Ten maize single cross hybrids were studied for their STABILITY in GRAIN YIELD, 1000 kernel weight, kernel depth, kernel numbers per row and rows number per ear using regression coefficient (bi), deviation from regression (S2di), STABILITY variance (σ2i), ecovalence(Wi), coefficient of determination (R2), coefficient of variation (C.V.) and simultaneous selection method for GRAIN YIELD and STABILITY (YSi) indices. The experiments were conducted in Randomized Complete Block Design with four replications at 14 locations for 2 years(1998/99). According to the results, using all STABILITY indices, S2di, σ2i, Wi, R2, C.Y. and YSi, hybrids No. 6(KL17/2-5 x MO17) and No. 10(KSC704) were determined as stable hybrids. The highest GRAIN YIELD belonged to hybrids No. 6 and ten with 10.346 and 10.362 t ha-1 respectively. The heterogeneity of regression coefficients were significant only for kernel depth and kernel rows number per ear. GRAIN YIELD showed positive and highly significant correlation with 1000 kernel weight (r=0.45**), kernel depth (r=0.40**) and kernel numbers per row (r=0.64**). According to the regression coefficients, hybrids No. 6 and No. 10 did not show good response to environmental improvement in term of kernel depth and kernel rows number per ear.  

In order to evaluation of adaptability and GRAIN YIELD STABILITY of durum wheat genotypes, an experiment was conducted under rainfed and supplemental irrigation conditions based on a randomized complete block design with three replications at Sararood dryland agricultural research station (Kermanshah, Iran) for three cropping seasons (-,-and-). Analysis of variance (ANOVA) indicated significant differences (P< ) between the main effects due to genotype, environment, and genotype x environment (GE) interaction. The magnitude of GE interaction was greater about twice times than the genotype effect that indicates the probability of different environmental groups for the genotypes adaptation. Biplot analysis of GRAIN YIELD data based on AMMI model showed that the genotypes had different responses to the environments, so the adapted genotypes were determined for each environmental group. According to Ebrahat and Russell's criteria, genotype G and G with higher YIELD than grand mean, and minimum variance deviation and regression coefficient close to unit, were found as desirable genotypes. Based on AMMI STABILITY value (ASV), genotypes G, G and G were identified as most stable genotypes.

This research, was conduction in order to study on YIELD STABILITY of 17 irrigated wheat lines and 3 varieties in different environments. Wheat genotypes were planted with an RCB design and 3 replications in three regions, Esfahan, Kermanshah and Varamin. The results of combined analysis of variance for GRAIN YIELD showed the significant differences among wheat genotype effect, environment and G*E interaction effect as well. For determination STABILITY and adaptation parameters of GRAIN YIELD methods of Eberhart and Russell method and Wricke and Shukla method. Based on Eberhart and Russell's method, in genotypes 6, 10 and 5 having regression coefficient near to 1 and higher GRAIN YIELD was known as genotypes with general adaptability to all environments.Based on Wricke and Shukla STABILITY analysis, results showed genotypes 11, 16, 15 and 6 were known as stable genotype.

To investigate the response of new maize hybrids to different environmental conditions and determine their GRAIN YIELD STABILITY, an experiment was conducted using eight maize hybrids in a randomized complete block design with three replications in six locations in 2016. Due to the significant hybrid × environment (G × E) interaction, STABILITY analysis was performed using two multivariate methods, AMMI and GGE-biplot. The results of the AMMI model showed that only the first principal component (AMMI1) was significant and accounted for 72. 52% of the G×E variation. Based on AMMI model statistics (SPCA1 and ASV), the hybrids No. 1 ( KSC715B) and 5 (KSC706) were selected as the highest stable hybrids. The results of STABILITY anlaysis by GGE-biplot procedure showed that 83. 32% of the total GRAIN YIELD variation was explained by the first and second component of GGE-biplot and the hybrids No. 1 (SC715B) and 7 (SC703) were identified as the hybrids with higher STABILITY. In total, based on GRAIN YIELD and the results of STABILITY analysis using these two methods, the hybrids No. 7 (SC703) and 1 (SC715B) with GRAIN YIELD of 13. 16 and 12. 82 t/ha, respectively, were identified as the most stable hybrids with most high YIELDing and due to high general adaptability, cab be cultivated in different regions of Iran. Also, biplot of correlation among environments revealed that Moghan, Shiraz and Kerman as well as Ghaemshahr, Kermanshah and Karaj, were very close to each other and were similar in ranking the studied hybrids. Considering high dicreament power of hybrids in Shiraz, Kerman, Karaj and Ghaemshahr regions and in order to save the costs of future experiments, it is recomanded that the experiments be carried out in these four regions instead of six.

