DISEASES AND THEIR CONTROL 133 



Copper carbonate 5 ounces 



Ammonia (26 Baume) 3 pints 



Water _ 50 gallons 



Dilute the ammonia with water to about five times its 

 volume. Make a thin paste of the copper carbonate with 

 a small quantity of water, and add this to the ammonia 

 by constant stirring. After diluting to 50 gallons of 

 water the mixture is ready for application. It should be 

 used as promptly as possible because the ammonia 

 evaporates rapidly. 



Potassium sulphide or liver of sulphur is sometimes 

 employed in the greenhouse, especially when it is desir- 

 able to avoid the discoloration of the foliage. From 

 three to five ounces of potassium sulphide is used to 10 

 gallons of water. 



Sulphur is sometimes applied as a dust over the plants 

 for the treatment of mildews. 



