BARK-RINGING FRUIT TREES
This is a simple operation designed to check the growth of very vigorous fruit trees and bring them into bearing. It is a very old method and was practiced by gardeners many years ago. In recent years it has been employed by commercial fruit growers and gardeners, particularly in Europe. The operation is carried out in the spring, usually in May: the actual date is unimportant but the sap must be running freely so that the bark lifts easily and cleanly without tearing.
What Bark-ringing Does. The effect of bark-ringing is to check the downward flow of elaborated sap, thus conserving the concentrated food supplies in branches and shoots. As a result, fruit buds are developed and strengthened and unfruitful growth is checked.
Bark-ringing may be practiced on strong-growing Apple and Pear trees quite safely. Plum and Cherry trees can be operated on, but bark-ringing these and other "stone" fruit trees may lead to an attack of gummosis. In the case of "stone" fruits, root pruning in autumn is much to be preferred to bark-ringing as a means of checking rank growth and encouraging fruiting.
Removing a Complete Ring of Bark. Two methods are now in common practice. The easier one is to operate on the main stem of the tree at a point just below the lowest branches. A complete ring of bark, about 1/8 in. wide, is cut out right round the stem; the strip of bark is peeled off cleanly and evenly with a sharp knife or small chisel, and taken out down to the hard wood of the stem, but not cutting into the actual wood. It is important that this narrow, encircling ring shall be allowed to heal over during the season; to assist healing and to prevent the entry of disease germs, it should be bound over with a strip of adhesive tape or covered with grafting wax. The complete ring must never be wider than 1/4 in., preferably less.
Removing Half-rings of Bark. The second method, favored by many commercial growers, is to take out two half-rings of bark on opposite sides of the tree stem, one half-ring being about 4 in. above the other. By a half-ring is meant the removal of a strip of bark encircling half the circumference of the stem. Each half-ring should be about 1/2 in. wide, and the bottom half-ring must begin and end immediately below the top half-ring—the second strip of bark being removed from the opposite side of the stem. When removing the bark, first cut round the edges with the knife point, then peel off the strip of bark with a chisel right down to the hard white wood of the stem.