SPRAYING DEMONSTRATIONS. 271 



trees in the demonstration orcliards. The lessened cost is due in part 

 to the use of somewhat cheaper materials (7 cents per pound for blue- 

 stone and 9 to 12 cents per pound for arsenate of lead), and doubtless 

 also in part to better arrangements for mixing the spray material and 

 getting it to the trees. An ample and convenient water supply was 

 provided in a large cistern and large elevated supply tank. The water 

 was discharged by gravity from the supply tank into two dilution tanks; 

 from them to a mixing tank, and from that to the spray tank or to the 

 tank of the "helper wagon" used to haul the spray mixture to the spray- 

 ing outfit in the orchard. The spraying outfit consisted of a Field Force 

 Pump Company's gasoline power sprayer, two leads of hose, two quad- 

 ruplex Vermorel nozzles. The spray was directed from an elevated plat- 

 form above the spray tank. 



EFFECT OF SPRAYING ON APPLE SCAB AND CODLING-MOTH. 



In all the orchards, careful records were made of the percentages of 

 wormy and scabby fruits on sprayed and unsprayed trees. In mid- 

 summer, preliminary observations of this sort were made in which ap- 

 proximately a fourth of the apples on three sprayed and three unsprayed 

 trees of several varieties in each of the orchards were examined and 

 the numbers of wormy fruits, scabby fruits, and fruits free from scab 

 and worms were determined. In the fall when the fruit was gathered, 

 an examination was made of all the picked fruits and windfalls from 

 about three sprayed and three unsprayed trees of most of the varieties 

 in the six demonstration orchards. The number of scabby fruits, wormy 

 fruits, and fruits free from scab and worms were again recorded. These 

 final records were obtained from 37 sprayed trees and 39 unsprayed ones. 

 Approximately 110,000 fruits were examined to get these records. 



The total number of fruits examined and the numbers and per cents 

 of scabby and of wormy fruits are given in the following table: 



