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- Avaliação do efeito de diferentes regimes hídricos na produtividade da água e rendimento do amendoalPublication . Ribeiro, A.C.; Barreales, David; Andrade, João Verdial; Pereira, Ermelinda; Victor, JoãoA amendoeira e uma especie muito tolerante a seca. Todavia, nao ha duvidas de que a rega e urn fator critico para o aumento da produtividade do amendoal e da qualidade da amendoa, em particular em regioes de clima mediterranico. 0 objetivo desse estudo consiste em avaliar o efeito de diferentes regimes hfdricos no rendimento e na produtividade da agua do amendoal. Neste trabalho, que enquadra num projeto mais amplo de avalia~ao de urn conjunto de estrategias integradas para o aumento da produtividade da amendoeira na regiao de Tras-os-Montes, apresentam-se os resultados de urn ensaio experimental que decorreu durante dois anos (2015-2016) num amendoal adulto (417 amendoeiras/hectare da variedade Ferragnes), localizado em Alfandega da Fe (lat. 41· 21'; long. 6· 57'; alt. 576 m). 0 dispositive experimental consistiu num sistema em blocos corn 4 tratamentos de rega e uma testemunha nao regada (NR). As dota~oes foram determinadas em fun~ao da evapotranspira~ao da cultura (ETc) : RP100 (100%ETc), RD70 (70%ETc) e RD35 (35%ETc) RDC (100%ETc ate ao enchimento do fruto e redu~ao posterior para 30%ETc). Os resultados mostram urn efeito significativo na melhoria do estado hfdrico das arvores regadas durante a esta~ao de crescimento. Os valores do potencial hidrico do ramo nas amendoeiras submetidas a RP100 variou entre -0,8 e -1,2 MPa diminuindo significativamente nos tratamentos submetidos a uma rega deficitaria. 0 potencial hidrico das amendoeiras nao regadas variou entre -2,0 e -3,5 MPa. Verificou-se, ao longo do periodo de crescimento, uma tendencia para urn maior aumento do peso seco do miolo da amendoa nos tratamentos RP100, RD70 e RDC relativamente ao tratamento RD35 e a testemunha NR. A produtividade da agua foi significativamente superior nas amendoeiras submetidas aos regimes hfdricos mais deficitarios. Os valores a variaram entre os 2,1 e 3,2 kg/ha/mm nos tratamentos corn rega plena e os 4,3 e 6,1 kg/ha/mm nos tratamentos de rega deficitaria.
- Response of two grapevine (Vitis vinifera L.) Portuguese varieties Tinta Roriz and Touriga Nacional to different irrigation regimes in the Douro RegionPublication . Ribeiro, A.C.; Barreales, David; Andrade, João VerdialThe vineyards located in regions with seasonal drought (e.g. climate of the Mediterranean type), where soil and atmospheric water deficits, together with high temperatures, have significant constraints in yield and quality. In the hot and dry Douro Region, limitations in water supply have a great impact on grape production as the annual rainfall is not adequate to provide grapevines with their water requirements, and water deficits usually develop gradually during summer causing important crop losses. Regulated Deficit Irrigation (RDI) is one of the most frequently used irrigation strategies in vineyards with the aim to balance grapevine vegetative and reproductive growth by applying less than the full vineyard water use at specific periods of the growing season. However, successful strategies may vary among regions with different climates and can even be site specific, depending on the interactions within the grapevine variety, soil type and vineyard management practices. The effect of several deficit irrigation regimes on vine water status, grape yield and quality parameters were studied in two Portuguese cultivars, Tinta Roriz and Touriga Nacional (Vitis vinifera L.) grown in a commercial vineyards located in the Douro region, Portugal. Treatments consisted of non-irrigated vines and three deficit irrigation regimes with a constant fraction of reference evapotranspiration (ETo): 0.2, 0.4 and 0.6. The reference evapotranspiration was calculated using modified FAO Penman-Monteith equation and water was applied three times a week, from pre-veraison until one week before harvest, through a drip irrigation system. The results showed that moderate water supplies during ripening period, for the region where the study was conducted (severe water deficits), improved significantly the grapevine water status, leaf photosynthesis and transpiration in both cultivars. Yield components and pruning weights showed a significant increase in irrigated treatments with more water supplied. There were no significant differences in the majority of fruit quality parameters. However, the total phenols and the colour intensity showed a tendency to decrease in irrigated treatments with more water supplied.
