Response of tef (Eragrostis tef [Zucc.] Trotter.) variety to varying seed rates and inter-row spacings for growth, yield and lodging severity in Western Ethiopia

Tef is a small-seeded staple crop endemic to Ethiopia. However, its yield is low, constrained partly due to improper agronomic practices and lodging. Thus, during the 2019–2020 cropping season, a field experiment was carried out at Reef Tokko Taanne Hamilee in Hababo Guduru district, Western Ethiopia to examine the effects of seed rate and inter-row spacing on growth, phenology, yield, and lodging severity of tef crop. Three levels of seed rates (10, 15, and 20 kg ha−1) and three styles of row spacing (10, 15, and 20 cm) were combined in a factorial combination in a randomized block design with three replications.Tef variety called ‘Guduru’ was used as planting material. The result showed that seed rate and inter-row spacing had significant (p < 0.01) effects on all phenological and yield-related characteristics studied. Moreover, days to heading, days to maturity, grain yield and harvest index were significantly affected by the interaction effects of both seed rate and inter-row spacing. Higher days to heading (68 days) and days to maturity (127 days) were recorded at a seeding rate of 20 kg ha–1  and10 cm inter-row spacing. Tef variety (Guduru) was taller (127.2 cm) under 10 kg ha–1 seed rate as compared to a higher seed rate of 20 kg ha–1 (120.8 cm). The highest dry biomass yield (51.3 kg plot−1) was obtained from a seeding rate of 20 kg ha−1 in combination with 20 cm inter-row spacing. Besides this, the maximum mean grain yield (19.8 kg plot−1) was recorded from 20 kg ha−1seed rate and 15 cm inter-row spacing to achieve a higher yield in the study area. Furthermore, the highest straw yield (35.99 kg plot−1) was produced from the highest seed rate of 20 kg ha−1, whereas the smallest inter-row spacing (10 cm) produced the highest straw yield (33.5 kg plot−1). The maximum harvest index (56.1%) was obtained from 20 kg ha−1 seed rate and 15 cm inter-row spacing, a similar treatment combination as in the case of grain yield. 10 kg ha−1 seed rate and 20 cm inter-row spacing showed lowest lodging severity (24.1%) and (32.3%), respectively. The result suggests that sowing of tef at 20 kg ha−1 seed rate combined with 10 cm inter-row spacing which resulted in higher grain yield, straw yield and harvest index, could be recommended in the study area to achieve higher tef production.