The Columbian. [volume] (Bloomsburg, Pa.) 1866-1910, 1909-05-20

San Jose Scale.
ARsENATe OF LEAD AND BoRDEAUs
FOR COOLING MOTH.
Prof. H. A. Surface, the Stat,
Zoologist, prefers arsenate of leac
to Paris green for adding to the
Bordeaux mixture, to be used il
killing fruit and foliage eating
insects.
III answering a letter received
from a farmer requesting intorma.
tion in regard to arsenate of lead
the Professor wrote as follows:
Concerning the use cf arsenate
of lead, l beg to say that it is, as
YOU know, an arsenical poison which
takes the place of Paris green or
London purple. 1t is generally
prepared in paste form, coming in
vessels, containing enough water
10 cover it. The proper way TO use
it is to stir it into thin paste with
slight quantity of water, using a
paddle so that it can be ground
against the sides of the vessels con-
tanning it, making plste and thus
breaking the Jumps. After a uni
form paste is made, with the Jumps
all crushed, more water can be adj
ded and this then should be stirred,
poured and strained into the spray
tank. 1t can then be used the
same as Paris green. Being partly
suspended and partly dissolved in
the water, it sticks better than
Paris green, as it sticks like house
paint, and thus would not be
washed off by ordinary rains, nor
blow off readily by the wind.
A great deal more can be used
without injury to the foliage than
in using Paris green, and this
means that it is more liable to
poison the pests for which it is ap-
piled.
The tormulae for the arsenate of
lead vary great deal. Some per-
sons recommend as high as three
pounds to fifty gallons of water,
while many give the standard for
nula as to pounds two fifty gallons,
but l am now we'll satisfied that if
you use good quality of arsenate
of lead, one pound in fifty gallons
will do the work perfectly. This
is what shall use in Our demon
stration orchards this year and |
am satisfied that we will have as
good results as we had last year
from the two pounds to fifty
gallons.
In using the arsenate of lead,
would recommend adding it to Bor-
deaux mixture, and using the
combined preparation. Make the
Bordeaux with three pounds of
bluestone and four of lime in fifty
gallons of water, and add a pound
of arsenate oflead to this, the same
as though it were plain water in
stead of Bordeaux. This formula
is all right for potatoes, apples,
pears and ounces, but for peaches
and plums the bluestone should be
reduced to one-half the amount
here mentioned. 1t is considered
that in spraying smooth plants like
cabbage, the smooth fruits of plum
and grape, ETC., on which Paris
green does not stick, arsenate OF
lead is better, as this poison does
stick and consequently, kills the
pests where other materials could
not be used with satisfactory
results.
1t has been said by some that
arsenate of lead and Bordeaux will
not go we'll togther for chemical or
other reasons, but l know that we
used them last year in combination
and destroyed e5 to 9S per cent. of
codling moth in nearly all our de-
monstration orchards over this
State, and we are so we'll satisfied
with the results from the practical
side, that we are recommending
this, and can not for a moment
doubt the advisabilty of the COM
bination.
The arsenate of lead will not in
jure chickens by sprinkling grass
under trees sprayed with it, as they
will not eat enough grass with it
to be injured. OF course if any
animals or fowls should drink
water that is strongly impregnated
by the poison they would doubtless
be injured or killed.
Also, the possibility of injuring
cattle is very slight indeed. If or
chards should have a considerable
quantity of long grass when spray
ing is done, and should be sprayed
in such a way that this grass is
thouroghly covered with any ar.
SeniCal DOieop ord tIa oottIo H.