Research in Plant Metabolites

Research in Plant Metabolites

Investigating the effect of humic acid and gibberellic acid foliar spraying on the yield and content of essential oil and some characteristics of peppermint medicinal plant (Mentha piperita L.)

Document Type : Original Article

Author
Ali Hamid
Senior expert of Khorramshahr Agricultural Jihad Institute, Khorramshahr, Iran.
10.22034/jrpsm.2023.196779
Abstract
Peppermint is one of the most important essential plants with various uses. The experiment was carried out to split split plot and in a randomized complete block design with three replications in the research farm of Agricultural Sciences and Natural Resources University of Khuzestan (2014). Chemical fertilizers were not used in this experiment. The main factor was included humic acid granules from the super humate source at four levels (no application, 8, 16 and 24 kg.ha-1) and gibberellic acid foliar spraying as a secondary factor at four levels (no application, 100, 200 and 300 mg.l-1). The interaction effect of humic acid and gibberellic acid was significant in all traits except essential oil percentage. The use of gibberellic acid increased the dry weight of the stem and decreased the harvest index and the ratio of the dry weight of the leaf to the dry weight of the stem. The highest stolon dry weight (892 kg.ha-1) was shown from the application of 16 kg.ha-1 of humic acid and foliar spraying of 300 mg.l-1 gibberellic acid. Only humic acid had a significant effect on the percentage of essential oil and increased the percentage of essential oil. Economically, the use of 16 kg.ha-1 of humic acid with 200 mg.l-1 of gibberellic acid was the best treatment combination.
Keywords
Essential oil
Foliar spraying
Growth regulator
Hormone