Determination of optimum plant density for faba bean (Vicia faba L.) on vertisols at Haramaya, Eastern Ethiopia

A field experiment was carried out to identify the optimum plant density, inter and intra-row spacing for the maximum agronomic performance of Gachena (a recently released faba bean variety). A three by three factorial combinations of inter-row (30, 40, and 50 cm) and intra-row (8, 10, and 12 cm) spacing were used as treatments and laid out in a randomized complete block design (RCBD) with three replications. The results of this experiment showed that there was a significant difference in all parameters measured except in 100 seed weight and harvest index. The widest inter and intra-row spacing (12 × 50 cm) gave a significantly higher number of branches per plant, number of pods per plant, seeds per pod and seed yield per plant. Besides, it helped the crop to mature earlier than under the narrowest spacing. On the other hand, the widest spacing produced a lower leaf area index (LAI), plant height, seed yield (kg ha−1) and total dry biomass (kg ha−1). 30 × 8 cm spacing combination was found to be optimum spacing that can give the optimum economic yield on vertisols