THE ORCHARD.

New Zealand Journal of Agriculture, Volume 54, Issue 4, 20 April 1937, Page 242

THE ORCHARD.

Harvesting and Storage of Fruit.

During the coming month picking, packing, and marketing of apples and pears will continue to engage the attention of the fruitgrowers. Every care should be exercised in the handling of the fruit so as to avoid the damage and subsequent deterioration which is caused through rough handling and lack of judgment in the picking. At this time of the year the fruit is frequently wet with rain or dews. As far as is practicable the fruit should not be gathered until it is perfectly dry. This point is more important in respect of fruit which it is intended to store for a time. Only sound, mature fruit should be placed in storage. Growers who have mid-season varieties stored in their sheds should examine the fruit at frequent intervals, and immediately it shows indications of “ going off ” no time should be lost in placing it on the market. Fruit which should be marketed at once is frequently held until it has deteriorated considerably. As a result of its condition of advanced maturity in conjunction with the handling, such fruit invariably arrives at the market in an almost unsaleable condition, which leads also to waste. Such late-maturing varieties as Statesman, Rome Beauty, Tasma, Stunner, &c., which are firm-fleshed, will, with proper treatment, keep longer than mid-season varieties.' In consideration of this, in the main, varieties of this class should be given preference in the matter of cold storage. Delicious, although classed as a mid-season variety, holds well, as a rule, in cold storage. A cool, even temperature should be maintained, moderately dry, but not sufficiently dry to cause the fruit to wilt. In situations at the orchard where the average daily temperature is not low at this time of the year, and when there is considerable fluctuation between the day and night temperature, fruit intended for long storage should be placed in a cool store. It is advisable to repack stored fruit before placing it on the market, as there are usually some fruit affected with storage rots, and these fruit, if not removed, will cause a considerable reduction from the price otherwise obtainable. Late Spraying. Following the completion of the harvesting it is advisable to spray stonefruit at leaf-fall— when the leaves commence to show autumn tints and to fall—with Bordeaux 5-4-50. For the better control of brown-rot, leaf-curl, die-back, &c., stone-fruit trees should be examined carefully and all cankered and . infested shoots, laterals,- branches, and mummified fruits removed and destroyed by burning, for in such tree-parts the fungous diseases over-winter. Drainage. Good drainage is very important. The drainage of heavy retentive soils should not be neglected. Tile drains, though more expensive, give the best results, and are the most convenient and permanent type of drain for the orchard. Existing open drains should be cleaned and put in order so as to enable the drainage water to pass away freely. Ploughing and Manuring. The orchard should be ploughed as early as possible after the fruit crop is harvested, so that the work may be completed before it is too wet for working.

In circumstances where a green crop has been sown and has not reached a sufficient height, it is as well to delay the ploughing for a while, to obtain the benefit of any additional growth the crop may make during late autumn and early winter. The soil is greatly benefited by being exposed to the winter frosts and rains. To facilitate the surface drainage the land should be ploughed with the fall, and not across the slopes. Plough to the trees, leaving an open furrow along the centre of the land between the rows •of trees. It is recommended- that deep-ploughing should be done, towards the centre of the rows, in autumn, as the effect of any injury to the feeding roots at this time of the year would be less than when the trees are in growth. When ploughing close to the trees shallow-ploughing is advisable, as otherwise serious damage to the root system may occur, which would result in a considerable check to the growth of the trees. Applications of phosphatic and potassic manures may be made during the autumn just prior to the ploughing of the land. Soils requiring lime may be top-dressed with approximately i ton of carbonate of lime per acre. The application of the quickly acting nitrogenous fertilizer may now be delayed until the spring.

—B. G. Goodwin,

Orchard Instructor, Christchurch

Citrus Culture.

By the time these notes appear in print the month of April will be practically over so that winter weather conditions will be close at hand, if they have not arrived already. In the notes for almost every month mention has been made of the application of —Bordeaux mixture, •summer oil, &c.- and it is just possible that critical readers may say that according to the writer one should be spraying almost continuously. This, of course, is exaggerating the case, although it would be safe to say that owing to the unfavourable weather conditions which have prevailed during the past two years, particularly with regard to the incidence of fungous diseases, more than the usual amount of spraying has been necessary. These notes are intended to be a guide and a reminder for the work which may be expected to be necessary under certain conditions. It is for the individual grower to work out and adopt his own programme to suit the particular requirements ■of his own grove. The local Orchard Instructor is always available to assist with advice if required. Although it is advantageous to exchange views with one’s neighbours it does not necessarily follow that the same time-table and spray programme should be carried out unless all conditions are identical. A few basic principles which may be used in determining the disease-control programme are—Prevention is easier and less costly than cure-; spray applications if applied at the correct strength and at the right time are good insurance against loss. of crop, and thus loss of the whole year’s labour ; thorough work is absolutely essential, as also is an efficient spraying plant; the trees should be kept in a condition which makes good crops a reasonable certainty, not a doubtful possibility.

