xt73xs5jbv2d https://exploreuk.uky.edu/dips/xt73xs5jbv2d/data/mets.xml   Kentucky Agricultural Experiment Station. 1939 journals kaes_circulars_003_308 English Lexington : The Service, 1913-1958. Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Circular (Kentucky Agricultural Experiment Station) n. 308 text Circular (Kentucky Agricultural Experiment Station) n. 308 1939 2014 true xt73xs5jbv2d section xt73xs5jbv2d ig111‘1·  _·
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11011 _» COLLEGE OF AGRICULTURE
1o11l1l  
'l*“`l¥  { Extension Division
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gl; nl  i THOMAS P. COOPER, Dean and Director
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  ii  CIRCULAR NO. 308
  1 
W?  
   
1*4; 1 
? `  g SWEETPOTATO GROWING
wg- i
 " Lexington, Ky.
I<)l`iIl'  `_·
· June, 1939
i()l`£lQi
  . 
i ty Published in connection with the ag1·icu1tu1·al extension work carried on by coopera-
_ ADW of UTC College of Ag1`iClliLul'C_ University of Kentucky, with the U. S. DED€1I`tm€¤t of
 _ Hriculturc and distributed in furtherance of the work provided for in the Act of Congress .
I,  of MAY 8. 1914. y

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 I Circular N0. 308
2 SWEETPOTATO GROWING
il  By JOHN S. GARDNER
 _ Sweetpotatoes rank fifth in value of Kentucky crops, the value
 i of the crop as reported in the census of l935 being $l,375,59(). The
 i climate of the whole state is well adapted to the crop, making it
“  possible for any home gardener to grow sweetpotatoes, but the com-
 - mercial industry is located in the jackson Purchase Region and
  along the Tennessee border.
  Sweetpotatoes thrive in a variety of soils, but light sandy loams.
°  "freestone" soils, are best, because they offer least resistance to for-
.   mation of shapely tubers.*" In such soil the tubers develop bright
E  . color unlike the dull or rttsset color of those grown in limestone
E   clays. The soil should not be too "rich," for a soil that carries too
   I much nitrogen and humus produces long, twisted "strings" instead
§   of the short, plump ones the market demands. ln such soil market-
5   able tubers may be covered with ridges or "yeins," and they move at
é T a discount in all markets for they are coarse and fibrous in texture.
Q  . In terms of (`()l`ll-l)l`()(lll(flllg ability, "25·bushel corn land" is about .
   E right.
_ VARIETIES
.t\ltho there should be no difficulty in growing all varieties of
 T sweetpotato in Kentucky it is wise to choose the one that best fits
Q the purpose for which the crop is to be produced. The list of
  varieties that follows includes those long and successfully grown in
  the state and offers wide enough choice to suit all conditions.
ii .\'rn1rry Half. This is the most widely used variety, a selection
Q from Florida Yam. Its golden flesh and bright skin color have made
 . it a favorite in the markets in which Kentttcky sweetpotatoes move
 L lt is of moderate top growth and acceptable average tuber size and
  uniformity, when properly fertilized and when certihed "seed" is
Q used.
7 Porto Rico. Quite vigorous in top growth and prone to make
_ tubers too large, when grown in good land. The red skin and deep [
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i

 #1 Ivmilizc/cy Ifxlwzsion Circular No. 308  
orange llesh of this variety make it increasingly a favorite, in inarlieiy  J, SCI
where Nancy Halls now freely move. Porto Rico`s proneness i.,   im;
make oversized tubers may be overcome by close setting or by using   Cm
land too thin to make good Nancy Halls.  { ml
Viziefess Porto Rico. .»\ relatively new variety in Kentucky, Oli`.  I 1
spring of Porto Rico. it removes much of the difficulty of over-sizetl  
tubers, and may displace the original, on good land. Skin color aiiti ¥· 
flesh are the same as in the original Porto Rico. i sho
Red and li',/II~f(’ lirriiiiida. Grown in a limited way by coiiuiier ·.  isa
cial gardeners who serve early-potato markets. The quality is ev  .
cellent, but they do not keep well under average storage conditioiiv   ant
Sou!/iern Qzzemi. .-\ white-fleshed, dry sweetpotato, easy to keel;   
without "curing." For this reason it is excellent for the home winter  Y IM
supply but its movement as a commercial variety is limited. `llie  _- Um
tubers are symmetrical and smooth, and few "_iumbos" occur wliere  `
care is taken to fertilize properly and to set close.  if (HP
Po/2/{ir Root. \\’hite fleshed with high starch content. Because  `
of its dry flesh it may be stored without "curing." Objection to it is  i
its long, crooked tubers but it is a home favorite in the Mountain  _
section where it moves also in local markets, in a limited way.
