SB 
 
 IZS 
 
 SHAMEL, A. D. 
 
 IkPROVSaSHT OF PLANTS 
 
 
 IkPROVS^SHT OF PLANTS 
 THROUGH BUD SELECTION. 1$21 
 
 
UBRARl AGRIC. DEPT, 
 

 EXPERIMENT STATION 
 
 OF THE 
 
 HAWAIIAN SUGAR PLANTERS' ASSOCIATION 
 
 The Improvement of Plants 
 Through Bud Selection 
 
 BY 
 
 A. D. (SHAMEL 
 
 Physiologist of the V. &~eepartment of Agriculture 
 
 HONOLULU, HAWAII 
 
EXPERIMENT STATION 
 
 OF THE 
 
 HAWAIIAN SUGAR PLANTERS' ASSOCIATION 
 
 The Improvement of Plants 
 Through Bud Selection 
 
 BY 
 
 A. D. SHAMEL 
 
 il 
 
 Physiologist of the U. S. Department of Agriculture 
 
 HONOLULU, HAWAII 
 
LETTER OF TRANSMITTAL 
 
 To the Experiment Station Committee of the 
 Hawaiian Sugar Planters' Association, 
 Honolulu, T. H. 
 
 DEAR SIRS: 
 
 I transmit herewith for publication a paper by Mr. A. D. Shamel, Physiolo- 
 gist of the U. S. Department of Agriculture, entitled "The Improvement of 
 Plants Through Bud Selection." This paper was presented by Mr. Shamel at a 
 meeting of the Social Science Association of Honolulu, March 7, 1921, and is 
 published through the courtesy of that organization. 
 
 Respectfully, 
 
 t V \l/l: I H. P. AGEE, 
 
 Director. 
 
PREFACE 
 
 The present paper was prepared at the suggestion of Mr. Alonzo Gartley 
 for presentation to the members of the Social Science Association of Honolulu. 
 After reading, the members of this Association kindly consented to the request of 
 Mr. H. P. Agee that it be published by the Experiment Station of the Hawaiian 
 Sugar Planters' Association. In this paper the writer has attempted to briefly 
 present his point of view and experience in the work for the improvement of 
 certain economic plants through bud selection. His experience has covered about 
 twenty years of active work with plant improvement, mainly with corn, tobacco, 
 asparagus, citrus fruits, and some other farm crops. Individual sugar cane plant 
 studies were begun in February, 1920, by the writer and associates of the 
 Experiment Station of the Hawaiian Sugar Planters' Association. The writer 
 believes that the results of this effort will be of particular scientific interest and 
 great commercial importance. 
 
 A. D. SHAMEL. 
 March 12, 1921. 
 
 909144 
 
CONTENTS 
 
 Page 
 
 Plant Improvement 1 
 
 Definition of the Terms Bud Variation and Bud Selection 2 
 
 Objects of Bud Selection 4 
 
 The Origin of Varieties from Bud Mutations 4 
 
 The Isolation of Strains in Established Varieties 12 
 
 The Elimination of Undesirable Strains 15 
 
 The Amelioration of Varieties and Strains Through Bud Selection 15 
 
 Individual Plant Performance Eecords 16 
 
 The Commercial Utilization of Individual Plant Eecords ^ 20 
 
 The Selection of Superior Parent Plants 21 
 
 Progeny Tests 21 
 
 The Scientific Study of Bud Mutations and Bud Selection 22 
 
 Pioneers in Bud Mutation and Selection Work 22 
 
 Summary 23 
 
 Literature Cited 24 
 
 Explanation of Plates 27 
 
The Improvement of Plants Through Bud 
 
 Selection 
 
 PLANT IMPROVEMENT. 
 
 We are indebted to Charles Darwin for much of our knowledge of the be- 
 havior of animals and plants under domestication (14, 15). His investigations 
 established many of the principles of, and laid the foundation for, the further 
 scientific study of organic evolution. The records of his observations and experi- 
 ments with plants have furnished a large amount of fundamentally important 
 data and reliable information which has constituted the basis for much of the 
 recent constructive work for plant improvement. He states that the conscious 
 or unconscious selection of superior plants for propagation by man has been 
 carried on for about as long a time as agriculture has existed. He found in 
 ancient Chinese encyclopedias (15), translated by the Jesuits in the 18th cen- 
 tury, records of recommendations for the preservation and propagation of the 
 best plants, the choice of large seeds for planting, and the history of an improved 
 variety of rice secured through the selection and propagation of superior plants 
 by the Emperor Khang-hi. Rice is one of the best examples of the value of plant 
 improvement work. At the present time there exist more than 5,000 local varie- 
 ties in different rice-growing districts of the world which have been developed 
 through plant selection and propagation. 
 
 The sexuality of plants was demonstrated by Camerarius in 1691. The first 
 hybrid of which we have a record was made by Thomas Fairchild, an English 
 gardener, in 1719. Knight, an eminent English student of plant life, contributed 
 a large amount of information to our knowledge of plant hybridization. Van 
 Mons, a Belgian horticulturist, produced a number of improved varieties of plants 
 through selection. 
 
 The re-discovery of Mendel's famous law in 1900 (3) and the publication 
 of De Vries' mutation theory in the following year (72) marked a new era in 
 plant improvement. These contributions stimulated a widespread interest in the 
 study of plant improvement which has been unequaled in the history of agricul- 
 ture. A large number of investigators are now devoting their entire time and 
 energy to a study of the various phases of this subject. Many universities have 
 inaugurated courses of instruction and study for students along these lines. A 
 number of research institutions have been established in the United States and 
 abroad for the purpose of investigating the fundamental principles underlying 
 the work of plant improvement. Several commercial organizations have been 
 built up for the sole purpose of carrying on practical plant improvement work for 
 particular crops. As a result of this intensive and systematic activity, plant im- 
 provement has become a subject of great scientific interest and large commercial 
 importance during recent years. 
 
 Much of the pioneer work for plant improvement has been carried on with 
 sexually reproduced plants. In science, sex, fecundation and the behavior of 
 hybrid plants have received the major share of attention. In practice, seed se- 
 lection has been the most important phase of plant improvement work. While 
 
it has been known for a long time that bud variation occurs in vegetatively propa- 
 gated plants, the study of this phenomenon has been somewhat neglected for 
 several reasons. It has been quite generally believed that when an asexually 
 propagated variety has become established no further selection is necessary. The 
 reasons for, and the necessity of, selection of plants grown from seed have become 
 matters of common knowledge. On the other hand, the causes of bud variations 
 are not fully understood as yet, the extent and frequency of this phenomenon 
 have not been determined except in the case of a few plants, and the facts con- 
 cerning the importance of bud variation and bud selection in the amelioration of 
 plants are not widely understood. Furthermore, the scientific study of seeds 
 produced under controlled conditions and of the behavior of the plants grown 
 from them provides particularly convenient and fascinating material for investi- 
 gation and demonstration. The results of such study have often been extremely 
 spectacular and have attracted a deservedly vital interest in the minds of the 
 general public. These and other related conditions have naturally led to a con- 
 centration of interest, both from the scientific and commercial standpoints, in 
 this phase of plant improvement and to a lack of interest in similar work with 
 vegetatively propagated plants. The purpose of this paper is to present evidence 
 to show that bud variations are of frequent occurrence in many plants and to 
 suggest the importance of bud selection in the economic improvement of those 
 plants. This discussion will be largely confined to the practical application of 
 bud selection work in the improvement of certain agricultural crop plants which 
 are of commercial value and importance and which are propagated without refer- 
 ence to sexual reproduction. 
 
 DEFINITION OF THE TERMS BUD VARIATION AND BUD SELECTION. 
 
 The term bud variation, as we understand it, applies to any variations that 
 take place in the soma of the plant as distinguished from the variations appar- 
 ently caused by sexual reproduction and shown by the behavior of seedlings. 
 Webber states (77) in this connection * * * "from our present knowledge 
 of the cytology of heredity we would assume that hereditary changes such as 
 those manifested by bud variation, as well as seedling variations, are due to re- 
 arrangements of the hereditary units or anlagen which occur during cell division. 
 In the case of seedling variation we assume that this rearrangement takes place 
 primarily during the progress of the reduction division that precedes the forma- 
 tion of sexual cells. So far as microscopic investigations go we have no evi- 
 dence that would strengthen the idea of such a redistribution of characters ever 
 taking place in somatic cells. However, we have the strongest of all possible 
 proofs that it does occur in the fact that in bud variation we get segregations of 
 character analogous to the segregations of seedlings." 
 
 Bud variations may be divided into two general classes: (1) those which are 
 not inherited and (2) those which are inherited. The non-heritable variations 
 include that type of variation which is the result of environmental influence and is 
 exhibited in the response of all kinds of plants in the same definite way to the 
 stimulation of environmental factors. 
 
In this discussion we are concerned primarily with the types of bud variations 
 which are inherited. These types may be conveniently divided into two classes, 
 (a) bud fluctuations or continuous bud variations and (b) bud mutations or dis- 
 continuous bud variations. Castle defines fluctuations as "those which are purely 
 quantitative, plus or minus, as compared with the prevailing racial condition" (10). 
 The value of bud fluctuation or continuous bud variations in the work of plant 
 improvement is a matter of dispute amongst some investigators. The particular 
 point at issue seems to be the possibility of changing the mode or increasing the 
 maximum through the continuous selection of maximum bud fluctuations. The 
 experience and observations of the writer have led him to believe that by con- 
 tinuous selection in isolated strains the mean of the variation in the selected popu- 
 lation may be raised to a point more nearly approximating the maximum exhibi- 
 tion of the character in the strain. This conclusion has been reached as the 
 result of study and observations in the amelioration of several of our important 
 economic plants, among which may be mentioned the increase of the average 
 percentage of oil, protein, and starch in the composition of maize through the 
 systematic selection of seed possessing the maximum amounts of these elements 
 in their composition ; the increase in the yield of varieties of tobacco through the 
 systematic selection of seed from the best individual plants ; the increase in yield 
 of violets through the selection and propagation of cuttings from the most pro- 
 ductive plants ; the increase in the yield of potatoes by the selection of tubers from 
 the high-yielding hills ; the improvement in the yield of citrus fruits through the 
 propagation of the best-yielding parent trees ; and many other equally striking 
 similar experiences. It is argued by some of the opponents to this conclusion 
 that even if these improvements in plant behavior have been effected it will be 
 necessary to continue the selection by means of which they were secured in order 
 to preserve and maintain them. This idea may or may not be correct, and even 
 granting that it may be sound in some cases, it does not vitiate the fundamental 
 importance of selection in developing and maintaining improved production. It 
 is the personal opinion of the writer that through the selection of observed bud 
 fluctuations in any plant character, such as size, number, or chemical composi- 
 tion, those of genetic character will be included so that through repeated selec- 
 tion races will be developed which are progressively larger, more productive, or 
 otherwise changed in the direction of the selection. From the commercial stand- 
 point it is thought that this phase of plant breeding is the most important one 
 concerned in the work for the improvement of plants. 
 
 The terms bud mutations or discontinuous bud variations in this discussion 
 will be used to define sudden or marked variations from the parental forms in 
 vegetatively propagated plants. Darwin called such variations bud sports, but 
 this term has been largely superseded by the term bud mutation as proposed by 
 De Vries. Many of our valuable varieties and strains of cultivated plants have 
 originated from bud mutations. It is probable that amongst vegetatively propa- 
 gated plants a majority of the important commercial varieties have originated in 
 this way. In seed propagated plants, it is the writer's conviction that a consid- 
 
erable number of important varieties, which are commonly thought to have arisen 
 from crossing, have, as a matter of fact, originated as bud mutations. 
 
