54 BULLETIN 395, U. S. DEPARTMENT OF AGRICULTURE. 
pluni curoulio, since in the more important peach-producing sections 
of the United States east of the Rocky Mountains any commercially 
successful scab treatment must combine satisfactorily and econom- 
ically with control measures for these associated troubles. 
THE TIME AND NUMBER OF APPLICATIONS FOR MIDSEASON VARIETIES. 
Treatment before the blossoming period. — Numerous writers have 
recommended as the first spray for scab a treatment just before the 
blossoming period. Sturgis (1897, p. 271), apparently on a priori 
grounds, suggested this treatment, while Selby (1904, p. 66) includes 
it in his recommendations. His tabulated results (1898, p. 251-252), 
however, show no decisive benefit resulting from this application, 
while, on the other hand, his best control in certain cases occurred on 
plats which did not receive this treatment. Evans (1911) and others 
make like recommendations. Scott (1907, 1908, and 1909), Scott and 
Ayres (1910), Scott and Quaint ance (1911), and others showed that 
scab can be successfully controlled when this winter application is 
omitted. Clinton and Britton (1911, p. 614; 1912, p. 374) concluded 
from comparative experiments that this treatment had little or no 
effect upon scab or rot. They (1912, p. 374) state — 
In 1910, all of the trees having this winter treatment gave just as high a percentage 
of scab * * * as did those not having it, neither lot having any summer treatment. 
In 1911, all the trees having this winter treatment and three summer treatments did 
not give any lower percentage either of scab or rot than those that received only the 
three summer treatments. 
Furthermore, the writer's life-history studies previously reported 
show that at the time of the winter treatment the fungus is so well 
protected by the cuticle of the host that it would not be feasible to 
combat it efficiently with any standard fungicide. It appears con- 
clusive, therefore, that a winter application is not necessary for 
efficient scab control. 
Treatment as calyces shed. — Clinton and Britton (1911, p. 614, 617) 
recommend the application of a suitable fungicide at about the time 
the calyces are shed. Their data (p. 614), however, do not show any 
better results from this application in conjunction with two later 
treatments than from the later treatments alone, and these authors 
(1912, p. 395) suggest that if any of these applications must be 
omitted it should be the first. Blake and Farley (1911, p. 19) 
reported that scab development was considerably checked, though 
by no means controlled, by a single application of a suitable fungicide 
when the calyces were being shed. They recommended (p. 26) 
this treatment in conjunction with two later applications. They did 
not, however, give a thorough test to the two later treatments alone, 
using self-boiled lime-sulphur or a sulphur spray. Selby's (1898, p. 
251) tabulated data, on the other hand, show no benefit from this 
