Plant growth regulators play an important role in control of seed germination. This experiment was conducted to investigate the effect of lant growth regulators (indole-3-acetic acid, gibberellin and kinetin) on seed germination of Hordeum spontaneum. Seeds of wild barley were soaked in distilled water (control) or different concentrations of gibberellin (25, 50, 75, 100, 125 and 150 mg L–1), indole-3-acetic acid and kinetin (5, 10, 15, 20, 25 and 30 mg L–1). The following germination parameters were determined: germination percentage, germination index, mean germination time, germination energy, germination value, seedling length and seed vigour index. The results showed that plant growth regulators, depending on the used concentration, effectively improved all germination parameters except the mean rate of germination, which was increased only by indole-3-acetic acid at concentrations of 20 and 25 mg L–1. Gibberellin was generally shown to be more effective on all evaluated traits except the mean rate of germination. The highest values in germination percentage, germination index, germination energy, germination value, seed vigor index were obtained by using gibberellin at 75 mg L–1 and followed by 100 mg L–1. Gibberellin also at concentration of 50 and 125 mg L–1 led to the greatest mean germination time and seedling length, respectively.
