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Produ??o org?nica de tomateiro tipo "cereja": compara??o entre cultivares, espa?amentos e sistemas de condu??o da cultura / Organic production of cherry tomatoes: cultivar comparison, plant densities and pruning regimes.Azevedo, Vlamir Fortes de 17 February 2006 (has links)
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Previous issue date: 2006-02-17 / Tomato plants are highly susceptible to a great number of pests and diseases . This is a constraint to organic
production, especially under field conditions. New technologies should be developed to improve organic tomato
yields and reduce disease incidence. Row spacing and pruning regimes are two aspects which may be targeted to
achieve these goals. Since cherry-type tomatoes are small, size variation resulting from pruning, will not
significantly affect market value. The objective of this dissertation was to evaluate the effect of the number of
stems per plant (through pruning) and plant densities on the yields and fruit quality of cherry-type tomatoes.
Also, the labor required to prune the plants was estimated. Two experiments were performed at the experimental
field of Departamento de Fitotecnia, Universidade Federal Rural do Rio de Janeiro, Serop?dica-RJ in the
Spring-Summer 2004 and Fall/Winter 2005. The first experiment evaluated the effect of three pruning regimes
(free growth, one stem per plant and two stems per plant) three plant densities (1.5 X 0,4m,1.5 X 0,6m and 1.5
X 0,8 m) and two cultivars (hybrid Super-Sweet and a local self pollinated - Perinha ). The second evaluated
the effects of three pruning regimes (free growth, two stem per plant and three stems per plant and two cultivars
(hybrid Super-Sweet and a self pollinated - A ). The spacing used was 1.0 X 0.6m. In the first experiment,
fruit yields were equivalent on the free growth and the two stems treatments. The free growth treatment had
lower labor cost, since no pruning was done. In the second experiment, the number of harvests was lower
compared to the previous experiment, since a severe occurrence of blight occured. Higher yields were achieved
on the three stem treatment, although a higher labor cost was associatesd to this treatment. / O tomateiro ? uma esp?cie altamente suscet?vel a um grande n?mero de pragas e doen?as, o que dificulta o seu
cultivo em sistemas org?nicos de produ??o, principalmente quando conduzida em ambiente n?o-protegido.
Assim, novas tecnologias que possam vir a viabilizar o seu cultivo em sistemas org?nicos devem ser testadas,
visando n?o s? o aumento da produ??o, como tamb?m a redu??o dos problemas fitossanit?rios. Entre os fatores
que podem ser trabalhados est?o o espa?amento e a elimina??o sistem?tica das hastes laterais, pr?tica esta
conhecida como desbrota , deixando-se uma ou mais hastes por planta. Como o grupo do tomate cereja
apresenta frutos pequenos, o tamanho do fruto n?o afeta significativamente a sua valoriza??o no mercado. O
objetivo do presente trabalho foi avaliar o efeito do n?mero de hastes por planta, combinado com diferentes
espa?amentos, sobre a produtividade e a qualidade de frutos de tomate tipo cereja e o gasto com m?o-de-obra
para se efetuar a desbrota. Para tanto, foram realizados dois ensaios no Campo Experimental da Horticultura do
Departamento de Fitotecnia da Universidade Federal Rural do Rio de Janeiro, em Serop?dica-RJ, nos per?odos
de primavera-ver?o de 2004 e outono-inverno de 2005. No primeiro ensaio, foram avaliados os efeitos da
combina??o de tr?s formas de condu??o (sem tutoramento e sem limita??o do n?mero de hastes por planta;
tutoramento e condu??o de uma haste por planta e, tutoramento e condu??o de duas hastes por planta), tr?s
espa?amentos entre plantas (0,4, 0,6 e 0,8 m) e duas cultivares de tomate cereja, o h?brido Super-Sweet e a
variedade Perinha . O espa?amento entre linhas utilizado foi 1,5 m. No segundo ensaio, foram avaliados os
efeitos da combina??o entre tr?s formas de condu??o (sem tutoramento e sem limita??o do n?mero de hastes por
planta; tutoramento e condu??o de duas hastes por planta e, tutoramento e condu??o de tr?s hastes por planta) e
duas cultivares de tomate cereja, o h?brido Super-Sweet e variedade A . O espa?amento adotado foi de 0,6 m
entre plantas e 1,0 m entre linhas. No cultivo realizado no per?odo de primavera-ver?o, observou-se que o
sistema n?o tutorado apresentou produtividade de frutos comerciais igual estatisticamente ? do tratamento onde
as plantas foram conduzidas sob tutoramento e mantendo-se duas hastes por planta. O tratamento onde n?o foi
