752 



EXPERIMENTAL FARMS 



7 GEORGE V, A. 1917 



Summary. 



CALCIUM CHLORIDE ADDED TO SOLUBLE SULPHUR TO PREVENT FOLIAGE INJURY. 



For the purpose of comparing the value of calcium chloride (chloride of lime) 

 with barium chloride as a substance suitable for use in a soluble sulphur arsenate 

 spray mixture, to prevent burning of the foliage caused by the combination formed 

 when arsenate of lead is mixed with soluble sulphur, tests similar to these with barium 

 chloride were made only in a much more limited way. The tests were made at Berwick, 

 using three King trees of uniform size to each plot and each were sprayed four times 

 in the same way on the same dates. The plots were carefully examined after each 

 application and the only injury detected was that shown on the plot where one-half 

 pound was used. 



This injury was confined entirely to the first spray ariH no injury could be detected 

 from later sprays. The other plots were entirely free from foliage injury. It would 

 appear that calcium chloride is much more valuable than barium chloride for over- 

 coming soluble sulphur arsenate injury to foliage. Calcium chloride has a commer- 

 cial value of from 10 to 15 cents per pound. It is a powder and is added to the soluble 

 sulphur arsenate spray in this form. One and one-half pounds of soluble sulphur^ and 

 5 pounds Swifts arsenate of lead was used to each 100 gallons of water and to this 

 the various amounts of calcium and barium chloride were added. 



SOLUBLE SULPHUR WITH AND WITHOUT ARSENATE OF LEAD. 



In order to find out whether soluble sulphur alone would cause injury to foliage 

 tests were conducted on Gravenstein trees at Berwick. Three trees were used to each 

 test and the material was applied at the same dates under uniform conditions. Dupli- 

 cate tests on adjoining plots of the same variety were made with Swifts arsenate of 

 lead paste added to the soluble sulphur at the rate of 5 pounds per 100 gallons. It 

 will be noticed that a slight injury was detected on the plot where 2^ pounds was used 

 to 100 gallons without the arsenate. This injury was confined to the third spray 

 June 14, and was the only injury noticed. It will be seen, therefore, that the injury 



Kextville. 



