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Starting upon the theory that we must subdue the vigor of the wilding to produce the best fruits, he cut off the tap roots when transplanting and shortened the leaders, and crowded the plants in the orchard or fruiting grounds, so as to stand but a few feet apart. He urged the "regenerating in a direct line of descent as rapidly as possible an improving variety, taking care that there be no interval between the generations. To sow, re-sow, to sow again, to sow perpetually, in short to do nothing but sow, is the practice to be pursued, and which cannot be departed from; and, in short, this is the whole secret of the art I have employed." (Arbres Fruitiers.)
Who else would have the needed patience and perseverance to pursue such a course? Very few, indeed—especially if they were not very fully convinced of the correctness of the premises upon which this theory is founded. Mr. Downing thinks that the great numbers of fine varieties of apples that have been produced in this country, go to sustain the Van Mons doctrine, because, as he assumes, the first apples that were produced from seeds brought over by the early emigrants, yielded inferior fruit which had run back toward the wild state, and the people were forced to begin again with them, and that they most naturally pursued this very plan, taking seeds from the improving varieties for the next generations and so on. This may have been so, but it is mere assumption—we have no proof, and, on the contrary, our choice varieties have so generally been conceded to have been chance seedlings, that there appears little evidence to support it—on the contrary, some very fine varieties have been produced by selecting the seeds of good sorts promiscuously, and without regarding the age of the trees from which the fruit was taken. Mr. Downing himself, after telling us that we have much encouragement to experiment upon this plan of perfecting fruits, by taking seeds from such as are not quite ripe, gathered from a seedling of promising quality, from a healthy young tree (quite young,) on its own root, not grafted, and that we "must avoid 1st, the seeds of old trees; 2d, those of grafted trees; 3d, that we must have the best grounds for good results"—still admits what we all know, that "in this country, new varieties of rare excellence are sometimes obtained at once by planting the seeds of old grafted varieties; thus the Lawrence Favorite and the Columbia Plums were raised from seeds of the Green Gage, one of the oldest European varieties."
Let us now look at an absolute experiment conducted avowedly upon the Van Mons plan in our own country, upon the fertile soil of the State of Illinois, and see to what results it led:—
The following facts have been elicited from correspondence with H.P. Brayshaw, of Du Quoin, Illinois. The experiments were instituted by his father many years ago, to test the truth of the Van Mons' theory of the improvement of fruits by using only the first seeds.
Thirty-five years ago, in 1827, his father procured twenty-five seedling trees from a nursery, which may be supposed to have been an average lot, grown from promiscuous seed. These were planted, and when they came into bearing, six of them furnished fruit that might be called "good" and of these, "four were considered fine." One of the six is still in cultivation, and known as the Illinois Greening. Of the remainder of the trees, some of the fruits were fair, and the rest were worthless, and have disappeared.
Second Generation.—The first fruits of these trees were selected, and the seeds were sown. Of the resulting crop, some furnished fruit that was "good," but they do not appear to have merited much attention.
Third Generation.—From first seeds of the above, one hundred trees were produced, some of which were good fruit, and some "even fine," while some were very poor, "four or five only merited attention." So that we see a retrogression from the random seedlings, furnishing twenty-five per cent, of good fruit, to only four or five per cent. in the third generation, that were worthy of note.
Fourth Generation.—A crop of the first seed was again sown, producing a fourth generation; of these many were "good culinary fruits," none, or very few being of the "poorest class of seedlings," none of them, however, were fine enough "for the dessert."
Fifth Generation.—This crop of seedlings was destroyed by the cut-worms, so that only one tree now remains, but has not yet fruited. But Mr. Brayshaw appears to feel hopeful of the results, and promises to continue the experiment.
Crops have also been sown from some of these trees, but a smaller proportion of the seedlings thus produced were good fruits, than when the first seeds were used—this Mr. Brayshaw considers confirmatory evidence of the theory, though he appears to feel confidence in the varieties already in use, most of which had almost an accidental origin.