feita a condu??o das plantas apresentou, ainda, menor custo de produ??o, decorrente do fato de n?o se ter gasto
m?o-de-obra para a pr?tica da desbrota. No cultivo realizado no per?odo de outono-inverno, no entanto,
observou-se redu??o acentuada do n?mero de colheitas neste sis tema devido, principalmente, ao ataque severo
de requeima. Neste mesmo per?odo, constatou-se que o sistema de condu??o com tr?s hastes foi o que
proporcionou maior produtividade de frutos comerciais, por?m com maior custo de produ??o devido ao aumento
do gasto com m?o-de-obra para realiza??o da referida opera??o.
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Influência do espaçamento, população de plantas e híbridos na intensidade de doenças e fatores de produção de milho safrinha / Influence of row spacing, plant population and hybrids on disease intensity and production factors of short season cornFontoura, Darci da 25 November 2005 (has links)
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Previous issue date: 2005-11-25 / Although the safrinha (short season) corn area had almost a tenfold increase during the last 15 years, few studies were reported on this specific environment. The objective of the current study was to evaluate the effect of the spatial arrangement created by row spacing or by plant population on corn disease intensity in the safrinha environment. The experiment was installed in Toledo/PR for two consecutive years, 2004 and 2005. It was a randomized complete block design with 4 replications, on a factorial scheme with hybrid as the first factor (X1392D, 30F80, 30K75 and 30P70) and row spacing (38 cm, mix with 38 and 76 cm or 76 cm) or plant population (45, 60 and 75 thousand plants ha-1) as the second factor. The hybrids were selected in order to fill the following requirements: two of them had erect leaf architecture and the other two had horizontal leaf architecture, besides a different tolerance level for the main corn diseases. The incidence and severity of the leaf, stalk and ear pathogenic fungus, the incidence of generic parameters as kernel rot, root lodging, stalk lodging, besides the production factors and productivity were evaluated. Although higher plant populations and narrower row spacing resulted in higher disease intensity, there was a tendency of better yields under these treatments. On the other hand, it was dependant on the hybrid and climate condition of each growing year. The internal temperature of each plot was not affected by the spatial arrangement, however the leaf architecture affected the maximum temperature, even though it was not directly related to the disease intensity / Apesar da área de milho safrinha ter aumentado em aproximadamente dez vezes nos últimos 15 anos, poucos estudos foram relatados nesse ambiente específico. O presente trabalho teve como objetivo avaliar o efeito do arranjo espacial gerado pelo espaçamento entre linhas e pela população de plantas na intensidade de doenças em milho safrinha. O experimento foi conduzido em Toledo/PR por dois anos consecutivos, nas safrinhas de 2004 e de 2005. O delineamento experimental foi em blocos casualizados com quatro repetições, em esquema fatorial, tendo como primeiro fator o híbrido (X1392D, 30F80, 30K75 e 30P70) e como segundo fator o espaçamento entre linhas (38 cm, misto com 38 e 76 cm na mesma parcela ou 76 cm) ou a população de plantas (45, 60 e 75 mil plantas ha-1). Os híbridos foram escolhidos de forma que dois tivessem arquitetura foliar ereta e dois tivessem arquitetura foliar horizontal, além de níveis diferentes de tolerância às principais doenças. Foram avaliadas a incidência e a severidade dos principais fungos fitopatogênicos responsáveis por doenças foliares, de colmo e de espiga, a incidência de parâmetros genéricos como grão ardido, acamamento de raiz, acamamento de colmo e doenças da base do colmo, além dos fatores de produção e produtividade. O microclima gerado pela redução do espaçamento entre linhas ou pelo aumento da população de plantas resultou em aumento na intensidade de doenças de colmo e de espiga, porém não reduziu a produtividade na mesma proporção. Por outro lado, essa resposta é dependente do híbrido e da condição climática de cada ano agrícola. A temperatura interna da parcela não foi afetada pelo arranjo espacial, porém a arquitetura foliar afetou a temperatura máxima ainda que não estivesse diretamente relacionada à intensidade de doença
