Made available in DSpace on 2014-06-11T19:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-09-26Bitstream added on 2014-06-13T18:45:41Z : No. of bitstreams: 1 reis_rf_dr_jabo.pdf: 717177 bytes, checksum: a3ad4a94a8ee559ded22f5ec2741cd35 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve como objetivos determinar o efeito da idade da lesão de mancha marrom de Alternária (MMA) na produção conidial em folhas, ramos e frutos, a produção conidial sob diferentes condições de umidade relativa, a influência da aplicação de fungicidas na supressão da produção de conídios, o efeito da idade de maturação de folhas na suscetibilidade ao patógeno e a influência do tamanho de frutos na suscetibilidade à Alternaria alternata. A reação de espécies cítricas à MMA também foi avaliada. A esporulação em folhas teve início cerca de 10 dias depois do aparecimento de lesões de mancha marrom de Alternária, sendo que a maior produção de conídios ocorreu a partir de 20 dias, estendendo-se até 40 dias de idade. A produção de conídios foi superior em folhas do que em ramos ou frutos. A esporulação por unidade de área de lesão em folhas foi maior nos tangelos Minneola e Orlando , em relação ao tangor Murcott . A produção conidial em lesões de folhas foi mais abundante a partir de 85, 92,5, 96 e 100% de umidade relativa. A aplicação de fungicidas do grupo das estrobilurinas e dos cúpricos suprimiu a esporulação em lesões nas folhas por cerca de 14 a 21 dias após a aplicação. Folhas de tangelo Minneola apresentaram maior quantidade e maiores tamanhos de lesões até 20 dias de idade. O híbrido Nova foi o mais resistente entre os materiais genéticos estudados, sendo que folhas a partir de 16 dias de idade... / The objectives of this study were to evaluate: i) the effect of age of Alternaria brown spot (ABS) lesions on conidial production on leaves, twigs and fruit, ii) conidial production under different relative humidities, iii) influence of fungicide application on conidial production and iv) effect of leaf age on susceptibility to the disease and the influence of fruit size on the severity of brown spot. The reaction of the different citrus species to ABS was also studied. Sporulation on leaves began about 10 days after symptoms developed, was abundant from 20 to 40 days, and declined thereafter. Conidial production was far greater on leaf than fruit or twig lesions. Spore production per unit area of leaf lesion was greater on the more susceptible hybrids, Minneola and Orlando tangelos than on the less susceptible Murcott tangor. Conidial production on leaf lesions was more abundant at 85, 92.5, 96 and 100% relative humidity (RH) and almost nil at lower RH. Application of pyraclostrobin, trifloxyztrobin, azoxystrobin and copper fungicides suppressed the sporulation on leaf lesions for about 14 to 21 days after application. Minneola tangelo leaves had the greatest number and the largest lesions by 20 days or later. The Nova and Murcott hybrids were the most resistant of the cultivars and leaves showed few lesions when they were 16-days-old or older at inoculation. Leaves of Dancy tangerine were more susceptible than on leaves of Orlando tangelo and the Sunburst mandarin. For disease severity, there was a significant... (Complete abstract click electronic access below)

Resumo: Este trabalho teve como objetivos determinar o efeito da idade da lesão de mancha marrom de Alternária (MMA) na produção conidial em folhas, ramos e frutos, a produção conidial sob diferentes condições de umidade relativa, a influência da aplicação de fungicidas na supressão da produção de conídios, o efeito da idade de maturação de folhas na suscetibilidade ao patógeno e a influência do tamanho de frutos na suscetibilidade à Alternaria alternata. A reação de espécies cítricas à MMA também foi avaliada. A esporulação em folhas teve início cerca de 10 dias depois do aparecimento de lesões de mancha marrom de Alternária, sendo que a maior produção de conídios ocorreu a partir de 20 dias, estendendo-se até 40 dias de idade. A produção de conídios foi superior em folhas do que em ramos ou frutos. A esporulação por unidade de área de lesão em folhas foi maior nos tangelos ‘Minneola’ e ‘Orlando’, em relação ao tangor ‘Murcott’. A produção conidial em lesões de folhas foi mais abundante a partir de 85, 92,5, 96 e 100% de umidade relativa. A aplicação de fungicidas do grupo das estrobilurinas e dos cúpricos suprimiu a esporulação em lesões nas folhas por cerca de 14 a 21 dias após a aplicação. Folhas de tangelo ‘Minneola’ apresentaram maior quantidade e maiores tamanhos de lesões até 20 dias de idade. O híbrido ‘Nova’ foi o mais resistente entre os materiais genéticos estudados, sendo que folhas a partir