We tested the impact of storage atmospheres in which the CO ₂ and O ₂ percentages sum to 21% on highbush blueberry ( Vaccinium corymbosum L.) fruit condition and quality. The CO ₂ and O ₂ combinations, in percent composition, were 19%/2%, 18%/3%, 16.5%/4.5%, 15%/6%, 13.5%/7.5%, 12%/9%, 6%/15%, and 0%/21% for CO ₂ /O ₂ , respectively. Nine blueberry cultivars were evaluated (Duke, Toro, Brigitta, Ozarkblue, Nelson, Liberty, Elliott, Legacy, and Jersey) after 8 weeks of controlled atmosphere (CA) storage at 0 °C. Surface mold, berry decay, skin reddening (associated with fruit pulp browning), fruit firmness, pulp discoloration, and the content of ethanol and acetaldehyde were assessed. Fruit firmness, skin reddening, and decay declined and the proportion of fruit with severe internal discoloration tended to increase as CO ₂ concentrations increased. Ethanol and acetaldehyde accumulation was minimal, indicating fermentation was not induced by the atmospheric conditions applied. Cultivar effects were far more pronounced than atmosphere effects. Some cultivars such as Duke, Toro, Brigitta, Liberty, and Legacy appear to be well suited to extended CA storage, whereas other cultivars such as Elliott stored moderately well, and Ozarkblue, Nelson, and Jersey stored poorly. The data indicate that responses to high levels of CO ₂ , while O ₂ is maintained at its maximum level practicable, can, in a cultivar-dependent manner, include significant negative effects on quality while achieving the desired suppression of decay.

Leaf-level physiology, yield, and fruit quality of two strawberry (Fragaria × ananassa Duch.) cultivars, “BG4.370” and “Splendor” grown in five growing substrates were assessed. Substrate ratios were T1: tuff (0–4 mm), T2: cocopeat + perlite 4:1, T3: peatmoss + perlite 4:1, T4: tuff + cocopeat 4:1, and T5: tuff + peatmoss 4:1. Strawberry parameters were greatly affected by substrate composition but not cultivars. Plants grown in cocopeat + perlite 4:1 had the highest photosynthesis, transpiration, radical scavenging activity, and fruit firmness while those grown in peatmoss + perlite 4:1 had the highest yield, total phenolics and nitrate concentration compared to other substrates. Given that peat-based growing substrate has raised concerns over the environmental impacts such as, a reduction of wet-lands and loss of soil organic carbon, the lower environmental impact and higher fruit quality grown on cocopeat justifies the use of cocopeat as an alternative substrate to peatmoss.

‘Honeycrisp’ apples were found to be sensitive to injury from O ₂ and CO ₂ partial pressures typical of those in controlled-atmosphere (CA) storage. A preliminary study was conducted in 2008 to investigate the effect of the following O ₂ /CO ₂ partial pressure (kPa) combinations: 1/0, 3/0, 1/3, 3/3, 21/3, 21/0 (air), and 21/0 with 1-methylcyclopropene (1-MCP; 1 μL·L ⁻¹ ) on CA-related injuries of 'Honeycrisp' during storage for 6 months at 3 °C. ‘Honeycrisp’ apples were found to be sensitive to an injury comprised of irregular-edged brown lesions in the cortex occasionally accompanied by the formation of lens-shaped voids. The symptoms are similar to CA-related injuries described for other apple cultivars and often characterized as a “CO ₂ injury.” Injury severity increased as O ₂ declined and as CO ₂ increased and was evident within the first month of storage. During 2009, 2010, and 2011, a study was conducted to evaluate options for avoiding injury during CA storage for this cultivar. Fruit were conditioned at 3, 10, and 20 °C for 5 days and then exposed to the following O ₂ /CO ₂ partial pressure combinations: 3/0, 3/3, 21/0 (regular air); 3/3 with diphenylamine (DPA) drench (1 g·L ⁻¹ ); and 21/0 with 1-MCP (1 μL·L ⁻¹ ). Injury severity declined as the temperature of the prestorage conditioning period increased; holding fruit for 5 days at 20 °C almost completely eliminated the disorder. The antioxidant DPA also provided nearly complete control of CA injury. 1-MCP, although not studied in conjunction with a modified atmosphere, was found to cause no injury in air storage and may provide an alternative to CA storage and avoid the risk of CA injury for ’Honeycrisp’. The relationship between disorder development and growing degree-days, rainfall, and maturity indexes was studied. Ethylene was the only factor with a significant linkage to the development of CA injury ( R ² = 0.35; P = 0.0043). Suggestions for handling of ‘Honeycrisp’ for extended storage are presented.