64 



THE TROPICAL AGRICULTURIST, 



[JULV I, 1S85. 



2 gallons ; common soap or wliale oil soap, J lb. ; water, 

 1 gallon. " Heat the solution of soap, " the directious state, 

 "and add it boiling hot to the kerosene. Churn the 

 mixture by means of a force pump and spray nozzle 

 for five or ten minutes. The emulsion, if perfect, forms 

 a cream, which thickens on cooling, and should adhere 

 ■without oiliness to the surface of glass. Dilute, before 

 using, one part of the emulsion with nine parts of cold 

 water. The above formula gives 3 gallons of emulsion 

 and makes when diluted, thirty (,30) gallons of wash. 

 The percentage of oil can be increased considerably 

 without danger to the plant, and a stronger emulsion, 

 may, in fact, be required in coping with some of the 

 Aspidiottis scales, but the amount of kerosene in the 

 emulsion cannot be greatly reduced without weakening 

 too much its power as an insecticide. The amount of 

 soap may also be varied, but less than J lb. to the 

 gallon of water forms an unstable emidsion. " 



The distrust of kerosene felt at the outset, it is stated 

 has now given place to confidence, and the emulsions are 

 now widely used by orange growers in eastern Florida. 

 Want of thoroughness in applying the wash, however, is 

 found to render repeated .applications necessary. The 

 invention and introduction of what is called the cyclone 

 nozzle by the Department of Agriculture greatly diminishes 

 the labour of applying the liquid to orange trees and 

 insures success with ordinary care and attention, at the 

 same time reducing to a minimum the amount of liquid 

 required and the expense of an application, and there is 

 no report of any case of loss or permanent injury resulting 

 from the use of kerosene enmlsions, although the reckless 

 use of emulsions imperfectly formed, or of unnecessary 

 strength, it is noted, may be expected to cause defoliation 

 and a temporary shock of greater or less severity. It is 

 indeed the opinion of a majority of the Florida growers 

 that in kerosene properly emulsified and diluted they 

 have a nearly perfect remedy, more effective than any 

 other insecticide in destroying scale insects and having 

 as slight an effect upon the plant as can probably be 

 expected from any remedy with sufficient penetrating 

 power to reach and kill the eggs of these insects. 



In regard to the physiological action of kerosene upon 

 the orange, cai-eful observations are reported as having 

 been made during the year, and the following conclusions 

 arrived at:— 1st. That kerosene dififers from most other 

 remedial agents in being entirely harmless to tender young 

 growth, blossom buds, and young fruit. It may, there- 

 fore be applied to bearing trees at seasons when other 

 insecticides would cause more or less loss of growth or 

 of fruit. 2nd. That the shock produced by an overdose is 

 felt more severely upon devitalized portions of the plant, 

 and is not appreciable where there is full vigor. This 

 shock is quickly followed by a healthful reaction, and is 

 not ordinarily attended with any serious consequences, 

 such as hardening of the bark. 3rd. That extremes 

 of heat and cold increase, sometimes to an injurious 

 extent, its action upon the plant. Applications made 

 in the hot sun, during the middle of the day, are observed 

 to cause a greater amount of defoliation than would result 

 from the same application made at evening or in the 

 shade. In winter, when the air is charged with moisture 

 and the nights are- cold, with frost or heavy dews, it 

 is found that the oil does not evaporate as rapidly as 

 iu warm or dry weather. Applications made under sucli 

 atmospheric conditions sometimes prove unexpectedly 

 severe and cause the tree to shed all its leaves or eveu 

 kill a portion of its branches. The most favorable season 

 for applying kerosene washes is agreed upon as being 

 early iu spring or as soon as all danger of frost is past. 

 The shedding of the last year's leaves, which takes place 

 naturally after the orange tree has renewed its foliage 

 in spring, is often accelerated by the action of the oil, 

 which is thus nuide to appear very severe, but the loss 

 of old and devitalized leaves is regarded of slight consequence, 

 and iu the case of badly infested trees is a positive advant- 

 age, as the leaves iu falling carry with them the scales 

 most difficult to reach with insecticides. 



