Application of PGPB Combined with Variable N Doses Affects Growth, Yield-Related Traits, N-Fertilizer Efficiency and Nutritional Status of Lettuce Grown under Controlled Condition

Nitrogen (N) fertilization is a crucial agricultural practice for boosting production traits in vegetables. However, N synthetic fertilizers—commonly adopted by farmers—have several counterproductive effects on the environment and humans. The research was performed to assess combined influence of plant growth promoting bacteria (PGPB) (Azospirillum brasilense DSM 1690, A. 2298 Pseudomonas sp. 25356) various doses (0, 30, 60 or 120 kg ha−1) growth, yield, quality nitrogen indices lettuce protected cultivation. Plant height, root collar diameter, number leaves fresh weight were enhanced inoculation at 30 ha−1. Overall, soluble solids content (SSC), ascorbic acid, total phenolics, carotenoids, chlorophyll sugars augmented effect strains Furthermore, PGBP improved potassium (K) magnesium (Mg) concentrations leaf tissues. PGPB increased concentration; however, it hastened indices. These results suggest that tested can be considered an eco-friendly tool improve particularly when with