Terroir 2020 banner
IVES 9 IVES Conference Series 9 International Terroir Conferences 9 Terroir 2020 9 History and innovation of terroir 9 Usefulness and limits of the crop water stress index obtained from leaf temperature for vine water status monitoring

Usefulness and limits of the crop water stress index obtained from leaf temperature for vine water status monitoring

Abstract

Aims: This work aimed i) to calibrate the accuracy of estimating vineyard water status by crop water stress index (CWSI) compared to stem water potential; ii) to determine the time interval during the day that best correlates to stem water potential and iii) to understand the its usefulness.

Methods and Results: Four levels of irrigation were set up in 2017 on a Cabernet-Sauvignon vineyard grafted to 110R in Morata de Tajuña (Madrid, Spain). The experimental design was a completely randomized four-block design. During two seasons, 2018 and 2019, stem water potential (SWP) and leaf temperature were measured at three time points during the day (8:00; 12.00 and 16:00 solar time) in five dates during 2018 and three dates in 2019. CWSI was calculated based on leaf temperature as the ratio: (Ttreat leaf  Twet)/(Tdry – Twet). Leaf temperature (Ttreat leaf) was measured with an infrared camera model FLIR-E60; Four shaded leaves per treatment were sampled at each time of measurement, for a total of 16 leaves per measurement interval. ANOVA for CWSI and stem water potential was also performed to compare the sensitivity of each parameter to vine water status. All statistical analyses were performed with the Statistix10 package.

Results showed that stem water potential was slightly more sensitive than CWSI to estimate vine water status. Different relationships were found during the season between CWSI and SWP. The determination coefficient was higher at midseason than at the beginning or late in the growing season. The highest R2 were found at noon and during the evening, being no-significant in the morning.

Conclusions: 

Crop Water Stress Index obtained from leaf temperature could be used to estimate plant water status although assuming that it is less sensitive than Stem Water Potential. The index was more accurate in describing the plant water status in midseason than either early or late in the season and better at midday and evening than in the morning.

Significance and Impact of the Study: The study confirms the use of CWSI as a tool to determine vineyard water status and its limitations. Limitations include its effectiveness being confined to midseason and measurements are recommended to be collected from noon onwards. We propose to keep CWSI lower than 0.6 from budbreak until bloom and to move within 0.6 to 0.8 during maturation to ensure SWP is over -1.0MPa (-10 bar) and within -1.0 and -1.2 MPa during ripening.

DOI:

Publication date: March 23, 2021

Issue: Terroir 2020

Type: Video

Authors

G. Camacho-Alonso, P. Baeza*, G. Mendoza, A. Hueso, A.M. Tarquis

Research Centre for the Management of Agricultural and Environmental Risks – CEIGRAM
Universidad Politécnica de Madrid, 28040 Ciudad Universitaria, Madrid, Spain

Contact the author

Keywords

Crop water stress index, stem water potential, thermal images

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

The revision of the delimitation of the AOC “Champagne”

The Champagne vine-growing region has played a pioneering role in the delimitation of appellations of origin (AOC). The implementation of the Act of July, 22nd 1927 has led to drawing up lists of vine plots based on the criterion of vine cultivation antecedence.

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.

Opportunities and challenges in the adoption of new grape varieties by producers: A case study from the Northeastern United

Grape breeding for resistance to fungal diseases is today very dynamic throughout the world notably in France. New varieties are obtained by hybridization between susceptible varieties of the vitis vinifera species and resistant genotypes, with breeding programs generally lasting between 15 and 25 years and resulting in the registration of a few new varieties. Though these varieties can provide several benefits and can be planted by winegrowers, they are not always systematically adopted.

Development of a novel UAV based approach for assessing the severity of spring frost and hail damages in vineyards

A solid feature of climate change is that the frequency and severity of weather extremes are increasing. Ranking European countries for the number of crop failures related to extreme events reports France on top followed by Italy and Spain (COM 2021).

Il ruolo dei comuni nella gestione del territorio e nella tutela dei vitigni autoctoni di qualita’

Questo simposio organizzato dall ‘Associazione nazionale Città del Vino, che mi onoro di presiedere, è per me motivo di particolare soddisfazione perché porta a compimento parte di un percorso iniziato dall’associazione da alcuni anni e che ha un obiettivo apparentemente semplice: sollecitare gli amministratori delle Città del Vino a perseguire con tenacia, tal­volta anche con la necessaria caparbietà, programmi ed interventi che abbiano al centro, sempre, la qualità della vita dei loro territori.