foliar levels of potassium of 1.97 percent or higher increased fruit suscepti- 
bility to scald in comparison to fruit from trees where the potassium level was 
1.41 percent. 
Effect of Fruit Size 
Large apples are usually more susceptible to scald than small apples (16, 
23, 109). However, in a year when scald is severe even most small apples will 
scald, Ginsburg (23) in South Africa found no difference in scald susceptibility 
between size 113 and size 216 apples. 
Fruit Maturity 
It has long been recognized that early picked fruit or immature fruit 
scalds worse and often sooner than mature fruit (4, 23, 29, 33, 41, 52, 59, 65, 
68, 89, 117, 121, 128, 133, 134). With Granny Smith apples in Australia, 
Tindale (128) demonstrated a fairly sharp break in scald susceptibility as fruit 
matures on the tree. Scald was high before a certain picking date, and much 
lower thereafter. 
Smock (109) reported an exception to the general rule. Overmature 
McIntosh stored in controlled atmospheres tend to scald worse than fruit picked 
earlier. Hardenburg and Siegelman (38) reported overmature Golden Delicious 
stored in polyethylene liners scald worse than early picked fruit. 
Effect of Delayed Storage 
A delay in getting apples from the orchard into refrigerated storage has 
not consistently increased or decreased the extent of scald (23). Padfield (65, 
67) found that delayed storage of Granny Smith apples increased scald and in- 
creased yellowing. Southwick (117) found that a delay in storage of more than 
1 day at 70° F. after harvest increased the amount of scald developing on both 
McIntosh and Cortland held in CA storage. Rose, McColloch, and Fisher (90) said 
delayed storage increased scald if ventilation around the fruit was poor during 
the delay. Fidler and North (17) found that delayed storage of 6 to 12 days at 
65° increased scald of Bramley's Seedling and Edward VII. Denmead, Vere-Jones, 
and Atkinson (11) reported that fruit held 6 days at ambient temperature before 
storage were less susceptible to scald than those placed in cold storage immedi- 
ately. Stevenson (121) found that delayed storage reduced scald but increased 
wastage from mold, breakdown, and softening. It is generally agreed that de- 
layed storage is not a practical approach to scald control because of ripening 
during the delay. 
Predicting Scald Intensity 
Early prediction of the scald susceptibility of various lots of apples 
would be most useful to the storage house manager. Smock (109) has shown that 
storing samples for 6 weeks at 70° F. in 1.5-mil nonsealed polyethylene box 
liners will produce scald on susceptible fruit and thus give useful information. 
However, the prediction method tended to underestimate the scald that eventually 
developed in storage or on removal from storage. 
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