vigorous branches. These mutilations have 

 been found to diminish the vigour of the shoots and branches, by forcing 

 the sap into new branches while the older branches are elaborating their 

 fruit-buds. 



505. When all other methods of checking the superfluous vigour of a tree fail, 

 late winter-pruning is sometimes practised, when the shoots have attained 

 a length of one-eighth of an inch, when the sap has already reached the 

 . summit of the branches, and the buds near the base push less vigorously. 



