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THE APPLE-A FRUIT WORTHY OF STILL FURTHER IMPROVEMENT

NEW APPLES AND HOW TO MAKE THEM

If you were to look in Regan's book on the Nomenclature of the Apple you would find that about eight thousand varieties of this fruit are listed by name, not counting synonyms, of which each variety has several. And you would receive assurance that the catalogue includes only such selected varieties as have attracted more or less attention in this country alone. After scanning this list you might be excused if you felt disposed to turn your attention to some other fruit. An orchard product that already possesses eight thousand named varieties may not seem at first glance to offer a very good opening for the plant developer. It may reasonably be supposed to be a fruit that is already pretty well developed. And in point of fact there is no disputing that the apple is a well-developed fruit. There are varieties of almost every supposable size and color and flavor and degree of early or late ripening, as the case may be, and of keeping quality. Yet it would be going much too far to say that nothing remains to be done, There are plenty of opportunities for the plant developer in dealing with this fruit, as I shall attempt to show in a moment. But before taking up that aspect of the matter in detail it will be worth while to clarify the situation by a few words of comment as to the eight thousand varieties of apples that make such an imposing array on the pages of the cataloguer.

VARIETIES VERSUS INDIVIDUAL TYPES

The average purchaser and consumer of fruit probably has very vague notions as to what is the real status of the particular variety of apple that especially appeals to him. He finds his favorite fruit-be it Baldwin or Northern Spy or Greening or Gravenstein or what not-in the market year after year at a given season. He sees that each fruit is always of approximately the same size, and color, and flavor. The differences between the named varieties are so radical that they could not possibly be overlooked. A greening apple, for example, bears much less superficial resemblance to a snow apple than it bears to a quince; and the average purchaser might be excused if he supposed these two apples, along with numberless other specialized varieties, to represent forms as distinct from each other as, let us say, blackberries are distinct from raspberries or oranges from lemons. But in reality the status of even the best market "varieties" of apples is quite different from this. It would scarcely be an exaggeration to say that each "variety" of apple manifests the peculiarities of an individual rather than those of a race. We have already had our attention called more than once to the fact that the apple, in common with most other cultivated fruits, does not breed true from the seed. It has been pointed out that we could not secure an orchard of Baldwins by planting the seeds of the Baldwin. In a word, the fact has been emphasized that the conventional and necessary method of propagating the different varieties of apples is by budding or grafting, or by the equivalent method of sprouting slips or twigs. And attention has furthermore been drawn to the fact that this method of propagation may be regarded as the division of an individual that has the property of restoring lost parts and continuing its growth indefinitely rather than propagation through a succession of generations. It has been suggested that all trees that represent a particular variety of cultivated fruit-say all Baldwin apple trees or all Seckel pears-are separated parts of the original tree of corresponding variety, and not descendants of that tree. Holding to this point of view, then, it is clear that the different "varieties" of apples might, from a biological standpoint, be classified as individuals rather than as races. Their inability to reproduce themselves in offspring through the ordinary processes of generation denies them the rank of races or varieties proper, let alone the rank of species. And after all the difference in appearance between two apples that rank in the catalogs as specific varieties is not greater than we sometimes see manifested between brothers and sisters of a human family. A man more than six feet tall with florid complexion, light blue eyes, and flaxen hair, certainly represents a type quite different from that represented by a woman less than five feet tall with swarthy complexion and black eyes and hair. Yet we sometimes see such divergences as these between a son and daughter of the same parents.

