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…

Analysis of climatic changes in different areas of Abruzzo region (Central Italy): implications for grape growing

The dynamic evolution of some bioclimatic indices largely used to define the vocation of areas to grape growing was assessed over 43 years (1965-2007) in four sites of the Abruzzo Region (Central Italy).

Cover crop management and termination timing have different effects on the maturation and water potentials of Glera (Vitis vinifera L.) in Friuli-Venezia Giulia

Inter-row soil tillage in vineyards, stimulates vigor and production due to the absence of competition for water and nutrients, however negatively affects organic matter content, soil erosion, and compaction, resulting in reduced fertility. In this study, we investigated the effects of different cover crop management approaches, including cultivation type and termination timing, on the physiological and productive responses of a Glera vineyard.
The experimental trial was conducted in Precenicco (UD) from 2019 to 2021. A commercial mixture for autumn cover cropping was sown in alternating rows, and the sowing pattern was changed each year.

Phenological stage dependency of Cabernet Sauvignon and Grenache response to water and nutrient limitation 

As the frequency and intensity of drought events increase, understanding the mechanisms of plant resilience to water deficit is crucial. To maintain an appropriate plant yield, a common practice is the application of high amounts of fertilizers with negative environmental impacts. The single and combined effect of water deficit and nutrient availability, namely nitrogen (N) and potassium (K), in Vitis Vinifera L. cv. Cabernet Sauvignon and Grenache was evaluated. Two-year-old grapevine plants grafted on SO4 rootstock were transferred in pots under semi-environmental conditions. During the growing season, plants were either maintained well-watered (100% ETc) or subjected to a controlled water deficit irrigation (33% ETc).

When organic chemistry contributes to the understanding of metabolism mechanisms

Many compounds of interest in wine are difficult to analyze since they are present in very small quantities or they are unstable. The need for reliable data led scientists to develop complex method in order to overcome the analytical difficulties and provide accurate quantitative data for grape or wine characterization.

HPLC-based quantification of elemental sulfur in grape juice

Elemental sulfur is commonly used in vineyards as a fungicide to prevent diseases and protect grapevines.1 The challenges of climate change are intensifying disease pressure, further increasing the reliance on sulfur use. Understanding the range of potential impacts of residual sulfur during the winemaking process is becoming increasingly important.