He thinks the result would have been more successful had the blossoms been protected from impregnation by other trees, and recommends that those to be experimented with should be planted at a distance from orchards, so as to avoid this cross-breeding, and to allow of what is called breeding in-and-in. If this were done, he feels confident that "the seedlings would more nearly resemble the parent, and to a certain extent would manifest the tendency to improvement, and that from the earliest ripened fruits, some earlier varieties would be produced, from those latest ripening, later varieties, from those that were inferior and insipid, poor sorts would spring, and that from the very best and most perfect fruits we might expect one in one thousand, or one-tenth of one per cent., to be better than the parent." This diminishes the chance for improvement to a beautifully fine point upon which to hang our hopes of the result of many generations of seedlings occupying more than a lifetime of experiments.
Mr. Brayshaw, citing some of the generally adopted axioms of breeders of animals, assumes that crosses, as of distinct races, will not be so likely to produce good results, as a system of breeding in-and-in, persistently carried out. This plan he recommends, and alludes to the quince and mulberry as suitable species to operate upon, because in them there are fewer varieties, and therefore less liability to cross-breeding, and a better opportunity for breeding in-and-in. He also reminds us of the happy results which follow the careful selection of the best specimens in garden flowers and vegetables, combined with the rejection of all inferior plants, when we desire to improve the character of our garden products, and he adopts the views of certain physiologists, which, however, are questioned by other authorities, to the effect that violent or decided crosses are always followed by depreciation and deterioration of the offspring.
The whole communication referring to these experiments, which are almost the only ones, so far as I know, which have been conducted in this country to any extent, to verify or controvert the Van Mons' theory, is very interesting, but it is easy to perceive that the experimenter, though apparently very fair, and entirely honest, has been fully imbued with the truth and correctness of the proposition of Van Mons, that the first ripened seed of a natural plant was more likely to produce an improved variety, and that this tendency to improvement would ever increase, and be most prominent in the first ripened seeds of successive generations grown from it.
The theory of Van Mons I shall not attempt in this place to controvert, but will simply say that nothing which has yet come under my observation has had a tendency to make me a convert to the avowed views of that great Belgian Pomologist, while, on the contrary, the rumors of his opponents, that he was really attempting to produce crosses from some of the best fruits, as our gardeners have most successfully done in numerous instances, in the beautiful flowers and delicious vegetables of modern horticulture, have always impressed me with a color of probability, and if he were not actually and intentionally impregnating the blossoms with pollen of the better varieties, natural causes, such as the moving currents of air, and the ever active insects, whose special function in many instances appears to be the conveyance of pollen, would necessarily cause an admixture, which, in a promiscuous and crowded collection, like the "school of Van Mons," would at least have an equal chance of producing an improvement in some of the resulting seeds.
The whole subject of variation in species, the existence of varieties, and also of those partial sports, which may perhaps be considered as still more temporary variations from the originals, than those which come through the seeds, is one of deep interest, well worthy of our study, but concerning which we must confess ourselves as yet quite ignorant, and our best botanists do not agree even as to the specific distinctions that have been set up as characters of some of our familiar plants, for the most eminent differ with regard to the species of some of our common trees and plants.
RUNNING OUT OF VARIETIES
It has been a very generally received opinion among intelligent fruit-growers, that any given variety of fruit can have but a limited period of existence, be that longer or shorter. Reasoning from the analogies of animal life this would appear very probable, for it is well known that individuals of different species all have a definite period of life, some quite brief, others quite extended, beyond which they do not survive. But with our modern views of vegetation, though we know that all perennial plants do eventually die and molder away to the dust from whence they were created, and that many trees of our own planting come to an untimely end, while we yet survive to observe their decay, still, we can see no reason why a tree or parts of a tree taken from it, and placed under circumstances favorable to its growth from time to time, may not be sempiternal. Harvey has placed this matter in a correct light, by showing that the true life and history of a tree is in the buds, which are annual, while the tree itself is the connecting link between them and the ground. Any portion of such a compound existence, grafted upon another stock, or planted immediately in the ground itself and established upon its own roots, will produce a new tree like the first, being furnished with supplies of nourishment it may grow indefinitely while retaining all the qualities of the parent stock—if that be healthy and vigorous so will this—indeed new life and vigor often seem to be imparted by a congenial thrifty stock, and a fertile soil, so that there does not appear to be any reason why the variety should ever run out and disappear.
The distinguished Thomas Andrew Knight, President of the London Horticultural Society, was one of the leading advocates of the theory that varieties would necessarily run out and disappear as it were by exhaustion.
