The simultaneous effect of seed quality, plant density, and nitrogen fertilizer on physiological and yield characteristics of wheat (Triticum aestivum L.)

In order to study the effect of seed aging, plant density, and nitrogen fertilization on physiological and yield characteristics of wheat, an experiment was performed as a split plot based on RCBD with four replications in 2015-2016. Experimental factors were three levels of nitrogen in recommended amount, 15 and 30 percent more than the recommended amount (125, 143.75, and 162.5 kgN.ha-1, respectively) and plant density at two levels, namely 350 and 420 plants per square meter which were the main plots and seed quality at four levels including control, 15, 30, and 45 hours of accelerated aging was subplots. Grain yield, protein and starch performance were significant under the triple effects of seed quality, planting density, and nitrogen fertilizer. With increasing levels of seed aging significant reduction were observed in all traits (except grain protein and nitrogen percentage). Application of nitrogen fertilizer 30 percent more than the recommended dose, as well as plant density of 420 plants per square meter significantly increased grain protein and nitrogen percentage. The highest average protein yield was achieved in the combined treatment of 350 plant square meters at 30-hour aging level and nitrogen fertilizer at 15 percent more than the recommended dose and also in combined treatment of 420 plant square meters, 45-hour aging level, and the nitrogen level 30 percent more than the recommended dose. Generally, seed deterioration reduced its quantitative and qualitative characteristics but more nitrogen fertilizer improved quality traits, thereby improving the quality loss.