Aleatoriedade da produção entre parcelas em experimentos de pimentão e feijão-de-vagem

It is important to know the production variability among experimental plots in a protected environment because this information reduces error and increases the reliability of the results. Therefore, the objective of this study was to characterize the spatial independence of fruit yield between plots of peppers and snap beans. Data on production uniformity were gathered from trials performed at the Department of Plant Science, Federal University of Santa Maria. Different plots sizes were created according to the number of plants in the crop row. To verify the randomness of the data distribution, we applied a sequence test between the plots within one line for individual and combined harvests. The use of ten plants per plot in experiments with peppers led to no randomness within the lines during the production of fruit fresh biomass. In experiments with snap beans conducted in a greenhouse, a plastic tunnel and by unprotected cultivation using plots with six or more basic units, 12 or more plants per plot produced random fresh biomass data for fruits within the crop row.O conhecimento da variabilidade da produção entre as parcelas experimentais no ambiente protegido se faz necessário, pois possibilita a redução do erro aumentando a confiabilidade nos resultados. Assim sendo, o objetivo deste estudo foi caracterizar a independência espacial das produções de frutos entre parcelas de pimentão e feijão-de-vagem. Foram utilizados dados de produção de ensaios de uniformidade realizados no Departamento de Fitotecnia da Universidade Federal de Santa Maria. Com os valores da produção individual foram simulados diferentes tamanhos de parcelas conforme o número de plantas na linha de cultivo. Para verificar a aleatoriedade da distribuição dos dados, foi aplicado o teste de sequências entre parcelas dentro da linha em colheitas individuais e agrupadas. O uso de dez plantas por parcela em experimentos com pimentão é suficiente para que não haja linhas com falta de aleatoriedade da produção de fitomassa fresca de frutos. Em experimentos com feijão-de-vagem conduzidos em estufa plástica, túnel plástico e cultivo não protegido o uso de parcelas com seis ou mais unidades básicas, 12 ou mais plantas por parcela, torna aleatória a produção de fitomassa fresca de frutos dentro das linhas de cultivo

Accuracy in the estimates of zucchini production related to the plot size and number of harvests

ABSTRACT: The productive variability in horticultural crops affects the planning and quality of the experiments, inflating the error and leading to wrong conclusions with low experimental accuracy and reliability. The objective of this study was to dimension the plot size and number of harvests that are necessary so that there is improvement in the accuracy of zucchini production. The production data used was the one from the uniformity trials where the basic units (BU) were identified with the number of crop row and were numbered according to the position inside the row. With the values of individual production, (fresh fruit biomass) different plots sizes were simulated by summing up the adjacent BUs in the crop rows and the two forms of harvesting groups. For each plot size simulated and their respective harvests, a variation coefficient (%) was estimated at the crop row. A response surface design was applied, with a dependent variable in the variation coefficient and, with the independent variable, the plot size and number of harvests. Best combination between plot size and number of harvests is seven plants and half the productive cycle in both growing seasons

The spatial and temporal independence of Italian Zucchini production

It is necessary to know the production variability of experimental units in a protected environment, both in terms of space and throughout different harvests. This knowledge helps reduce experimental error and increases result reliability in combination with the adoption of appropriate experimental techniques and cultural management. The objective of this study was to characterize the spatial and temporal independence of Italian Zucchini fruit production as cultivated in a protected environment. The study used production data from exploratory experiments under protected cultivation in the Department of Plant Sciences of the Federal University of Santa Maria. Different units sizes were simulated on the basis of known production values for the number of plants per row. To verify the independence or randomness of fruit production, a test run was applied to the units within the rows of individual and grouped harvests and in the same unit between individual and grouped harvests. There was a greater randomness of production in units with a higher number of plants. Using a lower number of harvests randomizes the production of units as the harvests are carried out. Groupings of harvests and units formed by four and five basic units are the most efficient combination for reducing non-randomness in the production of Italian Zucchinis

Spatial dependence and experimental precision in snap bean ( Phaseolus vulgaris L.) trials related to the number of plants and harvests

