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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.
121

Qualidade e conservação do morango tratado em pós-colheita com cloreto de cálcio e do armazenamento em atmosfera modificada ativa /

Silva, Cíntia de Souza, 1979- January 2004 (has links)
Orientador: Rogério Lopes Vieites / Banca: João Domingos Rodrigues / Banca: José Maria Monteiro Sigrist / Resumo: Este trabalho teve como objetivo avaliar a qualidade e conservação do morango tratado em pós-colheita com cloreto de cálcio e em armazenamento sob atmosfera modificada. O experimento foi conduzido com morangos (Fragaria x ananassa Duch.) 'Oso Grande', produzidos na cidade de Botucatu-SP e colhidos no estádio de maturação vermelho. O primeiro experimento consistiu da imersão das frutas em diferentes concentrações de CaCl2 durante 2 horas: 0% (testemunha), 1,0 %, 2,0%, 3,0% e 4,0%. Os parâmetros analisados foram: perda de massa fresca, aparência, tempo de vida útil, incidência de doenças, teor de sólidos solúveis, acidez titulável, pH, teor de cálcio, firmeza e análise sensorial. O segundo experimento realizado consistiu no armazenamento das frutas em embalagens de polietileno sob diferentes misturas gasosas: testemunha, vácuo parcial, 5% O2 e 1% CO2; 5% O2 e 3% CO2; 5% O2 e 5O2. Os parâmetros analisados foram: perda de massa fresca, aparência, tempo de vida útil, incidência de doenças, teor de sólidos solúveis, acidez titulável, pH, açúcar redutor e total, vitamina C, firmeza e análise sensorial. Para avaliação da conservação pós-colheita, os frutos foram armazenados a 0°C l 1°C/90l 5% UR por 12 dias e avaliados a cada 2 dias. O delineamento estatístico adotado foi o inteiramente casualizado, comparando-se as médias pelo teste de Tukey a 5% de probabilidade. Os resultados obtidos no 1° experimento permitem concluir que, apesar da imersão em CaCl2 ter sido eficiente para aumentar o teor de cálcio nas frutas, as diferentes concentrações testadas propiciaram aos morangos maior perda de massa fresca, incidência de doenças, depreciação na aparência, sabor, textura e aroma, diminuindo, portanto a qualidade e vida pós-colheita da fruta... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this work was evaluate has postharvest immersion in calcium chloride and storage in modified atmosphere, effect the quality and postharvest conservation of strawberries. The experiment was conducted with strawberries (Fragaria x ananassa Duch.) 'Oso Grande', produced in the city of Botucatu-SP-Brazil and picked in the maturation stage red . The first experiment consisted of the immersion of the fruits in different concentrations of CaCl2 for 2 hours: 0% (control), 1,0%, 2,0%, 3,0% and 4,0%. The analyzed parameters were: regarding fresh mass loss, appearance, shelf life, incidence of disease, soluble solids, titratable acidity, pH, calcium contents, firmness, and sensorial analysis. The second experiment consisted of the storage of the fruits in polyethylene packing under different gaseous mixtures: control, vacuous, 5% O2 and 1% CO2; 5% O2 and 3% CO2; 5% O2 and 5O2. The analyzed parameters were: regarding fresh mass loss, appearance, shelf life, incidence of disease, soluble solids, total titratable acidity, pH, reducer and total sugars, vitamin C, firmness and sensorial analysis. For evaluation of the post-harvest conservation the fruits were stored 0°C l 1°C/90l 5% UR for 12 days and appraised every 2 days. The statistical layout was completely randomized, by comparing the means with Tukey test in a ratio of 5% probability. The results obtained in the 1° experiment conclude that, although the immersion in CaCl2 has been efficient in increasing the content of calcium in the fruits, the different tested concentrations attributed to the strawberries with a greater loss of fresh mass, incidence of disease, depreciation in appearance, flavor, texture and aroma therefore decreasing the quality and post-harvest life of the fruit. The results of the 2° experiment already indicate that the treated fruits have a larger shelf life, better appearance, flavor and aroma,...(Complete abstract, click electronic access below) / Mestre
122

Extratos de canola no controle de botrytis cinerea in vitro e do mofo cinzento em pós-colheita de morangos

