Phenology, thermal demand, and maturation development of the ‘BRS Vitória’ grape cultivated on different rootstocks in subtropical conditions

Abstract The purpose of this study was to assess how ‘IAC 572’, ‘IAC 766’, and ‘Paulsen 1103’ rootstocks affected the duration of phenological phases, thermal demand, and chemical evolution throughout production cycle of the ‘BRS Vitória’ table grape cultivated in subtropical conditions. The duration of the following phenological stages was measured in days after pruning throughout two production seasons: budburst, flowering, setting, veraison, and harvest date. The thermal demand was determined using the degree-day concept. Titratable acidity, pH, soluble solids, and the maturation index were all measured throughout berry maturation. In general, the rootstocks ‘IAC 572’ and ‘IAC 766’ increased vine precocity in comparison to ‘Paulsen 1103’ during the early phenological phases. However, the vines grafted on ‘Paulsen 1103’ were earlier in the later phases, that is, at the veraison and at the harvest date, when compared to those grafted on the rootstocks ‘IAC 572’ and ‘IAC 766’. Under subtropical conditions, the total cycle period of the ‘BRS Vitória’ vine varied from 131 to 143 days, with thermal demands ranging from 1,545 to 1,725 DD. In comparison to the ‘IAC 572’ and the ‘IAC 766’, the ‘Paulsen 1103’ supplied the berries with a higher accumulation of soluble solids and a higher maturation index.

摘要 本研究旨在评估‘IAC 572’、‘IAC 766’与‘Paulsen 1103’三种砧木（rootstocks）对亚热带栽培条件下‘BRS Vitória’鲜食葡萄（table grape）全生产周期内的物候期（phenological phases）时长、需热量（thermal demand）及化学成分变化的影响。本研究在两个生产季中，以修剪后天数为计量尺度，测定了萌芽期（budburst）、开花期（flowering）、坐果期（setting）、转色期（veraison）及采收期（harvest date）等物候阶段的持续时长。需热量通过度日（degree-day）概念进行计算。在浆果成熟阶段，测定了可滴定酸度（titratable acidity）、pH值、可溶性固形物（soluble solids）含量及成熟指数（maturation index）四项指标。总体而言，相较于‘Paulsen 1103’砧木，‘IAC 572’与‘IAC 766’砧木可提升葡萄植株在早期物候阶段的早熟性。然而，与嫁接‘IAC 572’和‘IAC 766’砧木的植株相比，嫁接‘Paulsen 1103’砧木的植株在后期物候阶段——即转色期与采收期——表现出更早的成熟进程。在亚热带栽培条件下，‘BRS Vitória’葡萄的全生育周期时长为131至143天，需热量区间为1545至1725度日（DD）。相较于‘IAC 572’与‘IAC 766’砧木，‘Paulsen 1103’砧木可使浆果积累更多可溶性固形物，同时拥有更高的成熟指数。