The experience of the last fifteen
years has taught that the occasional failures to which even good
dry-farmers have been subjected have been caused almost wholly by
uncontrollable unfavorable conditions prevailing at the time of
sowing.
Conditions of germination
Three conditions determine germination: (1) heat, (2) oxygen, and
(3) water. Unless these three conditions are all favorable, seeds
cannot germinate properly. The first requisite for successful seed
germination is a proper degree of heat. For every kind of seed there
is a temperature below which germination does not occur; another,
above which it does not occur, and another, the best, at which,
providing the other factors are favorable, germination will go on
most rapidly. The following table, constructed by Goodale, shows the
latest, highest, and best germination temperatures for wheat,
barley, and corn. Other seeds germinate approximately within the
same ranges of temperature:--
Germination Temperatures (Degrees Farenheit)
Lowest Highest Best
Wheat 41 108 84
Barley 41 100 84
Corn 49 115 91
Germination occurs within the considerable range between the highest
and lowest temperatures of this table, though the rapidity of
germination decreases as the temperature recedes from the best.
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