Evaluation of <i>Chlorella vulgaris</i> S45 Application on Swiss Chard ( <i>Beta vulgaris</i> L. subsp. <i>cicla</i> ) Seed Germination, Pigment Content, Total Phenolic Content and Antioxidant Activity

Summary Contemporary agriculture faces the challenge of sustainably feeding constantly growing human population. Application of green algae in plant production is a new, relatively low-cost green technology with potential benefits for plant health. This study examines the application of Chlorella vulgaris S45 and its effect on seed germination, pigment content, total phenolic content and antioxidant capacity of Swiss chard. Treatments included 5% and 10% algal suspensions applied by spraying on plants and in substrate, respectively. C. vulgaris S45 positively affected all the investigated parameters. Seed germination percentage (GP) increased in comparison to the control treatment. The highest GP (46%) and germination index (GI) values were observed in the 10% suspension treatment. Photosyntetic pigment content also increased significantly under 10% suspension application, while both total phenol content and antioxidant capacity improved following plant spraying with 10% suspension. Correlation analysis indicated statistically significant interdependence among the tested parameters (pigment content, total phenolic content and antioxidant activity). Foliar application of Chlorella vulgaris S45 could be an alternative fertilization method in sustainable Swiss chard production.