 The term bud selection as used in this paper may be denned as the selection 
 and propagation of heritable bud variations which, for one reason or another, are 
 better suited for cultivation than the parent plants. Bud variations are of no 
 value in the work for the improvement of plants unless they are preserved and 
 propagated. Their preservation depends wholly upon selection. It naturally 
 follows, then, that bud selection is the agency through which bud variations are 
 perpetuated and utilized in the work of plant improvement. 
 
 OBJECTS OF BUD SELECTION. 
 
 The fundamental objects of bud selection in the work of plant improvement 
 may be classed as follows: (1) to secure new and better varieties of plants 
 through the selection and propagation of striking and valuable bud mutations; 
 (2) to isolate strains of established varieties which show characteristics of greater 
 merit or value than those of the parent varieties; and (3) to bring the average 
 performance of the population of a strain or variety up to that exhibited by the 
 maximum individual performance or as nearly so as is found to be practical. 
 
 THE ORIGIN OF VARIETIES FROM BUD MUTATIONS. 
 
 An impressive number of important cultivated varieties of plants are defi- 
 nitely known to have originated from bud mutations (8, 15, 13). This number is 
 probably only a small fraction of the actual total number of valuable varieties 
 which have originated in this way. This condition arises from the fact that 
 many of the supposed variations in seedlings which have been selected and propa- 
 gated as new varieties were doubtless the result of the seeds having come from 
 different branches of the parent plants. These branches as a result of bud 
 variations transmitted to the seeds their different tendencies which were discov- 
 ered as variations in the plants grown from these seeds. In such instances the 
 originators of the varieties propagated from such selected variations have often 
 assumed that the variations were the result of hybridization or other sexual 
 influences, when as a matter of fact they are actually the result of bud variation. 
 
 It will be possible in this paper to refer to only a small number of the known 
 cases of valuable varieties of plants which have originated from bud mutations. 
 A few typical instances in different plant groups will be cited in order to empha- 
 size the importance of this factor in plant improvement work and to indicate 
 something of the possibilities of further effort along this line. 
 
 Many varieties of roses have originated from bud mutations. Carriere (8) 
 gives in his account of bud varieties published in 1865 a list of fifty standard 
 rose varieties known to have originated from bud mutations and states that no 
 attempt was made to make the list complete. The 1919 Annual of the American 
 Rose Society contains a list (25) of 429 varieties of American roses, of 
 which 116, or more than 25 per cent, are definitely known to have originated from 
 bud mutations, for the most part within the past twenty-five years. Carriere (8) 
 
and Darwin (15) both present evidence, which has been confirmed repeatedly, 
 that the moss rose varieties have originated from bud mutations and, in turn, 
 smooth branch varieties have sprung from moss varieties through bud variations. 
 For example, the common double moss rose originated from the smooth-bran 
 Provence rose by bud variation. The moss rose has produced the Provence rose 
 in which the branches are partially or wholly destitute of moss. 
 
 From the Killarney rose, solid pink in color, a large number of varieties 
 have been secured through the selection of bud mutations (38). These bud varie- 
 ties have differed in color from white -to red, in flower arrangement from semi- 
 doubles to doubles, and in habit of growth from bush to climbing forms. Amongst 
 these varieties may be mentioned the White Killarney, Dark Pink Killarney, 
 Champ Weiland, Killarney Queen, Double White Killarney, Double Pink Killar- 
 ney, Red Killarney, Killarney Brilliant, Climbing Killarney (pink), and Climbing 
 White Killarney. 
 
 The Ophelia, a pink rose, is a variety of comparatively recent introduction 
 which is deservedly popular at the present time. This variety is very prolific in 
 the production of bud mutations (71), the most important of which include the 
 Ophelia Supreme, having light rose-pink flowers ; Rosalind, with coral-pink 
 flowers, changing to apricot-pink ; Silvia, having sulphur-yellow flowers, changing 
 to creamy shaded ; Evelyn, with larger flowers of a deeper shade and larger 
 blooms ; Rose Pink Ophelia, having smaller flowers but flowering more freely 
 than the Ophelia; May Martin, with mustard-yellow flowers; Madame Butterfly, 
 with flowers of greatly intensified color; White Ophelia, having white flowers; 
 and other varieties with flowers of varying shades of color and different types 
 of foliage. 
 
 The rose varieties having a climbing habit of growth have practically all 
 originated as bud mutations from bush forms (25). Examples of this phenome- 
 non include the Climbing Bridesmaid, the Climbing Cecile Briinner, the Climbing 
 Frau Karl Druschki, the Climbing La France, and the Climbing Rhea Reid. The 
 1919 Annual of the American Rose Society contains a list of 34 climbing varie- 
 ties of recent American origin which have been propagated from bud muta- 
 tions (25). 
 
 In chrysanthemums, a large proportion of the present cultivated varieties 
 Rave originated from bud mutations. Cramer (13) presents a list of 400 bud 
 varieties of the chrysanthemum. From this list of bud varieties the following 
 examples are presented: 
 
 Parent Variety. Bud Variety. Authority. 
 
 Alcester (Lord), 1882. Mr. Eobert Murdie, 1888. The Garden, 90, I, 145. 
 
 Inflected, butter-yellow. Inflected, salmon-yellow. 
 
 Andiguier (Edward), 1886. Mrs. William Walters, 1887. The Garden, 88, II, 498. 
 
 Jap., brown, purple, Jap., Carmine, 
 
 silver back. bronze-gold back. 
 
 Avalanche, 1887. Edw. Beckett, 1892. de Meulenaese, II, 49. 
 
 Snow-white. Jap., dark gold-yellow. 
 
In 1822, twenty-seven varieties of chrysanthemums were cultivated in Eng- 
 land, part of which had been imported, and some of which had originated from 
 the imported varieties through bud mutation. In 1836 three Chinese varieties 
 were imported which bore pink, speckled, and flesh-colored flowers, respectively. 
 The next year a single plant bore all three of these forms. 
 
 Chrysanthemum bud mutations frequently occur in the branches of the 
 plants and occasionally in the suckers. They may be propagated in either form. 
 The stability of the bud mutations must be determined by experimental propa- 
 gations unless it is a type which is known to be transmitted. The practicability 
 of this effort is shown by the fact that of the 8,800 varieties cultivated in Europe 
 in 1899 more than 5,000 were originated in this way. 
 
 In carnations, many of the valuable cultivated varieties have originated as 
 bud mutations. Dorsey (18) mentions among the important commercial bud 
 varieties the Victor, Chicago, White Lawson, White Enchantress, Rose Pink 
 Enchantress and Enchantress Supreme. 
 
 In hibiscus, Darwin (15) mentions several striking bud mutations, including 
 one where the bud variation produced flowers and leaves resembling in shape 
 those of another species. Both the parental form and the bud mutation were 
 extensively propagated by cuttings and came perfectly true. Stout (69) records 
 the origin of a dwarf form of Hibiscus oculiroseus as a mutation. Carriere (8) 
 cites two instances of varieties of hibiscus originating from bud mutations, viz., 
 H. syriacus, variety flore pleno variegaia, with variegated yellowish-white 
 leaves, appearing in a green-leaved plant in 1858, and H. syriacus, variety varie- 
 gata, with remarkably variegated leaves, an example of which is shown in Plate I. 
 While in Honolulu in 1920 the writer's attention was called to several cases of 
 bud mutation in hibiscus plants, including double flowers borne by single-flower 
 plants and the development of branches having very different foliage on the same 
 stem. 
 
 In dahlias, Darwin (15) cites the case of the Butterfly variety, in which the 
 same plants produced double and single flowers, "here white petals edged with 
 maroon, there of a uniform deep maroon." He also records the instance of a 
 plant which bore two different kinds of self-colored flowers as well as a third 
 kind which partook of both colors beautifully intermixed. Similar illustrations 
 of bud mutations in dahlias have been repeatedly observed in gardens in southern 
 California during recent years by the writer, an example of which is shown in 
 Plate 2. The Le Grand Manitou, a leading dahlia variety having white flowers 
 with purple stripes, has produced a purple-flowered variety, the Purple Manitou, 
 as shown in Plate 3, by bud mutation which is being cultivated at the present time 
 to some extent. 
 
 Many other instances of varieties of common flowering plants arising from 
 bud mutations might be mentioned. Bud varieties of the Sweet William, Snap- 
 Dragon, Stocks, Cyclamen, Gladiolus, Fuchsia, Violet, Hydrangea, Geranium, 
 and Evening Primrose are widely cultivated by gardeners and florists. We be- 
 
lieve, however, that the examples already given are sufficient to show the im- 
 portance of this phenomenon in the work for the improvement of flowers. 
 
 With ornamental plants the selection and propagation of bud mutations has 
 provided a large number of valuable varieties for cultivation. 
 
 The Euonymus varieties are amongst the most valuable and widely grown of 
 all ornamental plants. Carriere (8) calls attention to five bud varieties of 
 E. Japonica, viz., argentea, aurea, flavida, fasciata, and calamistrata, and states 
 that many other varieties which differ in variegation or sometimes by the form of 
 leaves have been produced by the selection and propagation of bud mutations. 
 
 Roeding (46), one of the leading plant propagators in California, propagates 
 and distributes the following varieties of E. Japonic a which he personally told the 
 writer in August, 1919, were originated from bud mutations: Albo-marginata 
 (silver-margined), albo-variegata (^silver- variegated), aureo-variegata (golden- 
 variegated), coiumnaris (tall-growing), viridi-variegata (Due d'Anjou), aureo- 
 marginata (golden-margined), and niicrophylla (dwarf form). The writer 
 recently has found all of these variations occurring as bud mutations in Euony- 
 mus plants growing in the vicinity of Riverside, an example of which is shown 
 in Plate 4, and has complete evidence as to the origin of the above mentioned 
 cultivated varieties from bud variations. 
 
 Pittosporum varieties are now widely grown as ornamental lawn plants and 
 for shrubbery. They rank in importance in this respect with the Euonymus 
 varieties. Carriere (8) mentions that P. Tobira variegatum originated from 
 P. Tobira as a bud mutation. This variegated-leaved variety is one of the most 
 popular ones in California and has been repeatedly found by the writer (52) 
 occurring as bud mutations in the green-leaved parental form. Other mutations 
 of P. Tobira, differing in leaf-form and variegation, have- been observed by the 
 writer in plants growing in the vicinity of Riverside, California, an example of 
 which is shown in Plate 5. Some of these have been isolated through bud selec- 
 tion and are now being cultivated to an increasing extent, an illustration of which 
 is shown in Plate 6. 
 
 In Coleus, Stout (70) found that bud variations are common and give rise 
 to numerous different types which may be quite constant from the first or can be 
 made so by selection. In pedigree cultures he isolated 15 distinct varieties through 
 bud selection which were characteristically different in color patterns. He con- 
 cludes from his investigations that in Coleus asexual and sexual reproduction 
 are not fundamentally different in respect to the extent and range of variation. 
 
 In ferns, Boshnakian (6) states that in the common Boston fern (Nephro- 
 lepis ex alt at a bostoniensis) over 65 commercial varieties have originated as bud 
 mutations since 1898. 
 
 In the Oleander (Nerium oleander), one of the oldest of cultivated orna- 
 mental plants, the writer found in 1918 near Thermal, California, a branch bud 
 mutation having variegated leaves borne by green-leaved plants, as shown in 
 Plate 7, and uniformly variegated plants which had been propagated from similar 
 mutations. 
 
