The Experts below are selected from a list of 80523 Experts worldwide ranked by ideXlab platform
George Lazarovits - One of the best experts on this subject based on the ideXlab platform.
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Suppressing Soil-Borne Diseases with residue management and organic amendments
Soil and Tillage Research, 2003Co-Authors: K.l Bailey, George LazarovitsAbstract:Changes in agricultural practices with time have led to a decline in soil structure and with it, an increase in Soil-Borne plant Diseases. Agricultural practices such as incorporating organic amendments and managing the type and quantity of crop residue, have a direct impact on plant health and crop productivity. Soil management practices involving tillage, rotation, and burning will impact the amount and quality of organic matter that is returned to the soil. These practices influence pathogen viability and distribution, nutrient availability, and the release of biologically active substances from both crop residues and soil microorganisms as illustrated by the model system of Cochliobolus sativus on the development of common root rot in cereals. The application of organic amendments, manures and composts that are rich in nitrogen, may reduce Soil-Borne Diseases by releasing allelochemicals generated during product storage or by subsequent microbial decomposition. The modes of action for disease suppression are elucidated for a number of Diseases including verticillium wilt and common scab of potato. Developing disease suppressive soils by introducing organic amendments and crop residue management takes time, but the benefits accumulate across successive years improving soil health and structure.
Christian Steinberg - One of the best experts on this subject based on the ideXlab platform.
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Identifying indicators of soil suppressiveness to fungal Diseases
2013Co-Authors: Katarzyna Siegel, Véronique Edel-hermann, Philippe Lemanceau, Sébastien Aimé, Emilie Chapelle, Jos M. Raaijmakers, Christian SteinbergAbstract:Soils suppressive to Soil-Borne Diseases are defined by a low disease incidence in spite of the presence of a virulent pathogen and a susceptible plant. In many cases, the inhibition of the disease development relies on the activity of the resident soil microbiome. To identify taxonomic microbial indicators linked to the suppressiveness phenotype of soils, culture independent-based methods have been employed to analyse and compare microbial dynamics in two different soils suppressive to either Rhizoctonia solani damping-off disease of sugar beet or Fusarium wilt disease on flax. Fungal and bacterial taxonomic biodiversity were estimated from ITS and 16S genes by amplicon pyrosequencing. To that end, metagenomic DNA was extracted from the rhizosphere of plants grown in soils with different level of suppressiveness. We obtained 218650 reads in total (125602 for fungi and 93048 for bacteria). At this moment, the analyses of fungal communities are in progress. 114641 reads was kept after filtering by bioinformatic pipeline, distributed into 2303 clusters and 3379 singletons. Although, the bioinformatic and statistical analysis are not finished yet, we have already noticed a difference in the taxonomic diversity composition between suppressive and conducive soils which could explain the suppressive/conducive character of given soil. The next step is to achieve the bacterial communities in Fusarium wilt suppressive/conducive soils and to assess the microbial diversity of other Soil-Borne Diseases suppressive soils. Once the analyses of sequencing data are finished and the taxonomic assignments done, the comparison of microbial diversity of all studied soils will be performed in order to find out the similarities or/and differences in these soils which will provide the suppressiveness indicators
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Search for indicators of soil suppressiveness to Soil-Borne Diseases: functional genomics approach
2012Co-Authors: Katarzyna Siegel, Philippe Lemanceau, Jos Raaijmaakers, Sébastien Aimé, W. Deboer, Christian SteinbergAbstract:Soils which are suppressive to Soil-Borne Diseases are soils in which pathogens, although present, sometimes in large inoculum density, cannot carry their infectious activity. In most cases, biotic factors are responsible for this inhibition, although the abiotic environment regulates these factors. In this thesis, we propose to conduct an intermediate approach between the metagenomic analysis of soil suppressiveness to Diseases and the search for fungi whose activities contribute to the inhibition of infectious pathogens. The aim is to define a set of fungal genes a priori associated with mechanisms reflecting the suppressiveness of given soils to a disease and to check whether these genes are common to all the suppressive soils to different types of disease regardless of the taxonomic biodiversity present in these soils. Bioassays were conducted in both suppressive and conducive soils, DNA was extracted from the rhizosphere of susceptible plants grown in these soils, 454 sequencing of prokaryotic and eukaryotic DNA is in progress and tools to manage the data are being setting up in the frame of the UE project Ecofinders FP7-ENV-2010-264465.
