SAN JOSE SCALE AND CRUDE PETROLEUM 
A GREAT INCREASE OF THE SCALE. 
Facts About the Use of Petroleum. 
SCALES INCREASING.—The demand for Bulletin 
No. 146, of the New Jersey Experiment Station, treat¬ 
ing on the above subject, has been so great that the 
edition is completely exhausted. Since the work was 
published much additional information has come in, 
and a very large number of oil samples have been re¬ 
ceived from all parts of the eastern oil territory. In 
no previous year in my experience has the scale bred 
so rapidly, late in the Fall, as in 
1900. Ordinarily, while breeding 
does not cease by the middle of Oc¬ 
tober, it is so much lessened that 
the condition then existing may be 
fairly recorded as that in which the 
tree goes into the Winter. In Octo¬ 
ber, 1900, larvae swarmed in count¬ 
less multitudes, and continued to in¬ 
crease, favored by the warm, dry 
weather, far into November. In fact 
on my experiment trees, larvae were 
yet active far into December. The 
result is a much greater infestation 
and a greater spread than in pre¬ 
vious years. As an example 1 may 
cite a peach grower in Hunterdon 
County, N. J., who offered $1 to any¬ 
one who could show him a scale in 
his orchard in August. In October 
he had no lack of infested trees, and 
in January he told me that the in¬ 
crease had been so gi*eat that he 
feared that many of the trees were 
doomed; so utterly coated with scale 
were they. A tree on my own place 
offered a similar example; only a 
little scaly in midsummer, it was 
not only coated in December, but 
the entii’e inner surface of the bark 
and bast was purplish red. Of 
course I might have checked this by 
timely spraying, but I preferred to 
let things go as 99 out of 100 fruit 
growers would do under similar cir¬ 
cumstances. 
SOME RESULTS.—As a result of 
this abnormal season many fruit 
growers did not get the results from 
spraying that they should have 
done. The inevitable few left-overs 
placed matters in much the same 
condition that they were the year 
before; a discouraging feature, to 
say the least. Those who success¬ 
fully used crude oil were in much 
better position than those who used 
soap or other mixtures, provided 
the mixture was strong enough. For 
instance, in Hunterdon County, N, 
J., at an experience meeting, one 
grower informed me that he had used a 15-per-cent 
mechanical mixture in the Winter of 1899-1900, and 
had then, January, 1901, as much scale as he had the 
year before. The man sitting next to him had used 
a 25-per-cent mixture liberally and had practically 
no scale left. A correspondent from Lakeside, O., who 
has published his experience elsewhere, wrote in No¬ 
vember that he had “used the kerowater sprayer, set 
for 25 per cent of crude oil, and sprayed from April 
6 to April 20 at intervals, as weather would permit, 
on peach, plum, apple and pear trees. May 12 and 13 
used 15 per cent of oil on above varieties of trees, and 
May 17 and 18 used 10 per cent of oil on peach, plum 
and apple trees with no bad results, except the loss of 
oils in fluidity. They were unfit for use undiluted; 
but can be safely used in a 25-per-cent mixture. Of 
course, when my bulletin No. 138, which was followed 
I y these gentlemen, was published, neither I nor any¬ 
one else had any idea how important for its effects 
upon the tree was the specific gravity of the oil. From 
Martinsburg, W. Va., I heard in December: “I ad¬ 
vised the test here on the Janney orchard, which was 
tne worst infested. They have showered it with crude 
oil, have checked the scale and hurt no tree. Where 
the work was thorough the scale was eradicated.” 
A correspondent writing from Hammonton, in south 
Jersey, late in November, stated 
that he had used five barrels of 
crude oil the previous Winter, un¬ 
diluted, and mostly on Bartlett 
pear trees in February. “I did not 
harm a single pear tree; but think 
it improved their growth, especial¬ 
ly in one young orchard, that has 
not been growing as well as I 
thought it ought to under the cul¬ 
tivation that I have been giving it 
for three or four years.* Last Sum¬ 
mer the trees made the most 
growth of any season. We were 
told here four or five years ago by 
a young man traveling through the 
country lecturing on the scale, that 
the San Josd scale would not move 
over one inch in the whole Sum¬ 
mer season. One year ago last 
Winter (1898-’99) when I went over 
my pear orchard, trimming and 
cutting out dead wood, I watched 
for scale, and did not find above a 
dozen trees that were infested, and 
those I treated with potash whale- 
oil soap. Last Winter (1899-1900) 
when I went over them again, I 
was greatly surprised to see the 
rapid progress they had made in 
one year. Many of the trees were 
literally covered, and they had scat¬ 
tered all over the orchard of about 
1,200 trees to such an extent that it 
was not safe to undertake to pick 
them out, but to spray thoroughly: 
I holding the nozzle myself. I only 
made one application, and now find 
but very few scale. I painted a few 
peach trees with some of the same 
petroleum that I sprayed the pear 
trees with, and it killed several of 
the trees. Mr. G. tells me he paint¬ 
ed his young peach trees with crude 
petroleum and did not kill a tree.” 
I obtained from Mr. G. a report of 
his proceedings as follows: “Here¬ 
with I send inclosed two pictures 
of peach trees. No. 1 will be two 
years from the nursery, in my or¬ 
chard of 200 trees set November 22, 
1898; treated last Winter with crude petroleum by 
brush and brushed thoroughly. No. 2 is one-year-old, 
cut back to a stick set last November, was treated at 
the same time and in the same way. The branch on 
the right is seven feet long and was pinched to retard 
growth.” I secured a sample of the oil that had kill¬ 
ed the peach trees mentioned in the first report, and 
found it decidedly below requirements as to specific 
gravity; but as it had been standing for almost a 
year it may have lost by evaporation. These reports 
from the same place, on applications made in appar¬ 
ently the same way, with opposite results, are con¬ 
fusing, and point to the possibility of factors not yet 
known, which infiuence the action of the oil. Reports 
about one per cent of foliage on last dates. I am unable 
to find any live scale on trunks or large limbs, where 
25 per cent of oil was used; but there were some spots 
on some trees that were not hit with the oil, and that 
left live scale to multiply; but they are all on these 
spots, and on this season’s growth of outer branches. 
All trees treated with fish-oil soap, two pounds to the 
gallon of water, still have the scale scattered all 
through them, probably as many as before treatment 
with the soap. I have arrived at this conclusion after 
this year’s experience: I can keep the scale in check 
at least, if not wholly eradicate it with crude peti’o¬ 
THE BABY PRIMROSE (PRIMULA FORBESII). Fig. 48. See Page 128. 
leum at little expense; but with fish-oil soap we can 
spend all the money and time we have a mind to, and 
have the scale as long as we live. Think I am safe in 
saying we can kill more scale with $25 worth of crude 
petroleum than with 100 worth of fish-oil soap. My 
brother used undiluted oil on a block of two-year-old 
peach trees and it killed them.” 
DIFFERENCE IN OIL.—The last sentence was not 
so satisfactory; but I secured, as the result of corre¬ 
spondence, 13 one-pint samples of Ohio crude oils, not 
one of which reached 40 degrees, while the majority 
ranged between 35 degi*ees and 37.5 degrees. All were 
black or dark oils, and none of them compared with 
the Pennsylvania or West Virginia green or amber 
ti per year. 
NEW YORK, FEBRUARY 23, 1901. 
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