Use of seaweed-based biostimulant (Ascophyllum nodosum) on ornamental sunflower seed germination and seedling growth

Abstract

Seaweed extracts are employed as biostimulants due to their beneficial effects on crop growth and yield. Ascophyllum nodosum seaweed extract aid to improve seedling growth and development, and decrease seedlings production costs; however, the correct concentration must be used in order to maximize the biostimulant effects. Consequently, this study aimed to analyze the effects of different concentrations of a seaweed-based (Ascophyllum nodosum) biostimulant on ornamental sunflower seed germination and seedling growth. Seeds of ornamental sunflower cv. “Sol Pleno” were sown in polyethylene trays containing commercial substrate. The treatments consisted of dairy spraying 60 mL of the solutions 0 (control), 5, 10 or 15 mL L-1 biostimulant on substrate. The experimental design was completely randomized with 4 treatments (concentrations of biostimulant) and 4 replicates (10 seeds replicate-1). The evaluated variables were percentage, index and time averages of germination, seedling height, fresh and dry mass of shoot and roots, and root system morphology (WinRhizo). The increase of the biostimulant concentration enhances seed germination and seedlings development. The concentration 15 mL L-1 biostimulant showed the best results for percentage and index of germination and the lowest mean germination time and increase plant height and fresh and dry mass of shoots in relation to the control treatment. Accordingly, 15 mL L-1 biostimulant (Ascophyllum nodosum) is recommended for ornamental sunflower “Sol Pleno” seed germination and seedlings growth.

Seaweed extract to enhance marigold seed germination and seedling establishment

“…Treatment with 15 g L −1 biostimulant decreased the MGT (7.5 days) with high GSI (1.26) and higher seed PG (84%). A. nodosum extracts consist of cytokines, auxins, abscisic acid, gibberellins, betaines and alginates [22], and under optimal concentration, these extracts can increase seedling production [23], as well as improve seed germination and seedling establishment [4], as observed in our study (Fig. 1).…”

“…1). Similar data were obtained with seaweed extracts on seed germination of Chicoria (Cichorium endivia) [19], and ornamental [4]. However, higher concentrations of seaweed extract were found to decrease the percentage of germination of parsley (Petroselinum sativum) seeds [20].…”

“…1). Treatment with 15 g L −1 biostimulant can favor the development of marigold plants by modulating seedling growth and facilitating its early establishment which would increasing their survivability; once, fully developed plants are more resistant to adverse environmental conditions [4].…”

“…A. nodosum extracts also contain macro-and micronutrients [5], stimulating seedling growth; however, if the plant is effectively fertilized, the extract may not be as effective on plant growth [25]. The increase of mass by A. nodosum extracts is described in diverse studies [4,15].…”

“…Biostimulants, such as Ascophyllum nodosum seaweed extract, are a sustainable alternative to stimulate root growth, seedling development and, at the same time, reduce production costs. However, to maximize biostimulant effects it must be applied correctly [3,4].…”