ORIGIN OF THE DIVERSIFIED TYPES

We shall gain a somewhat truer conception of the meaning of our apple catalog, then, if we think of each listed variety as having the status of an individual rather than that of a race. The diversity of individul types becomes explicable if we consider the history of their development. The apple has been under cultivation for some thousands of years. It has qualities that have made it a favorite with successive generations throughout the entire period. It has been taken everywhere with migrating races of men-it was brought to America, for example-until it girdled the globe and found its way almost to the Arctic Circle. The different races of apples thus developed have been from time to time intermingled through migrations of the peoples who cultivated the fruit, many of whom, doubtless from the earliest period, carried it with them in a dried state on their voyages, and thus incidentally transported its seeds and carried it into new regions. The varieties thus brought together have been cross-pollenized by the bees, and so the tendency to vary and to keep a great variety of ancestral traits in evidence has been perpetuated. Finally, in modern times there has been perhaps more attention given the apple by the horticulturist than to any other single orchard fruit. The qualities of the apple and its adaptation to all tastes, zones, and soils naturally account for this. And the result is recorded in the present day lists of the cataloguer. Whenever, through the chance blending of favorable ancestral strains an exceptional individual has appeared, cions have been cut from that individual and grafted on other trees, and new cions cut from this and again grafted, until the fruit of this individual grows on so many different trees and in so many different regions that its peculiar qualities are thought of as representing an established variety rather than an individual personality. But if you will gather the seed from the apples of a single tree of even the best market "variety" in any given season, and will plant these seeds, you may have, when the seedlings come to fruiting, new "varieties" of apple, each differing from all its fellows, in such profusion that you may, if you so desire, exhaust your ingenuity in finding new names and publish a catalog of your own with a list of eight thousand or so "varieties" of apple that no one hitherto has ever seen or heard of. That simple but rather startling fact brings into sharp relief the difference between the meaning of the word "variety" as applied to such a fruit as the apple and the meaning of the same word as applied to races, of plants in a state of nature. The seed of a plant of a valid wild variety (sub-species), or the seed of a hundred plants of that variety intermixed, will produce a generation of offspring which, though they number thousands or millions, all bear striking resemblance in their essential qualities of shape and leaf and flower and fruit to the parents from which they sprang and to one another. This is the fundamental difference. It is a difference that should be borne constantly in mind when we use the convenient word "variety" in connection with an orchard fruit. Perhaps it is unfortunate that the word has been applied with this double meaning; but it is obviously convenient, and if properly interpreted it may be used without danger of confusion of ideas.

FROM GERM CELLS TO APPLES

That the potentialities of numberless new varieties lie hidden in the pollen grains and ovules of a single flower-cluster is a thought that makes strange appeal to the imagination of the intelligent plant developer. When he pollenizes a flower he is bringing together two germinal microcosms each of which, rightly viewed, is a universe within itself. He is dealing with individual life histories and with the histories of races. He is performing, as I said before, the most marvelous of all experiments. He deals with the same matter with which the chemist deals in his laboratory; but with this matter aggregated into new and wonderful combinations which alone make possible those responses to the environment and that primeval capacity for growth and of self-reproduction that differentiates what we call living tissue from the matter out of which it is constructed. But if the plant experimenter must be allowed to indulge in such visions he must none the less remember that the microcosm of the germ cell represents after all only a transitory and transitional phase in the life cycle of the organisms with which he deals. He may love to ponder over the mysteries of the nucleus of the germ cell, but he cannot offer that nucleus for sale in the market. The tangible product of his investigations, the one that will have commercial importance, must find representation in germ cells that have infinitely multiplied until their descendants are piled together in such unthinkable numbers that they make up the structure of visible plants, and, to meet the exigencies of the case under consideration, of visible and tangible fruits of the orchard. To be quite specific, and to bring us back directly to the practicalities of the subject in hand, the development of the germ cell must have led to the production of the particular fruit called the apple. What, then, practically does there remain for the plant investigator to do in the apple orchard? With eight thousand varieties of apple on the market, just how shall we come in competition and produce a new variety that will commend itself as having some points of superiority to any existing? Unless we can do that, it assuredly is not worth while to cumber the market with a new apple. There are enough inferior fruits already in the field. Let us by all means refrain from adding to their number. What has been said suggests that the task ahead of us, in the perfectionment of the apple, does not lack difficulties. As a tangible illustration of the extent of these difficulties, I may note that I have grown on my experiment farms not fewer than 50,000 seedling apples, from the best standard varieties, since 1886, when I first definitely turned attention to this fruit; and that out of the entire number a single dozen now stand out somewhat prominently as being superior. There are others, to be sure, not yet come to the fruiting age, that may surpass any yet produced in a combination of good qualities. Some of the individuals improve in certain points from year to year, and reveal new strength in certain valued characters, while others may fail to fulfil their early promise. The test must extend over a series of years, after the trees have commenced to bear, and each new strength or weakness in every direction must be noted with unflinching fidelity. With the record of my own experiments as a guide, let us briefly glance over the field, to gain such clues as we may to the opportunities that still lie open for the betterment of this fruit.

