Apr. is, 1914 
Experiments with Apple Leaf'Spot Fungi 
61 
Alternaria, 3 contained bacteria only, and 2 were sterife. Out of a total of ic cultures 
from spot enlargements of experiment 4, 11 contained Alternaria and 4 developed 
bacteria. Out of a total of 12 cultures from experiment 5, xi contained Alternaria 
and 1 developed bacteria. 
On August 19 the following experiments were begun: 
The material used in experiments 1,2,3, an d 4 was sterilized as in No. 1 of the series 
of August 9. Circular spots were burned on all leaves, as in previous experiments. 
Nos. 1,2, and 3 were sprayed with distilled water containing spores of Coniothyrium 
pirinum , Phyllosticta limitata , and Alternaria sp., respectively. Experiment 4 corre¬ 
sponded to No.. 1 in the experiments of August 9 and was regarded as a check. The 
material used in experiment 5 was not sterilized nor inoculated, but received a 
thorough drenching. The branches with their cut ends in flasks of distilled water 
were then placed under bell jars lined with wet filter paper. The results are given 
in Table IV. 
Table IV. —Results of inoculation experiments of August ig on York Imperial and Ben 
Davis apple branches. 
York Imperial. 
Experiment No. 
Number 
of burned 
spots. 
Number 
of enlarged 
spots. 
Average 
width of en¬ 
largements. 
i 
Percentage 
of enlarged 
spots. 
I. 
86 
12 
Mm. 
I- 5 
14 
2 . 
69 
7 
5 
10 
3. 
81 
40 
3 
49 
4 . 
63 
3 
3 
5 
32 
23 
I 
3 
i 72 
Ben Davis. 
1 
2 
3 
4 
5 
32 
3 i 
30 
43 
12 ; 
12 | 
38 
38 
97 
3 
58 
Many of the enlargements in experiments 1 and 2 were somewhat doubtful ones, 
especially those on Ben Davis; in these two experiments the fungi fruited on practi¬ 
cally every spot, but no fruits were found on any of the enlarged portions. Fruits 
would appear up to and in fact were most frequently found at the very margins of the 
original spots, but in no case did they occur on the newly formed parts. This agrees 
with the observations of Hartley (1908), who found the margins of spots to be the favor¬ 
ite fruiting places of Coniothyrium pirinum. 
In cultures made as in previous experiments, material from experiment 1 produced 
6 growths of the Alternaria and 2 of bacteria, while the remaining 1 was sterile; of 7 
cultures from experiment 2, 2 developed Phyllosticta, 1 contained bacteria, and 4 
were sterile. Out of 8 cultures from experiment 3, 6 developed Alternaria and 2 
contained bacteria. Out of 15 cultures from experiments 4 and 5, 11 developed 
Alternaria, 2 contained bacteria, and 2 were sterile. 
Experiments begun August 30 were carried on as follows: 
Experiments 1,2,3, 4 were performed in the same manner as those of August 19. 
The leaves in experiment 5 received the same treatment as those in experiment 4, 
but in addition they were sprayed with water containing spores of Phomopsis mali. 
As before, the branches were placed under bell jars lined with wet filter paper. The 
results are given in Table V. 
36132 0 —14-s 