8 
 
 In Irish potatoes, Carriere (8) shows that many striking bud mutations 
 occur which have been preserved through selection. East (19) records bud mu- 
 tations as shown by the color, shape, character of eyes, and habit of growth, of 
 the tubers which remained constant in propagation. Gilbert (26) says that the 
 principal method of improving the Irish potato is through bud selection. 
 
 In the sweet potato, H. C. Thompson, formerly horticulturist of the U. S. 
 Department of Agriculture, in a personal statement in 1917 informed the writer 
 that this plant is exclusively propagated vegetatively and that all commercially 
 grown sweet potato varieties have originated as bud mutations. 
 
 In apples, Hedrick (28) describes four strains which are now commonly 
 accepted as varieties of the Twenty-ounce which originated as bud mutations. 
 Farmer (23) describes the Oswego variety as originating as a bud mutation of 
 the Northern Spy. Fletcher (24) gives an account of the Chesebro Spy variety 
 which originated as a bud mutation of the Northern Spy. Mead (34) records a 
 mutation of the Gravenstein variety having fruits with solid red color which has 
 been propagated through bud selection. A seedless mutation of the Porter apple 
 was discovered and called to the writer's attention by J. A. Dorrance at Scotland, 
 Connecticut, in 1913. This consisted of one of the main limbs in an old tree. 
 It has borne similar fruits each year since then and has been propagated. 
 Beach (4) describes the Banks apple as a mutation of the Gravenstein variety, 
 the Collamer as a sport of the Twenty-ounce, and the Red Russet and Olympia 
 as mutations of the Baldwin variety. Castle (9) refers to two strains of the 
 Williams apple, one having conspicuously striped fruits and the other having 
 nearly solid red color. Other striking mutations in apple varieties have been 
 observed, an example of which is shown in Plate 8, including red and russet 
 variations of the Rome (1, 2), oblong-shaped Grimes (1), solid dark-red varia- 
 tions of the striped Ben Davis, and various shaped fruits in Baldwin apple trees 
 observed by the writer at Seymour, Connecticut, during recent years in indi- 
 vidual tree performance record plats of trees of these varieties in the J. H. Hale 
 orchards. 
 
 In peaches, Darwin (15) records peach trees producing buds which when 
 developed into branches yielded nectarines and that six named and several un- 
 named varieties of the peach have thus produced several varieties of the nec- 
 tarine. Carriere (8) describes two varieties of the peach, the carnation-flowered, 
 having a flesh-rose color, and the many-colored-flowered, possessing white striped 
 colors, which originated as bud mutations. He also gives the willow-leaved red 
 Madeleine and the laciniate-leaved red Madeleine as varieties originating as bud 
 sports. Fletcher (24) mentions a white-fleshed clingstone or semi-freestone va- 
 riety originating as a bud mutation of the Early Michigan. Powell (40) records 
 the propagation of an early ripening mutation of the Mountain Rose peach. The 
 writer found several branches in Elberta trees in the performance-record plat 
 of this variety in the J. H. Hale orchards at South Glastonbury, Connecticut, in 
 1912, bearing fruits without pubescence and otherwise apparently identical with 
 fruits of the new J. H. Hale variety. Furthermore, branches were found in 
 
J. H. Hale peach trees bearing typical Elberta fruits, indicating that the J. H. Hale 
 variety originated as a bud mutation. The writer also observed branch muta- 
 tions in yellow-fleshed-f ruited Elberta trees bearing white-fleshed fruits but other- 
 wise like the Elberta fruits. 
 
 In prunes, a large-fruited variety Coates No. 1418, an illustration of which 
 is shown in Plate 9, originating as a bud mutation of the French prune, was 
 described by the writer in 1919 (57). Coates propagates commercially no less 
 than three varieties of the French prune which have originated as bud muta- 
 tions (11). Darwin (15) records that a tree of yellow Magnum Bonum plum, 
 forty years old, produced a branch mutation which bore red Magnum Bonums. 
 
 In grapes, Carriere (8) states that bud variation is comparatively common. 
 Amongst other examples he cites the origin of the white seedless Corinth as a 
 mutation from the parent seedy variety. Fletcher (24) records the King, a bud 
 variety of the Concord. Paddock (37) gives mammoth or giant forms of the 
 Concord identical with Eaton as originating from bud mutations of the Concord. 
 Ballou (1) records a bud variety of the Concord with exceptionally large berries 
 which came true under his observation for two successive crops. The Pierce 
 variety originated as a bud mutation from Isabella, according to Le Long (33). 
 The writer has photographed bud mutations of the Thompson seedless grape, as 
 shown in Plate 10, with conspicuously large berries and different foliage than that 
 of the parent form from the vineyard of C. L. Edmunds of Thermal, California. 
 Roeding has introduced and propagates commercially a mammoth or giant 
 Thompson seedless variety which he has stated to the writer originated as a 
 bud mutation. 
 
 In pears, Carriere (8) says that the following varieties have given by bud 
 variation variegated varieties, Duchesse d'Angouleme, Amanlis, Guenette, Saint- 
 Germain, Bergamotte d'Automne, Culotte de Suisse, and others. The writer 
 observed and photographed in 1918 in commercial pear orchards near Tehachapi, 
 California, limb mutations in Bartlett pear trees bearing striped fruits and in 
 other instances fruits possessing very different characteristics of shape, size, and 
 color from the normal fruits on the same or neighboring trees, as shown in Plate 
 11. Evidence was found to indicate that several of the strains of the Bartlett 
 variety in those orchards, including the Winter Bartlett, the Sheep's Nose Bart- 
 lett, and Corrugated Bartlett, originated as bud mutations. 
 
 In strawberries, Farmer (22) states that the Pan-American, an ever-bearing 
 variety, originated as a bud sport of the Bismark. 
 
 An illustration of bud variation in the artichoke is shown in Plate 12. 
 
 In citrus fruits, the investigations of the writer in Brazil in 1913 (17) indi- 
 cate that the Washington Navel orange, a typical tree of which is shown in Plate 
 13, one of the most important fruit varieties in existence, originated as a bud 
 mutation of the Selecta variety at Bahia, Brazil, and was first propagated in 
 1820. Reasoner (45) states that the Foster, a variety of grapefruit producing 
 pink-colored fruits, originated as a bud mutation of the Walters variety. In a 
 letter to the writer dated August 6, 1915, Reasoner describes a pink-fleshed mu- 
 tation of the Marsh grapefruit. A similar mutation was found by the writer in 
 
10 
 
 a Marsh tree on the L. V. W. Brown ranch at Riverside, California, in 1919 (61). 
 Conner (12) propagates commercially a variety of grapefruit, the Conner Pro- 
 lific, which he states originated as a bud mutation of the Bowen. The writer has 
 isolated through bud selection in the Marsh grapefruit variety, as grown in Cali- 
 fornia, a mutation having conspicuously flattened and commercially seedless fruits 
 (54, 66). An illustration showing a typical fruit of this strain is shown in Plate 
 20. It is of much greater commercial value than the parent variety and is now 
 being extensively propagated by nurserymen in California. 
 
 In cotton, the Pima, the Yuma, the Gila, and the Somerton, improved long 
 staple varieties, originated as mutations, according to Kearney (29, 30, 31), their 
 originator, and are amongst the most important commercially in the United States. 
 
 In tobacco, the writer (47) in 1904 in the Connecticut Valley originated the 
 Hazlewood variety as a mutation of the Cuban variety. This variety has fur- 
 nished the foundation for one of the important agricultural industries in America. 
 In 1903 and 1904 the writer secured through the selection of mutations the Uncle 
 Sam Sumatra, which is grown commercially in Florida, Georgia, and Alabama; 
 the Halladay, which is extensively grown in the Connecticut Valley, and other 
 commercial tobacco varieties. 
 
 In the cacti, Griffiths (27) records the origin of several spineless varieties 
 as bud variations of spiny forms. 
 
 In corn, Emerson (21) records the occurrence of recurring somatic varia- 
 tions in variegated ears. De Vries (74) describes mass mutations in maize 
 and (73) other forms of mutation, including unbranched varieties, loss of starch 
 in the grains, and dwarf forms. East and Hayes (20) report various forms of 
 somatic mutations in corn, including dwarf, bifurcated, and branched ears. 
 
 In sugar cane, Carriere (8) mentions this plant as one which shows a large 
 number of distinct bud varieties. Darwin (15) states that sugar cane is one of 
 several plants that sometimes produce new varieties from the stock or root. He 
 .quotes Caldwell (7) as saying that the Ribbon cane has sported in Mauritius 
 "into a perfectly green cane and a perfectly red cane from the same head. I veri- 
 fied this myself, and saw at least 200 instances in the same plantation and the 
 fact that completely upset all our preconceived ideas of the differences of color 
 being permanent. The conversion of a striped cane into a green cane was not 
 uncommon, but the change into a red cane, universally disbelieved, and that both 
 events should occur in the same plant, seemed incredible. I find, however, in 
 Fleischman's 'Report on Sugar Cultivation in Louisiana for 1848' by the American 
 Patent Office, the circumstance is mentioned, but he says he never saw it him- 
 self." 
 
 The Commissioner of Agriculture for the West Indies (35) reported several 
 instances of striking bud mutations in sugar cane that had recently come to his 
 attention, and presented colored illustrations of two of them. (An abstract of 
 this article with black and white reproductions of the illustrations has appeared 
 in the Journal of Heredity (39).) These observations were summarized as 
 follows : 
 
11 
 
 1. Bud variations occur in the sugar cane. 
 
 2. They have been recorded from widely-separated countries, Mauritius, 
 
 Louisiana, West Indies, and Queensland. 
 
 3. The difference between sport and mother-plant are often as considerable 
 
 as those between recognized distinct varieties of the sugar cane. 
 
 4. Bud variation may give rise to : 
 
 (a) Differently colored side shoots on one cane. 
 
 (b) Differently colored canes in one stool springing from the same 
 
 mother plant. 
 
 (c) A cane with some joints striped and some unstriped. 
 
 5. Plants grown from cuttings of the sports tend to come true to color. 
 
 6. The cane giving rise to sports, whenever recorded, has been a striped or 
 
 ribbon cane. 
 
 The observations of other writers have disproven this last conclusion, as is 
 shown by Deerr's account of the Home variety mentioned below. Some bud 
 varieties of cane also show differences in hardiness and in sugar content. 
 
 Deerr (16) states that the Lahaina and Bourbon varieties originated as bud 
 mutations from the Mignonne variety. He records that the yellow-violet 
 Cheribon and purple-violet Cheribon varieties originated as bud mutations of the 
 ribbon cheribon variety and that the white and black cheribon are bud varieties 
 of the ribbon cane. Also that the White Tanna and Black Tanna varieties origi- 
 nated as bud sports of the Striped Tanna. The Rose Bamboo and Purple Bam- 
 boo varieties arose from mutations of the Striped Bamboo, and the Yellow Tip 
 variety originated as a bud mutation of the Striped Tip. Deerr says that the 
 Home variety is of particular interest because it is one of the earliest, if not the 
 earliest, recorded instance of a striped cane originating from a self-colored cane 
 as a bud mutation. He also cites the Green Rose Ribbon variety originating as 
 a bud sport of the Otaheite variety. In the striped cane known as the Tsimbec, 
 a variety called the Iscambine rouge arose from a bud mutation. He says that 
 the Branchu blanche is a self-colored sport from the Branchu rayee. Further, 
 he records the case of green and yellow ribbon cane springing from the Yellow 
 Caledonia. 
 
