Últimos itens adicionados do Acervo: Universidade Federal de Lavras

A Universidade Federal de Lavras (UFLA) é uma universidade pública brasileira localizada na cidade de Lavras, Estado de Minas Gerais.

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Crescimento do maracujazeiro-doce (Passiflora alata Dryand.) em função da calagem, classes de solo e tipos de muda

Fonseca, Elda Bonilha Assis
Fonte: Universidade Federal de Lavras; Programa de Pós-graduação em Fitotecnia; UFLA; brasil; Departamento de Agricultura Publicador: Universidade Federal de Lavras; Programa de Pós-graduação em Fitotecnia; UFLA; brasil; Departamento de Agricultura
Tipo: Tese de Doutorado
Publicado em 15/12/2015 POR
Aiming to study the effect of the liming on the growth and nutrition of sweet passion fruit plants, two experiments were carried out in the greenhouse of the Agriculture Department of the Federal University of Lavras (UFLA). The statistical design used was randomized blocks in a factorial scheme (2x4) + 2, with four replications. The treatments involved two soil classes (Dystrophic Red-Yellow Latosol - LVAd and Dystrophic Red Latosol - LVd), four base saturation leveis (40%, 60%, 80% and 100%) and two more additional treatments, LVAd without liming and LVd without liming. The fírst experiment was carried out with seedlings (originated from seeds) and the second with cuttings. The experimental plot was constituted of four vases in the fírst experiment and two vases in the second. After 150 days, the stem length, number ofleaves, dry matter ofshoots and roots, the roots/shoots ratio, macro and micronutrients contents in the shoots dry matter and P, Ca and Mg in the roots dry matter were evaluated. It was concluded that in both experiments the largest growth happened in the LVd and the sweet passion fruit tolerates soils with low base saturation leveis. In the fírst experiment, with seedlings, the increase ofbase saturation leveis reduced vegetative growth ofplants in the LVd but had no influence in the LVAd. For both soil classes...

Evolução de sistema de apoio à leitura e navegação em sites web para usuários com dislexia

Rezende, Guilherme Camilo
Fonte: Não; UFLA; brasil; Ciência da Computação Publicador: Não; UFLA; brasil; Ciência da Computação
Tipo: Trabalho de Conclusão de Curso
Publicado em 18/12/2015 POR
The web is tool that is increasing in the society and it is essential that all regardless of disabilities will able to access your content. Dyslexia is a problem that affects the experience of users with the web. A tool that has a proposal to improve the user experience when accessing web pages is the WebHelpDyslexia, extension create for the Google Chrome browser. Thought a requirements elicitation made by studies of related works three new features have been added the rule of reading, the highlighter and the synonyms dictionary. In the end of study, a dyslexic user has performed an evaluation that shows the positive effect of the extension evolution.; A web é uma ferramenta que está cada vez mais presente na sociedade e é essencial que todos independente de deficiências consigam ter acesso ao seu conteúdo. A dislexia é um problema que afeta a experiência do usuário com a web. Uma ferramenta que tem a proposta de melhorar a experiência do usuário ao acessar páginas web é a WebHelpDislexia, extensão criada para o navegador Google Chrome. Por meio de um levantamento de requisitos feito por um estudo de trabalhos relacionados, três novas funcionalidades foram adicionadas: a régua de leitura, o marcador de textos e o dicionário de sinônimos. Ao final do trabalho foi realizada uma avaliação com um usuário disléxico que mostra que o uso da extensão foi positivo.

Uso da restrição hídrica na inoculação de Colletotrichum lindemuthianum em sementes de feijoeiro (Phaseolus vulgaris L.)

