The Leavenworth echo. [volume] (Leavenworth, Wash.) 1904-current, 1922-03-17
\ PROMISING NEW TREATMENT
FOR THE san JOSE SCALE.
Entomologist in Charge Fruit Inves-
LEGATIONS. |. 5. Dent. of Agriculture

LEGATIONS. L. ;. Dept. of Agriculture
The San Jose scale is just now ex-
ceedingly abundant and destructive in
many orchards in the Bentonville.
Ark, section. and growers state they
are unable TO adequately control the
pest with the usual dormant tree
treatments with lime-sulphur spray.
While the Bureau of Entomology be-
lieves that thorough spraying with
dormant tree strength of lime sui
phur will control the San Jose scale.
yet to meet the desire of orchardists
Tor other than lime-sulphur treat
ments, number of experiments with
sprays We're undertaken. The pur-
pose of the present article is 10 call
attention to results secured in the
treatment of the scale by the use Of
spray containing per cent of Tub
ricating or engine oil emulsifed with
potash fsh-oil soap.
The careful experiments in Florida
by ". W. Yothers with various
sprays for the control Of citrus scale
| insects and the orange white fly. as
published in Farmers Bulletin 993
and elsewhere. resulted in a formula
Of engine-oil spray which has been
found remarkably effective in view Of
the small amount of oil used, namely,
l per cent, emulsifed with potash
fsh-oil soap. Mr.. Yothers found that
any one of several oils Of the iubri-
eating type, when thoroughly emulsi-
fed and used at the dilution indicat-
ed, was quite effective against these
scale insects and the white fly. and
these sprays have now come into
large commercial use in Florida
The surprising efficiency Of spray
containing such a low per cent oil
suggested the desirability of testing
sprays of this character against the
San Jose scale. The abundance and
destructiveness Of the scale in the
Bentonville section of Arkansas am
the desire of growers for other than
lime sulphur sprays, has offered eX-
cellent opportunity for testing various
dilutions of engine oil sprays against
this pest. The experiments We're car
ried out by A. J. Alderman, of the
Office of Deciduous Fruit Investi-
cations, and have included tests of
lubricating oils of a strength Of from
| y per cent to per cent or ) per cent,
thoroughly emulsifed with potash
fish oil soap. The results showed
practically complete killing Of the
scale by one thorough application of
the spray of a strength as low a .
per cent of Oil. Orchardists have
been so pleased with the results that
the 2 per cent oil spray will be ex-
tensively used in their present neces-
sity of bringing the pest under sub
lection.
A point yet to be established in
connection with the present expert
ments is the possible injury of the ell
spray which may result to the trees
twigs, or fruit buds, and several Sc
sons experience will be necessary be-
fore a final decision on this question
can be reached. In view of the eX-
perience in Florida in spraying citru
trees in foliage with l per cert o.
oil, it is felt that dormant decidupus
trees will probably stand without in
jury one annual treatment containing
per cent of oil.
In order that entomologists who de
sire to do so may make tests Of the
treatment the present winter, ani al
so to render the treatment available
to orchardists who may wish TO te-;
it on a small scale, the following di-
rections for making the stock emul-
sion are given:
Formula for Stock Emulsion.
Red Engine Oil, or oil Of similar
grade .....-..-..-...--...---..-....... gallon
Water ACKNOWLEDGEMENTS y
Potash Fish Oil Soap pound ]
The oil, water and soap are placed
in kettle or other receptacle and
heated until the contents come to
boil. A brown scum appears on the
surface of the mixture as it first be
gins to boil. After boiling for a few
minutes the brown scum begins t.
disappear and at this stage the kettle
is removed from the fire and the en-
tire mixture is pumped twice under
pressure of about so pounds while
! still very hot. A proper emulsion can