Giesco
EFFECT OF WATER REGIME ON ANTHOCYANIN COMPOSITION OF FOUR RED WINEGRAPE CULTIVARS UNDER MEDITERANEAN CONDITIONS EFFET DU RÉGIME HYDRIQUE SUR LA COMPOSITION ANTHOCYANIQUE DE QUATRE CEPAGES NOIRS SOUS CONDITIONS MÉDITERRANÉENNES
THEODOROU, Nikolaos1; NIKOLAOU, Nikolaos1; ZIOZIOU, Eleftheria1; KALLITHRAKA, Stamatina2; KOTSERIDIS, Yorgos2; KOUNDOURAS, Stefanos1* 1 Laboratory of Viticulture, School of Agriculture, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece Laboratory of Enology, Department of Food Science and Technology, Agricultural University of Athens, 75 IeraOdos, 11855 Athens, Greece 2 *Corresponding author: skoundou@agro.auth.gr
Abstract: Grape anthocyanin content and composition exhibit a distinctive profile among red varieties, determining wine color intensity, hue and stability. Moreover, the manipulation of vineyard water conditions by irrigation is accepted as an effective tool for controlling berry skin phenolic ripeness, especially in semiarid environments. In this study, conducted during 2012 and 2013 in Thessaloniki, North Greece, three irrigation regimes were applied, from veraison to harvest, on four red grape varieties, namely Syrah, Grenache noir, Xinomavro and Agiorgitiko, according to a randomized block design: FI (Full Irrigation at 100% of crop evapotranspiration ETc), DI (Deficit Irrigation at 50% ETc) and NI (Non Irrigated). Stem water potential ranged, on average across years and varieties, from -1.47 to -1.67 MPa for NI and from -0.71 to -0.80 for FI. NI reduced yield and berry size in all varieties but skin-to-berry weight ratio was increased only in Xinomavro. Higher anthocyanins were observed in NI but maximum accumulation occurred 15-30 days prior to harvest in all treatments and varieties. For all varieties and years, 3'-5'-hydroxylated anthocyanins were enhanced under NI conditions compared to 3'-hydroxylated anthocyanins. Moreover, water deficit increased the percentage of acylated anthocyanins in Xinomavro, suggesting a more stable wine color, while it had the opposite effect in Agiorgitiko.
Keywords: grapevine, water deficit, irrigation, anthocyanins, wine color.
Abstract: Grape anthocyanin content and composition exhibit a distinctive profile among red varieties, determining wine color intensity, hue and stability. Moreover, the manipulation of vineyard water conditions by irrigation is accepted as an effective tool for controlling berry skin phenolic ripeness, especially in semiarid environments. In this study, conducted during 2012 and 2013 in Thessaloniki, North Greece, three irrigation regimes were applied, from veraison to harvest, on four red grape varieties, namely Syrah, Grenache noir, Xinomavro and Agiorgitiko, according to a randomized block design: FI (Full Irrigation at 100% of crop evapotranspiration ETc), DI (Deficit Irrigation at 50% ETc) and NI (Non Irrigated). Stem water potential ranged, on average across years and varieties, from -1.47 to -1.67 MPa for NI and from -0.71 to -0.80 for FI. NI reduced yield and berry size in all varieties but skin-to-berry weight ratio was increased only in Xinomavro. Higher anthocyanins were observed in NI but maximum accumulation occurred 15-30 days prior to harvest in all treatments and varieties. For all varieties and years, 3'-5'-hydroxylated anthocyanins were enhanced under NI conditions compared to 3'-hydroxylated anthocyanins. Moreover, water deficit increased the percentage of acylated anthocyanins in Xinomavro, suggesting a more stable wine color, while it had the opposite effect in Agiorgitiko.
Keywords: grapevine, water deficit, irrigation, anthocyanins, wine color.