31 



From the data given in this table it will be seen that the materials 

 for dusting are more expensive than those for spraying but that the cost of 

 application is greater for the spray than for the dust. In determining the 

 cost of application, only the actual time of operation was counted, no account 

 being taken of the time necessary to fill the sprayer tank or consumed in 

 driving to and from the orchard with each load of spray material. If this 



Dust spraying — covering the outer foliage (Original) 



item had been added the difference in labor cost of the two methods would 

 have been greater since enough of the dusting material can be carried on the 

 wagon for a half day's work. The table also shows that in this orchard of 

 very large old trees, the dusting was done five times as quickly as the spray- 

 ing. On smaller trees this difference is not so great. 



It is not probable that the dusting method of applying insecticides and 

 fungicides will replace spraying but it has some advantages which render it 



