Depolymerised Sodium Alginate as a Eco-Friendly Biostimulant for Improving Herb Yield and Nutrient Accumulation in Hyssop

Abstract

Sodium alginate and its derivatives present a promising tool for improving the quality of crops. Hyssop is one of the most important herb used both in foods and traditional medicines. The aim of this study was to investigate the effect of depolymerised sodium alginate (DSA) on yield and mineral status of hyssop plants under greenhouse conditions. The outcomes demonstrated that foliar application of DSA with a molecular mass of 64,000 g·mol-1 at 50 and 100 mg·dm-3 significantly improved the leaf chlorophyll index (by 22.9 and 30.3%, respectively), above-ground plant both fresh (by 24.1% and 28.2%, respectively) and dry weights (by 30.1% and 32.8%, respectively) relative to the control. The DSA at 50 and 100 mg·dm-3 stimulated nitrogen, calcium, copper, manganese and zinc concentration in above-ground hyssop tissues by 18.9–31.1%, 32.9–77.2%, 44.7–43.2%, 69.3–41.8 and 40.6–33.3%, respectively. Moreover, application of DSA at 100 mg·dm-3 increased phosphorus and potassium concentration by 38.9% and 24.3%, respectively. The magnesium, boron and iron contents were unaffected by biostimulant treatment. The use of DSA has shown commercially potential to increase herb yield and some mineral nutrients in potted hyssop.