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Produção de estruturas reprodutivas e efeito do ambiente nos tipos de sintomas produzidos por Guignardia citricarpa em Citrus spp. /Nozaki, Márcia de Holanda. January 2007 (has links)
Orientador: Antonio de Goes / Banca: Edson Luiz Furtado / Banca: Kátia Cristina Kupper / Banca: Rita de Cássia Panizzi / Banca: Jaime Maia dos Santos / Resumo: A mancha preta dos citros (MPC) doença causada pelo fungo Guignardia citricarpa Kiely [anamorfo: Phyllosticta citricarpa (McAlp.)Van der Aa], deprecia comercialmente os frutos, causando sua queda prematura e elevando o custo de produção. Até o presente momento, informações acerca da etiologia da doença são escassas. Portanto, o presente trabalho teve como objetivos: (i) criar metodologias alternativas de obtenção da estrutura reprodutiva do fungo em laboratório; (ii) observar a taxa de germinação in vitro de conídios do fungo; (iii) estudar a influência da poda de plantas cítricas no campo sobre a expressão de sintomas de falsa melanose; (iv) e, a relação entre a presença de sintomas de ácaro da falsa ferrugem e sintomas do tipo mancha trincada em frutos cítricos. De maneira geral, tanto pseudotécios quanto ascósporos foram obtidos em maior número quando da utilização da metodologia de discos foliares autoclavados, bem como a maior expressão dos sintomas mediante inoculações através desta metodologia. Com os resultados obtidos, pode-se afirmar que através da realização de práticas culturais como a poda dos ramos secos, bem como o controle do ácaro da falsa ferrugem, o progresso da MPC no campo é reduzido. / Abstract: Citrus black spot (CBS) disease caused by the fungus Guignardia citricarpa Kiely [anamorph: Phyllosticta citricarpa (McAlp.)Van der Aa], depreciates the fruit comercially, causing its premature fall and elevating production cost. Until the present moment, there is a lack of informations about the etiology of the disease. Therefore, the aim of the present work was: (i) create alternative methodologies to obtain reproductive structures on laboratory; (ii) observe the in vitro conidia germination rate; (iii) study the influence of the harvest of citric plants on the expression of false melanose symptoms; (iv) and the relation between the expression of symptoms of citrus rust mite on the presence of cracked spot symptoms. Both pseudothecia and ascospores were obtained in larger rate when using autoclavated leave discs, and also the larger expression of symptoms on inoculations made by this method. By the results obtained, it can be afirmed that the harvest of dead twigs, and the control of the citrus rust mite, the progress of CBS on field is reduced. / Doutor
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Produção de estruturas reprodutivas e efeito do ambiente nos tipos de sintomas produzidos por Guignardia citricarpa em Citrus sppNozaki, Márcia de Holanda [UNESP] 29 March 2007 (has links) (PDF)
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nozaki_mh_dr_jabo.pdf: 745023 bytes, checksum: 9d7c07f38a8943e8fa117a5e301b9c6f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A mancha preta dos citros (MPC) doença causada pelo fungo Guignardia citricarpa Kiely [anamorfo: Phyllosticta citricarpa (McAlp.)Van der Aa], deprecia comercialmente os frutos, causando sua queda prematura e elevando o custo de produção. Até o presente momento, informações acerca da etiologia da doença são escassas. Portanto, o presente trabalho teve como objetivos: (i) criar metodologias alternativas de obtenção da estrutura reprodutiva do fungo em laboratório; (ii) observar a taxa de germinação in vitro de conídios do fungo; (iii) estudar a influência da poda de plantas cítricas no campo sobre a expressão de sintomas de falsa melanose; (iv) e, a relação entre a presença de sintomas de ácaro da falsa ferrugem e sintomas do tipo mancha trincada em frutos cítricos. De maneira geral, tanto pseudotécios quanto ascósporos foram obtidos em maior número quando da utilização da metodologia de discos foliares autoclavados, bem como a maior expressão dos sintomas mediante inoculações através desta metodologia. Com os resultados obtidos, pode-se afirmar que através da realização de práticas culturais como a poda dos ramos secos, bem como o controle do ácaro da falsa ferrugem, o progresso da MPC no campo é reduzido. / Citrus black spot (CBS) disease caused by the fungus Guignardia citricarpa Kiely [anamorph: Phyllosticta citricarpa (McAlp.)Van der Aa], depreciates the fruit comercially, causing its premature fall and elevating production cost. Until the present moment, there is a lack of informations about the etiology of the disease. Therefore, the aim of the present work was: (i) create alternative methodologies to obtain reproductive structures on laboratory; (ii) observe the in vitro conidia germination rate; (iii) study the influence of the harvest of citric plants on the expression of false melanose symptoms; (iv) and the relation between the expression of symptoms of citrus rust mite on the presence of cracked spot symptoms. Both pseudothecia and ascospores were obtained in larger rate when using autoclavated leave discs, and also the larger expression of symptoms on inoculations made by this method. By the results obtained, it can be afirmed that the harvest of dead twigs, and the control of the citrus rust mite, the progress of CBS on field is reduced.
