Pythium ultimum

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform

Andre C Levesque - One of the best experts on this subject based on the ideXlab platform.

J M Lynch - One of the best experts on this subject based on the ideXlab platform.

  • effectiveness of municipal waste compost and its humic fraction in suppressing Pythium ultimum
    Microbial Ecology, 2002
    Co-Authors: J A Pascual, T Hernandez, Carlos Garcia, S Lerma, J M Lynch
    Abstract:

    The effect of addition of a municipal solid waste (MSW) compost and its water-soluble and humic fraction to suppress the effect of Pythium ultimum on pea plants was studied and compared with that of a chemical pesticide (metalaxyl). The biotic and abiotic characteristics of compost involved in the biocontrol effects of these materials were also evaluated. The addition into soil of whole composts and their humic fractions reduced the effect of the pathogen on pea plants, significantly reducing the number of root lesions and Pythium populations and avoiding reductions of plant growth. The greatest pathogen suppression was achieved with the chemical pesticide. However, it also caused a significant decrease in the number of nontarget bacteria and fungi and on beneficial soil microorganisms such as Trichoderma and Pseudomonas. Addition of organic amendments increased population size of nontarget and specific biocontrol microorganisms. The humic fraction showed similar results to compost. All this suggests that metalaxyl has a nonspecific effect, producing adverse effects on aspects of soil quality. This was avoided if the chemical pesticide was reduced and replaced by organic amendments such as an MSW compost or its humic fraction.

  • long term suppression of Pythium ultimum in arid soil using fresh and composted municipal wastes
    Biology and Fertility of Soils, 2000
    Co-Authors: J A Pascual, T Hernandez, Carlos Garcia, F A A M De Leij, J M Lynch
    Abstract:

    The effect of addition of municipal solid waste (MSW) at different degrees of stabilisation on the biological properties of an arid soil was studied 24 months after application. This included effects on the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium ultimum. The addition of organic waste (fresh or composted) reduced populations of culturable bacteria and fungi and disease symptoms caused by P. ultimum, and resulted in heavier plants with longer and more extensively branched roots. Addition of organic waste increased the population size of culturable bacteria and fungi, while enzymatic activity of the soil was higher in soil amended with organic matter than in non-amended soil. Populations of biological control agents, such as Trichoderma and fluorescent pseudomonads, were larger in soil amended with organic matter. The addition of urban waste could therefore be a suitable technique with which to restore soil quality by stimulating biological control against plant pathogens such as P. ultimum.

  • Long-term suppression of Pythium ultimum in arid soil using fresh and composted municipal wastes
    Biology and Fertility of Soils, 2000
    Co-Authors: J A Pascual, T Hernandez, Carlos Garcia, F A A M De Leij, J M Lynch
    Abstract:

    7 pages, 4 tables, 4 figures.The effect of addition of municipal solid waste (MSW) at different degrees of stabilisation on the biological properties of an arid soil was studied 24 months after application. This included effects on the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium ultimum. The addition of organic waste (fresh or composted) reduced populations of culturable bacteria and fungi and disease symptoms caused by P. ultimum, and resulted in heavier plants with longer and more extensively branched roots. Addition of organic waste increased the population size of culturable bacteria and fungi, while enzymatic activity of the soil was higher in soil amended with organic matter than in non-amended soil. Populations of biological control agents, such as Trichoderma and fluorescent pseudomonads, were larger in soil amended with organic matter. The addition of urban waste could therefore be a suitable technique with which to restore soil quality by stimulating biological control against plant pathogens such as P. ultimum.Peer reviewe

Eric B Nelson - One of the best experts on this subject based on the ideXlab platform.

  • Seed-Colonizing Microbes from Municipal Biosolids Compost Suppress Pythium ultimum Damping-Off on Different Plant Species
    Phytopathology, 2008
    Co-Authors: M.-h. Chen, Eric B Nelson
    Abstract:

    Chen, M-.H., and Nelson, E. B. 2008. Seed-colonizing microbes from municipal biosolids compost suppress Pythium ultimum damping-off on different plant species. Phytopathology 98:1012-1018. Composts are known for their suppressive properties toward many different seed- and root-infecting pathogens and diseases. Although disease and pathogen suppression induced by composts is believed to be mediated by microbial activities, the nature of the microbial species and processes responsible for suppressiveness remain unknown. We demonstrated previously that seed-colonizing microbial consortia from leaf compost could explain the observed levels of Pythium ultimum-induced damping-off suppression on cotton. The aim of the present work was to determine whether seed-colonizing microbial consortia could explain Pythium damping-off suppression in municipal biosolids compost on three different plant species. Significant levels of disease suppression were observed on cucumber, wheat, and pea at water potentials of –2 kPa. The suppression of damping-off on cucumber and wheat could be eliminated by autoclaving the compost prior to sowing. High levels of suppressiveness were expressed both on cucumber and on wheat seed surfaces within 8 h of sowing. However, the expression of damping-off suppression on the surface of pea seeds was inconsistent and highly variable. Our results demonstrate that compost-induced suppression of P. ultimum damping-off of cucumber and wheat can be explained by the microbial consortia colonizing seeds within 8 h of sowing. These results further suggest that disease suppression in composts is related to microbial species that interact with the pathogen in its infection court and not in the bulk compost.

