Browsing by Author "Rocha, Luís"
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- Autonomous robot navigation for automotive assembly task: an industry use-casePublication . Sobreira, Héber; Rocha, Luís; Lima, José; Rodrigues, Francisco; Moreira, António Paulo G. M.; Veiga, GermanoAutomobile industry faces one of the most flexible productivity caused by the number of customized models variants due to the buyers needs. This fact requires the production system to introduce flexible, adaptable and cooperative with humans solutions. In the present work, a panel that should be mounted inside a van is addressed. For that purpose, a mobile manipulator is suggested that could share the same space with workers helping each other. This paper presents the navigation system for the robot that enters the van from the rear door after a ramp, operates and exits. The localization system is based on 3DOF methodologies that allow the robot to operate autonomously. Real tests scenarios prove the precision and repeatability of the navigation system outside, inside and during the ramp access of the van.
- 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.
- 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.
- Deficit irrigation strategies in olive orchards: influence on fruit qualityPublication . Gonçalves, Alexandre; Silva, Ermelinda; Brito, Cátia; Martins, Sandra; Rocha, Luís; Pavia, Ivo; Gomes, Carlos; Fernandes-Silva, Anabela; Ribeiro, Carlos; Rodrigues, M.A.; Moutinho-Pereira, José; Nunes, Fernando M.; Correia, Carlos M.In order to overcome constrains that affect olive groves and its socioeconomic value, new cropping practices focusing on water use efficiency were investigated. The study was conducted in Northeast Portugal and different deficit irrigation strategies (DIS) were investigated: regulated (RDI, 10% ETc during pit hardening and 80% ETc in the remaining stages), sustained (SDI, 27.5% ETc), sustained usually applied by farmer (SDIAF, 21.2% ETc) and fully irrigated (FI, 100% ETc), as control treatment. The fruit metabolites fluctuations and quality parameters were evaluated. Using FI as reference, DIS treatments led to changes in the secondary metabolism in fruits with increased total phenolic compounds (+11% in SDIAF), ortho-diphenols (+25 in SDI and +44% in SDIAF), and flavonoids (+29% in RDI, +26% in SDI, +91% in SDIAF) concentrations, and higher total antioxidant capacity (+41% in SDI). DIS treatments influenced the profile of olive fruit phenolics with changes in oleuropein (-55% in SDIAF), chlorogenic acid and quercetin-3,4‟-di-O-glucoside (non-detected in FI), eriodictyol-7-O-glucoside (+64% in RDI and +95% in SDI), and procyanidin A2 (+59% in RDI and -59% in SDIAF). Olive fruits from DIS treatments also showed higher fat content (22, 29 and 24 % in RDI, SDI and SDIAF, respectively). Fruits from RDI and SDI presented lower palmitoleic and linolenic acids, while no significant differences were observed in the concentrations of saturated, monounsaturated and polyunsaturated fatty acids. When subject to a puncture test in a texture analyser, all DIS fruits presented higher peel break force than FI control. This work show that DIS are essential for sustainable olive growing, as they do not compromise the competitiveness of the sector in terms of olive production and associated quality parameters.
- Efeito da aplicação de glicina e betaína na atividade fotossintética da oliveira em regime de sequeiroPublication . Martins, Sandra; Silva, Ermelinda; Gonçalves, Alexandre; Brito, Cátia; Rocha, Luís; Pinto, Luís; Pavia, Ivo; Ferreira, Helena; Dinis, Lia Tânia; Luzio, Ana; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.A oliveira [Olea europaea L.) é uma espécie que frequentemente se encontra sujeita a longos períodos de seca e altas temperaturas, o que afeta a sua atividade fisiológica e, consequentemente, a sua produtividade. A glicina betaína é um importante soluto orgânico que apresenta um papel crucial na tolerância das plantas a alguns tipos de stresse/ incluindo o défice hídrico, por estar envolvido em processos como ajustamento osmótico, destoxificação de espécies reativas de oxigénio e proteção de macromoléculas, sendo também reserva de carbono e fonte de azoto. O objetivo do presente estudo foi investigar os efeitos da aplicação foliar de glicina betaína (25 mM) na atividade fotossintética de oliveiras (cv. Cobrançosa) em plena produção, cultivadas em regime de sequeiro na Terra Quente Transmontana (Suçães, Mirandela). A aplicação do bioestimulante foi efetuada no início do verão e a atividade fisiológica, centrada nas trocas gasosas e no estado hídrico, foi avaliada ao longo dos 3 meses seguintes. A aplicação de glicina betaína conduziu, em julho, a um aumento da taxa de fotossíntese e da eficiência intrínseca do uso da água durante o período da manha, e da condutância estomática durante a tarde. Por outro lado, as plantas tratadas com bioestimulante apresentaram aumento do conteúdo relativo em água no mês de agosto. Os resultados sugerem que a aplicação de glicina betaína provocou um aumento da atividade fisiológica a curto prazo, verificando-se perda de efeito a o longo do tempo. Justifíca-se a necessidade de estudos futuros no sentido de otimizar a concentração e o número de aplicações deste metabolito para obter uma melhor performance da oliveira em condições de sequeiro.