de 16 dias de idade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objectives of this study were to evaluate: i) the effect of age of Alternaria brown spot (ABS) lesions on conidial production on leaves, twigs and fruit, ii) conidial production under different relative humidities, iii) influence of fungicide application on conidial production and iv) effect of leaf age on susceptibility to the disease and the influence of fruit size on the severity of brown spot. The reaction of the different citrus species to ABS was also studied. Sporulation on leaves began about 10 days after symptoms developed, was abundant from 20 to 40 days, and declined thereafter. Conidial production was far greater on leaf than fruit or twig lesions. Spore production per unit area of leaf lesion was greater on the more susceptible hybrids, Minneola and Orlando tangelos than on the less susceptible Murcott tangor. Conidial production on leaf lesions was more abundant at 85, 92.5, 96 and 100% relative humidity (RH) and almost nil at lower RH. Application of pyraclostrobin, trifloxyztrobin, azoxystrobin and copper fungicides suppressed the sporulation on leaf lesions for about 14 to 21 days after application. Minneola tangelo leaves had the greatest number and the largest lesions by 20 days or later. The Nova and Murcott hybrids were the most resistant of the cultivars and leaves showed few lesions when they were 16-days-old or older at inoculation. Leaves of Dancy tangerine were more susceptible than on leaves of Orlando tangelo and the Sunburst mandarin. For disease severity, there was a significant... (Complete abstract click electronic access below) / Orientador: Antonio de Goes / Coorientador: Lavern Wayne Timmer / Banca: Eduardo Sanches Stuchi / Banca: Nelson Sidnei Massola Junior / Banca: Modesto Barreto / Banca: Antonio Baldo Geraldo Martins / Doutor

Made available in DSpace on 2015-03-26T13:39:34Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1636884 bytes, checksum: c966934c707a7e6bf40bfe5aee85e5a1 (MD5) Previous issue date: 2009-09-25 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The objective of this work was to promote the degreening, without losing internal fruit quality, of Poncã tangerine from two regions of Minas Gerais. Two experiments were carried out. In the first, the fruits were harvested from a commercial orchard in the northern region, and the second experiment used fruits from Zona da Mata. Fruits were harvested when showing minimum attributes of 35% juice, 9 ° Brix and soluble solids/tritable acidity ratio of 9.5. Then the fruits were packed in airtight boxes, which were exposed for 24, 48 and 96 h to different concentrations of ethylene gas: 0, 5, 10, 20 and 40 μL.L-1, at 20 + 1 °C and 90 + 5% relative humidity, respectively. Every 24 h, the boxes were opened for renewal of internal atmosphere, by reapplying the gas until treatment end. A post-treatment phase of 96 h duration took place at the end of each exposure time, when the fruits were kept in ethylene-free atmosphere, in cold chamber, at the same temperature and relative humidity used during the exposure to ethylene. During this phase, the fruits were evaluated every 24 h, and the difference in skin color, Hue angle of the peel, total chlorophyll and carotenoid content, soluble solids content, tritable acidity and SS/TA ratio of juice, solute leakage, CO2 production and loss of fruit fresh mass. In the first experiment, the fruits showed stronger degreening with increasing time of exposure to ethylene, most markedly for 96 h. After this exposure time, the Hue angle increased from 96.1o, in the first assessment days, to 82.3o, at the end of 96 h, which was lower than values observed in naturally degreened fruits. Fruits exposed for 24 h showed evolution of the yellow peel color similar to the untreated ones. It was observed that fruits left to ripe on the plant showed non-homogeneous peel degreening. The fruits exposed to ethylene for 96 h showed no visual signs of loss of commercial quality, although there was increased solute leakage from the peel during the treatment. Soluble solids content, tritable acidity and SS/TA ratio remained unchanged throughout the assessment period. The synthesis of total carotenoids in the peel was low, from 6.0 μg/cm2, in control fruits at the end of evaluations, to a maximum of 8.2 μg/cm2, in fruits exposed to ethylene for 96 h. This synthesis was insufficient to reach the orange color, therefore, the degreening of fruit peel was due, almost exclusively, to chlorophyll degradation. In the second experiment, the fruits showed yellowing of the peel stronger than fruits of the first experiment. The exposure time of 96 h proved to be the most efficient