98 Nebraska Agricultural Exp. Station, Research Bui. 10 
the complete closing of the calyces is usually seven to ten days. 
It is not safe to attempt to spray more trees than can be covered 
in five or six full days with one machine. 
Power machines are the most satisfactory where the orchard is 
large enough to warrant their use, tho not necessarily more efficient 
than a good type of hand pump outfit when the latter is properly 
used. With any outfit the nozzle capacity must be regulated to 
fit the capacity of the pump. No outfit will do good work when 
the pump is unable to supply the liquid fast enough to maintain 
a good pressure. It makes little difference whether a double act- 
ing horizontal pump or an upright duplex or triplex pump is used 
if the capacity is large enough and it is well made, provided plenty 
of power is supplied to operate it at full capacity and the outfit is 
not too heavy. The outfit shown in fig. 21 is of the horizontal 
type and the one shown in figs. 23 and 24 belongs to the upright 
plunger type. However excellent in all other ways, an outfit 
is not dependable unless it has a good pressure regulator. One of 
the best pressure regulators is shown in detail in fig. 25. 
It must be remembered that efficiency in spraying is secured 
only by doing the work thoroly and at a time that will prevent 
infestation and infection. Protection by spraying is preventive 
rather than curative. A spray applied at the wrong time is 
little better than no spray. Spraying in a half-hearted way is 
often worse than no spray. It costs money but does no good. It 
is cheaper to buy efficient machines than to ''kill time tinkering" 
with a poor machine. 
(10-24-' 16— 4 M) 
