THE ORCHARD.

New Zealand Journal of Agriculture, Volume XL, Issue 6, 20 June 1930, Page 421

THE ORCHARD.

Pruning.

Apples.— The longer economic life of the fruit-producing parts in appletrees allows of greater elasticity in pruning, and almost every orchardist has ■ his own particular variations, all of which in the aggregate arrive at about the same point from a weight-per-acre viewpoint. The systematise carries a mental picture of the tree during the last fruiting-season, and from that aims to eliminate the undesirable features and build towards his conception of the .ideal tree. The basic principles of pruning are dictated by.the tree, and the pruner’s efforts should be more in the direction of assisting than correcting nature if a continued battle between the tree and. the pruner is to be avoided.

Soil-conditions play an important part in determining just how much, wood may be left to-carry fruit-spurs, for it -is obvious that a tree which is having a hard struggle to find sufficient nutriment to maintain wood-, production must be treated differently to one which is running riot after each pruning, indicating that it desires some other outlet for its abundant energy. It is not uncommon to hear that notwithstanding regular pruning some trees refuse to produce fruit, and, excluding varieties such as Northern Spy, which are slow coming into bearing, in most instances it will be found that all the thin .laterals have been cut out because they did not look strong and . the strong shoots cut back to the base because they threatened to get out of reach, with the result that being shorn of its outlet for energy and to preserve the balance between root and top the tree produces fresh wood and -production suffers.

A good example of the inclination of • the tree is obtained from one which has been left unpruned for a season. It will be observed that in the first season strong clean shoots were made.- . In.the second season many of these growths will flower at the tip and fruit-spurs will be formed at some of the eyes near the terminal extremity. On lateral bearers the spurformation may -occur during the first season. Following .the spur-produc-tion fruit is carried and the wood-production decreases, and without sufficient stimulus, either in the form of pruning, manuring, or thinning, the tree will enter into a decline and eventually become an economic loss.

From this it will be seen that a certain amount of wood must -be removed, and at this point the various systems and their modifications come into play. For the home orchardist a system of yearly extension, and reasonable cropping offers fewest difficulties, and the more or less highly involved systems are best left to the professional grower who has his treesunder constant observation and who can quickly resort to any corrective measures.

In every tree a varying number of main limbs or leaders are developed and terminally extended each year. Secondary shoots or laterals are added each season, and cn these the bulk of the crop is carried. As the tree extends upward and outward more space becomes available and the leaders may be duplicated, but frequent duplication is not desirable, as there is a danger of the leaders loosing their identity, and the difficulties of pruning are greatly increased. Immediately below the point of last season’s cut two or more shoots will have developed. Of these one must be selected.to continue the lead, and is headed, removing about two-thirds of its length. During the next growing-season the uppermost eyes break into growth, and if too much wood was left the eyes on the lower portion will remain dormant and in time the limb will be a succession of fruitful and bare lengths. To eliminate the bare places the heading is regulated in that only sufficient is left to allow for The usual break and spur production peculiar, to the variety. If the shortening is too drastic each eye is forced into

vigorous growth and fruit-production prevented. With the laterals, strong ones on the inside of the leader will be removed at the base, as also will any which challenge the leader for supremacy. This will result in the production of one or two weaker shoots at the point of removal. The light laterals are left uncut the first season and the older spurred twigs thinned or shortened as desired. Varieties which carry the bulk of their crop on the tips of the shoots require treatment which will permit the tree to follow its natural inclinations, for shortening the shoots removes an appreciable portion of the succeeding year’s crop.

Jonathan represents a type which requires more severe treatment in order to frequently renew the fruiting-wood and maintain the necessary vegetative vigour. Here it is preferable to work rather on the severe side in heading ; all laterals may be shortened, and each season some of. the older, partially. exhausted fruiting-shoots removed, or if possible cut back to a weak shoot which is also headed, in order to stimulate growth beyond the fruit. This variety’s. fruitful habit and weak growth calls for careful treatment if a sturdy tree is to be developed. Opportunity should be taken to shorten every limb with a drooping tendency to an upright growth, and pruning to inside eyes is often advisable.

Citrus Culture.

Picking will be the most constant operation during the coming month. The usual heavy demand for lemons at this season is sufficient inducement to watch the crop very closely and gather everything that shows a tinge of yellow. It is often difficult to avoid gathering damp fruit, but the practice is not wise, and only dry fruit should be stored for keeping. The presence of moisture assists in the spread of fungal growth, and cases should be stacked to allow of . free circulation of air and frequent inspection. Draughty stores are to be avoided, and a fairly warm room hastens the process of wilting prior to dipping. The slight wilt is important, as immersion of the turgid fruit in the hot bath is liable to rupture the oil-cells in the rind and induce decay. Cottony cushion scale sometimes becomes active during the winter months and very early in the spring. Any colonies should be cleaned up without delay and trees showing Capnodium should be rigidly inspected. Citrus brown-rot may be expected during wet weather, and it is unwise to'await its appearance before spraying with bordeaux. Attention to drainage is vitally important to the citrus-grove, and the opening of temporary drains for the rapid removal of water becomes a routine matter. Of almost equal importance while the time is opportune is the topping or trimming of shelter belts or hedges which overhang or are higher than is necessary. .

G. H. McIndoe,

Orchard Instructor, Dunedin.