400 PEAR GROWING IN CALIFORNIA. 



CHAPTER XVII. 



INSECTICIDES AND FUNGICIDES. 



The treatment of pear trees for the various insect pests and diseases 

 that affect them at certain times requires the use of a number of ditler- 

 ent kinds of insecticides and fungicides. These, with formuhis, methods 

 of preparation and general directions for use, are discussed. 



CONTACT INSECTICIDES. 



Lime-sulphur (commercial). 



Lime-sulphur (homemade) . 



Nicotine (tobacco decoction, sulphate of nicotine, tobacco du.st, etc). 



Kerosene emulsion. 



Distillate emulsion. 



Crude oil emulsion. 



;\Iiscible oil. 



Sulphur (sublimed, atomic, milled, soluble, etc). 



Whale-oil soap (fish oils). 



Caustic soda. 



Distillate emulsion and tobacco (Government pear thrips formula). 



POISONOUS INSECTICIDES. 

 Arsenate of lead. 

 Paris green. 

 Arsenite of zinc. 



FUNGICIDES AND GERMICIDES. 

 Bordeaux mixture. 

 Lime-sulphur (commercial) . 

 Lime-sulphur (homemade) . 

 Lime-sulphur (self-boiled). 



Sulphur (sublimed, atomic, milled, soluble, etc.). 

 Bichloride of mercury. 



Formalin. 



Hydrocyanic acid gas. 

 Carbon bisulphide gas. 



Bordeaux mixture. 



Whitewash. 



Lime-sulphur. 



FUMIGANTS. 



REPELLANTS. 



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