PETE LEAL IDLE at i r haapilald as Au PUSGEUGRIEREVRLVANUAWIELEMIALTEGALLALIEIA ORI Ebib i so Lik Mlle Gh: ak Lda iy MERTEN META VTCiiant Cinna ei al VELL i CANUTE INE ETT \ \ } A | , ‘NE \\ + 143) . Aha | } 17 | NY i} \ WW \ i. FY \ . 4 4) ’ Me t ‘ at oP a ay u { Th itty 4 hbyiieet, bane Lana te Hay PoLibiet cats Seek traeaate ites te gah | j i} / ' j beat j jhe FV BPEL! iti bey f vet | | \ phat) ogi ee ’ At i ihe ee cite yal | ie HA i} i Hh Att 5 Pay Fut i Hite if Site bAyete i etd). j he : { ¥ i | \ Wy te Fl } : i Aah bei ti i Tee aEEtt H PEELS hl AF WAN PROVE PIEUEETIVELUIFIIETIRTTITILITR UTE UET ELT Cornell Aniversity Library BOUGHT WITH THE INCOME FROM THE SAGE ENDOWMENT FUND THE GIFT OF Henry W. Sage 1891 7 AB009 (si | . 3777 & Cornell University Library a 63.B94A3 Burbank, his methods and disc 3 The date shows when this volume was taken. To renew this book copy the call No. and give to the li pranan. olin HOME USE RULES. All Books subject to Racall.. 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There are no known copyright restrictions in the United States on the use of the text. http://www. archive.org/details/cu31924008976833 ‘Wsajiupu fij6ursjidms pup Ajj2a43p arp s}jnsaz ay} SIN? SD YINS sasuDjsul [D -uo}}da0zxa u} yng ‘AuaBord ay} up Ajuo yng ‘yinaf ay} Up Ajajpipawun sjjns -a4 $11 Moys jou saop u0i, -Dz1)}}4af-sso1d ajnt vo sy “paziyiitaj-ssoia fipy pup Paz1]1}4af-fjas atam si1amoyf ay? fo soubys ay} fo Joy *sjmms{ om} 6u}z}11}1aJ/-ss022 woif J7nsaz saunjawos wy} s}Iaffa snoiims ayy smoys ammjaid s}y,L ajddy sanog JMH ‘aang fwy LUTHER BURBANK HIS METHODS AND DISCOVERIES AND THEIR PRACTICAL APPLICATION PREPARED FROM HIS ORIGINAL FIELD NOTES COVERING MORE THAN 100,000 EXPERIMENTS MADE DURING FORTY YEARS DEVOTED TO PLANT IMPROVEMENT WITH THE ASSISTANCE OF The Luther Burbank Society AND ITS ENTIRE MEMBERSHIP UNDER THE EDITORIAL DIRECTION OF John Whitson and Robert John AND Henry Smith Williams, M. D., LL. D. VOLUME IV ILLUSTRATED WITH - 10S DIRECT COLOR PHOTOGRAPH PRINTS PRODUCED BY A NEW PROCESS DEVISED AND PERFECTED FOR USE IN THESE VOLUMES NEW YORK AND LONDON LUTHER BURBANK PRESS MCMXIV fc As 0047) | Copyright, 1914, by The Luther Burbank Society Entered at Stationers’ Hall, London All rights reserved II Volume IV— By Chapters Poreword.........ccccssssscceessseeeees insdieddenedseenas Page 3 Quick Possibilities in Fruit Improvement —Specifie Needs, and How to Accomplich Them Practical Orchard Plans and Methods —How to Begin and Carry on the Work, ........,cccsesccesccuscceecceesens Doubling the Productiveness - of the Cherry Vill newer meee erase eer ar er ene ean eseeseesaseteeete The Responsiveness of the Pear —What Has Been Done Is But the Beginning ree eee eee errr re Serer eee res Fuzzy Peaches and Smooth-Skinned Nectarines —Two Fruits Which Beg for More Improvement, |... . 1.2.0... cece eceeeeeeeneeseee The Apple — A Fruit Worthy of Still Further Improvement. —New Apples and How Po} Mace THOM 5,5 o.sjnss,cieiajsjoy0iareieie es sisie sierassinjeierstuleiareroiels The Transformation of the Quince —What Was Only a Cooking Fruit Pia Lice BAY oa wince nv ok caw in ee dews tanh iedeewn The Apricot and the Loquat —An Opportunity for the Experimenter, ..........ccccseesssccccssscuscevave Citrus Fruits — And Fruits From the Tropics —New Experiments Well Worth Trying. 5 scicsccjans seins mangeiisiasien dvadesisannars List of Direct Color Photograph Prints......... 105 141 177 211 241 273 FOREWORD TO VOLUME IV We begin, now, to take up with greater detail, practical combinations of method—particularly as applied toward producing new orchard fruits. In this volume Mr. Burbank has covered practically all the simple orchard fruits save the plum and the prune. Although the purpose, here as before, is to be as specific as possible, yet the facts are carried through in narrative form, showing, always, how the actual method employed fits into the scheme of work as outlined in Volumes I, II and III. From this volume the reader will glean much of practical interest and value from Mr. Burbank’s experience with laying out orchards, to making orchards pay, and to the practical management of orchards—with an eye always to the bearing of Mr. Burbank’s work upon the improvement of the human plant. THE EDITORS. The Plumcot This remarkable fruit was produced by Mr. Burbank by hybridizing the Chinese plum and the apricot, Most plant breeders held that so wide a cross was impossible, and in point of fact the hybridization was not effected without difficulty. ’ The story is told in detail in the text. The hybrid prod- uct ts virtually a new species, of which Mr, Burbank has developed many varieties. QUICK POSSIBILITIES IN FRUIT IMPROVEMENT SpeciFic NEEps, AND How To AccoMPLISH THEM your garden was perhaps planted by your father’s father. The twig you cut from it today may take root and become a thrifty tree that will bear fruit to gladden the hearts of your grandchildren long years after you are dead. And that possibility puts the tree on a very different footing as the friend and companion of man from that occupied even by the best-prized members of the company of forage plants and garden vegetables. When you work with fruit trees you are mak- ing permanent records. You are building on a rock. You are reaching out your hands to future generations, and erecting a monument that will remain as a testimonial to your foresight and wisdom long after you are gone. And doubtless this fact of the permanence of Te old pear tree out there in the corner of [VotcumME IV—Cuapter I] LUTHER BURBANK the tree accounts in large measure for the interest with which almost anyone will take up the culture of fruits if given the opportunity. Not that we are always thinking of posterity; but one can develop an enthusiasm about the production of something having an element of permanency that does not attach to such transient things as annual or bien- nial plants. The fruit tree in the old orchard is like an old friend when we get back to it. The mere view of it brings up reminiscences of our youth, and the tree that we planted in childhood may remain as a stimulus to us in old age. There is no friendlier compact than that be- tween man and the fruit tree. It is an age-long compact withal. Not so ancient as the compact of bees and flowers—for as compared with the archaic and honorable order of insects man is a parvenu—but far older than human civilization none the less. Indeed, it was probably the fruit tree, giving an example of fixity of habitat, that encouraged man to give up the life of a nomad and establish a fixed abode. Not unlikely it was the evidence presented by the fruit tree that first suggested to man the possi- bility of raising a supply of foods from the soil, and thus lured him away from the precarious [8] The Old Idea of an Orchard and the New The center of the picture shows the new type of orchard—the trees so small that a good part of the fruit can be picked without the use of a lad- der. At the right is the old type of orchard, in which much of the energy of the tree was allowed to go to the development of needless branches, mak- ing it difficult to care for the tree properly, and particularly difficult to gather the fruit. LUTHER BURBANK pursuits of the hunter and fisher and put him on the road to future greatness. And all along the road of advancing civiliza- tion the friendship with the fruit tree has been kept up. Yet it is only in comparatively recent times, probably, that rapid progress has been made in aiding our coadjutors of the pomological world to step forward and better themselves as man had long ago bettered himself with their assistance, To be sure, our forebears developed many forms of fruit that were not lacking in pal- atability; but the great advances in the improve- ment of orchard fruits are matters of the nine- teenth century. Recent progress in this field has been almost as wonderful as progress in the fields of mechanics and electricity, The orchard fruits of today that find their way to the markets are so different in size and quality from the fruits with which our grandparents were satisfied—even though some of them are grown on cions grafted on the old trees—as to seem to belong almost to different orders, certainly to dif- ferent species from the fruit stocks from which they have been developed. Yet what has been done is only the beginning. We speak of “perfected” fruits, and in a sense the word is justified, so conspicuous are the good [10] ON SPECIFIC NEEDS qualities of the new fruits as contrasted with the old. But no fruit has really been perfected, in the sense of having reached the limits of improve- ment. There are numberless opportunities for better- ment even in the case of the very finest varieties of fruits of every kind. The successive chapters of the present volume will be devoted to specific suggestions as to the betterment of each of the important classes of orchard fruits. In the present chapter, it is my purpose to take a general survey of the field, pointing out various lines of betterment not so much with reference to any particular fruit, al- though we shall constantly draw our illustrations from specific fields, as with reference to the entire class of orchard fruits. The suggestions here outlined are the result of lifelong association with trees of the orchard. Probably not less than half my experiments of every character have been conducted in connec- tion with one form or another of fruit trees. And a very large proportion of my most im- portant new products, considered from an eco- nomic standpoint, have been products of the orchard. As To Mere Size Almost the first thought that comes to one (11] LUTHER BURBANK who goes into the average orchard and looks about with a really observant eye is that orchard trees in general are not well-adapted to man’s needs in the matter of size. I have in mind certain orchards of New England and Long Island, for example, in which the apple trees seem to have done their very best to rival the elms and oaks in size. Their trunks and main central branches rise, barren of fruit- producing branches, to a height of twenty or even thirty feet. The strength of the tree has gone to producing wood instead of fruit-bearing twigs. Such fruit as does appear is suspended so high that long ladders are required to reach it when it has ripened. This is obviously all wrong. There is no reason why the apple tree should be permitted to grow high into the air even if it has the inherent pro- pensity to do so. By proper trimming, the young tree can be made to assume a spreading form, so that it will bear most of its fruit within easy reach. Moreover, it is easily possible through selective breeding to develop an apple stock that will have no tendency to grow into tall, or otherwise ill- shaped trees, but will naturally take on the com- pact, low-growing habit that is to be desired in a fruit tree. [12] A Perfect Apple This picture shows one of the many types of new crossbred apples that Mr. Burbank has de- veloped. He considers this as representing prac- tically an ideal form of fruit, and he urges that there is na reason why all the apples in the orchard should not conform to, or at least approximate, the ideal type. Selective breeding and _ intelligent supervision are of course required to accom- plish this. LUTHER BURBANK What is true of the apple is equally true of its cousin the pear. This tree also has been per- mitted in the old-time orchards to develop the pernicious habit of too slender upright growth and undesirable tallness, too much like a wildling. These defects have been corrected with some of the newer varieties, to be sure, but these have not been introduced universally. The same criticism applies to the cherry. Everyone knows how often this tree is seen grow- ing in the New England dooryard, with trunk like that of the sturdiest oak, and with its inviting clusters of red fruit suspended at such a height as to be quite beyond reach of everyone but the birds. ; A well-trained cherry should renounce this tantalizing habit and make its wares reasonably accessible to the wingless biped that has fostered it. The other notable members of the company of orchard trees, namely the plum, peach, quince and orange, have in the main developed a more commendable habit of growth. Their trees are for the most part not too large, and the best varieties have a spreading form that leaves little to be desired. But some of these, and in particu- lar the peach and orange, have other faults that urgently call for correction. [14] ON SPECIFIC NEEDS The peach in particular is a tender and short- lived tree, peculiarly subject to the attacks of insects and to fungoid pests. Seemingly the developers of this luscious fruit have been so concerned to foster the remarkable qualities of the fruit itself that they have neglected the tree on which the fruit grows. So the peach orchard, instead of outlasting a human generation as it should, is an ephemeral growth, the indi- vidual trees of which are in good bearing only for a few years, after which they must be replaced. The peach grower is always uprooting the dead trees in one part of his orchard and planting new ones in another. THE QUESTION OF STAMINA Unfortunately the peach is so specialized that it will not thrive on any roots except its own. It should be possible, however—at least the project is one that invites the experimenter—to develop a more vigorous and longer-lived race of peaches. Something could doubtless be done by mere selec- tion, taking cions for grafting or raising seedlings from the hardiest and most vigorous trees of the orchard. It has been shown that it is possible to hybridize the peach with its hardier relative the almond. Probably in successive generations there might be developed a hybrid stock of trees that would retain all the good qualities of the peach [15] LUTHER BURBANK and yet would be as long-lived and vigorous as the almond, and hardier and more resistant than either. It is true that no very striking results have yet been produced by crossing almond and peach, though many unusually vigorous and rapid-grow- ing trees have been produced which will far out- grow the most vigorous individuals of either species. But hybridizing, followed by rigid and persist- ent selection, is a practical method that is still in its infancy. It is not so very long since orchardists in general, supported by technical botanists, de- nied the possibility of hybridizing different species, My long series of varied experiments were perhaps more directly instrumental than any other influence in showing the fallacy of this belief. The reader will recall that I have in many instances interbred species belonging to different genera; and that the interbreeding of different species in my orchards and gardens is a commonplace. Yet it is still true that there are many cases in which there are seeming barriers erected between plants that obviously are closely related, which prevent the advantageous hybridizing and grafting of one species with another. And the peach is a case in point. It accepts the [16] The Ideal Peach— and Some Others At the left, some peaches of the type developed by Mr. Burbank through crossbreeding. At the right, peaches of a type of which the average peach orchard furnishes only too many examples. There is no reason why the main crop of the or- chard should not conform to the type of peaches at the left, if Mr. Burbank’s methods of selection are followed out. LUTHER BURBANK pollen of its nearest relations (except the almond) unwillingly, and as yet no useful product has come of such union. Yet the peach is not more isolated in this re- gard than its relative, the apricot, seemed to be until I was able, after many futile efforts, to break through the barriers and hybridize that fruit with the plum. The hybrid that resulted, named the plumcot, is virtually a new species. It combines the good qualities of both parents and is a very valuable addition to the list of orchard fruits. It seems not unlikely that some future ex- perimenter will be able to effect a correspondingly useful hybridization of the peach; then the way will be open for the development of a race of peaches that will combine with the existing quali- ties of fruit production the qualities of hardiness and resistance to disease that the present peach tree so notably lacks. Bic Fruir AND FREE BEARING Size of fruit and prolific bearing are charac- teristics of such obvious desirability that they cannot be overlooked even by the tyro. Yet the average amateur, who has a group of fruit trees in his garden or even a fair-sized orchard on his country place, is content to buy large, handsome, and well-seasoned fruits in the market, taking it for granted that his own trees [18] ON SPECIFIC NEEDS cannot. be expected to supply similar products. But in point of fact it is well within the possi- bilities to produce good orchard fruits wherever the trees exist that produce any fruit at all. Con- ditions of soil and climate cannot, of course, be ignored. One cannot grow oranges in Canada or grapefruit in New England—as yet. But if you have apple trees or pears or plums or cherries that bear fruit, it is a matter ‘of your own choice whether they shall bear good fruit or bad. All that is necessary is that you should send to some reputable nurseryman or orchardist and secure cions of good variety for grafting on your trees. All apple trees are closely related, the culti- vated varieties being without exception of mixed strains. The same is true of pears and plums and cherries. In each case you may graft on your native stock cions of any variety of the same species, or a dozen or a score of different vari- eties, and, if the work is done properly and at the right season, the new twigs will soon become a part of the old tree as regards vitality and capacity for growth and fruiting; but—as we have learned in earlier chapters—they will retain their inherent hereditary tendencies as to quality of fruit. Growing side by side, on the same tree, you may have summer apples and winter apples, sweet [19] LUTHER BURBANK apples and sour, green varieties and red varieties. And all this without any necessity for experi- mentation on your part. You need have no knowl- edge of plant breeding except an understanding of the simple technique of grafting. The professional experimenters have supplied the material; you have but to avail yourself of the results of their work. Of course, if you wish to go a step farther there are inviting fields that you may enter. With the materials furnished by a single old apple tree you may become a plant developer. You may plant the seed of any choice apple purchased in the market and from the seedlings you will develop an interesting variety of fruits, some of which may seem to you better than any existing varieties, We have already caught glimpses, in the out- lines of my work already given, of the possibili- ties of the development of various. orchard fruits as to size and flavor and other desirable qualities. If you desire to try your hand at similar im- provement either of the fruit now growing on your ungrafted trees, or of that growing on cions of improved varieties, it will require only reasonable attention to the principles already outlined in earlier chapters of this work, together with a fair degree of patience and persistency, to insure some measure of success. [20] ON SPECIFIC NEEDS There is one additional hint that it might not be amiss to emphasize. In selecting seed for planting, it is desirable, of course, to select the largest and best specimens. But it should be re- called that the real test of quality in a tree is not the production of exceptional individual fruits, but the size of the average fruit that it bears. Exceptional conditions of nutrition may cause a single apple to grow very large on a limb that as a rule produces only fruit of meager propor- tions. Seedlings from this exceptional fruit do not inherit the exceptional quality of their parent. It is the germ plasm of the tree itself that counts, Seed from a very small apple of a good variety will produce better offspring than the seed of a very much larger individual specimen of a poor variety; so it is far better to select the poorest fruit of a good variety rather than the best of an ordinary variety. This principle should be borne in mind in un- dertaking plant development of any kind, not merely with reference to orchard fruits. It is the inherent properties of the plant organism as a whole that will determine the average character of the fruit. BREEDING FOR QUALITY As to the special qualities of fruit that call for improvement, details, of course, differ with dif- [21] LUTHER BURBANK ferent species. We have seen that sugar content is an all-important item in the case of the prune; and that sweetness and flavor and color are mat- ters of importance in the case of the cherry. We have also seen with what relative ease varieties may be developed that surpass their parent forms in these regards. An interesting illustration of the possibility of breeding new qualities into a fruit or accentuating old ones, to which reference has not hitherto been made, is manifested by one of my new cherries, which, through selective breeding, became so sweet that its sugar content acts as a preservative, quite as in the case of the sugar prune. These cherries, instead of decaying rapidly after ripening, dry on the tree in a state of perfect preservation. This particular feature is of no present commercial value, but the case illustrates the possibility of altering the inherent qualities of a fruit, and of doing this in the course of a few generations through systematic selection. The same thing is illustrated by another of my cherries which, by careful attention to a combina- tion of qualities that would ordinarily be quite overlooked, had its stem so strongly anchored to the stone that when the fruit is picked the flesh tears away leaving stem and stone on the tree. Now it will be recalled that, in the case of the [22] ON SPECIFIC NEEDS prune, it is a serious defect to have the fruit so firmly attached to the stem that it clings to the tree after ripening. A prune must drop of its own accord when ripe or the prune dealer will have none of it. But the quality that would make a prune commercially worthless, when accentuated in the cherry, becomes a mark of possible cxcep- tional value. The cherry that leaves its stone on the tree might conceivably fill a special purpose. So this variation in the inherent properties of the cherry might produce a new race of commercial value to meet an exceptional need. ; It requires but little ingenuity to suggest pos- sible developments that would similarly give added value to the fruits of various species. For example, there is the matter of color in the pear. Unlike most other fruits, this one, as every- one knows, is for the most part lacking in the brilliant color that purchasers of fruit in the market usually find so attractive. But there is no reason why pears of various brilliant and at- tractive colors should not be developed just as colored apples have been developed. Our native crab apple is dull. greenish brown or dull red, and unattractive in color even when ripe. Of course this is not the direct progenitor of the cultivated apple, but it obviously belongs to a closely related strain, and it shows us the apple [23] *yuaunsadxa sty} jo s}jnsat ay} fo auo 3faz ayj jD auo fiapuipio ay} yyim = pajspajuoa sp ‘smoys qy611 ay} JO azdurpxra ay} sp ‘sulys patojoa fiyyars yim = smad fo uolonp -o1d ay} ul ‘raaamoy ‘Bur -jJuaunJadxa uaaq spy yUvG -ing ‘jy ‘sajddvo jo saa -110a fiupur 0} $sauaai}IDJ} -}p yons saaz6 yo1ym 10,03 2y} payon] japd jsour ayy dof spy Ipad ay} ojtayyy ing = ‘Jwap1 «so saamor6 qimaf fupur fiq— papsz08 -ai St adpys sy) pup ‘pass -ap 2q uno sp ahmD] SD 92 ‘sanjalipa 12}}2qQ $}1 Ul ‘mpad Aupulpio ayy IDId 2Y] oju1 10]07 6unjjan ON SPECIFIC NEEDS in a state of nature and gives us a clue as to what qualities of fruit are advantageous to the apple itself, and what ones have been bred into the stock to meet the demands of the fruit developer. So the fact that the wild crab apple is dull in color suggests that the variously pigmented coat of the cultivated apple is an artificial product, not primarily beneficial to the plant itself, that man has developed through selection. It is not unlikely tnat the relatively thin skin of the cultivated apple, coincidentally developed, makes pigmentation desirable, to protect the tis- sues of the fruit from too much sunlight. The fact that many apples redden where exposed to the sun, and remain green where protected by the shadow of a branch or leaf, suggests that such is the case. Be that as it may, the point I wish to emphasize at the moment is that the pigmented coat of the apple has been produced mostly by unconscious artificial selection. There can be no doubt that the pear could be similarly given a brightly col- ored skin should anyone care to take the trouble to make the experiment in selective breeding. Indeed, a few varieties of partly red pears have been developed, and have proved a valuable nov- elty in the market. Other and better varieties, variously tinted, should follow. [25] LUTHER BURBANK It has been suggested that a globular or apple- shaped pear with a short stem would be acceptable to the packers because it would crate more com- pactly and carry better than the ordinary pear. But this would rob the fruit of one of its distinctive characters, so on the whole the change would probably not be an improvement. In the matter of size, also, it would appear that the pear, in its best varieties, has attained a maximum develop- ment. To make it much larger would be detrimental, as it would probably be torn from the tree by the wind. Even now some varieties are so large that they break away from the tree before ripen- ing, and so these varieties are avoided. The Beurre Clairgeau, one of the best of pears, is little grown for this very reason. But in matter of flavor there is still oppor- tunity for indefinite variation. Some European cultivators have recently produced remarkably pleasing and varied flavors in this fruit. An illus- tration of how the flavor of a fruit may be rad- ically modified is furnished by my Apple Plum, which, while retaining the characteristic attributes of its race, curiously simulates the apple in the matter of form and even in taste and texture. Another instance is my Bartlett plum, which out-Bartletts the Bartlett pear in its own peculiar [26] ON SPECIFIC NEEDS quality and flavor. Yet others are the Pineapple quince, which has the flavor of the pineapple it- self, and the Sunberry, which has the exact flavor of the blueberry intensified. Corresponding modifications of the pear as well as of all other fruits lie within reach of the patient experimenter. LEAVING OUT THE CORE But perhaps the most inviting field of all, in connection with the possible development of or- chard fruits, is that having to do not with the form or texture or flavor of the pulp but with the seed of the fruit. Of course it must not be overlooked that, from the standpoint of the fruit itself, or rather from the standpoint of the tree on which it grows, the seed is the only really essential part of the fruit. All of the embellishment of juicy pulp and highly pigmented skin is but the lure put forth by the plant on behalf of the seed, in the interests of self- preservation. The really essential part of the entire structure is but an infinitesimal cell lodged at the heart of each kernel of the seed. Indeed, we may go even one step further, with the aid of the microscope, and say that the nucleus of a single cell, born of the union of the nuclei of _two germ cells, is the really important part not [27] | *sfadojyaaap jyunid dayjo fo j4nd ay] uo u0}} -Jallp s1y} ul Yom 3Ua}]29 -xa Joj fijiunjioddo ]}1}S $1 aday,y ‘Saypuiij> 1apjo09 40f pajdppp sjoo11dp fo sai} -almpa {o Juauidojaaap ay} ui pazuauijiadxa spy yupq -ing ‘Iy~ ‘sysoaf Gu1ids ayy fiq paddju aq oj fija411 aim sulosso}q ay} asnp2aq Ayayya—fpspy jou si jt yoy] st 22 Bulmos6 un fijjna -ufip