WHEN SEEDS SPROUT 



15 



How Germination Takes Place. The dry seed is in a dormant 

 state, with all life processes practically arrested. When proper con- 

 ditions are present, all the life processes are started anew and growth 

 begins. 



Before growth can take place, three conditions are necessary : (1) 

 There must be sufficient moisture, so the seed can secure all it will 

 readily absorb. (2) There must be air present. If the soil is so 

 compact and filled with water that no air can reach it, the seed will 

 rot. Whereas, pure oxygen was given off when the plant developed 

 starch and stored energy, the plant must now take up oxygen by 

 oxidizing or "burning" some of the carbohydrates. (3) There 



FIG. 4. Germination in corn. On the left is a kernel of corn before germination, 

 while the center shows a similar grain, with the surface shaved off to expose the germ. OP 

 the right is a kernel beginning to germinate. 



must be sufficient heat. Some seeds, as clover or oats, will grow at 

 rather low temperature (40 to 50 F.) and start growth very early 

 in the spring. Other crops, as corn or beans, require a higher tem- 

 perature for best growth (70 to 80 F. is most favorable), and 

 should not be planted until the ground is warm. When proper con- 

 ditions for germination are present, seeds begin to grow (Fig. 4). 

 Certain active agents in the seed (enzymes) begin to dissolve the 

 stored plant-food, converting starches into sugars, so they can be 

 readily absorbed by the growing plant. 



When Seeds Sprout. In two to four days after seeds have been 

 placed under favorable conditions, the " sprouts " begin to appear. 