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Aplicação de métodos geoestatísticos para identificação de dependência espacial na análise de dados de um experimento em delineamento sistemático tipo "leque" / Application of geostatistical methods to identify the spatial dependence in the data analysis of a fan systematic design experimentOda, Melissa Lombardi 20 May 2005 (has links)
Os delineamentos sistemáticos são usados nas mais diversas áreas, como: florestal, horticultura, solos, etc. Na área florestal, os delineamentos sistemáticos são freqüentemente usados para estudos preliminares e têm o objetivo de testar o maior número de espaçamentos possíveis. No entanto, existem algumas limitações para a sua utilização. A primeira é o arranjo sistemático (não casualizado) das plantas, que não permite o uso das análises convencionais. A segunda é a alta sensibilidade para valores perdidos. Quando uma planta é perdida, o espaçamento das plantas vizinhas é alterado, assim esses valores não podem ser incluídos no conjunto de dados e informações consideráveis são excluídas das análises. O objetivo deste trabalho foi aplicar a metodologia geoestatística para identificação de dependência espacial em um experimento em delineamento sistemático tipo "leque", levando-se em consideração: a eliminação dos dados das plantas vizinhas aos valores perdidos e as informações de ocorrência de parcelas perdidas e o tempo que ocorreram. Os dados de volume sólido por planta utilizados neste trabalho são provenientes de um experimento de espaçamento de Eucalyptus dunnii em delineamento sistemático tipo "leque". Neste trabalho foram utilizados os dados referentes ao sexto ano, idade comercial de corte da espécie, com os seguintes procedimentos: eliminação dos dados das plantas vizinhas às plantas mortas (Modelo I); as informações de mortes das plantas foram consideradas como uma covariável no modelo (Modelo II) e além da covariável morte das plantas, também foi levado em consideração o tempo da ocorrência da morte (Modelo III). Os parâmetros do semivariograma foram estimados pelo método de máxima verossimilhança e para seleção de modelos, utilizou-se o Critério de Akaike (AIC). Os resultados obtidos permitem concluir que se identificou uma fraca dependência espacial, o que não justificaria considerá-la com a aplicação de um modelo geoestatístico. A função de correlação que apresentou melhor desempenho foi a Matérn com k = 2 para os três modelos considerados. Comparando-se esses modelos e seguindo o critério de Akaike, o modelo mais adequado foi o II, pois apresentou menor valor de AIC. / Systematic designs are utilized in many areas, such as: forestry, horticulture, soils, etc. In forestry, the systematic designs are frequently used for preliminary studies and they aim at evaluating the largest number of possible spacings. However, there are some limitations on their use. The first limitation is the systematic design (non-randomized) of plants, which does not allow the use of conventional analyses. The second is the high sensitivity to lost values. When a plant is lost, the neighboring plant spacings are altered, so these values cannot be added to the data collection, and a great sum of information is excluded from the analyses. This study aimed at applying geostatistical methods to identify the spatial dependence in the data analysis of a fan systematic design experiment, taking into account: the exclusion of neighboring plant data to the lost values and the information regarding the occurrence of lost parcels as well as the time of their occurrence. The plant solid volume data utilized in this study were taken from a fan systematic design Eucalyptus dunnii spacing study. The data utilized were referent to the sixth year, commercial age for cutting of the specie, with the following procedures exclusion of the data from a neighboring plant next to a dead tree (Model I); the information of tree mortality as covariable in the model (Model II); and the time of occurrence of tree mortality, besides the tree mortality covariable (Model III). The semivariogram parameters were estimated by the maximum likelihood method, and the model selection was done by the utilization of the Akaike's Information Criterion (AIC). It was possible to conclude from the result analyses that there is a weak spatial dependence, which does not justify neither taking it into account nor the utilization of a geostatistical model. The correlation function that showed the best performance was the Matérn, with kappa=2 for the three models considered. By the comparison of these three models and the utilization of the Akaike's Information Criterion, the most suitable model was Model II, as it showed lower AIC value.
