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The nitrogen (N) requirement for barley cultivation can vary from 90 to 130 kg ha−1 cycle−1, representing 30% of production costs. Furthermore, obtaining mineral N is difficult due to constant conflicts involving producing countries. Excess N will increase the cost of production and contaminate the soil and groundwater, unbalancing the fauna, flora, and microbiology of the environment. The objective of this research was to evaluate the management of inoculation and N fertilization with A. brasilense on the development and productivity of barley. Field experiment was carried out for two years. A randomized block design was used in a 5 (Factor A) × 2 (Factor D) factorial arrangement with four replications. In which the "factor A" included five doses of A. brasilense, whereas the "factor D" was evaluated N management (with or without N management). The inoculant used had approximately of 2.0 × 108 viable cells mL−1 (Ab-V5 and Ab-V6 strains). Innoculation was carried out on the seeds 1 hour before sowing, in order to homogenize the inoculant in the seeds, to guarantee homogeneity of the distribution of microorganisms on the seeds. The best dose of A. brasilense was 12.5 mL kg−1 of seed, which provided an increase in plant height, number of ears, mass and grain productivity. The use of A. brasilense showed significant improvements in management with or without the use of mineral N. However, better results are obtained when the association between N management and the use of inoculant is made. Thus, when using up to 22.5 kg of N, the best results were observed. [ABSTRACT FROM AUTHOR]

The increase in the world population creates the need for sustainable food production and the use of synthetic fertilizers with growth-promoting bacteria. The objective of this research was to evaluate the acidity on the physiological and productive variables of wheat inoculated with Azospirillum brasilense and treated with osmoprotective additives. Combinations of A. brasilense, osmoprotectant and chemical treatment were evaluated in wheat seeds planted in contrasting acidity soil (pHs: 4.8 and 6.5). Evaluations of the physiological parameters were carried out in the foliar tissue (hydrogen peroxide content, superoxide dismutase activity, lipid peroxidation, content of chlorophyll a, b, and total and carotenoid and nitrate reductase enzyme activity) during the vegetative period and flowering. The grain yield components were evaluated after the physiological maturation. Plants grown in uncorrected soil acidity (pH: 4.8) showed higher lipid peroxidation. The other plants (pH: 6.5) have higher levels of nitrate reductase. Higher nitrate reductase activity was also observed in plants inoculated with A. brasilense. Therefore, in soil acidity 6.5, both A. brasilense isolate or combined with osmoprotective additive increased the grain yield. Nevertheless, the osmoprotectant application did not attenuate the effects of the chemical treatment of seeds and exerted a negative effect to inoculation with A. brasilense. [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 massive use of inputs is often applied in common bean for nitrogen (N) supply, better plant development, and to prevent plant disease. Instead, the co-inoculation of Rhizobium, Azospirillum and Trichoderma may play the same role; however, its effects are unknown in common bean. This work aimed to evaluate the effects of co-inoculating three microorganisms on the development, nodulation and grain yield (GY) of a common bean. The experiments were carried out on a randomized block design with four replicates. The treatments were NI: not inoculated; Rt: inoculated with Rhizobium tropici; Rt+Ab: inoculated with Rt and Azospirillum brasilense; Rt+Ab+Ta: inoculated with Rt, Ab and Trichoderma asperellum; Nf120: 120 kg ha−1 of N. In the inoculated treatments, the seeds were treated with Rt inoculant and with Ta inoculant before sowing, using a dose of 10 g of each inoculant kg−1 of seed. The inoculant containing the Ab was sprayed out in a dose of 300 mL ha−1 at the V2/V3 phenological stage. Evaluations were performed for the number of nodules (NN), nodule dry weight (NDW), root dry weight (RDW), shoot dry weight (SDW), pod number (PN), grain number (GN) and GY. NN and NDW were higher in NI and Rt treatments. The Rt+Ab treatment resulted in higher SDW, whereas the same treatment and Rt+Ab+Ta provided higher RDW and SDW, resulting in values similar to those of the Nf120 treatment. Innoculation with rhizobia (Rt) provided PN and GN equivalent to those of the Nf120 treatment. The inoculation (Rt) and co-iconulation (Rt+Ab) resulted on GY of 2946.27 and 2892.42 kg ha−1, respectively, surpassing the Nf120 treatment, which was 2741.91 kg ha−1. These results indicate that Rt inoculation and Rt+Ab co-inoculation can be alternatives to the substitution of nitrogen fertilizers, guaranteeing high GY levels in common bean. [ABSTRACT FROM AUTHOR]

