زیست سنجی اثر دگر آسیبی عصاره زعفران بر برخی خصوصیات کمی و کیفی چهار گونه دارویی خانواده نعناعیان.

Considering the growth period of saffron, intercropping it with species that have similar needs could be a favourable option for optimizing land use, provided that the allelopathic effects of saffron are taken into account. In order to investigate the allelopathic effect of saffron on quantitative and qualitative traits of some medicinal plants, an experiment was conducted under greenhouse conditions at Ferdowsi University of Mashhad, Iran. Treatments were a combination of 4 species (Thymus vulgaris, Zataria multiflora, Ziziphora clinopodioides and Teucrium polium and corm and leaf extracts in four levels (0, 3000, 6000, 9000 mg.kg^-1 ) arranged in a completely randomized design with four replications. Measured parameters were the fresh and dry weight of root and shoot, shoot-to-root ratio, stomatal resistance, SPAD reading and essential oil percentage and yield. Results indicated that interaction of corm and leaf extract concentrations affected fresh weight of root and SPAD reading. Four species showed different trends in different extract concentrations. In Thymus vulgaris and Zataria multiflora, with increasing extract concentration, stomatal resistance initially increased and then decreased, but other species did not follow this trend. By increasing extract concentration, SPAD reading initially increased and then decreased. In all species studied, except Thymus vulgaris, an increase in extract concentration led to an increase in the shoot-to-root ratio. Additionally, as extract concentrations rose, the percentage of essential oil decreased. Overall, across all investigated species, the physiological and qualitative traits of the plants decreased with the use of saffron leaf and corm extracts. [ABSTRACT FROM AUTHOR]