 In December, 1890, Mr. John Home (35), then Director of Forests and 
 Botanical Gardens, Mauritius, in a letter to the Director of the Royal Gardens, 
 Kew, published in the Kew Bulletin for 1891, wrote: "Of new varieties orig- 
 inating as bud sports we have eight or nine in Mauritius alone ; some of them 
 very fine canes and they are extensively planted. Most of them are hardier than 
 their parents and they yield more sugar. They are mostly obtained from new 
 canes recently introduced. The sudden change of climate, soil, and other circum- 
 stances cause them to be thrown off. More of them might be obtained if the 
 planters were more observing than they are and closely followed the cane cutters 
 throughout their fields. As things are, a new variety is only observed should it 
 chance to spring up in an outside row." 
 
 The Hawaiian Sugar Planters' Association Experiment Station has collected 
 a large amount of information showing the frequent occurrence of bud mutations 
 in sugar-cane varieties grown in the Hawaiian Islands. 
 
12 
 
 The writer is of the opinion that systematic economic bud selection work 
 with sugar cane will give particularly early and striking results in the way of 
 improved sugar production per acre, which will be worth millions of dollars 
 annually to the industry. 
 
 The simple elimination through bud selection of some of the undesirable 
 strains arising from bud mutations in the established varieties will in itself 
 achieve this result. This work can be carried on without any possibility of loss 
 to the industry or the rearrangement of any of the methods of culture other than 
 that of securing seed cane for planting. The cost of this work will be very 
 small in comparison with its value. The increased production of sugar through 
 the culture of uniform and superior varieties will be effected at no greater cost 
 than that previously sustained when growing the more variable varieties with 
 their resulting lower yields. 
 
 In pineapples, the writer observed in May, 1920, amongst the plants in a 
 commercial field of the Smooth Cayenne variety grown on the Island of Oahu, 
 T. H., many apparent striking bud mutations. The leaves of some plants were 
 smooth while others were sharply serrate. The shape of some of the fruits was 
 cylindrical, while in other cases it was pyriform, ovate, obovate, globular, or 
 modifications of these shapes. About 25 per cent of the plants had no fruits, 
 while others were bearing fruits of different stages of ripeness. Some of the 
 plants observed possessed a single crown, while others had multiple crowns. 
 Frequent examples of plants having distinct strain characteristics, apparently 
 originating as bud mutations, were found, indicating that bud variation is of 
 common occurrence in this variety. 
 
 The above list of varieties arising from bud mutations contains only a few 
 of those on record. Furthermore, the recorded instances constitute only a small 
 part of the total number of such cases. This condition exists to a large extent 
 because most observers have not realized the possibility of the occurrence of bud 
 mutations and their relation to the production of new varieties. For this reason 
 it has been quite generally believed that bud varieties are fixed, and any new 
 forms discovered in them have usually been ascribed to seed origin. Enough 
 instances have been given to prove the importance of bud mutations in plant 
 improvement work, and particularly so in the case of those plants which are 
 vegetatively propagated. 
 
 THE ISOLATION OF STRAINS IN ESTABLISHED VARIETIES. 
 
 The term strain as here used designates a group of individuals of an agri- 
 cultural variety differing from all other individuals of the variety in one or more 
 constant and recognizable characteristics and capable of perpetuation. This dis- 
 cussion will be largely confined to vegetatively propagated strains which in scien- 
 tific literature are frequently referred to as clones, as suggested by Webber (76). 
 
 Strains oftentimes arise from the unintentional propagation of bud muta- 
 tions. For example, the writer and his associates have found in their study of 
 the Washington Navel orange (64) that this variety as grown under California 
 conditions has given rise to fourteen strains through bud mutation within a few 
 
13 
 
 bud generations. Typical fruits of some of these strains are shown in Plate 14. 
 These strains for the most part have been unintentionally propagated by nursery- 
 men and others. Some of them have been found to be very undesirable from 
 the economic standpoint, while others apparently possess some value for par- 
 ticular conditions of culture. 
 
 Varieties of economic value and importance often degenerate or run out 
 through the unintentional or intentional propagation of undesirable strains origi- 
 nating as bud mutations. In the Washington Navel orange variety as grown in 
 California, the writer has found that the undesirable Australian strain, having 
 rank-growing trees, an example of which is shown in Plate 15, which character- 
 istically bear small crops of fruit of inferior quality, as shown in Plate 16, has in 
 some instances been propagated to such an extent as to render the variety an 
 unprofitable one. In a few cases the Australian strain has been intentionally 
 propagated by nurserymen because of the vigorous, hardy growth of the trees 
 and owing to a lack of knowledge of their fruiting habits. However, the propa- 
 gation of the Australian strain has usually been unintentional. The trees of this 
 strain produce unusual numbers of vigorous-growing branches, frequently called 
 suckers. This growth was formerly highly prized and commonly used for the 
 propagation of the Navel orange variety in California. Inasmuch as the supply 
 of such bud-wood was much more abundant in Australian trees than in the high- 
 yielding and desirable trees, budders naturally secured more bud-wood from the 
 Australian than from the Washington or best strain trees where it was obtained 
 without regard to fruit production. 
 
 The isolation of the valuable strains of commercial varieties through bud 
 selection is one of the important factors in plant improvement work. After 
 strains have been isolated, their value for cultivation determined, and their char- 
 acteristics recognized, they are frequently classed as agricultural varieties. 
 
 In potatoes, Myers (36) reports the results of hill selection from high-yield- 
 ing and low-yielding strains of potatoes in New York. The Cornell experiments 
 showed a five-years' average yield of three low-yielding strains of 82 bushels per 
 acre as compared with a five-years' average yield of three high-yielding strains 
 of 208 bushels per acre. The increase in yield secured through bud selection in 
 these experiments amounted to an average of 126 bushels per acre. Similar re- 
 sults were obtained by Daniel Dean (36) of Nichols, N. Y., who began hill selec- 
 tion with his variety of potatoes in 1904 and whose records show a difference in 
 production in his high-yielding as compared with his low-yielding strains of 280 
 bushels per acre in 1912 and 140 bushels per acre in 1913. The difference in 1913 
 would have been greater except for an early frost. G. D. Brill in one year's hill 
 selection work secured an increase of 107 bushels per acre as shown by the dif- 
 ferences in yields of a high-yielding as compared with a low-yielding strain of 
 the same commercial variety (36). 
 
 The comparative yields of high- and low-yielding strains of the Carmen No. 3 
 potato variety isolated through hill selection during 1904, 1905, and 1906, are 
 reported by Waid (75) of the Ohio Agricultural Experiment Station. In these 
 experiments the high-yielding strain produced a three-years' average of 774 
 
14 
 
 bushels per acre as compared with an average of 492 bushels per acre for the 
 low-yielding strain, and a yield of 607 bushels per acre secured from seed tubers 
 selected without reference to individual hills. The high-yielding strain produced 
 an average of 262 bushels per acre, or about 35 per cent more than the low- 
 yielding strain, and 167 bushels per acre, or about 22 per cent, more than the 
 check as the result of three years of bud selection work. His studies showed 
 clearly that with few exceptions the low-yielding plants remained unproductive 
 and that the high-yielding hills for the most part remained productive, as was also 
 shown to be the case in the Cornell experiments referred to above. 
 
 In citrus varieties, the writer and his associates have recorded the behavior 
 of 14 strains of the Washington Navel orange (64) [typical fruits of some of 
 these strains are shown in Plates 17, 18, and 19] ; 12 strains of the Valencia 
 orange (65) ; 7 strains of the Marsh grapefruit (66) [typical fruits of two of 
 these strains are shown in Plates 20 and 21] ; 8 strains of the Eureka lemon (67) 
 [typical fruits of three of the strains are shown in Plates 22, 23, and 24] ; and 6 
 strains of the Lisbon lemon (68) [typical fruits of several strains are shown in 
 Plates 25 and 26] . These strains originating as bud mutations have, for the most 
 part, been unintentionally propagated. They have been found to be capable of 
 perpetuation through bud propagation. The isolation of the valuable strains and 
 the elimination of the undesirable ones through systematic bud selection has been 
 demonstrated to be possible and commercially practicable. 
 
 In timothy, Webber (78) found great differences experimentally and com- 
 mercially in the yield of high- and low-producing strains isolated through bud 
 selection. Experimentally, he shows that the high-yielding strains produced 
 an average of more than six times the yield of the low-yielding strains. 
 
 In prunes, the writer has begun the study of the behavior of seven strains 
 originating as bud mutations of the French prune variety in California ; an 
 example of one of these mutations is shown in Plate 9. The data are incomplete 
 as yet, but enough information has been secured to warrant the statement that 
 these strains are very different in fruit and foliage characteristics and that these 
 differences are of great commercial importance to the prune industry. 
 
 In sugar cane, the writer and associates in the Hawaiian Sugar Planters' 
 Experiment Station during 1920 found in fields of the H 109, the Yellow Cale- 
 donia, and the D 1135 varieties many plants resembling distinct strains. Their 
 appearance and occurrence indicated that they originated as bud mutations. The 
 plant differences found in these strains included the number of stalks of each 
 stool and their habits of growth, weight, length, circumference, shape, and color 
 of stalks, amount of juice in the stalks and its sucrose content, and other impor- 
 tant characteristics. These data are not complete as yet, nor available for pub- 
 lication, but it is likely that they will be announced when these investigations 
 have proceeded far enough to warrant this action. 
 
 Most of the work in the isolation of strains has not been reported because 
 such records have usually been withheld until the strains have been tested and 
 introduced as varieties. In strawberries (5, 32), apples (41, 42, 43, 44), and 
 
15 
 
 other crops such work has been reported upon, but the writer feels that it is not 
 necessary here to quote them in order to demonstrate the importance of this 
 work. The isolation of valuable commercial strains arising as bud mutations of 
 established varieties in vegetatively propagated plants has been found to be prac- 
 ticable, and it seems likely that the work can be made increasingly useful when 
 once its importance is more generally understood. 
 
 THE ELIMINATION OF UNDESIRABLE STRAINS. 
 
 The undesirable strains in established commercial varieties arising from bud 
 mutations include those in which the plants produce unsatisfactory and unprofit- 
 able crops. For example, the Shade-tree strain of the Eureka lemon, (67) an 
 illustration of which is shown in Plate 27, which has been found by the writer 
 and his associates to constitute more than 25 per cent of the population in some 
 lemon orchards. The trees of this strain produce low yields of coarse thick-rind 
 fruits, lacking in juice. The culture of these trees has been found to be un- 
 profitable wherever investigated on account of their poor production. A number 
 of lemon orchards have been continuously unprofitable from this cause alone. 
 The elimination of the trees of the Shade-tree strain in established orchards 
 through top-working them with buds secured from productive trees of the de- 
 sirable Eureka lemon strain, an illustration of which is shown in Plate 28, has 
 resulted in the development of heavy-bearing trees and profitable orchards. 
 
 In established orchards or plantations where individual trees or plants of 
 undesirable strains are discovered, such trees or plants can be successfully 
 eliminated by top-working with carefully-selected buds or grafts secured from 
 desirable parent trees, as shown in Plate 29, or by replanting with young trees or 
 plants of a desirable strain. In the propagation of young trees or plants the 
 elimination of the undesirable strains can be effected by using as parent trees or 
 plants only those individuals which are known not to transmit the undesirable 
 strain characteristics. 
 
 The purity of commercial bud varieties can be maintained by eliminating or 
 avoiding the propagation of the undesirable strains which frequently originate 
 as bud mutations; examples of such mutations are shown in Plates 30, 31, and 32. 
 The improved varieties of plants are the most valuable and precious possession 
 of agriculture. Without selection most varieties are known to degenerate and 
 run out, largely due to the appearance of undesirable and unprofitable strains. 
 Therefore, the importance of purifying the proven and established varieties 
 through the elimination of undesirable strains must be obvious to every thinking 
 and unprejudiced person. 
 
