236 The Commercial Apple Industry 



ments conducted in western New York in 1911-1913 by 

 Blodgett of Cornell. These experiments have been con- 

 tinued elsewhere in different parts of the United States 

 by various state and federal investigators. The practice 

 of dusting has been adopted with greater or less success by - t 

 many commercial growers in different regions. Its status 

 has not been definitely determined, but certain conclusions 

 may be drawn from results thus far obtained. 



In the first place, dusting has certain inherent advant- 

 ages over the use of liquid spray: (1) More trees may be 

 covered in a given time and with less labor than with the 

 liquid spray; (2) dusting is more convenient in rough 

 hilly orchards; (3) considerable time is saved in loading 

 the machine with material; (4) the elimination of water 

 reduces very materially the weight of the spray material 

 to be hauled through the orchard; (5) the equipment cost 

 is much less than for liquid spraying machine. / 



In comparing the cost of common dust materials, such 

 as arsenate of lead and superfine sulfur, with that of 

 similar materials used in liquid sprays, it appears that the 

 dusting method is more expensive, particularly if much 

 dust is lost in the application in windy or unfavorable 

 weather. In considering labor cost, dusting may be 

 cheaper than spraying with liquids, and it is on this point 

 that advocates for dusting lay particular stress. The 

 spray-gun more recently developed has reduced this ad- 

 vantage of the dusting method over the liquid spray. But 

 certainly the grower may cover his trees at the critical 

 period in less time and with less labor cost by dusting than 

 with liquid spray applied with rods. 



A two-man crew operating a dusting machine can cover 

 from three to four times as many trees as a three-man 



