Optimizing Intrarow Spacing for Enhanced Growth and Yield Performance of Faba Bean (Vicia faba L.) Varieties in Western Ethiopia.

Faba bean (Vicia faba L.) is a critical legume for food security and soil fertility in Ethiopia, yet its productivity remains suboptimal due to multiple constraints, including poor agronomic practices, among which suboptimal plant spacing contributes to yield gaps. Farmers often use arbitrary spacing, leading to inconsistent yields, while the performance of improved varieties such as "Gora" and "Moti" under varying densities is underexplored in regions such as Guduru. This study aimed to (1) evaluate growth and yield responses of faba bean varieties to intrarow spacing; (2) identify optimal spacing for yield maximization; and (3) assess variety × spacing interactions. A factorial experiment (3 varieties × 4 spacings: 5, 10, 15, 20 cm) was conducted in a randomized complete block design (RCBD) with three replications during the 2023-2024 cropping season in Guduru, Ethiopia. Data on phenology, growth, yield components, and economic returns were analyzed. Two-way ANOVA was performed using GenStat 15, with significant differences separated by Fisher's LSD test (p < 0.05). "Gora" and "Moti" outperformed the local variety in yield (3643 and 3189 kg ha-1, respectively) and harvest index (43% and 40%). Wider spacing (20 cm) enhanced individual plant performance (e.g., 45.3 seeds plant-1 for "Gora"), but 10 cm spacing optimized population-level yield (3080 kg ha-1) and economic returns (MRR > 100%). Moderate intrarow spacing (10 cm) with improved varieties ("Gora") maximizes yield and profitability in faba bean production. Future studies should explore genotype-specific spacing under diverse agroecologies and integrate modern agronomic practices such as precision planting to further enhance productivity.