The genotype × environment (GE) interaction analysis is fundamental in crop breeding programs to guide selection and for recommendation of high performing and stable genotypes for breeding objectives. This study aimed at quantifying the GE interaction effects and determines grain yield stability among winter bread wheat genotypes under rainfed conditions of Iran. Twenty-four winter wheat genotypes were evaluated under nine test locations using a randomized complete blocks design with four replications during three cropping seasons (2019–21). The additive main effects and multiplicative interaction (AMMI) model and several parametric and nonparametric stability statistics were applied for analysis of grain yield data collected from the experiments. AMMI analysis of variance for grain yield revealed significant effects (p < 0.01) for genotype, environment, and GE interaction. The environment was the main source of variation and accounted for 83.5% of the total yield variation, followed by GE (6.5%) and genotype (1.0%) effects. The AMMI biplot analysis indicated the genotypes G3, G23, G22, G10, and G19 as high yielding with stability performance across environments. Genotypes G14, G13, G20, and G9 showed large positive interaction with the environments featuring the highest rainfall during growing season, while genotypes G7, G6, and G21 had a large positive interaction with environments with low rainfall. Spearman’s rank correlation analysis revealed that the AMMI stability value, Shukla’s stability variance (σ2i), Wricke’s ecovalence (W2i), coefficient of determination (R2i), variance in regression deviations (S2di), and nonparametric statistic of S2(i) were not correlated with mean yield in tested genotypes, showing they are related to static/biological concept of stability. In contrast, the genotypic superiority index (Pi) and regression coefficient (bi) were significantly correlated (p < 0.01) with mean yield and corresponded to dynamic/agronomic concept of stability. These findings suggest that selection of genotypes should be considered based on selection objectives of using the various stability parameters described here. In conclusion, the selected genotypes in this study should be recommended as new cultivars or parental lines for grain yield and stability improvement under rainfed conditions of Iran or similar agro-ecologies.

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Present study was carried out to evaluate the effects of irrigation regimes and zeolite on the yield and quality parameters of silage corn hybrids. Study was conducted at Seed and Plant Improvement Institute in Karaj, Iran during 2013. The experiment was arranged in a three-replicated split-spilt plot based on randomized complete blocks design (RCBD) including three irrigation regimes as main plots (irrigation after 70, 100 and 130 mm evaporation from standard class A evaporation pan), two levels of zeolite as sub plots (0, 10 ton/ha) and three hybrids of silage corn (KSC704, KSC705 and KSC720) as sub subplot. Results of this study indicated that increasing water stress from optimum irrigation (Ir70) to moderate (Ir100) and low irrigation (Ir130) caused 25 and 37% reduction in forage dry matter yield but no significant difference was reported in protein yield. Moreover, application of zeolite have significant effect on forage yield and also have significant effect on protein yield (P<0.01). Forage quality parameters including water soluble carbohydrates, crude protein, acid detergent fiber and neutral detergent fiber increased and dry matter digestibility reduced when there was limited irrigation imposition. Among the tested corn seed hybrids KSC704 hybrid produced the highest dry forage yield and in terms of protein yield, no significant difference was reported between KSC720. KSC705 hybrid had the lowest acid detergent fiber and neutral detergent fiber and the highest dry matter digestibility.