Cuzzi, Claucia 28 May 2013 (has links)
O mofo cinzento é causado pelo fungo Botrytis cinerea (Pers.: Fr.), causador de grandes perdas econômicas em várias culturas. Este patógeno é de difícil controle, devido à ampla gama de hospedeiros, sua atividade saprófita e por formar estruturas de resistência (escleródios). Uma das formas de controle deste patógeno é a utilização de produtos químicos, no entanto, principalmente na pós-colheita de frutos, a tolerância por resíduos químicos nos alimentos, é cada vez menos desejável do ponto de vista ecológico e de saúde pública. Os tratamentos alternativos, como a utilização de extratos de plantas, vêm sendo pesquisados na fitopatologia, para reduzir o uso dos fungicidas sintéticos. A canola (Brassica napus) é uma planta que possui compostos biocidas, com potencial de controle de pragas e doenças. Este trabalho teve como objetivos avaliar o efeito de diferentes extratos da canola (alcoólico, macerado, aquoso sem tempo de reserva e infusão) no controle de Botrytis cinerea in vitro e em pós-colheita de morangos. Foram realizados dois experimentos in vitro, sendo um para avaliar o crescimento micelial e outro a germinação de conídios. O delineamento experimental para os dois experimentos foi inteiramente casualizado, em esquema fatorial 4 x 5, sendo o fator modos de extração de extratos e concentrações (0, 3, 6, 9 e 12%), em 4 repetições. No ensaio de crescimento micelial, a unidade experimental foi uma placa de Petri, e um tubo de ensaio no teste de germinação de conídios. Em pós-colheita foram testados os quatro tipos de extratos na concentração de 16%. O delineamento foi inteiramente casualizado, com 4 repetições por tratamento, sendo a parcela composta por 10 frutos/bandeja. Os parâmetros físico-quimicos avaliados foram podridões, perda de massa, firmeza de polpa e acidez titulável. As análises bioquímicas avaliadas foram proteínas totais, antocianinas e flavonóides, e a atividade da enzima fenilalanina amônia-liase (FAL) e peroxidases. Os resultados obtidos permitiram concluir que houve redução do crescimento micelial e da germinação de conídios, em função das concentrações, mas não ocorreram diferenças entre os extratos. A maior eficiência dos extratos ocorreu na concentração de 8,31%, na avaliação com 96horas. Para a germinação o comportamento foi linear decrescente, ou seja, o aumento das concentrações influenciou na menor germinação dos conídios. Os extratos: alcoólico, maceração e infusão reduziram as podridões causadas por B. cinerea em pós-colheita de morangos. Os extratos atuaram na alteração do teor de acidez dos frutos, e no comportamento das peroxidases, mas não apresentaram efeito sobre sólidos solúveis totais (SST), firmeza de polpa, perda de massa, antocianinas, flavonoides,e atividade da FAL. Os resultados obtidos neste trabalho, comprovam o potencial da canola no controle do mofo cinzento em pós-colheita de morangos, bem como do fungo Botrytis cinerea. / The gray mold is caused by the fungus Botrytis cinerea (Pers.: Fr.), causer of great economic losses in various cultures. This pathogen is difficult to control, due to the wide range of hosts, its saprophytic activity and by forming structures of resistance (esclerodios). One of the ways to control this pathogen is the use of chemical products, however, mainly in post-harvest fruit, tolerance by chemical residues in foods is increasingly less desirable from an ecological and public health point of view. The alternative treatments, such as the use of plant extracts, are being probed in phytopathology, to reduce the use of synthetic fungicides. The canola (Brassica napus) is a plant that has biocidal compounds, with potential to control pests and diseases. This study aimed to evaluate the effect of different extracts of canola (alcoholic, macerate, aqueous without reserve time and infusion) in the control of Botrytis cinerea in vitro and in post-harvest of strawberries. Two experiments were conducted in vitro, being one to evaluate the mycelial growth and another the germination of conidia. The experimental design for the two experiments was completely randomized, in a 4 x 5 factorial scheme, and the modes of extraction of extracts and concentrations (0, 3, 6, 9 and 12 %), in 4 repetitions. In the trial mycelial growth, the experimental unit was a Petri dish, and a test tube in germination test of conidia. In post-harvest were tested four types of extracts at a concentration of 16 %. The experimental design was completely randomized, with 4 repetitions per treatment, being the plot composed by10 fruits/tray. The physico-chemical parameters evaluated were rotting, weight loss, firmness and titratable acidity. The biochemical analyzes were evaluated total proteins, anthocyanins and flavonoids, and the activity of the enzyme phenylalanine ammonia-lyase (PAL) and peroxidases. The results obtained allowed us to conclude that there was a reduction of mycelial growth and germination of conidia, as a function of the concentrations, but there were no differences between the extracts. The greater efficiency of extracts occurred at a concentration of 8.31 %, in evaluation with 96 hours. For germination, the behavior was decreasing linear, in other words, the increase of concentrations influenced the lower germination of conidia. The extracts: alcoholic, maceration and infusion reduced the rot caused by B. cinerea in post-harvest of strawberries. The extracts operate in fruits acidity modification, and in the behavior of peroxidases, but they had no effect on total soluble solids (TSS), pulp firmness, weight loss, anthocyanins, flavonoids,and activity of the PAL. The results obtained in this work, have demonstrate the potential of canola in the control of gray mold on post-harvest of strawberries, as well as the fungus Botrytis cinerea.
123

