An active football season during the fall acclimation period tests the traffic tolerance of bermudagrass. Exogenous applications of synthetic cytokinins or cytokinin-enhancing plant growth regulators (PGRs), such as trinexapac-ethyl, may improve the traffic tolerance of "Patriot" and "Tifsport" hybrid berudagrasses (Cynodon dactylon var. dactylon x Cynodon transvaalensis). This study was designed to mimic the agronomic practices and traffic stresses experienced at Virginia Tech's Worsham Field. Starting in September 2005, treatments were applied with a differential-slip traffic simulator. Following a traffic treatment, plots received an application of one of three PGRs: 6-Benzyladenine (6-BA), 2-Chloro-4-pyridyl-phenylurea (CPPU) or trinexapac-ethyl (TE). Physiological and morphological responses such as total non-structural carbohydrates and turf density were measured. Previous researchers have shown that increased tissue cytokinins are related to increased tiller density, delay of senescence and enhanced photochemical efficiency. For these reasons, the application of cytokinin enhancing PGRs may have potential to increase bermudagrass traffic tolerance. Patriot's aggressive growth and excellent cold hardiness are predicted to result in better overall traffic tolerance and repair as compared to Tifsport. / Master of Science

Made available in DSpace on 2016-04-28T14:59:49Z (GMT). No. of bitstreams: 1 Rosani Valeria M Matoso Silva.pdf: 2493800 bytes, checksum: c274b76a31f58fe821a3f98f2cabee11 (MD5) Previous issue date: 2009-12-16 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The purpose of this work was to evaluate the nutritional value of Tifton 85 (Cynodon spp) in response to nitrogen fertilization, in terms of bromatological composition and the nitrogen and carbohydrate fractions as defined by the Cornell University model. It also assessed the performace of a chlorophyll meter, as an indirect estimate of green dry matter production, and chemical bromatological traits fo the grass. This study was carried out during the period of november 2008 to january 2009, on Haplic Planosol at the campus of the Rural Federal University of Rio de Janeiro. Experimental design was a randomized block desing with four repetitions. Main treatments consisted of N rates allocated in the plots and cutting number were allocated in the sbplots. There are three levels of N soil : low N; represented by soil N, medium N: 75 N / ha / cut, and high N: 150 kg N / ha / cut. Herbage harvested twice, the first on November 30 and the second 29 days later. Cutting dates were determined according to data from canopy light interception. In the first study results showed that N rates increased green dry matter and the crude protein CP per cent in the forage and decreased asid detergent fibrous fraction contents. It was also verified the feasibility of using a chlorophyll meter as a probe for CP content and forage availability. In a second study it was verified that N fertilization showed no consistent results in regard to crude protein fractions with the sole exception of C fraction (%CP), that increased with increasing N availability. / Objetivou-se com este experimento avaliar o valor nutritivo do capim Tifton-85 (Cynodon spp) em resposta ? aplica??o de diferentes n?veis de nitrog?nio (N), com base na composi??o qu?mico bromatol?gica e nas fra??es nitrogenadas e de carboidratos, utilizando-se o sistema desenvolvido na Universidade de Cornell (The Cornell Net Carbohydrate and Protein System - CNCPS). Avaliou-se tamb?m o desempenho de um clorofilometro, como estimador indireto das disponibilidades de forragem, e das caracter?sticas qu?mico bromatol?gicas do capim. O experimento foi realizado durante o per?odo novembro de 2008 a janeiro de 2009, no campus da Universidade Federal Rural do Rio de Janeiro, utilizando-se um Planossolo H?plico. Os tratamentos constitu?ram-se de doses de N, na forma de ur?ia e de n?mero de cortes. Foram definidos tr?s n?veis de N: baixo, representado pelo N do solo; m?dio: 75 de N/ha/corte; e alto: 150 kg de N/ha/corte. Foram realizados dois cortes, o primeiro em 30/11/2008 e o segundo 29 dias ap?s. As datas dos cortes foram determinadas de acordo com dados de intercepta??o luminosa dos doss?is. O delineamento experimental foi em blocos casualizados, com quatro repeti??es, em esquema de parcelas subdivididas, com as doses de N alocadas nas parcelas e a seq??ncia de cortes na subparcela. No primeiro estudo, verificou-se que a aduba??o nitrogenada aumentou a produ??o de massa verde seca e os teores de PB da forragem e reduziu os teores das fra??es fibrosas em detergente ?cido, mostrando ainda a factibilidade do uso do clorofil?metro como um estimador indireto da produ??o de forragem e dos teores de PB na mesma. No segundo estudo, verificou-se que a aduba??o nitrogenada n?o apresentou resultados consistentes quando relacionada ?s fra??es prot?icas e nitrogenadas, com a exce??o da fra??o C (%PB) que respondeu positivamente.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Two experiments were carried out aiming to evaluate pasture attributes and productive and reproductive performance of beef heifers from nine to 13 months of age (Experiment 1) and subsequently from 15 to 18 months of age (Experiment 2). Pasture and livestock assessment in Experiment 1 totaled 112 days, from July to November 2008. The beef heifers were kept grazing on Italian ryegrass (Lolium multiflorum Lam), with heifers either exclusively on pasture or receiving fat as a supplement (0.15 or 0.30% of body weight (BW)). Experiment 2 was carried out from January to April 2009 and pasture attributes, productive and reproductive performance and beef heifers ingestive behavior in Coastcross (Cynodon dactylon (L.) with forage on offer (FO) of 10% and Alexandergrass (Urochloa plantaginea) with FO of 8 and 12% were studied. On both experiments continuous grazing method was used with variable number of animals. The experimental design was completely randomized with repeated measures over time. The following variables were measured in Experiment 1: animal performance, pasture and supplement efficiency of conversion to kg of body weight, height , body weight:height ratio, pelvic area and reproductive tract score of heifers. Pasture variables were similar between supplement levels and the average values of forage mass and forage on offer were 1497.6 kg ha-1 DM and 11.45 kg DM 100 kg-1 BW, respectively. The productive and reproductive variables were not affected by fat levels tested. Heifers supplemented with fat had higher average daily gain, body weight, height, condition score and body weight: height ratio than heifers exclusively on pasture. The use of supplemental fat promoted no change in pelvic area and reproductive tract score of heifers, which presents inadequate development to allow breeding at 