Percorrer por autor "Silva, Ermelinda"
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- Annual legume cover crops enhance the sustainability of rainfed olive orchards: from leaf ionome to tree physiologyPublication . Correia, Carlos M.; Martins, Sandra; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Moutinho-Pereira, José; Rodrigues, M.A.; Gonçalves, AlexandreThe olive sector has an important economic, social, cultural and ecological relevance in the Mediterranean region, where tillage and herbicides application still are generalized practices, although the recommendations of UE policy for a more sustainable agriculture. Cover crops with self-reseeding legumes of short-cycle, with mulch of dead vegetation during the dry season, is our option for soil management in olive tree rainfed orchards, as they provide protection against erosion, improve the physical and chemical properties, nitrogen fixation and soil moisture, enhance biodiversity and landscape beautification, while contribute to mitigation and adaptation to climate change and enable the organic production mode. The experiment was carried out during 2016 and 2017 on a commercial orchard (cv. Cobrançosa) in Northeast Portugal. The treatments laid out were: (1) ordinary tillage techniques used by local growers (two tillage trips per year) and (2) a mixture of 11 self-reseeding annual legumes (AL). The results revealed that cover crops influence positively the tree water status during the drought season, as well the nutritional status, namely the foliar concentrations of nitrogen, magnesium and manganese, both during the winter resting period and in summer, at endocarp sclerification. As a result, AL trees presented greater physiological performance during the summer, as evidenced by higher net photosynthetic rate, mainly due to inferior stomatal limitations, lower investment of resources in defensive metabolites, and enhanced yield. These results indicate that cover cropping should be included in the portfolio of adaptive management strategies against climate change, contributing to the sustainability of rainfed orchards.
- Aplicação de fungos micorrízicos arbusculares reduziu o crescimento de plantas jovens de oliveira devido a competição por fotoassimiladosPublication . Lopes, João; Correia, Carlos M.; Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Arrobas, Margarida; Rodrigues, M.A.Neste trabalho avaliou-se o efeito de fungos micorrízicos comerciais no desenvolvimento de oliveiras jovens cultivadas em estufa na fase de viveiro. O estudo constou de duas experiências, uma organizada num fatorial com três cultivares (Cobrançosa, Madural e Verdeal Transmontana) e três tratamentos de solo (fungos micorrízicos comerciais, zeólitos e testemunha) e outra segundo um delineamento completamente casualizado com quatro tratamentos [fungos micorrízicos comerciais, solo esterilizado, solo esterilizado mais um extrato de solo sem fungos micorrízicos arbusculares e testemunha]. A Cobrançosa desenvolveu-se melhor que as outras cultivares, apresentando bom enraizamento e melhores características iniciais de crescimento. As plantas micorrizadas apresentaram crescimento reduzido em comparação com as da testemunha. O resultado foi explicado pela competição por fotoassimilados entre o crescimento das plantas e o estabelecimento da simbiose, com a expansão das hifas dos fungos. O facto de as plantas apresentarem reduzida área foliar no início da experiência e a estufa ter uma cobertura de policarbonato de parede dupla, um tanto opaca à radiação fotossintética ativa, podem ter contribuído para reduzir a atividade fotossintética e retardar o crescimento das plantas inoculadas. Porém, nos vasos micorrizados, o carbono orgânico do solo e os teores da maioria dos nutrientes aumentaram, provavelmente devido à presença de hifas de fungos nas amostras e ao aumento da atividade enzimática do solo. Os zeólitos reduziram a produção de matéria seca das plantas e a concentração de fósforo nos tecidos em relação à testemunha, aumentando a disponibilidade no solo dos catiões que entram em sua composição. A esterilização do solo parece ter reduzido a biodisponibilidade de fósforo, talvez por ter inativado enzimas do solo. O extrato de solo sem fungos micorrízicos arbusculares não apresentou benefícios para as plantas ou qualquer efeito relevante nas propriedades do solo.
