The Kennewick courier-reporter. [volume] (Kennewick, Wash.) 1914-1938, 1919-02-20
Liquid Lime Sulphur VS..
IL the Dry Lime-Sulphur

question that is coming into this Of
flee daily. 1t is very delicate ques-
ton. The manufacturers have many
testimonials from growers claiming to
have used their spray with success.
On the other hand the fruit growers
should weigh carefully what the ex-
pertinent stations have to say. Ex-
cerpts from a circular issued by the
California Experiment Station, dated
November, 1918, are as follows:
eff intended for use as winter
spray against scale insects, sulphur
preparation is evaluated on the basis
of the percentage of sulphur combined
in the form of polysulphides and THO
sulphate. The uncombined sulphur
might also be included in the evalua-
ton of these products when they are
to be used against red spider, mildew
or other pests for which sulphur is
known to be effective.
The following will indicate the
amount of the dry preparation to use
as the equivalent of one gallon of
commercial 33 degree Beaume lime
sulphur solution. In order to give the
dry materials the benefit of the doubt,
the uncombined sulphur is included in
the calculations. The figures are bas-
ed on analyses made in the laboratory.
"Lime-sulphur solution (33 degree,
b., total active sulfur, approximately
26R; cost of 100 pounds active sui
phur, $8.03; gallon being equivalent
to 1918 pounds of lime-sulphur solu-
ton. Average retail price, $11.26 per
barrel. As against lime-sulphur, dry:
$50 total sctive sulphur, costing
$3.50 per 100 pounds of active sui
phur; 1 gallon being equivalent to SO
pounds of lime-sulphur solution, with
ana verage retail price of 5000 per
cwt. *
Samples of dry lime sulphur have
been analysed by the laboratory and
found to contain the same constituents
as the lime-sulphur solution, that is,
polysulphides and thiosulphate of lime.
In addition, however, they contain
about 20 per cent organic matter. The
material does not go entirely into solu-
ton in cold water and there is some
free sulphur.
$50 far as can be judged, the dry
form of Ime-sulphur when dissolved
in water will produce a spray in all
respects similar to the usual dilution
of lime-sulphur solution, provided
equivalent quantities are used. The
chief point for consideration, then,
in choosing between the dry form and
the solution, is the cost. Comparative
costs are shown in the table above.
"f the manufacturers directions for
winter spraying are followed (10 to IL
pounds dry lime-sulphur dissolved in
. SO gallons of water) a spray will be
obtained containing only about one
half as much active sulphur as in the
customary / to 10 solution of lime
sulphur. In defense of this half
strength recommendation the manu-
facturers say that certain organic ma
terial which is Incorporated into their
dry compound prolongs the effective
ness of the applied spay so that much
less than the usual amount of sulphur
is required.
"Field tests have not been made in
California to determine whether or,not
these claims are valid.
The fruit growers of California
cannot afford, for the sake of conven-
fence, to set aside a well-established
and thoroly tested spray practice and
reduce their remedies to af-strength
unless this has been shown to be feas-
IDLE by experiments of the most con-
vincing sort. 1t would be better to
use full-strength at double the cost"
Extracts from a letter received from
Prof. A. L. Melander, of Pullman, in
regard to the dry lime sulphur are as
follows:
I'VE have tried the dry form of lime
sulphur now for several years and find
1T has not measured up to expecta-
tons. 1t has not killed the scale as
will equivalent strength of the liquid
spray.
eff the dry form of lime sulphur
were to be diluted to the same strength
that we customarily use the liquid lime
sulphur, the cost of the dry material
would be prohibitive. You can easily
appreciate how in this way: A bar
rel of standard lime sulphur solution
contains practically 200 pounds of sol
ids in solution. 1t would take about
24o pounds of the dry lime sulphur to
make the equivalent Of the 200 pounds
of solids in the barrel on account of
the presence of the stabalizer. To
compete, therefore, with liquid lime
Ink, Il L