GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Crop water stress index as a tool to estimate vine water status

Crop water stress index as a tool to estimate vine water status

Abstract

Context and purpose of the study – Crop Water Stress Index (CWSI) has long been a ratio to quantify relative plant water status in several crop and woody plants. Given its rather well relationship to either leaf or stem water potential and the feasibility to sample big vineyard areas as well as to collect quite a huge quantity of data with airborne cameras and image processing applications, it is being studied as a tool for irrigation monitoring in commercial vineyards. The objective of this paper was to know if CWSI estimated by measuring leaf temperature with an infrared hand held camera could be used to substitute the measure of stem water potential (SWP) without losing accuracy of plant water status measure.

Material and methods – Four vine water status were set up in 2017 on a Cabernet-Sauvignon vineyard grafted onto 110R at Morata de Tajuña (Madrid). Data herein involved correspond to 2018 growing season. Total Irrigation amount was 157, 241, 470 and 626 mm for treatments 1, 2, 3 and 4 respectively in 2018. Plants were 2-bud spur pruned along a unilateral cordon with 11-12 shoots per meter of raw. Training system was a Vertical Shoot Position (VSP). Experimental design was a randomize complete 4-block design with 3 rows per single plot, one central control row and two adjacent ones acting as buffer. Canopy development was measured by determining shaded soil at 10:30. Weather data were collected from a weather station at the same vineyard site. To calculate CWSI, leaf-treatment, wet leaf temperature and dry-leaf temperatures were measured with an infrared camera model FLIR E60. All data were collected around noon at the same time as stem water potential (Ψs), on 5 cloudless days along 2018 – June 19th, July 24th, August 7th, September 4th and 25th-. Four leaves per treatment were sampled each time of measurement. It was established a linear regression between CWSI and stem water potential. One treatment per measuring date (4 pair data) was kept out of the lineal regression and saved them to validate the model; All statistics analysis was performed with the Statistix10 package.

Results – Differences in CWSI arose from the first date of measure, June 19th. Differences in CWSI arise even before than in SWP; Highest SWP was -5.32 and the lowest was -13.80bar. At the end of the season, when overwhelming ambient conditions stayed long time CWSI did not show any difference between treatments despite SWP widely ranged between -6.85 and -10.53 bar between treatments. We found a significant linear relationship between CWSI and SWP (Ψs = 23.58·CWSI -2.87 R2= 0.63***). In an attempt to dig into the variables involved in plant water status we looked into a multiple regression in which SWP was dependent either on CWSI, vapor pressure deficit (VPD), canopy development (SS) and soil water content (Θs). However, none of these variables turned out to be significant but CWSI (R2=0.63**). Shaded soil was significant for P = 0.08. So far we can conclude that CWSI works out when stem water potential is below 14.0 bar.

DOI:

Publication date: September 18, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Carlos ESPARTOSA1, Julián RAMOS, Elena GONZÁLEZ-SEARA, Concepción GONZÁLEZ-GARCÍA, Adolfo MOYA, Antonio HUESO, Pilar BAEZA*

1 Centro de Estudios e Investigación para la Gestión de Riesgos Ambientales. ETSI-Agronómica, Alimentaria y Biosistemas. 28040 Madrid, España

Contact the author

Keywords

grapevine, Stem Water Potential, leaf temperature, Vapor Pressure Deficit, canopy development, soil water content, Crop Water Stress Index, infrared camera data

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Elucidating vineyard site contributions to key sensory molecules: Identification of correlations between elemental composition and volatile aroma profile of site-specific Pinot noir wines

The reproducibility of elemental profile in wines produced across multiple vintages has been previously reported using grapes from a single scion clone of Vitis vinifera L. cv. Pinot noir. The grapevines were grown on fourteen different vineyard sites, from Oregon to southern California in the U.S.A., which span distances from approximately hundreds of meters to 1450 km, while elevations range from near sea level to nearly 500 m. In addition, sensorial (i.e. aroma, taste, and mouthfeel) and chemical (i.e. polyphenolic and volatile) differences across the different vineyard sites have also been observed among these wines at two aging time points. While strong evidence exists to support that grapes grown in different regions can produce wines with unique chemical and sensorial profiles, even when a single clone is used, the understanding of growing site characteristics that result in this reproducible differentiation continues to emerge. One hypothesis is that the elemental profile that a vineyard site imparts to the grape berries and the resulting wine is an important contributor to this differentiation in chemistry and sensory of wines. For example, various classes of enzymes that catalyze the formation of key aroma compounds or their precursors require specific metals. In this work, we begin to report correlations between elemental and volatile aroma profiles of site-specific Pinot noir wines, made under standardized winemaking conditions, that have been previously shown to be distinguished separately by these chemical analyses.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Assessing the climate change vulnerability of European winegrowing regions by combining exposure, sensitivity and adaptive capacity indicators

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.

VINIoT – Precision viticulture service

The project VINIoT pursues the creation of a new technological vineyard monitoring service, which will allow companies in the wine sector in the SUDOE space to monitor plantations in real time and remotely at various levels of precision. The system is based on spectral images and an IoT architecture that allows assessing parameters of interest viticulture and the collection of data at a precise scale (level of grape, plant, plot or vineyard) will be designed. In France, three subjects were specifically developed: evaluation of maturity, of water stress, and detection of flavescence dorée. For the evaluation of maturity, it has been decided first to work at the berry scale in the laboratory, then at the bunch scale and finally in the vineyard. The acquisition of the spectral hyperstal image as well as the reference analyzes to measure the maturity, were carried out in the laboratory after harvesting the berries in a maturity monitoring context. This work focuses on a case study to predict sugar content of three different grape varieties: Syrah, Fer Servadou and Mauzac. A robust method called Roboost-PLSR, developed in the framework of this work (Courand et al., 2022), to improve prediction model performance was applied on spectra after the acquirement of hyperspectral images. Regarding the evaluation of water stress, to work with a significant variability in terms of water status, it has been worked first with potted plants under 2 different water regimes. The facilities have allowed the supervision of irrigation and micro-climatic conditions. The regression models on agronomic variables (stomatal conductance, water potential, …) are studied. To detect flavescence dorée, the experimental plan has consisted of work at leaf scale in the laboratory first, and then in the field. To detect the disease from hyper-spectral imaging, a combination of multivariate curve resolution-alternating least squares (MCR-ALS) and factorial discriminant analysis (FDA) was proposed. This strategy proved the potential towards the discrimination of healthy and infected leaves by flavescence dorée based on the use of hyperspectral images (Mas Garcia et al., 2021).