The citizen. (Honesdale, Pa.) 1908-1914, 1913-03-18
CHESTNUT BLIGHT PLANT
LIKE AUTOMATIC RIFLE.
Seed is Shot an Astonishing Distance
Millions of Spores Produced.

Millions of Spores Produced.
A parasitic plant which not only
is continually forming millions of
spores, or microscopic Seeds" but
shoots them out into the air from
tiny tubes, like a miniature regi-
ment of soldiers with automatic
rifles, is both a formidable plant to
combat and an interesting plant to
study.
1t was through the investigations
of the scientific staff of the Pennsyl-
vania Chestnut Commission, which
have proved so useful in the past
two years of successful field work,
that the Shooting" habits of this
dangerous fungus were discovered.
The gun-like necks or tubes are
found in the red pustules or fruiting
bodies which break through the dis
eased portions of the bark. 1t is in
teresting to watch, under the micro
scope, how they shoot oftener and
oftener each day until a climax is
reached, suddenly subsiding after
the climax to begin all over again,
like a besieging battery which must
make new start. The quarter of an
inch that the spores are shot seems
like an immense distance when one
realizes that it is six hundred and
twenty times the length of the
spores. If a bursting peach were to
shoot it's seed say six hundred times
the length of that seed, it would go
hurtling fifty feet through the air.
1t is by this BATTERY method
that the parasitic fungus which
causes the chestnut blight dissemin-
ates or scatters itself. More than
this, although belonging to one of
the lowest orders of plant life, Dia-
porthe parasitica, as the chestnut
blight fungus is called, has a second
method of getting where they can
start new plants, plan almost as
odd and quite as effective as the
shooting method. In warm wet
weather, the plant forces out of it's
fruiting bodies long yellow 'horns, "
which are really threadlike masses of
spores. These horns" dissolve in
the first rain and the millions of
spores which form each thread are
washed down the trunk of the chest
nut tree to find new breaks in the
bark, in which to grow, or possibly
to be carried by winds, birds, squir-
rels or insects to neighboring healthy
trees.
For each of these methods of
propagation there is a different kind
of spore. The smaller spores, the
kind forced out in horns, are single
celled. At first they were called
summer spores" because they were
supposed to be formed chiefly in
warm wet weather, when the
horns" appear. But recently it has
been discovered that they are pro-
duced in great numbers in winter
also, although not in the form of
horns. All the year round these sin
gle-celled spores are being formed in
millions. An idea of their tremend-
Gus multitude can be obtained from
the fact that in a single small spore
horn there have been found, by act
ual calculation, to be 115, 100000
spores. 1t must be remembered that
each canker or diseased spot on a
blighted tree produces many spores
after every summer rain. The num-
ber of single-celled spores produced
on one diseased tree in a year is
practically infinite. The larger
double-celled spores which are shot
out into the air are not produced in
such immense numbers. However,
they can only be reckoned in mil
lions.
The Commission is gathering to-
gether seeds of some of the most
promising varieties of this kind with
the idea of using the seedlings next
summer in breeding experiments. A
very unusual variety of the Chinese
chestnut has been secured which
promises good results. AS a hybrid
chestnut will often produce nuts in
two years from the seed it will not
take long to establish a new variety
of chestnut resistant to the blight if
such a one can be developed. Even
a new race of resistant forest trees
might be produced for the next gen.
Grafton that would be free from the
disease if these experiments are sue
cessful. So far no blight has been
found in any Chinese chestnuts ex-
cept in a single case where artificial
inoculations were made and even
there the experiments have not gone
far enough to be sure that definite
cankers have been produced. There
is much promise, therefore, in the
Chinese chestnut as the parent of a
possible new, vigorous blight-free
variety.