Response of spring wheat (cv. Alvand) to gibberellin and cycocel

In order to evaluate the effect of gibberellin and cycocel on spring wheat, a factorial experiment based on completely randomized design with three replications was conducted in 2009 in the Greenhouse of the Faculty of Agriculture, University of Tabriz, Iran. Seeds of wheat were sown in pots with 9 liters volume in spring. Plants at two leaf stage were thinned to six plants per pot. At the stage of stem elongation, control pots were separated and treatments of gibberellin andcycocel were applied on other pots. Effect of different treatments on important traits, including plant height, internode length, stem diameter, leaves per plant, nodes per main stem and tillers per plant were measured during six consecutive weeks. Plant height, internode length, stem diameter, leaves per plant, nodes per main stem and tillers per plant increased with increasing days after sowing. The highest number of leaves per plant were observed at 70 days after sowing, but the highest values of other traits were observed 77 days after sowing. The highest plant height and internode length were recorded for plants treated with gibberellin, but the highest stem diameter and number of tillers per plant were observed in plants treated with cycocel. Thus, application of cycocel at stem elongation stage can reduce plant height and increased tillers per plant which are essential for preventing lodging and improving grain yield in spring wheat.