- Application of a grey anti-hail net in two apple tree cultivars: effect on physico-chemical characteristics of fruitsPublication . Pinto, Luís; Silva, Ermelinda; Gonçalves, Alexandre; Brito, Cátia; Ribeiro, C.; Fernandes, Helena Isabela Pereira; Moutinho-Pereira, José; Rodrigues, M.A.; Correia, Carlos M.Apple production in Portugal is a relevant agricultural activity, with 'Golden delicious' and 'Fuji' being included in the main cultivars. However, over the last 15 years there hás been increasing crop damage due to hailstorms and related meteorológica l extreme conditions in the Iberian Península. This concerning issue hás led farmers and researchers to find practical solutions to protect the orchards, such as netting devices. The application of anti-hail net in apple tree orchards looks to provide protection against the roughest meteorológica! effects (such as hail, strong winds, and sunburn) without hurting the development of the plant and, on the other hand, helping to improve the planfs productivity. On this work, carried out in Carrazeda de Ansiaes during 2016, was tested the application of a grey anti-hail net in an orchard with two cultivars (Golden delicious and Fuji) of apple tree (Malus domestica Borkh.). Contrais without screen net applied where also used. In order to understand the effects ofthe net, apples were collected and analyzed for their physico-chemical characteristics (total soluble solids (TSS), flesh firmness, skin strength, total titratable acidity (TTA) and fruit color Índices). The obtained results revealed a significant decrease in TSS (6. 5%) and TTA (21. 5%) on apple trees covered with anti-hail net, whereas the other traits were not affected. The drop of TTA was only significant in 'Golden delicious'. Substantial differences were found between cultivars, with higher values of brix, pH, skin "bioyield point" and flesh firmness on 'Fuji', while 'Golden delicious' presented higher lightness, chroma and hue angle. The use of a grey anti-hail net on apple orchards is a suitable alternative for the protection of apple trees against hail ensuring the production of the crop without compromising the fruit quality.
- Application of anti-hail net in apple orchards: effects on fruits chemical characteristicsPublication . Martins-Gomes, Carlos; Pinto, Luís; Silva, Ermelinda; Martins, Sandra; Gonçalves, Alexandre; Brito, Cátia; Moutinho-Pereira, José; Rodrigues, M.A.; Correia, Carlos M.; Nunes, Fernando M.Apple production in Portugal, over the last 15 years, has been subjected to increasing crop damage due to hailstorms and related meteorological extreme conditions. This problem has led farmers and researchers to find practical solutions to protect the orchards, such is the case of netting devices. The application of anti-hail nets in apple tree orchards looks to provide protection against the roughest meteorological events (such as hail, strong winds, and sunburn), while avoiding to upset the development of the plant and or, if possible, helping to improve the plant’s productivity. During 2016, this work was carried out in Carrazeda de Ansiães, a northeast Portuguese plateau zone that is a primary location for apple production, and the application of a grey anti-hail net, which reduces photosynthetically active radiation by 12 %, was tested in an orchard with the cultivars Golden delicious and Fuji of apple tree (Malus domestica Borkh). Control without screen net applied was also used. In order to understand the effects of the net, apples were collected and analysed for their chemical characteristics (total phenols, ortho-diphenols and flavonoids content, ABTS and polyphenolic profile). The obtained results in apple peel revealed, in both cultivars, a decrease in total phenols, ortho-diphenols and flavonoids concentration, whereas in the Fuji cultivar the antioxidant activity, determined by the ABTS assay, was maintained. Pulp results showed little difference with lower (P<0.001) ortho-diphenols content in Fuji cultivar and slightly lower (P<0.05) ABTS activity in Golden delicious cultivar. Peel and pulp methanolic extracts were analysed by HPLC-DAD. The phenolic profile was similar for both cultivars, with the exception of anthocyanins, being identified chlorogenic acid and derivatives of quercetin. The antihail net did not affect the phenolic profile, only decreased the polyphenols concentration. The use of a grey anti-hail net on apple orchards is a suitable alternative for the protection of apple trees against hail ensuring the production of the crop without compromising fruit quality.
- Arbuscular mycorrhizal fungi inoculation reduced the growth of pre-rooted olive cuttings in a greenhousePublication . Lopes, João Ilídio; Correia, Carlos M.; Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Arrobas, Margarida; Rodrigues, M.A.The effect of commercial mycorrhizal fungi on pre-rooted olive cuttings was assessed. The study consisted of two experiments, the first arranged as a factorial design with three cultivars (Cobrançosa, Madural, and Verdeal Transmontana) and three soil treatments (commercial mycorrhizal fungi, zeolites, and control) and the second as a completely randomized design with three treatments (commercial mycorrhizal fungi, sterilized soil, and control). Cobrançosa grew better than the other cultivars, showing good rooting and initial growth features. Mycorrhizal plants showed reduced growth in comparison to those of the untreated control. This result was explained by competition for photosynthates between plant growth and the expansion of fungi hyphae. Cuttings of reduced leaf area and a twin-wall polycarbonate cover of the greenhouse, somewhat opaque to photosynthetic active radiation, may also have contributed to limit the maximum photosynthetic rate and delay the growth of the inoculated plants. Accordingly, in the mycorrhizal pots, the soil organic carbon (C) increased, probably due to the presence of fungi hyphae in soil samples. Zeolites reduced plant dry matter (DM) yield and tissue phosphorus (P) concentration compared to the control, while increasing the availability in the soil of the cations present in their initial composition. Soil sterilization seems to have reduced soil P bioavailability by inactivating soil enzymes. This study showed that the inoculation with mycorrhizal fungi of pre-rooted cuttings can delay their initial growth. Although these plants may be better prepared to grow in the field, in the short term, their lower development can be a problem for the nurseryman.
