Anthropogenic intervention in shaping Terroir in a California Pinot noir vineyard

Abstract

In many vineyards optimal parcel size exceeds the geospatial complexity that exists in soils and topographic features that influence hydrological properties, sunlight interception and soil depth and texture (available water capacity). A premise of precision management is that such variation can be lessened, but the practices that would be used to achieve this have not been subjected to rigorous scientific evaluation. During 2004-2006 we examined spatial heterogeneity of soils and topographical features and related them to yield, industrial quality (soluble solids content, titratable acidity and pH), vine water status (predawn, ψPD, and midday, ψL, leaf water potential) and vigor (pruning weights), in an extremely complex hillside vineyard that had undergone terraforming as a means of increasing planted hectares and diminishing soils variation. Factor analysis was used to identify latent variables used in a multiple linear regression model with least squares estimation to identify correlations among soil and topographic factors, vine physiology and industrial quality parameters. Our results indicated that overall vine water status (ψPD and ψL) had the largest influence on within vineyard variation on an interannual basis, and that extreme spatial heterogeneity was evident in this vineyard in spite of terraforming efforts.

DOI:

Publication date: December 8, 2021

Issue: Terroir 2008

Type : Article

Authors

David R. SMART (1), Alison BREAZEALE (1), Joshua VIERS (2), Dr. Richard PLANT (3)

(1) Department of Viticulture & Enology, University of California, One Shields Avenue, Davis CA 95616
(2) Department of Environmental Science & Policy, University of California, One Shields Avenue Davis CA 95616
(3) Department of Plant Sciences, University of California, One Shields Avenue, Davis CA 95616

Contact the author

Keywords

Complex slopes, ripening uniformity, precision viticulture, water potential, terraforming

Tags

IVES Conference Series | Terroir 2008

Citation

Related articles…

La zonazione della Franciacorta: il modello viticolo della DOCG

La Franciacorta è una piccola regione collinare della provincia di Brescia. Il territorio è molto eterogeneo sia dal punto di vista geologico, che geomorfologico e pedologico. Circa 1.000 ettari sono destinati alla produzione di uve Chardonnay, Pinot bianco e Pinot nero per il vino Franciacorta ottenuto unicamente utilizzando la lunga fermentazione naturale in bottiglia.

Understanding the expression of gene families involved in anthocyanin biosynthesis during berry ripening: Tannat as a case study

The quality of wine is assessed, among other things, by its color, which is mainly due to its anthocyanin content. These pigments are polyphenols that give red, purple and blue hues depending on the relative proportion of anthocyanins produced by the action of flavonoid 3’5′ hydroxylase (delphinidin-3-glucoside, petunidin-3-glucoside, malvidin-3-glucoside) or flavonoid 3′ hydroxylase (cyanidin-3-glucoside, peonidin-3-glucoside). To study the genes involved in this biosynthetic pathway, we focused on Vitis vinifera cv. Tannat, known for producing wines with higher anthocyanin content and darker purple color compared to most red grape varieties. In this work, we have performed RNA-Seq analysis of skins during berry development, taking green and red berries at 50% veraison as separate samples, as an experimental strategy to focus on the differential expression of genes of interest.

Using ΔC13 to assess viticultural and oenological suitability for Sangiovese of different pedoclimatic conditions in Chianti

A two years trial was carried out in Chianti (Central Italy) to assess at the detailed scale the viticultural and oenological suitability for Sangiovese of different pedoclimatic conditions, by means of the ΔC13 measured in the must sugars

Soil quality in Beaujolais vineyard. Importance of pedology and cultural practices

A pedological study was carried out from 2009 to 2017 in Beaujolais vineyard, to improve physical and chemical knowledge of soils. It was completed in 2016 and 2017 by the current study, dealing with microbial aspects, in order to build a reference frame for improved advice in soil management. Microbial biomass was measured on representative plots of the six most common soil types identified in Beaujolais and, for each soil type, on plots with different levels of the main impacting parameters: total organic carbon, pH, cation exchange capacity, extractable copper. A total of 59 soil samples were collected. Confirming the results of various trials carried out in Beaujolais over the past 20 years, the results of the present study showed that the soils were still alive, but exhibited a large variability of biological parameters, which appeared dependant on both pedological and anthropic factors. Therefore, a good interpretation of biological parameters and advice for vine growers must rely on a pedologically-based referential with differentiated main driving factors. For example, the control of pH is of primary importance in granitic soils and in no way organic matter addition can improve soil quality if pH is too low. Conversely, in calcareous soils, biological parameters are more directly affected by direct or indirect (cover crops for example) inputs of organic matter. The use of biological parameters, such as microbial biomass, is of great potential value to improve advice on agro-viticultural practices (soil management, fertilization, liming, etc.), basis of a sustainable wine production on fragile soils.

Grapevine xylem embolism resistance spectrum reveals which varieties have a lower mortality risk in a future dry climate

Wine growing regions have recently faced intense and frequent droughts that have led to substantial economical losses, and the maintenance of grapevine productivity under warmer and drier climate will rely notably on planting drought-resistant cultivars. Given that plant growth and yield depend on water transport efficiency and maintenance of photosynthesis, thus on the preservation of the vascular system integrity during drought, a better understanding of drought-related hydraulic traits that have a significant impact on physiological processes is urgently needed. We have worked towards this end by assessing vulnerability to xylem embolism in 30 grapevine commercial varieties encompassing red and white Vitis vinifera varieties, hybrid varieties characterized by a polygenic resistance for powdery and downy mildew, and commonly used rootstocks. These analyses further allowed a global assessment of wine regions with respect to their varietal diversity and resulting vulnerability to stem embolism. Hybrid cultivars displayed the highest vulnerability to embolism, while rootstocks showed the greatest resistance. Significant variability also arose among Vitis vinifera varieties, with Ψ12 and Ψ50 values ranging from -0.4 to -2.7 MPa and from -1.8 to -3.4 MPa, respectively. Cabernet franc, Chardonnay and Ugni blanc featured among the most vulnerable varieties while Pinot noir, Merlot and Cabernet Sauvignon ranked among the most resistant. In consequence, wine regions bearing a significant proportion of vulnerable varieties, such as Poitou-Charentes, France and Marlborough, New Zealand, turned out to be at greater risk under drought. These results highlight that grapevine varieties may not respond equally to warmer and drier conditions, outlining the importance to consider hydraulic traits associated with plant drought tolerance into breeding programmes and modeling simulations of grapevine yield maintenance under severe drought. They finally represent a step forward to advise the wine industry about which varieties and regions would have the lowest risk of drought-induced mortality under climate change.