UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION California Berkeley, California Reserve CULTURE OFTHE ORIENTAL PERSIMMON IN CALIFORNIA KNOWLES A. RYERSON REVISED BY ROBERT W. HODGSON BULLETIN 416 January, 1927 Revised November, 1933 UNIVERSITY OF CALIFORNIA BERKELEY, CALIFORNIA CONTENTS PAGE History and spread 3 Botanical relationships and descriptions 8 Astringency 13 Varieties 14 Systems of classification 14 Commercial varieties 17 Varieties recommended for further trial 24 Fruit descriptions 25 Climatic requirements 29 Persimmon districts in California 31 Soils 33 Propagation 34 Orchard management 42 Planting and care of young trees 42 Care of bearing trees 45 Pests and diseases 50 Fruit shedding 53 Uses and treatment of the fruit 54 Utilization fresh 54 Removal of astringency 54 The ethylene gas treatment 56 Sun-drying and dehydration 57 Canning — frozen pack — fruit pulp 59 Marketing 60 Costs, yields, and returns 66 Outlook 68 Acknowledgments 68 List of selected references on Oriental persimmon culture 69 CULTURE OF THE ORIENTAL PERSIMMON IN CALIFORNIA KNOWLES A. EYEESONi REVISED BY EOBERT W. HODGSON2 Though grown in California for half a century or more, the Oriental or Japanese persimmon is still a fruit of minor importance in the horti- culture of the state. Interest in its culture has increased greatly in re- cent years, however, and much new acreage has been planted. The most recent statistics indicate that the total acreage now exceeds 3,000, of which slightly less than half is classed as of nonbearing age. The fruit reaches the market in the fall and winter months during the holiday season and thus far has been accorded a favorable reception, with rea- sonably satisfactory returns to the growers. Until recently the persim- mon has been grown primarily as a side line, but within the past decade in certain parts of the state its culture has become an industry of com- mercial importance. HISTORY AND SPREAD The Oriental persimmon has been grown extensively in China and Japan for centuries, and the ancient literature of these countries con- tains many references to it. Marco Polo mentions the fruit in his ac- count of his travels. Meyer 3 reports that he found topworked trees in China which were several centuries old and mentions whole valleys given over entirely to persimmon culture. In Japan, while there are districts where the fruit is especially cultivated, the trees are to be found, indi- vidually or in groups, widely scattered over the entire country. The persimmon has long been the most widely used staple fruit of the Orient. Both fresh and dried, it fills an important place in the diet of China and Japan and has been referred to as "the apple of the Orient," as indicative of its importance there. i Formerly Specialist in Agricultural Extension and Farm Advisor in Los Angeles County. 2 Associate Professor of Subtropical Horticulture and Subtropical Horticulturist in the Experiment Station. s Meyer, Frank N". Agricultural explorations in the fruit and nut orchards of China. U. S. Dept. Agr. Bur. Plant Indus. Bui. 204:10-16. 1911. [3] 4 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION The general name applied to the fruit in this state — the Japanese per- simmon — would seem to indicate Japanese origin. The evidence, how- ever, leads us to believe that it originated in China, from which country it was early taken to Japan. During the centuries in which it has been under cultivation in the Orient, many varieties have appeared and cultural practices have been developed to a high degree. In addition to the uses of the fruit, products from the tree, including the wood and stain, have found wide application in the industries and the arts of the Far East, to the extent that the persimmon tree is considered one of the important economic assets of that region. The Oriental persimmon was known in Europe and had been grown along the Mediterranean, especially on the Riviera, a hundred years before it was grown in the United States. Its cultivation there, however, has never developed to the stage of a commercial industry. The introduction of the Oriental persimmon to the United States is recorded as early as 1828 4 and it was later brought in as a direct result of the memorable visit to Japan made by Commodore Perry in 1856. He secured some of the seeds and sent them to Washington where they were planted at the Naval Observatory. Four years later the first of the trees bore fruit. No distribution of seedlings from these trees was ever made and after some years they died. In 1863, William Saunders of the United States Department of Agriculture imported another supply of seeds, and trees were grown and distributed for trial. The first importation of grafted trees was made by the Department in 1870. This was a fairly large shipment but because of the long journey and the difficulty of keeping the long taproots moist, most of the trees died. Among those that lived, however, were found several of the now best-known varieties including the Hachiya, Tanenashi, and Yemon. Distributions from this importation were made throughout the southern states and in Califor- nia. This shipment marked the beginning of extensive importations by both the Department of Agriculture and private concerns, which con- tinued actively for more than two decades, during which time the trees became distributed throughout the states of the cotton belt and in all parts of California. Importations were continued on a much less exten- sive scale until June 1, 1919, when they were discontinued as a result of Quarantine Order 37 of the Federal Horticultural Board. With the coming into production of the first trees in the southern states, a decided stimulus was given to commercial plantings. Varieties were tested, cultural problems studied, and the infant industry enjoyed the attention of a large number of investigators, which is reflected in the * Prince, W. A. A short treatise on horticulture. 196 p. New York, 1828. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA reports and bulletins issued by the United States Department of Agri- culture, the state experiment stations, and horticultural societies. Of those who have contributed most to the development of the industry in the South, no one person has done more than H. H. Hume of the Florida Agricultural Experiment Station, .whose studies over a long period of years concerning the behavior of varieties, cultural practices, and espe- cially pollination, have done much to remove uncertainties in the raising of persimmons in that region. After the extensive plantings during the period just mentioned, interest waned. It was found that large quanti- ties of persimmons could not be disposed of profitably, for the public was unacquainted with the fruit and its uses. Planting ceased, except in a minor way, and was not resumed until within recent years. The number of trees in the United States, together with their produc- tion in 1929, is shown in table 1. TABLE 1 Acreage and Production of Persimmons in the United States, 1929 State Trees of bearing Trees of nonbearing Total Production, in bushels Virginia North Carolina South Carolina Georgia Florida Alabama Mississippi Arkansas Louisiana Texas Arizona Oregon California Total 750 8 6 6,959 13,041 5,602 1,848 13 791 6,603 95 11 98,296 134,023 787 127 259 17,019 4,033 1,080 625 1,763 1,252 31 96,914 123,890 1,537 8 133 7,218 30,060 9,635 2,928 13 1,416 8,366 1,347 42 195,210 257,913 510 5 6 3,469 1,876 996 18 175 2,131 54 13 93,618 104,570 Source of data: U. S. Dept. Comm. Bur. of the Census. Agriculture; fruit and nuts. p. 28. Separate from: Fifteenth Census of the United States, 1930. vol. 4, chapter 12. 1932. Data on numbers of trees are for January 1, 1930; data on production are for the 1929 season. Within the past decade, however, interest has again been manifested in the commercial production of the Oriental persimmon in the southern states, and new planting's have been made. The new nonastringent va- riety known as Fuyu and the one supposed by some to be identical with it, Fuyugaki, have been planted in considerable numbers; these are de- b UNIVERSITY OF CALIFORNIA EXPERIMENT STATION scribed on page 27. The area in the southern states which can be devoted to persimmon-growing is large, and as the public becomes increasingly familiar with the uses of the fruit, it is reasonable to expect that there may again be a marked increase in acreage in that region. As has been mentioned, California received some of the first importa- tion of grafted trees made in 1870 and others in the years immediately following. These were planted in all parts of the state. Rev. Henry Loomis at this time began large importations direct to San Francisco, and for several years afterwards distributed hundreds of trees. Some of the first to come into bearing were located on the place of Colonel Hollis- ter at Santa Barbara. The fruits from these trees weighed from one-half to a pound or more and excited much curiosity and attention. At about this time some of the plantings were made which have since become famous throughout the state. The Elwood Cooper orchard in Santa Bar- bara on the now famous Elwood ranch was set out during this period. Carlot shipments were sent from this orchard for years. In 1874, R. H. Gilman planted an acre of supposedly Hachiya trees on what is now the Placentia Fruit Company ranch between Fullerton and Placentia. The planting proved to contain over forty varieties. Because of unsatisfactory market conditions most of the trees were later re- moved. However, one of them still remains and has an interesting his- tory. Scions were taken from this tree by C. P. Taft and inserted in trees on his place near Orange. When they came into bearing, the fruit was markedly superior to the ordinary strain of the Hachiya. He took scions from these trees and inserted them in trees on what is now the old Thales ranch, within a short distance from the original parent tree. It is from this start that the famous orchard on that ranch was developed. In 1876 the first planting was made in Placer County on the Ira Avery place. One of the trees of the original planting, of the Tsuru variety, is said to be still alive. This planting consisted of but a few trees, but be- cause of their success, the planting was gradually extended until it now comprises about 40 acres. Other plantings were made in the county in the years following, but development was slow. As the interest in the fruit increased, the California Experiment Sta- tion undertook the testing of some of the varieties both at Berkeley and at the substations, notably at Jackson in Amador County. The report of 1880 recorded the fact that fruits ripened at Berkeley but they were small and astringent. With the exception of occasional reduction of crop from spring frost damage the planting at Jackson was highly successful, corroborating the experience in Placer County that the tree is admirably suited to the foothill region of the Sierra Nevada. BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 7 The period since the earlier introductions has been marked by a very slow expansion in persimmon plantings until quite recently. Persimmon- growing has been maintained as a side line rather than a major crop. The fairly high return that was received over a long period of years, maintained primarily because of the relatively slow increase in produc- tion, at last attracted attention, with the result that the past ten years have witnessed a rapid expansion in planting, particularly in southern California, but also in other parts of the state. The acreage has more than trebled in this time. Realizing that such an unusual increase in production would be cer- tain to result in greatly reduced prices unless consumption could be in- creased, the persimmon growers of southern California wisely took steps to effect an organization to further their interests and to unite their efforts in the solution of their problems. Preliminary steps were taken in the fall of 1922, and in the following spring an organization known as the Persimmon Growers Department of the Southern Counties Farm Bureaus was launched. Its program included a survey of the industry in both California and the southern states, a study of the rootstocks now in use, the appointment of a committee for the study and the elimination from planting lists of all but a few of the best varieties for commercial planting, and a study of marketing practices with a view to standardiza- tion of methods of packing, handling, and selling. A portion of the first report of the variety committee is given in a later section. Standards were set for packing and grading, and in 1924 the first steps were taken toward controlling the sale of the fruit, an effort which in 1927 culmi- nated in the organization of the Southern California Persimmon Grow- ers Association, a marketing agency which now controls the distribution of the bulk of the production. The survey undertaken furnished the basis for a careful analysis of the industry, thus laying the foundation for sound development in the future. In 1924 a similar organization was started in the northern persimmon-growing districts with the forma- tion of the Northern California Persimmon Association, which, how- ever, has remained an educational organization. The part played by the United States Department of Agriculture in the development of the persimmon industry has been a most important one. Through the continuous search by explorers and others in the Orient, the best varieties have been brought in for trial and propaga- tion. One of these, Fuyu, appears to have considerable promise, although its growth habit is not so satisfactory as is the case with certain other varieties. The name of the veteran plant explorer, the late Frank N. Meyer, is closely associated with this and other varieties which he intro- O UNIVERSITY OF CALIFORNIA EXPERIMENT STATION duced as a result of his travels. At the Government Plant Introduction Garden at Chico, California, there is maintained a trial orchard con- taining the introductions of the United States Department of Agricul- ture, which serves to supply much-needed information on the possible commercial value of these introductions. BOTANICAL RELATIONSHIPS AND DESCRIPTIONS The Oriental persimmon belongs to the family botanically known as the Ebenaceae or ebony family. Members of this family comprise a large group of deciduous and evergreen trees and shrubs finding wide use as ornamental, fruit-bearing, and timber- producing trees. The genus Diospyros — named from Dios, meaning Jove, and pyros, grain, literally "food of the gods" because of the excellence of the fruits — contains nearly two hundred species, about a hundred and ninety of which are found in the tropics and the remaining few in the temperate zone. Many of them are of economic importance, notably those producing the ebony wood of commerce. The trees are either dioecious or monoecious, the staminate flowers appearing in the axils of the leaves of the previous year; staminate flowers smaller than the pis- tillate, commonly in the three-flowered cymes; pistillate flowers generally solitary; calyx f our-lobed, the lobes contorted in the bud, more or less contracted in the throat, the lobes spreading or recurved; stamens sixteen to twenty-four in number inserted on the bottom of the corolla in two rows and in pairs; filaments free, slender; an- thers oblong, the cells opening laterally by longitudinal slits; stamens mostly rudi- mentary or wanting in the pistillate flowers although perfect flowers are sometimes found; ovary usually four-celled, each cell more or less completely divided; styles four, spreading, two-lobed at the apex; stigmas two-parted or lobed; ovule solitary in each of the divisions of the cells. Fruit globose, oblong, or conical, one to ten- seeded, surrounded at the base by the enlarged persistent calyx. Seeds pendulous, oblong, compressed ; seed coat thick and bony, dark, more or less lustrous. NATIVE AMERICAN SPECIES Several members of the genus are native to the American continent and bear fruits that are used to some extent. The most widely known is the native American persimmon (Diospyros virginiana) which grows from Connecticut to Florida, and as far west as eastern Kansas and Oklahoma. Several improved and named varieties have been developed. Its use as a rootstock for the Oriental persimmon will be discussed later. Diospyros texana, a native of the Colorado and Concho river regions in Texas, yields a fruit that is extremely astringent until fully ripe, and finds little use except as a source of dye for staining black, for which purpose the Mexicans employ it to a limited extent. D. ebenaster, the sapote negro of Mexico, bears a fruit green in color and resembling a large, oblate apple. The soft flesh is almost black and not attractive in appearance. It is very sweet and cloying, resembling many other fruits of the tropics. It is too tender to grow in southern California. BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 9 DIOSPYROS LOTUS Another member of the genus of importance but native to China rather than this country, is Diospyros lotus. This species has been known to botanists for a long time, but was not used as a rootstock until Meyer r- ,.*£»>! Fig. 1. — Flower forms of the Oriental persimmon: A, staminate flowers; B, pistillate flowers. 