ABSTRACT The productive variability in horticultural crops affects the planning and quality of the experiments, leading to wrong conclusions. The objectives of this study were to verify the spatial dependence of the fresh biomass of snap beans and to dimension the number of plants and harvests that are necessary to improve experimental accuracy in trials. The data of the fresh biomass of snap beans from uniformity trials carried out in a greenhouse and in the field with semivariograms were created with data transformed into indicators. Thus, they were combined on scenarios of plot size and harvest grouping, and they were adjusted to the spherical, exponential and Gaussian models. A response surface was also applied, with the variation coefficient as a dependent variable and the numbers of plants per plot and harvests as independent variables. The estimates of the semivariogram models parameters indicated a weak spatial dependence. The average of the fresh biomass of snap beans is distributed randomly in the trials, and it is not influenced by the number of plants per plot or by the number of grouped harvests. The best combinations between the number of plants per plot and harvest, for the smaller variation coefficients, are plots of 24 plants for plastic greenhouse and field, and 28 plants for plastic tunnel, in the autumn-winter, combined with the grouping of all harvests. In the spring-summer the number of plants per plot was 30 for plastic tunnel and field, also combined with the grouping of all harvests

Posições das mudas de alface nas bandejas de poliestireno e efeitos na normalidade e homogeneidade dos erros na produção de plantas Positions of lettuce seedling on polystyrene trays and effects on normality and homogeneity of the errors in the plant production

A qualidade de um experimento pode ser descrita por intermédio de estatísticas, sendo o erro experimental um dos parâmetros de avaliação dessa qualidade. O objetivo do trabalho foi verificar a interferência de diferentes posições de mudas de alface em bandeja de poliestireno sobre a normalidade e homogeneidade dos erros em experimentos realizados em estufa plástica e em campo. Foram conduzidos seis experimentos no Departamento de Fitotecnia da Universidade Federal de Santa Maria, sendo três no verão (2006-2007) e três no outono-inverno (2007) com a cultura da alface, cultivar Vera. Os tratamentos foram 12 diferentes posições das mudas na bandeja de produção. As variáveis analisadas na produção de mudas e após o transplante aos ambientes foram a fitomassa fresca e seca da parte aérea e raiz e fitomassa fresca e seca da parte aérea, respectivamente. Foram testadas as normalidade e homogeneidade dos erros sendo comparadas às médias de cada tratamento. Há atendimento da homogeneidade e normalidade dos erros para as fitomassas fresca da parte aérea e de raiz de alface nos experimentos com diferentes posições de mudas na bandeja de produção, nos diferentes ambientes e estações sazonais de cultivo. Para a fitomassa seca da parte aérea não há atendimento da homogeneidade e/ou normalidade dos erros nos experimentos no verão, com produção de mudas e de plantas na estufa plástica. Para a fitomassa seca de raiz não há atendimento da normalidade dos erros no experimento no outono-inverno com produção de mudas.The quality of an experiment can be described through statistics, being the experimental error one of the parameters of the evaluation of such quality. The objective of this study was to verify the interference of different positions of lettuce seedlings on polystyrene trays on the normality and homogeneity of the errors in experiments conducted in plastic greenhouse and field. Six experiments were carried out in the Federal University of Santa Maria, being three in the summer (2006-2007) and three in the autumn - winter (2007) with the lettuce crop, cultivar Vera. The treatments were defined by 12 different positions of the seedlings on the tray of production. The analyzed variables in the seedling production and after their transplant to the environments were the fresh and dry phytomass of leaves and roots and the fresh and dry phytomass of leaves, respectively. Presuppositions of errors normality and homogeneity were tested being compared to the averages of each treatment. The assumptions of homogeneity and normality of experimental errors were adequate for the leaves and root phytomass of lettuce in experiments with different positions in the tray seedling production, in different environments and cultivation seasons. For the dry phytomass of leaves trere was no adequacy of homogeneity and/or normality of experimental errors in the summer experiments, with seedlings and plants in plastic greenhouse. For the dry phytomass of root there was no adequacy of the assumption of normality of experimental error in the autumn-winter experiment with seedlings