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Mikrotypografins inverkan på läsbarheten hos tryckt brödtext : En forskningsöversikt / How microtypography affects the legibility of running text in print : A research reviewSkoglund, Gabriel January 2012 (has links)
Hur en texts typografiska utformning påverkar hur enkel den blir att läsa är en fråga som har sysselsatt forskare under lång tid. Förhoppningen har varit att få en bättre förståelse för hur läsning går till och hur man bäst bör sätta text för att underlätta för läsaren. Ett problem har dock varit att skapa medvetenhet om forskningens resultat bland dem som arbetar med att sätta text. Tanken med detta examensarbete var att skapa en överblick av forskningen, med inriktning på hur mikrotypografin, det vill säga den typografi som berör detaljer i textens utformning, påverkar läsbarheten i brödtext. Efter litteratursökningar valdes tio vetenskapligt publicerade empiriska studier på detta område ut. Artiklarna beskrevs och diskuterades med hänsyn till deras metodik och deras resultat. Följande mikrotypografiska faktorer behandlades i studierna: skillnader i läsbarhet mellan typsnitt, x-höjdens och teckenavståndets inverkan på läsbarheten, skillnader i läsbarhet mellan gemener, versaler och kursiv text samt skillnader i läsbarhet mellan olika bokstavsformer. Slutsatsen var att forskningen kring läsbarhet ger intressanta inblickar i hur typografin inverkar på läsprocessen. Det begränsade antalet studier på varje område samt brist på studier utförda på svenska gör det dock svårt att skapa konkreta riktlinjer för hur text bör sättas. Vidare konstaterades att studier utförda i samarbete mellan forskare och typografiskt kunniga vore en möjlig metod att sprida kunskap till de typografiska yrkena och öka sannolikheten för praktisk tillämpning av forskningsresultaten. / How the typographic design of a document affects how easy it is to read is a subject that has long been of interest to researchers. The aim has been to reach a better understanding of the reading process, and to find an ideal way to design text for maximum legibility. However, the researchers have seemingly failed to raise awareness about their results in the typographic community. The aim of this thesis was to create an overview of the research into how microtypography – the typography concerned with individual letters and sentences – affects the legibility of running text. Ten empirical studies on this subject, published in scientific journals, were selected after literature searches. The methods and results of the studies were described and discussed. The studies were concerned with the following microtypographic factors: differences in legibility between typefaces, the role of x-height and letter spacing in, differences in legibility between lower case, upper case and italic letters as well as differences in legibility between specific letter shapes. The conclusion was that legibility research gives interesting insights into how typography can influence the reading process. However, the limited amount of studies found concerning each typographic factor, as well as the lack of studies concerning Swedish typography makes it hard to create typographic guidelines for Swedish typographers based on the research. It was also concluded that studies conducted in cooperation between researchers and typographers might be a way to raise awareness about the research and lead to greater practical application of research results.