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Efeito de fungicidas do grupo químico das estrobilurinas no controle da Mancha Preta dos Citros, na produção e na qualidade tecnológica dos frutosIkeda, Mário [UNESP] 05 December 2011 (has links) (PDF)
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ikeda_m_me_jabo.pdf: 375593 bytes, checksum: 6a24c080db13dd8a16ff7686dcbed145 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundecitrus / O objetivo deste trabalho foi avaliar a resposta do número de aplicações do fungicida pyraclostrobin no controle da Mancha Preta dos Citros (Guignardia citricarpa), assim como comparar o comportamento das diferentes estrobilurinas recomendadas no controle da doença. Também foi avaliada a influência dos tratamentos fungicidas sobre a produção e qualidade tecnológica dos frutos. Para tal foram realizados dois experimentos, em pomares de laranjeira „Valência‟ com histórico comprovado da ocorrência da doença em anos anteriores e com elevada intensidade e frequência na distribuição dos sintomas entre as plantas. Foram avaliados seis tratamentos, com três a quatro aplicações de fungicidas sistêmicos, isolado ou em mistura com cobre. Os tratamentos citados foram precedidos por duas aplicações de fungicida cúprico (CO), iniciando-se na fase de 2/3 de pétalas caídas e repetidas depois de quatro semanas. As aplicações de produtos sistêmicos (três ou quatro) foram realizadas quatro semanas após a segunda aplicação de fungicida cúprico, com intervalo de seis semanas entre elas. As estrobilurinas avaliadas foram pyraclostrobin (PY), azoxystrobin (AZ) e trifloxystrobin (TR) isolado ou em combinação com fungicida cúprico. Todos os tratamentos aplicados receberam um tratamento adicional com carbendazim (CA) como fechamento das pulverizações. Dessa forma, os tratamentos e as respectivas sequências foram:... / The objective of this study was to evaluate the number of applications of the fungicide pyraclostrobin for control of Citrus Black Spot (Guignardia citricarpa) and compare the action of the different recommended strobilurins for disease control. We also analyzed the influence of fungicide treatments on the production and technological quality of fruit. For this purpose two experiments were conducted in orchards of „Valencia‟ sweet orange with proven track records of disease occurrence in previous years and with high intensity and frequency distribution of symptoms among the plants. We evaluated six treatments, with three or four applications of systemic fungicides, alone or mixed with copper. The cited treatments were preceded by two applications of copper fungicide (CO), beginning on the phase 2/3 of petals fallen and repeated after four weeks. The applications of systemic products (three or four) were performed four weeks after the second application of cooper fungicide, with an interval of six weeks between them. The strobilurins tested were pyraclostrobin (PY), azoxystrobin (AZ) and trifloxystrobin (TR) alone or in combination with cooper fungicide. All treatments received an additional treatment with carbendazim (CA) as the closure of sprays. Thus, treatments and their sequences were:... (Complete abstract click electronic access below)
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Modelling the distribution of Citrus Black Spot caused by Guignardia citricarpa KielyPaul, Ida 30 May 2006 (has links)
Citrus is a valuable fruit crop in world trade. Citrus Black Spot (CBS), caused by Guignardia citricarpa Kiely, is a fungal disease of citrus. It occurs in many citrus producing countries including parts of Australia and South Africa, but it does not occur in the countries of the European Union (EU) or the United States of America (USA). To prevent the introduction of CBS, the EU and the USA have phytosanitary regulations that restrict the import of citrus fruit from areas where CBS is found. This study uses two bioclimatic modelling approaches — CLIMEX and response surface modelling — to predict which areas have climates suitable for CBS to establish. The work focuses on the citrus growing areas of South Africa and Europe, but other parts of the world are also considered. As CBS is dependent on citrus, geographical areas of global citrus production are also mapped, and models are used to predict which areas of South Africa have climates suitable for citrus cultivation under current and future climates. The potential impacts of climate change on CBS distribution in South Africa are also estimated. Results indicate that under current and future climates many areas in South Africa where citrus is not currently grown have a climate suitable for citrus cultivation, but most of these areas are also climatically favourable for CBS. Of the current citrus producing areas in South Africa, only the Northern and Western Cape Provinces are predicted to be unsuitable for CBS. Under climate change scenarios, some citrus