250 AGRICULTURE 



The copper sulphate is the active agent in killing the 

 fungi, while the lime prevents injury to the plant. Besides 

 this "4-6-50" mixture, other formulas frequently used are 

 of the proportions 4-4-50, and 5-5-50. 



Making the mixture. When but a small amount of 

 spraying is to be done the only equipment required for 

 making Bordeaux mixture is a fifty-gallon barrel, two twen- 

 ty-five gallon tubs, buckets and a fine-mesh sieve. 



Fill one of the smaller tubs with water, and suspend 

 just below the surface four pounds of copper sulphate in a 

 loose bag, giving it time to dissolve. This will require 

 about an hour, though the process can be hastened by using 

 hot water. Slake six pounds of lime in the other tub, us- 

 ing hot water and reducing the lime to a paste. When the 

 lime has cooled, dilute to twenty-five gallons. 



Now stir the contents of the tubs, and pour bucketfuls 

 of each mixture simultaneously through a sieve into the 

 larger barrel, making sure that the streams mix. Stir well, 

 and the compound is ready for the spraying machine. 



Use. The amount needed for a garden can be judged 

 from the fact that a tree in full leaf and having a spread 

 of twenty-five feet will require about four gallons of the 

 mixture. Most beginners use too little, hence fail to 

 get the best results. 



Bordeaux mixture is not effective against insects. If, 

 however, arsenate of lead in the proportion of two pounds to 

 each barrel of the mixture be combined with it, the com- 

 pound will serve as a check on both insects and fungous 

 diseases. Scab, apple blotch, bitter rot, wilt, mildew and 

 brown rot are controlled by Bordeaux mixture. 



2. Lime-Sulphur Mixture 



The lime-sulphur mixture, besides being an insecticide 

 for certain plant insects, is also a fungicide serving the same 



