> ^ 1 Sr m I ^SWEET k rOTATOES t$ ^ Issued by The AGRICULTURAL DEPARTMENT New York, N. Y. Medina, O. Athens, Ga. Berkeley, Cal. Number 91 Copyright 1918, by the Barrett Company MAV 10 1918 ©GI.A49725.'> ^ Sweet Potatoes and Yams INTRODUCTION ^TT^ 111-] swi'ft ])ot;it() is. so far as \vt' know, a native of Aiiicrica. It was t'ouinl y'i'(»\viii;i' lu'i't' Aviicii the early colonists arrived ami lias eontiinied to iii- ereaso in vohnne and in favor as a food crop, lieinji' of tropieal origin, it api^ears most extensively in the Southern States, where it is ;:ienerall.\' used and ajipreeiated : in faet.
r in the East Indies and the Philippines has the earlier (daim to the name. The sweet potato was a valued asset in oui' war of the Revolution, for his- tory I'elates that (Jeueral Fi'ancis .Marion, the ""Swamp Fox" of South Carolina, maintained his men for months at a time on little else. When a Hritish envoy came to ti'eat with him. he was invitei'itisli in Louisiana, had hut little food for his men except sweet potatoes. When the lii'itish <:eneral. l*a(djr by hand. SWEET POTATOES AND YAMS Fertilization Fei-tilizers are an important factor in i-aising profital)!*' crops. It is almost impossible to produce the smooth, well-shaped potato Avhich the market requires without using a sufficient quantity of a balanced ration of plant foods. It lias been noted, however, that an oversupply of vegetable mat- ter in the soil or an excess of nitrogen in the fertilizer will affect the quality of the potato and sometimes cause it to crack. It is desirable therefore that the ingredients of the fertilizer be proportioned with due allowance for the qualit}^ of the soil. Amount of fertilizer. An application of stable maiuire alone lias not been found satisfactory. At the New .Iers(\^' Experiment Station comparisons were made Avith the use of commercial fertilizers and stable manure. Com- mercial fertilizers produced a good crop, but a combination of the fci-tilizcr and manure produced a higher yield than when either was used alone. It is generally considered that the sweet potato crop can utilize a heavy amount of fertilizer. An application of from 600 to 1,200 pounds per acre, depending upon the condition of the soil. Avill be found profitable un- (piality. A rule o" tlmiiih. wliicli lias jjiovcd lirlpfiil, is to liafvcst at least ten da\s hci'ort' the avcrajic date of t'rce/iiij:'. iiiasiiiucli as sevcic injury is (H-rtaiii to occui- if the potatoes are still in tin- vroiinil wlifii the first frost eonies on. 'Phi' ero|) should he harvested wIk-ii the soil is dry. I'or it" the woi'k is done in wit weather eai'th will adhere to the potatoes and tlie.\ are liahle to rot. Where |)otatoes are raised on a small scale the oi'dinary iiiidilh' hiister is often used to throw the i-oots out of the f;round. If l;irj;ei' areas are <:i'own a potato di'ei' ina.\' well l)e used. i\e^'ai"dless of the iiiethods of harvestinji', <>reat caie should he taken to prevent l(i-uisin«i' or eiittin;^- the tuhers, and any thus injured should l>e sorted and inuiiediately sold on the local market or fed to live stock. They should never he .stored oi- shipped to a dis- tant market as they will not keej). STORAGE Pool" storajze facilities in the South, where most ol' our sweet |)otatoes aie jirown. ai'e the ei' cent, of the potatoes stoi'ed in hanks or i)its in the Southern States sp"ii ir are of an inferior (piality. This is a difticulty that heai's most heavily on the smaller fi'rowers. An ordinary type of pit is show n in tiji'ure 4. For a numher \n <)ry rot. 'riu' av«'i-a}.'(> Sonilit>rii fariiicr proihircs i-noii;;li swi-ol potatoes lo supply Ills family iifcds tliroiiRli the wliilcr lull liy sin'liiir tlio loss is so lioavy tlial lie lias not iMioiit'li ii'I'l lo liril fell- plants for iioxt season. Stoi'aj;e House. 'I'his large storage house was liuill liy Mi. .lolni I), .\rcliil.ald at Tlioniasville, Oa.. not to accommodate his own needs alone but to help the small growers in the community and to encour- age the industry. These houses are neither expensive nor difficult to build and they aid the '■ommunity by helping to conserve its food supply. 10 SWEET POTATOES AND YAMS markp:ting S^veet potatoes «^r(i\vii lOi- early iiiafUct are harvested, j^ratled. paekecl. aiitl usually shipped the same (la\ . Wliei-i- pioper storage faeilities have been ]>i-ovi(le(l, potatoes are dried in the tield. j;-raded. and placed in storage for \\in1e]' and spring shipment. They iiia.\ he safely shipped in barrels, crates, and ham])ers. Itiit not in l»nlk or in sacks as they are <'asily hi'uised. thereby inviting decay. VARIKTIES Thei-e are a great many varieties of sweet |)olat()es grown in the I'nited States and all dilVer, iin)i'e oi' less, in yiekl. tiavoi-. shape, color and earliness of maturity. Prof. Stuckey writes: "The variety to be grown depends upon the purpose for which the potato is to be used. Northern demand, "n' a grower wishes to suppl\ the .Xorthei-n market he should select a potato that has a light coloi-ed tlesh and is dry and mealy when cooked. To the average Noi-thiM-n famil\- the ideal potato is the Irish potato. The nearei- the sweet ])()tato approaches the hisli potato in texturi' and flavor, the nnn-e salable it will be on the Northern market. Southern demand. "In