Evaluation of growth phytohormones and different concentrations of plant derived smoke applications on growth characteristics and biological yield of medicinal plants Lemon balm (Melissa officinalis) and Basil (Ocimum basilicam)

Farmers have traditionally used fire and smoke in various parts of agriculture. Several studies have reported that smoke bioactive components acts as a new family of plant growth regulators. In order to evaluate and explore the potential of smoke-water as a phytohormone on growth characteristics and biological yield of medicinal plants of basil and lemon balm an experiment was conducted as a split plot based on complete randomized block design with three replications. This experiment was conducted in research greenhouse of Razi University in 2017. In this study, eight factors were including four concentrations smoke-water (included 1:5000, 1:1000, 1:500 and 1:100 (v/v)) accompanying with cytokinin, auxin and gibberellic acid (each of them with concentration 50 µM) and control were assigned to the main plots and two harvest stages were assigned to the sub plots. Results indicated that the gibberellic acid significantly increased basil canopy height in comparison to others treatments. While the maximum canopy height in lemon balm was obtained from smoke-water at concentrations of 1:500 (v/v). Foliar-application with cytokinin resulted in the highest leaf area index in both plants compared to control. Eventually the highest biomass yield in basil and lemon balm was obtained from smoke-water at concentrations of 1:100 (v/v) that has increased by 52 and 39 percent, respectively, compared with control. In the current study applying high level of smoke-water foliar (1:100 and 1:500 (v/v)) induced on growth characteristics and biological yield, similar to phytohormone treatments especially cytokinin.