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Efficient digital baseband predistortion for modern wireless handsetsBa, Seydou Nourou 10 November 2009 (has links)
This dissertation studies the design of an efficient adaptive digital baseband predistorter for modern cellular handsets that combines low power consumption, low implementation complexity, and high performance. The proposed enhancements are optimized for hardware implementation. We first present a thorough study of the optimal spacing of linearly-interpolated lookup table predistorters supported by theoretical calculations and extensive simulations. A constant-SNR compander that increases the predistorter's supported input dynamic range is derived. A corresponding low-complexity approximation that lends itself to efficient hardware design is also implemented in VHDL and synthesized with the Synopsys Design Compiler. This dissertation also proposes an LMS-based predistorter adaptation that is optimized for hardware implementation and compares the effectiveness of the direct and indirect learning architectures. A novel predistorter design with quadrature imbalance correction capability is developed and a corresponding adaptation scheme is proposed. This robust predistorter configuration is designed by combining linearization and I/Q imbalance correction into a single function with the same computational complexity as the widespread complex-gain predistorter.
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Numerical Study Of Heat Transfer From Pin Fin Heat Sink Using Steady And Pulsated Impinging JetsSanyal, Anuradha 04 1900 (has links)
The work reported in this thesis is an attempt to enhance heat transfer in electronic devices with the use of impinging air jets on pin-finned heat sinks. The cooling per-formance of electronic devices has attracted increased attention owing to the demand of compact size, higher power densities and demands on system performance and re-liability. Although the technology of cooling has greatly advanced, the main cause of malfunction of the electronic devices remains overheating. The problem arises due to restriction of space and also due to high heat dissipation rates, which have increased
from a fraction of a W/cm2to 100s of W /cm2. Although several researchers have at-tempted to address this at the design stage, unfortunately the speed of invention of
cooling mechanism has not kept pace with the ever-increasing requirement of heat re-
moval from electronic chips. As a result, efficient cooling of electronic chip remains a
challenge in thermal engineering.
Heat transfer can be enhanced by several ways like air cooling, liquid cooling, phase
change cooling etc. However, in certain applications due to limitations on cost and
weight, eg. air borne application, air cooling is imperative. The heat transfer can be increased by two ways. First, increasing the heat transfer coefficient (forced convec-
tion), and second, increasing the surface area of heat transfer (finned heat sinks). From previous literature it was established that for a given volumetric air flow rate, jet im-pingement is the best option for enhancing heat transfer coefficient and for a given volume of heat sink material pin-finned heat sinks are the best option because of their high surface area to volume ratio. There are certain applications where very high jet velocities cannot be used because of limitations of noise and presence of delicate components. This process can further be improved by pulsating the jet. A steady jet often stabilizes the boundary layer on the surface to be cooled. Enhancement in the convective heat transfer can be achieved if the boundary layer is broken. Disruptions in the boundary layer can be caused by pulsating the impinging jet, i.e., making the jet unsteady. Besides, the pulsations lead to chaotic mixing, i.e., the fluid particles no more follow well defined streamlines but move unpredictably through the stagnation region. Thus the flow mimics turbulence at low Reynolds number. The pulsation should be done in such a way that the boundary layer can be disturbed periodically and yet adequate coolant is made available. So, that there is not much variation in temperature during one pulse cycle. From previous literature it was found that square waveform is most effective in enhancing heat transfer. In the present study the combined effect of pin-finned heat sink and impinging slot jet, both steady and unsteady, has been investigated for both laminar and turbulent flows. The effect of fin height and height of impingement has been studied. The jets have been pulsated in square waveform to study the effect of frequency and duty cycle. This thesis attempts to increase our understanding of the slot jet impingement on pin-finned heat sinks through numerical investigations. A systematic study is carried out using the finite-volume code FLUENT (Version 6.2) to solve the thermal and flow fields. The standard k-ε model for turbulence equations and two layer zonal model in wall function are used in the problem Pressure-velocity coupling is handled using the SIMPLE algorithm with a staggered grid.
The parameters that affect the heat transfer coefficient are: height of the fins, total
height of impingement, jet exit Reynolds number, frequency of the jet and duty cycle
(percentage time the jet is flowing during one complete cycle of the pulse).