Carvalho, João Custódio Barbosa de
Fonte: Universidade Federal de Lavras; Program de Pós-Graduação em Fitotecnia; UFLA; brasil; Departamento de Agricultura Publicador: Universidade Federal de Lavras; Program de Pós-Graduação em Fitotecnia; UFLA; brasil; Departamento de Agricultura
Tipo: Dissertação
Publicado em 15/12/2015 POR
The present research was carried out aiming at to develop a more efficient methodology to inoculate Colletotrichum lindemuthianum in bean seeds by using the hidric restriction principie. The research work was conducted in tree steps. In the fist part, the effect ofdifferent hidric restriction leveis on PDA médium amended with PEG 6,000 or mannitol on the seed radicle emission was investigated. In the second step growth of C. lindemuthianum on PDA containing the PEG 6,000 or mannitol was measured. The third part ofthe work consisted ofevaluating the infection levei obtained by keeping the bean seeds in contact with colonies of C. lindemuthianum, 5 days old, developed on PDA médium amended with mannitol at different concentrations. The results showed that incorporation ofmannitol solution at -IMPa into PDA médium with 5 day incubation, proved to be efficient to obtain higher leveis ofbean seeds infected by the anthracnosis fungous. Growth ofC lindemuthianum was not affected by the hidric restriction produced by the addition ofmannitol, at the maximum levei of -1,0 MPa, into PDA médium. Incorporation of solutions of PEG 6,000 at hidric restrictions higher than -0,6 MPa into PDA caused reduction in the development of C .lindemuthianum. Radicle emission of bean seeds was efficiently impeded on PDA médium containing such components...

Avaliação da supressividade do solo a Thielaviopsis sp.; Evaluation to soil suppressiveness to Thielaviopsis sp.

Pereira, Priscilla de Fátima
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Agronomia/Fitopatologia; UFLA; brasil; Departamento de Fitopatologia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Agronomia/Fitopatologia; UFLA; brasil; Departamento de Fitopatologia
Tipo: Dissertação
Publicado em 16/12/2015 POR
The stem-bleeding caused by Thielaviopsis sp. has became cause of extreme concern for farmers, research institutions, technical assistance agencies, and health protection and monitoring agencies. This disease has been spreading and, thus, increasing the quantity of coconut trees and farms affected each year. The search for a sustainable control of this pathogen has become constant over time. In this study, we aimed to evaluate the suppressiveness and / or conduciveness of coconut planting soils of two Brazilian regions, as well as the possible variables responsible for such suppression and / or conduciveness. The influence of soils on Thielaviopsis sp. population was assessed by estimating the percentage of baits of ripe banana colonized by this pathogen on soils. This colonization percentage ranged from 4.61 to 83,08%. Then, based on the Scott Knott means test, samples of five most suppressive soils, and five most conducive soils were collected to estimate their nature, as well as determining factors for suppressiveness and / or conduciveness. Physical, chemical and biological characters were assessed for each sample. The total bacteria parameter was found to be higher in suppressive soils. Fluorescent Pseudomonas was only found in one type of soil. The pH...

Metodologia de pesquisa: guia prático com ênfase em Educação Ambiental

Martins, Ronei Ximenes; Martins, Ronei Ximenes
Fonte: Universidade Federal de Lavras Publicador: Universidade Federal de Lavras
Tipo: Livro
Publicado em 12/12/2015 PT_BR

Distribuição gama generalizada geométrica estendida; The extended generalized gamma geometric distribution

Bortolini, Juliano
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Estatística e Experimentação Agropecuária; UFLA; brasil; Departamento de Ciências Exatas Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Estatística e Experimentação Agropecuária; UFLA; brasil; Departamento de Ciências Exatas
Tipo: Tese de Doutorado
Publicado em 17/12/2015 POR
New probability distributions are proposed in order to get better fit to the complex data such as censored, skewed and bimodal. In this perspective, this work proposed new more flexible models for survival analysis. The first model proposed is the extended generalized gamma geometric distribution of five parameters, which includes well-known lifetime special sub-models such as the generalized gamma. We provided a mathematical treatment of the new distribution including explicit expressions for moments, moment generating function, mean deviations, reliability and order statistics. Further, we developed an extension of this distribution by assuming that a shape parameter can take negative values. Additionally, we derived the log-transformed distribution and its regression model. The new regression model represents a parametric family of models that includes as sub-models some widely known regression models that can be applied to censored survival data. Finally, an application of the new models to real data showed that they could provide a better fit than other statistical models frequently used in lifetime data analysis.; Novas distribuições de probabilidade são propostas com o objetivo de obter melhores ajustes a dados que apresentem comportamentos mais complexos...

