Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1920-02-10
AGRICULTURAL EDUCATION
~ DR. ANDREW M. SOULE

be an effective control for the boil
weevil and more than 0.75 per cent
water soluble arsenic is liable to
burn the foliage and injure the cot
ton plant. Calcium arsenate for poi
soning cotton must be in the form
Of a very finely divided powder if
it is to be applied with successful
results. If too finely divided, it is
difficult to apply satisfactorily be-
cause it is more pasty in character
and easily clogs the machinery used
in applying it. If the powder is not
finely divided it does not adhere to
the plants We'll enough to be effec-
tive and it will take greater quanti-
ties to cover the cotton completely,
A density of 80 to 100 cubic inches
per pound is the most satisfactory
flneness of division.
Dry Powder For Cotton
). Use only as q dry powder to
be busted on the cotton. Do not mix
with water or other liquid to use
as a liquid spray. The unmixed, I'M
diluted dry calcium arsenate pow
der busted on the cotton is the most
effective control and is easiest and
applied as a liquid spray the drop
let's of the solution have a tendency
to roll off the leaves or to collect
in big drops on the plant, but If
dust cloud is used the entire out
side surface of the plant is covered
with the small particles. In dust
ing, then, the plant is more COM
pletely covered and with a much
smaller quantity Of poison. Other
points to be considered are that there
is not the chance Of error in mix
ing and that there is much less
weight to be handled in hauling and
applying.
4. Apply the calcium arsenate
only when the plants are moist with
dew. The work will have to be done
very late in the afternoon, during
the night, or early in the morning.
while the air is still and the plants
are moist with dew. The cloud of
dust, floating through the plants IN
the row, adheres more readily to the
surfaces of stems and leaves if the
plants are moist and a greater pro-
portion of the poison used settles
on the plants. The poison that set
ties on moist surfaces is not so east
ly washed off by subsequent rains
nor 50 easily blown off by winds
because it is pasted to the leaf as
the dew dries off. The air is usu-
ally relatively still in late after
noon and at night and this makes
it much easier to apply the poison
satisfactorily.
5. Do not begin the poisoning I'M
til the infestation is heavy enough
to damage the cotton 10 per cent to
90 per cent, the per cent Of damage
is determined by the number of
squares punctured in every hundred
squares counted as you come to them
in the field. If an average of ten
or more squares in every hundred
counted have been punctured, it is
not too early to begin poisoning.
Many people, after hearing of this
method, have decided that it would
be better to begin poisoning as soon
as weevils made their appearance in
field, but this is a mistake. 1t
will never be possible to poison all
the weevils in a field and more
weevils can be destroyed by hand
picking of weevils and squares than
by poisoning early in the season and
it can be done at much less expense.
Infestation will seldom be heavy
enough to warrant the use Of poison
before the last of June or the mid
die of July. It will often be adj
visable to begin earlier in one field
than in others for very often the in
festation early in the season is con-
fined to small areas.
Use Poison Frequently
6. After beginning the work in a
field use the poison often enough to
keep the cotton covered with poison
at all times. Rains will wash the
poison off, especially if they fall
within twenty-four hours after it is
applied, and the work will have to
be done again as soon after O. rain
as possible. New growth Of leaves
| and squares is continually being
formed which makes it necessary to
make rather frequent applications
even when there are no rains. The
interval between applications will
vary under different conditions, but
it will generally be from about the
first or middle Of July to the mid
die of August. There will be four
to seven applications at intervals OF