Articles
Effects of different deficit irrigation strategies on yield components and must quality of Touriga Franca (Vitis vinifera L.) under Mediterranean climate conditions in Douro Region
Article number
1335_71
Pages
565 – 572
Language
English
Abstract
Located in the northeast of Portugal, Douro Region is characterized by high temperatures and low rainfall during the vine growing season, which may jeopardize yield and must quality.
In 2018, an irrigation trial was conducted in a plot of Touriga Franca cultivar.
Three deficit irrigation regimes and a rain-fed modality were applied in three replicated blocks: R0 (no irrigation, Control), R25 (25% of crop evapotranspiration (ETc)), R50 (50% of ETc) and R75 (75% of ETc). Water was supplied on a weekly (I8) or bi-weekly (I15) basis, since veraison until 15 days prior to harvest.
Leaf water status, canopy evolution, microclimate conditions, yield and quality of musts were evaluated.
In terms of climate, the year was characterized by higher precipitation and lower temperatures than the average at veraison and at the beginning of maturation, and hot and very dry conditions in the final period of maturation.
In this essay, no significant differences were found in total leaf area neither in most of the components of canopy density.
The level of water deficit, assessed through the predawn leaf water potential (Ψpd), was higher in I15 than I8, being the lowest values obtained in R0 and R25 (-0.48 and -0.49 MPa, respectively). At harvest, the majority of I8 modalities showed higher values of probable alcohol (%), total acidity and anthocyanins (14.37%, 4.37 g L‑1 and 220.75 mg L‑1). On the other hand, values of berry weight, polyphenols and malic acid were, higher in I15 (1.92 g, 1003.68 mg L‑1; 186.42 mg L‑1). Significant differences were observed on probable alcohol content in I15 between R0 and R75 (13.47 and 14.38% respectively). The number of clusters was affected by the frequency of irrigation, being the values in I15 higher than I8, with I15 showing significant differences in R75 in comparison to I8 (11.89 and 9.53). The yield was statistically higher in R50 between I15 and I8, with values of 2.41 and 1.47 kg vine‑1.
In 2018, an irrigation trial was conducted in a plot of Touriga Franca cultivar.
Three deficit irrigation regimes and a rain-fed modality were applied in three replicated blocks: R0 (no irrigation, Control), R25 (25% of crop evapotranspiration (ETc)), R50 (50% of ETc) and R75 (75% of ETc). Water was supplied on a weekly (I8) or bi-weekly (I15) basis, since veraison until 15 days prior to harvest.
Leaf water status, canopy evolution, microclimate conditions, yield and quality of musts were evaluated.
In terms of climate, the year was characterized by higher precipitation and lower temperatures than the average at veraison and at the beginning of maturation, and hot and very dry conditions in the final period of maturation.
In this essay, no significant differences were found in total leaf area neither in most of the components of canopy density.
The level of water deficit, assessed through the predawn leaf water potential (Ψpd), was higher in I15 than I8, being the lowest values obtained in R0 and R25 (-0.48 and -0.49 MPa, respectively). At harvest, the majority of I8 modalities showed higher values of probable alcohol (%), total acidity and anthocyanins (14.37%, 4.37 g L‑1 and 220.75 mg L‑1). On the other hand, values of berry weight, polyphenols and malic acid were, higher in I15 (1.92 g, 1003.68 mg L‑1; 186.42 mg L‑1). Significant differences were observed on probable alcohol content in I15 between R0 and R75 (13.47 and 14.38% respectively). The number of clusters was affected by the frequency of irrigation, being the values in I15 higher than I8, with I15 showing significant differences in R75 in comparison to I8 (11.89 and 9.53). The yield was statistically higher in R50 between I15 and I8, with values of 2.41 and 1.47 kg vine‑1.
Authors
L. Cabral, A. Carneiro, T. Nogueira, J. Queiroz
Keywords
canopy growth, evapotranspiration, RDI, leaf water status, microclimate
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