10 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION called attention to its value for this purpose. It is found growing wild in the mountainous parts of northern China and bears quantities of small fruits that turn black when ripe. They are about the size of cher- ries and are used in large quantities by the natives. The tree is usually dioecious. This species has found wide use in California as a rootstock upon which the kaki varieties are grafted. Its use in this connection will be discussed in detail in the section devoted to rootstocks. Many trees of this species are fruiting in California. As far back as 1882, the report of the California Experiment Station recorded the fact that it succeeded unusually well. DIOSPYROS KAKI Diospyros kaki includes all of the true Oriental or kaki persimmons. It is native to China, from which country it has been taken to many other parts of the world. It has been under cultivation for centuries and is probably the most widely distributed and common fruit of both China and Japan. The tree sometimes reaches a height of 40 feet. The crown is commonly rounded, though in some varieties very few branches of any size develop, the fruit being borne on short pendant laterals and little or no crown being evident. The leaves vary con- siderably in shape, ranging from obovate and oblong-ovate to ovate or ovate elliptic, acuminate at the apex, glabrous above and more or less finely pubescent underneath. The color is a dark, glossy green, in some varieties changing to bright yellow and red in the fall. The flowers of this species caused much confusion both botanically and also from a practical point of view, until Hume 5 made his thorough investigation of the flowering habits of the species, which cleared up the matter. Instead of being consistently dioecious as had been generally assumed, he found that three kinds of flowers may be produced — staminate, pistillate, and perfect. These three types may, though rarely, be found on a single tree. They are all borne on wood of the current season's growth. The staminate blossoms are borne usually in three-flowered cymes in the leaf axils, or they may be found singly or in groups of two (fig. 1). The calyx and corolla are f our-lobed. Two rows of stamens, sixteen to twenty-four in number, are inserted upon the corolla. The pistillate flowers are borne singly in the leaf axils ; the leaf -like calyx is large ; the four-parted corolla is yellowish white when first open, turning brown later. The eight stamens are abortive; the ovary is flattened, globose, and contains eight cells; the short four-parted style is surmounted with a much branched stigma. Perfect flowers are usually found associated with the staminate flower clusters and are intermediate in character. They are a development from the staminate type, according to Hume. Flowering Habits. — In his investigation of the flowering habits of this species, Hume found that the different varieties vary markedly as to the types of flowers borne and the regularity with which they are produced. s Hume, H. H. The flowers of Diospyros MM. Trans. St. Louis Acad. Sci. 22:125- 135. 1913. Bul. 410] THE ORIENTAL PERSIMMON IN CALIFORNIA 11 Certain varieties consistently produce only pistillate flowers; others pro- duce both staminate and pistillate flowers in varying proportions from year to year, some years the number of staminate flowers being exceed- ingly small or none. The number of perfect flowers produced is negligible and has no important effect on the f ruitf ulness of the tree. These studies have materially assisted in the solution of the problem of obtaining the setting of satisfactory crops in the southern states. The Tanenashi va- riety, he found, regularly set crops without pollination. Other varieties cannot be grown profitably in the southern states without provision for pollination. Hume classified the different varieties according to their flower-bearing habits. Those which always bear staminate flowers are termed staminate constants; those which produce them irregularly are termed staminate sporadics; while those which bear only pistillate flow- ers are termed pistillate constants. No varieties have been found which bear only staminate forms consistently. Staminate constants Gailey Masugata (probably) Siang (S. P. I. 21910) Miyotan (S. P. 1.47323) S. P. I. 27037 Staminate sporadics Okame TaberNo. 23 Taber No. 129 Pistillate constants Hachiya Tanenashi Hyakume Tamopan Tsuru Costata Yemon Yeddo Ichi Zengi Phelps Triumph As a result of these discoveries concerning persimmon flowers, the dif- ficulty of setting satisfactory crops in the southern states has been largely overcome by the use of the Gailey variety, which produces an abundant supply of staminate flowers annually. More recently a United States Department of Agriculture introduction, the Miyotan (S. P. I. 47323) , has been found to be an excellent pollinizer. While the problem of pollination is important in the southern states, experience in California has amply demonstrated that it is not of par- ticular importance here. The Hachiya, the best commercial variety, sets fruit readily without pollination — hence they are usually seedless. In mixed plantings where pollination sometimes occurs seeded fruits are frequently produced. These are certainly not superior to the seedless fruits and in the opinion of many are distinctly inferior in quality. Black, discolored .areas immediately surrounding some of the seeds are frequently found, which are apparently caused by the influence of pol- 12 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION lination, and by many these are considered objectionable. The concensus of opinion of the California growers is that the Hachiya variety should be grown as a seedless fruit. Most, if not all, of the other varieties grown in California exhibit a tendency to overbearing rather than the reverse. The planting of staminate trees in California, therefore, does not ap- pear to be justified, and pollination can probably be ignored as a prob- lem that must be considered in planting commercial orchards. Fruit Characteristics. — The fruit of the Oriental persimmon shows wide variation in all its principal characteristics. In shape it varies from broad oblate to slender conical, including all shapes intermediate. In cross section gradations from circular to quadrangular are found. The surface, commonly smooth, is in some varieties marked by from four to eight shallow to deep grooves running lengthwise of the fruit. In some varieties, notably Tamopan, an equatorial constriction circles the fruit in a characteristic manner. Other varieties are characterized by the presence of more or less prominent basal lobes under the sepals and this character is of assistance in the identification of some varieties. Sabu- roza is the only one of this group that is found commonly in California, although Tanenashi sometimes exhibits this characteristic to a slight degree. Some varieties possess the same type of structure present in the navel orange, a more or less clearly defined secondary fruit within the primary. This is particularly recognized in the variety Futaya, this word in Japanese meaning "double." The apex of the fruit may be pointed, rounded, flat or depressed, the pointed apex being a distinct disadvantage in packing because of the greater possibility of injury. The base may be depressed, flattened, or projected beneath the calyx lobes. The fruit varies notably in size, Zengi frequently having a diameter of not to exceed 1% inches. Hachiya fruits are usually from 3 to 4 inches in length and from 2 to 3 inches in diameter and frequently weigh a pound or more. Tamopan fruits sometimes have a diameter of from 4 to 6 inches. The skin of the fruit varies much in thickness. In Hachiya it is thin and almost transparent, and tender when the fruit is mature, which makes handling difficult when the fruit is soft. The skin of Tamopan is thick and tough, permitting rather rough handling even when the flesh has become exceedingly soft. The color of the fruit varies from a yellow- ish orange to a deep, tomato-red. Many varieties are marked by finely penciled, dark lines circling the apex and extending irregularly down the sides. The flesh is soft when ripe, in some varieties almost liquid, though dry and mealy in Tanenashi. It is yellow-orange in color in some varie- Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 13 ties and red-orange in others. The flesh of many varieties is colored by a varying number of small, brownish specks, caused by the* presence of tannin bodies. The number is sufficiently great in some fruits to give the flesh a decided chocolate color. The relation of pollination to these color characteristics will be discussed in another section. While as many as eight elliptic, thin, dark brown seeds may be found, usually the number that develops is fewer and seedless fruits are com- mon, particularly in Tanenashi and Hachiya. TABLE 2 Analyses of Persimmons Percentage composition Refuse Water Protein Fat Carbohydrates Starch, sugar, etc. Crude fiber Ash Large seedling, edible portion Large seedling, as purchased.. Tanenashi, edible portion Tanenashi, as purchased Yemon, edible portion Yemon, as purchased Average, edible portion Average, as purchased 22.40 1.88 30.7 23.97 77.04 59.77 81.93 66.53 81.66 56.59 80.21 60.96 1.61 1.25 1.16 0.94 1.32 0.92 1.36 1.04 0.31 .25 .55 .45 .85 .59 .57 0.43 19.39 15.05 12.81 10.40 13.19 9.14 15.13 11.53 0.93 0.72 2.93 2.38 2.37 1.64 2.08 1.58 0.72 .56 .62 .50 .61 .42 .65 0.49 Analyses of Persimmons. — The composition of the persimmon fruit has been studied by several investigators. The analyses given in table 2 were made and published in 1903 by the California Experiment Sta- tion. Earlier, in 1899, McBryde 6 made a study of the persimmon and its chemical composition and was unable to detect any trace of cane sugar in the large amount of total sugar present, all of it being in the form of glucose. The total amount of sugar present exceeds that of a number of the common fresh fruits, including the apricot, plum, and peach. ASTRINGENCY The quality called "pucker" has long been associated with the per- simmon fruit, indeed it has been largely influential in limiting the popu- lar favor to which the fruit is entitled. This astringency is caused by the presence of tannin. Much study has been given to the behavior of the s McBrvde, J. B. Persimmons; notes on the chemistry of the persimmon. Tennessee Agr. Sta. Bul. 43:220-223. 1899. 14 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION tannin in the ripening process, during which its undesirable effects dis- appear. At first it was supposed that the astringency was due to the presence of soluble tannin which became insoluble as the fruit ripened. Lloyd 7 has shown that this theory is not in accord with the true be- havior of the tannin masses within the fruit, but that apparently the tannin is associated with a carrier of a colloidal nature with which it completely unites during the ripening and softening process when its power to cause astringency is removed. This absorbed tannin undergoes oxidation in some varieties and appears as red-brown flecks scattered through the flesh, as is the case in the so-called "sweet" varieties. In these varieties the oxidation takes place before the fruit becomes soft, thus permitting them to be eaten while still firm. In some manner not yet fully explained, this oxidation is associated with the process of pol- lination and the physiological changes resulting therefrom. In certain varieties this oxidation always takes place after pollination, the flesh becoming chocolate-colored and the fruit puckerless; other varieties, notably Fuyu, Jiro, and several others, remain puckerless even though the flesh does not change color materially; while in still other varieties the development of seeds has no effect on the quality of astringency, the fruit remaining puckery until the ripening process is complete. Hume 8 believes that this peculiar behavior may indicate a mixing of species in ancient times, with the present widely varying behavior of the different varieties as a result. The processing of the fruit to remove this astrin- gency will be discussed in another section. VARIETIES SYSTEMS OF CLASSIFICATION From the time of the first importation of nursery stock from Japan, there has been an almost hopeless confusion in the names of persimmon varieties. This has resulted partly from the carelessness of the export- ers, orders having been filled, apparently, from any stock that happened to be on hand. On the other hand, a condition of great confusion and duplication in nomenclature exists in Japan, different communities and different sections of the country having different names for the same variety. This partially explains the more than eight hundred named va- rieties which, according to Ikeda, 9 are to be found in that country. 7 Lloyd, Francis E. The behavior of tannin in persimmons. Plant World 14:1- 14. 1911. s Hume, H. H. A TcaH classification. Jour. Heredity 5:400-406. 1914. 9 Ikeda, T. The fruit culture of Japan. (No date.) BUL. 416] T HE ORIENTAL PERSIMMON IN CALIFORNIA 15 Varieties that are clear-fleshed and seedless in one section have some- times proved to be seeded and dark-fleshed in another. Several early attempts at an adequate classification are on record. The old Japanese system based upon sweetness or astringency is obviously unsatisfactory, because a variety may be in one group in one locality and in another in a different part of the country. One of the first horticultural schemes of classification was that proposed by Hume 10 in 1904 in which all varieties were grouped into three classes — dark-fleshed, mixed light and dark, and light-fleshed — according to the color of the flesh. This classification is untenable, however, because as previously indicated, the changes in the color of the flesh of certain varieties are now known to be an effect of pollination. Later studies have shown that all of the varieties grown in the United States are light-fleshed when seedless, but when seeds are present some are wholly or partially dark-fleshed, according to the number of seeds that develop. Based upon these studies, Hume 11 later proposed a new classification which is still accepted as the most satisfactory yet pre- sented. Those varieties which experience no change of flesh color when pollinated and seeds develop are designated as pollination constants; those which are light-fleshed when seedless but dark-fleshed when seeded are designated as pollination variants. No varieties have yet been found which are dark-fleshed both when seeded and seedless; hence no division of the pollination constants group has been necessary to separate the light and dark-fleshed varieties. While as a general rule all varieties of the Oriental persimmon are light-fleshed when seedless, exceptions to the rule have been noted. Condit 12 reports the presence of cinnamon- colored flesh in seedless fruits which were believed to be of the Tsuro- noko variety. Under the classification just described, the better known varieties of the Oriental persimmon grown in California may be grouped as follows : Pollination constants (light-fleshed when seeded or seedless) Hachiya Tsuru Ormond Tanenashi Costata Fuyu Tamopan Pollination variants (light-fleshed when seedless, dark-fleshed when seeded) Hyakume Gosho Yemon Yeddo Ichi Maru Okame Zengi 10 Hume, H. H., and F. C. Keimer. Japanese persimmons. Florida Agr. Exp. Sta. Bui. 71:65-112. 1904. ii Hume, H. H. A TcaTci classification. Jour. Heredity 5:400-406. 1914. 1 2 Condit, I. J. The kaki or Oriental persimmon. California Exp. Sta. Bui. 316: 227-266. 1919. 16 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Fig. 2. — Two types of Hachiya fruits commonly found in the markets : A, broad type thought to be the Fuji; B, standard or true Hachiya. BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 17 COMMERCIAL VARIETIES As a result of the early importations, California fruit growers planted a large number of different persimmon varieties, and although there has been a great reduction in the number of varieties planted in more recent years, there are still far too many for the best interests of the industry. The most important of these, both in acreage planted and in popularity with the buyers and with the public, is the large-fruited, highly colored Hachiya (figs. 2 and 3) . Newer plantings in both northern and southern California are composed almost exclusively of this variety. Next in importance is Hyakume (fig. 3) ripening later than the Ha- chiya and less attractive because of its dull, mottled, yellow appearance. This variety is grown to a large extent in Placer County and to a lesser extent in southern California. Grouped under the general name of Maru (fig. 3) a number of me- dium to small-fruited, round varieties are to be found in the older plant- ings — the name Maru being more properly a group or class name than that of any specific variety. A separation of the different varieties marketed under this name is hardly possible. Yemon, Okame, and Yeddo Ichi are all marketed in small amounts and to a still less degree Gosho, Tsuru, and the more recently introduced Tamopan (figs. 3 and 4) . Tanenashi (fig. 5) formerly occupied a more important place in the state than it does now, though it offers more promise in the Imperial Valley than other varieties. The experience of growers in the southern states has been somewhat different from that of growers in California. There, Hachiya has not proved as satisfactory as Tanenashi, which is the present ruling market favorite. Two varieties originating in the south have also been planted to a considerable extent — Lone Star, orig- inating in Texas, and Triumph, in Florida. Many other varieties are to be found in the persimmon districts of the South, as in California, and in the same way add to the problem of marketing. During the past decade a new variety has been planted to a consid- erable extent both in California and the South — Fuyu (figs. 4 and 6), a yellow-fleshed, nonastringent persimmon that does not depend upon pollination to make it nonastringent when hard. Wherever the fruit has been tried it has excited interest and favorable comment. This va- riety was introduced by the United States Department of Agriculture from Japan. Fuyu and Hachiya are the only varieties of trees which are in demand in California. The shipment of mixed lots of misnamed or unnamed and undesirable persimmon varieties has been a serious handicap to the development 18 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION of the industry in California. In view of the very evident preference of the dealers and the buying public for a few known varieties, the elimi- nation of all others would undoubtedly prove to be of great benefit to the industry. Such elimination would not be difficult if only the growers Tamopan Maru Hyafcume Eachiya Fig. 3. — Four of the principal varieties of persimmons grown in California, showing comparative size and shape of the fruits. could be convinced of the benefits. The trees are easily topworked and the change could be made in the existing orchards without any great loss. The increase in returns from the premiums paid for the better va- rieties should more than make up for the loss of a few crops while the topworked trees are coming into bearing. