Rates of population growth in developing country cities are straining the capacity of sanitation service providers. In spite of widespread sector recognition of the need to adopt low-cost, people centred approaches, 80 per cent of investments in the water and sanitation sector continue to be allocated to high cost technologies for urban elites. Household level, on-plot sanitation systems potentially offer a solution to the sanitary needs of the urban poor. Nevertheless, commonly held assumptions amongst sector professionals that lower cost, on-plot systems are inappropriate and unacceptable in urban communities impede-their wider application. There is little empirical evidence to justify this position. The scope of this work examines the technical appropriateness and user acceptability of on-plot sanitation options. The thesis contributes to an improved understanding of the context in which on-plot systems operate, what factors constrain their application, and what issues need consideration when deciding on sanitary options in low-income communities. The research adopted a mix of methodological techniques to improve the reliability and validity of findings, with both quantitative and qualitative methods applied during fieldwork. Findings from Ghana, Mozambique and India are included in the thesis in order to permit sampling of key latrine types used internationally. The thesis concludes that user based perceptions of the performance and acceptability of on-plot systems varies markedly to those of sector professionals, particularly in relation to plot size, satisfaction levels and reasons for absence of household latrine. Furthermore, user based criteria of performance are developed for consideration practitioners when narrowing decision making on sanitary options. The implications of the study highlight the need for integration of user concerns into strategic planning for sanitation, more effective stimulation and negotiation of demand for sanitation systems and challenges for agencies in adopting a user oriented approach. The recommendations from the thesis include practitioner focused policy changes that affect project planning and support systems for user education. Potential areas of further research interest include ranking user perceptions, an holistic understanding of excreta management processes and institutional constraints affecting user-service provider consultations.

Preliminary plots are required when beginning a cruise for a timber sale in order to get an idea of how much variation in volume exists within the sale area. This variation is known as the coefficient of variation (CV) and is subsequently used to estimate the number of plots needed to implement the cruise to a desired level of accuracy (allowable error). By looking at a large number of sale inventories and finding similarities among key attributes (trees per acre, diameter at breast height and an estimate of variance), two models were derived based on simple stand observations to aid field personnel in determining a more accurate estimate of the CV. Furthermore, the models estimate the number of 1/10 acre plots needed to sample a stand to within a ± 10% allowable error at the 90% confidence level for total tonnage.

Knowledge of the impacts of management and scale are important for improved understanding and prediction of turf chemical runoff in urban environments. This study addressed the effects of mowing height, warm-season turf species and plot size on runoff of water, bromide, dimethylamine salts of the herbicides 2, 4-D, MCPP and dicamba, flutolanil fungicide, and chlorpyrifos insecticide from a Brooksville silty clay soil. The runoff plots were sloped at 3 % and arranged as split-plot in a randomized complete block design. The pesticides were applied as a tank mix: 2, 4-D at 1.12 kg ai/ha, MCPP at 1.80 kg ai/ha, dicamba at 0.50 kg ai/ha, flutolanil at 2.24 kg ai/ha and chlorpyrifos at 2.24 kg ai/ha. Bromide was applied separately at 15 kg ai/ha. The pesticides and bromide were applied 24 h and 0.5 h respectively, prior to each rainfall simulation event. Rainfall simulated at 38 mm/h was applied to treated plots for 1.5 h to generate runoff which was collected at 5 minute intervals. Pesticide runoff concentrations were determined by reverse-phase HPLC using UV-Vis detection. The limit of quantification for each compound was approximately 5 µg/L. Bromide was analyzed for by an ion selective electrode following EPA method 9211 with the limit of detection at 200µg/L. Plot size, mowing height and/or grass species significantly affected different runoff aspects of the pesticides investigated at p< 0.05. Averaged across treatments, percentages of applied pesticide lost in runoff were 43.3 ± 12.7 for 2, 4-D, 29.5 ± 8.3 for MCPP, 24.6 ± 8.3 for dicamba, 6.8 ± 1.0 for flutolanil and 0.22 ± 0.04 for chlorpyrifos. Similarly, average peak pesticide concentrations were 3.7 ± 0.9 mg/L for 2, 4-D, 4.2 ± 1.1 mg/L for MCPP, 1.2 ± 0.3 mg/L for dicamba, 0.8 ± 0.3 mg/L for flutolanil and 0.04 ± 0.02 mg/L for chlorpyrifos. Results obtained for water and bromide runoff suggest that the treatment effects observed for the pesticides were due to differences in retention mechanism rather than turf hydrology. Linear relationships were obtained between plot area and chemical mass and total runoff indicating that runoff from bermudagrass turf is ‘scalable’.

