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…

Effects of different organic amendments on soil, vine, grape and wine, in a long-term field experiment in Chinon vineyard (France)

In a long-term experiment carried out in Chinon vineyard (37, France) during 23 years, the effects of several organic amendments were studied on soil, vine, grapes and wine. Four main treatments were compared on a calcareous sandy soil: control without organic amendment, dry crushed pruning wood at 2.1.t-1.ha-1.year-1 (D1), cow manure at 10 t-1. ha-1.year-1 (D1) and cow manure applied at 20 t-1.ha-1.year-1 (D2). D1 levels were calculated to fill the annual humus losses by mineralization.

Kinetics modeling of a sangiovese wine chemical and physical parameters during one-year aging in different tank materials

The use of different tank materials during red wine aging has become increasingly popular, but little is known about their impact on wine chemical and physical parameters.

Frost risk projections in a changing climate are highly sensitive in time and space to frost modelling approaches

Late spring frost is a major challenge for various winegrowing regions across the world, its occurrence often leading to important yield losses and/or plant failure. Despite a significant increase in minimum temperatures worldwide, the spatial and temporal evolution of spring frost risk under a warmer climate remains largely uncertain. Recent projections of spring frost risk for viticulture in Europe throughout the 21st century show that its evolution strongly depends on the model approach used to simulate budburst. Furthermore, the frost damage modelling methods used in these projections are usually not assessed through comparison to field observations and/or frost damage reports.
The present study aims at comparing frost risk projections simulated using six spring frost models based on two approaches: a) models considering a fixed damage threshold after the predicted budburst date (e.g BRIN, Smoothed-Utah, Growing Degree Days, Fenovitis) and b) models considering a dynamic frost sensitivity threshold based on the predicted grapevine winter/spring dehardening process (e.g. Ferguson model). The capability of each model to simulate an actual frost event for the Vitis vinifera cv. Chadonnay B was previously assessed by comparing simulated cold thermal stress to reports of events with frost damage in Chablis, the northernmost winegrowing region of Burgundy. Models exhibited scores of κ > 0.65 when reproducing the frost/non-frost damage years and an accuracy ranging from 0.82 to 0.90.
Spring frost risk projections throughout the 21st century were performed for all winegrowing subregions of Bourgogne-Franche-Comté under two CMIP5 concentration pathways (4.5 and 8.5) using statistically downscaled 8×8 km daily air temperature and humidity of 13 climate models. Contrasting results with region-specific spring frost risk trends were observed. Three out of five models show a decrease in the frequency of frost years across the whole study area while the other two show an increase that is more or less pronounced depending on winegrowing subregion. Our findings indicate that the lack of accuracy in grapevine budburst and dehardening models makes climate projections of spring frost risk highly uncertain for grapevine cultivation regions.

The Hungarian system of geographical indications and the preparation of product specifications

Following the 2008-2009 reform of the European Union’s common market organisation in wine all protected designations of origin and geographical indications were imposed to prepare a product specification that described the conditions of their use. In this paper, we describe this process and the Hungarian system of geographical indications.

Ripening potential of Touriga Nacional variety with different canopy management techniques and in different regions (Dão, Bairrada and Vinhos Verdes)

Foreseeing climatic changes, the abnormally hot and dry year of 2005 can be revealer of some varieties behavior in different climatic conditions.