yoai6 ayy = “pazid Aqy6iy s1 yoyy auo puo ‘qinafe sno1sny fitaa BD $8} jO0RIdD ayy jooudy aul Dried Apricots The fruit devel- oper must consider many things in producing a new variety. In the case of the apricot, evenness of size and drying quality are essential. The boxes of dried apricots here shown illustrate the attractive- ness of a fruit in a per- fected variety of al- most ideal quality. LUTHER BURBANK merely of the fruit but of the tree on which it grows. For within the infinitesimal structure of the nucleus, by the most mystifying of all Nature’s feats of jugglery, are lodged those hereditary fac- tors or determiners that will ultimately transmit the traits of the ancestral tree to the tree of the future. In the widest sense it is true that the sole pur- pose of the entire plant is to produce a certain number of these germinal nuclei, each represent- ing the union of a pollen grain with an ovule; each carefully encased in the structure that we calla seed; and each capable of reproducing, with sun- dry modifications, the characteristics of the parent plant, or, in a profounder view, the blended char- acteristics of the entire ancestral race which the plant represents. When we consider the seed in this way it does not seem strange that all the resources of Nature should concentrate on the development of the fruit structure in which the all-important seed or cluster of seeds finds lodgment. And by the same token it is comprehensible that Nature will hold to the seed with the most unwavering persistency. And so it is not strange that the plant experi- menter should be able to alter the size and texture and quality of the fruit pulp far more readily than [30] ON SPECIFIC NEEDS he can modify the core or stone that lies at its center. Yet from man’s standpoint this inevitable cen- tral structure, forming the heart of every orchard fruit, is a conspicuous detriment. And it is alto- gether desirable that fruits should be developed in which the stony or fibrous covering of the seed is eliminated, or in which the substance of the seed itself has been substituted by juicy tissues. Everyone knows that this much desired modifi- cation has been effected, or all but effected, in the case of the so-called navel orange. An accidentally discovered mutant, doubtless a pathological speci- men, was seized on by some keen-eyed observer, and a race of seedless oranges was developed by selection, and widely disseminated by grafting. Also there are seedless grapes. The reader will recall the long series of experi- ments through which I was enabled, by taking advantage of a similar malformation in a wild European plum, to develop by hybridization and selective breeding a race of stoneless plums, Everyone knows, also, that there comes to us from the tropics a familiar fruit, the banana, that is seedless; although perhaps it is not so well known that this fruit has lost its seed through being propagated for long generations by division. The precise steps through which this development [31] LUTHER BURBANK has taken place in the case of the banana are not matters of record. But its condition is similar to that of the sugar cane and of the familiar horse- radish in our gardens, both of which have been so long propagated by division that they have aban- doned the habit of seed formation. The banana in its wild state was practically filled from end to end with large, hard, bullet-like seeds or stones, with just enough pulp surrounding them to make the fruit attractive to birds and wild animals that could not destroy the seeds. In this state it was practically worthless to man. Had not a patho- logical form appeared without seeds, which must be cultivated solely by division, the banana would be a practically useless fruit to-day. And, for that matter, the potato furnishes us with an even more familiar illustration of the re- nunciation of the most primitive and important of all plant functions, that of seed bearing, which has developed under cultivation within the past half century. But among orchard fruits of temperate zones the orange and the stoneless plum, as just in- stanced, are the only examples of plants that have been thus profoundly modified—although a seed- less (but not coreless) apple and pear, in the ex- perimental stage of development, have been an- nounced, These examples, however, are stimu- [32] The Nectarine The fruit here shown, the nectarine, is much less familiar than it de- serves to be. It is in reality a form of peach. The botanists question whether it is not specific- ally identical with the or- dinary cultivated peach. It will appear in the text that Mr. Burbank has made remarkable experi- ments in crossbreeding and hybridizing the nec- tarine with the peach and with the almond. ‘apm = siy} Up aBpjupapp poob of; yl? pasn spy yunqimg ‘AL yDy} aas yoYs aw = “SJuaUT -14adxa Guizpisqfy ul _ quampd a)qviisap D }1 ayDuL joy} saijaqjonb «soy yimaf s1y} ‘juaaa fiup up “pol -ad ajowazr D JD suvipul ay) Aig ‘uoipaijjna Jo iva ay? uz ‘42 pyod uojijuajqyo 0} az1s abs] fijeat}pjar $}1 samo jimi{ upoitaury ay? yoy} ajqissod st jy] *ajddp -qpi9 asaulyD ay} 7yO11 ay} qo asoy; ‘ajdipgpia uD} -daury ay? Mmoys ja} ay) jo saanby ay ajddpqni) ayy ON SPECIFIC NEEDS lative. They show that the possibility of co- operating with Nature is almost limitless; and it is hardly to be doubted that the plant experimenter of the not distant future will carry out the process of making all our orchard fruits seedless and coreless. As I said before, this is doubtless the most im- portant opening that presents itself for the fruit developer. It is a field in which there is room for all and the allurements of which should prove in- viting to a vast number of workers. —When you work with fruit trees you are making perma- nent records—reaching out your hands to future genera- tions—erecting a monument that will remain long after you are gone. Making Over An Old Orchard Countless farms and dooryards of the United States have orchard trees in larger or smaller number that are practically useless. These can be made over, by proper grafting, so that they bear the finest varieties of fruits. The picture illustrates the way. of rehabitating an old apple tree by grafting all of its larger limbs. The tree is thus entirely transformed, and may come to bear fruit of the most delicious quality. PRACTICAL ORCHARD PLANS AND METHODS How To BEGIN AND CARRY ON THE WoRE HAT kind of tree is that, Mr. Burbank?” W Seldom does an amateur visit my experiment farms without asking this question. And very commonly I am led to reply: “Why, it is hardly fair to speak of that as a tree; that is a concentrated prune orchard. If I were to name all the varieties of fruit that are growing on the branches from that single trunk, it would sound like reciting the names from an or- chardist’s catalog. Nearly all my important experiments in developing a particular variety of plum are made, at one stage or another, in these tree-colonies.” And when my visitor, observing now on closer inspection that practically every branch shows evi- dence of having been grafted, inquires what will be done next season, I explain that a fair propor- tion of the present branches will be cut away and {Votume IV—Cuapter II] LUTHER BURBANK grafts from other seedlings put in their place for further tests. The usefulness of a tree as _e basis of further experiments is not finished by any means when it has once been covered by grafted cions, The same process may be practised over and over. Doubtless no other observation made by the average amateur visitor is matter for greater sur- prise than this utilization of single trees for the carrying out of vast numbers of experiments. The utility of the method, in the saving of both land and the experimenter’s time, is altogether obvious once attention is called to it. Yet relatively few, even among professional fruit growers, have hith- erto gauged the possibilities of the method. Of course the average visitor who inspects my gardens has no thought of becoming an experi- menter on a large scale, and hence would not have occasion to practise multiple grafting and regraft- ing on any such scale as that employed at Santa Rosa and Sebastopol. But I call particular atten- tion to this matter of fruit-tree grafting, because there is a lesson in it not merely for the profes- sional fruit grower but for tens of thousands of persons scattered across the length and breadth of the country who have in their gardens a few fruit trees, at present of no apparent value, that might be made to bear in abundance. [38] A Box of Seedlings The first step, of course, in rehabilitat- ing an orchard, if new varieties are sought, is the Planting of seedlings and the proper care of them, which has already been described in a preceding volume, This picture shows sprinkling the box of seedlings with sulphur in order to prevent damping off. LUTHER BURBANK Moreover, there are other thousands who have on their farms neglected orchards, run riot with weeds and bringing no monetary return whatever, which might be made the most productive and val- uable portions of the entire acreage. And in each case the grafting of the cions of good varieties of fruit on the old and otherwise worthless stock is the key to the entire situation. Oxtp TREES Mape YouNna We shall have occasion in the successive chap- ters of the present volume to examine in detail the methods of cultivation and possibilities of im- provement of the different orchard fruits. Here it may be of service to take a brief general view of the subject. And at the outset I wish to emphasize the possibility of making over the orchard mate- rial which is now in hand, so to speak, and which is being so sadly neglected. Reports from all over the country tell the same story. In Ohio, for example, according to the re- port of experts of the Agricultural Station, there are thousands of acres of idle orchards. The product of apples—the chief orchard fruit—has fallen to less than a fourth of what it was a gen- eration ago. Apple trees themselves are about half as numerous as they were; and this implies that those that remain are only half as productive as the trees of twenty-five or thirty years ago. [40] ON PRACTICAL PLANS Such a record, coupled with the fact of an ever- increasing demand for orchard fruits, seems al- most incomprehensible. Yet similar reports might be had from numberless other regions where fruit production was formerly a more or less important industry. But fortunately the facts of the situation are now being called to the attention of the general public, in particular by the workers at the agricul- tural experiment stations. Bulletins are being issued that call attention to the possibilities of rejuvenating the old orchards, and in many re- gions results of this work are being manifested in the restoration of abandoned orchards. In one county in Ohio, in a recent season, 117 rejuvenated orchards added more than fifty thousand bushels to the apple crop. “In several cases,” says the Ohio report, “a net profit of $400 per acre has been secured from an abandoned orchard.” The report continues: “It is like reaping where one did not sow, to bring one of these orchards into its own again. An investment in one of these orchards is better than gold mine stock, for there is no ‘luck’ about it. If there is any risk about operations of this sort, it is because of lack of busi- ness capacity and industry. To take a neglected orchard and bring it back to usefulness does not [41] LUTHER BURBANK require much capital except in brain and muscle, but it is an achievement worth while.” An achievement worth while, the renovation of an old orchard, or even the rejuvenation of a single tree, certainly is. I can gauge something . of the growing recognition of this fact from the ever-increasing number of letters that come to me from all parts of the world asking my opinion or advice as to the possibility of restoration to use- fulness of trees that their owners not long since regarded as worthless. And I am usually able to assure the questioners with a good deal of confidence that if they go about it in the right way they will not merely restore trees to their former level of productivity, but may make them producers of fruit in such abundance and of such quality as quite to outclass their orig- inal record. HOUSECLEANING IN THE TREETOPS I need not here enter into details as to the exact methods of operation through which such restora- tion and rejuvenation of old orchard trees may be brought about. Such details can be given to better advantage in the chapters that deal with individ- | ual fruits. But there are a few general principles! applicable to the entire class of fruit trees that may be briefly outlined. First and foremost, perhaps, is the matter of [42] A Row of Plum Seedlings It will be seen that some of these seedlings have outstripped the others in the matter of growth, and in luxuriance of foliage. Experience has shown that seedlings that thus start out well are likely to continue their relatively rapid growth and to make far: better trees than the stunted ones beside them. A knowledge of the quali- ties of the seedling en- ables Mr. Burbank to se- lect at an early stage the ones that are to be pre- served, thus making ex- periments of an elaborate character, on a rela- tively small land area. LUTHER BURBANK cutting away the surplus growth of half dead twigs and branches that a neglected tree is sure to ex- hibit. These serve to distract the energies of the tree, if the phrase be permitted, and even though they may multiply the number of fruit buds, they will greatly minimize the average size of the fruit itself. Regardless of quality, fruit trees generally can- not bear to advantage unless properly pruned. The process may best be carried out late in the winter or very carly in the spring. It is well, as a matter of course, to make clean, sharp ampu- tations, so that the bark of the limb below the cut is never torn. No general rule can be given as to the amount of pruning for any species; much less for any individual tree. But it may be taken for granted that the amateur will usually err on the side of pruning too little rather than too much. Where small twigs are cut away by the pruning knife, it is not necessary to treat the stump; but larger branches, requiring the use of the saw, should have the stump covered with hot wax or paint to protect the injured tissues from the weather during the period of healing. This should not be done immediately, but should be delayed for a week or more until evaporation has dried the tissues sufficiently to allow absorption of the protective material used. [44] ON PRACTICAL PLANS In connection with this removal of supple- mentary branches, which is in effect a sort of housecleaning operation, it will be well to scrape off the rough bark of trunk and limb wherever it scales in such a way as to afford snug retreats for insects, And blemishes of a more important order, such as knotholes and decayed surfaces where limbs have been cut away or broken off in the past, should be carefully excavated, all un- sound tissue removed, and the cavity filled with ordinary Portland cement or concrete. The latter process has been variously charac- terized as tree carpentry and tree dentistry. Both terms are more or less suggestive of the work achieved, regardless of names. The opera- tion may result in prolonging indefinitely the life of a valuable tree that would otherwise soon have decayed beyond restoration. The trunk and branches of the tree having been put in order, thought should be given to its root system. The casual observer is likely to forget that only about half the tree is visible, and that the aerial half is not fundamentally more impor- tant than the subterranean moiety. Yet it is ob- vious that the root system furnishes the all-im- portant source of supply of moisture and mineral matter, lacking which growth could not take place at all, let alone fruit bearing. [45] LUTHER BURBANK Of course we cannot get at the branches of the roots to renovate them as we have renovated the aerial branches, nor would they require the same kind of attention if we could. There is no danger that a plant will have too many rootlets, for these are the mouths that reach out into the nutrient earth and take up the chem- icals in solution that are part of the materials for the building of branch and leaf and flower and fruit alike. But there is danger that the root sys- tem may not develop in the best manner, and there is obvious need that the soil into which the roots penetrate should not be depleted of its nourishing properties. As to the manner of development of the root system, of course it is too late to make radical changes if we are dealing with an old tree. With young trees just starting growth or recently trans- planted much may be done, as will be pointed out presently. But with the old tree all that can be accomplished is to see that the root already in is being given a fair chance. ATTENTION TO THE COMMISSARY DEPARTMENT To this end the ground about the tree should be cultivated with plow or spade, even at the hazard of destroying a certain number of super- ficial rootlets. The grass and weeds that have been permitted to spring up in the neglected or- [46] A Bunch of Selected Seedlings This picture shows a bunch of selected seedlings that have been carefully dug in the proving ground and are now ready for transportation and final disposition. It will be seen that care has been taken to dig up the entire root, without injury. Seedlings thus carefully transplanted will lose very little in the process, and are almost sure to continue growth if properly cultivated after transplantation. LUTHER BURBANK chard sap the ground and take the nourishment that the tree imperatively needs. But if the sur- face soil is turned under this vegetable matter will in itself constitute a fertilizer. Unless the soil is unusually rich this should be supplemented with artificial fertilizers, of which nitrates, phosphates and complete mineral fertilizers often appear to have the best effect in rejuvenating an old orchard. In case the soil is a sandy loam, subject to rapid leaching, it may be desirable to sow a so-called “cover crop” to prevent the too rapid washing away of the plant foods in the rainy season. If a leguminous crop is grown, such as clover, crimson clover, cow peas, or vetch, these crops will in them- selves add to the nitrogen of the soil, as their roots have the power of taking this from the air. But it is urged by some eastern .orchardists that care should be taken to avoid too much nitrogen. The roots of the tree reach down to rich subterranean sources that are likely to be well supplied with nitrogen, because the nitrates are very soluble and are pretty rapidly leached or filtered into the sub- soil. After preliminary treatment it has been found in many states best to sow a crop of clover, often with other perennial grasses, as a permanent crop, which should be cut and all material left on the ground for the protection and support of the or- [48] ON PRACTICAL PLANS chard. This has been found to be an extremely profitable method both in the old neglected and in the new orchards of New England and in the orchards of the northwestern Pacific coast. A small space about the trunk of the tree should be kept free from grass. The experts of the Indiana Experiment Station recommend as a fertilizer, for soil of fair natural fertility and where a leguminous nitrogen-gather- ing cover crop such as just suggested may be grown, the additional use of a fertilizer having the following formula: “A thousand to fifteen hundred pounds per acre of a mixture containing one part (100 pounds) each of ground bone, acid phosphate and muriate of potash. On soils that are some- what exhausted, 125 pounds nitrate of soda may be added in addition. “In order to get the greatest returns from this fertilizer it should be thoroughly worked into the soil. This can be accomplished very well by ap- plying it to the surface just before plowing. The plowing and working of the ground will get the fertilizer pretty thoroughly incorporated, and the tree will soon show the beneficial effect of its pres- ence. Hoe the ground often and keep it cultivated until midsummer, then sow a cover crop that will protect the ground until it is turned under the fol- lowing spring.” [49] LUTHER BURBANK After these reformatory measures have been carried out, it remains to guard the trees against the attacks of insects with some protective spray. The particular insect or fungus-destroying mix- ture required will of course depend upon the indi- vidual case. The Bordeaux mixture is doubtless used more than any other single spray for fungus diseases and for the codling moth in apples. A lime-salt-sulphur solution is the general mixture for San Jose scale. In general, it should be re- called that spraying is a preventive measure rather than acure. Bordeaux mixture, for example, will prevent the appearance of the fungus disease com- monly called scab. The attacks of the codling moth may be met in the same manner; but as there is a second crop of these moths, another spraying may be necessary later in the season. BATTLING THE PESTS I should add that as to this matter of fighting plant diseases and pests with the spray, as also in the matter of the renovation of neglected orchards, I must offer advice rather at second hand. My own orchards, as a matter of course, have not been neglected. While my orchards are cultivated thoroughly, so that a weed is seldom seen, very little fertilizer is used and rarely any spraying, as my object is to obtain varieties that are immune to fungus and insect diseases, and which will [50] Awaiting Final Transplantation ch as those shown in the preceding illustration have been set out temporarily en masse be found for their indi- to keep them in condition until time can In cold weather and in dry soil the vidual transplantation. seedlings may thus be preserved almost indefinitely, lity and being ready to take retaining their vita on growth when transplanted individually. Nursery Stock LUTHER BURBANK thrive in ordinary soils and under ordinary sys- tems of cultivation. No pampered pets are offered from my grounds for general culture. I would urge any orchardist who operates on a large scale to consider the matter of selecting as far as possible varieties of fruit trees that are more or less immune to disease, rather than to depend on the at best somewhat precarious method of warding off the enemies by spraying. Prevention is better than cure with plants no less than with human beings. But of course the renovator of an old orchard, whose task is at the moment under consideration, must work with the materials sup- plied him and cannot ignore the fungus and insect pests that attack his trees; although by dint of proper grafting he may hope presently to trans- form the character of the trees in such a way as to give them partial immunity. The orchardist of the future will have still better ones in these re- gards. PLANNING A NEW ORCHARD So much for the renovation of the old orchard. I have spoken thus at length on this aspect of the subject because of its obvious importance, and because it aims at the correction of a widespread condition and has to do with the possible restora- tion of properties in the aggregate of enormous value. [52] The Choice of Seedlings To economize space, seedlings may be grown close together during the first few months, until the individuals have revealed their qualities, Then, of course, the weaklings will be weeded out and room given for the thrifty ones to con- tinue growth, This picture illustrates the difference in growth—notably in sturdiness of stem—between two seedlings from the same lot of seeds. It is obvious that the orchardist will preserve the one at the left, as the much likelier fruit- producer. LUTHER BURBANK It takes time to grow a tree, and it is peculiarly fortunate that the would-be fruit grower can se- cure almost anywhere an abandoned orchard that may almost immediately be restored to a condition of productivity. But of course the orchardist who wishes to operate on an extensive scale will not be content with the renovation of an old orchard, however lucrative that process may prove, but will wish to produce a new orchard that may lack the defects of the old one. The ancient tree made over will still retain, in such important matters as height and spread of limb, the evidence that it really belongs to a past generation, however insistently the fruit that its grafted branches bear may seem to belie the evi- dence. But the trees of the new orchard may be trained in accordance with modern ideas; and it is not to be denied that ideas as to tree pedagogy have changed as rapidly in recent years as have the best conceptions of human pedagogy. Take the very important matter of height of tree as a case in point. Not long ago the orchard- ist, in developing a young tree, was careful to see that it was trained in the nursery so that its lowest branches were several feet from the ground. But the well-informed orchardist of today heads his tree in such a way that the bearing [54] Selecting Among Peach Seedlings Here two peach seedlings are shown between which it may be somewhat difficult to decide. The one at the right is somewhat larger and sturdier, but that at the left is much better formed, its branches being upright, growing at the ideal angle of about forty-five degrees. The latter will therefore make better trees, but the one at the right has qualities of color of stem, and of sturdiness that may make its preservation desirable. Two quite different varieties of peach may be expected from these two _ seedlings of the same stock, LUTHER BURBANK branches start only eighteen inches or two feet from the ground. Where formerly high ladders were required to pluck the fruit, a modern orchardist, for a good many years after his trees are in bearing, can stand on the ground and reach the main bulk of the fruit; and even that which falls is not mutilated and bruised as it used to be. Also the trees are much less apt to be broken or blown over by the wind. And in this I am not referring to such “freak” trees as, for example, my little bush-like quinces, scarcely waist high yet almost breaking under the weight of mammoth fruits. I am speaking of the commercial orchard, and have in mind in par- ticular the apple tree, because it is with regard to this tree that the most conspicuous transforma- tion has been effected. Plum trees and peach trees were never very large, but it used to be taken for granted that the apple tree should be of gigantic proportions; so the half dwarf trees on which the best apples of today are grown might seem to the casual observer to belong to a different family of plants from their progenitors. GAUGING YouR CLIMATE As to other desirable qualities, much depends upon the location of the orchard and the market that the orchardist has in view. [56] ON PRACTICAL PLANS It goes without saying that the varieties to be selected must be of a character adapted to the climate and soil of the chosen region. As to this, the restrictions imposed by Nature are more or less familiar to every fruit grower. In general, you may judge to a certain extent from observa- tion of what is already grown in your neighbor- hood as to what kinds of trees will thrive there. The chief restrictions are those imposed by con- ditions of temperature, and of course temperature is influenced not merely by the latitude but by dis- tance above the sea level and the neighborhood of large bodies of water. The presence of moisture in the air has a pro- tecting influence, chiefly in that it prevents radia- tion of heat at night. Every orchardist knows that the danger from frost increases in proportion as the night is clear. The now familiar method of fighting frost by burning brush or oil supplies direct heat, but also supplements this by filling the air with smoke, which retards the radiation of heat. It is familiarly known that seaboard regions have much milder winters than inland regions of the same