- Efeito de resíduos orgânicos e biochar no desenvolvimento inicial da oliveiraPublication . Garmus, Taís Gabriele; Rodrigues, M.A.; Arrobas, Margarida; Gonçalves, Alexandre; Grade, Vagner; Silva, Ermelinda; Rocha, Luís; Pinto, Luís; Brito, Cátia; Martins, Sandra; Vargas, Thiago de Oliveira; Correia, Carlos M.O aumento da produção de alimentos e a concentração populacional em grandes centros urbanos está gerando elevadas quantidades de resíduos sólidos urbanos (RSU) e industriais. Quando mal manejados, estes resíduos podem originar problemas ambientais. O objetivo do trabalho foi avaliar uma alternativa adequada para o destino dos resíduos utilizando-os como fertilizantes orgânicos associados com biochar, um condicionador de solo. Os tratamentos utilizados foram: 1) biochar 10 (equivalente a 10 t ha-1) + adubação NPK; 2) biochar 10 + resíduos cogumelos 20; 3) biochar 10 + resíduos lagar de azeite 20; 4) biochar 10 + RSU 20; 5) biochar 20; 6) biochar 10; 7) adubação NPK; e 8) testemunha sem adubação. O ensaio decorreu em Vila Real e consistiu no cultivo de oliveiras jovens em vasos de 10 L utilizando um delineamento experimental completamente casualizado, com quatro repetições. Avaliou-se a produção da matéria seca separada em folhas, caules e raizes, a relação raiz/folhas e raiz/parte aérea. Os dados foram submetidos à análise de variância e quando significativos as médias foram comparadas utilizando o teste de Duncan (α = 0,05). A produção de matéria seca variou significativamente para a variável folhas. A maior média foi encontrada no tratamento biochar 10 t + resíduos de lagar de azeite (30,76 g por planta) e a menor no tratamento biochar 20 t (22,44 g por planta). As relações raiz/folha e raiz/parte aérea foram estatisticamente semelhantes. A relação raiz/folha foi mais expressiva nos tratamentos compostos por biochar 20 e testemunha, apresentando uma relação raiz/folha maior que os demais tratamentos. Estes resultados iniciais parecem indicar que o biochar por ser um condicionar do solo com carbono orgânico muito resistente à decomposição promove a mineralização lenta de nutrientes regulando a sua disponibilidade para as plantas.
- Fertilização com boro melhora a fisiologia da oliveira em condições de sequeiroPublication . Silva, Ermelinda; Gonçalves, Alexandre; Brito, Cátia; Dinis, Lia Tânia; Rocha, Luís; Luzio, Ana; Pavia, Ivo; Ferreira, Helena; Pinto, Luís; Moutinho-Pereira, José; Ferreira, Isabel Q.; Arrobas, Margarida; Rodrigues, M.A.; Correia, Carlos M.O olival é uma das culturas amplamente distribuídas na região mediterrânica e com grande impacto em Portugal, nomeadamente na região de Trás-os-Montes onde apresenta elevada importância socioeconómica. Sendo a oliveira uma espécie muito exigente em boro e apresentado este micronutriente importantes funções nas plantas, entre as quais na estrutura da parede celular, divisão celular, integridade das membranas, transporte de açúcares e metabolismo dos hidratos de carbono, relações hídricas, floração, frutificaçâo e regulação hormonal, torna-se necessário aprofundar os conhecimentos sobre a resposta da oliveira à fertilizaçâo com boro. O presente estudo foi realizado num olival (cv. Cobrançosa) de sequeiro localizado em Bragança, tendo sido avaliados dois níveis de boro: 3 kg/ha e ausência de boro. Durante o stresse estivai foram avaliados parâmetros de trocas gasosas e fluorescência da clorofila o, conteúdo relativo em água, concentração de pigmentos fotossintéticos e indicadores de crescimento. Verificou-se que as plantas fertilizadas com boro apresentaram maior conteúdo relativo em água, condutância estomática, taxa de transporte de eletrões, quenching fotoquímico e concentração de ciorofilas, conduzindo a incrementos da taxa de fotossíntese líquida e do crescimento, expressa pelo diâmetro do tronco e pelo volume da copa. Estes resultados demonstram que a adição de boro melhora a fisiologia da oliveira em regime de sequeiro, fornecendo nova informação que poderá ajudar a aperfeiçoar as recomendações de fertilizaçâo para a cultura.
