SUMMARY
We investigated the effect of humic acid and new Zn nano fertilizer derived from some physiological traits and yield of Summer savory plant under greenhouse conditions. The treatments consisted of four levels of each of humic acid (0.0, 0.5, 1.0 and 1.5 mg/L) and nano Zn chelated fertilizer (0.0, 50, 100 and 200 mg/L). The application of humic acid and nano Zn chelated fertilizer alone and together increased amounts of studied characteristics. The highest amounts of these traits were obtained from the simultaneous utilization of both types of fertilizers. The combined use of these fertilizers improved the length of root and increased to access to more volume of soil. The enhanced root growth enabled the plant to uptake more nutrients resulting in improved growth and yield. A significant increase of leaf width (4 cm), number of branches (20) root length (12.7 cm), iron concentration (21.25 mg kg-1), zinc (0.95 mg kg-1), nitrogen (1.21 mg/g/fw) and potassium concentration (53.68 ppm), essential oil percent (2.58%) and yield (47.81 mg/pot) of savory were recorded in the application) H4=1.5 mg/L humic acid and N4= 200 mg/L nano Zn chelated) compared to the control (N1=0 nano Zn chelated and H1=0 humic acid). The study suggests that combined use of humic acid and the nano Zn chelated fertilizers can have greater impact on increasing the yield and quality of products such as savory.