- Análise sensorial de vários tipos de hidromelPublication . Gomes, Teresa; Dias, Teresa; Andrade, João Verdial; Cadavez, Vasco; Morais, Jorge Sá; Ramalhosa, Elsa; Estevinho, Leticia M.A região de Trás-os-Montes e uma das grandes produtoras de mel no pais. No entanto, existe dificuldade em escoar a produção surgindo o hidromel como uma alternativa possível para ultrapassar este problema. Com base em resultados obtidos pela nossa equipa, este trabalho teve como objective avaliar as características sensoriais do hidromel produzido a escala piloto. Resultados anteriores indicam que a levedura Saccharomyces cerevisiae Fermol® Reims Champagne (Pascal Biotech®) á a mais indicada para a fermentação do hidromel. As condições ideais para a produção de hidromel obtidas com base no desenho experimental foram: temperatura entre os 24°C e os 29°C e concentração de sais entre 85 e 100 g/hL.
- Optimization of mead production using response surface methodologyPublication . Gomes, Teresa; Barradas, Carla; Dias, Teresa; Andrade, João Verdial; Morais, Jorge Sá; Ramalhosa, Elsa; Estevinho, Leticia M.The main aim of the present work was to optimize mead production using Response Surface Methodology. The effects of temperature (x1: 20–30 ºC) and nutrients concentration (x2: 60–120 g/hL) on mead quality, concerning the final concentrations of glucose (Y1), fructose (Y2), ethanol (Y3), glycerol (Y4) and acetic acid (Y5), were studied. Twelve operational conditions were tested. No delays and moods were observed during fermentations. The second order polynomial models determined produced satisfactory fittings of the experimental data with regard to glucose (R2= 0.646, p = 0.001), ethanol (R2= 0.741,p = 0.049), glycerol (R2= 0.899, p = 0.002), fructose (R2= 0.902, p = 0.033) and acetic acid (R2= 0.913,p = 0.001). The optimum extraction conditions determined in order to maximize the combined responses were 24 ºC and a nutrients concentration of 0.88 g/L. The mead produced under these conditions had the following characteristics: ethanol concentration of 10.2%, acetic acid 0.54 g/L, glycerol 7.8 g/L, glucose 1.8 g/L and fructose 2.5 g/L. These values were in agreement with the predicted and were within the safe limit established for acetic acid and the recommended range for glycerol. Furthermore, the residual sug- ars concentration was also low, decreasing the possibility of occurring undesirable refermentations.
- Climate change potential effects on grapevine bioclimatic indices: a case study for the Portuguese Demarcated Douro Region (Portugal)Publication . Blanco-Ward, Daniel; Ribeiro, A.C.; Barreales, David; Castro, João Paulo; Andrade, João Verdial; Feliciano, Manuel; Viceto, Carolina; Rocha, Alfredo; Carlos, CristinaIn this work bioclimatic parameters and indices relevant to the grapevine are estimated for the years 2000 (past-recent), 2049 (medium-term future) and 2097 (long-term future), based on high resolution (1 km x 1 km) MPI-WRF RCP 8.5 climate simulations. The selected parameters and indices are mean temperature during the grapevine period (April to October), cumulative rainfall during the grapevine period, Winker index (IW), Huglin heliothermic index (IH), night cold index (IF) and dryness index (IS). In general, a significant increase in mean temperature during the grapevine period is observed, together with a significant decrease in precipitation. The present IW is associated with the production of high quality wines; the higher values predicted for the future represent intensive production of wines of intermediate quality. The IH show the passage of a growing region of the vine considered as hot-temperate to a warm category of higher helio-thermicity. At present, IF indicates very cool conditions (associated with quality wines), while in the future there is a tendency for temperate nights. Finally, IS indicates an increase in water stress considered already high in the present climate. An assessment on the statistical significance of climatic indices, their differences between the historical and the future scenarios and the potential impact on wine production is performed. Preliminary results indicate increased climatic stress on the Douro region wine production and increased vulnerability of its vine varieties. These results will provide evidence for future strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.
