Terroir 2020 banner
IVES 9 IVES Conference Series 9 The vascular connections in grafted plants under examination

The vascular connections in grafted plants under examination

Abstract

Aims: Decreasing longevity of vineyards due to the increase in the infection of different grapevine trunk diseases is a growing concern, and could be related to the quality of grafting. The main aim of this study was to evaluate the use of xylem hydraulic conductivity measurements as a potential indicator for the quality of vascular connections in the graft junction of grapevine plants. For that purpose, two specific trials were carried out: (1) the quality of different batches of plants whose subjective quality was previously known from the nursery’s experience was evaluated, and (2) the vascular connections between the rootstock and the scion were evaluated on a different set of plants grafted using different grafting techniques.

Methods and Results: (1) The XYL´EM conductivity meter was used to measure the specific hydraulic conductivity (Ks) of plants from six different batches whose quality was subjectively defined from the nurseryman experience. Hydraulic conductivity was measured in one-year-old dormant plants, which were kept in a cold chamber since leaving the nursery, first on the whole plant, then on the rootstock and finally at the graft junction. Results showed that two of the six batches evaluated had significantly lower values than the others. (2) After reflecting on the previous experience, we decided to perform the measurements in growing plants, for which we used different batches of plants grafted using different techniques but keeping the same scion (Airén) and the same rootstock (110 R) in all of them. The grafting techniques used were ‘omega’, ‘full cleft’, ‘manual whip and tongue’, ‘mechanical whip and tongue’, and ‘V’. This time, Ksmeasurements were only carried out on the whole plant by determining the water flow from the scion to the rootstock. Results revealed a tendency that the maWT, meWT and V grafts had higher Ks values than FC or OM grafts, which corresponds to higher growth rates according to results previously collected on a field trial performed on the same type of grafted plants.

Conclusions:

Hydraulic conductivity measurements may be a useful trait for the evaluation of vascular connections between the rootstock and the scion in grapevine.

Significance and Impact of the Study: To the best of our knowledge, there are no similar studies in grapevine combining hydraulics measurements with grafting techniques. Results suggest that the hydraulic functioning at the graft junction could be an interesting tool to measure the quality/quantity of vascular connections on grafted plants, and be used to characterize batches in experimentation or, even, to evaluate batches from the nurseries as a quality control.

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

Diana Marín1*, José M. Torres-Ruiz2, F. Javier Abad1, 3, Luis G. Santesteban1

Dept. of Agronomy, Biotechnology and Food Science, Univ. Pública de Navarra, Campus Arrosadia, 31006 Pamplona, Spain
Université Clermont-Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
3 INTIA, Edificio de Peritos Avda. Serapio Huici nº 22, 31610, Villava, Spain

Contact the author

Keywords

Grapevine, Vitis vinifera L., omega graft, whip and tongue, alternative graft

Tags

IVES Conference Series | Terroir 2020

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.

Influence of agronomic practices in soil water content in mid-mountain vineyards

In the context of LIFE project MIDMACC (LIFE18 CCA/ES/001099), several pilots have been installed in vineyards in mid mountain areas of Catalonia (NE Spain) to test well stablished agronomic practices to increase the adaptation of Mediterranean mid mountain to climate change. Soil water content (SWC) at three different depths (15, 30 and 45cm) was measured in continuum from August 2020. One pilot (WC) included a well-established green cover (GC), a new GC (NC) and a conventional soil management (CM, tilling+herbicides). NC presented an intermediate state between WC and CM, responding similarly to CM in autumn but quickly reaching similar SWC to WC, then following the same evolution till next spring, with CM presenting lower values along autumn and winter. Then vegetation activation decreased SWC in all plots, (much slower in CM, lacking GC). Sensibility to spring rains is again intermediate for NC, which joins SWC evolution of CM by the end of spring till next autumn. It is expected that NC will resemble WC more and more as its GC develops. In the pilot combining vine training (VSP vs Gobelet) and hillside management (slope vs terrace), no clear pattern could be related with these conditions. However, both terraces seem to be more sensitive to spring rains. A third pilot included new vineyards (7 and 1 year old). In the new vineyard (N), higher canopy development, a spontaneous green cover and row straw resulted in a slower SWC dynamic, not so sensitive to rains but conserving more soil water in spring and most of summer, even with presumably a higher water extraction by vines. In the newest vineyard (VN) the deepest sensor is still sensitive to rain events all over the year and SWC is always highest at this depth, revealing small water capture by vines.

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.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Analysis of some environmental factors and cultural practices that affect the production and quality of the Manto Negro, Callet and Prensal Blanc varieties

45 non irrigated vineyards distributed in the DO (Denomination) Pla i Llevant de Mallorca and the DO Binissalem Mallorca were used to investigate the characteristics of production and quality and their relationships certain environmental factors and cultural practices. The grape varieties investigated are autochthonous to the island of Mallorca, Manto Negro and Callet as red and Prensal Blanc as white. All plants were measured for four consecutive years in the main production and quality parameters. Among the environmental factors, the type of soil has been studied, more specifically its water retention capacity, the planting density, the age of the vineyard and the level of viral infection. The presence or absence of virus seems to have no effect on any component studied in the varieties studied. For the white variety Prensal Blanc age is negatively correlated with production and the number of bunches, nevertheless it does not cause any effect on the required quality parameters. However, for the red varieties Callet and Manto Negro, the age of the plantation is the variable that best correlates with the quality parameters, therefore the old vines should be the object of preservation by the viticulturists and winemakers in order to guarantee its contribution to the quality of the wines made with these varieties.