DataSheet_1_Impact of meteorological conditions, canopy shading and leaf removal on yield, must quality, and norisoprenoid compounds content in Franciacorta sparkling wine.docx

Climate change is a major concern in agriculture; in grapevine production, climate change can affect yield and wine quality as they depend on the complex interactions between weather, plant material, and viticultural techniques. Wine characteristics are strongly influenced by microclimate of the canopy affecting primary and secondary metabolites of the grapevine. Air temperature and water availability can influence sugar and acid concentration in grapes and relative wines, and their content of volatile compounds such as norisoprenoids. This becomes relevant in sparkling wine production where grapes are generally harvested at a relatively low pH, high acidity, and low sugar content and where the norisoprenoids significantly contributes to the final aroma of the wine. The effect of climate change on grapevine and wine, therefore, calls for the implementation of on-field adaptation strategies. Among them canopy management through leaf removal and shading have been largely investigated in the wine growing sector. The present study, conducted over 4 years (2010-2013) aims at investigating how leaf removal and artificial shading strategies affect grape maturation, must quality and the production of norisoprenoids, analyzed using an untargeted approach, in sparkling wine. Specifically, this paper investigates the effect of meteorological conditions (i.e., water availability and temperatures) and the effect of leaf removal and shading on Vitis vinifera L. cv. Chardonnay and Pinot noir, which are suitable to produce sparkling wine in the DOCG Franciacorta wine growing area (Lombardy, Italy). The effect of leaf removal and shading practices on norisoprenoids has been the focus of the study. No defoliation and artificial shading treatments play an important role in the preservation of the acidity in warm seasons and this suggests calibrating defoliation activities in relation to the meteorological trend without standardized procedures. This is particularly relevant in the case of sparkling wine, where the acidity is essential to determine wine quality. The enhanced norisoprenoid aromas obtained with a total defoliation represent a further element to direct defoliation and shading strategies. The obtained results increase knowledge about the effect of different defoliation and artificial shading applications in relation to meteorological condition supporting the management decision-making in the Franciacorta wine growing area.

气候变化是农业领域的重大关切议题。在葡萄种植生产中，气候变化可通过影响葡萄产量与葡萄酒品质——二者均由气象条件、种植材料与葡萄栽培技术之间的复杂互作关系决定——对其产生作用。葡萄酒的风味特征受葡萄冠层微气候的显著调控，而冠层微气候会进一步影响葡萄的初生与次生代谢过程。气温与水分可获得性可调控葡萄果实及对应葡萄酒中的糖、酸浓度，以及其中挥发性化合物（如降异戊二烯类化合物norisoprenoids）的含量。这一点在起泡葡萄酒生产中尤为关键：该类葡萄酒的酿酒葡萄通常在较低pH值、高酸度与低糖量的状态下采收，而降异戊二烯类化合物对葡萄酒的最终香气具有显著贡献。因此，气候变化对葡萄植株与葡萄酒产业的影响，亟需落实田间适应策略。其中，通过摘叶与遮荫开展的冠层管理措施，在葡萄酒种植领域已得到广泛研究。本研究于2010至2013年间开展，为期四年，旨在探究摘叶与人工遮荫策略对起泡葡萄酒用葡萄成熟度、葡萄醪品质，以及采用非靶向分析方法检测的降异戊二烯类化合物合成的影响。具体而言，本研究针对意大利伦巴第大区弗朗恰科塔（DOCG）葡萄酒产区的酿酒葡萄展开，探究气象条件（即水分可获得性与气温）以及摘叶、遮荫措施对霞多丽（Chardonnay）与黑皮诺（Pinot noir）这两种适配起泡葡萄酒生产的葡萄品种的影响。本研究的核心聚焦于摘叶与遮荫措施对降异戊二烯类化合物的影响。不实施摘叶与人工遮荫的处理措施，在暖季对葡萄醪酸度的保留具有重要作用；这表明需结合气象趋势调整摘叶作业的实施节奏，而不应采用统一标准化流程。这一点对于起泡葡萄酒而言尤为关键，因为酸度是决定其品质的核心要素。全摘叶处理所提升的降异戊二烯类香气，可为摘叶与遮荫策略的制定提供额外参考依据。本研究所得结果可深化对不同摘叶与人工遮荫措施在对应气象条件下的作用效果的认知，为弗朗恰科塔葡萄酒产区的葡萄园管理决策提供有力支撑。