Miccichè Daniele, de Rosas Maria Inès, Ferro Massimo Vincenzo, Di Lorenzo Rosario, Puccio Stefano, Pisciotta Antonino
Department of Agricultural, Food and Forest Sciences, University of Palermo, Palermo, Italy.
Universidad Nacional de Cuyo, Facultad de Ciencias Agrarias, Laboratorio de Fisiología Vegetal, Mendoza, Argentina.
Front Plant Sci. 2023 Sep 15;14:1210574. doi: 10.3389/fpls.2023.1210574. eCollection 2023.
The biology of the grapevine ( L.) is clearly influenced by the climatic conditions of the growing environment, where temperature and light play a major role in modifying plant physiology. In the scenario of climatic changes, radiative excess, correlated to the increase in temperature, can concretely subject the photosynthetic apparatus to a condition of light saturation and cause a drastic reduction in photochemical efficiency, giving rise to chronic photoinhibition phenomena. Undoubtedly, the ripening behavior also undergo evident alterations; the problem of sugar ripening, which is often strongly accelerated, is induced not only by high temperatures but also by the excess concentration of carbon dioxide (CO), which results in a higher ripening. In addition, high berry temperatures favor a reduction in the concentration of organic acids. The reported trends indicate that the need for urgent action is closely linked to the future environmental impacts that these changes could have on the entire wine sector. In recent years, shade treatments have been applied to the vine canopy to overcome this issue.
The objective of this study was to determine how artificial canopy shading affects the vines vegetative growth and the ripening processes of cv. Nero d'Avola during the 2019-2020 vegetative seasons. Three treatments were established: shading treatment with a green net (shade factor 27%), shading treatment with a white net (shade factor 32%), and untreated vines, thus naturally exposed to light radiation.
Artificial shading, applied at full fruit set, interfered with the microclimate of the vines, causing partial effects on the grape ripening processes. At harvest, significant differences were found between the treatments in terms of sugars, also shading treatments increased must acidity and decrease pH. Results obtained on vegetative parameters, suggest that the shading treatment delays leaf fall, with potentially positive effects on the starch accumulation on perennial reserve organs to be exploited at the following season's sprouting. Shading significantly reduced berry size, with obvious consequences on bunch weight and yield per vine. In 2020, shaded plants showed a delay in all the phenological phases. The total anthocyanins content was not changed by the shading treatment. The results obtained confirm the importance of net coverage on the microclimate of the vines, vegetative-productive activity, and grapes quality. From this point of view, the net covering technique can be a tool for controlling grapes ripening dynamics in the context of climate change.
葡萄（Vitis vinifera L.）的生物学特性明显受到生长环境气候条件的影响，其中温度和光照在改变植物生理方面起着主要作用。在气候变化的背景下，与温度升高相关的辐射过剩会使光合器官具体处于光饱和状态，并导致光化学效率急剧下降，从而引发慢性光抑制现象。毫无疑问，成熟过程也会发生明显变化；糖分成熟问题往往会被强烈加速，这不仅是由高温引起的，还由二氧化碳（CO₂）浓度过高导致，从而使成熟程度更高。此外，浆果温度高有利于有机酸浓度降低。所报道的趋势表明，迫切需要采取行动与这些变化可能对整个葡萄酒行业产生的未来环境影响密切相关。近年来，已对葡萄树冠层进行遮荫处理以克服这一问题。
本研究的目的是确定人工树冠遮荫如何影响2019 - 2020年营养生长季节黑达沃拉（cv. Nero d'Avola）葡萄藤的营养生长和成熟过程。设立了三种处理：用绿色网进行遮荫处理（遮荫系数27%）、用白色网进行遮荫处理（遮荫系数32%）以及未处理的葡萄藤，即自然暴露于光辐射下。
在坐果期进行人工遮荫会干扰葡萄藤的小气候，对葡萄成熟过程产生部分影响。收获时，各处理在糖分方面存在显著差异，遮荫处理还会增加葡萄汁酸度并降低pH值。关于营养参数的结果表明，遮荫处理会延迟落叶，对多年生储备器官上淀粉积累可能产生积极影响，这些淀粉将在下一季发芽时被利用。遮荫显著减小了浆果大小，对果穗重量和每株葡萄产量产生明显影响。在2020年，遮荫植株所有物候期均延迟。遮荫处理未改变总花青素含量。所获得的结果证实了网覆盖对葡萄藤小气候、营养生产活动和葡萄品质的重要性。从这一角度来看，网覆盖技术可以成为在气候变化背景下控制葡萄成熟动态的一种工具。
