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Issued by 


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 


^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. <dl tlirou<ih tlu^ South the term "'jiotato"" usuall\' means 
the sAveet potato, the white potato heiii^' distinjiiiished as the Irish or round po- 
tato. Certain varieties of sAveet potato are also called '"yams'" in the South 
and the name is now in <:'eiiei'al use, altliou^h histoi'icall.\' a ditl'erent family 
g:rowin>r in the East Indies and the Philippines has the earlier (daim to the 

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 invite<l to sliai'e this i-ation. and returning re- 
ported to his commander. Loid Cornwallis. that i)atriots so resourceful and 
self-den.\in;^' could nev<'i' he defeated. A;iain. in the wai' of 1812, General An- 
di-cw .Ia(d<son. in his campai^'n a^zainst the Spmnsh in l*'lorida and Alabama and 
against the I>i'itisli in Louisiana, had hut little food for his men except sweet 
potatoes. When the lii'itish <:eneral. l*a(d<euham. commaiidiiii:- at New Oi'leans. 
learned this, he rcjxuted home in sulistauce that the Americans never would he 
eouipiei-ed hecause of their det cMH iua t ion and hecause they could alwa\s raise 
enough sweet i)otatoes. on which food they could \\)i\\\ indetinitely. 


Sweet Potatoes and Yams 

The sweet potato is I'apidly gaining in favor and bids fair to become a food 
crop of national importance. It is easy to grow, the yield per aCre is large, it 
may be prepared in many attractive and palatable forms, and it has a high food 
value. It should constitute a large and permanent part of our diet, but despite 
its advantages the sweet potato has not received the attention of either pro- 
ducer or consumer that it deserves. In the South, wiiere the crop flourishes and 
where most of it is grown, the production is as yet insufficient and the quantity 
in storage does not adequately supply the local markets. 

Food Value. Table I shows why the sweet potato is of high food value. 
Its water content is low and it contains a considerable proportion of the 
energy-producing materials — sugar and starch (carbohydrates). When first 
harvested, starch forms from one-sixth to one-quarter of the potato, but after 
a period of storage, much of it turns to sugar, which accounts for its charac- 
teristic taste and name. Energy, or heat value, is usually measured in calo- 
ries. A pound of yams produces 570 calories as compared to 375 for the 
Irish potato. 

TABLE I. From "Feeds and Feeding," Henry. 





Sweet potatoes 





Irish potatoes 















Production — Three pecks per capita. In 1917 953,000 acres were planted 
to sweet potatoes in tlie United States. The yield was 87,141.000 bushels with 
a total farm value of $96,121,000. This yield provided only 0.85 of a bushel, or 
a little over three pecks per capita per annum. 

Climate and distribution. The climatic conditions best suited to cultiva- 
tion of the sweet potato are moderate rainfall through the growing season, 
warm nights and plenty of sunshine and a period of growth free from frost 
for at least four and one-half months. They are profitably grown as far north 
as forty-five degrees latitude. New^ York State and Michigan grow them suc- 
cessfully. Canada (Toronto section) has grown them on a small scale. 

Prolific. The sweet potato is one of the most prolific of crops, a quality 
tliat is particulai'ly important on the poor cotton or tobacco soils. Tender 
the ordinary system of cropping, land that will produce 20 bushels of corn 
•or half a bale of cotton, will produce 200 bushels of sweet potatoes. On the 
farm of the South Carolina Station, Prof. T. E. Keitt obtained an average 
of 250 bushels per acre with fifteen varieties. AVith intensive feitilization and 
cultivation, yields of 500 to 700 bushels per acre have been obtained. 



A friablr or loaiiix' soil is licsl suited to its iicrds. but aii\' w cll-di-jiiurd 
soil of inodcrate I'ciiility will ])r()(lucc a jzood fco]), j)rovidt'd it is not too 
cold. The sweet potato is siiii|)ly au enlarged toot, so that the soil plays a 
\vv\ iuipoi't aiil pait in its de\ flopnicnt . If it is t()o loose and deep the roots 
luive a teiideiu-y to leiij;tlien with a eousecpient shrinkiii^^ in diameter. A 
stitT (day is not desirable but ean be inipioved b\' tui-niu','' undei" i^^reen crops, 
and shoulil then produce a satisfactory yield. 