Big-Slain _]¢·rsey. _]erseys are of two kinds as to color of skin. rell  L. '
and yellow. The flesh is pale yellow. .-\ dry sweetpotato, it is ezisj.  L helm
to keep and is a market favorite, particularly in the East and in   thoi
centers where Kentucky sweetpotatoes are marketed. Of relativeli SCN
sparse top growth. a necessary part of its culture is to lift the \'lll€\ _ I
to break loose the roots that form at the stem nodes.  ` but
% tion
PLANT OR, "SLIP" PRODUCTION   [W C
Sweetpotatoes are grown from plants or "slips" that arise |`1‘<>lN   huny
bedded tubers. These are swcetpotatoes that are under inarketahlr  I thet
size but preferably not less than one inch in diameter, "Strings."t>1  _ tubt
underdeveloped tubers, may be used for "seed" but, bushel fur .3  once
bushel, fewer plants will result than when standard bedding llll)Cl`* .
are used. The same is true where large tubers are bedded. 'l`l1L’¤`¤° L ']
is little difference in the final crop whether the plants have lieui “ layer
produced from "strings," from large tubers or from sweetpotatiiu » laid
usually accepted as being of "seed" size, if the stock is disease-frctv  * of h
Those who grow their own “seed" may produce disease-free stock lll from

 t
 _ .Sztt¢·e/jmtuto Gmzuittg 5
alikw  { Sctting yitte ClllIlllgS lll ClC2lll léllltl. Usually such vines do not set
cbs I"   ];u·ge ttthers, l)lll. illl Zl(TCCpl2llllC l)l`()[)(ll`ll()ll ol thetn nttty he large
uml?  r Cmittglt to use li<>l` SCC(l. SWCCl]J<>l2ll0Cs lt) he used itt producing
  Ptattts should he lree ol all diseases and datnage ol any kind.
l’_°H`  X ··sEED·* TREATMENT
tt-stzetl _, 
nt mt ;.  ,\1w;tys, no matter how ctleztr ol` disettse tlte tuhers appear, they
i should he treated, to ntake sttre tltey are sale to ttse. The trcttttnent
Hmm-. .1  is tts lollows:
is ev  T ln tt woodett or crockery container, put 2 ttuttrts ol` boi/ing water
itiotts   and ittto it stir l ounce ol` corrosive stthlintttte tttttil it is completely
) kw') _'  tlissohed. .-\dd this solution to 7 gallons ol` water ol` ordinary tent-
wilm  j peygttttre itt tt wooden httrrel or tub, and sill` thoroly. This is the
·- A  . "tt`ettting solution."
iwlgx  i· ()ne hatch ol soltttiott sullices to treat ·l lots ol sweetpotatoes,
 f dipping thent tts lollows:
Calm  = lst lot. 8 tninutes
.0 it is  i· 2nd lot, IO ntinutes
ummm  y 3rd lot, l2 ntinutes
—lth lot. I5 tninutes
tt. tell  . The tuhers nttty he placed in tlte hed while wet. ll` they Illtlst be -
is me   lteld over. tlte ertttes or sttcrlcs in which tltey are kept should he
tml itt  { llltll`<>l)` wet Wllll the ll`C2lllllg` solution, to elettnse thetn ol` ttny disease
ttiyelt genus they nttty carry.
r vinci _ The sweetpottttoes nttty he dipped loose, or itt htttnpers or ertttes,
 ‘ httt tlte tttore closely tlte httntper [its tlte treating \`ttl the less solu-
  tion is needed. Ideal equipment consists ol` tt I5-gallon ttth ntade
  hy cutting itt two a 3(lgallott httrrel. The sack lilled with tubers is
5 Irottt   hung in tlte ttth containing 7% gallons ol soltttiott, which just hlls
ettthlt  y. the ttth. .»\t tlte end of the treating titne. the sack is withdrttwn. The
  rtl  _» llll>(‘l`S lllily he spread in tt (lean place to dry or put into llle llC(l ll'.
