عنوان مقاله [English]
In order to investigate the effects of different amounts of iron (1, 2 and 3 g L-1) in different stages of plant growth (20, 40, 60, 80 and 100 percent of ground cover) for sugar beet Beta vulgaris cv. AZARE) on the efficiency of iron consumption for production of leaf protein, aerial parts protein, root dry and wet weight, biomass and sugar yield in sugar beet, a factorial layout based on a randomized complete block design was conducted with three replications at Research Farm of Azar Ghand Naqadeh Factory in 2011. Analysis of variance showed the significant interaction effect of iron values × foliar spraying time on the Fe Use Efficiency (FeUE) for production of leaf protein, aerial parts protein, root dry weight, biomass and sugar yield. The highest FeUE for leaf protein (568) was obtained from 1 g L-1 at 40% of ground cover. While, the highest FeUE for aerial parts protein (1080), root dry (41769) and wet (268960) weight, biomass (98009) and sugar yield (128152) were observed in Nano-iron foliar application (1 g L-1) at 80% of ground cover. Reduction in Fe Use Efficiency along with higher concentration of iron spraying indicated low of diminishing returns for this micro nutrient.