A FEW PRACTICAL HINTS

Great emphasis has been laid on the fact that apples do not breed true from seed. It should be noted, however, that some varieties are much more nearly fixed than others. The Fameuse, Gravenstein, Garden Royal, and Golden Russet may be named among those that tend to reproduce a good many of their characteristics in their seedlings. Yet from any of these there may be produced apples showing almost every possible variation as to size, shape, acidity, flavor, and color. And so the growth of seedlings will be undertaken only for the purpose of securing new variations or to supply stocks on which to graft cions from old ones. In raising apple seedlings to obtain improved varieties it is best to select seed from some one standard apple that already possesses most of the good qualities sought in the improvement, because comparative tests are more easily made from one variety than from mixed seed. There is much variation among different varieties as to keeping qualities of the seed and characteristics of the seedlings. Seedlings of the Baldwin, for example, are peculiarly subject to mildew; seedlings of the Newtown are usually rather slow and slender growers. As a general rule it may be said that the seeds of winter apples have a greater tendency to produce winter apples than summer apples, whereas summer apples are almost as likely to produce winter varieties as to reproduce their own qualities as to time of bearing. Sweet apples are quite often produced from the seeds of sour ones and vice versa. The Yellow Bellflower produces a large proportion of seedlings good in most respects, and this is true also of the Newtown Pippin, Hubbardston, the Rhode Island Greening, Roxbury Russet, Haas Queen, William's Favorite, Swaar, Rambo, Fameuse, Lyscom, Alexander, Palmer, and Wagener. Especially fine seedlings have been obtained from the Garden Royal, Fameuse, Golden Russet, Wagener, and in particular the Gravenstein and the Newtown Pippin. Usually the weak point in Northern Spy seedlings is poor quality, notwithstanding its own exquisite quality. One can be almost certain of producing some early bearing seedlings, which will yield fruit of good quality, though lacking in size, from the Golden Russet, Garden Royal, or the Fameuse, and without raising a great number of seedlings. Apple seeds, like all other fruit seeds, germinate more readily if not dried too thoroughly. The best method is to place them when fresh, after thorough cleaning, in a box of slightly moist sawdust or coarse sand, moist enough to keep the seeds from drying, but not moist enough to cause germination or to induce mold or decay. Kept in this way in a cool place until desired for planting, they will germinate with unusual vigor. If the apple seeds are wanted in large quantities, crush the fruit in a cider mill and wash the seeds from the pomace. When only a few seeds are to be taken from rare specimens of apples, the seeds are usually removed by hand. The seeds may be planted in the open field as early as possible in the spring in rows three or four feet apart, if cultivation is to be done with horse plows. Ten to fourteen inches apart is sufficient space for hand cultivation. Details as to methods of planting and care of the seedlings have already been given in a separate chapter and need not be repeated here. No special cultural directions are required in growing the apple seedlings. They are cared for on my farms very much as peas and beans are cared for, and they are as easily grown. It may be well, however, to inspect the young seedlings occasionally and to remove all weak or slow-growing ones and those having slender stems and thin, small leaves; and in particular any that show the slightest evidence of mildew. It is not desirable to treat seedlings that are grown for the production of new varieties with fungicides; the persistent aim should be to produce trees that are thoroughly resistant to fungoid diseases. The seedlings that show large, thick leaves and thick, fat, prominent buds placed not too far apart, combined with stocky, short-jointed, juicy wood, are the ones most likely to be valuable. Let us emphasize again that in fruiting the seedlings an enormous amount of time and valuable space can be saved if they are grafted upon large bearing trees. I am accustomed to take one or two good cions from each of the selected seedlings at the end of the first season's growth, grafting them into a bearing tree on branches a quarter-inch or at most a half-inch in diameter. Thus placed, they will begin bearing in from two to four years; whereas if placed upon the large branches a much longer period would be required. By this method I have tested as many as 526 varieties by actual count at the same time upon a single tree. Thus twenty thousand or more varieties may be tested at once on a single acre. The same trees may serve in this way over and over indefinitely. It would be well if fruit growers in each geographical section would raise and test new seedlings, and also introduce and experiment with new varieties produced elsewhere, aiming always to select those best adapted to the requirements of the particular locality. In this way many localities where the apple cannot be grown today might produce thriving orchards.