production areas of Western Cape are predicted to become suitable for CBS, but the greater part of the Northern Cape will remain climatically unsuitable for the establishment of CBS in future. The climates of several CBS-free citrus producing areas around the world, such as Mexico, and Florida and Texas (USA) are suitable for CBS. However, European climate is unfavourable for CBS establishment, and provided importing countries comply to minimum standards, phytosanitary restrictions on the import of fruit from CBS infected areas may be unnecessary. This study is the first of its kind in citriculture, and in South Africa it is one of the few studies that investigates the effects of climate change on the potential distribution of a plant pathogen. Bioclimatic modelling was found to be a very useful means to combine complex data in order to make predictions relevant to Pest Risk Assessments. / Thesis (PhD (Environmental Management))--University of Pretoria, 2007. / Microbiology and Plant Pathology / unrestricted
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Studies on the black spot disease of citrus caused by Guignardia Citricarpa Kiely with particular reference to its epiphytology and control at LetabaKotze, Johannes Marthinus 18 January 2007 (has links)
Please read the Summary and Conclusions(04chapter4) on pages 141-143 / Thesis (DSc (Agriculture))--University of Pretoria, 1963. / Microbiology and Plant Pathology / unrestricted
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Application of Road Infrastructure Safety Assessment Methods at IntersectionsAdedokun, Adeyemi January 2016 (has links)
Traffic safety at intersections is a particularly difficult phenomenon to study, given the fact that accidents occur randomly in time and space thereby making short-term measurement, assessment and comparison difficult. The EU directive 2008/96/EC introduced road infrastructure safety management, which offers a five layer structure for developing safer road infrastructure has been used to develop tools for accident prediction and black spot management analysis which has been applied in this work to assess the safety level of intersections in Norrköping city in Sweden. Accident data history from STRADA (Swedish Traffic Accident Data Acquisition) and the network demand model for Norrköping city were used to model black spots and predict the expected number of accidents at intersections using PTV Visum Safety tool, after STRADA accident classification was restructured and the Swedish accident prediction model (APM) was configured and tested to work within the tool using the model from the Swedish road administration (SRA). The performance of the default (Swiss) and the Swedish APM was compared and identified locations with the high accident records, predicted accident counts and traffic volumes were audited using qualitative assessment checklist from Street-Audit tool. The results from these methods were analysed, validated and compared. This work provides recommendations on the used quantitative and qualitative methods to prevent accident occurrence at the identified locations.
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Efeito da quitosana e da radiação UV-C no controle de Guignardia citricarpa em laranja pós-colheita / Effect of chitosan and UV-C on the control of Guignardia citricarpa on postharvest orangeRappussi-da-Silva, Maria Cristina Canale 06 February 2007 (has links)
O Brasil é o maior produtor e exportador de suco de laranja, sendo esta uma das mais importantes atividades econômicas para o país. Os frutos são afetados pela mancha preta dos citros, causada por Guignardia citricarpa, que deprecia comercialmente os frutos, provoca queda prematura e eleva o custo de produção. Medidas alternativas ao controle químico clássico vêm sendo estudadas e, neste contexto, insere-se a indução de resistência. O presente trabalho teve como objetivo avaliar os efeitos in vitro da quitosana e radiação UV-C sobre o crescimento micelial, germinação e formação de apressórios por G. citricarpa e a ação destes agentes abióticos no controle da doença em laranjas pós-colheita, sob armazenamento ambiente e refrigerado, estudando-se também mecanismos de resistência ativados no tecido vegetal em resposta ao tratamento de melhor eficiência. Para tanto, foram utilizadas as concentrações de 0; 0,5; 1,0; 1,5; 2,0 e 3,0% de quitosana e as doses de 0,52; 1,04; 3,13; 10,44 e 15,66 kJ.m-2 da radiação UV-C. A quitosana inibiu o crescimento micelial do fungo e estimulou a germinação e formação de apressórios, os quais se mostraram morfologicamente alterados. A UV-C não inibiu o crescimento micelial, porém a maior dose ocasionou o menor crescimento. Para os experimentos in vivo, laranjas foram coletadas, lavadas, sanitizadas com hipoclorito e posteriormente tratadas. As concentrações de 0,5, 1,0 e 2,0% de quitosana e a dose de 7 kJ m-2 da UV-C apresentaram