latitude. Again, inland regions of low altitude, such as the Mississippi Valley, may be adapted to the growth of a fruit that would inevitably winter- [57] LUTHER BURBANK kill if grown on the high plateaus of Wyoming. In general, it may be said that no region at higher altitude than about six thousand feet is adapted for fruit growing. In putting out catalogs of new fruit it is often desirable to state the minimum temperature that a new production will stand. I have done this, for example, in announcing my spineless cac- tus. As to average annual temperature, it may be convenient to recall that there is likely to be a mean annual difference of three degrees for each hundred miles of latitude. Thus, for example, the mean temperature at the southern line of Iowa will be found to be about three degrees lower than the mean temperature at the northern line; and this difference might, in case of a given fruit, make it folly to plant in northern Iowa a fruit that might live in the southern part of the state. As already pointed out, however, one of the main objects of the plant developer today is to produce hardy varieties, and doubtless it will be possible in the future to grow most varieties of or- chard fruits in regions that are now regarded as lying wholly beyond the northern limits of their — possible culture. Stupyinc Your Market Of course the proximity of the market is an item of chief importance. Yet the experience of [58] vie, Combining Young Orchard and Berry Field This picture illus- trates the possibility of economizing space and labor by planting vines of the blackberry or rasp- berry between the trees of a young apple orchard. The vines come into bear- ing and produce a lucra- tive crop during the years when the apple trees are making their early growth, and are as yet un- productive. LUTHER BURBANK the California plant developer may be cited as showing that nearness to market is by no means an absolute essential. For of course it is well known that the California fruits are now chiefly grown for shipment to the Atlantic seaboard. So nearness to a railroad is even more important, as hauling fruit for any great distance before it is packed for eastern shipment is a great detriment to its shipping and keeping qualities. Except in a few cases, like that of the prune, it is always necessary for the California plant developer to consider the shipping quality of his fruit. A fruit to be shipped a long distance must be of firm flesh, a good color, and a reasonably tough skin. And especially it should be uniform in size and of such shape as to admit of econom- ical packing. Moreover, it should ripen at a season when the same kind of fruit is not abundant in the distant market. So it may happen that a fruit otherwise valu- able may lack this essential marketing quality, and hence must be avoided. This is the reason why my Abundance plum is not so popular in Cal- ifornia as it is in the Eastern States, as it will not stand a long shipment so well as other varieties. To the eastern fruit grower this is not important, as he lives near the market. But from the Califor- nia standpoint, such plums as the Wickson, the [60] ON PRACTICAL PLANS Burbank, the Formosa and the Climax, all of which are excellent shippers, are generally preferred. The advantages of entering the market at a particular season are illustrated by the Burbank cherry, which ripens so early that it reaches the eastern markets when almost no other fruit is on hand. The fact that these cherries often bring two or three times the market price to be secured a few weeks later shows the practical importance of this detail. Another seemingly minor point that the pro- spective orchardist should not overlook is the question of the color of the varieties of fruit he is to select. Color is one of the most important char- acteristics of the fruit from the market man’s standpoint. The purchaser at the fruit stand will very generally pick out the highly-colored fruit without considering its quality. The prospective fruit raiser should bear this in mind in selecting his stock. THE ORCHARD SITE In dealing with an old orchard the fruit grower must obviously take the trees as he finds them. But in developing a new orchard he should give very careful attention to the exact topographical conditions. The matter of drainage of the soil is important, and also the question of exposure to the sunlight and wind. (61] LUTHER BURBANK If your orchard site slopes toward the south, and does not lie in the shade of mountains nor where it is subject to the equalizing influence of a large body of water, the trees are likely to be so stimulated by the nearly perpendicular rays of the sun as to blossom before the time of the last frost. Early blossoming might at first thought be consid- ered an advantage; but in point of fact it is a gen- eral rule that plants which blossom early ripen their fruit late, whereas those that blossom late are usually early ripeners. The obvious explana- tion is that the trees that flower late and ripen early have had to adapt themselves to short sea- sons. The wisdom of their course is emphasized when we see the early blossoms of trees on a southern slope cut off by a late frost, while trees otherwise situated in the neighborhood have not yet come to blooming time. The danger of entire loss from late frosts may be obviated, however, by the selection of varieties that will mature fruit even after the blossoms have been frozen. I have developed such varieties of fruit trees in a number of instances. There are also varieties that have a long blooming season, and these may be depended upon to put forth new blossoms even if the earlier ones were blasted. But in general it is desirable to select a variety of [62] Orchard and Vine Field This picture shows a nearer view of the orchard shown in the pre- ceding picture, the first view being taken when the apple trees were two years old. it will be seen that the apple trees are now attaining a fair growth, yet that there is still am- ple room for the berries. If the apple trees are of the modern type, and are kept well pruned, the combination of vine, field and orchard may be per- manent, provided the ap- ple trees are not planted too close together. LUTHER BURBANK tree that naturally blooms late enough to avoid these frosts. This is especially important in view of what has just been said about frosts waylaying trees on a southern exposure, because precisely such ex- posure is of value at the other end of the season, to hasten the ripening of the fruit. This is not only important in the case of fruits designed to meet an early city market, but it applies to many varieties that tend to ripen late in the fall and which thus may suffer from the early frosts of autumn. It should be recalled that the warm southern exposure also tends to take the moisture from the soil early in the season, so varieties planted in such a location should be able to resist drought. Trees planted on a hillside will probably have natural drainage. Otherwise it may be necessary to drain the soil with tile or with open ditches, or else to select varieties of fruit that are known to thrive in a moist, cool soil. Such varieties must necessarily have an unusually large leaf surface and shallow root system. For this reason they should not be placed where they are subject to heavy winds, What may be called air drainage is sometimes quite as important as water drainage. Cold air flows down the hillsides and settles in the valleys. [64] A Typical, Regrafted, Rehabilitated Apple Orchard The trees here shown were not orig- inally of the best varieties, but by rigorous pruning and regrafting, they have been brought to approzi- mately ideal shape, and made to bear fruit in pro- fusion. of the finest quality. Early-Bearing Peaches The peaches here shown illustrate the possibility of remodeling an old peach orchard by grafting. This bunch of luscious fruit was borne on a cion only two years old, grafted ona tree that otherwise would have borne fruit of inferior qual- ity or no fruit at all. There are thousands of aban- doned peach orchards that might be rejuve- nated by proper grafting. ON PRACTICAL PLANS So the bottom of a valley is a very poor place to plant fruit; except, indeed, in certain canyons or gulches where there is a steady current of air in. motion throughout the night. In general, the or- chard site should be on a hilltop or hillside, or at least at an elevation above the lowest land sur- face in the neighborhood, unless the valleys are either naturally or artificially well drained. Without attempting further details in this place, enough has been said to show that there are almost numberless points to be considered by the up-to-date fruit grower in the development of a new orchard. What has been said will supply clues that the thoughtful orchardist may readily follow up. As to the specific fruits, further details, with particular reference to the practical aspects of the subject, will be given in succeeding chap- ters. —"In several cases,” says the Ohio report, “a net profit of $400 per acre has been secured from an abandoned orchard.” Mr. Burbank’s 400 The picture gives a direct glimpse into the foliage of the large cherry tree at Sebastopol on which Mr. Burbank has grafted more than four hundred different varieties of cherries. Prac- tically every branch here shown bears a different kind of cherry, and nearly all are of superlative quality. A single tree thus treated becomes in itself an orchard. DOUBLING THE PRODUCTIVENESS OF THE CHERRY More AND BetrerR CHERRIES HEN I chance to see mention in the \V \V newspaper headings of the doings of New York’s celebrated Four Hundred I am sometimes reminded of the Four Hundred of Sebastopol. The particular Sebastopol that I have in mind is the place where my fruit farm is located, about seven miles from Santa Rosa. By the Four Hun- dred of Sebastopol I mean a very aristocratic colony, comprising four hundred families of pedi- greed cherries, that are colonized on a single big tree in my cherry orchard. I could speak only from vaguest hearsay as to the lineage of New York’s aristocratic coterie, but may claim to discuss the pedigrees of the Four Hundred of Sebastopol with final authority. And I can vouch for the blueness of blood, so to speak, of every one of them. [VotumE [V—Cxapter IIT] LUTHER BURBANK That there are about four hundred families in my patrician cherry colony is a matter of acci- dent, quite uninfluenced by any thought of imita- tion. It chances that year by year the process of elimination about balances the process of addition to the family, and the census of the colony is not greatly altered. Reference has been made in various earlier chapters to the origin and development of the patrician cherries. They are closely related as to their remote ancestry, as I suppose is the case with the members of every other aristocracy. Yet, as we have seen, the ancestral traits are variously blended in the different families, and there is notable diversity among them as to individual traits. Some of them bear fruit that is vividly red in color, others fruit that is pallid; and there are corresponding divergences as to flavor, free- dom of stone, sugar content, and all the rest of the complex characteristics of a well-bred cherry. Of course these qualities are variously re- combined in the progeny of each new generation. So I can never tell what surprise is in store for me when I raise seedlings from the fruit. And there are always new additions to the colony that will only come into bearing next sea- son or the season after and reveal what they hold in store. [70] Some of the 400 Come to Judgment This picture shows a few of the several hundred varieties of cherries plucked on the same day from the same tree, and laid out for Mr. Burbank’s examination and selection. As new com- binations are effected each season through cross-pollenization, there are always unique varieties to be found on the tree each June-time, and these new varieties, may, of course, be perpetuated by grafting. LUTHER BURBANK Thus it chanced that in the season of 1908 I found among the cherries one that bore quite the largest fruit I have ever seen; fruit, moreover, of the most inviting color and having qualities of flesh to match. Cions from this new stock will be sent out and will in due course colonize many an orchard with a new variety of fruit that is sure to find great favor. But if I thus from time to time have pleasant surprises, I am also too often chagrined to find among my patrician cherries offspring that seem unworthy. But of course one hears of black sheep among the scions of even the noblest families, so it is not surprising that the blueblood cherries of Sebastopol offer no exception. And as the black member of any human family is always held up as a warning example, I have thought that I might in the same way make the black sheep of my cherry colony serve a useful purpose by explaining somewhat in detail the rea- son for their appearance. In so doing I shall be able, perhaps, to make a somewhat clearer exposition than has hitherto been attempted of certain aspects of heredity that are peculiarly important from the standpoint of the practical plant developer. Uprer CASE QUALITIES We have learned something in earlier chapters [72] South American Cherries Much of Mr. Burbank’s success has been due, as the reader is aware, to the hybridizing of plants brought from different geographical localities. This picture shows a South American cherry that has been used in the course of the crossbreeding and hybridizing experiments through which Mr. Burbank’s many varieties of perfected cherries have been developed. It will be seen that the South American cherry differs quite widely in appearance as well as in the foliage from the ordinary cherry of the northern hemisphere, LUTHER BURBANK about unit characters and the way in which they are blended or mosaiced together to make up the personality of any individual plant. It will be recalled that where the two parents of a given individual have opposing qualities as regards a given characteristic—where one, let us say, is black and the other white—it is quite the rule for one quality to dominate the other in such a way that the offspring precisely resembles, as regards that quality, the dominant parent—in this case the black one—and resembles the other par- ent seemingly not at all. And we have learned also that the latent or recessive character that is thus subordinated—in this case whiteness—will reappear in a certain proportion of the offspring of the succeeding generation. Now, it has been found convenient by recent experimenters to adopt a graphic method that will make the printed accounts of their experiments more readily comprehensible. The expedient in question is the simple one of using a capital letter to designate the dominant factor of any pair of unit characters, and a corresponding lower case or small letter to designate the recessive factor. Letting “D,” for example, stand for the domi- nant trait of blackness in the illustration just given, and “d” for the recessive trait of white- ness, we may concisely state the facts of inher- [74] The Catalina Cherry This cherry grows in the Catalina Islands, Southern California. It: defect is the very large stone and the very smalt relative quantify of pulp. Probably, however, the fruit may be improved by selective breeding. LUTHER BURBANK itance as just noted in the following formula: Parent “D” being mated with parent “d,” the offspring, whether few or many, bear in each in- dividual case in their germ plasm the factors “D” and “d” in combination. But if two of these off- spring are interbred, there will be a splitting up of the factors and re-combination in such wise that in any average group of four of their progeny the result will be this: One member that is pure dom- inant (DD), two members that are mixed dom- inants (Dd), and one member that is pure re- cessive (dd). The DD individual is “homozygous” for dominant factors and will breed true to black- ness. The dd individual is homozygous for the recessive factors and will breed true to whiteness. The two Dd individuals are heterozygous for the color factors, and whereas they are individually black their offspring will repeat the formala 1 DD + 2 Dd + 1 dd; they will reproduce, in other words, the conditions of the second filial genera- tion itself as just analyzed. Let me re-state all this, using only the letters, to show the convenience of the formula and at the same time to fix it in memory: D mated with d in the first generation gives us Dd + Dd + Dad, etc., in the second generation. Dd mated with Dd gives us in the third generation 1DD + 2Dd + 1dd. [76] Some Curious Short-Stemmed Hybrids These black cherries, it will be observed, have the pecu- liarity of growing on exceedingly short stems. Such variations as this are observed in many hybrids, and of course they give oppor- tunity for selection, through which permanent varieties are developed. Shortness of stem, however, in the case of the cherry is a merit that must not be carried too far, lest the cherries crowd each other too much in the bunches, LUTHER BURBANK If this is not absolutely clear, you will do well to re-read the above paragraphs, and it is quite worth your while to consider the matter somewhat attentively. If you have only theoretical interest in plant breeding you should be concerned in the matter no less personally, because the same laws of hered- ity that are about to be illustrated apply with full force to all life, including human offspring. If, on the other hand, you have thought of un- dertaking some experiments in plant developing, which I hope is the case, it is doubly important that you should get the full significance of these simple formule. Like other formule, they are devised solely for convenience in promulgating ideas. As used in the following illustration, they will make it possible to present vividly the case of our black-sheep cherry, and through this to clarify a large number of obscure cases that must prove very puzzling to the novitiate in plant develop- ment. EXPLAINING THE BLACK SHEEP Let us now stake our way, as it were, with the aid of the upper-case and lower-case letters, along the line of a series of plant experiments through which a certain patrician cherry was developed. To avoid complications and to escape getting into a tangle of ideas and a maze of letters, let us con- [78] ON THE CHERRY sider only a single quality in detail, keeping in the background of our minds the idea that the actual experimenter is at all times considering almost innumerable other qualities as well. The one quality that we will consider at the moment is, let us say, the matter of size. We wish, for some special purpose, to develop a cherry that shall be a giant among cherries, yet which of course shall combine size with quality. Now we have at hand a cherry that bears very large fruit of poor quality. We have also at hand a tree that bears small fruit of delicious quality. Our first step will be to transfer pollen from the stamens of one of these to the pistils of the other. We carefully mark the limbs bearing the hybrid- ized flowers; and subsequently we gather the fruit and save the seed and in due course plant it and nurture the seedlings by methods hitherto fully explained. So when a year and a half has passed from the inauguration of our experiment we have a row of hybrid seedlings ready for grafting. The one thought that is uppermost in our mind, for purposes of the present exposition, is that of securing a plant that will bear fruit of large size. Now we have learned that there are certain cor- relations of parts that will enable the plant ex- perimenter to predict, from the quality of the [79] LUTHER BURBANK seedling, a good many things about the quality of the fruit it will subsequently bear. Utilizing this knowledge, we pass along the row of seedlings and select from among the thousand or five thou- sand individuals the ten or twelve that seem to us to give greatest promise. Nor at this particular stage of the development is the selection very diffi- cult, for the first generation hybrids usually show no very great tendency to variation. That ten- dency is revealed in subsequent generations, as we have seen. In point of fact, as a moment’s reflection will tell us, the seedlings before us are really all of one quality as regards the particular characteristic of their innate tendency to bear large or small fruit. One of their parents bore large fruit; the other bore small fruit. If, then, we assume that here, as in many other cases of plant breeding, the quality of largeness is dominant to the quality of small- ness, it may be expected that all the hybrids of the first generation will tend to bear large fruit. If, introducing our convenient system of sym- bols, we designate the dominant quality of big- ness with the letter B, and the recessive quality of smallness with b, we may designate the mem- bers of the hybrid generation as all being mixed dominants, each bearing the factors Bb. This means that the factor B dominates the factor b, [80] Botan and Black Giants, Side by Side The two types of cherries are shown here together, that their similarities and differences may be seen at a glance. The Black Giants represent one of the newest varieties developed by Mr. Burbank in his famous colony of four hundred. LUTHER BURBANK and that the individuals in question will all bear large fruit. So we may expect (on this assumption), having grafted our selected seedlings, that each of them will show, two or three years hence, fruit of large size. But of course the other qualities of this fruit will not be all that we could desire, so it will be necessary to continue the experiment. Suppose we do this by cross-pollenizing differ- ent members of the same group. We shall thus mate Bb with Bb. And the result of this mating, as we know, will be to produce, in each group of four, one BB individual, two Bb individuals, and one bb individual. Being interpreted in terms of our actual row of seedlings, as they stand in our orchard in this, the fourth or fifth year of our ex- periment, this means that in every lot of four. thousand seedlings one thousand are pure domi- nants as regards large fruit, two thousand are mixed dominants, and one thousand are pure re- cessives. But now comes a very tangible and very prac- tical complication. As regards their external traits, and as regards the fruit that they will indi- vidually bear, the one thousand pure dominants (BB) and the two thousand mixed dominants (Bb) are identical. There is nothing in their exterior [82] ON THE CHERRY appearance, and there will be nothing in the ap- pearance of their fruit, to indicate which of them contain only the factors of dominance (BB), and which contain the recessive factor combined with the other (Bb). Yet for the purpose of future ex- perimentation, in which we shall be obliged to call on succeeding generations, it makes a vast differ- ence which individuals are selected. We are well aware of this as we walk along the row of our seedlings, but we are also aware that there is no method by which we can fathom the secrets of the germ plasm of our seedlings, to determine which are BB and which are Bb stock— save only the method of future breeding. In spite of our best endeavors it may very well happen that the ten or twelve seedlings that we now select, to be grafted for the continuance of our experiment, include not a single pure domi- nant (BB), but are made up exclusively of mixed dominants (Bb). We have seen that the latter are twice as numerous as the others, and that the two look just alike; therefore the chances are two to one that they will be chosen in the majority, and it will not be strange if they are inadvertently chosen to the exclusion of the others. Yet this choice will insure that the factor of smallness which we are striving to eliminate was carefully preserved in the germ plasm of the [83] LUTHER BURBANK cions of this second generation that we now graft into membership in the aristocratic cherry colony. And when, after another interval of two years, these cions come into flower and are mutually cross-pollenized, the seeds they bear, being the off- spring of mixed dominants (Bb x Bb), will pro- duce a generation of seedlings precisely repeating, as regards the quality under consideration, the formula of their parent generation. In a given lot of four thousand, let us say, one thousand will be BB, two thousand will be Bb, and one thousand will be bb. And precisely the same difficulty in selection confronts the experimenter that confronted him before. If he could only know which are the pure domi- nants and which the mixed one, all would be well. But not only is it impossible for him to know this, but he may not be able even to determine with certainty, from examination of the foliage of the seedlings, which ones belong to the group of three thousand that bear the dominant factor (either BB or Bb), and which to the group of one thousand that bear only recessive factors (bb). It must be borne in mind that the experimenter is really considering a large number of qualities, and it must be understood also that there may not be any clearly established point of correlation [84] Mr. Burbank’s Abundance Cherry This is another of the comparatively recent developments in the famous cherry colony. It is often difficult to find names for the many new varieties that are developed at Sebastopol, but in the present case the word “Abundance” seems almost to suggest itself. It may be added that the cherries taste as delicious as they look. LUTHER BURBANK between the foliage or stem or buds of the seedling and the qualities of its future fruit as regards the matter of size. So it may quite conceivably happen that the experimenter, using his best endeavors to make right selection, picks out for preservation, among the ten or twelve chosen out of the thousands, in- dividuals that (though they have only large-fruited ancestors in the two generations back of them), yet themselves are pure recessives (bb) as regards that quality, bearing no factor of large fruit what- ever. And in that event the experimenter will be con- fronted, after another two-year or three-year in- terval of waiting, with an array of fruit, borne on the branches of his long-nurtured and carefully selected cions, not a single specimen of which is other than insignificant in size. Other good qualities the fruit may have. But in the essential quality that we are keeping under consideration it is utterly lacking. In the matter of size it reverts to the recessive member of its great-grandparental ancestry. And so its telltale progeny, hanging there among the luscious fruits of surrounding branches (of other lineage), are like the black sheep in a patrician family. Not an enheartening experiment, thus far, for the would-be developer of a colossal cherry. [86] Z 4 Branch of 1909 Cherries The number 1909 here refers not to the actual number of cherries, but to the season in which they were first developed. They appeared that year on one of the branches of the famous tree, and they were at once scen to have such qualities as to merit further attention. The branch was therefore multiplied by grafting, and the new variety assured perma- nence. As yet, however, it has not been named. LUTHER BURBANK Yet the case is not really quite so bad as it seems. There is an old familiar saying that “blood will tell,” and our new formula, if properly ap- plied, gives full support to the saying. Making application of it, we may say that the dwarf cherry which we have developed as the re- sult of about nine or ten years’ efforts at the pro- duction of a giant, is after all a thing of quality, even though it lacks one of the qualities that we are seeking. It is a scrub as to size, but it is none the less a thoroughbred as regards a number of other qualities. In the matter of color, let us say, it is a vivid red; it is sweet and appetizing; it is resistant to disease; it will bear shipping, and so on. Nor so Bap as IT SEEMs Indeed, it is not unlikely that, as