McsM^c$am EXPERIMENT STATION OF THE HAWAIIAN SUGAR PLANTERS' ASSOCIATION The Improvement of Plants Through Bud Selection BY A. D. SHAMEL Physiologist of the U. S. Department of Agriculture S5 HONOLULU, HAWAII ®Ij? i. 1. Ml SItbrarg Jfortl( fflaroltna Stair fflolkg? S>5 ^7 9J^^ This BOOK may be kept out TWO WEEKS ONLY, and is subject to a fine of PIVE CENTS a day thereafter. It is due on the day indicated belovv-: EXPERIMENT STATION OF THE HAWAIIAN SUGAR PLANTERS' ASSOCIATION The Improvement of Plants Through Bud Selection BY A. D. SHAMEL Physiologist of tlie U. S. Department of Agriculture HONOLULU, HAWAII LETTER OF TRANSMITTAL To the Experiment Station Comuiittee of the Hawaiian Sugar Planters' Association, Honolulu, T. H. Dear Sirs : — I transmit herewith for pubhcation 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, 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. "fTfS"^ CONTENTS Page Plaait Improvement 1 Definition of the Terms Bud Yariatiou 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 V>i..4 boxes 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 pro])agation, 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 l)ud-wood in propagation are shown in I'lates 37 and 3S. 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 eft'ects 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 dift'erent 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, su])erior trees as sources of Inid-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- ty})e 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 5C0 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, D 1135, 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 oversiiadowing 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 w^ork 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. Sl'MMARV. 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 possil)ilities 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. Ballou, F. H. 1917. Letters to C. S. Pomeroy, U. S. Dept. Agr. Bateson, William. 1902. Mendel's Principles of Heredity. Beach, S. A. 1905. The Apples of New York. N. Y. Agr. Exp. Sta. Kept. 1903, Part 2. Beatty, F. E. 1905. Improving Strawberries by Selection. In Proc. 2nd meeting Am. Breed. Asso., Feb., Kept. v. I, pp. 107-108. BOSHNAKIAN, Sabkis. 1916. Breeding Nephrolepis Ferns. Jour. Hered. v. 7, no. 5, pp. 225-236, figs. 18-25. Caldvvell, J. 1874. Sports in Sugar Cane (in Mauritius). Gardeners Chron., p. 316. Carrii'.re, E. a. 1865. Production et Fixation des Varietes dans les Vegetaux. Paris. Illus. Castle, W. E. 1914. Pure Lines and Selection. In Jour. Hered., v. 5, no. 3, pp. 93-97. March. Castle, W. E. 1917. The Role of Selection in Evolution. In Jour. Wash. Acad. Sci., v. 7, no. 12, pp. 369-387. June 19. COATES, Leonard. 1920. Prunes. In Catalog, Coates Nursery Co., Inc., Morganhill, Calif., pp. 12-13. Cramer, P. J. S. 1907. Kritische Uebersicht der bekannten Falle von Knospenvaria- CONXOR, O. W. 1915. Connor Prolific Grapefruit. In Catalog Ocklawaha Nurseries, 1916. Tangerine, Fla., pp. 34-35. Illus. Cramer, P. J. S. 1907. Kritische Uebersicht der bekannten Fiille von Kuospenvaria- tion. Darwin, Charles. 1859. The Origin of Species by Means of Natural Selection. Darwin, Charles.. .1868. The Variation of Animals and Plants under Domestication. (2nd edition, N. Y., 1900, 2 vols.) Deerr, Noel. 1911. Cane Sugar. London. Illus. 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. 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. 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. and Hayes, H. K. 1911. Inheritance in Maize. Conn. Agr. Exp. Sta. Bui. 167, 142 p., 35 fig. 