SPRAYING AND DUSTING APPARATUS 67 



150-gallon tanks and may be arranged for filling the tank where 

 running water is not available. These pumps cost from $30 to 

 $50 and will maintain 100 to 125 pounds pressure with four to 

 eight nozzles. They are usually used with two men spraying 

 and another driving and pumping, or a fourth man pumps and 

 changes places now and then with the driver, as the operation 

 of this type is rather too heavy for one man constantly. 



Power Outfits. For orchards of much over 500 trees or for 

 extensive shade tree work a gasoline power outfit is more econom- 

 ical and enables a large area to be covered more quickly, which is 

 often a most important consideration. Most of the pump manu- 

 facturers and many gas engine companies are selling such outfits 

 mounted upon a truck, with spray tank, and tower complete for 

 from $250 to $1000. 



Traction Sprayers. For a small acreage of potatoes or other 

 row crops, a barrel pump with row attachment is very satisfac- 

 tory, but for any considerable acreage, a two-wheeled traction 

 sprayer is much more economical of labor and time which are 

 the two chief Items in the cost of spraying. Such traction 

 sprayers are made of widely different types, the power in all 

 cases being furnished by a gear or chain which operates the pump 

 from the wheels. The mechanical construction of the traction 

 sprayers should be carefully studied, and if possible tested, before 

 purchasing, as they differ greatly in efficiency. The better types 

 cost from $100 to $200 and usually have attachments adapting 

 them for all sorts of row crops, such as potatoes, strawberries, 

 bush fruits, grapes, etc., which require different styles of piping 

 to direct the nozzles properly. 



Several traction sprayers are sold for orchard work but, though 

 they are fairly satisfactory for small trees, they do not develop 

 enough power for spraying large trees, and have a heavy draft. 



Various other types of spraying machines have been tested 

 and some of them put on the market. Among these may be 

 mentioned gas-sprayers, where the gas in cylinders under pres- 

 sure is used to furnish the pressure; and compressed air sprayers, 

 where air compressed at a central station in large cylinders takes 

 the place of gas. These have some great advantages but diffi- 

 culties which arise in practical operations have kept them from 

 being widely used. 