;el Ittt t;  once.
ttthcts . PLANT BEDS
'l`ll¤l`*°   The sltttplest lornt ol sweetpotato plttnt hed is nterely Zl ’l·lll(`ll
2 heett lttyer ol` sttwdttst or light soil or sttttd spread oyer tlte seed ttthers
>ttttt»t·~ · lttid on the ground. otte deep. Tlte sttwdust is enclosed hy tt lratttc; `
se-[ree.  ‘· ol ltttnhet`. Such tt hed ttlllsl depend lor wttrntth on heat tthsorhed t
ncklll ltottt tlte sttn. .\ceordittgly, its ellicieney ttnd dependability are low.  
 2 l
 T t
t

 sa ,
6 Keniucky Extension Circular N0. 308  .
even when started April l. lf such a bed is covered with canvas Oy   lh
with muslin, its effectiveness is somewhat better, but it is still tm, A;  lil
much at the mercy of the weather. Covered with glass sash to keel)   Cn
out cold rains, the behavior of the bed is improved to the extent   ul
that home gardeners who use relatively few plants and who are mt   IC;
particularly concerned with setting their sweetpotatoes early, may  j`
find it adequate. Growers of sweetpotatoes on larger acreages tim.  
not rely on beds of this type but must use more dependable mezut~ .
for producing their plants.  Y N
Manttre-/ietiied Beds. The 111OSL obvious way to warm a sweet Z __
potato bed is with fermenting horse manure. A pit should be dug   » T
15 inches deep, to acconnnodate l2 inches of tramped manure, tht  { `i
remaining 3 inches, earth. lf glass sash is to cover the bed the width   E
and length of the pit should be made to aceonnnodate it. A box  ,  
frame of lO—inch lumber should be made to ht. lt should hart {  g
enough pitch to carry oil rains if the cover is glass.  i  
lf the bed cover is to be muslin, the width of the pit (and tht  Q  
frame) may be 6 or 9 feet, and the length as determined by the  · ifi
quantity of sweetpotatoes to be bedded. Muslin is 1lOt \V3lC1`l)l`()i)l  I  
but it gives fair protection if it can be supported by means of a wiit  ,  
stretched the length of the bed, forming a ridge, which allows much  [
of the rain to run oil. Soaking, cold rains delay both the sproutiug  Q
of the bedded tubers and the development of the sprouts that hzut  E
formed. A, 
Horse manure is not always to be had in sufficient amount and  A wit
in such condition that it will ferment, as it must, to give off heat.   be
Beds may be heated with wood, coal, crude oil or natural gas. Thr   lite
heat from these fuels may be applied to the bed indirectly as steam   qui
or hot W21tC1` led thru pipes buried in the soil, or directly, by passing  V the
the smoke and hot gases under the bed soil, thru flues. Sotiietime fire
waste steam from a building or factory can be utilized as a source til   .\ 1
heat. `   witl
["f‘Il(?-fl('(lf{'(f Berls. "l·`lue beds" are well within the ability of ztitt   cart
farmer to construct. The site should be on a slope, the hrebox ciitl  
downhill. See the diagram, hgure l, page 2. Usually such beth ml  · hei;
9 feet wide, with E5 fines, spaced as in the diagram. ,·\ltho it is betltl y to z
to use bell tile as the diagram shows, the "Ilues" may be ul€1‘¢`l‘  5 il is
tlllflles (TU\'Cl`C(l with sheet metal or stone; the upper half (l0\\'¤l"l  g llle

 ‘ i
 i Swectpotato Growirtg 7
vas or   the Stacks) may be covered with saw—1nill slabs. The ditches may be
ll me lingd or not, depending on the nature of the soil. At the firebox
t keep   end, tlte llues should be covered with 30 inches of earth and at tlte l
3Xl€1ll  Z l|l)l)Q)`Q1](l, 10 inches. lt is important that the llues have a rise of at
re not   least 5 inches in l0 feet.
