Changes in Java grass (Cymbopogon winterianus) physiology, essential oil production, and active constituents as influenced by catechol and some plant growth regulators applied through steaming technique.

Abstract

A study was done to find out how steam-applied chemical and plant growth regulators affected plant growth and determine the most effective PGRs and chemical for maximizing java grass oil yield and quality attributes. A chemical viz. catechol and PGRs, viz. indole acetic acid (IAA), kinetin (Kn), 6-benzyl amino purine (BAP), salicylic acid (SA), and triacontanol (TRIA), ethrel, were applied to the plants at a concentration of 5 × 10−6 M at 90 days after transplantation (DAT) through an innovative technique of steaming using an electric steamer five times after a week interval. To prevent the plants from being harmed, we operated the steam jet at a certain distance from them. All the parameters were evaluated at 150 DAT. The results showed that among all these PGRs, IAA proved the best for growth, yield, and other parameters. In comparison to the control, the EO production more than doubled. Our study indicated that IAA enhanced the fresh and dry weight by 30.7% and 42.9%, total chlorophyll and carotenoids contents by 44.1% and 47.1%, nitrate reductase and carbonic anhydrase activity by 18.0% and 28.1%, respectively, over the control. Compared with control, IAA treatment increased the content and yield of essential oil by 96.8% and 155.7%, and the active constituents of EO, i.e., citronellol, citronellal, and geranial content, by 47.4%, 90.9%, and 43.9%, respectively. As a result, IAA used in this technique was very effective in increasing EO production while causing no harm to the plant.