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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.
1

The Utilization of Vegetative Structure in the Interpretation and Differentiation of Certain Canadian Boreal Regions

Webb, Norman 05 1900 (has links)
The Development, presentation, and application of technique for interpreting examples of so-called muskeg terrain in Northern Canada. The emphasis is with a view to utilitarian aspects, not necessarily botanical implications, though the medium for the work is vegetal coverage. Illustrated with photographs. / Thesis / Bachelor of Arts (BA)
2

Comunidade microbiana do solo e podridão radicular em meloeiro em diferentes sistemas de manejo / Microbial community of soil and root rot in muskmelon with different management system

Nascimento, Paula Gracielly Morais Lima do 03 June 2015 (has links)
Made available in DSpace on 2016-08-12T19:18:36Z (GMT). No. of bitstreams: 1 PaulaGMLN_TESE.pdf: 802985 bytes, checksum: ea2cf5b10e3c0b5eb8042341897c1301 (MD5) Previous issue date: 2015-06-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to quantify the microbial community of soil cultivated with muskmelon and evaluate the incidence of root rot in muskmelon at the no-tillage (NT) and conventional tillage (CT) systems associated with soil coverages.Two experiments (two muskmelon crop cycles) were conducted in a naturally infested area with soilborne pathogens. The incidence of root rot was evaluated in both crop cycles, while the microbial community was quantified only in the first crop cycle.The experiments were conducted at the AgrícolaFamosa s farm, located between the cities of Tibau-RN and Icapuí-CE, in the Northeast region of Brazil.The randomized block design was used with split-plot.At the main plots evaluated two planting systems with and without soil revolving (NT and CT) and the subplots consisted of seven soil cover crops (Sunn hemp; Pearl millet; Sunn hemp + Pearl millet; Corn + Brachiaria; Spontaneous vegetation, Spontaneous vegetation + Black polyethylene film and Soil without vegetation).At the conventional tillage system, the plant materials were dried and incorporated into the soil, while in the no-tillage system were maintained on the ground.It was realized six soil samplings (Fallowed area; Green manure implementation; Muskmelon transplantation and at 20, 40 and 60 days after transplantation-DAT) in each subplot for quantification of total bacteria, fungi, Bacillus spp. and Pseudomonas fluorescens. For isolation and cultivation of microorganisms, serial dilutions were prepared and transferred to plates containing the desired solid medium for each analyzed group.After fruits harvest, all melon plants were collected from subplots, washed and analyzed for the incidence of root rot.The soil microbial communities (total bacteria, fungi, Bacillus spp. e Pseudomonas fluorescens) varied according to the tillage systems (no-tillage and conventional tillage) at the different epochs of sample collection during the muskmelon cycle. The sunn hemp cultivation associated with no-tillage in muskmelon provided greater amount of colony forming units (CFU) of total bacteria compared to the conventional tillage.The planting systems and soil coverages did not affect the amount of total fungi and Pseudomonas fluorescens. The microbial community of soil cultivated with muskmelon is influenced by the planting and soil coverage systems.The incidence of root rot in muskmelon was lower in the no-tillage system pre-cultivated with Sunn hemp, Pearl millet and Spontaneous vegetation. Fusarium solani, Macrophomina phaseolina, Monosporascus cannonballus e Rhizoctonia solani were the pathogens that occurred in muskmelon, being the first fungus the most frequent in both planting systems. The incidence of root rot in muskmelon depends on the cropping and planting systems / O presente trabalho teve como objetivo quantificar a comunidade microbiana do solo cultivado com meloeiro e avaliar a incidência de podridão radicular no meloeiro, nos sistemas de plantio direto (PD) e convencional (PC) associado à coberturas do solo. Dois experimentos (dois ciclos do meloeiro) foram conduzidos em área naturalmente infestada com patógenos habitantes do solo. A incidência de podridão radicular foi avaliada nos dois ciclos, enquanto a quantificação da comunidade microbiana do solo apenas no primeiro ciclo. O experimento foi conduzido na fazenda Agrícola Famosa entre os municípios de Tibau-RN e Icapuí-CE, no Nordeste do Brasil. O delineamento experimental foi o de blocos casualisados, no esquema de parcelas subdivididas. Nas parcelas foram avaliados dois sistemas de plantio com e sem revolvimento do solo (PC e PD) e nas sub-parcelas, sete coberturas de solo (Crotalária; Milheto; Consórcio crotalária + milheto; Consórcio milho + braquiária; Vegetação espontânea; Vegetação espontânea + filme de polietileno; Solo sem vegetação). Os materiais foram dessecados e, incorporados ao solo, no plantio convencional enquanto no plantio direto, foram mantidos sobre o solo. Foram realizadas seis coletas do solo (Área em pousio; Implantação dos adubos verdes; Transplantio do meloeiro e, aos 20, 40 e 60 dias após o transplantio-DAT), em cada subparcela, para quantificação de Bacillus spp. , Pseudomonas fluorescens, bactérias totais e fungos totais. Para a quantificação de microrganismos, utilizou-se o método de diluição seriada e plaqueamento em meio de cultura específico para cada grupo analisado. Após a colheita dos frutos todas as plantas de meloeiro das subparcelas foram coletadas, lavadas e analisadas quanto à presença de podridão radicular. A comunidade microbiana do solo (Bacillus spp. ,Pseudomonas fluorescens bactérias totais e fungos totais) variou em função dos sistemas de plantio (direto ou convencional) nas diferentes épocas de coleta de amostras no ciclo do meloeiro. O cultivo da crotalária associada ao plantio direto do meloeiro causou maior quantidade de UFCs de bactérias totais em relação ao plantio convencional. Os sistemas de plantio e as coberturas do solo não alteraram a quantidade de fungos totais e Pseudomonas fluorescens. A comunidade microbiana do solo cultivado com meloeiro é influenciada pelo sistema de plantio e de cobertura do solo. A incidência da podridão radicular no meloeiro foi menor no sistema de plantio direto pré-cultivado com crotalária, milheto, ou vegetação espontânea. Fusarium solani, Macrophomina phaseolina, Monosporascus cannonballus e Rhizoctonia solani foram os patógenos que ocorreram no meloeiro, sendo o primeiro fungo, o de maior ocorrência em ambos os sistemas de plantio. A incidência de podridão radicular do meloeiro é dependente do sistema de cultivo e de plantio

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