THE ORCHARD.

New Zealand Journal of Agriculture, Volume 54, Issue 3, 20 March 1937, Page 179

THE ORCHARD.

Spraying.

Growers are advised not to discontinue the application of arsenate of lead at too early a date. Codling-moth and leaf-roller caterpillar are usually still active, , and: it is therefore advisable to continue with the arsenical application until a few weeks prior to picking.

As the danger from black-spot infection is not yet passed, it is advisable to continue with fungicidal sprays for a while longer on susceptible late varieties of apples and pears. Where brown-rot fungus has been troublesome a careful examination should be made, and all mummified fruits removed from the trees and ground and destroyed by burning. In addition to this, an application of ~ Bordeaux 5-4-50 is recommended, and should be made as soon as possible after the fruit has been picked, to assist in controlling the disease.

Orchardists should, investigate thoroughly the results obtained during the season from the spraying-compounds used and the methods employed in preparation ’■ and application. When unsatisfactory results are obtained something is' : wrong. Factors which contribute to success are the thorough application of sprays at the correct times, use of the correct compounds, proper mixing of sprays, and an elementary knowledge, of the life-history ! of pests and diseases. J ...

Harvesting and Storage of Fruit.

During the coming weeks harvesting and storing of fruit will be engaging most of the orchardist’s attention. Every endeavour should be made to pick the fruit as soon as it is ready. It is again necessary to emphasize the necessity for the careful handling of the fruit, as the percentage of damaged fruit arriving on the markets is much higher than it should be. - ■ . . . ■ ' The result of careless handling is frequently not felt so severely during the earlier part of the season, when the fruit is sold immediately after it is picked, as it. is with the later varieties, which are usually held for a time. • ' Fruit intended for storage should be most carefully handled and graded, and all bruised fruit or fruit with a broken skin and : with other blemishes detrimental to the quality and appearance of the fruit should be rejected for cold storage. The graded fruit should be placed in the cold store as soon as . possible after picking. A little trouble in the way of placing the various sizes and grades of fruit in the store so that they may be readily got at will save much inconvenience and additional handling when the time arrives for marketing the fruit. It is the practice of some growers to wrap the fruit when it is being packed for storage for the local market, which is quite good practice, except that it entails extra work if the fruit requires to be sorted before being placed on the market. ■ Fruit-export Work. . Despite the wet and cold season experienced throughout New Zealand, reports from several districts indicate that both apples and pears are maturing earlier this season, consequently, where this condition is observed, picking-dates should be advanced accordingly. It should be borne in mind that overmature fruit, if exported, cannot be expected to arrive at its destination in a satisfactory condition. Fruit that has passed the suitable stage of maturity for export, : even though it may be packed some time prior to closing-date for the variety concerned, is certain to be rejected at the inspection. Any line of fruit that has reached the border-line between mature and overmature for shipment overseas should have the larger sizes withdrawn, and only the smaller sizes submitted for examination. Many varieties of fruit picked before the correct stage of maturity has been reached are inclined to wilt during transit, and fail to develop the. true and full flavour of the variety. While the condition is to be carefully guarded against to maintain the good reputation of New Zealand fruit on the overseas markets, it ; is possible that even greater damage to the reputation of our fruit and lower market realizations would result from the export of overmature fruit.

—B. G. Goodwin,

Orchard Instructor, Christchurch.

Citrus Culture. Disease-control.— The season for spraying is not yet over. 1 Temperatures will still be sufficiently high for the germination of the spores of verrucosis, and those who know the disease to be present in their orchards should apply Bordeaux 3-4-50 to their lemons, . timing the application so that it is made when a fair proportion of the autumn blossom is just over full bloom. As the fruit is known : to become infected only when it is small, it will not be advisable f to delay the application for verrucosis-control until a month later, which'time would most likely be more appropriate for a cover spray for protection from brown rot. . The fruit forming at present will be harvested in the summer-time, and although it is generally the lighter of the two main crops it is more valuable for that reason. In the past a number of growers who have kept the main spring setting clean have overlooked

