THE POTATO 243 



of California. In the Mississippi Valley the com- 

 mercial area extends as far north as the southern 

 part of Iowa, Illinois, and Indiana. The region 

 around Louisville, Ky., is noted for excellent crops 

 of sweet potatoes. 



"Sweet potatoes thrive on a moderately fertile 

 sandy loam which does not contain an excess of 

 organic matter. They are frequently grown upon 

 almost pure sand, especially where the subsoil is a 

 yellow clay. Soils containing considerable cal- 

 cium or underlain with limestone are well adapted 

 to the growing of the crop. The sweet potato is 

 exceptional in that a fairly good crop can be grown 

 upon soils that are too poor for the production of 

 the majority of farm crops. Sweet potatoes yield 

 a fair crop on the 'wornout' tobacco and cotton 

 lands of the South, especially when used in a rota- 

 tion including some leguminous crop for increasing 

 the humus in the soil. 



"The more common varieties of the sweet potato 

 have for a great many years been propagated by 

 cuttings, or sets, taken either from the potatoes 

 themselves or from growing vines, and as a result 

 the plants have ceased to flower and produce seed. 

 The greater portion of the commercial crop is 

 grown from sets, or 'draws,' produced by sprout- 

 ing medium-sized potatoes in a warm bed of soil. 

 In the Southern States the seed potatoes are fre- 

 quently cut into pieces in the same manner as Irish 

 potatoes and planted in the row where they are to 

 mature. Where several plants appear in one hill 

 they are thinned, and those removed are used for 

 planting other land. In the South Atlantic and 

 Gulf Coast States the sweet potato is frequently 

 propagated by making vine cuttings. A compar- 

 atively small bed of seed potatoes is planted quite 