Preparation of soil. The preparation of the soil invoUcs the same j^eneral 
principles as does the piolitable iirowiu"!' of any ci'o|). namely, care and 
thorou<ihness. The soil is bi'oken to a depth of from six to ten inches and 
well liari'owed. A furrow is then ojiened. the fei-tilizei's applied and bedded 
on. Later a liylit harrow or drai;' is passed over it befoi'e setting the plants. 

Bedding potatoes — Home grown plants best. .Most farmers can bed 
enou^ih sweet potatoes to pi'oducc theii' own j)lants at home. It has been 
demonstrated that honu' ^-I'own plants will ])i'p<luce a bettei- yield than 
plants of the same \ariety J:■ro^\■n undei' different conditions. There are vari- 
ous methods of beddin<: followed with success in ditl'erent rejrions. The wis- 
est course is to adopt the method advised by the State Experiment Station 
for a jjiven locality. Tlie plants should be diawii from the bed and planted 
oid\ aftei" all dan;^'ei' of frost has passed. 

Time of setting plants. The (leor-iia Station has found that the best 
yields are obtained if plants aie set between Ma\' Kith and .lune 11th. TIk^ 
same vai'ieties of potatoes planted befoi'e or aftei' these dates did init pro- 
duce as heavil\-. Local conditions will larji'ely determine this cpiestion for 
the indi\idual. « 

Rotation of crops. It is well to renu'inber. at this point, that it is not 
advisable to jirow sweet potatoes continuously on tiie same land, since that 
l)ractisp. if followed. ustui11\' I'esnlts in a disease infested soil. This condition 
can be lai";.;cly eoidrolled by i-otation. say. with coi-ii. |)eanuts and ji'rass. 

Spacing. The usual practise in spacintr jilants is to place them in I'ows 
three feet apart with from ei;jh1een to twenty-four in(dies Ix'tweeu jdants in 
the I'ow. 

Setting plants. If mori' than two or thi'ee acres of potatoes are «:rowu. 
it may be advisable to use a transplanter. These nnudiines are efficient and 
inexpensive. With a team of mules and three men to operate it a transjilanter 
often sets four acres a day Avhile sixteen men would be needed to cover the 
samc^ frround plantin>jr by hand. 



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<b'r most conditions 
and should be supplemented- with sonu^ stable manure. 

Formulas. The Georgia Station recommends a general formula containing 
approximately 8 per cent, of phosphoric acid, 5 per cent, of ammonia, and 8 
per cent, of potash, which may be made up as follows: 

Acid phosphate (16 per cent.) 1,000 ])ounds 

Sulphate of ammonia 350 " 

Cottonseed meal 250 

Sulphate of potash r?00 

J. H. Beattie of the U. S. Department of Agriculture recommends the 
following as a good mixture for sweet potatoes : 

Sulphate of ammonia 250 ponnds 

Dried blood, 200 pounds, or fish-scrap HOO 

Acid phosphate (11 per cent.) 1,200 

Muriate of potash 400 

Either of these formulas is good for general use when it is possible to ob- 
tain potash at a reasonable price. Under present circumstances the potash fig- 
ure in the first formula should be changed to 3 per cent, in place of 8, a part of 
this coming from the cottonseed meal : the proportion of nitrogen should also 
be varied to suit the soil type. 

2,000 pounds per acre profitable. ]\lan\ potato growers have used as much 
as 2,000 pounds of commercial fertilizer per acre with highly profitable re- 
sults. Potash, which we are now forced to leave out of consideration, has for 
a long: time been considered the most essential element for potatoes. Profs. 

'^xperiiiu'ut Made by II. U. MiUln-ll, .\tlnii-~. (..i 

Tliis oxpcriiiu'iit was made on a red clay ln.iiii thai had pri'viiiusl.v liet-ii sown in small snihi 
lollowed liy fowpeas. The yield of potatoes from the unfertilized plot was siuall and nearly un- 
MiarkctMldf. while the seeond [dot. with pliosphate and potash only, was lint little lictter. Most of 
ilhisi' li-imi the Sulpliate of Auimonia plot were of umid niMrketaliie unalily. 