‘, may ti 
és can- ’ _ ‘
means   n
sweet     ‘ we
I J _·t..,   2; ’·.. J _ J ,  . a ’§ ,  
le (lll  ° ’ —   r,     .;..    ,,
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-@» lll » ·_  _ 2 SVE;.    - `     §=ii$if?‘g    v    ‘
. . V   ., _ _   eww      -_       ·... . §Y"lJ‘ zt. J   "¥¤   1* i `
witltlt -·  *'      — ·   ¤ »    Y  < ‘
 .     ·»·-    
[ hm = ;;..   '··t ‘  
 » PN  M; qq » w ,·z~:_;\?;g•%L·&•2f$v·: ·;;,_z?__i.»)· ic`,-:4;;,4%-;2_,§g:`Z;—;?'4~?-\_;. A,-Ii',   ·
na ria     .     .t·      "      
bl [lf  t it`,    f   ( ·=’     ~:—:  .w‘**$€i"»
ll       `V r     g 4 V§»:·__  
I _ »   .V s¤te e ¤¢           - 
awire  ·.      ;;*~;»;f'Q ` ''ii     V     __l‘...,     V
2   "—T ·: ¥    ~ ...2%   _;;:} .... *2 sd  —
Olllllltl  ` Fmum: 2. Large sweetpotato plant bed; note multiple lireboxes.
tt have  in
1 The llues lead off front a lirebox made of masonry, roofed over
nt atttl   with sheet metal sttpported on pipe or iron bars. A drain should
f heat.  i he provided to prevent water frottt collecting. lf wood is to be tlte
s. The  ’ luel, tlte lirebox should be inade large enough to accontntodate
; steam i·  quite large chunks. A few rough stones shottld cover tlte bottont of
passing  — the flrebox, to serve as a grate. If it is designed to burn coal, the
lcrjme   l1l‘e|><>x may be smaller, and a grate of iron bars sltould be built in.
uree nl · .\ metal oil drtttn can be transfornted ittto a coal-burning lirebox,
A with little labor. The front of the lirebox ntav be closed with a dis-
()[[1Ill  ; <`¥\¥`   'V`»~ ·`~- ‘ kee
· * ~» "`  V   7.     urn;  ‘
  ` ‘ '“ l `""  itgaf-€a`?Y“` li    ° loot
 ·¢.y,,B» ·...   x-ce gf   we avg.; j
  i-..av g ··-,· ; .¢   ....;.    YZ' } -.»·-·     - Wl-
      l’  .· * 2   .
        ’*r.;r      
   is ‘ €l »~f-·.       W ,  ¢ [lm
 i   i liir   `` #5*     i me
  aw.   ,    j>"~=7’ M   5  _ ’
4 T,;_,» ,, it.  { ·_ {T'  y»r;L‘g=b(;4;r ' U `~ _~     i
.: ~"·lélli§%‘&%i;i?¢’i;é>i@;ZtTQs4sl;_; ~   g holt
A       _y,; j .= yi ..._  w···   bed
‘ — "* . · *<¢;=?*-¢‘§—i¤‘;T&;¢:f§%    L .
:. .... .....,.a;4L..........,   ‘s  mu:
Fromm 3. Siveetpotato plant bed in full production. Note "canyas" rolled back. sup-  _ iltltl
port while plants are being drawn, and specimens ol good plants in the foreground. , O1
y ie.
The seed tubers should be laid by hand, elosely, but with spztttf   lll li
between them. ll standard "seed" is used, a bushel will oeeupy am  { mm
area 3 leet by li leet or, in a 9-loot bed, one bushel lor each 2 lctt  I lvm
ol bed length. Growers usually estimate that lor one aere lllllllll ~ l’l`€l
>lants should be rrown and that they should be ready by um? li  i lllg
In a llue bed started April l or belore and managed l)l`O])Cl`ll·  I i
#l bushels ol` seed tubers should be allowed lor plants lor one 2\€l`#·  it lllll
.-\ manure—heated bed, being somewhat less dependable becauwc lll 3 llllll
t.he uncertainty ol the weather, produces plants somewhat llllllli . llllll
. slowly, and at least. a bushel extra should be allowed. l·`or a bell  aj lllm

 T
ii Szuccipola/o Growing 9
2 box  ;· without heat perhaps 8 bushels of seed tubers should be used, t0 get
tops.   V enough plants for setting an acre at the proper time.
