32 FIELD CROP PRODUCTION 



roots of plants 35 or 40 days old will meet between the 

 rows, and when the corn is in tassel, they will reach into 

 almost every inch of the upper soil. The depth to which 

 the roots will penetrate depends largely upon the position 

 of the water table and upon the texture of the soil. In 

 loose, fertile soil they have been known to penetrate 5 or 

 more feet, and even in clay soils they will extend as far as 

 4 feet into the ground. When the permanent root system 

 is well started, the temporary system withers and dies, 

 since its period of usefulness is ended. 



The brace roots spring from the first, second, third, and 

 sometimes from the fourth node above the ground. They 

 are so called because their chief function is to form braces 

 or props, to prevent the plant from being blown over. 

 When wind or rain bends the plants over, brace roots are 

 rapidly produced from the side of the node nearest the 

 ground, to prevent succeeding storms from laying them 

 low. Usually when the plant stands upright, the brace 

 roots do not grow very long, if at all, although they some- 

 times do when the plant is favored with good growing 

 weather, or by very fertile soil. The portion of the brace 

 root above the ground is considerably enlarged and is 

 dark green in color. Those which enter the ground are 

 reduced in size there, and perform the same function as 

 the underground roots. 



28. The stem or culm. The stem of the corn plant, 

 unlike that of wheat and oats, is filled with pith. It 

 differs also from the culm of the other cereals, in the shape 

 of the internodes, which, with the exception of those near 

 the top, are slightly flattened or grooved on the side next 

 to the leaf sheath. Where an ear is developing, the inter- 

 node beside it is greatly flattened, or even becomes curved 

 to make further room for the growing ear. Corn stalks 



