New Yoek Agriculttteal Experiment Station. 227 



chemicals and wear of machinery. In each experiment a strip 

 of a few rows was left unsprayed for comparison. 



'^ Spraying," as used in this bulletin, means the application of 

 bordeaux mixture exclusively. The application of paris green or 

 arsenite of soda in lime water is not called spraying. 



Whenever '' arsenite of soda " is mentioned it should be under- 

 stood to mean the stock solution prepared by the Kedzie formula 

 — ■ one pound white arsenic, four pounds sal soda and one gallon 

 of water boiled together twenty minutes. 



By " test rows " is meant the rows used in determining the 

 amount of the increase in yield due to spraying. These are, 

 usually, the middle unsprayed row and the second sprayed row 

 on either side. 



Unless otherwise stated, the yields given are for marketable 

 tubers only. 



The price used in computing the value of the increased yield 

 is, in every case, the market price for potatoes in the locality 

 where the experiment was made on the date on which the test 

 rows were dug. 



In ten of the experiments a few rows were double-sprayed ; that 

 is, at each spraying these rows were treated twice. The object of 

 this was to determine whether more thorough spraying would be 

 profitable. 