Identificação do sexo e variabilidade genética em uma população de Astronotus ocellatus (Agassiz, 1831) por marcadores ISSR

Paiva, Isadora Marques
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciências Veterinárias; UFLA; brasil; Departamento de Medicina Veterinária Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciências Veterinárias; UFLA; brasil; Departamento de Medicina Veterinária
Tipo: Dissertação
Publicado em 17/12/2015 POR
Studies conducted in order to investigate alternative methods for sexing fish species, such as Astronotus ocellatus, using reduced sexual dimorphism, are extremely important to facilitate reproduction management techniques. The objective of this study was to determine the feasibility of manual sexing, widely used by fish farmers and hobbyists, and the identification of specific molecular markers for a particular sex using ISSR markers. The latter technique also generates genetic diversity and similarity data, and is important for conservation studies. Manual sexing was performed by macroscopic analysis of the urogenital papilla. Fin and gonad samples of 30 A. ocellatus (±83,32g e ±15, 96 cm) were collected for DNA extraction and histology, respectively. For DNA extraction, we adopted the NaCl protocol (SAMBROOK, 1989). Quality samples were used for amplification, using universal ISSR primers with subsequent separation of the generated fragments by electrophoresis, and assessment of similarity and genetic diversity levels. The manual sexing did not appear as a viable technique to distinguish the sexes for this species, given the occurrence of 37% of errors during selection. Likewise...

Óleos essenciais de três espécies de myrtaceae:composição química, atividades antioxidante, hemolítica, antitumoral, antiocratoxigênica e citogenotóxica

Santiago, Juliana de Andrade
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Agroquímica; UFLA; brasil; Departamento de Química Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Agroquímica; UFLA; brasil; Departamento de Química
Tipo: Tese de Doutorado
Publicado em 17/12/2015 POR
The aim of this study was to determine the chemical composition and various biological activities of the essential oils from Melaleuca alternifolia (leaves and fruits), Melaleuca quinquenervia (leaves and fruits), and Backhousia citriodora (leaves). The EOs were extracted through the hydrodistillation technique and chemically characterized by GC/MS and GC-FID. The antitumor tests were performed in five cell lines derived from human tumors: A549, MCF7, HepG2, U251-MG and HT144. The frequency of apoptotic cells was analyzed by fluorescence microscopy; morphological changes through contrast microscopy, and DNA content, in the different phases of the cell cycle, through flow cytometry. In addition, several tests were performed to evaluate the antioxidant activity (ABTS, DPPH, hydroxyl radical, β-carotene/ linoleic acid, TBARS , and phosphomolybdenum complex). Hemolytic activity was evaluated in liquid medium (0.15% Ht) and solid medium. The oils extracted from the leaves were evaluated for inhibition of ochratoxin production by Aspergillus niger and A. carbonarius under two different conditions, 15 to 25°C. The cytogenotoxic effects of the essential oil (EO) from B. citriodora were evaluated on Lactuca sativa, using cytogenetic assays...

Aplicação de microesferas de vidro para avaliação da qualidade da superfície serrada da madeira de Eucalyptus grandis

Pigozzo, Fernando Jordão
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciência e Tecnologia da Madeira; UFLA; brasil; Departamento de Ciências Florestais Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciência e Tecnologia da Madeira; UFLA; brasil; Departamento de Ciências Florestais
Tipo: Dissertação
Publicado em 17/12/2015 POR
The use of machinery and software is growing in sawmills in order to increase the sawing yield. These measures also seek to improve the quality of sawn timber, given that warping, size variation and defects in the surfaces of the sawn pieces increase losses during finishing operations. Little is discussed in the literature concerning the surface quality of lumber. This occurs due to the shortage of evaluation methods. Therefore, the main objective of this study was to evaluate the quality of the sawn surface of Eucalyptus grandis lumber, after log sorting, defect analysis of the sawn pieces and yield calculation. For this, logs were sorted into four diameter classes. We evaluated their tapers, flattening and end checks. The sawing method was planned by Maxitoras® software - Optimber, and was compared with the actual yield. The quality of the sawn timber was assessed by measuring warping and size variation, as well as evaluating their surfaces by applying glass microspheres, based on the E-965 (ASTM, 1996) method. We concluded that: i) the shape of the logs was considered acceptable, according to the usual classification methods, however, the end check values were higher than the values found in literature; ii) the warping of sawn pieces was considered of high intensity...

