Terroir 2004 banner
IVES 9 IVES Conference Series 9 Canopy photosynthetic activity and water relations of Syrah/R99 as affected by row orientation on a particular terroir

Canopy photosynthetic activity and water relations of Syrah/R99 as affected by row orientation on a particular terroir

Abstract

[English version below]

L’activité photosynthétique et les relations hydriques de plantes de Syrah sur R99 un mois après la véraison ont été étudiées dans un vignoble de la région de Stellenbosch. Le vignoble, planté à 2,75 entre rangs et 1,5 m sur le rang, sur un sol de type Glenrosa, était en pente et exposé a l’ouest: pour les rangs on avait adopté une orientation nord –sud. Les plantes, conduites selon un système de type en cordon de Royat, avaient donc un port ascendant de la végétation, palissée dans un plan vertical à l’aide de trois paires de fils. Une irrigation à micro-jets était appliquée dans la phase comprise entre la nouaison et la fermeture de la grappe et à la véraison. Le tronc était ébourgeonné et la végétation rognée à 1,4 m de hauteur. On a mesuré la photosynthèse et le potentiel hydrique de feuilles en position basale, médiane et apicale soit des bourgeons principaux, soit des entre-cœurs. On a considéré des entre-cœurs en position apicale, médiane et basale le long du bourgeon principal. Soit le matin, soit l’après-midi on a examiné le coté est et le coté ouest du rang.. On a comparé la photosynthèse et le potentiel hydrique de feuilles situées à l’extérieur ou à l’intérieur de la végétation: on a considéré séparément les feuilles apicales, médianes et basales des bourgeons principaux et les feuilles médianes des bourgeons anticipés, situés en position apicale, médiane et basale.
Le nombre de couches du feuillage augmente typiquement du sommet à la base de la végétation et la pénétration de la lumière baisse en proportion. Sur les bourgeons principaux l’activité photosynthétique de toutes les feuilles était plus élevée le matin que l’après midi, soit pour la face au soleil soit pour celle à l’ombre. La photosynthèse des feuilles exposées directement au soleil diminuait du sommet vers la zone basale. Sur le côté à l’ombre la photosynthèse des feuilles médianes était plus limitée en comparaison aux feuilles apicales et basales. L’activité photosynthétique de la plante entière était donc plus importante le matin que pendant l’après-midi. Le potentiel hydrique des feuilles exposées au soleil était beaucoup plus bas que celui des feuilles ombragées. Même si on s’attendait un potentiel hydrique inférieur pour le côté ensoleillé, les différences n’ont pas été en ligne avec les différences importantes trouvées pour l’activité photosynthétique. Le côté ensoleillé du rang avait un potentiel hydrique légèrement plus bas le matin que l’après midi. Les bourgeons secondaires de la zone basale sur le coté exposé au soleil avaient une activité phothosynthétique plus élevée le matin par rapport à l’après midi, tandis que pour les bourgeons secondaires en position apicale et médiane l’activité était à peu prés la même pendant toute la journée. Dans le cas des bourgeons secondaires l’activité photosynthétique des feuilles exposées par rapport aux feuilles ombragées et leur potentiel hydrique suivaient un comportement (matin contre après midi et côté soleil contre côté ombragé) analogues à celui des feuilles des bourgeons principaux.
Si l’on compare l’activité photosynthétique et le potentiel hydrique des feuilles externes et internes du couvert en position différente on trouve le même modèle de comportement pour les deux types de bourgeons que l’on avait observé pour le côté exposé ou non exposé du couvert. Pendant la matinée des grandes différences se produisaient entre les feuilles internes et externes de la végétation sur la face ensoleillée du rang, tandis que, si l’on prend ces mesures du côté ombragé, les valeurs de toutes les feuilles sont pareilles à celles des feuilles internes du côté ensoleillé.
Ces résultats fournissent des indications sur les performances photosynthétiques et sur les relations hydriques que l’on peut s’attendre, en rapport à un terroir particulier, si l’on choisit une orientation donnée des rangs.

