TUBER CROP PROJECTS 221 



or potatoes and also in the outline of the leaves, but the most 

 common method of dividing them into groups is on the basis of the 

 amount of water and sugar present in the potatoes. The ones 

 with a dry, mealy, yellow flesh are usually called sweet potatoes 

 and are mostly used in the northern states. In this class belongs 

 the Jersey sweet potato, in which the roots are spindle-shaped. 

 The so-called yams have a watery flesh, are sweeter, and are soft 

 and jelly-like when cooked. These are most used in the southern 

 states. They should not be confused with genuine yams, which 

 belong to another family, closely related to the lily family. Several 

 species of insects, such as tortoise beetles, flea beetles, or the sweet 

 potato weevil, occasionally harm this crop, but the injury, except 

 from weevil, is usually not extensive. 



1. What are some of the close relatives of the sweet potato ? 



2. What is the nature of the part of the plant called the " potato " ? 



3. How do so-called yams differ from ordinary sweet potatoes ? 



4. What insects affect the sweet potato? 