Anatomia foliar de Brachiaria spp. em diferentes idades de rebrota associada com a qualidade da forragem; Leaf anatomy of Brachiaria spp. at different regrowth ages associated with forage quality

Mauri, Janaína
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Botânica Aplicada; UFLA; brasil; Departamento de Biologia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Botânica Aplicada; UFLA; brasil; Departamento de Biologia
Tipo: Tese de Doutorado
Publicado em 17/12/2015 POR
The present work intended to verify whether there is an effect upon the regrowth age of different genotypes in the leaf anatomy of Brachiaria spp., and how that can affect its quality as a forage plant. Leaf tissues of the genotypes of Brachiaria brizantha (Hochst.) Stapf. (cv Marandu), Brachiaria decumbens Stapf. Prain. (cv. Basilisk), Brachiaria ruziziensis (R. Germ & Evrad) (cv. Kennedy) and of three clones (1, 95 and 97) of Brachiaria ruziziensis were evaluated. Those plants were cultivated under ideal conditions recommended for the cultivation of Brachiaria. At first, the leaves were collected at three regrowth ages to determine which would be the ideal age; afterwards, with the ideal age determined, the genotypes within the ideal age were compared. By making use of the usual microtechnique, sections free hand were done and semipermanent slides were manufactured. Photomicrographs and proportions of the tissues in the interveinal region and of the midrib were done utilizing the image software Image J. for the determination of the regrowth age the design was completely randomized with three treatments and nine replications and to compare the genotypes the design was completely randomized with six treatments and six replications. The statistical analyses were conducted on software Sisvar and the means compared by the Scott-Knott te st. Over time...

Parâmetros genéticos em teste de procedências e progênies de Toona ciliata M. Roemer var. australis; Genetic parameters in test of provenances and progeny of the Toona ciliata M. Roemer var. australis

Rosado, Lucas Rodrigues
Fonte: Universidade Federal de Lavras; Programa de Pós- Graduação em Engenharia Florestal; UFLA; brasil; Departamento de Ciências Florestais Publicador: Universidade Federal de Lavras; Programa de Pós- Graduação em Engenharia Florestal; UFLA; brasil; Departamento de Ciências Florestais
Tipo: Dissertação
Publicado em 17/12/2015 POR
The increase the dimensions of the trees, by genetic improvement, without considering their architectures can make them mechanically unstable in situations of high winds. As consequence may occur falls, breaks and permanent buckling of stems, causing economic losses and environmental damage. In the present study had as objective to estimate genetic parameters and predict wood production gains with improvements in the trees architecture. It was used a test of provenances/progenies/plants of Toona ciliata M. Roemer var. australis, established in Campo Belo, MG, with 74 months old. This test involved 12 provenances of seeds widely distributed in the Australian east coast. Data of diameter to breast height (DBH), total tree height (Ht), volume (Vol), slenderness coefficient (S = Ht.DBH -1 ) and stem form (For), at 31, 54 and 74 months of age, there were obtained in individuals of 63 progenies from all provenances. The genetic parameters and prediction of genotypic values were estimated by REML/BLUP method. There was great genetic variability among and within provenances, showing that the test has an important role for the improvement and conservation of the species ex situ. Whereas the criterion of having a higher frequency of trees with low S or equal to 0.75...

Utilização de enzima transglutaminase e soro concentrado por nanofiltração na elaboração de queijo petit suisse

Gajo, Adriano Alvarenga
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciência dos Alimentos; UFLA; brasil; Departamento de Ciência dos Alimentos Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciência dos Alimentos; UFLA; brasil; Departamento de Ciência dos Alimentos
Tipo: Tese de Doutorado
Publicado em 17/12/2015 POR
This study was performed with the general aim of studying the use of concentrate fluid whey and the enzyme transglutaminase in the cheese formulation petit suisse and set technological manufacturing parameters. The specific objectives were: 1) to establish, through the delineation of statistical tool central composite, optimal concentrations of serum concentrate and enzyme transglutaminase (TG) (EC 2.3.2.13), evaluating the performance, texture, syneresis index and sensory acceptance and 2) define the optimal amount of the enzyme transglutaminase in the cheese formulation petit suisse with fixed value of serum concentrated fluid, assessing income, texture profile, syneresis index and sensory acceptance. The skim milk, the cream and the concentrated whey obtained by nanofiltration process were acquired in Dairy Campo Verde Ltda., located in Lavras, MG. The preparation of the cheese was made in dairy pilot plant at the Department of Food Science at the Federal University of Lavras (DCA / UFLA); the cheeses chemical composition , whey concentrate and milk analysis were held at Milk Analysis Laboratory and Milk Products, and the texture analyzes were conducted at the Engineering Laboratory and Microstructure, both also in DCA / UFLA. It can be seen that the ratio skimmed milk / whey concentrate showed a positive linear term...

