A COMPARISON OF ANALYSIS METHODS FOR LATE‐STAGE VARIETY EVALUATION TRIALS

• DOI: 10.1111/j.1467-842x.2010.00570.x
• Publication Date: 2010-05-26T14:38:14Z
• Authors: Sue J. Welham; Beverley J. Gogel; Alison B. Smith; Robin Thompson; Brian R. Cullis
• Keywords: 2. Zero hunger; mixed models; 0301 basic medicine; evaluation; analysis; variety evaluation trials; Statistics & Probability; trials; best linear unbiased predictor; late; heritability; stage; 310; methods; variety; 03 medical and health sciences; comparison; Physical Sciences and Mathematics; residual maximum likelihood

SummaryThe 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.