Mode of application influences the biofertilizing efficacy of cyanobacterial biofilm formulations in chrysanthemum varieties under protected cultivation

Abstract

Availability of nutrients in soil plays an important role in the productivity and quality of flowers in chrysanthemum. A set of novel biofilm inoculants- Anabaena-Azotobacter, Anabaena-Pseudomonas fluorescens (An-Psf) and Anabaena-Trichoderma (An-Tr) were applied as carrier based dry formulation or soil drench and their performance compared in two varieties of chrysanthemum (White Star and Zembla), in a climate-controlled greenhouse. Both the An-Psf and (An-Tr) inoculants enhanced glomalin related soil proteins in the rhizosphere of White Star, while in terms of polysaccharide content of soil, both these inoculants performed better in Zembla variety. Significant increases in the availability of selected macro and micronutrients in rhizosphere soil samples, in both chrysanthemum varieties were recorded, particularly when the inoculants were applied as soil drench. Principal Component analysis illustrated the significant interaction among soil and plant parameters, more specifically, the distinct effect of the inoculants, as compared to the application of carrier alone or control treatment. This investigation demonstrated the varietal effects on soil biological activities and significance of mode of application of microbial inoculants in influencing plant growth and rhizospheric metabolic activities.

Keywords

• biofilms
• nutrient availability
• microbial activity
• plant growth
• soil drench