Bark Ringing and Bark Slitting your Apple Trees
Bark ringing is a more simple operation than root pruning your apple trees, and also has the effect of encouraging the production of fruit buds. The normal food supply from the roots is partially or completely cut off, the sap being concentrated in the branches of the tree.
With a sharp knife cut a slit, 1 in. wide, half-way round the trunk of the tree, 2 or 3 in. beneath the lowest branch.
Cut a similar slit 1 in. lower on the opposite side of the tree. Cut down through the bark and no deeper.
As soon as the bark has been cut off, paint over the wounds with a thick white lead paint or protect them with adhesive tape.
Hinging should be done in March or April, though it is possible to carry out the operation in winter, when the tree is dormant.
A tree is bark-bound if the cells at the centre swell and the bark does not. The bark then acts as a tight corset and tends to split here and there.
A tree may also be bark-bound if :
(l) the top of the tree seems too large for the stem,
(2) it blossoms well but does not yield a good crop and
(3) an obvious cracking noise is heard when a knife blade is inserted into the bark and moved downward.
To relieve the constriction, make a perpendicular cut with a sharp knife in the bark on the north side of the tree and from the top of the main stem tolevel. The passage of the sap will thus be unimpeded, and the tree will grow naturally.
A cut made in this way heals rapidly and does no harm to the tree.