270 



THE AGRICULTURAL NEWS. 



August 22, 1908. 



USES OF SWEET POTATOS. 



SwL-et {Jotatos form such a staple article ot huinan 

 diet in the West Indies that their cultivation for this 

 purpose alone offers sufficient profit to ofrovvers, and 

 the question of raising the crop for utilization in other 

 directions has searcel)' been considered. The following 

 notes on other uses of sweet potatos, chieHy in com- 

 pounding stock foods, may be of interest. They are 

 taken from Farmers' Bullet in ./.'.^ of the United States 

 Department of Agriculture, a portion of the contents 

 of which was summarized in the last issue of the A;/ri- 

 cv.ltural Neivs, under the heading 'Sweet Potatos' : — 

 The u.ses of the sweet potato as a table vegetable are too 

 important and too well known to require more than brief 

 mention in a publication of this character. In lu'cparing 

 then) for the table they niay be baked, bdiled, liied, nr 

 bi-nised. 



A number (if attempts liavCj been made to Imild u|i an 

 industry for the production and .sale of dessicated sweet 

 potatos and sweet-potato flour. There is doubtless a. great 

 field for this class of goods, especially foi' export and For ship 

 .su]iplies. 



The vines of the sweet potato when ]iroperly cnied make 

 a medium grade of haj* for feeding to cattle and .sheep. In 

 the green state the vines arc. eaten by -sheep, cattle and 

 hogs, but their feeding value it; comparatively small. The 

 potatos are fairlj' well adapted to feeding to animals, although 

 their nutritive value is (piite low, and they require the addi- 

 tion of cotton-seed meal or grain to make a balanced 

 ration. On farms where sweet potatos are grown extensively, 

 the culls are fed to hogs, together with one-thinl or one half 

 ration of corn. 



r>y employing one of the heavy-yielding varieties of 

 sweet potatos, .such as the Southern ^ueen or the liernnida 

 lied, and drying and [julveri/.ing them, a splendid stock fooil 

 may be produced, especially when siitticieut grain is added to 

 form a balanced ration. 



The piinripal uses of sweet potatos are, howevei-, for the 

 table, and the demand foi- this purpose is rapidly increasing. 

 From the fa<'t lliat I ly the aid of conunercial fertilizer 

 alone .sweet potatos can liegrowijon comparatively poor land, 

 and largely hy the use of labour-saving machinery, this croj) 

 mav in a great measure .solve the problem of how to occupy 

 till- 'worn out' cotton and tobacco lands of the South, 

 especially if employed in a rotation including corn, peanuts, 

 and grass. By the perfection of some means by which sweet 

 ])otatos could be dried and converted into a condensed stock 

 food on the farm, they would, in conjunction with c<irn, 

 ]ieanuts, and a little hay, serve to keep the stock on .southern 

 farms in good condition during the winter. 



When removed from the ground the sweet potato 

 contains aV)out 71 per cent, of water, 1'5 per cent, of protein, 

 2-") per cent, of carbohydrates, and 0".'55 per cent, of fat. 

 It will be noted that both the protein and fat of the sweet 

 potato are comparatively low, and in order lo toini a .satisfac- 

 tory ration il i> iicci'»iir\ lo miv the sweet |piiiah>s with some 

 material rich in iho.^c ism mnstituents. The analysis of 

 j)eamits shows that the protein and fat are both ipiite high, 

 and by combining tlie latter with sweet i>otatos at the late of 

 1 bushel of peanuts ground in the shells, to .'i bushels of 

 sweet potatos, a splendid stock food is )iroduced. Three 

 bushels of sweet potatos are nearly equal to 1 Imshel of corn 

 in feeding value, lint in ordei- to make them satisfactiiry as 

 a stock food it is, as already |H)inted out, necessary to add 

 peanuts, cotton .seed meal or grain. 



The starch and sugar content of sweet potatos varies 

 consideral)ly in difterent varieties, but as a rule they contain 

 about IG per cent, of .starch and -I per cent, of sugar, making 

 a total of 20 per cent, of alcohol-producing material. It is 

 possible that sweet potatos will become one of the chief 

 sources of denatured 'alcohol in the United States, but at 

 present the methods of manufacture have not been sutKciently 

 perfected to warrant tlieir use for this i)ur[)ose on a farm or 

 community basis. Cu- 



SWEET POTATOS, CASSAVA, AND 

 MAIZE AS FOOD FOR HOGS 



Souu' feeding experiments to test the comparative 

 values of sweet potatos and cassava as pig foods have 

 lately been carried out at the Florida Agricultural 

 Station, and are reporteil upon in Bvlhl' ,i DC. i.ss\n'd 

 l)y the Station. 



In the first test two lots of three pigs weii- taken. The 

 first lot was given a ration composed of equal quantities of 

 sweet potatos and ' .slnu'ts,' while the second lot 'A-as fed with 

 a mixture, consisting hidf of cassava roots and half of shorts. 

 The weight of sweet potatos in the fir.st ration was equal to 

 the weight of cassava in the second. The te«t was carried 

 out for twenty-eight days. 



AVitli the sweet potato ration the average aaly gain per 

 lii'ad of the pigs Avas ]"8.'i lb., while the lot fed w-ith the 

 cassava ration gained 1'24 It). ]ier head per day. 



The insufficiency of such starchy foods as sweet potatos 

 and cassava to meet all the re(juirements of growing animals 

 is em]>hasized by the results of a .second test. In this four 

 lots of young pigs in a lean condition were taken, and fed for 

 forty-two days. The fir.st lot received a daily ration of sweet 

 potato.s, the second of cassava, the third was fed on a mixture, 

 in eipial parts, of the two materials, whih' the fourth lot was 

 fed on corn only. 



At the clo.se of the experiment period it was found that 

 the corn-fed lot showed an average (hiily gain |jer head of 

 0'-'5o7 lb., while the animals fed with the sweet |iotato and 

 cassava rations had actually lost weight. When this 

 second experiment was repeated with larg(>r pigs, the animals 

 fell on corn gained an average weight of 11.52 ft. per head 

 pel I lay. ( )n sweet potatos alone there was a gain of 0'.50.5 lb. 

 [ter head per day, on cas.sava 0-2.'b'! Ui., and on sweet potatos 

 and cas.sava together 0"179 Hi. 



The ditl'erent results obtained in these two latter experi- 

 ments are explained Viy the fact that growing animals require 

 a ration c(nitainiiig a higher propiu'tion of nitrogenous 

 <'oiistituents and mineral matter than is needed by animals 

 that have completed the growing stage. In the latter case 

 no more nitrogen and mineral matter is required than an 

 aiiionnl sultii'ient to replace the daily wa.ste, and the animal is 

 alili' to put on weight with the aid of a food consisting very 

 largely of starchy or carhonace.ms material. 



It may lie mentioyed that 1 Ih. of corn {maize) ccnitains 

 very nearly as niucli starchy matter, and more than twice the 

 ipiantity of nitrogenous constituents, as .S Ih. sweet potatos. 

 Ilia previons number of the A^irini/tiirn/ .Wz/'.f (Vol. Ill, 

 p. -i^iO), in discnssin.i; the value of sweet |iotatos as a stock 

 food, it was pointed out that the add'tion of .', lb. of cotton-seed- 

 nieal, or 1 It), of cowpeas, to every 10 It), of sweet potatos 

 supplied an amount of nitrogenous material sutticient to liring 

 the standard of the mixture, as regards this constituent, up 

 lo that cxistins' in maize. 



