U. S. DEPARTMENT OF AGRICULTURE. BUREAU OF PLANT INDUSTRY - -BULLETIN No. 34 b. T. GALLCVV 0! I'd'-IJUL. SILKWORM FOOD PLANTS CULTIVATION AND PROPAGATION. GEORGE W. OLIVEK, Expert, SEED AND PLANT INTRODUCTION AND DISTRIBUTION. Is.s:M;n jANrARv WASHINGTON: GOVERNMENT PRINTING OFFICE. 1903. Glass. Book. ^) 34, Bureau of Plant Industry, U. S Drpt. of Agriculture^ Frontispiece. U. S. DEPARTMENT OF AGRICULTURE. BUREAU OF PLANT INDUSTRY— BULLETIN No. 34. B. T. GALLOWAY, Chiff of Bureau. SILKWORM FOOD PLANTS CULTIVATION AND PROPAGATION. GEORGE W. OLIVEK, Expeet, SEED AND PLANT INTRODUCTION AND DISTRIBUTION. [ssuED January 15, 1903. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1903. MAR 31 1903 D. ot 0. millR OF TRAXSMIHAL U. S. Department of Agriculture, Bureau of Plant Industry, Office of the Chief, WaHhingion, D. ('., Oetoher 27, 1002. Sir: I have the honor to transmit herewith a paper entitled "Silk- worm Food Plants: Cultivation and Propagation,'' by George W. Oliver, Expert, Seed and Plant Introduction and Distril)utio''n, and respectfully recommend its publication as a bulletin of this Bureau. The paper has been prepared at the request of Dr. L. O. Howard, under whose direction the funds appropriated at the last session of Congress for an investigation into the subject of silk culture in this country are expended. Dr. Howard has made a number of sug- gestions in regard to the scope and character of the paper, and has furnished the illustration used as a frontispiece, selected from a large number of photographs taken by him during the past summer while investigating the silk-cultural industry in Italy and other countries. Respectfully. B. T. Galloway, Hon. James Wilson, Secretary of AgrleuUure. Chief of Bureau. CO XT l:\TS. Page. Introduction 7 Methods of reproduction ^ Propagation by cuttings 9 Summer cuttings 9 Winter cuttings 10 The cutting 10 Preparations for planting cuttings 10 Indoor spring cuttings 11 Propagation by seeds 11 Crrafting and budding l^^ Root grafting 13 Scion or sprig budding 1-t Shield budding 15 Raising stocks for grafting and l)udding Itj Soil '. Iti Planting I'l Pruning 1~ Description of ))lates 20 ILLUSTRATIOXS. rase. Mnlhcrrv tn-es and leaf s. fruit, and l)ark 20 IX. Summer cuttings of the white inullu'riy, witli leaves shortened X. Winter cuttings of l-year-old shnots nf the white mulberry, ready for planting XL Root grafting the nudlterry. A and 15. — Scions litted on stocks, ready to l)e tied. C. — Stock and scion wraiijied and ready to be planted XIL Scion or sprig budding. A and B. — Scions prepared for inserting. C. — Stock with bark raised, ready for scion. D. — Scion in posi- tion, ready to be wrapped. E. — Stock with scion held in place by wrapping. F. — Stock waxed to exclude air and moisture 6 S. p. I. D.— 30 SILKWOKM FOOD PLANTS: ( ULTIVATION AM) PROPAGATION. INTRODUCTION. There is a small family of plants t-losely allied to each other, a few of which supply the silkworm with food. This family is called 2Ioraceie. There are three crenera of trees in the ofroup — Momx, the mulberry (Pis. I. II. Ill, IV^, V. and VII); To.njJon, the Osage orange (PI. VIII), and Bronxxonefia, the paper mulberry (Pi. VI). The last named, being unsuitable for silkworm food, will not again b(> referred to here. The Osage orange provides palatalile food for the silkworm, and if the worms were free to select the leaves foi- themselves the tree would be satisfactory; but the leaves are selected for them often with bad results, for the young and immature leaves have a tendency to sicken the worms. Ignorance of this fact renders the use of the Osage orange dangerous. Of the mulberry there are manv so-called species and a great many varieties, but there are only one or two species and a few varieties which are of importance in silkworm propagation. Chief among these for producing silkworm food is the white mulberry, Morxx alba (PI. I). This is thought by some to be a native of China. It has long been known that the white mulberry and its varieties are hardy over a large area of the United States. The uninitiated should not be left to their own devices in growing mulberry trees, especially if the enterprise is to be an extensive one, for if failure results, silkworm propagation in the particular section of the country where the experiment is conducted wdl receive a seri- ous setback. It is not the purpose of this paper to discuss the question of the most suitable varieties of the white luulberry, as this could only be done from a European point of view. Bureau, in his monograph, describes :27 varieties of the white mulberry alone. In Italy, silk- worm gi'owers favor MoruM alba, variety morttti, and forms raised from it. France and Spain have each its favorite kinds. Japan has 8 SILKWOEM FOOD PLANTS. close upon 1()(> forms, one or two of which would probably answer all purposes, while most of the silkworms reared in China are said to be fed upon Moran muItu-auU.s. This mulberr\- was largely planted in the United States many