One of the big problems encountered in experimental yield trials of field crops is the variation that occurs in yield estimates regardless of how the trial is handled with respect to variety or treatment. This so-called "natural" variation is the result of such factors as heredity, human error, and environment.

No description available.

The cultivation of castor beans presents considerable advances in recent years, because it is a promising crop for production of biodiesel. The planning of experiments for evaluation the productivity of castor beans is important to qualify the search results. The objectives of this study were to determine the appropriate plot size and number of repetitions and the influence of spacing between plants in the experimental culture of castor oil.The experiment with the hybrid Lyra, with row spacing of 1.2 m, was conducted at the experimental area of the Federal University of Santa Maria in 2007. Were evaluated in each plant: number of racemes, fruit weight, average length of racemes and number of fruit, with identification of the plant by the number of rows and number of plants within the row. The optimum plot size is eight plants for all spacings and for all variables. However, the area of optimum plot size in each space depends on the area occupied by the basic unit. Thus the area of the plot is: 3.84 m2, 5.76 m2 and 7.68 m2 for the spacing between plants of 0.4 m, 0.6 m 0.8 m, respectively. The size of plot and/or the experimental area depends on the number of plants. / O cultivo da mamoneira apresenta avanços consideráveis nos últimos anos, por se tratar de uma cultura promissora para a produção de biodiesel. O planejamento dos experimentos de avaliação da produtividade de grãos de mamona é importante para qualificar os resultados de pesquisas. Os objetivos deste trabalho foram determinar o tamanho adequado de parcela e o número de repetições e verificar a influência do espaçamento entre plantas no plano experimental da cultura de mamona. O experimento com o híbrido Lyra, com espaçamento entre linhas de 1,2 m, foi conduzido em área experimental da Universidade Federal de Santa Maria no ano de 2007. Avaliaram-se, em cada planta: número de rácemos, peso de frutos, comprimento médio dos rácemos e número total de frutos, com identificação da planta pelo número de ordem da fileira e o número da planta dentro da fileira. O tamanho ótimo de parcela é de oito plantas para todos os espaçamentos e para todas as variáveis. No entanto, a área do tamanho ótimo de parcela em cada espaçamento depende da área ocupada pela unidade básica. Assim a área da parcela é de: 3,84 m2; 5,76 m2 e 7,68 m2 para os espaçamentos entre plantas de 0,4 m; 0,6 m e 0,8 m, respectivamente. O tamanho de parcela e/ou da área experimental depende do número de plantas.

Made available in DSpace on 2015-03-26T13:32:10Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2151125 bytes, checksum: df70f0822304c46808ad20a926f92a61 (MD5) Previous issue date: 2011-02-10 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The experimental unit, or plot, is the unit that receives a particular treatment and provides the data which will reflect its effect. Optimum plot size is directly related to experimental accuracy, since the appropriate size reduces the experimental error. The objectives of this study were to use the methods Linear Segmented Model with Response Plateau (MLRP), Quadratic Segmented Model with Response Plateau (MQRP), Exponential Segmented Model with Response Plateau (MERP) and the traditional Modified Maximum Curvature Method (MMCM) to determine the optimum size of experimental plots using real data of banana crop; compare the methods using the following goodness of fit indices: coefficient of determination (R2), Akaike information criterion (AIC) and Bayesian information criterion (BIC); and obtain confidence intervals for the optimum plot size. For the study, we used data from a blank experiment conducted in the municipality of Sebastiao Laranjeiras, Bahia, in two growing seasons (2006-2008), where the following traits were evaluated: plant height, pseudostem circumference, number of