Effects of Initial Oxygen Stress Treatments in Low Oxygen Modified Atmosphere Storage of ‘Granny Smith’ Apples1

Abstract

‘Granny Smith’ apples (Malus domestica Borkh.) harvested over 7 weeks were not affected by alcoholic taints and were firmer, greener and less susceptible to scald and core flush following storage in 1.0% CO2 and 1.5% O2 (1.0:1.5) at −0.5°C as compared to present commercial modified atmosphere (MA) storage at 3.5% CO2:3.5% O2. Storage response was optimized by harvesting fruit with a starch-iodine maturity index of 5 to 6. With lower starch-iodine indices the incidence of core flush was increased, and at higher indices the potential for scald development increased substantially. Exposure of fruit to an initial O2 stress at or below 0.5% for 9 days gave additional benefits in scald control, fruit firmness and color over continuous storage at 1.0:1.5. If O2 was totally excluded by a 14-day treatment with continuous flow-through of O2-free nitrogen, core flush and alcoholic tainting increased, but scald decreased. Core flush following initial flow-through nitrogen treatments was also significantly increased by the effect of postharvest diphenylamine calcium chloride treatment or by an increase in storage temperature from 0° to 4°.

Physiology and Control of Superficial Scald of Apples: A Review

“…Exposure of fruit to an initial 0 2 stress at or below 0.5% for 9 days gave additional benefits in scald control over continuous storage at 1.0% 0 2 : 1.5% C 0 2. Alcoholic tainting increased if 0 2 was totally excluded for 14 days, but scald decreased (44). Reducing storage C 0 2 from 2.0% to 0.5% increased scald in 'Spartan' apples stored at 2.5% 0 2, but not in those stored at 1% 0 2 (38).…”

“…Addition of Cu and Co increased scald, while Ba and Sr reduced the disorder (71). Cultivar susceptibility (50,54), rootstocks (54), eth ylene levels in storage (37,45), preharvest temperatures (1,52,55), orchard locality (43), ventilation and air movement in storage (34), and storage conditions (12,44) are some other factors influencing the susceptibility of ap ples to scald.…”

“…However, DPA is not labeled for concentrations >2 g -lite r 1. b) Manipu lation of storage conditions to bring about efficient scald control should be studied more thoroughly. Low-oxygen storage has been shown to be reasonably effective (44). c) Further studies on predicting scald incidence based on certain conditions at or before har vest (nutrient levels, a-farnesene, preharvest air temperatures), so as to manage fruit in storage according to scald potential and in tended use (fresh market or processing).…”

Effects of Sequential Low-oxygen and Standard Controlled Atmosphere Storage Regimens on Apple Quality

“…Little et al (15) and Lidster et al (13) attempted to minimize the incidence of low -02 injury in 'Granny Smith' and 'Mc-Intosh' and 'Spartan' apples, respectively, by limiting the du-ration of initial exposure to 1.0% 0 2 atmospheres or less. Preliminary evidence (10) indicated that the development of low -02 injury progressed with storage duration and that both low -02 and senescent disorders in 'McIntosh' apples could be reduced by an initial exposure to 1.0% 0 2 of 1.5 to 4.5 months followed by storage in SCA (13).…”

Postharvest and Storage Factors Affecting Superficial Scald and Core Flush of ‘Granny Smith’ Apples

“…Microsprinkler irrigation largely protects the lower part of young citrus trees through heat of fusion as spray water freezes on the trees. In addition to the heat of fusion, mi crosprinklers also help protect mature trees by releasing sensible heat into the orchard, increasing soil heat conductivity, and occa sionally creating fog (6). The young trees in the Vero Beach location were injured largely because volume output, location, and dis tance of jets from the trees were not adequate to provide enough heat of fusion for protec tion.…”