12/14 months old. In Experiment 2, the ingestive behavior was measured in four continuous 12 hour periods. Pasture variables, animal performance and ingestive behavior in Alexandergrass were similar in both forage on offer. There was both stocking rate and gain per hectare increase of 22 and 75%, respectively when heifers grazed on Alexandergrass in relation to Coastcross. The heifers present similar individual and reproductive performance when grazing on either Coastcross or Alexandergrass on both forage on offer and are considered capable of breeding at 18 months of age. / Foram conduzidos dois experimentos com o objetivo de avaliar os atributos das pastagens e o desempenho produtivo e reprodutivo de novilhas de corte dos nove aos 13 meses de idade (Experimento 1) e posteriormente dos 15 aos 18 meses de idade (Experimento 2). No Experimento 1 o período destinado a avaliação da pastagem e dos animais totalizou 112 dias, de18 julho a quatro de novembro de 2008. As bezerras foram mantidas em pastagem de azevém anual (Lolium multiflorum Lam.), com animais exclusivamente em pastagem ou recebendo suplemento lipídico (0,15% ou 0,30% do peso corporal (PC)). O Experimento 2 transcorreu de 29 de janeiro a 23 de abril de 2009 e foram estudados os atributos das pastagens, desempenho produtivo e reprodutivo e o comportamento ingestivo de novilhas de corte em Coastcross (Cynodon dactylon (L.)) com oferta de forragem (OF) de 10% e Papuã (Urochloa plantaginea) com OF de 8% e 12%. Nos dois experimentos foi utilizado o método de pastejo continuo com número variável de animais. O delineamento experimental foi o inteiramente casualizado com medidas repetidas no tempo. No experimento 1 foram avaliadas as seguintes variáveis resposta: desempenho animal, eficiência de transformação do pasto e do suplemento em kg de peso corporal, altura, relação peso corporal:altura, área pélvica e escore de trato reprodutivo das bezerras. As variáveis do pasto foram semelhantes entre os níveis de suplemento utilizados e os valores médios de massa de forragem e oferta de forragem foram de 1497,6 kgha-1 de MS e 11,45 kg de MS/100 kg de PC. As variáveis do desempenho produtivo e reprodutivo não foram afetadas pelos níveis de gordura utilizados. As bezerras suplementadas com gordura apresentaram maior ganho médio diário, peso corporal, escore de condição corporal, altura e relação peso corporal:altura do que bezerras exclusivamente em pastejo. O uso de suplementação com gordura não expressou alteração na área pélvica e escore de trato reprodutivo das bezerras, as quais não mostraram desenvolvimento adequado para serem acasaladas aos 12/14 meses de idade. No experimento 2, o comportamento ingestivo foi medido em quatro períodos contínuos de 12 horas. As variáveis do pasto, desempenho animal e comportamento ingestivo foram semelhantes em Papuã nas duas ofertas de forragem. Houve acréscimo na taxa de lotação e no ganho por área quando as novilhas pastejaram Papuã em relação à Coastcross de 22% e 75%, respectivamente. As novilhas apresentaram desempenho individual e reprodutivo semelhante quando pastejaram Coastcross ou Papuã em ambas as ofertas, sendo consideradas aptas a reprodução aos 18 meses de idade.

Perennial summer pastures are an excellent forage option for livestock feed, a fact that has boosted milk production in Rio Grande do Sul. However, the lack of animal load control coupled with high grazing intensities have contributed to the degradation of pastures and loss of soil quality. The study was conducted on a farm in northern Rio Grande do Sul, and the forage used was Jiggs (Cynodon dactylon) and management method adopted was the rotational grazing, covering a 268 days production cycle. The treatments consisted of different grazing intensities in a randomized block design with four replications which the following treatments were: T1 = intensity of 0%, T2 = 30%, T3 and T4 = 50% = 70%. The experimental area was disposed within a total area of 1,760 m2, which were distributed pickets 16 (4 treatments x 4 replicates) with dimensions equal to 100 m2 each (10 x 10 m). The production of forage Jiggs had no statistical difference among treatments and the production decreases with the end of the production cycle, however, the highest concentration of leaves was found at the end of the grazing cycle influenced by plant height. There is a reduction with respect to the length and root density with increasing soil depth and the treatment one where grazing intensity was zero, had the lowest average density with respect to other treatments. The air permeability of the soil (Kar) equilibrated to tensions of 6 and 100 kPa did not reach statistical difference between treatments and the depth in the periods pre and post grazing 1. The soil layer of 0-5 and 5-10 cm was that the only influenced by the treatments in Ksat, Kar and 6 and 100 kPa, leading to a reduction in the flow of air and water in the grazing periods post 3 is 5. The grazing intensity significantly alter the soil density and macroporosity and total porosity in the 0-5 and 5-10 cm. The T1 had increasing density mean values with increasing depth, however, the treatment had decreasing average values obtained in the course of depths, where the 0-5 cm layer obtained density 1.49 g cm-3. During the grazing cycle was observed generally that the microporosity remained virtually constant. The forage production showed no statistical difference in relation to grazing intensity, the roots are concentrated in the 0-5 cm layer and cattle trampling influenced root density. In general, the grazing periods influenced Kar, Ksat and bulk density in the surface layers of the soil and the micro, macro and total porosity were mainly influenced by grazing period post 3 and post 5. / As pastagens perenes de verão surgem como uma excelente opção de forrageira para alimentação do gado, fato esse que tem impulsionado a produção de leite no Rio Grande do Sul. Todavia, a falta de controle da carga animal aliada a intensidades de pastejo elevada tem contribuído com a degradação das pastagens e perda da qualidade do solo. O estudo foi desenvolvido numa propriedade rural no norte gaúcho, sendo que a forrageira utilizada foi o Jiggs (Cynodon dactylon) e o método de manejo adotado foi o pastejo rotacionado, contemplando um ciclo de produção de 268 dias. Os tratamentos foram compostos de distintas intensidades de pastejo em blocos ao acaso e contaram com quatro repetições as quais constituíram os seguintes tratamentos: T1= intensidade de 0%, T2= 30%, T3= 50% e T4= 70%. A área experimental estava disposta dentro de uma área total de 1.760 m2, onde foram distribuídos 16 piquetes (4 tratamentos x 4 repetições) com dimensões iguais a 100 m2 cada (10 x 10 m). A produção da forrageira Jiggs não apresentou diferença estatística com relação aos tratamentos, sendo que a produção decresce