10 
Colorado Experiment Station 
The seeds of many plants have a rest period. That is, they 
will germinate better after a period of rest than they will when first 
mature. This dormancy is more common among wild plants than 
among domesticated ones. For example, wild oat- experiences a 
delay in its germination, seldom germinating the same year that it is 
formed; on the other hand, the seeds of cultivated oats will ger¬ 
minate the same year in which they are formed. The seeds of a 
number of weeds will lie in the ground for years in a dormant state. 
It has been shown that some seeds are still viable after thirty years 
burial in the soil. Among such are the seeds of pigweed, black mus¬ 
tard, shepherd’s purse, common dock, green foxtail and evening 
primrose. 
There is an old saying that one year of seeds means seven years 
of weeds. A crop of seeds is borne; some of them may germinate 
immediately if the conditions are favorable; others may remain dor¬ 
mant for a year or two, and still others may remain dormant for five 
or six or seven years. In cultivation the seeds may be buried to 
such a depth that they do not get enough oxygen to germinate. Con¬ 
sequently, they lie dormant in the soil. Later, perchance, they may 
be turned to the surface in plowing and brought under conditions 
favorable to their germination. 
3. Freezing. Corn often suffers from freezing before the grain 
is thoroughly dry. The tissue of the grain is broken down by the 
freezing of the water in it. If the grain becomes thoroughly dried, 
it will withstand very low temperatures. Corn containing 13% 
moisture may be stored with safety in bins exposed to very low tem¬ 
perature. 
Corn raised along its upper altitudinal limits in Colorado may 
quite frequently suffer from an early frost; and although the grain 
may have the appearance of being healthy in every respect, many of 
the germs may be killed or their vitality considerably reduced as a 
result of the freeze, although slight. Consequently, it is very essen¬ 
tial that Colorado-grown corn be given a careful test for germination 
before planting. Where frost was known to have injured part of a 
crop, or there is any doubt about the viability of the seed, it is the 
safest plan to have germination tests made. If the test is low, and 
better seed is not obtainable, the deficiency can be made up by in¬ 
creasing the rate of planting. All seed corn, no matter what its source, 
should be carefully tested this year for germination. 
Corn grown in Colorado in 1917, that has been tested to date at 
the Colorado Seed Laboratory, shows extremely wide variations in the 
percentage of germination, from almost zero to 95%. 
4. The low vitality of seed may he due to the unfavorable con¬ 
ditions which prevail at the time the seeds are maturing. Most seeds 
mature best under dry atmospheric conditions. 
5. The vitality of seeds depends largely upon the manner of 
euring. 
6. Storage conditions affect in a very marked degree the vitality 
of seeds. 