years ago. Few, if any, of the original trees remain, but specimens which are thought to be wild seedlings of these are yery plentiful in the Southern States. These trees are thoroughly acclimated and free from disease. It is therefore probable that there is now in the United States an abundant supply of material for propa- gating purposes, at least. It is intended to show in these pages how the mull^erry may be prop- agated and grown so as to proyide the maximum amount of leayes for the food supph^ of the worms. The white mulberry, under good cultiyation, is a low-growing tree, seldom attaining a greater height than 2.5 or 30 feet. It will reach this height in a comparatively few years after planting. Although it will live to a good old age, its growth, like that of most other trees, is most rapid when young. As the trees attain their full height they become stocky and make a mul- titude of small growths, from Avhich flowers and fruit are produced. The fruit, which is usually abundant, is not a favorite in this country, being generally considered too sweet and insipid. In shape it may be said to resemble more or less that of an elongated l>lackberry. In the vicinity of Washington the trees flower about the middle of May and ri})en their fruit during June. METHODS OF REPRODUCTION. The usual methods of propagation in use for fruit trees are emploA'ed with varying degrees of success in the case of the mulberry. These methods consist of budding, grafting, layering, cuttings, and seeds. (i rafting and budding are by far the most expensive methods, and it is doubtful if the results justify their use, so far as raising mulberry trees is concerned. Part of the work connected with Imdding and grafting consists in raising stocks, which are seldom large enough for use until they are two j-ears old. At this age, the })uds or grafts are inserted, and tlien troubles previously undreamed of present themselves to the inexperienced cultivator. Were the mulberr}^ tree as easily managed so far as budding or grafting is concerned as is the i)each, the use of th(\s(^ methods would be feasible, but unfortunateh' the mulberry is far fiom being an easy subject in this respect, and a few failures are apt to produce disappointment and disgust. It will frequently happen that old trees must either be removed or desirable varieties worked on them; budding or grafting may be resorted to in such cases. Layering consists in bending down a portion of a branch so that its stem after being notched may take root in the ground while still attached to the parent tree. It is a cumbersome method, however. METHODS OF KEPRODUCTIOX. 9 Althoutih good-sized plants c-aii be raised in a short time by its use, it is seldom employed when any other method will produce the same results. Raising young trees from cuttings of the 1-year-old ripened wood is a method which requires but little skill. As with budding and grafting, this method is instrumental in perpetuating varieties, as ever}' rooted cutting will eventually be a reproduction of the tree from which it was taken. This is not the case with plants raised from seeds, which always vary considerably from the parent. For this reason some mulberry growers in Europe object to the seed method. Some of the seedlings, even from a single parent tree, will vary greatly in the value of the leaves for feeding purposes. Some will be thin in texture and lacking in the necessary chemical constituents; some, very hair}^; others thick, smooth, and in ever}- way desirable. However, experi- enced mulberry growers can readih' tell the value of a seedling tree for feeding purposes, and it is therefore possible to make a selection in this respect without nuich loss. rROPA(;ATioN rn' cuttings. SIMMKK (TTTINdS. In any group of seedlings there will always be found individuals the leaves of which possess great adaptal)ility for feeding purposes. These should certainly be propagated to perp(»tuate this desirable character- istic. Propagation should be started after the seedlings have made considerable growth in order to insure a good suppl}' of wood. These plants should be increased by cuttings during the sunnner months. At this season it is advisable to retain some of tne leaves on the cutting and give treatment which will prevent shriveling during the process of rooting. The cuttings shoidd be made from wood as ripe as possible: the leaves, besides being well matured, should be healthy and free from noxious insects. During Juh' the lower parts of the current season's shoots will ])e found in good condition for propagating. Trim the cuttings similarly to those shown in PI. IX. At least two leaves shortened to one-half their length should be allowed to remain on the cutting. When placed in the propagating bed, the slips should be inserted in the sand in a direction sloping from the opei-atoi'. Good results will follow if a cool propagating house is used, with clean sand as the rooting medium. When a propagating house is not avail- al)le, a wide frame provided with sash will answer the purpose. The frame should face north, and if in the shade of trees, so much the bet- ter. The sash should be kept closed, so that a humid atmosphere may be maintained until the cuttings take root. After they have made a considerable quantity of roots in the sand the}' should be transferred 10 SILKWOKM FOOD PLANTS. to beds in the open. The beds should be 5 feet wide. Place the rooted cuttings al)out inches apart each wa}^ and water copiousl}^ until established, when they must be freely- exposed to air and sunshine. AVIXTEK (ITTINC The enttln(i.