TREE SURGERY

Wairarapa Times-Age, 14 July 1939, Page 9

TREE SURGERY

BROKEN BRANCHES HARBOUR DISEASE. There are times when it becomes necessary to remove fairly large branches from fruit trees, large shrubs, or even shade trees. Much depends on the way the work is done. There is a right and a wrong way in tree surgery. There may be many reasons for removing a branch. For instance, it may be diseased or spoiling the shape of the tree, or it may have been broken in a storm. In the latter instance the branch will soon become diseased if not treated properly. Torn and ragged stumps are favourite places for destructive fungi to commence their activities. Once the fungus has penetrated well into the tissues it is not possible to destroy it by applying fungicides. and the first thing to do is to cut out the diseased and dead part. Where a small branch is diseased it can be cut back to healthy tissue or flush with the large branch from which it grows. Dead or dying wood is no good to any plant, so even in small shrubs, a dead branch should be cut right out. or back to living wood. With apple canker, half the battle is to observe the trouble at the outset and treat it at once. Sometimes a spur starts to canker on a large branch, and this must be pared out at once or the canker may girdle the branch. Smaller branches may be removed entirely. In a main stem the canker should be carefully cut away until white tissue is seen. Silver leaf in stone-fruits may necessitate the removal of whole branches. When cutting use a sharp saw to make a clean cut. Clean cuts usually heal well, but ragged, hacked wounds take much longer.

All wounds should be covered with a good paint until they heal. One of the best paints for the purpose is the ordinary Bordeaux powder stirred into linseed oil till of the consistency of paint. Anyone who has practised the process of “ringing" apple trees, will know how quickly the fresh tissue, cal led calus. forms at ihe edge of the cut. The very small cuts made in pruning do not need any protection because they quickly heal and there is not much time for the wood to decay.

Large wounds are, however, the places of entry for disease fungi and it is es ■ sential that valuable trees should be protected. Accidental wounds such ns those caused by the lawnmower injuring the stems, should be treated similarly. With most broadleaved trees, cutting can be done in winter and early spring, but where disease, such as apple canker is seen, treatment should be given at once. If any doubt exists, it is best to seek advice, for some trees, the walnut, for example, bleed badly, and should not be cut, unless this is essential. Coniferous trees can be cut during the winter, but as they lose resin to such an extent, they should not be mutilated any more than is necessary, and any unavoidable cutting of large branches should be completed well before the flow of sap commences in spring.