Terroir 2020 banner
IVES 9 IVES Conference Series 9 Partitioning of seasonal above‐ground biomass of four vineyard-grown varieties: development of a modelling framework to infer temperature-rate response functions

Partitioning of seasonal above‐ground biomass of four vineyard-grown varieties: development of a modelling framework to infer temperature-rate response functions

Abstract

Aims: Forecasting the biomass allocation among source and sinks organs is crucial to better understand how grapevines control the distribution of acquired resources and has a great meaning in term of making decisions about agricultural practices in vineyards. Modelling plant growth and development is one of prediction approaches that play this role when it concerns growth rates in response to variation in environmental conditions. This study was aimed to model the dynamics of current year’s above‐ground biomass in grapevine. Furthermore, the development of a relatively simple growth modelling framework aimed at the derivation of cardinal air temperatures for growth in grapevine.

Methods and Results: Trials were carried out over three growing seasons in field conditions with four grapevine cultivars. To compare the differences of growth-allocation models among cultivars, the non-linear extra-sums-of-squares method was used. Using measurements of mean daily air temperature and dry mass increments a beta-function model was fitted to the data and used to estimate cardinal air temperatures. Shoot growth and biomass allocation differed significantly among cultivars. The application of the non-linear extra-sums-of-squares procedure demonstrated to be a feasible way of growth models statistical comparison among cultivars. The results of this study highlight parameters most involved in the phenotypic variability of shoot growth. Variations among cultivars result from environmental and genetic factors. The temperature response functions obtained, confirm the initial working hypothesis that because the varieties may have either different temperature optima or different thresholds that a unifying model cannot be achieved.

Conclusions: 

These results suggest that some caution should be taken when incorporating shoot development and biomass partitioning coefficients in a growth model. Use of common coefficients estimates for all cultivars for dynamic modelling approaches, in fact, may result in a poor representation of the data early or late during the course of the season.

Significance and Impact of the Study: The described approach can be used to account for complex variation in seasonal growth patterns and provides insight into how well a cultivar may be matched to a particular site.

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Franco Meggio* and Andrea Pitacco

Department of Agronomy Food Natural Resources Animals and Environment, University of Padova, Viale dell’Università 16 35020 – Legnaro (PD), Italy

Contact the author

Keywords

Above-ground grapevine biomass, growth model, biomass partitioning coefficients 

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Post-plant nematicide timing for northern root-knot nematode in Washington wine grapes

Vigor declines in older vineyards and poor vine establishment in replant situations have been attributed to plant-parasitic nematodes. The northern root-knot nematode, Meloidogyne hapla, is the most prevalent plant-parasitic nematode species found in Washington wine grape vineyards. Management for nematodes in established vineyards is limited to the application of post-plant nematicides. We are evaluating new nematicides that are currently not registered in grape for their efficacy in controlling M. hapla and a part of that evaluation includes improving the alignment of nematicide application timing with the vulnerable second-stage juvenile (J2) life stage of M. hapla.

Deconstructing the soil component of terroir: from controversy to consensus

Wine terroir describes the collectively recognized relation between a geographical area and the distinctive organoleptic characteristics of the wines produced in it. The overriding objective in terroir studies is therefore to provide scientific proof relating the properties of terroir components to wine quality and typicity. In scientific circles, the role of climate (macro-, meso- and micro-) on grape and wine characteristics is well documented and accepted as the most critical. Moreover, there has been increasing interest in recent years about new elements with possible importance in shaping wine terroir like berry/leaf/soil microbiology or even aromatic plants in proximity to the vineyard conferring flavors to the grapes. However, the actual effect of these factors is also dependent on complex interactions with plant material (variety/clone, rootstock, vine age) and with human factors.
The contribution of soil, although a fundamental component of terroir and extremely popular among wine enthusiasts, remains a much-debated issue among researchers. The role of geology is probably the one mostly associated by consumers with the notion of terroir with different parent rocks considered to give birth to different wine styles. However, the relationship between wine properties and the underlying parent material raises a lot of controversy especially regarding the actual existence of rock-derived flavors in the wine (e.g. minerality). As far as the actual soil properties are concerned, the effect of soil physical properties is generally regarded as the most significant (e.g sandy soils being associated with lighter wines while those on clay with colored and tannic ones) mostly through control of water availability which ultimately modifies berry ripening conditions either directly by triggering biosynthetic pathways, or indirectly by altering vigor and yield components. The role of soil chemistry seems to be weakly associated to wine sensory characteristic, although N, K, S and Ca, but also soil pH, are often considered important in the overall soil effect.
Recently, in the light of evidence provided by precision agriculture studies reporting a high variability of vineyard soils, the spatial scale should also be taken into consideration in the evaluation of the soil effects on wines. While it is accepted that soil effects become more significant than climate on a local level, it is not clear whether these micro-variations of vineyard soils are determining in the terroir effect. Moreover, as terroir is not a set of only natural factors, the magnitude of the contribution of human-related factors (irrigation, fertilization, soil management) to the soil effect still remains ambiguous. Lastly, a major shortcoming of the majority of works about soil effects on wine characteristics is the absence of connection with actual vine physiological processes since all soil effects on grape and wine chemistry and sensorial properties are ultimately mediated through vine responses.
This article attempts to breakdown the main soil attributes involved in the terroir effect to suggest an improved understanding about soil’s true contribution to wine sensory characteristics. It is proposed that soil parameters per se are not as significant determining factors in the terroir effect but rather their mutual interactions as well as with other natural and human factors included in the terroir concept. Consequently, similarly to bioclimatic indices, composite soil indices (i.e. soil depth, water holding capacity, fertility, temperature etc), incorporating multiple soil parameters, might provide a more accurate and quantifiable means to assess the relative weight of the soil component in the terroir effect.

Sustainable agriculture and food innovation: preserving agrodiversity and advancing vineyard resilience in Madeira

The ISOPlexis – Center for Sustainable Agriculture and Food Technology, University of Madeira, is a research unit that develops activities in the fields of Sustainable Agriculture, Agri-food Technology and Bioeconomy, with focus on agrodiversity monitoring and phenotyping,

The use of unripe frozen musts for modulating wine characteristics throughout acidity correction – effects on volatile and amino acid composition

As environmental issues come more to the fore, vineyards residues are being looked at as solutions rather than problems. Aiming to develop a sustainable methodology for musts acidity correction in the process of winemaking, much needed in warm regions, the present study was performed according to Circular Economy values.

La protection des terroirs viticoles dans l’AOC Côtes du Rhône (France)

[English version below]

Les terroirs viticoles, et plus particulièrement ceux des vignobles AOC, sont aujourd’hui menacés par de multiples agressions. Ces territoires sont non seulement l’outil de production