Impact of Commercial Seaweed Liquid Extract (TAM®) Biostimulant and Its Bioactive Molecules on Growth and Antioxidant Activities of Hot Pepper (Capsicum annuum)

Abstract

Bioactive molecules derived from seaweed extracts are revolutionary bio-stimulants used to enhance plant growth and increase yield production. This study evaluated the effectiveness of a commercially available seaweed liquid extract, namely, True-Algae-Max (TAM^®), as a plant growth stimulant on nutritional, and antioxidant activity of <i>Capsicum annuum</i>. Three concentrations of TAM^® (0.25, 0.5, and 1%) of various NPK: TAM^® ratios were investigated via foliar spray, over 2017 and 2018 cultivation seasons, under greenhouse conditions. TAM^® is rich in phytochemical compounds, such as ascorbic acid (1.66 mg g^-1), phenolics (101.67 mg g^-1), and flavonoids (2.60 mg g^-1) that showed good antioxidant activity (54.52 mg g^-1) and DPPH inhibition of 70.33%. Promoting measured parameter results stated the extensive potentiality of TAM^® application, in comparison with conventional NPK treatment. Yield and composition of <i>C. annuum</i> were significantly improved in all TAM^® treated groups, especially the TAM_0.5% concentration, which resulted in maximum yield (4.23 Kg m^-2) and significant amounts of profuse biological molecules like chlorophyll, ascorbic, phenolic compounds, flavonoids, and total nutrients. Compared to the NPK control treatments, <i>C. annuum</i> treated with TAM_0.5% improved the total antioxidant activity of hot Pepper from 162.16 to 190.95 mg g^-1. These findings indicate that the extract of seaweed can be used as an environmentally friendly, multi-functional biostimulant in the agricultural field for more sustainable production, in addition to reducing the use of hazardous synthetic fertilizers.