The Propagation of Stone Fruit Trees

New Zealand Journal of Agriculture, Volume 89, Issue 4, 15 October 1954, Page 399

The Propagation of Stone Fruit Trees

THE raising of fruit trees is frequently * looked on as being difficult and requiring specialised knowledge and training, but this is not so. Provided certain operations are carried out carefully, any grower can establish a small nursery and raise his own trees. In this article J. Coombe, Horticultural Instructor, Department of Agriculture, Christchurch, describes the methods used to propagate stone fruit trees.

THERE are many advantages in raising one’s own trees. A number of varieties of stone fruit, particularly cherries, have several names for the one variety, some being incorrect; several distinct varieties may be known in different areas by the same name. Only after bought trees have been planted several years and have come into bearing is the grower sure that they are what he wanted. If he propagates his own trees, he can select the budwood himself from healthy trees of the variety and type he wants. He can also use the particular rootstock most suited to the situation in which he intends to plant. Another advantage is that when the trees are moved from the home nursery into their permanent positions in the orchard the roots need not be cut back to the same degree as would be required if the trees had to be packed and transported long distances; nor is it necessary to remove all the soil from the roots; consequently far less damage is likely to occur. The possibility of the rooting system drying out is also eliminated, and trees raised on the property can be lifted and planted out when soil conditions are suitable. Disadvantages are that for the commercial fruit grower, at least, the budding of the stocks to the required variety and general attention to the nursery often clash with the harvesting season, but as the amount of time required to raise the young trees is not great, their propagation is well worth while. Site of Nursery One of the most suitable sites for a nursery is a small area close to the house or the vegetable garden, as this

is more likely to receive constant attention than one some distance away. Areas where tomatoes, potatoes, or strawberries have been grown should be avoided, as the soil where these plants have been grown frequently becomes infected with verticillium wilt fungus. Stone fruit trees, particularly apricots, readily become infected by this disease if it is present in the soil, and once a tree becomes infected it may stunt badly or even die. The site chosen should have reasonably good, well-drained soil, be well sheltered from strong winds, and have sufficient water available for irrigation if it is needed. Rootstocks Most fruit trees are made up of two parts—the rootstock forming the rooting system and part of the trunk, and the scion variety which forms the top portion of the trunk and the branches. For some kinds of fruit trees there are various rootstocks available which

give a wide range of vigour, from very vigorous to dwarfing. In addition some stocks are suited only to certain soil types and conditions and generally produce very poor trees if they are planted in unsuitable localities. It is necessary, therefore, to select the rootstocks most suited to the condi-

tions under which trees will have to grow in the orchard.

VARIETIES OF ROOTSTOCKS SUITABLE FOR DIFFERENT STONE FRUITS Scion Stock Raised from Method and time Remarks Myrobalan Seed or cuttings Bud in January Best general stock uni ' Apricot Apricot Seed Bud in January For suitable soils Peach Seed Bud in January Only where known to do well Mazzard Seed, cuttings, Bud in December- Mazzard better in suitable Cherry Mahaleb or root cut- January or graft soils tings in September Mahaleb may be shorter lived, but tolerates wider range of conditions Peach (and Peach Seed Bud in February- Plum stock can be used, but nectarine) March rarely makes good trees Plum Myrobalan ■ Seed or cuttings Bud in February Develops large vigorous trees, (European) or graft in Sep- and has wide compatibility tember range Myrobalan Seed or cuttings Bud in February Wide range of compatibility or graft in SepPlum tember (Japanese) -- - : ; —— - ——- Marianna Cuttings ) p . •„ p „ b _„„ rv Suitable for vigorous variePeach Seed f Bud ,n February tjeg and n Hght soilg

