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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Sobrevivência de Colletotrichum acutatum, agente causal da podridão floral dos citros, em plantas daninhas / Survival of Colletotrichum acutatum, the causal agent of postbloom fruit drop, on weeds

Guilherme Fernando Frare 01 February 2012 (has links)
O Brasil é o maior produtor de laranja do mundo e, embora o cultivo ocorra em todos os estados brasileiros, o Estado de São Paulo é o maior produtor, responsável por 80% da produção nacional. Dentre as doenças que podem limitar a produção dos citros encontra-se a podridão floral do citros (PFC), causada pelo fungo Colletotrichum acutatum J. H. Simmonds. Os sintomas desta doença são caracterizados pela presença de lesões necróticas marrons ou alaranjadas nas pétalas e queda dos frutos recém formados, os cálices e os pedúnculos permanecem retidos nos ramos. Em citros, C. acutatum pode sobreviver aderido à superfície das folhas, na forma de apressório quiescente, por pelo menos um mês. As plantas daninhas podem atuar como hospedeiras alternativas de diversos patógenos, servindo como fontes de inóculo e desempenhando um importante papel na epidemiologia das doenças. O objetivo deste trabalho foi verificar se plantas daninhas, comuns em pomares de citros no Estado de São Paulo, podem servir como fonte de inóculo de C. acutatum para esta cultura. Sete espécies de plantas daninhas foram inoculadas com uma suspensão de conídios de C. acutatum, calibrada a 105 conídios/mL. Após a inoculação, estas foram mantidas em câmara úmida por 36 horas e, em seguida, amostras de todas as plantas foram coletadas e observadas em microscópio óptico para verificar a germinação dos conídios. Trinta, sessenta e noventa dias após as inoculações realizou-se o isolamento de C. acutatum das folhas inoculadas. Para isso, amostras de folhas de cada espécie de planta daninha foram coletadas, desinfestadas superficialmente e transferidas para placas de Petri, onde receberam 70 L de extrato floral de citros sobre o local da inoculação, para estimular a germinação dos apressórios ali presentes. As folhas permaneceram incubadas por 24 horas a 23°C, com fotoperíodo de 12 h. Após esse período, as áreas inoculadas das folhas foram cortadas e transferidas para placas de poliestireno contendo meio de Martin. Após o surgimento das primeiras colônias de C. acutatum, discos de quatro milímetros de diâmetro foram transferidos para meio BDA, para a obtenção de colônias puras. Em seguida foi realizado um teste de patogenicidade em flores de laranja doce de três anos de idade. Os dados de porcentagem de isolamento foram analisados análise de variância e testes não paramétricos. Foram observadas a germinação e a formação de apressórios de C. acutatum na superfície de todas as folhas inoculadas, após 36 horas de câmara úmida. Não houve diferença estatística na sobrevivência de C. acutatum ao longo dos 30, 60 e 90 dias e não foi observado nenhum tipo de sintoma nas folhas inoculadas. C. acutatum foi isolado de todas as plantas daninhas analisadas, embora o tempo de sobrevivência tenha variado em função da espécie de daninha. Todos os isolados obtidos das plantas daninhas apresentaram sintomas típicos de PFC em todas as flores inoculadas. Os resultados obtidos demonstraram que as plantas daninhas avaliadas podem servir como hospedeiras alternativas de C. acutatum, resultando em fonte de inóculo primário e secundário deste patógeno para a cultura do citros. / Brazil is the major orange producer in the world, and although the cropping occurs all over the Brazilian States, the São Paulo State is the major producer, responsible for 80% of the national production. Postbloom fruit drop (PFD), caused by the fungus Colletotrichum acutatum J. H. Simmonds is an important disease that can cause yield reduction. The symptoms of this disease are characterized by the presence of brown or orange necrotic lesions in the petals and the drop of young fruits; the calyces and peduncles remain in the branches after fruit drop. In citrus, C. acutatum can adhered to the surface of the leaves, in the form of quiescent appressoria, for at least one month. The weeds can act as alternative hosts of diverse pathogens, serving as inoculum sources and playing an important role in the disease epidemiology. The purpose of this research was to verify if weeds, commons in citrus orchards in São Paulo State, may serve as inoculum source of C. acutatum for this crop. Seven weed species were inoculated with a conidial suspension of C. acutatum, calibrated with 105 conidia/mL. After the inoculation, the weeds were kept in humidity chamber for 36 hours. Samples of all weeds were collected and observed in optical microscope to verify the conidia germination. Thirty, sixty and ninety days after inoculation, C. acutatum was isolated from the inoculated leaves. For this purpose, leaves of each weed species were collected, superficially disinfested and transferred to Petri dishes. The leaves received 70 L of citrus flower extract over the inoculation area to stimulate the appressoria germination. The leaves were incubated for 24 hours at 23°C, with 12 hours of photoperiod. After this period, the inoculated areas were cut and transferred to polystyrene dishes with Martin medium. After the appearance of the first colonies of C. acutatum, discs of four millimeters of diameter were transferred to PDA medium to obtain pure colonies. A pathogenicity test was carried out in three years old sweet orange flowers. The percentage of pathogen isolation was analyzed by variance analysis or non-parametric analysis. Conidia germination and appressoria formation of C. acutatum in all inoculated leaves were observed, after 36 hours of humidity chamber. There was no statistical difference in the C. acutatum survival during 30, 60 e 90 days and no type of symptom was observed in the inoculated leaves. C. acutatum was isolated from every weed analyzed, although the survival period varied among the weed species. Every isolated obtained from the weeds presented typical PFD symptoms in every inoculated flowers. The results showed that weeds can serve as alternative hosts of C. acutatum, contributing in primary and secondary inoculum source of this pathogen to the citrus crop.
52

