Semi-weekly herald., 1909-04-29
SHALL WE CONTINUE TO
SPRAY FOR COOLING MOTH

tion, has given most conclusive evi- |
dence that many apple trees that
have been heavily sprayed for years
and dying condition, or are already
dead
This malady has been going under
the names, collar rot" crown rot,p
and root rot" without any well
founded assignable cause There have
been several theories as TO the posi-
BILE cause, such as seepage, alkali and
disease organisms. The first two OF
these troubles are probably one and
the same, namely, too much water in
the soil. and no one has been able to
assign the trouble to definite micro
organism It should be remembered,
| also, that Doctor Headdens expert
| ments have nothing TO do with trees
| that died from drowning; and the
writer knows, personally, that many,
| at least, of the samples of trees
analyzed were from land where seep-
age conditions are absolutely un-
| known.
| Doctor Headden's discovery of the
real cause of this trouble has come,
we believe, in time to prevent very
extensive losses from the death OF
orchard trees in this manner. 1t will
be folly, however. for any one here
after to spray his orchard with ar
| senical preparations more times or
in greater strength than is absolutely
necessary TO get good results.
Personally, very much regret, as
does Doctor Headden, that arsenical
spraying is resulting disastrously to
any of our orchard trees; but 1t is
and | am thoroughly convinced that
Doctor Headden has been very con-
sefvative in his conclusions as to the
extent of damage that has already
where excessive arsenical spraying
has been carried on.
The symptoms. in rather advanced
stage of this disease, as described by
about as follows: Trees usually stunt
ed in growth; bark very yellow bark
often dead and black just below the
| surface of the ground the main roots
in similar condition; leaves yellow
and maturing early; apples very abun-
dant but small and highly colored !;
the bark of the trunk and main limbs
often with vertical cracks which may
oil may not give out an exudation.
Trees strongly exhibiting the above
condition one year are almost sure
to be dead the next year.
This trouble usually appears first
upon a few scattered trees, and from
year to year seems to spread to
others. In any orchard where few
tree are found in the above condi-
tion the utmost caution is necessary
in spraying with arsenical mixtures
for the codling moth or other insect
pests.
Since coming to Colorado, more
than eighteen years ago, the writer
has steadily urged the fruit growers
Of the state to depend chiefly upon n
thorough treatment or two Just after
the blossoms fall and has advised
not more than one late treatment
While this has now become very
general rule among Colorado apple
! growers, there are still many who
| think IL two or three sprayings are
good, more will be better, and IL is
in the orchards that have been spray
ed four or five times or more each
season that most of the mischief has
been done.
Now, instead of recommending two
or three applications for the codling
moth, | am fully persuaded that it
is best to recommend one, or at most,
two.
If an orchard has n few trees that
| show the characteristic symptoms OF
poisoning, as given above, or II the
trees have been heavily sprayed for
several years, would recommend one
spray only Just as the blossoms are
about ninety per cent off. II the trees
have not been excessively sprayed, and
If for any reason the first application
was not very satisfactory. II might
be advisable 10 make a second appli-
cation. from four weeks to thirty days
later, which will be the time for the |
eggs of the first brood to begin to
hatch well.
Arsenate Of lead is by odds the best
poison to use, as 1t is less soluble in
water.
We have been recommending from
three to five pounds of the poison to
each 100 gallons of water; but since
Professor Melander has demonstrated
that two pounds to 100 gallons are
sufficient for the best results In Wash.
ington state, believe 1t is advisable
to recommend two, or not more than
three pounds, to each 100 gallons of
spray, for Colorado. And no lime tc
the mixture.
Some Precautions.
Use a fne spray. with good force ,
(1bo to 200 pounds prsssurs), ~ . q