GRAFTAGE, the process and practice (origin unknown) of propagating plants by the insertion in one of a bud (stock) or twig (scion) of another. It also includes the dis cussion of all questions relating thereto. The stock may be a complete plant, as in peach budding, or only a part, in which case it may be a root or a stem part. In some in stances (marching, see below) both plants may have roots. Since the process is dependent upon the coalescence of the cambium (q.v.) of stock and scion the first essential is to make these two surfaces abut ; the second is to check evaporation from the cut surfaces.
The many scores of styles of graftage fall naturally into three main groups: 1. Marching, or grafting by approach, the uniting of two plants before the severance of the scion from the plant upon which it grows. After union the scion is severed below the point of contact and the parts of the stock above this point are removed. The method is rarely prac tised except with subjects hard to graft by more popular methods and for correcting defects of form, such as Y-crotches in fruit trees, a living brace being formed between the two arms. Since it is the only graftage found in nature, it is supposed to be the progenitor of modern methods.
2. Budding or bud-grafting, the inserting of a single bud beneath the bark of the stock or in some cases (for example, annular or ring bud ding) in the place of a piece of bark removed. It is always practised upon small stocks prefer ably under two years old, and always when the bark readily separates from the wood as in spring or late summer. Since spring is a very busy season in nurseries, budding is practically all done during summer. The universally pop lar method is the shield, so-called from the shape of the scion. It is practically the only method employed in propagating the stone fruits—peaches, plums, etc. The seedling stocks, which are usually not less than one fourth inch in diameter, are stripped of their leaves close to the ground, are cut through the bark twice on the shady side, the cuts forming a T, the bark lifted gently with the specially formed ivory knife-handle, and the bud in serted and tied with raffia, bast or cotton. A small portion of the bark and a little of the leaf stalk accompany the bud, the latter to act as a handle. In about two weeks, if the bud has
taken, the binding is cut on the side opposite the bud to prevent ustrangulation." In case of a failure other attempts are made. No visible growth occurs during that season, but in the spring the bud should become a shoot and the original top of the seedling stock should then be cut a few inches above the union, and later, when the union is firm, this stub is cut off short. At the close of that season the tree is ready for sale.
3. Grafting proper, the inserting of a twig into a stock. The methods under this head ing may be divided according to the maturity of the scion whether dormant or growing, and also as to the position the graft occupies, whether upon the root, the crown, the stem or the branches. By far the largest amount of graft ing is done with dormant wood, and probably upon roots, though grafting upon the brandies is widely popular. In whip-grafting, which is the one most practised with roots, especially in the nursery propagation of apples and pears and performed in early winter, the seedling roots are specially grown and are as nearly the size of the scions as possible. Both stock and scion are formed alike, two cuts being made, one rather long, diagonally across, and the other parallel with the direction of growth, thus form ing a sort of tongue. The tongue of each is then fitted into the slot of the other, the pieces wrapped with waxed string, and stored in a moist, cool place until spring, when they are planted in the nursery. Usually they are sold after two seasons' growth.
Cleft-grafting is most frequently used upon parts of trees above ground or with grapes just below the surface. The stock is sawed across at right angles to the direction of growth, split with a knife and held open with a wedge until the twigs (scions) bearing two or three buds and whittled to a wedge form below are in serted, one at each end of the slit. The wedge is then removed and the wounded surfaces waxed. This method is practised most upon stocks too large for whip-grafting, limbs even as large as three inches in diameter being some times used. As a rule small stocks give more satisfactory results. The method is universally employed to change long-established trees to other varieties.