Epidemiologia comparativa entre \'Candidatus Liberibacter asiaticus\' e \'Candidatus Liberibacter americanus\' em ambiente controlado / Comparative epidemiology between Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus under controlled environment

Maria Cândida de Godoy Gasparoto 30 September 2010 (has links)
Huanglongbing é a mais destrutiva doença da citricultura mundial. Seu recente relato no Brasil, em 2004, e a detecção de duas espécies bacterianas associadas à doença -Candidatus Liberibacter asiaticus e Candidatus Liberibacter americanus resultaram em poucos estudos do comportamento do Huanglongbing nas condições dos pomares brasileiros. Os objetivos deste trabalho foram (i) comparar a eficiência de infecção por Candidatus Liberibacter asiaticus e Candidatus Liberibacter americanus em plantas cítricas inoculadas por meio de enxertia com as duas espécies bacterianas, separadamente, e mantidas sob diferentes temperaturas, e (ii) comparar o progresso temporal e espacial do Huanglongbing causado por ambas as espécies, a partir da infecção natural por Diaphorina citri, tendo plantas de citros ou Murraya paniculata (murta) como fonte primária de inóculo. Para alcançar o primeiro objetivo, dois experimentos foram conduzidos em câmaras de crescimento com temperatura e fotofase controladas. A incidência da doença foi determinada por Real-Time PCR de amostras foliares. As temperaturas mais amenas foram favoráveis à infecção por Candidatus Liberibacter americanus, enquanto que altas temperaturas não afetaram a infecção de Candidatus Liberibacter asiaticus. A eficiência de infecção para esta última espécie foi favorecida nas temperaturas de 17/22°C e 22/27°C (noturna/diurna, respectivamente). Para cumprir com o segundo objetivo, um experimento foi conduzido com diferentes fontes de inóculo, que corresponderam aos seguintes tratamentos: (i) plantas de laranjeira doce da variedade Natal infectadas por Candidatus Liberibacter asiaticus ou Candidatus Liberibacter americanus, (ii) unicamente plantas de Murraya paniculata infectadas por Candidatus Liberibacter americanus e (iii) unicamente plantas de laranjeira doce da variedade Natal infectadas por Candidatus Liberibacter americanus. Cada tratamento foi aplicado em um compartimento isolado de uma casade- vegetação. O primeiro tratamento foi repetido. Em todos os compartimentos, 156 a 158 plantas de laranjeira doce da variedade Valência foram dispostas ao redor das plantas fonte de inóculo. Psilídeos livres das bactérias foram periodicamente confinados em plantas fonte de inóculo e, posteriormente foram liberados na casa-de-vegetação para livre movimentação e multiplicação. Quando as duas espécies bacterianas estavam presentes nas diferentes plantas cítricas utilizadas como fonte de inóculo, houve maior detecção de Candidatus Liberibacter asiaticus e maior eficiência de aquisição desta espécie bacteriana por psilídeos. Quando somente Candidatus Liberibacter americanus estava presente nas plantas fonte de inóculo, a eficiência de transmissão foi maior quando Murraya paniculata foi utilizada como fonte de inóculo, mostrando que Diaphorina citri pode adquirir naturalmente Candidatus Liberibacter 12 americanus de Murraya paniculata e transmiti-la para plantas cítricas. A eficiência de aquisição da espécie Candidatus Liberibacter americanus também foi maior tendo Murraya paniculata como planta fonte de inóculo e não citros. / Huanglongbing is the most destructive disease of citrus worldwide. There are few studies on the behavior of Huanglongbing in the Brazilian orchards conditions due to the recent report in Brazil, in 2004. Two bacterial species were associated with the disease in Brazil: Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus. The aims of this work were (i) to compare the efficiency of infection by Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus in citrus graft-inoculated plants with both bacterial species, separately, and kept under different temperatures, and (ii) to compare the spatio-temporal progress of Huanglongbing caused by both species, naturally transmitted by Diaphorina citri, having infected citrus plants or Murraya paniculata (jasmine orange) as primary inoculum sources. To achieve the first objective, two experiments were carried out in plant growth chambers with controlled temperature and light. Disease incidence in the inoculated plants was determined by Real-Time PCR of the leaf samples. The milder temperatures were favorable to Candidatus Liberibacter americanus infection, while the higher temperatures did not affect the infection by Candidatus Liberibacter asiaticus. The infection by this latter species was favored by temperatures of 17/22ºC and 22/27°C (night/day, respectively). To achieve the second objective, an experiment was carried out with different sources of inoculum, corresponding to the following treatments: (i) Natal sweet orange plants infected by Candidatus Liberibacter asiaticus or Candidatus Liberibacter americanus, (ii) only Murraya paniculata plants infected by Candidatus Liberibacter americanus and (iii) only Natal sweet orange plants infected by Candidatus Liberibacter americanus. Each treatment was applied in an isolated compartment of a screenhouse. The first treatment was repeated. In all of the compartments, from 156 to 158 Valencia sweet orange plants were located around the source of inoculum plants. Psyllids free of the bacteria were periodically confined in source of inoculum plants and, after this period, they were set free, and allowed to the free movement and multiplication inside the screenhouse. When both bacterial species were present in the different citrus plants as source of inoculum, there was higher detection of Candidatus Liberibacter asiaticus than Candidatus Liberibacter americanus and higher acquisition efficiency of the former bacterial species than the later by psyllids. When only Candidatus Liberibacter americanus was present in the source of inoculum plants, the higher transmission efficiency was reached when Murraya paniculata served as source of inoculum, showing that Diaphorina citri can naturally acquire Candidatus Liberibacter americanus from Murraya paniculata and transmit it to citrus plants. The acquisition efficiency of the 14 Candidatus Liberibacter americanus species was higher with Murraya paniculata as source of inoculum than with citrus plants was the source of inoculum.
53

