Effects of bio-stimulators on morphological and phytochemical parameters of Calendula officinalis L

Calendula officinalis L. from Compositae family as an important medicinal plant is used in Homeopathic methods and treatment of scalds and skin illnesses. This investigation is planned for the desirable effect of bio-stimulators foliar application on morphological and phytochemical parameters of plants. The experiment with completely randomized blocks design was conducted in 10 treatments with 3 replicates in 1390. Treatments of experiment included bio-stimulators with commercial formulations of Aminol forte, Kadostim, Fosnutren, Humiforte (0.75 and 1.5 L.ha^-1) and chemical fertilizer N, P, K (70kg.ha^-1 before sowing) and control treatment (without foliar application). Results showed that effect of these treatments was significant (P<0.01) on 6 parameters (except for chlorophyll) in a way that the most effect on leaf fresh weight (215g/m²), leaf dry weight (54.24g/m²), relative water content (RWC) (88.58g), leaf area (492.33mm²) and total flavonoides in leaves (18.76mg/g DW) with Humiforte 1.5 L.ha^-1, total flavonoides in capitols with Aminolforte 1.5 L.ha^-1 (50.02mg/g DW) and the least effect on all of parameters was obtained with control. According to these results application of Humiforte and Aminolforte is recommended because of existence of three macro elements Nitrogen, Phosphorous, Potassium and amino acid compounds.