Evaluation of Remobilization Indices in Wheat as Affected by Planting Density and Amounts of Nitrogen Fertilizer

This experiment has been performed to study the effect of seed sowing density and different amounts of nitrogen fertilizer application on the remobilization indices in wheat (Qaboos cultivar) in the field of Gonbad Kavous Agricultural and Natural Resources Research Station in two years (2018-19 and 2019-20) in three replications and as a split-plot in a randomized complete block design. The main plots include pure nitrogen at four levels, i.e., 0 (control), 46, 92, and 138 kg/ha of nitrogen from urea fertilizer source), and the subplots are planting density at six levels (150, 225, 300, 375, 450, and 525 seed/m2). The remobilization photosynthetic assimilate separately from leaves, main stem (without leaves), and seedless spike components are examined to study the process of photosynthetic material transfer to seed. Results show that there has been significant differences among planting density, nitrogen fertilizer, and interaction of planting density× fertilizer treatments in terms of grain nitrogen percentage and remobilization traits of wheat. The highest percentage of grain nitrogen (1.87%) has been obtained in the treatment of 138 kg/ha nitrogen and 450 seed/m2. In the first year, the highest remobilization from the plant is observed in the treatment of 92 kg/ha nitrogen and 375 seeds/m2 (0.528 gr/plant), and in the second year, in the control, the highest remobilization is observed in the planting density of 300 seeds/m2 (0.345 gr/plant), and then with increasing planting density, the remobilization from the plant is reduced.