MARKET TYPES 



289 



use of the sweet potato as a truck crop has had a rapid development. 

 It is now the most important vegetable next to Irish potatoes. 



Types and Varieties. While there are many varieties of sweet 

 potato, no very satisfactory classification has ever been worked out. 

 They are sometimes placed in two groups, called vine and vineless 

 potatoes, the term " vineless " applied to the varieties having a short, 

 upright vine. It has also been attempted to subdivide the groups on 

 the shape of the leaf, as certain types have deeply-lobed cut leaves, 

 and others regular leaves with uniform edges ; but this is not a satis- 

 factory character to use. They may 

 also be grouped as dry and moist 

 or syrupy types. The <dry types 

 are usually grown in the North 

 and are represented by the Jersey 

 Yellow variety. In the southern 

 States the varieties with soft flesh, 

 sometimes called watery or syr- 

 upy, are usually preferred. Most 

 of the varieties of so-called "yams" 

 in the South belong to this group. 

 They may also be grouped accord- 

 ing to color of tuber, as white, 

 yellow, or pink. Probably a hun- 

 dred varieties of sweet potatoes 

 are cultivated, but not more than 

 a dozen of these are very exten- 

 sively grown. 



Market Types. The northern 

 rather dry sweet potato, of medium size, and not very long (Fig. 

 116). The yellow color is generally preferred. . The most impor- 

 tant varieties in the northern market are the Big-stemmed Jersey, 

 the Yellow Jersey, and Red Jersey. The first of these varieties is the 

 most productive and preferred by the truck growers, but the latter two 

 are of a better quality and suitable for the home garden. In the 

 southern States the Hayman, a soft-fleshed variety, is very popular. 

 Several of the yams, which differ from the ordinary sweet potato in 

 being short and thick, somewhat larger, with a moist, syrupy flesh, 

 19 



Fio. 115. Sweet potato leaf and blossom. 



market usually demands a 



