San Antonio light. [volume] (San Antonio, Tex.) 1911-1993, 1923-04-01

used in combating the weevil and re-
suited in testing other chemicals. 1t
was found that the water soluble ar
senic which was found in paris green
even when it was used in small guam
titles, was injurious to the plants, SO
experiments were made with paris
green first soaked in water. The re-
suits thus obtained we're gratifying,
and the idea was then conceived that
powdered form of arsenate of lead
might solve the problem. Arsenate of
lead was unheard OF up to that time
and the first Of it was developed
in the laboratories of Wilmon Newell
of the Louisiana state crop pest CON-
mission in 1904. Subsequent tests
established the fact that a certain de-
gree of control could be obtained by
poisoning the weevils with the lead
arsenate in the early summer, but
that applications of the poison made
in mid summer during the rainy sea-
son would not hold the weevil in
check This brought out certain well
defined principles: namely that prior
to the appearance of the first squares
on the plants the weevis could be
poisoned in large numbers, and that
after the first squares appeared were
more profitable than applications
made later in the season.
These experiments were made in
1909 in Louisiana, by George ID.
Newell. Later when Mr.. Smith was
placed in charge of the boil weevil
poisoning tests for the United States
Bureau of Entomology at Tallulah,
La. he made the tests again with
practically the same results.
Cost Found Too High.
Still, however, the method was not
satisfactory for the reason that 1t
was too expensive in most sections of
the country. Unless the land where
the poison was used produced at least
one-half bale to the acre. it was found
that it cost more to apply the poison
than could be realized from the in
creased production. Realizing this the
state plant board Of Florida employed
MIR. Smith as associate entomologist
and inaugurated an intensive investi-
CATION. Mr.. Smith, taking into con-
sideration the weak point in the wee
wills existence, planned his attack
along lines that would take advant-
age OF this. 1t was known that the
weevil could be poisoned in large num-
Ders before the appearance of the
first squares. However. the last of
the. over-wintering weevils do not APP
pear until after the first squares had
come out, and these deposit their
eggs on the early squares. starting
the seasons infestation. The eggs
cannot be killed with poison. and the
adult weevil is also difficult to kill
in this manner.
The thought then presented itself
that the first weevil generation of the
season might be destroyed by stripping
the first squares from the plants. This
was tried with q noticeable result.
Next two strippings were tried. about
ten days apart. n marked increase
in the quantity of cotton was OBJ
tanned III this way. However there
was danger of delaying the fruiting
of the plants to dangerous degree.
1t was then found that the condition
in which the plant is left after the
first stripping is such that the moi
son can be applied with the most fell
ing effects. Deprived of squares in
which to hide, and on which TO feed.
the terminal or growing buds which
can be easily filled with poison with
suitable dust gun. At this time. it
was found, the Overwhelming boil
weevil has only few more days to
live and its instinct TO survive prompts
it TO feed freely making it an easy
prey to the poison.
Assures 30 Per Cent Crop.
l. xlo
in extensive tests in 1922 proved that
the upland cotton grower Of that state
could be assured of at least 80 per
cent of a crop, as far as weevil dam
age was concerned. Tests made on
poor soil developed the fact that
fields treated in this manner made as
good crops as IL there had been no
weevils, while the yield of untreated
fields not over 100 yards distance did
not pay for the seed and cultivation.
In the tests in Florida the cost per
acre of stripping the plants, and an
plying the poison, and the cost of the
poison varied from Sl.01 to SLIP. and
the increase in production of the treat
| ed fields over those untreated varied
from 240 pounds to AT pounds. This.
at the prices then paid, amounted TO
a gain of from x2O to S33 per acre.
Mr.. Alvord, in his circular to the
farmers of Bexar county. has estimat.
ed that the total cost of poison. ma.
chinery and labor to apply it will be
approximately 81 per acre. Accord.
} ing to his instructions. the cotton
should be planted in the ordinary
way at the usual time. About six q,
) ten days after the first squares an
pear they should be picked off ant
burned. This destroys all of the liy,
weeyils then in the field. 1t is adyis
able, when picking the squares to us,