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This study was developed to investigate the interactive effect of silicon (Si) application and the inoculation of plant growth promoting bacteria (PGPB) Azospirillum brasilense on wheat nutrient uptake and accumulation on biomass and grains when combined with nitrogen (N) application rates. The study was set up in a Rhodic Hapludox under no-till system, located in Selvíria, state of Mato Grosso do Sul, Brazil (tropical Savannah region). Treatments were tested in a randomized complete block design with four replicates, arranged in a full factorial design 2 × 2 × 5 and included: i) two soil amendment sources (Ca and Mg silicate as Si source and dolomitic limestone); ii) two seed inoculation (with and without A. brasilense) and iii) five N application rates applied as side-dress (0, 50, 100, 150 and 200 kg ha−1). Increasing N application rates positively influenced wheat nutrition with increased nutrient and Si uptake in shoot. Calcium and Mg silicate positively influenced wheat nutrition with greater shoot Si and grain N, P, K, B, Cu, Fe, Mn, Zn and Si uptake. In addition, Si was the third and sixth element most absorbed in wheat shoot and grain respectively. Inoculation with A. brasilense was found to increase nutrient uptake with greater shoot K and S and grain N, P, K, Mg, S, B, Cu, Mn, Zn and Si uptake. Azospirillum brasilense inoculation provided greater N uptake, with an increase of 5.8 and 8.9% on shoot and grain uptake. [ABSTRACT FROM AUTHOR]

Rainfall variations can occur with crops in field condition which can result in soil water restrictions and impair crop development. Inoculation with Azospirillum genus bacteria can be presented as an alternative, as it has the ability to fix N2, promote root growth and produce beneficial metabolites to plants under water stress conditions. Thus, the objective was to co-inoculate A. brasilense and Bradyrhizobium sp. in cowpea and verify the potential to minimizing the effects caused due to water availability on root growth and nodulation. The study was carried out in a greenhouse with completely randomized block design and 4 replications in 4 × 4 factorial arrangement, the treatments being: (i) non-inoculated, (ii) N-fertilizer, (iii) inoculated with Bradyrhizobium sp. and (iv) co-inoculated with Bradyrhizobium sp. + A. brasilense. All treatments were associated with soil water tension of 15, 30, 45 and 60 kPa. Co-inoculation increased dry mass and nodules number. The root surface area and dry mass of cowpea roots showed an increase from the 50.55 kPa tension with co-inoculation. [ABSTRACT FROM AUTHOR]

Field experiments were conducted for two successive seasons July 2018 to November 2018 and July 2019 to November 2019 at the Fruit Instructional Farm, Department of Fruit Science, College of Horticulture and Forestry, Jhalawar district under Rajasthan state of India. The experiment consisted of different treatments of Azospirillum brasilense (AZS) and Vermicompost (V.C.). It was laid out in a Randomized Block Design with three replications. The 16 different treatment combinations of AZS and Vermicompost were applied to soil canopy of custard apple cv. Balanagar plants during first week of July 2018 and July 2019 in canopy rhizosphere of black vertisols in custard apple plants. Among different treatment combinations, T10 treatment consisting of AZS @ 50 g + V.C. @10 kg/plant was found relatively better over all other treatments with respect to most of the plant growth characteristics, including soil health properties and microbial population density in soil availability in canopy of custard apple cv. Balanagar plants. The pooled results of two years revealed comparative better plant growth parameters viz. rootstock girth (74.20 mm), scion girth (61.52 mm), plant height attribute (3.46 m), number of nodes per shoot (13.00), number of nodes per branch (86.17), number of shoots per branch (26.00), number of shoots per plant (151.00) have shown augmenting response in improvement of plant growth parameters under T10 treatment (AZS @ 50 g + V.C. @ 10 kg /plant) in custard apple cv. Balanagar plants. However, key soil parameters concerning bulk density (1.32 g/cm3), soil pH (7.39), and electrical conductivity (0.46 dS m−1) reduced significantly under T10 treatment over other treatments. The soil physico-chemical properties especially change in porosity (55.04%), organic carbon (0.55%), available nitrogen content (350.55 kg/ha), available phosphorous content (46.51 kg ha−1) and available potassium content (322.34 kg ha−1), bacterial population (26.67 cfu g−1), fungi population (15.00 cfu g−1) and actinomycetes population (10.00 cfu g−1) have shown tremendous response in improvement of soil parameters under T10 treatment (AZS @ 50 g + V.C. @ 10 kg /plant) with respect to overall soil health. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of plant growth promoting bacteria (PGPB) inoculation in Zuri guinea grass [Megathyrsus (syn. Panicum) maximus] on shoot dry weight (SDW) and root dry weight (RDW) yield, morphological compositions, number of tillers, and nutrients concentrations in SDW. The experiment was carried out under greenhouse conditions in a randomized block design consisting of eight treatments with five replicates. The inoculation with the Ab-V5 and Ab-V6 strains of Azospirillum brasilense and Pseudomonas fluorescens or co-inoculation with Rhizobium tropici and Ab-V6, with nitrogen (N) fertilization, as well as re-inoculations of the plants after cuttings were taken were evaluated. The plant growth-promoting bacteria and N fertilization promoted increases in SDW and RDW yield, tillers dry weight, relative chlorophyll index (RCI) and nutrients uptake in shoots of Zuri guinea grass. There were effects of re-inoculation the PGPB by P. fluorescens in shoots, N, magnesium (Mg) and boron (B) concentration in SDW. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of strains of Azospirillum brasilense, Pseudomonas fluorescens and Rhizobium tropici on the shoot dry weight (SDW) and root dry weight (RDW) yield, N uptake and nutritive value of 'Mavuno' grass inoculated with plant growth-promoting bacteria. We evaluated the effects of inoculation with the Ab-V5 and Ab-V6 strains of Azospirillum brasilense and Pseudomonas fluorescens or co-inoculation with Rhizobium tropici and Ab-V6, with and without nitrogen (N) application, as well as re-inoculations. The growth promoting bacteria + N promoted increases in SDW and RDW yield, tillers dry weight, relative chlorophyll index and N uptake. There were no effects of re-inoculation by Azospirillum brasilense, Pseudomonas fluorescens and Rhizobium tropici on nutrition, nutritive value and SDW and RDW yield, demonstrating that this technique still needs further studies with 'Mavuno' grass in the form and the correct period to be performed. [ABSTRACT FROM AUTHOR]