regards all desirable characteristics but one, our cherries are of such quality that, even in the patrician ranks in which they find themselves, they must be ad- mitted to be “upper crust,” to use a phrase that is said sometimes to pass current in human patrician circles. Or upon reverting to our formule, and therefore to the terminology of the printer, we may say that they are “upper case” as regards all qualities other than size. As to bigness, to be sure, they are pure reces- sives and must be labeled bb; but as to juiciness [88] Other Nameless Seedlings This picture shows some extra early seedlings that are now being given particular attention by Mr. Burbank. They have not as yet reached the stage of development when they will be named and sent forth into the world, but their present appear- ance gives assurance that this is only a matter of time. The reader is aware that Mr. Burbank develops hundreds of varieties of fruit that are in many ways valuable, but they do not meet his tests in all directions, and hence are never in- troduced. LUTHER BURBANK they are JJ; for shipping qualities they are SS; for resistance to disease RR; for hardiness HH; and for productivity PP. That is to say, they are pure dominants for each of these qualities, Their germ plasm requires only an infusion of the dominant factor for bigness and their progeny will prove that breeding does tell. ‘There is a tradition that passes current among dog breeders which I do not vouch for but which suggests a condition so comparable to that of our cherry that I cite it by way of illustration. It is said that the greyhound had been bred so exclu- sively for speed that it developed all the desired speed qualities of a hunting dog, able to overtake any quarry, but lacked the courage to seize the quarry once it had been overhauled. To over- come this defect, so the story goes, some one crossed the greyhound with the bulldog, thus breeding in a strain of courage; and in subsequent generations eliminated all the bulldog traits ex- cept courage by selective breeding; and so gave us a race of greyhounds in which the one missing quality had been supplied. This greyhound legend seems much more plausible to-day, now that attention has been so generally called to the segregation of unit charac- ters, than it formerly seemed. But whatever its truth, the case of the hypothetical greyhound [90] ON THE CHERRY strongly suggests the case of our black-sheep cherry. This also lacks but a single quality. Can we not then breed this quality into our cherry and by remedying the one defect attain our ideal? SOLVING THE DILEMMA Fortunately, yes. This is precisely what we can do, and what the wise plant experimenter will do. We have but to look about in our cherry col- ony and we shall find another family, habiting perhaps a neighboring branch, the fruit of which exhibits in imposing measure the quality of size that our protege of the moment so notably lacks. This big cherry may even be the original domi- nant parent with which our experiment started. But it is a fruit which, although being everything that could be desired in size, is unfortunately quite lacking in color. In spite of its inviting big- hess, it cannot make its way in the market be- cause, even at full maturity, it has the appearance of unripeness. But it is big, and bigness is the thing we are seeking. So we cross-fertilize the flowers of our little cherry with those of this big one. The result is readily foretold. Bigness, as we have seen all along, is dominant, and so the off- spring of this union are individually big. They [91] LUTHER BURBANK are mixed dominants (Bb), to be sure, but that, as we have seen, is something that concerns their descendants rather than themselves. Individu- ally, they will bear big cherries, and that is all that we demand. But what as to the color of our new fruit? Here fortune again favors us. For it is very commonly observed that color of flower or fruit is likely to be dominant over lack of color. So our little red cherry, pure dominant as to color (CC) will stamp its influence in this regard on the progeny; the recessive color factor of the other parent (cc) being subordinated or made latent. In regard to color, as in regard to size, the progeny will be mixed dominants only (Cc). But here again the fact that they have the re- cessive factor (c) is of no consequence, since as we have seen the mixed dominant tangibly pre- sents the quality as markedly as if it were a pure dominant. So when we have raised seedlings of this union of our little red cherry with the big white one, and when we have waited yet another pair of years, we shall finally be rewarded with the appearance on the cions, of fruit that meets our original ideal as to size, is as red as could be desired, and ex- hibits the other good qualities that entitle it to a permanent place in our patrician colony. [92] Some That Have Proved Worthy Here are cherries that have proved themselves of superior quality, yet which have not been named, and which perhaps will never be introduced, They have admirable flavor, but they lack something of the aboundant production that characterizes other of the cherries shown in earlier pictures. This fault will probably be remedied in their descendants, and these cherries will be rep- resented in their progeny. The story of the combination of qualities of different parent forms to produce the ideal cherry is told in detail in the text, LUTHER BURBANK It has taken us about twelve years to accom- plish this result. And even now our new fruit must be propagated by grafting and budding, for it cannot be depended upon to breed absolutely true from the seed. The recessive factors for size and for color, as we have seen, are in its germ plasm; and these will make themselves manifest in the progeny. But so long as we confine ourselves to the method of grafting, we may hold the type of the new variety and spread broadcast our big red cherry with its combination of desirable qualities, with full assurance that, given reasonable condi- tions as to soil and climate, it will reproduce for- ever the qualities of the patrician fruit, the ances- tral history of which we have just traced. INVITING OPPORTUNITIES I have thought that by thus tracing in detail the history of a single experiment, paying heed chiefly to a single quality, but reminding the reader from time to time that other qualities can- not be ignored, we could perhaps gain a clearer notion than would otherwise be possible of the practical steps through which a new form of fruit is developed. It is through such series of experiments, lead- ing sometimes forward and sometimes backward in successive generations, that the four hundred [94] ON THE CHERRY families of cherries of my patrician colony have been developed. No two among the four hundred show precisely the same combination of qualities, but all of them show one combination or another of good qualities. Those that reverted to undesirable ancestral traits have been weeded out. And this is equivalent to saying that the se- lected varieties of cherries represent a fixed stock as regards many of their good qualities. We can- not expect that any given one will reproduce its kind precisely from the seed, for reasons that have been fully explained. But we can expect that there will be a goodly proportion among any company of seedlings from this stock that would produce fruit of excellent quality. In a word, then, these perfected varieties of cherries repre- sent stock that is immediately available for the purposes of further experimentation. What they have accomplished is an augury of still better things that may be expected of their descendants. And so the practical question arises as to what, specifically, are the qualities that the improved cherry still lacks; and as to what particular ex- periments in hybridizing should be undertaken to remedy the defects. The first and perhaps the most important de- [95] LUTHER BURBANK fect that suggests itself is that the newly devel- oped cherries, particularly the sweet ones, lack something of hardiness. They grow to perfection in California, but as yet they are little grown in the eastern United States, and not at all in regions north of Ohio and Missouri. Yet the race of cher- ries, taken as a whole, constitutes a very hardy stock. The wild cherries of the eastern United States grow far to the north and are able to with- stand the winters even in regions where the mer- cury sometimes freezes. It should be possible, and doubtless it will prove possible, to combine the best existing vari- eties of cherry with some of the wild cherries, and thus to develop a race of cherries that will retain the present qualities and introduce additional qualities of hardiness fitting them for growth anywhere in the United States; in fact this is a work in which I am now engaged. The common choke cherry (Prunus Virgini- ana) is a very hardy tree, unusually productive, and almost indifferent as to soil and climatic con- ditions. I have made experiments in the cultivation of this tree, raising thousands of seedlings from fruit of a large, handsome specimen that grew by the roadside near Westfield, Massachusetts. The ex- periments as far as conducted have been satisfac- [96] ON THE CHERRY tory. Of course the fruit of this tree is astringent and almost as bitter as a green persimmon. But the little beach plum from which one of my finest plums was developed, was scarcely of better quality, Perhaps it is not unreasonable to hope that it may be possible to make some such improvement in the cherry, through combination with the choke cherry, as I produced by hybridizing the beach plum with the Japanese plum. In that event, we shall in all probability have a cherry surpassing any existing one in size (be- cause of the virility that the cross with the wild species has given it), retaining the good qualities of the present Burbank cherries, and in addition being so hardy that it would thrive in any soil and in almost any climate. If the choke cherry should fail to prove a sat- isfactory parent, there are numerous other wild species from which to choose. The black cherry of the eastern United States (Prunus serotina), is a tree that grows from Nova Scotia to Florida and westward to Dakota and Texas. It is of large size, and bears a fruit resembling that of a choke cherry in color and appearance, but of less astrin- gent flavor. Then there is a small red cherry, commonly called the bird cherry (Prunus Penn- sylvanica), the fruit of which 1s sour and astrin- [97] 489q ay fo auo MNS 8] pup ‘yupqing “In iq: paonpomu, sate -4ay? 3814 ay} fo auo spm 4 ‘yuvqing jo aupu ay} / s4Daq jDy} suo s} umoys atay Aatayo 10jN3}}410d ay T “‘Buryood sof Adsaya yoap} up 1 Gulypur ‘ursof 409} -quo jsouljp ay] pup ‘azis fo Ajjurzefrun ay} ‘Asrsrayo yuvqung ay} fo az18 abuvy 243 0} Uol;ppD UI ‘ajON ‘uayn} som ydosGojoyd iy} adojaq Juau}jU0s ay} sso19D aojmy ~paddjys uaaq aavy umoys azay sajisaya apnpnoyiod «=a Saliiay) yupq.ing jo xog y ON THE CHERRY gent, but which is not without qualities of virility and hardiness that might make it a valuable hybridizing agent. This is perhaps the hardiest of all cherries. I have seen it growing wild nearly as far north as Hudson Bay, in regions where it is not uncommon for the mercury to fall sixty degrees below zero. The California holly-leaf cherry and the Cata- lina cherry are species that may be available for the development of other desirable qualities—for it is not in hardiness alone that the best varieties sometimes are found wanting; though the species just named are so far separated biologically and physiologically that it may be impossible to com- bine them. Many cultivated cherries, for example, are unable to withstand the warm spring rains with- out serious loss from cracking of the fruit. Some- times almost an entire crop will thus be ruined. Again many cherries are susceptible to blight. A bulletin issued by the State Commission of Hor- ticulture of California lists more than twenty in- sects—leaf hoppers, scales, mites, caterpillars, and borers—that prey more or less upon root or bark or leaf of the cherry tree, or that attack its fruit. Then there are inherent maladies, such as the tendency to overflow and condensation of sap, forming an injurious gum that may induce decay [99] LUTHER BURBANK of bark and wood (called gummosis), to which the cherry is peculiarly liable. Hybridizing with wild species, intelligently and systematically carried out, might produce vari- eties of cherry that would show exceptional re- sistance to insect pests as well as inherent vitality that makes for healthiness in the tree. It has long been my belief that a solution of the problem of protecting our fruit trees from both insect and fungus pests must eventually be found in the development of the qualities that make for immunity of the trees themselves, rather than in the resort to such expedients as spraying and “gasing.” In this regard the plant experimenter may well take a leaf from the note- book of the physician, who has learned that im- munity to disease often depends more upon .the condition of the patient than upon the presence or absence of disease germs. It is possible, furthermore, that the cherry may be hybridized even more widely, and that a fruit differing markedly from any cherry hitherto pro- duced may thus be developed. An inkling of the possibilities in this direction is given by some ex- periments made recently by Professor N. E. Han- sen, of the South Dakota Experiment Station, who has cultivated a variety of wild fruit, called the Sand Cherry, Prunus Besseyi, which is a dwarfed, [100] ON THE CHERRY compact grower, of heavy form and good foliage, and which had previously been put upon the mar- ket as the Improved Dwarf Rocky Mountain Cherry. This native tree has a fruit nearly as large as the Richmond cherry and sometimes of fairly good flavor. The Prunus Besseyi has al- ways been considered a cherry by horticultural and botanical writers. My experiments, however, seem quite clearly to demonstrate that it is more truly a plum. I have had the tree under cultivation for more than sixteen years. The fruits of the original plant were black and bitter, almost as astringent as a persimmon. By combining this plant with various other American and Japanese plums, I produced abundant seedlings, and in 1904 had de- veloped one especially promising variety. The fruit of this hybrid seedling ripens in California about August 10th, and is extremely large for this type. It is globular, and about one inch and a quarter in diameter. The color is pure, deep crimson, with a semi-transparent amber flesh, firm, juicy, and of a rich, sweet flavor, resembling that of the American plum. The tree is intensely productive, even breaking with its own weight of fruit. It has been suggested that this tree gives great promise as an aid in the production of a hardy [101] LUTHER BURBANK type of fruit that will withstand the rigorous climate and conditions of the cold northern plains of Nebraska, Minnesota, and the Dakotas. What has just been said suggests that the fruit is not truly a cherry, yet the botanists seem to feel that it occupies an intermediate station, and is more closely related to the cherry than any other fruit. Such being the case, it should be possible to hybridize this dwarf hardy species with the cherry. The tree has the further valuable prop- erty of being able to grow on dry, barren sands. A hybrid cherry having this characteristic from one of its ancestors might be expected to constitute a fruit that would grow in regions too arid for the existing cherry as well as in regions that are too cold. And this is but one of several lines of pos- sible development that invite the plant experi- menter who will give attention to this type of cherry. To suggest one other line of improvement, it is sufficient to call attention to the familiar fact that the cherry has a very brief season. The Burbank cherry fruits two or three weeks earlier than others, as we have learned in another chap- ter. But even so the total period during which cherries of different varieties are in fruit is very limited. One hears reports of an exceptional cherry tree that fruits a second time in the au- [102] A Large, Late-Bearing Red Seedling The cherry here shown, developed like the others prev- ieusly shown, in Mr. Burbank's celebrated colony, differs from the one specifically called the Burbank, in that it is a very late bearer. The Burbank bears particularly early. It is desirable to extend the cherry season, and this variety has been preserved chiefly because of its lateness, although it has many other desirable qualities, as the picture suggests. LUTHER BURBANK tumn., By the usual process of raising numerous seedlings, or by crossing and selection, a variety having this fall-bearing habit might be produced. The value of such a variety is obvious,—-though the early ripening of the cherry is at present what gives it greatest value,—and it is well worth the while of the amateur to attempt experiments in this direction. The fact that cherry trees of one kind or another grow throughout the United States makes it possible for almost anyone to experiment with this fruit. And the opportunities for improve- ment are especially inviting. --In cherry trees, as in the human plant, “blood will tell.” THE RESPONSIVENESS OF THE PEAR Wuat Has Been Done Is But THE BEGINNING to personify inanimate objects writes to ask which tree among our cultivated ones I regard as the most “human.” And then, without awaiting reply, my corre- spondent supplies the answer: “The pear, of course,” he says with full assur- ance. But when he goes on to state the reasons for this decision, I am not quite sure that his argument carries conviction. Perhaps the most striking bit of analogy that he offers is the fact that a pear tree sometimes fails to reach maturity until it is from fifteen to twenty years old, coupled with the cognate fact that the tree may continue to thrive for three score years and ten or even longer. He cites a good many other analogies, or sup- A CORRESPONDENT who is seemingly prone [Votume [V—Cuapter IV] LUTHER BURBANK posed analogies, to be sure,—the fact that the pear over-rides adversity, as it were, bearing abund- antly in bad soils and when totally neglected; the fact that it grows by roadsides and in dooryards showing a domestic habit and as it were a friendly spirit toward man; and finally, the fact that it responds to attention and proves as receptive and responsive to good treatment as it is resistant to bad. But I am by no means sure that as to most of these traits, and for that matter in regard to any others that might be mentioned, the apple tree is not to be given a place quite on a par with that which the pear can claim. There is no occasion to dispute about the matter, however, for at best such comparisons have no great significance. Let it suffice that the pear and the apple, close cousins as they are, may very well be considered the two orchard trees that are friendliest to man, in the broad use of the word. They have been his associates probably almost from the earliest times when he learned that plants would respond to cultivation. They have gone with him on his chief migra- tions throughout the temperate zone and even well into sub-arctic regions. They have proved themselves adaptable to all soils and nearly all climates; and they jointly pro- [106] Seedling Pears The pear ts a fruit that has been very long under cultiva- tion, and it has developed certain familiar and very individual characteristics. A comparatively few types have become popular and are raised everywhere, But nothing more is necessary than to plant the seeds, to secure seedlings showing the greatest variety as to their fruit. Two aber- rant types are here shown, and nu- merous others are shown in succeeding pictures. LUTHER BURBANK duce a_ ariety of pulpy fruits that stand in a class by themselves and are quite without competitors— or were until the quince came under the hand of the plant developer in very recent times. EarLy MIGRATIONS Which of the twain, pear or apple, was first adopted, no one can say, but it is certain that both were friendly with man even in prehistoric times. There is evidence from the ruins of remote civilization of the Lake Dwellers of Switzerland that the pear was known even in that day. Of course it was familiar to the Greeks and Romans from the earliest recorded periods of history. Long before that it had come out of its central Asian home—if, as is almost certain, that was its original habitat—and had become thoroughly do- mesticated about the Mediterranean. Other branches of the same race had migrated eastward until they found a home in China and Japan. And in these widely separated regions, at the extremes of the largest continent, the two descend- ants of the primitive stock developed, each in its own way, in response to soil, climate, and the di- verse temperaments of the peoples, until the pear of Europe was in many ways a different fruit from the pear of the Far East. But there was one migration made by prehis- toric man in which the pear, apparently, did not [108] The Long and the Short of It No one unfamiliar with practical horticulture would sus- pect that these two pears were grown from seeds of the same fruit. They illustrate the strangely varied hereditary factors that find lodgment in the germ cells of a cultivated fruit. And of course they furnish material for selective breeding through which new varieties may be developed. LUTHER BURBANK accompany him. This was the final stage of the eastward journey of our remote ancestors which carried them across a land bridge, now no longer in existence, between northeastern Asia and the present Alaska, and thus brought them to America. It seems a fair presumption that when prehis- toric man made this final migration he brought the apple with him. At all events, with or without man’s aid, the apple made its way across the bridge that joined the continents. Probably the fact that the seeds of the pear will not germinate when once dried may explain the failure of that tree to come with the forerun- ners of the Indian to the new continent. The seeds of all orchard fruits germinate far better if they have not been too thoroughly dried. But the seed of the pear is peculiarly susceptible to destruction through drying; and if the ancestral pear had the same quality, which we need not doubt, this fact may in itself have been instru- mental in restricting the spread of a tree which, when introduced in America in modern times, proved thoroughly adapted to our soil and climate. We must not press this point too far, however, for the plum seed also dies if dried; yet the plum came to America in prehistoric times along with [110] ON THE PEAR the apple. And, for that matter, we shall see else- where that there is another possible interpreta- tion of the story of the prehistoric migrations of the trees. Be all that as it may, the pear retains to this day evidence of the inherent need, in the interest of its race, that the seeds borne at the heart of its fruit shall be preserved in a moist condition. The skin of the pear, except in the most re- cently modified varieties, is firm and thick. It is of a green or mottled yellow color calculated to protect if from the observant eyes of birds and animals rather than to attract them. It has been assumed that the eatable pulp that surrounds the seed was designed by nature—that is to say, de- veloped through natural selection—for the pur- pose of attracting animals and birds, that these creatures may aid in disseminating the seed. But the case of the pear, in common with that of the wild crab apple, suggests that the chief purpose of the fruit-pulp is to keep the seeds moist through the winter. As a further aid to this, and in token of the moisture-loving quality of its seeds, the skin of the pear is fortified by a deposit of woody cells at its inner surface that give it a gran- ular or even gritty texture. This unique quality of the fruit may even ex- tend to the pulp itself, especially with the more [111] LUTHER BURBANK primeval forms, giving the pear a texture different from that of any other fruit. This unusual habit of depositing wood cells in the fruits, aside from the seed case itself, is-no longer of use to the cultivated pear; but the fact that it tends to be retained shows how important a part it bore in the struggle for existence of the pear’s remote ancestors, But let us put aside theories as to the remote history of the pear and consider the fruit in its modern relations. The significant thing to bear in mind is that in our day the pear is represented by two races, obviously related, yet quite as obviously long sep- arated, one of them finding its home in Europe and (since the Discovery) in America and the other being indigenous to eastern Asia, the two having thus migrated in opposite directions, circling the earth, and finally meeting on the Pacific Coast of America. And the fact that these two races of pears have thus diverged, yet still retain the capacity to hy- bridize, is an all-important one from the stand- point of the fruit developer. This fact is, indeed, the basis of the newest progress in the development of the pear, and it gives the augury of still more important develop- ments probably to take place in the near future. [112] Broad and Sturdy Types These are seed- ling pears of another type, although originated from the same_ source. They have qualities that make them worthy of preservation for further breeding experiments, but on the whole they have not been thought worthy of introduction. LUTHER BURBANK It is only fair to recall, however, that the new beginnings in the development of the pear took place in western Europe independently of an ori- ental alliance. New BEGINNINGS IN EvROPE The pears of to-day, as known in the eastern United States, and for that matter most of the finest Californian varieties, are the bearers of an impulse to development that was given by a French horticulturist, Jean Baptiste Van Mons, and Andrew Knight of England about a century ago. Van Mons acted on a theory, now aban- doned, that young plants produce the best prog- eny. But this led him “to sow, to re-sow, to sow again, to sow perpetually.” And he selected his seeds with such care as to develop many improved varieties. In particular, he taught some pears to bear fruit in three years from the seed. Van Mons produced by selection about four hundred new varieties of pears, among others a dwarf variety that was a prolific bearer. Meantime, however, the pear was making its way in America, and one of the most famous va- rieties, the Seckel, originated in the early part of the nineteenth century on the farm of a man whose name it bears near Philadelphia. This was a “spontaneous” variant or mutant, the precise origin of which is unknown. [114] Introducing Color Here are pear seed- lings that not only show wide diversity of form, but almost equally wide variation in color. It kas previously been point- ed out that the pear usu- ally lacks color. Here, obviously, particularly in the specimen shown in the center, is opportunity for the development of pears, having richly col- ored skins like those of the apple. Mr. Burbank’s experiments in this direc- tion have already had interesting results. LUTHER BURBANK At the time of its origin the Seckel was pro- nounced by the conservative London Horticultur- ist Society to be superior to any European variety of fall pear then known. Rather curiously it chanced that the next very notable step in the progress of the pear also took place on a farm near Philadelphia. The owner of the farm was Mr. Peter Kieffer. The thing for which he was responsible was the introduction of a pear bearing his name, which originated through the chance hybridization of a pear of European strain with the Chinese sand pear, which had been introduced as an ornamental garden tree not long after relations were established between America and the Far East. The oriental pear which thus at last came to mingle its racial strains with those of this remote