[01] Dereje Dobocha, Agronomy and Crop Physiology Program, Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Asella, Ethiopia. [02] Debela Bekele, Agronomy and Crop Physiology Program, Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Asella, Ethiopia. [03] Wegayehu Worku, Agronomy and Crop Physiology Program, Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Asella, Ethiopia. [04] Fasil Shimeles, Agronomy and Crop Physiology Program, Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Asella, Ethiopia. [05] Zenebe Mulatu, Agronomy and Crop Physiology Program, Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Asella, Ethiopia. [06] Almaz Admasu, Agronomy and Crop Physiology Program, Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Asella, Ethiopia.

The agronomic optimum plant density is decisive for future improvements in wheat production and productivity. A field experiments were conducted to study the effect of varieties and planting densities on yield and yield components of bread wheat at Lemu-Bilbilo district, Arsi Zone, on farmers’ fields during 2016 and 2017 main cropping seasons. The experiments were laid out in a randomized complete block design in split plot arrangements in which bread wheat varieties (Danda’a, Digelu and Hidase) were assigned to main plots and plant densities (100, 200, 300, 400 and 500 plants m^-2 with seed rate of 125 kg h^-1 as control) to subplots with three replications. Results pointed major factors varieties and plant densities showed significant differences for all parameters tested in specific sites and years except thousand kernels weight which was not significantly affected by different plant densities. Danda’a variety resulted in the highest grains spike^-1 (64.12), grain yield (6053.59 kg ha^-1) and biological yield of (14.29 t ha-1) whereas; 300 plants m^-2 was the optimum plant density for all the studied parameters. The difference in spike length, harvest index and thousand kernels weight of Danda’a variety was significantly at par with Hidase variety while the plant height was with Digelu variety. The interaction of varieties and plant densities did not show significant difference on parameters that have been taken except for grain and biological yields. The optimum grain and biological yields were found from Danda’a variety combined with plant density level of 300 plants m^-2. Therefore, the plant density of 300 plants m^-2 may be practiced for better production and productivity of Danda’a variety at Lemu-Bilbilo district and similar agro-ecologies.

Bread Wheat, Plant Densities, Varieties, Yield and Yield Components

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