Diigj^ar ami Williamson of the Alabama Station, however, make tht- following 
.statcuu'iit, based on tests on heavy soils: 

"Taken as a whole, tiiese experiments seem to imiicate tliat the pojjiilar 
idea tliat potasli is the most important eonstitiimt in a fert iji/n- Wm sweet 
poti'.toes is ineorreet, at least as to pi'aetieallv all the soils here repi'esented. 
On the other haiul, these tests sliow that phosphate and nitroj^en were mnclr 
more impoi'tant than potash. 

" experiments also seem to discredit the notion that the use of a 
fertilizer containing nitrogen causes the sweet potato plant to run to vines to 
an injurious extent. In our experience this danger does not occur where 
reasonable amounts of nitrogen are used in combination with acid phosphate." 

Experiin 111 1 W . L. la.vlor, Midluiul, (ia. 

'rhe soil was a cray. sandy loam, typiial of Sonth Ceor^'ia or Ilie lo.istal pl.iin. Hotb plots 
ha<l reielved aliont MM) pounds per aere of a r_'--_'-0 fertilizer. Sulphate of .\mmonia at the rate of 
HKt pounds per a' re was applied .Tune 1st. The yield was donliled and the .|iialitv of the pota 
loes reoelviniit tl "nlphate of .\mnionia far better. 


Top-dressing sweet potatoes. Successful growers have generally adopted 
the practise of top-dressiiig their sweet potatoes with some quickly available 
nitrogenous fertilizer. By applying from 100 to 150 pounds of Sulphate of 
Ammonia per acre at the second cultivation, they obtain substahtial increases 
in yield. 

Sulphate of Ammonia. The Florida Experiment Station found wlien com- 
paring the value of Sulphate of Ammonia and dried blood as ingredients of 
complete fertilizers, that Sulphate of Ammonia gave the better yield. Mr. 
J. R. Davis of Bartow, Florida, a well-known and successful sweet potato 
grower recommends it for this crop. The illustrations on the preceding page 
show the results of field tests with SulpJuite of Ammonia apjilied as a top- 
dressing and figures 7 and 8, at time of planting (see page 15). 

Harvesting SAveel Potatoes. 

A typical scene near Savannah. Ga. The vines have been cut and are lieins hauled away to 
he fed to live stt)ck. The potatoes are being- plowed from the sdH and carefully sorted into piles 
and baskets before l)eini;' hauled to the storage house. 


The cultivation of sweet potatoes does not differ in any essential way 
from that of any other farm or garden crop. Any of tlie ordinary farm tools 
employed to maintain a mulch may be used at intervals of from seven to ten 
days and particularly after each rain. Cultivation should begin soon after the 
plants are set and be kept ujo until the vines arc large enough to interfere 
with the work. After the vines begin to run they sliould be turnetl into every 
other middle to facilitate cultivation and then returned into the cultivated 
middles while the work is completed. At the last cidtivation as much soil 
as possible shotdd be thrown to the row in order to leave the plants in hills. 

Harvesting. Theic is little use in raising a ero}) unless it can be utilized 
to best advantage. Tlius, upon the care exei-ciscd in harvesting sweet pota- 
toes depends, to a considei-able degree, tlie success wliieh may be expected 
in storing them. Usually, it is desii-able to harvest as early as possible in 

SWEET P () T A T () K S AND Y A M S 

ordfi' to tiiUf iiilvaiit;i<^r ot" t';i\()i;il»lf pi'iccs. hut it is iifccssiiry to iivoiil *\\<i- 
'^liiii:. tile crop whilf still iinniiit iii-c Itrcjiiisr ot' tlif i'oiisf(|iH"iit (|<'ci-c;isr ill hotli 
yield and k»'t'piii<>- (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<i'<>'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). 


Pool" storajze facilities in the South, where most ol' our sweet |)otatoes 
aie jirown. ai'e the <ireatest ohstaele to increased production. II. ('. Thomp- 
son, of the r. S. Departnuuit of Ajii'icult ui'e. estimates that from 20 to ')() ]>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 <)r<liii;M\ Nx\eei I'otato I'it. 

■rills mctliiMl of'"' is tlio reason why iiciuly li;Uf of the swoot jiotatiK's irniwii in llu- 
S.iutli «'V«,'ry yi'ar arc lost l>y 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. 

