CULTURAL DIRECTIONS 
441 
power of reproduction, and this difference is often recog- 
nized in the charges made by plant dealers. In the far 
South, where the summers are very long, so that cuttings 
may be made with freedom after the plants begin to vine, 
an acre in the field may produce enough plants for 1 to 
4 acres, although too severe pruning will reduce the 
yield on the propagating area. Plants from cuttings 
are said to produce the best seed. Whatever the size of 
FIG. IOI. FRAMES FOR GROWING SWEET POTATO PLANTS 
tubers selected, they should be handled with extreme 
care to prevent bruising and injury and kept as directed 
in the notes on storage (637). Freedom from disease is 
especially important. 
630. Propagation. — Sweet potatoes are usually propa- 
gated by means of “slips,” also known as “sets” and 
“draws.” The tubers are first bedded in fine soil, with 
proper heat and moisture. The potatoes sprout and 
produce rooted plants, which are removed and planted 
in the field after all danger of frost has passed. 
