75 



dividing line between these two plots, and the heavy horizontal line 

 marked with a zero stands for the average infestation of these plots 

 before the spraying was done. The plus-figures at the left of each 

 diagram indicate degrees of increase in the infestation of the check 

 plot during the season following, and the minus-figures denote degrees 

 of decrease of the infestation at the end of the season as a conse- 

 quence of the treatment received. The broken line running diagonally 

 across the diagram is drawn in a way to show, at the point where 



Fig. 2. — Diagram showing Transition Zone, Orchard I, between Check Plot 

 and Experimental Plot, Lime and Sulphur Treatment. 



Pig, 3, — Diagram showing Transition Zone, Orchard II, between Check Plot 

 and Experimental Plot, Lime and Sulphur Treatment. 



