24 Nebraska Agricultural Exp. Station, Research Bui. 10 
A careful perusal of table 11 indicates that 2 pounds of arsenate 
of lead paste or 1| pounds of arsenate of lead powder is sufficient. 
Much complaint has been registered against certain brands of 
arsenate of lead. The above results show them to be of about 
equal value, in proportion to the amount of arsenic contained in 
combination. 
The results of the last year's work (1915) indicate that con- 
clusions drawn from the two preceding years' work were in the 
main correct, i. e., that the efficiency of a spray schedule for the 
control of codling moth depends very largely upon the thoroness 
of the petal-fall application. However, this application is not in 
itself sufficient, even though every calyx receive a good dose of 
poison. Approximately 20 per cent of the first-brood ''worms" 
normally enter the fruit at various points, other than the calyx, 
on unsprayed trees. The spray materials lodged in the calyces 
certainly will cause some of the larvae which would otherwise enter 
the calyx to seek other places of entrance, so that the percentage of 
the larvae which enter the fruit from other points must be appre- 
ciably increased. This is borne out by the fact that even with 
the most thoro calyx spraying in 1915, 20 to 40 per cent of the 
worms were controlled by the late applications. Comparing the 
number of calyx-wormy apples found on the sprayed and the 
unsprayed trees, the efficiency of the calyx spray was 97.7 per 
cent at Beatrice, 96.5 per cent at South Omaha, and 89 per cent 
at Lincoln. 
After carefully comparing all data for the three years' work, it: 
is apparent that in any orchard, unless very thoro spraying has 
been practiced in the past, it will be necessary to make three appli- 
cations during a normal season and four or possibly five during a] 
excessively hot, dry season like that of 1914. Even in well-spraye 
orchards the omission of one of these sprays for a single season 1 
inadvisable. Two or three per cent of a crop saved will pay for 
considerable spraying. 
It is very evident that the petal-fall application is by far th 
most important. The best results were obtained when the spra" 
was applied as a coarse mist (not necessarily with Bordeau 
nozzles) under considerable pressure and directed squarely agains 
the open calyx. For this reason the main part of the sprayin 
for this application should be done from the tower. If, on accoun 
of high winds or other unfavorable conditions, the applicatiq 
has not been thoro, it will pay to go over the orchard agai 
immediately. 
The highest efficiency from the next spray following the cal 
application was secured when it was applied just before the youn 
