The grain of faba bean contains a high protein content of 24 to 33% (Winch, 2006). It serves as a source of food and feed with a valuable and cheap source of protein. It is a suitable rotational crop with nationally important cereal crops like teff, wheat and barley etc due to its nitrogen fixing capacity (MoA, 2014). It is a good source of cash to the farmers, and generates foreign currency to the country.  However, its share in the countries pulse export is small (Newton et al., 2011; Amanuel et al., 1993)

Production has been constrained by several yield limiting factors. The inherent low yielding potential of the local varieties is one of the most important production constraints. Even the yields of improved varieties of faba bean varieties are severely affected by the variability among locations and years. Therefore, the present investigation aimed at finding out high yielding and most adaptable faba bean varieties in central zone of Tigray, northern Ethiopia. We hypothesized that at least one of the released faba bean variety group means would be significantly higher yielder than the local check.

Study areas description

Field experiments were carried out in Laelay maichew and Tahtay maichew districts of the Central zone of Tigray, northern Ethiopia. They are located at 14°6’N to 38°46’E and 14°11’N to 38°43’E, and at an altitude of 1500 to 2250 and1500 to 2260 meters above sea level, respectively. They are situated in the northern semi-arid tropical belt of Ethiopia. The rainy season is mono modal concentrated in one season from July to September and receives from 700 to 800 mm rainfall per annum.

Experimental design, treatments and procedures

Nine released faba bean varieties (Walki, Hachalu, Tumsa, moti, Dagm, Obse, Gebelcho, Dosha, and Lalo) and one local check were evaluated for their yield and yield contributing characters at Laelay maichew and Tahtay maichew districts. Varieties were obtained from Holetta Agricultural Research Center (45 km from Addis Ababa) and Debrebirhan Agricultural Research Center in (130 km from Addis Ababa) in 2014. Treatments were laid out in randomized complete block design (RCBD) with three replications. Seed rate of 200 kg ha^-1 was used. The plots were 4 m (length) x 2.4 m (width) with six total rows (4 middle or harvested rows). Spacing between replications was 1.5 m and spacing between plots, rows and plants were 1 m, 40 and 10 cm, respectively.  Two seeds where planted per hill. After emergence, plants where thinned to one seed to maintain normal plant density. DAP (Di-ammonium phosphate) fertilizer at 100 kg ha^‑1 rate was whole applied at sowing. Weeds were controlled by hand weeding.

Data collected

Data were collected on plant and plot bases on yield and yield related traits. Data on days to 50% maturity was taken on plot bases. Whereas, data like plant height, numbers of pods per plant, and number of seeds per pod were determined on plant bases from the 4 middle rows of 10 randomly pre-tagged plants. Grain yield was recorded from 4 harvested middle rows. Grain yield was separated from the straw after sun drying for two weeks and yield per plot was converted into kg ha^-1. Finally, hundred seed weight was recorded by counting 100 seeds from each harvested plots.

Data analysis

Prior to analysis of the data, homogeneity of residual variances were assessed whether the normality assumptions of the data was violated. Thus, data were homogenous and showed normal distribution. All the collected data were subjected to analysis of variance (ANOVA) with statistical analysis software (SAS) computer software version 9.2 (SAS, 2002). Correlation analysis and treatments means were compared using least significance difference (LSD) at 5% probability level (Fisher, 1935).

Statistical analysis shows that there was significant difference among varieties for all yield and yield related traits (days to maturity, plant height, Number of pods per plant, number of seeds per pod, grain yield and hundred seed weight). However, the combined results showed no significant difference for genotype environment interaction for all studied traits (Table 1).

Grain yield showed highly significant and positive association with plant height and number of pods plant^‑1 (Table 2). These findings are in line with the findings of Abdelmula and Abuanja (2007) who reported significant and positive correlation of seed yield with plant height and number of pods per plant. HSW is significantly and negatively associated with plant height, number of pods/plant and number of seeds per pod. Similar results were also reported by Ashenafi and Mekuria (2015). Hence, faba bean production and productivity could be improved by selecting faba bean yield traits like number of pods per plant and plant height.

The lack of best performing and high yielding variety is the main challenge for faba bean production and productivity in central zone of Tigray. Ten varieties including the local check were evaluated for their adaptability, yield and yield related traits. Walki variety was found to be the most adaptable and high yielding genotype followed by Hachalu. Hence, faba bean production and productivity could be improved by using better yielding varieties such as Walki and Hachalu. In addition, a strong and positive correlation between the different traits and seed yield of faba bean could be used as a selection criterion in order to improve faba bean production and productivity.

The authors have not declared any conflict of interests.

The authors would like to thank Tigray Agricultural Research Institute for their financial support. In addition to this, they are sincerely grateful to the research members of crop core process of Axum Agricultural Research Center for their support during the entire period of the study.