The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1907-01-19
A DISEASE WHICH THREATENs THE AMER
ICAN CHESTNUT TREE.

A new disease of remarkable de-
structive character has attacked the
native American chestnut, and has
gained foothol6 and attained pro-
portions which threaten the extinc-
ton of these trees in and about New
York. The same disease is known
to exist among the chestnuts of New
Jersey, Maryland, and Virginia, but
to what extent can only be ascertain
ed by extensive and painstaking work
in the respective fields.
The attention OF George w. Mer
kel, forester and engineer at the New
York Geological Park, was first at
tracted by the immense number of
dead and dying chestnuts in the
park. He suspected the presence
of destructive fungus. He found
that the disease was also creating
hovoc among the young chestnuts in
the park nursery. He sprayed the
young trees with Bordeaux mixture,
and extended the treatment to the
larger trees in the park. At best
this treatment could be called only
partially successful, and he appealed
to DR.. w. A. Murrill, mycologist
and first assistant in the New York
Botanical Garden. This occurred
last year, since which time DR.. Muir
rill has devoted all the time he could
spare from other important duties to
the careful study Of the disease and
to a long series of experiments as to
its nature, cause, and cure. His in
vestigations are not yet completed,
but the ravages of the disease have
now become so apparent that the sub
ject is one of great economic impor-
tance.
As Mr.. Merkel suspected, the dis
ease is of fungous origin. Pure cu,-
lures were made by DIR. Murrill from
affected chestnut sprouts in the Bo-
tanical Garden last autumn, and were
transferred to agar and sterilized
bean-sterhs and chestnut twigs. In
each of these situations the fungus
grew rapidly and fruited abundantly.
Living chestnut twigs were infected
and placed, with their ends in water,
under bell jars for inspection and
study of the fungus growth and
action as preliminary to experiments
in the field.
This year, as soon as actual spring
growth had begun, numbers of young
chestnut trees in the Garden propa-
eating houses were infected with ac-
tive fungus transferred from bean
stalks to the young trees. AS DR..
Murrill had been led to expect by re-
suits obtained in his preliminary ex-
periments, the fungus attacked the
trees vigorously, and soon caused
their death by girdling.
The work of observation was next
carried into the open, where the raw
ages of the disease among the older
trees through Bronx Park were watch
ed, as they also were among young
trees transferred from the nursery of
the Geological Park. In these in
stances infection had occurred natur-
ally, and the fungus found to be ex-
ceedingly active at the beginning of
the season of growth, before the
opening buds were able to utilize the
large quantity of nourishment at
hand.
The fungus works beneath the
cortex in the layers of inner bark and
cambium. It's presence is first indi-
Gated by the death of the cortex and
the change of its color to pale brown,
resembling that of dead leaf. La
ter the fruiting pustules push up
through the 1enticels and give the
bark rough, warty appearance and
from these numerous yellowlsh- brown
pustules millions of minute summer
spores emerge from day to day in
elongated reddish brown masses, to
be disseminated by the wind and
other agencies, such as insects, birds,
SQUIRRELS, etc. In late autumn the
winter spores are formed, which are
disseminated from the dead branches
the following spring. The present
supposition is that infection takes
place only through wounds or, possi-
bly,, through the lenticles. Wounds
are, unfortunately, only too frequent,
especially in the case of a tender,
rapidly-growing young tree like the
chestnut, which has the additional
misfortune of attracting lumbermen
and nut gatherers. Ifit escapes win
ter injuries to its trunk, the spring
storms are sure to break the smaller
branches and abrade the surface OF
the larger limbs !; if it is not disfgur-
ed by the green fly and twig-bore
during the summer, it is sure to be
mutilated by savage hordes of small
boys in autumn. Even the ubiqui-
tous squirrel may spread the disease
with tooth and claw while cutting
off ripe burs and racing up and down
the trunks; while every bird and in
sect that rests upon an infected spot
is liable to carry the spores upon its
feet or body to other trees.
The treatment of disease of this
nature must, of course, be entirely
preventive. When once allowed tc
enter, it cannot be reached by poison:
applied externally, nor can the spores
which issue continuously and abun
dantly through eruptions of the bark
be rendered innocuous by any coat.
ing applied at intervals. On the
other hand, no poisonous wash, ever
though covering every part of ths
tree, can prevent the termination o
the disseminating spores when they
fall into wound, since the wount
opens fresh tissues unprotected BY
the poison.
The spraying of young trees with
copper sulphate solution, or strong
Bordeaux mixture, in the spring be
fore the buds open might be of ad-
vantage in killing the spores that
have found lodgment among th'