Integrating parametric and non-parametric measures to investigate genotype × environment interactions in tall fescue

Abstract

Evaluation of yield performance and its stability is essential for yield trials conducted in different environments. We determined the forage yield stability of 24 tall fescue (Festuca arundinacea Schreb.) genotypes using different parametric and non-parametric stability measures and compared those stability statistics across 14 test environments (combination of year, location and moisture conditions) during 2008-2013 growing seasons. The results of parametric measures totally indicated that genotypes G21 and G3 were the most stable ones. However, the non-parametric measures identified G15 followed by G11, G3 and G13 as the most stable genotypes. These genotypes may be recommended for genetic improvement of tall fescue with high degree of adaptation. Principal component analysis based on the rank correlation matrix indicated that most of the non-parametric measures were significantly inter-correlated with parametric measures and therefore seem to be useful alternatives to complement parametric measures. Based on the static and dynamic concepts, the results revealed that stability measures can be classified into three groups.