Deciphering Nature’s Secret of Seaweed Extract as a Biostimulant on Horticultural Crops: A Review

Seaweed extracts have gained significant attention in horticultural practices due to their diverse range of beneficial effects on plant growth, development, and stress tolerance. The presence of antioxidants and Osm-protectants in seaweed extracts helps mitigate oxidative damage and maintain cellular integrity under adverse conditions. It also holds great promise as a valuable input in horticultural systems, offering a range of benefits including enhanced soil health, and sustainability. This review aims to summarize and analyze the benefits of seaweed extract application on horticultural crops. The extracts derived from seaweed are rich in essential nutrients which are available from through which plants can absorb easily and promote growth. It also contains numerous bioactive compounds including cytokinins, auxins, gibberellins, and betaines, which act as plant growth regulators. The application of seaweed extracts can induce systemic acquired resistance (SAR) in plants, triggering defense mechanisms against pathogens and pests, which can reduce the need for synthetic pesticides and fungicides, promoting sustainable and environmentally friendly horticultural practices. In addition to its direct effects on plants, seaweed extract enhances soil health and microbial activity. It serves as a natural biostimulant, promoting beneficial microbial populations in the rhizosphere, which facilitate nutrient uptake and cycling. Moreover, the humic substances present in seaweed extract contribute to soil structure improvement, water retention, and nutrient availability, fostering a conducive environment for plant growth.