Browsing by Author "Barros, Ana I.R.N.A."
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- Efeito da rega e da aplicação de caulino nas características sensoriais e parâmetros de biometria da amêndoaPublication . Prgomet, Iva; Barros, Ana I.R.N.A.; Pascual-Seva, Núria; Oliveira, Ivo; Morais, Maria Cristina; Afonso, Sílvia Martins; Bernardo, Sara; Ribeiro, A.C.; Barreales, David; Victor, João; Silva, A.P.; Vilela, Alice; Gonçalves, Berta C.C.Em Portugal, a amêndoa é uma cultura tradicional, que se encontra distribuída pelas regiões do Alentejo, Algarve e Trás-os-Montes, sendo, juntamente com a castanha, a mais produzida dos frutos de casca rija. Os amendoais são geralmente tradicionais, de sequeiro, sem técnicas de cultivo adequadas, o que leva a um baixo rendimento de produção. A produtividade, bem como a qualidade dos frutos, podem aumentar com a utilização das técnicas culturais como a irrigação e aplicação de substâncias, como o caulino, para mitigação dos efeitos de stresse estival. No presente estudo, diferentes regimes de rega (100% de ETC, 70% de ETC, 35% de ETC, 100%-35% de ETC, controlo sem rega) e caulino (4%) foram aplicados durante o verão de 2015, em amendoeiras da cultivar Ferragnés situadas no Norte de Portugal (Alfândega da Fé). Foram avaliados os efeitos destes tratamentos na biometria do fruto, nas características sensoriais, no rendimento de produção e na produtividade. Verificou-se que, no caso das amendoeiras regadas com 100% de ETC, se obteve uma maior produtividade, apesar de os parâmetros da biometria das amêndoas se terem revelado mais baixos. A maior ou menor disponibilidade de água forneceram às amêndoas atributos sensoriais que as diferenciam. Assim, a rega a 35% e 100%, tornaram as amêndoas mais doces, ao passo que a falta de água (sem rega), tornou as amêndoas mais rugosas. A presença de caulino nas folhas e "rega- 70% ou 100-35%" favoreceu a cor mais escura e a dureza dos frutos em estudo.
- Kaolin and salicylic acid foliar application modulate yield, quality and phytochemical composition of olive pulp and oil from rainfed treesPublication . Brito, Cátia; Dinis, Lia Tânia; Silva, Ermelinda; Gonçalves, Alexandre; Matos, Carlos; Rodrigues, M.A.; Moutinho-Pereira, José; Barros, Ana I.R.N.A.; Correia, Carlos M.Olive orchards, rainfed managed, are threatened by the current and predicted adverse environmental conditions, which change the yield and quality of olive products, largely known for its benefits to human health. To mitigate these problems, it is highly recommended to perform some adjustments in agronomic practices, such as the use of foliar sprays that cloud help the trees to cope with climate change. During two consecutive years, olive trees were pre-harvest sprayed with kaolin (KL) and salicylic acid (SA) to attenuate the adverse effects of summer stress. Olive yield was increased by 97% and 72% with KL and SA, respectively. Phenolics and antioxidant capacity of both olives and olive oil increased and decreased in the first and second year, respectively, in a closely association with the prevailing climatic conditions. The foliar sprays did not significantly affect the oil quality indices, free acidity, peroxide value and K232 coefficient and decreased the K270 coefficient. This study strongly suggests that the applied products might be effective in mitigating the adverse environmental conditions, without substantial changes in fruit and olive oil quality.
- Physiological and biochemical performance of almond trees under deficit irrigationPublication . Prgomet, Iva; Pascual-Seva, Núria; Morais, Maria Cristina; Aires, Alfredo; Barreales, David; Ribeiro, A.C.; Silva, A.P.; Barros, Ana I.R.N.A.; Gonçalves, Berta C.C.The almond tree is generally recognized as drought-tolerant, though it depends on water resources to achieve high yields. During the summer months of two consecutive years, several physiological and biochemical parameters were observed, to understand the almond tree’s seasonal sensitivity and behavior under different irrigation strategies based on crop evapotranspiration (ETc): T100 optimal water requirement regime (applying 100% ETc); T70 and T35 sustained deficit irrigation regimes (applying 70% and 35% ETc); T100-35 regulated deficit irrigation regime (reducing the application to 35% ETc during fruit filling stage); and T0 (rainfed). The total leaf chlorophyll and carotenoid reduction in T0 and T35 treatments was significant compared to T100-35. Leaf soluble proteins and total soluble sugar contents were significantly higher in non-irrigated trees compared to other treatments, while the starch content showed the opposite trend. Rainfed trees were under obvious water stress, displaying the lowest values for relative water content (RWC), stomatal conductance (gs), photosynthetic rate (A), and transpiration rate (E), and the highest for intrinsic water use efficiency (A/gs). Plant hormones (ABA and IAA) generally accumulated more in non-irrigated trees. The almond tree has been confirmed as a drought-tolerant species, and when water is scarce, reducing the water application to 35% ETc during fruit filling stage, results in no yield losses, and the plant status remains unstressed. However, to get the maximum crop potential, in years and areas where water is not restricted, full irrigation requirements have been shown to boost almond tree performance.
- Weather year-to-year variations determine the influence of kaolin and salicylic acid in olive fruits and oil phenolic compositionPublication . Brito, Cátia; Dinis, Lia Tânia; Silva, Ermelinda; Gonçalves, Alexandre; Rodrigues, M.A.; Moutinho-Pereira, José; Barros, Ana I.R.N.A.; Correia, Carlos M.Olive tree (Olea europaea L.) growing area is threatened by the current and predicted adverse environmental conditions, affecting negatively the quality of the olive products, largely known for its benefits in human diet. Thus, agronomic strategies may be implemented to offset those negative effects. During two consecutive years young olive trees under rainfed conditions were sprayed in the beginning of the summer season with 100 M salicylic acid (SA), a stress signaling phytohormone, or with kaolin 5% (KL), a heat and irradiance reflecting clay. The distinct weather conditions during the fruit development stage, with higher rainfall close to the harvest and the early frost events, in the first year, and the warmer and drier summer, in the second year, contributed to the increase in phenolic compounds in fruits and in olive oil from the first to the second year. Both KL and SA increased crop yield, while, in general, phenolics concentrations of both olives and oil were increased and decreased by the applied products in the first and second year, respectively. This dissimilar response was modulated by the distinct weather conditions, demonstrating the effectiveness of the applied products in attenuating the frost-promoted degradation of phenolic compounds in the first year and in mitigating the extreme adverse conditions felt in the summer of the second year. The phenolic composition was also distinctly affected, since total phenols, ortho-diphenols and flavonoids exhibited different trends. It is hard to conclude a specific influence of the applied products on olives and oil phenolic composition, since the weather year-to-year variations determine different plant responses.