In Egypt, the total area of agricultural land is 3.36 million acres, which is 3.8% of the country entire territory. One of the main obstacles to agricultural production in Egypt is soil salinization and degradation. Therefore, saline-sodic soil reclamation in arid regions is highly relevant. This study aimed to use Azospirillum inoculation with eco-friendly organic wastes for free remediation of saline-sodic soils. In this work, nine treatments included two levels of spent grain (S1 and S2), two levels of compost (C1 and C2), a mix of both sources (C1S1), Azospirillum (A1), a mix of both sources with Azospirillum (A1S1 and A1C1) and untreated control. The treatments were previously incubated with soil at field capacity for five months under laboratory conditions at 28°C. The most relevant chemical and biological parameters were analyzed every month for five months. Results indicate that Azospirillum inoculation with spent grain increased soil organic carbon (TOC), dehydrogenase and urease enzymes, micro-nutrients iron (Fe2+), zinc (Zn2+), manganese (Mn2+), copper (Cu2+), and boron (B+), and macro-nutrients nitrogen (N), phosphorus (P) and potassium (K); while decreased exchangeable sodium percentage (ESP), pH and EC, by 75%, 12%, and 43% respectively, compared to initial conditions. A significant variation was observed in chemical and biological properties among all treatments in the order of S2 ≥ A1S1> A1 > C2 > C1S1 > A1C1 > C1 > control > initial. In conclusion, the addition of Azospirillum with the spent grain is highly recommended for the saline-sodic soil amelioration. It is more effective than compost to remediate and enhance saline-sodic soils fertility. [ABSTRACT FROM AUTHOR]

Climate change is imposing high temperature resulting in prolonged drought episodes and shrinking of fresh water resources across the globe. In this scenario, even drought tolerant crops like quinoa are also losing significant yield. However, this study was planned to investigate the impact of drought on quinoa at critical growth stages and bacterial inoculation to improve drought tolerance. Drought was imposed by maintaining 25% pot water holding capacity (PWC) at multiple leaf, flowering, and seed filling stage (DSFS), while 80% PWC was considered as control. Three strains of plant growth promoting rhizobacteria (PGPR) named as: Bacillus licheniformis, Pseudomonas fluorescens, and Azospirillum brasilense were inoculated with quinoa seeds before sowing with respect to drought treatments. PGPR inoculation mitigated the drastic effects of drought by improving crop growth, net assimilation rate, water use efficiency, leaf chlorophyll, and phenolic contents, all of these ultimately contributed to improvement in grain yield and its contributing attributes. Moreover, PGPR markedly improves the grain quality attributes including protein, phosphorus, and potassium contents. Principal component analysis linked the different scales of study and demonstrated the potential of physio-biochemical traits to explain the quinoa yield variations under drought condition with response to PGPR inoculation. Among different PGPR, A. brasilense was found most effective both under normal and drought conditions. Overall, DSFS has more detrimental effects among critical growth stages of quinoa and A. brasilense can be used as a shotgun tactic to ameliorate drought stress in quinoa. [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]

Alternative options to feed an ever-growing global population requires to be developed to supplement chemical fertilizer use. Nitrogen (N) is the chemical fertilizer most used for non-legume crops. Research showing the potential for management practices which supplement the use of N fertilizer is utmost important. This research was developed to investigate the potential use of Azospirillum brasilense to enhance micronutrient accumulation in wheat cropping systems; and, to assess the potential interactions between biological nitrogen fixation (BNF) and urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT). The objective was to evaluate the effect of N sources and doses associated with inoculation with A. brasilense, regarding micronutrients accumulation, and its influence on wheat grain yield in Savannah conditions. The study was carried out in a Rhodic Hapludox under no-tillage. The experimental design was a randomized complete block design with four replications arranged in a 2 × 5 x 2 factorial scheme: two N sources (urea and urea with NBPT), five N rates (0, 50, 100, 150 and 200 kg ha−1), with and without A. brasilense inoculation. N rates increased the uptake and removal of micronutrients. Urea with NBPT was not efficient in optimizing nitrogen fertilization. Inoculation with A. brasilense provided a higher accumulation of Cu, Fe, Mn and Zn in the straw and Mn and Zn in grains. The inoculation with A. brasilense associated with 140 kg ha−1 of N provided increased wheat grain yield. [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]