Plant growth–promoting bacteria may play an important role on rice development; however, its interaction with different genotypes is still uncertain. This work aimed to assess the effect of inoculation ofAzospirillum brasilenseAbV5 strain on the agronomical performance of different rice cultivars under field conditions during two consecutive years and to determine the response of rice cultivars to indole-acetic acid (IAA) rates under in vitro conditions using for both conditions a randomized block design. Field experiments evaluated the productivity components and grain yield of inoculated and noninoculated cultivars and in vitro assays monitored the plantlet growth under different IAA rates. Field experiments showed that the general average grain yield of rice cultivars inoculated withA. brasilenseAbV5 strain was significantly greater. Fifty percent of the evaluated cultivars had statistically significant increase in yield varying from 40 to 108 percent upon inoculation withA. brasilenseAbV5 strain, while 35 percent showed no significant change in yield (−6 to −28 percent). In vitro assays showed rate- and cultivar-dependent responses of upland rice to exogenous IAA. These results show a cultivar-dependent response of rice to inoculation withA. brasilenseAbV5 strain, which can be related with IAA production by AbV5 strain. [ABSTRACT FROM PUBLISHER]

Soybean is widely cultivated in Argentina, and there are areas where a significant degree of nodulation by soil indigenous rhizobia prevents improved nitrogen nutrition. The aim of this study was to determine the effect of inoculation with selected strains of Azospirillum brasilense on the production of different varieties of soybean cultivated in Tucumán, Argentina. Azospirillum was selected on the basis of the extent of colonization of soybean roots, nitrogenase activity, and auxin production. We found that wild strains of rhizobia were not affected by inoculation with Azospirillum and increased grain yield and nodulation, and nitrogen fixation was largest. This research provides an alternative for soybean production. [ABSTRACT FROM PUBLISHER]

A modified approach was adopted to develop co-flocs consisting of Azospirillum brasilense MTCC-125 and Pseudomonas fluorescens MTCC-4828. The results of our study revealed that both Azospirillum and Pseudomonas strains exhibited a higher survivability when embedded in the flocs. The survivability of the strains in co-floc was found to be higher when compared to the log phase vegetative cells in different inoculant carriers, spermosphere rhizoplane and rhizosphere. The co-floc treatment has also significantly increased the germination percentage and vigour index of rice. In the present study flocculation was found to play a major role in enhancing adhesion of both the strains to rice roots. The co-flocs were studied for their efficiency to induce resistance in rice crop against rice blast. The relative role of Azospirillum and Pseudomonas co-flocs in the induction of resistance against the phytopathogen was evaluated. It was found that when the activities of polyphenol oxidase, peroxidase and phenol were high and when the relative amounts of the sugars were low, the disease infestation was less and vice versa. The association of these compounds strongly implies their role as casual agents of induced resistance against Pyricularia oryzae. [ABSTRACT FROM AUTHOR]