Exploring diversity of grapevine responses to Flavescence dorée infection

The vineyards extending between the hillslopes of ‘Apremont’ and ‘Les Marches’ that dominate the valley of Chambéry (Savoie, French Alps) define the terroir of the ‘Vins des Abymes’.

Context and purpose of the study – Viticulture faces significant challenges due to climate change, with increased frequency of extreme weather events impacting grapevine growth, grape quality, and wine production.

Context and purpose of the study ‐ An advancement of grapevine phenological development has been observed worldwide in the last two decades. In South Australia this phenomenon is even more accentuated since grapevine is often grown in a hot climate. The main consequences are earlier harvests at higher sugar levels which also result in more alcoholic wines. These are deemed undesirable for the Australian wine industry with consumer preferences shifting towards lower alcohol wines. Vineyard practices can be implemented to control and delay ripening. Amongst them, apical late leaf removal has been successfully applied in Europe to delay ripening by up to two weeks in Sangiovese, Aglianico and Riesling. In those studies, no negative effects were observed on grape colour, phenolics and on the carbohydrate storage capacity of the vines. To date, this technique has not been studied in Australia. In this study late leaf removal, apical to the bunch zone was applied to the variety Semillon for four seasons and compared to an untreated control.

Climate is one of the main components that defines the development and behavior of the plant, conditioning the health status and the final quality of the grapes. In temperate coastal climates such as in Uruguay (latitude 35° S, longitude 55° O), precipitations during the growing season present high interannual variability, with a average of 100 mm per month. This variability means that plants must adapt to conditions from one year to the next.

Among the different strategies used in vine growing to fight against mold diseases, it can be pointed out the hybridation of traditional grape varieties with others, presenting a genetic resistance to pathogen attack. The research in this field has been encouraged in recent years due to the increased concern about human safety and environmental pollution linked to the use of agrochemicals. This approach allows to limit the number of treatments and the type of active compounds used in vine management. The environment determines the pressure degree of the diseases on vines and the biologic response of the plant to their attack.