1908.] PUBLIC DOCUMENT — No. 33. 129 



The plots selected were those which were being used in the 

 agricultural department for testing the relative value of potash 

 compounds, 1 and for our purposes five of these were used. 

 With the exception of two plots, the standard Bordeaux mix- 

 ture formed the basis of the fungicides, the regular 4 — 4 — 50 

 formula being used. The plots were tested as follows : — 



Plot 1 was treated with Bordeaux and Paris green, 1 pound 

 of Paris green being added to 50 gallons of the Bordeaux. 



Plot 2 was treated with Bordeaux and " Disparene,'' or arse- 

 nate of lead, 5 pounds of "Disparene" being added to 50 gal- 

 lons of the Bordeaux. 



Plot 3 was treated with Bordeaux and sodium benzoate, 4 to 

 6 ounces of the sodium benzoate being added to 50 gallons of 

 the Bordeaux mixture. 



Plot 4 was treated with soda Bordeaux and Paris green, 

 1 pound of Paris green being added to the soda Bordeaux 

 mixture. 



The soda Bordeaux is made as follows : — 



Soda (commercial lye), ..... 2 lbs. 



Copper sulfate, ....... 6 lbs. 



Lime, y 2 to % lbs. 



Water, GO gals. 



The mixture was tested to insure its alkalinity, and the 

 amount of lime was modified according to the strength of the 

 lye. 



Plot 6 was treated with copper phosphate and "Disparene." 

 Copper phosphate is a compound prepared by the Bowker 

 Chemical Company, and is being tested as a fungicide. Our 

 formula is as follows : — 



Copper phosphate, ....... 5 lbs. 



"Disparene," ........ 5 lbs. 



Water, ......... 50 gals. 



The plots were sprayed July 6, when the sun was shining, 

 in the order given in the outline, the ordinary barrel spray pump 

 being used. No rain fell before the first observations were 

 made on July 11. The potato bug and flea beetle were present 



1 See report of the agricultural department, p. 39. 



