Microbial Population in Curcuma Species at Different Growth Stages

Turmeric (Curcuma spp.) is widely cultivated in tropical regions for its use in traditional medicine and culinary purposes. This study investigated the bacterial populations in the rhizosphere, stems, and leaves of the Curcuma species and strains at different growth stages. Bacterial population cultivated in the field and plastic house showed variations across growth stages. The rhizosphere possessed the highest bacterial populations in both experiments (1.8 to 11.9 × 106 CFU/g and 1.7 to 24.3 × 106 CFU/g, respectively), with C. amada and Ryudai gold as the highest. Endophytic bacteria in stems and leaves also peaked at the middle growth stage. Principal Component Analysis (PCA) revealed distinct separations among Curcuma species planted in the field and plastic house at different growth stages. C. aromatica and C. longa strain L2 clustered differently under field conditions, while C. zedoaria and C. xanthorrhiza were distinct under plastic house conditions. Combined PCA revealed a clear separation between the field and plastic house, with tighter clustering observed in the plastic house. Leaf-associated bacterial populations were compositionally distinct from those in the rhizosphere and stems. These findings suggest that the Curcuma growth stage and species significantly affect bacterial community structure, supporting the development of targeted cultivation strategies and microbial applications to enhance productivity and sustainability in turmeric farming.