com o fim do ciclo produtivo, em contrapartida, a maior concentração de folhas foi encontrada no fim do ciclo de pastejo influenciada pela altura das plantas. Ocorreu redução com relação ao comprimento e densidade de raiz com aumento da profundidade sendo que a intensidade de pastejo igual a zero, apresentou a menor densidade média com relação as demais intensidades. A permeabilidade do solo ao ar (Kar) equilibrado à tensões de 6 e 100 kPa não obteve diferença estatística entre as intensidades de pastejo e a profundidade nos períodos de Pré Pastejo e no Pós Pastejo 1. A camada de solo de 0-5 e 5-10 cm foi a única que sofreu influencia dos tratamentos na Ksat e Kar à tesões de 6 e 100 kPa, ocorrendo redução do fluxo de ar e água nos períodos de pastejo Pós 3 e 5. A intensidade de pastejo altera significativamente a densidade de solo bem como a macroporosidade e porosidade total nas camadas de 0-5 e de 5-10 cm. a intensidade de 0% obteve valores médios crescentes de densidade conforme o aumento da profundidade, no entanto, o tratamento 4 obteve valores médios decrescentes no decorrer das profundidades, onde a camada de 0-5 cm apresentou densidade de 1,49 g cm-3. No decorrer do ciclo de pastejo, observou-se de modo geral que a microporosidade manteve-se praticamente constante. Em síntese, a produção de forragem não apresentou diferença estatística com relação às intensidades de pastejo, as raízes se concentram na camada de 0-5 cm e o pisoteio animal influencia na densidade de raiz. De modo geral, os períodos de pastejo influenciaram a Kar, Ksat e densidade do solo nas camadas superficiais do solo e a micro, macro e porosidade total foram influenciadas principalmente pelos períodos de pastejo Pós 3 e 5.

The objective of this research was to evaluate three grazing systems with Coastcross-1 (CC) + 100 kg N/ha/year + common vetch; CC + 100 kg N/ha/year + arrowleaf clover; and CC + 200 kg N/ha/year. The experiment was carried out from May 2013 to April 2014. Lactating Holstein cows were used in the evaluation. The grazing method was the rotative stocking, with one day of occupation. Thirteen grazing cycles were performed during the experimental period (313 days). The forage mass, botanical composition, leaf/stem ratio; daily accumulation rate, production and forage intake; grazing efficiency and stocking rate were evaluated. Experimental design was completely randomized with three treatments (grazing systems), three replicates (paddocks) in completely split-plot time (seasons). The average of forage production and stocking rate were 20.8, 17.6 and 19.7 t/ha/year; 7.0, 6.8 e 6.8 animal units/ha/day, respectively. Better results were found on CC + 100 kg of N/ha + common vech and CC + 200 kg of N/ha pasture systems. The presence of the legumes did not affect the structural composition of Coastcross-1, but implies delay in the development of this grass. / Objetivou-se com esta pesquisa avaliar três sistemas forrageiros constituídos por: Coastcross-1(CC) + ervilhaca comum + 100 kg de N/ha/ano; CC + trevo vesiculoso + 100 kg de N/ha/ano e CC + 200 kg de N/ha/ano. O experimento foi conduzido entre maio de 2013 e abril de 2014. Para avaliação foram utilizadas vacas em lactação da raça Holandesa. O método de pastejo utilizado foi o de lotação rotacionada, com um dia de ocupação. Durante o período experimental (313 dias) foram realizados treze pastejos. Foram avaliados a massa de forragem, composição botânica, relação folha/colmo; taxa de acúmulo diário, produção e consumo de foragem; eficiência de pastejo e taxa de lotação. O delineamento experimental utilizado foi o inteiramente casualizado com três tratamentos (sistemas forrageiros), três repetições (piquetes) e parcelas subdivididas no tempo (estações do ano). Os valores médios de produção de forragem e taxa de lotação foram de 20,8; 17,6 e 19,7 t/ha/ano; 7,0; 6,8 e 6,8 unidades animais/ha/dia, respectivamente. Melhores resultados foram encontrados nos sistemas forrageiros constituídos por CC + 100 kg de N/ha + ervilhaca comum e CC + 200 kg de N/ha. A presença das leguminosas não afetou a composição estrutural da Coastcross-1, mas implica em atraso no desenvolvimento dessa gramínea.

As average global temperatures rise, cool-season C3 turfgrasses, such as the most commonly grown Kentucky bluegrass (Poa pratensis L.; KBG), struggle to tolerate extreme summer heat and increase their water consumption. Hybrid Bermudagrass (Cynodon dactylon [L.] Pers. × Cynodon transvaalensis Burtt Davy; HBG) is a warm-season C4 grass that may be increasingly suited for northern ecosystems traditionally classified as transition or cool-season climate zones. Glasshouse and field studies were conducted to compare HBG and KBG water use. The objective of the glasshouse study was to evaluate plant health and growth for two HBG cultivars (‘DT-1’ and ‘NorthBridge’) compared to a blend of KBG cultivars in all combinations of deficit, moderate, and high irrigation at optimum or short mowing height. The study was conducted in a glasshouse at Provo, UT, USA from 2020-2021. Grass was grown in pots arranged in a randomized complete block, full factorial design, with four replications of each treatment. The moderate KBG was also significantly different from both high and deficit for verdure and for the last half of NDVI. The objective of the field study was to evaluate two HBG cultivars (‘Tahoma 31’ and ‘Latitude 36’) compared to a blend of KBG cultivars for water loss and canopy health, temperature, and growth when subjected to deficit, moderate, and high irrigation. The study was arranged in a randomized complete block, full factorial design with three replications per treatment, and was conducted at Provo, UT, USA throughout the summer of 2021. In both the glasshouse and field trials, the deficit irrigated KBG consistently scored lower for NDVI and visual turf quality than all other treatments, including moderate and high KBG. This same trend was seen in the field study for percent cover. Although not observed in the glasshouse trial, it was observed in the field trial that the different irrigation levels of HBG resulted in no significant differences for any measurements but the HBG regularly scored better than KBG. The canopy temperatures of deficit irrigated KBG were also higher than all other treatments on most dates. The shoot mass, thatch mass, and total biomass of KBG were significantly less than either HBG cultivar. In the glasshouse trial it was observed that all deficit grasses were significantly lower than the other irrigation treatments and HBG had significantly deeper roots than KBG, although these results were not seen in the field trial. The data suggest that irrigation needs will be less for HBG than KBG and that HBG could provide a water-saving turfgrass alternative to KBG in semi-arid, cool-season regions with increasing water scarcity.

