      |
 |
|||||||||||||||||
|
|||||||||||||||||
|
|
|
|
|||||||||||||||
|
Market Diseases of Apples, Pears, and Quinces
Low Oxygen Injury |
|||||||||||||||||
|
The symptoms of low-oxygen injury vary with the oxygen level, the length of unfavorable storage, the variety of apple, and perhaps the storage temperature. McIntosh at 38 °F in 1 percent oxygen and zero percent carbon dioxide for 6 months may show only surface indentations somewhat like bruises (top photo) or may be somewhat more damaged. McIntosh stored at 38° in zero percent oxygen and zero percent carbon dioxide for just 6 weeks were much more seriously affected than the lot above with 1 percent oxygen. Most of the surface skin appeared cooked (second photo) and the flesh was killed and pale brown half way or more to the core (third photo) giving a somewhat similar appearance to soggy breakdown. Apples seriously affected by low oxygen, however, have a strong, fermented odor. Jonathan apples held in zero percent oxygen and zero percent carbon dioxide, but at 32° for 6 months, developed similar symptoms, but in some instances the brown, dead tissues occurred in the core area (fourth photo). Delicious apples stored in a similar atmosphere at 32° for 6 months and then held in air at 70° for 6 days developed extensive irregular brown skin areas (fifth photo). Some appeared similar to soft scald, but they had a decidedly fermented odor and usually lacked the sharply outlined, ribbon-like patterns typical of soft scald.
|
||||||||||||||||
|
|||||||||||||||||