- Boron nutrition affects membrane leakage and chemical composition of leaves and fruits of Olea europaeaPublication . Silva, Ermelinda; Brito, Cátia; Dinis, Lia Tânia; Rocha, Luís; Ferreira, Isabel Q.; Ferreira, Helena; Luís, M.M.; Moutinho-Pereira, José; Rodrigues, M.A.; Correia, Carlos M.Boron (B) is an essential microelement for plants, being its deficiency the most frequent micronutrient disorder in olive tree. The main functions of boron are related to cell wall strength and development, membrane function, cell division, fruit and seed development, water relations, sugar transport and hormone development. The study conducted in Bragança (Northeast Portugal), under rainfed conditions, shows that application of Bfertilizer decreased the symptoms of oxidative stress on leaves, both in summer and, with higher extent, in winter. In fact, B-treated trees presented lower electrolyte leakage, in a closely association with higher concentration of total thiols. Moreover, boron increased the concentration of soluble sugars, while decreased the accumulation of starch in both seasons. Meanwhile, total soluble proteins and total phenols levels were higher in Bfertilized plants during the summer period, whereas in winter, after frost events, the concentration of phenols was higher in B-starved trees. The chemical composition of fruits at final harvest revealed that B-supply increases the soluble sugars and the pulp ash content, decreases organic matter and dietary fiber, whilst the crude protein concentration was similar between treatments. Thus, the present study showed that addition of Bfertilizer affects the metabolism of olive tree and give new insights about the effect of boron on plant physiology and biochemistry that will help to refine the improvement in Bfertilizer recommendations for olive growing areas.
- Clinoptilolite zeolite foliar application on rainfed olive trees: effects on physiology, biochemistry, growth, yield and olive oil qualityPublication . Martins, Sandra; Gonçalves, Alexandre; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Arrobas, Margarida; Rodrigues, M.A.; Nunes, Fernando M.; Correia, Carlos M.With the advances of climate change, it is expected harmful consequences to olive tree (Olea europaea L.). Therefore, it is necessary to develop cost-effective practices to reduce the vulnerability of olive crops to the adverse impacts of environmental stresses. Rainfed olive trees were sprayed with zeolites, natural crystalline aluminosilicates, and its effects on photosynthetic activity, phenolic composition, antioxidant activity, leaf minerais concentrations, plant growth, yield, and olive oil quality were assessed. Zeolites application enhanced photosynthetic activity, as well the concentrations of N, Mg, Cu, Zn and Mn in leaves, and changed the secondary metabolism, with decrease oftotal phenols, ortho-diphenols and total antioxidant activity, signs of lower oxidative stress. As consequence, zeolites boosted plant growth, crop yield, and size and weight of fruits. The foliar spray did not significantly affect the oil quality indices free acidity, peroxide value and Km and K270 coefficients. This study strongly suggests that folial' zeolites might be an effective strategy to mitigate the adverse environmental conditions.
