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Vermicompost has been promoted as a viable substrate component owing to its physicochemical properties, nutrient richness, and status as an excellent soil improver. It is considered the best organic fertilizer and is more eco-friendly than chemical fertilizers. Plant-growth-promoting microorganisms (PGPMs) are defined as plant biofertilizers that improve nutritional efficiency—that is, they transform nutrients within substrates from organic to inorganic forms, making them available for plants. The main objective of this research study is to evaluate the effects of the application of three PGPM microbial consortia on different mixtures of organic substrates based on vermicompost (V) and coconut fiber (CF) on two different horticultural crops. We performed a yield analysis and drainage nutrient tests and determined the plant nutritional status and enzymatic activity in organic substrates based on the two crops, Cucumis melo L. and Solanum lycopersicum L. A multivariate analysis of variance and principal component analysis was conducted using substrate types and PGPMs as factors. Differences (p < 0.05) in yield, dehydrogenase activity, the nutrient concentrations in a petiole sap, and drainage were observed at 30, 60, 75, and 90 days after transplant. PGPMs such as Trichoderma sp. and plant-growth-promoting rhizobacteria (PGPR) in organic substrates (40V + 60CF) can significantly improve the nutritional status of plants for use in organic soilless container agriculture. Biofertilization with PGPMs and suitable mixtures of organic substrates together with aqueous extracts (tea) of vermicompost, as nutrient solutions applied by fertigation, has allowed us to achieve an adequate level of production through environmentally friendly techniques. The results obtained allowed us to affirm that it was possible to replace conventional fertilization using no chemical products and ensure adequate crop nutrition by supplying main macronutrients with organic sources and biofertilizers.

Eucalyptus benthamii is a tree species commonly planted in subtropical areas, including the Southern Brazil, due to its tolerance to low temperatures and frosts. The success of E. benthamii plantation depends on the seedlings vigor during transplantation. We hypothesized that improvement of chemical and biological properties of growth substrate would produce more vigorous E. benthamii seedlings. Thus, we applied increasing doses (0, 0.5, 1.0, 1.5 and 2.0 g per seedling) of the organic fertilizer Bacsol, which carries a consortium of potential plant growth promoting microorganisms, on the substrate, and measured the growth and development of E. benthamii seedlings. Two experiments were performed in 2011 and 2012. The first experiment included measurements in four growth stages to estimate the relative growth rates. The second one ended at the time that seedlings reached standard heights for transplantation (about ± 20 cm). Measurements on plant height, stem diameter, shoot dry weight and relative growth rates indicated that the application of Bacsol improved E. benthamii seedlings vigor and decreased the time needed in nursery, from 150 days to 90 days. The best responses occurred at doses from 1.3 g to 1.5 g per seedling. The data demonstrated that application of Bacsol in substrate is a promising technology to increase E. benthamii seedlings vigor. Made available in DSpace on 2018-01-29T23:37:51Z (GMT). No. of bitstreams: 1 document.pdf: 222573 bytes, checksum: 8ba5b3598c93a4acbdbc9457ed253acb (MD5) Previous issue date: 2017-12-14

Introduction: Arbuscular mycorrhizal symbiosis is formed by approximately 80% of the vascular plant species in all terrestrial biomes. Using soil microbial potential including arbuscular mycorrhizal fungi (AMF) has been widely considered for improving plant growth, yield and nutrition. Medicinal herbs are known as sources of phyto chemicals or active compounds that are widely sought worldwide for their natural properties. Members of the Lamiaceae family have been used since ancient times as sources of spices and flavorings and for their pharmaceutical properties. Peppermint (Mentha piperita) has a long tradition of medicinal use, with archaeological evidence placing its use at least as far back as ten thousand years ago. Essential oils - are volatile, lipophilic mixtures of secondary plant compounds, mostly consisting of monoterpenes, sesquiterpenes and phenylproponoids.Arbuscularmycorrhizal fungi with colonizing plant roots improve nutrient uptake as well as improving essential oil yield of medicinal plants by increasing plant biomass. The aim of the present study was to evaluate the effect of AMF inoculation on essential oil content and some growth parameters of peppermint (Mentha piperita) plant under glasshouse condition. Materials and Methods: This study was performed on a loamy sand soil. The samples were air-dried, sieved (

