A comparison of analysis methods for late-stage variety evaluation trials

Authors

Sue J. Welham, Rothamsted Research, UK
Beverley J. Gogel, University of Adelaide
Alison B. Smith, Wagga Wagga Agricultural InstitueFollow
Robin Thompson, University of London
Brian R. Cullis, University of WollongongFollow

RIS ID

36785

Publication Details

Welham, S. J., Gogel, B. J., Smith, A. B., Thompson, R. & Cullis, B. R. (2010). A comparison of analysis methods for late-stage variety evaluation trials. Australian and New Zealand Journal of Statistics, 52 (2), 125-149.

Abstract

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 a two-stage unweighted approach performed poorly in both cases. A generalized heritability measure was developed to compare methods.