312 
Journal of Agricultural Research 
Vol. XI, No. 7 
explanation of the contrast in scald is to be found in this difference in 
maturity of fruit. 
The results of the above experiment might seem to be in opposition 
to the generally accepted idea that immediate storage tends to decrease 
scald, but it is evident from the experiments (reported earlier in this 
paper) that the effects of delayed storage will depend upon the conditions 
under which the apples are held during the delay, and possibly also upon 
the initial maturity of the fruit. 
It has already been pointed out that when fruit is poorly aerated 
scald increases with an increase in temperature up to 15 0 or 20°, and 
that when it is well aerated it will remain free from scald at any tem¬ 
perature from 5 0 to 20°. The effect upon scald development of any 
delay in reaching storage should therefore depend very largely upon the 
aeration and humidity during the prestorage period. If the aeration is 
sufficient, there will not only be no scald tendencies developed at the 
warmer temperatures, but the fruit will mature rapidly during the delay 
and thus, in general, become less susceptible to scald. 
DISCUSSION OF RESULTS 
The results of the various experiments point to abnormal respiratory 
conditions as the cause of scald. The disease has been readily produced 
by storing the fruit in moist chambers, in loosely stoppered jars, or under 
any condition that furnished a slight restriction to aeration. Scald has 
not developed on well-aerated apples (at temperatures above o°); nor 
has it been found possible to produce typical scald in tightly-sealed 
containers. 
No evidence has been obtained that humidity has any effect upon the 
development of scald except under conditions that have caused the dep¬ 
osition of drops or films of water on the skin of the apple. In such cases 
it seems probable that the harmful effects were due primarily to the par¬ 
tial exclusion of the air or to the retention of oxidation products by the 
water. 
The rapidity of the development of scald has increased with an increase 
in temperature. In this fact it has followed the law of respiratory 
activities. Morse (15) found that between o° and 20° a rise of 10 degrees 
in temperature caused a doubling of the amount of carbon dioxid given 
off by Baldwin apples. Gore (10) reported that in determinations 
including 40 different kinds of fruits it was found that respiration increased 
from 1.89 to 3.01 times, an average of 2.376 times for each 10-degree 
rise in temperature. A study of figures 10 to 17 shows that the average 
rate at which the development of scald has increased with a rise in tem¬ 
perature is approximately the same as the rate of increase for respiration. 
The question might be raised whether the more rapid development of 
scald at the higher temperatures might not be entirely due to the greater 
