The Manning times. [volume] (Manning, Clarendon County, S.C.) 1884-current, 1922-08-16

to poison them. OF course, when a
field is completely infested by wee
wills and practically al l6f the younger
bolls punctured, defoliation by worms
is really more of a benefit than a
harm, but it should be remembered
that defoliation by worms forces pre-
mature opening of many bolls and,
furthermore, discolors much of the
cotton in the districts which have been
receiving an excessive rainfall, there
is now considerable amount of boil
rot, and under such conditions it is
often better to permit the worms to
defoliate the plants, allowing the
sunshine to penetrate to the lower
bolls and thus stop this rotting.
On account of the unusually threat
ening nature of this invasion, every
one should watch his cotton crop very
closely for the first appearance of the
worms, and whenever they are found
in threatening numbers in field,
where conditions will justify poison
ing, control should be started imme-
| days, when much of the cotton will be
stripped, making it much more diff
cult to poison the worms. Judging
from present prospects,, worms will
probably be found in serious numbers
all over the cotton belt within the
next two or three weeks, and a trc-
mendous acreage will still be suscep-
tible to serious damage at that time
Poisons to Use for Worm Control
The leaf worm is very susceptible
to control by the use of arsenical
poisons, but the unfortunate feature
of the situation is the fact that the
unprecedented demand for calcium
arsenate for controlling the boil wee
vii this year has not only consumed
the stock of this chemical but has also
enormously reduced the supplies of
other arsenicals. We have just COM
pleted a canvass of stocks of chemi-
Gals which can be used for leaf worm
control, and find an alarming short
age. Considering every chemical
which can be used, there is probably
not to exceed three million pounds
available, and this will be far short
Of the amount needed if the present
Indicated infestation develops. Al
comparatively small lamount of this
material is availablt in the South now,
but manufacturers have been notified
OF the emergency and the majosity of
stocks are already rolling southwark
In the early days Paris green was
first adopted as a means of leaf worm
control. This gave very satisfactory
control, but always produced more or
less burning Of the cotton plant,
which was undesirable though not
nearly as serious as the leaf worm
damage. Later, when powdered lead
arsenate was developed, it was very
largely adopted for the same purpose
with very satisfactory results. 1t
did not burn the cotton plants in the
slightest and stuck to the plants bet
ter than Paris green, but unfortunate
ly was not as poisonous to the worms
In the past few years calcium arscn-
ate has been used very extensively
for worm control, with very satisfac-
tory results. 1t is not injurious to the
rotton plant and is very nearly as
poisonous to the worms as Paris
green and much more than lead ar
aenate. In addition, however, there
are large variety of other arseni-
Gals which can be used for leaf worm
control with satisfactory results.
These include such as zinc arsenite.
magnesium arsenate, London purple
and numerous other trade mixtures of
arsenicals. In view of the present
shortage, it is going to be necessary
and advisabel for the farmer to take
practically any one of these which can
be secured, and any of them will ac-
complish satisfactory leaf worm con-
troll. The only arsenicals which
should be avoided are the highly So
luble ones, such as sodium and potas-
SUM arsenate and arsenite, which are
very injurious to the plants. The fol-
lowing outline covers the manner in
which these materials should be
used:
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