The Mason County journal. [volume] (Shelton, W.T.) 1886-1927, 1899-06-09
Black Spot.


Pacific coast. Various have been the
opinions as TO the cause and the es-
sence of this tree disease. Newton B.
Pierce, assistant pathologist at the
United States labratory, of the depart
ment of agriculture, at Santa Anna
California, calls it "black canker."
He has just written letter on the
subject to Hon. ]. 7. Blackburn, ex-
president of the board of horticulture
OF the state, in which he says: "In
relation to the black canker OF the APP
pie and other trees, will make the
following statements, which however
only involve facts which were published
in Oregon and Washington a number
of years since. My field ard labratory
work on this disease has shown that
the trouble is due to the action of a
parasitic fungus. incubation expert
ments conducted here, where this dis
ease is unknown by apple growers, en-
abled me to transmit the disease in
typical form to young and healthy trees
grown here. One young tree SO inoc-
ulated was entirely gridled by the dis
ease, and of course was killed. This
is the substance of the evidence OBJ
tained as to the fungus nature OF the
disease, and it is far better proof of
the cause than has been brought out
for most fungus disease of plants. 1t
was also proven that the fungus works
during the dormant period of the tree,
as the infection work was carried on
in the winter season. Both the sexual
and asexual spores of the fungus have
been studied. It's natural host plants
have been learned, as we'll as the cul-
tiyated forms. So much, then as to
the true nature of the trouble.
Prospecting the treatment of this dis
ease, Idon't know that anything of i'm
portance can be added to what was
written for the press OF your section
several years since. The best fungicide
known for the treatment of such dis
eases is the Bordeaux mixture. The
strength of this mixture and the best
time for application are matters which
should be thoroughly tested by the
fruit growers themselves. The stan
dard government formula is 6 pounds
of copper sulphate, 4 pounds OF quick
lime, As gallons of water. The's sui
phate is. dissolved in ten gallons OF
water in barrel; the lime is slaked
in a half barrel with cold water and
reduced to milk of lime with about
ten gallons of water; the milk of lime
| is then strained into the copper SOL
ution and the whole we'll mixed and
reduced to As gallons. Only cold
water should be used and the copper
sulphate should never be dissolved in
a metal vessel. The mixture should
be used the same day as prepared. 1t
should be used as spray for the pre-
vention of injection, and should be
applied to all parts of the trees.
| Thoroughness is an important matter
| in all such work, and the applications
should be made with sufficient freq
uency to keep the trees well covered,
especilly from time just before the
fall rains and we'll after the last rains
of spring.
ssFor trees which are already diseased
the control will prove more difficult,
and in come advanced cases may be
impossible. The diseased branches
should be pruned off as carefully as
possible. On large limbs and upon
the trunk of the tree the diseased spots
in the bark should be cut out, remov-
ing all parts to healthy bark. This
work will require great care and thor
oughness. AS soon as the pruning
and cutting out has been completed
and all twigs and fragments OF bark
have been burned such pieces OF bark
bear many thousands of spores of the
! fungus the trees should be thoroughly
sprayed with the above mixture.
Each tree should be thorou ghly
examined from time to time and all
newly injected spots or old spots not
complety removed should be cut out.
This practice of re-examination and
spraying will reed to be kept up for
considerable time, as it is very diff
cult matter to entirely disinfect a tree
once generally injected. Only great
thoroughness and repeated effort will
succeed in this curative work. The
most satisfactory treatment will be
that directed toward prevntion in
| orchard not already infected.
at is my desire to visit Washington
! this fall to set such spray work on foot
| in the different sections and / will
certainly try to do SO if my work will
allow, but the lines indicated are
those which would pursue in the