xt780g3gzr5q https://exploreuk.uky.edu/dips/xt780g3gzr5q/data/mets.xml   Kentucky Agricultural Experiment Station. 1940 journals kaes_circulars_003_307_02 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. 307 text Circular (Kentucky Agricultural Experiment Station) n. 307 1940 2014 true xt780g3gzr5q section xt780g3gzr5q  
  Extension Division
  THOMAS P. COOPER, Dean and Director
  Lexington, Ky.
  April, 1940
Z` _ Pub1l$h€d in connection with the agricultural extension work carried OD by ¤00D€¥`· `
ation of the College of Agriculture, University of Kentucky, with the U. S. Department of  
Agriculture, and distributed in furtherance of the work provided for in the Act of Congress y
V ¤f May 8, 1914. ,
` [

Page `
Soil and tnztnztgenient ...............,...................4. .|
Mztnures and fertilizers ..........,.....................,, _ 5 `
i· tu
Seed .......,..........................,..............,_ _ 9 g Su
. . . SJ
Ireattng the seed ..............,........................ . lit t  
 I t t
(ltttting the seed ...,.,................................,, , lj ` T
.. tn
Planting ..,........................ · .................... . lti Q dt
_ _ _ V- lo
(4lIil.1\'2lIl()l1 .................,.................,......., .. IU _ [.0
Digging ......................i........................ ., 2tl Q “‘
. gt
Insects ............................,..................., ..22
_ L _ tl~
l)tse;tses .................,............................... 21 _
— lit
Spraying ..................,........,.........,.......,. . 2ti  —
 _` tt.
l)llSl.il]g ................................................. 22 Q '1“
. . _, f ("
Spraying program lor early potatoes ..................... .. wi n K
For late potatoes ................................... .. 32 ~ ul
Dttsting program for early potatoes .........,..,.......... .. fi? V1
For late potatoes ................................... .. ·*·’   _\
. . . ...»  . ti
'I he early varieties ............................... - .....- · ·‘·’ {
· s
The late varieties ...................................... .. ii
Sl<>l‘2lgC ........................... - ................. · · ·· in U
. V

  Circular N0. 307 y
 .; (Revised)
Page   1; `
.. —l i. By JOHN S. GARDNER
U A   ,\1tho Kentucky lies south of the so—called "potato belt," po-
2 tatoes constitute an important crop, commercially and for home-
.. 9 { supply. A large part of the commercial crop is produced in the
_) spring and is sold on the general market extending to other states.
" I" Y  Nevertheless, Kentucky consumes more potatoes than she produces,
M U  , ’1`1iat some of this deficiency could be met by local production is
  undoubted, for altho the whole state may not offer conditions un-
  IH  1;, der which the potato can thrive best, great parts of it are suitable
  for this crop both in climate and soil, and it would be profitable
  W   for many more l·21l`lll€1`S to endeavor to produce potatoes. Certainly.
  all   every farmer. and every householder who has the space, should
  grow enough potatoes to meet home needs.
....YY  _:_ ln Kentucky, potato growing divides itself into three phases.
L   the early crop for table use, the late crop for use as seed, and the
  if  , late crop, of late varieties, for table use in winter.
tl'}  ` The early crop, mainly lrish (jobblers and Triumphs, begins
  -   to move to market soon after the crops of North Carolina, lower _
  YW   Tennessee and Tidewater Virginia have passed their peak. They
H 1 compete more or less directly with the (jobblers of Missouri and
  ‘ Kansas, and with those of (jalifornia, the Eastern Shore Region
gg  ij éltld lower New jersey,
  Fg The late crop, for seed, is exclusively Irish Cobbler and Bliss
  fi? Triumph. This "second crop" is so called because much of it is
M grown on land from which early potatoes have just been removed.
  "`”   .\ considerable proportion of this crop is certified. Kentucky cer-
tx;  , tified Cobbler and Triumph seed potatoes have repeatedly demon-
I I l  . strated their merit.
  Si   The production of late-crop winter table potatoes front late
M ig varieties is mainly a home enterprise, but farmers here and there
  `U . Uillllléilly raise surpluses for sale in local markets. This pllzlsc of
potato growing could well be expanded, even to the point of hav-
ing potatoes to ship, for weather conditions during the autumn
. ure usually favorable for producing large yields.  
 I \
F 1

