The Manning times. [volume] (Manning, Clarendon County, S.C.) 1884-current, 1910-04-27
Black Rot 0. Sweet Potatcc.
Article IT.

O3e OF the most vide spread :inG most
destructive diseases in this State 2t
present is the Black Rot OF Sweet Po-
tatoe This disease occurs quite com
monly and does considerable damage oo
potatoes botA in the field and in storage.
The rot is caused by = parasitic fungus
which. under certain conditions. IS able
70 pass from one plant 20 another and
thus spread the disease.
The troabIe frs; appears rs brown or
black patches or mott!cd. diScolored
areas on the surface Of the po;ates.
Quite frequently these discolored areas
are observed in potatoes when they are
! dug. but at this stage the diseases only
seems to penetrate the skin and IS ap-
parently doing 10 serious BARN. Later
the rot extends into the potatoe and
causes TIE affected area TO turn black
and 10 emit the odor which is so char
acter!stic Of rotten potatoes. When such
potatoes are stored in warm. moist
places. the rot producing fungus be-
comes especially active and by means
OF tiny spores, which are produced 10
small black puStules on the surface OF
the diseased areas, spreads rapidly from
one potatoe TO ane,her. Under such con-
di,ions the disease is also spread by the
filaments OF the fungu, growing from
the rotten po:a;oe directly into ad Join
ing healthy potatoes. Ia this wa: the
rot nigh. spread 10 erecy potatoe 10 4
bank.
II slightly diseased potatoes are stor-
ed in q place where conditions are un-
L f.t
they frcquenuv remain partly rotted
until Spr;ng The rea! danger OF spread
iug the disease from one field 10 another
comes in bedding such potatoes. Slight
ly diseased potatoes seem 20 Sprou: as
readily is healthy oaeS, and the slips
from: such potatoes are diseased. The
disease transferred with such slips 20
the fe!G remains on tie plant and at
:acks the potatoes when they cere.op.
The fungus which causes black rot also
lives over in the soil from year 10 year
anc where potatoes are planted every
wear on the same land, The disease con-
St:ptly gets worse.
To prevent black rot then we must:
First. secure disease free seed for plant
ing. Second. avoid planting potatoes
On lile SilIle !siils ioi wv .SAio AZ SuS-
ceSs;oC.
Quite frequently 1t is impossible 10
secure potatoes for bedding which are
entirely free from disease. In such case
it is well 20 use viCeS instead OF slips.
for the iuoguS which causes The disease
remains in the vicinity OF the roots OF
TIE plants. l, does 40, live in the vines
and leaves. so vines grown from diSeaS-
ed potatoes. If planted on land which IS
free from disease, will produce sound
potatoes.
Now, as have said. black rot occurs
on the majority OF the farms in this
state. and is responsible either directly
or Indirectly for the loss OF thousands OF
dollars worth of potatoes annually. SO 1t
is well for every farmer TO look out for
il and guard against its spread. II you
have already bedGed your potatoes aod
are 60, sure that they are free from dis
ease. plant Is much Of your crop as you
can from vines and on lao0 not previous
II planted il potatoes. When YOU gather
these potatoes, bank separately The ones
grown from the vines and the ones
grown from the slips AID note the keep
ing qualities o! each.
Potatoes should not be backed for two
years 10 succession in the same place.
because the fungi which cause these
ro,s vii! live over 10 the Old banks and
at,acis the new potatoes as soon as theY
are banked. Where po;atoe houses or
cellars are used for storing: they should
be cleaned OUT and disinfected before
the new crop is put in. ibis can De done
by cleaning them ou; thoroughly ard
then srayiDs The walls and floor with
a 3 per cent. solution OF !ormaiine or
i per cent, solution OF copper sulphate
fblue stone. n. W. BARRE
Bo:auis;, S. c., Experiment Station.