Terroir 2008 banner
IVES 9 IVES Conference Series 9 International Terroir Conferences 9 Terroir 2008 9 Climate component of terroir 9 The estimation of the clear-sky effective PAR resources in a mountain area

The estimation of the clear-sky effective PAR resources in a mountain area

Abstract

When evaluating the actual photosynthetically active radiation – PAR – resources available to plants the simple measurement or estimation of its total amount can lead to misleading interpretations, due to the frequent occurrence of radiation intensity above the light saturation threshold. In this case, besides the quantity of radiation, the use of other variables providing information on the temporal distribution of the resource (i. e. the insolation time) may be advisable. This work is an exploratory analysis of the effect of topography on the availability of PAR in an alpine viticultural region, the Aosta Valley, by the adoption of an index based on the summation over a given time period (in this specific case a day) of only the fraction of radiation effective for photosynthesis. Assuming clear-sky conditions, the resulting estimated maps widely differ from those of the total PAR, indicating spatial patterns closer to those of insolation time. The estimated ratios of “effective” to total PAR, assuming fully functional physiological conditions and fully developed canopies, vary from about 0.5 to 0.7 in the summer and from about 0.7 to 1 during the final ripening period; these values may be even lower in stress conditions.

DOI:

Publication date: December 8, 2021

Issue: Terroir 2008

Type: Article

Authors

O. Zecca (1), L. Mariani (2), O. Failla (2)

(1) Institut Agricole Régional, Rég. La Rochère, 1/A 11100 Aosta, Italy
(2) Dipartimento di Produzione Vegetale, Università degli Studi, via Celoria, 2, 20133 Milano, Italy

Contact the author

Keywords

solar radiation, PAR, climate data, viticultural zoning 

Tags

IVES Conference Series | Terroir 2008

Citation

Related articles…

Effect of mixed Torulaspora delbrueckii-Saccharomyces cerevisiae culture on rose quality wine

Alcoholic fermentation using no Saccharomyces wine is an effective means of modulating wine aroma. This study investigated the impact of coinoculating Torulaspora delbruecki with two Saccharomyces cerevisiae commercial yeast (QA23, Lallemand; Red Fruit, Sepsa-Enartis) on enological quality parameters, volatile composition and sensory analysis. The following assays were performed on Tempranillo variety: Saccharomyces QA23 (CTQA), Saccharomyces Red Fruit (CTRF), coinoculated T. delbrueckii + S.cerevisiae QA23 (CIQA) and coinoculated T. delbrueckii + S.cerevisiae (CIRF).

A combination of biotechnology tools and coopers elements for an alternative the addition of SO2 at the end of the malolactic fermentation in red wines or at the “mutage” for the “liquoreux” wines

In red wines the post-MLF SO2 addition is an essential event. It is also the case for the “mutage” during the elaboration of the “liquoreux”. At these moments SO2 plays an antimicrobial action and an antioxidant effect. But at current pH of wines, ensuring a powerful molecular SO2 has become very difficult. Recent work on Brettanomyces strains have also shown that some strains are resistant up to 1.2 mg / L of molecular SO2. It’s also the case of the some Saccharomuces or Zygosaccharomyces strains suitable to re-ferment “liquoreux” wines after the “mutage”.

Spatial variability of grape berry maturation program at the molecular level 

The application of sensors in viticulture is a fast and efficient method to monitor grapevine vegetative, yield and quality parameters and determine their spatial intra-vineyard variability. Molecular analysis at the gene expression level can further contribute to the understanding of the observed variability by elucidating how pathways responsible for different grape quality traits behave in zones diverging for one or the other parameter. The intra-vineyard variability of a Cabernet Sauvignon vineyard was evaluated by a standard Normalized Difference Vegetation Index (NDVI) mapping approach, employing UAV platform, accompanied by detailed ground-truthing (e.g. vegetative, yield, and berry ripening compositional parameters) that was applied in 14 spots in the vineyard. Berries from different spots were additionally investigated by microarray gene expression analysis, performed at five time points from fruit set to full ripening.

The challenge of quality in sulphur dioxide free wines: natural polyphenol alternatives

Sulphur dioxide (SO2) seems indispensable in winemaking because of its properties. However, a current increasing concern about its allergies effects in food product has addressed the international research efforts on its replacement. This supposes a sufficient knowledge of its properties and conditions of use. Several studies compared SO2 properties against new alternatives that are supposed to overcome SO2 disadvantages. Firstly, the state of art on SO2 wine replacements is revised, and secondly, the last promising results using natural enriched polyphenol extracts are shown.

Ceramic imprint in wine: influence of hydraulic ratio on ceramic dissolution and wine pH in amphorae systems

This interaction is primarily due to an acidic attack on the ceramic by the wine. It results in (1) the dissolution of the ceramic into the wine and the release of a wide variety of elements; and (2) an increase of the wine pH. The extent of these effects depends on the mineralogical and chemical composition of the ceramic, as well as the hydraulic ratio of the ceramic-wine system (the term hydraulic ratio (ρ) defines here the volume of wine over the surface area of the ceramic in contact with the wine).