For Peaches and Nectarines As a nectarine is really only a special type of peach, what applies to peaches will also apply to nectarines. Peaches are generally worked on peach stocks raised from seed. As commercial ■ nurseries used to collect the seeds from canning factories, the majority of their trees are on Golden Queen stock. Seedlings raised from Lady Palmerston peach stones also make good rootstocks. Seeds of midseason to late varieties of peaches should be chosen for raising rootstocks, as the percentage of germination of the early varieties is normally very low. Plum rootstocks can also be used for peaches in some circumstances such as in soil inclined to be heavy or likely to be slightly wetter than peach roots will tolerate, but the trees usually do not succeed as well as on peach, and with cherry plum particularly the percentage of bud “takes” is often low. Peaches on plum stocks usually have a shorter life than those on peach stocks and the results are often disappointing; therefore it is better not to attempt growing them this way. For Plums Myrobalan (cherry plum) is one of the most suitable stocks to use for plums, as it develops a large, vigorous tree and is compatible with nearly all varieties. Trees on this stock take longer to come into bearing than those on less vigorous stocks, but once bearing begins the crops produced generally exceed those from the weakergrowing trees.

Marianna plum is also quite a good stock, but the resultant trees are not quite as vigorous as those on Myrobalan. For very vigorous-growing Japanese varieties such as Purple King, Marianna is probably the more suitable stock to use. Like Myrobalan it does not sucker badly, but it is sometimes hard to bud, as the bark tightens early in a dry season, and it is not compatible with all varieties. Plum suckers dug up from under mature trees are not suitable for stocks, as they themselves will sucker in the same manner as the tree from which they were taken. Peach seedlings have occasionally ’ been used as stocks for plums,'but they usually reduce vigour considerably and shorten the trees’ life. They may be suitable for vigorous-growing Japanese varieties such as Purple King in some localities. Plum rootstocks for both European and Japanese varieties can be raised in various ways—by seed, by root cuttings, by hardwood cuttings, or from stool beds. Myrobalan stocks are generally raised from seed, but can also be propagated from both hardwood and root cuttings. Marianna stocks propagate quite readily from hardwood cuttings, and this is the method usually adopted for this stock, though root cuttings are also satisfactory. Trees raised from seed vary to some extent in their vigour. There is also some variation in their compatibility with some varieties. Trees raised from cuttings are more even in vigour and compatibility does not vary. Stool beds are necessary only where a large number of stocks are needed annually. For Apricots Apricots can be grown on plum, apricot, or peach roots, the choice depending largely on the soil conditions where the trees are to be grown. Plum stocks are most suited to a soil which is inclined to be slightly. heavier or slightly wetter than the ideal apricot soil, but even on this stock apricots should not be planted in heavy, wet soils. Apricots on apricot seedling roots are suited to welldrained, loamy to light soils; on peach stocks they often do well on some sandy or shingly soils. The life of the tree in most soils is much longer when it is grown on plum stock than when it is on peach. Myrobalan plum stocks are often used for apricots, but some variation in compatibility will be found if seedlings are used, and the percentage of takes is generally less than where apricot or peach stocks are used. Marianna has been used to a limited extent, but has a narrower range of compatibility than Myrobalan. For Cherries The Mazzard, a wild sweet cherry, parent of the cultivated varieties, is generally considered to be the best stock for cherries. It produces large, vigorous trees and is compatible with all varieties of cherries. Another stock that , has been used to some extent is Mahaleb, which can be grown in a greater range of soil types than Mazzard. Some varieties .on Mahaleb stock may not last as long

'as on Mazzard, nor are they generally as vigorous. Stocks for cherries are mostly raised from seed of the desired stock variety, but they can also be propagated from root cuttings a d- by layering. The table on page 399 shows the stocks considered the most suitable for the various kinds of stone fruit, how they are raised, the method used to work the scion variety on to the stock, and the time of year to do it. Selecting Roofstock Except in minor details, the methods of raising seedlings of peach plum, apricot, and cherry are the same. Seeds should be saved from trees free from any signs of disease, especially any of the viruses. The seed should be collected from mature fruits, and all flesh should

