14 



mant trees and plants) use respectively about 2^ and 1§ gallons 

 of water for each 1 gallon of stock emulsion. Agitate the mixture 

 in all cases, after adding the water. The preparation of the emul- 

 sion will be simplified by the use of a naphtha soap. No heat will 

 be required, as the kerosene will combine readily with the naphtha 

 soap, in water, when thoroughly agitated. Double the quantity of 

 naphtha soap given in the above formula, however, will be required, 

 and soft or rain water should be used in making the emulsion. In 

 regions where the water is ''hard," this should first be broken with 

 a little caustic potash or soda, as common lye, before use for dilution, 

 to prevent the soap from combining with the lime or magnesia present, 

 thus liberating some of the kerosene, or rain water may be employed. 



Crude petroleum emulsion. — Crude petroleum emulsion may be 

 prepared in identically the same way as described for kerosene 

 emulsion, substituting crude petroleum for kerosene. The grade of 

 crude petroleum employed in the East is that known as "insecticide 

 oil," having a specific gravity of 43° to 45° Baume. The same 

 dilutions for winter and summer spraying should be observed as 

 stated for kerosene emulsion, but it should be noted that for summer 

 treatments of trees in foliage the kerosene emulsion is preferable, 

 as it is less likely to cause injury. 



Whale-oil soap wasli. — There are several brands of whale-oil soap 

 on the market. Potash soap is preferable, and it should not contain 

 over 30 per cent of water. For spraying dormant trees the soap is 

 dissolved in hot water at the rate of 2 pounds to each 1 gallon, and 

 spraying should be done before the wash cools, otherwise it is forced 

 through the nozzle with difficulty. For spraying trees in foliage 

 use the soap at the rate of 1 pound to 3 or 4 gallons of water, or even 

 weaker. 



Lime-sulphur wash. — Lime-sulphur has become the main reliance 

 in spraying orchards infested with the San Jose scale, and is effective 

 in controlling numerous other insects and is valuable for certain 

 fungous troubles. The following formula is used only on dormant 

 trees : 



Stone lime pounds^.. 20 



Sulphur (flour or flowers) do 15 



Water to make gallons. . 50 



Heat in a cooking barrel or vessel about one-third of the total 

 quantity of water required. When the water is hot add all the lime 

 and at once add all the sulphur, which previously should have been 

 made into a thick paste with water. After the lime has slaked, 

 about another third of the water sliould be added, preferably hot, 

 and the cooking should be continued for an hour, when the final 

 dilution may be made, using either hot or cold water, as is most con- 



[Clr. 121] 



