This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
THE modes of multiplying improved varieties of fruits so as to retain the same qualities as exist in the parent tree, are various. Those most usually resorted to are increasing by eyes or buds from cuttings, layering, budding, or grafting. Unless we possess this power, so that we can apply it readily and with cer- tainty, our means of procuring improved fruit will be very much circumscribed.
The usual method of increasing plants provided by nature, is by seeds. Seeds increase species without error. The peculiarities of varieties can rarely be perpetuated in the same manner. Hence the necessity, to secure the increase of a variety with all its qualities unaltered, that a portion from the original tree or plant should be taken, and converted into a new plant. In the structure of plants there is a wonderful provision made for the preservation of their specific qualities, and also for the increase and extension of their varieties. In animals this is not practicable, except in the case of a few of the lower orders of animals. The system of plants is otherwise; a plant is really an animated body, composed of infinite multitudes of systems of life, having the principles of vitality and reproduction diffused over every part, all indeed, united in a whole, but each having an independent existence.
When, therefore, any number of these systems of life are removed, those that remain, as well as those which are separated, will, under favorable circumstances, continue to perform their natural functions as if no union had ever existed. These systems of life are buds, each having the power of sending forth descending fibres in the form of roots, and also ascending in the form of the stem. They are the most important part of the plant; and it is only by them and the various forms which they assume, that the increase or propagation of plants is effected.
The bud is the embryo tree. As secondary buds develop, their descending roots combine and form the woody vessels of the stem, which descend in successive layers to the extremities of the roots and thus promote their extension. Roots are the elongation of the stock. Experiments with the willow have shown that a part of the top at different periods may be covered in the soil, while at the same time a portion of the roots are exposed, and that in a short time the whole tree may thus be reversed, the top becoming roots and the roots top. The stems ascending give rise to new buds, thus producing a succession of independent systems of life combined together as a whole. These buds are all exactly alike, have the same constitution, the same organic structure, and the individuals they are capable of producing are consequently identically the same, allowance being made for any accidental injuries or alterations.
The growth of the stem of the tree is nourished by the ascending sap through the roots of the bud; and as buds and leaves multiply and increase, their constant office is, to draw the sap to the extremities of the tree, and in this manner supplying the necessary food for the new-growing wood, while at the same time the buds are shooting down between the bark and wood of the stock, in search of additional food for the supply of this new growth. It will be seen from this, that the limb produced by the graft or bud, is in itself a distinction incorporated with another, and deriving therefrom its sustenance. It is upon the existence of this remarkable peculiarity' of plants that propagation entirely depends. Take a cutting of a vine consisting only of the space which lies between two buds, and no art will succeed in making it become a new plant. The only exception to this rule is those plants which possess the power of emitting latent buds.
On the other hand, take a bud without any portion of the wood adhering to it, and it will throw out root and stem, and become a new and distinct plant. The ordinary way of propagating trees is by budding and grafting.
The end attained by these methods of propagation is, to multiply and increase varieties of fruit trees endowed with particular qualities, and which cannot with certainty be transferred to their offspring by seed, and which would be multiplied too slowly or ineffectually by any other mode of propagation; and also of rendering such trees as are somewhat tender, more hardy.
Budding and grafting are operations equally dependent for their success upon the property that buds possess of shooting roots downwards and stems upwards, and the theory of these processes is based on the power of union between the young tissue of the growing wood. When the parts are carefully placed in contact, the ascending sap of the stock passes into and sustains life in the scion. The roots of trees quite unlike will sustain the life of each other. An apple grafted into the root of the willow will sustain life until roots shoot from the scion. The pear and apple, the peach and plum, are like examples of this. The buds, whether single or in scions, excited by the supply of sap from the stock, and the warmth of the season, begin to elaborate and send down roots or woody matter between the bark and wood of the stock, which contact unites the graft or bud firmly with the stock, and the stem commences making its upward growth. The success of this operation depends upon the necessity that an adhesion should take place between the scion or bud and the stock, so that when the descending fibres of the bud shall have fixed themselves upon the wood of the stock, they may not be liable to subsequent separation.
This is facilitated by the fact, that in the vegetable kingdom there is a strong tendency to cohesion in bodies or parts that are placed in contact with each other. We often see this exemplified in the growth of trees, and fruits becoming united or double when in close connection with each other.
Budding and grafting is therefore, like layers, cuttings, and suckers, the dividing of the original tree into parts. Even when the operation is the most successful, no intimate union takes place between the bud and the stock. They grow firmly together, but do not incorporate. You may insert several buds of different varieties of fruits upon a stock, one above the other, and each will produce its distinct variety, while the stock will remain unchanged, and produce its original fruit, both above and below the inserted scion. Or insert portions of bark of different trees, and the wood underneath will be that of the tree from which the portion of bark is taken, while above and below the original wood will remain the same.
The range of grafting and budding is confined within certain limits. It is only those trees that are allied to each other, upon which these operation can be successfully performed; and it is only when there is a close relationship and similarity of structure between the scion and the stock, that a favorable result may with any certainty be looked for. As a general rule, the seed, cone, nut, and mast-bearing wood, should be worked upon each other. That the stock in some cases and to some extent affects the graft, and that the graft also affects the stock, is undoubtedly true. In this way we may, I think, account in some measure for the difference in the quality of some varieties of fruits upon different trees, and also why some trees of the same variety are more tender than others.
It however remains true, as a general proposition, that the fruit produced from the scion will be the same as that from the parent tree. The scion or bud is possessed with the power of drawing or forming from the stock that peculiar kind of nourishment which is adapted to its nature, and the specific character of the ingrafted plant remains unchanged, although its qualities may be partially affected, a risk which is always incurred when propagation is attempted from seed. The ancients boasted of vines and apples grafted on poplars and elms, and one speaks of a tree which he had seen "grafted and laden with all manner of fruits. One bough bearing nuts, another berries; here hung grapes, there figs; in one part you might see pears, in another pomegranates; and to conclude, there is no kind of apples or other fruit, but there it was to be found." He adds, "But this tree did not live long".
"And in our own day the Italian gardeners pretend to sell jasmines and honeysuckles on oranges and pomegranatcs." This is said to be ingeniously managed for a short-lived effect, by introducing the stems of these smaller plants through holes bored up the centre of the stock, their roots being in the same soil, and their stems after a little growth fill up these holes, appearing as if really grafted.
But repeated experiments by the most skilful cultivators of modern times have clearly proved that, although it may be possible in a thousand trials to succeed in effecting some of these ill-assorted unions, yet the graft invariably dies after a few months' growth.
Among the practical advantages of grafting and budding are, the preservation and dissemination of choice varieties of fruits; without the knowledge of this art, with the termination of the life of the original tree many of our best fruits would cease to exist - with it, we have the power of increasing them to almost an unlimited extent. J.