melhor resultado em laranjas ?Valência? na redução dos sintomas. Análise da cor da casca dos frutos irradiados revelou que houve leve escurecimento. Os fungicidas tiabendazol e imazalil não controlaram a doença em laranjas ?Pêra Rio?, porém, obteve-se menos lesões nos frutos tratados com os fungicidas em combinação com quitosana, tanto em temperatura ambiente quanto em refrigeração. Análises da cor da casca indicaram amarelecimento e não houve alterações significativas nos teores de sólidos solúveis, acidez titulável, pH, vitamina C e ratio. Nos ensaios com quitosana, tiabendazol e UV-C, a quitosana apresentou melhor controle da doença, aplicada isoladamente ou em conjunto com o fungicida e UV-C, em temperatura ambiente ou refrigeração. A quitosana e a proteína harpina apresentaram controle semelhante e, em comparação com o ácido cítrico, a quitosana ocasionou melhor controle em laranjas ?Valência?. Para análises bioquímicas, amostras de flavedo foram homogeneizadas em de tampão acetato, com posterior centrifugação, coletando-se o sobrenadante. Para as reações enzimáticas, foram utilizados os reagentes CM-chitin-RBV, CMCurdlan- RBB, guaiacol, catecol e L-fenilalanina para quitinase, glucanase, peroxidase, polifenoloxidase e fenilalanina amônia-liase, respectivamente. Para a determinação de fenóis, amostras do flavedo foram homogeneizadas em metanol acidificado e a dosagem feita com o reagente Folin-Ciocalteau. A quitosana induziu o aumento da atividade das enzimas nas primeiras 24 h após o tratamento, sendo neste tempo detectada a maior atividade. Não houve atividade de fenilalanina amônia-liase, bem como acúmulo de fenóis. Finalmente, fica evidenciado que quitosana e a UV-C apresentaram efeito in vitro sobre G. citricarpa, porém somente a quitosana exibiu potencial no controle da mancha preta em laranja pós colheita. / Brazil is the biggest producer and exporter of orange juice, and this is one of the most important economical activities for the country. The fruits can be affected by the citrus black spot, disease caused by the fungus Guignardia citricarpa, which depreciates then commercially, causes premature fall and increases the production cost. Alternative measures to the chemical control are being studied and, in this context, resistance induction can be considered. The present work had as objective evaluate the in vitro effects of chitosan and UV-C radiation on mycelial growth, germination and apressorium formation by G. citricarpa and the action of the abiotic agents on controlling the disease on postharvest oranges, under room temperature and refrigeration storage, also studying the mechanisms of resistance in the plant tissue in response to the better treatment. The chitosan concentrations were 0, 0.5, 1.0, 1.5; 2.0 and 3.0% and the UVC doses were 0.52, 1.04, 3.13, 10.44 and 15.66 kJ.m-2. Chitosan inhibited mycelial growth and stimulated the germination and the apressorium formation that were morphologically abnormal. UV-C did not inhibited mycelial growth, but reduced it at the highest dose used. For the in vivo experiments, oranges were collected, sanitized with hypochlorite and treated. Chitosan concentrations of 0.5, 1.0 and 2.0% and the UV-C dose of 7 kJ m-2 exhibited better results in ?Valência ? oranges. Analyses of peel color of irradiated fruits revealed a light browning. The fungicides thiabendazole and imazalil did not control the disease in ?Pêra Rio ? oranges, but fewer lesions appeared on fruits treated with the fungicides in association with chitosan, under room temperature and refrigeration. Color analysis of peel indicated yellowing and no significant differences among soluble solids, titratable acidity, pH vitamin C and ratio. In the chitosan, thiabendazole and UV-C assays, there was a better control of lesion appearing by treatment with chitosan, applied alone or in association with fungicide and UV-C, at room temperature or refrigeration. Chitosan and the harpin protein were similar on the controlling of the disease and, in comparison to the citric acid, chitosan presented better control on ?Valência? oranges. For biochemical analysis, flavedo samples were homogenized in acetate buffer, centrifuged, and the supernatant collected. The reagents used were CM-chitin-RBV, CM-Curdlan-RBB, guaiacol, cathecol and L-phenylalanine for chitinase, glucanase, peroxidase, polyphenoloxidase and phenylalanine ammonia-lyase, respectively. For phenol determination, flavedo was homogenized in acidified methanol and the evaluation was made with Folin-Ciocalteau. Chitosan increased enzyme activities in the first 24 h after treatment, with the highest activity in that time. Activity of phenylalanine ammonia-lyase was not detected, well as absent of phenolic compounds accumulation. Chitosan and UV-C exhibited in vitro effect on G. citricarpa, however, only chitosan showed potential on the control of black spot in postharvest oranges.