Extratos de canola no controle de botrytis cinerea in vitro e do mofo cinzento em pós-colheita de morangos

Cuzzi, Claucia 28 May 2013 (has links)
O mofo cinzento é causado pelo fungo Botrytis cinerea (Pers.: Fr.), causador de grandes perdas econômicas em várias culturas. Este patógeno é de difícil controle, devido à ampla gama de hospedeiros, sua atividade saprófita e por formar estruturas de resistência (escleródios). Uma das formas de controle deste patógeno é a utilização de produtos químicos, no entanto, principalmente na pós-colheita de frutos, a tolerância por resíduos químicos nos alimentos, é cada vez menos desejável do ponto de vista ecológico e de saúde pública. Os tratamentos alternativos, como a utilização de extratos de plantas, vêm sendo pesquisados na fitopatologia, para reduzir o uso dos fungicidas sintéticos. A canola (Brassica napus) é uma planta que possui compostos biocidas, com potencial de controle de pragas e doenças. Este trabalho teve como objetivos avaliar o efeito de diferentes extratos da canola (alcoólico, macerado, aquoso sem tempo de reserva e infusão) no controle de Botrytis cinerea in vitro e em pós-colheita de morangos. Foram realizados dois experimentos in vitro, sendo um para avaliar o crescimento micelial e outro a germinação de conídios. O delineamento experimental para os dois experimentos foi inteiramente casualizado, em esquema fatorial 4 x 5, sendo o fator modos de extração de extratos e concentrações (0, 3, 6, 9 e 12%), em 4 repetições. No ensaio de crescimento micelial, a unidade experimental foi uma placa de Petri, e um tubo de ensaio no teste de germinação de conídios. Em pós-colheita foram testados os quatro tipos de extratos na concentração de 16%. O delineamento foi inteiramente casualizado, com 4 repetições por tratamento, sendo a parcela composta por 10 frutos/bandeja. Os parâmetros físico-quimicos avaliados foram podridões, perda de massa, firmeza de polpa e acidez titulável. As análises bioquímicas avaliadas foram proteínas totais, antocianinas e flavonóides, e a atividade da enzima fenilalanina amônia-liase (FAL) e peroxidases. Os resultados obtidos permitiram concluir que houve redução do crescimento micelial e da germinação de conídios, em função das concentrações, mas não ocorreram diferenças entre os extratos. A maior eficiência dos extratos ocorreu na concentração de 8,31%, na avaliação com 96horas. Para a germinação o comportamento foi linear decrescente, ou seja, o aumento das concentrações influenciou na menor germinação dos conídios. Os extratos: alcoólico, maceração e infusão reduziram as podridões causadas por B. cinerea em pós-colheita de morangos. Os extratos atuaram na alteração do teor de acidez dos frutos, e no comportamento das peroxidases, mas não apresentaram efeito sobre sólidos solúveis totais (SST), firmeza de polpa, perda de massa, antocianinas, flavonoides,e atividade da FAL. Os resultados obtidos neste trabalho, comprovam o potencial da canola no controle do mofo cinzento em pós-colheita de morangos, bem como do fungo Botrytis cinerea. / The gray mold is caused by the fungus Botrytis cinerea (Pers.: Fr.), causer of great economic losses in various cultures. This pathogen is difficult to control, due to the wide range of hosts, its saprophytic activity and by forming structures of resistance (esclerodios). One of the ways to control this pathogen is the use of chemical products, however, mainly in post-harvest fruit, tolerance by chemical residues in foods is increasingly less desirable from an ecological and public health point of view. The alternative treatments, such as the use of plant extracts, are being probed in phytopathology, to reduce the use of synthetic fungicides. The canola (Brassica napus) is a plant that has biocidal compounds, with potential to control pests and diseases. This study aimed to evaluate the effect of different extracts of canola (alcoholic, macerate, aqueous without reserve time and infusion) in the control of Botrytis cinerea in vitro and in post-harvest of strawberries. Two experiments were conducted in vitro, being one to evaluate the mycelial growth and another the germination of conidia. The experimental design for the two experiments was completely randomized, in a 4 x 5 factorial scheme, and the modes of extraction of extracts and concentrations (0, 3, 6, 9 and 12 %), in 4 repetitions. In the trial mycelial growth, the experimental unit was a Petri dish, and a test tube in germination test of conidia. In post-harvest were tested four types of extracts at a concentration of 16 %. The experimental design was completely randomized, with 4 repetitions per treatment, being the plot composed by10 fruits/tray. The physico-chemical parameters evaluated were rotting, weight loss, firmness and titratable acidity. The biochemical analyzes were evaluated total proteins, anthocyanins and flavonoids, and the activity of the enzyme phenylalanine ammonia-lyase (PAL) and peroxidases. The results obtained allowed us to conclude that there was a reduction of mycelial growth and germination of conidia, as a function of the concentrations, but there were no differences between the extracts. The greater efficiency of extracts occurred at a concentration of 8.31 %, in evaluation with 96 hours. For germination, the behavior was decreasing linear, in other words, the increase of concentrations influenced the lower germination of conidia. The extracts: alcoholic, maceration and infusion reduced the rot caused by B. cinerea in post-harvest of strawberries. The extracts operate in fruits acidity modification, and in the behavior of peroxidases, but they had no effect on total soluble solids (TSS), pulp firmness, weight loss, anthocyanins, flavonoids,and activity of the PAL. The results obtained in this work, have demonstrate the potential of canola in the control of gray mold on post-harvest of strawberries, as well as the fungus Botrytis cinerea.
124