relative, after the two had traveled around the world in opposite directions, was a graceful tree having large and attractive flowers and bearing fruit of a pleasing fragrance but of such consist- ency as to be almost uneatable except when cooked. In spite of the defects of its fruit, how- ever, the oriental pear had certain qualities of hardiness and resistance to disease that made it a valuable mate for its European cousin. So the Kieffer pair soon gained popularity. So also did a number of other hybrid pears of [116] Diversified Colors Although of the same heritage, no two of these pears show char- acteristics suggesting close relationship. Of the four, the one at the right is in some respects the most in- teresting, owing to its cu- rious segregation of the different color pigments. The progeny of the seeds of this pear may be ez- pected to show green indi- viduais and red individ- uals, as well as those of various degrees of mottling. LUTHER BURBANK similar origin, including the Le Conte, the Garber, and the Smith. These hybrids soon became stand- ard pears in the Gulf States, where the European pears do not thrive. MAMMOTH Pears IN CALIFORNIA The hybrid pears did not gain popularity in California, because the climate and soil of this state seemed to be peculiarly hospitable to the European pears, notably the Bartlett. By crossbreeding and selection these have been so developed, without hybridization with the oriental species, as to assume almost colossal pro- portions, and while differing widely in flavor from the original stock, to retain enough characteristics of the original to constitute a most valuable mar- ket fruit. The California pears, indeed, have quite out- done themselves. They have been described as “grand in size, delicate in color and aroma, and of unsurpassed richness.” A specimen has been re- ported that was “nine inches high, sixteen inches around the base, and five pounds in weight.” Pears of allied varieties show scarcely less notable tendency to grow to unprecedented size; for example, five Vicar of Winkfields are reported as weighing four pounds, eight ounces; nine Easter Beurre as weighing 2414 pounds, the heaviest sin- gle specimen weighing 234 pounds, and the like. [118] ON THE PEAR In the mere matter of size, then, there remains little to be desired; but there are other qualities as to which not so much can be said. In particu- lar the pear is often susceptible to disease, and in gencral the extreme development of productivity has been more or less associated with a tendency to lose vigor, rapidity of growth and general vitality. For this and sundry other reasons it seemed to me that it might be desirable to make further experiments in the blending of the oriental and occidental heredities. So as early as 1884 I made importations of the seeds of the Japanese pear. In a shipment containing loquats, plums, chest- nuts, persimmons, gooseberries, blackberries, peaches and raspberries, I received also twenty pounds of pear seeds. The seedlings were grown, but at first little use was made of them except as grafting stocks. The valuable developments that ultimately came from the introduction of the oriental hered- ities were not secured at the outset. TRAITS OF THE ORIENTAL PEAR About 1890 I imported from Japan large quan- tities of the seeds of the Chinese sand pear. The seedlings proved extremely variable. Some of them grew six or seven feet the first year, while others from the same lot of seed, under exactly [119] LUTHER BURBANK the same conditions, grew only a few inches; and a corresponding rate of growth characterizes the seedlings as long as they live. But, although the seedlings themselves proved so variable, their fruit was singularly uniform in size and quality. As to shape, the fruit of the oriental pear is usually oblate, approaching the globular. This raises a rather curious, if not very important, question as to whether the European pear owes its very characteristic shape to artificial selection. The ordinary pear, as everyone knows, has a form that is so individual and so little duplicated, that no single word of familiar usage describes it. In this regard, as in a good many others, the pear is unique. One would not commonly think of describing anything as “apple-shaped,” or “peach-shaped,” or “plum-shaped,” but “pear-shaped” is a cogno- men that is at once convenient and definitive. So, as I said, the fact that the oriental pear has not assumed this shape has a certain interest and suggestiveness. The hybridizing experiments that were begun as soon as I was in possession of the oriental seedlings called for more patience, perhaps, than almost any other tests that the fruit experimenter can make, for the very obvious reason that the pear is the slowest to mature of all the fruits grown [120] A Patrician This seedling pear has qualities of form that entitle it to a special consideration. It has also good qualities of flesh, but, as will be seen, it is quite lacking in richness of color, except just about the stem, where there is a splash of red that suggests submerged hereditary color factors that might be brought to the surface by selective breeding. LUTHER BURBANK in temperate climates. It often requires from ten to twenty years for seedlings of the pear to come to their first fruiting. The matter may be forced a little by grafting the pear cions on quince stock, but while this makes them fruit earlier, it also tends to dwarf them, and I do not recommend this as a general practice, though highly desirable for special purposes. Whoever has not patience to wait had best not undertake experiments with the pear. With a tree of such slow development, it is peculiarly desirable to make no mistakes in select- ing seedlings for preservation. Judgment as to the future tree must be based, as with other fruit, largely on its growth, and the appearance of the foliage. Pear seedlings that have an abundance of large leaves, and strong, thick, short-jointed wood, and thick, fat buds, are those to be selected. But this is not by any means as sure an indication of superior fruit in the pear as in most of our cul- tivated fruit, for the reason that Van Mons and other workers in this line have mostly sought early-bearing and fine quality of fruit, neglecting the foliage and growth of the tree almost fully. Tue EFrrect or NEw BLoop I grew great quantities of pear seedlings from seed imported in 1884 from Japan. The selected seedlings of this original stock have enormous, [122] ON THE PEAR glossy leaves, some of which for weeks after the first frost show varied and brilliant colors almost like the autumn foliage of oaks and maples of the Northeast. Many of the best of these were dis- tributed for planting as ornamental trees. Very early in the experiments I found among many seedlings of a cross between the Bartlett and the hybrid Le Conte one that seemed to have exceptional qualities. This proved to be aston- ishingly productive of fruit of the largest size and best quality, and the tree had extraordinary vigor of growth and was apparently immune to the blight. But only one was selected as showing good promise as a fruit bearer. Through further hy- bridization and selection, during a period of near- ly a quarter of a century, the hybrid progeny of this Japanese pear developed a variety that was introduced in 1911 as the “Test.” Year after year it had produced two or three times as much as any other pear that I had ever grown. The fruit averages rather larger than that of the Bartlett, and it appears about four weeks later. The flesh is similar to that of the Le Conte but superior to it in quality, although hardly comparable to that of the Bartlett except when cooked. Although I have raised and fruited number- [123] LUTHER BURBANK less seedlings from a great variety of crosses, and have noted many variations, the Test is the only one that I have thus far thought worthy of intro- duction. Several hundred three-year-old seed- lings of this new pear, grafted on quince stocks, give great promise by their vigorous, compact growth, heavy foliage and full, round buds. Among those that have fruited are some mam- moth pears of exquisite quality when cooked; and a few are good when fresh. There is unusual variation in growth of wood, foliage, season of ripening, form, size, and quality of fruit. Some of the hybrids have a smooth, pol- ished skin with red cheeks; others are russet throughout. The varying qualities of the hybrids are doubtless due to the releasing of latent char- acters brought about by the commingling of the two widely diverse strains. It was necessary thus to hybridize and select through successive generations, because the ori- ental pear brought to the combination very unde- sirable qualities of fruit as to texture and flavor. Only when these were eliminated from later gen- erations, and the qualities of the Bartlett and its allies substituted, did the hybrid pear become a commercial possibility. But, along with its undesirable qualities of fruit, the oriental pear brought other qualities [124] Unhandsome but Luscious This seedling pear shows a tendency to depart from the typical pear shape, being much broader at the base, and corre- spondingly less graceful, than the favorite varieties. It has, however, qualities of flesh that commend it, but these were not considered by Mr. Burbank to be sufficiently exceptional to war- rant the introduction of. the fruit. LUTHER BURBANK that were pre-eminently desirable. First and fore- most it had fundamental vigor of constitution that -_promised to supply precisely what the European pear most lacked. This was manifested not only in the vigor of its growth, but in its seemingly al- most entire immunity to the attacks of the disease that has been the scourge of the pear growers of America for more than a century, and which made its appearance in California about ten years ago, the disease known as the pear blight. THe Pear TREE ScouRGE To appreciate the importance of this element of resistance to disease, as manifested by the ori- ental pear, it must be understood that the blight is a malady of such virulent nature that when it attacks the pear tree it very commonly results in killing it outright. This suggests, obviously, a pe- culiar susceptibility on the part of the pear. Such susceptibility is manifested, unfortunately, in ex- ceptional measure by the best European varieties, including the Flemish Beauty and the Bartlett. This, presumably, is the penalty of over-specializa- tion in a certain direction, or unbalanced selection. Until very recently the cause of pear blight was much disputed, but the agricultural experiment stations have now furnished conclusive proof that it is a bacterial disease, due to the presence of a germ that has been named Bacillus amolovorus. [126] ON THE PEAR This germ has close cousinship with the vari- ous tribes of bacilli that cause the contagious human maladies. And there is a curious resem- blance between the assault of the microbes on the pear tree and the corresponding assaults of cer- tain bacilli, for example the diphtheria bacillus, on the human organism. In one case as in the other, the bacilli, once they find a lodging place, multiply inordinately and give out excretions that are virulently poisonous. Located on the flowers and fruit of the pear, or finding their way to the inner bark or cambium layer of the tree, they multiply prodigiously and exert a malignant in- fluence that withers blossoms, blights the fruit, and causes the leaves to take on a bronzed red hue that is often premonitory of the death of the tree. If they find lodgment in the cambium layer of the trunk, they may spread rapidly in every di- rection, until they girdle the tree, shutting off its supply of sap as effectively as if it had been girdled with an axe. Wherever lodged, the colonies of bacilli may be located by the oozing out of a milky or dirty brown sticky liquid when the spring rains come. This liquid is attractive to insects, and as the feet and bodies of these marauders become covered with the germ-laden fluid, the transfer of the [127] LUTHER BURBANK germs to other trees and to flowers and fruit even fairly remote is thus assured. Not merely flies and gnats, but the bee itself may have a share in thus transporting the contagion from one tree to another till it infects every tree in the orchard. The nectary of a pear, which the hee may in- advertently inoculate, furnishes a most favorable medium for the multiplication of the bacilli, Thence they work their way from the fruit buds to the limbs. Once they gain access, through the links in the tree’s armor furnished by the buds, to the cambium layer of the inner bark, there is nothing to prevent the indefinite extension of their colony. A tree thus inoculated may soon take on the appearance of a tree scourged by fire. Indeed, the malady is sometimes spoken of as “fire blight.” ANTISEPTIC SURGERY IN THE ORCHARD The measures taken by the horticulturist to save his tree when thus attacked are curiously suggestive of the methods of the modern surgeon. Infected limbs must be amputated; local areas of infection in the bark or trunk or large branches must be thoroughly excised, including a goodly portion of healthy wood and bark to make sure of the removal of every microbe. Large wounds are then carefully disinfected with a sponge or bunch of waste soaked in kerosene or in a solu- [128] Dissimilar Twins These seedling pears are full sisters, not- withstanding their extreme dissimilarity of appear- ance. They illustrate the curious segregation of characters —in this ease the color of the skin—in organisms of mixed her- ifage. It is obvious that the pear at the right has qualifies of color that the plant developer is sure to seize upon. LUTHER BURBANK tion of corrosive sublimate, one part to the thou- sand, It is merely antiseptic surgery applied to the tree to combat a microbe closely similar to the ones that are man’s most malignant enemies. But, of course, such measures as these, how- ever necessary, can by no means be regarded as solving the problem of the pear blight. Just as the surgeon of to-day attempts to prevent the in- trusion of the germs, rather than to depend on killing them after they appear, so the orchardist must hope to find a means of preventing the blight instead of being obliged to practice such heroic and wasteful curative measures. One measure looking to this end that has been suggested is the destruction of old hawthorne and wild crab apple trees and of abandoned pear and apple trees in the neighborhood of the orchard, since a single infected tree would prove a source of danger to every tree within a radius of a mile or more. Such measures are important; but they do not go to the root of the matter. The real solution must come through making the tree immune to the attacks of the germ. This is the keynote of preventive medicine with the human subject to-day, as illustrated by the vaccine treatment, of which the most familiar example is [130] More Misfits This picture shows seedlings of the same heritage that illustrate the extremes of form, some- what as the preceding pic- ture illustrated extremes of color. The figure at the right shows the ideal pear shape, upon which tradition has set its seal of approval. Mr. Burbank feels that the ideal pear should retain this shape, in deference to the taste of the public. LUTHER BURBANK Sir Almroth Wright’s inoculation for the preven- tion of typhoid fever. It is at least within the pos- sibilities that a not dissimilar inoculation may give the tree immunity by developing its powers of re- sistance, quite as the human subject is given immunity. Of course the tree has no arterial system that can be inoculated with hypodermic syringe as the human subject is inoculated. But the life of the tree is dependent on the circulation of fluids with- in its tissues none the less. These fluids are taken in by the roots, and they find their way to the ut- termost leaf. So it is conceivable that by proper treatment of the soil about the tree, the tissues of the tree itself might be so altered as to become resistant to the attacks of the bacterial enemies. ImMouniTY THROUGH TREATMENT AND BREEDING Nor is this idea altogether theoretical. Experi- ments have already been made that look to the checking of the growth of the tree by withholding fertilizers and water, that the development of the tender buds and shoots, which are the usual points of attack of the enemy, may be made to take place slowly and thus to present tissue of a less succu- lent order. Such hardening of the wood by withholding water has proved effective in the case of some pear orchards in Colorado, where it appears that the [132] oe A Seedling Pear This is a seedling pear that departs from the ideal shape, but which has many other qualities that highly commend it. It is large, and of luscious quality of flesh. Owing to its form, and to its lack of color, however, it has not been introduced, but has been used in further breeding experiments in the attempt to develop an ideal pear. LUTHER BURBANK pear does not really need so much water as it or- dinarily receives. But the effort to give the tree immunity must go even deeper. Induced immunity is valuable, but the ideal condition is that of inherent resist- ance, bred in the tissues. Physicians tell us that the all-important thing in warding off bacterial infections in the human subject is the inherent vitality and resistance of the patient himself. In the last analysis, this is the prime essential. A thoroughly rugged organ- ism may be immune to almost every type of bac- terial disease. We are told that almost no one escapes infection with the germs of tuberculosis. The ones who show no evidence of the disease are simply those whose tissues are so resistant that the attacks of the bacilli are thwarted. The horticulturist must take a lesson from the experience of the physician, in particular with regard to the malady we are now considering; for, as we have just seen, the analogy between the pear blight and human infections is almost perfect. So the ideal at which the plant experimenter must aim is the development of a tree that will be im- mune to the attacks of the bacillus, however freely the germ finds access to it. My new hybrid pear, thanks to its Oriental heritage, seems to fulfil this condition. The same [134] ON THE PEAR thing appears to be true, at least in some measure, of the other hybrids that have the Oriental strain. So there is every reason to hope that we shall be able to develop races of pears, having all desirable qualities of fruit for the different markets, that will be free from the pest that hitherto has made the raising of this fruit a more or less precarious industry. IDEALS AND PossIBILITIES As to the other needs and possibilities of pear development, not much need be said. Reference has elsewhere been made to the desirability of giving the pear a brilliant color; but this can doubtless be accomplished without great difficulty. It has also been noted that as to size of fruit, as well as in the matter of form, there is little to be desired by way of change. There is, however, one quality that the special- ized pears have markedly lacked. They will keep for a time if plucked while green, and will ripen off the tree. But if allowed to ripen on the tree they decay very quickly after picking. It is ob- viously desirable that the pear should be given keeping qualities. But here, as in case of im- munity to the blight, the solution is already in sight. Among the varied fruits of my hybrid seed- lings, there are some that produce winter pears [135] LUTHER BURBANK that keep quite as well as ordinary winter apples. These furnish the foundation for future hy- bridizing and selecting experiments, through which, without question, it will be possible to produce races of pear having all the qualities of flesh that have hitherto made the fruit popular, and with the added property of keeping over winter. Other possibilities of pear development lying a little farther in the future and therefore some- what more vaguely outlined, have to do with the hybridization of the pear with the allied fruits of related species. It is well-known that the pear shows, in this regard, a strong disinclination for entering into such an alliance. The pear may be grafted on the quince but it is usually considered impossible to graft it on the apple. I successfully carried out such a grafting ex- periment, however, when I was a boy in Massa- chusetts, the cion being a Seckel pear. But al- though this grafted cion bore fruit for two sea- sons, it then died, probably because of the uncon- geniality of the alliance. This experiment shows that there is not com- plete antagonism between the two species; and the same thing is further demonstrated by the well-known fact that the apple may be grafted on the pear stock; although here also the alliance is [136] The Ideal Pear Thts is the pear which represents the culmination of Mr. Bur- bank’s many years of ex- periment with this fruit. it will be seen that the best qualities of the seed- lings shown in the earlier illustrations have been combined to produce a pear that is of ideal shape, large in size, and beauti- fully colored. When we add that the flesh of this pear is of corresponding. quality, it will be plain that the fruit justifies ihe name of “The Test,” under which it was introduced. LUTHER BURBANK not likely to prove fruitful and satisfactory. But of course grafting is only an incidental adjunct of the work of the plant developer. The impulse to progress must come through hybridiza- tion and selection. Here, it appears to me, there are great possibilities. I have hybridized the pear and the apple; also the pear and the quince. The seedlings from these unions have sometimes seemed thrifty, but were always infertile. They were highly interesting none the less. The most successful cross was obtained by us- ing the pollen of the Bartlett pear upon the Gravenstein apple. The seedlings from this cross were divergent in appearance, and variable as to growth. One of the seedlings grew fully as fast as the ordinary apple seedling, but most of them had a sickly, dwarfed appearance, and some died after having made a foot of growth. Three or four of those that lived were grafted on an apple tree. They main- tained moderate growth for several years, but were never healthy or vigorous, and never gave any intimation of blooming. The results of the crosses between the pear and quince were closely similar. From these hy- brids also I failed to secure fruit. Some grew with great vigor for years, while others almost refused to grow at all. In general appearance, and espe- [138] Seedling Pear Trees The wild pears have a protective equipment of thorns, as illustrated by the seedlings at the right. These thorns are no longer needed to pro- tect the cultivated pear, and they have been en- tirely discarded by the bes! cultivated varieties, as il- lustrated by the seedling at the left. An occasional seedling, however, still re- veris to the thorny type, showing the strong hold of heredity. LUTHER BURBANK cially in foliage, the hybrids bear a closer resem- blance to the pear than to the quince. But many appeared to be fairly good composites of these widely differing plants. As there are many varieties both of pears and quinces, each having individual characters and diverse hereditary tendencies, an inviting field is open to the careful and patient experimenter in crossing these distinct yet related species. If the right combination can be effected, the results undoubtedly will be profoundly interesting and valuable. Precisely what these results will be, no one can predict. But that new fruits, making most valuable additions to the dietary, may ulti- mately be thus developed, there is no reason to doubt. —The pear and its cousin the apple may well be considered the two orchard trees which are friendliest to man. FUZZY PEACHES AND SMOOTH- SKINNED NECTARINES Two Fruits Wuicu Bea ror More IMprovEMENT R. BURBANK,” said a visitor, “you have M taken the thorns off the blackberry bush and the spines from the cactus. Now why can’t you take the fuzz off the peach? “Most of us don’t deal much with blackberry briers or with cactuses, spiny or otherwise; but we all eat peaches, and a good many of us would about as willingly bite into a spiny cactus as a fuzzy peach. If you will only take the wool off this otherwise perfect fruit, we will raise a monu- ment to you by popular subscription.” “But nature took the wool off the peach some thousands of years before you and I were born,” I answered; “and I have not heard of any monu- ments being erected in commemoration of the event.” “What in the world do you mean? A fuzzless peach—who ever heard of such a thing?” [VoLtumME IV—Cwapter V] LUTHER BURBANK “Everyone has; the fruit that you call a necta- rine is precisely that thing—a peach without the fuzz.” “But that does not serve the purpose at all,” he insisted. “If the nectarine is a peach that has lost its fuzz, it is also a peach that has lost its flavor. What we want is a fuzzless peach with the true peach flavor remaining.” “Well, I think I shall be able to satisfy you even there before a very great while,” I answered; “for I am on the track of experiments that are likely to meet all your requirements in that direc- tion. Even now I have a fruit that is smooth- skinned and yet is unquestionably a peach—not only that, but a peach of excellent flavor. But it is not yet quite good enough to put on the market, and I shall have to carry the experiment a stage or two farther before I am ready to demand that monument.” And then I led the way to a part of the orchard where I was able to show a number of peaches with perfectly smooth skins, some of which are by no means ill-flavored, even though none quite com- pete with the best peaches now on the market. My visitor assured me that nothing else that he had seen gave him so much satisfaction or aroused such pleasurable anticipations as this smooth- skinned peach. [142] Flowering Peach in Blossom Mr. Burbank’s fondness for flowers has led him to experi- ment largely in the production of fruit trees having beautiful blossoms. The flowering peach here shown is an example of a tree that has been doubly specialized, so to speak, through selection. The Japanese are the pioneers in the production of fruit trees that bear beautiful flowers. LUTHER BURBANK And I suspect that a very large number of per- sons under the same circumstances would be of the same mind, for I am told that the aversion to the fuzz of the peach is a by no means uncommon form of phobia. It might be of interest to inquire just how this curious antipathy to anything so soft and delicate as the structure of the peach’s skin was developed. I know men of perfectly stable nerves who cannot touch a peach without experiencing a disagreeable sensation, and who cannot bite through the fuzzy surface without shuddering. And as there seem to be large numbers who experience more or less the same sensation, it goes without saying that there must be some hereditary basis for this curi- ous and seemingly absurd prejudice. It is somewhat comparable to the fear of the mouse so common with women, or the instinctive dread of the snake that most of us feel. Just how the peculiar antipathy was developed, would, as I say, be a curious matter for specula- tion. Here, however, we are concerned with the fuzz of the peach not in its direct relation to hu- man psychology, but in its bearing on the heredity of the peach itself. To the plant developer this is a matter of interest, because linked with it is the question of the way in which the superfluous skin-covering can be eliminated. [144] The Freestone Indian Peach In his extensive ex- periments in breeding better varieties of peaches, Mr. Burbank has followed his usual custom of going to all countries for mate- rial with which to make crossbreeding or hybridiz- ing experiments. This In- dian peach has been utilized chiefly because of its freestone quality. The tendency to loosen the flesh about the sione as the fruit ‘ripens is, fortunately, a