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

L’AOC Grignolino d’Asti (20000 hl environ de production) est un vin de la province de Asti, produit avec le raisin rouge du cépage de même nom originaire du Piémont (Nord-Ouest d’Italie).

Cabernet Sauvignon is one of the most important winegrape varieties in Chile. However, temperature raise and decreased rainfall due to climate change can lead to grape quality decrease in certain areas. Amino acids are essential as nitrogen source for yeast but also directly affect grape quality serving as precursors of certain volatile compounds that enhance the wine bouquet. Besides, glutathione is an important tripeptide acting as antioxidant, preventing the appearance of browning pigments in must and exerts a protective effect in volatile compounds.

The « Condado de Huelva » Registered Appellation Origin Mark (RAOM) is located in the Province of Huelva, in the southwest of Andalucía (Spain), being limited by the Atlantic Ocean and the Province of Sevilla. « Zalema », a white high productive grapevine plant is its major cultivar. The predominant rootstocks used are « Rupestris du Lot », « Castel 196-17 », « Couderc 161-49 », Couderc 33-09 », « Richter 110 » and « Millardet 41-B ». Traditionally, « Zalema » cv. has been dedicated to the elaboration of amber, bouquet-flavoured wines and in the last years mainly to young, fruit-flavoured white table wines.

An organoleptic defect, called fresh mushrooms off-flavor (FMOff), appeared in wines and spirits since the 2000’s. Numerous researches demonstrated that octen-3-one, 3-octanol and octen-3-ol (C8 compounds) were involved in the mushroom off-flavor in wines

Majority of California’s vineyards rely on supplemental irrigation to overcome abiotic stressors. In the context of climate change, increases in growing season temperatures and crop evapotranspiration pose a risk to adaptation of viticulture to climate change. Vineyard cover crops may mitigate soil erosion and preserve water resources; but there is a lack of information on how they contribute to vineyard resiliency under tillage systems. The aim of this study was to identify the optimum combination of cover crop sand tillage without adversely affecting productivity while preserving plant water status. Two experiments in two contrasting climatic regions were conducted with two cover crops, including a permanent short stature grass (P. bulbosa hybrid), barley (Hordeum spp), and resident vegetation under till vs. no-till systems in a Ruby Cabernet (V. vinifera spp.) (Fresno) and a Cabernet Sauvingon (Napa) vineyard. Results indicated that permanent grass under no-till preserved plant available water until E-L stage 17. Consequently, net carbon assimilation of the permanent grass under no-till system was enhanced compared to those with barley and resident vegetation. On the other hand, the barley under no-till system reduced grapevine net carbon assimilation during berry ripening that led to lower content of nonstructural carbohydrates in shoots at dormancy. Components of yield and berry composition including flavonoid profile at either site were not adversely affected by factors studied. Switching to a permanent cover crop under a no-till system also provided a 9% and 3% benefit in cultural practices costs in Fresno and Napa, respectively. The results of this work provides fundamental information to growers in preserving resiliency of vineyard systems in hot and warm climate regions under context of climate change.