EFFECT OF CONTROLLED ATMOSPHERE STORAGE AFTER INITIAL LOW OXYGEN STRESS TREATMENT ON SUPERFICIAL SCALD DEVELOPMENT ON SOUTH AFRICAN-GROWN GRANNY SMITH AND TOPRED APPLES

The effect of two controlled
atmosphere (CA) storage regimes and twelve CA storage periods following an
initial low oxygen stress (ILOS) treatment on the development of superficial
scald on ‘Topred’ and ‘Granny Smith’ apples was evaluated during two successive
seasons.
Apples harvested at pre-optimum and optimum maturity stages were
stored for 7 days under simulated commercial conditions.
Subsequently, fruit
were exposed to ILOS conditions and then stored for 20 w and 12 w respectively
at -0.5 °C in atmospheres containing 1.5% O₂/1.5% CO₂ or
1.5% O₂/3.0% CO₂ (Topred) and 1.5% O₂/1.0% CO₂
or 1.5% O₂/3.0% CO₂ (Granny Smith). The trial was
repeated with fruit not exposed to a low O₂ concentration and stored
at regular atmosphere conditions at -0.5°C. Samples were evaluated at 2-week
intervals.
ILOS, without diphenylamine (DPA) treatment, followed immediately by
CA storage, inhibited the development of superficial scald significantly on
both cultivars after a CA storage period of between 8 w and 12 w for fruit
picked at pre-optimum maturity and 2 w and 6 w for fruit picked at optimum
maturity.
CA storage regimes did not differ significantly in their effect on
superficial scald development.
Storage periods of longer than 14 w (Topred) and
16 w (Granny Smith) (pre-optimum maturity) and 6 w (Topred and Granny Smith)
(optimum maturity) inhibited the development of superficial scald completely.

VIII International Controlled Atmosphere Research Conference

J.A. van der Merwe, J.C. Combrink, F.J. Calitz

Superficial scald, apples

https://doi.org/10.17660/ActaHortic.2003.600.34