From the studies carried out it was found that:
a) beyond a certain height of the fin the rate of enhancement of heat transfer becomes
very low with further increase in height,
b) the heat transfer enhancement is much more sensitive to any changes at low Reynolds
number than compared to high Reynolds number,
c) for a given total height of impingement the use of fins and pulsated jet, increases
the effective heat transfer coefficient by almost 200% for the same average Reynolds
number,
d) for all the cases it was observed that the optimum frequency of impingement is around 50 − 100 Hz and optimum duty cycle around 25-33.33%,
e) in the case of turbulent jets the enhancement in heat transfer due to pulsations is very less compared to the enhancement in case of laminar jets.
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Pruning Deciduous Shade TreesDavison, Elisabeth, DeGomez, Tom 04 1900 (has links)
Revised; Originally published:1999 / 6 pp. / The pruning principles discussed in this publication have proven to provide the best possible out comes including tree longevity and safety. Although trees may live for years following improper pruning their life span and safety may be severely reduced. We encourage proper pruning so that the trees we care for may bring us pleasure for many years.
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Influence of stockplant management on yield and subsequent rooting of cuttings of cold-tolerant Eucalyptus grandis x E. nitens clones.Ziganira, Matabaro. January 2012 (has links)
Clones of the Eucalyptus grandis x Eucayptus nitens (GN) hybrids were produced and selected through the CSIR‟s breeding programmes for colder plantation sites in South Africa. Some GN clones consistently exhibit high and superior pulp properties, which makes them valuable for commercial plantations in South Africa. In nurseries, stockplants are usually seven cm in length and maintained at high (100 x1.5 m-2) planting density. However, rooting frequency varies with season and little is known about the impact of position of cuttings on overall rooting frequency of a clone. The aim of this study was to investigate the effect of size and planting density of stockplants in mini-hedges, on the yield and subsequent rooting of cuttings from various positions of GN clones of known rooting potential (i.e. GN 018B: difficult-to-root and PP 2107: easy-to-root clones).
Stockplants (10 cm vs. 20 cm) were established at high (100 x 1.5 m-2) and at low (25 x 1.5 m-2) densities for GN 018B and PP 2107 under commercial nursery conditions in a polyethylene tunnel. Cuttings were harvested every two to three weeks in September-October 2010 (spring), December 2010-January 2011 (summer), April-May 2011 (autumn) and June-July 2011 (winter). The harvested material was 5 – 7 cm in length and the light intensity received by individual stockplants at the two planting density levels was recorded. Harvested cuttings from the three positions (apical, middle and basal shoots) were used for: (i) rooting experiments under nursery conditions, (ii) bio-stimulant analysis using the mung bean bioassay, and (iii) analysis of soluble sugars.
Between spring and summer 2010, the two GN clones established at low density yielded a similar number of cuttings, but differences in the rooting frequencies were significant in favour of PP 2107 clone. Similar observations were made at high density in terms of production of cuttings, but the significant differences in the rooting observations were reversed between the clones. The GN 018B clone had low rooting rates in summer under nursery conditions but its tissue extracts promoted higher rooting in the bioassay during that time, when compared to spring. Spring and summer had similar effects on rooting responses of PP 2107 cuttings in nursery and bioassay experiments. For both clones, short stockplants produced fewer cuttings but had a higher rooting frequency than cuttings from tall stockplants, with a high rooting frequency recorded from basal cuttings. Similar results
were observed in the bioassay experiments which showed high rooting potential of mung bean hypocotyls cuttings using tissue extracts of PP 2107 cuttings maintained at high planting density. Although apical cutting tissues had high concentration of sugars (i.e. sucrose, glucose and fructose), their rooting rates were usually lower at high and low planting density compared to middle and basal cuttings. Sucrose concentration was the highest sugar present in stockplants grown under low planting density. A higher and lower rooting frequency was also observed in autumn although the two clones responded differently to Quambalaria eucalypti (Sporothrix eucalypti) disease infestations. Position, size and genotype had a significant impact on type and concentration of sugar (i.e. sucrose, glucose and fructose), particularly in PP 2107 clone, although rooting rates in the bioassay did not correlate with sugar contents of Eucalyptus cuttings.
