Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Entire DC Network
A Comparison Of Analysis Methods For Late-Stage Variety Evaluation Trials, Sue Welham, Beverley Gogel, Alison Smith, Robin Thompson, Brian Cullis
A Comparison Of Analysis Methods For Late-Stage Variety Evaluation Trials, Sue Welham, Beverley Gogel, Alison Smith, Robin Thompson, Brian Cullis
Dr Alison Smith
The statistical analysis of late-stage variety evaluation trials using a mixed model is described, with one- or two-stage approaches to the analysis. Two sets of trials, from Australia and the UK, were used to provide realistic scenarios for a simulation study to evaluate the different methods of analysis. This study showed that a one-stage approach gave the most accurate predictions of variety performance overall or within each environment, across a range of models, as measured by mean squared error of prediction or realized genetic gain. A weighted two-stage approach performed adequately for variety predictions both overall and within environments, but …
Enhanced Diagnostics For The Spatial Analysis Of Field Trials, Katia Stefanova, Alison Smith, Brian Cullis
Enhanced Diagnostics For The Spatial Analysis Of Field Trials, Katia Stefanova, Alison Smith, Brian Cullis
Dr Alison Smith
We report an analysis of a series of uniformity field trials using the technique proposed by Gilmour, Cullis, and Verbyla. In particular, we clarify the role of the sample variogram and present a range of enhanced graphical diagnostics to aid the spatial modeling process.We highlight the implications of the presence of extraneous variation related to commonly used agronomic practices, such as serpentine harvesting.