Trunk Girdling Increased Stomatal Conductance in Cabernet Sauvignon Grapevines, Reduced Glutamine, and Increased Malvidin-3-Glucoside and Quercetin-3-Glucoside Concentrations in Skins and Pulp at Harvest

Abstract

Girdling is a traditional horticultural practice applied at fruit set or other phenological stages, and is used mostly as a vine management. In grapevines, it is used primarily for table grapes to improve berry weight, sugar content, color, and to promote early harvest. The objective of this study was to evaluate the effect of trunk girdling applied at veraison, in 'Cabernet Sauvignon' wine grapes (Vitis vinifera L.), on agronomical and physiological parameters during vine development from the onset of ripening (veraison) to harvest, and additionally to quantify the effect of girdling on primary and secondary metabolism. Girdling was applied 146 days after pruning (dap) at veraison, when berry sampling for metabolomics and agronomical evaluations commenced, with a further three sampling dates until harvest, at 156 dap (30% maturation, 10 days after girdling-dag), 181 dap (70% maturation, 35 dag), and 223 dap (commercial harvest, 77 dag). Skin/pulp and seed tissues were extracted separately and metabolomics was performed using one-dimensional proton nuclear magnetic resonance (1D 1 H NMR) spectroscopy and high performance liquid chromatography (HPLC-DAD). At harvest, girdling significantly increased stomatal conductance (g s ) in vines, decreased glutamine concentrations, and increased anthocyanin and flavonol concentrations in the skin/pulp tissues of grape berries. Berry weight was reduced by 27% from 181 dap to harvest, and was significantly higher in grapes from girdled vines at 181 dap. Sugars, organic acids, and other amino acids in skin/pulp or seeds were not significantly different, possibly due to extra-fascicular phloem vessels transporting metabolites from leaves

Effect of Time of Girdling on Leaf Photosynthetic Performance and Kiwifruit Quality Characteristics at Harvest and Post-Storage

“…This disruption redistributes the 2 of 16 flow of assimilates, such as carbohydrates, and acropetally-produced compounds, such as auxins, towards the roots, leading to carbohydrate accumulation above the girdle zone [12] and provoking changes in mineral partitioning [12]. Furthermore, it can affect stomatal conductance [13], decrease leaf photosynthesis [14], and alter primary or secondary metabolism [13].…”

Molecular and physiologic mechanisms of advanced ripening by trunk girdling at early veraison of ‘Summer Black’ grape

“…Trunk girdling is a traditional horticulture practice for regulating the growth and development of fruit trees ( Binkley et al., 2006 ). Girdling has been shown to control vegetative growth, promote blooming and fruit development, increase fruit yield, and improve fruit quality and is widely applied in the cultivation of fruit trees such as apple, citrus, sweet cherry, and grape ( Rivas et al., 2006 ; Michailidis et al., 2020 ; Pereira et al., 2020 ; Matsumoto et al., 2021 ; Ülker and Kamiloğlu, 2021 ).…”