- Combined biochar and organic waste have little effect on chemical soil properties and plant growthPublication . Rodrigues, M.A.; Garmus, Taís Gabriele; Arrobas, Margarida; Gonçalves, Alexandre; Silva, Ermelinda; Rocha, Luís; Pinto, Luís; Brito, Cátia; Martins, Sandra; Vargas, Thiago de Oliveira; Correia, Carlos M.Biochar has received great attention as a soil conditioner since it can potentially sequester carbon (C) in soil, enhance soil physical, chemical and biological properties and improve crop productivity. This study reports the results of a pot experiment with olive (Olea europaea L.), carried out in an acidic and clay loam textured soil, and cultivated during two growing seasons under eight fertilization treatments. They included mineral fertilization equivalent to a rate of 100 kg ha-1 of N, P2O5 and K2O (NPK), biochar applied at a rate of 10 (B10), and at 20 (B20) t biochar ha-1, biochar-NPK mixture (B10+NPK), biochar-waste mixtures with mushroom waste compost (B10+MWC), olive mill waste (B10 + OMW), and municipal solid waste (B10+MSW), the organic materials applied at a rate of 20 t ha-1, together with a treatment without fertilization (control). Biochar in the B20 treatment increased the soil C content in comparison to the control. Biochar in the B10+NPK treatment reduced soil nitrate levels compared to NPK treatment. No other benefits to soil properties, nutrient uptake or plant growth were observed with the use of biochar or any positive synergistic effect with the mixture of biochar with the other organic amendments. MSW, OMW and MWC tended to increase soil pH in comparison to the control. Most of the studies with biochar were carried out in soils with edaphic limitations or harsh environmental conditions limiting plant growth, which may have facilitated the detection of favorable effects. Under less limited soils or stressful conditions for plants, such as the ones established in this experiment, the benefits of using biochar were poor.
- Combining zeolites with early-maturing annual legume cover crops in rainfed orchards: effects on yield, fatty acid composition and polyphenolic profile of olives and olive oilPublication . Martins, Sandra; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Martins-Gomes, Carlos; Gonçalves, Alexandre; Arrobas, Margarida; Rodrigues, M.A.; Correia, Carlos M.; Nunes, Fernando M.Under climate change threats, there is a growing need to adapt the conventional agronomic practices used in rainfed olive orchards by sustainable practices, in order to ensure adequate crop yield and olive oil quality and to preserve soil health. Therefore, for two years, the effects of conventional tillage practice (T) and two sustainable soil management strategies, a leguminous cover crop (LC) and its combination with natural zeolites (ZL), on the yield, fatty acid composition, polyphenolic profile and quality indices of olive fruits and oil were evaluated. Crop yield was significantly increased by LC and ZL in the first year. Although in the second year no significant differences were verified, the cumulative yield increased significantly by 31.6% and 35.5% in LC and ZL trees, respectively. LC enhanced the moisture and size of olives, while ZL increased, in general, the concentrations of oleuropein, verbascoside, caffeic acid and epicatechin, as well the oleic/linoleic ratio in fruits and the levels of 3,4-dihydroxyphenylglycol, tyrosol, verbascoside and caffeic acid in olive oil. Despite the higher concentration of total phenols in the fruits and oil from T trees in the warmer and dryer year, the quality of the oil decreased, mainly when compared with ZL, as evidenced by the peroxide value and K232 and K270 coefficients. In short, both sustainable soil management strategies appear to be promising practices to implement in olive orchards under rainfed conditions, but the innovative strategy of combining zeolites with legume cover crops, first reported in the present study, confers advantages from a nutritional and technological point of view. Nevertheless, studies subjected to the long-term use of these practices should be conducted to ensure the sustainability of the crop yield and olive oil quality.
- A controlled-release fertilizer improved soil fertility but not olive tree performancePublication . Silva, Ermelinda; Arrobas, Margarida; Gonçalves, Alexandre; Martins, Sandra; Raimundo, Soraia; Pinto, Luís; Brito, Cátia; Moutinho-Pereira, José; Correia, Carlos M.; Rodrigues, M.A.The use of a controlled-release fertilizer (CRF) was studied in a traditional rainfed olive grove in a Mediterranean climate where precipitation is very irregular, particularly in the spring. The objective of the study was to assess whether a CRF can improve the olive tree's performance compared to a conventional nitrogen (N) fertilizer (CF), by supplying N gradually and reducing the risk of potential N loss from leaching. The fertilized treatments showed better plant N nutritional status, which resulted in enhanced net photosynthesis and higher leaf concentrations of total soluble sugars, chlorophylls and soluble proteins which, in turn, increased olive yield by 43% in comparison to the unfertilized control. However, in general, no significant differences were found between fertilized treatments in the performance parameters of the trees evaluated, including olive yield. Somewhat unexpectedly, CRF consistently increased the soil organic carbon (C) (29%), kjeldahl-N (75%) and easily extractable glomalin-related soil proteins (EE-GRSP) (60%) and total GRSP (T-GRSP) (122%) compared to the CF. The result was ascribed to a stimulus on the development of herbaceous vegetation and eventually on the activity of the roots of the trees due to the higher soil inorganic-N availability in the autumn. Thus, some soil inorganic-N in the autumn seems to comprise a low risk of leaching, since weeds act as a catch crop and convert this inorganic N into an organic substrate, with potential benefits in the long-term for the agro-system.