INTRODUCTION

Vanilla monoculture often leads to wilt disease, affecting the industry globally.

METHODS

Here, we evaluated the effects of vanilla-black pepper, -pandan, and -sweet rice tea rotations (i.e., growing vanilla in soil previously planted with these crops) on abundance and rhizosphere microbial communities using real-time quantitative PCR and high-throughput sequencing.

RESULTS

Pandan rotation, in particular, reduced disease incidence to 17% and decreased copy numbers; sweet rice tea showed similar suppressive effects. Crop rotation significantly increased fungal diversity and richness. Different cropping systems, including fallow, monoculture and crop rotation, significantly influenced fungal and bacterial community development, with cropping system and rotated crops being the main drivers of rhizosphere community assembly. The black pepper and pandan rotations specifically enriched certain fungal OTUs, such as OTU1_, OTU37_, and OTU18_, which serve as biomarkers for the presence of . After pandan rotation, microbial interactions within the rhizosphere intensified, with notable enrichment of core bacterial taxa, including OTU22_, OTU56_, and OTU178_. Soil pH was identified as a significant factor influencing microbial community assembly. The fungal community structure, along with core OTU22_ and soil pH, was pivotal in curbing pathogen growth, explaining 25.19%, 8.61%, and 20.45% of the variance, respectively.

CONCLUSION

This study revealed that incorporating pandan into crop rotation may effectively alleviate soil-borne diseases during vanilla production.