The independent-reporter. [volume] (Skowhegan, Me.) 1909-1955, 1924-07-17
Potato Spraying

Potato plants should be sprayed
when six inches high. 1t is true that
you may waste some of your bordeaux
on the ground but it is essential that
the small leaves shall be thoroughly
covered with fine particles OF copper
Remember that bordeaux mixture and
all other sprays are representatives. and
not cures. You must have the spray
on the plants before the blight comes
II you get the first leaves covered
thoroughly, the new growth above will
protect them and to a very large ex-
tent. prevent the rain from washing
off the spray.
II the season is wet spray often;
that Is when you meet it most. Wet
weather and cool nights make ideal
conditions for the development Of
blight In all seasons spray often
enough to keep the new growth cover
ed and to renew the protective cover
ing of the old. The first applications
are very important. General speak
ing from four to eight applications in
a season are needed for the best re-
suits.
The active principle in any spray
that is effective against potato blight
Is copper. Copper sulphate or blue
vitriol as it is put on the market for
spraying purposes, is all of the same
strength. Do not be led into think
ing that copper sulphate that is light
err in color or grayish is of inferior
quality. 1t has merely lost little
of its water so by weight you actually
get more copper for your money
when it is gray.
1t ~ very important in the making of
bordeaux that the two solutions
should be diluted and mixed In the
proper proportions. Always remem
Der that the value of the mixture. as
a spray, depends upon The kind of a
precipitate that is formed.
If you wish to test your method of
mixing, pour some of the spray dill
ution out into a glass fruit jar and let
it set for an hour. If made properly
the gelatinous precipitate should
settle but very little. At the end of
one hour the precipate should occupy
over 80 per cent of the volume of the
solution. In poorly made mixtures
the precipitate will settle down to
about 70 per cent of the volume of
the solution in the same length of
time. 1t takes just as much time,
material and money to make poor
solution as it does good one.
Which are you going to make?
The methods given below have
been thoroughly tried and found to
give very satisfactory results. While
there are other ways of getting good
mixtures, it is believed that some one
of the following methods will be
found practical on the average farm.
The chief thing to remember is no
matter how or in what order you
wish to mix the solutions, never mix
your two stock solutions. Always
dilute one. or better, both OF the solu-
tions before mixing. Never mix your
solutions until you are ready to spray.
Method l. For those who have
need for large quantities of bordeaux
mixture, it is the best plan to make
stock solutions, Dissolve so pounds
of copper sulphate (blue vtrioD by
suspending it in a sack from the top
of a barrel containing 30 gallons of
water Stake so pounds of lime in
another barrel, then add water to
make so gallons. These two stock
solutions will keep indefinitely. Wat
er lost by evaporation may be re-
placed. Now one gallon of copper
sulphate solution contains one pound
of lime
If possible 1t is very convenient to
have these two barrels of stock solu-
tons and two empty barrels placed
upon a raised platform. The spray
er then may be driven alongside the
platform and easily filled. In order
to make 100 gallons of spray, stir the
two stock solutions thoroughly. es-
pecially the lime, then dip out 10
gallons of copper sulphate stock solu
ton and pour into one of the empty
barrels and add 40 gallons of water.
Stir each dilIion, then they are
ready to mix Run each of the dilu-
lions at the same time into a strainer
on the top OF the spray tank, by
means of rubber hose. This thor
oughly mixes the two diluted solu-
tons and insures an excellent spray.
Method 2. Pour 40 gallons of wat
er into the sray tanks, then add 10
gallons of the copper sulphate stock
solution. Dilute 10 gallons of the
stock milk of lime solution with 40
gallons of water in another vessel,
strain and pour into the spray tank,
stirring constantly to insure thorough
mixing
Method 3. To 70 gallons of water
in the spray tank add 10 gallons of
the copper sulphate stock solution.
Dilute 10 gallons Of the stock milk
Of lime solution with 10 gallons of
water. Strain and pour it into the
sulphate dilution in the tank and stir
thoroughly.
All the above methods are based
upon the standard $3.50 formula. or
10-10-100, five pounds of copper sui
plate and five pounds of lime (61a
pounds of hydrated lime) to fifty gal
Ions of water. Taking into consider
alton the climatic conditions of Maine,
thiS Ia the hest strength to usa