Percorrer por autor "Santos, D."
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- Biomarkers of oxidative stress in olive rainfed orchards under different cover cropsPublication . Correia, Carlos M.; Santos, D.; Brito, Cátia; Ferreira, Helena; Bacelar, Eunice; Gonçalves, Berta C.C.; Moutinho-Pereira, José; Rodrigues, M.A.In Northeast Por1ugal, as in •other regions of the Mediterranean Basin, most of the olive orchards are cultivated in hilly areas under rainfed conditions and this picture will not significantly change in the near future due to natural Iimitation on water resources. We propose cover crops to Iimit soil erosion, improve soil quality and fertility, reduce the use of herbicides and other chemicals and develop the nutritional value of food products.
- Cover crops for the sustainability of rainfed olive orchardsPublication . Bacelar, Eunice; Correia, Carlos M.; Santos, D.; Moutinho-Pereira, José; Gonçalves, Berta C.C.; Brito, Cátia; Ferreira, Helena; Rodrigues, M.A.Olive tree (Olea europaea L.) is present in large areas of mainland PortugaL predominantly in less-favored regions. In spite of the fact that irrigated areas are currently increasing, most of the olive orchards are still cultivated under rainfed conditions. The success of olive farming under rainfed conditions is mainly due to the high capacity of olive tree to develop anatomical, physiological and biochemical drought resistance mechanisms. Nevertheless, the productivity is low. We propose cover cropping to control soil erosion, improve soil quality and fertility of rainfed oli\'e orchards. Cover cropping is widespread in fruit farming in temperate climates and in irrigated olive orchards, where water is not a limiting resource. The effects of cover cropping were investigated on a 14-year-old olive orchard (Olea europaea L., c. Cobrançosa) with 240 trees ha-1, grown under rainfed conditions. The commercia! orchard was located in Mirandela, in the Northeast of Portugal (41 0 31' N; 7° 12' W). Four different soil management systems were compared: (i) development of natural vegetation, (ii) self-reseeding pasture species, such as subterranean clover and other annual legume species with short growing cycle grown as cover crop; (iii) white lupine cover crop; (iv) conventional tillage, included as the control treatment. We verified that self-reseeding pasture cover crop improved the photosynthetic activity of the olive trees in association with increases of stomatal conductance, the quantum effective efficiency of PSI!, the photochemical quenching and the apparent electron transport rate. The total leaf soluble protein content in the leaves was higher in trees with self-reseeding pasture cover crop that may represent increased activity of antioxidant enzymes. The level of lipid peroxidation, measured in terms of thiobarbituric acid-reactive substances (TBARS) contents, was lower in pasture cover crop and in the control treatments during the dry season. In early winter lupine cover crop and conventional tillage had higher TBARS concentrations, revealing increased peroxidative damage. At this early stage of the study, data support the use of cover crop in olive rainfed orchards, specially using self-reseeding pasture species.
- + Idade + Saúde: programa de actividade física regular para a população séniorPublication . Rocha, E.; Matos, Sara; Sadio, Alexandre; Santos, D.; Ferreira, Ana Sofia de Jesus; Ventura, Serafim; Monteiro, A.M.Segundo a Organização Mundial de Saúde (OMS, 2002), o número de indivíduos com mais de 65 anos irá duplicar nos próximos 50 anos, consequentemente têm surgido novos programas de actividade física de modo a tornar esta população mais activa e saudável. Objectivos: O programa consiste em observar os efeitos (“dose-resposta”) de diferentes tipos de treino na aptidão física e funcional dos idosos: Comparar os níveis de força e potência musculares ao longo de diferentes programas de treino; comparar as alterações da composição corporal ao longo dos diferentes programas de treino; comparar o nível da actividade funcional dos idosos ao longo dos diferentes programas de treino; comparar o nível da actividade física dos idosos ao longo dos diferentes programas de treino. Metodologia: A amostra foi composta por 100 idosos voluntários, de ambos os sexos com idade igual ou superior a 65 anos. Os idosos foram subdivididos em quatro grupos: Grupo I – Grupo de controlo (Não submetido à prática de actividade física); Grupo II – Grupo submetido a um programa de treino de força potência (programa A); Grupo III – Grupo submetido a um programa de treino força resistência (Programa B); Grupo IV – Grupo submetido a um treino predominantemente aeróbio baseado secções de ginástica de manutenção (Programa C). O treino de Força visou o desenvolvimento da força e potência, teve a duração de 8 meses com 3 sessões semanais. Cada sessão foi composta essencialmente por 7 exercícios: Prensa de pernas, tronco, supino, puxador alto, extensão de pernas e flexão de pernas. Avaliação da Força: A avaliação isocinética da força dos músculos flexores e extensores do joelho de ambos os membros inferiores (dinamómetro Biodex, System 2, USA). Foi avaliada a composição corporal através de bioimpedância e DEXA (Dual-energy X-Ray abs or ptiometry, da Hologic Mod Explorer ®). A actividade Física diária foi calculada através do questionário de Baecke modificado e de monitores de actividade física habitual CSA (Computer Science Applications). Foi utilizado a Sénior Fitness Test desenvolvida por Rikli e Jones (2001) para avaliar a aptidão funcional. Ao longo dos três anos do programa é notório um crescimento exponencial da população sénior a este programa.
