Page:Foods and their adulteration; origin, manufacture, and composition of food products; description of common adulterations, food standards, and national food laws and regulations (IA foodstheiradulte02wile).pdf/334

 condition of growth and, to a certain extent, its chemical composition and uses, the term potato has, in this country at least, become to be universally applied to both, although the prefix "sweet" is quite commonly used with the sweet potato, whereas if any prefix is used with the potato, properly so-called, it is the word "white" or "Irish." The sweet potato is grown extensively in the United States and in other respects, agriculturally, may be regarded as complemental to the potato.

While the potato grows best in the northern parts of the country and in mild climates, the sweet potato flourishes in the greatest abundance in the southern and warmer portions. In respect to the character of the soil the two vegetables are quite similar, both doing best in a sandy or loose soil, provided it is sufficiently supplied with plant food for the use of the growing plant. The sweet potato is a thickened root, and is propagated almost exclusively by means of shoots called "slips."

Planting and Cultivation.—There is a very distinct difference between the planting of the sweet potato and that of the potato. The former are rarely planted in the field where the crop is to mature. It is quite a universal custom to plant the sweet potato in beds where the young growth can be forced both by means of artificial heat and by a generous mulch of highly nutritious soil. The plants can then be set very early in the spring and by the time they are ready to be transplanted to the field have acquired a considerable size. When ready for transplanting the seed bed is prepared with the same care as that required for the potato. The ridging of the rows, which in the case of potatoes takes place during cultivation, is accomplished in the case of sweet potatoes before planting. If the soil is moist and the temperature not too high the young plants are removed from the seed bed and set on top of the apexes in the formed rows. The cultivation of the field during the growth of the crop is sufficient to keep the surface in good tilth and prevent the growth of weeds, grass, etc. Care must be exercised in the cultivation not to draw the earth away from the ridges which have been formed, but to increase their size by drawing the earth more and more toward the apex of the ridge. The cultivation is continued until the growing vines practically cover the surface of the soil and thus form a natural mulch, which not only conserves the moisture and tilth of the soil but also prevents the growth of weeds and grass. The sweet potato, in respect of its flavor, is particularly sensitive to the influence of frost, also the leaves are more sensitive to frost than those of the potato. If a heavy frost is experienced before the tubers are harvested it is apt to impart an unpleasant taste to the potato and injure its edible qualities. For this reason, if it is not possible to harvest the potato before the advent of frost, it is advisable to cut the vines at the point where they emerge from the soil. When this has been done the injurious effects of the frost, above mentioned, are not experienced. In the southern