the South the demand is ditf'ei-ent. To the average Southei-n family a potato with a rich, \ellow Hesh and a \-ery swi'et flavor is preferred. A potato that has a candied appearance after baking, as though it had been dipped in cane siru]). is ideal for the Southern market." The Jersey Yellow or Yellow Nancemond. Triumph and Red Jersey are typical of the dry mealy varieties belonging to the first class. The Pumpkin Yam, Providence. Nancy Tlall, Porto Rico Yam and riolden Beauty represent the yellow, moist, sweet varieties that are popular in the Southern markets. For feeding to live stoek such \arielies as Kiuu-mous. Triumph and SouthiMMi Queen ai'e suggested. FEEDING VALUK OF SWEirr POTATOES FOR LIVE STOCK The principal use of the sweet potato is for human food but this is by no means its only importance. The roots and vines make excellent feed for live stock. The South, which fails to proiluce enough corn and hay for its own con- sumption, can use the sw(M>t potato more largely as a supidenu-nt to its feed production fiom Septend)ei- to Jannai-y. The Southern farmer is interested in finding a cheaper and nH)re pi-oductive source of carl)ohydrates than corn, and the sweet potato tills the need, it is one of the best yielding of the Southern grown root crops. All kinds of live stock seem to be fond of both roots and vines. It is estimated that three bushels of sweet potatoes are equal to one bushel of corn, ami the Florida Experiment Station states that when a ration of oncJialf sweet potatoes and one-half grain was fed to work stock, better results were obtained than with a whole grain ration and at a lower cost. 11 SWEET POTATOES AND YAMS Sweet potato silage vs. corn silage. The same station finds that silage made I'l'oiii sweet ])otatoes is equal in nutritive vahu' to nearly twice the quantity of corn sila<^e. Comparing results ol)taiiU'd from these two crops he says: "Ex- perience in feeding these two silages has been that 100 p®unds of sweet potato silage will replace from 150 to 200 pounds of corn silage in the ration. This, no doubt, is due to the fact that tlu' sweet potato silage contains less water and two and a half tiuu's as luucli nitrogen-free extract as the corn silage." Sweet potato silage for milk. They investigated the relative values of sweet t)()tato and sorghum silage in milk production and found that the former gave better yields. The cows on the potato ration produced 307 gallons of milk, wdiile those on sorghum made 281 gallons. It is pointed out that "One noticeable tfact in this experiment is that the cows ate one-third less sweet potato silage than sorghum silage. This is quite a saving in the amount of feed consumed by a herd during the year." Vines as a feed for live stock. Sweet potato vines make an excellent soiling crop for all live stock. It is rathei" difficult to cure them, so the best results are usually obtained by feetling them when still green. They are nutritive and rank high even in comparison with legumes. In Table II Avill l)e found an analysis made by Prof. Keitt of the South Carolina Station giving the average from four of the common varieties of sweet potatoes, as compared wdtli ha}^ from red clover, crimson clover, cowpeas, and soy-beans. TABLE II. 14.52 8.90 29.28 7.82 44.98 16.81 :5.()8 80.09 9.51 40.51 18.59 2.46 22.51 8.40 48.14 17.86 5.86 25.14 8.12 48.52 (Water-free) Protein Fat Fiber Ash N-free extract Red clover hay Crimson cloNiT hay Cowpea hay Soy-bean hay Average 16.82 3.83 26.76 8.34 44.25 Sweet potato vines 12.48 4.86 18.22 8.73 55.71 CANNING S\VP:ET POTATOES The canning of sweet potatoes is assuming the importance of an industry. although more attention has been paid to it in the North than in the South. Each year many cai- loads of eaniied ]iotatoes are shipped from the North to the South, possible only because a large part of the Southern crop is annually lost or wasted. Canning is receiving more attention in the South but not as much as it deserves. Tiu' process is not a difficidt one and every family in rural eommuinties where the cro]-) is grown should preserve a s\ipply for the winter and spring. 12 SWEET POTATOES AND YAMS 111 lulditioii to the familiar methods of j)r('i)iiriii^- sweet potatoes, there are a few that arc espeeially adapted to tlie moist, sweet. Southern vai'ieties. Candied Yams This is prol)ably tlie most favored metiiod of cookiiijr sweet potatoes. Partially cook in boiling- water. Cool. peel, and slice one-fourth to one-third inches thick lengthwise of the potato. Place in layers in a hakiiig-dish. Make a simp of tlie sugar, water, lemon juice ami cinnamon and cook it for about ten minutes. Pour this sirup over the layers of potatoes, place in a moderate oven, and cook until the potatoes are gummy. A few marshmallows may be added a few minutes before removing from oven. 1-2 dozen sweet potatoes 1 teaspoon ful cinnamon 2 cups sugar 1 teaspoonful salt 1 cup hot water 1 tablespooiiful lemon juice 2 ounces butter Sweet Potato Custard Line a pie-tin Avith pastry and till with a mix- ture of 2 cups mashed potatoes. 1 cup sweet uiilk. 2 eggs, 1/) cup sugar. 2 ounces butter. 1 teaspoon- ful grated lemon-rind, and a little salt. Bake as usual. '* 'Possum an' Taters" To the Southern negro there is no more tempting delicacy than " 'possum an" taters." an