High carbohydrate (i.e. soluble sugar) content and auxin concentration increased production and subsequent rooting of cuttings across both clones, particularly in spring. Furthermore, rooting was enhanced by relatively higher light intensity intercepted by individual stockplants and in particular the GN 018B clone. Light intensity in the high and low planting densities caused variation in the rooting frequencies thereby increasing or decreasing soluble sugar and auxin concentrations of the two clones. Light intensity and fertiliser concentration received by tall and short stockplants impacted on endogenous hormone levels thereby increasing or decreasing rooting. High sugar concentration levels of PP 2107 clone increased its susceptibility to fungal infection thereby decreasing its rooting frequency in autumn, as its rooting rates increased in winter.
Overall results of the investigation revealed that PP 2107 clone has higher rooting potential than GN 018B clone, in particular at high planting density and if stockplants are not infected by fungal diseases. Higher sugar levels were recorded in spring for PP 2107, although rooting rates of mung bean hypocotyl cuttings were higher in summer for GN 018B, suggesting that sugars have nothing to do with rooting of GN cuttings. Season, planting density and size of stockplants affect the rooting frequency of GN clone. Thus, short stockplants maintained at low and high planting densities are recommended for GN 018B and PP 2107 respectively, although the impacts of fertilisers and pathogen resistance on rooting rates still need to be investigated under similar conditions. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
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The space of editing : playing with difference in art, film and writingStevens, Grant William January 2007 (has links)
This research project explores the creative and critical functions of editing in art, film and writing. The written component analyses the histories and discourses of 'cutting and splicing' to examine their various roles in processes of signification. The artistic practice uses more speculative and open-ended methods to explore the social 'languages' that inform our inter-subjective experiences. This project argues that editing is a creative methodology for making meaning, because it allows existing symbolic systems to be appropriated, revised and rewritten. By emphasising the operations of spacing, questioning and play, it also identifies editing as an essential tool for critically engaging with the potentials of art and theory.
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Sorgo forrageiro implantado com diferentes arranjos populacionais manejado sob pastoreio contínuo / Sorghum implanted with different arrangements population under grazing continuous managedRodrigues, Leonel da Silva 23 February 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Objective was to evaluate the effects of different population arrangements in forage sorghum grazing on forage production, morphogenesis, pasture structure, performance, and animal behavior. They were used 36 crossed heifers between Charolais and Nellore, with initial age of 15 months and 262 kg of body weight (BW). The experimental period lasted 84 days, divided into periods of 28 days. The animals received daily supplementation to the level of 1% of body weight. Treatments consisted of a combination of spacings of 22 or 44 cm in planting spacing with two densities of seeds per hectare, 12 or 24 kg, resulting in arrangements population E44D12; E44D24; E22D12; E22D24. The grazing method was continuous with variable number of regulators animals. The forage mass and the mass of leaf blades did not differ between population arrangements, with average values of 1279.11 and 232.99 kg DM / ha. Similarly the stocking rate, dry matter accumulation rate and weight gain per area, with average values of 1172.32 kg LW / ha, 58.47 kg DM / ha / day and 303.31 kg PV / ha, in that order. The performance and development of the animals were not affected by population arrangements grassland, with weight gain and average final weight between treatments of 0.891 kg / day and 330.36 kg of PV. The relation weight:height among the population arrangements was 2.67 kg / cm, indicating that cross heifers between Charolais and Nellore with 18 months of age have fat thickness and appropriate weight for slaughter. Productive parameters of pasture and animal performance were