be removed, especially if it is to be held for some time, and the seed dried before storing. Seeds of stone fruit trees, when freshly removed from fruit, will not germinate, ; eve n under ideal conditions of moisture and temperature. They need afterripening, which occurs when they are kept moist, but not wet, at a low temperature, 66 degrees to 4U degrees F. being the optimum range. This process, known as stratification, may take from 1 to 3 months, depending on the kind of seed. Peaches, plums, and . cherries will need at least 3 months at low temperatures; in warmer climates a longer period would be necessary unless artificial cold is used. Under most circumstances these seeds could be stratified almost as soon as they are harvested, because, though after-ripening may be completed before the end of winter, germination will not take place until conditions are favourable in spring. Apricot seeds need a much shorter after-ripening period, 1 month usually being sufficient. In addition apricot seeds germinate at a comparatively low temperature and therefore stratification should not be begun until a month or so before the expected time of sowing. The seed is mixed with sand and placed in a frame or box, which is ..sunk into the soil in- a cool position and maintained in a reasonably moist

condition until the seed begins to swell; coarse sand is much better than fine, as it allows better penetration of air and provides better drainage. Swelling should start in late winter, and once it has started the sand must not be allowed to dry out or germination will be adversely affected. The swollen seed should be sorted, those obviously not viable discarded, and those showing movement sown into nursery rows 30in. to 36in. apart. In the rows the seeds should be spaced 15in. to 18in. apart, the depth varying with the kind of peaches at 2in. to 3in., plums and apricots at lin. to 2in., and cherries at no more than lin. By selection and spacing in this manner very few gaps are likely to occur. The distances mentioned are far greater than those used by nurserymen, but the grower raising trees for his own use only does not require a large number, and more space can be given to each tree. These wider spacings also allow the ; tree to be grown in one spot until it is ready for

planting in its permanent position in the orchard; there will be no check in its development through transplanting in the nursery. General attention to the nursery bed, such as cultivation and irrigation, should be carried out when necessary so that the growth of the young stocks is not checked. Frequently the main stem of a seedling will send out a number of side growths; from time to time these should be pinched out, leaving only the main stem growing unchecked so that it has a better chance of developing to a size fit for budding in the first season. Propagating Hardwood Cuttings Hardwood cuttings should be col* lected from healthy trees only just before beginning of leaf-fall. Only well-ripened cuttings from the current season’s growth should be taken pre* ferably from the outside and top of the selected trees. The top of the shoot should be discarded and the remainder cut into pieces at least 12in. long. The advantage of a long cutting is that if there is insufficient young growth from it to be easily budded, the bud can be inserted into the bark of the original cutting. More satisfactory strikes are generally secured from cuttings taken from near the basal ends of the shoots. Water sprouts or soft, sappy growths should be avoided, as these seldom develop roots. . Best results are generally obtained if the cuttings are first planted in a special propagating bed, which should consist mainly of clean, coarse river sand. Three parts of sand to one part of soil, thoroughly mixed, will be found a satisfactory medium to start the callus forming. The cuttings may be planted as close as 2in. apart in rows in the propagation bed. They should be planted about Bin. deep in trenches. On no account should they be pushed into the soil, as this damages the bark at the basal end and may prevent callus and root formation. After planting, the sandy soil must be thoroughly firmed and kept moist, but not excessively wet. Small roots should be formed by late winter, when the cuttings can be carefully lifted and planted out in the nursery rows about 15in. to 18in. apart and about sin. to Sin. deep. This should leave sufficient of the cuttings above ground for the insertion of the bud. Rows should be 30in. to 36in. apart for easy cultivation. Propagating Root Cuttings Root cuttings from some varieties of plums and cherries strike fairly readily, and, like hardwood cuttings, they produce an even line of trees. Better strikes are usually secured from the roots of young trees (1 or 2 years old) than from those of older ones. Where propagation by root cuttings is ■ done the root prunings from young trees being transplanted may be saved. These should be from . Jin. to tin. thick and about sin. long. For a root cutting it is advisable to make the cut at the top of the root straight across and that at the lower end on the slant, to ensure that the cutting will be planted the correct way up. The cuttings should be completely covered with moist sand until earlv spring.. They should then be lined out 15in. to 18in. apart in a row in the nursery, with the top of the cutting level with the soil surface.