Made available in DSpace on 2016-04-28T14:59:47Z (GMT). No. of bitstreams: 1 2009 - Elio Barbieri Junior.pdf: 7095685 bytes, checksum: 1bcdc77a8d686ebd516a400693c004ae (MD5) Previous issue date: 2009-02-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Among the biochemical properties related to the use of nitrogen (N) for the plants, chlorophyll pigments occupy a relevant position. For that reason, and given the importance of the N fertilization for pasture productivity, it has been developed methodologies that allow determining leaf chlorophyll contents for indirect and non destructive procedures. With the purpose of supplying subsidies for N fertilization management in in pastures of Cynodon spp. cv. Tifton 85 was installed an experiment with purpose of verifying the performance of a commercial chlorophyll meter. The experimental strategy consisted of the induction of three levels of soil N availability, through N fertilization. The working hypotheses were the following ones: i) different soil N availabilities result in differentiated leaf chlorophyll contents in leaves recently emerged and fully expanded; ii) readings obtained with a chlorophyll meter are related with foliar Total chlorophyll contents; iii) chlorophyll contents are related with foliar N concentrations; e iv) chlorophyll content indicators keep relationship with green dry matter production. This study was carried out on a Haplic Planosol at the Experimental Campus of the Rural Federal University of Rio de Janeiro, Serop?dica, RJ, during the period of July to December 2008. An entirely randomized block design was used, with four repetitions. Main treatments were allocated in plots (4x4 m) and consisted of three N fertilization levels (0; 75 and 150kg N-ur?ia). Four sampling dates designed as days from a standardization cut made 131days after planting were allocated in sub-plots. Three of the sampling dates (8, 16 and 24 days) were pre-fixed, while the last was accomplished when the sward interception level of photosynthetically active radiation reached a value of 95%. Structural dynamics was followed by monitoring the following canopy variables: sward height; tiller density, leaf area index, green cover index and green dry mass accumulation. Chlorophylls a, b and (a+b) were measured always in the first fully expanded leaves of sun tillers by the Arnon method with modifications, and indirectly, with the chlorophyll meter ClorofiLOG?. In the same type of leaves, total N content was determined by Kjeldhal routine procedures. Principal results showed that concentrations of chlorophylls a, b and (a + b) in Tifton leaf blades were affected by nitrogen fertilization and sampling dates reaching maximal differences at the 24th day after cut. Chlorophyll meter readings (Falker Chlorophyll Index, FCI) and foliar N contents also responsed very sensibly to N rates, reaching maximal values at the16th day after cut. In the same day, Total chlorophyll contents and Total N leaf contents were also significantly correlated with FCI values, with r2 coefficients of 0,93 and 0,89 respectively. Correlation coefficient between total green dry matter and FCI values was 0,867. Total green dry matter accumulation at the last sampling date and FCI readings at 16th day after cut also resulted significantly related (r2 = 0,72), a promising relation for purposes of forage yield estimation. In conclusion, the obtained results allow affirming that, in Tifton 85, total chlorophyll content present in the first leaf totally expanded is a sensitive marker of soil N availability and therefore of N fertilization needs. Total chlorophyll content through its relationship with leaf N contents may be also a valuable tool for foliar N diagnosis. Both attributes were discriminated properly by the chlorophyll meter under evaluation. This apparatus maximized its performance in the period were happened Among the biochemical properties related to the use of nitrogen (N) for the plants, chlorophyll pigments occupy a relevant position. For that reason, and given the importance of the N fertilization for pasture productivity, it has been developed methodologies that allow determining leaf chlorophyll contents for indirect and non destructive procedures. With the purpose of supplying subsidies for N fertilization management in in pastures of Cynodon spp. cv. Tifton 85 was installed an experiment with purpose of verifying the performance of a commercial chlorophyll meter. The experimental strategy consisted of the induction of three levels of soil N availability, through N fertilization. The working hypotheses were the following ones: i) different soil N availabilities result in differentiated leaf chlorophyll contents in leaves recently emerged and fully expanded; ii) readings obtained with a chlorophyll meter are related with foliar Total chlorophyll contents; iii) chlorophyll contents are related with foliar N concentrations; e iv) chlorophyll content indicators keep relationship with green dry matter production. This study was carried out on a Haplic Planosol at the Experimental Campus of the Rural Federal University of Rio de Janeiro, Serop?dica, RJ, during the period of July to December 2008. An entirely randomized block design was used, with four repetitions. Main treatments were allocated in plots (4x4 m) and consisted of three N fertilization levels (0; 75 and 150kg N-ur?ia). Four sampling dates designed as days from a standardization cut made 131days after planting were allocated in sub-plots. Three of the sampling dates (8, 16 and 24 days) were pre-fixed, while the last was accomplished when the sward interception level of photosynthetically active radiation reached a value of 95%. Structural dynamics was followed by monitoring the following canopy variables: sward height; tiller density, leaf area index, green cover index and green dry mass accumulation. Chlorophylls a, b and (a+b) were measured always in the first fully expanded leaves of sun tillers by the Arnon method with modifications, and indirectly, with the chlorophyll meter ClorofiLOG?. In the same type of leaves, total N content was determined by Kjeldhal routine procedures. Principal results showed that concentrations of chlorophylls a, b and (a + b) in Tifton leaf blades were