The Hood River glacier. (Hood River, Or.) 1889-1933, 1916-01-06

second codling moth spray was applied
May %. This consisted of arsenate of
lead. three pounds to so gallons of wa
ter, plus the lime-sulphur to 30. Fruit
only received attention at this time. all
of which were thoroughly covered. In
early June great deal of fruit injury
was noted taking place and in many
cases the small apples were found
largely consumed. The worms in fold
ing and rolling the leaves often incor-
porate many of these little apples. and
those SO surrounded with foliage are in
variably ruined. This feeding on the
fruit, though often not very extensive,
devitalizes the apples to such an extent
that they stop growing and drop. On
account of this existing condition. it
was thought best to check up the ex-
peiiments as soon as the feeding period
of the insects was over rather than
waiting until harvest time. In so do.
ing, thinning of the fruit was permit
ted on the plats where il was found to
be necessary.
A thousand fruits or thereabouts
we're counted in the various expert
mental plats and checks. There were
made from representative trees chosen
at random in the plats. In comparing
the results that were obtained, it is
clearly indicated that none can be pro-
nounced az efficient in controlling the
leaf.roller, though some benefit may be
derived from as weak application as
two pounds to so gallons. In expert
ment /, where 2 pounds to SO gallons
we're employed in the delayed dormant
and in the pink sprays. benefit of 8
per cent was obtained when compared
with the check. Contrasting this ex-
pertinent with 3 in which the lead was
omitted in the pink spray, the results
clearly show the time at which the
poison is an active agent in destroying
the worms. In this experiment there
is only three per cent difference be-
tween sprayed and unsprayed fruit.
The inefficiency of the delayed DOR
mant spray is clearly shown in expert
ment a; here a pounds of the lead ar
senate we're used to so gallons. The
fruit count shows per cent loss on
account of roller injury or five tenths
of one per cent less than the check.
This is 2.5 per cent more injury than
was obtained where the weaker arsen-
ical was used This discrepancy falls
within that allowed for experimental
error.
The extra two pounds of lead to SO
gallon of water in experiment de-
creased the fruit loss by 3.8 per cent,
giving total fruit injury in this ex-
pertinent of Is per cent or reduction
of little less than half of the losses
that occurred on the unsprayed trees.
In experiment 5, where lead arsenate
at the rate of pounds to so gallons
was used in the two early sprays, more
encouraging results we're obtained.
Even with this heavy dosage, however.
II per cent of the fruit was found to
be damaged. On trees heavily loaded
with fruit. loss of this percentage
would not be very severe as large
part of this could be overcome by judi
cious thinning. In years of light
crop, however, condition which exists
this year, and where all of the fruit be
retained, more efficient remedial meas
ures than arsenical poisoning should be
should be employed. Unfortunately.
experiment 6 was conducted on Jona-
tDduo, variety WhiCH 10 not euDJcCt W
severe attack, in Hood River at least
by the roller, so that comparatively
data as noted in the other experiments
were not obtained.
In times past, oils have been used by
local growers in an attempt to control
the leaf.roller, with rather Indifferent
success. Owing to existing conditions
it was thought best to test out series
of materials. Four oils were used in
eight experiments, as follows: Kero-
sene emulsion, l8 per cent, distillate
emulsion, Is per cent, crude oil, (Bal-
four Guthrie Co.. in the ratio of to IL
and to Is and miscible oil No. |, man.
ufactured by the above company, in
four strengths, 5, 6, z and 8 gallons to
the 100 gallons of water.
Some of the pioneer workers in leaf
roller control have at various times
recommended kerosene as an effective
means of DESTROYING the eggs Of the
leaf-roller and the 1S per cent emulsion
of this material was placed on the trees
with confidence that many eggs would
be destroyed. The trees we're thor
oughly covered, in fact drenched, to 6
gallons of the material being applied to
each tree. When a count of the eggs
on the experiment and check was made,
it was found that larger portion of
the eggs on the sprayed trees, or 96.4
per cent, hatched as compared with 95
per cent hatched on the control trees.
A duplication of this experience was
encountered with the distillate; here
again no ovicidal properties were found
to exist when applying an 18 per cent
emulsion. The trees were examined
the day after the material had been
applied and it was found that nearly
all of the evidences of the oil had dis
appeared. When used within the
bounds of economy, both of these ma
terials are lacking in sufficient penetra.
tion qualities to be considered means
of destroying leaf-roller eggs.
The results that were obtained with
the crude oil proved disappointing, also,
from point of control. The material
was used in two strengths, at the rate
Of gallon of oil to IL gallons of water
and gallon of the oil to Is gallons of
water. These emulsions we're applied
May q. The variety of trees lin the
experimental plats were 12-year-old
Spitzenburgs on which many egg mass
es could be found. On the day that the
spray was applied the more advanced
buds were noted already burst and
some of the first leaves were out. Up-
on examining the plats a few days later
many of the early leaves we're found to
be injured. They, for the most part,
we're not burned, but seemed to be
stunted and had an oily appearance for
several weeks, condition which was
not observed in the other experiments.
This greasy condition existed on much
of the foliage for several weeks, re.
tarding and causing a malformation of
the leaf growth on many of the trees.
While the crude oil was being applied,
a very strong wind was blowing, max.
ing thorough work very difficult. This
may have affected the results to
slight degree, for a few egg masses
here and there were found to have been
sighted. In experiment 9, or where
the ] to IL formula was used. 43 per
cent of the eggs failed to hatch. In the
Oh A e.