Phosphate solubilizing bacteria, Pseudomonas aeruginosa, improve the growth and yield of groundnut (Arachis hypogaea L.)

Abstract

For agricultural safety and sustainability, instead of synthetic fertilizers the eco-friendly and inexpensive biological applications include members of plant-growth-promoting rhizobacteria (PGPR) genera, Pseudomonas spp. will be an excellent alternative option to bioinoculants as they do not threaten the soil biota. The effect of phosphate solubilizing bacteria (PSB) Pseudomonas aeruginosa (MK 764942.1) on groundnuts’ growth and yield parameters was studied under field conditions. The strain was combined with a single super phosphate and tested in different combinations for yield improvement. Integration of bacterial strain with P fertilizer gave significantly higher pod yield ranging from 7.36 to 13.18% compared to plots where sole inorganic fertilizers were applied. Similarly, the combined application of PSB and inorganic P fertilizer significantly influenced plant height and number of branches compared to sole. However, a higher influence of phosphorous application (both PSB and P fertilizer) observed both nodule dry weight and number of nodules. Combined with single super phosphate (100% P) topped in providing better yield attributing characters (pod yield, haulm yield, biomass yield, 1000 kernel weight, and shelling percentage) in groundnut. Higher oil content was also recorded with plants treated with Pseudomonas aeruginosa combined with single super phosphate (SSP) (100% P). Nutrients like nitrogen (N), phosphorous (P), and potassium (K) concentrations were positively influenced in shoot and kernel by combined application. In contrast, Ca, Mg, and S were found to be least influenced by variations of Phosphorous. Plants treated with Pseudomonas aeruginosa and lower doses of SSP (75% P) recorded higher shoot and kernel P. We found that co-inoculation with PSB and SSP could be an auspicious substitute for utilizing P fertilizer in enhancing yield and protecting nutrient concentrations in groundnut cultivation. Therefore, PSB can be a good substitute for bio-fertilizers to promote agricultural sustainability.