Biochemical and microbial interactions of Sargassum wightii extract and plant growth-promoting rhizobacteria consortia enhance growth and yield of tomato (Solanum lycopersicum L.)

Plant growth promotion of rice (Oryza sativa L.) with root endophytic bacteria, isolated from wild Solanaceous medicinal plants Solanum nigrum L., Solanum sisymbriifolium Lam., and Solanum virginianum L.

Modulation of germination physiology and biochemical metabolism in rice (Oryza sativa L.) through microbial seed biopriming

Seed biopriming is an eco-friendly technique that enhances seed germination and seedling growth through the application of beneficial microorganisms. The study evaluated the effects of seed biopriming with four plant growth-promoting rhizobacteria (PGPR) such as Azospirillum lipoferum, Bacillus megaterium, Paenibacillus mucilaginosus and Pseudomonas chlororaphis at concentrations of (10–40 %) on seed quality traits of rice cultivars CO 53 and TKM 15, compared with hydroprimed and untreated seeds. The results revealed that biopriming with 20 % A. lipoferum significantly improved seed quality parameters in both varieties. In CO 53, the 20 % A. lipoferum recorded the highest germination percentage (90 %), total seedling length (33.0 cm), vigour index (2970) and dry matter production (0.135 g seedling-1) compared to the untreated control. Bioprimed seeds also exhibited enhanced α-amylase activity (1.630 mg maltose min-1 g-1), reducing sugar content (2.56 mg g-1) and dehydrogenase activity (0.47), along with a reduction in starch content (7.6 mg g-1), indicating efficient mobilisation of seed reserves during germination. Similar trends were observed in TKM 15, where 20 % A. lipoferum significantly enhanced both physiological and biochemical seed parameters. The enhanced performance of bioprimed seeds was attributed to microbial stimulation of enzymatic activities, improved nutrient availability and increased production of growth-promoting metabolites, which collectively promoted rapid germination and vigorous seedling growth. The findings demonstrate that seed biopriming with A. lipoferum is an effective and sustainable strategy for improving seed vigour and physiological performance in paddy. Seed biopriming with beneficial rhizobacteria represents a promising strategy for improving seed quality and supporting sustainable rice cultivation.

Effect of plant growth promoting rhizobacteria on the growth promotion of Mustard CS61 (Brassica juncea)

Plant growth-promoting rhizobacteria consortia are used in the growth and augmentation of Mustard CS61 (Brassica juncea) under saline conditions to discover novel genes associated with stress tolerance and plant growth–promoting traits.

Impact of PGPR Seed Priming on Germination, Yield, and Metabolite Profile of Basil (Ocimum basilicum L.) and Sage (Salvia officinalis L.)

This study evaluated the potential of plant growth-promoting rhizobacteria (PGPR) from the genera Bacillus and Actinomycetes to enhance growth and secondary metabolite production in basil (Ocimum basilicum L.) and sage (Salvia officinalis L.). Six isolates obtained from the rhizosphere of Urtica dioica, including three Bacillus spp. (Bac1-Bac3) and three actinomycetes (Act1-Act3), were morphologically and biochemically characterized and screened for physiological tolerance and plant growth-promoting (PGP) traits, identifying two isolates with strong PGP potential. The selected strains were further evaluated in in vitro seed inoculation assays and pot experiments under controlled conditions. Plant yield parameters were assessed alongside biochemical analyses of plant material including total phenolics, rosmarinic acid content, phenylalanine ammonia-lyase activity, and antioxidant capacity. Inoculation with selected strains significantly improved early seedling performance, including germination (Act1 up to 117% in sage), root elongation (Act1 up to 200%), and shoot elongation (Bac3 up to 175%). After six weeks, Act1 maximized sage fresh biomass (77.6%), while Bac3 enhanced basil dry matter (60% increase). Beyond growth promotion, PGPR treatments significantly increased phenolic content, rosmarinic acid concentration, phenylalanine ammonia-lyase activity, and antioxidant capacity (lower IC₅₀ values), indicating activation of the phenylpropanoid pathway. Molecular identification (16S rRNA sequencing) revealed Bac3 as Bacillus pretiosus (97.95% identity) and Act1 as Streptomyces ardesiacus (97.73% identity).

