176 The Sweet Potato 



gun may be employed. This duster has tuhes which 

 will direct the dust on two rows, or on both sides of one 

 row, and regulates the amount of dust used. Large 

 power dusters are also on the market, but the average 

 sweet potato grower would rarely need such an outfit. 



When dusting is resorted to, it must be remembered 

 that the material must be put into the finest form of 

 powder possible. This is necessary in order that the 

 leaves may be thoroughly covered. Coarser dust will 

 not stick to the leaves and cover them as evenly as the 

 finer kind, neither will it feed through the machine as 

 satisfactorily. The chief advantage in dusting is in the 

 time saved. 



Nozzles, hose, and fixtures. 



Three types of nozzles are the Bordeaux, Vermorel, 

 and the Disk. Tor applying most of the ordinary in- 

 secticides and fungicides, the Vermorel and Disk are 

 preferable. These make a cone-shaped spray. 



For applying bordeaux mixture, the Bordeaux type 

 is very satisfactory. This makes a fan-shaped spray. 



The nozzle that can be easily taken apart and cleaned 

 is the most desirable. 



An angle-form nozzle or nozzles with elbow joints 

 should be used in order that the spray may be applied 

 to the under side of the leaves. A good quality rubber 

 or fabric hose and good clamps should be used so that no 

 leakage will occur. Where the hose bends near the 

 pump or near the extension rod, it should be wrapped 

 or supplemented with tape, or a good- coil of wire around 

 it, which acts as a supporter. 



