Methods of Application 



The simplest method of application of sodium arsenite solution 

 is distribution with a long-handled dipper from an unpainted tub 

 placed in the front ead of a boat. With some practice, the solution 

 may be distributed in almost a spray-droplet size by giving a quick 

 jerk of the wrist to the handle of the dipper as the solution is 

 being broadcast . This method serves well in small ponds up to 

 about two acres in area. While simple, it is not as thorough as 

 spraying at 40 to 60 -pounds pressure with a pneumatic tank and spray- 

 ing apparatus, but it is safer because of larger droplet sizes. 



Another simple method is to mix the commercial material with 

 water and allow the mixture to flow from the container through a 

 weighted piece of garden hose as a boat is rowed in parallel lanes 

 10 to 20 feet apart over the area to be treated. No dilution is 

 needed if the amount used is large. 



A gun-type tree sprayer, Figures 7 and 8, such as is used in 

 apple orchards, connected by a 15-foot length of pressure hose to 

 a 30 or 40-gallon pneumatic tank has been used successfully for 

 several years for treating hatchery ponds. The tank, which may be 

 a wide, squat type to avoid tipping, is provided with an air connec- 

 tion to a gasoline-driven air compressor, handles for lifting the 

 tank into and out of a boat or truck, and a glass steam guage which 

 enables the operator to see how much liquid remains in the tank. 

 Before applying the chemical, the tank may be partly filled with 

 water before the sodium arsenite solution is introduced into it. 

 The tank is then filled to within a short distance of the top and 

 the contents mixed. An air space should be allowed at the top of 

 the tank for air compression. The spray is applied under a pressure 

 of 40 to 60 pounds to the square inch. The entire apparatus, con- 

 sisting of tank, tree sprayer and connecting hose, tank and air 

 compressor, can be placed in a boat or in the back of a pickup 

 truck from which the spraying of long narrow ponds, 50 to 60 feet 

 wide, can be done by driving about them. 



At 50 pounds pressure, with the gun illustrated in Figures 7 

 and 8, distances up to 50 feet from the boat or truck can be reached 

 for spraying. The type of spray can also be regulated from a fine 

 mist spray to a stream which is usually used because it reaches 

 farther and produces less spray drift. 



Precautions in Handling 



The operator should use rubber gloves in the mixing to avoid 

 getting the sodium arsenite solution in open cuts in his hands. 

 Protective covering, such as face shields, goggles, coats, etc.. 



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