The Home Orchard in Spring

New Zealand Journal of Agriculture, Volume 87, Issue 2, 15 August 1953, Page 123

The Home Orchard in Spring

Bulletins for the Home Orchardist Free Bulletins Nos. 81 The Budding of Pip and Stone Fruit Trees. 101 Cause and Control of Brown-rot in Fruit. 104 Silver Leaf in Orchards. 112 Powdery Mildew in the Orchard. 135 Passion Fruit Culture. 285 Grafting of Fruit Trees. 306 Tree Tomato Culture. 310 The Home Orchard. 314 Disinfection of Glasshouse Soil. Bladder Plum and Its Treatment. . The above bulletins, part of a series of over 350 on all aspects of farming, are available post free from the nearest office of the Department of Agriculture, or from the Head Office of the Department, Box 2298, Wellington.

THE art of grafting has been practised ■ for ages. The people of the old world, although not fully understanding the science of the art as it is known today, were very adept in the practical work. Only modifications of the work have been evolved in later years, the principle remaining the same: That the cambium layers of both stock and scion must be placed in firm contact, as it is at that point that the union takes place through the formation of new ■cells. The requirements for successful grafting and other aspects of home orchard ■management in spring are discussed here by C. E. K. Fuller, Horticultural Instructor, Department of Agriculture, Hamilton. HOME gardeners who are contemplating grafting should have the scions on hand in readiness for this work. Grafting may be done from about mid-September, when growth has begun and the sap is flowing freely. If grafting is done too early, the scions may fail to take, and if the work is delayed until the trees have reached the flowering stage, the scions may be “drowned” by the rush of sap and fail to make satisfactory growth. Grafting is a ■ convenient method of reworking pip fruit trees with a more favoured variety or of growing several varieties on a single tree. Stone fruit and citrus are generally reworked by budding, as grafting is more difficult and less successful, unless the operator is highly skilled.

Grafting is confined to plants which have a cambium layer beneath the bark layer, but botanical relationship is necessary for success, which is usually easy between varieties of the same species (for example, apple on apple); and closely related species (pear on quince); but strangely enough quince do not take on pear, and gooseberry thrives on black currant but not on red currant. Peaches and plums will grow one on the ’ other. Incompatibility between varieties is not uncommon. Horticultu r a 1 varieties may generally be intergrafted freely, species less freely, genera only occasionally, and plant families rarely. Stock: That portion of the tree which is retained and grafted. It furnishes the root system .of the tree.

Scion wood: Mature, dormant shoots of the previous season’s growth. The scion: A section of 1-year-old wood containing one or more buds which is used for grafting on to the stock. Cambium layer: The growing tissue of the tree, located between the wood and bark. Suckers: New shoots arising below the graft. Grafting: The process of inserting the scion into the stock. Trees Suitable for Grafting Any variety of apple or pear which is strong and healthy is suitable for grafting. Weak, undernourished trees rarely do well, although scions of a vigorous growing variety such as Gravenstein may develop into a good tree. Scions of about pencil thickness should be collected from 1-year-old wood (mature, dormant shoots of the previous season’s growth) from mature, healthy trees of the desired variety during the dormant period of the tree at,, or about, pruning time. Scion wood should not be gathered from prunings on the ground, but be taken direct from the tree, tied tightly in small bundles, and placed in a cool but moist position. The bundled scions will keep in good condition if placed upright with their bases in about 6in. of soil on the shady side of a building or thick hedge. The site should be protected from drying winds, but the heeled-in bundles should be open to the sky.

The equipment necessary for successful grafting is a pruning saw, secateurs, a stout knife, raffia, shoemaker’s tingles or tacks, a tack hammer, and sealing compound (grafting wax or green crude petrolatum). Kinds of Grafts There are numerous methods of grafting, but only those considered most suitable for use by the ' home gardener are described. Whip-and-tongue graft (upper left illustration on page 127): The most widely used type of graft for the propagation of apples and pears and other suitable subjects is the whip-and-tongue graft. Whip-and-tongue

grafting is used to the best advantage when stock and scions are of equal diameter, but when the stock is larger the scion may be offset, care being taken that the cambium layers of both stock and scion are in contact at least along one side of the join. A flat, slanting cut, the length of which is about 4 to 6 times the thickness of the scion, is made at the basal end of the scion. A downward pointing tongue (A) is made in the upper half of this slanting surface. A slanting cut corresponding in length to that of the scion is made on the stock. An upward pointing tongue (B) is made in the upper half of this slanting surface. The cut surfaces of the scion and stock are placed together so that the tongues interlock (D) and the cambial regions (C) are in contact over as great a length as possible. Tying (E) and sealing of all exposed cut surfaces complete the operation.

