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CHEMISTRY OF FARM PRACTICE 



They are more expensive than self-boiled lime-sulphur, and 

 about equally effective. Their advantages are that they are 

 more easily prepared and that they leave less residue upon 

 both fruit and foliage. 



FIG. 74. Gasoline power spray. (Bulletin 243, U. S. Dept. Agr.) 



Copper sulphate (CuSCU) is used as a dormant spray for 

 certain types of fungus diseases of plants. A notable 

 example of this is its use in connection with the control of 

 peach leaf curl. It is one of the most toxic of fungicides, 



