THE FRUIT SECTION.

New Zealand Herald, Volume LXIV, Issue 19698, 26 July 1927, Page 14

THE FRUIT SECTION.

BY S.T.R.

IMPORTANCE OF SPRAYING.

During the winter months the orchardist finds all his time occupied in carrying . out necessary operations, the chief of which, up to the present, has been pruning. The time has now arrived, however, when attention must be givsu to another equally important work —the spraying of the various trees. This work is absolutely essential. Both the pruning and the spraying should be continued, the two being worked in together so that both may be carried out satisfactorily, and also expeditiously. All orchardists are advised to make immediate preparations lor the carrying out of the extensive programme of spraying in the near future. A spray pump is an important part of the equipment, and if not in possession of one at the present, every orchardist should provide himself with one. For those who cannot afford a knapsack sprayer, a small atomiser, the cost of which is only a matter of shillings, will serve the purpose. A hand syringe is also fairly cheap and is exceptionally easy to handle. As a matter of fact the writer would advise an amateur who has only a few trees to obtain a syringe rather than a knapsack sprayer, for the amount of work to bo done would not warrant the extra expenditure. A most, important factor in spraying operations is the use of the correct spray for the particular pest or disease that is being dealt with. One could not expect to control aphides by spraying with a mixture which is intended for the control of fungous diseases. Of course, there are combined sprays, that is, mixtures which are both insecticides and fungicides, but even these may not be used universally. > Therefore, the choosing of the spraying mixture is another matter to be seen to immediately, if stocks .have not been procured already. There are two classes of pests with which we have to contend, viz., insects and fungous pests. There are three kinds of sprays, namely, insecticides, for combating insect pests, fungicides, for controlling fungous diseases, and combined sprays, which are mixtures combining the properties of the former two. Any one insecticide is not suitable for combating every insect pest, however, nor is every fungous pest controlled by any fungicide. Therefore, it is folly to use iany particular fungicide for all fungous pe and the same with regard to insects. It will be necessary, therefore, to procure all the sprays which will be required for the numerous pests.

Scale Insects. Scale insects may be found on various fruit trees, their presence being detected by the numerous scales to be found on the trees. There are several varieties of scale insects, but all are essentially the same. The insects live under the scales at one end and suck the sap of the tree. As winter approaches they lay eggs which are sheltered under the scales until they hatch in the spring. The mussel scale is one of the most common scale insects, and is to bo found on several different fruit trees. Its most popular host, however, is the apple, on some varieties of which it may be found in thousands. This scale derives its name from its shape, that of a mussel, in miniature. Cilrus trees are also common hosts of scale insects. The time at which control measures prove to be most effective is when the scales are full of eggs. A spray which will destroy the eggs will reduce the number of scales to almost, none. There may be a few eggs that are not destroyed and hatch into scales, but these may be treated later. It is obviously time that something was done in connection with the control of these pests. An excellent spray to use for this purpose is the caustic soda solution. This spray is of a caustic (burning) nature. On account of its caustic properties this spray must be handled carefully, for it burns anything with which it comes in contact. Should any get on the operator's hands or clothing apply water at osice. This will dilute the spray and lessen its effect. Making the Solution.

To make the caustic soda solution, dissolve lib. of caustic soda (obtainable from the grocer) in 1 gallon of water by stirring until all the soda is dissolved. Then add another 4 gallons of water. Next dissolve -<{ lb. soft soap in a little boiling water, and when this has completely dissolved, add i,t to the mixture and stir well. This is a comparatively new spray, but it is becoming very popular. The mixture is effective as it is, but it has been found that it can be made more effective still by the addition of gib. of carbonate of potash.

The caustic scda solution is effective in controlling several pests. It destroys the eggs of scale insects, as mentioned above, and also destroys the eggs of aphides which were laid in small crevices before winter. These will hatch in spring, and the foliage of the tree will soon become badly infested. Of course these may be controlled easily, but it is far better that the eggs should not be given any chance of hatching. Another good result which is brought about by the soda solution is that the trunk and main arms are cleaned of any mossy growths on them, which is most desirable. Whitewashing the trees also has the same,,effect, but it is much easier to clean them by spraying. For the San Jose scale on stone-fruits a spraying of red oil emulsion, of a strength of 1 in 15, may be made now. This spray is made by heating lib. of soft soap in , a gallon of red oil until all the soao is dissolved. Remove this from the fire and add 5 gallon of soft water. It is essential that the water is soft, for otherwise the oil will not emulsify. To soften hard water, add of carbonate of soda (washing soda). On the addition of the water the mixture must be stirred thoroughly. When it has emulsified more water may be added, the quantity depending on the. strength which is desired. In the present instance, 14£ gallons more should be added. Of course, it is not necessary to make such a large quantity of spray if it will not be needed. The quantities of all the constituents may be reduced as much as is desired as long as the proportions are kept. The final water should not be added until the oil has emulsified,, To ascertain whether it has formed ari emulsion, aliow it to stand a while. If the oil comes to the surface it has not yet emulsified and most likely the water requires softening. When tho mixture may be left for a considerable time without the oil rising it may safely be concluded that it has emulsified satisfactorily, and the bulk of the water may then be added.

Combating Leaf Curl. On trees on which woolly aphis was prevalent last year a spraying of red oil emulsion may be given now. This will help considerably to control this pest,, although it may bo checked easily later on by dabbing the white, fluffy patches with kerosene. However, seeing that the red oil is being used in any case, the apples and pears on which woolly aphis was bad might as well receive an application also, for it certainly is beneficial. Any application of red oil should be made, if possible, on a warm, sunny day, as the spray will then penetrate better into the cracks- and crevices. Stone fruits which were badly attacked by the leaf curl fungus last season should now receive an application of Bordeaux 3-8-40, to assist in preventing an attack in the forthcoming season. Bordeaux may be prepared in the following manner:— Three wooden'containers are required, one of which should be twice the capacity f»f either of the others. To make the formula mentioned above (8-8-40) 81b. of oluestone (copper sulphate), Sib. quick-

lime and 40 gallons of water are required. Such a large quantity may not be needed for a small orchard and so the quantities may be reduced proportionately. For example, to make 4 gallons of sprays powder jjlb. bluestone and suspend it in a cloth in one of the smaller containers in which there are 2 gallons of water. Slake Jib. of lime in the other small container, by gradually adding water until 2 gallons have been poured in. When the bluestone has dissolved in the water the two solutions should be stirred well and poured simultaneously through a strainer (a piece of sacking tied over the top) into the larger wooden vessel. Straining is essential in order to remove any insoluble substance, which, if left, would block the nozzle of the sprayer. A little stirring should be necessary, for although the solutions will have been mixed fairly well when they were poured in, the mixture does not remain an even solution for long. Test the mixture by dipping the blade of a knife into it for about a minute. If copper is deposited it will be necessary to add a little more lime, for there should never be an excess of copper sulphate. Bordeaux should be used soon after being made.