Comparison of models for estimating homeostasis in agronomic species

The results of five models which have been proposed for estimating a cultivar's stability were compared using vegetative yield in alfalfa and grain yield in wheats The five models compared were those proposed by Plaisted and Peterson, Plaisted, Wricke, Finley and Wilkinson, and Eberhart and Russell. The models were compared across 15 environments and five cultivars of alfalfa and 11 environments and 11 strains of wheat. Upon completion of data analyses rankings were made for stability under each of the proposed models. A comparison of the stability rankings from each model indicated that three models resulted in similar rankings. The other two models, Eberhart and Russell and Finley and Wilkinson yielded rankings which were different not only from the other three models but also different from each other. The model which was the easiest of the five to use was that proposed by Wricke.