Physiological, Enological and Agronomic Characterization of Pedro Ximénez Grapevine Cultivar under Organic Farming in a Warm Climate Zone

Abstract

One of the challenges that European agriculture will have to face will be to adapt conventional agriculture to procedures of the new European agricultural policies. In this way, organic farming will have more importance in the coming years. One of the most important crops worldwide is grapevine. The main objective of this research work focuses on the physiological, agronomic, and enological characterization of Pedro Ximénez with the purpose of knowing the viability of the organic cultivation of this cultivar in a warm climate zone. Two experimental plots were selected with two different types of management, organic and conventional. In both plots, photosynthetic capacity (AN), stomatal conductance (gs), and intrinsic water-use efficiency (WUEi) were measured, and physicochemical composition of grape must was analyzed during ripening. In addition, bunch and pruning weight were measured as agronomic parameters. Physiological results were not significantly different between management at a general level in gs and WUEi, being possible to identify a difference in AN just before the harvest. At the level of fruit ripening, significant differences were found between the two managements. At harvest, grape must had a higher sugar concentration, amine nitrogen (α-NH2), and yeast assimilable nitrogen (YAN) in the organic management than in conventional, where higher values of pH and l-malic acid were observed. Taking into account the preliminary results obtained it could be concluded the viability of the organic management for Pedro Ximénez crop in a warm climate zone.