plant propagation, Grafting method , types of grafting , method of propagation

Plate 7.2: Steps involved in tongue grafting The lower tip of the scion should not overhang the stock as there is a likely hood of the formation of large callus knots. The use of scions larger than root stock should be avoided. After the scion and rootstock are fitted together, they should be securely held by tying with budding/grafting tape or polythene. This method gives better success than splice grafting because of better cambial contact between stock and scion due to formation of tongue. Regular de-shooting of sprouts on stock is required to obtain better growth of scion. Cleft grafting: It is one of the oldest methods of field grafting. It is used to top work trees, either in the trunk of a small tree or in the scaffold branches of a bigger tree. . Wedge grafting (saw-kerf grafting): It is performed in late winter or early spring before the bark begins to slip. A sharp, heavy, short bladed knife is used for making a V-wedge in the side of the stub or stock about 5cm long. 7.2f Fig.7.2: Wedge grafting Saddle grafting: The saddle grafting can be bench grafted by hand or machine. The rootstock and scion should be of the same size. The scion is prepared by cutting upward through the bark and into the wood opposite sides of the scion. The graft is tied and cut surfaces are sealed by polythene until the graft-union is formed. t is used for the propagation of grape and rhododendron cultivars. B. Side grafting methods Side veneer grafting: This method is used for grafting small potted plants such as seedling of deciduous trees, shrubs and fruit crops. A shallow downward and inward cut from 2.5-3.5 cm long is made. At the base of this cut, a second short inward and downward cut is made, inserting the first cut, so as to remove the piece of wood and bark. The scion is prepared with a long cut along one side and very short one at the base of the Side-tongue grafting: In this method, the cut is made at the base of the scion, like the cut made in whip-and tongue graft. Then, a thin piece of bark and wood from stock and scion is completely removed. Then a reverse cut is made downward in the cut on the rootstock starting 1/3rd of the distance from the top of the cut. This second cut in the rootstock should be of the same length as the reverse cut in the scion. C. Detached scion grafting methods Bark Grafting (Rind grafting): It is very simple method of propagation and some nurserymen prefer it, because it can be done without splitting the stub, which prevents the entry of pathogens. It can be done in branches, which are 25 to 30 cm long. It should be done in spring when the bark of the stock slips easily. It is important to note that the scion used in bark grafting should be dormant. The rootstock is first sawed off at a point, where bark is smooth. If the stock is thick many scions can be inserted. For each scion, bark is split downward, about 5 cm from the top of the stub. Scions of 10-12cm length containing 2-3 buds are prepared by giving a slanting cut (5cm) downward along one side of the base. On the other side, a small cut is made. The scion is then inserted in the centre of split between the bark and wood of the rootstock. The longer cut of the scion is placed against the wood. The scion is held firmly by using adhesive tape. Afterwards, all the exposed portions of the stub and scion should be tied with polyethylene strip tightly. The scions will start sprouting after 6-8 weeks in case of successful grafts. D. Root grafting (Whole root and Piece-root grafting): In this method, the seedling rootstock, rooted cuttings or layered plant is dug up and the roots are used as the rootstock for the graft. The entire root system may be used (whole-root graft) or the roots may be cut into small pieces and each piece is used as a rootstock (piece-root graft). As the roots used are relatively small (0.5-1.5 cm) in diameter, the whip and tongue graft is generally used. Root grating is usually bench grafted indoor during the late winter or early spring. In preparation of root-grafts, the root-pieces should be 7.5 to 15.0 cm long and the scions of about the same length containing two to four buds are used. After the grafts are made and tied properly, they are bundled together in groups of 50 to 100 and stored for callusing in damp sand, peat moss or other packing material.