Jan. 22,1917 
Temperature Relations of Apple-Rot Fungi 
151 
Tabi^E II. —Results of natural infection with Glomerella cingulata 
Temperature. 
Container. 
°C. 
39 a . 
35 a . 
28 a. 
20 to 26, 
averaging 
22. 
Closed chamber 
.do. 
.do. 
I Open basket. .. 
Closed chamber 
fOpen basket. . . 
[Closed chamber 
fOpen basket. . . 
[Closed chamber 
fOpen basket. . . 
\Closed chamber 
f Open basket. .. 
[Closed chamber 
' 
Experiment started on Septem- 1 
ber 8. Diameter of rot in mil- | 
limeters after— j 
15 days. 
29 days. 
36 days. 
43 days.i 
28. 7 
3-6 
O 
O 
O 
O 
O 
O 
O 
9 - 7 
20. 5 
2. 2 
4. 2 
0 
0 
0 
0 
18. 0 
3 1 - 5 
28. O 
42. O 
6. 2 
8.7 
O 
0 
O 
O 
1 
Experiment started on Septem¬ 
ber 28. Diameter of rot in mil¬ 
limeters after— 
9 days. 
16 days. 
23 days. 
37 days. 
4. 4 
q. 0 
IS- 5 
16. 2 
y y 
6. 0 
13. 6 
7- 1 
O 
24- 3 
25. 2 
3- 7 
7.8 
0 
0 
0.9 
4-7 
0 
1. 
0 
0 
O 
0 
0 
O 
O 
a The three higher temperatures were not constant. At these temperatures the apples soon broke down 
internally, making it difficult to obtain reliable data. 
In the later stages of the experiment the development of the rots 
appeared to be more rapid in the moist chambers than in the open 
packages. This was probably due to the fact that the exposed apples 
became considerably withered as the experiment proceeded and were 
probably not so easily broken down by the rot fungi. 
The results with Sphaeropsis malorum are in close agreement with 
those obtained in the artificial inoculation experiments. This was 
also true of Glomerella cingulata , with the exception that there was no 
growth at io° with the artificial inoculations while a slight growth was 
obtained at that temperature with natural infections. The develop¬ 
ment at this temperature, however, occurred only with rots that were 
several millimeters in diameter at the beginning of the experiment. 
After two months’ exposure to temperatures of o°, 5 0 , or io° 
infections of G. cingulata developed rapidly when the fruit was removed 
to a temperature of 25 0 . 
apple rots in commercial cold storage 
Experiments were also made with apples in a commercial cold-storage 
plant, in which the temperature was held at o° C. (32 0 F.). The apples 
(from the Shenandoah Valley of Virginia) were gathered on October 6, 
were received in Washington on October 16, and were inoculated on 
October 19. They were not washed, sterilized, or treated in any way 
before inoculation. The stems were not recmoved, as was the case in 
other inoculation experiments. Fruit was selected that was of. uniform 
size and quality and apparently in perfect condition. Ten York Im¬ 
perial and ten Arkansas apples were inoculated with each fungus by 
