PARAMETRIC AND NON-PARAMETRIC STABILITY ANALYSES FOR GRAIN YIELD OF BREAD WHEAT (TRITICUM AESTIVUM L) GENOTYPES IN KAHRAMANMARAŞ CONDITIONS OF TURKEY

Abstract

Grain yield of 11 bread wheat genotypes, tested in a randomised complete block design with 3 replications over 6 years under Kahramanmaraş conditions was analysed by using seven parametric and 2 non-parametric stability criteria. The objectives were to assess genotype by environment interactions and to determine stable genotypes. The fallowing nine stability statistics were calculated: Eberhart and Russell's (1966) regression coefficient (b_i) and deviation from regression (S²_di), Pinthus's (1973) coefficients of determination (R_i²), Francis and Kannenberg's (1978) coefficient of variability (CV_i) and genotypic variance (S_i²), Tai's (1971) environmental effects () and deviation from the linear response (), Nassar and Huehn's (1987) ranks over environments (S_i⁽²⁾), mean of absolute rank differences (S_i⁽¹⁾). Furthermore, three-dimensional plots of mean response versus each parametric stability statistic and two-dimensional plots of mean grain yield versus non-parametric stability statistics were shown to visually evaluate the yield potential and stability estimates of the genotypes. According to these stability parameters genotype 2 (URES/BOW"S") was the most stable genotype for grain yield.