Investigating the Effect of Different Levels of Gibberellic and Salicylic Acids on the Improvement of Germination Indices of Festuca arundinacea under Allelopathic Compound Stress

This study was carried out to investigate the allelopathic effects of Eucalyptus camaldulensis on germination and early seedling growth of Festuca arundinacea under laboratory condition in order to determine the effect of pretreatments with gibberellic and salicylic acids on decreasing the destructive effects of allelopathic compounds. The chemical stimulators used in this study included: three levels of gibberellic acid (125, 250, and 500 ppm), three levels of salicylic acid (100, 200, and 300 mg/L) and 5 levels of allelopathic compounds of Eucalyptus camaldulensis (0, 25, 50, 75, and 100 %). The experiment was carried out in a factorial completely randomized design with four replications. The obtained data was analyzed using MSTAT-C software and the comparison of means was performed by Duncan test. The results of variance analysis and comparison of means indicated that Eucalyptus camaldulensis extract had inhibitive effect on germination and the early seedling growth of Festuca arundinacea. Early seedling growth of Festuca arundinacea was increased by the pretreatment of seeds in chemical stimulators. The highest effect on growth parameters belonged to gibberellic acid. The interaction effects of allelopathic levels and pretreatment with chemical stimulators were significance on the germination percentage and speed, root, shoot and plant length, and the seed vigor index.