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 19 Fig. 4. — Promising new persimmon varieties: A, Fuyu; B, Godbey Seedless C, Tamopan. 20 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Fig. 5. — The Tanenashi variety. Natural size. BUL. 416] TITE ORIENTAL PERSIMMON IN CALIFORNIA 21 * I- ) Fig. 6. — The Fuyu variety. 22 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION As a step in the direction of standardization of varieties, the Persim- mon Growers Department of the Southern Counties Farm Bureaus in 1923 appointed a committee to study the varieties now being grown, as well as those now under trial by the United States Department of Agri- culture. After careful investigation this committee recommended three varie- ties for commercial planting and two varieties for further trial. This Fig. 7. — A tree of the Hachiya variety. When 19 years old (1925) this tree, located at the Chico Plant Introduction Garden, produced 1,120 pounds of marketable fruit. report was adopted and is now being made the basis of a campaign for the topworking of off -types and of poor varieties to the standard recom- mended sorts. Part of the report of this committee is as follows : The following three varieties are recommended for commercial planting in the order named, and a brief outline of their merits and drawbacks are presented here- with. 1. Hachiya. — Of all the persimmon varieties now grown or known in California, this variety stands in a class by itself and is by far the most popular and is to be recommended above all others [figs. 2 and 3]. Bitl. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 23 Merits. — Its large size, high color, and distinctive shape are already known and recognized by the trade and by the consuming public. The fruit ripens uniformly and is ordinarily seedless, with a clear yellow flesh whether seeds are present or not. The flavor is exceedingly rich and pleasant. Drawbacks. — The tree is a light bearer in some sections. When pollinated, black areas sometimes occur around the seeds which, while apparently normal, give the fruit a distasteful appearance when cut. The large gelatinous membrane surrounding Fig. 8. — A tree of the Tanenashi variety. the seeds when present or occupying the core of the fruit when seeds are absent, is objectionable to some people. The skin is thin and breaks rather easily. There appear to be several strains, of which some are much less desirable than the standard variety. The Tree. — The tree is the best growing of any of the varieties. It makes a strong growing, well-developed framework, and has a well-spread top [fig. 7]. 2. Tanenashi. — This variety is the most popular one grown in the southern states, where it succeeds better than Hachiya [fig. 5]. 24 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Merits. — The fruit remains on the tree a little later than the Hachiya and the va- riety is apparently a surer bearer except in the more favorable districts. The skin is tougher than that of the Hachiya. The flesh is firmer and the fruit dries in a more satisfactory manner. It is of large size and ships well. Drawbacks. — The fruit is not so high in quality as the Hachiya. The color is not so deep nor so attractive. The flesh is somewhat dry and mealy and while preferred by some for eating with sugar and cream, it is ordinarily not so well liked as that of the Hachiya. The fruit is subject to a defect at the stem end; in many fruits an opening forms exposing the core to mold. The tree [fig. 8] is not quite so vigorous or satis- factory a grower as the Hachiya. 3. Hyakume. — This variety [fig. 3] is next to the Hachiya in popularity in Placer County but is not favored in southern California. Merits. — The fruit has very good flavor and quality with a fairly thick skin. It is a good shipper and is later in season than the Hachiya, and consequently may be held later for marketing. Drawbacks. — The color of the fruit is poor, frequently blotched with dark brown. Eipening is not very even, giving the fruit rather an unattractive appearance on the market. The flavor and quality is not so good as Hachiya. The Tree. — The tree [fig. 9] is a poor grower, being upright in habit with weak laterals which tend to break and does not reach the size attained by Hachiya. VARIETIES RECOMMENDED FOR FURTHER TRIAL 1. Tamopan [fig. 4]. — Merits. — The fruit is late in season and meets the requirements for the holiday trade. It is large and has a distinctive shape differing from most other varieties, be- ing marked by a constriction from a quarter to halfway down on the fruit. This skin is unusually tough and will hold its shape, making a natural cup from which the pulp can be spooned, even when the fruit is fully ripe and the flesh is almost of a watery consistency. The quality is very good, not quite as rich as the Hachiya but more pleasing to some. Drawbacks. — The tree is a light bearer in some sections but has not been tested sufficiently for final opinion. The Tree. — An upright, vigorous grower, not so spreading as the Hachiya, but making a very satisfactory top, able to carry abundant crops [fig. 10]. 2. Fuyu [figs. 4 and 6]. — Merits. — The fruit has a high color and a round flat shape which makes it pack well. Its nonastringent qualities commend it to many people and its rather pleasing favor also recommends it. The tree is a good bearer and is a fair grower [fig. 11 j. The variety has not been tested in southern California sufficiently to determine its adaptation and the fruit is not known to the trade nor to the consuming public. The fruit also contains a number of rather large seeds. BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 25 —#L * •> <& fi, \ rA Fig. 9. — A tree of the Hyakume variety. FRUIT DESCRIPTIONS Abbreviated technical descriptions of the more important and better known varieties are here given. The location of the original detailed de- scription is given under the variety heading in this section. Hachiya (figs. 2, 3, and 7). — Fruit very large, oblong-conical, usually deep orange- red, very attractive ; surface glossy ; flesh astringent until soft ; sweet, rich, excellent in quality; usually seedless; the leading commercial variety, although regarded as a light bearer in some sections; often bearing heavily in alternate years. Season me- dium. Especially fine in Orange County. Colored plate and description in the United States Department of Agriculture Yearbook for 1887, page 644. Probably identical with Fuji of Japan. 26 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Hyakume (figs. 3 and 9). — Fruit medium to large, mostly four-angled ; color light orange, often mottled or dappled and unattractive at maturity; brown when soft; surface glossy, usually with fine russet lines around the apex and down the sides; flesh dark cinnamon color when seeded; sweet, moderately rich; quality very good; keeping quality excellent. Season medium. Colored plate and description in the United States Department of Agriculture Yearbook for 1880, page 450. Fig. 10. — A tree of the Tamopan variety. Tanenashi (figs. 5 and 8). — Fruit large, broadly conical, tapering gradually up- ward from near the base ; color light orange-red ; surface fairly glossy, smooth, with distinct areolations visible through the skin; flesh astringent until soft, characteris- tically mealy or pasty ; of very good quality ; practically always seedless ; fruits often defective at the core, with an opening under the calyx exposing the interior to dust, dirt, and mold. Season medium. Trees bear heavily in alternate years. Colored plate and description in United States Department of Agriculture Yearbook for 1887, page 644. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 27 Fuyu (figs. 4, 6, and 11). — Fruit medium to large, indistinctly quadrangular; color deep tomato-red, attractive; surface fairly glossy; flesh light orange, fairly rich; perfectly nonastringent even when seedless and firm; quality very good; seeds few or none. Above description refers to fruit produced on tree at Plant Introduction Gardens, Chico, imported under S.P.I. No. 26491. A very promising variety. Fruits Fig. 11. — A tree of the Fuyu variety (rather better than average) of S.P.I. No. 32868 are very similar if not identical. S.P.I. No. 26733 lias fruited in Florida and is regarded as the most promising variety yet tested. Trees of the same number have fruited at Mountain View, California, the fruits being entirely non- astringent. It was introduced under the name Fuyugaki. Tamopan (figs. 4 and 10). — Fruit very large, often from 3 to 5 inches in diameter and sometimes over a pound in weight; usually more or less quadrangular with a prominent equatorial constriction or crease below the middle; color light red-orange 28 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION changing little at maturity; skin thick and tough, enabling one to eat the flesh with a spoon from the half shell; flesh light orange, very juicy, stringy, mostly astringent until soft, fairly rich; quality very good; usually seedless. Season medium. Tree hardy, vigorous, productive. First introduced by the United States Department of Agriculture from China in 1905. Maru (fig. 3). — Fruit medium with a broad, rounded apex; color orange-red, at- tractive; surface somewhat glossy, with heavy bloom; flesh dark cinnamon when seeded, very sweet, rich ; quality excellent. Tree a regular heavy producer in Placer County ; season medium. The name Maru, meaning round, is used as a suffix of several variety names such as Zengi-maru, Daidai-maru and Sagami-maru, signifying that the fruits have a general roundish form. The name should properly be used, therefore, as a type rather than a variety name. The same is true of the name "Kineri." Sdburoza. — Fruit small to medium, characterized by four prominent lobes or "seats" extending beyond the calyx; color very dark tomato-red, very attractive; sur- face glossy ; flesh very dark cinnamon when seeded, sweet, rich ; quality excellent. Il- lustrated and described in the California Cultivator, January 28, 1915. Tsuru. — Fruit oblong-cylindrical with rounded apex; longer in proportion to its size than any other variety ; color bright orange-red, attractive ; skin smooth, glossy, rather thick, granular ; flesh astringent until soft, often failing to ripen uniformly ; quality good; usually seedless. Season late. Fruit especially sought after by Orien- tals. Colored plate and description in the United States Department of Agriculture Yearbook for 1890, p. 423. The Costata illustrated and described in the United States Department of Agri- culture Yearbook for 1892, p. 265; the Orrnond (Yearbook for 1912, pp. 270, 271) ; and probably the Yama Tsuru (Yearbook for 1891, p. 387) belong to the same group as the Tsuru. Yeddo Ichi. — Fruit often more roundish than flattened, medium, apex slightly de- pressed at center; color very dark tomato-red, attractive; surface somewhat glossy, usually marked with fine penciled lines around the apex; flesh very dark cinnamon when seeded, sweet, rich; quality excellent. Colored plate and description in the United States Department of Agriculture Yearbook for 1889, p. 450. Yemon. — Fruit medium, decidedly flattened and quadrangular; color light orange- red; surface somewhat glossy with a heavy ashy-gray bloom; flesh cinnamon when seeded, sweet, fairly rich ; quality good. Season late. Tree a very heavy, regular pro- ducer. Seedless specimens illustrated in color and described in the United States De- partment of Agriculture Yearbook for 1887, p. 644. The Yama Yemon is very similar to the Yemon, but generally larger, earlier, and often furrowed on the four sides. Zengi. — Fruit small; color dark orange-red, attractive; surface glossy, often marked with russet lines around the apex; flesh very dark, almost black when seeded,' sweet, rich; quality very good. Season early. Fruit too small for commercial use. The Gailey, Taber's 129, and Miyotan, grown in the southern states, belong to this group. BuL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 29 CLIMATIC REQUIREMENTS TEMPERATURE The Oriental persimmon is distinctly a subtropical fruit. While it is found in the northern part of the mainland of Japan, and withstands zero weather in China, it does not reach the perfection there that it does in the milder, southern parts of these countries. In the United States it has failed to grow satisfactorily as far north as Washington, D. C, and, as has been indicated, is suited only to the states of the Cotton Belt and to California. This is also the experience in Europe where it finds a con- genial home only along the shores of the Mediterranean. In general the persimmon may be said to be limited to the same climatic zone as the fig; however, the same amount of high summer heat and lack of humidity are not required to mature the fruit, as is evident from the fact that in California fruit of excellent quality is produced in the coastal belt of southern California where the humidity is commonly high and the daily temperature range much lower than in the interior regions. The season of ripening in the cooler districts of the state is somewhat later than in the interior valleys, but as the fruit is grown primarily for the holiday trade this is a distinct advantage. With the exception of the foothill areas, the persimmon has not been tested as thoroughly in the hotter interior sections as it has in other parts of the state, and its behavior in these regions is not as well known. Trees are bearing in the Imperial Valley and in the south San Joaquin Valley. The poor showing made by some of these plantings may possibly be caused by lack of sufficient irrigation rather than by intense heat and dryness of the atmosphere. Observations made by Packard 13 on the be- havior of the persimmon in the Imperial Valley indicate that the trees are somewhat sensitive to dry heat, but if adequate protection be given against sunburn, satisfactory growth is made and good crops are pro- duced although sunburning of the fruit is always present. Certain varieties, notably the Hachiya, are very sensitive to sunburn- ing of the fruit, which markedly affects its salability, though usually not the eating quality. For this reason this variety is much better adapted to the cool equable southern coastal belt than the hotter interior valleys. Late spring frosts are a limiting factor in the mountain valleys of the foothill belt, occasional losses having been recorded in Placer County and the San Fernando Valley of Los Angeles County. Ordinarily such J s Packard, Walter E. Agriculture in the Imperial Valley — A manual for settlers. California Exp. Sta. Cir. 159:1-71. 1917. (Out of print.) 30 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION damage is confined to the trees on the bottom lands. Loss of the crop was reported at the Jackson substation in 1898 because of frost damage to the flower buds. Losses from this cause could undoubtedly be eliminated or greatly reduced by means of orchard heating such as is sometimes practiced with other deciduous fruits. WATER SUPPLY No data are available concerning the maximum and the minimum amounts of water required to grow the persimmon. In general it may be said that it requires at least as much as do other deciduous fruits grown in California. Experience in the southern part of the state, where the trees have been interset in citrus orchards, indicates that superior yields are obtained when amounts of water are used equal to those required for the citrus fruits. On this basis the water requirement in California may be said to range from 30 to 45 inches annually, including rainfall. WIND Both the persimmon tree and fruit are markedly and injuriously af- fected by winds, whether prevalent or occasional. Sudden winds during late summer and fall, when trees are heavy with fruit, are very injurious WKm -'jjljfr-jjs&ii:! • :i * lik? v ^..C^vt*"" 1 * ' ■" ^LZM -k' : l''4 WKm^^Imm^ Z :?