Middletown transcript., 1911-07-29
DISEASE OF CHESTNUT TREES

Probably the most destructive disease
Of forest trees now known in North
America is the bark disease of the chest
nut. Through the kindness of the Press,
the writer called the attention of the pub.
| lie to the presence of this pest in Delaware
two years ago exhibited specimen of dis.
ease was known to occur at but three
points in Delaware, viz; the vicinities of
of Wilmington, Newark and FELTON,. Re.
| cent reports and inquiries indicate that it
| has OCCURS in ten or tWelvs places, most
| OF which are in the northern New Castle
county, and in Kent county, from Dover
/ to FELTON,.
The disease is due to a fungus known
by the scientific name of Diaporthe paras-
itica and was first described and reported
in 1904 by DR.. Murrill of the New York
Botanical Garden. 1t is supposed to have
been introduced into this country on the
japanese chestnut, a variety which ap-
pears to be very resistant to the disease
but is not nearly so valuable forest tree
as our native American chestnut. The
disease first appeared on Long Island and
has practically destroyed all the chestnut
in the vicinity of New York City. The
lower point of New York state, the south
western corner OF Connecticut, all of
Long Island, the greater part of New Jer.
sey, and the eastern tier of counties Of
Pennsylvania are now thoroughly infect.
ed. Il has also been reported from other
points in Massachusetts, Rhode Island,
New York, Connecticut, Western Penn.
sylvania, Delaware, Maryland, Virginia
and West Virginia.
It is estimated that the loss in and
about New York is now between 5 aud
10 million dollars aud that the total loss
in the injected area will aggregate fully
100 million dollars. The last legislature
of the State of Pennsylvania made large
appropriation for fighting this disease,
which if allowed to 60 unchecked will
cost that Commonwealth fully so million
dollars.
The first appearance of the disease is u.s.
ually in the tops of the trees and is easily
recognized by the dying of the leaves and
branches. A more careful examination
will show canker on the branches be.
yond which the parts are dead or dying.
This canker is at first small but gradully
enlarges in all directions until il COM
pleteIy girdles the branch and causes death
of the part beyond the point of attack,
The eanker is at first black, becomes
gradually sunken below the general sur.
face of the bark, then roughened and
eventually covered with small orange.col.
ored papillae. This latter condition is
most noticeable in rainy weather. These
papillae contain the spores or fruit which
when dry are carried by the wind to
other parts OF this same and neignbor.
ing trees. They are frequently carried for
very long distances. Eventually cankeFs
may be formed on the trunk resulting in
the death of the entire tree.
When trees are only slightly affected
the diseased parts should be pruned out
and burned and the wounds painted.
The fungus will continue to live and fruit |
on dead wood, therefore great care should
be taken to remove and burn all the dis.
eased parts, so that all the spores OF the |
fungus will be destroyed. When trees |
are seriously affected it is much better to |
cut them down and burn the affected |
parts. The fungus does not penetrate the |
wood which ma kes it possible to remove |
the bark from tile trunks and larger |
branches and thus save the wood for farm |
use. The bark should be collected and
burned.
The spread OF this disease shroHgh out |
the state of Delaware presents serious
economic problem in our people. II the
disease ia allowed to spread unchecked it |
will result in a very great loss which can /
only be regained only after the lapse of |
long period of time. However, by |
prompt action and cooperation Of the |
people the ravages of the disease can be
checked and probably eliminated. All |
citizens are urged to report outbreaks or
suspected outbreaks Of this diseases ID |
Prof. Wesley Webb, Secretary of sbe /
State Board Of Agriculture, Dover, DeIa-
ware, or to the writer who will gladly |
make examination OF tie affected trees
and give suggestions for treatment or re-.
moval Of same.
MEL 7. CooK,
Del. Agri Exp Station,
July, 1911, 1911, Newark, Del.