In his Pomona Herefordiensis, he tells us that "those apples, which have been long in cultivation, are on the decay. The Redstreak and Golden Pippin can no longer be propagated with advantage. The fruit, like the parent tree, is affected by the debilitated old age of the variety." And in his treatise on the culture of the apple and pear, he says: "The Moil and its successful rival, the Redstreak, with the Must and Golden Pippin, are in the last stage of decay, and the Stire and Foxwhelp are hastening rapidly after them." In noticing the decay of apple trees, Pliny probably refers to particular trees, rather than the whole of any variety, when he says that "apples become old sooner than any other tree, and the fruit becomes smaller and is subject to be cankered and worm-eaten, even while on the trees."—Lib. XVI, Chap. 27.
Speechly combated the views of Mr. Knight, and says: "It is much to be regretted that this apparently visionary notion of the extinction of certain kinds of apples should have been promulgated by authors of respectability, since the mistake will, for a time at least, be productive of several ill consequences."
Some of the old English varieties that were supposed to be worn out or exhausted, appear to have taken a new lease of life in this country, but we have not yet had a long enough experience to decide this question. Many of the earlier native favorites of the orchard have, for some reason, disappeared from cultivation—whether they have run out, were originally deficient in vigor, or have merely been superseded by more acceptable varieties, does not appear.
Mr. Phillips, in his Companion, states "that in 1819, he observed a great quantity of the Golden Pippin in Covent Garden Market, which were in perfect condition, and was induced to make inquiries respecting the health of the variety, which resulted in satisfactory replies from all quarters, that the trees were recovering from disease, which he thought had been induced by a succession of unpropitious seasons. He cites Mr. Ronald's opinion, that there was then no fear of losing this variety; and Mr. Lee, who thought that the apparent decay of some trees was owing to unfavorable seasons. Mr. Harrison informed him that this variety was very successfully grown on the mountains of the island of Madeira, at an elevation of 3000 feet, and produced abundantly. Also that the variety was quite satisfactory in many parts of England, and concludes that the Golden Pippin only requires the most genial situation, to render it as prolific is formerly."
It is quite probable, as Phillips suggests, that Mr. Knight had watched the trees during unfavorable seasons which prevailed at that period, and as he found the disease increase, he referred it to the old age of the variety, and based his theory to that effect upon partial data.
Mr. Knight's views, though they have taken a strong hold upon the popular mind, have not been confirmed by physiologists. For though the seed would appear to be the proper source whence to derive our new plants, and certainly our new varieties of fruits, many plants have, for an indefinite period, been propagated by layers, shoots or scions, buds, tubers, etc., and that the variety has thus been extended much beyond the period of the life of the parent or original seedling. Strawberries are propagated and multiplied by the runners, potatoes by tubers, the Tiger Lily by bulblets, some onions by proliferous bulbs, sugarcane by planting pieces of the stalk, many grapes by horizontal stems, and many plants by cuttings, for a very great length of time. The grape vine has been continued in this way from the days of the Romans. A slip taken from a willow in Mr. Knight's garden pronounced by him to be dying from old age, was planted in the Edinburgh Botanic Garden many years ago, and is now a vigorous tree, though the original stock has long since gone to decay.11
CHAPTER III
PROPAGATION.—SECTION I
ALL GROWTH IS DEPENDANT UPON THE DEVELOPMENT OF CELLS—THE SEED AND THE BUD; THEIR RESEMBLANCE—THE INDIVIDUALITY OF BUDS—THE BASIS OF ALL PROPAGATION—BUDS ARE DEVELOPED INTO TWIGS; HAVE POWER OF EMITTING ROOTS—IMPORTANCE OF THE STUDY OF CELL-GROWTH—BY CUTTINGS: PREPARATION AND SELECTION—HEEL-CUTTINGS—SOFT WOOD—HARD WOOD—SEASONS FOR EACH—FALL PLANTING—THE CALLUS, OR DEVELOPMENT OF CELL-GROWTH—BOTTOM HEAT; WHY BENEFICIAL—WHY SPRING CUTTINGS FAIL—STIMULUS OF LIGHT UPON THE BUDS, CAUSES THEM TO EXPAND, AND THE LEAVES EVAPORATE TOO FREELY—ROOT CUTTINGS; DIFFERENT FRUITS THUS PROPAGATED—BY SUCKERS: OBJECTIONS TO ANSWERED—SUCKER ORCHARDS; BEAR EARLY—SUCKER TREES APT TO SUCKER AGAIN—BY LAYERS: A NATURAL METHOD—HOW PERFORMED—THE RASPBERRY AND THE GRAPE—ILLUSTRATIONS OF NATURAL AND ARTIFICIAL METHODS—QUINCE STOCKS—ADJUVANTS TO LAYERING, NOTCHING, ETC—BY SEEDS: HOW IT DIFFERS FROM THE OTHERS—APPLE SEEDLINGS—THEIR TREATMENT, SEPARATING, AND PREPARING THE SEED—APPARATUS—SPROUTING—SOWING—CULTIVATION—SEEDLINGS—TREATMENT—SORTING—PACKING.
