138 Report of the Botanist of the 



diagram showing method of determining the increase in 

 yield in salisbury experiment no. i." 



Row 1 ) 



" 2 ',- Sprayed 5 times. 



" 3 ^ ) 



4 f Sprayed once. 



" 5 I Not sprayed. 



6 - Sprayed once. 



" 7 



8 . Sprayed 5 times. 



Since Row 5 was the only one which had not been sprayed at all, 

 its yield should be taken as representing what the yield of the field 

 would have been had there been no spraying done. Rows 4 and 6, 

 although badly blighted, were evidently somewhat benefited by the 

 one spraying they received and remained green a little longer than 

 Row 5. Rows 3 and 7 appeared to suffer a little from being next 

 to the badly blighted Rows 4 and 6. For this reason it was thought 

 unfair to use them as representatives of the sprayed portion of the 

 field. Accordingly, one-half the combined yield of Rows 2 and 8 

 was decided upon as being the proper basis for comparison with the 

 yield of the unsprayed Row 5 for the correct determination of the 

 increase in yield due to spraying. 



Row 2 yielded 793 pounds and Row 8, 773 pounds, the average 

 being 783 pounds ; while Row 5 yielded only 466 pounds. Thus the 

 increase in yield due to spraying was 317 pounds per row which is 

 at the rate of 62^ bushels per acre. The yield of the sprayed rows 



"The yields were as follows: 

 Rows I and 3, combined, 1542 lbs. marketable, 43 lbs. culls. 



Row 2 793 " " 28 " 



Rows 4 and 6, combined, 1056 " " 67 " " 



Row 5 466 " " 43 " " 



Rows 7 and 9, combined, 1434 " " 42 " " 



Row 8 773 " " 33 " " 



Number of rows required to make an acre, 11.872. 