The photosynthetic activity and water relations of a Syrah/R99 vineyard, situated in the Stellenbosch region, were investigated approximately one month after véraison. Vines were vertically trained, spur pruned, and spaced 2.75 x 1.5 m in North-South orientated rows on a terroir with Glenrosa soil and a West-facing slope. Microsprinkler-irrigation was applied at pea berry size and at véraison stages. The 1.4 m high canopies were suckered, shoot-positioned and topped and accommodated by means of three sets of double wires. Photosynthetic activity and water potential were measured on leaves in apical, middle and basal positions on both primary and secondary shoots. Lateral shoots in apical, middle and basal positions were measured. Both East and West sides of the canopy were measured in the morning and in the afternoon. In addition, photosynthesis and water potential of interior and exterior leaves on primary (apical, middle and basal leaves) and secondary (middle leaves in apical, middle and basal positions) shoots were compared.
The canopy typically increased in number of leaf layers from top to bottom. Light penetration decreased in tandem. On primary shoots, photosynthetic activity of leaves on sunny and shaded sides of the canopy was higher in the morning than in the afternoon. Photosynthesis of sun-exposed leaves decreased from the apical to basal position. On the shaded part of the canopy, photosynthesis of middle leaves was reduced compared to apical and basal leaves. The photosynthetic activity of the canopy was therefore higher in the morning than in the afternoon. Water potential of leaves on the sunny side of the canopy was also consistently lower than that of leaves on the shaded side. Although the sunny side is expected to display lower water potential, the differences were, however, not in line with the large differences found for photosynthetic activity. The sun-exposed side of the canopy had slightly lower water potential in the morning than in the afternoon.
Basally positioned secondary shoots on the sunny side of the canopy had higher photosynthetic activity in the morning than in the afternoon; that of secondary shoots in apical and middle positions was, however, similar in the morning than in the afternoon. Photosynthetic patterns of leaves on the sunny side of the canopy versus the shaded side of the canopy were similar to those on the primary shoot. Water potential patterns of leaves on secondary shoots (morning versus afternoon and sunny side versus shaded side) were similar to those of leaves on primary shoots.

Comparing the photosynthetic activity and water potential of exterior and interior leaves in different positions on either primary or secondary shoots, similar patterns than those found for sunny and shaded sides of the canopy occurred. In the morning, large differences between the exterior and interior leaves occurred when measured from the sunny side. However, when measured from the shaded side, values were similar to those of interior leaves measured from the sunny side and no marked differences between exterior and interior leaves were found.
The results are useful for application to terroirs forcing different row orientations. It provides an indication of the photosynthetic performance and water relations that can be expected with a particular row orientation.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

V. Novello (1) and J.J. Hunter (2)

(1) Dipartimento di Colture Arboree, University of Turin, Via Leonardo da Vinci 44, I-10095 Grugliasco (TO), Italy
(2) ARC Infruitec-Nietvoorbij, Private Bag X5026, 7599 Stellenbosch, South Africa

Contact the author

Keywords

Terroir, row orientation, vegetative growth, reproductive growth, water relations, photosynthesis

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

The modification of cultural practices in grapevine cv. Syrah, does it modify the characteristics of the musts?

The work shows the results of a year of experimentation (2020) in a Syrah variety vineyard in La Roda (Castilla-La Mancha, Spain). The trial approach was on a randomized block design with two factors: Irrigation (I) and Pruning (P).
Irrigation schedules were adjusted to apply amounts close to 1,500 m3/ha. With this provision, 2 different irrigation treatments were proposed: I1) Start of irrigation from pea-sized grape to post-harvest (providing at least 20 % of the total amount of irrigation water to be provided post-harvest); I2) Start of irrigation from pea-sized grape to harvest (usual irrigation practice in the study area). Pruning was proposed with two treatments, one at the end of January (P1), which is pruning on a conventional date; and P2) pruning carried out at the beginning of budding. In total, 4 repetitions were designed with 4 elementary plots, each one of them representing one of the proposed treatments (I1P1; I1P2; I2P1; I2P2). In total, 16 plots were worked on and each elementary plot consisted of 30 strains, distributed in 3 lines.
The productive response was evaluated with the yield results of the harvest harvested at 23 ºBrix. The qualitative response was measured in the musts through the indices of technological (acidity, pH and potassium) and phenolic maturity and aromatic compounds in free and glycosylated fractions. The treatments tested had, in general, an effect on the different variables analyzed.