affected by nitrogen fertilization and sampling dates reaching maximal differences at the 24th day after cut. Chlorophyll meter readings (Falker Chlorophyll Index, FCI) and foliar N contents also responsed very sensibly to N rates, reaching maximal values at the16th day after cut. In the same day, Total chlorophyll contents and Total N leaf contents were also significantly correlated with FCI values, with r2 coefficients of 0,93 and 0,89 respectively. Correlation coefficient between total green dry matter and FCI values was 0,867. Total green dry matter accumulation at the last sampling date and FCI readings at 16th day after cut also resulted significantly related (r2 = 0,72), a promising relation for purposes of forage yield estimation. In conclusion, the obtained results allow affirming that, in Tifton 85, total chlorophyll content present in the first leaf totally expanded is a sensitive marker of soil N availability and therefore of N fertilization needs. Total chlorophyll content through its relationship with leaf N contents may be also a valuable tool for foliar N diagnosis. Both attributes were discriminated properly by the chlorophyll meter under evaluation. This apparatus maximized its performance in the period were happenedAmong the biochemical properties related to the use of nitrogen (N) for the plants, chlorophyll pigments occupy a relevant position. For that reason, and given the importance of the N fertilization for pasture productivity, it has been developed methodologies that allow determining leaf chlorophyll contents for indirect and non destructive procedures. With the purpose of supplying subsidies for N fertilization management in in pastures of Cynodon spp. cv. Tifton 85 was installed an experiment with purpose of verifying the performance of a commercial chlorophyll meter. The experimental strategy consisted of the induction of three levels of soil N availability, through N fertilization. The working hypotheses were the following ones: i) different soil N availabilities result in differentiated leaf chlorophyll contents in leaves recently emerged and fully expanded; ii) readings obtained with a chlorophyll meter are related with foliar Total chlorophyll contents; iii) chlorophyll contents are related with foliar N concentrations; e iv) chlorophyll content indicators keep relationship with green dry matter production. This study was carried out on a Haplic Planosol at the Experimental Campus of the Rural Federal University of Rio de Janeiro, Serop?dica, RJ, during the period of July to December 2008. An entirely randomized block design was used, with four repetitions. Main treatments were allocated in plots (4x4 m) and consisted of three N fertilization levels (0; 75 and 150kg N-ur?ia). Four sampling dates designed as days from a standardization cut made 131days after planting were allocated in sub-plots. Three of the sampling dates (8, 16 and 24 days) were pre-fixed, while the last was accomplished when the sward interception level of photosynthetically active radiation reached a value of 95%. Structural dynamics was followed by monitoring the following canopy variables: sward height; tiller density, leaf area index, green cover index and green dry mass accumulation. Chlorophylls a, b and (a+b) were measured always in the first fully expanded leaves of sun tillers by the Arnon method with modifications, and indirectly, with the chlorophyll meter ClorofiLOG?. In the same type of leaves, total N content was determined by Kjeldhal routine procedures. Principal results showed that concentrations of chlorophylls a, b and (a + b) in Tifton leaf blades were affected by nitrogen fertilization and sampling dates reaching maximal differences at the 24th day after cut. Chlorophyll meter readings (Falker Chlorophyll Index, FCI) and foliar N contents also responsed very sensibly to N rates, reaching maximal values at the16th day after cut. In the same day, Total chlorophyll contents and Total N leaf contents were also significantly correlated with FCI values, with r2 coefficients of 0,93 and 0,89 respectively. Correlation coefficient between total green dry matter and FCI values was 0,867. Total green dry matter accumulation at the last sampling date and FCI readings at 16th day after cut also resulted significantly related (r2 = 0,72), a promising relation for purposes of forage yield estimation. In conclusion, the obtained results allow affirming that, in Tifton 85, total chlorophyll content present in the first leaf totally expanded is a sensitive marker of soil N availability and therefore of N fertilization needs. Total chlorophyll content through its relationship with leaf N contents may be also a valuable tool for foliar N diagnosis. Both attributes were discriminated properly by the chlorophyll meter under evaluation. This apparatus maximized its performance in the period were happened Among the biochemical properties related to the use of nitrogen (N) for the plants, chlorophyll pigments occupy a relevant position. For that reason, and given the importance of the N fertilization for pasture productivity, it has been developed methodologies that allow determining leaf chlorophyll contents for indirect and non destructive procedures. With the purpose of supplying subsidies for N fertilization management in in pastures of Cynodon spp. cv. Tifton 85 was installed an experiment with purpose of verifying the performance of a commercial chlorophyll meter. The experimental strategy consisted of the induction of three levels of soil N availability, through N fertilization. The working hypotheses were the following ones: i) different soil N availabilities result in differentiated leaf chlorophyll contents in leaves recently emerged and fully expanded; ii) readings obtained with a chlorophyll meter are related with foliar Total chlorophyll contents; iii) chlorophyll contents are related with foliar N concentrations; e iv) chlorophyll content indicators keep relationship with green dry matter production. This study was carried out on a Haplic Planosol at the Experimental Campus of the Rural Federal University of Rio de Janeiro, Serop?dica, RJ, during the period of July to December 2008. An entirely randomized block design was used, with four repetitions. Main