Indian Corn Culture p 48-50 (1895)

Charles S. Plumb, B. Sc.

* New York agricultural experiment station. Report 1884, p. 118, and report 1885, p. 64.
+ Ibid.,pp. 123-124.

Germination temperature.—Seeds of different classes of corn do not germinate with equal rapidity under the same conditions. Corn from a hot climate, such as the soft varieties, will not germinate at as low a temperature as will that grown in cooler latitudes, as for example, the flints. Sturtevant made an extensive study of germination temperatures for corn at the New York experiment station.* These germination tests were conducted in boxes where the temperature was uniformly under control. Seeds of dent corn germinated at as low a temperature as 43.4 deg. F., after 233 hours, probably the lowest temperature recorded for this seed up to this time. In reporting upon the general results of his trials in 1884, Sturtevant says:+

"First, all the kernels of an ear do not germinate with equal ease or with the same increment of temperature; second, that there is a difference in the time and temperature required between some of the agricultural species of maize; third, that the dent corns germinate at a temperature of 47.6 deg. F., or slightly below; flints at a temperature of 47.8 deg. F., or slightly below; pops and softs ditto; while sweets required 48.5 deg. F., or slightly below; fourth, that the increment of temperature required in our trials was far greater for the sweets than for the other agricultural species."

Under the same conditions of temperature, the dents germinate first, flints second, pops and softs next and sweets last, the range being from 168 to 228 hours.

As observed farther on in the chapter on planting a soil temperature of from 50 to 60 deg. F., will justify planting. While the seed may germinate at below this, the chances are that it will decay, or the young plants make a most unsatisfactory growth. It would not even be especially advisable to plant when the surface soil has a temperature of 50 deg. F., unless quite warm weather could be expected.