Apart from spraying, however, there are often other matters in connection with disease-control which require the careful consideration of the grower. One of these is drainage. Instances have come under notice of patches of orchard containing a few trees which were always infected with fungous disease while the balance of the orchard was clean. Investigation revealed the fact that in these patches the soil was water-logged, and in hot weather the humidity around the trees was excessively high. Improvements in drainage eliminated the trouble. It may be that, in cases where it is particularly difficult to control fungous diseases, the drainage of the whole orchard is poor, in which case extra money spent on improvements in this direction should be well repaid by better fruit and reduced sprayingexpenses. Physiological diseases, such as die-back, are often caused by poor soil drainage. Lack of shelter is often the indirect cause of a fungous disease,

wither tip, which does considerable damage to the foliage, twigs, and fruit. The fungus gains entry to trees which have become low in condition. Several instances have occurred of a bad outbreak in young trees which have been exposed to high winds. Attention to the matter of improving shelter is thus an important part of disease-control. However, it is possible for shelter to be overdone, and an endeavour to obtain the happy medium of shelter from damaging high winds while maintaining sufficient ■ air circulation to reduce humidity should be aimed at. From the foregoing it will be seen that, apart from spraying for the control of disease, careful attention must be given to other important factors, and it is suggested that this time of the year, when the pickings are not yet heavy and the soil is still workable, is appropriate for action in this matter. Frost -protection is a problem which must be considered by nearly all citrus growers in this country, since there is not a very great area which is frost-free. Here again the matter must be investigated thoroughly by each individual orchardist, as even adjacent groves vary considerably in their liability to frost. While damage to citrus trees in New Zealand is often measured only by the amount of injury done to the young wood, there is evidence that more serious, though often not so noticeable, harm is done to the crop, particularly in the case of lemons. Severe frosts, of course, cause a dropping of fruits and foliage, but lighter ones cause premature colouring, a slowing of the growth of the fruit, and often extensive blemishes which reduce the grade of the fruit. Through die failure of the fruit to “ size up." normally, its natural life has been almost expended before it is picked, with the result that keeping-quality suffers, and this is reflected by the increased amount of decay in curing-rooms at the period when the bulk of the frostinjured fruit has been picked. The avoidance of this trouble may play a definite part in the production of better fruit. Unfortunately, whereas deciduous trees while dormant are able to stand most of the frosts of winter, and require protecting only against one or two which generally come at the critical fruit-set time, citrus trees, provided the frosts are severe enough, are liable to damage over the whole period of winter : this makes the task of protection much more costly and difficult. There are some growers who have successfully carried out orchard-heating, while others who have purchased oil-pots have thrown them aside after a trial or two and given the job up. The nature of frosts varies so much from orchard to orchard and from time to time that even those who are more or less prepared are taken, unawares at some period or other, and the expense and hard work of the other occasions are nullified. In places the drift of cold air is so great that it is difficult to keep the heated air over the orchard, but this same drift, provided there is a ravine or gully alongside the grove, is the means of saving the situation, as the cold air is drawn off into these gullies, where it settles and causes there a hard frost, while the orchard escapes with a much lighter visitation. In localities where there are no lateral air currents and the cold air stays close to the ground, thus, while a very low temperature may be recorded on the grass, that of the air up in the trees is several degrees higher and no . damage is done. In still other cases the movement of the air is sufficient to bring the cold layer well up into the trees, and damage results. Altogether the difficulties and uncertainty of protecting citrus orchards from frosts are such as to encourage many growers to trust to luck and hope for the best. In spite of the difficulties, however, the benefits to be derived from frost-protected citrus orchards are such that it is to be hoped that some cheap yet efficient method may be evolved in the near future.

Pruning. The ordinary cutting-back of light spent laterals to more vigorous wood may be continued as opportunity offers, either during picking or in spare time, but as winter is now close at hand no really heavy cuttingback should be done until spring. Skeletonizing citrus trees in the wintertime may cause severe damage.

Brown-rot.— The month of May has often proved to be a time for considerable development of 'brown and therefore growers should see that all trees have a good covering of Bordeaux mixture 3-4-50. Spray residue from a previous application, such as the one for the protection of the autumn .setting from verrucosis, may still be visible on the trees, but the efficiency ■of a Bordeaux spray should not be regarded as extending for more than .a month at the outside, while under excessively wet conditions it might be reduced to less than half that time. The practice of spraying only half ■of the tree for protection from brown-rot is not to be recommended, since total coverage may still be necessary against other fungous diseases, and if the 1-per-cent, oil has been added the insecticidal value is also obtained throughout. Young Trees. Special attention should be paid to these to see that they dace the winter well protected from the elements—cold winds and frosts. If windbreaks are not yet adequate the expense of individual protection •of small trees will generally pay well. Scrim, brushwood, or fern can be utilized for this purpose not only for protection from wind, but also from ■.frost. A bad setback may mean an additional year without revenue, and sometimes trees are lost altogether through outbreaks of disease following low condition contracted during the winter.

—A . R. Grainger,

Orchard Instructor, Tauranga.