258 T'he Philippine Journal of Science i9i£ 



as the Bordeaux mixture. The results obtained with this spray 

 are about on a par with Bordeaux mixture. 



Materials. 



Copper sulphate (blue vitriol) , kilos 1.4 



Sodium carbonate (salsoda), kilos 1.65 



Water, liters 190 



PREPARATION 



1. Dissolve each chemical separately in 95 liters of water. 



2. Mix by pouring the two solutions into a third container as in making- 



Bordeaux mixture. 



3. Apply with a good pressure spray pump as soon as the solution is 



prepared. 



SODA BORDEAUX MIXTURE 



It may be impossible in certain sections to obtain good stone 

 lime. If this be the case, soda Bordeaux mixture can be 

 used. Soda Bordeaux mixture will not color the foliage and 

 fruit to such an extent as the Bordeaux mixture. The soda 

 Bordeaux mixture is more expensive and should be used only in 

 cases where it is impossible to prepare the real Bordeaux. 



Materials. 

 Copper sulphate (blue vitriol), kilos 1.8 



Commercial caustic soda (sodium hydroxide), kilos .6 to 1 

 Water, liters 190 



APPARATUS 



The same as that used in the preparation of Bordeaux mixture. 



PREPARATION 



1. Dissolve 1.8 kilograms of copper sulphate in hot water, place in half- 



barrel, and add water to make 95 liters. 



2. Dissolve the caustic soda in the proportion of 0.6 kilogram to 4 liters 



of water. 



3. Gradually pour the caustic soda solution into the copper sulphate 



solution, stirring continuously, until the solution becomes alkaline. 

 The exact amount of caustic soda to use cannot be given because 

 of the great variation in strength of the commercial product. The al- 

 kalinity of the solution can be determined by dipping a piece of red 

 litmus into the solution. The red litmus will turn blue when the 

 mixture is alkaline. 



4. Add enough water to make 190 liters and stir vigorously. 



5. Strain the mixture into a spray tank and apply as indicated under 



Bordeaux mixture. 



AMMONIACAL SOLUTION OF COPPER CARBONATE 



In cases where it is desirable to prevent staining the foliage 

 or fruit of plants, the ammoniacal solution of copper carbonate 

 is recommended. 



