ABSTRACT Maize intensive cultivation with excessive fertilizer use generates environmental impacts. Plant growth-promoting bacteria offer a sustainable alternative by favoring nitrogen fixation, phosphorus solubilization, and phytohormone production. This study aimed to evaluate the effect of microorganisms previously recognized as growth promoters in rice on maize biomass and yield. The experiment was conducted under laboratory and greenhouse conditions, in a completely randomized design, with 13 treatments (12 microorganisms and one control). Lysinibacillus boronitolerans (BRM 71995) promoted the greatest increase in shoot dry mass (48.64 %, compared to the control), whereas Acinetobacter sp. (BRM 71990) stood out for root dry mass (217.12 %, compared to the control). For 100-grain weight, Herbaspirillum seropedicae (BRM 71996) increased values by 110.40 %, compared to Bacillus velezensis (BRM 71986). H. seropedicae (BRM 71997) was responsible for the greatest productive gains, increasing the number of grains (57.35 %, compared to the control) and yield per pot (85.14 %, compared to the control).
Background: Maize (Zea mays L.) is one of the world's most important cereal crops, and improving its productivity while reducing dependence on chemical fertilizers has become a major goal of sustainable agriculture. The potential role of plant growth promoting rhizobacteria (PGPR) as a biofertilizer evolved as appropriate substitute to neutralize adverse environmental impacts wielded by manmade agrochemical.
Objective: This study aimed to evaluate the effects of Pseudomonas fluorescens and Bacillus subtilis, individually and in combination, on the growth and yield of maize compared with conventional NPK fertilization.
Methods: A field experiment was conducted during the 2025 growing season at the Field Crops Research Station, College of Agriculture, University of Samarra, using a Randomized Complete Block Design (RCBD) with three replicates. Six treatments were evaluated: Untreated control (T1), Pseudomonas fluorescens (T2), Bacillus subtilis (T3), combined inoculation (P. fluorescens + B. subtilis) (T4), combined inoculation with NPK fertilizer (T5), and NPK fertilizer (20:20:20) only (T6). Vegetative growth and yield-related traits were recorded and statistically analyzed.
Results: Inoculation of plants with PGPR bacteria resulted in a significant improvement in both vegetative growth and yield compared to the untreated control group. Pseudomonas fluorescens (T2) exhibited the highest vegetative growth rate, recording the highest plant height (148.00 cm), leaf area (365.00 cm²), leaf area index (2.63), and number of grains per spike (688 grains) compared control group recorded (92.33 cm), (10.67 plant⁻¹), (151.73 cm²), (0.70) respectively. Bacillus subtilis (T3), achieved the highest productivity, producing the largest number of spikes per plant (2.67 spikes) and the highest spike weight (283.50 g) compared control group recorded (2.00) and (161.60 g).
Conclusion: The use of PGPR, and especially Pseudomonas fluorescens and Bacillus subtilis as potential biofertilisation agents is a promising sustainable alternative to chemical fertilisation that can enhance maize growth and production, while decreasing dependence on mineral fertilisers.
Waser saad Khalaf, Ahmed waleed Abdulrahman· International Journal of Bio...· 0 citations
Soil degradation is a major concern, causing a decline in crop productivity and making sustainable agricultural practices essential for humankind. Biochar and plant growth-promoting bacteria (PGPB) are currently applied as affordable and environmentally safe alternatives. Biochar, a porous, carbon-rich by-product of biomass pyrolysis, was applied at 3 % (w/w) alone (control) and in combination with microbial inoculants, including a bacterial consortium. A 15-day pot experiment was conducted under controlled conditions to evaluate the effects of biochar and plant growth-promoting bacteria (PGPB) on plant growth. This study investigates the effects of biochar and PGPB (three Pseudomonas spp. and one Diaphorobacter spp.) on rice (Oryza sativa L.) and mustard (Brassica juncea L.) when applied individually and in combination. The results were evaluated based on plant growth-promoting criteria namely root and shoot length and chlorophyll content. It was observed that biochar had a positive impact on plant growth parameters when applied individually, however in combination with bacterial inoculants, the results were significantly improved. The consortium treatment showed higher values for root length, shoot length and chlorophyll content compared with individual treatments. This study highlights the major scope and potential of utilising plant growth promoting bacteria and biochar to achieve sustainable increases in plant growth and yield. However, some treatments showed variability in results, which could be attributed to the compatibility between biochar and microbial inoculants. This underscores the need for further optimisation studies on the interaction between biochar and bacterial inoculants.
D. Ruchi, S. Sunita, G. Arpita et al.· Plant Science Today· 0 citations
Plant growth-promoting rhizobacteria (PGPR) widely improve plant growth. Siderophore-producing bacteria (SPB) are a valuable PGPR type worthy of in-depth exploration. In this study, five SPB strains were selected as the research subjects. Pot experiments were conducted to evaluate their impact on maize growth in Alfisol. It was observed that the five SPB strains improved maize growth and nutrient uptake to varying degrees. Among them, CNRSB01 had the most significant effect. Compared with the control, CNRSB01 raised maize P, K, Ca, Mg, Fe, Mn, Cu and Zn content by 27.33%, 45.60%, 15.78%, 13.12%, 40.63%, 30.81%, 31.39% and 38.23%, respectively. Maize dry weight in the CNRSB01 treatment increased by 93.45%. Soil invertase activity and soil phosphatase activity in the CNRSB01 treatment increased by 39.12% and 29.04%, respectively. It also revealed that SPB modified soil bacterial diversity. Both Simpson index and Shannon index of CRSB02 and CNRSB01 treatments were significantly different from the control. PCA analysis showed that CNRSB01 treatment had the most divergent bacteria community composition. Research results suggested that SPB promote maize growth and nutrient uptake primarily by optimizing the soil microenvironment. These results provide theoretical reference for microbial application to enhance crop growth.
