The effect of methanol and ethanol foliar application on peppermint morpho-physiological traits

Using of substances such as ethanol and methanol can be considered as a way to improve plants yield helping carbon dioxide fixation increment. The effect of methanol and ethanol spraying on growth and essential oils of peppermint has been studied in field conditions based on randomized complete block design with 10 treatments including spray concentrations of 10, 20, 30 and 40% methanol and ethanol, distilled water and no spraying. There was an enhancing effect of ethanol and methanol spraying on most of studied traits. Methanol had positive effect on leaf number, longest lateral branch length and leaf width. Also, ethanol increased essential oils content, shoot fresh and dry weight and lateral shoot number. In general, the best treatments effecting on plant traits were ethanol 20 and 30% and methanol 10 and 30%. The highest essential oils content was observed at concentrations of methanol 10 and ethanol 20 and 30%. To foliar improvement, the concentration of 30% of methanol was the most suitable treatment. Therefore, with economic and availability consideration, methanol would be recommendable for more essential oils content achievement. Also, for the best peppermint business performance, 30% methanol could be applicable.