, and   .-\fter the tubers have been placed, it is of decided advantage to
ict tn _  spread over them small-mesh chicken wire, to keep them from being
ioultl ,  pulled up when the plants are drawn. Then, the tubers should be
rings.   covered with 4 to ti inches of sawdust or with soil light enough to
 - provide minimum resistance to the plants to push up thru it. The
`·  h;iwdust or other Covering material should not have been used for
 gi this purpose before. lest disease be carried over.
  The bed may be covered with muslin or tobacco cotton, but glass
·i or glass substitute is better, to provide run-off for cold spring rains.
,,  _»\ltho this is more important for beds without heat and those
  warmed with manure. it is advantageous even for the flue beds, in
 V that heat is saved. Before the bed cover is placed. the sawdust should
  be thoroly moistened and it should be watered from time to time to
‘ keep it moist. This serves. not to start sprouts, but to aid the plant
 Q [ood in the mother tuber in making plants attain proper length to
  set.
  [fer! i\f{l)I(/g`(’}}I(’}If. Beds without heat and those warmed with
"  manure require no management; they perform automatically. whe-
E ther well or ill. .—\ flue bed, on the other hand, behaves just in the .
 _ nianner it is managed.
is The desired minimum bed temperature is abottt 60 degrees. To
I_ hold it there, well diffused, may require individual study of each
 J bed. lt is well to make a preliminary hring before the bed is put
‘  into operation, as it may be found that some of the stacks may need
Cie np-  i iltlditional height; that a windbreak should be set about the Hre—boX
i'   Opening; and perhaps other details arranged because of peculiarities
qua;   in the location of each bed. Experimenting should be done to deter-
ypy mi g mine the times of firing and banking for the night. at certain outside
g [Cn  ’ 'l2lC·
nc li,   ing the seed tubers, causing them to start without delay.
qyyyly.   ` No nlatler how well designed the bed and no matter how faith-
C Mit,   fUll}' flred, the tubers in the firebox half of the hed will Slilrlt ETSI.,
use nl imil <]l1ite likely this half will have furnished two-thirds of the pl11lli$
mm-t= A lmltllleetl by May ]5_ ,\i`tei· th;tt_ with outside temperature lngllel`, l
a betl   plants will be produced uniformly over the entire surface. X
` l
I  1
l

 ‘i
lf) lventzurlty Extension Circular N0. 308  I
FIELD PREPARATION  T
Land for sweetpotatoes shottld be broken deep and thoroly har i
rowed so there is plenty of loose soil from which to make the ridgqt  E ·1·t
and some besides, to absorb and hold moisture, for sweet-potatttet hh
need moisture to make large yields. Ten inches is not too deep tt,  3 hh
plow, and tho some subsoil may be brought to the top, soil dilutitttt  Y hh
is taken care of by the fertilizer that is used.  ¤ Uh
After the field has been dragged level, it should be marked tttt j th,
in rows 3 feet apart, and along these marks the fertilizer should by  L
sown. Sweetpotatoes use all three plant foods that occttr in cout ‘ ,\
plete fertilizer, but because they need less nitrogen and ntore potttvlt V tut
than do crops in general, sweetpotato fertilizer is 2-8-8 or 2—ltt-N,  { fur
Suggested rate for sowing is l pound to 30 feet of row, making ilttt   pot
pounds per acre, tho good results may be had when it is used tu tt  · ing
rate as low as 300 pounds per acre, or l pound to 50 feet.   the
()ver this "ribbon" of t‘et—tt1tzet—, the ridges are made. The matt-  
ter of whether to use ridges or level culture is a moot one. As tt  U tak
matter of fact, more tubers can be made in level culture, but tltt   tul
difficulty of digging them whole arises, also that of putting the let   uns
tilizer under the row, where it should be, to feed the crop proptrlt. ' in 3
\~Vhen ridges are used, perhaps the crop is smaller, bttt the tttt   bec
amount of marketable tttbers is greater. - to 1
The plants are set between May l and june I5, depending tttt  _ tftr
the latitude, and on the purpose for which the crop is grotttt.  
