Elucidating the Dynamics of Physiology and Essential Oil Production in Lemongrass Using Alginate Oligomers under Field Conditions

Cymbopogon flexuosus (Steud.) Wats. (lemongrass) essential oil (EO) is valued for its aromatic and medicinal properties as it holds an important share among volatile oils traded worldwide and exhibits massive diversity in commercial and consumer utility. The last decade witnessed several pot experiments to test the ability of radiation-processed sodium alginate as a plant growth elicitor. Therefore, the present work was designed to authenticate the pot experiment findings and the study was carried out in the field (30 × 30 m2), according to the simple randomised block design at Agricultural Farm, Aligarh Muslim University, Aligarh, UP (India). Different foliar concentrations of irradiated sodium alginate (ISA; 0 (control), 40, 60, 80 and 100 mg L–1) were applied to scrutinise the performance of lemongrass with regard to ISA under field conditions. The effect of ISA, at a given concentration range of 40–100 mg L–1, was found significant in terms of growth, physiological and biochemical as well as quality attributes. However, ISA-60 mg L–1 proved most favourable and substantially enhanced the activities of carbonic anhydrase and nitrate reductase by 18.4 and 15.1%, respectively and chlorophyll fluorescence by 12.8% in comparison to control. Further, due to applied treatment, the content and yield of EO was increased by 35.6 and 91.4%, respectively, over control. Moreover, citral yield was also enriched by 90.4% over control due to ISA applied at 60 mg L–1.