Frequently a number of shoots grow from each cutting. All except one of these should be eliminated by' carefully rubbing them off when they are an inch or two long. It may be necessary to do this several times during the season. In favourable years a number of the root cuttings may produce sufficient growth to be budded the same season. It is important that the nursery into which either hardwood or root cuttings are planted has good soil which will hold moisture readily and not pack too tightly, thereby excluding air. If the soil is inclined to be heavy, it can be improved by mixing coarse sand with it and by placing a small quantity of sand at the base of each rooted cutting. Budding and Grafting There are two methods by which the scion variety can ■be worked on to the stock—budding and grafting. The choice of method is determined largely by climatic conditions. Peaches, nectarines, and apricots can be budded successfully in most districts. With plums and, particularly, cherries the buds seem to be more easily killed by cold in the winter and in some districts, for instance, Canterbury and Otago, better results are obtained by grafting. Budding Time to Bud The time to bud varies a little from season to season and is influenced by the condition of the sap flow in the stock. Budding must be done while the bark still lifts readily from the stock. If it is not possible to lift the bark cleanly from the wood without tearing it, budding should not be attempted. During a drought period it may be found that after a few days the bark will become hard to lift. If this occurs, budding should be postponed and the trees given a good watering to start the sap flowing again and so enable budding to be done. The various kinds of fruit are normally budded in a definite

sequence, though there may be some overlapping owing to the condition of the stock, and also a difference in the maturity of the buds of different varieties within each kind of fruit. First come cherries in December or January, depending on the season and district, then apricots, followed by plums, and lastly peaches and nectarines, the best time . for the lastnamed being from the middle of February to nearly the end of March. Selecting Budwood Sticks Budwood should be taken only from the best trees available. Any tree to be used as a source of budwood should be examined several times during the growing season to make sure that there are no symptoms of disease and that the fruit is of good typical shape and colour. Whenever possible budwood should be taken only from trees which crop consistently. Shoots of about pencil thickness will be found most suitable for budsticks, as buds taken from thick shoots are sometimes hard to fit snugly, particularly if the stocks are thin. The shoots on the outside and top of the tree, where they get the maximum light, usually have good foliage and bud development and are the best. Water or sucker shoots that arise direct from the heavy wood, particularly on the inside of the tree or where saw cuts have been made, should be avoided, as the buds on these shoots are generally under-developed. If budwood is required from a special tree and the growth is poor, it can be invigorated by severe pruning the year before the buds are required. The shoots must not have completed their growth nor the buds be fully ripe when the wood is collected. The sap must still be flowing in both the bud and the stock before a union can take place. One point that cannot be stressed too strongly is that the trees from which the budwood is collected must be inspected thoroughly to ensure that they are not infected with virus or any other disease

which can be transmitted to the stock. This also applies to trees from which cuttings or seeds are collected for propagation of stocks. Preparation of Budsticks The leaves should be removed from the budsticks as they are collected or as soon after as possible. This operation is important, as it reduces the loss of water by transpiration through the foliage. When the leaves are being removed about jin. to Jin. of the petiole (leaf stalk) should be left attached to the budstick. This short piece of stalk acts as a handle when the bud is placed in position on the stock and makes the operation easier. A few inches of both the top and bottom of the budstick should also be removed, as the buds on these portions are usually not well developed. The stipules, which are small, leafy outgrowth from the&base of the petiole, should also be removed to reduce transpiration. This applies particularly to varieties of fruit which have large stipules. On other varieties the stipules are insignificant. .