(Lardeners who wish to benefit from the price early sweetpottttoo 5
command, set theirs early, whereas growers who raise them to fw  i hh,
sold from winter storage, and home gardeners who produce tlttttt   Th
as winter supply, wait until later in May. Generally, the crops ~tt  e ven
after june l are designed for seed, tho in the extreme southern putt  l {irc
of the state, these tubers sometimes reach marketable size.  _ the
Most plant setting is done by hand with dibbles, sometimes with 1  sprt
water and sometimes without, tho several growers have setting   sho
tnachines, bttilt after the manner of tobacco setters. Depth of setting  1 the
depends on the length of the plants and the height of the ritlgtr  *
but generally the roots are covered 3 inches deep. The usual spat- ;
ing is l8 inches, but if fertilizer is ttsed with varieties that utztft  i t
l2lI`g`t‘ p<>lZtlt>es, I5 inches is better, because fewer ttnsalable `fjlllttllmf . (hil-
are prodttced.  j gm

   Sweetjyotato Growing 11
 V CULTIVATION
y har  . As with other crops, cultivation is needed to keep down weeds
ridges _  'l`his is done by scraping the ridges shallowly, afterwards repairing
tatoey   a11y da111age tl1at llliiy have been do11e them. '1`here is virtue in
rep in   pulling loose tl1e roots tl1at lllily have taken hold at the nodes of the
.llllUll  A stems but. this is 11ot (>ll(fll done except in the case ol the smaller-
ii  [;)pl)e<_l_le1`SC)'S. Rather, the vines are let grow to fill tl1e middles,
ed oll Q tl1us ending weed trouble lor tl1e season.
tld In   When the tubers 21re large (j1]()llgl1 to market, digging may begin.
CO1ll· `. A n1ecl1a11ical digger 1nay be employed, il set deep enough not to
)0lilSll . cut oll tubers. More commonly El tt1rni11g plow is used to plow kl
2-10-N. ._  furrow away l1`()l1l one side of the ridge and the clumps ol sweet-
ng alltl   potatoes are pushed over; or the ridge itsell is pushed over by plow»
tl at il   ing under it so as to upend the clumps ol sweetpotatoes, alter which
, they are shaken clean of earth.
gmat T lll digging sweetpotatoes in wl1atever manner, care should be
As il  ` taken 11ot to bruise them or cut them or even to rub oil earth, lor
nt tht  · tubers that are injured in any way keep poorly i11 storage and are
1e let   unsightly even tho tl1e wounds heal over. They should be gathered
yperly,   in rigid crates, not in sacks where tl1ey may jostle one another and
1e nu Q become abraded. They should not be dumped from one contai11er .
? to another; 1`2lll1Cl`, tl1ey sl1o11ld be handled with llll]l()SL gentleness
ng {lll  J thrnout.
grown.   CURING
>i21l‘><`* 1 l·`reshly dug sweetpotatoes contain an excess ol moisture which
I0 l>V   nnnst be removed belore they can be expected to keep in storage.
IUCN [ This is accomplished by heating the house to about S5 degrees and
>[J> Wl  2 \'Cl1ll12ll.ll1g to prevent excess humidity. Usually about three weeks
I1 [Wl   are required lor tl1e curing process, but the L1l11C 1nay vary with
° the condition ol the tubers and the weather. Curing ends when
¤S\\'l*ll t *[)l`<>lIllllg` begins on the tubers in the top layers. Then the llll>t‘l`S
sclliltl  if dltlliltl be stored at once, Usually the storage house is utiliiefl lol`
settins 2 the curing process alter which the temperature is reduced.
ridgr. é
l gpm  E STORAGE
mk,  { $\\‘Q€ipotatoes require special storage. '1`he atmosphere lI1llSl be
n1l1n»" i dry ZlIl(1 the l.CIll])Cl`2llQlll`t' IUUSI. be kept constantly at about 50 de-  
yl  §l`(`(?*- alter tl1e curing period is over. Accordingly, sweetpotato  
  l
- 1
 ` l
l

 12 Ivwttzte/cy Extension Cirr:11IarN0. 308 A
storage houses are built to conserve heat and provision is made tn in
heat them when necessary. Ventilators are provided; outlets at the or
highest point in the ceiling, thru which foul, moist air may escape :~  sw
and inlets at the lloor, thru which fresh, dry air may be admittetl. lllt
A necessary piece of equipment is a tliermotneter, which should be = as
consulted daily. Heat should be used or the ventilators opened, H, {  
necessary to hold the temperature constant. From time to time ` re;
.-   . V · ket
y A __   i `— cot
.   4  § · V tw
  · T  .._’ ii; V:  wif "  
 y _ '  r m; .,r,...'i....;,s,A/2 .,... .:.2.su  V ·
  . __  _ /.     `./tA *?Y*Yt  .
