|SERBAN, CORINA - Washington State University|
|KALCSITS, LEE - Washington State University|
|DEELL, JENNIFER - Omafra (ONTARIO MINISTRY OF AGRICULTURE & FOOD/RURAL AFFAIRS)|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2019
Publication Date: 9/23/2019
Citation: Serban, C., Kalcsits, L., DeEll, J., Mattheis, J.P. 2019. Responses of ‘Honeycrisp’ apples to short-term controlled atmosphere storage established during temperature conditioning. HortScience. 54(9):1532-1539. https://doi.org/10.21273/HORTSCI14182-19.
Interpretive Summary: Apple fruit are often held in refrigerated storage for long periods after harvest. This allows orderly marketing of large fruit volumes but can lead to losses if physiological disorders occur. One disorder, bitter pit, is formation of dark, brown, dry patches on the fruit peel. Damage is usually limited to the peel but fruit with bitter pit are not acceptable in retail markets. Postharvest procedures can limit development of this disorder but the most effective procedure, rapid cooling, cannot be used for some apple varieties including ‘Honeycrisp’ due to development of low temperature injury. Delayed cooling that reduces low temperature problems can make bitter pit development more likely. Another postharvest technology, controlled atmosphere storage, slows fruit ripening and, when established during delayed cooling of ‘Honeycrisp’ apples and held for several months, reduces bitter pit development. The current research shows CA established soon after ‘Honeycrisp’ harvest and held for as little as one week can reduce bitter pit as well. This strategy could be useful for ‘Honeycrisp’ apples marketed soon after harvest without the need for months of CA storage.
Technical Abstract: ‘Honeycrisp’ apples are susceptible to bitter pit, a physiological disorder that impacts peel and adjacent cortex tissue. ‘Honeycrisp’ is also susceptible to chilling injury that can be prevented by holding fruit at 10-20 °C after harvest for up to 7 d. This temperature conditioning period reduces chilling injury risk but can enhance bitter pit development. Previous research demonstrated CA established during conditioning can reduce ‘Honeycrisp’ bitter pit development without inducing other physiological disorders. The objective of this research was to evaluate the duration of CA needed to reduce bitter pit development. Experiments were conducted in 2014, 2016 and 2017 with fruit obtained from commercial orchards in Washington State and, in 2017 only, Ontario, Canada. Half the fruit were treated with 42 µmol·L-1 1-MCP for 24 h at 10 °C immediately following harvest. The untreated fruit were held at the same temperature (10 °C) in a different cold room. Following 1-MCP treatment, all fruit was conditioned at 10 °C for an additional 6 d, then fruit was cooled to 3 °C. During conditioning, fruit were held in air or CA (2.5 kPa O2, 0.5 kPa CO2) established 1 d after harvest, for 1 to 8 weeks, then in air. All fruit were removed from cold storage after 4 months and then held 7 d at 20 oC. Fruit from most orchards/years stored in CA developed less bitter pit compared with fruit stored continuously in air. CA during conditioning also reduced post-storage peel greasiness but CA 2 weeks or longer enhanced cortex cavity development in some orchard lots. Treatment with 1-MCP did not reduce bitter pit but enhanced development of peel leather blotch and core browning for some orchards/years. 1-MCP treated fruit slowed the loss of soluble solids content, titratable acidity and reduced internal ethylene concentration. Results suggest the potential for postharvest management of bitter pit development in ‘Honeycrisp’ apples by CA established during conditioning with minimal development of other postharvest disorders.