Influence of irrigation on yield and quality of cv. Touriga Franca in the Douro Region

¹ DGAOT, Faculty of Sciences, University of Porto, Campus Agrário de Vairão, Portugal
² Quinta do Crasto S.A., Gouvinhas, Sabrosa, Portugal
³ GreenUP/CITAB-UP, DGAOT, Faculty of Sciences, University of Porto, Campus Agrário de Vairão, Portugal

Abstract

The Douro Region is characterized by a typically Mediterranean climate, with extreme temperatures and irregular rainfall throughout the year. This experimental trial was carried out on a vineyard plot of Touriga Franca, grafted in 110R, at Quinta da Cabreira, property of Quinta do Crasto, S.A., located in the Douro Region. Four irrigation modalities were established, in three blocks, according to the percentage of cultural evapotranspiration (ETc): R₀, the control, without irrigation; R₂₅, irrigated with 25% ETc; R₅₀, with 50% ETc and R₇₅, with 75% ETc. Irrigation had repercussions on total leaf area, with statistically significant lower value for R₀ and greater for R₇₅. Concerning the ecophysiological parameters, the water leaf potential was lower in R₀ than at R₅₀ and R₇₅. On the yield components, it was observed a higher number of clusters in R₇₅ and a smaller quantity in R₀ and the bunch weight was also affected by the amount of water provided, with the R₅₀ or R₇₅ having a higher value. Even if the berry weight has not presented differences, those factors affect yield, that was higher in the R₅₀ and R_75. Concerning the quality, no significant differences had been found on the various components tested.