668 research outputs found

    NEW DYAD FROM RENEWABLE SOURCE FOR APPLICATIONIN ORGANIC SOLARCELLS

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    This work was supported by the Araucária Foundation, a Research Founding Agency from Paraná State – Brazil, CAPES and CNPq

    Ecophysiological potential of the Dão terroir for the production of Touriga Nacional red grapes

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    Proceedings - IX International Terroir Congress, 2012Aiming to evaluate the potential of the portuguese Dão winegrowing region for the production of Touriga Nacional (TN) red grapes, climatic, ecophysiological and viticultural data from two different climatic years (2004, wet year and 2005, dry year) are presented and discussed. The data was collected in the control non-irrigated plants of an irrigation experiment installed at the Dão Research Station, Nelas, Portugal. The vineyard is established in a typical granitic soil and trained on a vertical shoot positioning. According to the Géoviticulture Multicriteria Climatic Classification System, the Dão region is classified as temperate/temperate warm for the heliothermal index, with cool nights (night cold index) and moderately dry (dryness index). In 2004 the predawn leaf water potential presented always values higher than -0.2 MPa from flowering to harvest but in 2005 moderate to severe water stress was observed during the ripening period (-0.4 MPa at veraison to -0.6 MPa at harvest). Leaf stomatal conductance and photosynthetic rate displayed a decreasing pattern from flowering to harvest in both years but attained much lower values in the 2005 ripening period as compared to that of 2004. The yield was similar in both years but 2005 showed lower sugar content, similar titratable acidity and a higher anthocyanin berry skin content. Our data shows that the Dão terroir presents a high inter-annual climate variability which has important repercussions on TN responses being the most unfavorable climatic years those were the high temperatures are coincident with water stress during the first half of the ripening period. In those years irrigation should be applied in order to obtain better quality grapes

    Response of growth, yield and berry composition to basal leaf removal in Jaen grapevine

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    Results from a leaf removal experiment located at Dão Winegrowing region of Portugal are presented. Three intensity levels of defoliation (control non-defoliated, leaves removed up to the third basal node and up to the sixth basal node) are compared. Defoliation treatments had no significant effect on yield and on must soluble solids, showing that the remaining leaves were able to guarantee berry development and sugar accumulation in the fruit. The more intense defoliation treatment induced favorable effects on light microclimate in the cluster zone, with positive consequences for polyphenols synthesis and reduction of Botrytis cinerea Pers. incidenceinfo:eu-repo/semantics/publishedVersio

    Effect of vineyard floor management practices on water use: A case study at a terroir of the "Dão" winegrowing region in Portugal

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    Aiming to evaluate the effect of vineyard floor management practices on water use and vine performance, a field experiment was carried out at the Dão Wine Research Station, located at Nelas, Center Portugal. The experiment was set up in 2010 in a mature vineyard planted with the red grape variety ‘Touriga Nacional’, using a 2x2 factorial design with the following treatments: inter-row soil management (permanent resident vegetation vs. soil tillage) and undervine floor management (mulch vs. herbicide). In this paper it will be presented data from 2013 growing season (four seasons after experiment setup). The volumetric soil moisture, assessed with a capacitance probe to a 1.5 m depth, showed a decreasing pattern throughout the growing season in all treatments with the resident vegetation presenting lower values as compared to the tillage treatment, while no significant differences were observed between the two undervine floor management practices. From budburst to flowering the resident vegetation treatment showed a higher soil water depletion (up to 1.5 m depth) than the tillage treatment but the relative situation was reversed during the flowering-veraison period, while no significant differences were observed during the ripening period. Vine stem water potential values showed a decreasing pattern along the season attaining very low values during September but with no significant differences between treatments. In general the soil management practices did not significantly affect vine vigor, yield and berry composition however, since these results are only from one season, further data analysis in ongoing in order to allow stronger conclusions.info:eu-repo/semantics/publishedVersio

    Effects of irrigation on the vigour, yield and berry composition of the red variety Touriga Nacional at the Dão winegrowing region, Portugal