—'Y\\Q principal supply of plants may ])e secured l)y propao-ating- from cuttings, which should be made from dormant wood taken from the trees just after the leaves have fallen. In no case should the cutting wood be less in diameter than a quarter of an inch. The cuttings (PI. X) should be about 10 inches in length, mak- ing the upper cut about one-half inch above a bud. The position of the lower cut is immaterial. The cuttings should now be tied in bundles of fifty and either stored for the winter or be inunediately put out where they are to root. ^Vhere the winters are not too severe, or in the Eastern States south of the thirty- ninth parallel, they should be put in the ground during autumn. North of this it will be found best to keep them undcu- cover until the ground is in a condition to be worked in early spring. If they are kept even for a short time in a dry place, they will lose their sap and ])ecome shriveled. Therefore they should be buried in moderately moist sand or sand and ashes. Under such conditions a good callus will have formed aiouiid the lower cut surface before the time arrives when they an^ to be ])ut in the open. If sphagiuun moss be easily procural)le, it can l)c used very successfully as. a substitute for sand or ashes; but in Ihis case the bundles of cuttings should be smullei- and they should be ])lac(Ml with the buds pointing upward, the moss to b.. packed tightly around them, with the top part uncovered. This is an excellent nieth(.d foi' induc- ing the formation of a good callus. Preparat'wnHf(>rj>I,iiiin,,i e poured oS. The seeds should be exposed to the air until dry. If it is desired to sprout them the same sununer, they should be sown in l)cds in the open, the soil of which sliould previously be well worked by deep plowing and gone over several times with a harrow and a roller. When the soil is sufficiently pulverized the ground should be marked oft' into ])eds 5 feet wide and of any convenient length . leaving a space of 2 feet between the beds. To prevent washing of the soil and also to mini- mize the evil eftects of drying winds, drive some stout stakes into the ground along the sides and ends of the beds, and to these nail eight or twelve-inch boards. The surface of the bed should be leveled and all stones and roots of plants removed with a hand rake. Sow the seeds broadcast, taking- care not to sow them too thick, as there is a danger of the seedlings crowding each other. Crowding produces weak plants, because even the best soil is capable of sup- porting only a certain numl)er of plants to the scjuarc foot. Press the seeds into the soil with the back part of a spade and cover lightly with soil screened through a quartei--inch sieve. In order to have the best results, the seed l)eds should not be exposed to the sun until a considerable time has elapsed after germination. This condition may be arranged as follows: Procure some pieces of 2 by 3-inch scantling; place two of the pieces parallel to each other 5^ feet apart. Nail laths from one to the other, using the 2-inch surface in which to drive the nails. Leave 1-inch spaces between the laths. The slats are put lengthwise over the beds, and can be used with or without the side boards. Over the slats spread archangel mats, or can- vas, until germination takes place; these coverings should be fre- quently dampened. After the seedlings show above the ground, the GRAFTING AND BUDDING. 13 cloth covering-s are to be kept on during the hottest part of tlie day onh', and when the first true leaf appears the}' ma,y be removed alto- gether and the shade necessary thereafter supplied by the lath slats. Water must be supplied if the soil needs it. With spring-sown seed, the coverings over the lath slats ma}' be dispensed with, but the sur- face of the bed should not be allowed to become dry until the seedlings are large enough to take care of themselves. CRAFTING AND BUDDING. In Italy and other silk-raising countries it is claimed that the leaves of trees raised from cuttings and seeds are superior for silk produc- tion, but that the quantity of leaves produced by trees so propagated is only about one-half the bulk of those from grafted or budded trees. Therefore, to produce a large quantity', grafting and budding methods of propagation are practiced to a great extent. Before the beginner undertakes these expensive methods of propagation in the United States, however, he should consider that