Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1917-10-16
Potato Rot and the Seed Trade.
SOUND ruBERs FROM INFECTED STOCK
SAFE FOR PLANTING.

are oy no means confined to Maine thi
season the reports appear 10 indicat,
that this disease Of the potato has bee,
moro prevalent and has done NOR,
damage here than In other important
Northern seed-growing sections. Some
years ago, when somewhat similar con
ditions prevailed, certain agencies in .,
least one other State attempted to die.
credit Maine grown seed on this account
Al the present time Maine Agricultural
Experiment Station 10 receiving inquiries
a. to whether potatoes grown on blight.
ed fields and In which more or less rot
has developed may Be safely used for
seed purposes. Il 10 we'll known that
this type of tuber decay always begins
before harvesting or during the early
part OF the Storage period. After this
time no new rot will appear although II
may continue to increase on the original
ly infected tubers. There 10 absolutely no
reason Why sound potato tubers sorted
ont from such lots, and which show NO
signs of decay at planting time should
not be used for seed purposes.
The rot following late blight results
from infection that comes from spores of
the fungus, produced on the blighting
foliage, which are washed down into
the upper layers OF the soil before har-
vesting or which como In contact with
the tubers at digging time. There is no
evidence that the disease spreads from
tuber to tuber in storage, although
such appears to DO the case.
Il often happens that potatoes which
appear, with few exceptions, perfectly
sound and healthy when harvested show
q large amount of decay after being
q few weeks in the cellar or storage
house. This results from infection
which takes place just before or at
digging time rather than from spreading
from tuber to tuber. Potatoes which
show no signs Of late blight decay after
several weeks In storage may be con-
sidered to be free from the disease.
The rot following late blight may be
Of two types. In vet seasons when the
disease 10 progressing rapidly In the
field or in the first few weeks of storage
. large amount OF the decay may be soft,
wet and foul-smelling. This decay is
usually secondary and due to sparophytic
bacteria which follow along after the
blight fungus has invaded and killed the
tissues Of the potato. Typical late
blight rot, which 10 the primary cause
Of the trouble, appears first az brown
on any part Of the skin OF
the affected tuber. At first this may
spread over the tuber fairly rapidly, In
volving . considerable portion OF the
surface. II the conditions Of storage
are dry and cool dry, brown decayed
area 10 slowly produced on the infected
tuber during the winter. Typically this
decay does not 60 very deep into the
flesh OF the potato and when cut across
has characteristic rusty brown color.
However, az the result Of the secondary
invasion of the diseased areas BY other
fungus the entire affected timber may be
changed into . dry, withersd brown
msss.
As far a. known the means by which
late blight can be carried from place 70
place and by which it survives the
winter 10 entirely restricted to these
dry-rot tubers mentioned above. They
carry the fungus In o semi-dormsnt
state. Such tubers when planted pro-
duce plants which become infected with
the disease early In the season, and
serve AZ the first centers Of Infection.
Regardless of the source there ID no
evidence that, ~ 10 the case with some
other potato diseases, potatoes which
appear perfectly healthy after passing
The winter in storage can ever carry
With them the germs of the late blight
fungus. The purchaser of seed potatoes
has the matter In his own hands. II he
insists on sound tubers and plants only
such there will be no danger OF intro
iucing late blight with them, regardless
of the amount of late blight and rot
which appeared upon the helds upon
which they were grown.
Spraying with bordeaux mixture 10
the only efficient and safe method OF
preventing late blight and rot. NO
tubers should ever be plantsd which
show any signs Of decay whatever, 1u'
his practice viii not insure immunity
from the disease the following season,
provided weather conditions during
hat season are especially favorable TO
Its development and spread. II seed
tubers are planted without any regard 20
those which are diseased It
vould be idle 10 contend that ~ good
results could be obtained from unsort-
cd seed, from badly infected fields rs
from seed grown on fields which were
practically free from blight. However,
there is every reason to believe that ID
ain Northern states whore late oiignt
has appeared and where climatic CON,
ditions are favorable to Its occasional
occurrence in epidemic form that is 10
always present to some extent every
YEAR on at least q few fields In eacn
locality. On account Of the wonderful
powers of reproduction and spreso
possessed BY the fungus which causes the
disease it takes but few centers OF IN,
faction TO cause general infestation OF
4 laree area provided favorable weather
conditions are experienced for sumcien'
period of time. -,
By planting only sound seed tnoers
the grower can prevent center. ei IN
fection starting on bis own heids ano
nndoubtsdly delays the appearance OF sne
Sisesse thsreop. The only way that ne
can prevent Its spreading from DIE
fields to his ID to spray WIN
horSeanx mixture early and ofsen.-
CHAs. d. WooDs, Director.
Paws to Fatten Chickens.
.r.t chickena which have NOT