Page:The Olive Its Culture in Theory and Practice.djvu/111

Rh present less opposition to its course than the older wood. Having reached the leaves, the lungs of the tree, it undergoes some change in its properties and then returns to the roots again; so we have the ascending sap and the descending sap.

The descent of the sap can be verified and turned to advantage. It is claimed that the tree can be compelled to bear fruit whether it will or no. Having selected a fruit branch, ring the bark near its base, making a perfect ring whose ends meet, A double-bladed knife with the blades about half an inch apart is the proper instrument to use. The descending sap will be forced into fruit and the yield of that particular branch will be in marked contrast to its neighbors. The upper side of the ring will exude sap and it will finally swell into a circle there showing its desire to come down. It is claimed that this ringing of the bark of minor branches can be done annually without any detriment to the tree. It will be better to select horizontal branches, as without the bark and with a weight of fruit, vertical branches are apt to be broken off by the wind. But as much is required from a tree by this process, so, more than usual care must be expended on it in cultivation and manuring. The tendency of a tree is to reach the height of its species, and as only the vertical branches are useful for this purpose, the sap always tends to nourish the upright branches at the expense of the horizontal and lower ones.

It is necessary to avoid pruning too long, which would carry the sap to the extremities of the branches to the detriment and destruction of the center. On the other hand too short pruning would force the sap into a small number of buds that would be found on the young branches and flowing back to the old, would result in false wood, that is, branches out of place and contrary to nature. If one side of a tree grows with too much vigor the strong branches should be pruned short but the feeble ones left long in order to encourage the sap to flow into them, and on the other hand the reverse should be done with the feeble side, the weaker branches