 ·l lvcztlzzr/ry liv/mzszou Circular No. 307  
'1`he best "potato land" is sandy loam, but potatoes can lic ? Su
grown in any soil that is capable of holding sufficient rtioistum   FC
and is loose enough to permit tl1e formation of shapely [l1l)Q]`$_ f mf
The character of tl1e subsoil is i111portant. lt must be well drained.
for potatoes cannot thrive i11 water-logged soil. O11 tl1e otl1er hand, Y
the subsoil should not be so ope11 and porous as to i11terfere with ~
its moisture·holding capacity.
Hzzmus. Because moisture plays sucl1 an important part in the _ M
production of profitable yields of potatoes, and because tl1e liumtis my
content -of soil is an important factor in determining its water. _, IW
holding capacity, maintenance of the l1un1us supply is iniportam   my
in tl1e management of potato land. \\’he11 potatoes are grown in it  ij bc
rotation that includes grasses or, preferably, clover, tl1e htnnus com- ; lh
tent is n1ai11tained sufficiently, so far as moisture is concerned. i
\\'hen, however, high value of land or restricted acreage makes con- I
tinuous cropping necessary, other means for supplying lllllIlllS must 1 IT
be found. These include the application of stable manure or the _
turning under of green-manure-crops grown between seasons. fx
Stable manure is not always to be reconnnended as a source ol ` IK
l1tnn11s. Applied fresh, immediately before the crop, it may it1· I
crease scab. On tl1e other hand, to use it composted is wasteful It
because plant food may be lost in composting. Nevertheless, if 21 SU
gardener wants to keep his land fully occupied witl1 crops ntore · M
remunerative lll2lll green material to be turned under, there i» m
11othing better than manure for putting humus into potato land. I In
This is true particularly of land for early potatoes. Cf
Grmut-rzzznztzre Crops. For the grower who has a large acreage.  
green—manure crops afford an effective lllC£<1llS for building up :1 [_
humus supply. (Lreen-manure crops grown between seasons not  
only furnish tl1e cheapest and most easily applied form of l1lllllU*· y O
but tl1eir use minimizes tl1e loss of plant food tl1rt1 leaching, lessenw M
tl1e danger of wi11ter soil-washing and has a corrective effect (lll A gl
land infected with potato scab. Because leguminous and non-le A
guminous cover crops are available, both hardy and tender, a range V
of choice wide enough to meet any condition is offered. 1
On land to be used for first-crop potatoes, tl1e green-manure · ,,

  . a
 » .
 ; Polaio Growing 5
  crop should be sown early in the fall, so that it will have made
hc   Sufficient growth by the time the land is to be plowed, usually in
Ulm   February. The following gl`eell-nlanure Crops are satisfactory, The
my   rate of seeding IS for one acre;
my-  if Hairy vetch, 1 bushel, sown August 1 to September 1,
 VY Hairy vetch, 30 lbs. and rye 1 bushel, sown August 1 to September 15.
ML ,· Crimson clover. 10 lbs. and hairy vetch, 30 lbs., sown August 1 to 15.
titlt  I Rye, 2 bushels, sown as late as October 15.
, Green-manure crops to be used on late-potato land need not
lm be turned under until late spring; hence, they may be sown much
ml"   later than those for early»potato land. In fact, sowing may be de-
ll"`   layed with a fair chance of success until after harvesting the
Tum   late-potato crop. lf potato digging is delayed until after Novem-
m H   ber l. however, it is better to wait until the following spring and
Coll   then sow oats, l bushel, and Canada field peas, %, bushel, per acre.
lid  i` The best time to plow under rye or oats is when 'they begin to
gs;   head. Clover or vetch should be turned under when in full bloom. t
mv   ll breaking is delayed until the stems become too mature, decom»
 I position will not be rapid enough to furnish the moist humus
I  g. necessary for the use of the growing potatoes.
,Li(I;_   Breaking I/we Ground. The variation in seasonal conditions in
Lch,]   Kentucky is such that no fixed time for breaking ground can bc `
iy A V stated to apply everywhere within the state. However. since a sod
mm, or coyer crop must be partially decayed before it can supply huinus
1.C ix · or plant. food, it must be turned under in time for this change to
wd.  _ take place. Usually, fall breaking or winter breaking is best for
_ early-potato land, especially if the soil is heavy; for thc late crop.
WSU   late spring breaking is recommended. lt is a good practice to disk
up H r the land thoroly before breaking, whether there is any plant
um gfewtli to turn under or not. Thus, a deep, well-pulverized seed-
mu`. y bed is assured. The depth of breaking is governed by the depth
mm U  Oilthe top soil; it is not wise to turn up more than one inch of sub-
1 on   Soil il- year. Subsoiling is beneficial in dense subsoils. but if the
m-lu . sllbsoil is gravelly it had best be left undisturbed.
.\n important item in potato growing is the cost of the fertili- y
ulmic  . MT l|$t`tl. Usually this ;im()u|]ts to ;1l)0ut 20 l)Cl`(`(‘Ill (lll |ll(‘ ltllill y
. l .
— t
 ‘ l

