Association of Different Parametric and Non parametric Stability Models in Durum Wheat (Triticum turgidum Desf.) Genotypes

Thirteen durum wheat genotypes were evaluated in a randomized complete block design with three replications across four locations of north western Ethiopia for two consecutive years (2010 and 2011). The objective of this experiment was to investigate the association of different parametric and non parametric stability models that can be used for stability analysis of multi location trials. Spearman rank correlation showed that a significant positive perfect correlation between Shukla’s stability variance (σi2) and Wricke's ecovalence (Wi) stability models. This indicated that instead of using the two stability models, only one of these stability models can be used for identifying stable genotypes in multi location wheat trials. However, Coefficients of determination (ri2) and deviation from regression (Sdi2) showed a highly significant negative rank correlation (r = - 0.8581), which implies neither of these stability model alone could be sufficient for identification of stable genotypes that had consistence grain yield performance across different locations.