AGRICULTURAL EXPERIMENT STATION. 109 



was about as well protected as any."* It is probable that this 

 disagreement is due, as before suggested, to the character of the 

 varieties used in the trial. 



From the experiments of Cookf and Bailey J the conclusion is 

 reached that Paris green is much less liable to injure the foliage 

 than is London purple. London purple is exceedingly variable in 

 composition, and frequently contains large amounts of soluble 

 arsenic — in some cases as much as 40 per cent. The presence of 

 soluble arsenic is specially dangerous to foliage. 



Summary. 



1. All sprayed trees had a smaller percentage of wormy- 

 fruit than did the unsprayed. 



2. A mixture of one pound Paris green in 250 gallons water 

 gave better results than did a weaker mixture ; but 



3. A mixture of 1 pound to 320 gallons, applied once, saved 

 a large percentage of the fruit. 



4. The number of windfalls was greatly lessened by 

 spraying. 



5. The proportion of wormy fruit among the windfalls was 

 much smaller from the sprayed trees. 



6. A large proportion of the wormy fruits from sprayed 

 trees is entered from the side or base, while in fruits from 

 unsprayed trees, the entrances at the calyx are largely in 

 excess. 



7. There is no danger from the use of fruit which has been 

 sprayed as directed. 



8. The best time to spray probably varies with different 

 varieties, but in no case should any trees be sprayed before 

 the blossoms fall. 



9. The difference in the opinions of experimenters as to 

 the proper time for spraying, is probably due to well known 

 characteristics of different varieties. 



10. There is greater liability to injury of foliage from the 

 use of London purple than from the use of Paris green. 



* Bulletin 7, Iowa Experiment Station. 



| Bulletin 53, Michigan Experiment Station. 



% Bulletin 18, Cornell University Experiment Station. 