 a t 
6 Kentucky Extension. Circular No. 307  
expense or nearly half the cash expense. The following item.   U
ized statement of the cost of raising an acre of potatoes represent, { b(
the average cost found by leading growers. s. is
Rent of land, etc. ......................................,..... $15.00 ju
Seed—15 bu. at $1.50 ........................................ 22.50  . _
Fertilizer, 1000 lbs. 5-10-5 ................................ 20.00 if
Labor, about ........................................................ 35.00 fe
Insecticide and Bordeaux ............ . ..............   8.25 bt
Since the price of potatoes is quite variable the fertilizing should S
be done judiciously. All three of the plant foods contained in com- b
plete fertilizer are needed; nitrogen to establish a vigorous.  `·
thrifty plant quickly: phosphorus, to hasten the starting of tubers; “ ,
potash, to swell them. From demonstrations conducted under n » gi
variety of conditions, it appears that a proper ratio of the com- 4 m
mercial plantfood is 1:2:1 or, expressed as a fertilizer analysis, 5- , 1
10-5. This general recommendation may be modified by the kind P
of crop that preceded potatoes and how it was handled; also by , SG
whether manure is used in conjunction, whether a cover crop. 4  
whether legume or not, and so on. Specific cases are discussed later. gl`
Nitrogen. Nitrogenous fertilizers should be used cautiously. j QU
because an excess of nitrogen causes rank top growth and light set- i
ting of tubers. On the other hand, prompt and vigorous plant
growth is necessary to produce a heavy yield of potatoes, and such P]
growth is obtained mainly thru an adequate supply of nitrogen. »_ CB
A sod, top dressed with manure, or a cover crop of legumes.  S ll]
contains enough nitrogen for a heavy crop of potatoes, but this ni-
trogen must first become available thru the rotting of the organic -
matter. For the early crop these sources of nitrogen are not de- »
pendable, so recourse must be had to commercial fertilizers. With
late potatoes, partial decay of the manure or legume will llZl\1<` m
taken place and some of the nitrogen becomes useful to the crop. 1 S,
Even then, it is often wise to apply some commercial nitrogen. y (1,
Nitrate of soda and sulfate of ammonia are the nitrogen Cm`- ll-
riers commonly used in potato fertilizers. Both have the virtue of S m
easy solubility, the nitrate releasing its plant food first, and the SH
sulfate following close behind. The exclusive use of nitrate of soda K
might result in making soil so alkaline as to make potato will t 0,

   Potato Growing 7
mm   troublesome, whereas if sulfate were used alone the land might
lem it become so acid that yields would be reduced. Because of this, it
i` is good practice for growers to specify such percentages of these i
ingredients, in commercial fertilizers, that a proper balance with
 ’ respect to soil acidity may be maintained. Assuming that a ton of
fertilizer contains 5 percent of nitrogen, the nitrogen carriers may
be proportioned as follows:
200 lbs. of sulfate of ammonia (20% N) :40 lbs. of nitrogen
mlm ‘ 375 lbs. of nitrate of soda <16¢i N) :60 lbs. of nitrogen
COIN- g 575 lbs. 100 lbs.
    P/zosja/torus. Potatoes need phosphorus. Phosphorus serves to
ki 2 g induce maturity, and plays a large part in the formation of starch.
L _ Because the growing period of the potato is relatively short, thc
Fon}- A most quickly available form of phosphorus should be used; super-
  i phosphate is recommended. Phosphorus is present in all Kentucky
O by soils, but outside the Bluegrass region the amount that can become
4 1 available is too small to supply the need of a good crop of potatoes.
  Even on the rich soil of the Bluegrass, a fertilizer' for potatoes
mshvl V should contain superplrosphate because not enough soil phosphorus
v· t may become available in a 90-day season. ·
$1;; From demonstrations thruout the state, it appears that the
Such proper ratio of phosphoric acid to nitrogen is 2 to l. A fertilizer
Cn. g carrying 5 percent of nitrogen should contain lO percent of phos-
rlmcsl  i phoric acid. A ton of such fertilizer should contain:
is ni- 1000 lbs. of 20% superphosphate, or
gmlit i 625 lbs. of 32% superphosphate, or
It do . 500 lbs. of 40% superphosphate,
with Potassium. Potassium has several functions, but the one that
lmw ` most concerns a potato grower is that it aids in the formation of
(ml) Stflrtih. ot which potatoes so largely consist. Altho the CXQICI YC-
n' , tllllrelllents of a potato crop are not known, demonstrations show
lm" _ that under average Kentucky conditions, with the humus well
UC Oi lllililltftined, the proportions of potash and nitrogen should be tllC
il thc Willi?. This makes the complete fertilizer formula 5-lO-5, Zllld 21
smh YOU would contain 200 lbs. of muriate of potash. l\Juriate is rec l
smb ‘ Omlllentletl because of its relative cheapness, compared with sulfate. i
A l
I2 A
t .

