Vilas County news. [volume] (Eagle River, Vilas County, Wis.) 1896-1927, 1898-08-08
THAT APPLE BLIGHT
IT INJURIES TREES BUT DOES
NOT KILL THEM.
CUT OFF THE DEAD TWIGs
That is the First and Best Thing to
Do-The Disease Due to Bacteria
Spraying not Effective-Prof.
Goff's Timely Information and
Advice.

Many apple trees are disfgured
this season with patches of dead
foliage scattered more or less thick
ly over their tops. Sometimes the
dead leaves appear to be nearly or
quite as numerous as the living
ones, at others only here and there
few dead leaves appear. Many
are inquiring as to the cause Of this
diseased condition, and some apple
growers are alarmed at the prospect
of losing their trees.
Prof. 3. S. Cor, norticu1tnrist at
the University of Wisconsin, says the
dead twigs are the result of infection
by a true bacterial disease. The
trouble is by no means new, but in
many localities the attack is much
more serious than usual this year,
so that many have observed it who
would have passed it by IN seasons
when the attack was lighter. The
disease is known as fire blight or
pear blight, for it attacks the pear
with even greater virulence than the
apple. The bacterium that causes
it has been isolated by specialists
and has been given name that
would tend, were it mentioned, to
increase the alarm of the uninitiated
fruit grower. The disease, says Fof.
Golf, gains entrance to the twigs
through microscopic spores that
alight on the tender tissues of the
growing point, or upon the flowers,
and the bacteria that develop from
these spores feed and multiply within
the juices of the plant, extending
backward from the growing points
more or less rapidly, causing death
of the tissues as they proceed. In
the pear, the disease very often ira
verses the entire branches and trunk
causing total death of the tree. In
the apple, it progresses less rapidly,
and rarely proceeds much farther
than the current seasons growth
Except in extreme cases, therefore,
the apple grower need not fear the
total destruction of his tree, though
the dead twigs are of course damage
that is to be dep1ored.
what is the remedy?" was asked
Unfortunately" was the reply, "the
sprays that are so effectual in pre-
venting the apple scab and the mil
dews and black rot of the grape are
not effectua1 against the fire blight,
because the places where the disease
gains access, being the tender tissues
of the growing points, are being con-
stantly renewed, and hence cannot
be kept covered with the application.
Something may be done, however,
to check the ravages of the disease
after it has gained entrance to the
tree, and to render the tree less sus-
ceptible to it's attacks. For the
first, the affected twigs should be cut
off as soon as their presence is dis
covered, and the cut should be made
at least six inches below the point
Of visible infection, since the disease
proper is always somewhat in adj
vance Of the dead tissues. The parts re-
moved should always be burned to pre-
vent the dissemination of spores. For
the second, we should withhold Guilt
walton about the trees and permit the
ground to dry out to some degree,
and we should avoid manuring the
soil. Any treatment that favors
active growth Of the tree, predisposes
it to blight, and conversely, the
treatment that checks growth re-
duces the tendency to blight. Some
varieties are more subject to blight
than others. Among apples, the
Alexander and Yellow Transparent
are especially liable to it. AS a rule
badly blighting varieties should be
avoided in planting"
Prof. Golf declares that a tree that
blights habitually should be removed
from the orchard, for it tends to.
disseminate the spores to trees that
might otherwise escape infection.
The fire blight only affects trees of
the apple family, i. e., the apple, pear,
ounce, medlar, hawthorne, etc. 1t
neved attacks the plum, cherry, april
cot or peach.