•£ 3[gQ& Fig. 12. — The effect of a sudden windstorm on a poorly trained young bear- ing tree. The persimmon is very subject to wind injury. Persimmons and Valen- cia oranges are interplanted in this orchard. (Courtesy of H. E. Wahlberg.) BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 31 on account of the breakage of the weak crotches (fig. 12) and brittle scaffold limbs, which characterize the persimmon tree, and the bruising of the tender fruits, which results in a lowering of the quality. In re- gions of prevailing winds it is extremely difficult to train the Hachiya variety to a satisfactory framework, and staking them seems only to aggravate the problem. Prevailing cool ocean breezes markedly reduce fruit bearing in this variety. The importance of wind as a factor mitigat- ing against success in commercial persimmon culture is altogether in- sufficiently appreciated. The use of windbreaks, while highly beneficial, is not sufficient to overcome satisfactorily the effects of strong prevail- ing winds. HUMIDITY The persimmon is grown in California under a wide range of atmos- pheric humidity. Where the irrigation practice is good the trees produce crops even in extremely arid regions. Since fair crops are produced throughout the great interior valleys, humidity cannot be considered as of especial importance if other environmental conditions are satisfac- tory. However, in the coastal belt, particularly in the southern part of the state, where fogs are more frequent and the humidity higher, the tree seems to thrive especially w r ell, and here the best growth and high- est quality of fruit are found. This may be due in part, however, to the deeper soils and better cultural practices employed. It is to be noted, however, that sunburn of the fruit is markedly reduced in regions of moderate to high atmospheric humidity. PERSIMMON DISTRICTS IN CALIFORNIA As previously mentioned, the Oriental persimmon was widely scat- tered throughout California in the early days. Plantings, portions of some of which still exist, were made in Butte, Napa, Solano, Placer, Tu- lare, Kern, Santa Barbara, Ventura, Los Angeles, Orange, and River- side counties. In only a few regions, however, has any considerable expansion of plantings taken place. In northern California the princi- pal persimmon-producing district is Placer County, while in southern California the main plantings are in Orange, Los Angeles, Riverside, and Santa Barbara counties. In Placer County the development of persimmon plantings has been incidental to the more extensive plantings of shipping plums, pears, and grapes. The persimmon early proved its ability to withstand adverse soil conditions, and when other deciduous fruit trees died, particularly in the poorly drained and cold mountain valley bottoms, persimmon 32 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION trees were planted in their places. The result has been that much of the persimmon acreage there is in small plantings, interplanted in orchards of other fruit. The total acreage in Placer County planted to persim- mons is about 150, according to the latest figures available. Many of the trees are situated on hillsides where the soil is shallow and where cultural practices are difficult. Under these conditions the trees have not made the growth which is attained under more favorable conditions, but they bear good crops consistently; in fact show a marked tendency to over- bearing. Most of the northern California plantings were made prior to the federal quarantine order prohibiting the importation of nursery stock, and the trees were obtained direct from Japan and are on kaki root. Nearly all of the orchards are of mixed varieties and the topwork- ing of the seedlings and undesirable varieties would undoubtedly greatly improve the standardization and sale of the crops. While irrigation has been practiced on most of the plantings, no records are available rela- tive to the amount of water used, which has been the same as applied to the other deciduous fruits. The conditions in Placer County are typical of much of the foothill belt in the Sacramento and San Joaquin valleys and the success of the persimmon there affords reason for believing that the area which might be devoted to the raising of this fruit is extensive. The behavior of the trees at the Government Plant Introduction Gardens near Chico and in several other plantings located at lower elevations in both the Sacra- mento and San Joaquin valleys, demonstrates that the persimmon can be grown wherever other deciduous fruits are grown. It is certain, there- fore, that in California the limited development of persimmon culture to date is the result of causes other than unsuitable soil and climatic conditions. In southern California, plantings have been made generally through- out the citrus belt, particularly in the coastal area. One of the oldest is that on the Elwood ranch in Santa Barbara County, previously men- tioned. Much of the original orchard still remains, though a consider- able part was washed away during a flood some years ago. The most ex- tensive orchards are to be found in Orange and Los Angeles counties. The older plantings are rather commonly found interset with citrus trees — orange, lemon, grapefruit, and tangerines. Just how the practice became established is not known, but it has spread and the combination has been a satisfactory one. Excellent examples of this combination are to be seen in the G. W. Sherwood orchard at Fullerton, where grapefruit and persimmons have been interset, and in the Richter grove at San Dimas, where both lemon and tangerine trees have been used. The rapid BUL. 416] T HE ORIENTAL PERSIMMON IN CALIFORNIA 33 growth of the trees and the heavy production of fruit experienced in these orchards indicates that the Oriental persimmon responds well to the cultural practices given citrus groves. In recent years, in all parts of southern California there has been a pronounced increase in interest in the growing of persimmons which has led to the setting out of many solid plantings. The future of the persimmon industry in some parts of southern Cali- fornia is rendered problematical by continued subdivision activities which have brought about greatly increased land valuations. These, to- gether with the high valuation of land suitable for citrus culture, con- stitute a distinct handicap to the raising of persimmons in districts affected by these factors. If the growing of this fruit were limited to the same climatic zone as the citrus fruits, its production on high-priced land would not be accompanied by risks or problems uncommon to many other subtropical fruits. On the other hand, since the persimmon can be grown on large areas in other parts of the state, where land values and costs of water are much lower, the unlimited expansion of plantings in southern California would seem to be decidedly hazardous. While limited plantings in the Imperial Valley have indicated that crops can be produced there, and the experimental planting at the Gov- ernment Farm at Bard is now coming into bearing and will soon afford more specific knowledge as to the behavior of the different varieties, there does not seem to be at the present time sufficient evidence to war- rant the general assumption that persimmon culture can be profitably carried on in this valley in competition with other areas in' the state. Further experimental plantings should be tried before extensive acre- age is planted. SOILS Judged by its behavior in both California and the southern states, the Oriental persimmon is not particular in its soil requirements, appar- ently growing about equally well on a wide variety of soils, though the response the tree makes indicates some degree of preference. On the deep silt loams of Orange County and the heavy loams of other parts of southern California, the tree reaches its maximum size, while on the lighter and especially on the shallower soils, the tree makes much less growth but comes into bearing earlier. This difference in response is par- tially attributable, however, to differences in cultural treatment. It has been a common assumption that the persimmon is naturally re- sistant to excessive soil moisture and that therefore it is especially adapted to low, wet areas. This is true only of the native or virginiana 34 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION root, which can withstand a higher water table, or periods of continuous wet soil conditions much better than other rootstocks. It should be em- phasized, however, as will be adverted to later, that this root is not gen- erally so satisfactory for the conditions in California as are the other stocks which are used. Neither the kaki nor the lotus root are tolerant of poorly drained soils, the former less so than the latter, and illustrations of failure to recognize this fact are not lacking in both northern and southern California where many trees have died from this cause. The difference in resistance between the lotus and the kaki is well illustrated on a grove in Orange County, where on account of excessive irrigation and poor drainage the original planting of trees on kaki root has almost completely died out, while the few trees on lotus root have lasted much longer, although several have succumbed recently. The ideal soil condi- tions for the optimum growth of this fruit are provided by a well- drained, medium heavy loam, well supplied with organic matter. PROPAGATION ROOTSTOCKS Three rootstocks have been used for the persimmon in California, the kaki, virginiana, and lotus species. The older plantings are almost en- tirely on the kaki root since the trees were imported from Japan where the root has been almost exclusively used. In recent years some ship- ments of trees have been made from the southern states where the native or virginiana stock has been favored. From the beginning of interest in persimmon planting a few trees have also been propagated on this stock by California nurserymen. As a result of Meyer's observations on the use of Diospyros lotus in China, this stock came into prominence some years ago and large impor- tations of seed were made both by the United States Department of Agriculture and by private agencies. Importations of nursery trees on the kaki stock continued to supply the majority of trees, however, until prohibited by Quarantine Order No. 37, which became effective on June 1, 1919. This order made it necessary for growers to secure trees propa- gated in this country and resulted in a marked stimulus to the growing of nursery trees in California. Some importations have been made from the southern states, but the interception of the persimmon borer in some of the shipments has resulted in quarantine restrictions. The result has been that with the exception of some few trees imported from the south- ern states, all persimmon trees grown in California since the issuing of the federal quarantine order have been on the lotus stock. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 35 Diospyros Kaki. — As has been stated, the oldest orchards in Califor- nia are on this stock. Its habit of growth is to produce a long tap root with few fibrous laterals, in this respect resembling the walnut. These long taproots are easily broken or injured in handling and shipping, are difficult to pack, and in general have caused much dissatisfaction with this root on the part of nurserymen and growers. There is no question, however, that the stock makes a satisfactory union with all varieties at present grown, and produces fine orchard trees. When the experience and practices of both the walnut and pecan nurs- erymen in the handling of trees with the same type of root are avail- able, it is difficult to understand just why such practices have not been used in handling the kaki root. In order to limit the length growth of the taproot and to stimulate the development of fibrous laterals in the case of both the walnut and pecan the taproot is cut while the trees are in the nursery row, a long-bladed spade being used for this purpose. This prac- tice gives very satisfactory results, and it is believed that it is applicable to the kaki root, and that if used, much better results could be obtained than have been in the past. The kaki root is not as resistant to excessive soil moisture as either the lotus or the virginiana. The kaki is not as susceptible to crown-gall attack as is the lotus, and this quality is reviving interest in a possible resump- tion of its use. Further, it is reported that one of the most widely used stocks in Japan and parts of China is a wild form of Diospyros kaki which is said to be very hardy. This form was introduced some years ago by the United States Department of Agriculture, but was lost before it received widespread distribution. What is believed to be the same form has recently been introduced again and is being propagated for further trial. Efforts are also being made to locate a large supply of this form. The few trees of this rootstock now growing at the Plant Introduction Garden at Chico seem to be more resistant to crown gall than lotus stock growing nearby. They are vigorous and thrifty and give decided prom- ise of affording an excellent rootstock. Diospyros Virginiana. — In the southern states the wild native Ameri- can persimmon early came into use as a rootstock and soon demon- strated its superiority over the kaki root for the conditions in that re- gion. It was found to be adapted to a much wider range of soil condi- tions, and trees on this stock showed superior growth. Its habit of growth is to produce many fibrous roots, which make it easier to transplant than the kaki. In the opinion of H. H. Hume this stock is the best root for the Oriental persimmon in the south. It has the disadvantage of suckering badly, however, particularly if the roots are injured. Trees 36 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION on this stock have grown well in California, both those imported from southern nurserymen and those grown from seed here. It has been the experience in this state, however, that it is difficult to get a uniform stand of nursery trees from this root. Trees on this root will stand un- favorable soil conditions, and particularly excessive moisture, much better than on either of the other two stocks. In Placer County J. A. Teagarden reports that the use of this stock in the low and colder parts of his orchards has delayed the blooming period of the trees about thirty days in the spring, thus insuring freedom from frost injury. In poorly drained areas where water may stand for considerable time during the rainy season, this root has also been found to produce better trees. Diospyros Lotas. — Although this is the newest stock to be used for the propagation of the Oriental persimmon, Diospyros lotus has rapidly superseded all others in California. Meyer 14 reported it as the stock upon which he found the oldest topworked trees growing in northern China. Trees were observed which he estimated to be several hundred years old. The use of this rootstock was suggested in 1882 in the report of the California College of Agriculture, 15 which stated that it was su- perior to the virginiana because of the better root system which it pro- duced. The lotus stock has produced the most thrifty, rapidly growing, uniform stands of nursery trees of all stocks yet tried in California and this rapidity of growth has been maintained by the young orchard trees. It produces an excellent fibrous root system, does not sucker, and is easily handled in the nursery. The greatest drawback of the lotus stock is its susceptibility to infection by crown gall, which has become so wide- spread in recent years as to constitute a serious menace to the continued use of this stock. Nurserymen are, therefore, looking for a strain of this stock that possesses its good qualities but in addition is resistant to this disease. The lotus stock is more resistant to drouth conditions than the virgin- iana and probably the kaki. It will not withstand poorly drained soils, but as this is an exceptional condition in most parts of California, it can be recommended generally for planting except where crown-gall infec- tion is known to exist. SEEDING Seed of the lotus may be planted either in flats or in field beds if the latter are shaded from the direct rays of the sun and covered to keep the birds away. The usual practice is to stratify the seeds in sand in the fall, 14 Meyer, Frank 1ST. Agricultural explorations in the fruit and nut orchards of China. U. S. Dept. Agr. Bur. Plant Ind. Bui. 204:10-16. 1911. is Klee, W. G. The Diospyros lotus or so-called Italian persimmon. Report of the Col. of -Agr., Univ. of California 1882:102-1.03. 1883. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 37 covering them with about an inch of sand, which is kept moist until early spring, when they are planted in nursery rows or in flats. Some nursery- men plant them in the spring without stratifying, using a mixture of half sand and half soil. The flats should be kept in the partial shade of a lath house, or the beds should be shaded, until germination is complete, as the seedlings are very susceptible to sunburn. If planted in field beds, Fig. 13. — Foreground, shading young seedlings by means of shingles. Back- ground, young grafted trees recently staked. the seedlings should be thinned to a distance of 8 inches in the row, and in transplanting from flats this distance should be maintained. Shade must be provided for all newly transplanted seedlings until they become well established and growth has begun. For this purpose shingles are frequently used (fig. 13) ; lath screens are also employed. In general the same methods are used in the handling of kaki seed. Where possible the seeds should be stratified soon after removal from the fruit. Where drying has occurred they should be soaked in warm water for two or three days before stratification. 