One of the most important characteristics in determining the dendrometrical properties of a stand is the annual height increment of the trees. On the basis of these increments, natural phases of the trees’ life are defined. In the present study the data concern the height increments of the main trunk of 25-year-old Scots pine, as well as simulated data. Our research deals with the application of longitudinal data analysis. This analysis is usually used when measurements are taken at the same treatments...
Annual height increments are a very important characteristic of Scots pine. They have a direct effect on the determination of the dendrometric properties of a stand, such as volume increment. In the present study the data concern height increments of the main shoot in selected age classes of trees (age 72 to 92 years). A relationship is determined between the values of the increments and meteorological conditions such as temperature, precipitation and sunshine. On the basis of lasso regression analysis,...
In studies of organic soil degradation and transformation, alongside the conventional methods used in soil science, an increase in the importance of advanced statistical methods can be observed. In this study some multivariate statistical methods were applied in an investigation of organic soil transformation in the central Sudetes. Andrews curves, linear and kernel discriminant variable analysis and cluster analysis were used. The similarities among peatland soils and their layers were determined....
A method of discriminant variable determination was used to visualize the division of oak trees into Kraft classes. Usual discriminant variables and several types of kernel discriminant variables were studied. For this purpose the traits of oak (Quercus L.) trees, measured on standing trees, were used. These traits included height of tree, breast height diameter and crown projection area. The use of the Gaussian kernel and modified Gaussian kernel enabled the clearest division into Kraft classes....
An analysis is made of the possibility of reducing numbers of measurements in DUS (distinctness, uniformity and stability) trials on varieties of white mustard and oilseed rape, based on the results of DUS trials performed in the years 2005–2009 by the Research Centre for Cultivar Testing. It is shown that, when decisions are taken after three years of testing, it is possible to decrease the number of measurements by 50%, with the decisions practically unchanged for both considered species. For...
In breeding experiments conducted prior to tests connected with the registration of new breeding lines of crops, pre-preliminary and preliminary trials are carried out. In this study a comparison was made among some models of analysis of variance, in relation to the selection of new breeding lines of spring barley (Hordeum vulgare L.). The aim is to determine whether the choice of model of analysis of variance may influence the choice of tested breeding lines. The trait considered was the yield...
The differences between individual breeding lines of spring barley and a control variety were tested in terms of several measured (continuous) and qualitative traits. The impact of the qualitative traits (diseases) on the quantitative traits, especially yield, was assessed on the basis of the significance of differences for both qualitative traits and yield. Depending on the type of trait, either a logistic model or analysis of variance was used as a statistical tool. The statistically significant...
One of the main problems in plant breeding is the selection of the best genotypes. Most often the selection is made using yield as a main trait of continuous type, and ignoring the other traits of discrete type. Here, a simple procedure is proposed for dealing with the selection problem using not only the yield, but also an auxiliary discrete trait. The method is based on transforming the continuous variable into a discrete one and testing the dependence of variables with the use of contingency...
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