Climate change has already affected food security in many parts of the world, and this situation will worsen if nothing is done to combat it. Unfortunately, agriculture is a meaningful driver of climate change, through greenhouse gas emissions from nitrogen-based fertilizer, methane from animals and animal manure, as well as deforestation to obtain more land for agriculture. Therefore, the global agricultural sector should minimize greenhouse gas emissions in order to slow climate change. The objective of this review is to point out the various ways plant growth promoting microorganisms (PGPM) can be used to enhance crop production amidst climate change challenges, and effects of climate change on more conventional challenges, such as: weeds, pests, pathogens, salinity, drought, etc. Current knowledge regarding microbial inoculant technology is discussed. Pros and cons of single inoculants, microbial consortia and microbial compounds are discussed. A range of microbes and microbe derived compounds that have been reported to enhance plant growth amidst a range of biotic and abiotic stresses, and microbe-based products that are already on the market as agroinputs, are a focus. This review will provide the reader with a clearer understanding of current trends in microbial inoculants and how they can be used to enhance crop production amidst climate change challenges.

Arbuscular mycorrhizal (AM) fungi and plant growth-promoting rhizobacteria, responsible for enhancing plant nutrition, vigour and growth, may be used to reduce dosages of chemical fertilisers. Technologies that allow an economically viable and efficient application of these beneficial microbes in large scale agriculture must be studied. Seed coating is a potential delivery system for efficiently introducing minor amounts of bioinoculants. Despite the dramatic reduction on inoculum dose per plant, inoculation of AM fungi via seed coating was as effective as conventional soil inoculation. Fertilisation and inoculation had a significant impact on maize shoots nutrient concentrations. Different fertilisation regimes did not influence mycorrhizal colonisation. Plants without fertilisation and singly inoculated with R. irregularis showed shoot nutrient concentration increments of 110, 93, 88 and 175% for nitrogen, phosphorus, potassium and zinc, respectively, comparing with non-inoculated controls. Plants singly inoculated with P. fluorescens via seed coating under full fertilisation, presented enhancements of 100, 75 and 141% for magnesium, zinc and manganese, respectively, comparing with non-inoculated controls. Seed coating is a promising tool for delivering microbial inoculants into the soil, while promoting sustainable production of maize. This technology is particularly pertinent in low input agriculture, with potential environmental profits and food quality improvements.

As the processes facilitated by plant growth promoting microorganisms (PGPMs) become better characterized, it is evident that PGPMs may be critical for successful sustainable agricultural practices. Microbes enrich plant growth through various mechanisms, such as enhancing resistance to disease and drought, producing beneficial molecules, and supplying nutrients and trace metals to the plant rhizosphere. Previous studies of PGPMs have focused primarily on soil-based crops. In contrast, aquaponics is a water-based agricultural system, in which production relies upon internal nutrient recycling to co-cultivate plants with fish. This arrangement has management benefits compared to soil-based agriculture, as system components may be designed to directly harness microbial processes that make nutrients bioavailable to plants in downstream components. However, aquaponic systems also present unique management challenges. Microbes may compete with plants for certain micronutrients, such as iron, which makes exogenous supplementation necessary, adding production cost and process complexity, and limiting profitability and system sustainability. Research on PGPMs in aquaponic systems currently lags behind traditional agricultural systems, however, it is clear that certain parallels in nutrient use and plant-microbe interactions are retained from soil-based agricultural systems.