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Potato Soil-Borne Diseases. A review
Agronomy for Sustainable Development, 2012Co-Authors: Marie Fiers, Catherine Chatot, Véronique Edel-hermann, Yves Hingrat, Claude Alabouvette, Christian SteinbergAbstract:Potato crop is the fourth main food crop in the world and it will certainly feed a big part of the global population in the next years. The economical outlets for this crop are great; however, numerous Diseases either soil- or airborne can cause huge losses in the production. Worldwide, about 40 Soil-Borne Diseases affect potato and cause severe damages especially on tubers, the economically most important part of the plant. The occurrence and development of soilborne Diseases depend on very diverse factors affecting either the pathogen or the plant. Favorable conditions for potato Diseases development are frequently the same as the conditions needed for potato growth: temperature between 10°C and 25°C, high humidity, medium pH, etc. Adapted cultural practices such as a rotation longer than 4 years, appropriate fertilization and water management, an adapted delay between haulm killing and harvest, and dry and cool conditions for tuber storage are good ways to control potato Diseases. In most cases, potato pathogens develop specific survival forms, dissemination ways and host penetration methods. The genetic variability of the pathogens implies the use of adapted diagnostic and control methods. Decision support systems developed to predict yield losses allow choosing good control methods such as the use of healthy seeds, adapted pesticides, cultural practices, and biological control agents for each potato disease. The complexity of the interactions between a pathogen and its host, influenced by biotic and abiotic factors of the environment, make the control of the Diseases often very difficult. However, deep knowledge of pathosystems allows setting up integrated pest management systems allowing the production of healthy and good quality potatoes.
K.l Bailey - One of the best experts on this subject based on the ideXlab platform.
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Suppressing Soil-Borne Diseases with residue management and organic amendments
Soil and Tillage Research, 2003Co-Authors: K.l Bailey, George LazarovitsAbstract:Changes in agricultural practices with time have led to a decline in soil structure and with it, an increase in Soil-Borne plant Diseases. Agricultural practices such as incorporating organic amendments and managing the type and quantity of crop residue, have a direct impact on plant health and crop productivity. Soil management practices involving tillage, rotation, and burning will impact the amount and quality of organic matter that is returned to the soil. These practices influence pathogen viability and distribution, nutrient availability, and the release of biologically active substances from both crop residues and soil microorganisms as illustrated by the model system of Cochliobolus sativus on the development of common root rot in cereals. The application of organic amendments, manures and composts that are rich in nitrogen, may reduce Soil-Borne Diseases by releasing allelochemicals generated during product storage or by subsequent microbial decomposition. The modes of action for disease suppression are elucidated for a number of Diseases including verticillium wilt and common scab of potato. Developing disease suppressive soils by introducing organic amendments and crop residue management takes time, but the benefits accumulate across successive years improving soil health and structure.
T. Martijn Bezemer - One of the best experts on this subject based on the ideXlab platform.
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Carry-over effects of soil inoculation on plant growth and health under sequential exposure to Soil-Borne Diseases
Plant and Soil, 2018Co-Authors: Hai-kun Ma, Ana Pineda, Andre W. G. Van Der Wurff, T. Martijn BezemerAbstract:Background and aims Most plant-soil feedback and inoculation studies are limited to one growth cycle. We examined the effects of inoculation with eight plant-conditioned soils on chrysanthemum during two sequential growth cycles. The plants were also exposed sequentially to soil Diseases. Methods In cycle 1, plants were grown in sterile soil inoculated or not with plant-conditioned soils, and exposed or not to Pythium or root feeding nematodes. In cycle 2, new plants were grown in soil from cycle 1 or in new 100% sterile soil. Plants were exposed again to Pythium, or to soil with pathogens and nematodes collected from a commercial chrysanthemum greenhouse. Results After two cycles, effects of soil inoculation on plant growth were still present. Chrysanthemum exhibited a negative conspecific feedback response, but this was less strong in inoculated soils. Pythium or nematode addition did not affect plant growth. However, addition of pathogen-containing soil from the commercial greenhouse reduced plant growth in sterile soil but increased growth in plant-conditioned soils. Conclusions Inoculation with plant-conditioned soil can reduce the negative conspecific plant-soil feedback of chrysanthemum. Our study further advances our understanding of the temporal dynamics of conspecific and heterospecific plant-soil feedbacks, and how they interact with Soil-Borne Diseases.