Once the budsticks have been prepared they should be stood in. a bucket containing an inch or two of water. covered with a damp cloth, and kept m the shade. If only a few trees are being budded, the budsticks can be wrapped in damp cloth or paper and left m the shade. , operation or isuaamg Side growths should be cleaned off the lower , parts of the stocks a few weeks before budding (see illustration on page 403). This not only allows

the budding to be done more speedily, but also assists in the development of a thicker stock. To do budding neatly and quickly a very sharp knife is necessary. A special budding knife will be found most suitable, as the end of the handle is shaped for lifting the bark of the stock. Some strands of raffia about 12in. long or rubber bands specially made for budding will be necessary to bind the bud in place. Speed is necessary in budding so that the back of the bud shield and the exposed part of the stock do not dry out. Rough handling with the knife should be avoided; otherwise the wood or the bud may become damaged and spoil the union. It is essential that wood buds be selected, as blossom buds will not grow. Wood buds are more pointed and thinner than fruit buds. When in doubt as to whether the buds are wood or blossom ones, especially with peaches or nectarines, it is better to select double or triple buds or bud clusters, as one of the buds is always a wood bud. The operator should stand just in front of the tree with his back to it, then move backward until the tree is between the legs (see upper left illustration on this page). This pushes any side growths out of the way and enables the tree to be held firmly between the knees. All trees in each row should be budded on the same side so that inspection .of the buds and cutting of the ties- are simplified. The general practice is to insert the buds

th cnnth ciHp n f tho «tnrkq tn avoi? excessive heat from the sun. When the bud is removed from the budstick the shoot should be held with the thick or base end away from the body. The knife should be inserted into the budstick about jin. to gin. below the bud and then drawn up until it is about jin. past it (see upper illustration on page 407). At this point the blade should be turned slightly so that it nearly reaches the surface about fin. to lin. above the bud. The bud shield

is then held between the thumb and the knife blade and given a quick pull upward, which will drag off a strip of bark. When the bud shield is being cut from the stick a shallow cut should be made so that the piece of wood at the back of the bud does not require removing. If the cut has been made too deep and the wood is not removed, it will be hard to make the bud shield curve around the stock to secure a good union. The wood behind the bud can be removed quite readily by inserting the point of the knife under the wood above the bud and pulling sharply downward. After the wood has been removed the bud germ can be seen at the back of the bud as a small raised lump; if a hollow appears instead, the bud should be discarded, as the bud germ has been destroyed and the bud will not grow. Generally it is only on wood in which the buds are too ripe that the bud germ is damaged when the wood is removed. However, it is not necessary to remove the wood when shallow cuts are made, and it speeds up the work to leave the wood in (see upper illustration on this page).

Before any cut is made in the stock dirt should be cleaned off so that there is no chance of its getting on the cut surfaces and spoiling the union. A T-shaped cut should be made in the stock from 3in. to 6in. above ground level. The height varies according to the condition of the stock. On stocks which are thin or have had a number of fairly thick side growths it is much easier to bud low, where the wood is thicker and is free from knots (see lower illustration on this page). The horizontal cut should be made first, by pressing the knife into the stock to the depth of the bark. The vertical cut is made by inserting the point of the knife about lin. below the horizontal one and then drawing the knife up

until the cuts meet, Before the knife is removed it should be given a slight twist to both sides to lift the bark at the intersection of the cuts, thus avoiding the necess? of , USl ?® f Ju? htndle The cuts are made right but should not go into the wood. u . j The bud is placed in position by inserting the lower P- t j e shield under the bark at the intersection of the cuts an ri pushing it gently downward. Either the short piece of stalk remaining on the bud shield or the bark at the top of the bud can be used as a handle for placing the bud shield into position, The lower end of the shield must go down to at least the bottom of the vertical incision. The bark at the top of the bud, which projects

