Terroir 2020 banner
IVES 9 IVES Conference Series 9 International Terroir Conferences 9 Terroir 2020 9 History and innovation of terroir 9 Prospects of thermal imaging as a non-invasive tool to assess water status for irrigation scheduling in commercial vineyards

Prospects of thermal imaging as a non-invasive tool to assess water status for irrigation scheduling in commercial vineyards

Abstract

Aim: Irrigated viticulture is expanding worldwide mainly as a short-term adaptation strategy to climate change. Plant-based methods are increasingly being used for irrigation scheduling in commercial vineyards. Canopy temperature (TC) has long been recognized as an indicator of plant water status. TC, but also the thermal stress indices, e.g. crop water stress index (CWSI) and stomatal conductance index (IG) have been used to support and manage irrigation in several crops including grapevine. The goal of this work was to review thermal imaging as non-invasive tool to assess water status in commercial vineyards in Rioja (Spain) and in the wine regions of Douro and Alentejo (Portugal). 

Methods and Results: Thermal cameras were used as ground based portable sensors to manually assess water status. Significant correlations between TC and/or thermal indices and stomatal conductance or stem water potential (Ψstem) were observed in the vineyards of these top wine regions. Recently, a thermal camera was also mounted in an all-terrain-vehicle for the on-the-go acquisition of thermal images. TC, CWSI and IG were significantly correlated to Ψstem at both canopy sides. Water status of a commercial Tempranillo vineyard was also evaluated using on-the-go thermal imagery retrieved from a moving quad at 5 km/h in Rioja. Moreover, an infrared radiometer was installed in an autonomous terrestrial robot to assess and map water status of commercial Touriga Nacional vineyard in the Douro Valley. 

Conclusions: 

Several trials carried out in Spain and Portugal showed the effectiveness of thermal imaging to monitor water status in commercial vineyards.

Significance and Impact of the Study: Our results are promising and show the potential of thermal imaging as a non-invasive technology in precision viticulture to evaluate vineyard water status, helping grape growers to optimize irrigation management.

DOI:

Publication date: March 23, 2021

Issue: Terroir 2020

Type: Video

Authors

Javier Tardaguila1*, Maria P. Diago1, Juan Fernández-Novales1, Inés Hernández1, Salvador Gutierrez2, Fernando Alves3, Joana Valente3, Ricardo Egipto4, Gonçalo Victorino5, J. Miguel Costa5, Carlos M. Lopes5

1Televitis Research Group. University of La Rioja. 26006 Logroño, Spain
2Department of Computer Science and Engineering, University of Cádiz, 11519 Puerto Real, Spain
3 Symington Family Estates, Travessa Barão de Forrester 86, 4431-901 Vila Nova de Gaia, Portugal
 4INIAV, I.P. Pólo de Dois Portos, Quinta da Almoínha. 2565-191, Dois Portos, Portugal
5LEAF, Instituto Superior de Agronomia. Universidade de Lisboa. 1349-017 Lisboa, Portugal

Contact the author

Keywords

Sensing technologies, non-invasive sensor, CWSI, IG, precision irrigation

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Soil chemistry as a measure of the distinctiveness of american viticultural areas of the Columbia basin, USA

The Columbia Basin, a semi-arid region centered in the eastern part of Washington State, is the second largest wine grape growing region in the United States and presently contains 10 American Viticultural Areas

TCA – A status report on South African cork closures

Cork taint decreases the commercial value of wine as tainted wines are rejected by consumers. Although other compounds in wine and cork can also be responsible for causing a taint, 2,4,6-trichloroanisole (TCA) is regarded as the primary cause of cork taint. As cork taint is often used in marketing campaigns against natural cork closures,

Bentonite fining in cold wines: prediction tests, reduced efficiency and possibilities to avoid additional fining treatments

Bentonite fining is widely used to prevent protein haze in white wines. Most wineries use laboratory-scale fining trials to define the appropriate amount of bentonite to be used in the cellar. Those pre-tests need to mimic as much as possible the industrial scale fining procedure to determine the exact amount of bentonite necessary for protein stability. Nevertheless it is frequent that, after fining with the recommended amount of bentonite, wines appear still unstable and need an additional fining treatment. It remains a major challenge to understand why the same wine, fined with the same dosage of the same bentonite, achieves stability in the lab, but not in the cellar.

CHARACTERIZATION OF ENOLOGICAL OAK TANNIN EXTRACTS BY MULTI-ANALYTICAL METHODS APPROACH

Oak tannin extracts are commonly used to improve wine properties. The main polyphenols found in oak wood extracts are ellagitannins¹ that release ellagic acid upon hydrolysis and comprise numerous structures². Moreover, oak tannin extracts contain other compounds giving a complex mixture. Consequently, the official OIV method based on gravimetric analysis of the tannin fraction adsorbed on polyvinylpolypyrrolidone is not sufficient to describe their composition and highlight their chemical diversity.

Recent advances in measuring, estimating, and forecasting grapevine yield and quality

Grapevine yield and fruit quality are two major drivers of input allocation and, ultimately, revenue for grape producers. Because yield and fruit quality vary substantially from year-to-year and within a single block, opportunities exist for optimization via precision management activities that could lead to more profitable and sustainable grape production. Here, we review recent advances in the techniques and technology used to measure, estimate, and forecast grapevine yield and fruit quality. First, we discuss direct “measurement” of yield and quality (i.e. ground-truth data generation), with an emphasis on potential for scalability and automation. Second, we discuss technology and techniques that do not directly measure yield and quality, but use correlated measurements for their estimation.