The competitiveness of the South African citrus industry in the face of the changing global health and environmental standards

Ndou, Portia January 2012 (has links)
In recent years, concern about food safety linked to health issues has seen a rise in private food safety standards in addition to the regulations set by the Food and Agriculture Organisation (FAO) in collaboration with the World Health Organisation (WHO). These have presented challenges to producers and exporters of agricultural food products especially the producers of fresh fruits and vegetables. In spite of the food safety-linked challenges from the demand side, the vast range of business-environment forces pose equally formidable challenges that negatively impact on the exporting industries’ ability to maintain or improve their market shares and their ability to compete in world markets. The objective of this study was therefore to establish the competitiveness of the South African citrus industry in the international markets within this prevailing scenario. Due to the diversity of the definitions of competitiveness as a concept, this study formulated the following working definition: “the ability to create, deliver and maintain value and constant market share through strategic management of the industrial environment or competitiveness drivers”. This was based on the understanding that the international market shares of an industry are a function of forces in the business environment which range from intra-industry, external and national as well as the international elements. The unit of analysis were the citrus producers engaged in export of their products and the study made use of 151 responses by producers. The study adopted a five-step approach to the analysis of the performance of the South African citrus industry in the global markets, starting with the analysis of the Constant Market Share (CMS) of the South African citrus industry in various world markets, establishing the impact of the business environmental factors upon competitiveness, establishing the costs of compliance with private food safety standards, determining the non-price benefits of compliance with the standards, as well as highlighting the strategies for enhancing long-term competitiveness of the industry in the international markets. South Africa is one of the top three countries dominating the citrus fruit export market. Since its entry into the citrus fruit exports market in the 1900s, the industry has sustained its activity in the international market. The Constant Market Share Analysis shows that, amidst the challenges on the international market side, and the changes in the business environment, over much of which the industry has limited control and influence, the industry has maintained its competitive advantage in several markets. The CMS shows that South Africa’s lemons are competitive in America. Despite a negative trend, the South African grapefruit has been competitive in France, Greece, Italy, the Netherlands and Spain. Oranges have been competitive in the Greece, Italy, Portugal, UK, Asian and Northern Europe markets. Competitiveness in these markets has been due to the inherent competitiveness of the industry. Competitiveness in such markets as the Middle East has been attributed to the relatively rapid growth of these markets. The South African citrus industry has similarly undergone many major processes of transformation. The business environmental factors influencing its performance have ranged reform to the challenges beyond the country’s borders. These factors directly and indirectly affect the performance of the industry in the export market. They have influenced the flow of fruits into different international destinations. Of major concern are the food safety and private standards. Challenges in traditional markets as well as opportunities presented by demand from newly emerging citrus consuming nations have seen a diversification in the marketing of the South African citrus. The intensity of competition in the global market is reflected by the fluctuations in the market shares in different markets as well as the increase and fluctuations of fruit rejection rates in some lucrative markets such as America. A combination of challenging national environmental forces and stringent demand conditions negatively impact on revenues especially from markets characterised by price competitiveness. This study identified cost of production, foreign market support systems, adaptability, worker skills, challenges of management in an international environment and government policies such as labour and trade policies as some of the most influential obstacles to competitiveness. Some of the most competiveness-enhancing factors were market availability, market size, market information, market growth and the availability of research institutions. However, compliance with private standards still poses a challenge to the exporters. The different performance levels of the industry in various markets prove the dissimilarity of the demand conditions in the global market. These are supported by the negative influence associated with the foreign market support regimes as well as the challenges associated with compliance with private food safety standards. While market availability, market growth, market information and size were identified as enhancing competitiveness, the fluctuations and inconsistencies in the competitiveness of the industry in different foreign markets require more than finding markets. Resource allocation by both the government and the industry may need to take into account the off-setting of the national challenges and support of farmers faced with distorted and unfair international playing fields. Otherwise, market availability is not a challenge for the industry save meeting the specifications therewith as well as price competitiveness which is unattainable for the South African citrus producers faced with high production costs. For the purposes of further study, it is recommended that account should be taken of all the products marketed by the industry (including processed products such as fruit juices) in order to have a whole picture of the competitiveness of the industry in the international market. This study also proffers a new theoretical framework for the analysis of the business environment for the citrus industry and other agro-businesses. This framework takes into account the indispensability of the food safety standards and measures as well as the diversity of the global consumer and the non-negotiability of food trade for the sustenance of the growing population.
54

