Dec. 15.1923 
Control of Apple Scald 
5 2 5 
Wrapper No. 7 was hand oiled, as described for No. 1, but with an 
odorless, tasteless, colorless oil derived from an asphalt base and mar¬ 
keted by a Pacific coast oil company. 
Wrapper No. 8 was an oiled, medicated wrapper marketed by the 
same company as the unoiled medicated wrapper already described. It 
had been treated with the same oil that was used on wrapper No. 7 
and carried 15 per cent of its weight of oil. 
Wrapper No. 9 was a specially prepared wrapper sold by the same 
company as 3a; it had been treated with an odorless, tasteless, colorless 
oil combined with a small amount of paraffin and carried about 18 per 
cent of the two combined. 
Wrapper No. 10 was apparently very similar to wrapper No. 9 but it 
was prepared by a middle west paper company. 
Wrappers No. 11, 11a, 11b, 11c, nd, ne, and nf were prepared by 
an eastern paper company and were treated with the same oil as wrapper 
No. 4. Wrapper No. 11 was from 14-pound paper, and No. 11a from 
12-pound paper, both guaranteed to contain as much as 22 per cent of 
oil. See Table III. Wrappers 11b, 11c, nd, ne, and 1 if were guaran¬ 
teed to contain 30, 25, 20, 18, and 15 per cent of oil, respectively. 
They were prepared by the paper company for experimental use. 
Wrapper No. 12 was prepared by a New England paper company. 
It was a 14-pound paper and treated with the same oil as wrapper No. 
4. See Table III. 
Wrappers No. 13 and 13a were prepared by the same company as 
wrapper No. 4b and 4c. No. 13 was a 14-pound paper carrying 24 per 
cent of oil and No. 13a a 12-pound paper. See Table III for oil content. 
RELATIVE EFFICIENCY OF OILS 
All of the oils used have given good scald control. A comparison of 
the results with the hand-oiled wrappers Nos. 1, 2, 3, 4, 5, 6, and 7, as 
shown in Table II, might suggest some slight contrast in efficiency, but 
perhaps not enough to be of practical importance and beyond experi¬ 
mental error. 
dosage of oil in the wrapper 
Experiments have shown that wrappers with free oil on their surface 
may sometimes cause slight injury to the skin of the apple, but fortu¬ 
nately such excessively oiled wrappers are impractical for general use on 
account of the wrappers sticking together. The hand-oiled wrappers used 
in the previously reported experiments had from 17 to 25 per cent of oil, 
or practically all the paper would carry. These wrappers gave good 
scald control and caused no injury, but the most completely saturated 
ones sometimes delayed the natural yellowing of the ground color of the 
apples, making them appear abnormally green at the time of removal 
from storage. The dosage of oil in the commercial or machine-made 
wrappers ranged from 4 to 30 per cent. The wrappers with 4 per cent 
of oil have sometimes given good scald control but under severe tests 
have been an almost complete failure. Wrappers carrying 11 and 12 
per cent of oil have given good results on western apples and fair on 
eastern, but where apples have been held rather late there have been 
indications that these wrappers had about reached their limit in scald 
control. Commercial wrappers carrying 15 per cent or more of oil 
(about 28 grams to each 100 wrappers) have given good scald control with 
no objectionable results. 
