26 FARMER'S BOOK OF GRASSES 



water than any other variety that I have examine^!. Hence I 

 object to it. It has so little solid matter that it may be cooked 

 through in one-half or one-fourth the time required to cook 

 some other varieties. 



The Bermuda is another red variety with mostly elongated 

 brittle tubers very many of them breaking in harvesting and 

 the skin slipping off easily on prsssure. Yet I prefer this to the 

 preceding. It yields largely and is more dense than the Cuba in 

 texture. 



The Shanghae has a white tuber very hard, rather insipid, 

 sometimes with much woody fibre, few rounded, but rather in- 

 clined to elongate indefinitely, gradually diminishing in size as 

 the roots of a tree. It yields largely of both vines and tubers. 

 In harvesting the tubers are broken, the milky gum probably com- 

 bined with some resin adheres tenaceously to the skin and what- 

 ever else it may come in contact with, and it is very difficult to 

 scrape or wash off. 



The Brazilian yam, another white variety is my preference 

 for forage. It is not so early perhaps as one or two other varie- 

 ties; but it produces immense crops of vines and tubers, a good 

 proportion of the latter rounded, and containing a very large 

 quantity of nutritious material. They grow very large too, ran- 

 ging from one to fifteen pounds in weight. Sometimes one is 

 found that cannot be put into a peck measure. The Southern 

 Queen is perhaps as valuable as the preceding. 



Soil. The sweet yam attains greatest perfection on a rather poor 

 sandy clay soil. The Spanish requires a similar soil but richer. 

 The. other varieties named above require still richer soils with 

 less sand. The more sod, straw and weeds turned into the bed 

 and covered the better provided there be earth enough to enable 

 the plants to take root. The crop must be kept free from grass 

 and weeds. No crop is more seriously damaged by grass than 

 the sweet potato. They require a large, loose, deep bed, and -A 

 little earthing up about once. I greatly prefer a high flat bed to 

 the sharp ridge or conical hill. With the flat bed the cultiva- 

 tion can be managed mostly with the plow, and the plants suf- 

 fer less from drought, than in the sharp topped ridge. 



Whatever mode be adopted, there is a tendency in the vines 

 to strike root at every joint, especially if there be frequent falls 

 of rain. These roots form tubers and diminish the size and 

 quantity of those in the bed. Hence it is well, v/hen this occurs 

 to lift the vines from the ground so as to destroy these seconda- 

 ry roots. 



Harvesting After removing the vines as above described or 

 otherwise, the bed may be opened with the digger, or with any 

 large turning plow, hands following to pick up and pile the po- 

 tatoes turned out at each passage of the plow. After all visible 

 are thus removed a heavy harrow mav then be run over the 



