Citral accumulation in Cymbopogon citratus plant as influenced by N6-benzylaminopurine and light intensity

Cymbopogon citratus (lemongrass) is an aromatic species whose essential oil is rich in citral, with industrial applications due to its lemon scent. The effects of environmental factors on the percentage and composition of essential oils are the main challenges in commercial cultivation. Various studies have indicated the positive effect of cytokinin on terpene production. The present work aimed to evaluate the effect of N6-benzylaminopurine (BAP) associated with light intensity on the production and composition of essential lemongrass oil. Plants were grown under field conditions (FIELD) and shade (SHADE). The study employed a 2x7 factorial scheme with two growing environments, seven BAP concentrations, and five replicates. After seven months of growth, a single application of the synthetic cytokinin BAP was performed at concentrations 0, 30, 60, 90, 120, 150, and 180 mg L-1. One week after the BAP application, plants were harvested and the essential oil was extracted in a Clevenger apparatus. The chemical composition of the essential oil of plants treated with 60, 120, and 180 mg L-1 of BAP was determined by Gas Chromatography (GC). The essential oil percentage was not affected by the treatments, showing 1.08% on average. On the other hand, the citral percentage was negatively influenced by BAP, and light intensity had no effects. In plants treated with 60 mg L-1 of BAP, citral percentage was 72%, on average, while in plants treated with 180 mg L-1, the mean percentage of citral was 33%.