hereditable quality. LUTHER BURBANK I speak thus of the fuzz of the peach as being superfluous, but on second thought we cannot be too sure that it really serves the fruit no useful function. Indeed, the inference should be rather the other way. At least we may feel sure that unless the woolly coating at some time served a very important purpose, it would never have been developed; or, having been developed, it would not have been retained. That is assuming, however, that the peach de- veloped this unusual fruit covering in a state of nature, and without the aid of man’s selective in- fluence, which it certainly did. How THE Peacu Got Its Coat If it could be shown that the fuzz was devel- oped only after the peach came under cultivation, and in response to man’s wishes, the case would be altered. In that event it might readily be that the fuzzy covering, appearing first as an acci- dental “sport,” had been retained because it pleased the fancy of some plant experimenter, or met the taste of some influential. market man— say of Athens in the olden days, or of Rome in the time of its power. But in all probability the peach had its fuzzy coat at a time vastly more remote than this. It is 1146] The Exquisite Peach This is one of Mr. Burbank’s crossbred peaches, which must be admitted fully to merit its name. It has qualities of flesh that correspond with its attractiveness of form and color. LUTHER BURBANK almost certain that the coat was developed long before the fruit came under cultivation. The fair presumption is, probably, that the an- cestor of the peach, wandering from one territory to another as all plants do, found itself at a certain stage of its career in an environment where the conditions of moisture and wind and sunshine were peculiarly trying, or where some insect or fungoid or bacterial pest menaced its immature fruit. And in such a case it may readily have chanced that a peach that tended to produce a skin of exceptionally resistant texture, one in which the bloom assumed a more than usually powdery or fibrous character, was given protection against the enemies, and thus preserved where fruit with smoother skin was destroyed. Under these circumstances, the incipient fuzz on the peach would serve as material for the oper- ation of natural selection, and a race of peaches bearing fuzzy-skinned fruit would presently sup- plant the tribe of smooth-skinned peaches. Something like this, I suspect, we should find to be the history of evolution of the fuzzy-skinned peach, could we look with some necromantic mi- croscope into the germinal center of the peach seed and translate the marvelous history of end- less generations of peaches, back to the beginning, that is therein recorded. [148] Late Clingstone Peach This crossbred peach has the merit of ripen- ing very late, thus extend- ing the peach season. it also has size, good form, and fine quality of flesh in its favor. The chief de- fect is that it is a cling- stone. This defect may be remedied in the offspring, by combination witha freestone variety. LUTHER BURBANK There is no such microscope as this, of course. But we can, in a sense, perform the same necro- mantic feat, and lay bare the mysteries of the history of the evolution of the race of peaches, in a quite different manner. If you have read the earlier chapters of this work, you will know that the method I have in mind is the familiar one of causing the germ plasm of the peach, with its weird record of past events, to blend with the germ plasm of another tribe of plants having a somewhat different his- tory; in order that the conflict of tendencies thus brought about (as we used to say; or the blending of hereditary factors, to use the popular phrase of the moment), shall bring to the surface and make tangible in the hybrids of a new generation, the traits that were submerged and hidden in the in- dividual plant before us. And when this familiar yet no less wonderful test is applied, we learn, among other things, that the peach which now holds to its fuzzy coating so tenaciously, at one time had a cheek as smooth as that of any other fruit. For among the offspring that appear as the result of blending peach strains, there now and again is one that bears smooth fruit. Moreover, the smooth fruit that thus appears is closely similar to another fruit which, from its [150] ON PEACHES AND NECTARINES general appearance, would be declared by any competent observer to be a close relative of the peach, namely, the nectarine. So this bit of evidence from heredity—this freak of atavism—may be taken as furnishing substantial evidence that the ancestor of the nec- tarine was also the ancestor of the peach. Or, stated otherwise, that the peach is in reality a modified nectarine. It may be added that both are undoubtedly modified from a plum-peach- apricot-almond ancestor. That the nectarine, rather than the peach, rep- resents the ancestral form is witnessed by the fact that the nectarine is rarely observed—at least in my experience—to produce a fuzzy fruit, however closely it may otherwise simulate the peach. And, of course, this evidence is in keeping with the natural inference one would draw from the fact that pulp fruits in general have smooth skins, or skins with at most a delicate bloom quite lacking the texture of the peach’s almost woolly covering. THE MARRIAGE OF COUSINS In any event, there can be no question that the peach and the nectarine are very closely related; in fact, they are generally classified as a single species, the trees differing very slightly in any re- spect, the only difference being in the fruit. It is probably but a short time, as compared (151) LUTHER BURBANK with the entire stretch of their racial histories, since the two fruits branched from the same stem. And so it is quite to be expected that the two would readily cross. In point of fact, the experi- ment of cross-pollenizing is so readily performed that it is very often carried out by the bees. The hand pollenizer may make the test suc- cessfully without the slightest difficulty. I was led to experiment along this line by the recollection of an old peach tree called a “Meloco- toon”, four of which stood in our home garden in New England, and one of which, as I well recall, had a single branch high up in the tree that al- ways bore a fruit quite different from the peaches with which its other branches were laden. This anomalous fruit, which appeared as a “bud- sport” was in fact a nectarine. I had learned also that when peaches and nec- tarines were grown in the same neighborhood, one could never be certain as to which fruit would grow when the seed of either fruit is planted. You may plant a peach seed and grow a nec- tarine tree; or, far less frequently, you may grow a peach tree from a nectarine seed. The explanation, of course, is that the two tribes are constantly intercrossed when growing side by side, through the agency of the bees. Pondering these facts, I determined to make [152] The National Peach This crossbred peach was named National because of its varied ex- cellent qualities; in par- ticular its adaptability to different climates, making it available for growth in widely different sections of the United States. It is a peach of average size, but of exceptional qualities of flesh. As compared with some other crossbred peaches, it is some- what lacking in color. LUTHER BURBANK some definite experiments in hybridizing. I first selected for the experiment the white nectarine and the Muir peach. In 1895 numerous crosses were made, using principally the: white nectarine pollen to fertilize the blossoms of the Muir peach, a very hardy, vigorous, abundantly productive variety of the peach that is largely cultivated in California. The white nectarine has a rich flavor, but it is too acid to eat without cooking. It is of large size, has a large stone, and white flesh, with per- fectly smooth white skin. The Muir peach, on the other hand, is very sweet, with firm yellow flesh, and an unusually small, free stone. A tree of this variety is unusually hardy, long-lived, and im- mune from that pest of the peach orchard, curl- leaf. It may be grown in a large variety of soils in locations where other peaches and nectarines often fail. The offspring of this union of nectarine and peach in due course came to fruiting age, and in some cases the fruit they bore was found to be of a quality superior to that of any peach or necta- rine at that time ever seen. In the second and third generation there appeared a varied com- pany, showing remarkable new combinations of qualities, and anomalies of form, size, color and flavor. [154] The Lemon Muir Peach This seedling of the familiar Muir peach has many qualities to rec- ommend it. It was given the name Lemon Muir be- cause of the lemon tint which is well reproduced in this color photograph, and partly also because of the somewhat lemon- like form of the fruit itself. LUTHER BURBANK Many of them combined the sweet yellow flesh of the peach and the acid quality of the nectarine, producing delectable and altogether novel flavors. SMOOTH-SKINNED PEACH HYBRIDS There are now large numbers of these cross- bred peach-nectarines on my place, some of them being of the fifth and sixth generation from the original crossing. Some have a crimson leaf like that of the crimson-leaved peach. Some that have the characteristic rough stone of the peach, retain the smooth skin of the nec- tarine. These constitute a smooth-skinned vari- ety of peach such as the visitor with the aversion to fuzzy skin longed for. First and last, these hybrids show almost all possible combinations of a score or so of qualities as to which the two fruits in their divers varieties differ. Among these there are some that are of such desirability as to make the fruits worthy of introduction, notwithstanding the very excellent assortment of peaches already on the market. The first member of the hybrid company to be sent out into the world was named the Opulent. It grew on a vigorous tree that bore abund- antly even when quite young, and produced a full crop of superlatively luscious fruit each season, ripening here about July 30th. The fruit has a [156] An Unnamed Peach In his extensive ex- periments in the breed- ing of peaches, Mr. Bur- bank has of course pro- duced many varieties that have not been introduced. The picture shows one which certainly looks good enough to eat, and is good enough to eat, but it is being subjected to further tests before its ulti- mate fate is de- termined. LUTHER BURBANK white skin with numerous beautiful dots and shadings of light and dark crimson, and the flesh is pale lemon yellow, suggesting a blend of the deeper tint of the Muir peach and the white flesh of the nectarine. In flavor the fruit has an in- describably delicious quality that in my estimate surpasses that of all other peaches. But it is too soft for long shipment, although having all the desirable qualities of a home fruit. The Opulent has been acknowledged by all who have tested it to be the best in quality of any peach ever pro- duced. The tree is unusually hardy. It has been culti- vated as far north as Canada and has proved able to endure a temperature of 40 degrees below zero, bearing a full crop after other peaches in the same locality were destroyed by the severity of the winter. Among the numerous seedlings from the Opu- lent, some are white nectarines pure and simple, some are red or pink nectarines, and some closely resemble the Muir peach. Yet here and there one differs from any known variety of peach or nec- tarine. Similar results have been obtained in a subse- quent series of experiments, in which the white nectarine was crossed with the early Crawford and peaches of other varieties. These crosses pro- [158] Other Attractive Foundlings These are examples of yet another variety of peach that is still in the testing orchard. The speci- mens here shown speak for themselves, and the reader will not doubt that they have many excellent quali- ties. But Mr. Burbank’s fixed rule is that a new fruit must be equal to any already in the market in all qualities, and. superior in at least one quality; and it has not yet been deter- mined whether this par- ticular fruit meets this test. LUTHER BURBANK duced some seedlings of unusual size and good quality. The trees are nearly all resistant to curl- leaf and mildew. As might be expected, the seedlings from succeeding generations differ widely. While nearly all possess one or more desirable qualities, it is rare that any one com- bines enough good qualities to entitle it to special consideration. THE UNION oF PEACH AND ALMOND Another series of hybridizing experiments, begun about eighteen years ago, used for the original cross the purple-leaved peach and the Languedoc almond. In the first and second generations, the four or five thousand seedlings produced had green leaves like the almond. In the succeeding generation, however, there appeared a few seedlings having purple leaves suggestive of those of the peach ancestor. A par- ticularly dark one was saved. As is usual with the peach and almond hybrids, this tree was very fertile. One season I obtained more than 500 fruits from it. In every respect this fruit was intermediate between the peach and the almond. About nine-tenths of the seedlings grown from the fruit of this purple-leaved hybrid had purple leaves like the parent plant; most of the others [160] ON PEACHES AND NECTARINES had leaves of pure green, but a small proportion showed leaves of an intermediate color. Looking at the row of seedlings from a short distance one would hardly perceive anything but a line of deep crimson or purple. Some of the individual seedlings were much darker than the parent, being fully as dark as the original purple- leaved peach. Most of the seedlings resemble the peach in foliage, but some have longer and more pointed leaves like the almond parent, and these grow more rapidly than the others and have a more upright appearance, in this respect also resembling the almond. Although the exact parentage of the hybrids of the later generations of this combination of the almond and the purple-leaved peach was not traceable, and although no close record was kept of precise numbers, it will be obvious that the result of the first cross showed that, as between green leaves and purple leaves, in the relations of these two species, the influence of the green leaf was prepotent or dominant. This is perhaps what one would expect, con- sidering that green is the normal color of leaves, and purple exceptional. The reappearance of the purple leaf in later generations is, of course, precisely what would be expected of a recessive character. [161] LUTHER BURBANK In any event the reappearance of the purple leaf, fully pigmented, after its submergence, af- fords another interesting illustration of the seg- regation of hereditary characters that we have repeatedly had occasion to note in connection with other experiments. Cousins FRoM THE ORIENT Continuing the experiments in peach better- ment, I not unnaturally turned to the Orient for the material for further experiments in crossing. There is a double-flowering peach that has long been under cultivation in China and Japan. It is a slender, willowy tree, generally with droop- ing branches. The blossoms are about an inch and a quarter across, snowy white, or pink, or deep crimson. They are quite double, resembling little roses, and they are produced in great profusion. The trees, however, are dwarfed and ill-shaped; they are also peculiarly subject to mildew and curl-leaf. The fruit of the flowering peach is somewhat almond-shaped and unusually pointed. It has flesh of light color and a large stone. The fruit is hardly edible even when cooked. I have taken particular pains to cross this double flowering exotic with standard and the new cross bred peaches, and have succeeded in producing some fine varieties. The most striking [162] Big String Nectarines The nectarine is in effect a smooth skinned peach, It is believed that the two fruits are really identical superficially, and have only somewhat re- cenily been modified through selective breeding. Nevertheless there are vb- vious differences in the peach and the nectarine, and there is opportunity for interesting experiments in crossbreeding. Mr. Bur- bank has taken full ad- vantage of these opportu- nities, and this picture shows one of his many interesting results. LUTHER BURBANK result, up to date, was a tree bearing a rich, rosy, pink blossom, fully two inches in diameter, which is produced in greatest abundance, on trees of strong growth, which show no propensity to droop like the oriental tree, and which appear to be resistant to curl-leaf and mildew. This large, vigorous, healthy tree, bearing a profusion of bright pink flowers, has obvious or- namental value. But in addition to this, this new variety bears an abundance of fruit, large in size, and almond-shaped, which is of fairly good qual- ity when fresh, although scarcely to be compared with standard peaches, but which when cooked is probably unsurpassed by any peach, having a delightful almond flavor. This particular variety is a cross of the crim- son flowering oriental peach and the hybrid Muir peach, and is a product of the first generation. Especial interest attaches to the results of crossing the oriental peaches with peaches of the occidental stock because, as in the case of so many other fruits, the peach of the Orient is widely divergent from the European type, although doubtless both have the same remote origin. As in the case of our other chief fruits, the native home of the peach was doubtless southern and central Asia and eastern Europe, and there was a double migration in prehistoric days which re- [164] Bully Nectarine The name may be a trifle slangy, but there is something about the fruit that seems to justify the name, It is a blunt, round, prolific, sturdy, lus- cious, wholesome fruit —in short, a bully nectarine. LUTHER BURBANK sulted in stocking China with peaches of one type and Europe with quite another. The peach most commonly grown in the United States is usually spoken of as belonging to the Persian race. The Chinese type of peach has been variously tested in California, and for the most part found wanting. The chief defect of the Ori- ental variety is the pointed almond shape of its fruit, and susceptibility to mildew and curl-leaf. It will be recalled that the oriental pear showed precisely the qualities of hardiness and resistance to disease that the oriental peach notably lacks. The difference, in all probability, is to be explained by the different treatment the two fruits have received in their Asiatic home, The pear has been developed for its fruit, and the oriental taste de- manded certain qualities of firmness and perhaps slight astringency that might be said to be in keeping with the natural character or propensity of the wild fruit. But in the case of the peach special develop- ment has taken place along the line of flower pro- duction. Doubtless more attention has been given to this than to the question of fruit. And as with most specialized races of plants, there are inci- dental defects due to the selective breeding for a single quality, and the overlooking of other qualities. [166] ON PEACHES AND NECTARINES But whatever the explanation, the fact remains that the Chinese peach is not to be looked to as introducing the elements of hardiness and virility. Nevertheless in the southern states the Chinese peach, which seems to be of tropical origin, thrives and is even quite as popular as the Persian strains. Fortunately some of the varieties of the Eu- ropean stock are vigorous and hardy growers. But the development of new varieties that will be absolutely resistant to the diseases to which the peach is peculiarly subject is a task that invites the plant experimenter. I have already referred to the success in this regard that attended some of my hybridizing experiments. My new peaches, named respectively the Leader and the National, both of them crosses of the Muir and Crawford stock, have been entirely free from any suspicion of mildew or curl-leaf. But there is demand for a great variety of peaches, and it is highly desirable that the aver- age stock of this important fruit should be greatly improved in regard to virility. That the peach may under favorable conditions live to an old age and continue in bearing is dem- onstrated by exceptional trees that are known to be half a century old, yet still retain their vigor and productiveness. When we contrast with this the familiar fact that the average peach orchard [167] LUTHER BURBANK bears only for a relatively short term of years— often only ten or fifteen at most—the vast eco- nomic importance of this possible improvement will be quite obvious. A STONELESS PEACH? As to the fruit itself, there is one opportunity for improvement that is particularly inviting—the possibility of producing a stoneless peach. The desirability of such a development, from the standpoint of the peach consumer, requires no demonstration. From the standpoint of the tree itself, a reduction in the stone would be highly important. It costs a peach tree to produce a pound of stones probably as much as to produce many pounds of pulp. The drain on the vitality of the tree in pro- ducing the stone that it no longer'needs must take from it in some measure the capacity for produc- tion of fruit pulp that it might otherwise have. The hybridizing experiments with the almond have influenced the stone of the fruit in a sug- gestive way. Some of my hybrid peaches have a kernel that is almost as sweet and edible as the kernel of the almond. As yet I have not secured a peach having really good quality of flesh com- bined with the edible seed. But that this combi- nation might be effected, if one were to select for it, admits of no question. [168] A Peach Triumph Here is a peach seedling, crossbred, that is as good as it looks. It represents one of Mr. Burbank’s triumphs in the betterment of a familiar fruit. It is not a new crea~ tion, but it is improved all along the line. Perhaps it comes as near to the ideal of what a peach should be as any fruit ever grown. LUTHER BURBANK And a peach retaining its recognized qualities of flesh and having at its center an edible nut like the almond with thin shell would obviously be a desirable acquisition. Such a combination of fruit and nut would be doubly desirable if the stone that surrounds the kernel can be eliminated as it has been eliminated in the stoneless plums. As yet very little has been accomplished in this direction. There is, to be sure, a Bolivian peach which is remarkable in that it has a globular stone very little larger than a good-sized pea. The fruit itself is of intermediate size and poor quality; moreover, it is produced sparsely, and the tree is peculiarly subject to the peach maladies. The fruit has been thought hardly worth crossing with our ordinary peaches on account of its inferior qualities, yet the diminutive stone suggests that it would be possible by such crossing to produce a superior peach having an exceedingly small stone. Time and patience would, of course, be re- quired to carry out such an experiment, but its results could hardly be in doubt. It is possible, however, that the experiment of reducing the size of the peach stone will prove less inviting than the attempt to remove the stone altogether. My success in producing the stoneless plum points the way to a possible development [170] Nectarine-Peach Cross This picture has peculiar interest as illustrating the great diversity of form that may be shown by fruit of mixed heritage. growing on the same branch. As one parent is smooth-skinned and the other fuzzy, interesting experiments may be carried out in noting the way in which these qualities are transmitted to different members of the progeny, particularly in the sec- ond generation. LUTHER BURBANK through which the peach also may at some time become stoneless. And it is not unlikely that the Bolivian pea- stone peach, which has shown a propensity to minimize the stone, may be utilized advanta- geously in the course of these experiments. It is true that no stoneless peach of whatever quality is known, comparable to the original wild bullace of Europe, that gave the opportunity in the development of the stoneless plum. But, for- tunately, I have been able to demonstrate that the peach may be hybridized with the plum. I have made the hybridization successfully with both the Japanese plum and the Chickasaw plum. Should it prove impossible to hybridize the peach directly with a stoneless plum, one of these peach-plum hybrids might perhaps be made to bridge the gap. No doubt a vast deal of ingenuity would be required to find the combination that would work out successfully. But it was shown in the case of the stoneless plum that it was possible to re- assemble the good qualities of the fruit of one parent and the stoneless condition of the other in the progeny of the hybrids of later generations. There is no obvious reason why the same thing might not be done in the case of the peach. The possibility seems the greater because the [172] Nectarine-Peach Cross This picture shows the crossbred fruit cut open, revealing the stone. lt will be seen that in these specimens the stone is unduly large, and that the fruit clings to the stem. Where peaches and nee- tarines are growing in the same neighborhood, cross- breeding experiments are often made by the bees, without human interference. LUTHER BURBANK peach has been cultivated in so many different regions and for so many different purposes that it is highly variable. Its affinity with other stone fruits has been illustrated over and over in the story of hybridizing experiments already related. So it seems at least within the possibilities that a way may he found to combine the stoneless condition which has now been bred into the germ plasm of one member of the stone-fruit family, with the recognized qualities of the peach, in a hybrid—produced, no doubt, only after a series of experiments extending over many years—that will represent the ideal of a stoneless peach. If the qualities of the almond seed were also bred into the combination, the final product—a fruit having the matchless flavor of the peach, a perfectly smooth skin, and a stoneless seed of de- licious edible quality—would assuredly be the paragon of orchard fruits. That such a fruit will ultimately be produced there can be little doubt. When we reflect on the long gap that separates the peach of to-day from its primitive wild ancestor, we need not regard such further development as that just suggested as being very formidable. But, of course, there is a time element that can- not be ignored. So here, as with other orchard fruits, it is only such experimenters as have the gift of patience [174] ON PEACHES AND NECTARINES who can enter the field with prospect of success. Granted that endowment, however, and a rea- sonable comprehension of the principles of plant breeding already presented, any intelligent ama- teur may undertake experiments in the further education of the peach that may well lead to re- sults of the highest interest and of notable economic importance. —The peach with its luscious meat, the nectarine with its smooth skin, the almond with tts delightful kernel, and the stoneless plum with its un- sheathed seed—who will breed these together and thus pro- duce a unique and valuable fruit-nut? ‘uojjonp . 