 THE AMELIORATION OF VARIETIES AND STRAINS THROUGH BUD SELECTION. 
 
 The term amelioration of varieties and strains as here used may be defined 
 as the keeping up or the bringing up of the average performance of the indi- 
 viduals to that shown by the behavior of the best individuals in the variety or 
 strain through bud selection. The writer is of the opinion that from a com- 
 mercial standpoint this phase of plant improvement is the most important one of 
 
16 
 
 all. This work can be accomplished (1) by means of individual plant perform- 
 ance records whereby the best individual parent plants for propagation can be 
 found, and (2) through the propagation of the superior plants selected on the 
 basis of performance records and progeny tests. 
 
 INDIVIDUAL PLANT PERFORMANCE RECORDS. 
 
 Individual plant performance records for plant improvement work include 
 systematic records, for as long a period as is found to be necessary in order to 
 determine the inherent plant characteristics, of the quantity and commercial 
 quality of the crop, the variability of the product, the season of production, the 
 habit of growth of the plant, and any other data likely to be of value in judging 
 the behavior and value of the plant. In order to illustrate this work the method 
 of securing individual citrus tree performance records as carried on by the 
 writer and his associates in southern California for the past eleven years will be 
 briefly described (48, 49, 51, 64). There have been two phases in the evolution 
 of this work first, the investigational, and, second, the commercial. In the in- 
 vestigational work carefully-selected plats of about one hundred full-bearing trees 
 each were located in several of the best commercial orchards of the Washington 
 Navel orange, the Valencia orange, the Marsh grapefruit, the Eureka and Lisbon 
 lemon varieties. These locations were decided upon with particular regard to 
 environmental influences and cultural conditions, so that reliable data of inherent 
 tree characteristics could be secured. The location of two orchards in which the 
 investigational tree performance records were secured is shown in Plate 33. 
 
 Each individual tree in these plats was given a number so arranged as to 
 both identify and locate it. This number was painted on the tree trunks with 
 pure white lead paint, always in the same relative position and so as to be easily 
 legible and conveniently found when desired. 
 
 The fruits from each tree were picked by or under the immediate supervision 
 of the writer or his associates by expert pickers for the entire period of the 
 investigation. The fruits from each tree were studied immediately after picking, 
 as shown in Plate 34. They were assorted into the standard commercial grades 
 for the variety. The fruits of each grade were then assorted into the standard 
 commercial sizes for the variety. The weight and number of fruits of each size 
 in each grade were then carefully determined by the writer or his associates. So 
 far as possible, the same man conducted this work in each plat every year in 
 order to avoid differences due to the personal equation. After weighing and 
 counting each lot, the fruits were examined for variations and the number of 
 variable fruits of each class was recorded, as shown in Tables 1 and 2. During 
 the course of this performance record work descriptions of tree and fruit char- 
 acteristics were recorded. These studies were conducted on a total of 858 Wash- 
 ington Navel orange trees, 179 Valencia orange trees, 253 Eureka lemon trees, 
 128 Lisbon lemon trees, 104 Marsh grapefruit trees, and a number of trees of sev- 
 eral citrus varieties of minor commercial importance. These records covered periods 
 of 4, 6, and 8 successive years, as the circumstances warranted, in order to carry 
 out the purposes of this investigation. The work entailed a large amount of 
 
TABLE 1. ORANGE PERFORMANCE RECORD. 
 
 DATE: Feb. 24, 1914. STRAIN: Washington. LOCATION: Highgrove, California. 
 
 GROWER: National Orange Company. GROVE: Vivienda. 
 
 VARIETY: Washington Navel. PLOT: 3. ROW: 14. NO. OF TREE: 27. 
 
 
 
 ORCHARD 
 
 STANDARD 
 
 CULLS 
 
 TOTAL 
 
 
 Orchard 
 
 
 
 
 946 
 
 
 Standard 
 
 
 
 
 58 
 
 NUMBER 
 
 Culls 
 
 
 . 
 
 
 38 
 
 GRADES 
 
 
 
 
 
 
 
 Total 
 
 
 
 
 1,042 
 
 
 
 
 
 
 
 
 300 
 288 
 
 8 
 
 6 
 
 
 14 
 
 
 250 
 
 19 
 
 3 
 
 
 22 
 
 
 216 
 
 59 
 
 7 
 
 
 66 
 
 
 200 
 
 133 
 
 7 
 
 
 140 
 
 
 176 
 
 277 
 
 16 
 
 
 293 
 
 NUMBER 
 
 150 
 
 238 
 
 9 
 
 
 247 
 
 SIZES 
 
 126 
 
 167 
 
 8 
 
 
 175 
 
 
 112 
 
 33 
 
 2 
 
 
 35 
 
 
 96 
 
 11 
 
 
 
 
 11 
 
 
 80 
 
 1 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 Total 
 
 946 
 
 58 
 
 38 
 
 1,004 
 
 
 
 
 
 
 461- 8 
 
 
 
 
 
 
 24- 7 
 
 WEIGHT 
 
 fulls 
 
 
 
 
 17- 4 
 
 GRADES 
 
 
 
 
 
 
 
 Total 
 
 
 
 
 503- 3 
 
 
 
 
 
 . 
 
 . . 
 
 
 300 
 
 OQO 
 
 11 n 
 
 1-1 
 
 
 2-11 
 
 
 
 -1U 
 
 n -i K 
 
 
 6- 5 
 
 
 6O() 
 
 - o 
 
 o in 
 
 
 22- 8 
 
 
 216 
 
 iy-14 
 
 Rt f K 
 
 912 
 
 
 54-11 
 
 
 z()0 
 
 01-10 
 
 61 O 
 
 
 133- 6 
 
 WEIGHT 
 
 176 
 
 Izb-lu 
 
 A O 
 
 
 130- 5 
 
 SIZES 
 
 150 
 
 IZO-l-i 
 
 A Q 
 
 
 103-14 
 
 
 126 
 
 yy- o 
 
 1-4 
 
 
 23- 2 
 
 
 112 
 
 &\.-jA 
 
 On 
 
 
 8- 4 
 
 
 96 
 
 - 1 
 
 A. n 
 
 
 0-13 
 
 
 80 
 
 -lo 
 
 
 
 
 
 Total 
 
 461- 8 
 
 24- 7 
 
 17-4 
 
 485-15 
 
 NOTES: Fine quality. 
 
 Australian 1 
 
 Wrinkled 
 
 Flattened 
 
 Corrugated 
 
 Protruding 3 
 
 Yellow 
 
 Ridged 3 
 
 Ribbed . 
 
 boxes. 
 
 SPORTS 
 
 Creased 
 
 Very smooth 
 
 Coarse 
 
 Raised section . . . 
 Sunken section . . . 
 Raised and sunken 
 Yellow section .... 
 Golden nugget . . . 
 
 Abnormal shape 1 
 
 Split navel 7 
 
 Split side 3 
 
 Pear shape 
 
 Elliptical 
 
 Long 
 
 Striped 
 
 Off bloom 
 
18 
 
 TABLE 2. OKANGE PEEFOEMANCE EECOED. 
 
 DATE: 1910-1915. STEAIN: Washington. LOCATION: Highgrove, California. 
 
 GEOWEE: National Orange Company. GEOVE: Vivienda. 
 
 VAEIETY: Washington Navel. PLOT: 3. EOW: 14. NO. OF TEEE: 27. 
 
 
 
 SEASON 
 1909-10 
 
 SEASON 
 1910-11 
 
 SEASON 
 1911-12 
 
 SEASON 
 1912-13 
 
 SEASON 
 1913-14 
 
 SEASON 
 1914-15 
 
 AVERAGE 
 
 
 Orchard 
 
 738 
 
 385 
 
 581 
 
 310 
 
 946 
 
 661 
 
 604 
 
 NUMBER 
 GRADES 
 
 Standard 
 Culls 
 
 19 
 
 
 45 
 
 38 
 
 57 
 41 
 
 80 
 311 
 
 58 
 38 
 
 151 
 165 
 
 68 
 99 
 
 Total 
 
 757 
 
 468 679 
 
 701 
 
 1,042 
 
 977 
 
 771 
 
 
 300 
 
 
 
 
 
 
 
 
 
 288 
 
 10 
 
 1 
 
 14 
 
 2 
 
 14 
 
 2 
 
 7 
 
 
 250 
 
 36 
 
 
 
 13 
 
 6 
 
 22 
 
 4 
 
 14 
 
 
 216 
 
 41 
 
 2 
 
 19 
 
 34 
 
 66 
 
 21 
 
 30 
 
 
 200 
 
 117 
 
 6 
 
 80 
 
 43 
 
 140 
 
 49 
 
 73 
 
 NUMBER 
 SIZES 
 
 176 
 150 
 126 
 
 141 
 
 189 
 49 
 
 13 
 66 
 15 
 
 72 
 174 
 54 
 
 77 
 98 
 80 
 
 293 
 247 
 175 
 
 98 
 165 
 252 
 
 116 
 156 
 104 
 
 
 112 
 
 111 
 
 98 
 
 131 
 
 25 
 
 35 
 
 120 
 
 87 
 
 
 96 
 
 40 
 
 135 
 
 59 
 
 15 
 
 11 
 
 69 
 
 55 
 
 
 80 
 
 23 
 
 94 
 
 22 
 
 10 
 
 1 
 
 32 
 
 30 
 
 Total 
 
 757 
 
 430 
 
 638 ' 390 
 
 1,004 
 
 812 
 
 672 
 
 
 Orchard 
 
 382- 7 
 
 271-14 
 
 315- 
 
 152-14 461- 8 
 
 352- 2 
 
 322.6 
 
 WEIGHT 
 
 GRADES 
 
 Standard 
 Culls 
 
 7-10 
 0- 
 
 75-15 
 23-14 
 
 23-11 
 16- 3 
 
 34- 7 24- 7 
 103-12 17- 4 
 
 78-12 
 69-13 
 
 32.8 
 38.5 
 
 Total 
 
 390- 1 
 
 323-11 
 
 354-14 
 
 291- 1 503- 3 500-11 
 
 393.9 
 
 
 300 
 
 
 
 
 
 
 
 WEIGHT 
 
 288 
 
 2- 9 
 
 0- 4 
 
 3- 5 
 
 0- 7 2-11 
 
 0- 5 
 
 1.6 
 
 SIZES 
 
 250 
 
 11-12 
 
 0- 
 
 4- 2 
 
 1-13 6- 5 
 
 1- 2 
 
 4.2 
 
 
 216 
 
 15- 8 
 
 0-12 
 
 7- 
 
 11- 1 22- 8 
 
 7- 1 
 
 10.6 
 
 Expressed 
 in pounds 
 and 
 
 200 
 176 
 150 
 
 48-11 
 66-10 
 98- 
 
 2- 8 
 6- 1 
 35- 7 
 
 32-11 
 32-11 
 90- 1 
 
 15-10 
 32- 6 
 47- 6 
 
 54-11 
 133- 6 
 130- 5 
 
 18- 8 
 41- 7 
 79- 5 
 
 28.8 
 52.1 
 
 80.1 
 
 ounces 
 
 126 
 
 28-14 
 
 8- 7 
 
 30- 2 
 
 45- 1 103-14 
 
 139-11 
 
 59.3 
 
 Averages 
 in 
 decimals 
 of Ibs. 
 
 112 
 96 
 
 80 
 
 70-11 
 28- 7 
 18-15 
 
 62- 2 
 98-12 
 
 85- 8 
 
 79-13 
 41- 
 17-14 
 
 15-13 
 
 10- 
 7-12 
 
 23- 2 
 
 8- 4 
 0-13 
 
 73- 3 
 46- 3 
 24- 1 
 
 54.1 
 
 38.8 
 25.8 
 
 Total 
 
 390- 1 
 
 299-13 
 
 338-11 
 
 187- 5 485-15 
 11V 2 boxes 
 
 430-14 
 11% boxes 
 
 355.4 
 
 NOTES: Abraham Lincoln tree. Fruit is fine colored, large, and smooth. 
 
