Fuente: PubMed "medicinal and aromatic plants" Front Plant Sci. 2026 May 8;17:1845091. doi: 10.3389/fpls.2026.1845091. eCollection 2026.ABSTRACTINTRODUCTION: Optimizing fertilization strategies in Melissa officinalis L. requires an integrated assessment of biomass production and secondary metabolite synthesis.METHODS: This study evaluated the effects of organic and organomineral fertilization on herbage yield, essential oil (EO) yield, and leaf rosmarinic acid (RA) content under field conditions in Ödemiş (Türkiye) during the warm and dry 2024 growing season. A split-plot design was used, with two cultivars (Melis and Quedlinburger) assigned as main plots and six fertilization treatments (G0-G5) as subplots, evaluated across two harvest times (H1 and H2).RESULTS: Fertilization significantly affected all parameters (p < 0.01). The highest fresh herbage yield was obtained with G3 (ammonium sulfate combined with humic and fulvic acids) at H1, reaching 15.41 t ha-¹ in Quedlinburger. Organomineral fertilization (G5; 12-12-12, 50% organic matter) maximized EO yield at H1, reaching 118.10 L ha-¹ in Melis, and maintained higher mean RA content than the control across both harvests (62.47 and 53.41 mg g-¹ at H1 and H2, respectively; mean across cultivars), corresponding to 69-99% higher RA content than the control. A marked phenological shift was observed, with EO content declining by ~50% from H1 to H2, while RA content also decreased by ~20% across harvests but remained highest under G5 treatment, which may be associated with changes in carbon allocation between the terpenoid (MEP) and phenylpropanoid pathways. Multivariate analysis supported these findings, with principal component analysis explaining 88.2% of total variance and clustering identifying G5 and G3 as the most effective treatments.DISCUSSION: Overall, integrated nutrient management enhanced both yield and phytochemical quality under heat and water-deficit conditions.PMID:42179515 | PMC:PMC13195004 | DOI:10.3389/fpls.2026.1845091