MAKING HARDY APPLES

The apple is relatively hardy, but improvement is still possible in the way of producing varieties that will stand the excessive cold of our northern winters. The work of crossing hardy Russian apples and also the hardy American crab with the better varieties of apples is now being carried on quite extensively, especially in Iowa. By this means some good varieties have been produced that are especially adapted to withstand the extremes of temperature of the northern Mississippi Valley, and others are in prospect. Especial efforts are being made, also, to develop varieties that will be immune to the attacks of the insect pest known as the woolly aphis, which does great damage in apple orchards, especially on heavy soils and in moist climates. This pest is relatively harmless to the treetops, but does great damage when it infests the roots of a tree. Because of the immunity of the pear to the attacks of the woolly aphis, I have made many attempts to find a variety of pear that would serve as stocks on which to graft apples. In a very few cases the grafts have taken well at first, but the final result was a failure, from a commercial standpoint. It is possible that a variety of pear will eventually be found which will be congenial to the various varieties of apples; and, if so, the problem of combatting the woolly aphis will have been solved. My experiments consisted in growing seedling pears to get new varieties on which to graft the apples. This is probably the only way to approach the subject, for attempts have been made with practically all the existing varieties of pears, and in every case the result has been failure. Fortunately there is one well-known variety of apple, the Northern Spy, that is aphis-proof. Trees of this variety are never injured by these insects, even when planted beside trees seriously infected. It has been found expedient, therefore, to graft other varieties on roots of the Northern Spy, and an orchard that has practical immunity to the attacks of the aphis may thus be produced. Unfortunately the seedlings of the Northern Spy do not generally inherit this quality of resistance to the aphis, so it is necessary to grow the roots from cuttings. Apple twigs do not root very readily, but if cuttings from vigorous Northern Spy branches are placed in the soil and allowed to grow for a year or longer they develop a good root system and the roots may be severed into small pieces, each of which will produce a stock upon which grafts of any variety may be placed.

