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

efficiency that those skepticslly inclined |
might look upon them with suspicion. |
As has been stated before, the miscible |
oil was applied in four strengths, s, 6,
z and gallons to the 100 gallons of
water. Owing to the fact that delay
occurred in the receipt of the material,
followed by rainy weather, the emul-
sions were not applied until April 8,
at which time the trees-of the New
town vsriety--were beginning to send
out foliage. This foliage development
was sufficient to give the orchard a
faint green coloration. In few cases
the leaves about the fruit spurs had
unfolded to such an extent as to expose
the tips of the fruit buds. The trees
were thoroughly sprayed, in fact
drenched. five to six gallons being ap-
piled to each.
On the day following the spraying.
the experiments we're carefully gone
over; little or no foliage injury was
observed. Two days later. however, a
large amount of foliage burn was found
to have resulted. In experiment IL,
where to 100 was used, the injury
was of little consequence. In the other
experiments. the foliage burn was
found to increase in direct proportion
with the greater strengths Of oil used,
reaching a rather alarming condition in
experiment Ia, where 8 to 100 had been
applied. In this plat practically all of
the foliage that was exposed dried up
and dropped off within week or two.
At first it was thought that many of
the fruit spurs were killed; the leaves
all dropped away. but most Of the buds
continued to grow and the resulting
bloom was almost normal, though many
Of the flowers seemed little smaller
than those on the control trees. These
were closely watched and soon after
the petals fell many of these smaller
ones dropped. Upon examining these
weaker flowers. the bases of the stems
were found to invariably possess a
brown discoloration-in some cases they
even seemed burned in much the same
manner as that found on the leaves.
No other injury to the flower buds was
observed. Many Of the small buds on
the larger limbs. which in time would
develop into fruit spurs, were killed.
with result that in the forming of
new buds and the resulting foliage
growth, the development the leaves
on the plats seemed several weeks be-
hind that of the checks. Today. how
ever (July 2O), little or no visible diff
ference in the amount of foliage ana
fruit exists between sprayed and check
trees. In fact (perhaps my imagina-
tion), many of the sprayed trees appear
more vigorous and possess a richer
green coloration than is found in the
checks. Just what effect this burning
of the fruit spurs will have OIL next
years crop is point of interest that
will be watched keenly during this fall
and next spring.
All of the miscible oil applications
proved to be decidedly efficient as
agents in killing the leaf-roller eggs.
In checking up the experiments it was
found that the numbers of Matching
eggs taken from the different plats
varied directly with the strengths of oil
used. These same variations, though
of very narrow margins, we're found to
exist when the fruit counts we're made.
In experiment II, where gallons to
100 were used, 1921 per cent of the roll
Ter eggs failed to hatch. In the check
rows two rows left across the orchard
on either side of which were two ex.
perimental plats), 96.8 per cent of the
worms emerged. When the countings
were made to determine the fruit in
jury it was found that the worms that
escaped the oil caused 3.6 per cent
injury. On the check rows, 18 per cent
Of the apples were damaged by the
In spnraactrn Tho att Aa
Ions to the 100 in experiment IL, the
efficiency increased from 92.l per cent
to 98.S percent. In this experiment,
80 per cent of the apples were injured
by rollers or very slight decrease
from that noted in number II.
In experiments l3 and Ia the results
that were obtained seem to APPROACH the
incredulous. The high pecentages at
tanned in destroying the eggs is SUBJ
stantiated by the figures that were OBJ
tanned in counting the fruit for roller
injury. In number ]3, 99.3 per cent of
the eggs were killed, and in number IA,
out of l,006 eggs examined, only four
hatched. This gives killing percent
age of 1916 per cent. The fruit loss in
this last experiment amounted to 8
per cent, eight injured apples being
found in examining 1000.
In summing up the experimental re-
suits it is found that efficiency is ap-
preached in experiment 5, where lead
arsenate is used at the rate of pounds
to the so gallons of water and obtained
in experiments II to ID inclusive, where
miscible oil was used. In comparing
the costs attached to using these ma.
terial. the miscible oils must be consid-
cred by far the most economical The
lead application costs for materials
alone in the neighborhood of s.. .65 per
tank of 200 gallons. The miscible oil,
as used In experiment IL, will cost
about Sl.50 per tank and, as it cannot
be used in combination, the application
will be extra. The marked increase in
efficiency attained with the oil, how.
ever, more than warrant its use. For
complete safety to the foliage, the oil
applications should be made before the
buds burst. Apparently no permanent
injury occurred in our experimental
plats this season from the late applica-
tions, but the margin of safety is ex-
tremely small and such a procedure
should not be generally followed.
The author wishes to thank F. W.
Radford and Frank Davidson for their
generous assistance and cooperation,
which has made possible the conducting
of the large series of experiments dur
ing the past season.
Inral piouaor Wor,.u naad