3290 



SWEET PEA 



SWEET POTATO 



the plants are piled in small heaps and left for several 

 days to dry. They are then put in large piles to cure 

 which takes from three to four weeks. As soon as all 

 the seed is perfectly cured and sufficiently dry, the 

 thrashing begins. This is usually performed by gasoline 

 power, and the clean seed is run directly from the 

 thrasher into the sacks. ANT. C. ZVOLANEK. 



SWEET POTATO. The plant Ipomaea Batatas, 

 grown for its large edible root^tubers (Fig. 3750). The 

 origin is not definitely known (see page 1662, Vol. Ill), 

 but it is probably tropical American. It is a widely 

 variable plant in foliage, as shown by the leaf-forms in 

 Fig. 3751. The top is herbaceous, form a running vine. 

 Flowers and fruits are rarely seen. 



Neither the acreage, production, nor the money value 

 of the sweet potato crop give an adequate idea of its 

 economic importance. In those parts of the earth's 

 surface where it thrives, it forms an important food 

 staple for the inhabitants, and thus occupies a position 

 not accorded crops which, though of great money worth, 

 do not contribute directly to the food-supply of the 

 territory in which they are grown. 



The sweet potato, being native to tropical and sub- 

 tropical regions, is restricted in its range of cultivation 



3750. A good hill of sweet potatoes. 



more by climatic than by soil conditions, although its 

 commercial cultivation is confined almost exclusively 

 to sandy or loamy soils. It is, in fact, one of the staples 

 of the southern states which thrives well on lands that 

 have been considerably depleted by cropping with 

 other plants, and one which can be made to produce 

 a profitable return on light sandy soils carrying little 

 humus, provided an adequate supply of plan Wood in the 

 form of commercial fertilizer is available. The ability 

 of this plant to thrive and produce under such condi- 

 tions, together with its great food value, which is con- 

 siderably higher than that of the Irish potato, has served 

 to advance it to the position of second place among 

 the truck crops grown in the South and to seventh place 

 among the standard agricultural crops of the nation. 



Botanically the sweet potato belongs to the Con- 

 volvulus or morning-glory family. The edible part is 

 the thickened root. It does not possess eyes or scars 

 as do some other roots and tubers, but it possesses the 

 ability to develop adventitious buds, which character 

 is taken advantage of in reproducing the crop by vege- 

 tative means. 



Roots to be used for seed purposes, selected at the 

 time of harvest, are usually small, from 1 to 1J4 inches 

 in diameter, of uniform shape, and characteristic of the 

 variety. These roots are cured and stored under con- 

 ditions most certain to insure an adequate supply of 

 seed material, which, at the northern limit of the culti- 

 vation of the crop, is needed for bedding in April to 

 insure a supply of "draws" for planting during the 

 second and third weeks in May. 



The seed-supply should not only be selected as above 

 stated but it should be chosen from healthy plants and, 

 in addition, should be carefully examined for disease. 

 All specimens showing the slightest trace of decay or 

 rot of any kind should be discarded. 



The soil for the plant-bed, whether it be in the 

 open or a manure- or fire-hotbed, should be free from 

 contamination preferably sterilized. If such precau- 

 tions are observed, the first step in the insurance of 

 the crop against loss from rot either in the field or in 

 the storage house has been taken. Young sprouts 

 which grow from the bedded seed roots are known as 

 "draws" or "sets." These are chiefly used for planting 

 in the field, but roots, or pieces of roots, may be and 

 sometimes are used. In the warmer sections where 

 seasons are long, it is a common practice to grow enough 

 early draws or sets to plant an area large enough to give 

 a sufficient quantity of vine cuttings to plant the com- 

 mercial area. This is a good system as it insures disease- 

 free plants, so far as the root-rots are concerned, for 

 setting the field. An even closer approach to a let-alone 

 system is followed in some sections. Instead of har- 

 vesting and storing seed and propagating sets, a portion 

 of last season's crop is allowed to remain unharvested 

 over winter and it is from the volunteer plants of such 

 an area that a supply of vine cuttings for the com- 

 mercial plantation are secured. 



Sweet potatoes are for the most part long-stemmed, 

 creeping, or viny plants. They can be planted in hills 

 but are more often set on parallel ridges thrown up 

 30 to 36 inches apart. The ridges are often made by 

 throwing two furrows together over a trench in which 

 well-rotted stable-manure has been scattered, or in 

 which commercial fertilizer containing a liberal per- 

 centage of potash has been placed. On such ridges the 

 draws are usually planted, either by the use of a hand 

 dibble, tongs, or transplanting machine, 14 to 16 

 inches apart. 



The subsequent culture consists in keeping the area 

 free of weeds with horse-drawn implements as long as 

 the growth of the plants will permit even by the use 

 of a vine-lifter, after which all large weeds are removed 

 by hand. 



The signal which summons all hands to the sweet 

 potato harvest is the first frost which causes the leaves 

 to blacken. The home-garden plantation will be har- 

 vested with potato forks or with a turning plow after 

 the vines have been cut away with a hoe, but the com- 

 mercial area will be entered with a special digging-plow 

 with rods in place of a moldboard and two rolling coul- 

 ters so arranged on a cross-piece fastened to the beam 

 of the digger that they cut the vines on either side of 

 the ridge, thus preventing their interference with the 

 operation of digging. As soon as the roots have been 

 turned out and have dried in the sun, they should be 

 carefully gathered, so as to avoid breaking or bruising, 

 into one-half- or five-eighths-bushel hampers and hauled 

 on spring wagons to the curing and storage house. 

 In placing the roots in the house, care should be exer- 

 cised to avoid breaking or bruising them. Some growers 

 spread layers of pine straw between each 12- or 15-inch 

 layer of roots placed in the storage house. This practice 

 is less common at the present time since especially 

 designed storage houses have come into general use. 



The storage houses in most general use both North 

 and South are frame structures built entirely above 

 ground, although there are a few houses at the North 

 that possess a basement or semi-basement story used 

 for the storage of sweet potatoes. These frame struc- 

 tures are so built that their contents are exposed in the 

 least possible degree to outside changes of temperature. 

 While the buildings are not insulated, they are provided 

 with paper between the studding and sheeting, between 

 the sheeting and the clapboarding, and on the inside 

 under the sheeting. In the more exposed situations, 

 either back plaster or a strip of paper is used between 



