46 BULLETIN 614, U. S. DEPARTMENT OF AGRICULTURE. 
Third lead-arsenate spray.—The third lead-arsenate spray is made 
from 10 to 15 days after the second codling-moth spray. This spray 
was made by 72 per cent of the growers visited. In this spray, asin ~ 
the second lead-arsenate, there is about an acre more done per day by 
hired than by owned outfits, but less material is applied per acre. 
It is obvious from the figures that the difference in cost between the 
owned and hired outfits in this spray is somewhat less than in the 
former sprays. The necessity of a thorough application of material 
is not felt so keenly by the growers as in the previous sprays, for up to 
and including this spray there is a gradual increase in the amount of 
ground covered per day, and a decrease in the material applied per 
acre, especially where the spraying is done by the owners themselves. 
The total labor and material cost for the North Yakima district (29 
orchards) was $3.53; while in the Zillah district (44 orchards) it was 
$4.52 per acre. Considering all records, regardless of crew used or 
whether the spray outfit is owned or hired, the total labor and material 
~ cost per acre for the third lead-arsenate spray was $2.89, or 11.50 per 
cent of the total labor and material spraying cost. (See Table 
XXXVI.) 3 | 
Fourth lead-arsenate spray.—The fourth lead-arsenate spray is 
usually made from 9 to 10 weeks after the calyx spray. One hun- 
dred and eighteen orchardists visited, or 98 per cent, used this spray. 
From the number of orchardists who make this spray, together with 
the amount of material applied and the labor required, it appears that 
this spray is the second most important codling-moth spray. Table 
XXXIV shows the number of acres sprayed per day and the material 
applied per acre for both hired and owned outfits. The cost per acre 
for labor and material was $1.18 more for those who owned outfits 
than those who hired. Total labor and material cost in the North 
Yakima district (53 orchards) for this spray was $3.64; while in the 
Zillah district (50 orchards) it was $4.40. Considering all records, 
whatever size of crew used or whether the spray outfit 1s owned or 
hired, the total labor and material cost per acre for the fourth lead- 
arsenate spray was $3.85, or 15.32 per cent of the total labor and 
material spraying cost. (See Table XXXVI.) 
Fifth lead-arsenate spray.—The time for the fifth spray is usually 
the early part of August. It is made by 41 per cent of the growers 
considered in this study. Thirty-five orchardists owning, and ten 
hiring outfits made this spray, each using a crew of three men and two 
horses. From Table XXXIV it will be seen that the cost per acre for 
Jabor and material is $0.58 more for those who own outfits than those 
who hire. Considering all records for the valley, regardless of crew or 
whether the spray outfit is owned or hired, the total labor and mate- 
rial cost for the fifth lead-arsenate spray was $1.74, or 6.92 per cent of 
the total labor and material spraying cost. (See Table XXXVI.) 
