58 CORN 



The Department of Agriculture in seed investigations has tried to 

 imitate nature in the germination of seeds. A temperature of 64 

 degrees to 68 degrees F. was maintained, but during six hours out of 

 each twenty-four, the temperature was raised to 86 degrees F. *Pam- 

 mel gives the minimum degree for the germination of corn as 49.9 

 degrees F., the optimum 91.4 degrees F., and the maximum as 134.8 

 degrees F. The lowest temperature at which maize will germinate, 

 according to Sturtevant, is 43.7 degrees F. for all varieties. Corn 

 seems to do much better under a constant, rather than a changing 

 temperature, which is not the case with more northern native plants. 



Some heat i= generated in the process of germination, but where 

 the seeds are planted in hills by themselves this radiates so rapidly 

 as to be unnotioeable. Low temperature at the time of germination 

 retards growth. Cold, wet, mucky soil which excludes the warmer 

 surface air, produces a weak plant and feeble advancement. Seed 

 beds in the best tilth are conducive to increased activity of the roots 

 and a higher coloring of the stem sprout, showing greater strength and 

 vigor. 



OXYGEN. Oxygen is present in the seed, both in a free and a 

 combined state, but this supply is insufficient for germination. Ger- 

 mination will not take place in water which has been boiled to drive 

 off oxygen. The inhalation of this vital element is followed by the 

 oxidation of the constituents stored in the seed and a consequent evo- 

 lution of energy. With the intaking of oxygen, there is a comparable 

 outgoing of carbon dioxide gas. This process, which is slow and 

 imperceptible,, except by direct and careful experimentation, is called 

 respiration. 



The princij-le upon which the tilling of the soil lies, is in the assist- 

 ance of nature. A soil impenetrable to the air, resists the processes 

 which bring about rapid and substantial growth. It is not alone to 

 eliminate weeds that the seed bed is prepared so carefully. The more 

 delicate operations of vegetation are facilitated. 



The unheahhy appearance of corn on poorly drained soil is usually 

 considered to be due to too much water, when it is really the lack of 

 oxygen. When corn, which has been planted very deeply, is slow in 

 germinating in the spring, especially when continual rains come on, it 

 is due largely to a reduction of temperature and an exclusion of 

 oxygen. 



TIME REQUIRED FOR GERMINATION. The time required 

 for germination depends upon the presence of the conditions just men- 



*Grasses oj Iowa. Vol. 1, Page 91. 



