THE ORCHARD.

New Zealand Mail, Issue 1160, 25 May 1894, Page 7

THE ORCHARD.

SOME USEFUL INSECTICIDES. HOW TO MAKE AND APPLY THEM. The insects which attack and destroy farm and garden crops are too numerous to detail, and while their effectual destruction can best be attained by a special treatment for each variety, a general grouping of the species and a general form of treatment may be attempted. Indeed, for all but exceptional cases this is all that is really practicable or profitable. The following recipes and information, gleaned chiefly from American works on the subject, published by the Department of Agriculture, will interest farmers who have neither the time nor opportunity to consult lengthy scientific treatises: KEROSENE EMULSION. This insecticide is recommended for destroying non-masticating insects, such as plant lice and scale insects. Kerosene emulsion may be made the basis of various emulsifying agents, but the most satisfactory substances and those most available to the average farmer

and fruit-grower are milk and soapsuds. In each of these cases the amount of the emulsifying agent should he one-half the quantity of kerosene. One of the most satisfactory formula is as follows : Koroseno ... ... ... 2gah Common soap ilb. Wator 2 gal. Heat the solution of soap and water, and add it boiling hot to the koroseno. Tho emulsion, if perfect, forms a cream which thickens upon cooling, and should adhere without oiliness to the surface i of glass. For use against scale-insects dilute one part of the emulsion with ! fifteen parts of water. For soft insects | like plant lice from 20 to 25 parts of j water may he added. The milk emulsion is made in the same way as the above. TIIE RESIN WASHES. These washes are also used for detroying scale and other insects by forming an impervious coating which effectually smothers the insects treated. A formula recommended for red and yellow scale is made of the following ingredients : Rosin ... ... ... 181 b. Caustic soda ... ... 51b. Fish oil ... ... ... 2£ pints. Water (to make) ... ... lOOgal. 'The various substances are placed in a kettle and cold water added to cover them ; they are their boiled until dissolved, being ocasionally stirred in the meantime, and after the materials are dissolved the boiling should be continued for about an hour, and a considerable degree of heat should be employed, cold water being added in small quantities to keep the preparation from boiling over. When boiled sufficiently it will assimilate perfectly with water, and should then be diluted with tho proper quantity of cold water, adding it slowly at first, and stirring occasionally during the process The un diluted preparation is pale yellowish in colour, but by the addition of water it becomes a very dark brown. Before being sprayed on the trees it should b© strained through a fine sieve or muslin cloth, and this is usually accomplished when pouring tho liquid into the spraying tank. This insecticide may bo applied at any time during the season. In obdurate cases, wliero the scale is move difficult to subdue, the quantities of resin, soda, and oil employed may be doubled. The strong preparation should, however, only be appliec in winter during the dormant period ; applied in the growing season it wil cause tho loss of foliage and fruit. In using these washes a very fine spray is not essential, as the object is not simply to wet the tree, but to thoroughly coat it over with tlife compound, anc this can be best accomplished by the use of a rather coarse spray, which can be thrown upon the tree with considerable force. FOR SUBTERRANEAN INSECTS. Recent experiments have shown the practical value of the resin compounds against the phylloxera and other underground insects. The cheapest, and one of the most satisfactory compounds used in America is the following : Caustic soda 51b. Rosin 401 b. Water (to make) 50gal. Dissolve the soda over fire with four gallons of water, add the resin, and after it is dissolved and while boiling, add water slowly to make 50 gallons of compound. For use dilute to 500 gallons, 1 xcavate basins above the vines six inches deep and about two feet in diameter, and apply to each vine five gallons. '1 he results will be more satisfactory if the treatment is made in the winter, so that the rain will assist in disseminating the wash about the roots. LONDON PURPLE, PARIS GREEN, AND WHITE ARSENIC. These poisons are serviceable against all maiulibulate insects, as larvae and beetles, and they furnish tho most satisfactory means of controlling most leaf feeders, and the best wholesale remedy for the codlin moth. Caution must be used in applying them on account of burning or scalding the foliage The poisons should be thoroughly mixed with water at the rate of from one pound to 100—250 gallons water, and applied with a hand-spray nozzle or force pump. In preparing the wash it wil! be best to first mix the poison with a small quantity of water, making a thick batter, and then dilute the latter before using. When freshly mixed, either London purple or Paris green may be applied to apple, plum, and other fruit trees, except the peach, at the rate of lib to 150—200 gallons, the latter amount being recommended for the plum, which is more susceptible to scalding than the apple. White arsenic does little, if anv, injury, at the rate of lib to #

50gal of water. When al'owed to stand, however, for a week or two, the white arsenic acts with more energy, scalding, when used at tho rate of lib to lOOgal, from 10 to 90 per cent, of the foliage ( the action of tho other aisenites remains practically the same, with perhaps a alight increase in strength in the case of London purple. By the addition of a little lime to the mixture, London purple and Paris green may be safely applied at tho rate of lib to 125 —l5O gallons of water to the peach, or tho tenderest foliage. With the apple in spraying for the codlin moth, at least two applications should be made the first on the falling of tho blossoms, the apples being about the size of peas, and the second a week later ; but the poison should never be applied after the fruit turns down on the stem, on account of the danger of the poison collecting and remaining permanently in the item cavity. . , Great care is necessary, both in the making and application of these insecticides, and all of them should be first used in a comparatively high dilution. Fruit trees should not be prayed with arsenical poison before the blossoms fall, on account of the danger of poisoning honey bees.