New York Agricultural Experiment Station. 139 



was 154 bushels and 55 pounds per acre and of the unsprayed row 

 92 bushels and 12 pounds. 



In order to determine how much Rows 4 and 6 had been benefited 

 by the single spraying given them, the combined yield of these rows 

 was taken and found to be 1056 pounds or 518 pounds each which 

 is greater than the yield of Row 5 by 62 pounds or at the rate of 12 

 bushels per acre. 



In order to determine how much Rows 3 and 7 had been injured 

 by the adjacent blighted Rows 4 and 6 the combined yield of Rows 

 I and 3 was compared with the yield of Row 2 ; and the combined 

 yield of Rows 7 and 9 compared with the yield of Row 8. The com- 

 bined yield of Rows i and 3 was 1542 pounds. Assuming that Row 

 I yielded the same as Row 2 the yield of Row 3 must have been 749 

 pounds or 44 pounds less than the yield of Row 2. Hence, the dam- 

 age to Row 3 was at the rate of 8% bushels per acre. Likewise, 

 assuming that the yield of Row 9 was the same as that of Row 8 the 

 yield of Row 7 must have been 661 pounds or 112 pounds less than 

 the yield of Row 8. Hence the damage to Row 7 was at the rate of 

 22 bushels per acre. These figures are of considerable interest be- 

 cause they show the unfairness of comparing the yield of an un- 

 sprayed row with that of an adjacent sprayed row. Such a com- 

 parison makes the increase in yield due to spraying appear to be 

 considerably less than it really is.i^'^ 



"a Some have expressed the opinion that when a single row in a field is 

 left unsprayed " bugs " and flea-beetles leave the sprayed rows and attack 

 the unsprayed row more severely than they would if no spraying were done. 

 Perhaps this sometimes happens, but we have seen no evidence of it. On 

 the contrary, in four of the business experiments it was very noticeable that 

 the unsprayed rows lived longer and suffered less from blight than did 

 the unsprayed fields in the same neighborhood. Consequently, we believe 

 that the actual gain from spraying was greater than the figures here given 

 show it to be. 



