The progressive farmer. [volume] (Winston, N.C.) 1886-1904, 1900-12-18
Vol. 15.
Agriculture.
NEW DISEASE OF COTTON.

Correspondence of The Progressive Farmer.
A good deal of complaint has been
made during the past fall in regard
tn a disease of cotton which some of
the eomplainants call wilt and 9th
ers ,lightningblast. " The latter name
terious way the damage was wrought
by electricity. Samples of the dis
eased cotton from the vicinity OF
Red Springs show that the trouble
is of fungous origin and not due to
lightning. 1t is also different from
the old root rot disease.
The cause of the new wilt disease
is a fungus belonging to the genus
FusGriunl This genus includes
many species most of which are
saprophytes on the roots of dead
plants. A microscopical examina-
ton of the sections of the root and
stem shows the sap vessels or tubes
more Oh. less chOked by the spawn
of the fungus. These vessels are the
channels by which the crude sap and
water normally ascend from the soil
TO the leaves. When they become
choked by the spawn of the fungus
the water evaporated from the leaves
is not promptly restored by the soil
water. The plant as a consequence
willis and soon dies of sunstroke, not
lightning stroke.
So far this disease has been re-
ported only from the southern and
eastern counties. 1t is especially bad
in fields where melons have been re-
Gently grown. Correspondence shows
that the disease also exists in the
coastal counties of South Carolina.
No complaints have been received
from the red clay regions. But it is
likely to invade all regions where
cotton is grown.
1t is well known to economic botan-
8sts that a species OF TttSarfttnl also
eauses a wilt disease in watermelOns.
Another species of same genus causes
..sore-shin'' in tobacco. And it is
significant that the present COM
plants about wilt diseases all come
from the sandy eastern section where
watermelOns are standard crop.
On account of the mild winters the
melon plant there frequently re-
mains in the soil from year to year
as a voluntary weed. incubation
experiments with the fungus from
watermelon to cotton and vice versa
are necessary to show whether or
not the fungi in these two crops are
the same or different species. Pres
ent indications are that the fungus
is the same species, and that it was
originally developed in the soil by
and upon watermelon plants.
Complains are also being made by
farmers in sections where water
melon and cotton wilt is known, that
the cow pea often Wits and dies be-
fore producing flowers or seed. A
sample of diseased COW pea vines re-
Gently examined by the writer shows
fungous infection similar to that
above described. The sap vessels
of the pea plants were nearly plug
ged by the spawn of a f1ISGrittnl and
probably the same species we find
upon cotton. incubation expert
ments are, however, requisite to set
tie this practically very important
point.
What practical farmers want to
know is how to eradicate the disease
or prevent it from destroying their
crops. But Il rational remedy re-
quires d fuller knowledge of the life
history and specific identity of the
fungus attacking these different
crops. If the fungus is one species
only it will attack several widely
different crops and is therefore very
dangerous. If the fungus upon diff
Ierent crops are specially distinct,
We can Starve them out by planting
peas on cotton land and cotton on
pea land. Rotations of crops is the
most rational treatment for such
diseases. The lack of such rotation
mas probably been the chief agency
IN developing these diseases. Fungi
are naturally saprophytes. That is,
they naturally feed upon dead or
dying plant tissue. But when they
are offered year after year the same
species of food they eventually de-
Velop such an appetite for it that
they attack it while still living. In