VIII How an Apple-Tree Is Made
If the seeds of a Baldwin or Winesap apple are planted, we do not expect to get a Baldwin or Winesap; we shall probably raise a very inferior fruit. The apple has not been bred “true to seed” as has the cabbage and sweet pea. To get the tree “true to name,” of the desired variety and with no chance of failure (barring accident), is one of the niceties of horticulture. This is accomplished with great precision and despatch.
The apple-tree is started from the seed. It cannot be grown freely by means of cuttings, as can the grape and currant. In commercial practice the seeds are collected mostly from cider mills or from pomace. The seeds may be washed from the pomace, allowed to dry, and then mixed in sand, charcoal, sawdust or other material to prevent dessication and kept until spring, when they are sown. Or, if the land is not so wet in winter that the seed will drown or be washed out, the seed in the pomace (not separated) may be sown in autumn. The seeds are sown in drills, after the manner of onions or turnips, one to two or even three inches deep. They germinate readily in the cool of spring, and the plants should reach a height of twelve inches and more the first year.
If these plants were grown directly into bearing trees, it is probable that no two trees would produce the same kind of fruit. Some of the fruit might be summer apples, some of it winter apples, some red, yellow or striped, some of it flat, oblong or spherical, most of it sour but perhaps some of it sweet. Probably every kind would be inferior to the parent stock or to standard varieties, although there is a fair chance that a superior kind might originate from a field of such plants.
Therefore, it is not the variety (that is, the top) that is wanted in the raising of these numerous plants, but merely the roots, on which desired varieties may be grown by the clever art of graftage. Yet not even all the roots may be wanted, for the growing plants may differ or vary in their stature and vigor as well as in their fruit. The discriminating grower, therefore, discards the weak and puny treelings at the digging time; or if the weak plants seem still to have promise, they may be allowed to grow another year before they are dug for the grafting.
This digging time is the autumn of the first year, when the plants have grown one season. They are then to be used as “stocks” on which to graft Baldwin, Winesap or other varieties. The growing of these apple stocks is a business by itself. Formerly, most of the stocks used in North America were imported from France, where special skill has been developed in the growing of them and where the requisite labor is available. But now the stocks are grown also in deep rich bottom lands of the Middle West, as in Kansas, where, in the long seasons, a large growth may be attained.
The methods of graftage of the commercial apple-tree are two—by cion-grafting whereby a bit of wood with two or three buds is inserted on the stock, by bud-grafting (budding) whereby a single bud with a bit of bark attached is inserted under the bark of the stock.
Cion-grafting is practiced in winter under cover. The stock is cut off at the crown and the cion spliced on it, or the root may be cut in two or more pieces and each piece receive a cion. The union is made by the whip-graft method (Fig. 16). The cion is tied securely, to keep it in place. The piece-root method is allowable only when the root is long and strong, so that a well-rooted plant results the first year. The cion is a cutting of the last year’s growth (as of No. 1, in Fig. 14). However accomplished, the process is to supply the cion with roots; it is planted in another plant instead of in the ground.
The cion-grafts are now planted in the nursery row in spring. The cion starts growth rapidly, only one shoot being allowed to remain; this shoot forms the trunk or bole of the future tree. At the end of the first season, the little tree is said to be one year old, although the root is at least two years old; at the end of the second year it is two years old; the tree is sometimes sold as a two-year-old, but usually a year later as a three-year-old having a four-year-old root. In fact, however, the root and top may be considered, in a way, to be of the same age, particularly if only a piece of the root is employed, for the cion grew on its parent tree the same year the root was growing in the nursery.
The tree grew from the seed but it is no longer a “seedling” or a “natural;” it is now a grafted tree, destined to produce a named recognized variety of apple, maybe York Imperial, maybe Jonathan. We find seedling trees in old fields, in fence-rows, and in woods. These have grown from scattered seeds and have come to fruit without the arts of the propagator. They bear their own tops or heads, rather than the heads that a thrifty horticulturist would have put on them. Now and then such a tree produces superior fruit; then a discriminating pomologist discovers it, names it a new variety, and propagates it as other varieties are propagated. Thus have most of the prized varieties originated, without knowledge on the part of man of the ultimate processes. But now with the accumulating knowledge of the plant-breeder we hope to be able to foresee and probably to produce varieties of given qualities.
Bud-grafting is practiced in summer. The young trees, obtained from the grower of apple stocks, are planted regularly in nursery rows in spring, the top having been cut back to the crown so that a strong vigorous shoot will arise. In July and August or September, when this shoot is the size of a lead pencil and larger and the bark will peel (or separate from the wood), a single bud is inserted near the ground (Fig. 17). This bud is deftly cut from the current year’s growth of the desired variety; it grows in the axil of a leaf (Fig. 15). The leaf is removed but a small part of the stalk or petiole is retained with the bud to serve as a handle. A boat-shaped or shield-shaped piece of bark is removed with the bud. This piece, known technically as a “bud,” is inserted in an incision on the stock, so that it slips underneath the bark and next the wood, with only the bud itself showing in the slit; it is then tied in place.
The stock on which the bud is inserted has a two-year root, and the root is entire. For this reason, budded trees are usually very large and strong for their age when compared with piece-root trees grown under similar conditions of climate, tillage and soil.
The bud does not grow the year it is inserted in the stock; it is dormant until the following spring, as it would have been had it remained on its parent branch; but soon after it is inserted it attaches itself fast to the stock: it is a bud implanted from one twig to another. The following spring, if the operation is successful, the bud “grows,” sending up a strong shoot that makes the trunk of the future tree. The top of the stock is cut away; in the merchantable tree, the bend or place may be seen where the stock and cion meet.
As in the case of cion-grafting, we now have a top of a known variety growing on the root of an unknown kind. The tree is sold at two or three years, counting the age of the top; and of course the tree is no longer called a seedling, and it produces its implanted variety as accurately as does the cion-grafted tree. Equally good trees are produced by both cion-grafting and bud-grafting.
The apple-tree is now “propagated,” and is ready for the planting. Great hopes will be built on it, and the tree will probably do its part to justify them. Nobody knows how a bud from a Baldwin tree holds the memory of a Baldwin or from a Winesap tree the memory of a Winesap. Neither does anyone know why of two seeds that look alike one will unerringly produce a cabbage and the other a cauliflower. So accustomed are we to these results that we never challenge a twig of apple or a seed of cabbage: we assume that the twig or the seed “knows.” Nor have we yet approached this question in our elaborate studies of plant-breeding. Here is one of the mysteries that baffles the skill of the physiologist and chemist, yet it is a mystery so very common that we know it not, albeit the life on the planet would otherwise be utter confusion.