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MISC. PUB. 52 6, U. S. DEPT. OF AGRICULTURE 



Bellows or knapsack dusters. — This type of duster (fig. 10) is carried 

 •on the back like a knapsack. Essentially it consists of a metal hopper 

 for the insecticide, equipped with a bellows which when operated forces 

 air through a discharge chamber and pipe, carrying the insecticide with 

 it. The hopper is usually provided with a dust-feeding device. The 



Figure 10. — Bellows or knapsack duster. 



dust is discharged in puffs with each stroke of the bellows. This type 

 of equipment is especially suited for use on crops planted in hills. 



Bellows-type dusters are adapted for use in a variety of situations, 

 from the home garden to good sized commercial plantings. However, 

 they are probably best suited for use by commercial growers in plant- 

 ings where the use of power equipment is not feasible. 



Fcm or blower type of duster. — In this type of duster (fig. 11) the 

 hopper, which has a capacity of 5 to 10 pounds, depending upon the 

 powder used, is usually located over the air chamber. An enclosed 

 fan geared to a hand crank forces an even and continuous flow of air 



Figure 11. — Fan or blower duster. 