Preparação, propriedades e aplicação de biofilmes comestiveis a base de gluten de trigo / Preparetion, properties and application of wheat gluten-based films

Palmu, Patricia Sayuri Tanada 31 July 2003 (has links)
Orientador: Carlos Raimundo Ferreira Grosso / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T18:12:57Z (GMT). No. of bitstreams: 1 Palmu_PatriciaSayuriTanada_D.pdf: 1612085 bytes, checksum: 538e68bde3ca35cc56464ce19f8fb800 (MD5) Previous issue date: 2003 / Resumo: Recentemente surgiu um grande interesse no desenvolvimento de biofilmes comestíveis ou degradáveis biologicamente, principalmente devido à demanda por alimentos de alta qualidade e preocupações ambientais sobre o descarte de materiais não renováveis de embalagem para alimentos. Os biofilmes são geralmente produzidos com macromoléculas, como polissacarídeos, proteínas, lipídios e derivados. O objetivo desse trabalho foi o desenvolvimento e caracterização de biofilmes simples de glúten de trigo, composto e de duas camadas contendo cera de abelha e ácidos palmítico e esteárico, bem como testar a aplicação dos filmes e das coberturas em frutas frescas. A solução formadora de filme foi preparada usando glúten de trigo, etanol, glicerol e hidróxido de amônio (6N) para ajustar o pH da solução. As composições das formulações dos filmes foram calculadas segundo um planejamento fatorial 24. As propriedades funcionais utilizadas para verificar os efeitos dos fatores foram as propriedades mecânicas (resistência à tensão e elongação na ruptura), permeabilidades ao vapor d¿água e ao oxigênio e solubilidade em água. A partir da formulação que apresentou as melhores propriedades funcionais, foram desenvolvidos e caracterizados os filmes compostos e de duas camadas contendo glúten de trigo, cera de abelha e mistura 1:1 de ácidos palmítico e esteárico em várias concentrações. Outras análises como efeito da umidade relativa sobre as propriedades mecânicas dos filmes e análises microestruturais através da microscopia eletrônica de varredura foram realizadas. A seguir, realizou-se o estudo da aplicação das coberturas e filmes comestíveis à base de glúten em morangos frescos mantidos sob refrigeração, através das análises de: perda de peso, retenção da firmeza, cor, acidez titulável, sólidos solúveis e totais, açúcares redutores e totais e análise sensorial de aparência para determinar a vida de prateleira dos morangos e de degustação para verificar a aceitação das coberturas à base de glúten. Para complementar o estudo, foi realizada uma reação de lipofilização do glúten de trigo, verificada através da porcentagem de grupos amino livres pelo método de TNBS. A partir do glúten modificado, o biofilme foi preparado e caracterizado, comparando-se com o filme de glúten não modificado. Outro trabalho complementar foi a preparação e caracterização de biofilmes preparados a partir de farinhas de trigo brasileiras e também a comparação das propriedades com os filmes de glúten vital (comercial). Os resultados obtidos indicaram que as propriedades mecânicas dos filmes simples foram influenciadas pelas concentrações de glúten e glicerol, sendo o filme mais resistente o de maior concentração de glúten e menor de glicerol. A menor permeabilidade ao oxigênio foi obtida no filme com menor concentração de glúten, glicerol e etanol e a permeabilidade ao vapor d¿água mais baixa foi no filme com menor concentração de glicerol. Os filmes compostos e de duas camadas ficaram opacos e o filme de duas camadas com 10% de ácidos esteárico e palmítico e cera de abelha apresentou a menor permeabilidade ao vapor d¿água, porém a resistência à tensão e a elongação foram baixas. A morfologia observada através do microscópio eletrônico de varredura para o filme simples de glúten foi completamente modificada quando se adicionou a mistura de ácidos palmítico e esteárico e cera de abelha. O estudo da aplicação dos biofilmes e coberturas em morangos mostrou que a cobertura de duas camadas com glúten e lipídios teve efeito na retenção da firmeza e na diminuição da taxa de perda de peso nas frutas cobertas. As frutas embaladas com o filme de glúten retardaram a senescência por apresentarem os menores parâmetros (a/b) em relação à cor da fruta. A análise sensorial dos morangos indicou que as coberturas simples de glúten e composta com lipídios mantiveram a qualidade dos morangos durante o tempo de armazenamento em termos de aparência e que o sabor dos morangos com a cobertura simples de glúten foi aceito pelos consumidores. A reação de lipofilização modificou o glúten através da diminuição da porcentagem de grupos amino livres, porém