Study of fungal and bacterial laccases for the reduction of ochratoxin A content in model wine

Climate change has varied effects across French vineyards, with marked regional differences in temperature shifts. Fine-scale studies highlight significant local climate variability, emphasizing the need for precise regional characterization to adapt vineyard management at the regional scale.

Context and purpose of the study ‐ Crop load management by cluster thinning can improve ripening and the concentration of key metabolites for grape and wine quality. However, little work has been done on testing the impact of crop load management on terpene content of white grapes. The goal of the study was to assess if by reducing crop load via cluster thinning growers can increase terpene concentration of grapes, as well as to test if the timing of thinning application affects terpene concentration.

In order to avoid the loss of grapevine intra-varietal diversity of DOCa Rioja grape varieties, Regional Government of La Rioja established a germplasm bank with more than 1.600 accessions, whose origin lies in the prospecting and sampling of ancient vineyards located throughout the whole region. 30 clones of Tempranillo and 13 clones of Graciano were preselected and multiplied in a new vineyard for further observations. The aim of this work is to describe the first results from the physiological characterization by an optical sensor of these preselected clones, which constitute the base of a new clonal selection that aims to increase the range of available certified clones and to improve the adaptation of these varieties to future objectives and environmental conditions.

The Pomerol vineyard, located 35 km east of Bordeaux, covers around 800 ha on the left bank of the Isle. There is a system of fluvial terraces with more or less coarse gravel and pebble spreading, resting on a Tertiary substratum ranging from the Middle to Upper Eocene to the Lower Oligocene (Dubreuilh, 1993). This interweaving of terraces of varying thickness results in a brutal superposition of differentiated materials which give rise to various types of soil. Several site studies in this sector of the Libounais show significant morphological and analytical differences from one point to another (Guilloux et al ., 1978; Duteau, 1982; Van Leeuwen et al.., 1989). The distribution of the soils of the Pomerol vineyard was studied and resulted in a cartography at 1/25000th (Merouge, 1995).

Plant water status of grapevine plays a critical role in affecting berry and final wine chemical composition. The environmental variabilities existing in vineyard system have significant impacts on plant water status, but it is challenging to individualize environmental factors from the temporal and spatial variabilities in vineyard. Therefore, there is need to monitor the ecophysical variation through utilizing precision viticulture tools in order to minimize the separation in berry composition. This study aims at delineating vineyard into different management zones based on plant water status explained by soil texture, and utilize differential harvest to equilibrate the final berry and wine composition.