- Effects of irrigation and collection period on grapevine leaf (Vitis vinifera L. var. Touriga Nacional): Evaluation of the phytochemical composition and antioxidant propertiesPublication . Barreales, David; Malheiro, Ricardo; Pereira, J.A.; Andrade, João Verdial; Bento, Albino; Casquero, Pedro Antonio; Ribeiro, A.C.The cultivation of grapevines (Vitis vinifera L.) has extended worldwide, with great economic importance. From this crop, we can obtain grapes for fresh consumption, raisins, juices, wine, and other derived products. The cultivation of grapevines also generates some byproducts, such as seeds, skins, wood and leaves. The leaves can be removed from the plant, as is common agricultural practice, to improve the production and quality of the grapes at certain periods in the crop cycle. In the present work, the phytochemical composition (total phenols content, hydroxycinnamic acids derivatives and flavonols) and antioxidant potential (reducing power, ABTS and DPPH radical scavenging capacity) of grapevine leaves from cv. Touriga Nacional were evaluated. The studied cultivar was under three severities of regulated deficit irrigation (RDI60, RDI40, and RDI20; providing 60, 40 and 20% of reference evapotranspiration, respectively) and non-irrigation (NI; exclusively rain-fed), in a vineyard located in the Demarcated Douro Region (Portugal). The leaves were collected at three different phenological stages: veraison, maturation, and grape harvest. For the first time, the interactions between different irrigation regimes and the collection period were evaluated on grapevine leaves. The results obtained for the phytochemical composition revealed that increasing irrigation reduced total phenols content, hydroxycinnamic acids derivatives, and flavonols in all of the phenological stages studied. For instance, compared to that of the control treatment (NI), the total phenols content reduced 19% in RDI20 (from 189 mg GAE g−1 to 153 mg GAE g−1), 28% in RDI40 (136 mg GAE g−1), and 33% in RDI60 (127 mg GAE g−1). The antioxidant activity suffered a reduction when the irrigation amount was increased for all assays. Additionally, the antioxidant activity suffered a reduction over time, presenting higher values in veraison. For harvest sampling, the loss of antioxidant activity was more notable, with EC50 values varying between 0.092 mg mL−1 (NI) and 0.187 mg mL−1 (RDI60). Altogether, the results suggest that grapevine leaves are a potential source of natural compounds with valuable antioxidant properties that could be explored by the pharmaceutical, chemical and food industries.
- Importância dos inimigos associados à oliveira para azeitona de conserva no planalto mirandêsPublication . Bento, Albino; Andrade, João Verdial; Ribeiro, A.C.; Rodrigues, M.A.; Cabanas, J.E.; Pereira, J.A.Em Trás-os-Montes, a oliveira É uma das culturas mais importantes. Nesta região, a maioria da produção de azeitona e destinada à obtenção de azeite. Contudo, nos concelhos de Freixo de Espada à Cinta e Mogadouro, a quase totalidade da produção é destinada para azeitona de conserva podendo ser certificada como "Azeitona de Conserva Negrinha de Freixo" DOP.
- Pesquisa de resíduos de fungicidas no mosto e no vinhoPublication . Pinto, Miguel; Pereira, Sandra; Fernandes, Conceição; Andrade, João Verdial; Estevinho, Leticia M.
- Mead production improvements after using a factorial desingPublication . Gomes, Teresa; Dias, Teresa; Andrade, João Verdial; Cadavez, Vasco; Morais, Jorge Sá; Ramalhosa, Elsa; Estevinho, Leticia M.Anexo
- Efeito da rega deficitária no estado hídrico, rendimento e composição do bago da cv. Touriga Nacional (Vitis vinífera L.) cultivada em modo de produção biológicoPublication . Ribeiro, A.C.; Ferrão, Diogo; Andrade, João VerdialA rega deficitária é uma das estratégias de rega mais utilizadas na cultura da vinha. O efeito da rega deficitária no rendimento e qualidade da uva depende da severidade e do padrão do stresse hídrico que é imposto. O objectivo principal da rega deficitária na cultura da vinha é o de maximizar a qualidade da uva para a produção de vinho, sem comprometer o rendimento. A resposta da videira à rega deficitária é influenciada pelas condições climáticas, características do solo, variedade e porta-enxerto e práticas culturais. Neste estudo foi avaliado o efeito de três estratégias de rega deficitária. As estratégias consistiram na aplicação de três níveis de rega calculados com base na evapotranspiração de referência diária (ETo): 20, 40 e 60% da ETo. A rega foi efectuada desde o início no pintor até à vindima. Os trabalhos de campo foram conduzidos em 2014 e 2015 numa vinha comercial, localizada na região Demarcada do Douro. O estado hídrico da videira foi avaliado através da medição do potencial hídrico foliar. A dimensão e composição do bago foram avaliadas semanalmente, durante o curso da maturação. Na vindima foi determinada a produção e a composição do mosto. Foi determinado o índice de área foliar, medido o diâmetro do tronco e pesada a lenha da poda. Ao longo da maturação, as videiras estiveram submetidas a um de stresse hídrico que variou entre o moderado e o severo. As videiras dos tratamentos regados com dotações mais elevadas (40 e 60%ETo) apresentaram os maiores valores de produtividade e vigor. Na maioria dos parâmetros relativos à composição do bago não se observaram diferenças significativas. Contudo, observou-se uma tendência para o aumento da acidez total e um decréscimo dos teores em fenóis totais e da intensidade corante nos tratamentos com maiores dotações de rega.