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. Farmer, L. J. 1911. Fall Bearing Strawberries. In Farmer on the Strawberry, Pulaski, N. Y., pp. 67-68. Farmer, L. J. 1918. The Oswego Apple. In Spring and Fall Special Price List, p. 14. Fletcher, S. W. 1910. Mich. Agr. Exp. Sta., Spec. Bui. 44; Chesebro Spy Apple, p. 11; Davidson Peach, p. 35; King Grape, p. 68. Gersdorff, Chas. E. F. 1919. A Partial List of Roses Introduced in America. In The Am. Rose Ann., pp. 134-147. Gilbert, A. W. 1917. The Potato. New York. 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. D. H. HILL LIBRARY 25 Kearney, T. H. 1910. Breeding New Types of Egyptian Cotton. U. S. Dept. Agr., Bur. Plant Indus. Bui. 200. Kearney, T. H. 1914. Mutation in Egyptian Cotton. Jour. Agr. Research, v. 2, no. 4, pp. 287-302, pi. 17-25. July 15. Kearney, T. H. 1918. A Plant Industry Based Upon Mutation. Jour. Hered., v. 9, no. 2, pp. 51-61, figs. 1-8. Feb. Kellog, E. M. 1902. Bud Variation in the Strawberry Plant. Inter. Conf. Plant. Breed, and Hybrid., N. Y. In Kept. N. Y. Hort. Soe., v. 1 Le Long, B. M. 1891. The Pierce Grape. 7n Calif. State Board Hort. Eept., 1891, pp. 131-132, 1 col. pi. Mead, H. 0. 1916. A Red Gravenstein Apple. In The Rural New Yorker. March 4. Morris, D. 1901. Bud Variation in the Sugar Cane. In West Indian Bui., v. 2, no. 3, pp. 216-223, 2 col. pi. Myers, C. H. 1914. Improving the Potato Crop by Selection. Cornell Reading Courses, v. 3, no. 68, pp. 229-248, figs. 121-133. July 15. Paddock, W. 1896. Bud Variation of the Concord Grape. In Gard. and For., v. 9, p. 464. Nov. 18. PiERSON, Wallace R. 1918. Rose Families and Their Tendencies. In The Am. Rose Ann., pp. 99-100. Pomeroy, C. S. 1919. Bud Variations in Sugar Cane. Jour, of Hered., v. 10, no. 3, pp. 129-135, figs. 16-17. March. 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. Powell, G. T. 1902. Bud Variation in the Apple. Inter. Conf. Plant. Breed, and Hybrid., N. Y. In Rept. N. Y. Hort. Soc, v 1. 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. Powell, G. T. 1916. Transmitting Productive Qualities in Fruit Trees Through Bud Selection. West. N. Y. Hort. Soc. (Rochester). 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. Reasoner Bros. 1914. Foster Grapefruit. In Catalog Royal Palm Nurseries, 1915, Oneco, Fla., p. 11, 2 illus. (1 col.). ROEDING, Geo. C. 1919. Euonymus. In Catalog Fancher Creek Nurseries, Fresno, Calif., p. 15. Shamel, a. D. 1907. New Tobacco Varieties. In U. S. Dept. Agr. Yearbook 1906, pp. 387-404, figs. 11-14, pi. 33-36. Shamel, A. D. 1911. A Study of Bud Selection in Citrus Fruits. In Proc. 39th Calif. Fruit. Gr. Conv., pp. 89-105. March 8. Shamel, A. D. 1911. A Study of the Improvement of Citrus Fruits Through Bud Selection. XJ. S. Dept. Agr., Bur. Plant Indus. Circ. 77, 19 p., 5 fig. June 2. Shamel, A. D. 1917. A Humidifier for Lemon Curing Rooms. U. S. Dept. Agr. Bui. 494, 10 p., 7 fig. Jan. Shamel, A. D. 1917. Citrus Fruit Improvement: How to Secure and Use Tree- Performance Records. U. S. Dept. Agr., Farmers' Bui. 794, 16 p., 4 fig. Feb. Shamel, A. D. 1917. A Bud A^ariation of Pittosporum. In Jour. Hered., v. 8, no. 8, pp. 357-358, fig. 1. August. 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. Shamel, A. D. 1918. Can California Produce Good Grapefruit. At Calif. Grape- fruit Club, March 20. In Calif. Citrograph, v. 3, no. 7, pp. 153, 163, 2 fig. May. 26 Shamel, a. D. 1919. Some Eesiilts from an Experiment with Pruning as Com]iared Avith Xo Priming of Full-Bearing Washington Navel Trees. In Calif. Citrograph, V. 4, no. 7, pp. 174-175, 3 fig. May. Shamel, A. I). 