influenced by evaluation periods. The different population arrangements change the behavioral patterns of animals, E44D24 and E22D12 treatments increase the grazing time. The E44D24 treatment decreases the bit rate when compared to E22D24. The lower density of plants per square meter causes the increase in the number of feeding stations / minute and the displacement rate of the animals. The spacing between rows 22cm promote a larger number of bits/food station. The use of higher density of seeds and larger spacing between lines increases the density of leaf blades in the lower and upper stratum of the pasture, respectively. The E44D12 and E22D24 treatments have higher amounts of stems in the upper stratum of the pasture (over 60 cm). Morphogenic variables were not significantly influenced by the different arrangements of plants used and the evaluation periods, being obtained elongation rate and leaf senescence of 1.43 and 1.11 cm/day/tiller, respectively, leaf appearance rate and leaf appearance interval of 0.28 leaves/day/tiller and 3.81 days phillochron and leaf life span of 72.99 and 351.68 degree day, in that order. Have the structural characteristics of pasture were influenced by evaluation periods, reflecting the forage production decline with advancing the use of the pasture cycle. The first to the third evaluation period was verified a reduction of 65.53% in the number of sheets in elongation and 47.79% in the number of living leaves. / Objetivou-se avaliar os efeitos de diferentes arranjos populacionais em pastagem de sorgo forrageiro na produção forrageira, morfogênese, estrutura do pasto, desempenho e comportamento animal. Foram utilizadas 36 novilhas de corte cruzadas entre as Charolês e Nelore, com idade média inicial de 15 meses e 262 Kg de peso vivo (PV). O período experimental durou 84 dias, divididos em períodos de 28 dias. Os animais receberam suplementação diária à nível de 1% do peso vivo. Os tratamentos consistiram na combinação de espaçamentos de 22 ou 44 cm na entrelinha de plantio com duas densidades de sementes por hectare, 12 ou 24 Kg, resultando nos arranjos populacionais E44D12; E44D24; E22D12; E22D24. O método de pastoreio utilizado foi contínuo, com número variável de animais reguladores. A massa de forragem e a massa de lâminas foliares não diferiram entre os arranjos populacionais, apresentando valores médios de 1279,11 e 232,99 Kg de MS/ha. Da mesma forma a carga animal, taxa de acúmulo de matéria seca e o ganho de peso por área, apresentando valores médios de 1172,32 Kg de PV/ha, 58,47 Kg de MS/ha/dia e 303,31 Kg de PV/ha, nessa ordem. O desempenho e o desenvolvimento dos animais não foram influenciados pelos arranjos populacionais da pastagem, apresentando ganho de peso e peso final médio entre os tratamentos de 0,891 Kg/dia e 330,36 Kg de PV. Os parâmetros produtivos da pastagem e desempenho animal foram influenciados pelos períodos de avaliação. Os diferentes arranjos populacionais alteraram os padrões comportamentais dos animais, os tratamentos E44D24 e E22D12 aumentam o tempo de pastejo. O tratamento E44D24 diminui a taxa de bocado quando comparado ao E22D24. A menor densidade de plantas por metro quadrado ocasiona o aumento no número de estações alimentares/minuto e a taxa de deslocamento dos animais. O espaçamento 22 cm entrelinhas promove um maior número de bocados/estação alimentar. A utilização de maior densidade de sementes e maiores espaçamentos entrelinhas aumenta a densidade de lâminas foliares no estrato inferior e superior da pastagem, respectivamente. Os tratamentos E44D12 e E22D24 apresentaram maiores quantidades de colmos no estrato superior do pasto (acima de 60 cm). As variáveis morfogênicas não foram influenciadas significativamente pelos diferentes arranjos de plantas utilizados e pelos períodos de avaliação, sendo obtidos taxa de alongamento e senescência foliar de 1,43 e 1,11 cm/dia/afilho, respectivamente, taxa de aparecimento foliar e intervalo de surgimento de folhas de 0,28 folhas/dia/afilho e 3,81 dias, filocrono e duração de vida foliar de 72,99 e 351,68 graus dia, nessa ordem. Já as características estruturais da pastagem foram influenciadas pelos períodos de avaliação, refletindo a queda de produção forrageira com o avançar do ciclo de utilização da pastagem. Do primeiro para o terceiro período de avaliação foi verificado uma redução de 65,53% no número de folhas em alongamento e de 47,79% no número de folhas vivas.
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