treatments were allocated in plots (4x4 m) and consisted of three N fertilization levels (0; 75 and 150kg N-ur?ia). Four sampling dates designed as days from a standardization cut made 131days after planting were allocated in sub-plots. Three of the sampling dates (8, 16 and 24 days) were pre-fixed, while the last was accomplished when the sward interception level of photosynthetically active radiation reached a value of 95%. Structural dynamics was followed by monitoring the following canopy variables: sward height; tiller density, leaf area index, green cover index and green dry mass accumulation. Chlorophylls a, b and (a+b) were measured always in the first fully expanded leaves of sun tillers by the Arnon method with modifications, and indirectly, with the chlorophyll meter ClorofiLOG?. In the same type of leaves, total N content was determined by Kjeldhal routine procedures. Principal results showed that concentrations of chlorophylls a, b and (a + b) in Tifton leaf blades were affected by nitrogen fertilization and sampling dates reaching maximal differences at the 24th day after cut. Chlorophyll meter readings (Falker Chlorophyll Index, FCI) and foliar N contents also responsed very sensibly to N rates, reaching maximal values at the16th day after cut. In the same day, Total chlorophyll contents and Total N leaf contents were also significantly correlated with FCI values, with r2 coefficients of 0,93 and 0,89 respectively. Correlation coefficient between total green dry matter and FCI values was 0,867. Total green dry matter accumulation at the last sampling date and FCI readings at 16th day after cut also resulted significantly related (r2 = 0,72), a promising relation for purposes of forage yield estimation. In conclusion, the obtained results allow affirming that, in Tifton 85, total chlorophyll content present in the first leaf totally expanded is a sensitive marker of soil N availability and therefore of N fertilization needs. Total chlorophyll content through its relationship with leaf N contents may be also a valuable tool for foliar N diagnosis. Both attributes were discriminated properly by the chlorophyll meter under evaluation. This apparatus maximized its performance in the period were happened the highest leaf N content and linking directly with final green dry matter accumulation. / Dentre as propriedades bioqu?micas relacionadas ? utiliza??o do nitrog?nio (N) pelas plantas, os teores de clorofila ocupam posi??o de destaque. Por essa raz?o, e dada a import?ncia que a aduba??o nitrogenada tem na express?o da produtividade das pastagens, tem sido desenvolvidas metodologias que permitem a determina??o do teor de clorofila por procedimentos indiretos e n?o destrutivos. No intuito de fornecer subs?dios para a defini??o de estrat?gias de aduba??o nitrogenada em pastagens de Cynodon spp. cv. Tifton 85 foi instalado um experimento com o prop?sito primordial de verificar o desempenho de um clorofil?metro comercial. Foi utilizada uma estrat?gia experimental consistente na indu??o de tr?s n?veis de disponibilidade de N no solo, atrav?s de aduba??o nitrogenada. As hip?teses que guiaram o experimento foram as seguintes: i) n?veis diferenciados de N no solo, resultam em teores diferenciados de clorofila em folhas rec?m emergidas; ii) leituras obtidas com um clorofil?metro guardam rela??o com os teores foliares das clorofilas; iii) teores de clorofila total relacionam-se com os teores foliares de N; e iv) os indicadores ligados ? clorofila foliar guardam rela??o com a produ??o de mat?ria seca. O experimento foi desenvolvido sobre um Planossolo H?plico, no campo experimental da Universidade Federal Rural do Rio de Janeiro, munic?pio de Serop?dica, RJ, durante o per?odo de julho a dezembro de 2008. O experimento foi disposto segundo um desenho em blocos inteiramente casualizados, com quatro repeti??es. Os tratamentos, alocados nas parcelas (4x4m), consistiram de tr?s n?veis de N (0; 75 e 150kg N-ur?ia/ha), enquanto que nas sub-parcelas, foram alocadas quatro dias de coletas, contados a partir um corte de uniformiza??o, realizado 131 dias ap?s o plantio do capim. Tr?s das datas de amostragem foram pre-fixadas, aos 8, 16 e 24 dias, enquanto a ?ltima foi realizada quando a pastagem atingiu um n?vel de intercepta??o de 95% da radia??o fotossint?ticamente ativa incidente. A din?mica estrutural foi acompanhada atrav?s da mensura??o das seguintes vari?veis do dossel: altura; densidade populacional de perfilhos; ?ndice de ?rea foliar, ?ndice de cobertura verde, e ac?mulo de massa verde seca. As clorofilas a, b, e (a+b), foram quantificadas, sempre em primeiras folhas completamente expandidas de perfilhos de sol, pelo m?todo de Arnon modificado, e indiretamente, com um aparelho ClorofiLOG?. Os teores de N total foram determinados nas mesmas folhas, pelo m?todo de Kjeldhal. Os resultados mostraram que os teores de clorofila a, b e (a+b) diferiram entre doses de N, e dias de amostragem, atingindo diferen?as m?ximas entre as doses de N aos 24 dias ap?s corte. As leituras do clorofil?metro (?ndice de Clorofila Falker, ICF) e os teores de N foliar tamb?m responderam sensivelmente ?s doses de N, atinguindo valores m?ximos aos 16 dias. Nesse mesmo dia, a an?lise de regress?o linear entre os teores de clorofila total e de N total, contra os respectivos valores de ICF resultou em coeficientes de determina??o de 0,93 e 0,89 respectivamente. O coeficiente de correla??o entre a massa verde seca total e os valores de ICF foi de 0,867. O ac?mulo de mat?ria verde seca total aos 28 dias ap?s o corte relacionouse linearmente com as leituras do clorofil?metro feitas aos 16 dias (r2=0,72), um tipo de resultado promissor em termos de estimativas de disponibilidade de forragem. Como conclus?o, os resultados permitiram verificar que os teores de clorofila total presentes na primeira folha totalmente expandida, responderam ? aplica??o de doses diferenciadas de N e se relacionaram estreitamente com os teores de N foliar. Ambos os atributos foram discriminados de forma precisa pelo clorofil?metro sob avalia??o. Este aparelho maximizou o seu desempenho no per?odo onde ocorreram os m?ximos teores de N foliar, relacionando-se diretamente com a mat?ria seca acumulada no final do per?odo de rebrota.

