The effect of different nitrogen fertilizer sources and doses on yield, yield components and some quali̇ty traits in bread wheat

To achieve high grain yield and quality in wheat, the appropriate dose, form, and timing of nitrogen application are crucial. This study was conducted during the 2022-2023 growing season to determine the effects of different nitrogen fertilizer forms and six doses on the yield and yield components of three bread wheat cultivars. The experiment was designed as a split-split plot design with three replications, with cultivars assigned to the main plots, fertilizer forms to the subplots, and nitrogen doses to the sub-subplots. In the study, the bread wheat cultivars Alada, Adalı, and Halis were treated with traditional urea containing pure nitrogen at doses of 4, 8, 12, 16, and 20 kg per decare, as well as urea with urease and nitrification inhibitors as the top-dressing fertilizers. Statistical differences at the 1% level were found among cultivars (excluding the number of grains per spike) and doses regarding the investigated characteristics. The effects of fertilizer forms and their interactions with the treatments applied in the study on all characteristics were statistically insignificant. Among the cultivars, the average plant height ranged from 99.6 to 107.2 cm, spike length from 8.7 to 10.4 cm, number of spikelets per spike from 14.3 to 18.1 no, number of grains per spike from 33.2 to 36.7 no, kernel yield per decare from 487.0 to 580.4 kg, thousand-grain weight from 37.1 to 42.8 g, test weight from 78.4 to 79.1 kg, wet gluten content from 24.9 to 26.4 %, and Zeleny sedimentation value from 33.8 to 35.6 ml. In the study, the average plant height ranged from 97.7 cm (D₁) to 104.8 cm (D₆), spike length from 9.1 cm (D₁) to 10.0 cm (D₅), number of spikelets per spike from 15.6 (D₁) to 17.1 no (D₅), number of grains per spike from 30.5 (D₁) to 37.9 no (D₅), grain yield from 475.7 kg da⁻¹ (D₁) to 548.1 kg da⁻¹ (D₅), thousand-grain weight from 38.1 g (D₁) to 40.5 g (D₄), test weight from 77.7 kg (D₁) to 79.0 kg (D₃, D₄, and D₅), protein content from 11.6 (D₁) to 12.9 % (D₆), wet gluten content from 23.7 ml (D₁) to 26.7 ml (D₆), and Zeleny sedimentation value from 31.7 ml (D₁) to 35.8 ml (D₆). The highest kernel yield was obtained from the Alada cultivar, while the nitrogen doses of 12 kg and 16 kg per decare resulted in higher yields compared to other doses.