Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1917-08-04
SPRAY FOR LEAF
SPOT OF PLANTS
Resin Fishoil Soap Added to
Bordeaux Mixture Prom
ises Method of Control

Washington, ID. c. Aug. .--rhe
addition of resin fishoil soap to Bor-
deaux mixture promises to control
tomato leafspot, although Bordeaux
alone has not prevented losses.
Plant disease specialists in the
Federal Department of Agriculture
describe the leaf-spot disease as one
which causes defoliation of the
plants, greatly reduced yields and in
ferior fruit. Small circular spots de-
Velop on the leaves and sometimes
on the stems. They first appear as
tiny dots, having a dark or water
soaked appearance. Gradually they
enlarge and turn brown, and the
leaves shrivel and drop, beginning
at the base of the plant.
Making the Solutions o.
Bordeau mixture is best prepared
by making stock solutions of the
separate ingredients. The copper
sulphate should be mixed in the
proportions of a gallon of water.
preferably soft water, to a pound of
the sulphate crystals and there
should be five gallons of this stock
solution for each acre of tomatoes
to be sprayed. The crystals should
be dissolved in the usual way by sus-
touches the surface OF the water;
the solution should be well stirred.
The lime suspension or milk of
lime, is also pound to a gallon,
but only three-fourths as many gall
Ions are needed as of the copper
solution. Thus, if there are twenty
gallons of the copper solution there
would be only fifteen of, the lime
milk. The lime should be slaked
u
small quantities and at intervals un-
til all has crumbled. Finally larger
quantities are added with constant
stirring until the volume is COM
pleted. If quicklime cannot be had
and hydrated lime is available use
as many pounds of the latter as of
copper sulphate, but do not in
crease the qauntity of water. Air
slaked lime must not be used.
The resin fish-oil soap suspen-
sion is made with pound of soap to
a gallon of water. AS with the lime,
only three-fourths of the quantity of
water is necessary. Hot water will
hasten the dissolving of the soap.
To avoid the formation of trouble
some Jumps the water must be add
ed slowly at first with constant STIR
ring.
Preparing the Mixture
For general commercial operations
two fifty-gallon barrels with outlets
at the bottom are placed on a raised
platform so their outlets will be
higher than the top of the spray
tank. To make 100 gallons measure
eight gallons of the copper-sulphate
solution into one barrel and six gal
Ions of the milk of lime into the
other. Add to each enough water
to make forty-seven gallons, stirring
the contents thoroughly, and then
let the two solutions run with equal
rates into a trough leading to the
spray tank. At the same time add
six gallons of the resin fish-oil soap
solution very gradually and in a
small stream through the spray
tank strainer along with the copper
and lime should be mixed before the
soap is added.
Notifications of the method may
be used for smaller quantities.
Applying the Spray
A traction sprayer such as that
employed in the spraying of potatoes
may be used except where the vines
are too large. There should be three
noZzles for each row. one to spray
downward and two on the sides
spraying toward each other. These
lateral noZzles should be set low and
pointed slightly up to get the spray
on the under side of the leaves.
Thorough spraying, repeated at from
seven to ten-day intervals, is neces-
sary for the best results, and must
be continued through August. When
the paints are too large for a trac-
ton sprayer in the rows, roadways
should be opened and the spraying
continued with long lines of. hose.