19 
 
 systematic attention and required sustained effort. Some of these records are 
 being continued in order to secure further and more complete information upon 
 certain phases of tree behavior and additional data of some tree and fruit char- 
 acteristics. 
 
 These investigations have revealed the occurrence and frequency of bud 
 mutations in the varieties studied, an example of which is shown in Plate 35, the 
 existence and extent of occurrence of the various strains arising from bud muta- 
 tions and their comparative commercial value, the tree and fruit characteristics 
 of the trees of these strains, and other information of fundamental importance 
 to the citrus industry. In the course of this work improved methods of propa- 
 gation have been discovered and developed, such as the use of fruit-bearing bud- 
 wood for propagation, an example of which is shown in Plate 36, instead of the 
 sucker growth which was formerly used for this purpose. Illustrations showing 
 the method of using this bud-wood in propagation are shown in Plates 37 and 38. 
 Individual tree performance records of pruned and unpruned trees of each of 
 the commercially important varieties led to the discovery of the very injurious 
 and disastrous effects of early or severe pruning (55, 58, 63) with healthy, 
 normal citrus trees. This information has resulted in the general abandonment 
 of such practices amongst citrus growers. The individual tree records, showing 
 the behavior of trees grown under different methods of soil fertilization, led to 
 the origination by the writer of an improved system of applying organic ferti- 
 lizers in citrus orchards called the furrow-manure method (53, 56, 62), which 
 has proven to be more economical and efficient than any formerly used. A study 
 of the behavior of the fruits from the lemon performance-record trees in curing 
 rooms led to the discovery of the importance of a uniform condition of atmo- 
 sphere humidity in the curing of lemons and other citrus fruits and to the inven- 
 tion of a humidifier for securing and maintaining the optimum conditions (50, 
 59). Other results might be cited, but the above are considered to be sufficient to 
 show the importance of this work. 
 
 The results of the investigational citrus tree performance record work nat- 
 urally led to the development and use of commercial tree performance record 
 work by citrus growers for the following purposes : ( 1 ) to locate drone trees of 
 undesirable strains in the established orchards for top-working or replanting; 
 
 (2) to locate, if possible, superior trees as sources of bud-wood for propagation; 
 
 (3) to determine the results of cultural experiments or tree treatments; and 
 
 (4) to carry on intelligent individual tree care in the orchards. Up to the present 
 time, 1921, commercial tree records have been kept in more than 50,000 acres of 
 citrus orchards in California and in considerable citrus acreages in southern Ala- 
 bama and in Florida. 
 
 In commercial citrus tree records the yield of the individual trees in weight 
 or number of boxes of fruit are recorded by the foreman of the picking crew or 
 some other person at the time of picking, as shown in Plate 39. Notes are made 
 as to the production of any striking variations observed in the fruits or the trees. 
 In the investigational record work it was found that there is a definite correla- 
 
20 
 
 tion of the amount of yield and the commercial quality of the fruits, the highest 
 yielding trees usually producing the highest proportion of first-grade fruits of 
 the most desirable commercial size. From the commercial records of individual 
 tree production for a reasonable period, a classification of the trees with regard 
 to their value for cultivation can be made, the undesirable trees top-worked or 
 replanted, trees located for individual care and attention as needed, superior 
 trees, if any be found, located as sources of bud-wood for propagation ; and the 
 results of tree treatments definitely determined. 
 
 THE COMMERCIAL UTILIZATION OF INDIVIDUAL PLANT RECORDS. 
 
 The commercial plant records may be utilized in the origination of new 
 varieties, the isolation of valuable strains, and in the amelioration of strains 
 and varieties. The manner in which this utilization is effected in the citrus 
 industry in California will be briefly described (60). 
 
 The California Fruit Growers' Exchange, a cooperative non-profit organi- 
 zation of more than ten thousand citrus growers, established in May, 1917, a 
 bud department of the Fruit Growers' Supply Company, which is a subsidiary 
 organization furnishing materials and orchard supplies of all kinds to the mem- 
 bers of the Exchange at cost. The bud department was established for the pur- 
 pose of carrying out commercially the results of the investigational individual 
 tree performance record work in the citrus fruits. In order to make this service 
 available to the citrus industry as a whole it was provided by the Exchange that 
 the bud department should supply reliable buds secured from superior parent 
 trees, selected on the basis of their performance records, to all persons desiring 
 them, whether they were members of the Exchange or not. In this way the 
 work of the bud department is a public service. Within three years since the 
 founding of the bud department it has furnished more than a million selected 
 buds to propagators at a cost of five cents each to members of the Exchange, 
 and for six cents each to non-members. The buds have been chiefly used by 
 nurserymen in the propagation of nursery trees and to a less extent by growers 
 for top-working undesirable trees in established and bearing orchards. The buds 
 have been secured, for the most part, from superior parent trees found in the 
 best citrus orchards existing in California. The parent trees have been selected 
 as sources of bud-wood from a study of the commercial individual tree per- 
 formance records in these orchards and in some instances from the best trees in 
 the investigational performance record plats previously studied by the writer. 
 This bud department has been a success and self-sustaining from its beginning. 
 The young trees in the orchards grown from these buds and others selected and 
 distributed by the writer during preceding years have produced earlier and more 
 uniformly good crops of fruit than trees in comparative orchards which were 
 propagated in the ordinary way. The value of this improved production, due to 
 bud selection at this time, has been estimated by Mr. G. H. Powell, general man- 
 ager of the California Fruit Growers' Exchange, to amount to more than one 
 million dollars annually. In connection with the work of securing and dis- 
 tributing selected citrus buds, the bud department maintains an experimental 
 
21 
 
 citrus nursery for the study of problems in budding, stocks, and other phases 
 of propagation. It also furnishes to growers reliable information as to the 
 adaptation of citrus varieties to local soil and climatic conditions, accurate data 
 as to the production of the varieties and the relation of this production to market 
 conditions, and other information of value to the prospective planter or the 
 established grower. 
 
 Potato growers in Maine, California, and in several other States have or- 
 ganized successful cooperative associations for the purpose of making available 
 commercially the results of bud selection work in potato varieties. 
 
 Other associations of growers or propagators in industries founded upon 
 varieties of plants originated as mutations are in operation at this time. Amongst 
 these may be mentioned the Arizona-Egyptian Cotton Growers' Association, the 
 New England Tobacco Growers' Association, and the Nurserymen's Bud Selec- 
 tion Association of California. 
 
 THE SELECTION OF SUPERIOR PARENT PLANTS. 
 
 The selection of superior parent plants for propagation can be made on the 
 basis of individual plant performance record data and the intimate knowledge 
 of plant characteristics gained in the course of the plant performance record 
 work. 
 
 In the citrus, the selection of superior parent trees is made after an ade- 
 quate number of performance records have been secured. Only the high-yielding 
 trees producing the best commercial fruits are considered as sources of bud-wood. 
 If the records or other observations show the production of any markedly off- 
 type fruits or striking variations, such trees are immediately discarded from fur- 
 ther consideration as sources of bud-wood for propogation. Only those high- 
 yielding trees which consistently produce uniformly good fruits are selected as 
 parent trees. 
 
 PROGENY TESTS. 
 
 The bud-wood from each parent citrus tree is kept separate. The buds from 
 each parent tree are used in separate blocks so identified in the nursery that 
 the progenies can be traced back to the individual parent trees. Examples of 
 the fine growth and early fruiting habits of such trees are shown in Plates 40 
 and 41. When the nursery trees are transplanted each progeny is kept separate, 
 and wherever possible the trees of each progeny are planted in the orchard so 
 that at any time the behavior of any progeny and its parent can be studied. In 
 this manner, as well as through additional experimental progeny tests now under 
 way, the transmitting power of the parent trees can be determined. In the 
 California citrus industry the foundation has been laid for the future selection 
 of parent trees on the basis of progeny records. It is probable that through this 
 work the most reliable sources of propagating material will be secured that has 
 ever been attained in any industry in the history of agriculture. In this con- 
 nection it may be stated that in addition to extensive cooperative commercial 
 progeny tests the writer and his associates are keeping investigational individual 
 
22 
 
 tree-performance progeny records with 5,464 lemon trees, 450 orange trees, and 
 about 500 trees of other citrus varieties. As soon as funds can be secured for 
 this work, the number of trees where investigational records are kept will be 
 greatly increased. 
 
 Similar investigational and commercial progeny tests to those carried on in 
 the citrus are also being conducted with cotton, tobacco, corn, oats, wheat, flax, 
 timothy, and varieties of other agricultural crops under different auspices in 
 various agricultural districts of the United States. 
 
 The Hawaiian Sugar Planters' Experiment Station in 1920 made a begin- 
 ning of progeny test work with selected plants of the Yellow Caledonia, H 109, 
 D1135, and other sugar cane varieties grown in the Hawaiian Islands. The 
 purpose of this work is to establish and maintain reliable sources of propagating 
 material. 
 
 THE SCIENTIFIC STUDY OF BUD MUTATIONS AND BUD SELECTION. 
 
 The overshadowing interest amongst scientists in the study of the phenome- 
 non of sexual variations in plants and the behavior of seedlings grown from 
 these variations during the past century, has resulted in the partial neglect of the 
 equally interesting and important field of the investigation of bud mutations and 
 the characteristics of plants originating from them. 
 
 As the writer sees it, the scientific problems in this connection include a 
 study of the extent and frequency of bud mutations in all of the agricultural 
 varieties, an investigation of the fundamental causes of the phenomenon of bud 
 mutation, and the development of improved methods of propagation. This in- 
 vestigational work should precede and lay the foundation for the commercial 
 work. While this arrangement may apparently delay the utilization of bud 
 selection, it may, as a matter of fact, hasten the time when economic results can 
 be obtained. The scientific studies of bud mutations, their origin and develop- 
 ment, will probably result in the discovery of simplified methods of bud selection 
 and insure protection from disappointments due to operations founded upon 
 defective plans based upon incomplete knowledge leading to premature and 
 oftentimes erroneous conclusions. In some instances it may be found to be 
 feasible to carry on the investigational and the commercial work simultaneously. 
 The writer believes that such is the case in the work for the improvement of 
 sugar cane through bud selection. As the result of an experience covering more 
 than twenty years in both the investigational and commercial work of plant 
 breeding, the writer wishes to emphasize the necessity for scientific studies in 
 this connection in order to discover the underlying principles of bud mutation 
 and bud selection as a means for establishing this work in every instance upon 
 a sound and lasting foundation. 
 
 PIONEERS IN BUD MUTATION AND SELECTION WORK. 
 
 It seems fitting in this paper to refer to the pioneer students. of bud variation 
 and bud selection. No attempt will be made here to mention all of the men who 
 have been concerned in this activity. These names include Carriere, Darwin, 
 
23 
 
 De Vries, Cramer, Babcock, Bailey, Castle, Collins, Cook, Dorsey, Galloway, 
 Kearney, Shull, Stout, Swingle, and Webber. Of the men who have been more 
 particularly concerned in the introduction and development of commercial bud 
 selection work, the following names may be mentioned: Powell, Burbank, Fraser, 
 Chase, Winberg, Farmer, Coates, and Milliken. To this list many other names 
 of important workers might be added, but the writer considers that sufficient 
 names have been given to indicate the type of workers concerned in this work. 
 
 SUMMARY. 
 
