WSU Tree Fruit Research & Extension Center

Tree Fruit Market Diseases

Sunday, March 24, 2019

WSU-TFREC/Postharvest Information Network/Tree Fruit Market Diseases/Apples (in general)

Apples (in general)

Spoilage in apples from tree to table has been greatly reduced in the past decade by new and improved handling methods, materials, and equipment. New, effective spray materials that leave a low residue eliminate the need for spray-residue removal. New types of sprayers provide fast, uniform coverage. Orchardists exercise increased care in handling during harvest and storage, and improved refrigeration equipment provides fast cooling and uniform temperatures. New scald-inhibiting chemicals provide excellent control if properly used.

There is an increase in controlled-atmosphere storage, not only at 38 °F to slow the ripening of varieties that develop low-temperature disorders at 31° to 32°, but also at 31° to 32° to prolong the storage life of varieties not subject to low-temperature disorders. Apples that are to be stored should be stored promptly and cooled rapidly to the desired temperature.

Apples grown and harvested in favorable seasons and handled with good horticultural practices generally do not develop serious decay in storage or during marketing.

New, improved shipping containers are one of the most favorable advances in preventing serious bruising injury. Most serious bruising now occurs in over-ripe apples.

Temperatures near 32 °F or at least a range between 32° and 40° should be maintained during transit. In subfreezing weather heater service should be provided.

Mass displays of apples in retail stores are nearly always attractive and are generally free of disease. The problem at the retail level, especially during the latter part of the storage season, is over-ripeness and some bruising. This is increased by overmaturity at harvest, prolonged storage, and inadequate refrigeration during retail. Apples ripen twice as fast at 70 °F as at 50°, twice as fast at 50° as at 40°, and twice as fast at 40° as at 32°.

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