- Impacto de sistemas de gestão do solo na fisiologia do olival de sequeiroPublication . Brito, Cátia; Bacelar, Eunice; Moutinho-Pereira, José; Gonçalves, Berta C.C.; Ferreira, Helena; Santos, D.; Rodrigues, M.A.; Correia, Carlos M.A oliveira (Olea europaea L.) é uma espécie bem adaptada às condições da região Mediterrânica. Contudo, longos períodos de seca e elevadas temperaturas estivais prejudicam a fisiologia e a produtividade dos olivais de sequeiro. Uma das soluções para minorar este problema passa pela otimização do uso da água através da gestão cuidadosa da superfície do solo. Nesse sentido desenvolveram-se duas experiências em olivais de sequeiro na região de Trás-os-Montes.
- Oxidative stress and antioxidant responses in olive tree subjected to cover crops under rainfed conditionsPublication . Correia, Carlos M.; Brito, Cátia; Santos, D.; Bacelar, Eunice; Gonçalves, Berta C.C.; Ferreira, Helena; Moutinho-Pereira, José; Rodrigues, M.A.Since Mediterranean basin is particularly vulnerable to present and future climate variability and climate change, olive tree will experiment some hard changes in its environment. Under adverse conditions, imbalances in metabolic processes may lead to increased accumulation of ROS, forming a potential threat of oxidative damage to cells. We propose green manure legumes to shift tillage, in order to improve soil water relationships during the drought period. The research was carried out in northeast Portugal under rainfed conditions. The treatments laid out were: ordinary tillage techniques and a mixture of eleven annual (AL) pasture self-reseeding legumes. The results obtained in summer 2011 revealed that olive in AL plot had higher concentrations of chlorophylls, carotenoids and total thiols, as well stomatal conductance, net photosynthesis, qP, FvN/FmN, quantum yield of PSII, ETR and APX activity. Conversely, olive trees subjected to tillage had higher qN and GST activity. No significant differences were reported in electrolyte leakage, CAT activity and in TBARS and total phenols concentration. Thus, legume species may be a promising strategy contributing to the sustainable management of olive orchards.
- Short and long-term benefits of white lupin as a cover crop on olive physiologyPublication . Brito, Cátia; Moutinho-Pereira, José; Bacelar, Eunice; Gonçalves, Berta C.C.; Ferreira, Helena; Santos, D.; Rodrigues, M.A.; Correia, Carlos M.Several positive effects of cover crops in orchards have been documented, including improvement on soil properties, which are reflected on tree physiological performance and yield. The use of legume species, such as white lupin, can provide other gains since they can fix atmospheric N2, reducing the cost with N fertilizers. However, this species need to be sown every year, which is costly and laborious. So, we aim to test if still remain in the year after it had been grown the benefits of cover crop on physiological performance of olive tree. Three different soil management systems were investigated on a 15-year-old olive orchard (Olea europaea L. , cv. Cobrançosa) grown in rainfed conditions: (1) conventional tillage, included as the control treatment (CT); (2) white lupin sowed in two consecutive years, 2009 and 2010 (LCY); (3) white lupin sowed in the first year, 2009 (LFY). The physiological parameters were determined in three periods of 2011: April, July and September.