Impact of microclimate on berry quality parameters of white Riesling (Vitis vinifera L.)

Over the past two years, the AWRI has received 69 wine samples suspected of being affected by mousy off-flavour. The character has been mostly observed in white wines.

The measurement of carbon isotopic discrimination in grape sugars 13 at harvest (δ C) is an integrated assessment of water status during ripening.

In the current viticultural context, global warming leads to advanced and possibly accelerated ripening which can alter the balance among desirable grape quality traits sought for winemaking. Evaluation of genetic material that displays delayed and/or slower ripening could uncover a potential “slow ripening” trait for incorporation into commercial varieties through breeding. In this study, we evaluated a white-fruited selection discovered in the Grape Breeding and Genetics program at E. & J. Gallo Winery that displayed an unusual ripening pattern compared to standard varieties. Vines of the slow-ripening selection did not differ in their visual appearance, water status or gas exchange characteristics compared to vines of its normal-ripening sibling.

High quantities of chemicals are applied in the vineyard for pest and disease control. Transition towards low pesticide viticulture is a key issue to improve sustainability. Winegrowers have to gradually change their practices to engage in this transition. This work aims at analysing the pesticide use evolution during transition towards low pesticide vineyards and identify some management options mobilized by winegrowers. To understand the diversity of pathways taken towards agroecological transition, we characterized different types of pesticide use evolution.

Studies suggest that ethanol (EtOH), triggers plant adaptation to various stresses at low concentrations (10 µM to 10 mM).