Optimization of nitrogen rate and application time on grain yield and protein content of durum wheat (Triticum turgidum spp. durum) in Yilmana Densa district of northwest Ethiopia

Durum wheat is one of the cash and food crops in Ethiopia. Nowadays, the demand for the crop has increased enormously due to the expansion of pasta-making industries in the country. However, the productivity and quality of the crop have remained low partly due to a lack of appropriate N rate and application timing. Therefore, a field experiment was conducted to optimize N rate and application time on Nitosols of Yilmana Densa in 2022 and 2023 main rainy seasons. The treatments consisted of a factorial combination of four N levels (0, 80, 160, and 240 kg N ha-1) and four application time (A1 = 1/3 at planting + 2/3 at tillering, A2 = 2/3 at tillering + 1/3 at booting stage, A3 = 1/3 at planting + 1/3 at tillering + 1/3 at booting stage, A4 = 1/6 at planting, 4/6 at tillering + 1/6 at booting stage) in randomized complete block design with three replications. Data on plant height, thousand seed weight, hectoliter weight, grain yield, and protein content were collected and subjected to analysis of variance using SAS system. Maximum grain yield (4432 kg ha-1) and protein content (13.18%) were recorded at the interaction effect of 240 kg ha-1 of N rate and application time of 1/6 at planting + 4/6 at tillering + 1/6 at booting stage. This N rate and time of application gave the highest net benefit (ETB = 159650 ha-1) with acceptable MRR (256%) and could therefore be recommended for Nitosols of Yilmana Densa district.