EFFECT OF CALCIUM ON RESPIRATION RATE, ETHYLENE PRODUCTION AND OCCURRENCE OF CORK SPOT IN D’ANJOU PEARS (PYRUS COMMUNIS L.)

D’Anjou pear fruits were sampled from 10 commercial orchards near Hood River, Oregon, and analyzed for calcium concentrations by plasma emission spectrophotometer (ICPA). Fruits with high, medium, and low Ca⁺⁺ were evaluated at harvest and after storage 3 and 7 months at -1.1°C and 96% RH.

Calcium concentration in the fruits was closely correlated to cork spot; the symptoms increasing with decreasing fruit Ca concentration and increasing storage duration.
Respiration, C₂H₄ evolution and internal C₂H₄ of fruits varied with different Ca levels at harvest, 3 and 7 months in storage.
Higher Ca levels were related to lower respiratory activities of the fruits.
The higher the Ca in the fruits, the lower the ethylene evolution.
Initial C₂H₄ production was high only in low Ca fruits.
Fruit with high Ca had delayed onset of C₂H₄ evolution.
The higher the fruit Ca, the longer was the chilling requirement.

Therefore calcium has a marked effect on delaying ripening and senescence of D’Anjou pear tissues.
Fruits with high Ca concentrations can be stored successfully for longer time periods.

Postharvest Handling of Vegetables

Rui L. Vaz, Daryl G. Richardson

https://doi.org/10.17660/ActaHortic.1985.157.30