Response of Winter Wheat Growth and Yield to Planting Date and Nitrogen Application Rate

The aim of this study was to investigate the interaction between planting date and the nitrogen application rate on the growth and yield of winter wheat in Torbat-e-Jam, Khorasan Razavi province. The field experiment was conducted in a randomized block design with split plot arrangements and three replications in Torbat-e-Jam, in the 2019-2020. Experimental treatments included three planting dates: 1 October, 17 October and 2 November as the main plot, and nitrogen fertilizer at levels 0 (as a control), 100, 125, 150, 175 and 200 kg nitrogen ha-1 as a subplot. Pishtaz cultivar was planted in experimental plots which included 7 planting lines with a row spacing of 15 cm and a length of 8 m. The results of the analysis of variance showed that planting date and nitrogen fertilizer application and their interaction had a significant effect on all measured traits. The results showed that the yield and yield components were the highest on 1 October, and the values of most of these traits showed a significant decrease in planting on 12 November compared to 10 October. The highest grain yield was obtained from a nitrogen application rate of 200 kg ha-1 on 1 October and 16 October, while the maximum yield was obtained with an application rate of 175 kg ha-1 on 2 November. The growth and yield response of wheat to the rate of nitrogen application decreased with a delay in planting date, and the option of planting date must be considered in order to recommend efficient fertilizer usage.