o filme preparado com o glúten lipofilizado apresentou propriedades mecânicas e de barreira inferiores ao filme com glúten sem modificação. Os filmes preparados a partir das farinhas de trigo ¿semi-duras¿ brasileiras apresentaram propriedades mecânicas e de barreira semelhantes ao filme com glúten vital (comercial), podendo até serem usadas em substituição ao glúten comercial / Abstract: Recently interest in the development of edible films and coatings for foods has grown considerably due to consumer demand for high quality foods and environmental concerns over the disposal of non-renewable food packaging materials. Polysaccharides, proteins and lipids can be used as edible film-forming agents. The objective of this work was the development and characterization of simple, composite and bilayer wheat gluten films with lipids (beeswax and stearic and palmitic acids) and the application of the films and coatings on fresh fruits. The base film was prepared from a solution of gluten, absolute ethanol, glycerol and 6 N ammonium hydroxide to adjust the pH. The composition of the film formulations was calculated according to a 24 factorial planning. The functional properties used to verify the factor effects were mechanical properties (tensile strength and percent elongation at break), oxygen and water vapor permeabilities and solubility in water. The simple film with the best functional properties was used to prepare the composite and bilayer films of wheat gluten, beeswax and a 1:1 blend of stearic and palmitic acid. Other analysis as effect of the relative humidity on the mechanical properties and morphology of the surface by scanning electron microscopy were effected. After this, the application of the gluten-based coatings and films was effected on fresh strawberries maintained upon refrigeration, and the analysis of weight loss, retention of the texture, color, titratable acidity, soluble and total solids, reducing and total sugars and sensory evaluation of appearance to determine the shelf life of the strawberries and of taste to verify the acceptance of the gluten-based coatings, were effected. To complement the study, a reaction of lipofilization of wheat gluten was effected, and it was verified through the percentage of free amino groups by the TNBS method. Biofilms were prepared from the modified gluten and were characterized and compared with the film from unmodified gluten. Another complementary work was the preparation and characterization of biofilms prepared from Brazilian wheat flours and also comparison of the properties with the films from vital gluten (commercial). The results showed that the mechanical properties of the simple films had been influenced by the concentrations of gluten and glycerol, being the most resistant film with higher concentration of gluten and less glycerol. The lowest oxygen permeability was obtained in the film with lower concentration of gluten, glycerol and ethanol and the lowest water vapor permeability was in the film with lower concentration of glycerol. The composite and bilayer films were opaque and the bilayer film with 10% blend of stearic and palmitic acids and beeswax showed the lowest water vapor permeability, however the mechanical resistance and the elongation were low. The morphology observed through the scanning electron microscopy for the simple film of gluten was completely modified when the mixture of palmitic and stearic and beeswax was added. The application of biofilms and coatings in strawberries showed that the bilayer coating of gluten and lipids had a significant effect in the retention of the texture and the reduction of weight loss in the coated fruits. The senescence was decreased in fruits packed with the gluten film verified by the lower parameters in relation to the color of the fruit. The sensory evaluation of the strawberries indicated that the simple coating of gluten and the composite with lipids had kept the quality of the strawberries during the time of storage in terms of appearance and the consumers accepted the flavor of the strawberries with the simple coating. The lipofilization reaction really modified the gluten through the reduction of the percentage of free amino groups, however the film prepared with the lipophilized gluten presented lower mechanical and barrier properties comparing to the film with unmodified gluten. The films prepared from Brazilians ¿semi-hard¿ wheat flours had presented similar mechanical and barrier properties than the film from vital gluten (commercial), being able to be used in substitution / Doutorado / Doutor em Alimentos e Nutrição
125