All propagation of plants must depend upon the development of seeds or of buds, and all will arise from the growth and extension of cells. The seed and the bud are much more nearly related than a casual observer would at first sight suppose. The early phylologists thought they discovered that in the seed was enwrapped the image of the future tree—a dissection of the seed would appear to demonstrate this. It is composed of separate parts which are capable of being developed into the root, stem, and appendages, but they have yet to be so developed; the several parts that we find in the seed are merely the representative parts. But the seed has the future of the tree within itself, it has certain qualities of the future tree impressed upon it in its primary organization, within the capsule of the fruit of the parent plant, so that in a higher sense the image of the future tree does exist within the seed. Within the bud, still more plainly and more distinctly visible, is the future tree manifest, and we may produce a tree from a bud as certainly as we do from a seed. Subjected to circumstances favorable for growth, the bud, as well as the seed, will emit roots, will form its stem, branches and appendages, and will become a tree; differing from the product of the seed only in this, that in the latter the resulting organism constitutes a new individual which may vary somewhat from its parent, in the former it is only a new development of a part of a previously existing organization. The similarity existing between the two is exceedingly close, and is a matter of great importance in horticultural operations. Dr. Lindley, in the Gardener's Chronicle, says very truly, that "every bud of a tree is an individual vegetable, and a tree, therefore, is a family or swarm of individual plants, like the polype with its young growing out of its sides, or like the branching cells of the coral insect." Similar opinions, more or less modified, have been expressed by subsequent physiologists, and are familiar to men of science in every country and, we may add, are also universally accepted as true by all who claim a right to express an opinion upon the subject.—Men of science recognize the individuality of buds.—Nobody doubts the individuality of buds.—In a gardening aspect, the individuality of buds is the cardinal point upon which some of our most important operations turn; such, for example, as all modes of propagation whatever, except by seed. If this be not fully understood, there is no possible explanation of the reasons why certain results are sure to follow the attachment of a bud, or the insertion of a graft, or the planting of a cutting, or the bending of a layer, or the approach of a scion, or the setting of an eye—our six great forms of artificial multiplication. In his Elements of Botany, the same writer says: "An embryo is a young plant produced by the agency of the sexes, and developed within a seed—a leaf bud is a young plant, produced without the agency of the sexes, enclosed within the rudimentary leaves called scales, and developed on a stem." "An embryo propagates the species, leaf-buds propagate the individual." He shows each to be "a young plant developing itself upwards, downwards and horizontally, into stem, root, and medullary system."