1919. Applying the Furrow Manure in Citrus Groves. Li Calif. Citrograph, v. 5, no. 1, p. 4, 4 fig. Nov. Shamel, A. D. 1919. Origin of a New and Improved French Prune. In Jour. Hered., v. 10, no. S, pp. 338-343, fig. 1-3 and frontispiece. Nov. Shamel, A. D. 1920. Results of Five Years' Individual Tree Performance Records with Pruned and Unpruned Lemon Trees. In Calif. Citrograph, v. 5, no. 4, pp. 102, 122-123, 128, 3 fig. Feb. Shamel, A. D. 1920. Control of Humidity Conditions in Lemon Storage Rooms. In Calif. Citrograph, v. 5, no. 5, pp. 137, 170-171. March. Shamel, A. D. 1920. Cooperative Improvement of Citrus Varieties. In U. S. Dept. Agr. Yearbook, 1919, pp. 249-275, 15 fig. (Issued as Yearbook Separate No. 813.) Shamel, A. D. 1920. Origin of a Grapefruit Variety Having Pink-Colored Fruits. In. Jour. Hered., v. 11, no. 4, pp. 157-160, fig. 5-8, April. Shamel, A. D. 1920. The Conservation and Application of Manures. //( Calif. Citrograph, v. 5, no. 7, pp. 213, 240-243, 3 figs. May. Shamel, A. D. 1920. Results of Individual Tree Performance Studies With Pruned and ITnpruned Marsh Grapefruit Trees. In Calif. Citrograph, v. 5, no. 8, pp. 248, 268-269, 4 fig. June. Scott, L. B., and Pomeroy, C. S. 1918. Citrus Fruit Improvement: A Study of Bud Variation in the Washington Navel Orange. U. S. Dept. Agr. Bui. 623, 146 p., 16 fig., 19 pi, Scott, L. B., and Pomeroy, C. S. 1918. Citrus Fruit Improvement: A Study of Bud Variation in the Valencia Orange. U. S. Dept. Agr. Bui. 624, 120 p., 9 fig., 14 pi. 'Scott, L. B., and Pomeroy, C. S. 1918. Citrus Fruit Improvement: A Study of Bud Variation in the Marsh Grapefruit. U. S. Dept. Agr. Bui. 697, 112 p., 14 fig., 11 pi. AND Dyer. C. L. 1920. Citrus Fruit Improve- ment: A Study of Bud Variation in the Eureka Lemon. IT. S. Dept. Agr. Bui. 813, 88 p., 22 fig., 7 pi. : AND Dyer, C. L. 1920. Citrus Fruit Improve- ment: A Study of Bud Variation in the Lisbon Lemon. IT. S. Dept. Agr. Bui. 815, 70 p., 14 fig., 8 pi. Stout, A. B. 1915. The Origin of Dwarf Plants as Shown in a Sport of Hibiscus oculiroseus. Bui. Torr. Bot. Club, v. 42, pp. 429-450, pi. 26-27. Sept. 22. Stout, A. B. 1915. The Establishment of Varieties in Coleus by the Selection of Somatic Variations. Carnegie Inst. Wash. Pub. 218, 80 p., 4 pi. (3 col.). Oct. 7. ToTTY, Charles H. 1918. Ophelia and Its Progeny. In The Am. Rose Ann., pp. 96-98. DE Vries, Hugo. 1901-3. Die Mutationstheorie, 2 v., illus. Leipzig. (Eng. trans. 1909-1910. Chicago.) DE Vries, Hugo. 1905. Species and Varieties; Their Origin by Mutation. Chicago. DE Vries, Hugo. 1918. Mass Mutation in Zea mays. In Science, n.s., v. 47, no. 1219, pp. 465-467. Waid, C. W. 1907. Results of Hill Selection of Seed Potatoes. In Rept. Am. Breed. Asso., V. 3, pp. 191-198. Webber, H. J. 1903. New Horticultural and Agricultural Terms. In Science, n. s., V. 18, pp. 501-503. Webber, H. J. 1909. Clonal or Bud Variation. In Rept. Am. Breed. Asso., v. 5, pp. 347-357. Webber, H. J. 1912. The Production of New and Improved Varieties of Tinu^thy. Cornell Univ. Agr. Exp. Sta. Bui. 313, pp. 337-392, fig. 86-96, pi. 1-10. April. EXPLANATION OF PLATES Plate. 1. Branches of the variegated Shrubby Althea or Eose of Sharon (Hibiscus syriacus) showing solid green-leaved branches arising as bud variations. Riverside, 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 toiira var. variegatiim, showing green- and white-leaved bud variations. Riverside, Cal. <3. A bush of Pittosporum tobira var. variegaium, 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 projiagiited 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. 1.3. 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 Thomson 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. IS. 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 Seedy strain of the Marsh grapefruit. Highgrove, Cal. 28 22. A few of the Eureka lemon tyjies 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. Escondido, 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 U. 