Desenvolvimento gonadal de fetos suínos e sua relação com medidas fetais

Pontelo, Thais Preisser
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciências Veterinárias; UFLA; brasil; Departamento de Medicina Veterinária Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciências Veterinárias; UFLA; brasil; Departamento de Medicina Veterinária
Tipo: Tese de Doutorado
Publicado em 18/12/2015 POR
The objective of this work was to evaluate the histomorphometric traits of the testes and ovaries at different gestational ages, and correlate them with the length and head circumference, and thoracic perimeter. We divided by gender and gestational age 44 fetuses obtained from DB-90 pregnant gilts (DanBred). The gestational ages were of 50, 80 and 106 days. In the first and second groups, 5 males and 7 females were studied, and in the third, 5 males and 9 females. After slaughtering the gilts, the fetuses were removed, determining the head length and head and thoracic perimeters. Subsequently, the gonads were collected, weighed and subjected to histomorphometric analyses, such as cell counts and measuring the gonad structures. All gonad traits were subjected to ANOVA, statistically comparing the different gestational ages using the SNK test at 5% probability. Histomorphometric variables were correlated with fetal measurements by means of Pearson correlation. The weight of the testes increased (P<0.05) significantly during pregnancy, especially during the final third. The same occurred to the weight of the ovaries. After 106 days of gestation, the cordonal length and number of Sertoli cells increased (P<0.05) in the testes, however...

Diferentes manejos de irrigação de adubação no progresso da ferrugem do cafeeiro

Barbosa Junior, Mauro Peraro
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Agronomia/Fitopatologia; UFLA; brasil; Departamento de Fitopatologia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Agronomia/Fitopatologia; UFLA; brasil; Departamento de Fitopatologia
Tipo: Dissertação
Publicado em 18/12/2015 POR
Rust is an important disease for coffee. Its occurrence affects nutritional balance and water supply to plants. In certain cases, irrigation can impart greater resistance to the host. However, a provided microclimate can increase the progress rate of the disease. Poor or unbalanced mineral nutrition may predispose plants to fungus infection. Thus, the aim of this study was to evaluate the incidence of rust in coffee plantations with different irrigation and fertilization managements. The study was conducted with adult coffee of cultivar MGS Travessia, in an experimental area of the Department of Agriculture of the Universidade Federal de Lavras, in Minas Gerais, Brazil. Disease ratings were elaborated from March of 2012 to November of 2014. The experimental design was a completely randomized block design, with twelve treatments (3 fertilization managements) x (4 drip irrigated managements) and three replicates, in a total of 36 installments. The results for the average rate of disease incidence was graphically plotted in a disease progress curve for rust incidence (AACPDIF). We observed higher AACPDIF values (P<0.05) in no irrigation (NI) and treatment with suspended irrigation for 70 days (I70) throughout the study period. Plants that have suffered greater water stress were more susceptible to infection.; A ferrugem é uma das principais doenças do cafeeiro...

Identificação por Maldi-Tof MS de isolados de Aspergillus seção Nigri e avaliação do potencial biotecnológico na produção de biossurfactantes

Faria, Lucas Vieira de
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Microbiologia Agrícola; UFLA; brasil; Departamento de Biologia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Microbiologia Agrícola; UFLA; brasil; Departamento de Biologia
Tipo: Dissertação
Publicado em 18/12/2015 POR
Species belonging to section Nigri form a subgroup of genus Aspergillus, and are cosmopolitan. Many species of this section are used in food and fermentation industries, being A. niger the most reported, presenting GRAS status. However, this section is considered by many taxonomists as one of the most difficult to identify due to high genetic variability. Surfactants are amphipathic molecules that present two portions in the same molecule: a hydrophilic portion and a hydrophobic portion. Biosurfactants are a group of many molecules produced by different microorganisms and mainly classified by chemical structure and microbial origin. The objectives of this work were to identify 32 Aspergilus section Nigri fungal isolates by means of the MALDITOF MS technique, and test the biosurfactant production capacity of three Aspergillus niger isolates, using bacteria Bacillus subtilis CCMA 0087 as control. We tested three different protein extraction methodologies by MALDITOF MS, comparing them by means of grouping in dendrograms. The results showed that the grouping could vary depending on the methodology used. Regarding biosurfactant production capacity, the fungi isolates were tested to obtain the emulsification index, considering many aspects for its favoring...

