Decomposing the notion of vine vigour with a proxydetection shoot sensor: Physiocap®

Abstract

The vigour and the vegetative expression of grapevines are parameters of great interest in viticulture, as they describe a general state of growth capacity. Understanding the impacts of agricultural practices on vine vigour, under particular soil and climate conditions, is essential to give a more accurate technical advice, especially on what soil management and vine nutrition are concerned. A shoot sensor called Physiocap®, designed and developed by the CIVC (Comité interprofessionel du vin de Champagne), is used during dormancy season to measure the shoot section, the shoot number and an estimation of the aboveground biomass. The sensor maps vigour spatial variability within a plot, among plots and over years. Physiocap database in Champagne has been analysed since 2011 at different scales, in order to determine the factors impacting the vine vigour. The vintage appeared to be the most impacting factor. For example, climate variability or accidents like dry springs and early spring frosts reduce vine vigour. Champagne vine varieties did not significantly impact vine vigour according to the database. At the scale of the Champagne vineyard, the aboveground biomass estimation of Physiocap® was strongly correlated with the yield of the following year, leaving a promising basis for analysing the impact of different factors on vine vigour. At the scale of the plot, winegrowers are able to compare their plot vigour to a Champagne threshold, which is being refined every year as the Physiocap database is enriched. They can therefore manage their fertilization and soil tillage program more accurately according to their objectives. The Physiocap® sensor appears to be an interesting multidimensional tool binding vine physiology, agronomy and precision viticulture at different scales. When coupled with other data, especially the one describing soil characteristics, it could even be the baseline for creating a decision-aid tool in Champagne for fertilization, tillage and pruning practices.