170 
Journal of Agricultural Research 
Vol. XXIV, No. a 
At the University of California, where apples of the Pajaro Valley have 
been stored at -i.i®, 0°, and 2.2° C. since 1916, it has been found that 
considerable browning occurs after the first of February, even in the fruit 
stored at 2.2°. Aside from the browning, however, these apples keep 
satisfactorily. It was, therefore, thought advisable to store apples at 
various temperatures above 2.2® in order to determine (i) the lowest 
temperature at which internal browning will not develop during the 
normal storage period and (2) whether or not the temperature which is 
sufficiently high to prevent internal browning is also sufficiently low for 
practical storage purposes. 
During the season of 1919-20 the only other temperature available 
above 2.2^ C. was that of room temperature. However, in 1920-21 
apples were stored at 5°, 8.3®, 13.9°, and 21° in addition to the 
usual temperatures used for these apples. In the 1919-20 season 15 
lots of the second picking were used in these tests, while in 1920-21 two 
lots of fruit from the same two trees for each of the first two pickings 
were used. Since all the apples browned in relatively the same propor¬ 
tions at each of the temperatures, only the averages for the second pick¬ 
ing are given in Table III. 
Table III .—Effect of storage temperature upon internal browning 
SEASON 1919-20 
Condition of fruit after 4 months’ storage. 
storage temperature. 
Nor¬ 
mal. 
Trace. 
Slight. 
Mod¬ 
erate. 
Severe. 
•c. 
—I. I 0. 
Per 
cent, 
IS 
15 
40 
100 
Per 
cenU 
60 
Per 
cent. 
20 
Per 
cent- 
e 
Per 
cent. 
0 
35 
55 
0 
30 
c 
0 
15 
0 
5 
2.2. 
0 
0 
0 
0 
0 
SEASON or 1920-21 
15 
35 
25 
20 
5 
40 
35 
20 
5 
0 
95 
5 
0 
0 
0 
100 
0 
0 
0 
0 
100 
0 
0 
0 
0 
100 
0 
0 
0 
0 
o There was considerable freezing at in the early part of the storage season, which retarded the 
browning. 
The figures of Table III show a definite relation between the amount of 
browning and the temperature of storage. The effect on browning of 
only a few degrees change in temperature is very striking. At o® C., 
for instance, in the 1920-21 season, only 15 per cent of the fruit remained 
normal, while at 2.2° 40 per cent was normal, and at 5° 95 per cent of the 
fruit was normal. Browning did not occur in any of the fruit stored at 
a temperature of 8.3® or above. 
It becomes manifest, therefore, that internal browning does not occur 
at a temperature a few degrees above that used in the commercial storage 
