Physiological Disorders

Physiological Disorders

 Scald is one of the storage disorders in apple. Light mottling on greener surface of fruits are initial symptoms of scald. Darkening becomes more severe with elapsed time and ultimately extends to red surface also. Scald usually affects the skin only but in severe cases it may extend to fruit flesh. The immature fruits are most susceptible to scald which is aggravated by warmer temperatures in storage.

Bitterpit is characterized by small sunken spots on the fruit surface which are more prevalent near the blossom-end. Initially small water-soaked areas appear which shrink and turn brown with the loss of water and ultimately become brown localized areas of the dead tissue. Unlike the name, these corky tissues are never bitter in taste. The immature picked fruits and large-sized fruits in ‘off’ year are most affected, Golden Delicious, Yellow Newton and Gravenstein being most susceptible apple varieties.

Internal browning is associated with apple Yellow Newton and is characterized by brownish streaks radiating into flesh from the core. Controlled atmospheric storage with higher temperature can be helpful to control this disorder. Appearance of disorder is less at 1°C in cold storage.