organic fertilizers in the cultivation can accelerate their growth and better performance (Zarei 2019), D. moldavica L. has been able to have an inhibitory effect on various types of bacteria (Acimovic, Šovljanski et al. 2022)). This research was conducted in order to investigate the effect of different concentrations of humic acid on the vegetative and biochemical characteristics of the D. moldavica L. The experiment was conducted as a factorial in the form of a completely randomized block design in three replications.The results of analysis of variance showed that the effect of 1.5 g/ml humic acid on the measured traits was significant at 1% level. Average comparisons showed that the highest number of leaves was 33 and the lowest was 4 of the control, and the maximum root length, fresh weight, and dry weight at the concentration of 1.5 g/ml humic acid were significantly different from the control. The measurement of biochemical traits showed that the highest percentage of phenol, anthocyanin was related to humic acid with a concentration of 1.5 g/ml, but there was no significant difference compared to the control. The highest amount of DPPH with 46.3 percent is related to the treatment of 1.5 g/ml humic acid, which was increased compared to the control. Therefore, it can be concluded that humic acid can be used in order to reduce the consumption of chemical fertilizers and use organic fertilizers by supplying the plant's nutrient requirements and improving the quality of plant growth and inhibiting E. coli bacteria.

humic acid, antioxidant activity, DPPH