Determining the critical success factors enabling RFID technology in the South African citrus industry

Nel, Andre 03 1900 (has links)
Thesis (MBA (Business Management))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: RFID technology may be the most capable technology to address the track and trace requirements within the Agri-food supply chain. RFID technology has become a prominent research area in recent times, with multiple benefits being promised and envisaged. The list of applications and deployments within the supply chain is numerous, with the ambassadors of this technology promising increased supply chain effectiveness, inventory management capabilities and enhanced information visibility. Deregulations within the South African citrus industry created changes to the internal structure of the industry, with the requirements of enhanced information visibility for traceability becoming a high priority. Current information structures and initiatives are providing the basic requirements for the changing business environment, with limitations to real-time and visible information for improved decision-making and planning initiatives. The purpose of this exploratory study was to identify the critical success factors for RFID technology deployment in supply chains in general and to identify the critical success factors relevant to the South African citrus industry. The study also researched the benefits and challenges of deploying RFID technology within the South African citrus industry, relating to citrus supply chain performance improvements of RFID adoption. The research indicates that certain limitations and challenges pertinent to the citrus industry exist, which would require industry level priority for successful implementation of RFID technology within the South African citrus industry. This study provides the South African citrus industry with a guideline to address the current non-collective management of information, information systems and requirements and collaboration initiatives. The use of this research should be of great assistance to the South African citrus industry role-players by providing a strategic framework for addressing information improvement initiatives. / AFRIKAANSE OPSOMMING: RFID tegnologie kan moontlik die mees bevoegde tegnologie wees om die naspeurbaarheid vereistes van n Agri-voedsel voorsiening ketting aan te spreek. RFID tegnologie is huidiglik 'n prominente navorsingsgebied, met beloofde meervoudige voordele. Die lys van aanwendings en toepassings binne die voorsiening ketting is veelvoudig, met beloftes van die ambassadeurs van die tegnologie, vir verbeterde voorsienings ketting doeltreffendheid, inventaris bestuur en verhoogde inligtings sigbaarheid. Deregulasie van die Suid Afrikaanse sitrus industrie het interne strukturuele veranderinge in die industrie teweeg gebring, met prioriteit fokus vir verhoogde inligting sigbaarheid vir naspeurbaarheid doeleindes. Huidige inligting strukture en initiatiewe verskaf die basiese grondslag vir die deurlopende veranderende besigheids omgewing, met intyd en sigbaarheids inligtings beperkinge, vir verbeterde besluitneming en beplanning initiatiewe. Die doel van die ondersoekende studies was om die generiese kritieke sukses faktore van RFID tegnologie implementering en die kritieke sukses faktore direk verwant tot die Suid Afrikaanse sitrus industrie te identifiseer. Die studie het ook die voordele en uitdagings van RFID implementering binne die Suid Afrikaanse sitrus industrie nagevors, spesifiek verwant tot die prestasie verbeterings van RFID implementering in die sitrus voorsienings ketting. Die navorsing dui aan dat sekere beperkinge en uitdagings spesifiek tot die sitrus industrie bestaan wat industrie vlak prioriteit vereis, vir suksevolle implementasie van RFID tegnologie binne die Suid Afrikaanse sitrus industrie. Die resultate van die studie verskaf die Suid Afrikaanse sitrus industrie met 'n riglyn om die uitdagings van die huidige nie-kollektiewe bestuur van inligting, inligting stelsels en vereistes en samewerkings initiatiewe aan te spreek. Die gebruik van die navorsing behoort van groot waarde te wees vir die rolspelers van die Suid Afrikaanse sitrus industrie, in die verskaffing van 'n strategiese raamwerk vir die aanspreking van inligting verbeterings intiatiewe.
55

Processamento mínimo de tangor 'Murcott': caracterização fisiológica e recobrimentos comestíveis. / Fresh-cut tangor ‘Murcott’: physiological characterization and edible coatings.