- Foliar application of arginine, jasmone, and kaolin ameliorate photosynthesis of olive treesPublication . Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Luzio, Ana; Dinis, Lia Tânia; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.In Northeast Portugal, olive orchards cover over 75000 ha and involve approximately 36000 producers, being olive oil the only saleable product for many families. Despite the physiological defense strategies that olive trees dispose against summer stress, the projected climate change characterized by severe summer conditions, with low rainfall, excessive heat load and high irradiance leveis might affect this crop. Cropping practices for adaptation of olive orchards to climate change must be pursued. In this work we aimed to investigate the introduction of foliar applications of compounds that have shown a central role in stress tolerance in different plant species. The study was conducted in an organic orchard at Quinta do Prado, Lodões, Vila Flor (41°20'13. 3"N, 7°05'54. 2"W) and shows the impact of the application of arginine (l mM), jasmonate (100 |-iM) and kaolin (5%; w/v) on leaf gás exchange parameters at 6 different times between July and October 2016. Ali compounds, specially kaolin, contributed to the improvement of the photosynthetic activity of olive trees during measurements made during August and September, mainly due to lower stomatal limitations, although a drop of non-stomatal limitations were also recorded at midday period, namely by the end of August. The present study gives new insights about the effect ofthis new cropping practice for olive orchards that can help to mitigate the harsh climatic conditions projected forthe Mediterranean summers.
- Foliar application of jasmonic acid ameliorate photosynthesis and yield of the olive tree under summer stressPublication . Gonçalves, Alexandre; Martins, Sandra; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Macedo, Fabrício; Freire, António; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.Despite the physiological defence strategies that olive trees dispose against summer stress, the projected climate change for the Mediterranean Basin characterized by severe summer conditions, with low rainfall, excessive heat load, and high irradiance levels, right affect this crop. New cropping practices allowing better water use efficiency and protection against summer stress as with the introduction of foliar jasmonic acid were pursued. The study was conducted in an organic orchardat Quinta do Prado, Lodões, Vila Flor(41 °20'13.3"N, 7°05'54.2"W) under sustained deficit irrigation and shows the impact of the application of jasmonic acid (100 pM) on leaf gas exchange and yield during the 2017 season.
- Foliar application of melatonin to mitigate olive tree summer stressPublication . Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Luzio, Ana; Dinis, Lia Tânia; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.Olive crop is widely distributed in the Mediterranean region and has a distinct socioeconomic importance in Portugal, namely in the Northeast region, where mostly rainfed olive orchards cover over 75000 ha and comprise approximately 36000 producers. The projected climate change characterized by severe summer conditions, with low rainfall, excessive heat load and high irradiance levels might affect this crop, notwithstanding the defense strategies that olive trees dispose against summer stress. In this work we aimed to investigate a new cropping practice with the introduction of a foliar application of melatonin (Nacetyl- 5-methoxytryptamine; 100 ~M) that have shown a central role in stress tolerance in different plant species. The study was conducted in an organic orchard of seven-years-old at Quinta do Prado, Lodoes, Vila Flor (41°20'13.3"N, 7"05'54.2"W), Portugal, and shows the impact on leaf gas exchange, chlorophyll a fluorescence, relative water content, concentration of photosynthetic pigments and fruits total phenolic content at 6 different times between July and October 2016. Melatonin sprayed plants consistently showed higher stomatal conductance (18-73% during morning measurements and 11-136% at midday), net photosynthesis (25-81% morning and 32-130% at midday), electron transport rate (12-23% morning and 0.1-13% at midday) and photochemical yield of photosystem 11 (12-24% morning and 0-13% at midday). The better physiological status of the melatonin sprayed olive trees was reflected in a decrease in fruits total phenolic content (21%). The results suggest that the foliar application of melatonin boost the physiological activity of olive trees, giving new insights about the effect of this new cropping practice in olive orchards. Future studies to optimize the concentration and the number of applications of this metabolite must be pursued in order to get a better performance of olive tree under the harsh climatic conditions projected for the Mediterranean region.