Silagem de milho ou cana-de-açúcar e o efeito da textura do grão de milho no desempenho de vacas holandesas

Corrêa, Clovis Eduardo Sidnei
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Zootecnia; UFLA; brasil; Departamento de Zootecnia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Zootecnia; UFLA; brasil; Departamento de Zootecnia
Tipo: Dissertação
Publicado em 21/12/2015 POR
Brazilian corn hybrids have primarily hard type endosperm of high vitreousness, while in other countries, as in the United States, dent type hybrids ofsoftendosperm prevails. Dentcornhas greater ruminal starch digestibility and smallerrate of decay in digestibility with advancing maturity than hard hybrids. In the fírst experiment it was tested the hypothesis that the use of soft cultivars may enlarge the ensilage period of corn. A hard texture hybrid (P3041) was ensiled at the half milk line stage ofgrowth (MD) and a dent hybrid (AG4051) at the black layerstage (MM). A third treatment tested the viability of sugarcane (CA) as a forage for high producing dairy cows. Nine lactating Holstein cows were allocated to a sequences ofthe three treatments in three 3x3 Latin squares with 21-day periods. The experimental diets contained 200 g offorage NDF per kg of dry matter. There was no detectable difTerence between corn hybrids in production (34.2 vs 34.6 kg/d) and composition ofmilk, dry matter intake (23.0 vs 23.2 kg/d) and total tract apparent digestibility of nutrients CP>0.37 for the contrast MM vs MD). Sugarcane decreased intake (21.5 kg/d) and milk production (31.9 kg/d) (P<0.05 for the contrast CA vs MM+MD). The lower sugarcane NDF digestibility compared with corn silage NDF (23.1 vs 42.1%...

Calibração de sensores de capacitância (FDR) para estimativa da umidade em diferentes solos; Capacitance sensors calibration (FDR) to estimate the moisture in differents soils

Pizetta, Samuel Cola
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Recursos Hídricos em Sistemas Agrícolas; UFLA; brasil; Departamento de Engenharia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Recursos Hídricos em Sistemas Agrícolas; UFLA; brasil; Departamento de Engenharia
Tipo: Dissertação
Publicado em 22/12/2015 POR
Measurement of soil water content is one of the main challenges of agriculture and knowledge of available equipment to perform it is extremely important. This research aimed to calibrate capacitance sensors (FDR) such as 10HS manufactured by Decagon Devices and two low cost sensors referred to as Grove and Eletrodex. The calibration was carried out through comparisons to soil water content determined by dry oven at 105 o C for three soil classes designated as dystrophic Red Argisol, dystroferric Red Latosol and eutroferric Red Nitosol. For 10HS sensor, the obtained values were compared to calibration curve supplied by the manufacturer. The experiment was set at the Hydraulics Laboratory at Federal University of Lavras, Minas Gerais State in Brazil. It can be concluded that the calibration curve supplied by Decagon Devices did not describe well the results obtained, although this sensor can be satisfactorily used to measure soil water content. According to determination coefficients calculated, low cost sensors did not estimate properly the soil water content at the moisture range evaluated at any soil class.; Um dos maiores desafios de domínio agrícola é a mensuração prática...