 The fundamental factors in the economic work for the improvement of 
 plants through bud selection are (1) the development of new and important 
 varieties originating from bud mutations; (2) the isolation of valuable strains 
 of established varieties originating as bud variations; and (3) the amelioration 
 of the cultivated varieties and strains by bringing up their average production to 
 as nearly that of the best individuals in them as may prove to be possible through 
 the systematic selection and propagation of superior parent plants. 
 
 The experience and achievements to date in both the investigational and 
 commercial work for the improvement of plants through bud selection, warrant 
 the belief that much greater progress along these lines may be expected in the 
 future than has been accomplished in the past, when the possibilities of this work 
 become more generally recognized and more fully understood. 
 
 The writer believes that in the plants with which he is familiar, asexual and 
 sexual reproduction are fundamentally alike in respect to the extent and range 
 of variation, and that equally valuable results have been achieved and may be 
 expected in the way of plant improvement from bud selection as has been the 
 case with seed selection. 
 
LITERATURE CITED 
 
 ( 1 ) BALLOU, F. H. 1909. Report of the Division of Horticultural Inspection. Ohio Agr. 
 
 Exp. Sta. Circ. 94. 
 
 ( 2 ) BALLOU, F. H. 1917. Letters to C. S. Pomeroy, U. S. Dept. Agr. 
 ( 3 ) BATESON, WILLIAM. 1902. Mendel 's Principles of Heredity. 
 ( 4 ) BEACH, S. A. 1905. The Apples of New York. N. Y. Agr. Exp. Sta. Kept. 1903, 
 
 Part 2. 
 ( 5 ) BEATTY, F. E. 1905. Improving Strawberries by Selection. In Proc. 2nd meeting 
 
 Am. Breed. Asso., Feb., Eept. v. I, pp. 107-108. 
 ( 6 ) BOSHNAKIAN, SARKis. 1916. Breeding Nephrolepis Ferns. Jour. Hered. v. 7, no. 5, 
 
 pp. 225-236, figs. 18-25. 
 
 ( 7 ) CALDWELL, J. 1874. Sports in Sugar Cane (in Mauritius). Gardeners Chron., p. 316. 
 ( 8 ) CARRIERS, E. A. 1865. Production et Fixation des Varietes dans les Vegetaux. Paris. 
 
 Illus. 
 ( 9 ) CASTLE, W. E. 1914. Pure Lines and Selection. In Jour. Hered., v. 5, no. 3, pp. 
 
 93-97. March. 
 
 (10) CASTLE, W. E. 1917. The Role of Selection in Evolution. In Jour. Wash. Acad. Sci., 
 
 v. 7, no. 12, pp. 369-387. June 19. 
 
 (11) COATES, LEONARD. 1920. Prunes. In Catalog, Coates Nursery Co., Inc., Morganhill, 
 
 Calif., pp. 12-13. 
 (13) CRAMER, P. J. S. 1907. Kritische Uebersicht der bekannten Falle von Knospenvaria- 
 
 (12) CONNOR, O. W. 1915. Connor Prolific Grapefruit. In Catalog Ocklawaha Nurseries, 
 
 1916. Tangerine, Fla., pp. 34-35. Illus. 
 
 (13) CRAMER, P. J. S. 1907. Kritische Uebersicht der bekannten Falle von Knospenvaria- 
 
 tion. 
 
 (14) DARWIN, CHARLES. 1859. The Origin of Species by Means of Natural Selection. 
 
 (15) DARWIN, CHARLES.. .1868. The Variation of Animals and Plants under Domestication. 
 
 (2nd edition, N. Y., 1900, 2 vols.) 
 
 (16) DEERR, NOEL. 1911. Cane Sugar. London. Illus. 
 
 (17) DORSETT, P. H. ; SHAMEL, A. D., AND POPENOE, WILSON. 1917. Origin and History 
 
 of the Navel Orange of Bahia. In The Navel Orange of Brazil with Notes on Some 
 Little Known Brazilian Fruits. U. S. Dept. Agr. Bui. 445, pp. 1-3. 
 
 (18) DORSET, M. J. 1917. The Inheritance and Permanence of Clonal Varieties. In 
 
 Proc. 13th Ann. Meeting Am. Soc. Hort. Sci., N. Y., pp. 41-71. Dec., 1916. 
 
 (19) EAST, E. M. 1910. The Transmission of Variations in the Potato in Asexual Repro- 
 
 duction. Conn. Agr. Exp. Sta. Rept. 1909-10, pp. 119-160, pi. 5. 
 
 (20) AND HAYES, H. K. 1911. Inheritance in Maize. Conn. Agr. Exp. Sta. 
 
 Bui. 167, 142 p., 35 fig. 
 
 (21) EMERSON, R. A. 1913. The Inheritance of a Recurring Somatic Variation in Varie- 
 
 gated Ears of Maize. At Am. Soc, Naturalists, Cleveland, O., Jan., 1913. In Am. 
 Nat., v. 48, no. 566, pp. 87-115, fig. 3. Feb., 1914. 
 
 (22) FARMER, L. J. 1911. Fall Bearing Strawberries. In Farmer on the Strawberry, 
 
 Pulaski, N. Y., pp. 67-68. 
 
 (23) FARMER, L. J. 1918. The Oswego Apple. In Spring and Fall Special Price List, 
 
 p. 14. 
 
 (24) FLETCHER, S. W. 1910. Mich. Agr. Exp. Sta., Spec. Bui. 44; Chesebro Spy Apple, p. 
 
 11; Davidson Peach, p. 35; King Grape, p. 68. 
 
 (25) GERSDORFF, CHAS. E. F. 1919. A Partial List of Roses Introduced in America. In 
 
 The Am. Rose Ann., pp. 134-147. 
 
 (26) GILBERT, A. W. 1917. The Potato. New York. 
 
 (27) GRIFFITHS, DAVID. 1913. Behavior, under Cultural Conditions, of Species of Cacti 
 
 Known as Opuntia. U. S. Dept. Agr. Bui. 31, 24 p., 1 fig., 8 pi. 
 
 (28) HEDRICK, U. P. 1915. Remarkable Sports of the Twenty-Ounce Apple. The Rural 
 
 New Yorker, v. 74, no. 4307, p. 722. May 22. 
 
25 
 
 (29) KEARNEY, T. H. 1910. Breeding New Types of Egyptian Cotton. U. S. Dept. Agr., 
 
 Bur. Plant Indus. Bui. 200. 
 
 (30) KEARNEY, T. H. 1914. Mutation in Egyptian Cotton. Jour. Agr. Kesearch, v. 2, 
 
 no. 4, pp. 287-302, pi. 17-25. July 15. 
 
 (31) KEARNEY, T. H. 1918. A Plant Industry Based Upon Mutation. Jour. Hered., v. 9, 
 
 no. 2, pp. 51-61, figs. 1-8. Feb. 
 
 (32) KELLOG, E, M. 1902. Bud Variation in the Strawberry Plant. Inter. Conf. Plant. 
 
 Breed, and Hybrid., N. Y. In Eept. N. Y. Hort. Soc., v. 1 
 
 (33) LE LONG, B. M!. 1891. The Pierce Grape. In Calif. State Board Hort. Kept., 1891, 
 
 pp. 131-132, 1 col. pi. 
 
 (34) MEAD, H. O. 1916. A Bed Gravenstein Apple. In The Eural New Yorker. March 4. 
 
 (35) MORRIS, D. 1901. Bud Variation in the Sugar Cane. In West Indian Bui., v. 2, 
 
 no. 3, pp. 216-223, 2 col. pi. 
 
 (36) MYERS, C. H. 1914. Improving the Potato Crop by Selection. Cornell Eeading 
 
 Courses, v. 3, no. 68, pp. 229-248, figs. 121-133. July 15. 
 
 (37) PADDOCK, W. 1896. Bud Variation of the Concord Grape. In Gard. and For., v. 9, 
 
 p. 464. Nov. 18. 
 
 (38) PIERSON, WALLACE E. 1918. Eose Families and Their Tendencies. In The Am. 
 
 Eose Ann., pp. 99-100. 
 
 (39) POMEROY, C. S. 1919. Bud Variations in Sugar Cane. Jour, of Hered., v. 10, no. 3, 
 
 pp. 129-135, figs. 16-17. March. 
 
 (40) POWELL, G. HAROLD. 1898. Plant Breeding: Its Application Through Bud Selection 
 
 to the Improvement of Varieties. In Amer. Gard., v. 19, pp. 466-467, 514-515. 
 July 14. 
 
 (41) POWELL, G. T. 1902. Bud Variation in the Apple. Inter. Conf. Plant. Breed, and 
 
 Hybrid., N. Y. In Eept. N. Y. Hort. Soc., v 1. 
 
 (42) POWELL, G. T. 1908. $1000 an Acre from Pedigreed Trees. In Country Life in Am., 
 
 v. 13, no. 5, pp. 504-6, 538, 540. Illus. 
 
 (43) POWELL, G. T. 1916. Transmitting Productive Qualities in Fruit Trees Through Bud 
 
 Selection. West. N. Y. Hort. Soc. (Eochester). 
 
 (44) POWELL, G. T. 1920. Thirty Years' Experience in Application of Bud Selection in 
 
 the Fruit Industry. Asso. Calif. Nurserymen, San Francisco. In Calif. Citrograph, 
 v. 5, no. 11, pp. 344, 364-6. Illus. Sept. 
 
 (45) EEASONER BROS. 1914. Foster Grapefruit. In Catalog Eoyal Palm Nurseries, 1915, 
 
 Oneco, Fla., p. 11, 2 illus. (1 col.). 
 
 (46) EOEDING, GEO. C. 1919. Euonymus. In Catalog Fancher Creek Nurseries, Fresno, 
 
 Calif., p. 15. 
 
 (47) SHAMEL, A. D. 1907. New Tobacco Varieties. In U. S. Dept. Agr. Yearbook 1906, 
 
 pp. 387-404, figs. 11-14, pi. 33-36. 
 
 (48) SHAMEL, A. D. 1911. A Study of Bud Selection in Citrus Fruits. In Proc. 39th 
 
 Calif. Fruit. Gr. Conv., pp. 89-105. March 8. 
 
 (49) SHAMEL, A. D. 1911. A Study of the Improvement of Citrus Fruits Through Bud 
 
 Selection. U. S. Dept. Agr., Bur. Plant Indus. Circ. 77, 19 p., 5 fig. June 2. 
 
 (50) SHAMEL, A. D. 1917. A Humidifier for Lemon Curing Eooms. U. S. Dept. Agr. 
 
 Bui. 494, 10 p., 7 fig. Jan. 
 
 (51) SHAMEL, A. D. 1917. Citrus Fruit Improvement: How to Secure and Use Tree- 
 
 Performance Eecords. U. S. Dept. Agr., Farmers ' Bui. 794, 16 p., 4 fig. Feb. 
 
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 pp. 357-358, fig. 1. August. 
 
 (53) SHAMEL, A. D. 1918. A Method of Feeding Manure to Orange Trees. In Calif. 
 
 Citrograph, v. 3, no. 6, pp. 124-125, 4 fig. April. 
 
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26 
 
 (55) SHAMEL, A. D. 1919. Some Eesults from an Experiment with Pruning as Compared 
 
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 (56) SHAMEL, A. D. 1919. Applying the Furrow Manure in Citrus Groves. In Calif. 
 
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 102, 122-123, 128, 3 fig. Feb. 
 
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 (75) WAID, C. W. 1907. Results of Hill Selection of Seed Potatoes. In Rept. Am. Breed. 
 
 Asso., v. 3, pp. 191-198. 
 