  • extracted fatty acids from gossypium hirsutum stimulatory to the seed rotting fungus Pythium ultimum
    Phytochemistry, 1997
    Co-Authors: Thomas R Ruttledge, Eric B Nelson
    Abstract:

    Abstract Specific germination of the pathogenic fungus Pythium ultimum in response to a viable host is a vital point in its life cycle. It must have the means to elucidate information on the proximal host, and a response to specific germination signals from the host seed was suspected. Active fractions from cotton seed extract containing unsaturated fatty acids induced high levels of germination in Phythium , whereas several saturated analogs did not. © 1997 Elsevier Science Ltd. All rights reserved

Gregg P Robideau - One of the best experts on this subject based on the ideXlab platform.

J A Pascual - One of the best experts on this subject based on the ideXlab platform.

  • effectiveness of municipal waste compost and its humic fraction in suppressing Pythium ultimum
    Microbial Ecology, 2002
    Co-Authors: J A Pascual, T Hernandez, Carlos Garcia, S Lerma, J M Lynch
    Abstract:

    The effect of addition of a municipal solid waste (MSW) compost and its water-soluble and humic fraction to suppress the effect of Pythium ultimum on pea plants was studied and compared with that of a chemical pesticide (metalaxyl). The biotic and abiotic characteristics of compost involved in the biocontrol effects of these materials were also evaluated. The addition into soil of whole composts and their humic fractions reduced the effect of the pathogen on pea plants, significantly reducing the number of root lesions and Pythium populations and avoiding reductions of plant growth. The greatest pathogen suppression was achieved with the chemical pesticide. However, it also caused a significant decrease in the number of nontarget bacteria and fungi and on beneficial soil microorganisms such as Trichoderma and Pseudomonas. Addition of organic amendments increased population size of nontarget and specific biocontrol microorganisms. The humic fraction showed similar results to compost. All this suggests that metalaxyl has a nonspecific effect, producing adverse effects on aspects of soil quality. This was avoided if the chemical pesticide was reduced and replaced by organic amendments such as an MSW compost or its humic fraction.

  • long term suppression of Pythium ultimum in arid soil using fresh and composted municipal wastes
    Biology and Fertility of Soils, 2000
    Co-Authors: J A Pascual, T Hernandez, Carlos Garcia, F A A M De Leij, J M Lynch
    Abstract:

    The effect of addition of municipal solid waste (MSW) at different degrees of stabilisation on the biological properties of an arid soil was studied 24 months after application. This included effects on the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium ultimum. The addition of organic waste (fresh or composted) reduced populations of culturable bacteria and fungi and disease symptoms caused by P. ultimum, and resulted in heavier plants with longer and more extensively branched roots. Addition of organic waste increased the population size of culturable bacteria and fungi, while enzymatic activity of the soil was higher in soil amended with organic matter than in non-amended soil. Populations of biological control agents, such as Trichoderma and fluorescent pseudomonads, were larger in soil amended with organic matter. The addition of urban waste could therefore be a suitable technique with which to restore soil quality by stimulating biological control against plant pathogens such as P. ultimum.

  • Long-term suppression of Pythium ultimum in arid soil using fresh and composted municipal wastes
    Biology and Fertility of Soils, 2000
    Co-Authors: J A Pascual, T Hernandez, Carlos Garcia, F A A M De Leij, J M Lynch
    Abstract:

    7 pages, 4 tables, 4 figures.The effect of addition of municipal solid waste (MSW) at different degrees of stabilisation on the biological properties of an arid soil was studied 24 months after application. This included effects on the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium ultimum. The addition of organic waste (fresh or composted) reduced populations of culturable bacteria and fungi and disease symptoms caused by P. ultimum, and resulted in heavier plants with longer and more extensively branched roots. Addition of organic waste increased the population size of culturable bacteria and fungi, while enzymatic activity of the soil was higher in soil amended with organic matter than in non-amended soil. Populations of biological control agents, such as Trichoderma and fluorescent pseudomonads, were larger in soil amended with organic matter. The addition of urban waste could therefore be a suitable technique with which to restore soil quality by stimulating biological control against plant pathogens such as P. ultimum.Peer reviewe

Related terms

Pythium ultimum - 15 days free trial to Access Experts & Abstracts