Nov. 12, 1917 
Jonathan-Spot and Scald of Apples 
3i5 
of maturity in the fruit, and both increased with a rise in temperature, 
having an optimum at about 20° and a maximum at about 30° C. 
(2) On Grimes and York Imperial apples scald developed in moist 
chambers at o°, 5 0 , io°, 15 0 , and 20° C., the rapidity of development 
increasing with the rise in temperature. In open containers, how¬ 
ever, no scald developed at any of the above temperatures except o°. 
Grimes apples in closed jars but with the air renewed once a day have 
scalded much more slowly than similar apples in moist chambers. 
(3) Apples stored at 15 0 C. in an atmosphere having a high percentage 
of carbon dioxid (probably more than 5 per cent in all cases) have not 
developed typical scald, but have first passed into a sort of rigor, have 
later developed a pungent alcoholic taste, and have finally broken down 
throughout like a baked or frozen apple. 
(4) The writers are of the opinion that apple-scald is largely due to 
abnormal respiratory conditions resulting from poor aeration. It has 
been pointed out that the occurrence of scald has been accompanied by 
a decrease in total acids and sugars, by a mealiness in the flesh of 
the apple, and by a checking in the color changes in the skin (Grimes). 
In looking for the final cause of scald, one should consider both the 
abnormal consumption of the organic food materials and the accumu¬ 
lation of the products of incomplete oxidation. 
(5) The conditions within the apple tissue which finally result in scald 
are of a cumulative nature and apples removed from unfavorable storage 
conditions before a certain critical period was reached have shown little 
or no increased susceptibility to the disease. 
(6) The rate of skin color development in Grimes apples has increased 
with a rise in temperature from o° to 30° C. It has been checked by 
poor aeration, but apparently has been little affected by the degree of 
humidity. 
(7) Apple-scald has been found more serious on green fruit than on 
ripe fruit, but it has developed more rapidly on the latter. 
(8) Apples that have been delayed in storage have developed less scald 
than those stored immediately, but results of other experiments reported 
make it evident that the effect of delayed storage upon apple-scald will 
depend upon the initial maturity of the fruit and the degree of aeration 
given during the delay. 
(9) Grimes apples held in commercial cold storage for five weeks, 
about one-third the time required to produce scald under cold-storage 
conditions, have shown much less susceptibility to the disease upon 
removal to other conditions than apples of the same picking tested five 
weeks earlier. 
(10) The important r 61 e that aeration appears to play in the preven¬ 
tion of apple-scald may furnish an explanation for the small amount of 
this disease usually found in cellar and air-cooled storage. 
