262 Subtropical Vegetable-Gardening 



good condition until they begin to sprout in the spring. 

 The harvesting may be done by plowing out the row and 

 then picking up the tubers that are in sight. A harrow 

 is then run over the furrow to drag out as many more as 

 is practicable. Hogs may be turned into the field to 

 gather what is left. If the hogs are not left in the field 

 too long, tubers enough will be left to produce plants for 

 another year, but these will not be in rows, so they can- 

 not be cultivated as before. This difficulty may be 

 avoided by saving tubers enough to plant the field again. 

 The tubers may be stored in dry earth. 



YAM 



Different species of yam (genus Dioscorea) grow wild or 

 are cultivated throughout the tropical belt, and even in 

 the subtropical regions of China and Japan. They have 

 large perennial rootstocks containing much starch (seldom 

 sugar). From these arise long twining vines with heart- 

 shaped leaves. Some varieties of sweet potato are called 

 "yams" in the southern United States, but the real yams 

 have no resemblance to the sweet potatoes. Yams 

 form an important article of food for the laboring classes 

 in the West and East Indies, and the best varieties are 

 served at the table in all houses where the potato cannot 

 be obtained, as is often the case. 



As a table vegetable, even the best yams are inferior 

 to the potato, although when properly cooked they make 

 a passable substitute. It does not seem likely that the 

 yam will come in favor at any northern market where the 

 potato can be obtained, except perhaps as a curiosity. 