<d' small <:rowei's these methods are possihly the only practicahle ones. 
They can he made i"eas(Mialily safe, howevei-. if proper cai'e is taken that the 
potatiM's are t horout!hl\' dr\ when stored and that the hank is kept di-y. proji 

A Good Storage Pit. 

'I'liis is a jioiid typL' 111' small storage pit for bousiug' sweet potatoes. Aiiiple proxisioii Jjas 
licfii luatle to protect the potatoes from rain, to keep them dry, and for veiitil.ntioii. Small 
loss by rotting occurs when pits are built with these provisions. 

eiiy ventilated, and warm. A better type of pit is shown above. The 
specially designed storage house, however, is by far the best method. Sevt^'al 
types of houses have been developed in different sections, and their use by large 
growers and by communities of smaller growers is increasing. In fact, ac- 
cording to Prof. H. P. Stuckey, of the Georgia Station, taking it year i.; and 
year out, sweet potatoes cannot be grown and stored at a profit unless some 
such storage house is pi'ovided. A satisfactory type is shown below. The 
liouse is provided with artificial heat and air-circulating passages so tluit tlie 
potatoes can be cured for a week or so at about 90 'F., and tlit^ tempei-atiii-e 
then maintained constantly at 50'^ to 60'^F. Full ])lans for such houses nvo 
given in Bulletin 548, U. IS. Department of Agriculture. 

A ('oniiminit> 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. 




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. 


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. 



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. 



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 

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. 






















(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 


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. 



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 

'* 'Possum an' Taters" 

To the Southern negro there is no more 
tempting delicacy than " 'possum an" taters." an<l 
the richest humor in the folklore of the race is to 
be found in the ancient tales which have been 
handed down alxuit it. Rut only the "oP colored 
mamiiiN." and we have her still, knows the se- 
ei'ets of the dish when made as it should be made. 




In Table III will be found the acreage production, and total farm value 
for the more important sweet potato states. The South grows practically 
all the sweet potatoes, about 90 per cent, of the total. Tlie only important 
producer among the northern states is New Jersey, which also plants the 
largest acreage per farm. 


Sweet Potatoes: 

Acreage, Production and Total Farm Value by States, 1917. 


Acreage Acreage Production Yield 
per farm Bushels per acre 

Georgia 125.000 

North Carolina 90.000 

Alabama 178,000 

Texas 84.000 

Mississippi 85,000 

South Carolina 80,000 

Louisiana _______ 62,000 

Virginia 40,000 

Arkansas 40.000 

Tennessee _ 80.000 

Florida 35,000 

Total South 849,000 

New Jersey 24,000 

Other States 80.000 

Total TT. S 953,000 












































The yield per acre for this crop falls slightly below the average for tlie 
past ten years, 93 1-3 bushels. The crop sold at an average of $1.10 per bushel, 
so that its value per acre Avas nearly .$101 .00. A noticeable feature in tlie 
table is tliat in tlie six heaviest producing states (first six in order) but litth' 
over one-tlii)-d of an acre on the average is devoted to this crop. The average 
yields art- also low when comjjarcd to ciops of from 200 to 400 Ijushels per acre, 
which ai'c I'cadilv obtained bv careful ji'rowers. 



Test Made 1).\ Lind-^as ( rawley, I'l'in. Appomattox Ajiiicultural llijili S(li<»ol. 

This test on sweet potatoes was made by Lindsay Crawley, Principal Appomattox 
Agricultural High School, on sandy loam low in fertility. The previous crop of oats 
yielded onlv 20 bushels per acre. The check plot received no fertilizer, and yielded 
30 bushels;" the PK plot received 44U pounds acid phosphate and IGn pounds muriate 
of potash per acre, and the yield was 5 5 bushels; the NPK plot received in addition 
150 pounds Sulphate of Ammonia, and yielded KMt bushels, a gain of 45 bushels, 
worth ii!24.!Mt aliove the cost of the Sulphate of Ammonia. 

Test Made by IMeree Odor, .ApiMniiattox, \ a. 

Test with sweet potatoes made by Pierce Odor, .\ppomattox. Va. The addition of 
Sulphate of .Ammonia at the rate of l.'iii pounds per acre increased the yield from 210 
bushels to 2G0 bushels, a gain of 50 bushels, which sold for $28.25 over and above the 
cost of the Sulphate of Ammonia. 



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