38 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION GRAFTING Most of the nursery stock grown in California has been propagated by grafting, either bench-grafting or in place in the nursery row. The ordi- nary whip or cleft grafts are used, the former giving a somewhat better union, though the trees produced by either method are satisfactory. Seedlings of one or two years' growth are used. If the whip graft is to be employed, the top is removed by a sloping cut about an inch in length, and a scion from the previous season's growth of about the same diam- eter as the stock, and having two buds, is prepared. A long sloping cut is made at the base of the scion similar to that made on the stock and the two are fitted together by means of incisions in both stock and scion in the manner illustrated and described by Fletcher 16 or in any standard text on propagation. 17 If the seedlings are to be cleft-grafted, they are cut off squarely just above the surface of the ground and are then split with a sharp, strong knife. The scions should be taken from well -matured wood of the previous year's growth, with two buds. The lower portion of the scion is cut so as to form a long wedge with one edge thicker than the other. The cuts are made so as to have the lowest bud at the top of the wedge. In order to insure contact of the cambium layer of the scion and the stock, the former is tilted outward slightly so that the lines of the two cambium layers cross. The scion is firmly tied with strong cotton cord and the wound and union covered with grafting wax. After growth starts, all suckers arising below the union should be removed so as to force all growth into the scion. This method can be used with advantage on stocks that are too large to be readily whip-grafted. BUDDING The propagation of the Oriental persimmon by budding is not ordi- narily practiced. The experience has been that this method of propaga- tion does not give a satisfactory percentage of stand or the uniformity of growth desired by the nurserymen. J. E. Morrow, of the Government Plant Introduction Garden at Chico reports recently, however, much greater success from the use of buds removed by outlining or cutting through the bark only and peeling it off, rather than cutting through and taking a part of the wood. This procedure gives much more cam- bium surface and should produce much better results. is Fletcher, W. F. The native persimmon. U. S. Dept. Agr. Farmers' Bulletin 685: 1-28. 1915. 17 Stahl, J. L. Propagation of deciduous fruits. California Agr. Exp. Sta. Cir, 294:1-24.1925. BlTL. 416] the ORIENTAL PERSIMMON IN CALIFORNIA 39 Budding may be done in the spring as soon as the sap is good and the bark slips readily or in the fall before the sap flow has ceased. The buds are taken from the previous season's growth. Where seedlings of the current season are to be used, budding usually must be delayed until early fall to permit them to become large enough. The ordinary "T" incision is made from 2 to 3 inches above the sur- face of the ground, the vertical cut being about 1% inches long. The bud is cut with a shield from l 1 /^ to 1^2 inches long and is gently forced down into the incision until the shield is entirely beneath the flaps of bark. A narrow strip of budding cloth % to % inch wide is used for wrapping. This is started above the bud and wrapped downward. As soon as the buds have united with the stock the wrapping should be cut. When growth begins, the stock should be cut off just above the bud, and stakes provided as soon as the new shoot is long enough to tie. The method of budding the native persimmon has been well described and illustrated by Fletcher. Meyer 18 reports that the varieties in north- ern China are ring-budded on the lotus root. This method is also de- scribed by Fletcher. Regardless of the method used, staking and tying should begin when the scion or bud has made a growth of from 12 to 14 inches (fig. 13). This will protect the buds from being broken by wind or other means, facilitate cultivation and irrigation, and develop strong and straight trees. Ordinary building laths are satisfactory for this purpose. TOPWORKING Reference has already been made to the desirability of top^brking many of the trees in the older plantings in California as a means of elim- inating inferior varieties and for the purpose of promoting standardiza- tion of packs. Trees to be topworked should be cut back in late winter. The branches to be grafted should be selected so as to form a desirable framework and should be cut back to stubs from 18 to 24 inches long. Several should be left uncut to act as nurse limbs until the scions have grown for a year or two. The ordinary cleft graft is employed (fig. 14) the number of scions being two or more, according to the size of the limb to be grafted. In the case of large stubs it is an advantage to use more scions than are needed since they encourage rapid healing-over of the Avound. The scions should be from % to % i ncn i n diameter with two or three strong buds. The wounds should be kept waxed until they are com- pletely healed over. After a year or two all scions but one to each limb is Meyer, Frank N. Agricultural explorations in the fruit and nut orchards of China. U. S. Dept. Agr. Bur. Plant Ind. Bui. 204:10-16. 1911. 40 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION can usually be removed, since the healing of the cuts will have prog- ressed far enough. The trunk and crotches should be kept whitewashed until the new top is grown, as a means of preventing sunburn. For the purpose of keeping birds from breaking out the scions by perching on them when first inserted, paper bags should be inverted over the stubs and tied. Holes should be cut in the bags to provide air circu- 11 Si* Fig. 14. — Kecently topworked persimmon tree showing cleft-graft method employed and rapid growth of scions. #'■ Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 41 lation. The growth made by scions on large trees is rapid and there is danger that the new branches will break out at the union unless they are braced. This may be accomplished by lashing a strong 1 by 2-inch up- right to the old limb and tying the new limb to it until the union becomes strong enough to maintain the additional weight. It is usually necessary to head back the vigorously growing scions to prevent the new limbs from becoming willowy and to cause them to branch. .s? X Fig. 15. — A bud variation in the Hachiya variety: A, the standard type; B, the variant form. (Courtesy of A. D. Shamel, United States Department of Agriculture.) BUD SELECTION In the propagation of nursery stock and in the topworking of old trees, care should be used in the selection of buds and scions. The occur- rence of occasional bud variations has been noted in many sorts of fruit, and there is some evidence to indicate that they have occurred in the persimmon. Thus, in the Hachiya variety there has occasionally been 42 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION found a fruit of rounded form on trees which produce mainly normally shaped fruits (fig. 15) . It would, therefore, seem desirable to select bud- wood while the fruit is still on the trees, although the hazard from not so doing would appear to be slight. It should be emphasized in this connec- tion that Hume 19 has shown that in many persimmon varieties pollina- tion has a decided effect on the size and shape of the fruits. Since these are two of the important characters used in bud selection, it is neces- sary that they be considered in connection with the selection of buds or scions. The presence of seeds frequently causes a reduction in size of the fruit, which may explain in part the difference in size previously noted in fruits of the Hachiya variety, as grown in northern California and southern California, the older orchards in the north invariably contain- ing a number of varieties and usually producing seeded fruit, while in southern California most of the plantings contain but the one variety and the fruits produced are seedless. In some varieties the presence of seeds alters the shape from conical to oblate or flattened. There is ob- viously, therefore, always the likelihood that suspected bud variations may be nothing more than the normal result of seed development. There has been no systematic work done on this phase of persimmon culture in California and no specific recommendations can be made. The general policy of selecting budwood from trees producing good crops of uniform fruits, typical of the variety under normal orchard conditions, should be followed until there is more specific information available. ORCHARD MANAGEMENT PLANTING AND CARE OF YOUNG TREES Planting Distances. — Planting distances vary with the variety and with soil conditions. In northern California on the shallower soils of the hill slopes, a distance of 15 by 15 feet has not resulted in crowding, while in southern California on some of the deep, rich soils, trees planted 24 by 24 feet have eventually crowded each other. There is strong evidence to indicate that under these conditions a distance of 30 by 30 feet will probably not be too great for strong-growing, spreading varieties such as the Hachiya and the Tamopan. The Hyakume is more slender and up- right in its growth and can be planted at a distance of 20 by 20 feet under most conditions. Inter planting. — It has been the practice to interset persimmon groves with citrus trees in southern California at the usual distance of citrus 19 Hume, H. H. Effect of pollination on the fruit of Diospyros MM. Amer. Soe. Hort. Sci. Proc. 1913:88-93. 1914. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 43 plantings, 24 by 24 feet (figs. 12 and 18), and in general this arrange- ment has proved very satisfactory. In at least one interplanted orchard where a smaller distance was used the trees have become too crowded, the fruit being produced in the tops almost entirely, and the yield mate- rially reduced. Fig. 16. — Left, well-pruned tree with desirable framework. The distribu- tion of scaffold branches is good. Eight, poor framework formation. This will give trouble later. See also figure 17. Planting Operatioiis. — Holes 1 foot in diameter and 2 feet deep and the use of top soil for filling in around the roots are recommended. Blast- ing the holes in shallower soils has given good results in Placer County. All broken or torn roots should be pruned off and the cuts disinfected with bordeaux paste or bichloride of mercury solution. The trees should be headed back to a height of from 24 to 30 inches and the main frame- work branches developed from the best-spaced four or five shoots pro- duced from the 18 to 36-inch level of the trunk (fig. 16) . Irrigation should follow the planting of the trees, even though the soil is moist, in order that it may be thoroughly settled around the roots. 44 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION While not absolutely necessary, it is an advantage to whitewash the trunks of young trees to prevent sunburning, especially in regions where summer temperatures are high. Wrapping with newspaper will serve the same purpose, provided there is sufficient air space between the paper and trunk. Fig. 17. — The result of the lack of proper spacing and thinning of young branches. The center is now too dense and the crotches are weak. Training. — The object of training is to develop a strong framework capable of carrying heavy crops (see figs. 12 and 17 for illustrations of weak framework) . How best to accomplish this is still a debatable ques- tion. Experience indicates that with the Hachiya variety the develop- ment of the open-vase form is both difficult to obtain and undesirable, owing to the inherent weakness of the crotches. It is also difficult to train the trees to the central-leader form. The natural growth habit of this variety appears to favor the modified leader form more than any other and it is probably best, therefore, to encourage the trees to de- BUL. 416] T HE ORIENTAL PERSIMMON IN CALIFORNIA 45 velop this type of framework system. The principal difficulties encoun- tered in the studies on this subject conducted thus far, are the selection of the branch which is to become the leader and the maintenance of the necessary dominance to insure the proper development of the leader branch. During the first few years there appears to be a pronounced tendency for the main laterals to catch up with the leader, even though suppressed by shortening in or heading back. From the present evidence it seems best to confine training during the early years to the selection of 4 to 5 well-spaced and well-distributed main laterals, suppressing all others by pinching, and to leave the selection of the leader until it is clearly evident which is likely to become the most satisfactory. Experience indicates that the young trees stand up against prevail- ing winds much better if not staked and that the development of branches on the windward side is better. During the early years it appears advisable to remove the young fruits from the terminal portions of the main scaffold limbs. Irrigation. — Irrigation to insure steady and uninterrupted growth should be provided throughout the dry growing season, the interval being determined by the results of an examination of the soil with a soil auger or some other means of disclosing the condition of the subsoil. If a good top soil is used in filling in around the roots of the young trees, no fertilization will be required, though where the cost of water is not too high, the growing of covercrops during this period is recommended. CARE OF BEARING TREES Tillage Operations. — The cultural practices followed are in general similar to those employed with other deciduous fruits, no special depar- tures being required by the persimmon. One plowing a year, usually in the spring, is the common practice. This keeps the roots below the surface 6-inch mulch with consequent less exposure to variation in ex- tremes of heat and dryness. If a winter covercrop is grown, spring plowing should be done early enough for the green matter to become thoroughly incorporated in the soil while there is still moisture enough to bring about immediate decay and availability. Cultivation sufficient to keep down weeds and to leave the soil in good condition to take water is all that is required. Irrigation. — The amounts of irrigation water applied vary notably in different parts of the state. Actual measurements on orchards are diffi- cult to obtain in northern California. In southern California as much as 3 acre-inches a month during the growing season is used on some of the 46 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION orchards, especially those interset with citrus trees. On most soils 2 acre-inches a month is probably sufficient. While monthly irrigations are sufficient in the deeper soils of both northern and southern California, more frequent irrigations, using smaller amounts of water, are needed on the shallow hillside soils because of the reduced water-holding capa- city. The furrow method is most commonly used; however, in a few orchards on sandy soils, the basin system has given most satisfactory results. The use of the soil auger, or some similar means of examining the condition of the soil beneath the surface is indispensible in good orchard management, in order that the application of water may be uniform, adequate, and properly timed. During the winter months, irrigation may be necessary during years of light rainfall, as is the case with other deciduous fruits. The relation of adequate soil moisture to the quality of the fruit pro- duced is well demonstrated in some districts by the correlation which has been observed between the sunburn or blackening of the fruit and insufficient water supply. Orchards with similar soil conditions but sufficient moisture exhibit much less of this difficulty. It is especially important that water be supplied during the last two or three weeks of the ripening period; for there seems to be a relation between the size of the fruit and the presence of ample moisture during this period. Insuffi- cient moisture at this time seems to result in small fruit, even though conditions have previously been favorable. Fertilization and Covercrops. — There is no uniform "practice in the application of fertilizers, although the importance of organic matter in the soil is generally recognized. In some of the northern California dis- tricts an annual application of manure is practiced, although many of the orchards are not fertilized at all. In southern California where many of the orchards are interset with citrus trees, the regular citrus orchard fertilization practice is followed, namely, the application of from 1 to 2 pounds of nitrogen to a tree a year. The best results seem to occur where at least half of the nitrogen is secured from bulky organic matter. In the absence of any systematic tests, the superior results obtained from the fertilization program just mentioned, indicates that the general practice is a satisfactory one. Since California soils are in general deficient in organic matter, persimmon trees in common with other varieties of fruit trees undoubt- edly profit by the regular application of bulky manures and coarse, leguminous materials such as bean and alfalfa straw, and the growing of summer and winter covercrops where this is possible. Purple vetch, BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 47 Melilotus indica, horse beans, and