 · 1 
S Kculuc/:y lixlrmsion Circufrzr N0. 307  
.-\lso, tests made with it in Kentucky have shown no advantyigc, Z U
in yield or in quality in favor of the higher priced sulfate. ‘ tj
Summing up the foregoing, a ton of fertilizer well suited ii,   et
potatoes under average conditions can be mixed from: ·
425 lbs. nitrate of soda, 16% : 68 lbs. nitrogen .i l*
225 lbs. sulfate of ammonia, 20% : 45 lbs. nitrogen N
113 lbs. nitrogen : 5.6% i I)
1,125 lbs. superphosphate, 20% :225 lbs. phosphoric acid : 11.% A
225 lbs. muriate of potash, 50% :112 lbs. potash : 5.6¢ ji
2,000 lbs. of 5.6-11.2-5.6 fertilizer . tl
.#\ltho growers may mix their potato fertilizer, following the  E f)
directions just given, they frelal<> y
540.5 1l`<`lg`l1S 5 ounces and should be cut into four l)l(F(`(`$.  
itjltqw (i11<>fliCll(llllg plant. `
—l. lflllllll}', tl1e desirable l`ClllllZllllS lllily be planted by lll21(TlllllL‘.  
resulting i11 better Sl2lll(lS l.ll2`ll] l12ll](l planting sometimes gives. in S
llll(lSllll\lllCl`.  ;
It sl1ould ll()l be expected tl1at seed stocks selected by \\'llill· i. 
ever lllC2lllS will long stay superior, for there is always the risk ol .`
fresh disease i11fectio11 from potatoes grown nearby. The vvnrl Q
should be done continually, if superiority is to be 111ai111;1i11t· _
  ..... »       ·‘@*€= ·s~t  -     ia-, i
·2 »....J:?;·•·¤.~' ’   ,·;$ ‘,,f:.Z,¢ ' "-   ·".  ’ ~
.;;;.     E     _  tt
usr     was `   3*  ·
 J? i‘ .o'V ?   i`..    i H
_ Fromm 1. An effective seed—treating outfit.  . H
VE.?  {
1 3 P
Qizick-l)ip Corrosive Subfimritc Trmtvmznl. At the request ol  I g
potato growers in Fayette and jefferson Counties for tests which  ' l:
would demonstrate the value of shorter methods of treating seetl  Q n
potatoes, the writer developed the "quicl<-dip" corrosive sublimate  _ tl
treatment and demonstrated it in these two counties during the Q ‘
past ten years. This treatment. gave apparently the same results  , m
as the "standard" method of treatment used for comparison in  _
these tests. { I
(Zorrosive sublimatc was used in the same proportion as for   Q

  . _
 y Potato Growzlzg ln
ets Ti *‘tanclard" treatment, addin one ounce of hydrochloric acid
. tie S ., .
as   [(,1- Cach ounce of corrosive sublimate. The formula used was;
Vi 1 ounce of corrosive sublimate, ~
ier ·g 1 fluid ounce of hydrochloric acid, tmuriatim
,§ 7% allons of water.
to t g
o ,»\ batch ol the solution was used to treat lour lots ol potatoes
ces ; . . . . .. . .
. and the time ol dipping each lot was live minutes. Alter the
ts » . . . . .
{ solution had been used lour times, water was added to bring its
E level up to the original mark, and half the original quantities
  of corrosive sublimate and hydrochloric acid were put in. This
F  il solution was used three times and then reinforced as before. after
 . which three lots more were treated. After that it was found best
§   to make a fresh solution as in the beginning.
1  — Two 50—gallon barrels. used alternately, with 22%, gallons of
Il   solution, constitute equipment to keep two men working at top
El}   speed.
Zi   The "<|uick-dip" formula is a modification of the "i·\cid—Mer-
il V cury l)1p * recommended by some northern states, but does not
El Q contain so much acid and corrosive sublimate.
Il ii C()}II))l(’7`(`f{(f Tl`(’(lfli}Ig` Cozztjmitntds. Several commercial treat-
j   ing materials are on the market. By th