The Richmond climax. (Richmond, Ky.) 1897-1914, 1914-06-24
ArSenate of Lead For Tobacco
HoOkWOrm.
Washington. ID. C.. June %, 10

1 lOOdCCO gTOWeTS Ill heHtuOhy, LOL-
nessee and adjoining States are advised
| by Government specialists to use arsenate
of lead in freeing their crop of hookworm
the greatest pest that the grower in
the dark tobacco districts has TO face
| Arsenate of lead is said TO be both effec-
tive and safer than Paris Green, which
has been used extensively against the
pests for some years With it there is
no risk of burning the tobacco, and this
alone, in the opinion of the United States
Department of Agriculture, makes its
use advisable despite the somewhat in
creased expense. In addition it appears,
unlike Paris Green, to have no injurious
effect upon the operator.
Until recent years it was customary
to pick off hookworms by hand-'hand
worming" as The work was called. AS
labor grew scarcer and less effective,
however, this method became too ex
pensive and growers were compelled to
employ an insecticide. OF those first
/
satisfactory-or rather the least unsatis
factory. for it frequently causes cor
siderable loss. In 1912, for example, in
several fields in Tennessee it was esti-
mated that the damage done by Paris
Green ranged from 10 to % per cent of
the gross value of the crop. Exceptional
cases are on rec ord where the damage
has run as high as 80 per cent. Arsenate
of lead causes none of this damage, &C
cording to statements in Farmers Bull
letin 595, "Arsenate of Lead as an Insec-
ticide Against the Tobacco Hookworms
in the Dark Tobacco Districts" just
published by the U. S. Department of
Agriculture. On one occasion four acres
of Kentucky tobacco were treated with
an application of IA pounds per acre
of powdered arsenate of lead at time
when the worm averaged two plant.
Two days later only four live worms
were found in the entire field. Weather
conditions undoubtedly contributed to
establish this extraordinary result, but
they do not account for the fact that
there was no injury to the tobacco from
poison burn. The crop was we'll ad-
vanced and at stage when Paris Green
burn is very common.
| To secure the best results, arsenate of
lead should be mixed with some form of
carrier. A number of experiments indi-
cate that the most satisfactory carrier is
finely sifled, freshly burned wood ashes,
of which a quantity at least equal to
| that of the poison should be used. The
two should be mixed very thoroughly
and then applied when there is no breeze
and the dew is still upon the tobacco.
A dust gun more powerful than the hand
power ones now in general use is requi-
site if the application is TO be even,
thorough and therefore effective.
The cost of this treatment depends, of
course, upon the condition of the crop.
1t is estimated, however that in years
when worms are plentiful hand worm
ing costs from Sc to $40 an acre. Paris
Green will do the same amount of work
for not more than 81 an acre and arsen-
ate of lead at a cost of from So TO So an
acre. From IL to pounds of the
after should be used at each application
4 not including, of course, the weight of
the carrier. Since powdered arsenate of
lead retailS at approximately % cents
pound, the cost of each application will
range from SSc TO $l25, or less if the
material is purchased in large quantities
| exclusive of the cost OF carrier, labor
and other factors. This may seem ex-
pensive, but it must be remembered,
the bulletin points out, that arsenate of
| lead is recommended not for its cheap
ness, but because it is certain not to in
jure the tobacco. In some years one
application may be sufficient; in others,
two or even three may be necessary.
The number of eggs and young worms
that appear on the plants will decide
this.
Although the arSenate can be applied
as water spray in the proportion of
three or four pounds TO 100 gallons of
water, the powdered form is the one rec
commended by the Government experts
1t is important, moreover, that there
should be large percentage of arsenic
oXid in the poison. In order to obtain
this the customer should insist upon
what is known as the iiplumbic and not
the triplumbic form of arsenate of lead.
For his guidance the bulletin lays down
the following rule:
In order to be sure of receiving the
diplumbic form, demand that the man
ufacturer and dealer guarantee that the
arsenate of lead you buy contains at
least 30 per cent of arsenic oxid in which
not more than per cent is free or wa
ter soluble
1t is necessary to have small percen-
tage of free or water-soluble arsenic in
order 10 insure against burning the
tobacco.
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