The Breckenridge news. (Cloverport, Ky.) 1876-1955, 1921-01-19

|
en- from Tobacco, a journal of the
trade published in New York. 1t deals
with the diseases of tabocco, especial
" of wildhre and angular-spot which
made inroads into all crops grown
this year,
Losses from tobacco disease have
been especially severe during the past
four seasons. The greater part of
these losses have been due to two
diseases. wildhre and angular-spot;
which attack the leaves. and which
are particularly troublesome in wet
seasons. In the Virginia crop report
for September 1920 the forecast
shows a decrease of 2I,720,OOO pounds
of tobacco during the month OF .tug-
ust due to damage attributed 20 the
continued wet weather Tive greater
! part of this loss is undoubtedly due
to the two diseases mentioned. They
are not caused by wet weather. but
! like many other diseases spread aud
develop more rapidly during wet sea
/ sons.
These two diseases, although quite
similar in their general effect on the
tobacco leaf are distinct and produce
different kinds of spots. Farmers as
rule do not distinguish between
them. until the differences have been
pointed out to them and they general
" call both wildfre. blackfire, or
some similar name A comparison of
the two illustrations will show the
chief differences in the appearance of
the two spots at glance. The angu-
lar-spot is irregular or angular. while
the wildfre spot is found and is Dor
dered by a pale green or yellow halo.
Angular-spot is not SO angular in
shape. when found on heavy tobacco,
but it never has the halo which is
characteristic of wildhre Both spots
enlarge rapidly. and the leaf tissues
involved is killed. browns and dries
up or rots out in wet weather. Affect
ed leaves are sometimes completely
ruined and although the leaf may
still be marketable. there is consid-
cradle loss in weight and grade. ,
Although both diseases occur to
some extent in all parts of the state. .
they are especially prevalent in the
hue-cured belt. Angular spot is found
to some extent in nearly every field !,
while wildhre occurs i'll about one
field in five Angular spot is usually
found rather evenly distributed
throughout field, while wildire is
often restricted to one or more spots
in field
Cause of the Disease
Both spots are diseases in the true
sense of the word: they are caused by
specific bacteria, or germs as they are
commonly called, which so far as is
known attack tobacco only. The bac-
terium which causes wildhre is known
technically as bacterium tabacum. and
that which causes angular-spot as
bacterium angulatum.
Farmers generally have attributed
these diseases to wet weather. the
fertilizer. or other agencies. but these
are only secondary causes. If the bac-
terra which cause the spots were not
present there would be no angular
spot or wildhre no matter what the
weather conditions were. 1t is true,
however, that wet weather and other
factors are important in determining
the amount of injury caused by the {
two diseases OF these factors wealth ,
er is the most important a promis-
ing field OF tobacco may become gen [
orally infected after a few days of
rainfall This is due to the
TACT that the bacteria are spread from I
plant to plant by the splashing and i
glowing of rain drops. and that mois- t
lure favors the entrance of the bac- c
terra into the leaf. They are also
'preadby insects. especially flea. beet S
es. and by handling the plants in l
suckering, and topping.
Fertilizers affect the size of the G
pots and the severity of the disease t
n so far as they modify the growth t
If the tobacco plants. The most for i
ward or vigorous plants in field are S
Usually infected more seriously than v
he slower growing plants. Expert b
nents with fertilizer do not indicate.
However. that either diseases may be 4
controlled by modification of the fer il
ilizer. The fertilizer applications a
which tend to produce good crop t
will at the same time tend to make II
he crop more susceptible to the dis
aSe il
Source of Infection.
1t has been found that both diseases d
'ccur on plants in the plant bed. and ,
hat the amount of disease which
develops in the field is determined in
arge measure by the amount of dis d .,
aSe found in the bed. Cases have :
'een seen where the disease has y
pread from one field to another but !,
his has been found true only of fields !,
n close proximity, and there seems y
o be little danger from this source if :.
he fields are separated by hundred :.
ards or even less, unless of course "
hey are carried there on the clothes II