50 MISC. PUB. 526, U. S. DEPT.. OF AGRICULTURE 
for use on plantings varying from one-half acre to many acres, depend- 
ing upon the size of the machine. Hoods or cloth trailers are often 
used behind the machine on low-growing crops to obtain better plant 
coverage and to reduce (often by as much as one-half) the quantity 
of dust required. 
H1IGuRE 13.—A power duster in operation. When poisonous dusts are being used, 
the operator should use full face and respiratory protection. 
CARE OF INSECT-CONTROL DEVICES 
Proper care of spraying and dusting equipment is essential to 
assure satisfactory performance and long life, especially during the 
present emergency. All equipment should be kept clean. 
Sprayers.—Unused spray material should be drained from spray 
pumps and hose at the completion of a job. The tank, hose, valves, 
and nozzles should be thoroughly flushed with clean water and the 
pump run for a few minutes to rinse thoroughly and remove all the 
insecticide. Unless this is done, these parts and connections may 
corrode or become clogged. Spray equipment should be kept in a cool, 
shady place to avoid rapid deterioration of gaskets, hose, and other 
parts. During cold weather the pump, tank, and hose should be 
drained of all excess liquid to avoid freezing and breaking, or the 
sprayer should be stored in a warm place. All unpainted metal parts 
that are subject to rusting should be well oiled or greased. Wooden 
tanks should be stored in a damp place or clean water kept in them 
(except where freezing temperatures occur) to prevent drying out and 
shrinking. 7 
It is advisable to have extra hose connections, pump gaskets, cup 
leathers, valves, valve seats, plungers, and other working parts on hand 
for prompt replacement in case a break-down occurs. 
Dusters —Dusters should be kept in a dry place, and, if used irreg- 
ularly, the excess dust should be removed after each operation and 
returned to the container in which it is stored. The dust will dete- 
riorate less rapidly in such containers, and the mechanism of the dust- 
ing equipment will not be subject to corrosion. Working parts should 
be properly lubricated. 
