The gazette-times. [volume] (Heppner, Or.) 1912-1925, 1914-06-04
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By 0. M. MORRIS, Horticulturist; J. g.
HALL, Plant Pathologist, and M. A.
YOTHERS, Asst. Entomologist
at Washington Experiment
Station,

planting potatoes is to get seed
that is free from disease 30 that
the plants may start in a healthful
condition. After the plants reach q
height of six inches they should be
sprayed with Bordeaux every ten to
fourteen days until five or six appli-
cations have been made. For the first
two sprayings the solution should con-
tain four pounds of copper sulphatc
to fifty gallons of water and for the
Others each fifty gallons should con
tain six pounds Of the copper.
In case insects are present in the
field and doing damage the poison to
kill these may be added to the Bor-
deaux Mixture and applied with it at
such of the regular applications for
the late blight as are necessary to con-
troll the insects. For the amounts to
be added consult that portion of this
bulletin dealing with insect pests.
"Scab."
Scab (Oopora scables, Thaxt.) is
readily told by the rough pitting of
the surface of the tuber. When the
tuber is attacked early the scab is very
apt to be deep, while later attack
will cause only shallow pitting. Some
times the diseases becomes so bad as to
cause the tuber to crack. In the very
young stage the scab is small, reddish
spot upon the surface of the tuber.
These spots increase in size and depth
until they give the Characteristic ap-
pearance of the scab. Scab is more
prevalent in soils that are alkaline than
those that are acid and on this account
it is sometimes recommended that wood
ashes and commercial fertilizers be ap-
piled to infected soils. There are also
some varieties that are not SO much
subject to the disease as others.
Realizing that this is soil disease
clean seed upon clean soil will produce
clean crop. In case it is not pos
sible to get seed that is surely free
from the disease it is possible to treat
the seed and thus free it from the
trouble. To treat potatoes for scab
place them IN sack and immerse
them in a solution of formalin Gone
pint to thirty gallons of water) for two
hours. They may then be removed,
drained and dried, then cut to the usual
size and planted.
Formaldehyde Treatment.
In case there are large quantities
of seed to be treated it will be well
to treat with formaldehyde gas, as
as large quantities can be treated
more quickly in this way. To treat
seed potatoes with formaldehyde gas
build shed that is air tight and will
accommodate the amount of seed you
wish to treat. The potatoes may be
treated in sacks, but they must be so
piled that the gas can easily get all
around each sack. In order to accom-
plish this all that is necessary is to
pile them up in tiers with pieces Of
scantling two by four inches between
each tier and allow a little space be-
tween each sack in the tier. Leave a !
space in the middle of the shed in
which to place the vessel to contain
the formaldehyde. No potatoes should
be piled directly over the vessel used
for treating and they should not be
piled closer upon the sides than three
feet to this same vessel on account of
the danger of injuring the germinat-
ing quality of the tuber by the strong
gas at these points. To make the gas,
provide fiat shallow vessel, like a |
galvanized wash tub, put potassium
psrmanganate in the vessel and add
tho commercial formaldehyde GO per
ssnt), stir wen and quickly and leave
the shed ut once. Then closethe shed |
and leave it closed for twenty-four !
hours. The tub and the formaldehyde
should be At about the temperature of !
= room, that is about seventy five de- |
grees Fahrenheit in order to get the
best results from the mixing of it with