54 Nebraska Agricultural Exp. Station Research Bul. 16 
I lie dates on which the first freezing temperatures recorded 
by the weather bureau, three miles distant, have occurred during 
the last seven years are as follows: 1911, October *21 * 191*; 
October 22; 1913, October 20; 1914. October 27: 191 of October 
8; 1916, September 29; 1917, October 8. 
This shows October 15 to be the average date for the first 
freezing temperature recorded by the weather bureau, during 
this period, whereas the average date for the first killing frost 
was October 12. The freezing temperatures which occurred 
on the above dates were not low enough, however, to affect the 
vitality of the corn in any way, unless the corn should have 
been exceedingly immautre. Even this class of corn is rarely 
injured by the first freezing temperatures because of their short 
duration. (See Table 13.) 
1 he approximate moisture content of the average corn crop 
in eastern Nebraska on October 15, 1911, was 22 per cent; in 
1912, it was 20 per cent; in 1913, it was 17 per cent; in 1914, 
it was 15 per cent; in 1915, it was 35 per cent; in 1916, it 
Avas 18 per cent; and in 1917, it Avas 37 per cent. These 
figures are based on the moisture content of corn harvested 
from the general field plats of the Experiment Station. They 
represent, no doubt, very nearly the aA^erage maturity of corn 
in eastern Nebraska at the time Avhen freezing temperatures 
are likely to occur. It will be seen that usually corn is too 
mature to be injured in vitality by the first freezing weather. 
EA r en in 1915 when the moisture content, was large the first 
freezing did little or no damage to the life of the seed. (See 
I able 22.) farther north and AA^est in the State, however, the 
season is shorter and freezing comes earlier. The corn in these 
sections, therefore, should be correspondingly earlier in order 
to insure normal vitality in the seed. Heavier freezing during 
the late fall and AA’inter is more likely to do serious damage 
to the germination of corn not fully matured. 
FIELD SELECTION IN 1913 
In the fall of 1913, corn samples of variou> degrees of 
dryness were selected from the field on October 30, after 9 
days of considerable freezing weather, during Avhich time 98 
hours ()t freezing temperature prevailed, with a minimum of 
bi f- I notes on viability and color of germ are given 
in Table 16. The freezing temperatures which occurred 
during the hill and to which the corn had been exposed are 
indicated in 1 able 1». I able 18 summarizes these tempera- 
ture.*'. giving the duration and the ine*n and minimum tem- 
perature of each freezing period. 
