Varieties of Roots. 



133 



at the expense of the food already stored in the stem and root and reduce 

 the feeding vahie of the root, hence plants showing these characters 

 should never be kept for breeding purposes. 



The stem or hypocotyl. This part of the mangel is rich in nutrients. 

 It varies in length in different varieties. In some varieties it is above 

 ground, in others, as in the Kleinwanzlebener sugar-beet, it is below 

 ground. It is an observed fact that those plants having a large part of 

 the hypocotyl below ground 

 are richer in sugar and of 

 better feeding value than 

 those having a large part 

 above ground. Roots rare- 

 ly arise and grow from the 

 hypocotyl. 



The primary root ap- 

 pears as a continuation of 

 the hypocotyl. It should 

 terminate in a single small 

 tap root, when the root may 

 be said to be smooth; 

 secondary roots, prongs or 

 forks are undesirable, not 

 only because of increasing 

 the cost of harvesting, 

 but because they indicate 

 that the plant is of a coarse 

 and fibrous nature, and the 

 amount of soil they hold 

 renders the roots undesir- 

 able food for stock. Such 

 roots are described as 

 forked or rough in contra- 

 distinction to smooth. 



Fig. 44. — Kleinwanzlebener. One of the best sugar- 

 beets, although itjgrows well into the ground and 

 is expensive to harvest. Six-inch squares. 



The primary root is characterized by two depressions running length- 

 wise down the root, and opposite to each other ; these are known as the 

 dimples. They should be vertical and not too deep. In some cases three 

 dimples may be seen. 



The lateral roots spring from the dimples ; they should be fine, fibrous 

 and fairly abundant, and their origin confined to this area, as when they 

 spring promiscuously from the surface they render the root more difficult 

 to harvest and carry much more soil into the root cellar. 



The fibrous root system breaks off when the plants are harvested. 

 It is quite extensive and where opportunity permits, it will fill the soil to 



