Nov. 12, 1917 
Jonathan-Spot and Scald of Apples 
309 
relationship between a particular degree of maturity and the develop¬ 
ment of scald. 
In order to obtain further information on the relation of maturity 
of fruit to susceptibility to scald, careful notes were taken in the various 
experiments already reported on the development of the skin color in 
the apple. The degree of color was determined in a manner similar to 
that already given for the estimation of the amount of scald, the intens¬ 
ity of the color being compared with the maximum color that the fruit 
was likely to acquire. Records were always made by two observers 
and notes were taken without reference to earlier records. 
The results given in figures 18, 19, and 20, were from the same lots of 
apples, respectively, as the scald notes of figures n, 13, and 14. Tem¬ 
perature is indicated on the base line and percentage of color on the 
perpendicular. The conditions of the experiments have already been 
described; the apples in the open containers were exposed in an atmos¬ 
phere that had less than 0.05 per cent of carbon dioxid and that had 
a relative humidity of 85 to 95 per cent, while those in the moist cham¬ 
bers were subjected to an atmosphere that was practically saturated 
and that sometimes had as much as 4 per cent of carbon dioxid. 
It is interesting to note that the color changes were made more rapidly 
during certain periods of storage than in others and that there was often 
a correlation between the time of greatest color change and that of great¬ 
est scald development. If figures 11 and 18 are compared, it will be 
seen that at 15 0 and 20° there was a decided increase in color in the open 
containers in the fourth week and in the moist chambers in the fifth 
week and that at these temperatures scald made its most rapid develop¬ 
ment in the fifth week. At io° the most rapid color changes came in 
the seventh week while the most rapid scald development came in the 
ninth week. A comparison of figures 13 and 19 brings out similar con¬ 
ditions. At 15 0 and 20° there was a big increase in color in the moist 
chambers during the sixth week and a big increase in scald during the 
seventh week. At io° there was a big increase in color in the eighth 
week and a big increase in scald in the ninth week. In general the 
period of most rapid scald development has come about one week later 
at these higher temperatures than the time of most rapid color change. 
This correlation gives further evidence of the close relationship between 
the chemical changes in the apple and the development of scald. 
A comparison of the results obtained in moist chambers with those 
in the open containers (as given in fig. 18, 19, and 20) shows that in 
the early stages of the experiment a particular degree of color was attained 
one or two weeks earlier in the latter case than in the former. The 
results indicate that the conditions that have already been reported as 
favoring scald have also tended to check the development of the skin 
color in the apple. 
