St. Johnsbury Caledonian. [volume] (St. Johnsbury, Vt.) 1867-1919, 1917-07-18
SPRAYING POTATOES.


into the Office in regard to spraying
spraying as given in the June Circular
Letter:
Spraying Potatoes.
For Colorado Beetle Common pota-
to bug) spray with three pounds paste
form of arsenate Of lead, one and one
half to two pounds of dry arsenate of
lead, or one-half to one pound of Paris
Green to SO gallons water at the first
appearance of the potato beetles or
other insects feeding on the foliage.
For early or late blight and Flea
beetle:
Systematic spraying of potatoes was
begun first at the Vermont Expert
ment Station. The first results with
Bordeaux mixture were so satisfactory
that workers at other experiment sta
lions took up spraying, and it was
adopted generally as a regular prac-
tice. 1t is now certain that Bordeaux
is the most efficient spray for pota-
to diseases and that spraying pays,
provided that it is thoroughly and fire.
quently DONE. That Bordeaux mix
ture is the most efficient spray for po-
tatoes has been demonstrated many
times and in many states, where al
most every substitute has been used
for comparison. The results show that
home made Bordeaux mixture, if thor
oughly applied, will increase the yield
from SO to 100 bushels per acre. Bor-
deaux has two distinct effects on the
potato plant, it protects the plant from
~, lof u ;rI,
ulates growth and tuber formation.
How to Make Bordeaux Mixture.
Bordeaux mixture is made of cop
per sulphate, burned lime and water.
The proportion for potatoes is three
pounds copper sulphate, three pounds
of burned lime, ana SO gallons of wa
ter About 100 gallons of this spray
are required to cover each acre of po-
tatoes If this amount is desired place
six pounds of copper sulphate in a
loose sack and suspend in 10 gallons
of water. AS several hours are re-
quired to dissolve the crystals that
may be done best by starting the mix
ture at night and leaving the crystals
in the water until morning, then add
40 gallons of water. The lime is placed
in some receptacle and covered with
enough water to Stake it. AS soon as
slaked add water to make so gallons
of lime water. The most important
part of the process follows. Keep each
solution thoroughly stirred. Have a
large container covered with a fertiliz-
err sack to strain the Bordeaux mix
ture. If two men are to do the dip
ping and pouring each should dip a
bucketful from the separate solutions,
then pour them at the same time into
the container. This serves both to mix
and to strain the solutions. The mix
ture should be thoroughly stirred with
wooden stirrer to insure complete
mixing. The mixture resulting from
| this is Bordeaux, which is of a milky
| blue color. 1t is then ready for ap-
plication and should be applied as
soon as possible. Where large guam
titles of Bordeaux are to be used it
will pay to make considerable stock
quantity of the lime water and copper
sulphate solutions. Such stock solu-
tons may be kept separately in bar
rels if covered to prevent evaporation.
The two solutions should not be mixed
except for Immediate use, since the eff
| ficiency is almost entirely lost by
standing more than a few hours.
! When and How to Spray.
Spraying should usually begin when
the first flower buds appear or when
the first brood of beetles show on
leaves which is generally the first week
in July, and at least three applications
/ preferably four to six, should be made
at intervals of about two weeks. This
spraying must be thorough. as this
plants must be covered with fine mis-
in order to be protected efficiently.
spraying machine, which develops a
least 100 pounds pressure, is recon
mended. This should have for the lat
est sprays two MOBILES for each row
, SO arranged that fine mist is throw
| on the leaves. thoroughly coverinl
= every part of them. If a power spray