Effectiveness of biological control of Phytophthora capsici in pepper by Trichoderma asperellum strain T34

Pepper (Capsicum annuum L.), one of the most widely grown vegetables worldwide, is susceptible to root rot caused by Phytophthora capsici. Many biocides have recently been banned in Europe because of human health and environmental concerns. Integrated pest management is a European priority, where biological control together with other agronomic practices should replace pesticide management of plant diseases in the future. Application of different concentrations of the fungus Trichoderma asperellum strain T34 (the in T34 Biocontrol®) on incidence of disease caused by P. capsici in pepper was studied. Different methods of application of the microbial control agent and inoculation of the pathogen were examined. T34 and etridiazole (Terrazole®) were compared for their ability to suppress P. capsici. T34 reduced disease in most of the assayed situations (up to 71% disease reduction), while etridiazole was effective only when applied at the same time as the pathogen. The results obtained are discussed on the basis of the different modes of action of T34 and etridiazole. T34 is a useful biological alternative to chemicals for the control of P. capsici in peppe

Beneficial effects of Rhizophagus irregularis and Trichoderma asperellum strain T34 on growth and fusarium wilt in tomato plants

Fusarium tomato wilt is one of the most prevalent and damaging diseases wherever tomatoes are grown intensively. Progress in agriculture in the twenty-first century is set to be based on lowering agrochemical inputs (implementation of Directive 2009/128/EC on sustainable use of pesticides), which can be achieved to some extent through the use of beneficial microorganisms. This study aimed at comparing the effects of the mycorrhizal fungus Rhizophagus irregularis and the biological control agent Trichoderma asperellum strain T34 on the incidence of fusarium wilt and the growth of tomato plants. Both R. irregularis and T34 lowered disease incidence at similar rates, compared to control plants. R. irregularis added below the seedlings reduced disease incidence more than when it was mixed with the substrate. T34 and R. irregularis increased plant height to the same extent, compared to both control and diseased plants. R. irregularis gave the highest levels of chlorophyll, followed by T34 and control plants; however, the measures for infected plants were slightly better for T34 than for R. irregularis. T34 and R. irregularis had similar effects on Ca, Mg, S, Mn, B and Si uptake in tomato plants, but R. irregularis induced a greater P, K, Zn, Cu and Mo accumulation than T34. Interestingly, at the end of the experiment, the depletion of the substrate was lower on Ca, Mg and S for plants inoculated with either R. irregularis or T34 compared to control plants, while the substrate for T34-treated plants had the lowest levels of Fe, Mn, Zn and Cu

Modelization of a molten salt thermal energy storage for concentrated solar power

A numerical model for studying a storage tank for concentrated solar power is presented. The model consists of solving the heat equation for the solid part made from ceramic materials, a one-dimensional model for the molten salt circulating inside the solid, and a coupling between them. Then, some results are presented for a reference case with some typical parameters for the storage system.This work has been carried out in the framework of the Newcline project, which is supported under the umbrella of CSP-ERA.NET 1st Cofund Joint Call, and by the following National Agencies: AEI (Spain), CDTI (Spain), Jülich (Germany), SFOE (Switzerland). CSP-ERA.NET is supported by the European Commission within the EU Framework Programme for Research and Innovation HORIZON 2020 (Cofund ERA-NET Action, N° 838311). J. Vera has been financially supported by the Ministerio de Educación y Ciencia (MEC), Spain, (FPI grant PRE2018-084017).Peer ReviewedPostprint (published version

An energy-preserving unconditionally stable fractional step method on collocated grids

Preservation of energy is fundamental in order to avoid the introduction of unphysical energy that can lead to unstable simulations. In this work, an energy-preserving unconditionally stable fractional step method on collocated grids is presented as a method which guarantees both preservation of energy and stability of our simulation. Using an algebraic (matrix-vector) representation of the classical incompressible Navier-Stokes equations mimicking the continuous properties of the differential operators, conservation of energy is formally proven. Furthermore, the appearence of unphysical velocities in highly distorted meshes is also adressed. This problem comes from the interpolation of the pressure gradient from faces to cells in the velocity correction equation, and can be corrected by using a proper interpolation.This work has been financially supported by the project RETOtwin [PDC2021-120970-I00] funded by MCIN/AEI/10.13039/501100011033 and European Union Next Generation EU/PRTR. D. Santos acknowledges a FI AGAUR-Generalitat de Catalunya fellowship (2020FI B 00839). The authors thankfully acknowledge these institutions.Peer ReviewedPostprint (published version

An energy-preserving unconditionally stable fractional step method on collocated grids

Preservation of energy is fundamental in order to avoid the introduction of unphysical energy that can lead to unstable simulations. In this work, an energy-preserving unconditionally stable fractional step method on collocated grids is presented as a method which guarantees both preservation of energy and stability of our simulation. Using an algebraic (matrix-vector) representation of the classical incompressible Navier-Stokes equations mimicking the continuous properties of the differential operators, conservation of energy is formally proven. Furthermore, the appearence of unphysical velocities in highly distorted meshes is also adressed. This problem comes from the interpolation of the pressure gradient from faces to cells in the velocity correction equation, and can be corrected by using a proper interpolation

