Impact of Amino Acid Sprays on Rosmarinus officinalis L. Vegetative Growth, Oil Production, and Quality in Soilless Culture Systems

Abstract

For two seasons in a row (2022 and 2023), this study was conducted at the Central Laboratory for Agricultural Climate Research Centre (CLAC) in Dokki, Giza, Egypt, beneath an unheated plastic house. This study investigated the effects of foliar sprays containing amino acids on the vegetative growth, oil output, and quality of Rosmarinus officinalis L. Plants were given aqueous solutions containing 100 and 200 parts per million of the amino acids glutamine and tryptophan three weeks after transplanting. Two harvests of the plant were made: one in mid-May and another three months later. For both harvests, the essential oil % was calculated and important growth and yield metrics were assessed. Gas Chromatography (GC) was used to study the composition of essential oils. The findings showed that foliar spraying with amino acids greatly increased yield, essential oil percentage, and vegetative development. Important constituents of the essential oil profile comprised 1–8 Cineol, Camphor, α-Pinene, and β-Pinene; significant compositional variances were ascribed to various amino acid treatments.