Debido a la aplicación constante de insumos químicos en los agroecosistemas, el costo de producción de las cosechas y la calidad ambiental del suelo y agua se ha visto afectada. Los microorganismos realizan la mayoría de los ciclos biogeoquímicos; por tanto, su función es fundamental para mantener el equilibrio de los agroecosistemas. Uno de esos grupos funcionales son los microorganismos solubilizadores de fosfato, reconocidos promotores de crecimiento vegetal. Estas poblaciones microbianas realizan una actividad importante, ya que en muchos suelos se encuentran grandes reservas de fósforo insoluble, resultado de la fijación de gran parte de los fertilizantes fosforados aplicados, que no pueden ser asimilados por la planta. Los microorganismos solubilizadores de fosfato usan diferentes mecanismos de solubilización, como la producción de ácidos orgánicos, que solubilizan dichos fosfatos insolubles en la zona rizosférica. Los fosfatos solubles son absorbidos por la planta, lo cual mejora su crecimiento y productividad. Al utilizar esas reservas de fosfato presentes en los suelos, se disminuye la aplicación de fertilizantes químicos que, por una parte, pueden nuevamente ser fijados por iones Ca, Al o Fe volviéndolos insolubles y, por otra, incrementan los costos de producción de las cosechas. Las poblaciones microbianas han sido ampliamente estudiadas en diferentes tipos de ecosistemas, tanto naturales como agroecosistemas. Gracias a su efectividad en estudios en laboratorio y campo, el fenotipo solubilizador de fosfato es de gran interés para los ecólogos microbianos que han empezado a establecer las bases moleculares de dicho rasgo. Because of the constant application of chemical inputs in Agroecosystem, the cost of crop production and environmental quality of soil and water have been affected. Microorganisms carry out most biogeochemical cycles; therefore, their role is essential for agro ecosystem balance. One such functional group is the phosphate solubilizing microorganisms, which are recognized plant growth promoters. These microbial populations perform an important activity, since in many soils there are large reserves of insoluble phosphorus, as a result of fixing much of the phosphorus fertilizer applied, which cannot be assimilated by the plant. The phosphate solubilizing microorganisms use different solubilization mechanisms such as the production of organic acids, which solubilize theses insoluble phosphates in the rhizosphere region. Soluble phosphates are absorbed by the plant, which enhances their growth and productivity. By using these phosphate reserves in soils, application of chemical fertilizers is decreased, on the one hand, can again be fixed by ions Ca, Al or Fe making them insoluble and, by the other hand, increase the costs of crop production. Microbial populations have been widely studied in different types of ecosystems, both natural and Agroecosystem. Thanks to its effectiveness, in laboratory and field studies, the phosphate solubilizing phenotype is of great interest to microbial ecologists who have begun to establish the molecular basis of the trait.

Eucalyptus benthamii is a tree species commonly planted in subtropical areas, including the Southern Brazil, due to its tolerance to low temperatures and frosts. The success of E. benthamii plantation depends on the seedlings vigor during transplantation. We hypothesized that improvement of chemical and biological properties of growth substrate would produce more vigorous E. benthamii seedlings. Thus, we applied increasing doses (0, 0.5, 1.0, 1.5 and 2.0 g per seedling) of the organic fertilizer Bacsol, which carries a consortium of potential plant growth promoting microorganisms, on the substrate, and measured the growth and development of E. benthamii seedlings. Two experiments were performed in 2011 and 2012. The first experiment included measurements in four growth stages to estimate the relative growth rates. The second one ended at the time that seedlings reached standard heights for transplantation (about ± 20 cm). Measurements on plant height, stem diameter, shoot dry weight and relative growth rates indicated that the application of Bacsol improved E. benthamii seedlings vigor and decreased the time needed in nursery, from 150 days to 90 days. The best responses occurred at doses from 1.3 g to 1.5 g per seedling. The data demonstrated that application of Bacsol in substrate is a promising technology to increase E. benthamii seedlings vigor., Eucalyptus benthamii es una especie arbórea comúnmente plantada en áreas subtropicales, incluyendo el sur de Brasil, debido a su tolerancia a bajas temperaturas y heladas. El éxito de su plantación depende del vigor de las plántulas durante el transplante. Se planteó la hipótesis que la mejora de las propiedades químicas y biológicas del sustrato de crecimiento produciría plantas más vigorosas de E. benthamii. Por ello, en el substrato se aplicaron dosis crecientes (0, 0,5, 1,0, 1,5 y 2,0 g por planta) del fertilizante orgánico Bacsol, que contiene un consorcio de potenciales microorganismos promotores del crecimiento vegetal y se midió el crecimiento de plantas de E. benthamii. Los experimentos fueron realizados en 2011 y 2012. El primero incluyó cuatro etapas de crecimiento para estimar tasas de crecimiento relativas. El segundo terminó cuando las plantas alcanzaron alturas estándar para trasplante (≈ 20 cm). La altura de la planta, el diámetro del tallo, el peso seco de los brotes y las tasas de crecimiento relativo indicaron que Bacsol mejoró el vigor de las plantas y disminuyó el tiempo necesario en vivero, de 150 a 90 días. Las mejores respuestas ocurrieron con 1,3 a 1,5 g por planta. Los datos demostraron que la aplicación de Bacsol al sustrato es una tecnología prometedora para aumentar el vigor de las plantas de E. benthamii.

