Non-parametric stability analysis of sunflower oil yield trials

Abstract

A three-year experiment (2008, 2009, 2010) on twenty sunflower hybrids grown in 13 (2010) to 15 (2009, 2008) locations in the region of Vojvodina and central Serbia was carried out in order to study GEI (genotype × environment interaction) on oil yield and stability of hybrids using non-parametric measures of stability. The non-parametric test indicated the presence of significant crossover interaction [G(E) and E(G)]. Non-parametric measures Si(1) and Si(2) were used to determine stability of sunflower hybrids. The level of association among stability measures was assessed using Sperman's rank correlation. Significant differences in rank stability among 20 sunflower hybrids grown in 13 (2010) or 15 (2009, 2008) locations were found. According to non-parametric stability parameters Si(1) and Si(2), hybrids Baća and Vranac were most stable in all locations. Baća also had high oil yield in 2008 and 2009. In 2010 two new hybrids (NS-H-6612, NS-H-2069) were high yielding and stable for oil yield. Hybrid NS-H-111 was also stable in all locations in 2009 and 2010 and its oil yield was above average. The Spearman's rank correlation between non-parametric stability parameters, showed highly significant (P<0.01) rank correlations between Si(1) and Si(2), indicating that the two measures were similar in classifying the hybrids according to their stability under different environmental (location) conditions. Non-parametric measures of stability, based on ranks, could be recommended to agronomists and plant breeders.