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…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.