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Carry-over effects of soil inoculation on plant growth and health under sequential exposure to Soil-Borne Diseases
Plant and Soil, 2018Co-Authors: Ana Pineda, Andre W G Van Der Wurff, T. Martijn BezemerAbstract:Most plant-soil feedback and inoculation studies are limited to one growth cycle. We examined the effects of inoculation with eight plant-conditioned soils on chrysanthemum during two sequential growth cycles. The plants were also exposed sequentially to soil Diseases. In cycle 1, plants were grown in sterile soil inoculated or not with plant-conditioned soils, and exposed or not to Pythium or root feeding nematodes. In cycle 2, new plants were grown in soil from cycle 1 or in new 100% sterile soil. Plants were exposed again to Pythium, or to soil with pathogens and nematodes collected from a commercial chrysanthemum greenhouse. After two cycles, effects of soil inoculation on plant growth were still present. Chrysanthemum exhibited a negative conspecific feedback response, but this was less strong in inoculated soils. Pythium or nematode addition did not affect plant growth. However, addition of pathogen-containing soil from the commercial greenhouse reduced plant growth in sterile soil but increased growth in plant-conditioned soils. Inoculation with plant-conditioned soil can reduce the negative conspecific plant-soil feedback of chrysanthemum. Our study further advances our understanding of the temporal dynamics of conspecific and heterospecific plant-soil feedbacks, and how they interact with Soil-Borne Diseases.
Zhen Wenchao - One of the best experts on this subject based on the ideXlab platform.
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The control effect of a multifunctional bacterial agent fit for straw amendment against wheat Soil-Borne Diseases
Frontiers of Agriculture in China, 2011Co-Authors: Yongsheng Zhang, Yanan Wang, Chunqi Liang, Zhen WenchaoAbstract:Soil-Borne Diseases of wheat are getting more and more serious in the wheat/maize rotation growing system in northern China. A multifunctional microorganic strain called B1514 was found to have an inhibitory effect against major pathogens of winter wheat Soil-Borne Diseases, have the ability to decompose maize straw, and have the ability to utilize the straw for multiplication. The strain was processed into bacterial agent HAD-1. Field experiments were conducted from 2008 to 2010 to test the control effect of HAD-1 on the major wheat Soil-Borne Diseases, on decomposing ability to maize straw, and on reproductive capacity. Results showed that HAD-1 had significant control effects on sharp eyespot, take-all, and root rot on wheat. The control efficacy at wheat jointing stage was 59.63% to 72.59%, 57.64% to 59.29%, and 54.48% to 63.25%, respectively. The yield loss decreased by 8.67% to 11.70%. The population numbers of the strain B1514 increased 2.68×107−4.83×107 times during the wheat growing season. HAD-1 significantly accelerated the decomposition rate of maize straw in the soil. The decomposition rate increased by 18.7% to 24.3% during wheat growing season.
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Influence of maize straw amendment on Soil-Borne Diseases of winter wheat
Frontiers of Agriculture in China, 2009Co-Authors: Zhen Wenchao, Shutong Wang, Chengyin ZhangAbstract:A field experiment was conducted during the 2006–2007 wheat growing season at Baoding, Hebei Province, China, aiming at exploring the influence of different amendment rates of maize straw on winter wheat Soil-Borne Diseases induced by Rhizoctonia cereali, Gaeumannomyces graminis and Bipolaris sorokiniana in field conditions. Wheat root vitality, ion infiltration, SOD activity, MDA content and microbial population of the tillage layer were measured. The results showed that the occurrence of three Soil-Borne Diseases tested was significantly different under different amendment rates. During the greening stage and jointing stage, the disease indexes of three Soil-Borne Diseases were reduced significantly by treatments at the maize straw amendment rates of 7500 kg · hm−2 and 3750 kg · hm−2. However, disease indexes of wheat common rot and sharp eyespot increased dramatically when the amendment rate increased to 15000 kg · hm−2. At the amendment rate of 15000 kg · hm−2, wheat root vigor and SOD activity decreased, and ion infiltration and cell membrane-lipid peroxidation level increased, respectively. In the meantime, higher amounts of bacteria and actinomycetes were recorded in the 7500 kg · hm−2 amendment rate treatment, while a higher amount of fungi was recorded in the 15000 kg · hm−2 amendment rate treatment.
