Freezing Injury of Seed Corn 
IT 
Table 11 — Effect of freezing temperatures on the germination 
of corn which had been cured in a dry room before freezing 
( 1911 ). Moisture range in grain 12 to 1J+ per cent. 
Length of drying period 
Temperature 
range 
(degrees F.) 
Per cent germination 
Number 
of samples 
tested 
Normal 
grain 
Frozen 
grain 
28 to 32 
100 
100 
8 
1 month 
20 to 24 
100 
100 
8 
12 to 16 
100 
100 
8 
4 to 8 
100 
97 
8 
28 to 32 
100 
100 
8 
3 months 
20 to 24 
100 
100 
8 
12 to 16 
100 
100 
8 
4 to 8 
100 
100 
8 
NATURAL RESISTANCE OF GREEN CORN TO COLD 
It was thought desirable in connection with this work to 
determine as nearly as possible not only the degree of cold 
necessary to weaken or destroy the vitality of the corn kernel 
but also the length of time necessary for cold to operate before 
injury results. The latter tests were made as nearly under 
natural field conditions as possible, so far as the corn itself was 
concerned, — the ears being undisturbed in the husks, and placed 
in the freezing apparatus as soon as brought from the field. 
Five or six ears were frozen at a time. The plan was, to select 
ears of the four degrees of maturity used in previous tests, and 
subject them to a given range of temperature for varying 
periods of time. Again similar sets of ears were subjected for 
a given time to varying ranges of temperature. As soon as the 
ears were removed from the freezing chamber, moisture samples 
were taken and the ear husked and laid away to dry. Later, 
germination tests were made and notes taken regarding the color 
of the embryo. The data are compiled in Table 12. The ger- 
mination tests tend to indicate that light freezing temperatures 
of short duration are not particularly injurious even to corn of 
high moisture content, while long exposure, 20-21 hours, to 
the same temperature may prove fatal. As the temperature is 
reduced, the duration of exposure necessary to injury becomes 
shorter. This is indicated in summary Table 13. The data for 
the 24 hour period in this table are calculated from Tables 
5 to 9. While tests at this temperature are not strictly com- 
parable with those of 1915 in that the husks were removed from 