Strawberry and cranberry response to growth regulators and fertilizers

McArthur, David Albert James January 1987 (has links)
The growth and yield response of strawberry (Fragaria X annassa Duch.) and cranberry (Vaccinium macrocarpon Ait) to various growth inhibitors, but especially to paclobutrazol (PP333), and fertilizers were investigated in glasshouse and field studies. PP333 decreased vegetative growth in a rate-dependent manner in both strawberry and cranberry. PP333 delayed fruit ripening in strawberry and decreased fruit set and fruit size in cranberry. PP333 decreased pollen germination of strawberry. Soil residues of PP333 were biologically active when measured 11 weeks after application in the strawberry study and when measured after 50 weeks in a cranberry study. In a field study with cranberry, PP333 caused a decrease in vegetative growth and an increase in flowering in the next season after treatment. Two-dimensional partitioning was used to account for yield variation from treatment effects on adjusted yield variates. The truss number was the most important contributor to yield variation in the strawberry, but was not affected by treatments. PP333 made a substantial contribution to yield variation in strawberry through its effect on fruit development and ripening. In the cranberry, fruit set was the major contributor to yield variation and PP333 influenced yield substantially through its effect on fruit set. In glasshouse studies, PP333 decreased shoot elongation in cranberry within 3 weeks of application, and increased the number of branches on primary shoots. Buds were formed within 7 weeks of treatment and some of the buds contained flowers. Shoot growth was greater with a high rate of NPK fertilizer than with the low fertilizer rate and was greater in peaty soil than in sandy soil. While bud set was not modified by soil type or fertilizer rate, high NPK fertilizer decreased floral induction. Some effects of PP333 treatment were decreased by gibberellic acid, but generally these effects here not reversed. In a field study with the cranberry, PP333 increased flower bud set for flowering and non-flowering uprights but slightly decreased floral induction for non-flowering uprights. / Land and Food Systems, Faculty of / Graduate
126

Chemical and morphological factors of resistance against the twospotted spider mite (Tetranychus urticae Koch) in beach strawberry Fragaria chiloensis (L.) Duchesne