Plants and microbes coexist or compete for survival and their cohesive interactions play a vital role in adapting to metalliferous environments, and can thus be explored to improve microbe-assisted phytoremediation. Plant root exudates are useful nutrient and energy sources for soil microorganisms, with whom they establish intricate communication systems. Some beneficial bacteria and fungi, acting as plant growth promoting microorganisms (PGPMs), may alleviate metal phytotoxicity and stimulate plant growth indirectly via the induction of defense mechanisms against phytopathogens, and/or directly through the solubilization of mineral nutrients (nitrogen, phosphate, potassium, iron, etc.), production of plant growth promoting substances (e.g., phytohormones), and secretion of specific enzymes (e.g., 1-aminocyclopropane- 1-carboxylate deaminase). PGPM can also change metal bioavailability in soil through various mechanisms such as acidification, precipitation, chelation, complexation, and redox reactions. This review presents the recent advances and applications made hitherto in understanding the biochemical and molecular mechanisms of plant–microbe interactions and their role in the major processes involved in phytoremediation, such as heavy metal detoxification, mobilization, immobilization, transformation, transport, and distribution.

Con el fin de probar la efectividad de dos inoculantes microbianos (aislados a partir de raicillas de mangle rojo y negro) en el crecimiento y establecimiento de plántulas de mangle y de patilla, se realizaron cuatro pruebas en campo en San Andrés Isla, Colombia. Se aplicaron dichos inoculantes en: propágulos de Avicennia germinans colectados en un área de manglar y sembrados en macetas sobre sustrato solarizado (con el fin de disminuir la carga microbiana), plántulas de A. germinans y Rhizophora mangle colectadas en cercanía de árboles semilleros, plántulas de A. germinans y R. mangle sembradas y mantenidas en vivero y en semillas de patilla (Citrullus vulgaris) sembradas en un cultivo libre de fertilizantes químicos. Las variables tomadas como indicativo de crecimiento y desarrollo vegetal fueron: número de nodos, número de hojas y longitud del tallo. Los inoculantes (microorganismos solubilizadores de fosfatos -MSF- y bacterias fijadoras de nitrógeno -BFN-) se aplicaron en el material vegetal mencionado, efectuando mediciones durante tres meses. Los resultados muestran un efecto positivo de estimulación de crecimiento medido en longitud del tallo en las plantas tratadas con los inoculantes, específicamente en patilla y propágulos de A. germinans mantenidos en vivero. In order to test the effect of two microbial inoculants (obtained from red and black mangrove roots) on the growth and stability of mangrove and watermelon plants, four treatments were carried out in San Andres Island, Colombia. The treatments consisted in the application of the inoculants in: A. germinans propagules collected in a mangrove area, and then individually planted in gavels with sun-pasteurized soil (in order to decrease the microbial load), A. germinans and R. mangle plants collected in the proximity of nursery trees, A. germinans and R. mangle planted and maintained in nursery, and in Citrullus vulgaris seeds planted in a traditional cultivar without chemical fertilizers. The growth and vegetative development variables were: number of nodes, number of leaves and steam length. The inoculants (phosphate solubilizing microorganisms -PSM- and nitrogen fixing bacteria -NFB-) were applied in the mentioned vegetable material, doing measures during three months. The results show a positive effect on growth measured by steam length in plants treated specifically with the inoculants in C. vulgaris and A. germinans seedlings maintained in nursery.