Drought is one of the major abiotic stresses limiting productivity worldwide, highlighting the need for sustainable strategies to improve crop resilience under water-limited conditions. This study evaluated the effects of the plant growth-promoting bacteria Bacillus aryabhattai and Pseudomonas fluorescens, applied individually or in combination, on soybean growth under well-watered and water-deficit conditions. The experiment was conducted in a completely randomized design arranged in a 2 × 4 factorial scheme, consisting of two irrigation regimes (well-watered and water deficit) and four biological treatments (control, B. aryabhattai, P. fluorescens, and co-inoculation with both bacteria). Plant growth variables, including shoot and root length, root volume, fresh biomass, and dry biomass, were evaluated after the stress period. Under well-watered conditions, co-inoculation promoted the greatest fresh root biomass and consistently increased shoot biomass compared with the untreated control. Under water-deficit conditions, B. aryabhattai alone produced the highest fresh root biomass and root volume, demonstrating superior performance in promoting root development during drought stress. Although most variables did not differ significantly among treatments, inoculated plants consistently exhibited greater vegetative growth than non-inoculated plants. These findings demonstrate the potential of B. aryabhattai and P. fluorescens as plant growth-promoting bacteria capable of enhancing soybean development, with B. aryabhattai showing particular promise for improving plant performance under water-limited conditions.
Thiago Ghedin Cappellesso, Sérgio Miguel Mazaro, Maira Cristina Schuster Russiano et al.· REMUNOM· 0 citations
ABSTRACT The use of plant growth-promoting microorganisms (PGPM) is a promising strategy to enhance crop productivity while improving soil functionality. This study evaluated the efficacy of fungal-bacterial consortium of Trichoderma asperellum, Pseudomonas fluorescens, and Bacillus subtilis, for promoting the growth of soybean and maize cultivated under distinct edaphoclimatic conditions across Brazil. Field trials were conducted in five locations within Rio Grande do Sul, Santa Catarina, São Paulo, and Minas Gerais. Treatments consisted of a fungal-bacterial consortium (200 g ha-¹, in-furrow at planting) combined with 50% or 100% of the recommended nitrogen rate. Shoot dry biomass, foliar nitrogen (N) and phosphorus (P) concentrations, grain yield, and soil microbial activity determined by fluorescein diacetate hydrolysis were assessed. The fungal-bacterial consortium significantly improved all variables in both crops. In soybean, shoot biomass increased by 10.7-13.4% and grain yield by 9.2-9.9%, while foliar N and P rose by 10.2-12.4%, and soil enzymatic activity increased up to 11.0%. In maize, biomass increased by 10.4-11.8% and grain yield by 13.1-13.9%, with foliar N and P increasing by 9.5-14.1% and soil enzymatic activity by up to 12.5%. Notably, positive responses were maintained under 50% nitrogen fertilization. These findings demonstrate that fungal-bacterial consortium enhances nutrient acquisition and soil microbial activity, improving crop performance under variable environmental conditions and reduced N input, supporting its potential as a biological tool for sustainable nutrient management in soybean and maize systems.
A.C.C. Bortolassi, Anna Flávia Neri de Almeida, E. Meyer et al.· Ciência e Agrotecnologia· 0 citations
Abstract Soybean has significant importance in the global agricultural sector. However, yield is often compromised by the low availability of phosphorus in the soil. The inoculation of phosphate-solubilizing bacteria has shown promise in increasing the absorption of this nutrient. Therefore, this study aimed to evaluate the efficiency of Bacillus licheniformis as a phosphorus solubilizer, as well as to investigate its impact on soybean crop development. The experimental design was a randomized block design arranged in a 4x2 factorial scheme, with four replications. Treatments consisted of four phosphate fertilization rates (0, 40, 60, and 80 kg ha−1 P2O5, applied as single superphosphate and equivalent to 0, 50%, 75%, and 100% the recommended rate) associated or not with inoculation with Bacillus licheniformis. Morphological variables (plant height, root length, stem diameter, and branch number) and yield components (pods per plant, seeds per plant, seeds per pod, thousand grain weight, and grain yield) were determined. There were no significant effects of biological inoculation or phosphorus rate on morphological characteristics or some yield components, attributed to the high content of available phosphorus in the experimental soil (39.3 mg dm−3). On the other hand, inoculation with B. licheniformis significantly increased thousand grain weight and grain yield, even under high phosphorus availability. Regression analysis indicated that both variables had a positive linear response to phosphorus rate. These results reinforce the agronomic potential of B. licheniformis as a complementary technology to phosphate fertilization, contributing to the sustainability of soybean production.
G. Fumagalli, T. R. B. Silva, A. Nolla et al.· Brazilian Journal of Biology· 0 citations