Evaluation of Seed Yield Adaptability of Spring Safflower Genotypes Using Nonparametric Parameters and GGE Biplot Method in Rain-fed Conditions

In order to quantify GEI effects on the seed yield of 17 spring safflower genotypes and to identify stable genotypes under rain-fed conditions, multi-environment yield trials (MET) were conducted for four consecutive years (year-location combinations during 2003–06) at nine research stations in Iran. The results indicated that all factors (environment, genotype, interaction) were significant in this MET as judged by ANOVA, by Hildebrand procedure for non-crossover interaction (no change in genotypic rank) and by the de Kroon/van der Laan test for crossover interaction (change in genotypic rank). According to the results of all Hühn and Tennarasue nonparametric methods, genotype no. 11 (Gila)was found as the stable genotype. In addition, genotype no. 15 (Sina) was the most stable genotype among the others according to Fox et al. superiority index. Based on yield-stability statistic (YSi), genotypes no. 2 (S-541), 15 and 4 (Syria) were selected as the most stable genotypes in all environments. The GGE biplot analysis revealed that genotypes no. 15, 1 (Cyprobergon) and 4 were both high yielding and stable. GGE biplot and YSi identified genotype no.15 (Sina) as the most desirable genotype across years.