the matter of protecting their autumn set of fruit, with the result that verrucosis has been prevalent and they have been unable to enjoy the benefit of the higher prices. It will be necessary to apply Bordeaux 3-4-50 to oranges and New Zealand grapefruit before the winter sets in. Where leaf-roller caterpillar is present, arsenate of lead powder, lb. to 100 gallons, should be added to this spray. Instances have come under notice of the foliage of newly planted . New Zealand grapefruit trees becoming infected with verrucosis, so that young trees should receive attention where necessary. The scale insects, particularly the red scale, and in some localities the various species of wax scales, will still need to be considered according to the prevalence of the pests and the specifics which already have been applied. Those who have decided that two applications of summer oil 1—33 are necessary should get the second one on during the period March-April, and those who have aimed at applying only one •oil spray should also have the work completed by this time. Not only ■experiments carried out by the Government but also growers themselves have demonstrated that red scale can be eradicated provided that the job is done thoroughly. This needs three thingsviz., an efficient highpressure spraying .plant ; reliable, energetic, and determined operators ; and the trees in such a condition that they , can be sprayed properly. It is very pleasing to note that a considerable number of citrus growers have brought their spraying-apparatus up to date during the past twelve months, most of them having installed the piping-system with stationary •pump and electric motor. Those who have not done so should seriously consider the matter, as competition in production is now so 'keen that only the efficient and up-to-date grower can hope to succeed. The cost of installing a spraying-outfit complete with shed, tank, motor, hose, piping, &c., may be worked out approximately as follows : Z2O •per acre lor the . first five acres, £lO for each additional acre. Costs'-are rising, so that those whose plants are inadequate should endeavour to finance new installations without further delay. Pruning. —While the picking is light growers may find it convenient to pay more attention to pruning. Experiments carried out in America appear to prove that pruning, in the form of a methodical thinning-out of the tree as practised with deciduous fruits, reduces the . yield and does not improve the grade or quality of the fruit. In spite of this, however, there appears to be a certain amount of work to be done, not as straight-out pruning, Tut more in the form of a touch-up here- and there during picking operations. In addition to cutting back weak and spent wood to healthy foliage, ' some attention should be given to shortening of long spindly leaders and laterals. This will tend to obviate bad breaks, and, just as important, will lessenthe amount of blemished fruit produced. The present need is for better ■citrus fruits, and while factors beyond the control of the grower, the weather for instance, cause some of the “ rejects,” there is still much that can be done to improve the grade of the fruit The year of heavy crops is naturally the best time to practise pruning by way of thinning, because during that year the grower will not miss the fruit taken off, while in a light-crop year he wishes to harvest all he possibly can. It is generally agreed that the poor keeping-quality of lemons at certain times of the. year is due partly to the fact that they have taken too long to come up to size, in that by the time they are large enough to pick their natural life is nearing its end. This indicates that the tree carrying this fruit has not sufficient vigour to develop‘it all satisfactorily. The remedy, therefore, is to reduce, the amount of fruit the. tree is carrying by the judicious pruning mentioned above, with particular attention to eliminating-” branch-rubs.” Attention should also be paid to manurial and soil-condition requirements and if necessary to the control of disease.

Green-spot is a condition which causes a considerable lowering of the grade of lemons during several months of the autumn-winter period. The primary cause is bruising, brought about by rough handling of the fruit at some period during transit from tree to curing-room. The bruises are not very noticeable in the early stages, but show up after colouring. As the result of the bumps which they receive, the oil-cells at the point of impact are fractured and oil flows on to the surface of the rind, which at this point shrinks slightly, thus causing the oil-cells to stand out more prominently. If oil from a bruised lemon makes contact with an undamaged one, it causes a green spot at that point. Thus the number of lower-grade fruit is accentuated. As the typical green-spot does not show up until after the lemons, have been in the colouring-room, the grower who supplies a central depot does not see the damage, a percentage of which happens in the orchard. Green-spot occurs most often when the fruit being, picked is dark green. At this stage the rind is very tender and thus liable to damage. Later on when the bulk of the fruit coming up to correct size is silver or coloured the rind has toughened considerably.- Although growers at all times should take great care in handling the fruit, one would like to emphasize the point that during the .next few months, when large quantities of “ dark greens ” will be handled, even greater care should be taken to prevent blemishes due torough handling. ' . ... Warning.— Growers generally are aware of the standard spraying practices and of the specifics which may be applied with safety in the working of -their, groves. In spite of this, new and sometimes ancient : ones are being tried, some of which may be good while others may be harmful. It .is in keeping with the . progressive spirit of the age for one to make experiments in the orchard, but they should be carried out only in a very small way until these new practices have 1 been proved safe and worthy of adoption on a large scale. Recently instances of severe loss have occurred in both young and old groves through the indiscriminate use of materials which have been harmful to the trees. Safety is the best policy where one’s livelihood and capital are at stake. . . ‘

Orchard Instructor, Tauranga.

—A. R. Grainger, (