Audubon Republican. [volume] (Audubon, Iowa) 1894-1925, 1908-05-28
Scabby Potatoes.

where a five-year rotation is followed
to show some curious results. One
field would show far more seal than
another and some seasons seem to
favor the growth of scab. On those
farms potatoes follow corn, and we
think there is less scab when crimson
clover is seeded in the corn and
plowed under in spring. Tais seems
to show that the theory about a sour
soil is sound.
There are three methods of treating
the seed-dusting with sulphur, soak
ing with some chemical to destroy the
germs, and fumigation. The busting
Is easiest, but not always effective. We
cut the seed into peach baskets and
scatter three handfuls of sulphur over
the seed as it is put in. The basket is
shaken down at intervals. AS it stands
on a paper the sulphur which falls
through can be saved. For soaking for
malin is now generally used. This
liquid chemical, also called Tornado
hyde, can be bought at drug stores.
The proportion is one pint Of formalin
u OF SdtlOhS vi "dICl II Sdu uS pun
in a barrel or large tank, depending
on the amount of seed to be soaked.
We use two barrels, n with the
soaking liquid and the other contain
ing clear water. The potatoes are first
rinsed in the water. They are put in
a coarse sack and soused up and down
in the barrel. An easy way to do this
a., - HouA r,1Ioxy fo.toroI zxyHu 49,
barrel so that the bags can be easily
raised or lowered. After rinsing the
bag Is lowered into the solution and
kept there two hours. Then the pota-
toes are taken out, dried and cut. The
rinsing takes off the dust, nus making
the solution cleaner. Farmers have
different methods of doing this soak
ing. The principle is to keep the seed
IN long enough to XII. the scab germs
without hurting the sprouts.
Fumigation is now used by some
large growers, says the Rural New
Yorker. At first experiments were
tried with sulphur fumes, as they are
used for fumigating houses, but this
did not succeed. Now the gas from
formaldehyde is used with success. In
stead of soaking the seed in a solution
of this chemical it is turned into a
gas and held in a close room with the
seed. The process is described as fol
lows:
For a generator a small galvanized
washtub about Is inches in diameter
at the bottom was placed in the center
of the room about a foot from the
floor, midway between. the two lines
of crates filed with potatoes. When
ready to use BIZ nee of potassium
permanganate was spread evenly over
the bottom of the tub, her four pints
and one ounce of 40 per cent. formal
dehyde poured over this. The tub
was given one rapid tilt to entirely
wet the potassium permanganate with
the formalin and then the door
was quickly and tightly closed from
without. The almost entire absence
of the odor of escaping gas while the
treatment was in progress indicated
that the room was practically air tight.
The door remained closed for "a hours,
and when opened the gas was still
so strong that it was impossible to
work in the room for from 20 to 80
minutes. In fact, three weeks after
the disinfection was finished a dis.
tinct odor of formaldehyde could be
detected in the room. The seed for
the entire 20 acres was treated in this
way, care being taken to place the
treated seed in barrels which had
never been used for potatoes before.
This is to avoid contamination in
taking to the field after treatment"
This amount Of the chemicals was
figured for the size Of the room. The
rule is to use 23 ounces of potassium
permanganate and three pints of
formalin to each 1000 cubic feet. I'M
der this treatment the seed potatoes
gave about as good results as when
soaked. The room should be arranged
SO that non of the potatoes are put
directly over the rising gas. 1t is
better to fumigate before the sprouts
start. Do not wet the potatoes before
f~umigating. but pour a small quantity
of boiling water on the floor just be-
fore starting.