above the cross cut, is cut off by pressing the knife into the original horizontal cut. This will allow the shield to fit snugly under the bark of the stock. It is a wise precaution for the beginner to collect a few shoots an( j practise cutting the bud shields and placing them in position before beginning to bud good stocks. The bud should be bound into position as soon as it has been inserted, otherwise drying out may occur. To do e centre of the raffia should pi ed against the back of the stock and both ends brought around simultaneously so that they pass over the i nc i s ion just below the bud. A further one or | wo turns are made below the bud, then both ends are brought aroun d the stock, just above the bud, w here one or two more turns are m ade before tying. Care must be taken that the bud j s not covered or damaged by the rama " The horizontal cut above the bud should be completely covered by the raffia, but it is not important to cover the vertical cut fully. The binding mus t be done firmly, particularly the first round below the bud, but it must no cut into the bark. Another simple and fast method of binding is to place one end of the raffia around the stock, holding it firm

with the first complete turn, then bind upward until past the cross. incision, where two half hitches are made. Such binding should also begin below the bud.

It will be found that raffia which has been soaked in water before use will be stronger and also far easier to tie securely. It is not necessary to use a sealing compound after budding.

Rubber bands which are specially made for tying buds will also be found satisfactory and easy to use. These bands expand as the stocks increase in size and do not cut in to the same extent as the raffia. Only bands specially made for this purpose should be used, as they are made to rot and fall away within 3 to 4 weeks. The second method of tying described should be used with rubber bands.

Treatment after Budding

At the time of the year when budding is carried out the stocks should be growing strongly and increasing in circumference fairly rapidly. This rapid growth makes it necessary to examine the stocks 10 to 15 days after they have been budded to make sure they are not becoming strangled. If this is occurring, the raffia should be cut on the back of the stock with a sharp knife, but the ties should not be removed, as they assist in shading the bud. The ties should not be cut until at least 10 to 12 days have elapsed from the time of budding.

The portion of leaf stalk left on the bud shield is quite a good indicator as to whether the bud has taken. If these stalks shrivel and adhere to the bud when not supported by the binding material, the bud has failed. Another bud may be inserted in a fresh position on the stock, provided the stock is still in a suitable condition.

Rootstocks on which buds have taken should not be cut off until the end of the winter after budding. The stock can then be cut off either 4in. to 6in. above the bud or immediately above it; in the latter method the cut should slope away from the bud to run rain oft. If the stock is cut off immediately above the bud, it may be necessary to support the young growth from the bud with a stake to prevent wind damage. If a stub is left, the young growth can be tied to it, but when the stub is finally removed, the cut does not callus as quickly as one made earlier. (See illustrations on this page.)

The treatment of the resultant growth depends largely on how it develops, and this is influenced by soil, climate, and other factors. If under favourable conditions strong growth is made early in the season, this can be pinched back at about lain, from ground level, causing the stem to branch. Three strong, well-placed branches are retained to form the basic framework of the future tree. Where only weak growths are made it is better to grow a single stem in the first season, all side growths being removed as they appear. In the winter this stem is cut back to about 15in., care being taken that the top three buds are sound and well spaced. In the following growing season three mam arms should develop. Grafting In the grafting of nursery trees the whip and tongue graft is used. The

operator will require a supply of treesealing compound as well as a knife and some raffia. The best sealing agents are those specially prepared for grafting. These are the least likely to be harmful to the bark of the tree and they remain pliable, thereby excluding air and moisture from the wound made in grafting. , Grafting is done in spring, but as it is necessary for the stock to be in a more forward condition than the scion, the grafting wood is collected while it is still dormant. When a source is being selected the same precautions should be taken as when choosing budwood; the trees selected must, have been carefully examined during the growing season to make sure that they are healthy and carry good crops of fruit which is true to type. The trees should be clearly marked. Neither rank, sappy growths nor spindly twigs are suitable as scions. Well-grown shoots of the previous season’s growth, showing good bud development, should be selected and cut off at their bases. Wood of each