704;u2 -$}} Payuaa . eaad aavy joy} $jaafap ujd}iaa9 spy ‘fijayounjs0f -un ‘yarym auo jnq ‘shu}] -paas jnf{1jnvaq jsoul ay} fo auo smoys ainjajd juasaid ayy ‘saimjoid Bujpaavons ul umoys adD syuau4i3ad -xa sly jo s}]msal ay} jo awos pup ‘yim4j sty} YM Ajaaysuajxa =fidaa = payuaul -j4adza spy yunging ‘AW *shuljpaas ay}; Suourw uo}} -oajas 40f fiyyunjioddo Jupp -ungD aq I]1M alayL “AIO? fiup fo spaas Gujjun)d fig ajddp ayy ym syuaut -1uadxa_—- Bu} paatq u16aq fivu auo Auy ‘loapjf pup 10]09 pup witof pup az} jo fijzsaazajp ysourjn 9} moys Apu: ajddp fo Haima pippupjs flu woi1f umoiB sOuljpaas yoy} aipaD sz ysipapyoio fiaaag ajddy 6uzjpaes njynvag V THE ApPPLE—A FRuIT WORTHY OF STILL FURTHER IMPROVEMENT New ApPLEs AND How To MAKE THEM 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 cat- alogue includes only such selected varieties as have attracted more or less attention in this coun- try 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 pos- sesses 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 I: YOU were to look in Regan’s book on the {[VotumME IV—Cwaprter VI] LUTHER BURBANK 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 oppor- tunities 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 sit- uation 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 sea- son. He sees that each fruit is always of approxi- mately 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 [178] ON THE APPLE 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 rasp- berries 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 peculiari- ties 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 se- cure 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 propa- gating the different varieties of apples is by bud- ding or grafting, or by the equivalent method of sprouting slips or twigs. And attention has fur- thermore 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. [179] LUTHER BURBANK It has been suggested that all trees that repre- sent a particular variety of cultivated fruit—say all Baldwin apple trees or all Seckel pears—are separated parts of the original tree of correspond- ing 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 off- spring through the ordinary processes of genera- tion denies them the rank of races or varieties proper, let alone the rank of species. And after all the difference in appearance be- tween 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, [180] Mr. Burbank’s South Apple This crossbred seed- ling, while lacking some qualities, notably of size, that characterize other seedlings in Mr. Burbank’s orchard, it has merits that have on the whole made its introduction desirable. It is acknowledged to be a fruit of great merit in the regions. where it ean be success- fully grown. LUTHER BURBANK think of each listed variety as having the status of an individual rather than that of a race. The diversity of individul types becomes ex- plicable if we consider the history of their devel- opment. 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 voy- ages, 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 per- haps more attention given the apple by the horti- culturist than to any other single orchard fruit. The qualities of the apple and its adaptation to all tastes, zones, and soils naturally account for [182] Winterstein Apple This well-known va- riety of apple is con- sidered by Mr. Burbank to be in some respects supe- rior to almost any other of the familiar cultivated varieties. He has used it very extensively in his crossbreeding experiments, and its blood enters into the heritage of nearly all of his best seedlings. LUTHER BURBANK 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 fruit- ing, 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 mean- ing 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. [184] Burbank Seedling Apples These seedlings, par- ticularly the one at the left, show the influence of the Winterstein parent. They are of complex her- itage, hewever, and have many characteristics that cannot be traced to the Winterstein. The speci- mens here shown repre- sent.an intermediate stage in the breeding experi- ments, and they have not individually been intro- duced or named, LUTHER BURBANK 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 con- stantly 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 ob- viously 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 va- rieties 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 intelli- gent plant developer. When he pollenizes a flower he is bringing to- gether 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. [186] The Roman Beauty Apple This excellent va- riety of apple shows a good deal of diversity, particularly as regards col- or, in individual spect- mens, as the two here shown will suggest. The fruit -has qualities that commend iit, both for tis own sake, and as a parent in breeding experiments for the development of new varieties. LUTHER BURBANK 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 mat- ter aggregated into new and wonderful combina- tions 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 transi- tional 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 in- finitely 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 consider- ation,—of visible and tangible fruits of the or- chard. [188] Seedling Apples If you wish to raise new varieties of ap- ples, it is quite possible to do so without practicing cross-fertilization. The cul- tivated varieties are so mixed in their heritage that nothing more is nec- essary than to plant seeds of almost any variety to secure a great number of aberrant new types. The ones here shown are seedlings of the Winterstein, LUTHER BURBANK To be quite specific, and to bring us back di- rectly 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 va- rietics, 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 pro- [1901 ON THE APPLE duced 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 Practica 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, Graven- stein, 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. [191] LUTHER BURBANK 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 pro- duce winter apples than summer apples, whereas summer apples are almost as likely to produce winter varieties as to reproduce their own quali- ties 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 pro- portion of seedlings good in most respects, and this is true also of the Newtown Pippin, Hubbards- ton, the Rhode Island Greening, Roxbury Russet, Haas Queen, William’s Favorite, Swaar, Rambo, Fameuse, Lyscom, Alexander, Palmer, and Wag- ener. Especially fine seedlings have been obtained from the Garden Royal, Fameuse, Golden Russet, P1925 More Seedling Apples These are seedlings of a quite different type from those shown in the preceding picture. They show the mixed heritage that characterizes mest of the Burbank seedlings. Al- though of excellent quality, the ones here shown have not been introduced or specifically named. LUTHER BURBANK Wagener, and in particular the Gravenstein and the Newtown Pippin. Usually the weak point in Northern Spy seedlings is poor quality, notwith- standing 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, germi- nate 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 saw- dust 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 plant- ing, they will germinate with unusual vigor. If the apple seeds are wanted in large quanti- ties, 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 pos- sible 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. [194] ON THE APPLE Details as to methods of planting and care of the seedlings have already been given in a sep- arate 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 pro- duce 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 valu- able 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 seed- lings at the end of the first season’s growth, graft- ing them into a bearing tree on branches a quar- [195] LUTHER BURBANK ter-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 geo- graphical section would raise and test new seed- lings, 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 lo- calities where the apple cannot be grown today might produce thriving orchards. MAKING Harpy APPLES The apple is relatively hardy, but improve- ment is still possible in the way of producing va- rieties 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 pro- duced that are especially acapted to withstand the [196] Nameless Beauties These Burbank seed- lings are also name- less, although they would merit introduction were it not that there are already so many excellent varieties of apples on the market. As it is, they have proved useful in further cross- breeding experiments. LUTHER BURBANK extremes of temperature of the northern Missis- sippi Valley, and others are in prospect. Especial efforts are being made, also, to de- velop varieties that will be immune to the attacks of the insect pest known as the woolly aphis, which does great damage in apple orchards, es- pecially 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 at- tacks of the woolly aphis, I have made many at- tempts 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 [198] Two Fine Specimens The chance that there may be among your seedlings some trees that bear apples like these should give peculiar inter- est to the experiment in the production of new va- rieties. These are Burbank seedlings of heritage so complex it would be dif- ficult to trace their precise anie- cedents. LUTHER BURBANK 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 at- tacks of the aphis may thus be produced. Unfortunately the seedlings of the Northern Spy do not generally inherit this quality of resist- ance 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. Hysrip APPLES I have experimented very extensively, as al- ready noted, with the crossing of different familiar varieties of apple, and have produced several new varieties that have been deemed worthy of intro- duction. 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 with a related species. In endeavoring to introduce new traits I imported in 1890 all of [200] More Nondescripts Illustrating the wide diversity among apples of the same inheritance. The apple has been so long under cultivation and has Deen developed under such diversified conditions of soil and climate, that tts germ plasm contains mis- cellaneous facfors of great diversity. Just which ones of these factors will make themselves manifest in any given case, it is impossible to say, and the uncertainty adds zest to the work of the fruit developer. LUTHER BURBANK 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 re- sults 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 inter- vals throughout the summer; others stubbornly declined to bud or blossom until nearly the begin- ning 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 Coun- ties. 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. [202] Large and Toothsome These Burbank seed- lings represent several generations of selective breeding and general en- couragement. They taste as good as they look, and they are worthy of a place in any orchard or on any table. LUTHER BURBANK 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 be- fore 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 un- likely that something of value may be developed from this stock by further hybridizations and se- lections. 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 hybrid- izing experiments with the apple tree are those in [204] Gold Ridge Apple This Burbank cross- bred apple, unlike a good many others that have been shewn, does not reveal the characteristics of the Winterstein, at least as to color, although it has strains of that apple in its heritage. Mr. Burbank thinks so weli of this par- ticular variety, that he has given it the name of his Gold Ridge Farm, where his chief orchards are lo- cated. It illustrates the possibility of developing valuable new _ varieties, even of this most widely cultivated of fruits, LUTHER BURBANK 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 resem- bled the quince. I expected good results from these interesting hybrids, but not one ever produced even a blos- som. The developments were the same in all seed- lings, 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 [206] Extremes of Development The Burbank apple at the left is one of the largest apples ever grown; whereas the wild apples at the right are fruits of insignificant size. Note that the small apples are nearly ail seeds, where- as the large apple is nearly all pulp. No more striking example could be given of the possibility of modify- ing a fruit through se- lective breeding. The wild apple may still be of serv- ice as a hybridizing agent in the development of hardy strains of eui- tivated apples. LUTHER BURBANK crossed with the apple. But none of them gave any indication of producing blossoms, let alone fruit. These, like the quince-apple hybrid seed- lings, 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 hybridiz- ing the apple with its remoter cousins. Never- theless the proof that such hybridization is pos- sible 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 com- bine more advantageously and produce fertile off- spring. 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 or- chardist. But even if the practical or economic results should prove meagre, such a series of experiments might still have a large measure of scientific in- terest, more than justifying the time and labor de- voted to them. So little work—relatively speak- [208] Getting on in the World Three big cross- bred Burbank apples are here shown in compari- son with three tiny wild apples, the latter probably not very different from the parent forms from which the cultivated apple originated. Note the simi- larity in the outward ap- pearance of the fruit, not- withsianding the enor- mous disparity in size. LUTHER BURBANK ing—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? THE TRANSFORMATION OF THE QUINCE Wuat Was ONLY A CookInG Fruit Now DELIcious Raw formula for cooking the quince. His rule was this: Take one quince, one barrel of sugar, and sufficient water. This rule was given, I hasten to explain, at a time when my Pineapple quince had not been developed. Had Mr. Beecher tasted one of these perfected quinces he would have seen that his joke no longer had its former force. For my Pineapple quince, and one or two others that have been de- veloped even more recently, retain very little of that acrid quality which Mr. Beecher’s barrel of sugar was designed to hide. On the contrary, the new quinces, when fully ripe, are to be compared in texture of pulp and in edibility with some of the best apples, rather than with their quince forebears; and at the same |: IS said that Henry Ward Beecher once gave a [VoLtuME I]V—Cnarter VII] LUTHER BURBANK time they retain the matchless flavor that made the quince a favorite fruit for jellies and pre- serves even when its other qualities made it alto- gether inedible before cooking. Indeed, the new fruit not only retains the indescribable but exquisite savor of its tribe, but has taken on quite pronouncedly the flavor of the pineapple, justifying its name in the estimate of most persons who have eaten it. The transformation thus effected in the quality of the quince has been brought about through a series of experiments that began as long ago as 1880. When I first gave the matter consideration I reflected that the quince, although it had been under cultivation for at least two thousand years, had been distinctly neglected by the horticulturist. There was a prevailing idea that the quince tree would thrive on neglect, and that the inherent qualities of the fruit were such as to place it hope- lessly beyond the reach of experiment except as material for cooking. But I could see no good reasons why the quince should not be improved somewhat as the apple and pear had been. So I commenced work by obtaining seeds of all the best strains of quinces, including among others the Orange, Angus, Portugal, Rae’s Mammoth, West’s Mammoth, and Champion. All of these are [212] ON THE QUINCE varieties derived from the common species which the Romans called Mala Cydonia, or Cydonian apple, because an improved variety came to them from Cydon, in Crete. From this old Roman name we have for the common quince the scientific name of the present time, Cydonia vulgaris. Finast SuccessFuL MartInGs One of my earliest experiments was to cross the Orange quince with the Portugal quince. The Orange type is generally much more pro- ductive than the Portugal, and the fruit is larger and more pleasing in form, being nearly round and quite smooth. It is also of a more attractive color. On the other hand, the pear-shaped Portu- gal quince, although having an objectionable rusty coat, is of a better quality, having a very pleasing flavor when cooked. It seemed certain that from the combination of these two varieties it might be possible, by subse- quent selection, to produce a quince superior to either. Seedlings from this cross of Orange and Portu- gal quinces were raised extensively for several years, Large trees upon which to graft and test them all not being available, the selected ones were set out on the Sebastopol place rather closely, in rows about 41% feet apart. Although a thorough test [213] LUTHER BURBANK could not be made in this way of all the varieties, it was possible to make a very fair comparative test. The poorer seedlings were from time to time removed, leaving space for better development of those that remained. Later some of the trees whose fruit was not promising were used as stocks on which to graft hybrid pears and other seedlings. By this method I have tested probably fifty thousand quince seedlings. . The first important result of this experiment in crossbreeding was the production of a quince of large size from a seedling produced by pollen- izing a Portugal quince with the Orange quince. Among my seedlings one individual showed marked superiority over its fellows even in the seed-bed, by its unusual vigor and the rich green of its large, finely formed foliage. Among the entire lot of 700 cross-bred seed- lings, this one alone proved really valuable. The fruit it bore received the Wilder Medal at the meeting of the American Pomological Society at Washington, D. C., in September, 1891. It was so generally admired and promised to be so valu- able that Professor H. E. Van Deman, then Chief of Division of Pomology, U. S. Department of Ag- riculture, was pleased to have it named for him. The Van Deman quince inherits great productiv- [214] The Japanese Quince Like a good many other fruit trees, the quince has been modified by the Japanese in the direction of brilliant foliage and beautiful flowers. It thus becomes an ornamental shrub in addition to its fruit-bearing qualities. LUTHER BURBANK ity, size, nearly globular shape, smooth skin, and attractive color from the Orange quince, while it received its spicy flavor and tenderness from the Portugal. It has continued to be extremely pro- lific, and an unusually strong grower, and at the present writing, 1914, it is quite generally pro- nounced the best of all quinces, and the only quince worth raising in the eastern states, It has proved to be of remarkable hardiness and produc- tiveness under the most adverse conditions. Under favorable conditions the Van Deman produces three distinct crops each season in Cali- fornia. The first or main crop ripens on my experi- ment farm during the latter part of September. The fruit of this first crop is of extremely large size, often being over five inches in diameter, and weighing 25 ounces. The second crop ripens about November, and the third a month later. With these later crops the fruit is usually much smaller. But all are of good flavor, texture, and quality. They bake as quickly as apples, and are tender when thus pre- pared. The dried or canned fruit retains the much desired quince flavor. At the time when the Van Deman quince was introduced, in 1893, I had growing for compari- [216] Fruit of the Japanese Quince The Oriental taste in fruit is different from the Occidental. As a rule the fruits developed in the East are somewhat harder in texture, and more acrid in quality than those that have been de- veloped in Europe and America. There is less difference in this regard, however, in the case of the quince than with some other fruits, notably the pear. The Japanese quince has been used by Mr. Bur- bank in crossbreeding ex- periments in the devel~ opment of his per- fected varieties. LUTHER BURBANK son trees of all the other varieties above men- tioned. But no one of them bore fruit at all comparable to the new variety. The new tree, in addition to being a very pro- lific bearer, also had the habit of early-fruiting. Trees two years old have been reported as bearing fruit. From Florida a Van Deman quince is reported that took on eight feet of new growth within one year from the time of planting. In Washington two trees in their third season bore twenty fine quinces weighing from twelve to fourteen ounces each as their first crop, and a little later a second crop declared to be quite equal to the other. SEEDLING TESTS AND NEW. Crosses I had, of course, made crosses between various other varieties in the quince orchard and in due course developed other seedlings that showed valuable characteristics. I learned by experience to be able to select seedlings of the quince, as of other fruit trees, by observing the character of the leaf and stem. Seedlings having leaves that are large, thick, dark green, and glossy, and that show prominent rounded buds and upright branches with thick, bright wood are those that may be expected to pro- duce the largest and finest fruit. Werthless seedlings are known by the oppo- [218] Foliage of the Japanese Quince The thick, fibrous leaves of the Japanese quince add to the beauty of the tree. The branches, however, are likely to be spiny. The quince appears to represent a somewhat more primitive type of plant than most other of our cultivated fruits. Mr. Burbank suggests that the cultivated quince of to-day is in about the condition of development represented by the pear of the Roman time, LUTHER BURBANK site characters. Seedlings having small, knotted, twisted wood; slender, small, sharp buds; long joints; woolly, wild-looking leaves, and irregular rambling tendency of growth should be rejected, as they will rarely produce fruit of any value. There are notable exceptions to these rules of correlation between twig and foliage and fruit- quality, but, as a rule, the qualities just noted may be depended upon to serve as useful guides. My second important new quince was grown as a seedling from Rae’s Mammoth. It was, I am confident, a third generation seedling of a cross between Rae’s Mammoth and the Portugal quinces. Its immediate pollenate parentage is not a matter of record, as a great number of cross- bred quinces were under observation at the same time, and specific record was kept only of the first pollenations. This offspring of Rae’s Mammoth was at first called the Santa Rosa, but was subsequently re- christened by the introducer as the Child’s quince. It is remarkable for its great size and productive- ness, for beauty of form, and for its pale lemon yellow or almost white skin; also for the tender flesh and delicious flavor of its fruit, and the di- minutive size of the core. So fine-grained and tender is the fruit, and so free from the harsh acidity of the old quince, that [220] ON THE QUINCE it is equal to some popular apples for eating raw, and fully equal to the best apples or pears when baked, stewed, or canned. It will cook as tender as the best apple in five minutes. Moreover, it makes a superior light-colored dried fruit. In form the fruit is somewhat intermediate be- tween the Portugal and Rae’s Mammoth, inherit- ing from both parents; but in quality it is far su- perior to either. This new variety has been rather extensively distributed in the eastern states. The only complaint heard of it in the colder climates is that it does not bear so well as in California, but this is the case with all quinces, The soil and climate of California are peculiarly hospitable to this fruit. THE PINEAPPLE QUINCE I have elsewhere called attention to the fact that once a tendency to variation has been intro- duced by crossing among plants of a given com- pany, the effect appears to be cumulative. Thus opportunity is often given in later gen- erations for selections that will lead to relatively rapid progress along the desired line of develop- ment. . Such was the case with the quinces. As selec- tion proceeded one generation after another, the tendency to improvement became more pro- nounced. The new varieties already secured were [221] LUTHER BURBANK a very great advance upon their. progenitors, but there ultimately appeared a seedling that pro- duced a fruit far superior even to the very good ones already introduced. This superlative variety, which appeared as the culminating product, for the moment at any rate, of fifteen years of selective breeding, was the one referred to at the beginning of this chapter. Because of its peculiar flavor this new quince, as already stated, was named the Pineapple. It is additionally remarkable for the early- bearing and great productiveness of the trees, for the large and uniform size of the fruit, which is moreover exquisite in form and of a pleasing light lemon yellow color. Everyone knows that the ordinary quince can- not be eaten raw with any degree of satisfaction, nor with any expectation of personal comfort in the immediate future. Even children, voracious and unexacting as are their appetites, will scarcely eat a common quince. But the Pineapple quince when thoroughly ripe rivals the apple as a fruit to be eaten raw. It will also cook as tender as the tenderest cook- ing apple in four and one-half minutes. No other quince previously known can be cooked so quickly. It makes a delicious jelly with a strong, pure pine- apple flavor. The jelly, indeed, is far superior to [222] ON THE QUINCE that made from any other quince, and in the esti- mate of many it is superior to that made from any other fruit. The Pineapple quince, moreover, is probably the first variety to be profitably shipped from California to eastern markets. In 1910 Mr. H. A. Bassford, one of the largest growers of California, shipped this variety in ordi- nary twenty-pound plum crates. The earliest ship- ments sold at auction for $3.50 per crate. Later shipments brought $1.50 per crate. A PracticaL SHIPPING FRUIT I mention these practical details because the value of the quince as an orchard fruit for ship- ment to distant markets has been very little rec- ognized. Doubtless the forbidding qualities of the ordinary quince are responsible for this lack of popularity. But now that the Pineapple quince has been introduced, there should be an entire change of popular attitude toward this really ad- mirable fruit. I may add that I have even more recently found among the seedlings one that rivals the Pineapple, and which has qualities that fully justify its intro- duction as another new and distinct variety. This newest of my quinces—called the Burbank —is somewhat larger than the popular Orange quince and of much better form. It is as smooth [223] LUTHER BURBANK as an apple, having completely dropped the objec- tionable habit of producing wool on the skin. The tree is vigorous; it grows in fine form; and it is an early and astonishingly prolific bearer. The fruit has the cooking qualities of the Pine- apple quince, and is superior for drying and can- ning, and quite unrivaled except by the Pineapple for the making of jelly. TESTING REMOTER COUSINSHIPS It goes almost without saying that I did not carry the work with the quince far before I under- took to introduce new blood from more remote sources. All the varieties hitherto named are descend- ants of European stock, and are of the same spe- cies. But the quince, like the other orchard fruits, has Oriental representatives,—races that migrated eastward from their Central Asiatic home while the parents of the European quince were migrat- ing westward. In China and Japan there are quinces that are listed as belonging to three dif- ferent species, named Cydonia sinensis C. japon- ica, and C. maulei. All of these are quite different from the European quince as to growth, foliage, and fruit. As early as 1884 I began making hybridizing tests with these Oriental quinces. Particular interest attaches to the experiments [224] Chinese Quince The Chinese quince somewhat resembles a cucumber. It has no