34 Eeport of the Acting Director and Chemist of the 



yield. The proportion of culls was largest on plot 1, where no 

 fertilizer was used ; though on plot 26, where no fertilizer was 

 used, the proportion of marketable potatoes was larger than on 

 plot 1. In most cases the fertilizer increased the marketable quality 

 of potatoes even when it did not afl'ect the yield in bushels. 



5. Relation of Yield of Potatoes to Cost of Fertilizers 



Used. 



The essential point to be considered is the cost of production. 

 The increase of yield may be misleading. We must know how 

 much it costs us to increase our production before we can determine 

 whether the increase is made at a profit or loss. 



In the following table, we give the cost of fertilizer used for each 

 bushel of potatoes produced and also the cost for each bushel pro- 

 duced as compared with, the plots on which no fertilizer was used. 

 We call the average yield of plots 1 and 26, 151|- bushels, this being 

 the yield wliere no fertilizer was used. 



* Loss. 