Luczynski, Anna January 1988 (has links)
Host-plant resistance is an important component of integrated pest management. Host resistance to phytophagous insects and mites based on chemical and morphological characteristics has been identified in various agronomic crops. The present study was undertaken to examine how variation in selected morphological and chemical characteristics of beach strawberry Fragaria chiloensis (L.) Duchesne affects population parameters of the twospotted spider mite Tetranychus urticae Koch. The results from this study show that clones of F. chiloensis and the cultivar "Totem" vary in suitability for the twospotted spider mite. Selected clones of F. chiloensis and the cultivar "Totem" differed also in the following foliar characteristics: densities of glandular and nonglandular trichomes and concentrations of total and catechol-based phenolics. In contrast, qualitative analysis of phenolic compounds, determined via HPLC, revealed a close similarity between F. chiloensis and F. x ananassa (cultivated strawberry) and among selected clones of F. chiloensis. Mite oviposition was negatively correlated with densities of glandular and nonglandular trichomes and concentrations of total foliar phenolics. In spite of these significant relationships, mite oviposition was best predicted by a combination of interacting plant characteristics rather than by any individual characteristic. Entrapment by sticky exudates from glandular trichomes appears to explain the negative relationship between mite survival and density of glandular trichomes. Spider mite development was negatively related to concentrations of foliar phenolics; twospotted spider mite development is delayed on leaves with high concentrations of phenolics. The correlation between mite development and foliar phenolics was greater when catechol-based phenolics were used. / Land and Food Systems, Faculty of / Graduate
127

Vybrané mikronutrienty a těžké kovy v ovoci / The selected micronutrients and heavy metals in fruits

Formanová, Kristýna January 2012 (has links)
Today is the food quality a discussed topic not only in the Czech Republic. In this work we focused on micronutrients and heavy metals in strawberries. Strawberries are very attractive fruit consumed by all age groups from children to seniors. These bring not only gustatory pleasure but also positive effects on human organism. Soft fruit structure could contribute to the accumulation of heavy metals, which can be dangerous in certain quantities in terms of acute toxicity or what is more likely in terms of chronic exposure. In the spring - autumn of 2011 samples from the home cultivation of strawberries in the Czech Republic were collected and also samples of fruits that are commonly available in supermarket chains in this period were purchased. The element analysis was performed by the mass spectrometry with inductively coupled plasma, which belongs to a very sensitive method of elements determination.
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Use of Gamma Radiation, Chemicals, and Packaging Films to Control Post Harvest Diseases and to Extend Refrigerated Life of Strawberries and Cherries

Cooper, Gerald M. 01 May 1961 (has links)
In recent years there has been a considerable amount of work done on developing chemicals that would inhibit mold growth when applied to fresh fruit, and at the same time, be acceptable to man when taken orally. This would save many thousands of tons of fresh produce that are lost each year by spoilage before it ever reaches the consumer. Along with the development of new chemicals to inhibit mold growth there is a substantial amount of research being done on developing a packaging film that will prevent recontamination of the produce, at the same time allowing the passage of gasses into and out of the package to allow respiration of the fruit. During the present century much emphasis has been placed on growing certain varieties of fruit for our specific needs. It has been found that particular varieties are better for canning and that other varieties are better for freezing. With the release of atomic energy for peaceful use in 1933 by the United States Congress, a new era of food preservation was introduced. Men in the scientific fields believe it is possible to extend the shelf-life of fresh fruits without altering their physical condition to great extent. Many institutions have been awarded grants and contracts to work on various phases of food preservation with atomic energy. Utah State University was awarded a contract by the United States Army Quartermaster Corp to study the use of gamma radiation for extending the shelf-life of fresh produce. It was with this idea in mind that work for this thesis was conducted to study the effects of gamma radiation, fungicides, and packaging film on the microbial growth on certain varieties of strawberries and cherries. In addition, experiments were conducted using fungicides and packaging films in order to lower the dose of radiation necessary to prevent mold growth. In order for this method of preserving fresh fruit to become successful, new and more economical methods and techniques in handling the materials will have to be developed.
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Use of a monoclonal antibody to detect gray mold (Botrytis cinerea) in strawberry

Mohr, Alexandra. January 2001 (has links)
No description available.
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Comparing hand watering, automated, and subsurface irrigation treatments for cost, labor, and water use in community gardens.

De Leon Gonzalez, Eloísa Maria 06 August 2021 (has links)
Community gardens are places where people gather to share the experience of gardening. However, users often struggle to find time in their busy schedules to care for their plots and crops. This research explores the impact of different watering systems on gardening based on plant quality, cost, labor, and time for. The study analyzed the inputs and outputs of hand watering, automated, and subsurface irrigation treatments in hopes of identifying how to design community gardens for the most efficient application of water, ultimately striving to increase crop production, crop quality, and community interest. Results indicate that subsurface irrigation systems are more likely to save time, reduce water use, and produce a higher quality crop when application and setting is adequate.

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