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JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
March  31,  1898. 
aeration  of  the  soil  by  digging  and  pulverising  brings  new  life  to  the 
grasses,  with  death  to  the  moss  owing  its  existence  chiefly  to  an 
impervious  bed  upon  which  the  turf  rests.  Assuming  that  no 
alteration  of  the  existing  level  is  necessary  beyond  making  good  those 
defects  previously  noticed,  operations  may  commence  by  stripping  a 
breadth  of  say  10  feet,  and  removing  the  whole  of  the  turves  taken 
from  it  completely  off  the  ground  and  in  proximity  to  where  the 
work  will  be  concluded,  to  be  there  unrolled  to  prevent  bleaching 
if  the  work  is  likely  to  take  some  considerable  time.  This  arrangement 
gives  a  fair  field  for  operations,  and  the  work  will  proceed  smoothly  and 
satisfactory  from  start  to  finish. 
Having  a  breadth  of  10  feet  cleared  space  running  transversely 
from  side  to  side  of  the  plot,  this  should  be  prepared  by  forking  over 
to  a  uniform  depth,  picking  out  all  weed  roots,  and  thoroughly 
pulverising  the  soil,  bring  all  to  a  firm,  smooth  surface  level.  The 
application  of  a  given  quantity,  by  measure  or  weight,  of  an  artiOcial 
manure  to  each  section  as  the  work  proceeds,  and  well  incorporating 
it  with  the  surface  soil,  is  worthy  of  consideration  as  a  tonic  apart 
from  any  after  measures  of  top-dressing.  Bonemeal  is  sometimes  used, 
but  after  various  trials  my  experience  does  not  commend  its  use  either 
as  a  top-dressing  or  sub-dressing  for  lawns,  and  farmyard  manure  is  a 
thing  to  be  avoided  for  our  purpose.  For  the  sub-dressing  from 
2  to  3  ozs.  per  square  yard  of  a  prepared  guano,  several  kinds  of  which 
are  in  use  for  farm  purposes,  with  the  same  quantity  of  superphosphate 
of  lime  applied  to  the  lawn  surface  when  turfed,  will,  although  it  is 
apparently  buttering  the  bread  on  both  sides,  prove  to  be  as  practically 
inexpensive  as  it  will  be  found  to  be  satisfactory  and  efBcient.  To 
resume  the  operation  of  turt  lifting  and  relaying,  the  turf  lifted  from 
No.  2  section  will  be  at  once  laid  as  it  is  removed  on  to  No.  1  section 
already  prepared,  the  principle  of  the  operation  being  similar  to  that 
of  trenching  a  piece  of  ground,  the  first  removed  being  held  in  reserve 
for  the  final  process. — Sylva. 
(To  be  continued.} 
“BLACKS”  IN  POTATOES. 
The  condition  of  the  “noble  tuber”  is  often  very  unsatisfactory 
when  placed  on  the  table.  The  cooked  article  may  be  apparently  all 
right  to  look  at  outside,  but  when  dissected  for  cutting  is  found  to 
contain  dark  stains,  agglomerations  of  adhesive  matter — hard,  un¬ 
sightly,  and  of  a  bad  tasting  nature.  In  some  cases  a  dark,  flesh-like 
substance  surrounds  a  core  extending  inwards  from  the  skin  to  various 
depths,  and  this  has  a  very  unpalatable,  earthy  flavour.  The  defects 
are  present  whether  the  Potatoes  are  baked  or  roasted,  steamed  or 
boiled,  pared  or  unpared,  so  we  may  conclude  that  the  fault  is  not  in 
the  cooking,  but  is  either  induced  by  procedure  in  cultivation  or 
storing,  for  the  “blacks”  are  almost,  if  not  quite,  confined  to  the  late 
varieties.  I  have  known  such  defects  more  than  half  a  century,  and, 
in  my  opinion,  there  has  been  no  improvement,  unless  in  shapeliness 
without  quality,  in  Potatoes  since  the  advent  of  the  disease  in  1844, 
when,  as  now,  there  were  two  forms  of  blacks — namely : 
1,  “  Skin  or  cylinder-black.”  This  commences  at  the  skin  of  the 
Potato,  and  may  be  compared  to  a  quill-like  body  that  has  grown 
around  the  tuber  and  then  entered  it  at  right  angles.  This  outer  ring 
of  dark  flesh  has  a  very  unpleasant  flavour  when  cooked,  and  besides 
being  discoloured  is  waxy  in  texture.  I  have  examined  many  such 
tubers  in  the  raw  state  under  the  impression  that  the  evil  was  caused 
by  the  larvae  of  insects,  but  have  not  been  able  to  detect  any  animal 
in  the  affected  parts.  The  early  varieties  appear  free  from  the  dis¬ 
colouration,  at  least  the  earliest  lifted,  and  it  appears  to  a  small  extent 
only  in  the  second  early  sorts,  but  the  defect  becomes  very  decisive  in 
the  late  varieties,  especially  those  of  the  Magnum  Bonum  type. 