land rentals are high in Europe and that land is cheap in the United States; therefore the American can afford to grow more trees l)y the methods which are instrumental in giving the best grades of silk. This is an important point to consider, and the writer is inclined to the belief that in the propagation of plants giving the highest grades of silk there will be little danger of a scarcity of material, as the mulberry thrives as well, if not better, in most parts of the I'nited States as anywhere in Europe. For those who decide to try propagating by grafting and budding two of the most successful methods of performing the operation are here described. ROOT (;kaftin<;. This is performed in February and March. The stoi-ks. which are two-year-old seedlings of the Russian mulberry (J/o/v^s tdha^ variety tatarica), should show a diameter of at least three-eighths of an inch to give a satisfactory union. The stocks should be lifted in the fall and "heeled in" out of the reach of frost. The scions should be cut while in a dormant state and buried in damp sand in a protected place. In the latter part of February the work of root grafting (PI. XI) may be started. The preparatory work consists in securing a quantity of strong tidy cotton, and of grafting wax made of beeswax two parts, of resin two parts, and of mutton tallow one part. Put the ingredi- ents in a small tin l)ucket, place on a hot stove, and when melted drop in one or more balls of the cotton, allowing them to remain in the melted wax for live minutes; remove with a pointed stick. When cool they are read}- for use. Procure a deep box in which place the stocks, keeping them covered with a dampened sack; another box 14 SILKWORM FOOD PLANTS. should be provided for the .scions .similarly protected, and a third one for the grafted roots. These precautions are necessar3', as a little exposure to dr}- air is alwa3"S detrimental. In beo-inning work with the stocks sever the top from the root at the collar; this can be done best with a pair of pruning- shears. Take a scion at least 8 inches long and attach by the tongue method, as shown in PL XI. Select stocks and scions of as nearly the same diameter as possible; make a slanting cut at the bottom of the .scion and a similar cut at the top of the stock. In the ca.se of the scion, make an upward incision at a point about one-third of the length of the cut surface from the base; this will form a tongue. Next make a corresponding incision downward near the top of the .slanting cut on the stock. The idea is to have the tongue of the scion take the place which the knife blade occupies when making the incision in the stock. When the two parts are neatly fitted so that the bark of stock and of scion come neatly together at one side, or at both if possible, bind lirmly with the waxed cotton. This material should be used in preference to raffia, because when the grafted stock is buried in the ground, raffia would be certain to rot before the union took place, while cotton will remain in good condition for a long time. After the fitting and tying have been done, the grafted stocks should be tied in bundles of twenty-five, the first tie to be made rather firmly near the upper part of the scions; secure them again near the base of the scions, but not as firmly as before. Care must be taken so as not to displace the fitted parts. The bundles should now be buried in sand in a frame or other protected place until planting time arrives. The grafted stocks should be planted out just as soon as the condition of the .soil will permit. Plant them deep enough .so that only the top bud is expo.sed to the light. The subsequent treatment is in all respects similar to that given for cuttings. Mark the kinds, with the dates of grafting and planting, on large labels which will not l)e easily displaced. .SCION OR SPRIG BUDDING. Scion or sprig budding, as shown in PL XII, is perhaps the most successful and easiest to accomplish of all methods. It is practiced on stocks which have not been transplanted for at least one 3^ear previous to the time when it is desired to bud. The stocks should be larger than those used for root grafting. The most desirable time for the operation is in spring, when the bark lifts easih^; this will necessarily be after the stocks come into leaf. The scions must be selected from shoots of the previous season's growth, short and stocky, with two buds present (PL XII, A and B). They should be cut from the parent plants in the fall and kept dormant until the opportune moment arrives when the stock plants are in a receptive condition. SCION AND SHIELD BUDDING. 