in promoting the fruit degreening in comparison with other times. Color evolution was quite similar between the control and fruits treated for 24 and 48 h. Fruits of all treatments had very low synthesis of total carotenoids in the peel, changing from 7.3 μg/cm2 in control fruits to 9.2 μg/cm2, maximum value observed in fruits exposed to ethylene for 96 h. Even in fruits showing the strongest yellowing, there was little participation of new synthesized carotenoids in the composition of the final color. Fruits fully developed in the plant reached the maximum degreening, becoming orange, the typical color of the species. Thus, for fruits produced in the Zona da Mata region, the post-harvest degreening with ethylene is only justified to anticipate the harvest, since the region has favorable climate to natural degreening. However, for fruits produced in northern Minas Gerais, where the high temperatures prevailing throughout the year impair the natural degreening, the postharvest use of ethylene may serve to obtain a more uniform peel color. / The objective of this work was to promote the degreening, without losing internal fruit quality, of Poncã tangerine from two regions of Minas Gerais. Two experiments were carried out. In the first, the fruits were harvested from a commercial orchard in the northern region, and the second experiment used fruits from Zona da Mata. Fruits were harvested when showing minimum attributes of 35% juice, 9° Brix and soluble solids/tritable acidity ratio of 9.5. Then the fruits were packed in airtight boxes, which were exposed for 24, 48 and 96 h to different concentrations of ethylene gas: 0, 5, 10, 20 and 40 μL.L-1, at 20 + 1 °C and 90 + 5% relative humidity, respectively. Every 24 h, the boxes were opened for renewal of internal atmosphere, by reapplying the gas until treatment end. A post-treatment phase of 96 h duration took place at the end of each exposure time, when the fruits were kept in ethylene-free atmosphere, in cold chamber, at the same temperature and relative humidity used during the exposure to ethylene. During this phase, the fruits were evaluated every 24 h, and the difference in skin color, Hue angle of the peel, total chlorophyll and carotenoid content, soluble solids content, tritable acidity and SS/TA ratio of juice, solute leakage, CO2 production and loss of fruit fresh mass. In the first experiment, the fruits showed stronger degreening with increasing time of exposure to ethylene, most markedly for 96 h. After this exposure time, the Hue angle increased from 96.1o, in the first assessment days, to 82.3o, at the end of 96 h, which was lower than values observed in naturally degreened fruits. Fruits exposed for 24 h showed evolution of the yellow peel color similar to the untreated ones. It was observed that fruits left to ripe on the plant showed non-homogeneous peel degreening. The fruits exposed to ethylene for 96 h showed no visual signs of loss of commercial quality, although there was increased solute leakage from the peel during the treatment. Soluble solids content, tritable acidity and SS/TA ratio remained unchanged throughout the assessment period. The synthesis of total carotenoids in the peel was low, from 6.0 μg/cm2, in control fruits at the end of evaluations, to a maximum of 8.2 μg/cm2, in fruits exposed to ethylene for 96 h. This synthesis was insufficient to reach the orange color, therefore, the degreening of fruit peel was due, almost exclusively, to chlorophyll degradation. In the second experiment, the fruits showed yellowing of the peel stronger than fruits of the first experiment. The exposure time of 96 h proved to be the most efficient in promoting the fruit degreening in comparison with other times. Color evolution was quite similar between the control and fruits treated for 24 and 48 h. Fruits of all treatments had very low synthesis of total carotenoids in the peel, changing from 7.3 μg/cm2 in control fruits to 9.2 μg/cm2, maximum value observed in fruits exposed to ethylene for 96 h. Even in fruits showing the strongest yellowing, there was little participation of new synthesized carotenoids in the composition of the final color. Fruits fully developed in the plant reached the maximum degreening, becoming orange, the typical color of the species. Thus, for fruits produced in the Zona da Mata region, the post-harvest degreening with ethylene is only justified to anticipate the harvest, since the region has favorable climate to natural degreening. However, for fruits produced in northern Minas Gerais, where the high temperatures prevailing throughout the year impair the natural degreening, the postharvest use of ethylene may serve to obtain a more uniform peel color.

