The Hood River glacier. (Hood River, Or.) 1889-1933, 1912-10-03
FIRE BLIGHT MOST
DESTRUCTIVE PEST

Fire blight is caused by bacterium
which lives in the diseased tree during
the winter. During the spring drops
of gum exude from the diseased areas.
carrying countless numbers of bac-
terra. Bees and other insects feed
upon the gum and their feet and
mouthparts become covered with the
organism. While collecting nectar in
fruit blossoms bacteria are deposited
IN the nectar in which they thrive and
multiply. These bacteria work their
way downward into the fruit spurs,
limbs, larger branches, trunks, roots
progressing until the tree is dead, un-
less stopped by the removal of the in
fected portion by pruning, after which
all pruned surfaces have been saturated
with corrosive subimate, the work of
sterllizing the tools and surfaces being
done as the surgery work on the tree
progresses.
Fire blight, pear blight or pome
blight is the most destructive OF all
diseases of the pome fruits. Ii is par
tlcularly injurious to the ounce, has
practically terminated the pear indus
try IN many of the pear growing Sec
tions, not only throughout the west,
but over the entire country and has
become the disease of greatest concern
to growers of the apple. During 1910,
for the first time fire blight made its
appearance in the Hood River valley
and spread over an area of more than
5000 acres. The fact that this disease
did spread over so large an area has
puzzled many who are not familiar
with the action of bacteria and the
progress of disease caused by them.
Bacteria are minute plants measuring
about 10000 to 10000 of an inch in
length. The minuteness of these or
gansims cannot be appreciated. They
occur everywhere and oftentimes in
great abundance. The New York ex-
pertinent station found 692 543 average
of IL tests) in one cubic centimeter
tabout 1900 of a quartz of milk
drawn with milking machine. Soils
of ordinary fertility and in good tIth
contain 1000, 600 to 5000, 900 bacteria
In each gram (about 28 grams in each
ounce). Under ideal conditions a bac-
terium of the shape of the one causing
fire blight will elongate and divide,
forming two individuals in twenty to
thirty minutes and these will in turn
divide into four, then eight. Increas-
ing in this manner and rate a single
bacterium is capable of producing L.
0OO,OO0 progeny in less than hours.
At this rate mores than 10000, 900
would mature in less than IL hours.
Unchecked it would only take a few
days for the air, water and earth to be
completely occupied with them. When
it is remembered that fire blight is
caused by such an organism it is easily
understood why epidemics occur and
why thousands of infections may occur
In single tree, or entire orchards are
completely eradicated in single sea
son. Fortunately the location of areas
in which the bactercia occur in fruit
trees are very conspicuous on the
smooth portions of the tree, as more or
less irreguarly shaped black and
shrunken areas extending along the
sides of the limbs or even girdling the
branches or trunk of the tree. These
areas are hold over cankers and must
be cut out as soon as located. Every
cut surface must be treated with So
luton of corrosive sublimate not
weaker than one part of poison to 1000
parts of water. The pruning tools
must also be disinfected frequently as
the work progresses. Should blight
make its appearance it any time dur
ing the year it should be removed at
once and with all the above mentioned
precautions.
Fire blight has apparently been erad-
icated in this valley. There is danger,
however, that some cases have been
overlooked. Everyone should be more
than cautious to observe all abnormal
conditions and report the same at once
to the frult-inspector. Since this val
ley is naturally favored by barriers on
all sides the introduction and rapid
spread of disease in many places at
one time which might he introduced
from nelghboring sections give US
little concern. Our greatest concern
is, therefore, to eradicate the pests al
ready established. By close coopera-
tion of all, such results may be accom-
plshed. W. H. Lawrence.
Won are not pXnarlmentinp on vo1r-