live leaves, number of suckers and yellow-Sigatoka score at flowering. At this evaluation, each plant was considered as a basic unit of 6 m2, totaling 240 basic units, whose combinations formed 19 different plot sizes. The results indicated that the estimates for plot sizes, in general, varied according to the evaluated characteristics, the production cycle and the used models. This variation corresponded to the range from 7 to 66 plants in the first cycle and 70 to 40 in the second cycle. The MERP model determined sizes for the basic units larger than the MQRP model, which, in turn, estimated larger sizes than the MLRP model. Based on the goodness of fit, the best model for the analyzed data was MERP, estimating a mean optimum plot size of 31 basic units. MLRP estimated mean optimum plot size of nine basic units and MQRP estimated a mean optimum plot size of 22 basic units. Statistically, the best model fitted was MERP, but for practical reasons, as itestimates larger optimum plot sizes, it may not be feasible for the researcher. The findings of this study indicate that the models MLRP, MQRP and MERP can be used to determine optimum plot size. Thus, we suggest the simultaneous use of more than one method fordetermining the optimum plot size, as it will meet the factors considered by each method and the needs of the researcher. / Unidade experimental, ou parcela, é a unidade que recebe a aplicação do tratamento e fornece os dados que deverão refletir o seu efeito. O tamanho ótimo de parcela experimental está diretamente relacionado com a precisão do experimento, uma vez que o tamanho apropriado reduz o erro experimental. Este trabalho teve como objetivos utilizar os métodos Modelo Linear Segmentado com Response Platô (MLRP), Modelo Segmentado Quadrático com Response Platô (MQRP), Modelo Segmentado Exponencial com Response Platô (MERP) e o tradicional Método da Máxima Curvatura Modificada (MMCM), para determinação do tamanho ótimo de parcelas experimentais empregando dados reais na cultura da bananeira; comparar os métodos utilizados através dos seguintes avaliadores de qualidade de ajuste: coeficiente de determinação (R2), critério de informação de Akaike (AIC) e critério de informação baysiano (BIC); e obter intervalos de confiança para o Tamanho Ótimo de Parcela. O material utilizado correspondeu a um experimento em branco que foi realizado no Município de Sebastião ix Laranjeiras, BA, onde foram avaliadas, em dois ciclos de produção (2006-2008), as características: altura da planta, perímetro do pseudocaule, número de folhas vivas, número de filhos emitidos e nota de sigatoka-amarela na época do florescimento. Nessa avaliação, cada planta foi julgada como uma unidade básica com área de 6 m2, perfazendo, assim, 240 unidades básicas, de cujas combinações foram formados os 19 diferentes tamanhos de parcelas. Os resultados indicaram que os valores das estimativas dos tamanhos de parcela obtidos, de forma geral, oscilaram de acordo com as características avaliadas, o ciclo de produção e os modelos utilizados. Tal oscilação correspondeu à variação de 7 a 66 plantas no primeiro ciclo e 7 a 40 no segundo. O método MERP determinou valores para as unidades básicas maiores que os do método MQRP, que por sua vez estimou valores maiores que os do método MLRP. De acordo com a qualidade de ajuste, o melhor modelo para os dados analisados foi o MERP, que estimou tamanho ótimo de parcela médio de 31 unidades básicas. O método MLRP indicou tamanho ótimo de parcela médio de nove unidades básicas e o método MQRP, tamanho ótimo de parcela médio de 22 unidades básicas. Estatisticamente, o melhor modelo seria o MERP, mas por razões de ordens práticas, uma vez que estima valores maiores para o tamanho ótimo de parcela, pode não ser viável para o pesquisador. Verificou-se que os métodos MLRP, MQRP e MERP podem ser utilizados na determinação do tamanho ótimo de parcelas experimentais. Assim, recomenda-se a utilização simultânea de mais de um método para determinação do tamanho ótimo da parcela, a fim de que o tamanho adotado atenda aos diversos fatores considerados em cada método e às necessidades do pesquisador.

