BOOT SYSTEM OF PLANT 205 



weight of water. How many pounds of water in a 

 bushel of potatoes? 



7. If 150 bushels per acre of potatoes is a good yield, 

 how many pounds of water in the potatoes grown on an 

 acre? 



LESSON LXI 



THE ROOT SYSTEM OF THE PLANT 



Kinds of root systems. The root system of the plant 

 consists of the entire group of roots upon the plant. 

 There are two kinds of root systems : 



(1) Tap-root central main root with smaller roots 

 coming out from it. Examples may be found in the 

 beet, radish, and turnip. 



(2) Fibrous root many roots of nearly the same 

 size. Examples of this type are seen in the grasses, 

 such as timothy and blue grass. Either of these two 

 types may have many modifications. 



Roots and tillage. Methods of cultivation should 

 take into account the nature of the roots of the plants. 

 Tap-rooted plants require depth of soil, and will permit 

 deeper and closer cultivation than fibrous rooted plants. 

 On the other hand, fibrous rooted plants, such as the 

 corn, are often injured by too deep cultivation during 

 the growing season. The fibrous roots of such plants 

 are near the surface of the ground, and when destroyed 

 by deep cultivation, much of the food supply of the 

 plant is cut off, and to that extent the plant is injured 

 or retarded in its growth. 



