New York Agricultural Experiment Station. 



499 



three portions which we shall call Plots I, II, aiid III. The soil 

 was uniform throughout. The three plots were planted on the 

 same day, with the same variety of potato, Michigan Rose, treated 

 with the same quantity of fertilizer, 1,825 lbs. per acre, and 

 given the same cultivation. 



Plan of Exprrimental Field. 



Spraying was begun June 4, when the plants were from 6 to 

 8 inches high, and repeated at intervals of about two weeks, until 

 Plot I had received five applications and Plot III three applica- 

 tions. Plot II was not sprayed. The last application to Plot 1 

 was made Aug. 2. 



The Bordeaux mixture used was made according to the 1 to 7^ 

 formula, that is, six pounds of copper sulphate to forty-five gal- 

 lons of water, with sufficient lime to neutralize the copper sul- 

 phate. When Paris green was used it was used at the rate of 

 three-fourths of a pound to forty-five gallons of the mixture. 

 The first application was made with a knapsack sprayer; all the 

 others were with a horse nia<'hine. 



The difference in the treatment of the th^ee plots will be made 

 clearer by the following table: 



1st spraying 



Plot I. 



Plot II. 



Plot III. 



Bordeaux mixture Paris green in lime i Bordeaux mixture 

 and Paris green. | water. and Paris green. 



