Studying the Antifungal Effects of (Sprengel) R. King and H. Robinson (= Sprengel) as a Bio-Fumigant Plant Alone and in Combination with Biochar Against (Edson) Fitz.

spp. are soil-borne pathogens that cause damping-off and root rot diseases in many plant species such as cucumber. In the current study, the effect of dried roots-stems and leaves of (Sprengel) R. King and H. Robinson (= Sprengel) alone and in combination with pyrogenic biomass biochar to control (Edson) Fitz was assessed. In four treatments of leaves, roots-stems, leaves + biochar, and roots-stems + biochar, it was observed that the treatment with leaves at an E (maximal effective concentration on control fungi) of 79 g/kg of soil had the most antifungal effect on . Also, the C (the highest level of control) increased with time and reached 82.4% and 71% on days 30 and 60, respectively. The highest cucumber fresh fruit weight and the highest height of the stems in the greenhouse were observed in leaf treatment of . Biochar did not have any remarkable controlling effect on , and its population increased. The main compounds extracted from the dried leaves and roots-stems of , including α-pinene, nonanone, hexahydronaphthalene, 3-undecanone, muurolene, and heneicosane, had antifungal properties. We concluded that the leaves of have the potential to be used as a bio-fumigant for management.