mustard are used for winter cover- crops in southern California. Where there is adequate water at a low rate during the summer months, the perennial sweet clover, Melilotus alba, furnishes an excellent, deep-rooted covercrop, especially adapted to breaking up heavy subsoils. Cowpeas are also used as a summer covercrop. Pruning. — Persimmon varieties vary notably in their habit of growth, and pruning practices should be adapted to these varietal character- istics. The Hachiya is a broad, upright-growing, almost ideal orchard tree, somewhat spreading in habit, and requires little pruning. The Tamopan is similar, though inclined to a somewhat more willowy habit of growth. On the other hand, the Hyakume tends to the development of a strong central leader with rather short, drooping laterals. In general, the pruning of bearing trees should be limited to the renewal of the fruiting wood. Since the fruit is borne on the growth of the current season, sufficient thinning should be given to insure vigorous growth each season from the secondary scaffold branches. Because of the general tendency toward vigorous growth, care is required to thin sufficiently to admit light to the interior. If this is not done, the interior fruiting wood dies, and all the crop is borne on the outer parts of the tree. The possibilities of the crops are consequently materially decreased, and the danger of breakage is augmented. All cuts should be made to laterals so as to avoid heading or "stubbing," which is very objectionable. Water-sprouts on the trunk and main branches should be rubbed off except where they are needed to fill in spaces opened by breakage. Excessive cutting and stubbing results largely in the production of vigorous vegetative growth and failure to fruit. Old, neglected trees can be rejuvenated by a rather vigorous thinning and cutting back to laterals and by shortening the main branches to force out laterals where, through long neglect, all interior fruiting wood has disappeared. Thinning. — Many persimmon varieties exhibit a marked tendency to alternate bearing. This seems more pronounced where pollination occurs than where the fruits are seedless. In southern California the very heavy drop that takes place throughout the growing season usually thins the crop sufficiently to insure large size in the remaining fruit. In northern California, where pollination and seed development are common, large crops of relatively small fruit alternating with smaller crops of fruit of fairly good size is the usual occurrence. It has been shown at the Chico Plant Introduction Garden that thinning increases the size of the fruits and reduces the tendency to alternate bearing. Since the market pays substantial premiums for large fruits, in all probability the operation 48 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION would pay. No extended experiments have been conducted on this prac- tice, however, which constitutes one of the most important problems awaiting investigation. In the absence of specific information, it is recommended that the clusters be thinned to one or two fruits and that each individual fruit be given ample space for development. Each grower should determine for himself the optimum number of fruits of standard size and quality that his trees can carry and mature each season. It is believed that between 300 and 400 fruits for a mature Hachiya tree is sufficient, though there are trees which under exceptional circumstances have produced as many as 1,000 good fruits in a single crop. Bracing and Propping. — The wood of the persimmon is very brittle, and propping is almost invariably required as the trees come into bear- ing (figs. 8 and 9). Much can be done to encourage the development of a strong framework by careful training and judicious pruning of the young trees, and this will save extra work in later years. Additional support by means of props is usually required, however, if danger of loss from breakage is to be avoided. Several means of accomplishing this are employed by the growers. Propping alone, even though the poles are fastened at the top by wire clasps over the branches, is not entirely satisfactory. Winds may lift the branches and the props, if not fastened, fall, and if fastened, do not always come back in place, with the result that the limbs break. A com- bination of wire bracing and propping is the most general practice. Wires are fastened with large screw eyes to, or are wrapped around, the main uprights and then dropped to the laterals and fastened in a similar manner, props being placed under the smaller laterals. Wrap- ping wire around the branches is objectionable since it eventually leads to breakage of the wrapped branches, from constriction. Because of the habit of growth, the central ring wire-bracing system used with peaches and other deciduous fruits is applicable without modification only to certain varieties, but adapted and supplemented with propping it can be used with advantage on practically all the com- mercial sorts. One of the successful methods consists of a series of wires dropped from the top of a 2 by 4 inch pole which has been erected in the center of the tree, and extends 2 or 3 feet above the top of the crown. The wires are passed around the limbs through sections of old hose, or leather bands are used to prevent binding. In large limbs, screw eyes may be used successfully, but are not advised for small branches because of the brittleness of the wood, which frequently results in breakage at the point of attachment. The advantage of this system lies in the smaller Bul. 41GJ THE ORIENTAL PERSIMMON IN CALIFORNIA 49 number of poles necessary, thus aiding cultivation, irrigation, and pick- ing operations. Because of their cost, props should be gathered up and stored during the winter. Harvesting. — The legal maturity requirement for the Oriental per- simmon in California is based on color alone and is as follows: "No Oriental persimmon shall be considered mature unless the entire surface has attained an orange or reddish color." 20 This requirement does not prevent the picking of partially colored fruit and its subsequent color- f ^1«tfl%& Fig. 18. — Picking scene in a young persimmon orchard, interset with orange trees. Note the clippers, picking box, and special type of sling employed. (Courtesy of H. E. Wahlberg.) ing by artificial means. As a consequence it does not fully protect either the consumer or the responsible grower who is anxious to prevent im- mature fruit from reaching the market. The practice of picking unripe fruit and coloring it artificially cannot be too strongly condemned, for it results in fruit of poor eating quality, injuriously affecting price levels for the good-quality fruit which follows it within a few weeks. It has been found possible, however, to extend the local marketing season by approximately two weeks and still supply fruit of acceptable quality by the use of artificial coloring, provided the fruit is sufficiently mature at the time of picking. Experience indicates that with the Hachiya variety this condition is reached when the pink color affects at least a portion of the basal half of the fruit and not less than half the 2 o The California Fruit, Nut, and Vegetable Standardization Act of 1931. Section 23, p. 3. California State Printing Office, Sacramento, 1931. 50 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION fruit surface is well colored. The Hyakume and Tanenashi varieties are ordinarily of satisfactory quality when the yellowish tinge extends almost to the basal or calyx end. It appears that the Fuyu variety should be fairly well colored before picking. The advantages of delaying picking until the fruit is firm ripe have been well established, and include greater size and weight, as well as certainty of acceptable quality. For home use the fruits can be left on the trees until they are fully colored, though there is danger of loss from bird damage. When well-colored they can be picked and placed in a cool, dark place to ripen. The fruit should be clipped from the trees with an orange type of clipper, the cut being made close to the calyx, which is left attached to the fruit. The fruits should never be pulled from the tree. They must be handled very carefully to avoid bruises and injuries which later turn brown and lower the grade. Shallow boxes should be used in picking and transportation of the fruit from orchard to packing house (fig. 18) . The Hachiya is particularly susceptible to injury because of the pointed apex and special care must be used in handling this variety. PESTS AND DISEASES The persimmon is particularly free from both serious insect pests and diseases in California, although a number of insect pests have been reported in foreign countries, some of which might become serious if introduced into California. The citrus mealybug, Pseudococcus citri (Risso), is becoming increas- ingly prevalent in southern California orchards. It attacks the fruit under the calyx and because of this protected position is exceedingly difficult to reach by sprays. Satisfactory control of this insect involves the elimination of the Argentine ant 21 in order that the natural insect enemies of the mealybug can function ; if unhampered they usually keep it under control. Spraying of the trees during the dormant season with oil emulsion or crude carbolic acid emulsion, with sufficient pressure to force the liquid into the cracks in the bark where the infestation is heavy, is also of assistance in controlling this insect. The orange tortrix worm, Toririx citrana (Fern.) has also been re- ported as attacking the fruit in Orange County. Presumably spraying or dusting with lead arsenate will effect its satisfactory control in the event control measures become necessary. 2i Borden, A. D. Control of the common mealybug of citrus in California. U. S. Dept. Agr. Farmers' Bui. 1309:1-10. 1923. BUL. 416] T HE ORIENTAL PERSIMMON IN CALIFORNIA 51 At least two borers attack the persimmon. In the southern states the persimmon borer, Sannina uroceriformis Walker, is the most serious insect pest in persimmon orchards and is a limiting factor in production in some districts. This pest is almost impossible to reach since it works inside of the trunk, tunneling upward. It has been intercepted in several shipments of nursery stock from southern states, although exceedingly difficult to detect without almost completely destroying the trees. Be- cause of the danger of introducing this insect, importations from these states have been prohibited. The flat-headed borer, Dicer xa obscura (Fabr.) , attacks the tree in the southern states, Whitewashing the trunks to prevent sunburn and maintaining the trees in good vigor tends to reduce the occurrence of this pest. When once established in the tree, the only method of eliminat- ing the borer is to dig them out with a knife or stiff wire. Occasionally the red-humped caterpillar, Schizuva concinna ( A. & S. ) , is found attacking trees in California, and if uncontrolled sometimes de- foliates them. Spraying with lead arsenate at the rate of 2 pounds to 50 gallons of water is recommended for its control. Other insects occasionally found on persimmon trees in California include the soft brown scale, Coccus hesperidum Linn., the black scale, Saivsetia oleae (Bern.) , the San Jose scale, Aspidiotus perniciosus Com., the barnacle scale, Ceroplastes cirripediformis Com., and the oyster-shell scale, Lepidosaphes ulmi (Linn.) . In Florida the twig girdler, Oncideres cingulatus (Say), the white peach scale, Aidacaspis pentagona (Targ), and the citrus white fly, Dialeurodes citri (R. & H.), in addition to sev- eral of those already mentioned, attack the tree, the twig girdler being especially serious. The root-knot nematode has been reported on injured persimmon roots but apparently the persimmon is not very susceptible to this pest. R. R. McLean, Agricultural Commissioner of San Diego County, has made a study of persimmon roots and fig roots in a soil area heavily in- fested with nematode at Point Loma. No infestation of the persimmon roots was found even when intertwining with fig roots which were badly infested. In foreign countries there are several important insect pests that have thus far not become established in this country. The most dangerous of these is the Mediterranean fruit fly, Ceratitis capitata (Wied.), which has caused extensive damage in persimmon plantings in Australia and elsewhere. In Japan the larva of a moth, Kakivoria flavofasciata Nag., somewhat similar to the codling moth of the apple, causes serious 52 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION injury in some persimmon-growing districts. The importance of rigid quarantine restrictions to prevent the introduction of these insects into the United States cannot be overestimated. In Imperial and Coachella valleys a cicada, Tibicen cinctifera (Uhler), does considerable damage (fig. 19). This insect emerges from June to September and attacks the fruit as it nears maturity. Dates are protected from its attack by means of bags. Should the persimmon ever become commercially important in these sections, similar protection may be required. 9 I Fig. 19. — Injury caused by cicada, Tibicen cinctifera (Uhler), in the Imperial Valley. It has not been observed as yet in other parts of the state. Croivn Gall. — Crown gall, caused by the organism Bacterium tume- faciens S. and T. is the most serious disease that attacks the persimmon tree. As has already been noted, it seems to be more prevalent on the roots of the lotus stock. There is some doubt as to whether all of the rough and warty growth found at the bud union on nursery trees on this root is caused by this disease. This problem is now under investigation at the Citrus Experiment Station. Young trees should be carefully inspected before planting, and the roots examined to detect cuts where galls may have been removed before shipment. Large galls around the crown may be cut away, the wounds sterilized with corrosive sublimate solution of a strength of 1 :1000 and then covered with asphaltum paint. Usually the galls are scattered over the roots so that complete removal is not possible. The remedy lies in planting clean trees. BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 53 FRUIT SHEDDING The shedding of immature fruits, particularly by young bearing trees, is a common phenomenon and one that frequently causes concern. The causes of the dropping are not clearly understood, since no thorough study has been made of the problem in California. In Florida, Hume has demonstrated that fruit drop is often caused by lack of pollination and seed formation. While this may have a bearing on persimmon dropping in California, the fact remains that in most parts of the state, sat- isfactory crops are regularly produced without pollination and seed formation, especially with older trees of bearing age. During periods of extreme heat and low humidity the loss of moisture from the foilage is excessive. At such times water may be withdrawn from the fruits and the periodic occurrence of this phenomenon may lead to their dropping. This has not been demonstrated with the persim- mon, but the work of Coit and Hodgson 22 has established this relation between sap withdrawal and June drop in the Washington Navel orange. The maintenance of an adequate soil-moisture supply during the growing season, and especially during periods of hot weather, is calculated to reduce the likelihood of loss from this cause and moreover is good orchard practice. It is probable that, as in the case of the citrus fruits in regions where excessive fruit shedding occurs, the applica- tion of quickly available fertilizers in early spring will be found to be beneficial. Girdling the trees in early summer has recently been shown to reduce fruit shedding markedly and thereby increase the yield. It cannot be recommended, however, until its effects on tree growth and vigor have been determined. On the other hand, the moderate dropping of fruits in mature orchards which are properly cared for is a desirable condition and obviates the necessity of thinning. It has been noted that the number of fruits remaining: is usually all that the tree can properly mature if adequate size is attained. This is particularly true in southern California where most of the fruits are seedless. In northern California much if not most of the fruits are seedy, and the problem is usually one of too heavy crops, fruit-drop not being an important factor in that district. 22 Coit, J. Eliot, and Robert W. Hodgson. The June drop of Washington Navel oranges. California Agr. Exp. Sta. Bui. 290:203-212. 1918. (Out of print.) 