Moreira, Raquel Capistrano 31 January 2005 (has links)
Os objetivos deste trabalho foram determinar o efeito do processamento mínimo e da temperatura de armazenamento na fisiologia do tangor ‘Murcott’ minimamente processado e determinar os recobrimentos comestíveis que promovam a manutenção da qualidade microbiológica, sensorial e físicoquímica de tangor ‘Murcott’ minimamente processado. No primeira etapa foram testados dois níveis de processamento (tangores inteiros sem a casca e tangores em gomos) e cinco temperaturas de armazenamento (1º, 6º, 11º, 21º e 31ºC). Frutos intactos foram utilizados como controle. No segundo experimento os tangores em gomos foram tratados com diversos recobrimentos comestíveis e armazenados sob duas temperaturas (6º e 12ºC). Os recobrimentos utilizados foram: gelatina a 4% p/p, gelatina a 8% p/p, concentrado protéico de soro de leite a 8% p/p e emulsão a base de parafina. Tangores sem recobrimentos foram utilizados como controle. No primeiro experimento foram determinadas as taxas respiratórias e de produção de etileno a cada hora durante as 10 primeiras horas após o processamento e, em seguida, a cada 24 horas por sete dias. Determinaram-se também os quocientes de temperatura (Q10). No segundo experimento determinaram-se: as características físico-químicas a cada dois dias por um período de seis dias; a taxa respiratória diariamente por oito dias; as características microbiológicas no quarto e sétimo dias após o processamento e as características sensoriais no quarto dia após o processamento. Os níveis de etileno foram baixos e inconstantes ao longo do tempo de avaliação. O aumento da temperatura de armazenamento e o nível de processamento mínimo influenciaram a taxa respiratória. Os recobrimentos comestíveis foram pouco efetivos na redução da taxa respiratória e na manutenção das características físico-químicas, microbiológicas e sensoriais de gomos de tangor ‘Murcott’. / The objectives of this work were to determine the effect of minimally processing and the storage temperature on the physiology of fresh-cut tangor ‘Murcott’ and to determine the edible coatings that maintain the microbiological, sensorial and physico-chemical qualities of fresh-cut tangor ‘Murcott’. In the first experiment two processing levels (peeled fruits and segments) and five storage temperatures (1º, 6º, 11º, 21º and 31ºC) were tested. Whole fruits were used as control. In the second experiment the segments were treated with several edible coatings and stored under two temperatures (6º and 12ºC). The edible coatings were: gelatin 4% w/w, gelatin 8% w/w, whey protein 8% w/w and paraffin wax emulsion. Segments without recovering were used as control. In the first experiment the respiratory rate and the ethylene production were determined every hour for 10 hours and then, every day for 7 days. The temperature quotients (Q10) were also determined. In the second experiment were determined: the physico-chemical properties every two day for six days; the respiratory rate daily for eight days; the microbiological analysis on the fourth and seventh days of storage; and the sensorial analysis on the fourth day of storage. The storage temperature and the processing level did influence the respiratory rate. The ethylene levels were low and inconstant during the study. The edible coatings were little effective on reducing the respiratory rate and on maintaining the physico-chemical, microbiological and sensorial properties of fresh-cut tangor ‘Murcott’.
56

Processamento mínimo de tangor 'Murcott': caracterização fisiológica e recobrimentos comestíveis. / Fresh-cut tangor ‘Murcott’: physiological characterization and edible coatings.

Raquel Capistrano Moreira 31 January 2005 (has links)
Os objetivos deste trabalho foram determinar o efeito do processamento mínimo e da temperatura de armazenamento na fisiologia do tangor ‘Murcott’ minimamente processado e determinar os recobrimentos comestíveis que promovam a manutenção da qualidade microbiológica, sensorial e físicoquímica de tangor ‘Murcott’ minimamente processado. No primeira etapa foram testados dois níveis de processamento (tangores inteiros sem a casca e tangores em gomos) e cinco temperaturas de armazenamento (1º, 6º, 11º, 21º e 31ºC). Frutos intactos foram utilizados como controle. No segundo experimento os tangores em gomos foram tratados com diversos recobrimentos comestíveis e armazenados sob duas temperaturas (6º e 12ºC). Os recobrimentos utilizados foram: gelatina a 4% p/p, gelatina a 8% p/p, concentrado protéico de soro de leite a 8% p/p e emulsão a base de parafina. Tangores sem recobrimentos foram utilizados como controle. No primeiro experimento foram determinadas as taxas respiratórias e de produção de etileno a cada hora durante as 10 primeiras horas após o processamento e, em seguida, a cada 24 horas por sete dias. Determinaram-se também os quocientes de temperatura (Q10). No segundo experimento determinaram-se: as características físico-químicas a cada dois dias por um período de seis dias; a taxa respiratória diariamente por oito dias; as características microbiológicas no quarto e sétimo dias após o processamento e as características sensoriais no quarto dia após o processamento. Os níveis de etileno foram baixos e inconstantes ao longo do tempo de avaliação. O aumento da temperatura de armazenamento e o nível de processamento mínimo influenciaram a taxa respiratória. Os recobrimentos comestíveis foram pouco efetivos na redução da taxa respiratória e na manutenção das características físico-químicas, microbiológicas e sensoriais de gomos de tangor ‘Murcott’. / The objectives of this work were to determine the effect of minimally processing and the storage temperature on the physiology of fresh-cut tangor ‘Murcott’ and to determine the edible coatings that maintain the microbiological, sensorial and physico-chemical qualities of fresh-cut tangor ‘Murcott’. In the first experiment two processing levels (peeled fruits and segments) and five storage temperatures (1º, 6º, 11º, 21º and 31ºC) were tested. Whole fruits were used as control. In the second experiment the segments were treated with several edible coatings and stored under two temperatures (6º and 12ºC). The edible coatings were: gelatin 4% w/w, gelatin 8% w/w, whey protein 8% w/w and paraffin wax emulsion. Segments without recovering were used as control. In the first experiment the respiratory rate and the ethylene production were determined every hour for 10 hours and then, every day for 7 days. The temperature quotients (Q10) were also determined. In the second experiment were determined: the physico-chemical properties every two day for six days; the respiratory rate daily for eight days; the microbiological analysis on the fourth and seventh days of storage; and the sensorial analysis on the fourth day of storage. The storage temperature and the processing level did influence the respiratory rate. The ethylene levels were low and inconstant during the study. The edible coatings were little effective on reducing the respiratory rate and on maintaining the physico-chemical, microbiological and sensorial properties of fresh-cut tangor ‘Murcott’.
57

