Biocontrol of Rhizoctonia solani by Chaetomium cupreum CT07 in cruciferous vegetables

This study investigated the biocontrol potential of the Chaetomium cupreum strain CT07 against Rhizoctonia solani, the causative agent of damping-off disease in cruciferous vegetables. Thirteen Chaetomium strains (CT01–CT13) were isolated from 80 soil samples collected across southern Vietnam via a soil baiting technique. Dual culture assays revealed that strain CT07 exhibited the strongest antagonistic activity, with an inhibition rate of 83.4%. Greenhouse experiments demonstrated that seed pretreatment with CT07 significantly reduced disease incidence in Brassica juncea (68.6–70.1%) and Brassica rapa var. integrifolia (73.6–74.1%) while also increasing plant growth parameters, including height, root length, and biomass. Foliar application of CT07 post infection further suppressed disease progression, maintaining high control efficacy (60.4–72.0%) up to 15 days after treatment. ITS sequencing confirmed CT07 as Chaetomium cupreum with 99.6% similarity. These findings underscore the potential of CT07 as an eco-friendly biocontrol agent for managing soilborne diseases in cruciferous crops.