terclim by ICS banner
IVES 9 IVES Conference Series 9 Mobile device to induce heat-stress on grapevine berries

Mobile device to induce heat-stress on grapevine berries

Abstract

Studying heat stress response of grapevine berries in the field often relies on weather conditions during the growing season. We constructed a mobile heating device, able to induce controlled heat stress on grapes in vineyards. The heater consisted of six 150 W infrared lamps mounted in a profile frame. Heating power of the lamps could be controlled individually by a control unit consisting of a single board computer and six temperature sensors to reach a pre-set temperature. The heat energy applied to individual berries within a cluster decreases by the squared distance to the heat source, enabling the establishment of temperature profiles within individual clusters. These profiles can be measured by infrared thermography once a steady state has been reached. Radiant flux density received by a berry depending on the distance was calculated based on a view factor and measured lamp surface temperature and resulted to 665 Wm-2 at 7cm. Infrared thermography of the fruit surface was in good agreement with measurements conducted with a thermocouple inserted at epidermis level. In combination with infrared thermography, the presented device offers possibilities for a wide range of applications like phenotyping for heat tolerance in the field to proceed in the understanding of the complex response of plants to heat stress. Sunburn necrosis symptoms were artificially induced with the aid of the device for cv. Bacchus and cv. Sylvaner in the 2020 and 2021 growing season. Threshold temperatures for sunburn induction (LT5030min) were derived from temperature data of single berries and visual sunburn assessment, applying logistic regression. A comparison of threshold temperatures for the occurrence of sunburn necrosis confirmed the higher susceptibility of cv. Bacchus. The lower susceptibility of cv. Sylvaner did not seem to be related to its phenolic composition, rendering a thermoprotective role of berry phenolic compounds unlikely.

DOI:

Publication date: May 31, 2022

Issue: Terclim 2022

Type: Article

Authors

Kai Müller, Manfred Stoll, Marco Hoffmann and Matthias Friedel

Hochschule Geisenheim University, Department of General and Organic Viticulture, Geisenheim, Germany

Contact the author

Keywords

fruit surface temperature, heat-stress, sunburn, thermography, Vitis vinifera

Tags

IVES Conference Series | Terclim 2022

Citation

Related articles…

Projected changes of grapevine phenology in Belgian and South African vineyards under climate change scenarios

The concept of ‘terroir’ describes the interplay of the environmental factors that affect the grapevine. This includes but is not limited to climate, soil composition, vineyard management, topography, and geology.

Using remotely sensed (UAV) and in situ field measurements to describe grapevine canopy characteristics

Row orientation and canopy management are essential for high quality grapevine production. Microclimatic conditions of the leaves and fruits can be influenced by the canopy geometry. Remote sensing is a very promising tool to describe vegetative growth and physiological behavior of vineyards. However, the correlation between remotely sensed data and in situ field measurements has been described scarcely in the scientific literature so far. The aim of the study was to correlate remotely sensed data obtained with Unmanned Aerial Vehicle (UAV) with in situ field measurements to describe canopy structure.

Methodological approach to zoning

An appellation or geographic indication should be based on the terroir concept in order to ensure its integrity. The delimitation of viticultural terroirs must include two consecutive or parallel steps, namely (a) the characterisation of the environment and identification of homogenous environmental units (basic terroir units, natural terroir units) taking all natural factors into account, as well as (b) the characterisation of the viticultural and oenological potential of these units over time.

Grassland and patch scale diversity in supporting avian diversity and potential ecosystem services

The composition and structure of vineyard landscapes significantly affect bird communities and the ecosystem services they provide in agriculture.

NEW INSIGHTS INTO THE EFFECT OF TORULASPORA DELBRUECKII/SACCHAROMYCES CEREVISIAE INOCULATION STRATEGY ON MALOLACTIC FERMENTATION PERFORMANCE

Winemaking is influenced by micro-organisms, which are largely responsible for the quality of the product. In this context, Non-Saccharomyces and Saccharomyces species are of great importance not only because it influences the development of alcoholic fermentation (AF) but also on the achievement of malolactic fermentation (MLF). Among these yeasts, Torulaspora delbrueckii allows in sequential inoculation with strains of S. cerevisiae shorter MLF realizations [5] . Little information is available on the temporal effect of the presence of T. delbrueckii on (i) the evolution of AF and (ii) the MLF performance.