The central record. (Lancaster, Ky.) 18??-current, 1914-06-25
.ARSENATE OF LEAD
FOR TOBACCO WORMS.
Government Experiments Prove That 1t Is
More Efficient fhan Paris Green
And VIII kot Burn The Crop.

Tobacco growers in Kentucky, Ten
nessee anu adjoining States are advised
by Government specialists to use ar
senate of lead in freeing their crop of
hornworms-the greatest pest that the
grower in the dark-tobacco districts
has to face. Arserate OF lead is said
to be both effective and safer than
Paris green which has been used ex-
tensively against the pests for some
years. With it there is nc risk of
burning the tobacco and this alone, in
the opinion Of the United States De-
partment of Agriculture. makes it's use
advisable despite the somewhat increas-
ed expense. In addition it appears, I'm
like Paris green, to have no injurious
effect upon the operator.
Until recent years it was customary
t pick off the holnwolms by
hand worming' as the work was
called. As labor grew scarcer and less
effective, however, this method became
too expensive and growers We're COR
PEELED to employ an insecticide. Of
those first employed, Paris green prov
ed the most satisf actOry-or rather the
least unsatisfactory for it frequently
causes considerable loss. In 1912,
| for example. in several fields in Ten
nessee it was estimated that the dam
age done by Paris green ranged from
10 to 25 per cent Of the gross value of
the crop. Exceptional cases are on
record where the damage has run as
high as 80 per cent. Arsenate of lead
causes none of this damage, according
to statements in Farmers Bulletin 500,
"ArSenate OF Lead as an Insecticide
Against the Tobacco Hornworms in the
Dark-Tobacco Districts" just publish
ed by the U. S. Department of Agri-
culture. On one OCCASION four acres of
Kentucky tobacco We're treated with an
application of 81 pounds per acre of
powdered arsenate of lead at a time
when the worms averaged two a plant.
| wv NoFo ihISA OIliy IOut Hfe WOIIilS
We're 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
advanced and at stage when Paris
/ Urfpn huFn uary oOpop,oo
To secure the best results, arsenate
OF lead should be mixed with some form
of carrier. A number of experiments
indicate that the most satisfactory car
rier is finely-sifted, freshly-burned
wood ashes of which 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
requisite 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
Worming costs from So to $40 an acre.
Paris green will do the same amount OF
work TOR not mole than 81 an acre and
arsenate of lead at cost of from S. to
So an acre. From 81 to ) pounds of
! the latter should be used at each ap-
plication. not including. of course, the
weight of the carrier. Since powdered
arsenate of lead retails at approx
mately % cents pound, the cost of
cash application will range from SO
cents to S1,25, or less if the material
is purchased in large quantities ex-
elusive of the cost of the carrier labor
ana 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
cheapness but because it is certain not
to injure the tobacco. In some years
one application may be sufficient; in
others two or even three may be neces-
sary. 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 of water.
the powdered form is the one recon-
mended 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 diplumbic 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 .
manufacturer and dealer guarantee
that the arsenate of lead you buy con- !
tains at least 80 per cent of arsenic
oxid (As 205) in which not more than l
per cent is free or water-soluble
1t is necessary to have a small per.
centage of free or water-soluble arsenic
-, o,Jo H., Al