54 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION USES AND TREATMENT OF THE FRUIT UTILIZATION FRESH The persimmon is preeminently a fruit for consumption while fresh. It should preferably be served when soft, the pulp being spooned out and eaten as a dessert, with or without fresh cream. It makes an attrac- tive and delicious ice cream. When peeled, the large red-fruited varie- ties, particularly the Hachiya served whole, make a delectable fruit salad on lettuce, with French, cream, or mayonnaise dressing. Non- astringent varieties can be eaten hard and are used for dicing in fruit salads in much the same manner as are apples. One of the drawbacks to the increased use of the persimmon at the present time is the difficulty of determining the proper stage of ripeness at which to pick the fruit. When ready for eating the astringent varieties are too soft to be shipped safely very far. The best practice is to purchase them when firm but well colored and to hold them for a few days until fully softened. Perhaps the most desirable characteristic of the Fuyu variety is its lack of astringency even when hard, which favors its successful shipment and provides satisfactory eating quality any time after color develop- ment has begun. For these reasons this variety may prove very popular when the buying public becomes acquainted with it. REMOVAL OF ASTRINGENCY In order to overcome the disadvantage of astringency in the fruits, the Japanese long ago worked out methods of artificially ripening them. The first which came to the attention of California growers, reported in 1877, 23 consists in subjecting the unripe fruits while still hard to the fumes of alcohol by placing them in tubs recently emptied of sake or rice beer. The fruits are left in these tubs from five to fifteen days, according to the variety and temperature, and when removed are entirely non- astringent though still hard. This method was first tried in California in 1905 by George C. Roeding 24 of Fresno at the suggestion of the United States Department of Agriculture. The experiment was entirely suc- cessful; after eleven days the fruit was removed still hard but non- astringent. 23 Anonymous. Japanese persimmons. California Horticulturist 7:69, 73, 90, 237, 281,376.1877. 24 Roeding, George C. Unpuckering persimmons. Pacific Rural Press 74:333. 1907. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 55 McClure 25 has recently reported two other methods developed by the Chinese for removing the astringency of persimmons. One of these, known as the lime-water method, consists in placing the fruits in large earthen jars and covering them with a solution of lime-water, 1 part of lime to 10 of water, by weight. The process requires from two days to a week or more, according to the variety, stage of maturity, and the length of time between harvesting and processing. On removal the fruits are nonastringent and juicier but still firm and are covered with a white bloom-like coating of lime which the merchants are careful to preserve. Fruits treated by this process are said to have better keeping quality than those ripened on the trees or in other ways. Another method said to be in common use in China is that known as smothering, and may be applied in one of several ways. That most often employed consists in placing an upright bamboo cylinder of open weave in the center of a large earthen jar in which the fruits are packed. A large stick of incense is burned in the bamboo cylinder and the smoke is said to bring about, or to assist in, the removal of the astringency. The method is said to act rapidly, requiring only one or two days to give satisfactory results. Fruit processed in this manner, however, must be consumed within a few days. Considerable work has been done on this subject in the United States, notably by the United States Department of Agriculture, 26 the Alabama Agricultural Experiment Station, 27 and the California Agricultural Experiment Station. 28 It was early shown that the Japanese process depends for its efficiency on the alcohol contained in the sake, but that alcoholic fumes cause cracking of the skin and other injury to an unde- sirable degree. Carbon dioxide was found to give good results with many varieties, especially if applied at higher than normal pressures, the astringency disappearing in 3 to 5 days. It was also learned that im- 25 McClure, F. A. Some preliminary notes on persimmons in Kwantung. Lingnaam Agr. Eev. 3:91-98. 1925. 26 Gore, H. C. Experiments on the processing of persimmons to render them non- astringent. U. S. Dept. Agr. Bur. Chem. Bul. 141:1-31. 1911. Gore, H. C. Large scale experiments on the processing of Japanese persimmons. U. S. Dept. Agr. Bur. Chem. Bul. 155:1-20. 1912. Davis, W. B., and C. G. Church. The effect of ethylene on the chemical composi- tion and the respiration of the ripening Japanese persimmon. Jour. Agr. Ees. 42: 165-182. 1931. 27 Lloyd, Francis E. The artificial ripening of persimmons. Alabama State Dept. Agr. Bul. 42:42-49. 1911. Lloyd, Francis E. The behavior of tannin in persimmons. Plant World. 14: 1-19. 1911. 28 Overholser, E. L. Some studies upon the ripening and removal of astringency in Japanese persimmons. Amer. Soc. Hort. Sci. Proc. 1927:256-266. 1928. 56 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION mersing the fruit in warm water, 75° to 105° F, for 10 to 15 hours will usually remove the astringency, and this method may be recommended for home use. Injuring the fruit by mechanical means such as punctur- ing it with a knife blade or large needle will also hasten ripening and usually with no attendant decay. More recently the effects of ethylene and other related gases and the fumes of certain compounds of these gases have been studied and several of them, notably ethylene gas, have been found to be effective, not only in the removal of the astringency but also in the development of color. Thus far, however, so far as can be ascertained, no treatment has been devised which renders the fruit nonastringent and develops or improves its color, and still leaves it in a firm condition suitable for storage or long- distance shipment. The work done thus far strongly suggests, therefore, that the sale of artificially ripened persimmons will necessarily be limited to the local markets or that treatment will have to be applied in the distributing centers from which the fruit goes to the retail markets. At present the latter appears to be impracticable, which lends support to the conclusion that the growing of nonastringent varieties may eventually provide the best solution to this problem. THE ETHYLENE GAS TREATMENT Primarily because of its effect on color development, as well as the loss of astringency it produces, which makes possible lengthening the marketing season in the local markets or those within short shipping distance, the ethylene gas treatment has come into use in recent years. As practiced by the Southern California Persimmon Growers Associa- tion it consists of subjecting the fruit to four successive doses of the gas at the rate of 1 pound to 367 cubic feet of storage space, the treat- ments being applied at 12-hour intervals. The treatment is very effective and relatively inexpensive. When properly used the fruit can be brought to any degree of coloring and softening desired. This is accomplished by regulating the exposure and dosage. It has been found, however, that fruit picked immature does not attain the full rich color characteristic of the ripe fruit and does not hold up well in storage after treatment. The outstanding drawback to the treatment is, of course, the softening of the flesh which follows and makes it necessary for the fruit to go into early consumption. Its misuse to place immature fruit on the early market has already been referred to. Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 57 Recent studies 29 of the effects of ethylene on the persimmon have shown that the composition of the fruit is not significantly changed, the principal effects having to do with softening, color development, and increased respiratory activity. Fig. 20. — Method of drying persimmons employed in China. (Courtesy of C. C. Thomas, United States Department of Agriculture.) SUN-DRYING AND DEHYDRATION Dried persimmons are used extensively in both China and Japan. The less juicy varieties, such as the Tanenashi, are usually prepared in this way, as are also a number which are never suitable for eating fresh because of their excessive astringency. The fruits are cut from the tree, leaving a "T "-shaped portion of the twig attached, which serves to attach them to the long strings into which they are braided after being peeled. These are then hung in the sun and wind for about three weeks (fig. 20) , or in open sheds. After drying they are cured in piles covered with mats where they undergo a sweating process, during which a coating of 29 Davis, W. B., and C. G. Church. The effect of ethylene on the chemical composi- tion and the respiration of the ripening Japanese persimmon. Jour. Agr. Ees. 42: 42-49. 1931. 58 UNIVERSITY OP CALIFORNIA EXPERIMENT STATION grape sugar forms on the surface. They are then ready for consumption. A description of the methods employed is given by Meyer. 30 Both Japanese and American growers in California have dried per- simmons for home use and in some instances a rather good quality of product has been obtained with the Hachiya variety. Some of the smaller dark-fleshed varieties are said to give a product of better quality. Few attempts have been made to dry persimmons commercially, however, although experiments conducted by the United States Department of Agriculture 31 and the California Agricultural Experiment Station 32 have shown that dehydration at temperatures of 125° to 150° F results in a fairly satisfactory product. In these experiments the Tanenashi variety has been found to be somewhat better adapted to drying than the Hachiya as are also the Fuyu, Suyugaki, and Kurokuma varieties, of lesser importance. The most comprehensive studies have been conducted by the Division of Fruit Products of the California Agricultural Ex- periment Station, and since the Hachiya variety is of outstanding importance in California most of the work has been with this variety. The simplest, and perhaps the best, method is to quarter the fruit and dehydrate it at temperatures of 140° to 150° F, using as rapid drying as possible with a strong blast of air. There is some darkening of the color but the orange-brown color which results is rich and not displeasing to the eye. Peeling causes the fruit to dry more rapidly and gives a more tender and lighter-colored product, but because of the expense and loss in weight it may not be economically practicable. The best appearing product, however, is that which is peeled and then sliced before drying. The fruit should be in the firm-ripe state; if too soft it is difficult to handle, sticks to the trays, and a high percentage becomes "slabs." Stainless steel knives should be used to avoid iron staining, and if the fruit is peeled, wooden rather than screen trays should be used. Sulf ur- ing should not be employed as it causes the fruit to retain its astringency, which otherwise disappears entirely during drying. The drying ratio of the unpeeled fruit is about 4 to 1 ; that of the peeled fruit slightly higher. The texture of the product is fairly tender but unlike that of other dried fruits. The flavor is mild and not unpleasant but compared to most 30 Meyer, Frank N. China, a fruitful field for plant exploration. U. S. Dept. Agr. Yearbook 1915:212-214. 1916. si Gore, H. C. Large scale experiments on the processing of Japanese persim- mons with notes on the preparation of dried persimmons. U. S. Dept. Agr. Bur. Chem. Bui. 155:1-20. 1912. 32 Cruess, W. V., and M. A. Joslyn. The utilization of surplus persimmons. Cali- fornia Cultivator 72(10) :285, 301. 1929. BUL. 416J THE ORIENTAL PERSIMMON IN CALIFORNIA 59 other dried fruits it is rather flat. During storage, or slow drying, there gradually develops a surface covering of dextrose sugar crystals; this adds to the appearance of the product, however, rather than detracting from it. One grower has reported a marked improvement in the quality of the dried product from treatment of the fruit with ethylene prior to dehydration. The market possibilities for dried persimmons in the United States are of course unknown but it is difficult to believe that they will ever successfully compete with the many other products of more pronounced flavor. There may be possibilities, however, particularly in the Oriental quarters of the larger cities. CANNING— FROZEN PACK— FRUIT PULP A canned product of fair quality but far inferior to other canned fruits can be prepared but seems to have no market possibilities. The fruit is first treated with carbon dioxide or ethylene to remove the astringency before the flesh softens. It is then peeled, quartered or sliced, placed in a medium-degree syrup and sterilized in the cans. While the product has a fair resemblance to the fresh fruit, it is mark- edly inferior to other preserved forms and must be used uncooked; for on heating, a portion, at least, of the astringency returns. The completely ripe fruit can be kept in perfect condition for long periods by placing it in freezing storage, 0°-10° F, in a sirup of medium concentration, 20 to 30 per cent sugar. On removal from storage the fruit should be allowed to thaw, the sirup drained off, rinsed in water and then served like fresh. One of the most promising commercial products developed thus far is persimmon pulp, which lends itself especially well to use in ice cream and milk drinks. Thoroughly ripe fruit is first peeled, using stainless steel knives, and then ground in a food chopper, or if very ripe rubbed through a monel metal screen. To the pulp is added sugar in whatever proportion is desired. One of sugar to 5 or 6 of pulp is apparently the most satisfactory proportion. On placing in freezing storage it retains the fresh flavor and fruit color almost indefinitely. It can be stored in any kind of container, provided the temperature is kept low enough. This product should find an immediate market with ice-cream manu- facturers and the soda-fountain trade and may eventually find retail trade outlets. It is one of the best of all fruit pulps for ice creams and milk drinks. In making persimmon ice cream approximately 15 per cent by weight of the pulp is added to an unflavored ice cream mix or to a vanilla mix and frozen in the regular manner. 60 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION MARKETING PRINCIPAL MARKETS At the present time approximately half the production is marketed locally, the two principal markets being San Francisco and Los Angeles, the latter comprising the chief center of persimmon consumption in the United States. Of the southern California crop nearly half is shipped to eastern markets, principally New York, Philadelphia, and Chicago, though shipments are regularly made to all cities of a half-million population or more. During the past three years the carlot shipments have ranged from 65 to 85 per season. The greater part of the northern California crop is shipped to eastern markets in mixed cars with other fresh fruits — plums, grapes, and pears. Small shipments are regularly made to the Hawaiian Islands and experimental shipments have been made to Great Britain and other European countries. MARKETING METHODS, PROBLEMS, AND RESULTS Approximately three-fourths of the production is controlled by one cooperative marketing organization, the Southern California Persim- mon Growers Association, and most of the out-of-state shipments are made by this agency. An outgrowth of the Persimmon Growers Depart- ment of the Southern Counties Farm Bureaus organized in 1927 in time to market the crop of that season, this association has been a factor of incalculable importance in meeting the distribution and marketing problems of the rapidly expanding persimmon production. And, while these problems are still by no means all successfully solved, there can be little doubt that this organization has succeeded, thus far at least, in averting an imminent and serious crisis in the industry. By means of a greatly increased distribution of the fruit coupled with trade promotion and dealer-service w r ork, and advertising, it has been surprisingly suc- cessful in increasing consumer demand and in marketing the crops of its members, though not always at profitable prices. These results, obtained in large measure during a period of severe economic depression, augur well for the future of the organization and of the industry. At present the Association, through its member associations, main- tains packing houses at Tustin and Fullerton in Orange County, at Monrovia and Canoga Park in Los Angeles County, and at Bryn Mawr in San Bernardino County. It is affiliated with and utilizes the sales organization of the California Fruit Exchange, a state-wide cooperative fruit-marketing agency which makes joint use of the salaried sales Bul. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 61 representatives of the California Frnit Growers Exchange, the major citrus cooperative marketing organization. The advantages of this affiliation have been marked, both in developing distribution and in low operation and sales costs. Most of the fruit shipped to eastern markets is sold at auction; that reserved for local consumption is placed in cold storage and sold in accordance with the requirements of the trade. Fig. 21. — Means employed to acquaint the consumer with the proper condi- tion for eating the persimmon — display card, instructions on wrappers, and reference to recipe book. A standard pack in a standard package is shown. (Courtesy of California Fruit Exchange.) 