The Kennewick courier-reporter. [volume] (Kennewick, Wash.) 1914-1938, 1915-02-25
M|LDEW...
HOW TO FIGHT It
District Horticultural Inspector
Tells Farmers How to Mix
Different Sprays

OAAcICut sprays
The powdery mildew is spreading so
rapidly through our orchards that it is
a trouble no longer to be smiled at,
and trust to nature to cure, but it is
one that we must control and that at
once.
The following sprays are recon-
mended to control it: iron sulphide, at
omic sulphur and milled sulphur.
The iron sulphide has to be made by
the rancher, and while it is some
trouble it is much cheaper than the
prepared sulphur.
Formula for making the iron sui
phide:
Take ten pounds of iron sulphide
(copperas) two-thirds of barrel of
water and 2A gallons of sulphur lime
spray SO degrees Baume. If the sui
phur-lime IS weaker, use more of it.
Put the iron sulphide in sack and
suspend it in the water until it all dis
solves. Then slowly pour in all of
the sulphur-lime except about one
quart. Stir the mixture we'll and when
it has settled dip out little and add a
few drops of the remaining sulphur
lime. If black precipitate is pro-
duced, it shows that there is still some
iron sulphide in the solution. Add
about one pint more Of the sulphur
lime and then after thoroughly mixing
it and it has settled, dip out a little
and test it. Continue this process UNI
til pale yellow sulphur lime solution
is seen and there is no black precipi-
tate formed in the liquid that is dip
ped out and tested with the sulphur
lime. There should be black precip-
itate in the bottom of the barrel and a
pale yellow liquid on top. This liquid
is of no use. Pour it off carefully
and then fill the barrel again with
water and stir it well. Let it settle a
few hours and then pour off the liquid.
this operation of washing the precip-
itate should be continued until the
water poured off no longer shows the
yellow tinge. Then fill the barrel with
water to exactly so gallons. This is
called stock solution and will make
500 gallons of dilute spray. It should
always be well stirred when dipped
out for spraying.
General Formula for the
Spray Mixture
Stock iron sulphide, as prepared
above, twenty gallons; arsenicals and
nicotine solutions to be added as re-
quired; water to make 200 gallons.
When the arsenate of lead and the
black leaf 40 are to be used either
separately or together in conjunction
with the iron sulphide spray, first run
about $50 gallons Of water in the tank
then add 20 gallons of the iron sui
phide, keeping the agitator running,
after which add the arsenate or black
leaf or both and fill the tank with wa
ter.
costs
Ten pounds iron sulphide (copperas)
at go cents; 2A gallons sulphur-lime
spray, 10 cents; labor for making the
same, say about half dollar, making
total of $1.20.
This spray can be made up several
weeks before the rancher is ready for
it and held in stock solution.
The atomic sulphur is 81k cents a
pound, f. o. b. Kennewick in 100-fb.
lots. Both of these preparations are
prepared and ready to put in the tank
and go to spraying. They are used at
strength of pounds to the 100 gal
Ions.
Cost of 500 gallons of dilute iron
sulphide spray, $1.2O; 500 gallons Of
dilute atomic sulphur spray, $500; and
of 500 gallons of dilute milled sulphur
spray, $40.
First Application
This should be made at the time and
in conjunction with the calyx spray.
Second Application
This should be about three weeks
later and if it is the time for the Sc
cond coddling moth, spray can be made
in conjunction with it.
Third Application
This comes about three weeks after
the second application, and if fourth
is necessary it will come about three
weeks later.
This is the year that apples should
be worth something and it behooves US
to take the best of care of our or
chards this year. The powdery mil
dew has done lot of damage in the
valley in the past year or two and
there is not any orchard that is inn
mune to it.
Bulletins on the powdery mildew can
be obtained from this Office upon ap-
plication.
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