Influence of Irrigation on Vigor, Quality and in and Touriga Francesa varieties in Region

A. Silva1, I. Cabral1, J. Queiroz1 1 GreenUPorto – Research Centre for Sustainable Agrifood Production & DGAOT, Faculty of Sciences, University of Porto

INTRODUCTION RESULTS  in is an important socio-economic and cultural sector, as countless  TOURIGA NACIONAL Portuguese reach the world;

Pre-Dawn Leaf Water Potencial  Studies show that in the future, Portugal will undergo major climate changes by Total Leaf Area (m²/vine) increasing temperature and drought, leading to lower water availability and rising water (MPa) stress. I15

These will cause physiological changes in the plant affecting the productivity and quality of . Therefore, the study of the influence of irrigation is essential. Quality

AIM

 Understand the impact of different water regimes on vigor, quality and productivity in the Touriga Nacional and Touriga Francesa varieties; I8

 Obtain a wider range of data to allow for greater consistency in results, considering possible interactions with the climate that varies annually

Define the most appropriate treatment of irrigation to achieve the highest quality and productivity in the Touriga Nacional and Touriga Francesa varieties. Yield METHODOLOGY Field Characterization:

 Located at Quinta da Cabreira, Vila Nova de Foz Côa, in Douro Superior Sub-region;  Treatment I15 (biweekly irrigation): 10 vines x 2 rows x 4 modalities of watering x 3 blocks;  Treatment I8 (weekly irrigation): 5 vines x 2 rows x 4 modalities of watering x 3 blocks.  TOURIGA FRANCESA  Modalities in each treatment:

R0: Control: Rain fed; Pre-Dawn Leaf Water Potencial Total Leaf Area (m²/vine) R25: Watering of 25% of evapotranspiration (Etc); (MPa) R50: Watering of 50% of ETc; R75: Watering of 75% of ETc; Records Performed:; . Total leaf area (m²), according to Lopes & Pinto (2005). (September 4 – Ripening period); I15

. Pre-dawn Leaf Water Potential, with a Schölander pressure chamber: from June 24th, every 15 days;  Irrigation started when level of pre-dawn leaf water potential reached -0.30MPa.

. Berry quality: probable alcohol (%), total acidity (g/L), anthocyanin content (mg/L) at Quality ; . Yield: number of clusters and yield (kg/plant) at harvest. I8

CONCLUSION

 Vigor and Vegetative Expression : The I8 test obtained relatively higher values; I8  Quality:  Touriga Nacional variety, the I8 test obtained higher values in relation to the I15 test.  Touriga Francesa, the I15 test in probable alcohol, malic acid, anthocyanins and polyphenols showed higher values;  Yield: Higher in both varieties, in the modalities with higher irrigation allocations, in the I8 test;

• The modalities R50 and R75 The most favorable values; • In qualitative and quantitative terms Higher irrigation allocations seem to have a positive impact on vines and particularly in the production of for Yield .

REFERENCES Almeida, C. (2006). História do Douro e do Vinho do Porto. E

(1) Significance of the test to the Analysis of Variance of Means (ANOVA). “n.s” – not Smart, Richard; Robinson, M. (1991). Sunlight into Wine: A Handbook for Winegrape significant; “*” – p<0,05 - significant; “**” – p<0,01 – very significant. Canopy Management. (Winetitles, Ed.). Austrália. Lopes, C., & Pinto, P. A. (2005). Easy and accurate estimation of grapevine leaf area with simple mathematical models. - Journal of Grapevine Research, 44(2), 55–61