The Marietta journal. [volume] (Marietta, Ga.) 1866-1909, 1902-12-25
SAIL JOSE SCALE.


| LSAts 90 AOI materially cnanSe the
former recommendation of this Of
fce for tie treatment of the San Jose
scale, but they broaden the field of
effective remedies. giving the orchard
list the option of choosing one of sew
| eral. The petroleum oils (kerosene
and crude petroleum., which have fur
nished the almost exclusive remedy
for the scale in this State, came
| through the experiments with more
points In their favor than any other
substance tested, although the lime,
salt and sulphur wash gave almost
equally as good results. In dealing
with insecticides 1t Is not usually safe
to base recommendations upon one
years experience, and for this reason
alone we are not willing to give the
lime, salt and sulphur wash the en-
dorsemapt that the results obtained
from It's use In the tests would war
rant. However, 1t deserves to be re-
corded as very promising and given a
place In the recommendations, allowing
the orchard owners to choose between
It and the oils. Results of further
tests, which are planned for next win
ter, may place this wash upon an equal
with oils. or even show It's superiority
to them.
1t will be remembered that In al
former recommendations issued from
this Office bulletin 1. and Circulars
4 and 81 two applications during the
course OF the winter have been In
sisted upon. One application appears
to be sufficient for trees that have
reached full growth, but the results
OF our experiments show most conclu-
sively the necessity for two In the
treatment Of young orchards. The
scale insects on young trees are more
virulent, multiply much more rapidly
and are afforded better food supply
than those on older trees, hence the
number OF surviving scales that would
do no particular damage to old trees
might seriously damage those not yet
full grown. Moreover, 1t is quite
impossible to reach every portion of
a tree with one application, particu-
larry If much wind Is stirring, and It
is usually advisable to make two. even
IN case Of old trees
Concluding not only from the recent
| experiments but In part from practi.
cal results obtained by the growers,
the recommendations for next win
ter's work stand as follows:
| l. Oil Emusion-In November or
early December apply a Is per cent
strength OF either crude oil or kero
sene in emulsion with soap, and in
February or early March (before the
bloom buds open. repeat the appli-
cation at a strength of 20 per cent.
| When obtained in car lots Gas was
| done last winter) the crude oil ia
some cheaper and in general practice
IS has given slightly more satisfactory
results in its effect upon both the scale
and the trees. hence it should be civ
en- the preference. Not having vet
completed the experiments with low
grade crude oils we can recommend
only the Peyynsylvania product. regis
sering not less than 43 degrees gravity
on the Beaume oil scale.
| In spraying tree the work should
| be done thoroughly, but quickly, mois.
tenlng every por.ion Of the rec above
| the ground without allowing the sub.
stance to run down the trunk. Begin
on the side OF the tree opposite tho
| pump and walk completely around,
spraying from the top downward, AMI
taxing care to reach the tEigs ana
! the inside of the limbs. If even small
spots or twigs are left the best re.
suits cannot be expected. On the
other hand, the use of an excess Of
oil will endanger the tree and should
be carefully avolued.
2. Oil in Mechanical Mixture-The
| mechanical mixture of either crude oil
or kerosene, applied by the use of the
oil-water pumps. may be substituted
for the emulsion recommended above.
SO long as the pumps discharge a uni
form percentage of oil, results equal.
ly as good as those obtained from
emulsion may be expected. In add.
ton to the precautions to be observ-
| ed In the use OF emulsion the mechan.l
ical mixing pumps require constant
Justed and the percentage of oil dis
charged should be frequently tested.
To make these tests catch the mixture,
as it is discharged from the nozzle in
a bottle with straight side, allow it
to stand until the oil rises to the top
and then with rule measure the vol.
ume of oil as compared with the vol
ume of water beneath it. This Will
show the proportion of oil to water dis.
charged. If the desired perc antage is
not obtained, the pump should be look
ed into and readjusted,
3. Lime, Salt and Sulphur Wash-The
lime, salt and sulphur wash should be
applied in February or March, before
the trees bloom. This remedy gave
such results in the tests that we ven.
ising results in the tests that we ven
ture to include 1t in the recommends
tons, feeling confident of it's success
! Whan nr0narlv Drano rad ard tboco,ob