HYBRID APPLES

I have experimented very extensively, as already noted, with the crossing of different familiar varieties of apple, and have produced several new varieties that have been deemed worthy of introduction. But my most interesting experiments have had to do with the wider hybridization in which one or another variety of cultivated apple has been crossed witn a related species. In endeavoring to introduce new traits I imported in 1890 all of the best varieties of apples theretofore originated in Australia and New Zealand. It was necessary to graft these cions into older trees to test the fruit, and some very curious results were observed. Most of these new varieties from another hemisphere appeared to be surprised to find the winter over so soon and the spring now opening upon them. Some varieties immediately put out buds and blossoms and continued to do so at intervals throughout the summer; others stubbornly declined to bud or blossom until nearly the beginning of the following spring. For two or three years thereafter all seemed quite confused and disturbed by the transposition of the seasons; but ultimately they became adjusted to the new order of things. One or two of them have proved to be unusually fine apples, and are now thriving well in northern Sonoma and Mendocina Counties. About 1894 I began experimenting with our native crabs, crossing them with pollen of our best cultivated apples, more to see what would result than with any expectation of securing improved commercial varieties. One striking result was produced by using the pollen of the Gravenstein. Numerous seedlings were thus produced from this little native crab. Strange to say, among the seedlings of the first generation was an apple which was fully as large as the Gravenstein and very much like it, except that, though quite good for a short time just before ripening, it changed rapidly to a punky or mealy state. Others were about halfway between the two species in size, color, quality, growth, and other characteristics, both of trees and fruits in all variations. But among the second-generation seedlings raised from these hybrids some fairly good apples were produced. In form, some almost duplicated the Gravenstein itself; very few of them resembled the true wild crab type, except that nearly all had a certain crablike acidity and lack of flavor. Some of these hybrids are still growing on my Sebastopol farm. No one of them gives promise of being worthy of introduction, but it is not unlikely that something of value may be developed from this stock by further hybridizations and selections. The wild crab has certain qualities of hardiness and prolific bearing that might be of value in combination with the fruiting qualities of some cultivated variety. This, at all events, is a line of investigation that offers opportunity for further tests. Doubtless the most interesting of these hybridizing experiments with the apple tree are those in which this species was crossed with the quince and with the pear. I have grown numerous seedlings from a cross of the apple and the common quince, Cydonia vulgaris, and also the giant Chinese quince, Cydonia sinensis. This cross was made both ways in both cases. This is a cross between genera. Some of these hybrid seedlings grew quite rapidly. The growth was generally peculiar, being compact and stubby, and often with an unhealthy appearance, especially towards the last of the season. The foliage and bark most often resembled the quince. I expected good results from these interesting hybrids, but not one ever produced even a blossom. The developments were the same in all seedlings, however the cross was made. After a few years they would decline and die, whether grafted on the quince or the apple or growing on their own roots. Several varieties of apples were also crossed with the Bartlett and other pears. This is also a bigeneric hybrid, and the result was in the end similar to that of crossing the apple and the quince. Most of these seedlings were abnormal in their growth. They were generally dwarfed,' but in some cases exceedingly rapid growers were produced, especially when the Bartlett pear was crossed with the apple. But none of them gave any indication of producing blossoms, let alone fruit. These, like the quince-apple hybrid seedlings, being only cumberers of ground which was needed for other purposes, were destroyed. It will be seen, then, that nothing of practical importance came of my experiments in hybridizing the apple with its remoter cousins. Nevertheless the proof that such hybridization is possible must be regarded as highly interesting. It seems by no means unlikely that further tests along these lines might result in revealing some varieties of these various fruits that would combine more advantageously and produce fertile offspring. As I have said in another connection, there is perhaps no opportunity open to the amateur fruit grower that suggests greater possibilities of really important discoveries than this. Out of a union of apple and quince or apple and pear might very possibly come a new fruit that would constitute an acquisition of the very greatest value to the orchardist. But even if the practical or economic results should prove meagre, such a series of experiments might still have a large measure of scientific interest, more than justifying the time and labor devoted to them. So little work-relatively speaking-has hitherto been done in this line, that the field may be said to be almost virgin. Opportunity beckons the would-be plant developer alluringly. And, fortunately, this is a case where the material for experimentation is freely available. Apples, pears and quinces grow in thousands of dooryards. Thousands of men and women might test their mating possibilities. There will be stimulus of novelty and the lure of unknown goals in such an endeavor.

-There are eight thousand named varieties of the apple, but who shall estimate the uncounted opportunities for further apple improvement?

This text is from: Luther Burbank: his methods and discoveries and their practical application. Volume 4 Chapter 6