Resumo: O nitrogênio é o nutriente que proporciona melhores respostas no crescimento das gramas, bem como a formação do tapete em menor tempo, com boa qualidade. A espessura do corte do tapete de grama também pode afetar a produtividade. Tapetes muito finos podem romper no manuseio, sendo descartados, ou apresentam menor pegamento e tapetes muito espessos prejudicam a rebrota na área de produção. Dessa forma realizaram-se os experimentos com os objetivos de determinar a dose de N que permita a produção de tapetes de grama bermuda com qualidade e em menor tempo, bem como avaliar os benefícios da aplicação de ajifer, "coproduto" do processo de fabricação do Glutamato Monossódico como fonte de N na grama esmeralda, avaliando a espessura de corte na qualidade do tapete formado. Os dois experimentos foram instalados e conduzidos em propriedade comercial de produção de grama, localizada na cidade de Capela do Alto, SP. As espécies utilizadas foram: a grama Zoysia japonica Steud. - esmeralda e a grama Cynodon dactylon (Pers) L. variedade Celebration - bermuda. O delineamento experimental utilizado para a grama esmeralda foi em parcelas subdivididas com 4 repetições, em esquema fatorial 7x3 em blocos casualizados. As parcelas principais foram compostas por cinco doses de Ajifer que corresponderam a 0, 100, 200, 300 e 400 kg de N ha-1, com complementação de P e K, mais duas testemunhas relativas, sendo uma composta por 300 kg ha-1 de N-ajifer e outra por 300 kg ha-1 de N-uréia + P e K, e as subparcelas por três espessuras de corte de tapete (0,9; 1,6 e 2,2 cm). O delineamento experimental utilizado para a grama bermuda foi em blocos ao acaso, com cinco doses de N: 0, 150, 300, 450 e 600 kg de N ha-1, e quatro repetições. Doses acima de 300 kg ha-1 de N-ajifer não proporcionaram maiores respostas na formação de tapetes de grama esmeralda avaliados pela taxa de cobertura do solo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Nitrogen is the nutrient that gives greater responses in turfgrass growth, as well as turfgrass sod formation in less time, with good quality. The thickness of the turfgrass sod cut may also affect the yield. Very thin sods can break with handling, being disposed, or presents less regrowth and very thick sods affect the regrowth in the production area. Thus the objectives of the experiments were to determine N rate that allows the production of Bermuda grass sod with quality and in less time, as well as assess the benefits of implementing Ajifer, coproduct of the manufacturing process of monosodium glutamate, as a source of N in zoysiagrass, evaluating the cut thickness of the sod formed related to quality. The two experiments were conducted in a property of turfgrass commercial production, in the city of Capela do Alto / SP. The species used were: Zoysia japonica Steud. - zoysiagrass and Cynodon dactylon (Pers) L. - Bermuda grass. The experimental design for zoysiagrass was split plot in a 7X3 factorial scheme. The plots were composed of five Ajifer doses corresponding to 0, 100, 200, 300 and 400 kg N ha- 1, complemented with P and K, plus two more controls, one composed of 300 kg ha-1 of N-ajifer and another by 300 kg ha-1 of urea-N + P and K. The subplots consisted of three slice thicknesses of sod (0.9, 1.6 and 2.2 cm). The experimental design for the Bermuda grass was randomized blocks with five treatments: 0, 150, 300, 450 and 600 kg N ha-1, and four replications. Doses above 300 kg ha-1 of N-ajifer did not provided responses in the formation of zoysiagrass sod measured by the soil cover rate. The use of Ajifer as nitrogen source provided responses similar to urea for the zoysiagrass sod formation. The lack of phosphorus and potassium provided lower... (Complete abstract click electronic access below) / Orientador: Dirceu Maximino Fernandes / Coorientador: Roberto Lyra Villas Bôas / Banca: Leonardo Theodoro Büll / Banca: Hélio Grassi Filho / Banca: Leandro José Grava de Godoy / Banca: Marco Antonio Tecchio / Doutor

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-10-17T13:34:05Z No. of bitstreams: 1 texto completo.pdf: 4089586 bytes, checksum: d870cc4b1e255a4c1ee3e8dc54183ced (MD5) / Made available in DSpace on 2016-10-17T13:34:05Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4089586 bytes, checksum: d870cc4b1e255a4c1ee3e8dc54183ced (MD5) Previous issue date: 2005-03-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A água doce é fonte primária de recursos para a sociedade, tais como produção de alimentos e atividades industriais. As previsões com relação a escassez de água para o suprimento das necessidades básicas do homem, têm sido motivo de intensas pesquisas visando a maximização do seu aproveitamento. Assim sendo grande atenção é dada a plantas com capacidade de limpar a água, principalmente as aquáticas e o uso de filtros plantados com macrófitas aquáticas - sistema “wetland”, surge como uma alternativa eficiente e de baixo custo operacional quando comparado com os sistemas clássicos para o tratamento de água. Foi construído um sistema “wetland” de fluxo subsuperficial, para o tratamento de água residuária de suinocultura na “Área Experimental e Drenagem” do Departamento de Engenharia Agrícola da Universidade Federal de Viçosa, Estado de Minas Gerais (UFV), utilizando Alternanthera philoxeroides (Mart.) Griseb., Cynodon dactylon (Tifton 85) e Typha latifolia L. Os objetivos foram verificar as alterações morfo-anatômicas apresentadas no sistema radicular e parte aérea destas espécies quando cultivadas no sistema “wetland’; avaliar o comportamento das mesmas em ambientes eutrofizados, verificando a relação entre a quantidade de nutrientes acumulada nos tecidos e a morfo-anatomia, e fornecer subsídios para a escolha correta de espécies vegetais a serem utilizadas neste sistema. Foram analisados órgãos subterrâneos e aéreos destas espécies, coletadas em três tratamentos: Tratamento 1 onde o dejeto de suinocultura chega, tratamento 2, que corresponde ao final do tanque, local menos eutrofizado e tratamento controle, livre de dejeto. Foi confeccionado laminário permanente com inclusão em resina e parafina, coloração com azul de toluidina e azul de astra/fuccina básica para análise do material em microscopia de luz. Para a análise quantitativa dos dados foi usado o software Image Pró-Plus Version 4.5. O material foi fotografado em microscópio de luz acoplado à câmara digital. Após a coleta, amostras foram pesadas para obtenção dos dados de peso da matéria seca e posteriormente moídas para a análise de nutrientes. De modo geral, o sistema empregado pode ser considerado eficiente na despoluição de ambientes contaminados com dejeto suíno, pois foi constatado o acúmulo de diversos elementos químicos na parte aérea e no sistema subterrâneo das plantas em resposta a adição de dejeto no substrato. As três espécies toleraram bem tanto as condições de inundação como a exposição a altas