The influence of different types of mulch on the yield and content of bioactive compounds of immortelle

Immortelle (Helichrysum italicum) is a perennial Mediterranean plant known for its medicinal and aromatic properties. Various biotic and abiotic factors influence the yield and quality of immortelle. Mulching is a sustainable agricultural practice that conserves soil moisture, prevents weed growth, and regulates soil temperature. The aim of this research was to examine the influence of different types of mulch on the yield and quality of immortelles. The study had three types of mulch (alfalfa, straw, and perennial mulch) and a control (no mulch). The research mulches significantly affected the yield, essential oil (EO) content and content of bioactive compounds. The highest yield of inflorescences was recorded with alfalfa mulch (67.5 g-¹), while the control had the lowest yield (37.3 g-¹). The EO content was highest in treatments with straw and control (0.33 mL 100 g-1), whereas the lowest content was observed with alfalfa mulch (0.28 mL/100 g). The total phenolic content reached its maximum in the control variant (75.1 mg GAE g¹), while perennial mulch resulted in the highest flavonoid content (20.4 mg CAE g-¹). A total of 63 constituents were identified in the EO. The largest share was: neryl acetate, α-curcumen, italidione, α-pinene and D-limonene, and others in smaller quantities.