SPRAY MANAGEMENT 23 



cial apple production on a specialized scale has been underway for at 

 least a generation and, in general, the objectives in spraying for control 

 of pests and diseases are similar on all farms; yet the cost in terms of the 

 three general measures of efficiency indicate no common pattern. The 

 data indicate that even with approximately the same size of spray outfit 

 the variation in amounts of spray applied varies considerably. 



The chief factors which determine the gallons of spray applied per 

 man hour and machine hour are: 



1. Size of crew 



2. Topography 



3. Water Supply 



4. Capacity of tank, pump, and nozzle 



5. Size of trees and spacing 



6. Type of spraying procedure 



7. Psychology and personnel of operators 



The size of the crew affects the number of gallons of spray applied 

 per machine hour and per man hour. One-man crews with medium- 

 sized or small-sized machines are able to apply more gallons of spray per 

 man hour than two-men crews — and two-men crews, more than three- 

 men crews. For instance, one grower, in 1933, with a medium-sized ma- 

 chine, reduced his spraying crew from two men to one man and increased 

 the gallons of spray per man hour from 99 to 158. Another grower 

 with a small machine reduced his crew from three men to two men and 

 increased the gallons per man hour from 34 to 47. However, the re- 

 duction in the crew resulted in a decrease in the gallons of spray per ma- 

 chine hour. In the two cases mentioned above the change from a two- 

 to a one-man crew resulted in a loss of 20 per cent in the application per 

 machine hour and the change from a three-man to a two-man crew re- 

 sulted in the loss of eight per cent in gallons per machine hour. The 

 larger number of gallons applied per machine hour by some of the two- 

 man crews is due to continuous operation of a large capacity nozzle 

 which was possible on account of the level orchard site and the practice 

 of spraying closely set uniform trees, one side at a time, while riding past 

 on the tank. With some three-man crews, spraying from the ground, 

 it is the usual practice to spray all around a tree in one operation. Since 

 the nozzle must be shut off while the man is traveling from one side of 

 the tree to the other, or to another tree, such a practice results in inter- 

 mittent spraying and decreases the efficiency of both man and machine. 

 So the influence of the size of the crew depends somewhat on the pro- 

 cedure and method of spraying. A two-man crew may be as effective 

 as a larger crew if large multiple nozzles are used on a compact orchard. 



The topography of the orchard site has considerable influence on 

 the spraying operations. It is important in determining the method of 

 spraying, whether from the rig, or the ground, the number of men in 

 the crew, the way the machine is to be drawn, and the size of the ma- 

 chine and nozzle. One orchardist operating a medium-sized pump with 

 a two-man crew on a rough site applied 65 gallons of spray per man 

 hour while another grower, using a one-man crew on a level site, applied 

 158 gallons per man hour. 



