Effect of different levels of humic acid and nano-zinc fertilizer on the antioxidant enzyme activities And essential oil of Savory (Satureja hortensis L.)

Fertilizer management is utmost important factor in success of pharmaceutical crops cultivation. Application of biological fertilizers is important in production of these plants. Therefore the use of this type of fertilizers in the production of medicinal plants is expanding and seems to be becoming a global approach. The effect of humic acid and nano-chalate zinc fertilizer on activity of catalase, peroxidase, superoxide dismutase enzymes and essential oil of savory plant was investigated using a factorial experiment based on completely randomized design two factors and with four replications in a greenhouse at Zabol University in 2014. The factors were humic acid with four levels (zero, 5.0, 1 and 1.5 mg/L) and nano-chalate zinc fertilizer with four levels (0, 50, 100 and 200 g/L). The results of variance analysis showed that humic acid, nano zn chelated fertilizer and the interaction of factors had significant effects at 1 % probability level on leaf length, leaf area index, chlorophyll index, essential oil content and zinc conten, phosphorus, catalase enzyme, peroxidase enzyme and superoxidase dismutase enzyme but the interaction of nano zinc chelated and humic acid fertilizers was not significant on plant dry weight. The treatments showed significant effects on chlorophyll index, leaf length and area, enzyme activity of catalase, peroxidase, superoxide dismutase, zin contentc and percentage of essential oil. At all levels of humic acid, application of nano fertilizer increased the activity rate of catalase and peroxidase enzymes, zinc, phosphorus and essential oil percentage in the application of 1.5 mg/L humic acid and 200 g/L nano fertilizer increased 58, 34, 75, 26 and 77%, respectively. Application of 1.5 mg/L humic acid and 200 g/L of nano fertilizer had the greatest effect on leaf area index (4), plant dry weight (16.15 g), leaf length (3/20 cm), zinc conten (0/950 mg/kg) catalas enzyme (1.88 Mg.-1 Protein. Min-1) and peroxidase enzyme (0.180 Mg.-1 Protein. Min-1).