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Market Diseases of Apples, Pears, and Quinces
Senescent Scald of Golden Delicious |
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For many years Golden Delicious was considered to be virtually scald-free. However, a scald-like disorder began to occur with increasing frequency after the use of polyethylene box liners extended the storage period for this variety to 7 months or more. The symptoms of the disorder consist of a superficial brown discoloration of the skin similar to mild to moderate ordinary scald on certain other varieties. Differences in development and in the maturity of the fruits on which it occurs suggest that this disorder is not true ordinary scald. The skin discoloration develops first on the calyx end and then on the cheek of the fruits (see photo). Unlike ordinary scald, which is associated with immaturity of the fruits at harvest, this disorder is more severe on fruits harvested late in the season than on those harvested early. Among fruits in the same harvest, it is worse on yellow fruits than on green ones.
It appears to be associated with fruits that are past their prime and may be nearing the end of their storage life. Therefore, it is proposed that this disorder be designated as senescent scald. The amount of skin discoloration that develops late in the storage season on Golden Delicious apples can be greatly reduced by the use of sprays, dips, wraps, or waxes containing ethoxyquin. Diphenylamine (DPA) should not be used (see Diphenylamine Injury). |
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