Growth and Yield Response of Tomato Plants (Solanum lycopersicum L.) to the Application of Liquid Organic Fertilizer and Plant Growth Promoting Rhizobacteria

Tomatoes (Solanum lycopersicum L.) are horticultural plants from the Solanaceae family that contain protein, carbohydrates, calcium, phosphate, iron, fat, and vitamins. Tomato production in Indonesia has declined due to the lack of nutrients absorbed by tomato plants. Efforts that can be made include the application of Liquid Organic Fertilizer (LOF) and Plant Growth Promoting Rhizobacteria (PGPR). This study was conducted to examine the interaction between LOF and PGPR and to determine the appropriate concentrations of LOF and PGPR for tomato plant growth and yield. The research was conducted from February to June 2025 in Ampeldento Village, Karangploso District, Malang Regency. The design used was a Factorial Randomized Group Design (FRGD) consisting of two treatment factors, namely LOF and PGPR. The LOF factor consisted of 4 treatment levels and the PGPR consisted of 3 treatment levels. Each treatment was repeated 3 times, resulting in 36 experimental units. If there was a significant effect, it was followed by a Honest Significant Difference (HSD) at the 5% level. The results showed that there was an interaction between the application of LOF concentration and PGPR concentration on the growth and yield parameters of tomato plants. The combination of 30 ml L-1 LOF and 40 ml L-1 PGPR produced higher average plant height, number of leaves, leaf area,fresh weight, dry weight, crop growth rate, total number of fruits per plant, fruit weight per plant, and fruit weight per hectare, so that combination is the appropriate treatment to support tomato plant growth and yield.

Interactive Effects of Humic Acid and Seaweed Extract on Growth, Yield and Quality of Tomato (Solanum lycopersicum L.)

Background: Tomato (Solanum lycopersicum L.) productivity and fruit quality are strongly influenced by nutrient availability and crop-management practices. Humic acid and seaweed extract are plant biostimulants that may enhance vegetative growth, yield, and quality when applied at appropriate concentrations. Aims: This study evaluated the individual and interactive effects of foliar-applied humic acid and seaweed extract on the growth, yield, fruit quality, and economic performance of tomato (Solanum lycopersicum L.) cv. Arka Samrat. Place and Duration of Study: The experiment was conducted at the Agricultural Research Farm, Suresh Gyan Vihar University, Jaipur, during the Rabi season of 2025–26. Methodology: The experiment was laid out in a factorial randomised block design with two factors: humic acid at four concentrations (0, 2, 4, and 6 mL/L) and seaweed extract at four concentrations (0, 2, 4, and 6 mL/L). The 16 treatment combinations were replicated three times, and the observed data were analysed using OPSTAT. Results: Significant differences were observed among the treatments. Among the treatment combinations, humic acid at 4 mL/L combined with seaweed extract at 4 mL/L (M3T3) recorded the greatest plant height (312.62 cm), number of branches per plant (9.07), plant spread (65.92 cm), number of leaves per plant (69.13), number of clusters per plant (11.80), and number of flowers per cluster (9.01). It also recorded the fewest days to first flowering (27.69), 50% flowering (36.96), and first fruiting (41.95), together with the greatest number of fruits per cluster (8.24), average fruit weight (109.73 g), fruit yield per plant (6.40 kg), number of fruits per plant (58.35), total soluble solids (4.99 °Brix), ascorbic acid content (26.68 mg/100 g), and benefit–cost ratio (2.97). Conclusion: The treatment combination of humic acid at 4 mL/L and seaweed extract at 4 mL/L (M3T3) produced the most favourable growth, yield, quality, and economic responses under the conditions of this experiment. However, these findings are indicative and require further experimentation across seasons and locations before broader recommendations can be made.