Spraying Experiments in Nebraska 
63 
from this Station by Emerson in 1913 shows that the first or 
cluster-bud spray has comparatively no effect on the amount of 
injury from rust, but that the petal-fall spray and the one follow- 
ing give a very high per cent of control. 
Fig. 13 — Cedar rust on apple leaves 
In order to secure the best results, spraying should be given 
as soon as the knots on the cedar trees known as "cedar apples" 
begin to enlarge and show gelatinous orange-colored exudations. 
This orange-colored mass contains the spores which spread to the 
apple trees and produce the well-known orange-colored blemishes 
on fruit and leaves. 
SOOTY BLOTCH AND FLYSPECK 
Sooty blotch and flyspeck are considered by most patholo- 
gists to be caused by the same fungus and were so treated in the 
