Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1882-09-21
The Potato Rot.

Inc rotate kOt.
Fortunately the potato disease, per
inospora infestans), is not one of the af-
tticuons OF this country; if it we.e, the
fight with that and the potato bug
would probably be an unequal war.
But 1t has visited us at times, and per
haps, if we ever finish the bug, We may
be called upon then, if not sooner, to
devote some of our skillful care to that
predaceous visitor In Great Britain il
has never wholly disappeared since it
vas first known there. Last year was
a particularly favorable season, the
blight doing but little damage compared
with It's usual ravages. The large po-
tato crop of that country last year was
n great boon; and q new trade sprang
up with this country, supplying us with
potatoes which we I,ere lacking on &C.
count OF the very general drouth. For
years the British agriculturst has been
trying with little avail almost number.
less methods to prevent or mitigate the
attacks of the deadly potato fungus.
1t has long been an accepted theory
that the spores of this fungus effect an
entrance into the potato plant through
the leaves. In fact, this position il
not controverted. That this is true there
may be undeniahle proof but it has
also been held that the spores did not
and could not enter the tuber directly
through the skin. Mr.. j. l.. Jensen of
Copenhagen, claims that the spores do
not enter the tuber through the skin,
and, by great number of careful
tests made from the protection of the
tubers from the spores brings weighty
evidence to the support of his position.
The fungus first effects the leaves OF
the potato plants, causing brown and
lack spots on them, and if the attack
is sc.ere enough finally destroys them
altogether. The spores fall from the
leaves to the ground and Mr.. Jensen
states that they are carried by the rains
down to the tubers, germinate on the
skin and penetrate to the interior. Ia
this manner he claims that the injury
to the tuber is mostly affected II the
spores from the diseased leaves could
he prevented from falling where they
would reach the tubers the disease
would be controlled to great extent.
This Mr.. j. succeeded in doing, so that
his success is indeed very marked.
The process is a simple one, and con
sists II earthing up the potatoes, which
are planted III drills, SO that sharp
ridge is formed over them and this
is done before the disease manifests
itaelf on the leaves, or at its commence
ment. The following is Mr.. Jenseu's
account of the process
THE usual moulding hitherto prac-
tised IN all countries is n Hat moulding,
by which the uttermost tubers are only
covered by layer of one or two inches
of earth, but my protective system re
quires-after preceding Hat moulding
IA high and sharp moulding, by which
| the upper surface of the uppermosl
! tubers is covered with about five inches
of earth. To effect this it ia necessary
that the ridge be so high that the top
of it Is from ten to twelve inches above
the surface Of the adjoining furrow, or
ditch, whilst the ridge must be very
broad at the bottom. My system also
| requires that the top Of the Potatoes
shall be moderately bent to one side,
with a view to prevent the raln-water
from running down the stems and thus
carrying the spores to the tubers. by
| this contriyance also more spores will
| fall between than upon the ridges
In five places i'll Denmark last year
eight experiments were made with the
common Hat moulding, and eight others
with the high or protective moulding,
and the result was that there was IN
average Of twenty-three and half per
cent OF diseased tubers IN each Of the
former, and one and half average
percent of diseased tubers in each of
the latter experiments. In eight other
similar experiments tried at Antvorsko
there was an average Of nearly forty
one per cent. of diseased tubers in the
fiat moulding rows, and only a small
fraction of one per cent. in those hign-
moulded with the tops bent down.
This is an exceedingly interesting state
ment and the difference in the two
practices is sufficiently appreciable.
Care Is necessary in digging the pO-
tatoes to preserve them from the
spores. After the leaves are withered
the tops are cut off and carried away
out Of the field, and this is done a
number of days before lifting the tu-
bers.
so many experiments carefully car
RED out as these were, and the details
Of which our space does not admit to
give in full, all without exception,
showing results of the same kind, al
most establish with certainty the theo-
| ry that the spores enter the tubers
through the skim Vich'S Magosine.