32 PLANT DISEASES 



From amongst the numerous solutions and powders that 

 have been experimented with, the following have proved 

 most effective : — 



Solutions 



(i) Bordeaux mixture. 



(2) Ammoniacal solution of copper carbonate. 



(3) Solution of potassium sulphide (liver of sulphur). 



(4) Solution of iron sulphate. 



(5) Solution of potassium permanganate ( = Condy's fluid). 



(6) Paraffin. Formalin. Lysol. 



Powders 

 (i) Sulphur. 

 (2) Quicklime. 



Bordeaux Mixture. — This substance is universally 

 admitted to be the most effective fungicide known. Its 

 various advantages are indicated as follows by Professor 

 B. T. Galloway of the United States Department of Agri- 

 culture : (i) Its thorough effectiveness as a fungicide; 

 (2) its cheapness ; (3) its safety from a hygienic standpoint ; 

 (4) its harmlessness to the sprayed plant ; and (5) its 

 beneficial effects on plants other than those resulting from 

 the mere protection against the attacks of parasites. 



The same high authority gives the following improved 

 method of preparing Bordeaux mixture : — 



'All things considered, it is beUeved that the best 

 results will be obtained from the use of what is known as 

 the 50-gallon formula of this preparation. This contains : 



Water . . . .50 gallons. 

 Copper sulphate . . 6 pounds. 

 Unslacked lime . . 4 pounds. 



