GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Soil proximal sensing provides direction in delineating plant water status of ‘crimson seedless’ (Vitis vinifera L.) vineyards

Soil proximal sensing provides direction in delineating plant water status of ‘crimson seedless’ (Vitis vinifera L.) vineyards

Abstract

Context and Purpose of the Study – ‘Crimson Seedless’ (Vitis vinifera L.) is a late-ripening, red seedless table grape cultivar with inadequate anthocyanin accumulation and less than ideal berry size issues. It was necessary to understand the natural variations in the vineyard as well as the application of proximal sensing to monitor, and estimate these variations to get desirable attributes in this cultivar. The objective of this study was to use of proximal and remote sensing tools, specifically soil electrical conductivity (EC), canopy normalized difference vegetation index (NDVI), and carbon isotope discrimination in a precision agriculture context, to assess the water status variability, and determine the effect of inferred variability on skin anthocyanin and flavonol concentration at harvest.

Material and Methods – A ‘Crimson Seedless’ (V. vinifera L.) grafted on to ‘Freedom’ (27% vinifera hybrid) rootstock vineyard was studied for two years with contrasting precipitation amounts. Soil electrical conductivity (EC) was proximally sensed with electromagnetic induction and canopy reflectance was sensed remotely to calculate normalized difference vegetation index (NDVI). Random and equi-distant (30 m × 30 m) sampling grids were utilized in 2016 and 2017 to ground truth proximally sensed data. Grape primary metabolites, including total soluble solids, total acidity, isotopic discrimination of berry sugars (δ13C) and pH were measured, and secondary metabolites were characterized with a C18 reversed-phase HPLC.

Results – Soil EC was related to the variation of season-long plant water status in 2016 (Deep EC: r = -0.71; Surface EC: r = -0.53). There was not a significant relationship between NDVI and plant water status in either year.  The vineyard was separated and delineated into two water status zones based on stem water potential (􀀁stem) in each year, and the water status between two zones were significantly and consistently different. The juice pH showed significant differences between two zones. The δ13C was directly and significantly related to 􀀁stem integrals and the differences between the two water status zones were confirmed by either method in 2016. There were no differences in total anthocyanins in 2016. However, anthocyanin derivatives were greater in the low water status zone in the following year. Flavonol amounts were not consistently different between the two zones in either year. Our results indicated deep soil EC, season-long water status or δ13C can be used interchangeably to spatialize and cluster management zones in commercial table grape vineyards.

DOI:

Publication date: June 18, 2020

Issue: GiESCO 2019

Type: Poster

Authors

Runze YU1, Luca BRILLANTE2, Johann MARTÍNEZ-LÜSCHER1, S. Kaan KURTURAL1

(1) Dept. of Viticulture and Enology, University of California, Davis, CA, 95616, USA
(2) Dept. of Viticulture and Enology, California State University, Fresno, CA, 93704, USA

Contact the author

Keywords

Crimson Seedless, table grapes, anthocyanins, flavonoids, water status, electrical conductivity, normalized difference vegetation index (NDVI), spatial variability, viticulture

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Climate and the evolving mix of grape varieties in Australia’s wine regions

The purpose of this study is to examine the changing mix of winegrape varieties in Australia so as to address the question: In the light of key climate indicators and predictions of further climate change, how appropriate are the grape varieties currently planted in Australia’s wine regions? To achieve this, regions are classified into zones according to each region’s climate variables, particularly average growing season temperature (GST), leaving aside within-region variations in climates. Five different climatic classifications are reported. Using projections of GSTs for the mid- and late 21st century, the extent to which each region is projected to move from its current zone classification to a warmer one is reported. Also shown is the changing proportion of each of 21 key varieties grown in a GST zone considered to be optimal for premium winegrape production. Together these indicators strengthen earlier suggestions that the mix of varieties may be currently less than ideal in many Australian wine regions, and would become even less so in coming decades if that mix was not altered in the anticipation of climate change. That is, grape varieties in many (especially the warmest) regions will have to keep changing, or wineries will have to seek fruit from higher latitudes or elevations if they wish to retain their current mix of varieties and wine styles.

Effect of one-year cover crop and arbuscular mycorrhiza inocululation in the microbial soil community of a vineyard

The microbial composition of the soil is an important factor to consider in viticulture, since its influence on the “terroir” and on the organoleptic properties of the wine have been demonstrated. Different agronomic techniques have the potential to modify the composition and functionality of the soil microbial community. Maintaining green covers is known to increase soil microbial diversity. The direct application of inoculum of beneficial microorganisms to the soil has also been used to increase their abundance. However, the environmental conditions of each site seem to have a determining weight in the result of these practices. In this study, we compared the effect on the microbial community of a cover crop with legumes in autumn and the inoculation of grapevines with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseae in the previous spring. The study has been carried out in a vineyard in Binissalem, Mallorca, Spain. After applying the treatments, we will analyze the soil microbial communities using the data obtained from Illumina amplification of soil DNA from the 16S and ITS regions to analyze bacteria and fungi community, respectively. In addition, we will record the physicochemical characteristics of the soil at each sampling point. The result showed that agronomic management, in the short term, has less influence than soil characteristics on the composition of the soil microbiome. With these results, we can conclude that in a vineyard, agricultural techniques should focus on improving the characteristics of the soil to improve the biodiversity of the soil microbiota.

The combined effects of climate, soils, and deficit irrigation on yield and quality of Touriga Nacional under high atmospheric demand in the Douro Region

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.

Anthocyanin profile is differentially affected by high temperature, elevated CO2 and water deficit in Tempranillo (Vitis vinifera L.) clones

Anthocyanin potential of grape berries is an important quality factor in wine production. Anthocyanin concentration and profile differ among varieties but it also depends on the environmental conditions, which are expected to be greatly modified by climate change in the future. These modifications may significantly modify the biochemical composition of berries at harvest, and thus wine typicity. Among the diverse approaches proposed to reduce the potential negative effects that climate change may have on grape quality, genetic diversity among clones can represent a source of potential candidates to select better adapted plant material for future climatic conditions. The effects of individual and combined factors associated to climate change (increase of temperature, rise of air CO2 concentration and water deficit) on the anthocyanin profile of different clones of Tempranillo that differ in the length of their reproductive cycle were studied. The aim was to highlight those clones more adapted to maintain specific Tempranillo typicity in the future. Fruit-bearing cuttings were grown in controlled conditions under two temperatures (ambient temperature versus ambient temperature + 4ºC), two CO2 levels (400 ppm versus 700 ppm) and two water regimes (well-watered versus water deficit), both in combination or independently, in order to simulate future climate change scenarios. Elevated temperature increased anthocyanin acylation, whereas elevated CO2 and water deficit favoured the accumulation of malvidin derivatives, as well as the acylation and tri-hydroxylation level of anthocyanins. Although the changes in anthocyanin profile observed followed a common pattern among clones, such impact of environmental conditions was especially noticeable in one of the most widely distributed Tempranillo clones, the accession RJ43.