variety should be bundled up separately and labelled; the tips of the shoots should not be cut off. The wood must be stored so that it will not dry out, and the most suitable place is in the shade of a building or beneath a tree, where the soil will remain moist without waterlogging and where there is no likelihood of the wood becoming frozen. A trench should be opened deep enough to take one-third of the length of the shoots. Care should be taken that the bases of the shoots touch the bottom of the trench before the soil is filled in round them. It is immaterial whether the shoots are upright or at an angle. Grafting can usually be begun when stocks are at the advanced green-tip stage, and normally can be done over a period of 2 weeks or 3 weeks. It is useless starting before the sap in the stock is flowing sufficiently for the bark to be lifted readily from the wood, for if grafting is done too early, the scion will dry out and die before a union is made. The stocks should be tested by making a cut and lifting

the bark, as various kinds of stocks may differ by a week or more in the time required to reach the correct stage. Operation of Grafting It is advisable to prepare the scions before beginning to graft, but only enough for about 1 hour’s work should be cut at a time; a small box to keep this quantity clean and shaded from the sun will be found useful. The wood should be taken from the trench where it has been stored, a few inches of both tip and base of each shoot should be discarded, and the remainder cut into scions with three or four buds on each. The cut at the top of each scion is made immediately above, and sloping away from, a bud (see illustrations on this page). The . base of the scion is prepared by making a slanting cut, about 2in. long, on the side opposite the lowest bud, as shown in the illustration at right. The base is then split by another cut (see illustration) to form a tongue; this cut is made parallel to the bark from nearer the pointed end of the slanting cut rather than up the centre. At a height of about 12in. similar cuts are made on the stock and the two pieces are fitted together (as in the illustration at right) so that they are held firm by the tongues. To ensure a good union between stock and scion the cambium of one must be in contact with that of the other to the greatest extent possible. (The cambium is the layer of actively dividing cells between the wood and the bark.) If the scion is of the same diameter as the stock, and the two barks are of equal thickness, the main precaution necessary in fitting them together is to see that the cut surfaces of stock and scion are in contact. If the scion has a smaller diameter than the stock, it should be placed toward one side, so that the cambium layers on that side are in close contact. . When the scion is in its correct position the join is bound firmly with

raffia and sealed. The method of binding is similar to that described for budding trees. The material used for sealing should make a pliable, airtight, waterproof film over the union. There are. many recipes for grafting wax, and many need to be applied hot. Some bitumastic compounds are suitable, and green crude petrolatum is often used successfully. It is essential that the join be covered completely, particularly all exposed cut surfaces; the top of the scion should also be sealed to prevent drying out. Two workers can do grafting much more satisfactorily than one; the more

skilful should do the cutting and fitting of the grafts and the other the tying and sealing. If only one person is doing the complete operation, extreme care is required to see that the hands are cleaned thoroughly each time the sealing compound is handled, as the slightest trace of foreign material on the cut surfaces of stock and scion that are in contact may cause failure of the union. Within a few weeks of the buds being grafted the scion should begin to grow, and both scion and stock will swell. As soon as this occurs the raffia should be cut with a sharp knife, but not removed, care being taken not to damage the union. Buds on the stock may also start growing. These shoots should be rubbed off from time to time, preferably before they have grown more than an inch or so. Rubbing off is better than cutting, as it reduces the chances of the shoots growing again. During the first growing season after grafting the trees should develop at least three good shoots. Provided these are well spaced, all three should be allowed to grow until the following winter, when they should be headed back to about one-quarter to one-third of their original length and any other shoots removed. If fewer than three shoots come away, the tree should be reduced to a single rod, which should be headed back in the winter to form a head m the following season. In the late summer preceding transplanting to the orchard the trees should be wrenched when the soil is m a suitable condition. .Wrenching assists in forming a more compact rooting system, which enables the tree to recover from transplanting more readily. Reference “Fruit Tree Raising: Rootstocks and Propagation , Bulletin No. 135, Ministry of Agriculture and Fisheries, England.