Nov. 12, 1917 
Jonathan-Spot and Scald of Apples 
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Fig. 12 . —Graphs showing the effects of 
temperature on apple-scald at the end of 
6, 7, 8, 9, ii, 14, 15^ 18, 21, and 23 weeks. 
The dotted graphs show the amount 3 
days after removal from storage at the 
end of the given week. The apples were 
Grimes from Vienna, Va. They were 
picked on August 10 and the experiment 
was started on August 11, 1916. 
This was particularly true of apples at o°. The dotted lines in figures 
9 to 15, inclusive, show the results at the end of the given week, but after 
the fruit had stood for three days at laboratory temperature. Half of the 
fruit under the particular condition was 
removed in each case. A comparison of 
this data with that obtained before re¬ 
moval, as shown by the solid lines having 
the same numbers, makes it evident that 
the scald on apples at 5 0 may appear 
several times as bad after a few days of 
free exposure to warm air, and that apples 
at o° may be rather badly scalded with¬ 
out showing it while remaining at that 
temperature. In some cases the Grimes 
had developed a latent scald at o° by the 
end of 10 weeks, but the York Imperial 
failed to show any scald upon removal 
from storage at that time, and the 
Jonathan had none at either o° or 5 0 
upon removal at the end of 15 weeks. 
While the fruit at low temperatures showed a greater amount of scald 
upon removal, the nature of the temperature contrasts was not changed, 
the difference between the amount of disease at o° and 5 0 usually being 
nearly as great after removal as before. The 
whole series of experiments has been consistent in 
showing that an increase in temperature is accom¬ 
panied by an increase in rate of scald up to an 
optimum of 15 0 or 20°. The critical period for 
scald development appeared about a month ear¬ 
lier with each 5-degree rise in temperature. 
Experiments were made to determine whether 
the increase in disease upon removal from stor¬ 
age was due to the sudden change in tempera¬ 
ture. York Imperial apples that had been held 
in commercial cold storage till the first of April 
were removed and divided into various lots that 
were distributed at temperatures of o°, 5 0 , io°, 
15 0 , and 20°. Some of the apples were allowed 
to remain at each of these temperatures, while 
others were gradually moved to higher tempera¬ 
tures. At the end of 10 days practically no 
scald was evident at o° and 5 0 , and only about 
half as much at io° as at 15 0 and 20°. At this time all of the apples 
from the lower temperatures were removed to 20°. After two days at 
this temperature all of the fruit was scalded practically alike, regard- 
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TEMPERATURE CERT/GRADE 
Fig. 13.—Graphs showing the 
effect of temperature on apple- 
scald at the end of 4, 5,6, 7, 8, 
9, 12, 15, 16, 19, and 21 weeks. 
The dotted graphs show the 
amount 3 days after removal 
from storage at the end of the 
given week. The apples were 
Grimes from the same orch¬ 
ard as those of figure 12, but 
were picked on August 28 and 
the experiment was started 
on August 29, 1916. 
