Co-inoculation of Indigenous Pseudomonas sp. and Priestia sp. to Improve the Soil Health, Plant Growth, Yield and Fruit Quality Parameters of Tomato (Solanum lycopersicum L.)

This study investigated the impact of co-inoculating Pseudomonas sp. and Priestia sp. on soil microbial activity, plant growth, yield, and fruit quality parameters in tomato. From twenty-three morphologically distinct rhizobacteria, 12 exhibited phosphate solubilization capabilities (PSI: 0.5-4.1), while three showed zinc solubilization abilities (ZSI: 3.0, 2.6, and 3.0). All isolates produced IAA, and six demonstrated siderophore production (zones ranging from 1.2 to 3.1 cm). Based on their functional traits, five isolates (TM8, TM11, TM19, TM24, and TM26) were selected for further evaluation in a greenhouse experiment. In the pot experiment, isolates TM8 and TM19 significantly enhanced plant height (40.32%), available nitrogen (37.4%), available potassium (52.1%), and available phosphorus (25.56%) compared to the uninoculated control. Isolate TM8 showed 100% similarity with Pseudomonas sp. and TM19 showed 99% similarity with Priestia sp. based on 16S rRNA gene sequencing. The field evaluation of these selected isolates as a liquid consortium with Farm Yard Manure (FYM) and inorganic fertilizers revealed a synergistic increase in soil microbial population and enzyme activities. Treatment T10 (N100 FYM + Pseudomonas sp. and Priestia sp.) showed a significant 45.27% increase in available nitrogen and 49.54% in available phosphorus, while treatment T11 (N75 FYM + NP25 + Pseudomonas sp. and Priestia sp.) resulted in a 25.77% increase in available potassium. The inoculation of rhizobacterial strains significantly improved tomato growth parameters, with the maximum number of fruits (14.04), higher fruit weight (96.87 g), maximum fruit yield (1.36 kg/plant), and enhanced fruit quality attributes observed in treatment T10. This study has led to the identification of a novel plant growth-promoting bacterial liquid consortium as a potential inoculant for improving tomato growth, yield, and fruit quality.