The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1904-01-29
Treatment of Orchards Infested With
San Jose Scale.

Prom Pamphlet Issued by Georgia State Board OF
neutrality-suspicious. No. 8. BY Wimon Newell
State Entomologst.
Bulletin No. of the Georgia State
Board of Entomology issued in Septem-
Der, 1902, and Bulletin No. b, issued In
November, 1902, by Prof. W. Nj. Scott,
former state entomologist, give full and
practical instructions for treating scale
infested orchards. A number of expert
ments have been conducted by this Of
flee since the publication of the above,
and the results have been such that 1t
seems advisable to place them before the
fruit-growers in the present bulletin.
The development of successful meth
DDS of controlling the San Jose scale has
been rapid, but not until recently mas
full and satisfactory control been possl-
BILE. When the Georgia State Board OF
Entomology was established in 1898,
the occurrence of San Jose scale IN a
commercial orchard was commonly con
sidered as meaning total destruction,
and several owners of infested orchards
had even given up all hope and had al
lowed their trees to succumo TO TINS
dreaded pest. The undertaking before
Prof. Scott was a formidable one, out
through the ready support and co-opera-
tion of the State Board of Entomology,
as well as the hearty assistance gwen
by the horticulturists of the state, he
was enabled to bring to the aid OF the
orchardists all known methods OF hght'
ing the Sar Jose scale, as we'll as the re-
suits obtained by experiments in various
parts of the United States. In addition
to this, Prof Scott carried on extensive
experiments each year, looking to the
improvement of methods and the posi-
BILE introduction of new and better
measures. His efforts in this line have
been attended by marked success, and
the progress made by Georgia In success
fully controlling the San Jose scale has
not been exceeded by any other state.
Indeed. we feel safe in saying that to-
day the commercial orchardists of Geor-
eia are better equipped for, and more
thoroughly understand controlling this
dreadful pest than those of any other
state in the Union.
The various materials, washes and
patent compounds that have promised
to prove at all successful have been
tested in Georgia. OF all the substances,
however, none have proved at all salts
factory under Georgia conditions except
the oil treatments and the lime-sulphur-
salt wash.
WINTER TREATMENT.
The use of oils, both kerosene and
crude petroleum, has been extensive IN
Georgia orchards. The results upon
the whole have been highly satisfactory
and the efficiency of the oil in killing
San Jose scale cannot be doubted. While
a few isolated cases of injury of the
trees have occurred, they are IN most
cases traceable to defective spraying ma
chinery or to carelessness on the part OF
the negro laborers employed. The oils
have been applied with "mechanicaI
mixture" pumps or in the form OF emul-
sions with soap. The latter has proved
the most satisfactory, and we have
heard of but one case of injury TO trees
where the emulsion was used. Even II
this case, the evidence indicates that the
mixture was not properly emusified by
powerful agitation and hence perfect
emulsion was not obtained.
The mechanical mixture pumps re
ferred to consist essentially of two sep
arate tanks for containing the oil ano
water, separate pump for each, anc
mechanical devices whereby the flow o.
each can be regulated to secure the per
centage Of oil desired. During the pas
few years the writer has made careful
tests of several such pumps, manufac
tured by different firms. In no case have
we found a pump which can be depend
ed upon to maintain even approximate,
given percentage. In one experiment
new pump direct from the factory anc
pronounced by the makers as being II
perfect condition, was kept constant,
running for one hour. The levers anC
pumps were set to throw mixture o
Is per cent. oil and 50 per cent. water
Tests made during the hour showed
that the percentage Of oil varied from II
to S2lb per cent. Such pumps canno
be depended upon, especially as an.
slight arrangement or clogging is mos
certain to result in the percentage vary
ing to a dangerous degree or in stopping
the flow of either the oil or water. Tn
diluted oil sprayed upon peach tree
almost certain to kill the tree, while pur
water is useless so far as the scale IN
sects are concerned.
Where intelligent white labor is avail
able, and the pumps are kept in orde
and frequently tested to see that tn
percentage is fairly constant, the me
chanical mixture pumps can be effect
lively used. Indeed, large commercial oil
chards have been sprayed without
single tree being injured. Where negr
help is used, however, the risk is CREATE
The laborers are prone to stop the pun
long enough for the oil and water in tn
hose to separate. They also exercis
less judgment in keeping pumps In Of
der and properly adjusted. tits likewis
almost impossible for foreman to kee
several pumps under constant supel
vision and keep all properly ADJUSTED
To the orchardist who has successful
controlled the scale by using the M
chanical mixtures of oil and water, will
ont ;niury tn his trees we do not recon