62 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION The major marketing problems confronted by the industry, as indi- cated by experience thus far, have to do with : (1) educating the con- sumer as to the proper condition when the fruit should be used, i.e., when soft and entirely free from astringency; (2) obtaining a wider dis- tribution for the products-introducing it to new consumers; and (3) regulating distribution in the local markets, principally Los Angeles. The Association has made notable progress in the solution of the first two but it does not now possess sufficient control of the supplies in the local markets to effectively stabilize price levels. Practically all the crop marketed through other agencies finds its way to these markets and as a consequence price levels are at times unnecessarily low. The efforts of the Association to acquaint the consumer with the proper condition at which the Hachiya variety should be used have included the printing of instructions on the fruit wrappers and on paper bags supplied with each box and the distribution of display cards carrying this information (fig. 21). Wider distribution of the fruit has been obtained by greatly increasing the number of markets to which shipments are made. Consumer demand has been increased by the dis- tribution of recipe booklets and display cards, dealer-service work, and billboard and radio advertising. The results of this wider distribution, at moderate to even low prices, have been pronounced, and the demand for the fruit has increased considerably, particularly in markets where the Oriental persimmon was not known prior to 1928. GRADING AND PACKING Owing to the tender nature of the fruit, especially the Hachiya variety, success in its preparation for market requires the greatest of care in the handling operations, and the reduction of these to the lowest possible number necessary to proper grading and packing. The most modern and efficient handling methods are perhaps best illustrated in the operations as practiced in the Tustin packing house of the Southern Orange County Persimmon Growers Association, one of the local pack- ing associations affiliated with the Southern California Persimmon Growers Association (fig. 22). The fruit is picked into one-layer boxes of the same type in which it is shipped, which are carried in front of the pickers on specially con- structed slings which fit over their shoulders. In the packing house these boxes are placed on a long slowly moving belt provided with a movable division board near the center. The graders separate the fruit into the two shipping grades, one on either side of the division board, and as the Bul. 416 THE ORIENTAL PERSIMMON IN CALIFORNIA 63 graded fruit proceeds each packer selects the size she is j)acking, wraps the fruit in tissue paper, and places it in the shipping box. The packed boxes are then placed on a moving belt behind the packer which conveys them to the lidder at the end of the belt. The sizing is done by the eye, Fig. 22. -Packing-house scene. Note the combination grading and packing table. Fig. 23. — Standard one-layer persimmon packs, wraps removed. (Courtesy of H. E. Wahlberg.) the number of fruits per box ranging from 20 to 44 (fig. 23) . The fruit shipped out of the state is wrapped before packing; the local markets exhibit a preference for the unwrapped fruit. This packing house has a daily capacity of 5 carloads, each consisting of 1,736 boxes of 12 pounds net weight. The cars are sent under standard refrigeration. 64 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION The Association employs two standard grades for out-of-state ship- ment, a first grade under the designation Solid Gold, and a second designated as Possum. Both are, of course, above the legal requirements. Fig. 24. — Two-layer peach crates used for express shipments in Placer County. Most of the fruit is packed in a single layer and shipped in the standard peach box, 33 the net weight of which is 12 pounds of fruit. Fruit sizing smaller than 36 to the box (44 and smaller) is packed two layers deep in boxes of the same length and width but slightly deeper. This is the package employed almost exclusively in northern California (fig. 24) ; its weight ranges from 18 to 25 pounds, according to the variety and size of fruit. Another package used to some extent is the standard persimmon box, a single layer pack of standard-orange-box size. A large amount of fruit, much of second grade, is packed unwrapped in Los Angeles lug boxes — weight 25 to 30 pounds — and sold without brand in the local markets. Experience clearly indicates that the one-layer pack is not only better for the Hachiya variety but also preferred by the eastern trade. 33 For the legal requirements concerning standard containers for persimmons con- sult Section 23 (pp. 23-27) of the California Fruit, Nut and Vegetable Standardiza- tion Act of 1931. BUL. 116] T HE ORIENTAL PERSIMMON IN CALIFORNIA 65 STORAGE The persimmon does not hold well at ordinary temperatures. When stored in firm-ripe condition the fruit rarely remains in condition suitable for handling or shipment longer than 10 to 15 days. As a consequence of its rapid ripening and softening it is necessary to resort to cold storage to keep the fruit in satisfactory condition for any considerable length of time. Fortunately, however, the persimmon lends itself well to cold storage, which occupies about the same relation to the successful marketing of this fruit as it does to that of the pear. At first too-high temperatures were used and the losses were heavy. Primarily as the result of investigations conducted by the California Agricultural Experiment Station 34 the conditions necessary for satis- factory storage have been determined. The best storage temperature appears to be 29°-30° F. In the experimental work Hachiya fruit stored at 30° F kept in excellent condition for 60 to 90 days; and at 36° F, for 30 to 50 days. At 28° F it kept well but the more immature fruits ex- hibited some freezing, particularly at the basal end. More shriveling seemed also to occur at this temperature than at slightly higher tem- peratures, this being also more marked in the less mature fruit. From extensive experience the Association now employs 29° F for the storing of its fruit and reports excellent results. As might be expected, however, there still remain certain storage problems to be solved. Perhaps the most serious of these is the failure of the fruit to color at the basal end during storage. This seems to be associated with too early harvesting. Experience during the 1930 season demonstrated rather conclusively that delaying picking considerably beyond the normal period not only eliminates this problem but also results in decidedly better size, appearance, and eating quality. It is difficult, how- ever, to induce the growers to delay harvesting because of the hazard of losing part of the crop and of tree breakage from fall windstorms. Another problem is the shriveling of some of the fruit. This also appears to be associated with too early harvesting, though it may be due in part to low humidity in the storage chambers. The development of black spots on some of the fruits has given some concern. It varies greatly from season to season and in different localities and hence is believed to be a climatic effect present in the fruit before it is harvested. Fortunately it is rarely present to a serious degree. 34 Condit, I. J. The kaki or Oriental persimmon. California Agr. Exp. Sta. Bui. 316:229-266. 1919. (Out of print.) Overholser, E. L. Further studies upon the ripening and cold storage of Japa- nese persimmons. Blue Anchor 4(11) :17, 36, 38. 1928. 66 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION The use of cold storage has made possible a notable extension of the marketing season, which formerly ended with the Christmas holidays. It is now possible to keep the fruit in good condition as late as April 1 but experience has shown that the normal season of consumptive demand ends about the middle of February. Cold storage is now employed extensively in marketing the persimmon crop in both local and eastern markets. The storage of persimmons in frozen form, which provides a market- ing season of four to five months, has been practiced in China for many years, perhaps centuries. 35 The fruit is stored in the open in shallow beds, protected above and below by a thin layer of straw or reed matting. The fruit freezes and remains in good condition until thawing weather occurs in spring. The quantities stored in this manner are said to aggregate millions of pounds. Even though the fruit may be astrin- gent when stored the astringency is said to disappear during storage. Preliminary studies on the freezing storage of persimmons in Cali- fornia 30 have shown that thoroughly ripe Hachiya persimmons when frozen and stored at temperatures of 10° to 12° F keep for six months or longer with no impairment of quality or flavor. They should be consumed, however, shortly after thawing. The use of freezing storage for the cold-pack whole fruit in sirup and for persimmon pulp has already been referred to. COSTS, YIELDS, AND RETURNS The cost of production of persimmons is very much lower than it is with the citrus fruits and, other things being equal, should compare favorably with such fruits as the peach. The only unusual item of expense not found with many other fruits is the propping of the trees to prevent excessive breakage. No data on actual production costs are available, but in comparison with other fruits, under present conditions, they should not exceed a cent per pound of fruit and may be less. Costs of preparing the fruit for market vary considerably as might be expected and obviously have to do with the volume of fruit handled and the efficiency of operation. The only cost data available on this subject are from- the largest bearing orchard in the state, consisting of 6,400 trees, now in its eighth year. In 1931, when the crop averaged 35 Dorsett, P. H., and J. H. Dorsett. Culture and outdoor winter storage of per- simmons in the vicinity of Peking, China. IT. S. Dept. Agr. Cir. 49:1-12. 1928. 36 Condit, I. J. The kaki or Oriental persimmon. California Agr. Exp. Sta. Bui. 316:229-266. 1919. (Out of print.) BUL. 41GJ THE ORIENTAL PERSIMMON IN CALIFORNIA 67 about 200 pounds per tree, the costs of picking and hauling the fruit to the packing house 7 miles away were 26 cents per 100 pounds. Packing costs in the largest and most efficiently operated packing house were approximately 6 cents per box of 12 pounds net. The present freight rate is $1.76 per 100 pounds on the gross weight of the package and the refrigeration charge 5% cents a box. These plus the cost of the boxes and the handling charges and selling cost — about 4 per cent — have amounted to about 60 cents a package. Reliable commercial yield data are meager in quantity but indicate a relatively high yield under favorable conditions. The oldest and heaviest-yielding commercial planting in southern California, near Santa Ana, has produced at the rate of 20 to 24 tons an acre. The best large-scale criterion for judging production possibilities is the planting of 6,400 trees already referred to, near Irvine (Orange County) . At the age of six years this orchard produced 540 tons, or 168 pounds per tree, and the next year the crop was 632 tons, or 197 pounds per tree. These yields are undoubtedly above the average, however, and reflect un- usually favorable conditions. The relation of yield to good soil and favorable climatic conditions is evident with the persimmon, and the effect of climatic conditions on the quality of the fruit very pronounced. Orchards in the coastal belt of southern California, well protected against the cool ocean breeze, will produce about 60 per cent first-grade fruit and about 25 per cent second-grade. In the hotter interior districts the percentage of first- grade fruit is normally much lower though by means of special care it can often be materially raised. The high prices received for the fruit some years past, 10 to 15 cents a pound or more, were undoubtedly responsible in large measure for the extensive planting which occurred a few years ago. These high prices reflected a condition of under supply. Within recent years, however, the increase in production has been many hundredfold and the situation has been changed from under supply to marked overproduction with the necessity of diverting a large part of the production to new markets in eastern United States, and this during a period of severe economic distress. The inevitable consequence has been a marked decline in price levels, to the point where for many growers the past two seasons have witnessed returns at or below cost of production. Association members for the 1931 season received 1 cent a pound for the first-grade fruit and % cent for second-grade fruit, whereas the 1927 crop returned approxi- mately 6 cents a pound. 68 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION OUTLOOK The present situation in the California persimmon industry is one of overproduction with attendant distressingly low price levels. The in- crease in production from the present acreage will continue for some years and will present difficult marketing problems even though im- provement in general economic conditions may be expected. It does not appear advisable to extend plantings at this time or in the near future. There are thousands of acres of land in California on which persim- mons can be grown though admittedly much of it will not produce yields or quality of fruit equal to that grown in the coastal belt of southern California. And in addition, there is a vast area in the Gulf Coast states where persimmons can be grown. On the other hand, the Hachiya variety as grown in California and particularly the southern part of the state, is undoubtedly a superior product of distinctive quality, though much more sensitive than other varieties. Moreover it now enjoys the advantage of promotion in the great consuming centers of eastern United States by a well-organized, aggres- sive, and thus far highly successful cooperative-marketing agency, the Southern California Persimmon Growers Association, which controls the greater part of the crop. As with other specialty California fruit crops, the success of the industry will unquestionably depend on the production of the highest quality fruit at the lowest possible cost and its efficient standardization, distribution, and marketing through the agency of a well-managed, grower-supported cooperative-marketing organization. ACKNOWLEDGMENTS Acknowledgment is made of helpful assistance from A. J. McFadden of Tustin, President of the Southern California Persimmon Growers Association, and H. E. Wahlberg, Farm Advisor in Orange County, and appreciation expressed to Messrs. C. C. Thomas and J. E. Morrow of the Bureau of Plant Industry, United States Department of Agriculture, who by supplying specimens, photographs, and notes, have materially assisted in the study of the persimmon varieties introduced by the government. BUL. 416] THE ORIENTAL PERSIMMON IN CALIFORNIA 69 LIST OF SELECTED REFERENCES ON ORIENTAL PERSIMMON CULTURE Bailey, L. H. 3914. Persimmon. In Standard Cyclopedia of Horticulture 5:2556-2560. Burnett, F. H. 1907. Japanese persimmons. Louisiana Agr. Exp. Sta. Bui. 99:1-23. figs. 1-13. Camp, A. F., and Harold Moavry. 1929. The Japanese persimmon in Florida. Florida Agr. Exp. Sta, Bui. 205:527- 562. figs. 139-160. CONDIT, I. J. 1919. The kaki or Oriental persimmon. California Agr. Exp. Sta. Bui. 316:229- 266. figs. 1-20. (Out of print.) Davis, W. B., and C. G. Church. 1931. The effect of ethylene on the chemical composition and the respiration of the ripening Japanese persimmon. Jour. Agr. Research 42:165-182. figs. 1-8. DORSETT, P. H., AND J. H. DORSETT. 1928. Culture and outdoor winter storage of persimmons in the vicinity of Peking, China. U. S. Dept. Agr. Cir. 49:1-12. figs. 1-9. Fletcher, W. F. 1915. The native persimmon. U. S. Dept. Agr. Farmers' Bui. 685:1-28. figs. 1-17. (Revised September, 1923.) Fuji, Sumito. 1916. The persimmon in California. California State Comm. Hort. Mo. Bui. 5:361- 366. figs. 121-127. Gore, H. C. 1912. Large scale experiments on the processing of Japanese persimmons, with notes on the preparation of dried persimmons. U. S. Dept. Agr. Bur. Chem. Bui. 155:1-20. figs. 1-3. Gore, H. C, et al. 1911. Experiments on the processing of persimmons to render them non-astringent. U. S. Dept. Agr. Bur. Chem. Bui. 141:1-31. pis. 1-3. figs. 1-5. Hume, H. H. 1914a. Planting persimmons. Jour. Heredity 5:131-138. figs. 16-19. 1914&. A kaki classification. Jour. Heredity 5:400-406. figs. 6-11. 1914c. Effect of pollination on the fruit of Diospyros kaki. Amer. Soc. Hort. Sci. Proc. 1913:88-93. Hume, H. H., and F. C. Reiner. 1904. Japanese persimmons. Florida Agr. Exp. Sta. Bui. 71:69-110. 70 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Lloyd, F. E. 1911a. Tannin-colloid complexes in the fruit of the persimmon, Diospyros. Biochem. Bui. 1:7-41. pis. 1-3. 1911&. Behavior of tannin in persimmons with some notes on ripening. Plant World 14:1-14. figs. 1-14. 1916a. The red color of the mesocarp of seeded fruits in the persimmon (Diospyros TcaU). Plant World 19:106-113. fig. 1. 1916&. A visual method for estimating astringency. Plant World 19:113. Meyer, Frank N. 1911. Persimmons. In Agricultural explorations in the fruit and nut orchards of China. U. S. Dept. Agr. Bur. Plant Industry Bui. 204:10-16. pis. 1-3. figs. 1-6. 1916. Oriental persimmons suited for drying purposes. In China a fruitful field for plant exploration. U. S. Dept. Agr. Yearbook 1915:212-214. pis. 33-35. McClure, F. A. 1925. Some preliminary notes on persimmons in Kwangtung. Lingnaam Agr. Kev. 3:91-98. figs. 1-17. OVERHOLSER, E. L. 1928. Some studies upon the ripening and removal of astringency in Japanese per- simmons. Amer. Soc. Hort. Sci. Proc. 1927:256-266. Rehder, Alfred. 1914. Diospyros. In Bailey, L. H. Standard cyclopedia of horticulture 2:1014- 1016. Roeding, George C. 1907. Unpuckering persimmons. Pacific Rural Press 74:333. Saunders, Wm. 1898. Japan persimmons. U. S. Dept. Agr. Yearbook 1897:187. Van Deman, H. E. 1888. History and varieties of the persimmon. U. S. Dept. Agr. Rept. 1887:642- 645. 1892. Kaki in Georgia and Florida. Rept. U. S. Dept. Agr. 1891:385-388. pis. 4-6. 6m-2,'34