The aim of this paper is to analyze and describe the historical, institutional and structural factors of deforestation taking into account the dynamics of intensification or «extensification» of land use in the Amazon region of Tena in Ecuador. A first conclusion was finding the reproduction of an extensive pattern of agriculture in Tena as an important direct agent of deforestation. We believe that this agricultural system originates in historical processes from the sixties, when the state intervenes promoting certain policies of extensive land use, through road construction and specific mechanisms of land titling. The current social and institutional dynamics have failed to reverse such situation, since deforestation is still playing, although there is a tendency to close the agricultural frontier. The indicated form of farming and the corresponding rates of deforestation are played today as a result of structural factors, such as farm size, proximity to roads, the type of technology used and unfavorable market linkages. / El objetivo del presente artículo es analizar y describir los factores históricos, institucionales y estructurales de la deforestación teniendo en cuenta la dinámica de intensificación o «extensificación» de uso del suelo en la región amazónica de Tena, en Ecuador. Una primera conclusión fue constatar la reproducción de una agricultura extensiva en Tena como un importante agente directo de la deforestación. Creemos que dicho sistema agrícola se origina en procesos históricos, desde la década de 1960, cuando el Estado ecuatoriano interviene fomentando ciertas políticas de ocupación extensiva del suelo, a través de la construcción de caminos de penetración y algunas modalidades específicas de titulación de tierras. Las dinámicas sociales e institucionales actuales no han logrado revertir tal situación, pues la deforestación se sigue reproduciendo, a pesar de que existe la tendencia a que se cierre la frontera agrícola. La indicada forma de agricultura y las correspondientes tasas de deforestación se reproducen en la actualidad como resultado de factores estructurales, tales como el tamaño del predio, cercanía a las carreteras, el tipo de tecnología utilizada y una desfavorable articulación con el mercado.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / In order to determinate technicals to execution trials in protected environments for italian pumpkin was accomplished an experiment, from 18/08/2003 to 07/12/2003, in the area of the Department of Fitotecnia UFSM, in plastic greenhouse, with four rows and each row consisted of twenty-four plants. A total of twenty-seven harvests were made, evaluating fruit weight with length ≥15cm. The sample soil was sampled before accomplishment the experiment; one sample point is equal to four sub sample. The Smith heterogeneity index was estimated using SMITH s method (1938) and optimum plot size using method modified maximum curvature (MEIER & LESSMAN, 1971). Estimate, for how long productive period of italian pumpkin, in plastic greenhouse, must be evaluated aiming to estimate the experimental error and the difference among four intervals of harvest, was the aim in order to first paper. The harvest and evaluation of the initial half of the productive period of Italian pumpkin in plastic greenhouse was sufficient to estimate the experimental error, using six plants by plot, to evaluate different intervals of harvest. Because of high experimental error, the evaluation of the Italian pumpkin production during all the productive period is not sufficient to differentiate four treatments of intervals of harvest. The aim the second paper, was evaluate the chemicals characteristics of the soil heterogeneity index under environmental protect and determinate sample size. The values the Smith heterogeneity index were considerate small. The optimum plot size was equal to one basic unit, in other words, one sample point. The sample size estimated was ten sample points for the half width of the confidence interval of 20%, to 5% of error probability. The third paper, aimed evaluate the Smith heterogeneity index in order to different intervals of the harvest of fruits in different levels of the accumulate harvests of italian pumpkin in greenhouse, estimate the optimum plot size and determinate the least significant differences within treatments with variation in the size plot and number of replications. The Smith heterogeneity index is smaller and the use of smaller plots with larger number of replications benefit the experimental precision. The optimum plot size in order to yield italian pumpkin varying between one and seven plants, promoted appropriate evaluation of the yield italian pumpkin in the different studied treatments. Plots with three plants and six replications is better in order conduction the experiments, with least significant differences within treatments (average percentage) in 75,94%. / Para se determinar técnicas para execução de experimentos, sob ambiente protegido, para a cultura da abobrinha italiana, foi realizado um experimento em estufa plástica no período de 18/08/2003 a 07/12/2003, em área pertencente ao Departamento de Fitotecnia, na UFSM, Santa Maria, RS. As mudas foram transplantadas para a estufa plástica com espaçamento de 0,80 m entre plantas e 1,0 m entre filas, totalizando 24 plantas por fila. Foram realizadas 27 colheitas de frutos,com comprimento ≥ 15 cm. As amostras de solo foram coletadas antes da implantação do experimento, cada ponto amostral era composto por quatro subamostras. O índice de heterogeneidade de Smith (b) foi estimado pelo método de SMITH (1938) e o tamanho ótimo de parcela