326 



CONTROLLING INSECTS AND DISEASES 



fine mist; that at a distance may be reached by a driving 

 spray. The gun is light and easy to carry and handle, being usu- 

 ally from 18 to 36 inches long and weighing from 3 to 4 pounds. 

 It is commonly constructed of brass, but aluminum guns with 

 brass nozzles and brass movable parts are now available. They 



are both light and durable. 

 (Figs. 119 and 120.) 



The spray gun has 

 largely replaced the rod and 

 nozzle on power outfits. It 

 makes possible the applica- 

 tion of large quantities of 

 material in a short period. 

 A pressure of 400 pounds 

 or more is usually needed. 

 The spray gun saves time, 

 applying 3 to 6 gallons per 

 minute, or a larger quantity 

 with a double gun. It ap- 

 preciably reduces the labor 

 cost of application. It may 

 (John Bean Mfg. Co.) not save material — ^that de- 

 FiG. 120. Spray guns with a battery pends on the agility of the 

 of nozzles. operator. 



Much poor work has 

 been done with the spray gun, largely because too much was 

 expected of it. Some growers have returned to the rod and 

 nozzle. The temptation is great merely to stand on the ground 

 or spray tank, turn on the pressure, shoot a driving spray at 

 the tree, and assume that the job is done. It is true that the 

 force of the spray will turn many of the leaves as it strikes 

 them, thereby coating the lower leaf surfaces, but this will be 

 true of only a fraction of the leaves. The gun does not elim- 

 inate the necessity of spraying from the ground, and where 

 the trees are headed low, it is difficult to coat the lower leaf 

 surfaces thoroughly with this device. 