 (76) WEBBER, H. J. 1903. New Horticultural and Agricultural Terms. In Science, n. s., 
 
 v. 18, pp. 501-503. 
 
 (77) WEBBER, H. J. 1909. Clonal or Bud Variation. In Rept. Am. Breed. Asso., v. 5, 
 
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EXPLANATION OF PLATES 
 
 PLATE. 
 
 1. Branches of the variegated Shrubby Althea or Rose of Sharon (Hibiscus syriacus} 
 
 showing solid green-leaved branches arising as bud variations. Eiverside, Cal. 
 
 2. Variations in a Dahlia plant which have persisted during the five years of the life of 
 
 the plant. The normal color of the flowers is deep velvety red, and the variations 
 are white and pinkish white. Riverside. Cal. 
 
 3. Dahlia flower of Le Grande Manitou variety and a bud variation found on a plant of 
 
 that variety. Riverside, Cal. 
 
 4. A branch of Euonymus japonica showing the bud origin of the silver-variegated horti- 
 
 cultural variety argenteo-variegatus. Several, if not all, of the other sub-varieties 
 of this plant originated as bud mutations. Riverside, Cal. 
 
 5. Branches of Pittosporum tobira var. variegatum, showing green- and white-leaved bud 
 
 variations. Riverside, Cal. 
 
 6. A bush of Pittosporum tobira var. variegatum, which has several green-leaved and 
 
 white-leaved branch sports. Riverside, Cal. 
 
 7. Branches of the oleander (Nerium oleander} showing (right) the normal green 
 
 foliage and (left) a variegated form found as a branch variation in the same 
 bush. Thermal, Cal. 
 
 8. Winter Banana apples, showing a red and two large fruits occurring as limb variations. 
 
 C. H. Whittum, Eaton Rapids, Mich. 
 
 9. Prunes from a single tree of a new bud strain, the Coates 1418. Upper right, typical 
 
 Coates 1418; lower right, typical ordinary French prune; left, four Coates 1418 
 and one ordinary French. Morgan Hill, Cal. 
 
 10. Thompson Seedless grapes, showing (left) the normal fruit and (right) a large- 
 
 fruited form discovered as a bud mutation and propagated by its owner. Thermal, 
 Cal. 
 
 11. Bartlett Pears, showing (right) ordinary strain, (center) oblong strain, and (left) 
 
 sunken section occurring as bud variations. Tehachapi, Cal. 
 
 32. Leaves and flower buds (the edible portion) of two strains of the common artichoke 
 (Cynara scolymus) found on neighboring plants and doubtless resulting from a 
 bud variation. Riverside, Cal. 
 
 13. A representative tree of the Washington strain of the Washington Navel orange, 
 
 bearing heavy crops of high-grade fruit. Highgrove, Cal. 
 
 14. Fruits showing variations occurring on a single tree of the Thomstm strain Washing- 
 
 ton Navel orange. These variations have been propagated and each of the two 
 progeny trees are producing fruit of the same character as their several bud 
 parents, showing these forms to be true mutations. Highgrove, Cal. 
 
 15. Characteristic trees of the Australian (left) and Washington (right) strains of the 
 
 Washington Navel orange. Highgrove, Cal. 
 
 16. A typical fruit of the Washington Navel orange variety and an Australian fruit found 
 
 as a limb sport in the same tree. Highgrove, Cal. 
 
 17. A basket of Washington Navel oranges from a tree of the Washington strain. River- 
 
 side, Cal. 
 
 18. Fruits of the Corrugated strain of the Washington Navel orange occurring as a limb 
 
 mutation in a tree of the standard strain. Highgrove, Cal. 
 
 19. Fruit of the Dry strain of the Washington Navel orange, occurring as a branch muta- 
 
 tion in a tree of the standard strain. Riverside, Cal. 
 
 20. Typical fruit of the Marsh strain of the Marsh seedless grapefruit. Note the desirable 
 
 shape, thin skin, fine texture, and seedless character. Highgrove, Cal. 
 
 21. A fruit of the Se*edy strain of the Marsh grapefruit. Highgrove, Cal. 
 
28 
 
 22. A few of the Eureka lemon types that frequently occur as bud variations on a single 
 
 tree. Corona, Cal. 
 
 23. Branches of the Variegated Eureka lemon showing the characteristic markings of 
 
 fruits, leaves, and young twigs. This strain originated as a branch mutation and 
 has been propagated through three bud generations. Corona, Cal. 
 
 24. A Navel lemon found as a bud variation on a tree of the Eureka variety. Eseondido, 
 
 Cal. 
 
 25. Typical lemons of the Lisbon strain, the type of the Lisbon variety. Five other 
 
 strains of this variety have been found as bud variations, recorded and propagated 
 during the bud selection work of the IT. S. Department of Agriculture. Corona,. 
 
 Cal. 
 
 26. Lisbon lemons showing pronounced variations occurring on a single tree of an inferior 
 
 strain. Corona, Cal. 
 
 27. A typical tree of the Shade Tree strain of the Eureka lemon. The trees of this strain 
 
 are vigorous and rapid in growth but low in production and bear fruits of a low 
 grade. Corona, Cal. 
 
 28. A young Eureka lemon tree of the Eureka strain. Note the productive condition of 
 
 the tree and the fine type of fruit. Corona, Cal. 
 
 29. Marsh grapefruit top-worked on an undesirable tree. Highgrove, Cal. 
 
 30. Euby Blood oranges showing typical fruit and others from a branch mutation, showing- 
 
 various stages of dryness, the most of the fruit being entirely dry. Nearby tree& 
 bore heavy crops which were all of the Dry strain. Corona, Cal. 
 
 31. Branch from a Kuby Blood orange tree showing the occurrence of a Navel fruit as a 
 
 bud variation. In this way the Bahian Navel orange is frequently found in 
 Brazil as bud mutations in trees of the Selecta variety. Corona, Cal. 
 
 32. Thomson orange tree in which the entire upper part and right side are barren every 
 
 season, the lower left portion bearing normally. Eiverside, Cal. 
 
 33. Washington Navel orange orchards along the foothills, showing two orchards in which 
 
 individual tree performance records were secured in the investigational work of the 
 TJ. S. Department of Agriculture. Highgrove, Cal. 
 
 34. View in a Washington Navel orange orchard showing the method of grading, sizing,. 
 
 weighing, and recording the production of individual trees in the investigation per- 
 formance record work of the U. S. Department of Agriculture. Highgrove, Cal. 
 
 35. Typical flowers of the Washington strain and the Seedy strain of the Washington 
 
 Navel orange. Note the abundance of pollen produced by the anthers of the- 
 Seedy strain, while the flowers of the Washington strain do not produce pollen. 
 Eiverside, Cal. 
 
 36. View in an Eureka lemon tree, showing the type of fruit-bearing bud-wood advised 
 
 for use in propagating from select parent trees. The leaves have been cut from 
 one twig in order to show its characteristics to better advantage. Corona, Cal. 
 
 37. Citrus propagation: Cutting a bud from a typical bud-stick of fruit-bearing wood for 
 
 insertion into the seedling stock. 
 
 38. Citrus propagation: Steps in the budding of a citrus nursery tree (from left to right) : 
 
 seedling stock; inverted T-shaped cut for bud; bud inserted; inserted bud wrapped 
 with waxed cloth; budding knife. Eiverside, Cal. 
 
 39. View in a Washington Navel orange orchard, showing the method of securing com- 
 
 mercial individual tree performance records in this 1500-acre planting. Highgrove,. 
 Cal. 
 
 40. Two-year-old Eureka lemon nursery propagated from selected fruit-bearing bud-wood. 
 
 showing the fine tree development and the early fruiting tendency. Eedlands, Cal. 
 
 41. Eureka lemon tree, 2 years 9 months old, propagated from select performance record 
 
 trees. Note fruitful condition and fine character of fruit. Claremont, Cal. 
 

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Plate 2. Variations in a Dahlia plant which have persisted during the five years of the life 
 of the plant. The normal color of the flowers is deep velvety red and the variations 
 are white and pinkish white. Riverside, Calif. 
 
ffl p 
 
 II 
 
 II 
 
 00 
 
Plate 4. A branch of Euonymus japonica, showing the bud origin of the silver-variegated 
 horticultural variety argewteo-varieffatus. Several, if not all, of the other sub-varieties 
 of this plant originated as bud mutations. Riverside, Calif. 
 
Plate 5. Branches of Pittosporum tobira var. variegatum, showing green- and white- 
 leaved bud variations. Biverside, Calif. 
 

 
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Plate 12. Leaves and flower buds (the edible portion) of two strains of the common arti- 
 choke (Cynara scolymus) found on neighboring plants and doubtless resulting from a 
 bud variation. Riverside, Calif. 
 
Plate 13. A representative tree of the Washington strain of the Washington Navel orange, 
 bearing heavy crops of high-grade fruit. Highgrove, Calif. 
 
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Plate 16. A typical fruit of the Washington Navel orange variety and an 
 Australian fruit found as a limb sport in the same tree. Highgrove, 
 Calif. 
 
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 Plate 21. A fruit of the Seedy strain of the Marsh grapefruit. Highgrove, Calif. 
 

 Plate 22. A few of the Eureka lemon types that frequently occur as bud variations on a 
 
 single tree. Corona, Calif. 
 
Plate 23. Branches of the Variegated Eureka lemon, showing the characteristic markings 
 of. fruits, leaves, and young twigs. This strain originated as a branch mutation and 
 has been propagated through three bud generations. Corona, Calif. 
 

 .35 
 
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 Plate 26. Lisbon lemons, showing pronounced variations occurring on a single tree of an 
 
 inferior strain. Corona, Calif. 
 
Plate 27. A typical tree of the Shade Tree strain of the Eureka lemon. The trees of this 
 strain are vigorous and rapid in growth but low in production, and bear fruits of a 
 low grade. Corona, Calif. 
 
Plate 28. A young Eureka lemon tree of the Eureka strain. Note the productive 
 condition of the tree and the fine type of fruit. Corona, Calif. 
 
Plate 29. Marsh grapefruit top-worked on an undesirable tree. Highgrove, Calif. 
 
Plate 32. Thomson orange tree in which the entire upper part and right side are barren 
 every season, the lower left portion bearing normally. Kiverside, Calif. 
 
13 
 
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 bJDCS 
 
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 ^ 
 
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 25 
 
 o 
 
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 OJ >rH 
 
 > rrj 
 
 Is 
 
 1 
 
 be gj 
 
Plate 36. View in an Eureka lemon tree, showing the type of fruit-bearing bud-wood 
 advised for use in propagating from select parent trees. The leaves have been cut 
 from one twig in order to show its character to better advantage. Corona Calif 
 
Plate 37. Citrus propagation: Cutting a bud from a typical bud-stick of fruit-bearing 
 wood for insertion into the seedling stock. 
 
Plate 38. Citrus propagation. Steps in the budding of a citrus nursery tree (from left to 
 right): seedling stock, inverted T-shaped cut for bud, bud inserted, inserted bud 
 wrapped with waxed cloth, budding knife. Eiverside, Calif. 
 
Plate 40. Two-year-old Eureka lemon nursery propagated from selected fruit-bearing bud- 
 wood, showing the fine tree development and the early fruiting tendency. Redlands, 
 Calif. 
 
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Makers 
 
 Syracuse, N. Y. 
 PAT. JAN. 21, 1908 
 
 9G9144 
 
 THE UNIVERSITY OF CALIFORNIA LIBRARY 
 
 UNIVERSITY OF CALIFORNIA LIBRARY 
 BERKELEY 
 
 Return to desk from which borrowed. 
 This book is DUE on the last date stamped below. 
 
 17