Comparação de métodos de monitoramento e controle do bicho-furão, Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera, Tortricidae) em citros. / Comparison of ecdytolopha aurantiana (lima, 1927) (lepidoptera, tortricidae) monitoring methods and control in citrus.

Diogo Rodrigues Carvalho 08 October 2003 (has links)
O presente trabalho teve como objetivo comparar três métodos de amostragem de adultos do bicho-furão, quais sejam: 1) monitoramento com armadilhas de feromônio sexual; 2) monitoramento do inseto criado no campo em dietas artificiais; 3) previsão baseada em exigências térmicas do inseto. Para complementar tal pesquisa, que visa facilitar o manejo e o controle da praga, foram estudados o nível de controle para o método utilizando-se feromônio sexual e o efeito de agroquímicos sobre a fase adulta do inseto com base no monitoramento mais adequado. Os três métodos de monitoramento de Ecdytolopha aurantiana (Lima, 1927) mostraram eficiência para serem utilizados em condições de campo. O método de monitoramento do bicho-furão por meio de feromônio sexual foi o que exigiu menor mão-de-obra. O método de monitoramento através de exigências térmicas foi aplicável no verão, exigindo fatores de correção para as demais estações do ano. O nível de controle, determinado para o monitoramento com feromônio sexual, foi de 4 a 6 adultos/semana; a partir destes números, as perdas foram maiores a despeito do maior número de aplicações de produtos químicos. Como o tempo de penetração da lagarta do bicho-furão foi rápido (100% em 24 h), com cerca de 42,9% atingindo a polpa em 72 h, torna-se difícil o controle do inseto nesta fase através de produtos químicos ou biológicos. A alta mortalidade larval do bicho-furão durante a penetração no fruto, pode mascarar os resultados de avaliação da eficiência de controle com produtos químicos ou biológicos. O piretróide bifentrine foi eficiente no controle de adultos de E. aurantiana, desde que adicionado a óleo mineral. / The goal of this work was to compare three sampling methods for adult citrus fruit borer, as follows: 1) monitoring with sexual pheromone traps; 2) monitoring of insects reared under artificial diets in the field; 3) Forecasting based on the thermal requirements of the insect. In order to complete this research, which is intended for an easier pest management and control, one studied the control level for the method with sexual pheromone and the effects of agrochemicals on the adult stage of the insect based on the more suitable monitoring. All three methods of Ecdytolopha aurantiana (Lima, 1927) monitoring were efficient under field conditions. The citrus fruit borer monitoring method by means of sexual pheromone was the least laborious one. The monitoring method through thermal requirements was applicable in the summer, requiring correction factors in the remaining seasons of the year. The control level as determined for the sexual pheromone monitoring was 4 to 6 adults/week; following these figures, the losses were greater despite the higher amount of chemicals application. Since the penetration time of the citrus fruit borer was brief (100% in 24h), with approximately 42.9% reaching the pulp in 72h, it is difficult to control the insect at this stage through chemical or biological products. The high larval mortality of the citrus fruit borer during fruit penetration can conceal the results of the control efficiency evaluation with chemical or biological products. Pyrethroid bifenthrin was efficient to control adult E. aurantiana provided that mineral oil was added.
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Desenvolvimento de um modelo para previsão de ocorrência de Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera: Tortricidae) e um Sistema WEB Integrado de Apoio ao Citricultor. / Development of a model to predict the occurrence of Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera: Tortricidae) and an integrated web system to support citrus producers.

