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Piepho H.-P.,University of Hohenheim | Williams E.R.,Australian National University | Michel V.,Landesforschungsanstalt fur Landwirtschaft und Fischerei Mecklenburg Vorpommern
Journal of Agricultural, Biological, and Environmental Statistics | Year: 2015

When generating experimental designs for field trials laid out on a rectangular grid of plots, it is useful to allow for blocking in both rows and columns. When the design is nonresolvable, randomized classical row–column designs may occasionally involve clustered placement of several replications of a treatment. In our experience, this feature prevents the more frequent use of these useful designs in practice. Practitioners often prefer a more even distribution of treatment replications. In this paper we illustrate how spatial variance–covariance structures can be used to achieve a more even distribution of treatment replications across the field and how such designs compare with classical row–column designs in terms of efficiency factors. We consider both equally and unequally replicated designs, including partially replicated designs. Supplementary materials accompanying this paper appear online. © 2015 International Biometric Society Source


Piepho H.-P.,University of Hohenheim | Williams E.R.,Australian National University | Michel V.,Landesforschungsanstalt fur Landwirtschaft und Fischerei Mecklenburg Vorpommern
Agronomy Journal | Year: 2015

Field experiments oft en show heterogeneity and trend in both rows and columns. It is therefore useful to consider blocking in both rows and columns of the field layout of plots. We provide a brief review of row-column designs and demonstrate the particular advantage of resolvable designs, which allow the treatments to be spread out over the experimental field by latinization of rows and/or columns of plots and by evenly distributing treatments between complete replicates, thus largely avoiding a clumped placement of replications of a treatment in a limited area of the experiment. An example from a field trial with silage maize (Zea mays L.) is used to illustrate the analysis of a latinized design using mixed model procedures. © 2015 by the American Society of Agronomy 5585 Guilford Road, Madison, WI 53711 USA All rights reserved. Source


Bull I.,Landesforschungsanstalt fur Landwirtschaft und Fischerei Mecklenburg Vorpommern | Gienapp C.,Landesforschungsanstalt fur Landwirtschaft und Fischerei Mecklenburg Vorpommern | Wiedow D.,University of Rostock | Burgstaler J.,University of Rostock
Journal fur Kulturpflanzen | Year: 2011

A long-term cultivation trial was established to estimate the agricultural potential of the perennial legume Galega orientalis (Lam.) in Mecklenburg-Western Pomerania. Herbage productivity was monitored for four years. The average annual dry-matter yield of fodder galega was about 10 t ha-1. This legume species was found to be very resistant to frost. Drought induces reduced growth, however there is no danger of dead loss. Diseases or pests were not observed. The plants reliably accomplished seed maturity. Laboratory experiments demonstrated that galega can be ensiled successfully according to the common principles of ensiling. The fermentation batch tests demonstrated the suitability for bio-energy production. Our results indicate that galega is suitable for cultivation under the natural conditions of Mecklenburg-Western Pomerania. Source

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