Seaweed extract to enhance marigold seed germination and seedling establishment

Abstract

The brown seaweed Ascophyllum nodosum and seaweed-derived products have been widely used as nutrient additions, biofertilizer and biostimulant in horticultural crop systems. This study aimed to evaluate the effects of a seaweed extract obtained from whole brown algae (A nodosum) on seed germination and seedling growth of ornamental marigold (Tagetes erecta). The seeds of marigold were daily sprayed with 0 (control), 5, 10 or 15 mL L−1 commercial seaweed extract Acadian Seaplants™ (70 ml). The percentage, index and average time of seed germination, seedling height, fresh, dry mass of shoots, roots and root system morphology were evaluated. The results showed that the seaweed extract enhanced all parameters related to seed germination and seedling growth and development. The best results were obtained with 15 mL L−1 seaweed extract which increased by two-fold marigold seed germination and 84.00% seedling height, and both fresh and dry shoot mass and root morphology. We suggest algal extracts of Ascophyllum nodosum should be used as natural biostimulant on marigold crop, improving seed germination and seedling development.