The Washburn times. [volume] (Washburn, Wis.) 1896-1976, 1915-01-07

APPLE TREE AFTER TREATMENT FOR Bills
TER CANKER.
bring brought out that the most seri-
Gus canker disease of that state is that
caused by the fungus Nummularia dis
creta Tul. and named by him the ILL
nois apple tree canker. For purposes or
this discussion it is somewhat better to
adopt the characteristic descriptive
common name of 'blister canker" for
the disease caused by this fungus.
The recommendations for the proven
ton of this disease have been known
for many years. In cutting a branch
from a tree it is desirable to make the
cut smooth and close to the member
from which it is to be severed and to
cover wounds that are larger than an
inch in diameter. 1t would be still bet
ter to cover all wounds with some
dressing. but generally this is not
practical.
During the past season we have used
paraffin, thick white lead paint and
asphaltum. and it will require further
experiments and more time is heces-
sary before definite conclusions can be
drawn. The substance known as as
phaltum is an oil refining product that
has variable melting point depending
upon its source. However. this varies
from 225 to 2S5 degrees f.
While this temperature is its melt
ing point, it cannot be applied at such
temperature because it becomes rigid
as soon as cooled to very slight de-
gree; hence it is necessary to apply
this substance at temperature some
where near it's boiling point. which is
in the vicinity of 45O to 500 degrees F.
This is applied with daub or brush
and as soon as it cools it forms semi
rigid covering. This covering is soft.
similar to heavy tar, in summer, while
In winter it has a tendency to become
brittle and may crack. This crack may
be closed again later in the year.
The paraffin used was the same as
that ordinarily applied for sealing pur-
poses and has a melting point Of 113 to
125 degrees f. To apply this 1t is
necessary to have blow torch to heat
the paraffin to liquid condition. This.
however, is objectionable because OF
the possibility of injury caused to the
growing tissues.
1t is generally agreed that some sub
stance is necessary to protect the
wounds by preventing drying out OF
the tissues and a subsequent infection.
kn
all the pruned brush and some men pile
the same outside the orchard. usually
in a ditch. and allow the wood to de-
cav as best it can. 1t is true that such
brush prevents erosion. but it is also
true that such brush is real hotDed
for fungus diseases. 1t is a common
sight to see side by side well kept
commercial orchard and a neglected.
unkept orchard.
The best policy is to burn the brush
and thus prevent trouble that may
cause financial loss. Should an entire
tree be found to be killed by some
cause or other it is always advisable
immediately to grub it out rather than
to cut it off near the surface OF the
ground. Should any portion OF the
dead tree be allowed to remain IN the
soil it is very subject to the attacks
of the root rot fungus tArmlllarria
mellea L.. and from there the disease
may spread through the ground 10
neighboring healthy trees. 1t Is clear
that orchard sanitation is necessary
and that 1t requires but little labor II
constant vigilance is kept against the
blister canker or any disease that de-
sires to introduce itself.