Spraying Experiments in Nebraska 
91 
Tables 58 and 59 show the cost of spraying with the large 
capacity machines similar to fig. 23 or similar to fig. 24, but of 
larger capacity. Machines of this capacity are efficient for 1,000 
to 2,000 trees. 
Efficient service cannot be secured where the capacity of the 
machine is too small to spray the orchard in five or six full days of 
good weather. The capacity of the machine needed may be de- 
termined by the length of time the calyx cups remain open. 
This is usually 7 to 10 days. A single machine may be used to 
spray more than this if the varieties are so arranged that one part 
of the orchard comes into bloom later than another; but with our 
standard varieties of apples, not more than two or three days can 
be gained in this way. It is little wonder that the fruit grower 
who sprays (?) 50 to 100 acres of orchard with one machine fails to 
get results. 
The cost of spraying with lime sulphur is shown in table 58. 
This table also shows the comparative cost of the mist and the 
penetration methods of spraying. The penetration method is 
more expensive from the fact that more time is consumed in apply- 
ing the spray and for the reason that more material is used. 
That this excess is wasted is shown by the fact that the efficiency 
was no higher than when the spray was appHed as a mist. This 
superfluous amount of material may account for a part of the 
excessive spray injury caused by the penetration method of 
spraying. 
