126 



THE OLIVE 



should be cut away till the sound wood is reached and this should 

 be well spread with grafting wax. 



INSECTICIDES. 



If the orchard is sprayed once a year it will be sufficient, and the 

 best time is in the winter after all danger from frost has passed. 

 Whale oil soap is an excellent remedy but it has not the efficiency 

 of kerosene. It will kill the coccids but has no effect upon their 

 eggs. Kerosene pure and simple would be a dangerous and entirely 

 unnecessary remedy to use, but diluted ten times with water it be- 

 comes much less expensive and by far the most efficacious. 



The United States Department of Agriculture has published the 

 following recipe to make thirty gallons of wash. 



EMULSION. 



Kerosene, 2 gallons 67 per cent, 



Whale oil soap, h pound 

 Water, 1 gallon 



Boil the soap in the water till entirely dissolved then add it to 

 the two gallons of kerosene, and churn the mixture thoroughly for 

 five or ten minutes. The emulsion if perfect forms a cream which 

 thickens on cooling, and should adhere without oiliness to the sur- 

 face of glass. Any danger in the use of kerosene lies in the faulty 

 or half-made emulsion. The soap may be of insufficient strength 

 through exposure or some similar cause, when an increase will 

 oblige the oil and water to emulsify, and will also make the emul- 

 sion nearly permanent. 



The percentage of kerosene should not exceed eighty per cent,, as 

 the oil weighs six and a half pounds to the gallon, while water 

 weighs eight, and more cannot easily be held in suspension in water. 

 On the other hand in the process of emulsification, kerosene loses 

 a portion of its value as an insecticide, and emulsions containing 

 less than thirty per cent, of oil, although they may not separate 



33 per cent. 