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Pedestrian Safety Around Elementary SchoolsCicek, Bunyamin Erkan 01 September 2009 (has links) (PDF)
This study establishes pedestrian safety focused environment around elementary schools. In order to reach this objective 3 consecutive goals are fulfilled / firstly / proposing, a newly designed black spot analysis, &ldquo / Behavioral Black Spot Analysis&rdquo / , secondly / documenting pedestrian behavior around black spots, and finally stimulating effective interventions around elementary schools. This study proposes a newly designed methodology / &ldquo / Behavioral Black Spot Analysis&rdquo / which is namely based upon pedestrians&rsquo / route choice and risk perception statements. Additionally it is observed that students choose the shortest route on their way. &ldquo / Behavioral Black Spot Analysis&rdquo / reveals that traffic flows, pedestrian visibility, vehicle visibility, waiting time, road width are most important parameters of pedestrians&rsquo / perception of traffic safety. Results of unobtrusive observations indicate that interventions have significant effect on vehicle speed, number of conflicts, yielding behavior of drivers, total number of cars forming a queue, number of pedestrians stopping on the curb, head movements, crossing angles, crossing tempos, and crossing distances of pedestrians. Behind this interventions affects pedestrians&rsquo / waiting time in negative manner. Recommendations for pedestrian safety interventions are suggested.
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Controle de Guignardia citricarpa e Penicillium digitatum em laranja com óleos essenciais e agentes de biocontroleMattos, Liliana Patrícia Vital de [UNESP] 10 December 2010 (has links) (PDF)
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mattos_lpv_dr_botfca.pdf: 1675965 bytes, checksum: 3faf029e6aef13589d4485a2b0a651ee (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Penicillium digitatum, agente causador do bolor verde, e Guignardia citricarpa, agente causador da mancha preta, depreciam os frutos citricos. O controle desses patógenos em frutos é realizado com fungicidas sintéticos. Devido a preocupação da sociedade com os riscos de contaminação ambiental, intoxicação humana principalmente infantil e animal e ao surgimento de isolados fúngicos resistentes aos fungicidas sintéticos, estão em desenvolvimento técnicas alternativas aos fungicidas para uma agricultura mais sustentável. O objetivo do trabalho foi avaliar os efeitos de óleos essenciais e fixos e dos agentes de biocontrole no controle de P. digitatum e G. citricarpa em frutos laranja Pêra em pós- colheita. Assim, foram testados os óleos fixos de Allium sativum, Copaifera langsdorffii, Azadirachta indica; e os óleos essenciais de Pogostemon cablin, Mentha arvensis, Eucalyptus spp., Cymbopogon citratus, Ocimum basilicum var. Maria bonita, Romarinus officinalis, Lippia sidoides, Zingiber officinale, Citrus aurantifolia, Piper aduncum e Ocimum basilicum. Além dos óleos, também foram estudados os seguintes agentes de biocontrole: Bacillus subtilis (Serenade®), Bacillus subtilis e Bacillus lichiniformes (Nemix®), Pichia guilliermondii (L29), Sporobolomyces roseus (L41), Rhodotorula mucilagenosa (L17), Sporodiobolus pararoseus, Pichia sp. (L4-1), Debaryomyces hansenii (L62), Pichia membranifaciens (L21) e uma bactéria isolada da laranja. Tanto os agentes de biocontrole, quanto os óleos foram testados in vivo e in vitro contra os dois patógenos. Para a avaliação da atividade dos óleos essenciais e dos antagonistas in vivo, no controle de P. digitatum, foram utilizadas laranjas Pêra. Cada fruto foi ferido em dois pontos opostos, na região equatorial, atingindo a região do albedo. Após o ferimento, os frutos foram inoculados com 20 μL da suspensão de conídios... / Penicillium digitatum, causal agent of green mold, and Guignardia citricarpa causal agent of black spot. Detracts the citrus fruit, the control of these pathogens is made with synthetic fungicides. Due to concern about the risks of environmental contamination, human, mainly children and animal toxicity and the emergence of fungal isolates resistant to fungicides, various researches has been development to obtain alternative techniques for a fungicides. The objectives of this work was to evaluate the effetives fix and essencial oils and biocontrol agents for the control of P. digitatum and G. citricarpa on Pera orange fruits in