Topgrafting, topworking, or reworking is the operation of cutting back the main branches of a tree and grafting another variety on it. The method may be so used by the home gardener that several varieties may be had on one tree. The whip-and-tongue method described may be used on

small branches of the stock (smaller than lin. in diameter). ' Crown, rind, or bark graft (illustration at right): This graft is generally used on trees beyond the nursery stage or on mature bearing trees on branches too thick for whip-and-tongue grafting. The sawn ends of the stock limbs should be pared smooth first. The scion (A) is cut on a long slant and one edge (1) of the bark is cut to make a close contact with the bark of the stock (B2) when the scion is inserted between the bark and the wood on the stubs of the'cut-off limbs. The knife cut on the stock (B2) should be made vertically into and through the bark but not into the wood. If necessary, the bark may be lifted to one side. The scion should be pushed down beneath the bark so that the cut portion fits closely against the wood and the bark at 2. The bark and scion should be tied tightly or a tack should be driven through them. The affected parts should be covered with ■ a sealing compound when the scion is in position as shown in C. One or more of these grafts may be used ‘on each stub, depending on its size. ' After-care The sealing compound should be checked regularly for cracks and other damage, and at the same time any suckers should be removed which are arising from the stock and competing with the scion. On topworked trees any such growths growing well away from the scions may be left, or merely shortened, to give the tree a little leafage until foliage develops from the scions. Where necessary the grafts should be given mechanical support from wind damage, as they are likely ,to become top-heavy once they have taken and are making growth. A graft cannot be considered to have united with the stock until good growth is arising from it. Once the graft has taken the ties should be cut by lightly running a knife over the raffia, where possible on the side away from the graft union. The tie should not be

removed immediately it is cut, but should be allowed to fall away as the scion develops. Grafts for Special Purposes Bridge . grafting (bottom illustration on page 127) is the operation of connecting the cambium above and below damaged portions of trunks or limbs of trees damaged by cats, opossums, rabbits, and other animals. - The bridge is made by the use of supple scion wood of lead-pencil thickness and 3 or 4in. longer than the width of the damaged area. All damaged tissue should be removed, the upper and lower edges of the wound being cut back evenly to live, healthy bark and the exposed area covered with a suitable wound dressing. The scions should be cut at both ends with sloping cuts about ljin. long as for rind or bark grafts. Vertical cuts should be made through the bark on the stock at opposite points, the bark lifted, and the lower end of the scion slipped under the bark at the lower end of the wound; the upper end of the scion is placed similarly, the scion being slightly sprung in the middle. The

bark and scions should be tacked into position and the affected parts covered with a sealing compound. More than one scion may be used if necessary. Routine Work Cultivation Deep cultivation should now have been . completed. Light cultivation should be begun by hand hoeing around the trees as soon as the weather permits. Pruning Pruning of stone fruit trees should be completed by the end of July and of pip fruit trees by the end of August. It is generally believed that citrus trees do not require pruning, but some pruning, principally in the nature of moderate thinning, is recommended to prevent overcrowding of fruiting wood. Citrus trees should not be pruned as heavily as pip and stone fruits. A moderate pruning in spring each year, enough to admit light and air for the proper development of shoots, buds, and fruits, is sufficient. The principal points to be kept in mind when citrus trees are being pruned are:— The encouragement of a sturdy framework of limbs by the judicious thinning out or shortening of less desirably placed branches. '■ &

Keeping lower branches clear of the ground. ' Shortening excessively long side or top branches. Thinning out weak or spent fruiting wood, especially from lemon trees. Refraining from pruning out healthy branches carrying good foliage unless it is absolutely necessary. Manuring Manures for different fruits and the rate of application are as follows: — For apples, pears, apricots Parts (by weight) 2 of blood and bone 2 of superphosphate 1 of sulphate of ammonia * 1 of sulphate or muriate of potash For peaches, plums, citrus, sub-tropicals Parts (by weight) 2 of blood and bone 14 of superphosphate 1 of sulphate of ammonia 1 of sulphate or muriate of potash Rate of application: For trees not yet in bearing from 1 to 31b. should be sufficient; for bearing trees the quantity may be increased, up to 151 b. for large, heavy-bearing trees. A dressing of 101 b. would be sufficient for bearing trees of average size. The manure should be hoed in.

National Film Unit's “Farming in New Zealand

FOR its fairly short length—just less than 1 000ft.—"Farming in New Zealand", a 16mm. colour film recently made by the National Film Unit for the Department of Tourist and Publicity, gives a remarkably comprehensive picture of the main primary industries in New Zealand. It has been made principally to attract farmer tourists from overseas, particularly from Australia, but it has much to offer New Zealand audiences, who will have opportunities of seeing copies ordered by film libraries in New Zealand.

THE film shows the diversity of the Dominion’s livestock farming and deals in detail with lamb fattening, dairying, and small seeds production. The importance of pasture manage-

ment and the development of mechanisation in many farming operations are emphasised. The farmlands filmed are typical of most farming districts, ranging from

lush river flats to high tussock country, and in all scenes the rich colours of summer and autumn form an impressive background for the photography. Different parts of the film were taken in the Gisborne district, the Mackenzie Country, and the Wairarapa, near Tirau and Hastings, and around Timaru. Some of the shots, such as aircraft in flight topdressing hill country and the approach of rain clouds along the hills in the Tai Tapu district, are unusual and spectacular. Though the New Zealand farmer, his family, and farm help have the chief parts in the film, tribute is paid to those other people—the research and extension workers and agricultural teachers—who are continually guiding

and assisting farmers and encouraging them to reach higher standards of production and efficiency. This work is exemplified in the film by views of the certification and testing of seeds and of trials being carried out to evolve new and better strains of grasses for pasture establishment.

The commentary of “Farming in New Zealand” is well written and presents facts and figures interestingly and concisely. The showing time of the film is 27 minutes.