cargas orgânicas; a morfologia foi mais alterada que a anatomia quanto as respostas apresentadas frente à exposição ao aumento de nutrientes foram comparadas. A. philoxeroides foi a espécie que promoveu a extração de um número maior de nutrientes e C. dactylon a que menos acumulou. Em geral o nitrogênio foi o elemento químico mais expressivo nos tecidos das plantas. / Fresh water is primary source of resources to society as the production of food and industrial activities. The forecasts in relation to water scarcity to the supply of basic human needs, has been the cause of intensive researches aiming the maximization of its utilization. So, much attention is given to plants with the capacity of cleaning the water, mainly the aquatic ones and the use of filters with aquatic macrophytes – wetland system, comes out as an efficient and cheaper alternative when compared with classic systems to water treatment. A wetland system of subsuperficial flux was built to the treatment of swine wastewater in “Experimental Area and Drainage “ of Department of Agricultural Engineering of Federal University of Viçosa (UFV), Minas Gerais State, using Alternanthera philoxeroides (Mart.) Griseb., Cynodon dactylon (Tifton 85) and Typha latifolia L. The objectives were to verify morpho-anatomical modifications presented in root system and aerial part of these species when cultivated in wetland system; evaluate their behavior in eutrophic environments, verifying the relation between the quantity of nutrients accumulated in tissues and morpho-anatomy; and provide subsidies to the correct choice of plant species that will be used in this system. Subterranean and aerial organs of these species were analyzed, collected in three treatments: Treatment 1 where the swine culture residues come, treatment 2, that corresponds to the final portion of the reservoir, less eutrophic place, and control treatment, free of those residues. Permanent slides were made with inclusion in resin and paraffin, stained with Toluidine Blue and Astra Blue, and Basic Fuchsine. Qualitative analysis was made and to the quantitative analysis of the data, the software Image Pro-Plus Version 4.5 was used. The material was photographed in light microscope joined to a digital camera. After the collection, samples were weighed to provide the data about dry matter weight and later they were ground to the nutrient analysis. In general terms, the system used can be considered efficient in the despollution of environments contaminated with pig residue, because it was verified the accumulation of several chemical elements in aerial part and subterranean system of those plants in response to the addition of residue in the substrate. The three species were well adapted to the system, and tolerated the conditions of flood and the exposition to high organic loads; and in respect to the responses showed by the exposition to the increase of nutrients, the morphology was much altered when compared with the anatomy. A. philoxeroides was the species with the extraction of a higher number of nutrients and C. dactylon was the one which accumulated the smallest number of nutrients. In general, nitrogen was the most expressive chemical element in tissues of those plants. / Dissertação importada do Alexandria

Made available in DSpace on 2014-06-11T19:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-23Bitstream added on 2014-06-13T19:44:36Z : No. of bitstreams: 1 silva_ar_dr_jabo.pdf: 434685 bytes, checksum: 7a18945b647512a2133168a7a96479ee (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi avaliar respostas do capim-tifton 85 a doses de nitrogênio (N) associadas a doses e fontes de boro (B). Em casa de vegetação, conduziu-se um experimento fatorial 3 ´ 3 ´ 3 {três doses de N (0, 100 e 200 mg kg–1), três doses de B (0, 1,3 e 2,6 mg kg–1) e três fontes de B [colemanita fundida ao termofosfato (CF), colemanita em mistura com termofosfato (CM) e ácido bórico (H3BO3)]} em delineamento inteiramente ao acaso. As plantas cresceram em vasos preenchidos com amostra de um Latossolo Vermelho distrófico. Elas foram avaliadas em três ciclos de crescimento. O N foi aplicado no início de cada ciclo e o B apenas antes do plantio. A aplicação de N aumentou a massa seca da parte aérea e o número de perfilhos do capim nos três ciclos. A aplicação de B, isolada ou associada à de N, não teve influência nesses atributos, embora o solo tivesse baixo teor de B disponível. O suprimento de N aumentou também os teores de carboidratos de reserva na raiz da planta nos dois ciclos em que foram avaliados (primeiro e terceiro). O suprimento de B aumentou o teor desses carboidratos na base do caule no primeiro ciclo. Os fornecimentos de N e B aumentaram seus respectivos teores na parte aérea do capim no três ciclos, exceto no caso do teor de B no terceiro ciclo. Todas as fontes de B aumentaram o teor de B disponível no solo, mas a CM e o H3BO3 aumentaram mais do que a CF. O efeito mais evidente da aplicação conjunta de N e B ocorreu no acúmulo de B na parte aérea da planta, aumentando mais com a combinação das duas aplicações. O teor inicial de B no solo (0,15 mg dm–3) foi suficiente para atender as necessidades do capim-tifton 85 nos três ciclos de crescimento. / The objective of this work was to evaluate responses of Tifton 85 bermudagrass to nitrogen (N) rates associated with boron (B) rates and sources. In greenhouse, it was carried out a factorial experiment 3 ´ 3 ´ 3 {three N rates (0, 100 and 200 mg kg–1), three B rates (0, 1.3 and 2.6 mg kg–1) and three B sources [colemanite fused to termophosphate (CF), colemanite in mixture with termophosphate (CM) and boric acid (H3BO3)]} in complete randomized design. The plants grew in pots filled with sample of a Typic Haplustox. They were evaluated during three growth cycles. The N was applied at the beginning of each cycle and the B just before the planting. The N application increased both top dry mass and tiller number of the grass in the three cycles. The B application, isolated or associated with N application, did not have influence on these attributes, though the soil had low available B content. The N supply increased reserve carbohydrates contents in plant root in the two cycles in which they were evaluated (first and third). The B supply increased the content of these carbohydrates in the stem base in the first cycle. The N and B furnishings increased their respective contents in top grass in the three cycles, except in the case of the B content in the third cycle. All the sources increased the available B content in soil, but CM and H3BO3 increased more than CF. The most evident effect of the N and B applications together occurred in the B accumulation in top plant, increasing more with the combination of the two applications. The initial B content in soil (0.15 mg dm–3) was enough to attend necessities of Tifton 85 bermudagrass in the three growth cycles.