Pre-Harvest Foliar Applications of Calcium Chloride and Glycine Betaine Reduce Stem Bowl Cracking and Enhance the Cuticle in ‘Picnic’ Apples

• Published in: Weon'ye gwahag gi'sulji Vol. 43; no. 4; pp. 435 - 447
• Main Authors: Kim, Hong Kyoo, Kwon, Jung-Geun, Win, Nay Myo, Yoo, Jingi, Kim, Kyoungook, Han, A Reum, Kim, Dae Hyun, Kim, Seonae, Kang, In-Kyu
• Format: Journal Article
• Language: English
• Published: 한국원예학회 31.08.2025
• Subjects: 농학
• ISSN: 1226-8763; 2465-8588
• DOI: 10.7235/HORT.20250039

Stem bowl cracking in apples can significantly reduce fruit quality and market value. Therefore, this study evaluated the efficacy of pre-harvest foliar applications of calcium chloride (CaCl2), glycine betaine (GB), and water (control) in reducing stem bowl cracking, enhancing fruit quality, and improving the cuticle of ‘Picnic’ apples at harvest and during 3 months of cold storage at 0°C. Both CaCl2 and GB treatments significantly reduced the incidence and severity of stem bowl cracking at harvest compared to the control, with GB exhibiting greater effectiveness. Foliar applications also enhanced the morphological characteristics (area, weight, and thickness) of the fruit cuticle. Furthermore, pre-harvest treatments did not affect fruit quality parameters, such as fruit weight, size, firmness, titratable acidity (TA), internal ethylene concentration (IEC), and starch pattern index (SPI) at harvest, apart from an increase in soluble solids content (SSC). During cold storage, CaCl2 and GB treatments did not affect IEC, firmness, or SPI but slowed the rate of TA loss and moderated changes in fruit color, including an increase in a* and a decrease in L*, particularly on the sun-exposed side of the fruit. Additionally, the GB-treated group exhibited higher SSC during storage compared to other groups. Overall, this study demonstrates that pre-harvest foliar applications of CaCl2 and GB effectively mitigate stem bowl cracking in ‘Picnic’ apples by enhancing the cuticle’s structure and composition. However, their influence on overall fruit quality at harvest and during postharvest storage is relatively limited. KCI Citation Count: 0