postharvest. Thus, were tested the fixed oils from Allium sativum, Copaifera langsdorffii, Eucalyptus spp. Azadirachta indica,and the essential oils of Pogostemon cablin, Mentha arvensis, Cymbopogon citratus, Ocimum basilicum var. Maria bonita, Romarinus officinalis, Lippia sidoides, Zingiber officinale, Citrus aurantifolia, Piper aduncum and Ocimum basilicum. In addition were also studied the following biocontrol agents: Bacillus subtilis (Serenade ®), Bacillus subtilis and Bacillus lichiniformes (Nemix ®), Pichia guilliermondii (L29), Sporobolomyces roseus (L41), Rhodotorula mucilagenosa (L17), Sporodiobolus pararoseus, Pichia spp. (L4-1), Derbaryomyces hansenii (L62), Pichia membranifaciens (L21) and a bacterium isolate of the orange. Both biocontrol agents as the oils, were tested in vivo and in vitro against both pathogens. For the assessment of activity of essential oils and antagonists in vivo in controlling P. digitatum were used Pera orange. Each fruit was wounded in two opposite points in the equatorial region, reaching the albedo. After the injury, the fruits were inoculated with 20 mL of conidial suspension of P. digitatum (105 conidia / mL), followed by immersion in a suspension of cells of each biocontrol agent in the concentration: ...(Complete abstract click electronic access below)
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Efeito de fungicidas do grupo químico das estrobilurinas no controle da Mancha Preta dos Citros, na produção e na qualidade tecnológica dos frutos /Ikeda, Mário. January 2011 (has links)
Orientador: Antonio de Goes / Banca: Rita de Cássia Panizzi / Banca: Kátia Cristina Kupper / Resumo: O objetivo deste trabalho foi avaliar a resposta do número de aplicações do fungicida pyraclostrobin no controle da Mancha Preta dos Citros (Guignardia citricarpa), assim como comparar o comportamento das diferentes estrobilurinas recomendadas no controle da doença. Também foi avaliada a influência dos tratamentos fungicidas sobre a produção e qualidade tecnológica dos frutos. Para tal foram realizados dois experimentos, em pomares de laranjeira „Valência‟ com histórico comprovado da ocorrência da doença em anos anteriores e com elevada intensidade e frequência na distribuição dos sintomas entre as plantas. Foram avaliados seis tratamentos, com três a quatro aplicações de fungicidas sistêmicos, isolado ou em mistura com cobre. Os tratamentos citados foram precedidos por duas aplicações de fungicida cúprico (CO), iniciando-se na fase de 2/3 de pétalas caídas e repetidas depois de quatro semanas. As aplicações de produtos sistêmicos (três ou quatro) foram realizadas quatro semanas após a segunda aplicação de fungicida cúprico, com intervalo de seis semanas entre elas. As estrobilurinas avaliadas foram pyraclostrobin (PY), azoxystrobin (AZ) e trifloxystrobin (TR) isolado ou em combinação com fungicida cúprico. Todos os tratamentos aplicados receberam um tratamento adicional com carbendazim (CA) como fechamento das pulverizações. Dessa forma, os tratamentos e as respectivas sequências foram:... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate the number of applications of the fungicide pyraclostrobin for control of Citrus Black Spot (Guignardia citricarpa) and compare the action of the different recommended strobilurins for disease control. We also analyzed the influence of fungicide treatments on the production and technological quality of fruit. For this purpose two experiments were conducted in orchards of „Valencia‟ sweet orange with proven track records of disease occurrence in previous years and with high intensity and frequency distribution of symptoms among the plants. We evaluated six treatments, with three or four applications of systemic fungicides, alone or mixed with copper. The cited treatments were preceded by two applications of copper fungicide (CO), beginning on the phase 2/3 of petals fallen and repeated after four weeks. The applications of systemic products (three or four) were performed four weeks after the second application of cooper fungicide, with an interval of six weeks between them. The strobilurins tested were pyraclostrobin (PY), azoxystrobin (AZ) and trifloxystrobin (TR) alone or in combination with cooper fungicide. All treatments received an additional treatment with carbendazim (CA) as the closure of sprays. Thus, treatments and their sequences were:... (Complete abstract click electronic access below) / Mestre
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