SPRAYING AND DUSTING APPARATUS 



75 



Dusting Apparatus. The simplest method of applying dusts 

 is by means of a perforated can or a cheese-cloth or muslin bag 

 and much dust is still applied to garden crops in this way Dust 

 bellows to force dust into cracks for household pests, or to dis- 

 tribute it more economically and evenly on plants, represent 

 the next step. Various small dusters, but with larger capacity 

 than the bellows, are used for small plantings. These are usually 

 of the plunger type and the dust is puffed out rather than de- 

 livered continuously. Dusters with a rotary fan or blower, de- 

 livering the dust in a continuous stream are made in many sizes. 

 Some are operated by hand, 

 others are geared to the truck 

 upon which they are hauled 

 so they operate only when 

 the truck is in motion and 

 some, the more modern or- 

 chard outfits, are supplied 

 with power from a gasoline 

 engine. All types have their 

 uses but we are more con- 

 cerned with the commercial 

 forms than with the more 

 primitive apparatus. Or- 

 chard dusters operated by 

 hand are not satisfactory for use on any large scale. The power 

 dusters on the market are quite efficient and will deliver large 

 quantities of dust in dense clouds which have considerable carrying 

 power. Dusting machines, owing to their more limited use, 

 have not been mechanically perfected to the same degree as the 

 sprayers but they undoubtedly will keep pace with the require* 

 ments as they come into general use. 



Dusting mixtures are composed of arsenate of lead or of cal- 

 cium mixed with some other substance which acts as a carrier. 

 The carrier is often the fungicide or is a mixture of the fungicide 

 with some inert material such as land-plaster or gypsum. The 

 common formulas call for from 10 to 15 pounds arsenate with 85 

 to 90 pounds finely ground sulfur, a special grade being pro- 

 duced for this purpose. An inert material may displace any 

 part of the sulfur but it is not the common practice to dilute 



FIG. 54. Spraying with power outfit from 

 a tower. (Bean Spray Pump Co.) 



