Integrated role of mushroom waste compost in suppressing Rhizoctonia solani and enhancing cucumber seedling growth

The present study was carried out to assess the potential of compost waste from the Agaricus bisporus mushroom to control in vitro and in vivo growth of Rhizoctonia solani, the cause of damping-off and root rot diseases in cucumber. Three concentrations (10, 20, and 30%) of mushroom waste extract were used in vitro to evaluate their effects on the radial growth of R. solani grown in Petri dishes using potato dextrose agar (PDA) as the growth medium. There were up to 36 and 31.9% reductions in fungal growth with one-year- and two-year-old compost waste extracts, respectively, over the control. The 100 mL L-1 concentration displayed the most substantial antifungal activity. In vivo experiments under plastic pot conditions further revealed that compost maturity and sterilization status significantly affected seed germination and radicle growth. Sterilized two-year-old compost extract enhanced cucumber seed germination by 83.9% and radicle length by 60.6 mm, while sterilized one-year-old extract showed phytotoxicity, reducing germination to 40.5% and radicle length by 29.41 mm. Unsterilized extracts from both compost ages completely inhibited seed germination. These findings highlight the integrated role of mushroom compost waste extracts as antifungal agents and growth modulators, emphasizing that only properly matured and sterilized compost should be applied. The study evaluates that the aqueous extracts of mushroom compost waste may serve as an alternative to synthetic fungicides for managing soil-borne pathogens in cucumber production.