Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1918-07-12
,on 70 be poisoned had been weevil-

cent OF the squares were punctured.
During the same period the infestation
in the adjoining imprisoned cotton
had been increasing steadily. Pruc-
tically all of the poisoned cuts s'art-
ed blooming again at this time anc
mimi or o: them reached what Is o.di-
narily termed the flower garden
stage of blooming. five 70 Sven
blooms per plant on single ca: i've
irG not at all rare.
In starting the treatment OF this
large area it had been anticipated
that several applications would be
necessary to produce the desired re-
suit, but the effect OF a single appn-
cation was so pronounced that II
seemed unnecessary to repeat II. Inc
wcevils had been so reduced that
only SO per cent OF the squares were
puncturcd and although thousands OF
wecvils were being bred out from the
squares on the ground or were COM
ing in from other plantations every
day, il was still obvious that the wee
wills would greatly reduce their at
tacks on the bolls until they had
caught up with the squares then
present. and that this period would
he long enough to allow the bolls TO
become sufficiently hardened to avoid
wecvil damage. Owing to the ncces-
sity for poisoning considerable areas
in this case and TO the inability to
leave unpoisoncd plats as checks, II
was, OF course, impossible to deter
mine the exact benefit derived from
the treatment. Rough comparisons,
however based on yields OF surround
ing cuts made it Obvious iat a COIL
siderable gain had been secured ana
.ha, poisoning had been 81 very rto-
itablc operation.
Poisons and Time Of Application
In the early experiments the tri-
plumbic form of lead arscnatc was
used but was not sufficiently effective,
and the di-hydrogcn form OF lead
arscnatr proved 10 be a better poison
for the work. Later additional tests
demonstrated that a high grade OF
calcium arSenatc was still more cHcc-
tive and has the great advantage OF
being cheaper than lead arscnatc. a
number of tests were made with va
rioIis mixtures and dilut:ons of arseni-
Gals. This work, however, is still in
the experimental stage and. according
to Mr.. Coad, il Is difficult to prophcsy
just what the results will b". IL Is
Obvious. however. according to the
scientist, that either di-hydrogcn
lead aIScnatc powder containing not
less than 81 per cent Of arsenic PEN
loXid or Il calcium arsenutc containing
at least - per cent of arsenic pen
tOXid will produce an effective con-
troll if handled properly. 1t also Is cX-
pcctcd that it will be possible to di-
lutte these considerably with some
cheap carrier such as lime, though
this las not been definitely dctcrmin-
I'd. The experiments have shown that
Il very fine powder is taken up more
readily by the dew and held in sus-
tension for the weevils than coarsely
powdered chemicals. This physical
condition is especially important since
the poison is applied in the form OF
Il dust spray.
The time of applying the poison. of
course. varies under different con-
ditiQns, i lhss proved met ss eftsf3ixs
when applied just as the cotton OBJ
viously slackens in blooming, but
further work along this line is still to
he done. 1t seems probable that the
effective interval between applications
is about one week. II Is well known
that much more effective poisoning
with dry dust can he done while the
dew is on the plant, as the poison not
only clings to the plant better, but
has much less tendency to drift from
the cotton. The most effective time
.or application, therefore. usually Is
between p. m. and a. m. Several
machines are OH the market for dust
spraying. I'm the carly experiments a
hand dust gun was used, with which
il was possible to cover four to five
acres n day. In order to cover larger
areas. however, n special power ma
chine was developed, which will cover
nearly 200 acres per day. The depart
mcnt ROW expects to develop an inter-
type which can be sold cheap
ly and which will cover twenty to
thirty acres per day.
The amount of poison required for
application so far has depended more
upon the requirements of the machin-
cry used than on the amount nccessa-
ry for thoroughly busting the cotton.
In general about five pounds per acre
l.av" been applied. but this is excess
sivc. and with further Improvement in
the machinery and the use of the poi
son with mixtures, such as lime,
smaller amounts will be effective. In
most of the experiments from three to
five applications were made. but the
of these was consider
ably reduced by the fact that they
were on such small plats. In the
large scale experiment the effect Of n
single application was rs great as was
secured from about three applications
on n smaller plat. This. more eff
cient work on the large field was due,
of course. to the fact that there was
no migration of wecvils
from adjoining areas.
The cost Of treatment averaged
about 81 per acre for each application.
This. however. may be reduced con-
siderably when large areas are spray
cd and when improved machinery, re-
Quiring less poison. is employed. The
cost may be still further reduced when
1t is possible to mix the poison with
other powders. such rs lime, which
will act rs carriers. Further. 1t will
rarely be necessary to poison an en-
tire plantation to control the wccvil,
since on emerging In the spring they
always concentrate near the area in
which they passed the winter. The
wecvils remain rather closely to these
points until they have multiplied suf-