To select stable and high GRAIN YIELD wheat varieties as well as to determine suitable sowing date for cold agro-climatic zone in Iran, eight wheat varieties were studied using randomized complete block design with four replications in six locations (Sanandaj, Gorveh, Marivan, Divandarreh, Saggez and Baneh) during three growing seasons (2007-2010). Since interaction of cultivar´year´location was significant, STABILITY analysis was performed using different methods. Results of STABILITY analysis with shukla’s STABILITY variance method showed that the Zarrin and Sabalan varieties were more stable than other varieties. Also, lowest environmental variance was belonged to Azar 2. The results of ranking method showed that cultivars Sabalan, Bezostiya, Alvand, Alamout and Omid had the lowest i R and cultivars Alvand, Sabalan, Navid, Zarrin and Omid had also the lowest SDR among the experimental cultivars. Results of STABILITY analysis with YIELD - STABILITY statistic (YSi) method indicated that the varieties Alvand and Alamout were the most stable varieties, respectively. Results of this research showed that the Alvand and Sabalan varieties had the highest YIELD STABILITY than the other varieties and can be recommended for studied locations.

In order to study effect of G*E interaction on YIELD of 17irrigated wheat lines and 3 varieties in three different environment this research was done under late season water stress.These genotypes were planted using RCB design with 3 replication in; Esfahan, Kermanshah and Varamin. The results of combined analysis of variance for YIELD showed significant difference for genotype, locations and G*E interaction effect.Because of significant G*E interaction STABILITY analysis methods of Wricke and AMMI were used for determination of desirable genotypes for YIELD. Based on Wricke's STABILITY analysis genotypes no.12, 20 and 6 were known as stable genotype.Based on AMMI method, genotypes no.12, 6 and 20 showed general adaptability and genotypes 14 and 15 recognized to have specific adaptability to Varamin and genotypes no.9, 8, 7, 11 and 4 had specific adaptability to Kermanshah.Overall, based on STABILITY analysis on YIELD under late water stress genotypes no.6, 20, 10, 12 and Marvdasht with having good adaptability were determined as desirable genotypes.

The objectives of this study were to analyze genotype by environment (GE) interactions on the GRAIN YIELDs of 18 promising durum wheat lines selected from joint project between Iran and ICARDA along with two national durum (Zardak) and bread wheat (Sardari) checks by the additive main effects and multiplicative interaction (AMMI) model and to evaluate genotype (G), environment (E) and GE interactions using statistics parameters i.e., AMMI STABILITY value (ASV) and ecovalence (W2). The trials were conducted at four locations, representative for multi-location durum YIELD trials, in Iran under rain-fed (unfavorable) and supplemental irrigation (favorable) conditions for three successive cropping seasons (2005-07). Main effects due to E, G and GE interaction as well as three first interaction principal component axes (IPCA 1-3) were found to be significant (P<0.01). AMMI biplots were able to distinguish genotypes, with wide and specific adaptation, and environments, with high and low genotype discrimination ability. The genotype G9 with the highest mean YIELD was to be most stable genotype, while the G16, G17 and G18 with the highest contribution to GE interaction were to be most instable. The results of recommended genotypes based on AMMI analysis showed the G15, G9 and G12 were highly adapted to rain-fed and supplemental irrigation conditions of Kermanshah.The all genotypes from ICARDA (G16, G17, G18) were highly adapted to both rain-fed and irrigation conditions of Ilam. The best genotypes for rain-fed condition of Maragheh were G15 and G1 while the G15 and G16 were the best for supplemental irrigation condition. The genotypes G15, G9 and G1 were the best for Shirvan. In this study the G15 was the genotype with the best adaptation in three locations of Sararood, Maragheh and Shirvan.

