Rootstock-scion contributions to seasonal water and light use diversity under field conditions

Context and purpose of the study. Albeit standing as a fashionable research topic dual use of land as viti-voltaic still lacks of fundamental knowledge about whole canopy grapevine response to altered microclimate under panels vs open field conditions.

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.

There is an urgent need to develop protective measures for grapevines in historically significant dry-farming vineyards, particularly on Mediterranean islands.

AIM: The objective of this work is to study the effect of the addition of polysaccharides extracted for grape pomace by-products and musts on sensory and chemical composition of white wines. Much of the waste obtained in the wine sector is not used, and they can have some valuable compounds, such as the polysaccharides (PS).

Chitosan is an effective antimicrobial agent available in the wine industry, because it ensures the control of a of spoilage microorganisms, such as Brettanomyces of lactic acid bacteria.