Grafting Can Give Much Satisfaction For Years

Press, Volume CVI, Issue 31178, 30 September 1966, Page 6

Grafting Can Give Much Satisfaction For Years

The time for grafting has arrived and this fascinating work can give great satisfaction for yean afterwards, if properly done.

There are several important factors to be taken into account for the success of the venture, however. The scion, which is the wood to be cut and fitted to the rootstock or framework of an existing tree, must be in a dormant condition. It should have been selected from completely healthy trees of desired variety. One-year-

old pencil thickness material is required. The stock should have the sap rising and be about to come into growth. This stage is usually reached towards the end of September. If it is desired to change a variety completely from the existing one the tree is headed back and the butt edges lightly pared so that only the leaders remain. The latter are reduced to a height which makes their cut surfaces easily accessible. This is known as top working. At least one leader should he

left uncut to act as a sap drawer, to help feed the root system and aid quicker healing.

Heading back should be done carefully to avoid tearing the bark. Scions are inserted in the top of remaining growths. Frame working does not entail removal of much existing growths other than some of the heavier or profuse lateral growth. In frame working the scions are inserted and spaced over the entire network of branches if so desired.

Requirements are a pair of sharp secateurs, a knife with a razor edge, possibly a clefting tool, a rub stone and light oil, a sealing compound such as petrolatum, 5 Sin copper wire nails, or gimp pins, and some tape such as a glasshouse sealant (a putty impregnated material) which I have found ideal for the purpose. There are very.many different types of grafts which can be employed, some of which are difficult to execute, while others are not so reliable. Irrespective of which grafts are used, and only a few are described here, contact of the cambiums of stock and scion is of the greatest importance, followed by the necessity to prevent drying out of cut surfaces. These factors therefore require the operator to be well acquainted with his task beforehand and then to work accurately and quickly. Top Working

The rind graft consists of a scion piece of four or five buds which is inserted into a slit made into the bark of the headed back stock. Take the scion and make a tapered cut about IJin in length from the base as illustrated. Next slightly bevel one side. Ensure that the cut surface, as in all subsequent cuts, is perfectly flat. Next make a vertical slit into and through the bark and lift one side. Slide the scion down until its cut surface is no longer visible, with the bevelled side towards the unlifted bark. Tack into place and thoroughly cover all cut surfaces with sealant. Taping or binding is optional and need not be done where very close fits have been accomplished. At least two rind grafts should be made on each leader, depending on size,

spaced out in suitable positions.

The Cleft Graft entails splitting the top surface of the stock with the clefting tool, which can be fashioned from a piece of scrap metal and sharpened. Having split the surface, prepare the scion by cutting a blunt-edged wedge of even thickness and similar length to the ring graft. More care must be taken when matching cambiums of stock and scion so that they touch on both sides on the outer side and for the full length of the scion on either side. (Forget about the bark of the stock and concentrate on matching the cambiums.) Only two scions, one at either end of the cleft, can be fitted in this kind of graft, which requires particular care in sealing to' make it not only airtight but waterproof as well. Nailing is not needed as pressure from both sides of the split stock will hold the scion very tightly. In fact sometimes the scion may be crushed from this effect and where this is thought likely a small solid spacer of wood could be slipped in between.

Frame Working In frame working it is necessary to use longer scions, of seven or eight buds in order to suppress vigour. There is need to exercise even more care in their preparation and it is not just a case of inserting them here and there. They must be situated in such a way that growth arising from them is well placed.

Whip and Tongue. This graft could also be used on one or two-year-old stocks. Make a sloping cut on one side of the stock l|in in length. Half an inch or so from the top make a short, shallow reverse cut so as to form a tongue. Cut the wood of the scion in a corresponding way to match that on the stock and also a tongue in the same position. Interlock the tongues, checking that no light is evident between the two surfaces. Bind tightly with tape and seal the tip. About five buds are again sufficient for scion wood lengths. Stub Graft. Preparation of scion entails cutting it on both

sides so as to form a wedge with sides of uneven lengths. A suitable branch of about lin diameter should then be selected and a cut made at an angle towards its centre and about lin from its junction with the main branch. This branch is then carefully pulled down so that the scion can be slipped in (long cut side down). The branch is then allowed to spring back and, if the job has been well done, the scion should be very firmly held in place. Cover well with sealant and tape firmly. This particular graft can prove tricky to the uninitiated but has been found very satisfactory otherwise.

Inverted L Rind Graft The scion is prepared by first making one sloping cut of about Ijin in length at the basal end and then a very shallow cut at one side just to expose the cambium. A shallower cut than the first should then be made on the reversed scion but a little to one side and away from the second cut. An - angled L shaped slit with the bark pared back at the junction of the two bars forming the L is then cut into a limb of the stock. The scion is inserted and carefully nailed. The cut surfaces should be well and carefully sealed.