15 In preparing the stock for the scion the preliminary work is siinihir to that in shield budding the peach, cherry, or rose. At a point a little above the collar of the stock a transverse cut is made through the bark for a distance of half an inch or more around the stem (PI. XII, C.) This is followed by a longitudinal cut, beginning in the middle of the first cut and extending downward for about an inch. Prize up the bark at each side of the long cut (PI. XII, C) and it is ready for the scion, which is prepared for insertion by making an oblique cut through the base, so as to leave a cut surface about an inch long (PI. XII, A and B). The scion is then fitted in place so that its cut surface is neatly placed against the wood of the stock (PI. XII. D) laid bare by the raising of the bark. The next operation is shown in PI. XII, E, and consists in tying the parts together so that they will l)e held firmly while the union is taking place. In order to exclude air and moisture, grafting- wax or clay should be applied, as shown in PI. XII, F. Within two weeks from the time of l)udding. th(> union will l)e effected, if everything has gone well. The ligature should not be removed, however, until there is danger of its cutting into the bark. The most essential part of the subsequent treatment consists in head- ing back the stock, so that the future head of the tree will be formed by the growth of the scion, and to do this successfulh' good judgment must be exercised. Cut oft' onlv a part at first, leaving some foliage on the stock until the buds on the scion ])egin to push, when that part of the stock above the union should ))e i-emovod with a sharp knife. Cover the wound thus made with grafting wax. (SHIELD IUni)IN(;. The shield SA'stem of Imdding may be used, but only in the spring, as the mulberry does not take kindly to shield buds inserted during the season suitable for most of our fruit trees. Shield budding consists in selecting a stock, either a l)ranch or st(Mn. from which the bark slips readily. In raising the bark of the stock for the reception of the bud, the work is similar to that described for scion or sprig budding. The bud is usually selected from dormant wood kept over winter in ashes or sand; but for this there exists no necessity, because there is always present an abundance of dormant buds on a growing plant, and these answer the purpose much better than buds from dormant wood. To remove them, with a sharp knife make an incision in the stem about five-eighths of an inch l)elow the bud; bring the ))lade up under the bud, severing a section of bark three- eighths of an inch in width, with the bud in the center; bring the blade out a little above the Inid. If this operation is neatly performed the l)ud will require no further trimming before being inserted under the bark of the stock. The bark of the stock is then firmly bound over that of the bud and the parts kept in position with raSia. No 1(> SILKWORM FOOD PLANTS. waxing- is necessary. Tlie union should take place within fifteen days, after which the lig-ature should l)e loosened or removed as proves necessary. RAIfSIN(i stocks; for (iRAFTIX(; AND BrDDIXG. In grafting and budding irom any particuhir variety which it is desired to perpetuate, the Russian mulberry, Jlorns a/ha, variety iatai'ica, is the one used as stocks. It is of a robust-growing nature and has been found well adapted to the soils and climates of all the agricultural belts of the United States. It is this variety that is so much used in the West and Northwest for hedges, as it is the hardiest of all the nmlberries. Stocks are best raised from seeds, and a supply for this purpose should be obtained from a reliable source, to avoid unnecessarv delay and disappointment. The sowing and the subsequent management of the seedlings are the same with stocks as with seedlings for general planting, except that when planted in nursery rows they should l)e placed about a foot apart, so as to give an al)undance of space for the operator to work. SOIL. So far as has been ascertained, the mulljcrry is not particular as to the character of the soil. It seemingly grows equally well in a great variety of well-drained soils. Even in sandy and gravelly situations it holds its own. In shallow soils over hardpan the mulberry thrives after most of our fruit and ornamental trees have given up the struggle. Under the same conditions the Per:?ian mulberrj^ has been found to fruit abimdantly. Notwithstanding its behavior under what would be supposed adverse conditions, there are few plants which respond more vigorously to applications of manure. In Japan it has recently been shown that by linnng alone the percentage of fiber in the leaves decreased very per- ceptibly. Again, by liming and also manuring with sodium nitrate and calcium sulphate a still further reduction in the fiber was appar- ent. The trees operated on were \\ meters (5 feet) high. Each tree was treated with 500 grams (1.1 lbs.) of lime, -iOo grams (.9 lb.) of sodium nitrate, and 200 grams (.-1:4 lb.) of calcium sulphate. How the cater- pillars fared as a result of this change in the composition of the leaves is not stated. PLANTING. This all-important operation may be performed either in the fall or spring. After the leaves have fallen or are matured, no delay should occur in transplanting to permanent positions. When this period is selected, it gives good opportunities for the formation of new roots. PLANTING AND PRUNING. 