GERMINATION OF FROZEN AND NONFROZEN WHEAT 
HARVESTED AT VARIOUS STAGES OF MATURITY 1 
By W. O. Whitcomb and Paul Francis Sharp, Montana Grain Inspection 
Laboratory and Department of Chemistry, Montana Agricultural Experiment 
Station, Bozeman, Mont. 
INTRODUCTION 
In the northern part of the United States, and especially in the 
Rocky Mountain region and in western Canada, where the growing 
season is relatively short, spring wheat is frequently subjected to 
temperatures below freezing at immature stages of growth. Kernels 
threshed from frosted wheat may be recognized by the blistered 
or wrinkled appearance of the outer layers of the bran and by their 
green pigmentation. Usually the more immature the wheat at the 
time of frost the greater the number of green kernels. The green 
kernels may not be blistered. 
Lugger ( 10 ) 2 attempted to distinguish between frosted and 
frozen wheat. He states: 
We see at once the important difference between frosted wheat and frozen 
wheat. In the former germination may take place in most cases; in the latter 
never, because the living substance of the seed, the protoplasm, is dead and can 
not be resurrected by any known means. 
Harper (7) states more clearly the difference, saying: 
Frozen wheat is badly shrunken, has lost the normal translucent amber color, 
is of an opaque bronzed appearance, and has had the composition of its chemical 
constituents changed as well as the internal structure of its cells destroyed. 
Blistered (frosted) wheat retains the normal amber color, but has in many cases 
more gluten and protein and less starch than sound wheat, and is injured for mill¬ 
ing on account of the bad condition of the hull. Only in extreme cases has there 
been any injury tb the germ and its surrounding food, so that it is all right for 
seed, if well cleaned, except in some cases where frost has caused the injury 
because of the tardiness of the wheat to mature. 
Green ( 5 ) tested the germination of frosted wheat in soil in the 
greenhouse. He found that the germination in the series of graded 
Frosted wheats which he investigated ranged from 68 to 92 per cent. 
The lowest value found for 8 samples of wheat classed as chicken 
feed was 42 per cent. Some of these samples had been injured by 
both frost and rust. 
Keffer ( 8 ) examined 13 samples of wheat. He determined the per¬ 
centages of “plump,” “slightly shriveled,” and “much shriveled” 
kernels in each sample. Seven samples which contained 50 per cent 
or more of much shriveled kernels and averaged 72 per cent gave an 
average germination of 72 per cent in soil and 82 per cent between 
moist papers. Three samples with a content of much shriveled ker¬ 
nels ranging from 29 to 47 per cent gave an average germination of 
about 76 per cent in soil and 91 per cent between moist papers. 
The wheat which he reported as normal contained 5 per cent of much 
shriveled kernels and gave a germination of 82 per cent in soil and 99 
per cent between moist papers. 
1 Received for publication May 2, 1925; issued December, 1925. Published with the approval of the 
director of the station. 
2 Reference is made by number (italic) to “Literature cited,” p. 1188. 
Journal of Agricultural Research, 
Washington, 1). () 
(1179) 
Vol. XXXI, No. 12 
Dec. 15, 1925 
Key No. Mont-13 
