Effect of Nitrogen Fertilizer and Seed Rates on Growth, Yield and Yield Components of Bread Wheat in Jimma Zone South Western Ethiopia

Wheat is one of the most important cereal crops in terms of production and consumption in Ethiopia. The country has the potential to produce a sufficient amount of wheat grain using irrigation, and government also gave attention to produce wheat and export it. But inappropriate agronomic practices, soil fertility depletion, and drought are among the constraints to the low yield of wheat crops in the country. In view of this, the field experiment was conducted during the irrigation season of 2020/2021 in two districts that are selected as irrigation potential and irrigation facilities namely, Sekacokorsa and Tiroafetadistricts of Jimma zone. The field experiment consisted of four N fertilizer rates (0, 23, 46, 69, and 92 kg Nha^-1) and three seed rates (125, 150, and 175 kg•ha^-1). The experiment was laid out in a randomized complete block design with a factorial arrangement in three replications. From the field experiment results, the growth, yield and yield components of the crop were improved by optimizing plant population density and nitrogenfertilizerapplication. Numerically the highest grain yield and above ground biomass of 6.7 and 13.09 t•ha^-1at Tiroafeta and 3.67 and 9.61 t•ha^-1 at Sekacokorsawas recorded in response to the seed rate of 175 kg•ha^-1 respectively. On other hand in response to N fertilizer rate the maximum grain yield of 6.9 t•ha^-1and above ground biomass of 14.04 t•ha^-1 at Tiroafetawas recorded from 92kg N ha^-1and 69 kg N ha^-1 respectively. Whereas at Sekacokorsa the highest grain yield of 3.72 t•ha^-1and above ground biomass of 9.76 t•ha^-1 was obtained from nitrogen fertilizer rate of 46kg N ha^-1. In conclusion, N fertilizer rate of 46kg•Nha^-1 and seed rates of 125 kg•ha^-1in both locationsgavethe optimum yield. But due to the field experiment was done for one year only it should be repeated over the years to give sound recommendationsunder similar agro ecologies.