ASHS 2025 Conference

Watercress (Nasturtium officinale) is a nutrient-dense leafy green from Brassicaceae family, rich in secondary metabolites, including phenolics that contribute to its antioxidant and disease-preventing and/or health-promoting properties. Magnesium was identified as a nutrient that stimulates secondary metabolic pathways including synthesis of phenolic compounds in leafy greens from Brassicaceae family. This study aimed to evaluate the effect of different supplemental magnesium fertilization rates on phenolic accumulation in watercress grown hydroponically under a controlled environment condition. A split-plot design with four treatments: magnesium concentrations (100 mg/L, 150 mg/L, 200 mg/L, and 250 mg/L) was applied using a Nutrient Film Technique (NFT) hydroponic system with constant monitoring of environmental parameters such as temperature, light y, pH, and electrical conductivity to ensure optimal watercress growth. light, temperature, pH, and electrical conductivity. Different extracts of harvested watercress tissues (roots, stem and leaves) were analyzed and quantified including total phenolic content (TPC) using spectrophotometer and High-Performance Liquid chromatography (HPLC). Additionally, fresh and dry biomass yield was recorded. The preliminary results revealed a positive correlation between magnesium application and phenolics, with the increase in concentration rate significantly enhancing total phenolic content and biomass production. These results have practical implications for hydroponic growers aiming to improve leafy greens nutritional quality and productivity through nutrient optimization in hydroponic systems. In summary, watercress exhibits strong antioxidant properties and contains phenolic compounds that may hold potential biological interests. Keywords: Watercress, Phenolics, Antioxidant, Magnesium, Controlled environment.