In dealing with an enemy so thoroughly protected as 

 are many of the bark lice, the lic|uid insectiuides, it is 

 recommended, should be applied in as fine a spray as 

 possible, or at least in moderately fine spray, driven witL 

 couBiclei'al)l« forco iu order to iucrewe to tlio utmost 



their penetrating power. The aim should also be to 

 reach and thoroughly wet every portion of an infested 

 tree, so that no individual scale insect shall escape the 

 action of the liquid. This result was not fouud attainable 

 by the old method of sending a jet from a distance into 

 the tops of the trees, and an ordinary garden syringe is 

 practically useless. There is needed a force pump aud a 

 hozzle giving a fiuely atomised .spray. This nozzle, it is 

 noted, should be attached to a sufficient length of flexible 

 hose, to allow it to be introduced into the top of the 

 tree. The orifice of the nozzle, it is explained, should 

 be directed at a right angle to the hose, and not in line 

 with it, so that the jet of spray may thus by a turn of 

 the wrist be directed upward or downward, and brought 

 into contact with all parts of the foliage and branches, 

 from beneath as well as from the upper side. 



The Cyclone nozzle, which answers the above conditions 

 and is easily attached to any force pump, is described 

 as consisting of a "shallow, circular, metal chamber soldered 

 to a short piece of metal tubing as an inlet. The inlet 

 passage penetrates the wall of the chamber taugentially, 

 admitting the fluid eccentrically, and causing it to rotate 

 rapidly in the chamber. The outlet consists of a very 

 small hole drilled in the exact centre of one face of the 

 chamber. The orifice should not be larger than will 

 .admit the shaft of an ordinary pin, Through this outlet 

 the fluid is driven perpendicularly to the plaue of rotation 

 in the chamber. Its whirling motion disperses it broadly 

 from the orifice, and produces a very fine spray, which 

 may be converted into a cloud of mist by increasing the 

 pressure in the pump. The perforated face of the nozzle 

 chamber is removable for convenience in clearing the 

 orifice when it clogs. The diameter of the chamber inside 

 need not exceed J inch, and its depth J inch. A nozzle 

 of these dimensions attached to an Aquapult pump covers 

 1^ square yards of surface at a distance of 4 or 5 feet 

 from the orifice. The amount of dispersion depends some- 

 what upon the thickness of the perforated face of chamber. 

 The diameter of the cone of spray may be increased by 

 countersinking the exit hole and making its edges thin. 

 Half inch gum tubing is sufficiently large to supply one 

 or a gang of several nozzles. The tubbing must be 

 strengthened with one ply of cloth. " In use, the end 

 of the hose is supported by being fastened to a light rod 

 of wood, which forms a han.lle, by mea is of w-hich the 

 nozzle may be applied to all parts of the tree. For full 

 sized trees a rod long enough to reach nearly to their 

 tops must be used. For this purpose, a conveuient device, 

 it is explained, may be made by passing the small rubber 

 hose through a hollow bamboo rod of the required length, 

 and a three-sixteenth brass tube inserted in a bamboo 

 rod has also been used. 



The following is the estimated cost for a standard was'' 

 of whale oil soap and kerosene emulsion containing 67 per 

 cent, of oil, aud diluted 1 to 9 ; Kerosene, 2 gallons, retail 

 at 20 cents, 40 cents; soap, J lb., retail at 10 cents, 5 

 cents; water,! gallon; emulsion, 3 gallons: total cost, 45 

 cents, or 1-5 cents per gallon. One gallon of emulsion 

 will make 10 gallons of diluted wasli ; cost lo cents. 

 Cost of wash per gallon, IJ cents. With the Aquapult 

 pump and Cyclone nozzle, 4 gallons of wash is sufficient 

 for thirty nursery trees of one aud two years from the 

 bud. Cost per tree, two-tenths cent. Trees which have 

 been transplanted and have made two years' average 

 growth in the grova (three or four years "from the bud), 

 it is stated, require about two-thirds of a gallon of wash, 

 Cost, 1 cent per tree. Bearing trees of full size will 

 require from 5 to 10 gallons of wash. Cost, 7 to 1 5 cents 

 average about JO oeuts per tree.— Melbourne Leader. 



Or.vnherriks.— Although nmch of this fruit is impnrted 

 into this country, notably fi-oni America, its cultureniight be 

 profitably imdertaken in naturally suitable places at home, 

 Much swampy land still exists tliatniight be turned to such 

 a use. Where the soil isnaturally damp and rsts on a bed 

 of porous material and there is free circulatiou of air, the 

 American Cranl berry (O.xycoccus macrocarixi) grows quite 

 Ittsutisutly.— ea)'d(ne«' Ohromcle, 