y . y   yr: ».’i£ z.`Zi<£i?5;YifEKi;;E?QZTii .,.,. i :i:.;f}.`  TY,  ·
  ai  . · li;       ri***}£*°2 .issl~* ~ *~ t sit.     y...   ` bla
    ”il”°i ”“   e a ‘ * t ' it i   s.      e
y he it t     .
·       [ .
; M y gg     a~* `’     ¤  4 {   ‘°·'
TZ Q t   ' 'éi ~ if"?] .,.. =*-93%      
   .        A   ‘‘V  2:    ’t » s  i t·  » *1 ll
  t         ~:\   l’l¥*·
" ‘ $   15    t,.tv»    `“ ‘   t ttm
  <   .3-     ‘"··· ~ m a s t; *»*· 5,,%% .; ’
  .... . .._ .  ~  . t    i   -.t-   .:;  t  -.  `iie.   - il l>=
  .  ’   ‘·-   t  t t
    , ..,.    _..  M        - ,,..   . ~,;;,,,,,a¤{,,  i. .. M U)
. J,.     t t   ‘   ‘ ’~t/   `·tt     ‘
‘·`’   »»/,   .     . .. ````     may
s '.   rm wes ~ ~—   ~*“   ww, ~ .,   5- .j?~*¥<”/ Mi  
‘   mea,  .»- ..,.E.;..4:z»..::s...;;...¤....»..t.;..,.......;~. ’...».. .;..4.; .Jt@i;.,... ./....2;   ... t
Fmum: 4. An 800-bushel sweetpotato storage house, with lean—to garage. (U)
. . . _ _ sw‘t
moisture given oll by the sweetpotatoes may gather on the ceiling `]
, . . . . seet
or o11 the tubers. llns Sl1()Lll(l be removed by opening all the ven- V
. . . . . . I Covt
tilators and supplying heat 1l necessary to maintain the house at _
usut
about 50 degrees. . I
. . . . » V wo
1·or plans ol sweetpotato houses, write to the Agricultural Engr _
. . , . . . ._ 213*11
neering Department ol the Ciollege ol. .\gl`lCtllLll1`C, Lexington. lmm `*‘
whom blueprint plans for houses of any capacity are obtainable at t l
. : an
small cost. (I
—· 7 . .· · ; see
figure —l shows an 800-bushel sweetpotato storage house wilt . [ lil
. . _ , y u
lean—to garage. lt is not necessary, however, to build anew; ><>ml‘ l
. . . . . ...  Seed
times existing buildings may be remodeled satisfactorily at small K I
. . . . . _ V . _ tut
cost, and sometimes ll is possible to combine a sweetpotato sl<>\<\2* l_
. . . . 3 l )$
house with some other necessary larm building. I
Often swcetpotatoes are put into storage in the boxes t>1`U`¥'lf` 1 5

 ° Szueeljwtztlo Growing 13
[C U)  _ iii which they have been gathered, sometimes in lots of hve bushels
Y [hg ` or so in slatted bins built in the house, but most growers sort their
QPU  t Sweetpotatoes as they are dug, directly into the hampers in which t
md they are finally to be sold. replenishing any that are under weight
(I bc  y iis gr result of shrinkage that takes place during the "euring." The
dy H5 : *·jiiinl;os" and the "seed" sweets are generally stored in bulk. The
time reason for storing sweetpotatoes in containers or in small lots is to
keep down the diseases which may spread from tuber to tuber by
` contact, but rarely spread beyond the hamper or the partitions be-
tween bins.
f DISEASES AND INSECT PESTS
E. ()f` the diseases that affect sweetpotatoes, the most serious are
i black rot, soil stain and stem rot or wilt.
‘ 13/ack Rot. ln the field, the sign is unthrifty growth and perhaps
death of the plants. (This symptom is shared with stem rot, des—
M  E eribed below.) Plants that survive are found to have tubers with
  ; blackened flesh at the stem end, this condition sometimes extending
Q thru the whole. Even apparently unaffected flesh is found to have
tg t , a bad flavor, and always a characteristic odor is given off. Affected
  l tubers should be sorted out and not put into storage, for the disease _
i l may spread.
