Iron County record. [volume] (Cedar City, Utah) 1893-1982, 1914-05-01
DISEASES OF OUR
UTAH POTATOES
DIR. Geo. Hill of the U. A. c. Writes
Valuable Paper on Prevention
of the Prevailing Infections.

Utah is fortunate in not being pes
tered with many potato diseases, yet
those which we have cause a great
loss to the farmers and need mention
ing so that we may apply the old ad-
dage, "an ounce of prevention is worth
a pound of cure" Now that the plant
ing season is at hand it will be well to
select the best seed possible and treat
it to guard against disease.
The following article by Dr. George
Hill, botanist, Utah Agricultural Col
lege, should be of special interest to
Utah farmers engaged in this line OF
work.
We have three more or less ser
ious potato diseases in Utah, the ear
ly blight, the dry rot, sometimes
called the black rot or the brown rot
or potato wilt, and potato scab.
early blight is disease of the po-
tato leaves. Small dry brown almost
round spots gradually becoming larg-
.er occur on the leaves in June, July.
and August. These are areas in
which the blight fungus has killed the
cells of the leaf. These spots are Of
ten not large, but they may be numer-
Gus and cause the leaf to die and fall
off. The damage may be as high as
30 per cent. or more.
early blight can be controlled by
spraying the plants with bordeaux
mixture, consisting of five pounds lime
and FIVE pounds copper sulphate dis
solved n fifty gallons of water. The
plants should be sprayed when about
eight inches high or when the firsf
spots on the leaves are found, agar
two weeks later. This spray is to pre-
vent the first spores which are pro
duced from injecting new leaves.
"Dry rot is Utah's most serious po-
tato pest. The disease lives over win
ter in the soil and in diseased pota-
toes. It is the cause Of the black
ened ring or area about one-fourth
inch under the potato skin. Only dis
ease free seed should be used. Care
should be taken in cutting the pota-
toes to cut off the stem end first. If
any signs of blackening or browning
are found in the potato, that potato
should be discarded. To plant it is
to plant the dry rot, thus injecting the
rest of the patch. Potatoes should
not be planted on the same ground
two years in succession or heavy loss
es are likely to occur. The dry rot
fungus produces spores and these may
stick to the potatoes and thus spread
the disease when such potatoes are
planted. Soaking the seed potatoes
for two hours in solution of forma-
lin, one pint in thirty gallons of water
is recommended for killing the spores
on the outside of the potato. This
treatment is of little use, however,
unless in addition all diseased pota-
toes are discarded at time of cutting.
Since this disease lives in the soil, the
greatest care should be taken not to
plant diseased potatoes on land free
from Jile ulSedSc. TIC ShSN' 10 wy
similar to planting, a very noxious
weed in the land. The disease, how
ever, is very difficult to eradicate If
once established in the soil.
"Potato scab is caused by number
of agents, one of which is fungus.
Scab is a heavy development of cork
on the surface of the potato as re-
suit of injury to the growing tuber
The potato scab fungus also lives IN
the soil for some years. Rotation OF
crops should be carefully followed and
only disease free tubers should be
planted The seed potatoes should be
immersed in formalin solution, one
pint in thirty gallons Of water, for
two hours.
"Thres things which are necessary
in the control of potato diseases are;
81. Plant only disease-free tubers
%. Kill spores adhering to these
potatoes by soaking the potatoes in a
formalin solution of one pint in thir-
ty gallons of water for two hours.
"3. Do not plant potatoes on the
same ground two years in succession
particularly if the potato has been