Dec. is, 1923 
Control of Apple Scald 
53 i 
was composed of 40 parts by weight of mineral oil, 5 parts beeswax, and 
55 parts paraffin. The BP2 wax was composed of 40 parts of mineral oil, 
10 parts beeswax, and 50 parts paraffin. The BP3 wax was composed of 
29 parts mineral oil, 10 parts beeswax, and 61 parts paraffin. Approxi¬ 
mately 0.018 gm. of the beeswax-paraffin-oil mixtures was applied to 
each apple. The relatively low dosage in this case was due to the fact that 
these waxes were comparatively firm and did not stick to the fruit in as 
heavy layers as the other waxes. The results of the various oil and wax 
experiments are reported in Table VIII. 
In most cases the apples that were treated with oil had a less attractive 
appearance upon removal from storage than the untreated ones. The 
natural bloom of the fruit was lacking, and the apples that had received 
heavy or medium applications of oil, and many of them that had received 
light ones, still had an oily appearance. The apples that received the 
beeswax-oil, paraffin-oil, or vaseline-oil mixtures were usually slightly 
sticky or greasy, but those that received the beeswax-paraffin-oil com¬ 
binations had little that was objectionable in feel or appearance. 
Many of the lots treated with oil and a few of those treated with bees¬ 
wax-oil mixtures had a higher percentage of blue mold rot than the 
untreated fruit. 
Most of the apples that were treated with either oil or wax were much 
greener and firmer than the untreated fruit and were often lacking in 
flavor and quality. The condition of the fruit was much like that 
described in an earlier publication 3 as resulting from short periods of 
storage in carbon dioxide. The fruit that received heavy or medium 
applications of oil was affected most, that which received light applica¬ 
tions of oil or was treated with beeswax-oil, paraffin-oil, or vaselin-oil mix¬ 
tures was less affected, while that which was treated with the beeswax- 
paraffin-oil mixtures was entirely normal in color, firmness, and taste. 
A study of Table VIII shows that all of the oils and most of the waxes 
decreased the development of scald but that they fell far short of the 
oiled wrappers in efficiency. If an average is taken of the comparable 
tests, it gives 14.7 per cent of scald on the lightly oiled apples, 9.1 per cent 
on the heavily oiled ones, 40.5 per cent on the untreated fruit, and 0.5 
per cent on the apples in mineral-oil wrappers. The beeswax-oil, paraffin- 
oil, and vaseline-oil mixtures gave approximately as good results as the 
heavy applications of oil, but the beeswax-paraffin-oil mixtures had 
little or no value in scald control. As already noted, the beeswax-paraf¬ 
fin-oil mixtures not only had a low oil content but also were applied to 
the apples in much smaller quantities than the other materials. The 
poor scald control secured with these mixtures and the contrasts in con¬ 
trol with the heavy and light applications of oil indicate a correlation 
between quantity of oil applied and degree of efficiency in scald control. 
NATURE OF SCALD CONTROL 
Investigations in regard to the general nature of apple scald were 
reported in an earlier publication. 3 It was established by experimental 
data that in so far as the usual storage conditions were concerned scald 
was the result of tight packages and tight storing and that the disease 
could be prevented by free air movement over the apples. It was shown 
that while tight storage naturally resulted in a decrease in the oxygen 
3 Brooks, Charles, Cooley J. S., and Fisher, D. F. op. cit. 