Impact of olive saplings and organic amendments on soil microbial communities and effects of mineral fertilization

Plant communities and fertilization may have an impact on soil microbiome. Most commercial olive trees are minerally fertilized, while this practice is being replaced by the use of organic amendments. Organic amendments can both fertilize and promote plant growth-promoting organisms. Our aims were (i) to describe the changes in soil bacterial and fungal communities induced by the presence of young olive trees and their interaction with organic amendments and (ii) to compare the effects of mineral and organic fertilization. We set up two parallel experiments in pots using a previously homogenized soil collected from a commercial olive orchard: in the first one, we grew olive saplings in unamended and organically amended soils with two distinct composts and compared these two soils incubated without a plant, while in the second experiment, we comparatively tested the effects of organic and mineral fertilization. OTUs and the relative abundances of bacterial and fungal genera and phyla were analyzed by 16S rRNA and ITS1 gene amplicon using high-throughput sequencing. Basal respiration and substrate-induced respiration were measured by MicroRespTM. The effects of the different treatments were analyzed in all phyla and in the 100 most abundant genera. The presence of olive saplings increased substrate-induced respiration and bacterial and fungal richness and diversity. Organic amendments greatly affected both bacterial and fungal phyla and increased bacterial richness while not affecting fungal richness. Mineral fertilization increased the relative abundance of the less metabolically active bacterial phyla (Actinobacteria and Firmicutes), while it reduced the most metabolically active phylum, Bacteroidetes. Mineral fertilization increased the relative abundance of three N2-fixing Actinobacteria genera, while organic fertilization only increased one genus of Proteobacteria. In organically and minerally fertilized soils, high basal respiration rates were associated with low fungal diversity. Basidiomycota and Chytridiomycota relative abundances positively correlated with basal respiration and substrate-induced respiration, while Ascomycota correlated negatively. Indeed, the Ascomycota phyla comprised most of the fungal genera decreased by organic amendments. The symbiotrophic phylum Glomeromycota did not correlate with any of the C sources. The relative abundance of this phylum was promoted by the presence of plants but decreased when amending soils with composts

Un estudio muestra la eficacia de composts de residuos agroindustriales para reducir enfermedades de las plantas

Algunos residuos agroindustriales ya compostados y usados como sustratos pueden presentar supresividad a distintas enfermedades de las plantas. Algunos de estos sustratos son el compost de corcho (usado solo o mezclado con cascarilla de arroz), orujo de uva compostado, alperujo con residuo de desmotadora (2/3, v/v) compostado y posteriormente formulado con cascarilla de arroz (1/1, v/v) y sustrato de champiñón agotado compostado y mezclado con turba (1/1, v/v). Esta supresividad se ha evaluado en ensayos con inoculación artificial de patógenos y posterior evaluación del desarrollo de cada enfermedad, siendo el compost de orujo de uva maduro el que mejores resultados presenta.Ministerio de Ciencia y Tecnología AGL 2002-04313, 2005-08137, 2008-05414 y 2010-21982Junta de Andalucía P06-AGR-0231

Effectiveness of biological control of Phytophthora capsici in pepper by Trichoderma asperellum strain T34

Pepper (Capsicum annuum L.), one of the most widely grown vegetables worldwide, is susceptible to root rot caused by Phytophthora capsici. Many biocides have recently been banned in Europe because of human health and environmental concerns. Integrated pest management is a European priority, where biological control together with other agronomic practices should replace pesticide management of plant diseases in the future. Application of different concentrations of the fungus Trichoderma asperellum strain T34 (the in T34 Biocontrol®) on incidence of disease caused by P. capsici in pepper was studied. Different methods of application of the microbial control agent and inoculation of the pathogen were examined. T34 and etridiazole (Terrazole®) were compared for their ability to suppress P. capsici. T34 reduced disease in most of the assayed situations (up to 71% disease reduction), while etridiazole was effective only when applied at the same time as the pathogen. The results obtained are discussed on the basis of the different modes of action of T34 and etridiazole. T34 is a useful biological alternative to chemicals for the control of P. capsici in pepper

Parallel algorithm for the solution of the Boltzmann transport equation on unstructured meshes

The Boltzmann transport equation is solved by means of a parallel explicit algorithm known as parallel sweep, and a source iteration procedure to solve the coupling between different angular directions. Using an explicit solver implies that the nodes have to be visited in a specific order. Factors that influence the scalability of the algorithm have been analysed, namely the different strategies to group the tasks to be done at the calculation stage, and how deep should the task graph be worked prior to the communication stage. Two and three dimensional unstructured meshes have been considered. With relatively small meshes, good weak and strong speedup results are obtained, using up to ≈ 900 processors.Postprint (author’s final draft