Yasin Norouzi - Department of Plant Production and Genetic Engineering, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran.
Mokhtar Ghobadi - Department of Plant Production and Genetic Engineering, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran.
Mohsen Saeidi - Department of Plant Production and Genetic Engineering, Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran.
Hulya Dogan - Department of Plant and Animal Production, Vocational School of Technical Science, Yozgat Bozok University, Yozgat, Turkey

In order to investigate the effect of nitrogen and cytokinin on the quantitative and qualitative characteristics of thyme, a three-year factorial experiment was conducted at Razi University based on a randomized complete block design with ۳ replications. Factors included nitrogen levels (۰, ۵۰ and ۱۰۰ kg N/ha) and cytokinin concentrations (۰, ۱۰۰, ۲۰۰ and ۴۰۰ μM). The results of analysis of variance showed that the interaction effect of nitrogen × cytokinin on plant height, number of branches, leaf, stem and whole plant dry weights, essential oil percentage and yield was significant (p ≤۰.۰۱). With increasing the amount of nitrogen and cytokinin, all the studied traits (except harvest index) increased significantly compared to the control. The highest plant height and number of branches were obtained in the treatment of ۱۰۰ kg N/ha × ۴۰۰ μM cytokinin. The treatment of ۱۰۰ kg N/ha × ۱۰۰ μM cytokinin resulted the highest production of dry weights of leaf (۳۲۸۷ kg/ha), stem (۳۱۱۰ kg/ha) and whole plant (۶۳۹۸ kg/ha); aproximately ۶۰.۵, ۵۹.۸ and ۶۰.۹% more than the control treatment, respectively. Also, the highest percentage of essential oil (۲.۴۵ %) was obtained by applying ۵۰ kg N/ha × ۴۰۰ μM cytokinin. Application of ۱۰۰ kg N/ha and foliar application of ۲۰۰ μM resulted in the highest essential oil yield (۷۷.۶۰ kg/ha). In general, the results of this experiment showed that the quantitative and qualitative yield of thyme can be increased by consuming the appropriate amount of nitrogen and cytokinin.

Essential oil, Fertilizer, hormone, leaf dry weight