72 



called the ratio of benefit.* In the following table both these ratios 

 are shown for Orchard II, but the ratios of benefit are not given for 



Etherton Orchards, 1907-08 

 Orchard I 



Treatment 



None (check) 



Lime-Sulphur 



15 L., 15 S., 50 W. 



Eex Lime-Sulphur, 

 1 part; water, 11 



Target Brand, 



1 part; water, 20 



Scalecide, 



1 part; water, 20 



Date 



Nov. 19 

 March 11 



Nov. 19 

 March 11 



Nov. 23 

 March 11 



Nov. 23 

 March 12 



Loss 



(— ),or 



gain 



(+) 



—2.058 

 +2.6 



4-2.85 



+1.5 



+1.7 



Perct. i„ 

 oflosslPe^j^^- 



or I «^ 

 gain benefit 



—32.9 

 +31. 

 +34.4 

 +20. 



-4-28.8 



Orchard II 



None (check) 



Lime-Sulphur 



15 L., 15 S., 50 W. 



Eex Lime-Sulphur, 

 1 part; water, 11 



Target Brand, 



1 part; water, 20 



Scalecide, 



1 part; water, 20 



Lime-Sulphur 



15 L., 15 S., 50 W. 



Rex Lime-Sulphur, 

 1 part ; water, 11 



Target Brand, 



1 part ; water, 20 



Scalecide, 



1 part; water, 20 



53.8 



50.6 



48.6 



53.3 



61.1 



61.5 



50. 



53.7 



h — a 



*The following is a convenient formula for use in this computation: 



c + c — d 



= 0"; a being the degree of original infestation of the check 



b — -a 



• c -\- c 



a 

 plot; b, the final infestation of that plot; c, the original infestation of the 

 experimental plot; d, the final infestation of the same; and x, the ratio of 

 benefit. 



