m. barzali

The aim of the present study was to evaluate and interpret the genotype × environment interaction for advanced rainfed lentil lines. Fifteen advanced rainfed lentil lines (genotypes) along with two commercial cultivars (cv. Gachsaran and cv. Sepehr) as check were evaluated using randomized complete block design with three replications in Gachsaran, Moghan, Khorramabad and Ilam field stations in Iran in 2019-20 and 2020-21 cropping seasons. The mean seed yield of trials was 891 kg ha-1. Genotype 10 with 1031 kg ha-1 had the highest mean seed yield, and genotype 16 (cv. Gachsaran) with 728 kg ha-1 had the lowest. Since genotype × environment interaction was significant, yield stability analysis was performed. Evaluation of the seed yield stability of genotypes by rank method showed that genotypes 12 and 10 had high seed yield and yield stability. In addition, yield stability analysis using WAASB index, as a multivariate method, was also performed. The seed yield × WAASB index biplot showed that most of the lentil genotypes had higher seed yield and yield stability than the check cultivars (cv. Gachsaran and cv. Sepehr). Genotypes 12, 13, 11, 10 and 1 had higher seed yield and yield stability than the superior check cultivar (cv. Sepehr). Considering the equal contribution for mean seed yield and yield stability in the calculation of WAASBY index, genotypes 10, 13, 11, 12, 1 were ranked as the most desirable genotypes for target environments.

In this study, 14 advanced chickpea genotypes selected from regional experiments with Adel and Azad, as control cultivars, were cultivated in a randomized complete block design with three replications in eight environments (Gonbad, Gachsaran, Ilam and Khorramabad in three, two, two and one years, respectively) in Iran during 2017-2020 growing seasons. Combined analysis of variance showed that environment, genotype and genotype by environment interaction (GEI) explained 43.5, 19.8 and 36.7% of the total variation of grain yield, respectively. The first and second principal components accounted for 50.89% and 19.39% of variation, respectively. The polygonal view of biplot showed that genotypes G11, G14 and G9 were the most adaptable genotypes for environments E2, E3, E6, E7, E8, E4 and E5 and G8, G5 and G13 for E1. Based on average tester coordinate (ATC) view, genotypes G11, G5, G13 and G14 were the most stable and high-yielding genotypes. The GGE-biplot based on genotype-focused scaling showed that genotypes G11, G14, G8, G9 and G13, in the circles around the ideal genotype, were the most preferred genotypes. The priority index (PI) showed that in all environments and favourable environments (environments with higher than average grain yields), genotypes G11, G9, G16, G13 and G14 and in unfavourable environments (environments with lower than average grain yields), genotypes G11, G13, G14, G12 and G5 were superior genotypes. Based on different biplot views as well as priority index, genotypes G11, G14 and G5 had grain yields higher than average yield and yield of Adel and Azad cultivars. Further, given their grain yield stability in all environments they can be suitable candidates for introduction of new cultivars.

Sixteen chickpea genotypes and two commercial cultivars; Adel and Azad as check were evaluated under rainfed conditions using randomized complete block design with three replications at four filed stations; Gachsaran, Gonbad, Khorramabad and Ilam for three cropping seasons (2016-2019). Genotypes 5, 12, 11, 17 and 4 had the highest seed yield. Genotypes 18, 16, 6, and 3 had high seed yield stability based on Shukla variance (2i ), Wrick's equvalence (Wi), root mean square error (RMSE), Si1 and Si2 statistics. Genotypes 16 and 18 with regression coefficient close to one, seed yield higher than average yield and the lowest deviation from regression line were the superior genotypes. Analysis of variance using Eberhart and Russell method showed a significant genotype × environment interaction effect (linear) which indicated different response of genotypes to environmental conditions. Genotypes 4, 5, 9, 11, 12, 15, 16 and 18 were the best genotypes based on yield-stability index (YSi). Based on TOP nonparametric statistics, genotypes 5, 12, 15, 9 and 4 were superior genotypes. Based on Lin and Binns priority index, genotypes 12, 5, 11, 17 and 18 were desirable genotypes in all environments. In conclusion, genotypes 4, 5 and 12 can be considered as high yielding with yield stability and suitable for further verification in research and development projects.

Lentil cultivar Sepehr was first introduced as FLIP 2005-53L line through LIDTN-L-08 ICARDA international nursery and was evaluated in Gachsaran and Maragheh stations in 2007-2008 cropping season. FLIP 2005-53L line in the cropping seasons 2008-2009 and 2009-2010 was evaluated in the preliminary and advanced yield trials in Gachsaran and Khorramabad research stations. After evaluating the results of advanced experiments, this line was selected to participate in the national uniform regional yield trial (2010-2013) in Gachsaran, Khorramabad, Gonbad and Moghan research stations. Stability analysis of genotypes grain yield in this experiment showed that this line had the lowest contribution in the interaction of genotype × environment using different statistical methods and also it had the lowest mean rank values ​​for non-parametric stability parameters as well as 19% increases in the grain yield (with grain yield of 1166 kgha-1) ‌ compared to the control cultivar Gachsaran (with grain yield of 978 kgha-1) and therefore can be considered as "one of the most stable genotypes" with high grain yield. FLIP 2005-53L line with average grain yield of 1902 kgha-1 in farmers field in the research-extension trials, had a 15% advantage of grain yield over control cultivar Gachsaran with grain yield of 1651 kgha-1. In addition to high grain yield, good yield stability, high resistance to fusarium disease, desirable 100-seed weight (4.2 g) and suitable plant type and plant height for machine harvesting were other reasons for releasing Sepehr cultivar. Sepehr cultivar is suitable for cultivation in subtropical regions of the country including Khuzestan, Fars, Kohgiluyeh and Boyer-Ahmad, Lorestan, Kermanshah, Ardabil (Moghan) and Ilam provinces.

In order to study the effects of four tillage systems on yield components of three soybean cultivars, an experiment was conducted in a field at Araghi -Mahalleh Research Station of Gorgan in summer of 1997, after wheat was harvested. The experiment was factorial based on a randomized complete block design with four replications and 12 treatments. Treatments ware the combinations of four tillage systems and soybean cultivars. The tillage systems were T__1) burning wheat straw two perpendicular disks irrigation a shallow disk planting, T__2) burning wheat straw irrigation direct drilling (no-tillage), T__3) two perpendicular disks on the field consisting of wheat straw irrigation planting and T__4) irrigation direct drilling on the field having wheat straw (no-tillage). The three soybean cultivars used in the experiment were williams, Gorgan 3, and Sahar. Characteristics such as number of days from sowing to flowering and maturity, number of seeds per pod, number of pods plant, number of seeds per plant, 1000 seeds weight, and grain yield were measured. The results indicated that the T__3 and T__4 tillage systems increased number of days flowering and maturity, 1000 seeds weight, and grain yield, compared to the other systems. However, there was no significant difference among four systems in number of seeds per pod. The number of days from sowing to flowering and maturity and number of pods per plant in sahar cultivar were higher than those of the other two cultivars. The highest grain yield was obtained from sahar cultivar under T__4 tillage system. In this experiment, 1000 seed weight was the only component that showed significant positive correlation coefficient with the grain yield.