quali- ties that commend it fo the Occidental palate, yet it might prove serviceable as a hybridizing agent in the production of new va- rieties of quince. ae LUTHER BURBANK in which the first-named member of this Oriental trio was used. This is popularly known as the Chinese cucumber quince, sometimes called Pyrus cathayensis, the Cathay pear. In its general appearance this Chinese tree is a small, upright grower, quite unlike the ordinary quince. It is not hardy in the northern United States. The leaves resemble those of the apple or pear more than those of the quince. They turn scarlet in the fall. The flowers for which the tree is mostly grown vary from pink to crimson, mak- ing a gorgeous display in the early springtime. The fruit is variable, but is usually long, green, very hard, bitter, and uneatable however pre- pared, but quite fragrant. In shape as well as in size the fruit suggests a large, full-grown, white-spine cucumber. It has usually a smooth, though sometimes netted waxy skin. A single fruit from it may weigh more than two pounds. It will be clear from this description that the Chinese quince, or Cathay pear, differs very widely from the European quince. Its fruit is wholly in- edible, yet there is no reason why this might not be made over into a profitable and delicious fruit. It is merely a fruit that has retained the qualities, undesirable from the human standpoint, of its re- mote ancestors. Perhaps it is not much worse to- [226] ON THE QUINCE day than the common quince was in the time of the Romans. In hybridizing this peculiar fruit with the com- mon quince I worked with an open mind, anxious to see what result the experiment might bring forth. The pollen of the common quince was appliea to the pistils of the Chinese species. Pollenation was successful; the appearance of the young seed- lings grown the following season left no doubt of that. A glance showed that a certain proportion were hybrids, and even when they first broke the soil they presented much larger cotyledons of a different color from those of either parent. These seedlings were carefully planted in open ground at Sebastopol with some uncrossed seed- lings of the Chinese quince in the same row for comparison, the hybrids, however, being given the choice of soil and location. We have previously learned that hybrids usu- ally grow more vigorously than uncrossed seed- lings, but the case of these quinces proved a very notable exception to this rule. At the end of two years the Chinese quinces of pure stock ranged from eight to twelve feet high, while the hybrids, which had been given more room and the best soil, were dwarfs only six inches high, some of them even less. [227] LUTHER BURBANK The foliage of these curious miniature trees was generally a composite, somewhat suggestive of each parent. But in a few instances plants showed leaves much shorter and more rounded than those of either parent, and having the edges coiled back in a semi-circular form. This peculiar coiling of the leaves was probably due to the fact that the mid-rib was inclined to grow more rapidly than the edges of the leaf. Unavailing effort was made for two years to stimulate the growth of these interesting hybrids. The pure bred Chinese quinces in the same row came in due course to the time of fruiting, but the hybrids showed no propensity to flower, and the tallest were less than a foot in height when their uncrossed relatives had grown to the height of ten or twelve feet. Transplanting to orchard soil and special cul- tivation appeared to have no effect on the dwarfs. The experiment was made of grafting some of them into old quince trees of each of the parents. Some of the grafts grew and had rambling, spiral- shaped branches, but they stopped growing when they had attained a length of two or three feet. Grafting appeared to give them somewhat en- hanced powers of growth, but, like the hybrid seedlings from which the cions were cut, they re- mained absolutely sterile. [228] ON THE QUINCE No bush or tree of the entire lot put forth a single blossom. OTHER Dwarrs RECALLED It is interesting to recall, in connection with the curious result of this experiment in hybridiz- ing the quinces of widely varying species, the re- sults of my hybridization of the California and Persian walnuts. It will be remembered that the hybrids thus produced were of extraordinary growth, but that they produced very few nuts, and that among the seedlings of the second generation there were many trees of dwarfed growth, suggesting the quince hybrids. We found reason to believe that the curious result of hybridizing the walnuts might be ex- plained on the supposition that the parent forms had diverged almost to the point of mutual antag- onism. They had not varied quite to the point where their offspring were sterile, but they were approaching that limit. The quinces of the experiment now under con- sideration had diverged one stage farther. They are still within the limits of affinity that permit cross-fertilization, but not within those that per- mit the production of fertile offspring. Their case is rather to be likened to that of our petunia and tobacco hybrids, which, as the reader will recol- [229] LUTHER BURBANK lect, were lacking in virility and produced no blos- soms. The similar case of the motley hybrids made hy crossing various members of the rose family with their cousin the dewberry will be re- called. Also the strange progeny of the straw- berry and the raspberry. ; The Chinese-European hybrid quince, then, in its dwarfed growth and its sterility merely illus- trates the principle of growth that we have pre- viously seen manifested with various other plants. But the extreme dwarfness of the progeny gives an element cf added interest. It would be worth while, could time be found for it, to make more extensive hybridizing tests along the same lines, Possibly some other strains of the two species than those employed might prove to have slightly greater affinity. In that case it is conceivable that a new race of quinces might be produced that would bear fruit of a new character and give us an interesting and perhaps valuable addition to the rather small list of orchard fruits. In this connection I may refer again to the ex- periments in which I hybridized the quince and the apple, and to others in which the quince and pear were similarly united. The story of these experiments has been told in earlier chapters, and no detailed account of them need be given here. It suffices to repeat that the hybrids in each case [230] Van Deman Quince This was the first of Mr. Burbank’s im- portant quince produc- tions. It was descended from an original cross be- tween the orange cross and the Portugal quince. It took the Wilder medal at the meeting of the Ameri- can Pomological Society in Washingion in 1891; and was named after Professor Van Deman, then head of the Department of Pomol- ogy of the U. S. Depart- ment of Agriculture. It. is very prolific, hardy, and is regarded in many parts of the East as almost the only quince worth rais- ing. Its productivity, size, shape, smooth skin, and attractive color are in- herited from the orange quince; its spicy flavor and tenderness from the Portugai. LUTHER BURBANK failed to blossom; hence that the experiment, quite as in the cross with the Chinese quince, came to no result of practical valuc. But here, again, it should be borne in mind that more extensive experiments in hybridizing these related species might give us a combination that would be slightly less antagonistic. It goes without saying that a fertile hybrid be- tween quince and apple or between quince and pear would be a fruit of altogether exceptional interest and of the most inviting possibilities. The experiment of hybridizing these common fruits may readily be made by the amateur, and there are few simple hybridizing experiments that are more attractive as to their possible results or more instructive from a scientific standpoint. Tests WitTH JAPANESE QUINCES The two remaining Oriental quinces have al- ready been named as Cydonia Japonica and C. maulei. It should be added that the latter is prob- ably to be considered as a sub-species. Japanese quinces do not bear very freely, and their fruit has a great variety of forms, and is of such ex- treme acidity as fully to justify Beecher’s cele- brated formula—which, indeed, is said to have been suggested by an unfortunate experience with the Japanese quince. There is great diversity of bloom among [232] Santa Rosa Quince This was Mr. Burbank's second important new quince, and was grown as a seedling from Rae’s Mammoth, crossed with the Portugal quince, It is remarkable for its great size and pro- ductiveness, for beauty of form, and for the tender flesh and delicious flavor of its fruit, and the diminutive size of the core, It was rechristened Child’s Quince by the introducer to whom it was sold. LUTHER BURBANK established varieties, the flowers ranging in color from pure white to bright scarlet and deep crim- son. Some of them are double.. The tree is raised for ornament only. The bushes are aflame with leaf buds early in the spring. A little later they light the landscape with their gorgeous array of deep crimson, scarlet, pink, and yellowish or white blossoms. Again, late in the autumn, they are brilliant with bronzed leaves, and present fruits of curious and interesting forms. This, obviously, is a very different tree from the common quince. It seems so distinct that I have never attempted to hybridize the two. But I have crossed the various Japanese quinces among themselves. The crossbred seedlings vary widely in foliage, blossom and fruit. Some of the fruit produced was as large as ordinary apples, and of varying shape. Where experiments were made with the sub-species C. maulei, there was greater promise than in the case of the other flowering quinces. This sub-species is a more abundant bearer than the others, and its fruit is of less objectionable quality. The uncrossed specimens of this sub-species are low, spiny shrubs, not more than two or three feet high, with short, stiff, spiny branches, which are often woolly when young. The bushes are multi- [234] The Pineapple Quince on the Tree Mr. Burbank's Pine- apple Quince, the cul- minating effort of fifteen pears of selective breed- ing, combines the good qualities of the other quinces with especial prop- erties of its own. It has the flavor of the pine- apple, and has such quali- ties that it may be. eafen raw like the apple. It will cook as tender as the ten- derest cooking apple in four and one-half min- utes. The tree is extraor- dinarily precocious, some- times bearing fruit when only four months old. Tiny trees of the pineapple quince are sometimes borne to the ground with their weight of relatively colos- sal fruits. LUTHER BURBANK plied readily by division; that is, from rooted suckers, which spring up from the parent plant. The flowers, which are usually borne in abun- dance, are of a bright orange-scarlet. There are races of the sub-species that have variegated leaves tinged with delicate pink and white. This type of flowering quince has much to recommend it as an ornamental shrub. Moreover, my hybridizing experiments, as far as they went, indicated that the C. maulei has valuable latent possibilities as a fruiting shrub. From the many thousand seedlings a good many promising specimens were obtained. Some of these produced large, handsome, light crimson blossoms, and extremely large orange-like waxy golden fruit in the greatest profusion. These quinces, indeed, are among the handsomest of all fruits. They always attract attention by their peculiar form, golden color, and exquisite fra- grance. The flesh, however, is usually hard and very acid, though not unlike some varieties of the common quince. The extreme hardiness of this species, and its great productivity make it a very valuable parent for crossing with other allied varieties. It would be highly interesting and perhaps important to experiment in crossing these shrubs with the com- mon quince. If the cross could be effected, it is [236] Pear Seedlings Grafted on Quince Stocks The quince root system makes an ideal stock for grafting, and the pear thrives admirably on this stock. More than a thousand such grafis are to be found in the space shown in this picture, LUTHER BURBANK not unlikely that very valuable betterments could be brought about. It is at least within the possi- bilities that a quince might be developed that would be superior in various ways to even the best of the European varieties. But doubtless a long series of experiments would be necessary to attain this goal. Whatever the precise steps through which the further development of the quince is brought about, there can be no question that this fruit has a very important future. It has been neglected in the past, and the fact of its tendency to vary toward the wild type, demonstrates the compara- tively slight improvement that has been made in it through artificial selection. But the production of the new quinces that I have described opens a broad new field in quince culture. The first steps in improvement have sufficed to show that the fruit is responsive. The quince of to-day is, indeed, a half wild product that has waited long for its opportunity. It remains for the fruit growers of tomorrow, working with the partially developed product in hand, to see that the possibilities of this unique fruit are realized. So hardy, prolific and generally attractive a tree should make especial appeal to the amateur orchardist. The fact that the quince has been neglected, and thus has abundant possi- [238] The Medlar—A Cousin of the Quince The Medlar, known to the. botanist as Mestilus, is a native of cen- tral Europe. There is a single species only, but there are several culti- vaied varieties. The fruit is too acid for most tastes, but after being ‘mellowed by the frost it is relished by those who care for acid fruit. It is hardy as far north as central New York in the eastern states, and of course throughout Cali- fornia. It is worthy of more attention than it has received from the Ameri- ean fruit developer. Mr. Burbank has grown it, and has made tentative efforts at its improvement, but these have not been car- ried to a conclusion. LUTHER BURBANK bilities as yet unrealized gives it additional attractiveness from the standpoint of the amateur. In case of apple or pear or peach we have to do with fruits that have been carefully studied in thousands of experiments generation after genera- tion. Even so, we have seen that there are still good opportunities for further experiment. But how much larger and, so to say, more acces- sible are the opportunities in case of a fruit that has been generally ignored as has the quince. Why not avail yourself of these opportunities? —It remains for the fruit growers of tomorrow working with the partially developed product in hand, to see that the possibilities of this unique fruit are realized. THE APRICOT AND THE LOQUAT AN OPPORTUNITY FOR THE EXPERIMENTER HE only use I have for the apricot,” said a visitor, “is to supply a flavor for soda water; but that use justifies the fruit’s existence. No other flavor can match it.” Doubtless my visitor spoke facetiously, but we may all agree with her that there is no other flavor quite to match the flavor of the apricot. Fortu- nately, however, there are uses to which the fruit may be put in addition to the one she suggested. Otherwise it would not be possible to find a market for the two hundred million pounds or so of apricots that California raises each year. In point of fact the uses of the apricot are quite as varied as those of most other fruits. It is an admirable table fruit in the fresh state for those who live near enough the orchards to secure it. It is in considerable demand by canners who find ready sale for the fruit when preserved (VotumeE IV—-Cuapter VIII] LUTHER BURBANK in this way. But the chief demand, and the one that gives the apricot its real economic importance is based on the exceptional qualities of the fruit when dried. Something like three-quarters of the entire output of the California orchards is preserved in this way and shipped as dried fruit to all parts of the world, and brings about the highest price of any tree fruit under cultivation. A perhaps clearer estimate of the value of the industry may be gained if we recall that there are nearly three million apricot trees in California orchards. Indeed, this state has a practical mo- nopoly of commercial apricot growing. Nowhere else in the world is the fruit of cor- responding economic importance. The apricot has been cultivated from an early period of history, like the allied orchard fruits, and it has been grown more or less extensively in America for many years. But it is a fruit that is greatly restricted as to the regions in which it can advantageously be cultivated. The fact that there are very large areas of California where it thrives, sufficiently explains the virtual monopoly in the growth of this fruit that the Pacific Coast enjoys. Why Apricot Cutture Is DirFicutt The difficulty that the apricot grower en- counters may be said to center on a single char- [242] ‘Siberian Apricots The Siberian apricot dries on the tree, or after falling to the ground, when it may be preserved for a long period. This naturalty dried fruit is sought out by the Nomadie tribes, for some of whom it provides an important element of diet during the winter season. LUTHER BURBANK acteristic of the tree—the extreme sensitiveness of its blossoms to the slightest fall in temperature. The apricot tree itself under proper conditions is relatively hardy and extremely productive. It is long-lived, and it attains great size. Moreover, it sends out a very extensive root system; demand- ing plenty of room, and justifying the demand by its increased production when the trees are not crowded. It continues to grow for many years, constantly extending its root system; so that some orchardists recommend planting the trees origi- nally twenty feet apart and then, after a number of years, as the trees increase in size, removing every other one, thus securing a forty foot space for the roots of each tree. In the matter of pests that attack it, the apricot is relatively favored. It is on the whole a very healthy and vigorous, as well as very beautiful tree. But the sensitiveness of its blossoms to the slightest chill has hitherto put a restriction upon the spread of the tree beyond the sub-tropical zones, except in such a territory as that of Cali- fornia, where, because of exceptional topograph- ical conditions, a sub-tropical climate prevails even at relatively high latitudes. There are ex- tensive areas of the middle and eastern states, well toward the north, where the apricot tree may be [244] ON THE APRICOT AND THE LOQUAT grown without difficulty, but where no fruit can be produced because the blossoms are invariably blasted by the frosts or near-frosts that are sure to come after they are put forth. It is obvious, then, that this fruit presents a very specific and unusual problem for the plant developer. In case of many other fruits, to be sure, it is desirable to increase hardiness; but with no other fruit that we have hitherto considered is it so preeminently desirable to focus on this single ob- ject. For in the case of no other is there so strik- ing a disparity between the roots and the blos- soms as regards the climate to which they are adapted. MAKING THE APRICOT HARDY The idea that naturally suggests itself to the plant developer is that of selective breeding, in which the individuals chosen are those that have shown themselves relatively able to withstand cold. These, of course, can readily be selected in any region along the outer limits of the apricot’s pres- ent zone of productivity, by merely noting the exceptional individuals that produce fruit in the season when their fellows are rendered infertile by the frost. Seedlings grown from these relatively hardy [245] LUTHER BURBANK plants would, on the average, tend to manifest exceptional hardiness; and by successive selection through many generations it would thus be pos- sible, without question, to modify the sensitiveness of the apricot blossom in such a way as to adapt it for cultivation far beyond the limits of its present range. Of course such selective breeding would be subject te the usual difficulties and complications that attend the development of any new or ex- ceptional quality in an orchard fruit. Here, as elsewhere, there are complications due to the fact that the fruit will not grow true to type from seed. In this regard, however, the case of the apricot is somewhat more favorable than that of most other orchard fruits, because this species has been less widely cultivated, and is therefore less complex as to its hereditary tendencies than most others. Moreover, it is fairly easy in the case of the apricot to predict the qualities of the fruit from observation of the very young seedlings. In gen- eral the buds and leaves and wood in the first sea- son give one a fairly good idea as to what size and quality of fruit the future tree will bear. On the other hand, the apricot has a peculiar habit of sending out a young shoot, and then post- poning further growth until the buds set and [246] Japanese Apricot The Japanese apricet bears a small fruit of very poor acid quality, and used only for cooking. It is not an abundant bearer, and has few qualities that can commend it. But it cresses readily with the cultivated apricot,and Mr. Burbank suggests the pos- sibility that in later gen- erations such a progeny may develop unex- pected qualities, LUTHER BURBANK ripen, and this complication may make the choos- ing of the seedlings a more difficult matter than it is in the case of apples, pears and peaches. For when the growth is checked in this manner the buds may become turgid and the leaves of unusual size on some plants, suggesting great possibilities, whereas, in point of fact, these plants may have no greater intrinsic merit than others that have continued their growth and so will show at the moment smaller buds and leaves. These complications must be very carefully taken into account in choosing seedlings to save for the development of improved varieties. The general rule that large leaves, full buds, and large short-jointed stems indicate individ- uals that will bear large fruit of fine quality must be constantly regarded, but the complications in- troduced by the anomalous habit of growth just referred to must not be overlooked. CaN THE Microscorist HELP? In carrying out a series of selections with the. idea of developing a race of apricots with blos- soms resistant to low temperature, there is un- fortunately little to be expected from crossing different varieties of this species, because all ex- isting varieties have been cultivated under more or less the same climatic conditions. Indeed, the outlying forms to which one would [248] Japanese Apricots Cut Open The picture shows the relatively large size of the stone, and suggests the inferior quality of the flesh of the Japanese apri- cot. This oriental fruit, while lacking in the quaii- ties that are prized in Europe and America, may prove valuable because of its hardiness in develop- ing new races of apricots through hybridization. It represents a different spe- cies from the Euro- pean apricot. LUTHER BURBANK naturally appeal are chiefly natives of Asia Minor, Palestine, and Persia, and while they might serve a useful purpose, if hybridized with races now growing in America, in giving a tendency to varia- bility and perhaps also an added virility, it is hardly to be expected that they bear hereditary factors that would greatly aid in the particular matter under consideration, because of the warm climate to which they and their ancestors have been habituated. Nevertheless, the experiment is well worth making for we know that there are latent quali- ties in the germ plasm of almost every race of plants that are revealed only through hybridiza- tion, and the presence of which would otherwise be quite unsuspected. In any event there are differences to be ob- served between individual apricot trees as to the relative hardiness of their blossoms. So material is at hand, with or without hybridization, from which to begin the work of selection. Doubtless this work might be carried forward much more rapidly if we had a clearer knowledge as to what the precise anatomical conditions are that are associated with extreme sensitiveness of the blossoms. We know that some blossoms (those of certain Japanese plums, for example) may retain their [250] Foliage of the Apricot The leaves here shown are from one of Mr. Burbank’s improved apricots.. With the apricot, as with other fruit bearers, Mr. Burbank was able to make selection in the case of seedlings by examina- tion of the foliage and of the buds. Leaves of a rich deep color like those here shown,.and fat, well- rounded buds, indicate qualities of tree that will make a good fruit bearer. LUTHER BURBANK fertility even when subjected to freezing tempera- ture; being able to live even through snow storms, in contrast to the apricot blossoms which wither under influence of the lightest frost. But no elaborate studies have been made to determine whether this difference is associated with anatomical differences of structure, the knowledge of which might guide the plant developer. That such differences really exist is suggested by the observed fact that the leaves of very hardy varieties of apples, for example those grown in Siberia, have exceptionally deep layers of epi- dermal cells to give protection to the less hardy cells that make up the bu’k of the leaf. Possibly some similar modification of the cells may ac- count for the resistant quality of blossoms that are observed to be able to withstand frost. Tue Microscope May HELP If such is really the case, the microscopist might come to the aid of the practical fruit grower, pointing out to him the particular trees in his orchard that tend to produce flowers having their structure thus favorably modified. This method of selection would have obvious advantages over the method of planting trees at random in the colder regions, and waiting the selective influence of frost. [252] Apricot and Seed This is an improved variety of apricot, the result of selective breed- ing. Further improvement in the way of decreasing the size of the stone is de- sirable, however, and no doubt this can be brought about by careful se- lection, with or with- out hybridization. LUTHER BURBANK If the fruit grower could gain such information as this in advance, thus planting only the hardier individuals and subsequently making selection of the best among these, he might obviously hope to advance with greater rapidity. And as the task at best is a tedious one, the plant developer should welcome any aid that may be offered, from whatever source. As yet, however, we have no assurance that definite assistance can be given us by the micro- scopists. It may be that the physical conditions that determine hardiness or sensitiveness in the flower are dependent on molecular arrangements that lie far beyond the limits of microscopic vision. In that case, we shall be obliged to depend upon the old method of selection, picking out plants that have proved somewhat hardier than their fellows, and being on the alert at all stages to discover the correlations as to color or form of stem or leaf that are associated with hardiness of blossom, that these may aid us in making early selection among our seedlings. SEEKING Aip From THE PLuM I have said that the plant experimenter who attempts to give us a race of apricots with blos- soms resistant to cold can perhaps expect little aid from crossing the existing varieties of apricot. [254] The Seed of the Apricot The apricot is, of course, a near relative of the almond, and the re- lationship is suggested by the stones and seeds here shown. With the apricot, however, the stone is a wasie product, and the de- sirability of decreasing its size has already been sug- gested.