Post-packing sweet cherry stem and fruit quality attributes influenced by cultivar

Authors: Leisso, Rachel; Turner, Janet; McMurtrey, Shawn; Klarer, Emmi; EMMOMS, JADE - Former ARS Employee; Wiessner, Jacob; Wang, Kevin; Wang, Eric; Imler, Christopher

Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Relative suitability of sweet cherry cultivars for export is a stakeholder priority and stakeholders requested evaluation of fruit post-commercial packing. The use of commercially grown fruit post-commercial-packing imposed the experimental challenge that preharvest management and postharvest handling (e.g., production, picking, cooling, selection, grading, packaging) could not be uniformly set and controlled for statistically, providing a pragmatic lens into the extent of pre-harvest management and postharvest handling influence on fruit quality outcomes. In the present study, the use of fruit post-packing led to both sufficiently variable and physiologically consequential outcomes such that cultivar-specific influence for many quality attributes were below detection; of the cultivars compared (Black Pearl, Chelan, Bing, Regina, Skeena), ‘Black Pearl’ and ‘Chelan’ stored at 31 °F in modified atmosphere bags were most similar to an “ideal” sweet cherry after 4 weeks of storage (simulating export on an ocean liner). However, results indicate pre-harvest management and postharvest handling has as much influence on post-packing fruit and stem quality outcomes as cultivar.

Technical Abstract: Sweet cherries (Prunus avium) destined for travelling to export markets must retain fruit and stem quality for 2-5 weeks postharvest. This 2-year study evaluated commercially sorted and packed sweet cherry cultivars (Chelan, Black Pearl, Bing, Regina, Skeena) fruit and stem quality outcomes following 4 weeks storage at -0.6 ± 0.5 °C or 4.4 ± 0.5 °C in modified atmosphere (MA) bags. Cultivar-specific influence on physiochemical quality outcomes included pedicel fruit retention force (PFRF), fruit firmness, color, soluble solids content (SSC), and titratable acidity (TA) at 4 weeks postharvest. Comparison of quality attribute change within each lot from initial evaluation to 4 weeks indicated color and firmness changed with respect to cultivar, with ‘Skeena’ having the least change in firmness and ‘Bing’ undergoing the most darkening. Many visual attributes, including stem weight-to-length ratio (an indicator of thickness or desiccation), stem retention, fruit cracking, pitting, and pebbling, were not statistically influenced by cultivar, indicating that in a commercial setting, lot-to-lot differences in horticultural, harvest, and packing management influence stem and fruit quality outcomes as much as cultivar. Stems whose distal end was removed by packinghouses’ cluster-cutter had lower stem weight-to-length ratio than stems whose ends were not removed, indicating that this aspect of packing leads to desiccation of cut stems. Packinghouse (four in 2023, and five in 2024) did not statistically influence fruit or stem quality. Respiration rates differed among cultivars, with ‘Black Pearl’ exhibiting the lowest and ‘Regina’ the highest; overall respiration rates were higher at 4.4 °C. There were significant (p < 0.05) but weak (circa Spearman r2 =0.50) correlations between respiration rate at 1 week and 4 week fruit quality attributes: increased loss of stems, decrease in pitting and pebbling incidence, and a change in a* (red/green fruit color component derived from colorimeter instrumentation). In a multivariate analysis, ‘Black Pearl’ and ‘Chelan’ lots stored at -0.6 °C typically were closest to an “ideal” lot of sweet cherries. Understanding cultivar-specific quality attributes as well as the impact of management decisions can aid in new planting choices, strategic planning in packinghouses, and proactive treatment to mitigate quality loss.