Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1919-04-11
AGRICULTURAL EDUCATION
~ DR.. ANDREW M. SOOLE

/ being wind-broken., Severely dis
! eased plants often produce no ears
or, if ears are produced, the grain
| fails to mature properly. The leaf
| blades tfOdder) do not season prop
erly and become prey to various
mOldS and rOts, rendering the mate
rial unfit for feeding purposes
The disease appears first as small
water-soaled Spots in the sheath or
midrib of the blade. Within a short
| celebration being confined to the in
ner tissue. For this reason the
spots are more distinct when the
blade or sheath is held to the light
The spots enlarge and run togeth-
sheath and resulting in the death
of the blade. From the sheath the
disease penetrates the stalk at or
near the node, resulting in a dark
brown blotching of the surface and
rot of the interior. Often the
stalks of diseased plants remain
season. long after the leaves have
been destroyed. AS the diseased
tissue dries and breaks, a mass of
brown dust (spores) is noticed. 1t is
from these spores that the disease
ori~inates the following year
Control measures. Physoderma is
disease of succulent. rapid grow
moist, fertile bottom lands" of the.
mountain section and to the moist,
open soils of the coastal plain re-
gion. A wet" season tends to in
crease the amount of damage, as
does also heavy applications of barn
noticeable in those sections where
no systematic selection of seed corn
is practiced, and there is a tendency
for the corn plant to degenerate, both
as regards yields and disease re-
sistance. AS with practically all
plant diseases, the damage is great
est where no crop rotations is prac-
ticed.
In working out a system of con-
troll, first consideration should be
given to the adoption of a definite
crop rotation. In addition, the dis
eased stalks should be destroyed, or
at LEI least o completely it turned under"
ing from diseased fodder will carry
the disease, and should never be
applied to a field to be planted to
corn. Careful seed selection in the
field should be practiced, and only
plants which stand up" show no
Indication of disease and which pro-
duce heavily should be considered.
The tendency toward disease is as
inherent a characteristic as is yield
or form.
Smut of corn differs from that of
other cereals Cd in that it attacks
any part of the plant and CD in
that it cannot be controlled by seed
treatment. The disease spores are
able to penetrate any part. of the
plant where the tissue is moist and
succulent. Usually, however, the silk
and tassel prove most susceptible,
although the attacks of early spring.
appear on the sheath mostly. This
is explained by the fact that the
spores lodge in the space between the
sheath and stem where the. moisture
collects.
Smut occurs commonly over the
entire state, but is most general
in garden plots in south Georgia,
in lot, Invariably such fields have
been planted to corn year after year
indefinitely. .
Usually the first appearance of
smut in the field goes unnoticed, since
the smut masses are small and rather
inconspicuous on the young plant.
AS these smut masses break the
disease is spread, and in the next
generation is characterized by large,
distorted masses of spores covered
by a silvery membrane, which later
breaks and liberates more spores.
Thus infections are occurring and
smut masses. are forming continuous
ly throughout the sea- son. An in
lection on the stalk may result in
a general weakening of the plant and
barrenness. On the ear the infec-
ton may result in either partial or
total destruction of. the grain.
Control measures. The smut or
ganism is carried over on the old
plants left in the field or may be
brought in on manure resulting from
smutted corn, The adoption. of a
definite crop rotation and the destruc-
ton of old stalks, presumably by
early winter blowing, will aid ma
terially in eliminating damage. How
ever, it must be understood that a
small infection early in the season
may become very general by harvest
time. During the growing season it
is advisable to make bi-monthly in.
spections of the corn fields, collect
ing and destroying all smut masses
as they appear. This practice is en-
tirely practicable and need not add
more than fraction of a cent per
bushel to the cost of the corn.
No doubt proper seed selection
tends to breed a more resistant plant.
Seed treatment is of no value, how
ever, since it has been demonstrated
that the seed cannot carry the dis
ease.
Root Rot is name for an old