The public ledger. [volume] (Maysville, Ky.) 1913-1968, 1919-07-19
ROOT ROT IS FCUNDIN
MASON TOBACCO, AC-
C0RDING TO EXPERT
Some Signs Of Tobacco Disease Found
In Mason County Through Inyes-
legations Of Expert Made Fri
day and Saturday-Reslst-
ant May Be Tried
Here.

G. M. Slagg, an expert in the Office
Of Tobacco Investigation of the Fed
eral Department of Plant Industry,
who came to Mason county Friday for
some Investigations and experiments
with tobacco to learn whether or not
the disease commonly called root rot
was affecting tobacco here, Saturday
said that in his Investigations Friday
he found evidences of the disease in
this county.
The root-rot is caused by a fungus
which lives as a parasite on the roots
of the plant. This organism, or germ,
although so small that it can not be
seen except with high-powered mi=
croscope, is still large organ
ism as compared with other parasites
which produce well-known diseases in
plants and animals. This organism is
called Thielavin basicola and techni-
cally this disease should be called
the Thielavia root-rot, since there are
many other organisms which cause
root diseases in other plants. This
fungus can grow into the roots of the
tobacco plant and feed of its tissues,
which results in their decay. More
over, it can live on dead organic ma
terial in the soil, though not as read
lily, and in the absence of the tobacco
plant from the soil it gradually dies
out, though this may require from s
to 10 years or more. The exact time
has not yet been determined, but 1t
probably varies somewhat with differ
ent types of soil. The disease spreads
very much in the same way as other
diseases of plants and animals. 1t is
sometimes very difficult to account for
the first infection by the fungus. The
most common means of spreading 1t is
through the transference of sick soil,
either by wind, water, or animals, to
healthy soil or by the transplanting
of diseased plants from infested seed
beds.
With this description of the nature
and cause of the disease. the skeptical
grower has still the right to ask foH
proof that the root-rot Is doing the
amount of damage claimed and that it,
and not depletion of soil fertility, is
the reason why tobacco soils in the
Burley section require several years
of "rest" after having grown one, two,
or three crops of tobacco. There exists,
fortunately, convenient and convinc-
ing proof of this fact. This lies in
varietal differences in resistance and
susceptibility to the disease.
Although a high measure of control
Of the root-rot in the Burley section is
attained by the system of rotation in
use it is evident that, on account OF
the extreme susceptibility of the Bur-
ley variety, considerable disease oc'
this variety not only prevents con-
tinued culture when desired, but also
makes the growing of second and third
! crops on the soil quite game OF
chance. A type Of Burley as resistant
as some of the cigar varieties and
still possessing the yield and quality
of the ordinary Burley strains there
fore would be extremely valuable in
reducing the animal loss from disease
Two possible means of producing such
type are selection for disease resist
ance among commercial varieties now
grown and crossing resistant greer
types, such as some Of the cigar to-
baccos, with White Burley, for the
purpose of adding disease resistance
to the White Burley characteristics
The first method, that is, selection fol
resistant strains in diseased fields, hai
been resorted to in obtaining results
presented. All tobacco growers hav,
seen fields in which the crop hal
made very uneven growth, though
all the plants apparently had an equa
chance to START and develop. 1t some
times happens that these fields behave
in this manner besause of the pres
ence of the root-rot and the use of i'm
pure seed Those plants which grow
rapidly and stand out distinctly from
their neighbors may be resistant to thu
disease. A large number of these hav'
been selected and the seeds saved
from the individual plants and growI
in separate rows ON sick soils the fol
lowing year A few of these selec
tions have shown very distinct resist
ance when compared with ordinar!
Burley. and these strains propagates
and tested over period of severa
years under many varied conditions
have continued to maintain their orig
inal degree OF resistance, In som,
cases these strains have been testet
, on rather large scale on both health!
and sick soils for the purpose OF com
pairing the quality OF the cured lea
produced with that OF the ordinar.
White Burley. The results ON tn,
whole have been very encouraging. al
though the Ideal In mind has not ye
been reached. The resistant strain