Biological Control Efficacy of Indigenous Antagonistic Bacteria Isolated from the Rhizosphere of Cabbage Grown in Biofumigated Soil against Pythium aphanidermatum Damping-Off of Cucumber

Soil biofumigation is a widely used farming practice for soil-borne disease management in vegetable crops. the of incorporation fresh plant materials from members Brassicaceae family into soil which release antimicrobial volatile organic compounds (VOCs), namely glucosinolates and their hydrolysis products. However, VOCs may affect non-target beneficial biota including microbial biocontrol agents (MBAs) due to broad-spectrum toxicity. In this study, native antagonistic rhizobacteria were isolated cabbage plants grown biofumigated fields potential Pythium aphanidermatum cucumber damping-off was evaluated with also without using leaf residue. A total 20 morphologically distinct, culturable bacterial strains recovered rhizosphere cultivated field, largest fraction isolates belonging genus Bacillus. The other genera Pseudomonas, Serratia, Stenotrophomonas, Microbacterium Priestia. Of isolates, Pseudomonas aeruginosa B1-SQU, indica B2-SQU, Serratia marcescens B3-SQU brenneri B4-SQU exhibited inhibitory activity against P. co-culture assay. deformation shrinkage hyphae diffusible these witnessed through scanning electron microscopy. biofilm formed by vitro they compatibility each other; however, had no significant growth promotion effect on cucumber. These significantly reduced under greenhouse conditions when applied singly, but failed show combined treatment, though population maintained at higher levels. alone not effective suppressing Gas chromatography–mass spectrometry analysis revealed that 1-butanol, n-butyl butyrate butyl acetate predominant amended results suggest residue has high inoculum levels; furthermore, it affects efficiency antagonists controlling