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…

Vitis vinifera Manseng noir is an alternative red variety for low alcohol wines of strong structure and soft tannins

In 2019, we have planted the red variety Manseng Noir, as it has been shown that it is the only sister of the Tannat grape. Tannat was introduced to Uruguay in 1870 from the south-western regions of France.

La zonazione in due zone viticole dell’emilia Romagna

Entre 1988 et 1995, dans la région Emilia-Romagna, deux zonages viticoles ont été complétés en zones assez differentes, soit géographiquement, soit par les conditions pedo-climatiques, soit par l’encépagement.

Significance of factors making Riesling an iconic grape variety

Riesling is the iconic grape variety of Germany and accounts for 23% of the German viticulture acreage, which comprises 45% of the worldwide Riesling plantings. Riesling wines offer a wide array of styles from crisp sparkling wines to highly concentrated and sweet Trockenbeerenauslese or Icewines. However, its thin berry skin makes Riesling more vulnerable to detrimental environmental threats than other white wine varieties.  

Cover crops sown in the inter-rows shape the weed communities in three vineyards across Italy

The use of cover crops (CCs) is widely proposed as an alternative to traditional soil management in vineyards to exploit a wide range of ecosystem services. The presence of a CC in the inter-row space is known to control spontaneous vegetation in vineyards, primarily through the biomass of the sown crop, which competes with other spontaneous species for soil resources.

Smoke tainted wine – what now?

The frequency of bushfires close to wine regions around the world has increased in the last two decades. The economic losses incurred when grapes and wines are discarded due to ‘smoke taint’ are substantial (i.e., hundreds of millions of dollars). Efforts to mitigate and ameliorate smoke taint are therefore crucial. Chardonnay, rosé and cabernet sauvignon wines made from grapes exposed to smoke during the 2020 wildfires in eastern Australia were subjected to various amelioration techniques: the addition of activated carbons, molecularly imprinted polymers (mips), and a proprietary resin (either directly, or following membrane filtration); spinning cone column (scc) distillation; and finally, transformation into vinegar.