17 III s])rino- the trees may l)e tnm.splanted any time after the iiround is in a workable condition and up to the period when the buds are al)out to })urst into growth. Spaces intended to l>e phiiited shoukl be deeply worked beforehand by plowing- and harrowing, and after planting the weeds should be kept down. The distance between the trees should not be less than 10 feet in the rows, and the rows should be the same distance apart. If the field devoted to the trees is more than -1 or 8 acres in extent, wider spaces should be left at intervals for wagons, etc. It is certain that trees planted 10 feet apart will eventually occupy all the space; ))ut when there is danger of their becoming too much crowded, enough of the plants may be rooted out and l)urii('(l to allow the remainder abundant space to de\-elop. If this is done, those which are to remain permanently should be trained accordingly. The above arrangement is the best for trees nearly all the branches of wdiich can l)e reached fi'om the ground, not only for pruning, but also for leaf gathering. In planting trees similar precautions should })e taken to those in the case of ordinary forest trees; that is, not to allow the roots to become in the least dry from the time they are lifted from the nursery rows until i)lanted in the Held. As soon as they are lifted the roots should be dipped in a mixture of soil and water and kept covered until })laiited, so that the}' will not become dry. If the ground is naturally hard and the soil is poor, dig large holes, even for very young trees, as they grow rapidly and should be encouraged to make good, stout growths from the beginning. Put some good soil in the hole, spread out the roots on this, and cover with several inches of tine soil before firming with the feet. Allow the roots to be about the same depth in the hole as the}' were in the nurser}- rows. Prune back the growth of young trees one-half in the fall, and if necessary cut back to strong buds in early spring. PRUNING. The pruning of the trees presents no special difficulties so long as it is done early enough in the season to avoid late growth, which, if caught by cold weather before ripening, will perish during the winter. The principal pruning should be done in winter and should consist of shortening back strong growths so as to form a low, spreading tree. Keep the central part of the tree as free of growth as possil)le, to admit light and air. After the first cutting back, select three or more of the strong- shoots to form the principal branches. If they are strong and show a disposition to grow upright, they may be kept apart b}'^ using three sticks tied in the shape of a triangle; place these in the center of the tree and tie the branches to them until they grow in the desired 11805— No. 34—02 2 18 8ILKW0KM FOOD PLANTS. direction. By careful attention to cutting- out the undesirable growths the tree can be made to assume any desired shape. In gathering- the leaves always allow enough to remain on the tree to insure its perfect health. If some of the trees show signs of fail- ing- vigor as a result of excessive leaf gathering, it is advisable to allow them to grow for a season without picking, and b}' early prun- ing out of unnecessary growth perinit those growths which are desir- able to become ripened. P ] . A T E S DESCRIPTION OF PLATES. Froxtispikce. — ()1<1 niul})erry trees, showiii'/ Italian inethoil of pruninij;, witli a tiroup nf eml)ryo silk <'ulturists (leaf gatherers) in the foreground, Loni hardy, Italy. By this method of pruning, tall trunks from 8 to 10 feet from the ground are produced, necessitating the use of ladders for leaf gath- ering. From a i)hotograph taken August 2(>. 1002, hy Dr. L. O. Howard. Plate I. Branch of the white mulberry, ^[onl.•< alha. with large undivided leaves, of thick texture and smooth surface. The leaves nf this variety are pre- eminently adai)ted for silkworm food. From photograph of a tree in the grounds of the I\ S. Department of .\griculture. II. r>ranch of seedling white mulberry, Morux dlbo, with divided leaves. Seed- lings from the same parent will sometimes have leaves of the divided form, others assuming the undivided shape shown in Plate I, while some may have both forms on the same tree. III. An ornamental variety of nuill>erry, .][nrii.ropagation can be used on strong seedling stocks or on branches of trees. A and B. — Scions pre- pared for inserting. C. — Stock with bark raised, ready for scion. D. — Scion in position, ready to be wrapped. E. — Stock with scion held in l^lace by wrapping. F. — Stock waxed to exclude air and moisture. 20 34, Bureau of Plant Industry, U. S. Dept. of Agncultun Branch of White Mulberry (Morus albai, with Large Undivided Leaves. 34, Bureau of Plant Industry, U. S. Dept. of Agri Plate II. Branch of White Mulberry iMorus alba', with Divided Leaves. 34, Bureau of Plant Industry, U. S. Dept. of Agriculture. Branch of White Mulberry