SWEET POTATO 



SWERTIA 



3291 



the studding in addition to the construction above 

 noted. The floors as well as the ceilings are made as 

 nearly frost-proof as possible and to add still greater 

 safety the roots are not placed on the main floor of the 

 building itself but upon slat floors raised 

 at least 2 inches off the main floor. Besides 

 adding a factor of safety against frost, 

 these slat floors serve another important 

 function, that of facilitating the distribu- 

 tion qf heat throughout the heap of roots 

 during the curing process. The partitions 

 between the bins should also be double- 

 slatted partitions in order to act as venti- 

 lators or chimneys so that the ventilation 

 of the material in the storage may be 

 insured as well as more rapid and more 

 uniform curing. 



The curing of sweet potatoes at har- 

 vest-time is of equal importance with a 

 proper storage room, good ventilation, and 

 the maintenance of a proper storage tem- 

 perature subsequently. As the sweet 

 potatoes come from the field, they should 

 be placed in the bins in layers distributed 

 evenly over the surface, and during the 

 time the house is being filled and for a 

 period of ten days or more thereafter the 

 temperature of the storage house should 

 be maintained at 85 to 90 F. both night 

 and day. After this drying or curing 

 period, the temperature should be gradu- 

 ally reduced, but at no time during the 

 storage period should it fall below 45 F. 

 The temperature which has proved most 

 satisfactory for holding the roots after the 

 curing period is 50 F. While sweet pota- 

 toes can be successfully stored in hamp- 

 ers or crates, most commercial storages 

 depend on the use of bins with slat floors 

 separated by hollow slat partitions. A 

 convenient arrangement is so to construct 

 the storage that each bin holds one car- 

 load or other unit quantity, depending 

 on marketing facilities. In no case should 

 sweet potatoes once placed in storage be 

 rehandled or disturbed in any way until 

 the contents of that particular receptacle, 

 be it hamper, crate, or bin, is to be pre- 

 pared for immediate delivery to the mar- 

 ket. Sweet potatoes will not tolerate 

 sorting or handling of any kind while in 

 storage. The successful keeping of sweet 

 potatoes in storage, therefore, depends on 

 care in using disease-free seed or sets, 

 careful handling of the roots from field 

 to storage, a frost-proof storage provided 

 with adequate heat for curing and ven- 

 tilators for insuring rapid change of air 

 during the curing-period as well as at sub- 

 sequent periods when atmospheric con- 

 ditions demand it, and the load of the 

 house so placed, at time of storing, that 

 any given unit may be discharged without 

 disturbing the remainder of the material 

 in storage. At harvest-time, and at all 

 subsequent periods, except in severe 

 weather when there is liability of injury 

 from frost, sweet potatoes can be dis- 

 tributed in double-headed or burlap- 

 covered, ventilated barrels. Such contain- 

 ers are economical, are more convenient 

 to handle than crates or hampers, and 

 form a satisfactory market unit. Bags 

 should never be used. In cold weather 

 when perishable freight or express is liable 

 to frost-injury, strong hampers holding 



3751. Leaves of sweet potato. 



one and one-half bushels or one-half barrel are often 

 used as containers for sweet potatoes. Such packages 

 are prepared for shipment by first lining them with a 

 tough grade of paper, and, after the container has been 

 filled and covered, wrapping it with a 

 similar material. One of the great handi- 

 caps to the sweet potato industry at the 

 present time is the highly perishable nature 

 of the crop, making it difficult for those 

 who do not have the best of facilities to 

 market the crop during severe weather 

 except to nearby markets. 



There are two important types of sweet 

 potatoes grown in the United States, one 

 with a dry mealy flesh and another with a 

 flesh of a soft, moist, sugary consistency 

 when cooked. The northern markets gen- 

 erally prefer the dry mealy varieties with 

 yellow color, while the soft, moist sorts, 

 either light or deep yellow in color, are 

 preferred by the southern markets. The 

 commercial grower will therefore grow the 

 sort or sorts demanded by the markets in 

 which he expects to dispose of his product. 

 His own likes and dislikes should not be 

 given any weight in choosing market sorts. 

 Among the dry mealy-fleshed sorts may 

 be mentioned Big Stem Jersey, Yellow 

 Jersey, Early Carolina, and Triumph; 

 characteristic representatives of the other 

 class include such sorts as Nancy Hah 1 , 

 Georgia, Pumpkin Yam, Dooley, ana 

 Porto Rico. L. c. CORBETT. 



SWEET SCABIOUS: Scabiosa. Sweet-scented 

 Shrub: Calycanthus. S.-Sop: Annona squamosa. S. 

 Sultan: Centaur ea moschata. S. Vernal Grass: 

 Anthoxanthum. S. William: Dianthus barbatus. 



SWERTIA (named for Emanuel Swert, 

 a bulb-cultivator of Holland and author of 

 "Florilegium," 1612). Also spelled Sweer- 

 tia.Gentianacese. Erect, simple or branched, 

 perennial or annual herbs, some of which are 

 hardy, others adapted to the greenhouse; 

 mostly border or rock-garden plants. 



Leaves opposite, or radical in the peren- 

 nial species, long-petioled, some of the 

 cauline Ivs. sometimes alternate: fls. blue, 

 rarely yellow, arranged in racemose pani- 

 cles or laxly corymbose; calyx 4-5-parted, 

 segms. linear or lanceolate; corolla-tube 

 very short, rotate, glandular-pitted, lobes 

 4-5, overlapping to the right; stamens 4-5; 

 ovary 1-celled: caps, dehiscing by 2 valves 

 at the sutures. About 85 species, widely 

 scattered about the world but mainly 

 from S. Asia. 



A. Nectariferous pits destitute of a fringe. 



dilute, Benth. & Hook. (Ophelia dUitta, 

 Ledeb.). A tender perennial about 1 ft. 

 high : st . winged and angled, branching from 

 near the base: Ivs. glabrous, ovate-lanceo- 

 late, 3-nerved, rather obtuse, rounded at 

 the base, short-petioled: fls. 4-merous, 

 blue, in a dense, fastigiate umbel; corolla- 

 lobes ovate, rounded at the apex and bear- 

 ing at the base a single ovate,'nectariferous 

 pit destitute of a fringe. E. Asia, Japan. 



AA. Nectariferous pits with a fringe. 



B. Pits oblong. 



punctate, Baumg. Perennial: sts. as- 

 cending from the base, many-fld. : Ivs. sev- 

 eral, alternate, elliptic-oblong, acutish; 

 lower attenuate to a broad petiole : fls. erect, 



VIMtLESMUA.J 