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 imdesirable 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 trees bore heavy crops which were all of the Dry strain. Corona, Cal. 31. Branch from a Euby 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. Riverside, 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 LT. S. Department of Agriculture. Highgrove, Cal. 3-4. 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 L^. 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. Riverside, 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. Riverside, 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 flne tree development and the early fruiting tendency. Redlands, Cal. Eureka lemon tree, 2 years 9 months old, propagated from select performance record trees. Note fruitful condition and fine character of fruit. Claremont, Cal. 41. o 5 Plate 2. Variations iu 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. Plate 4. A branch of Euoiujmus japonica, showing the bud origin of tlie silver-variegated horticultural variety fnncntco-varicfjatus. Several, if not all, of the other sub-varieties of this jilaut originated as bud mutations. Eiverside, Calif. Plate 5. Branches of Pitto.spornm iohlra var. r(irir;iat niu. show- leaved buil variations. Eiverside, Calif. oroen- ami white- 5h o o s^ bJD & "> s 5 c« Plate 12. Leaves and flower buds (the edible portion) of two strains of the common arti- choke {Cynara scolyinus) found on neighboring plants and doubtless resulting from a bud variation. Riverside, Calif. ^ •^IflBM^' M ^^ |H|HSHR^S9KS&Hb_%£^ V w "V;]S^|^fi|H ^m ^^^^^ /,'^^^^^^Q^S m 1^^ k ^r^vjP"! ^^S mtK^^ ^^ Plate 13. A ro]iiT-('iit;it i \ r tier nt iiir Wii-liiii-iiiii strain of the Washington Navel orange, bearing heax y crops of high-grade fruit. Highgrovej Calif. 5f z :^ cS -*^ bjo a> ? =« s Plate 16. A typii-al fruit of the Washington Navel orange variety and an Australian fruit fouml as a limb sport in the same tree. Highgrove, Calif. 5oQ 5 3 r^ !-l > > SI c3 o Plate 21. A fruit of tlie Seedy strain of tlie Marsli grapefruit. Highgrove, Calif Plate A few of the Eureka lemon types that frequently oeeur as bud variations single tree. Corona, Calif. Phite 23. Branches of the V;tiieKated 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. «3 I en Plate 26. Lisbon lemons, showing pronounced variations occurring on a single tree of an inferior strain. Corona, Calif. Plate 1^7. A tvpiral tree of the .Sli;i.lc' Tie,' >tiaiu of the Kiiieka lonuni. The trees of this strain are vigorous and rapid in growth but low in produetion, 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. ]Marsli grapefruit top-worked on an undesirable tree. Highgrove, Calif. 2Q .13 i fP ^(T v'^^^- ^^ ;^M, Ij^ ■^^^ ^^m 1^ ^^^ '■ ' ■■■' ''■'^:\ , •. •■'. • --Vr.. ^^^^ite- , . vviji^jS|HH '.-.v"'* ^ BH^ \ i^p '"•''•'•"% J',^^-^- i i ''^^v -' ..-^"^ : ---^ ';K'^''^vi ^ ^ ^ ■^^V' ■ ■■: ■■■■'^-d/i% ^ v^-^ , - * ■■-- ■ . -. -■ " " ^yi»r^^^l'N«'>^:^^l«^ ^^^^m ■^^^ ps^ki^y^^^^ mm Plate -'. Thomson orange tree in which the entire upper part and right side are barren every season, the lower left portion bearing normally. Eiverside, Calif. Plate 3(3. View in an Eureka lemon tree, showing the type of fruit-bearing bud-wood advised for use in propagating from select parent trees. Tlie leaves have been cut from one twig in order to show its character to better advantage. Corona, Calif. I'late ;!7. Citrus propagation: ("iittiiig a bml from a typical binl-stick wood for insertion into tlie 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 witli waxed cloth, budding knife. Eiverside, Calif. Plate 40. Two-year-ohl Eureka lemon nursery propagated from selected fruit-bearing bud- wood, showing the fine tree development and the early fruiting tendency. Eedlands, Calif. be a< WertftCerollw State "»> 5f^. :>'»., ''W/=«".'^S5 :^^r.... *'*'<^i/6..