Reis Junior, Ronaldo 19 April 2004 (has links)
Os frutos cítricos são uma das principais fontes de exportação do Brasil, sendo que São Paulo responde por cerca de 80% da produção total. Dentre os fatores que limitam a produção citrícola brasileira, especialmente no estado de São Paulo, vem se sobressaindo nos últimos anos, a clorose variegada dos citros (CVC), a podridão floral, o minador-dos-citros e o bicho-furão-dos-citros, Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera: Tortricidae), além dos ácaros, moscas-das-frutas, pinta preta e mais recentemente a morte súbita. O presente trabalho teve como objetivo desenvolver um modelo para previsão de ocorrência de E. aurantiana, baseado em dados de monitoramento através de armadilhas de feromônio sexual e desenvolver um sistema computacional que possa utilizar este modelo para gerar as previsões de ocorrência, além de fornecer um local de troca de informações entre o citricultor e a comunidade científica. O tipo de solo, temperatura do local, variedade de citros, idade das plantas e uso de agroquímicos para controle de E. aurantiana, influenciaram na dinâmica populacional deste inseto. A maior influência sobre a flutuação do bicho-furão foi exercida pelo tipo de solo, seguido pela temperatura local, variedade de citros, idade das plantas e uso de agroquímicos para controle de E. aurantiana. A ocorrência de E. aurantiana em função da temperatura é diferente para cada combinação de tipo de solo, variedade de citros, idade das plantas e uso de agroquímicos. O modelo desenvolvido pode prever o potencial de ocorrência de E. aurantiana em função da temperatura ou dos meses do ano, levando-se em consideração o tipo de solo, variedade de citros, idade das plantas e aplicação de agroquímicos. O programa (BF) elaborado na linguagem R conta com equações para simular as diversas situações de ocorrência de E. aurantiana. O SIAC (Sistema Integrado de Apoio ao Citricultor) é um sistema que facilita o uso do modelo, sem a necessidade de conhecimento de R e fornece uma gama de recursos que visa facilitar o acesso do citricultor às informações e ao pesquisador aos problemas do citricultor, criando com isto uma maior interação de ambos. O modelo de previsão de ocorrência de bicho-furão pode ser aperfeiçoado com coleta de dados mais regulares e de forma contínua. / Citrus fruits are Brazil’s major exporting sources, and São Paulo is accountable for approximately 80% of the total production. Among the factors that limit the Brazilian citriculture, especially in the state of São Paulo, one points in the past few years the citrus variegated chlorosis (CVC), flower rot, citrus leaf miner and citrus fruit borer, Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera: Tortricidae), in addition to mites, fruit flies, black spot, and more recently, sudden death. The goal of this work was to develop a model to predict the occurrence of E. aurantiana, based on monitoring data collected through sexual pheromone traps, and to develop a computer system capable of using such model to generate occurrence predictions and to provide a place for information exchange between citriculturists and the scientific community. Soil type, site temperature, citrus variety, age of plants and use of chemicals to control E. aurantiana influenced the population dynamics of the insect. The highest influence on the citrus fruit borer dynamics was exerted by the soil type, followed by site temperature, citrus variety, age of plants and use of chemicals for E. aurantiana control. The occurrence of E. aurantiana according to temperature is different for each combination of soil type, citrus variety, age of plants and use of chemicals. The model developed can predict the occurrence potential of E. aurantiana according to temperature or months of the year, taking into account soil type, citrus variety, age of plants and chemicals spraying. The elaborated software (BF), designed in R language, includes equations that simulate the various situations of E. aurantiana occurrence. SIAC ("Sistema Integrado de Apoio ao Citricultor") is a system that simplifies the use of the model, does not require previous knowledge on R, and provides a wide range of resources to facilitates the access of citriculturists to information and that of researchers to citriculturists’ problems, thus creating a better interaction between them. The predicting model of citrus fruit borer occurrence can be improved with more frequent and continuous data collecting.
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Comparação de métodos de monitoramento e controle do bicho-furão, Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera, Tortricidae) em citros. / Comparison of ecdytolopha aurantiana (lima, 1927) (lepidoptera, tortricidae) monitoring methods and control in citrus.