~   The disease can be prevented by (I) using only CLEAN seed;
(2) treating the seed sweets, even when certified seed is used; (3)
film stvabbing all lumber and glass sash with the same-solution used in
WIL . seed treatment or, if mushn or tobacco canvas is to be used to
SC M Z tttyer the bed, only NEXV materials should be used; (4) always
using NEW sawdust and soil;   letting at least a year or, better,
EIM llml )'Cftl`s, elapse before sweetpotatoes are planted in the same field
min again.
HC H, ( lu drawing slips. "blank spots" in the bed should be examined,
  and if the failure to produce plants arises from black rot on the
wil]. ¤ WUI. ])l£llllS that are drawn from surrounding areas should be CZ11`@·
Smm,  , fUll}"CXLltttf11ed for the tel]-tale black streak on the stem. SKDIIIGUIDCS
Small E Wil llll)Cl`S fail to make slips because they rot fl`Olll Otl1€1` CEIUSGS
Omg. ltttt llliltk rot decay is eharaeteristic, (Best, if possible, is not IO USC `
2 shps at all from a bed that is for any reason backward or “spotted.")  
mites _ SUI.] Sf(lf7l, or .S`(;m‘[, This disease causes the tttbers to be l)lOlCll€d i
t
l
4 I

 1-l Kcnitzzc/cy Extension Circular No. 308  
with dark areas which affect their salability. ln storage the flesh B tub
under the blotches shrinks and the tubers become pitted, whint  ‘ qua
makcs them all the more unsalable. Soil stain is usually worse in   for
heavy soil to which an excess of manure or other organic 111atter has otht
been added, and in wet seasons. Seed treatment as for black rot is at  . is li
somc effect but plant treatment should be given, too, as follows:  j swet
Put a handful of fine dusting sulfur into a 20-lb. paper sack. ln  T '
bundles of 25 or 50 put the plants into the sack, 1`t)t>ls down. Tlteti,  T "sl1e
holding the mouth of the sack close about the tops of the plants. Q ing
shake until the stems and the roots are well covered. The plants tieed
should be set immediately. Another way to treat plants for soil whe
stain is to dip them in Semesan Bel and water, l to 10. inset
Stem Rot or Wilt. The hrst sign of stem rot in the field is j watt
yellowing of the foliage and general unthriftiness. The stents ol   rate
affected plants are found to be discolored with yellow or brown. l blacl
just at the ground line and, later, thrttout. ln severe cases the stent ;
split and become shredded and the plants die. E I
The disease is sometimes present in seed tubers and may spreutl f imo
from them to the slips but this is not the usual method of infection j (jj. so
of plants in the field. The disease usually enters thc broken entlttl  U Pm :4
the slip from thc soil soon after setting. The slips may be protetlttl f [hc j
from infection that may occur after setting, by dipping the lowtt 5(-jjm
half in 20-20-50 Bordeaux or in Semesasn Bel and water, 1 part ltt — jj
l0, or dusting with monohydrated copper sulfate mixed with mam
hydrated lime, l part to 3. These treatments are to be given jlltl BPM
before the plants are set. Treated plants do best when not ztllotttll - um I
to wilt and when set in moist soil. j  . Bj
Growers who raise their own plants should use none but Ctljit {_ mm"
fied seed sweetpotatoes, and always new soil and new sawdust. ll lf t jjmg
is the practice to save one’s own seed the grower should select lllwll V jmum
from parts of the Held where the stand is perfect. (jj 20
The B/ac/ri Flczzberatlrc. This small, black, hopping insect Stvtlllf g (jj mj
times comes in swarms just after the plants are set and soniCl1¤¤¤‘ “,hi(_jj
]Jllll(ILll1`CS the leaves so severely as to make resetting 11eceSSHl`§'.l’jl“ ‘ mmw
always to cause damage. Its control is to spray with Bordeaux mn- I __r_r
ture as soon as any beetles are seen. Usually one spraying is Sllff tt»»tf·hé
cient, tho sometimes a second should follow, 10 days later. i Cum N‘
I·’V