The  stains  always  extend  straight  into  the  tuber  at  right  angles 
to  the  skin,  and  the  substance  about  the  quill-like  centres  mostly  egg- 
shaped,  smallest  end  outwards,  chiefly  exist  at  the  heel  end  of  the 
tuber.  The  individual  “cylinder-black”  accords  with  a  miniature 
stab  or  puncture,  around  which  the  flesh  has  healed,  internally 
forming  a  sort  of  skin  corresponding  to  the  wound,  the  dark  waxy 
core  thus  formed  seldom  exceeding  one-eighth  inch  in  diameter,  and 
rarely  passing  into  the  tuber  more  than  an  inch. 
On  appealing  to  several  veteran  growers,  suggesting  some  kind  of 
grub  or  worm  as  the  destroying  agent,  the  verdict  has  invariably  been 
decisively  in  the  negative.  However,  I  am  not  so  certain  about  that, 
for  the  presence  of  scorpion  flies  (Panorpidae),  and  observing  that  the 
Potatoes  were  always  the  worst  afected  when  grown  in  the  hollows  of 
a  field,  or  badly  drained  soil  and  indifferently  tilled  land,  rather 
tended  to  confirm  the  view  of  the  injury  being  caused  by  some  pest 
from  without.  It  seems  strange  that  the  producing  agent,  if  of  an 
animal  nature — and  it  certainly  is  not  vegetable— cannot  be  detected, 
but  this  may  be  my  misfortune  in  not  hitting  the  right  time  for 
catching  the  enemy.  If  any  correspondent  can  throw  light  on 
this  (to  me)  mysterious  infection  by  sending  to  the  Editor  tubers  con¬ 
taining  any  creature  suspected  of  giving  rise  to  evil,  I  shall  be  very 
much  obliged. 
I  have  striven  to  connect  the  infection  with  the  thread  from  an 
“  eye,”  which  has  gone  blind  at  a  very  early  stage,  the  thread  dying  in 
consequence,  giving  rise  to  the  egg-like  substance.  The  physiologist 
and  chemist  rather  support  this  view,  as  there  occurs  the  same  thing 
at  the  heel  string  in  modified  degree.  Every  “  eye  ”  of  the  stem — the 
tuber  is  an  underground  stem — has  its  central  axis  springing  from  the 
interior  of  the  tuber,  and  if  we  kiU  this  by  salting  the  tubers  to  make 
them  keep  late  in  the  season  and  weigh  well  for  market,  we  get  the 
blacks  in  the  flesh  with  a  vengeance.  There  remains  also  to  be  con¬ 
sidered  the  important  point  of  the  assimilation  of  the  nutrient  elements 
by  the  tops,  and  the  consequent  nature  of  the  plastic  material  com¬ 
posing  the  underground  stem  or  tuber,  which  is  waxy,  dark  coloured, 
and  unwholesome  or  mealy,  white  and  nutritive  according  to  the 
contained  components  and  measure  of  their  elaboration. 
2.  “  Flesh-black.”  This  may  obtain  in  either  the  waxy  or  mealy 
Potato,  pervading  the  tuber,  and  forming  lumps  here  and  there  through 
the  flesh.  There  is  nothing  in  either  case  of  an  organic  alien  body  to 
account  for  the  effect.  Of  course  the  raw  Potato  may  be  diseased,  and 
in  cooking  have  “  blacks ;  ”  but  this  has  no  relation  to  the  present 
inquiry.  In  perfectly  sound  tubers  which  turn  black  when  cooked 
there  does  not  appear  any  micro-organism,  but  the  tissue  is  more  or 
less  broken  down  in  the  cell- walls,  especially  in  the  soapy  stamp  of 
Potato. 
Nowhere  does  the  Potato  grow  so  well  as  on  the  warp  lands  and 
alluvial  soils,  or  the  washings  from  the  hills  of  higher  land — all  mix¬ 
tures  of  many  earths,  largely  commingled  with  dead  animal  and 
vegetable  remains.  These  alluvial  silts  and  warps,  where  left  high 
and  dry,  or  drainage  is  properly  attended  to,  do  not,  as  a  rule,  produce 
Potatoes  affected  by  “  blacks,”  and  even  fens  have  been  so  improved 
that  they  have  greatly  lost  the  property  for  which  they  were  long 
famed  in  growing  “  black  ”  cooking  Potatoes.  Moor  land  also  produces 
splendid  tubers. 
