BACKGROUND: Growth regulators are organic substances besides nutrients, synthesized in plants, causing alteration in their cellular metabolism. Synthesis of some plant hormones is adversely affected by environmental factors, which causes restriction on physiological processes of the plant and ultimately, limits their growth potential. OBJECTIVES: Current research was done to evaluate plant growth regulator (Auxin Hormone) on crop production of Bread Wheat cultivars. METHODS: This study was conducted via split plot experiment based on completely randomized block design (RCBD) with three replications. The treatments included wheat cultivars at three levels (Chamran 2, Behrang and Mehregan) and auxin hormone at three levels (including zero or control, 50 ppm and 100 ppm.ha-1), which were placed in the main and sub plots, respectively. RESULT: According result of analysis of variance effect of Auxin, cultivar and interaction effect of treatments (instead harvest index, number of seed per spike and 1000 seed weight) on all studied traits was significant at 1% probability level. Evaluate means comparison result indicated in different level of cultivar the maximum harvest index, number of seed per spike and 1000 seed weight was noted for Chamran 2 and minimum of that belonged to Mehregan cultivar. Compare different level of Auxin Hormone showed that the maximum and the minimum amount of harvest index, number of seed per spike and 1000 seed weight belonged to 100 ppm and control treatments. Assess means comparison result of interaction effect of treatments indicated maximum seed yield, biologic yield and number of spike per m2 was noted for Chamran 2 and 100 ppm Auxin hormone and lowest ones belonged to Mehregan cultivar and nonuse of auxin treatment. CONCLUSION: Finally, according result of current research foliar application 100 ppm Hormone with Chamran 2 Cultivar achieve highest amount of seed yield and its components and can be advised to producers in studied region. پرونده مقاله