Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1917-04-06

throughout the country. and perhaps
native to some soils. Common scab is
favored by a neutral or slightly aka
line soil, and seldom gives trouble in
acid soils. 1t therefore Is increased by
lining and fresh stable manure, wood
ashes. and alkaline fertilizers. such
as nitrate of soda and ground bone,
while acid phosphate and sulphate OF
ammonia tend to diminish the scab.
Rhizoctonia occurs in some extent
in nearly all soils, but appears to at
tack potatoes most when the conditions
are unfavorable to the best develop
ment OF the potato plant. Bring the
land to an ideal state of filth to mini
mize loss from Rhizoctonia.
Powdery scab is worst on cold, wet,
or poorly drained soils. Blackleg, on
the other hand. is carried by infected
seed. No potatoes showing a deep
brown discoloration at the stem end
should be planted.
sulphur tends to prevent common
scab. 1t is not substitute for cor
rosive sublimate or formaldehyde, but
is good drier for sut seed. Applied
to scab-infected soils at the rate of
500 pounds per acre ii reduces the
scab. but such heavy applications can
not generally be recommended as prof
table. Preliminary experimental trials
are advised.
How to DisInfect Seed
It is considered better to treat po-
tatoes before they are put into seed,
especially IL the cut seed is to be very
small. Put into the solution all the
potatoes it will cover and keep the
batch covered by the solution for the
period named under the treatment be-
ing used.
The "formaldehyde treatment" con-
sists in soaking the potatoes, before
cutting, for two hours in solution
made by adding one pint of formalde-
hyde to thirty gallons of water. The
solution can be used repeatedly. The
gas treatment is no longer recon-
mended.
The corrosive sublimate treatment"
is more effective than formaldehyde.
particularly against Rhizoctonta, or
russet scab, and powdery scab. Cor
rosive sublimate is used at the rate OF
1000 for one and one-half to two
hours. Dissolve ounces of the salt in
hot water and dilute to 10 gallons.
This is a deadly poison. Use with
great care. 1t must be kept in wood.
porcelain or glass vessels, as it attacks
metal Seed so treated must not be
used in the household or left where
animals can reach 1t.
In using the corrosive sublimate dip
it has been found that the solution be-
comes weaker each time it is used. The
taken out of the solution varies ac-
cording to the amount of dirt on the
potatoes, the character of the water,
and the kind of container. For prac-
tical purposes it will be sufficient to
add l ounce of dissolved corrosive sub
Innate to each 80 gallons of solution
after each batch of potatoes has been
treated. When this has been done four
times, throw away the old solution and
prepare new solution.
To treat large quantities of potatoes.
set several barrels on a slightly ele-
waited platform. Fit a plug in hole
in the bottom of each barrel, fill with
potatoes, cover with solution, let stand
two hours, draw off solution, and pour
into another barrel. Increase the num-
ber of barrels in proportion to the
quantity to be treated. Another meth
cd is to use a large wooden vat or
trough. into which the potatoes in
sacks are lowered by a rope and pull
ley and later hauled out, drained, and
dried on Slated racks.
Seed potatoes may be treated sew
eral weeks before planting, provided
they are not reinfected by storing in
old containers or storage bins.
Sprouted potatoes are injured by
treatment, but will throw out new
sprouts. In general. however, pota-
toes will not be injured by following
the above directions. Many growers
believe termination is improved by
treatment.