Effect of Methylobacterium on the yield and quality of cauliflower (Brassica oleracea)

Biofertilizer based on mycorrhizal fungi and rhizobacteria in maize cultivation under two water regimes

Biostimulants are able to increase tolerance to water and salt stress and help enhance the absorption of nutrients from the soil, in addition to increasing the extension of roots, they are also effective in the synthesis of plant hormones (such auxins, gibberellins, cytokinins) and in the capacity to make insoluble phosphorus in the soil available to plants, minimizing the effects of biotic and abiotic stresses. The objective of this study was to evaluate the phytotechnical and physiological responses of maize subjected to two water regimes and a biostimulant containing mycorrhizae and rhizobacteria of the genus Bacillus spp., through the characterization of the antioxidant response conditioned by this association. The experiment was set up in a 5x2 factorial scheme, with five treatments related to the doses of biostimulant [negative control; 0.250 kg ha-1; 0.500 kg ha-1; 0.750 kg ha-1 and 1 kg ha-1] and two water availability levels (60% and 100% of field capacity), with four replicates, totaling 40 pots. The following growth parameters were analyzed at 15 and 30 days after planting: plant height, stem diameter, number of leaves, root length and root volume, as well as the following biochemical parameters: lipid peroxidation, total peroxidase and catalase of leaf and root. The biostimulant promoted an increase in the growth of the aerial part and root system of corn plants, in addition to an adjustment of antioxidant enzymes, indicating that, up to 30 days after planting (DAP), corn plants show better adaptability to the water regime with 60% of field capacity.

MYCORRHIZAL FUNGI ACTIVITY AND DIVERSITY DRIVEN BY THE APPLICATION OF ORGANIC AMENDMENTS IN WHEAT

APPLICATION OF BIOINOCULANTS FOR OPTIMIZING THE USE OF MINERAL FERTILIZERS IN THE PRODUCTION OF SILAGE CORN

 Maize is one of the most important agricultural crops globally and in Bosnia and Herzegovina, where cereals are cultivated on 204,368 ha, of which 57% (116,490 ha) is dedicated to maize production. The application of plant growth-promoting rhizobacteria (PGPR), such as the genera Pseudomonas and Bacillus, represents a sustainable alternative to mineral fertilizers, particularly in phosphorus-deficient soils commonly found in Bosnia and Herzegovina. A field experiment with ten fertilization treatments, arranged in a randomized block design with three replications, was conducted to evaluate the effects of seed inoculation, organic fertilization, and mineral fertilization on silage maize production. Grain yield, ear characteristics, and nutrient concentrations in maize leaves and grain were determined using standard analytical methods. The highest grain yield (15.2 t ha⁻¹) was achieved with the combined application of organic fertilization (30 t ha⁻¹) and bacterial inoculation, with a statistically significant difference compared to the control treatment. The applied fertilization treatments improved nutrient uptake and increased the content of protein, nitrogen, phosphorus, and magnesium in the grain, while zinc concentration generally decreased, indicating an antagonistic relationship between phosphorus and zinc. The obtained results confirm the potential of combining rhizobacterial inoculation and organic fertilization to enhance maize productivity and improve plant nutrient status. 

Evaluation of different levels of nitrogen and

Biostimulant potential of lactic acid bacteria in hydroponic lettuce production: growth and nutritional quality

The use of microbial biostimulants has become an important strategy for improving the productivity and quality of soilless vegetable production systems. However, the potential role of lactic acid bacteria (LAB) in hydroponic crop production remains insufficiently explored. This study evaluated the effects of three LAB strains, namely Lactiplantibacillus plantarum (LP), Levilactobacillus brevis (LB), and Pediococcus pentosaceus (PP), their combined mixture, and a commercial PGPR-based product, Rhizofill, on the growth, yield, physiological performance, and nutritional quality of lettuce grown in a floating hydroponic system. The experiment was conducted under greenhouse conditions using Batavia-type lettuce cv. ‘Caipira’ in a randomized complete block design with four replications. Bacterial suspensions were applied to the nutrient solution at 7-day intervals. Bacterial inoculations significantly improved plant growth, yield, SPAD chlorophyll index, leaf sap EC, and antioxidant-related quality traits compared with the untreated control. Among the tested treatments, LP showed the strongest overall performance, increasing plant fresh weight and total yield by 34.0% and 36.0%, respectively, compared with the control. LP also enhanced total phenolic, flavonoid, and L-ascorbic acid contents, indicating a simultaneous improvement in productivity and nutritional quality. LB was particularly effective in promoting root fresh weight and produced the lowest nitrate accumulation among all treatments. Compared with Rhizofill, LP showed equal or superior performance in several growth and quality parameters, suggesting that selected LAB strains may provide an effective alternative to conventional PGPR-based microbial biostimulants. Overall, the findings highlight the potential of LAB, particularly L. plantarum, as emerging microbial biostimulants for sustainable hydroponic lettuce production.

Agronomic, Biochemical and Metabolic Responses of Tomato to Vermicompost and Mineral Fertilization in Loam and Clay Soils

The intensive use of mineral fertilizers in horticultural systems has improved crop productivity but also increased concerns regarding soil degradation and environmental sustainability. In this context, vermicompost derived from buffalo manure may represent a sustainable alternative for nutrient management and organic waste valorization. This study evaluated the effects of four fertilization strategies on tomato (Solanum lycopersicum L.) grown in loam and clay soils: unfertilized control, mineral fertilization, vermicompost applied at an equivalent nitrogen rate, and the residual effect of vermicompost from a previous cauliflower crop. Agronomic performance, fruit quality, carbon and nitrogen metabolism, and antioxidant-related traits were assessed. Mineral fertilization produced the highest marketable yield, reaching 9.68 and 7.69 kg m−2 in loam and clay soils, respectively, mainly through increased fruit number. Direct vermicompost application maintained substantial productivity, with yields of 7.55 and 5.18 kg m−2 in the two soils. The fertilization strategies also induced distinct changes in fruit composition. Mineral fertilization increased total free amino acids to approximately 160 mg g−1 DW, mainly through the accumulation of glutamine, glutamate, asparagine and γ-aminobutyric acid, but was associated with lower soluble solids and antioxidant activity. Vermicompost promoted the highest lycopene concentration, approximately 2.1 mg g−1 DW, in clay soil and maintained intermediate antioxidant activity and amino acid concentrations. Soil texture also influenced carbohydrate partitioning, with greater fructose accumulation in clay soil and greater starch accumulation in loam soil. The residual vermicompost treatment alone did not adequately sustain tomato productivity or metabolic activity, particularly in clay soil. Overall, vermicompost partially replaced mineral fertilization while maintaining satisfactory yield and modulating fruit metabolic quality, although its effectiveness depended strongly on soil texture.