Rare earth elements distribution in grape berries

Aims: The objective of the present work is to review strategies applied to decrypt multidimensional and ill-defined concepts employed by winemakers and to illustrate these strategies with recent applications.

The phenomenon of quercetin precipitation in wine (flanovol haze), has been manifested for many years in several wine-producing regions

In a scenario of changing climate conditions, grapevine is significantly affected at multiple levels. Advancements in phenology and berry ripening, however, are the major dynamics of the generalized increase in average temperature and evaporative demand, negatively affecting berry quality and productivity. The aim of this work was to unravel the underlying mechanisms of bunch-zone auxin application (NAA; 1-Naphthaleneacetic acid) and source-limiting canopy management approaches in delaying berry ripening. In randomized block design experiments, control vines were compared to vines treated with NAA, subjected to apical-to-bunch defoliation or antitranspirant application (n=10-to-42 plants per treatment).

A unique “terroir” can be found in southern Bolivia, which combines the specific features of climate, topography and altitude of high valleys, with the management of grapevines staked on trees. It is one of the rare remnants of agroforestry viticulture. A survey was carried out among 29 grapegrowers in three valleys, to characterize the structure and management of these vineyards, and identify the services they expect from trees. Farms were small (2.2 ha on average) and 85% of vineyards were less than 1 ha. Viticulture was associated with vegetable, fruit and fodder production, sometimes in the same fields. Molle trees were found in all plots, together with one or two other native tree species. Traditional grapevine varieties such as Negra Criolla, Moscatel de Alejandría and Vicchoqueña were grown with a large range of densities from 1550 to 9500 vines ha-1. From 18 to 30% of them were staked on trees, with 1.2 to 4.9 vines per tree. The management of these vineyards (irrigation, fertilization and grapevine protection) was described, the most particular technical operation being the coordinated pruning of trees and grapevines. Three types of management could be identified in the three valleys. Grapegrowers had a clear idea of the ecosystem services they expected from trees in their vineyards. The main one was protection against climate hazards (hail, frost, flood). Then they expected benefits in terms of pest and disease control, improvement of soil fertility and resulting yield. At last, some producers claimed that tree-staking was quicker and cheaper than conventional trellising. It can be hypothesized then that agroforestry is a promising technique for the agroecological transition of viticulture. Its contribution to the “terroir” of the high valleys of southern Bolivia and its link with the specificities of the wines and spirits produced there remain to be explored.

Today’s viticulture is facing a new climatic scenario with temperature increases and rainfall deficits, generated by the effect of climate change. As a result of these new conditions, there are earlier harvests, increased plant water stress and higher disease risk in wetter wine-growing regions.