Enhancing banana health with key antagonistic taxa by crop residue-driven strategies

Panama disease (Fusarium wilt of banana), which is caused by Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4), is the most devastating threat to banana production. The retention of crop residues enhances disease suppression in banana rotation systems. We performed quantitative PCR and MiSeq sequencing to investigate the effects of crop residues on soil microbial communities and to assess the suppressive impacts of residue extracts on FocTR4. Pepper and eggplant residues significantly reduced Panama disease incidence (DI) and FocTR4 abundance. The incorporation of pepper residue as a soil amendment reduced the DI to <20 % in the second pot experiment, indicating sustained disease suppression. Residue extracts confirmed the residue inhibitory effects. The pepper and eggplant residues increased the bacterial copy number and decreased the fungal copy number in the amended soil. Pepper residues enhanced soil microbial richness and diversity more than eggplant and banana residues did. The microbial communities of the pepper and eggplant residues were similar but distinct from those of the banana residues and controls, with differences between the rhizosphere and bulk soil communities. Structural equation modeling identified available phosphorus as a key mediator linking residue inputs to pathogen suppression via the enrichment of key soil taxa. Pepper (OTU180_Rhizomicrobium) and eggplant (OTU187_Gp4) residues promoted key microbes, exerted antagonistic effects on FocTR4, and reduced DI. Overall, these findings establish crop residue management as an effective strategy for sustainable banana cultivation, thus overcoming continuous cropping challenges through key taxa-mediated disease suppression.