Dr. Schleiden thus beautifully expresses his views of their individuality: "Now the bud essentially is nothing more than a repetition of the plant on which it is formed. The foundation of a new plant consists equally of a stem and leaves, and the sole distinction is that the stem becomes intimately blended at its base with the mother plant in its growth, and has no free radical extremity like that exhibited by a plant developed from a seed. However, this distinction is not so great as at the first glance it appears. Every plant of high organization possesses the power of shooting out adventitious roots from its stem, under the favoring influences of moisture; and very frequently, even plants that have been raised from seed, are forced to content themselves with such adventitious roots, since it is the nature of many plants, for instance the grasses, never to develop their proper root, although the radicle is actually present. We are, it is true, accustomed to look upon the matter as though the buds must always be developed into twigs and branches, on and in connection with the plant itself; and thus in common life, we regard them as parts of a plant, and not as independent individuals, which they are in fact, although they, like children who remain in their paternal home, retain the closest connection with the plant on which they were produced. That they are at least capable of becoming independent plants, is shown by an experiment frequently successful when the necessary care is taken, namely the breaking off and sowing of the buds of our forest trees. The well-known garden operations of grafting and budding are also examples of this, and layering only differs from the sowing of the buds, in that the buds on the layers are allowed to acquire a certain degree of maturity before they are separated from the parent plant. All here depends upon the facility with which these bud plants root as it is called, that is develop adventitious roots, when they are brought in contact with moist earth. * * * Nature herself very often makes use of this method to multiply certain plants in incalculable numbers. In a few cases, the process resembles the artificial sowing of buds, as when the plant spontaneously throws off the perfect buds at a certain period; an instance of this is afforded by some of our garden Lilies, which throw off the little bulb-like buds which appear in the axils of the lower leaves. The more common mode of proceeding is as follows: Those buds which have been formed near the surface of the soil, grow up into shoots provided with leaves; but the shoots are long, slender and delicate, the leaves too are stunted into little scales; in their axils, however, they develop strong buds, which either in the same or in the following year take root, and the slender shoot connecting them with the parent plant, dying and decaying, they become free independent plants. In this manner the strawberry soon covers a neglected garden."12
Upon the development of a cell in any living tissue, and its power of reproducing other cells, and upon its function of communicating by endosmosis and exosmosis with other like cells, depend all our success in propagating vegetables, whether from seeds or buds, and parts containing these. We must study the circumstances that favor the development of cells, if we would be successful in propagating plants. Each bud being considered an individual, and capable, under favorable circumstances, of taking on a separate existence, we can multiply any individual variety indefinitely, and be sure of having the same qualities of foliage and fruit that we admire in the original, and that we may desire to propagate. This applies equally to a group of buds, as in cuttings, grafts and layers, etc.; but, more wonderful still, there are cells capable of developing buds where none existed before, and even in tissues or parts of a plant where we do not usually find buds—hence we have a mode of propagation of many woody plants, by root cuttings, and by leaves, and even parts of leaves.
Propagation by Cuttings.—Many fruits are multiplied by this means. Healthy shoots of the previous year's growth are usually selected and taken when the parent is in a dormant state, or still better, when it is approaching this condition. Sometimes a small portion of the previous year's growth is left with the cutting, making a sort of heel; when this is not to be had, or not preferred, the slip is to be prepared for planting by cutting it smoothly just below a bud, as this seems to be the most favorable point in many plants for the emission of roots. Some plants will throw out radicles at any point indifferently along the internodes or merithallus. The preference for heel-cuttings depends upon the fact, that near the base of the annual shoot there are always a great number of buds, many of which, however, being imperfectly developed, are inconspicuous, but though dormant, they seem to favor the emission of rootlets. Cuttings may be made to grow if taken at any period of their development, but when green and soft, they require particular conditions of heat and moisture in the soil, and atmosphere, that are only under the control of the professional gardener. They are usually taken in the dormant state, because they are then susceptible of being made to grow under the ordinary conditions of out-door gardening. If cut early in the season, on the approach of autumn, after the wood-growth has been perfected, they may be planted at once with good prospect of success, or they may be put into the soil, out of doors, in the cellar, or in a cold frame or pit, and a very important step in the progress of their growth will commence at once. The leafless sticks are not dead, and whenever the temperature will admit of the quiet interchange of fluids among their cells, this curious function will go on, and will be accompanied by the development or generation of new cells that soon cover the cut surfaces, constituting what the gardeners call the callus. This is the first step toward growth, and it most readily occurs when the earth is warmer than the air; hence the value of fall planting, whether of trees or of cuttings, if done before the earth has been chilled, and hence also, the importance of bottom heat in artificial propagation. If on the contrary the air be warm and the ground cold, the buds are often stimulated to burst forth, before the rootlets can have started. The expanding foliage which so delights the tyro in propagation, offers an extended surface for evaporation, the contained juices of the cutting itself are soon exhausted, no adequate supply is furnished, and the hopeful plant soon withers, or damps off, and dies.13 The cutting, like the seed, must have "first the root, then the blade." The length of time that is allowed for cuttings to prepare for rooting, if they are designed for spring planting, should be as great as possible, and the circumstances under which they are kept should be such as to favor the development of the cells, so that roots may form freely with the breaking of the buds, if not before.
