Atlanta tri-weekly journal. [volume] (Atlanta, Ga.) 1920-19??, 1922-08-29
AGRICULTURAL EDUCATION
BY DR.. ANDREW Nj. SOULE

ent in defoliating abundance is still
susceptible to serious injury. Oh
course, the heaviest invasion will
not develop for some two weeks yet
and there will be much more cotton
which will be beyond damage at that
time. However, there will still be
an enormous amount of cotton which
can be seriously injured by the
worms even after the first Of Sep
TENDER, owing to the fact that sc
much Of the cotton crop is from one
to three weeks late in maturity. The
question of whether or not to at
tempt to control the worms Is going
to be an individual one for each
grower to decide. Many fields are
already so thoroughly infested with
weevils that defoliation by the
worms can do no harm, and many
more fields will reach this condition
within the next two weeks. Before
deciding on whether or not to poi.
son the worms the grower should ex.
anime his fields closely and note es.
| pecially the condition of the bolls.
If there are many bolls present less
than two-thirds grown and still un-
infested with weevils, and the worms
start operations in threatening
numbers, it will generally pay to
poison them. OF course, when q
field is completely infested by wee.
wills and practically all of the
younger bolls punctured, defoliation
by worms is really more of a benefit
than harm, but it should always
be remembered that defoliation by
worms forces premature opening. of
many bolls and, furthermore, dis
colCrs much of the cotton, generally
very seriously reducing the grade.
On the other hand, in very rank cot
ton in the districts which have been
receiving an excessive rainfall, there
is now a 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
threatening nature of this invasion,
everyone should watch his cotton
crop very closely for the first ap-
pearance Of the worms, and when
ever they are found in threatening
numbers in a field, where conditions
will justify poisoning, control should
be started Immediately rather than
waiting few days, when much of
the cotton will be stripped, making
it much more difficult to poison the
worms. Judging from present pros
poets, worms will probably be found
in serious numbers all over the cot
ton belt within the next two or three
weeks, and a tremendous acreage
will still be susceptible to serious
damage at that time.
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
weevil this year has not only con-
sumed the stock of this chemical,
but has also enormously reduced the
supplies Of other arsenicals. We
have just completed a canvass OF
stocks Of chemicals which can be
used for leaf worm control, and find
an alarming shortage. 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 in
festation develops. A comparatively
small amount OF this material is
available in, the south now, but
manufacturers have been notified Of
the emergency and the majority Of
stocks are already rolling south
ward.
In the early days Paris Green was
first adopted as means of leaf
wYrm control. This gave very sat
isfactory control, but always pro.
duced 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 develop
ed, it was very largely adopted for
the same purpose with very salts
tory results. It did not hurn the
cotton plants in the slightest and
stuck to the plants better than Paris
green, but unfortunately was not
Is poisonous to the worms. In the
past few years calcium arsenate has
been used very extensively for worm
control, with very satisfactory re.
suits. 1t is not injurious to the cot
ton plant and is very nearly as
poisonous to the worms as Paris
green and much more so than lead
arsenate. In addition, however,
there are a large variety of other
arsenicals which can be used for
leaf worm control with satisfactory