, 1903-05-07

called blight The fungus re-
mains over winter in the soil, and
also on the potatoes themselves,
where it is easily seen in the
brown or black spots which look
like particles of soil, and these are
difficult TO remove, but when rub
bed open they look something
like smut of the wheat kernel.
potatoes are
grown on soil which has become
affected with the fungus, little can
be done, though Rolls found that
after the vines showed '.blight,"
spraying with Bordeaux mixture
increased the crop. 1t is believed
that the fungus will live at least
three years in the soil, and be
ready to produce the disease on
potatoes planted therein, so il is
important that the crop be grown
on clean land. 1t is well to follow
grain crops, upon which this fun
gus does not work, with potatoes
in rotation. If the seed is free
from disease, alfalfa land is used
with apparent Good
crops can be produced by select
ing those tubers which do not
show the disease, but our seed is
so completely affected that this is
difficult to do, and could not be
practiced by those who do not
know what to look for. The dark
spots (sclerotia) carry the fungus,
through the winter, on the potato
tubers, and anything which will
destroy their life will help the
seed. 1t has been found that dry
nag out in the bright sunshine &C
complishes this purpose quite ef-
fectively, and thoroughly summing
the potatoes for a few days before
they are but is good treatment.
Sunshine does not reach the fun.
gus in deep eyes or scab pits, and
to make the treatment thorough,
the potatoes, before being cut, are
dipped in a solution of corrosive
sublimate.
Diocniya tun n,n.a. IS oonr1uo
sublimate in two gallons of hot
water, and mix this with fourteen
gallons of water in a barrel. This
gives a solution containing one
ounce of corrosive sublimate in
eight gallons of water. Soak the
potatoes in this solution for one
and one-half hours, after which
spread out in the sun to dry be-
fore they are cut for seed.
This treatment not only kills
the RHYZOCTONIA fungus, but
it also destroys the fungus which
produces potato scab and protects
the seed from rotting in the soil,
should sprouting be delayed by
long continued wet or cold weather.
In the experiments of the Wyo-
ming Station. we found that treat
ing the seed with corrosive subll-
mate greatly increased our crop.
Care must be taken in using this
treatment, because corrosive sub
Innate is a deadly poison. 1t
must be used in wooden or earth
enware vessels, and these, or the
sacks in which the potatoes are
placed, must not be used for any
other purpose. The solution must
not be too strong, nor the pota-
toes soaked longer than the time
stated, because it is apt to kill the
potato sprouts, or make them very
slow to come up.
After soaking the seed, it should
DE- treated with sunshine for n few
days, and cut not more than a day
or two before planting. Our best
results have been obtained by
planting small potatoes whole, OF
by quartering the potato length
wise. leaving a part Of the seed
end on each piece. Plant a liber-
al amount of seed.
There are a few copies of Bulle-
tins Nos. rs and 80 of the wyo-
ming Experiment Station on po-
tatoes. These al be obtained by
addressing the Director at Lara.
mic. Those interested may be
able to obtain Bulletin No. 10 of
the Colorado Station by REQUEST