GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Can soil water content be used as a predictor of predawn leaf water potential for deficit irrigation scheduling? A case study at Alentejo wine region

Can soil water content be used as a predictor of predawn leaf water potential for deficit irrigation scheduling? A case study at Alentejo wine region

Abstract

Context and purpose of the study: Water and heat stress impose new challenges to irrigation management in the Mediterranean areas. This reality has a major impact on the vineyard ecosystem, particularly on the scarce water resources of the Alentejo region (South Portugal). To mitigate this problem, irrigation management should focus on optimizing yield and fruit quality per volume of water applied. This work aims to discuss the use of predawn leaf water potential and soil water status relationships as a decision tool for irrigation management taking as basis data from a field trial where two deficit irrigation strategies were compared.

Material and methods: A deficit irrigation experiment was conducted from 2013-2015 at a commercial vineyard locatedat Reguengos de Monsaraz, Alentejo, Portugal (38o22’ N 7o33’ W) with the V. vinifera variety Aragonez (syn. Tempranillo). A sustained deficit irrigation (DI) strategy used by the farm consisting of a constant proportion of crop evapotranspiration (0.28) was applied along the irrigation period (DI1) and was compared with DI2, a similar strategy but with 48% lower water volumes than DI1, using a randomized complete block design with four replications of 15 plants. Predawn leaf water potential (ψPD) was used to define the beginning of each irrigation event.Soil water content until one meter depth was assessed and the fraction of transpirable soil water (FTSW) was calculated. Yield, berry composition and pruning weight were assessed. This paper reports the first year (2013) results.

Results: The DI strategies induced a decrease of ψPD along the season. In parallel, the progressive water withhold decreased FTSW (accessed after each irrigation event) along the season from 80 to 20%, while atmospheric water demand was increasing. The strong correlation between ψPD and FTSW observed may support the use of FTSW as a robust predictor of ψPD. The stressful conditions imposed by this irrigation strategy had no significant effect on yield, berry composition and vigor. The crop WUE (amount of fruit produced per unit of water applied) was higher for DI2 strategy and, at the same time, allowing water savings as compared to grower’s irrigation strategy.

DOI:

Publication date: September 28, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Ricardo EGIPTO1,2*, Joaquim Miguel COSTA2, José SILVESTRE1, Manuela CHAVES3, Carlos M. LOPES2

INIAV, I.P., Pólo de Dois Portos, Quinta da Almoínha, 2565-191 Dois Portos, Portugal
LEAF, ISA, Universidade de Lisboa , Tapada da Ajuda Lisboa, Portugal
LEM-ITQB, Universidade Nova de Lisboa, Oeiras, Portugal

Contact the author

Keywords

deficit irrigation, water stress, crop WUE, yield and berry quality

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

How to reduce SO2 additions in wine with the aid of non-conventional yeasts

Among the factors that influence the sensory quality, style, safety, sustainability, and sense of place of a wine, the contributions of microbial biodiversity are widely becoming more recognized. Throughout winemaking, multiple biochemical reactions are performed by a myriad of different microorganisms interacting in many ways.

The tolerance of grapevine rootstocks to water deficit is related to root morphology and xylem anatomy traits 

Climate change is altering water balances, thereby compromising water availability for crops. In grapevine, the strategic selection of genotypes more tolerant to soil water deficit can improve the resilience of the vineyard under this scenario. Previous studies demonstrated that root anatomical and morphological traits determine vine performance under water deficit conditions. Therefore, 13 ungrafted rootstock genotypes, 6 commercial (420 A, 41 B, Evex 13-5, Fercal, 140 Ru y 110 R), and 7 from new breeding programs (RG2, RG3, RG4, RG7, RG8, RG9 and RM2) were evaluated in pots during 2021 and 2022.

Pinot noir: an endemic or a flexible variety?

Pinot noir has its historical roots in Burgundy and is generally considered as an endemic vine variety which means that its adaptation is very specific to this environment

A blueprint for managing vine physiological balance at different spatial and temporal scales in Champagne

In Champagne, the vine adaptation to different climatic and technical changes during these last 20 years can be seen through physiological balance disruptions. These disruptions emphasize the general grapevine decline. Since the 2000s, among other nitrogen stress indicators, the must nitrogen has been decreasing. The combination of restricted mineral fertilizers and herbicide use, the growing variability of spring rainfall, the increasing thermal stress as well as the soil type heterogeneity are only a few underlying factors that trigger loss of physiological balance in the vineyards. It is important to weigh and quantify the impact of these factors on the vine. In order to do so, the Comité Champagne uses two key-tools: networking and modelization. The use of quantitative and harmonized ecophysiological indicators is necessary, especially in large spatial scales such as the Champagne appellation. A working group with different professional structures of Champagne has been launched by the Comité Champagne in order to create a common ecophysiology protocol and thus monitor the vine physiology, yearly, around 100 plots, with various cultural practices and types of soil. The use of crop modelling to follow the vine physiological balance within different pedoclimatic conditions enables to understand the present balance but also predict the possible disruptions to come in future climatic scenarios. The physiological references created each year through the working group, benefit the calibration of the STICS model used in Champagne. In return, the model delivers ecophysiology indicators, on a daily scale and can be used on very different types of soils. This study will present the bottom-up method used to give accurate information on the impacts of soil, climate and cultural practices on vine physiology.

OTR determination of aged closures: Impact on aroma compounds composition of Sauvignon blanc wines

Oxygen transfer rate (OTR) is a technical property of closure, and it modulates the oxygen supply to the wine during its bottle aging. It’s an important parameter to take into account in the analysis of wine aroma evolution. OTR distribution is well documented for new closures, but little research has been published on its determination for aged closures. Initial oxygen release after bottling impacts the composition of wines during the first years of storage), but the link between OTR, sensory perception and aroma composition after many years of aging has not yet been clearly studied.