Journal of Crop Production and Processing

  To study the effect of cycocel, nitrogen and planting density on nitrogen (N) content, remobilization and use efficiency of Esfahan 14 safflower cultivar, a field experiment was carried out as a factorial split-plot based on randomized complete blocks design with three replications at Research Farm of College of Agriculture, Yasouj University, in summer of 2010. Main plots were the factorial level of N (50, 100 and 150 kg/ha) and level of cycocel (0 and 10^{- 6} M ) and subplots were planting density (20, 25 and 33.3 plants / m²). Results showed that the highest N remobilization (1.21%) was gained from 10^{-6 M cycocel application and the highest amount of N and planting density. The highest N treatment, along with planting density of 25 plants/m 2}, produced the highest seed protein (14%) and aerial N at flowering stage (2.15%). The highest grain yield (3146 kg/ha) and N use efficiency (62.9 kg/kg) was obtained from 10^{-6 M cycocel, lowest N level and 25 plants/m 2}. In general, increasing N application and planting density, with cycocel application, increases shoot N content and remobilization. However, lower amount of N application is associated with higher N use efficiency and seed yield.