Made available in DSpace on 2014-08-20T14:22:07Z (GMT). No. of bitstreams: 1 Dissertacao_Simone_Padilha_Galarca.pdf: 1726388 bytes, checksum: 86ac76aea24f6a9fb434c5486a67b029 (MD5) Previous issue date: 2009-03-30 / The objective of the present work was to evaluate the sensory and physical-chemical characteristics of organic blueberry ‗Bluegem and tangerine ‗Ponkan fruits, submitted to controlled or modified atmosphere, respectively. Also, it was tested the use of two concentrations of propolis as fruit coating of the citrus. Therefore, the blueberries ‗Bluegem (2007) and tangerines ‗Ponkan (2008) were harvested at the consumption stage. Then, the fruits were selected and storage after treatment. ‗Bluegem was stored at 1.5ºC with relative humidity (RH) of 90-95% and submitted to the following treatments: control 21KPa O2 + 0.03KPa CO2 (T1 - natural atmosphere), 4KPa O2 + 5KPa CO2 (T2) or 4KPa O2 + 10KPa CO2 (T3). The fruits were kept under storage for a period of 14 (P1), 28 (P2) or 42 (P3) days at 1.5°C, plus one day of simulated commercialization at 20°C and 70-75% RH. ‗Ponkan was stored at 4°C and 90-95%RH. The fruits were treated with: no wax (T1); ‗Carnaúba -based wax, 18% (T2); extract of propolis, 100% (T3) or extract of propolis, 90% + soybean oil, 10% (T4). Each fruit was individually treated with 0.25mL of the product. Subsequently, fruits were stored for a period of 15 (P1), 30 (P2) or 45 (P3) days plus three days of simulated commercialization at 15°C and 70-75% RH. A completely randomized design was used for the physical-chemical analysis, and for the sensory analysis a randomized block design; each judger was considered as a replication. Data were submitted to analysis of variance, and for mean comparison it was applied the Tukey test at 5% of error probability. The Pearson correlation was also carried between the physical-chemical and sensory variables. Blueberries ‗Bluegem can be stored up to 28 days at 1.5ºC plus one day of simulated commercialization at 20°C to keep their quality, whether treated with 5 or 10KPa CO2 and 4KPa O2. Using cold storage fruits could be stored up to 14 days at 1.5°C plus one day of simulated commercialization at 20°C, without compromising the quality of in natura consumption. Tangerines kept for 30 days at 90-95%RH and 4ºC suffered depreciation due to physiological disturbs. The essence of propolis reduced mass loss; however, whether added soybean oil it conferred slighter brightness to the fruit. ‗Carnaúba -based oil provide brighter fruits. According results, changing in the atmosphere of the storage environment (either controlled or modified storage) optimizes the storage of blueberries ‗Bluegem and tangerines ‗Ponkan , delaying senescence and keeping quality (support: CAPES). / O objetivo do presente trabalho foi avaliar o efeito nas características físico-químicas e sensoriais, da atmosfera controlada para mirtilo ‗Bluegem e da atmosfera modificada para tangerina ‗Ponkan produzida em sistema orgânico, além de testar a utilização de própolis em duas concentrações no recobrimento deste citrus. Sendo assim, os mirtilos ‗Bluegem (2007) e tangerinas ‗Ponkan (2008) foram colhidos no estádio de maturação para consumo, selecionados e armazenados após serem tratados. O mirtilo ‗Bluegem foi armazenado à temperatura de 1,5ºC umidade relativa (UR) de 90-95%, sendo realizados os seguintes tratamentos: controle - 21KPa O2 e 0,03KPa CO2 - (T1 - atmosfera natural), 4KPa O2 + 5KPa CO2 (T2), 4KPa O2 + 10KPa CO2 (T3). As frutas ficaram armazenadas por um período de 14 (P1), 28 (P2) e 42 (P3) dias a 1,5°C mais 1 dia de simulação de comercialização em temperatura de 20°C e UR 70-75%. A tangerina ‗Ponkan foi armazenada a temperatura de 4°C, UR de 90-95%. Os tratamentos foram: sem cera (T1), cera a base de Carnaúba 18% (T2), extrato de própolis 100% (T3) e extrato de própolis 90% + óleo de soja 10% (T4). Os produtos foram aplicados em cada uma das frutas em quantidade de 0,25 mL. Posteriormente foram armazenados por um período de 15 (P1), 30 (P2) e 45 (P3) dias mais 3 dias de simulação de comercialização em temperatura de 15°C e UR 70-75%. O delineamento experimental utilizado para as análises físico-químcas foi inteiramente casualizado e para análise sensorial blocos casualizados, sendo cada julgador uma repetição. Os dados foram submetidos à análise de variância e para comparação das médias, foi aplicado o teste de Tukey ao nível de 5% de probabilidade de erro. Foi realizada também a correlação de Pearson entre as variáveis físico-químicas e sensoriais. Os mirtilos ‗Bluegem podem ficar até 28 dias de armazenamento a 1,5ºC mais 1 dia de simulação de comercialização a 20°C com qualidade, desde que tratadas com 5 ou 10KPa de CO2 e 4KPa de O2. Se for utilizado o armazenamento refrigerado comum as frutas podem ficar até 14 dias de armazenamento a 1,5°C mais 1 dia de simulação de comercialização a 20°C e UR 70-75%, sem comprometer a qualidade para o consumo in natura. As tangerinas armazenaram-se por 30 dias a 90-95% UR a 4ºC, com depreciação do produto por distúrbios fisiológicos. A essência de própolis diminuiu a perda de massa, porém conferiu um pouco mais de brilho quando foi adicionado óleo de soja, porém a cera de carnaúba confere maior brilho. Com os resultados obtidos pode-se concluir que a mudança de atmosfera no ambiente de armazenamento, seja, controlada ou modificada auxilia favoravelmente o armazenamento de frutas de mirtilo ‗Bluegem e da tangerina ‗Ponkan , retardando sua senescência e mantendo sua qualidade (apoio: CAPES).