Carvalho, Diogo Rodrigues 08 October 2003 (has links)
O presente trabalho teve como objetivo comparar três métodos de amostragem de adultos do bicho-furão, quais sejam: 1) monitoramento com armadilhas de feromônio sexual; 2) monitoramento do inseto criado no campo em dietas artificiais; 3) previsão baseada em exigências térmicas do inseto. Para complementar tal pesquisa, que visa facilitar o manejo e o controle da praga, foram estudados o nível de controle para o método utilizando-se feromônio sexual e o efeito de agroquímicos sobre a fase adulta do inseto com base no monitoramento mais adequado. Os três métodos de monitoramento de Ecdytolopha aurantiana (Lima, 1927) mostraram eficiência para serem utilizados em condições de campo. O método de monitoramento do bicho-furão por meio de feromônio sexual foi o que exigiu menor mão-de-obra. O método de monitoramento através de exigências térmicas foi aplicável no verão, exigindo fatores de correção para as demais estações do ano. O nível de controle, determinado para o monitoramento com feromônio sexual, foi de 4 a 6 adultos/semana; a partir destes números, as perdas foram maiores a despeito do maior número de aplicações de produtos químicos. Como o tempo de penetração da lagarta do bicho-furão foi rápido (100% em 24 h), com cerca de 42,9% atingindo a polpa em 72 h, torna-se difícil o controle do inseto nesta fase através de produtos químicos ou biológicos. A alta mortalidade larval do bicho-furão durante a penetração no fruto, pode mascarar os resultados de avaliação da eficiência de controle com produtos químicos ou biológicos. O piretróide bifentrine foi eficiente no controle de adultos de E. aurantiana, desde que adicionado a óleo mineral. / The goal of this work was to compare three sampling methods for adult citrus fruit borer, as follows: 1) monitoring with sexual pheromone traps; 2) monitoring of insects reared under artificial diets in the field; 3) Forecasting based on the thermal requirements of the insect. In order to complete this research, which is intended for an easier pest management and control, one studied the control level for the method with sexual pheromone and the effects of agrochemicals on the adult stage of the insect based on the more suitable monitoring. All three methods of Ecdytolopha aurantiana (Lima, 1927) monitoring were efficient under field conditions. The citrus fruit borer monitoring method by means of sexual pheromone was the least laborious one. The monitoring method through thermal requirements was applicable in the summer, requiring correction factors in the remaining seasons of the year. The control level as determined for the sexual pheromone monitoring was 4 to 6 adults/week; following these figures, the losses were greater despite the higher amount of chemicals application. Since the penetration time of the citrus fruit borer was brief (100% in 24h), with approximately 42.9% reaching the pulp in 72h, it is difficult to control the insect at this stage through chemical or biological products. The high larval mortality of the citrus fruit borer during fruit penetration can conceal the results of the control efficiency evaluation with chemical or biological products. Pyrethroid bifenthrin was efficient to control adult E. aurantiana provided that mineral oil was added.
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Avaliação do potencial de controle biológico da mancha marrom de alternaria com Trichoderma spp., Bacillus subtilis e fertilizante organomineral

Porto, Bianca Luzardo 28 October 2016 (has links)
O Brasil é o maior produtor de citros, sendo um dos seus principais produtos de exportação da cadeia agroindustrial. Um dos fatores que afetam a qualidade e a produção do produto final obtido é a Mancha Marrom de Alternaria, causado pelo fungo Alternaria alternata. A doença provoca desfolha, seca de ramos e queda de frutos em tangerinas e seus híbridos. Para controle dessa doença são utilizados fungicidas, porém, a mancha marrom é uma doença de difícil controle podendo ser necessárias de 7 a 10 aplicações do fungicida, aparecimento de resistência dos fungos, intoxicação nas pessoas e contaminação do meio ambiente devido ao emprego de fungicidas. Métodos alternativos como o controle biológico com aplicações de micro-organismos antagonistas e a nutrição das plantas são opções de menor impacto ao meio ambiente. Sendo assim, o objetivo deste trabalho foi avaliar o potencial de Trichoderma spp., Bacillus subtilis e fertilizante organomineral, no controle da Mancha Marrom de Alternaria em plantas cítricas de tangerina Ponkan. O experimento foi realizado com delineamento casualizado, constituído de oito tratamentos com quatro repetições. Os experimentos foram avaliados quanto a incidência da doença. Os dados mostraram que o melhor controle foi o tratamento químico, porém os tratamentos com Trichoderma spp., Trichoderma spp. + fertilizante e Trichoderma spp. + Bacillus subtilis apresentaram ótimas taxas de controle, podendo inclusive substituir o tratamento químico no controle desta doença. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-06-13T14:28:19Z No. of bitstreams: 1 Dissertacao Bianca Luzardo Porto.pdf: 1070166 bytes, checksum: 4e890666fce3c2b0d8ce25ef2c71241f (MD5) / Made available in DSpace on 2017-06-13T14:28:19Z (GMT). No. of bitstreams: 1 Dissertacao Bianca Luzardo Porto.pdf: 1070166 bytes, checksum: 4e890666fce3c2b0d8ce25ef2c71241f (MD5) Previous issue date: 2017-06-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. / Brazil is the largest citrus producer, being one of its main exports of agro-industrial chain. One of the factors that affect the quality and production of the final product is the Brown Spot Alternaria, caused by the fungus Alternaria alternata. The disease causes leaf drop, dry branches and fruit drop in tangerines and their hybrids. To control this disease fungicides are used, however, the brown spot is a difficult to control disease, may be required from 7 to 10 applications of fungicide, appearance of resistance of fungi, intoxication in people and environment contamination owing the application of fungicides. Alternative methods such as biological control with applications antagonistic microorganisms and plant nutrition are options of smaller impact to the environment. Therefore, the objective of this work was to evaluate the potential of Trichoderma spp., Bacillus subtilis and fertilizer, in control of Alternaria Brown Spot in citrus plants Ponkan tangerine. The experiment was carried out in a randomized design, consisting of eight treatments with four replicates. The experiments were evaluated for the incidence of the disease. The data showed that the best control was the chemical treatment, but the treatments with Trichoderma spp., Trichoderma spp. + Fertilizer and Trichoderma spp. + Bacillus subtilis presented excellent control rates, and may even replace chemical treatment in the control of this disease.

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