APPLE DISEASES 
and has been reported doubtfully fiom 
Idaho It has not been 1ecorded in Cali- 
tornia to our knowledge, though it 1s not 
ympiobable that it occurs in the northern 
counties, since it is common in Jackson 
and Josephine counties in Oregon. It is 
most serious in those sections having 
considerable rainfall west of the Cascade 
mountains. It is rarely a serious disease 
in the fruit sections east of the Cas- 
cade mountains. It has been reported 
once from Nebraska. 
Life History Studies 
The apple tree anthracnose has prob- 
ably occurred in the Northwest for many 
years. It began to attract attention as 
an orchard trouble during the period 
from 1891 to 1893. The serious nature of 
the disease was realized at that time and 
through the efforts of the Boards of Horti- 
culture of Oregon and Washington, the 
United States Department of Agriculture 
sent Professor M. B. Pierce to investigate 
this trouble. He made considerable study 
of this disease in both Oregon and Wash- 
ington but made no official report. The 
records of his work are contained in ex- 
tracts of letters published in the Second 
Biennial Report of the Washington State 
Board of Horticulture and in the Fifth 
Biennial Report of the State Horticul- 
tural Board of Oregon. It is evident from 
these reports that Pierce recognized the 
true nature of the disease and probably 
isolated the causal fungus and studied it 
in culture and produced the disease 
by inoculation. 
The first published work regarding this 
disease was made by Professor A B. Cord- 
ley (1900) of the Oregon Experiment Sta- 
tion, who published a full statement of 
the life history of the disease and a de- 
scription of the organism causing it, to- 
gether with the results of inoculation 
work. He named the fungus Gloeosporium 
malicorticis. At about the same time Dr. 
C. H. Peck described the same fungus un- 
der the name of Macrophoma curvispora. 
The writer has used the former name 
upon the grounds that Cordley places the 
fungus more nearly in the proper genus, 
and since the name which he proposed 
441 
has of late come into more general use. 
The disease was studied in Washington 
by Lawrence (19U4) who verified all of 
Cordley’s work and also records many 
interesting and important biological 
phases of the disease He was the first 
to publish an account of the disease as 
a cause of a rot of stored fruit. 
In 1906, on account of the fact that 
many points regarding the life history of 
the disease had not been thoroughly work- 
ed out, the Oregon Experiment Station un- 
dertook a detailed investigation of the life 
history and control of this disease, 
Mr. C. C. Cate, a graduate student, made 
a thorough orchard survey of the disease 
in various parts of that state in an effort 
to determine whether any information 
could be obtained regarding the suscep- 
tibility of varieties, and whether the con- 
ditions of the soil had anything to do 
with the degree of susceptibility. He 
found very little evidence to indicate that 
soil conditions had any influence upon 
the abundance of the trouble. The fol- 
lowing quotation (Cate, 1908) indicates 
the results of the investigations regarding 
the susceptibility of varieties: 
“From investigations made during the 
past summer, it was found that Anthrac- 
nose attacks practically all varieties of 
apples, although some are more sus- 
ceptible than others. Those most sus- 
ceptible are Baldwins, Spitz and Jona- 
thans; next are Newtowns, Greening, 
Gravenstein and most of the summer vari- 
eties, while those attacked only slightly 
are the Ben Davis, Northern Spy, Wine- 
sap and Blacktwig. No varieties seem 
to be entirely immune and occasionally 
some of the least susceptible varieties are 
nearly or entirely ruined by the disease. 
In the varieties like Baldwin and Spitz, 
the cankers are of all sizes and most of 
them extend very deep and hence greater 
damage is done, while on the Ben Davis 
cankers or wounds are smaller and more 
superficial, hence very little damage is 
done to trees of this nature.” 
The writer began the study of this 
disease in the summer of 1909, which has 
been continued as time would permit, 
since that date. In the course of this 
