HANDLING APPLES FROM TREE TO TABLE 25 



earlier, it is soft and juicy. Frequently, rot fungi invade the fruit 

 through the dead skin. They make black or brown spots of decay and 

 soon destroy what is left of the apple. Blue mold and Alternaria are 

 the most common invaders of soft-scald tissue. Jonathan, Rome 

 Beauty, and Mcintosh are the varieties most often affected with soft 

 scald, but other varieties are sometimes affected also. 



Much experimental work has been done on this disease, but very little 

 has been discovered to explain its nature and cause, except that it is a 

 low-temperature disorder. As a result, no categorical statements can 

 be made regarding its control. In general, its incidence appears to be 

 reduced or prevented by early harvest and prompt cold storage at 30° 

 to 32° F. Delay up to 10 days or 2 weeks in placing the fruit at 30° to 

 32° seems to increase the tendency to the disease, but after longer de- 

 lays the susceptibility of the fruit decreases. Well-matured or over- 

 matured fruit is more susceptible to soft scald and should not be stored at 

 temperatures below 36°. The disease is erratic; it may be bad one year 

 and absent the next. 



Soggy breakdown is most serious in Grimes Golden and Golden Deli- 

 cious and appears to be the manifestation in these varieties of the same 

 disorder exhibited by soft scald in others. Soggy breakdown differs 

 from soft scald chiefly in its location, being typically a disease of the 

 flesh, whereas soft scald is confined to the skin and adjacent flesh. Soft 

 scald has a sharply defined margin in the skin; in soggy breakdown there 

 is a more extensive involvement of the flesh beneath, without the sharp 

 margin between the sound and the affected tissues (fig. 11, D). It seems 

 to be associated with the same storage conditions as soft scald. 



SCALD 



Scald occurs principally in storage; it is a rather generally diffused 

 browning of the apple skin. At first it is superficial, but eventually 

 the skin may become soft and it can be readily sloughed off. Then the 

 flesh beneath either dries out or is opened to infection by rot fungi. 

 The green, or unblushed, parts of the fruit are most affected, and im- 

 mature apples are more susceptible than those picked later. 



Scald can be understood best by thinking of it as a disease induced 

 by suffocation or auto-intoxication; that is, it appears to be caused by 

 products given off by the apple itself. The particular products involved 

 apparently are connected with the odorous constituents of the apples. 



Scald itself affects the appearance and not the dessert or cooking 

 quality of the fruit. However, the presence of scald means that the 

 further storage life of the fruit is limited because scalded skin is dead 

 and offers no further protection to the fruit. The disease is likely to 

 spread rapidly until almost all the surface, particularly the green-colored 

 areas, is involved. It does not ordinarily begin to appear until 60 days 

 or more after harvest and commonly is more serious on apples in cold 

 storage than on those in common storage. Sometimes it does not be- 

 come manifest until after the apples are removed to a warmer place. 

 Usually it becomes more serious after such transfer, but this is a result 

 of conditions that prevailed during cold storage. 



In the prevention of scald, picking the fruit at proper maturity and 

 selecting only the best-colored fruit for long-time storage are important, 

 but in preventing loss from the disease further measures must be taken. 



