The Dawson news. (Dawson, Ga.) 1889-current, 1922-04-11
SCIENCE OvERC0MES
THE ROOT ROT EVIL
REMEDY rs FOUND FOR DE-
STRUCTIVE PEST BY TEXAS
EXPERIMENT STATION.

Announcing important new discov-
cries as to the nature and life history
of the cotton root rot disease and pos
sibilities for control, the first success
full infection OF plants in the green
houses and the growing in the labora-
tory of abundant seed spores OF the
fungus causing root rot DR.. b.
Youngblood director, Texas agricul-
tura experiment station, A. & M. col
lege, stated that Dr. ]. ]. Taubenhaus,
chief of the division of plant pathology
and physiology, who has had charge
of the root rot investigation OF the
Texas station for the past seven years,
has just succeeded in transmitting cot
ton root rot to growing plants in the
greenhouse.
Continuing, DR.. Youngblood said:
"The plants inoculated with cultures
of ozonum omnivorum, the fungus
| causing root rot. died typical root
rot death without exception, while the
check plants, not inoculated, remained
growing and are in perfect vigor. The
fungus was reisolated from the plants
so killed and other plants inoculated
with cultures obtained. These, in
turn, died promptly. The whole pro-
cess was checked up in accordance
with the rules of science and is now
thoroughly established for the first
time in the history OF the struggle to
learn something OF the nature OF this
! disease.
New methods of incubation were
necessary. These were perfected by
Dir. Taubenhaus after thirty-hve years
of effort with the old methods had
! failed to enable scientists to transmit
the disease This transmission of the
| disease was essential in order to Tx the
cause on the proper parasite. Circum-
stantial evidence had led scientists to
suspect ozonium omnivorum, name
applied to the fungus by DR.. Shear in
/ 1907 while working with the United
States department OF agriculture.
History of Experiment.
The Texas station was first to rec
ognize the importance OF root rot,
which has taken heavy toll from the
| cotton crop of Texas for years and
now takes probably more than $20,
100000 annually from the production.
! The first project undertaken by the
station, after its establishment in 1888,
attacked the cotton root rot problem.
| The next year Dr. Pammel, MEM
Der of the Texas station staff, initiated
considerable work on the project and
discovered that the disease was caused
! by fungus, which he described, and
not by alkal, as was popularity sup
posed by the farmers. DR.. Shear rede-
scrbed this fungus eighteen years la
! ter and gave it its present name. He
also carried out some tests as to the
effect of deep blowing, soil aeration
| and crop rotation, but no effective
means of checking the disease resulted.
at was necessary to find out wheth-
er the fungus lives on living plant
roots only or whether it lives over in
the soil only or in dead organic mat
ter, or whether it lives over on both
| living and dead matter or whether it
| fruits and bears seed spores; also if
| it spreads by more than one of these
methods DR.. Benjamine Duggar, of
the Missouri Botanical gardens, in
1916 published paper in which he
announced that the Texas root rot
fungus is not sterile organism but
possesses fruiting stage through
which the fungus propagated itself
from year to year.
Roots Nourish Pests.
"Dr. Taubenhaus, during his work
upon the project for the Texas sta
ton, has made the discovery through
tedious Investigations that the fungus
does live over on living roots of GER
tain plants in the soil and will attack
susceptible roots coming in contact
| Herewith the next season. He has
definitely identified cotton, castor bean,
| okra, sweet potatoes, pepper, beets,
carrots, tie vine, morning glory and
number OF other weeds as we'll as ros-
es and other shrubs and fruit trees
which are known to be susceptible
and on whose roots the fungus will
| live over as long as the roots are alive.
The ANIMALS OF the plants have
that part above the ground killed
by the frost, while the roots Of some
of them will remain alive through the
winter and will nourish the fungus I'M
! til new susceptible root groWths come
to the rescue in the spring. He thinks
the fungus Enthusiastically spreads for
the most part by means of sterile
| threads and in which function living
host is essential; but the evidence sub
mitted by DR.. Duggar and other evil
dence which Dr. Taubenhaus had col
lected, as, for example, the appearance
of the disease in spots and in widely
separated regions, which pointed to
the improbability of the disease hav-
ing been led to these localities through
a continuous system of susceptible
roots in contact, made it necessary to
know whether there are other ways
in which the fungus reproduces, par
ticularly wether it has a fruiting stage
in which seed spores are produced
which can transmit the disease after
they have been distributed by the wind
or other vehicle
Or. Duggar reported the collection
of fruiting stage, but had not been
able to produce root rot in growing
plants with these spores, nor had he
been able to make the fungus bear
fruit in the laboratory. DIR. Duggar
found his spores in the field at Paris,
Texas, and though he sent some Of
them to the Texas station DR.. Tau
benhaus was unable to make them
grow. The spores have also been re-