Granting  some  local  land  improvements,  still  Potatoes  as  now 
grown  are,  taking  them  in  the  bulk,  a  sorry  lot.  The  Up  to  Date 
varieties  all  lack  the  high  qualities  of  the  Ashleaf,  Lapstone,  and  York 
Eegents.  Quality  has  given  place  to  appearance  in  the  raw,  and  to 
waxiness  and  “  blacks  ”  with  a  modicum  of  mealiness  in  the  cooked 
article.  Worse  Potatoes  were  never  known  within  the  past  fifty  years 
than  the  present  day  varieties  as  grown  and  placed  in  the  market. 
Let  both  raisers  and  growers  see  to  this,  for  assuredly  if  the  home 
grower  will  not  supply  an  unimpeachable  article  the  foreigner  can. 
“Blacks”  enter  the  underground  stems  or  tubers  of  Jerusalem 
Artichokes,  and  even  the  true  roots  as  well  as  the  tubers.  What  are 
they  but  a  product  of  unsweetened  soil,  such  as  exists  in  the  feus  and 
low-lying  lands  of  Great  Britain  and  in  the  bogs  of  Ireland  ?  High 
land  now  receives  very  little  real  tillage  as  compared  with  former 
times.  Aeration  by  tillage  and  sweetening  by  the  periodical  use  of 
lime,  with  keeping  drains  in  order,  are  matters  that  are  not,  broadly 
speaking,  pursued  with  the  same  energy  as  formerly.  This  neglect 
of  the  land  is  seen  almost  everywhere  in  the  fields  and  felt  in  every 
household. 
“  Potatoes  will  not  pay  for  growing,”  is  the  modern  cry,  “  there¬ 
fore  let  us  cheapen  the  cost  of  production.”  As  a  result,  the  land  is 
“  chemically  manured  ” — stewed  with  acids,  muriatic  and  sulphuric, 
along  with  the  bones  of  countless  animals  ?  Is  it  not  the  way  to 
produce  “blacks”  in  Potatoes?  Why  not  see  to  the  drainage  of 
hollows,  thorough  aeration  of  the  soil,  and  dressing  with  lime  ? 
Surely  the  land  contains  enough  acids  from  the  long  course  of  culti¬ 
vation  without  adding  more,  especially  for  this  important  crop. 
Potatoes  can  only  be  improved  by  withdrawing  the  excess  acids  from 
the  soil.  Let  anyone  try  the  simple  process  of  draining  wet  land, 
tilling  the  §oil  deeply,  and  dressing  occasionally  with  lime. 
A  farmer,  who  had  long  been  in  the  habit  of  using  muriate  of 
potash  and  superphosphate  of  lime  for  Potatoes,  went  back  to  the 
procedure  of  half  a  century  ago,  but  instead  of  u.sing  lime,  as  then, 
had  recourse  to  basic  slag,  relying  on  well-made  yard  manure  for 
potash,  and  on  rape  dust  for  nitrogen.  The  farm,  notorious  for  its 
black  and  waxy  Potatoes  when  the  “acid”  manures  were  used, 
became  again,  as  in  former  times,  as  famous  for  its  white  and  mealy 
Potatoes  ;  and  though  an  agent  for  the  sale  of  “  acid  ”  fertilisers,  he 
gives  them  a  wide  berth  in  his  Potato  fields. 
The  chemist  made  out  an  excess  of  sulphuric  acid  and  chlorine  in 
the  black  Potatoes,  partly  due  to  the  slow  decomposition  of  crop 
residues  in  the  soil  through  the  low  percentage  ot  lime,  which  was 
considered  the  only  thing  the  land  needed  to  set  it  right.  This  the 
farmer  gave,  also  a  steady  supply  of  phosphate  in  the  basic  slag. 
Muriate,  or  rather  chloride,  of  potash  has  the  well-known  character  of 
causing  Potatoes  to  produce  waxy  tubers,  sulphate  being  more 
appropriate ;  but  I  am  not  at  all  convinced  of  the  innocence  of 
sulphuric  acid,  for  even  without  the  muriate  the  tubers  boil  “  black,” 
while  with  neither  in  the  land  on  the  same  farm  the  Potatoes  cook 
dry,  white,  and  floury. — Experimentalist. 
