The Palatka news and advertiser. [volume] (Palatka, Fla.) 1908-19??, 1915-02-12
A SPRAYING SYSTEM
FOR CITRUS FRUITS.
The Crop, It Is Believed, Can
Be Increased At Least
Is Per Cent At A
Small Cost.

Washington, D. c., Feb. 10-In or
der to minimize the damage done by
insect pests to citrus fruits in Florida,
which on the average amounts to from
rs to 40 per cent of the crop, the De-
partment of Agriculture has worked
out a spraying scheme which has CIV
en- striking results in the three years
that it has been practiced.
Practically all of the damage that
insects do to citrus fruits in Florida
can be, attributed to six species. The
most destructive is the citrus white
fly; the second the purple scale; and
the third the r1st mite. To do away
with these pests Government special
lists advocate four sprayings, two of
which are primarily intended to kill
the whitet1y and scale insects and the
two others to destroy the rust mites.
The number of sprayings, however, is
not fixed but depends to large meas
ure upon the thoroughness of the work
and the seriousness Of the infestation.
The first spraying should be done in
May after the adults of the first brood
of whitefies have disappeared and be-
fore the appearance of those of the
second brood. At that time the fruit
should be an inch or more in dame
ter. A paraffin-oil emulsion is used,
prepared in accordance with The for
mula described in Bureau of Entomol-
ogy Circular 1853. Following is the
formula:
Whale oil soap, pounds or 1 gal
lon,
Paraf1in oil, gallons,
Water, l gallon.
The mixture is prepared by adding
the oil very slowly to the soap, the
whole being vigorously stirred
throughout the process. 1t is impor-
tant that the oil should be added in
small quantities and the stirring be
sufficient to keep oil and soap in the
form of an emulsion. After the re-
quired amount Of oil has been added
and after free oil has ceased to appear
on top of the soap, the water is slow
ly poured in. After being prepared in
this way the mixture is diluted by the
addition of so gallons of water to
of mixture, which leaves a spray APP
proXimately l per cent oil. This is
the maximum strength required for
white-fies and purple scale.
In June or July the rust mites
should be attacked by lime-sulfur
solution of the strength of l to so
or | to rs. This spraying should be
done when the maximum number of
rust mites have made their appear
ance and before any russeting APP
pears. 1t will also kill some scale
and whiteflies, but should not be re-
lied upon for this purpose. Some
time between August 25 and October
81, the trees should be sprayed again
with the paraffin-oil emulsion in order
to kill all the whitefy larvae which
are the progeny of the third and last
brood. The earlier these are killed
the better it is for the tree. This
spraying will also serve to remove
the sooty moulds from the trees and
from the fruit, enabling the sun to
color it.
In November or December it is fire.
quently desirable to spray again with
the lime-sulfur solution in order to
kill off what rust mites there may be.
The cost of following such a scheme
is estimated at from 20 to 35 cents a
year for each tree. One grower was
able to carry it out at a cost of 8
cents per box of fruit, and on the 9TH
er hand it cost another cents. Eight
cents may be taken as the maximum
figure. In return for this outlay the
trees yield not only more abundant but
much larger fruit. The increase in
the size of the fruit alone should re-
suit, it is estimated, in an increased
production of from II IL to 25 per
cent, amounting approximately to q
100000 boxes for the entire citrus
crop in Florida. If this scheme was
followed throughout the entire State
it is thought that the output would
be at least 25 per cent greater than
it is now, and that the appearance of
the fruit would also be much better
In one orchard, sprayed rows yielded
60 to 70 boxes of fruit while adioin-
ing rows which were left unsprayed
had only about boxes.