através do método da máxima curvatura modificado (MEIER & LESSMAN, 1971). A estimativa do erro experimental e a diferença entre quatro intervalos de colheita foram avaliados no primeiro trabalho. A colheita e avaliação da metade inicial do período produtivo da abobrinha italiana em estufa de plástica foi suficiente para estimar o erro experimental, usando seis plantas por parcela, para avaliar diferentes intervalos de colheita. O objetivo do segundo trabalho, foi avaliar o índice de heterogeneidade de Smith das principais características químicas do solo, em estufa plástica, e determinar o tamanho de amostra. Para todas variáveis analisadas, o índice de heterogeneidade de Smith, foi próximo a zero e o tamanho ótimo de parcela, foi igual à uma unidade básica, ou seja, um ponto amostral. O tamanho de amostra estimado, foi de dez pontos amostrais, como representativo para todas as variáveis analisadas, com semiamplitude do intervalo de confiança da média em porcentagem, de 20% em nível 5% de probabilidade de erro. O terceiro trabalho teve por objetivos avaliar o índice de heterogeneidade de Smith da produção de abobrinha italiana, para os diferentes intervalos de colheita dos frutos, em diferentes níveis de colheitas acumuladas, em ambiente protegido; estimar o tamanho ótimo de parcela e determinar a diferença mínima significativa entre tratamentos, variando o tamanho da parcela e o número de repetições. Como conclusão, o índice de heterogeneidade de Smith, foi baixo e o tamanho ótimo de parcela para a produção total de abobrinha italiana varia entre uma e sete plantas, conforme a freqüência de colheitas. O uso de parcelas com três plantas, seis repetições é mais adequado e apresenta uma diferença mínima significativa entre tratamentos, em porcentagem da média, de 75,94%.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The interior of a plastic greenhouse whose plants had been cultivated on soil can be considered a heterogeneous environment due high variability in the production, being necessary the use of experimental techniques for improvement of the statistical inferences precision. Between the main forms of obtain experimental error reduction is the use of the optimal plot size that has special importance in experiments inside plastic greenhouse, where the experimental area is normally restricted to the preexisting installations. Therefore, it is necessary to know the optimal plot size (Xo) for the cultures as well as understanding the relations among the parameters that determine it. The aim of this work is to estimate the relation of the equations parameters that determine the optimal plot size and estimate the optimal plot size for fruit fresh phytomass of chili pepper cultivated in plastic greenhouse. It was conducted four blank experiments under plastic covering, each one with ten culture lines of 70 plants. The fruit fresh phytomass was evaluated in each plant, identifying its position inside the greenhouse, by the line number, and its position in the line in each harvest. The optimal plot size was estimated and related with the parameters used for its estimate by the Pearson correlation coefficient, the path analysis and the response surface methodology. In the end of this work is recommended the use of parcels with ten plants in the line and at least three harvests for parcel. It was observed that Xo was negatively correlated with the number of harvested plants and the average of each culture line in the harvests. The positive and high correlation of the coefficient of variation estimate for the parcels of a basic unit and Xo indicates that this is its main determinative one, reducing the importance of the heterogeneity index (b), that if related weakly with Xo. / O interior de uma estufa cujas plantas foram cultivadas no solo pode ser considerado um ambiente heterogêneo devido a grande variabilidade na produção, sendo necessário o uso de técnicas experimentais para melhoria da precisão das inferências estatísticas. Entre as principais formas de redução do erro experimental está o uso do tamanho ótimo da parcela, que apresenta especial importância em experimentos com estufa plástica, visto que a área experimental normalmente é restrita às instalações preexistentes. Dessa forma, é importante conhecer o tamanho ótimo de parcela (Xo) para as culturas bem como compreender as relações entre os parâmetros que o determina. Sendo assim, os objetivos desse trabalho foram: estimar a relação dos parâmetros das equações que determinam o tamanho ótimo da parcela e estimar o tamanho ótimo para a fitomassa fresca de frutos de pimentão cultivado em estufa plástica. Para isso, foram conduzidos quatro experimentos em branco sob cobertura plástica, cada um com dez linhas de cultivo de 70 plantas. Então, coletou-se em cada planta a fitomassa fresca dos frutos, identificando sua posição dentro da estufa pelo número da linha e a sua posição dentro da linha em cada colheita. Estimou-se o tamanho ótimo da parcela e relacionou-o com os parâmetros usados para sua estimativa através do coeficiente de correlação de Pearson, da análise de trilha e da metodologia de superfície de resposta. Ao fim deste trabalho recomendou-se o uso de parcelas de dez plantas na linha e ao menos três colheitas por parcela. Observou-se que Xo correlacionou-se negativamente com o número de plantas colhidas e com a média obtida por linha de cultivo nas colheitas. A correlação positiva e alta da estimativa do coeficiente de variação para as parcelas de uma unidade básica e Xo indica que esta é sua principal determinante, reduzindo a importância do índice de heterogeneidade do solo (b), que se relacionou fracamente com Xo.