Validação de modelo fenológico de produtividade de cafeeiro no sul do estado de Minas Gerais; Phenological model validation of coffee productivity in the southern state of Minas Gerais

Miranda, Wezer Lismar
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Recursos Hídricos em Sistemas Agrícolas; UFLA; brasil; Departamento de Engenharia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Recursos Hídricos em Sistemas Agrícolas; UFLA; brasil; Departamento de Engenharia
Tipo: Tese de Doutorado
Publicado em 22/12/2015 POR
Coffee production is influenced by the variations of the climatic elements, by the occurrence of adverse conditions (frost, dry spells, etc.) and by plant physiology (bieniannial). The prediction for coffee productivity is very complex due to the intricate physiological mechanisms, cultivar diversity and management conditions. Considering the importance of predicting the productivity for market regulation, with the present study we aimed at validating a model for estimating coffee productivity, based on the use of phenological indexes, submitted to the edaphoclimatic conditions of the southern region of Minas Gerais, Brazil. For this, we used 10 sample plots, distributed in the municipalities of Lavras, Varginha, Carmo de Minas, Ijaci and Santo Antonio do Amparo. The criteria for choosing the plots was based on the existence of a history of productivity superior to 40 sc ha-1 . The necessary meteorological information were collected from the Main Climatological Station belonging to INMET and installed at the campus of the Universidade Federal de Lavras (UFLA, considering as representative of the region. We conducted a hydric balance for the period in which the study was conducted, encompassing the harvests of 2012/2013 and 2013/2014. The collection of phenological data was conducted during the months of September/October...

Variação radial e longitudinal da densidade aparente e estimativa de massa de Toona ciliata; Longitudinal and radial variation of apparent density and mass estimation of Toona ciliata

Silva, Tatiane Antunes da
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciência e Tecnologia da Madeira; UFLA; brasil; Departamento de Ciências Florestais Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Ciência e Tecnologia da Madeira; UFLA; brasil; Departamento de Ciências Florestais
Tipo: Dissertação
Publicado em 22/12/2015 POR
Australian Cedar (Toona ciliata), belongs to the Meliaceae family and has been cultivated in many Brazilian sites. When compared to natural forest species it has fast growth and has been used as an option to substitute native woods, such as mahogany (Swietenia macrophylla) and cedar (Cedrella odorata). The main purpose of this work was to evaluate the variation in apparent density and propose a model for stem mass estimation this study used trees with 52 months old, from plantation areas, in Campo Belo county, Minas Gerais state, Brazil. Two distinct progenies were chosen and had wood discs removed in the following positions from the tree base: 0.15 m, 0.70 m, 1.30 m and 30%, 50%, 70% and 85% of the total height. Wood samples from the disks were collected in order to conduct X-ray densitometry. The X-ray densitometry allowed us to know density variation from pit to bark and from base to top of trees. The density increases from pit to bark. From base to top of the tree, the density decreases up to DBH position and, after that, increases until the top of the tree. The estimated value for mean apparent density was 0.422 g/cm³. Based on the longitudinal variation of apparent density it was possible to propose a model for mass estimation. The model...

Bacillus subtilis e bactérias endofíticas autóctones como agentes de biocontrole para Fusarium solani e bioacúmulo de ferro na cultura da mandioca

Freitas, Mônica Aparecida de
Fonte: Universidade Federal de Lavras; Programa de Pós-Graduação em Agronomia/Fitopatologia; UFLA; brasil; Departamento de Fitopatologia Publicador: Universidade Federal de Lavras; Programa de Pós-Graduação em Agronomia/Fitopatologia; UFLA; brasil; Departamento de Fitopatologia
Tipo: Tese de Doutorado
Publicado em 22/12/2015 POR
Cassava is a culture of high socio-economic importance. However, the nutritional value of the root is poor. It contains little protein, vitamins or nutrients, such as iron. In addition, the culture suffers quality and productivity loss due to the occurrence of disease, among which, the main disease is root rot caused by Fusarium solani. In this sense, we conducted trials adopting bacterial isolates beneficial to improving the culture. To evaluate the antagonism against F. solani and the induction of iron accumulation in cassava plants, we used endophytic and autochthonous bacterial isolates and the GBO3 rhizobacteria. Of these, AMRAC31 (Rhizobium radiobacter), MGRTSA05 (Bacillus subtilis), MAIIF2a (Microbacterium imperial) and GBO3 (Bacillus subtilis) promoted growth, iron accumulation and/or absence of root rot symptoms caused by F. solani. New trials were conducted with the most promising bacteria for inducing the accumulation of iron by plants cultivated in nutritive solution. MAIIF2a, MGRTSA05 and GBO3 were capable of inducing significant iron accumulation by plants in ideal conditions and iron deficiency conditions. The isolates also presented fungicide and fungistatic effect, protecting cassava gems and branches against colonization by F. solani after in vitro bacterization. With the combination of the obtained results...