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Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Universidade do Porto. Faculdade de Ciências The following thesis is included in the European project INNOVINE, which includes the collaboration of several scientific areas, with the purpose of presenting results of an essay in the Alentejo (Reguengos) wine region. This essay consists on the use of phytomonitorization as a tool to monitor two types of deficit irrigation, RDI – Regulated Deficit Irrigation and SDI – Sustainable Deficit Irrigation, with the purpose of understanding some determining physiological parameters of a vineyard in response to water stress, using the variety “Touriga Nacional”. For both types of deficit irrigation a representative vine was selected on which the following phytomonitoring sensors were installed (sap flow, leaf and berry temperature and trunk diameter). Leaf temperatures ranged from 7.7 °C to 52.1 °C in both modalities. It was also observed that the maximum temperature registered in both modalities was the leaves more exposed on the west side of the canopy. Berry temperature in RDI and SDI ranged between 9 ºC and 50.1 ºC. These maximums were both noticed in the most exposed cluster in the west side of the canopy. As possible estimators for physiological parameters, when analyzing a single irrigation period, we obtained high determination coefficients for the leaf temperature (R2=0.77) and for the soil humidity (R2=0.93) when related with the ΨPD. As possible estimators of ΨLeaf parameters we obtained determination coefficients of de R2=0.46 after irrigation and R2=0.56 before irrigation, both for the leaf temperature. About the stomatal conductance parameter, none of the installed sensors were able to predict with relative significance it´s values

The timing of diel stem growth of mature forest trees is still largely unknown, as empirical data with high temporal resolution have not been available so far. Consequently, the effects of day–night conditions on tree growth remained uncertain. - Here we present the first comprehensive field study of hourly-resolved radial stem growth of seven temperate tree species, based on 57 million underlying data points over a period of up to 8 yr. - We show that trees grow mainly at night, with a peak after midnight, when the vapour pressure deficit (VPD) is among the lowest. A high VPD strictly limits radial stem growth and allows little growth during daylight hours, except in the early morning. Surprisingly, trees also grow in moderately dry soil when the VPD is low. Species-specific differences in diel growth dynamics show that species able to grow earlier during the night are associated with the highest number of hours with growth per year and the largest annual growth increment. - We conclude that species with the ability to overcome daily water deficits faster have greater growth potential. Furthermore, we conclude that growth is more sensitive than carbon uptake to dry air, as growth stops before stomata are known to close., New Phytologist, 231 (6), ISSN:0028-646X, ISSN:1469-8137

RESUMO O presente trabalho teve como objetivo avaliar a sazonalidade do incremento em diâmetro do tronco de árvores de Eucalyptus grandis e sua relação com as variáveis climáticas e de fertilização nitrogenada e com lodo de esgoto. As árvores foram plantadas no espaçamento de 3 x 2 m e fertilizadas com nitrogênio (plantio, 6, 12, 18 meses) e lodo de esgoto (plantio e 8 meses), sendo selecionadas 20 árvores de eucalipto por tratamento, de acordo com a distribuição de área basal do povoamento, instalados dendrômetros de aço no DAP e mensurado o incremento em diâmetro de fevereiro/2006 a fevereiro/2008. Os resultados permitem concluir que houve efeito das variáveis climáticas na sazonalidade do incremento em diâmetro do tronco das árvores de eucalipto, sendo observado um período de defasagem (lag) de 28 dias para a resposta das árvores em relação às variáveis climáticas. Com relação ao efeito da fertilização, determinou-se que o incremento em diâmetro do tronco foi maior nas árvores de eucalipto com tratamento de lodo de esgoto em relação à adubação mineral com nitrogênio. ABSTRACT The present work aimed to evaluate the seasonal increment in diameter of Eucalyptus grandis trees for 24 months and its relationship with the climatic variables and fertilization with nitrogen and with sewer mud. The trees were planted in the spacing of 3 x 2 m and fertilized with nitrogen (planting, 6, 12, 18 months) and sewer mud (planting and 8 months). 20 trees were selected by treatment according witch the distribution of basal area and installed dendrometer bands at a 1.3 meter. The results showed a clear effect of the climatic variables on the seasonal increment in diameter of trees, being observed a delay period (lag) of 28 days for the answer of the trees in relation to the climatic variables. Regading to the fertilization effect, it was observed that the increment of trunk diameter was higher in the eucalypt trees with organic in relation to mineral fertilization with nitrogen.