20-Year-Old data set: scion x rootstock x climate, relationships. Effects on phenology and sugar dynamics

Global warming is one of the biggest environmental, social, and economic threats. In the Douro Valley, change to the climate are expected in the coming years, namely an increase in average temperature and a decrease in annual precipitation. Since vine cultivation is extremely vulnerable and influenced by the climate, these changes are likely to have negative effects on the production and quality of wine.
Adaptation is a major challenge facing the viticulture sector where the choice of plant material plays an important role, particularly the rootstock as it is a driver for adaptation with a wide range of effects, the most important being phylloxera, nematode and salt, tolerance to drought and a complex set of interactions in the grafted plant.
In an experimental vineyard, established in the Douro Region in 1997, with four randomized blocs, with five varieties, Touriga Nacional, Tinta Barroca, Touriga Franca and Tinta Roriz, grafted in four rootstocks, Rupestris du Lot, R110, 196-17C, R99 and 1103P, data was collected consecutively over 20 years (2001-2020). Phenological observations were made two to three times a week, following established criteria, to determine the average dates of budbreak, flowering and veraison. During maturation, weekly berry samples were taken to study the dynamics of sugar accumulation, amongst other parameters. Climate data was collected from a weather station located near the vineyard parcel, with data classified through several climatic indices.
The results achieved show a very low coefficient of variations in the average date of the phenophases and an important contribution from the rootstock in the dynamic of the phenology, allowing a delay in the cycle of up to10-12 days for the different combinations. The Principal Component Analysis performed, evaluating trends in the physical-chemical parameters, highlighted the effect of the climate and rootstock on fruit quality by grape varieties.

The combined effects of climate, soils, and deficit irrigation on yield and quality of Touriga Nacional under high atmospheric demand in the Douro Region

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

From a local to an international scale: sensory benchmarking of PDO wines. Quincy and Reuilly PDO wines (Sauvignon blanc) as a case study (France)

In a collective marketing strategy, the Protected Designation of Origin (PDO) can be used as a quality indicator. To highlight terroir specificities, it is useful to know how the wines are positioned on the local, national or international market from a sensory point of view. This is especially true for a comparison of varietal wines (e.g. Sauvignon blanc). We focus on the case of two closed Loire Valley PDO (France): Quincy and Reuilly. Three distinct tastings were organized. Firstly, at the local level comparing the 2 PDO (11 and 9 wines, 17 professional assessors); secondly at a regional level adding 3 closed PDO: Menetou-Salon, Sancerre and Pouilly-Fumé (3 wines per PDO, 16 assessors) and thirdly at an international level comparing these 5 PDO with Sauvignon Blanc wines coming from South Africa, New Zealand and Chile (1 to 3 wines per PDO, 19 assessors). All the wines were from the 2019 vintage and were considered to have a traditional elaboration process without contact with oak. A sensory descriptive analysis was performed using an aroma wheel allowing to combine a Check-All-That-Apply methodology, often used in sensory benchmarking, with a hierarchical structuration of the attributes. The aim is to facilitate data acquisition in a professional context without common training, to consider the hierarchical relationships among the attributes during the data analysis and to be able to characterize wines with a large range of sensorial variability. We use univariate, multivariate and clustering analyses. Similarities and differences between Quincy and Reuilly PDO wines and other Sauvignon blanc wines were identified. Specific attributes can distinguish the two PDO and different proximities exist with other local PDO, while clear differences were observed compared to international wines. Our study contributes to propose and discuss a method to do a wine sensory benchmarking highlighting sensory specificities linked to origin.

Elevational range shifts of mountain vineyards: Recent dynamics in response to a warming climate

Increasing temperatures worldwide are expected to cause a change in spatial distribution of plant species along elevational gradients and there are already observable shifts to higher elevations as a consequence of climate change for many species. Not only naturally growing plants, but also agricultural cultivations are subject to the effects of climate change, as the type of cultivation and the economic viability depends largely on the prevailing climatic conditions. A shift to higher elevations therefore represents a viable adaptation strategy to climate change, as higher elevations are characterized by lower temperatures. This is especially important in the case of viticulture because a certain wine-style can only be achieved under very specific climatic conditions. Although there are several studies investigating climatic suitability within winegrowing regions or longitudinal shifts of winegrowing areas, little is known about how fast vineyards move to higher elevations, which may represent a viable strategy for winegrowers to maintain growing conditions and thus wine-style, despite the effects of climate change. We therefore investigated the change in the spatial distribution of vineyards along an elevational gradient over the past 20 years in the mountainous wine-growing region of Alto Adige (Italy). A dataset containing information about location and planting year of more than 26000 vineyard parcels and 30 varieties was used to perform this analysis. Preliminary results suggest that there has been a shift to higher elevations for vineyards in general (from formerly 700m to currently 850 m a.s.l., with extreme sites reaching 1200 m a.s.l.), but also that this development has not been uniform across different varieties and products (i.e. vitis vinifera vs hybrid varieties and still vssparkling wines). This is important for climate change adaptation as well as for rural development. Mountain areas, especially at mid to high elevations, are often characterized by severe land abandonment which can be avoided to some degree if economically viable and sustainable land management strategies are available.