PESTS AND DISEASES OF PLANTS 221 



Distillate Oil Mechanical Mixture. 



Water 200 gallons 



Caustic soda (95 per cent) 7 pounds 



Distillate (28 degrees Baume) 10 gallons 



Fill spray tank with the required amount of water ; add the distillate 

 and caustic soda, which has been dissolved in a small amount of water. 

 Keep agitator going rapidly while applying the spray. 



This spray has been thoroughly tested by the writer and is one of the 

 cheapest and best for spraying black scale or the European fruit Lecanium 

 on apricot and olive trees. 



Distillate Emulsion and Tobacco. 



Water 12 gallons 



Whale oil soap 30 pounds 



Distillate (32 to 34 Baume) 20 gallons 



This is the "Government Formula for Pear Thrips." The emulsion is 

 prepared in the ordinary way as a stock solution. For use in the orchard 

 dilute one to twenty parts of water. To every two hundred gallons of this 

 diluted spray add one pint of tobacco extract containing forty per cent 

 nicotine or about three and one half gallons of tobacco extract containing 

 two and three-quarters per cent nicotine. This spray is especially recom- 

 mended for pear thrips. 



Rosin Wash. 



Though not a true emulsion and fast losing prominence as a spray, 

 this wash is included here because of its value as a spray and dip for 

 plants with tender foliage. 



Rosin 10 pounds 



Caustic soda (76 per cent) 3 pounds 



Fish oil \ l / 2 pounds 



Water 50 gallons 



Put oil, rosin and a gallon of water in an iron kettle and heat until 

 the rosin is softened; add the caustic soda (dissolved in a small amount of 

 water) and stir thoroughly, after which add enough water to make fifty 

 gallons of spraying material. 



This wash is only effective for young scale insects, plant lice, or other 

 soft-bodied insects. 



Soap Washes. 



A simple and easily prepared spray for use in small gardens is made 

 from soap as follows : 



Whale oil or hard laundry soap 1 pound 



Water 5 gallons 



The soap is first dissolved in a small amount of hot water and the 

 remainder added afterward. This spray will not injure tender plants or 

 foliage, and is recommended only for young scale insects, plant lice and 

 other soft-bodied insects. 