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    Proceedings - 17 th International Symposium GIESCO, Asti, Italy, 2011In a field trial installed at the Centro de Estudos Vitivinícolas do Dão, Nelas, Portugal, the effect of three irrigation treatments on the agronomic behaviour of cv Touriga Nacional (Vitis vinifera L.) were studied during three growing seasons (2006-2008). Three irrigation treatments (DI30 - irrigation with 30% of ETc; DI50 - irrigation with 50% ETc, FI - full irrigation – 100% Etc) were compared to a control non-irrigated treatment (NI). Compared to NI, the deficit irrigation treatments (DI30 & DI50) showed no significant differences on the yield and its components. The full irrigation treatment induced a significantly higher yield due to a higher bunch weight, as compared with the others treatments. Compared to the control, the deficit irrigation treatments presented similar berry composition during all the three seasons. The FI treatment presented, in all seasons, a significantly higher total acidity and a significantly lower Brix and total anthocyanins concentration as compared to the other treatments. The pruning weight and shoot weight increased with the amount of irrigation water applied, but significant differences were found only between the FI and the NI treatments, the last presenting the lowest values. Despite the fact that in the non-irrigated vineyards of the Dão winegrowing region it is very common to observe vine water stress symptoms, mainly during the ripening period, during the three studied seasons (2006-2008), the deficit irrigation treatments showed no advantages relatively to the control non-irrigated. Despite the higher yield produced in the full irrigation, this treatment had the disadvantages of the excessive vine vigour and lower must quality produced

    Daily evolution of the components of the balance of radiation of vines in a vineyard in the Dão region

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    Proceedings - 17 th International Symposium GIESCO, Asti, Italy, 2011In order to validate a model of vine transpiration based on radiative surface temperature a field trial was conducted in a vineyard in the Dão region, centre of Portugal, with the cultivar “Touriga Nacional”. The model is based on the partition of net radiation between the components of the canopy (vines, soil, and grass cover), considering that the vines and the undercover (soil plus grass cover) act separately and in parallel. Thus, the latent heat flux from the vines to the atmosphere (lTc) is determined from vine net radiation (Rnc) and sensible heat flux (Hc). The partition of net radiation (Rn) between the undercover (Rns) and the vines (Rnc) is made considering the exponential form for radiation extinction, with the coefficient of extinction being corrected with a factor dependent on the zenital solar angle (j) while leaf area index (LAI) is corrected with a clumping factor, Ω(φ). Sensible heat flux from the vines (Hc) is calculated from radiative temperature (Tc) considering that the fluxes from the different origins are independent and that there are two resistances in series between the canopy and the atmosphere: the leaf boundary layer resistance (raHc) and the aerodynamic resistance of the crop (raH). Besides the estimation of the daily values of transpiration, the model allows to study the evolution of the different components of the radiation balance throughout the day. The daily evolution of the evaporation fraction from the vines (FEc) can be approximated by a concave curve. Values of FEc > 1 show that, under certain circumstances and periods of the day, energy used for transpiration (lTc) is greater than crop net radiation, which indicates that there are exchanges of energy between the several components of the surface, namely when evaporative demand from the atmosphere is high and there are no soil water restrictions. The model also shows that, regardless of the soil water status, transpiration is a big part of Rn when these values are low (in the beginning of the morning and late afternoon)

    PHOTOCATALYTIC ACTIVITY OF GRAPHENE OXIDE/ZnO COMPOSITES FOR DYE DEGRADATION

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    This work was supported by the Araucária Foundation, a Research Founding Agency from Paraná State - Brazi

    Monda de cachos na casta ´Touriga Nacional´, região do Dão

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    Num ensaio instalado na Quinta da Cale, Nelas, durante dois anos consecutivos (2004-2005) foram comparadas duas intensidades de monda ao pintor - M30 (monda de 30% cachos) e M50 (monda de 50% cachos), com uma testemunha não mondada. Foram analisados o rendimento e seus componentes, os parâmetros de qualidade das uvas e calculado o retorno financeiro da produção com e sem a realização da monda. Os vinhos resultantes do ciclo de 2005 foram sujeitos a prova organoléptica. Comparativamente à testemunha não mondada, a monda não provocou alterações significativas na fertilidade, abrolhamento e vigor mas induziu uma redução da produção de 37% (M30) e 52% (M50) em 2004 e de 36% (M30) e 20% (M50) em 2005. Com excepção do grau álcool provável do mosto, a monda de cachos não induziu alterações significativas quer na composição do mosto quer nas características organolépticas dos vinhosinfo:eu-repo/semantics/publishedVersio
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