Effects of foliar calcium applications and maturity stage on ‘Lemonato’ peach fruit quality and bruising severity

Abstract

‘Lemonato’ peach is a traditional Greek series of clones particularly valued by the consumers because of its high fruit quality, flavor and aroma. The main problem of ‘Lemonato’ peach is flesh softening during ripening and the susceptibility of ripe fruit to bruising. Our hypothesis was that harvesting the fruit earlier than its commercial maturity could reduce fruit quality losses during postharvest handling. Secondly, innovative Ca formulations could reduce bruising incidence by strengthening cell walls and reducing flesh softening. In this work, two clones of ‘Lemonato’ peach (a mid-season ‘Andrea’ and a late-season ‘Mytera’) were used in order to study the effects of maturity stage, such as early harvest (EH) and commercial maturity (CM) on fruit quality. Moreover, the influence of foliar Ca applications on fruit quality with two formulations containing calcium-silicate in nanoparticles (CaSi) and organic Ca (OrCa) were also tested. Estimated fruit quality parameters included total phenols content (TPC), total antioxidant activity (TAA), and bruising severity. Compared to ‘Andrea’ clone, ‘Mytera’ fruit had better quality traits, higher TPC and TAA in both maturity stages, whereas at EH it had fruit mass similar to ‘Andrea’ and higher browning index (BI) fruit because of differences in tree fruit load. In all treatments and clones, CM fruit improved organoleptic characteristics compared to EH fruit. ‘Andreas’ fruit harvested at CM had higher fruit mass and significantly softer flesh than EH fruit without any effect from Ca applications. ‘Mytera’ fruit at CM had higher TPC and TAA than EH fruit in all treatments. Flesh browning caused by mechanical bruising increased with time mainly during the first 10 min after bruising in all treatments and maturity stages of both clones. Ca-treated fruit had slightly increased TPC and TAA, except of CM OrCa ‘Mytera’ fruit, which had lower quality parameters compared to control. Hovewer, this was not associated with BI. In both ‘Lemonato’ clones, Ca applications did not improve flesh firmness and BI at any maturity stage. © 2021 International Society for Horticultural Science. All rights reserved.