ig 
Ee 
SOURCES OF APPLE BITTER-ROT INFECTIONS. 5 
Von Schrenk and Spaulding (13) in 1903, after investigations 
carried on in Missouri, state— 
Another source of infection is found in the dried mummies hanging on the 
trees and lying on the ground under the trees. The diseased apples of one 
season either fall to the ground (most of them do) or they remain on the trees, 
where they dry and shrivel up. When examined in the spring many of these 
mummified fruits are found to contain spores of the bitter-rot fungus in 
quantity. 
Again they state— 
It was formerly supposed that the fungus passed the winter in the mummies, 
but as most of these were on the ground it was difficult to understand how the 
apples high up in the trees became infected. It now seems probable that the 
mummies play a comparatively small part in serving as distributing points for 
spores from year to year. 
In 1902, Alwood (1), as the result of observations and experiments 
in Virginia, came to the conclusion that the mummied fruits on the 
tree and the rotted fruits on the ground were the chief sources of 
infection. He states— 
It appears to be well established that the mummied fruits hanging to the 
trees and the rotten fruits upon the soil constitute in large measure the source 
of the annually recurring infection. To my mind these fruits are the source 
of infection. 
Scott (14, p. 12) in 1906, in his discussion of sources of infection, 
states— 
The results [of observations made in Virginia and West Virginia orchards] 
lead to the conclusion that the overwintering mummies hanging on the trees 
constitute the chief source of infection, at least in this particular region. In 
the majority of cases examined, a mummy could be found in the upper portion 
of the infected area. 
Burrill (3) in 1907 considered that mummies on the ground rarely 
acted as infection sources. 
The writer (10) in 1915, as the results of investigations in the 
Ozarks of Arkansas, stated— 
Masses of spores were also obtained many times from mummies, and where 
mummies are present they undoubtedly are important sources of infection. In 
many of the badly infected orchards, however, they had been removed both from 
the trees and from the ground. 
It will be noted that eastern investigators consider mummied and 
rotted fruits as the principal means by which the fungus is carried 
over from season to season. Investigators working in the Middle 
West, however, consider them as of only secondary importance in 
the survival of the fungus through the winter. 
The writer during the past three years has examined mummied 
and rotted fruits of previous seasons from orchards in Virginia and 
in Arkansas. In both mummies and rotted fruits of the preceding 