In order to determine the adaptation and STABILITY of GRAIN YIELD in 8 rice promising genotypes as well as two commercial cultivars (Khazar and Neamat), as control, a field experiment was carried out in three locations in Gilan province during 1997 and 1998 cropping seasons. The experimental design was randomized complete block with 4 replications and planting distance was 25 cm ´ 25 cm. Analysis of variance showed significant differences for GRAIN YIELD among genotypes. Combined ANOVA was also performed following Bartlett test (for uniformity of error variances). Year and location effects were considered random while genotypic effect fixed. The F test was calculated based on expected mean squares. Results showed significant differences among the genotypes. The effects of location and year and genotype´location and genotype ´year interactions were not significant. It means that the genotypes had similar response over different locations and years. However, the interaction effects of year´location, and year´location´genotype were significant. STABILITY of genotypes were evaluated using six different methods including: variance (S2i) and coefficient of variability (CVi) of environment (parameter no.1), coefficient of regression of mean YIELD on environmental index (bi) (parameter no.2), variance of deviation from regression (S2di) (Parameter no.3) and within location variance (MSy/p) and C.V. (parameter no.4). Results of these methods were different more or less; however, genotypes no.7604 and 7606 as well as Khazar and Neamat were determined as stable genotypes, because low S2i, CVi and MSy/p and bi equal to unity and low and non- significant S2di. Consequently, due to higher mean YIELD compared to Khazar and the desired cooking and milling qualities, these two genotypes were selected to be released.

To study the STABILITY and adaptability of GRAIN YIELD and genotype x environment interaction, 19 promising triticale lines/varieties were evaluated in Moghan, Mashhad and Zabol Experimental Stations during 2001 to 2003 cropping seasons. The experimental design in all the locations and years was completely randornized block design with three replications. Combined analysis of variance carried out over locations and years. The place x year and genotype x place x year interactions were significant (P<1%). There was not significant difference between genotypes. The different STABILITY methods were used to identify stable genotypes in this research. The results of analysis on GRAIN YIELD using parametric method of Eberhart and Russell (1966), STABILITY of variance and Ecovalance indices (Shukla, 1972 & Wricke, 1962), environmental variance (Si2), coefficient of determination (R2), coefficient of variation (C.V.) and non-parametric method of rank (based on Rand SDR parameters) showed that genotypes No. 4, 12, 14, 17 and No. 11 were stable and high adaptable genotypes. The genotype No. 4 with high mean YIELD (6382kg/ha), the lowest deviation of regression (S2di=0.05, bi=1.08), the lowest STABILITY of variance (si2=0.01), the lowest Wricke ecovalance (Wi=0.24), the highest R2 (96.7%), the lowest standard deviation of rank (SDR=1.72) and low environmental variance (Si2=1.25) and coefficient of variation (C.V%=17.52) was determined as the most stable genotype.

In order to study the genotype environment interaction for GRAIN YIELD in new maize hybrids, 12 single crosses were evaluated based on a randomized complete block design with four replications (in 24 environments including 12 stations) within 2 years. Simple and combined analyses of variances showed that there were significant differences among genotypes. Significance of Bartlet test indicated the requisiteness of environment (with the highest coefficient of variation) elimination in all analyses. In order to evaluate interaction and determine the adaptation of genotypes, eight different parametric STABILITY analysis methods were employed in the study, including: Roemer environmental variance, Environmental coefficient of variation of Francis and Kanenberg , Finlay and Wilkinson's regression method, Eberhart and Russell's deviation of regression coefficient, Penthus coefficient of determination, STABILITY variance of Shukla, Wrick ecovalance and finally Muir method based on partitioning of GxE interaction sum of squares into change in order and in value. Based on Muir method it was indicated that 96/65% of interaction sum of squares were composed of change in rank. Based on SSIC which represents the two first types of Line and Binns STABILITY concepts Sc 76 was the most stable and high YIELDing genotype and this method was the most efficient one among the univariate parametric methods.