Diseases and Pests of the Apple and Their Control 231 



under pressure of 200 to 300 pounds. The grower can 

 profitably study the different makes of power sprayers 

 before making a selection. Before buying he should insist 

 on seeing a thorough orchard demonstration of the model 

 in question. 



No other one new device since the power sprayer was 

 invented has met with such general interest as the spray- 

 gun, for which the fruit industry is indebted to John Hull 

 of Gasport, New York. The idea has been developed by 

 a number of manufacturers. The gun consists of a short 

 metal rod attached to the end of a spray hose. The orig- 

 inal spray-gun was constructed so as to deliver a maximum 

 of 15 gallons of spray a minute. Under heavy pressure, 

 a great cloud of spray could be sent out, reaching a height 

 of 46 feet. Experiments have not actually determined 

 the relative value of the spray-gun as compared with the 

 old rod and nozzle, but growers Ijave not waited for pub- 

 lished reports. The spray-gun was introduced to offset 

 the effect of dusting and is now being used by hundreds of 

 growers. Some criticism is voiced against the gun for the 

 calyx spray in controlling codlin-worms. When used from 

 a tower, this criticism is mitigated to a greater or less 

 extent. Speed is the chief recommendation for the spray- 

 gun. The operator usually stands on a tower and with a 

 single gun sprays two rows from a steadily moving spray 

 outfit. 



For apple orchards in full bearing, the spray tower is a 

 necessary accessory if thorough work is to be performed. 

 Planting schemes should provide sufficient space between 

 mature trees to permit the use of a tower in reaching the 

 topmost branches. Various tower designs are in use. 

 Strong iron rods supporting a small square platform with 



