138 



Nature-Study Agriculture 



Sprouting 

 and setting 

 out 



Keeping 



Methods of 

 propagating 

 onions 



Growing 

 sets 



sandy soil. In the South the large, juicy varieties 

 known as " yams " are preferred, while in the North 

 the smaller, drier kinds are better liked. Sweet potatoes 

 will grow in almost pure sand, but they need a good deal 

 of moisture. 



In starting the plants a hotbed is used. The plot is 

 covered with a layer of the potatoes laid about half an 

 inch apart, so that any rot that starts in one will not 

 spread to others. The potatoes are then covered with 

 four or five inches of sand or light soil. Many sprouts 

 come up from them, and when these sprouts are about 

 six inches above ground they are carefully pulled. The 

 potatoes are left in the hotbed to produce more sprouts. 

 The first pulling yields ten or twelve sprouts from 

 each potato. In the South " slips " for later plantings 

 are obtained by cutting the ends off earlier vines. 

 Sprouts or slips should be set about sixteen inches apart 

 in ridges three feet apart. The vines will spread over all 

 the ground. During cultivation they should be moved 

 with the hoe to prevent them from taking root (Fig. 112). 



Sweet potatoes must be fully ripe to keep well, and 

 they keep best in a warm place. A test for ripeness is 

 made by breaking a potato in two. If drops of water 

 form at the broken ends, the potato is not ripe. 



Onions. Where many onions are to be raised, it is 

 customary either to plant seeds or to transplant young 

 seedlings from a nursery. But onions may be most 

 quickly grown from sets. These are raised like ordinary 

 onions, but they are planted thicker about two 

 hundred seeds to the foot in each row and usually 

 upon land not very rich or very well supplied with 



