384 INSECTS AFFECTING VEGETATION 



facturers now put out a large variety of spraying apparatus suited 

 for all ordinary needs, including the small knapsack pumps, barrel 

 and tank pumps, and geared and power sprayers. For limited in- 

 door operations a hand atomizer or even a sprinkling can with fine 

 rose tip may be made to do fair service. 



The Barrel Pump. This is the commonest form of spraying 

 apparatus, and is supplied in many different styles; or, a suitable 

 spray pump can be combined with an empty 50-gallon kerosene 

 barrel without much difficulty. This apparatus may be hauled about 

 on a sled or in a wagon or a two-wheeled cart. 



Tank Outfits. For larger operations it is much better to have 

 a specially constructed rectangular or half-round spray tank of a 

 capacity of 200 or 300 gallons. Such an apparatus enables an ele- 

 vated platform to be mounted on the wagon and tank, greatly 

 facilitating spraying of the higher parts of trees, as indicated in the 

 accompanying illustration. The ideal sprayer for extensive work 

 combines such a tank, with platform, with gasoline or steam power 

 spray pump. 



Geared Sprayers. For low-growing regularly planted crops it 

 is sometimes possible to use spraying apparatus which gets its power 

 by means of a sprocket wheel from the axle of the wagon. Several 

 types of spraying apparatus of this kind are on the market, suited 

 especially for the treating of crops like potatoes and strawberries, 

 and the spraying of vineyards. In orchards it is not often possible 

 to have the wagon constantly in motion, and geared sprayers are not 

 as a rule available. 



Gas-Pressure Sprayers. Some very successful spraying ma- 

 chines have been made which have as their motive power gas pres- 

 sure. This pressure may be derived from compressed air or carbonic 

 acid gas cylinders. It is an ideal way of applying liquid sprays, 

 and has a special applicability to oil-water mixtures. Ultimately 

 this principle may come into much more general use. 



Hose, Nozzle, and Agitator. The hose and nozzle are two very 

 essential elements of a good spraying apparatus. The very best 

 three-eighths, one-fourth, or one-half inch 3-ply or 4-ply hose should 

 be bought. A cheap or inferior hose will not stand the pressure and 

 heavy wear of spraying. For orchard spraying a length of 25 feet 

 is the least that should be used, and better 35 feet, and longer with 

 large apparatus where it may be possible to spray more than one 

 row at a time. Several lines of hose may be operated with a strong 

 spray pump. Each line of hose should be supplied with an exten- 

 sion rod 8 or 10 feet long. This rod may be an ordinary bamboo 

 pole into which a small brass tube is fitted carrying the nozzle, or 

 the hose may terminate in a small gas pipe a rather heavy device 

 and useful for short length only. The best nozzle for general use is 

 the "Friend type." 



A very necessary feature of spray tanks is a device for keeping 

 the liquid constantly agitated to keep up a uniform mixture or pre- 

 vent the settling of the poison or solid constituents of the wash. 

 This may be accomplished by constant stirring with a paddle. Most 