Root-cuttings should be made in the spring, just before the usual period of the bursting of the buds in the plant to be propagated. The tendency to develop buds appears to be then most active. Gentle bottom heat, though not essential, is still very desirable, and will conduce to the success of the operation. Some plants are best propagated by this means, and those too, which never naturally produce suckers, may often be successfully grown by sections of the roots. All plants do not equally admit of propagation by division as cuttings, some woody tissues refusing to emit roots under almost any circumstances.
Nobody thinks of propagating the stone fruits, such as the cherry, plum, peach, or apricot, by attempting to plant cuttings, and yet some of these will emit roots very freely, as we may often observe when the shoots or trimmings are used as supports for plants in the green-house. The plum tree is exceedingly apt to form new roots when planted too deeply, and upon this fact depends the success or failure of the finer varieties when worked upon certain varieties of the wild stock. If the young trees are earthed up in the nursery, and set rather deeply in the orchard, they will soon establish a good set of roots of their own, emitted above the junction of the scion and stock, which is very preferable to the imperfect union and consequent enlargement that often results from using uncongenial stocks. The raspberry and blackberry do not grow so well from cuttings of the wood, which is always biennial in this genus, as they do from root-cuttings.
In some parts of the country, peaches are mainly produced, or the favorite varieties are multiplied, by planting the sprouts that come from the base of the trunk of the trees; these have little or no roots when taken off with the mattock, but they soon establish themselves and make good trees, bearing fruit like their parents, in soils and climate that are well adapted to this fruit.
Refined and scientific horticulture has been extensively applied to the multiplication of the grape, which is now produced in immense numbers, from single eyes, or buds. Formerly our vineyards were formed by planting long cuttings at once in the field in the stations to be occupied by the vines, or by setting them first in a nursery, whence they were transplanted to the vineyard, when one or two years old. Only the most refractory kinds, which would not grow readily in the field, or such as were yet rare, were propagated from cuttings, by using the single eye and artificial bottom heat. Now, however, the appliances of our propagators are called upon for the production of grape-vines by the million, and they find it advisable to multiply all the varieties in this manner. The propagation of the grape by using single eyes affords the most beautiful illustration of the subject of the individuality of buds, and though denounced by some as an unnatural, steam-forcing process, it is really an evidence of the advance of horticulture, since every step is supported by a philosophical reason, and the whole process, to be successful, is dependent upon the application to practice of well established scientific truths.
Fig. 1.—FRENCH AND COMMON MODES OF SETTING CUTTINGS.
It has already been stated that the first effect of cell-growth upon a cutting, is the production of a callus. This callus may form upon any cut surface, or even where the bark has been abraded. It is the first effort of nature to repair an injury by the reproduction of new parts; it is most generally found at the base of the cutting, but under favorable circumstances, it will be seen also at the upper end of the shoot if this has been placed in contact with the earth. Cuttings will sometimes be set up-side down, when we find the callus upon the smaller end, and roots will be emitted from that portion whence we should have expected to see the branches issue. Upon this fact, and to multiply the chances of living, has been based the French method, as it is called, or that of inserting both ends of the cuttings. The common mode, (fig. 1), is to set the cuttings in a slanting direction in the ground, so placed that the upper eye or bud only shall reach the surface. Formerly there was a preference for long cuttings, and these were often made eighteen inches or more in length. The practice with most of our cultivators has been modified in this particular, and they have reduced the length of the slips to six and eight inches, so as to have in grape wood about three or four eyes. Some have gone still further, and use but two, even for out-door planting of the grape, and some have been very successful when using but a single joint. The Germans have advocated longer cuttings, upon the theory that there was a retroaction in the pith of the internodes and in all the buds of the cutting, upon the lower point, enabling it to push roots more strongly from a long than from a short cutting. This theory has for its support the fact, that there is in such a cutting a larger amount of organizable matter to be developed into the new parts to be produced, and certainly, if neglected, short cuttings will be very apt to suffer from drought, but in practice, it is found that the short cutting plants have better roots, which are near the surface, and even those plants, grown from single eyes, are better burnished than long cuttings produced upon the old plan, which placed the roots deep in the soil.
