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J M Lynch - One of the best experts on this subject based on the ideXlab platform.
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effect of biocontrol strains of trichoderma on Plant growth pythium ultimum populations soil microbial communities and soil enzyme activities
Journal of Applied Microbiology, 2001Co-Authors: D C Naseby, J A Pascual, J M LynchAbstract:D.C. NASEBY, J.A. PASCUAL and J.M. LYNCH.2000.Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 8% respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the Plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced Plant Damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved Plant growth in the absence of Pythium and reduced Plant Damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of Plant pathogens.
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effect of biocontrol strains of trichoderma on Plant growth pythium ultimum populations soil microbial communities and soil enzyme activities
Journal of Applied Microbiology, 2001Co-Authors: D C Naseby, J A Pascual, J M LynchAbstract:D.C. NASEBY, J.A. PASCUAL and J.M. LYNCH.2000.Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 8% respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the Plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced Plant Damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved Plant growth in the absence of Pythium and reduced Plant Damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of Plant pathogens.
D C Naseby - One of the best experts on this subject based on the ideXlab platform.
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effect of biocontrol strains of trichoderma on Plant growth pythium ultimum populations soil microbial communities and soil enzyme activities
Journal of Applied Microbiology, 2001Co-Authors: D C Naseby, J A Pascual, J M LynchAbstract:D.C. NASEBY, J.A. PASCUAL and J.M. LYNCH.2000.Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 8% respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the Plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced Plant Damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved Plant growth in the absence of Pythium and reduced Plant Damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of Plant pathogens.
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effect of biocontrol strains of trichoderma on Plant growth pythium ultimum populations soil microbial communities and soil enzyme activities
Journal of Applied Microbiology, 2001Co-Authors: D C Naseby, J A Pascual, J M LynchAbstract:D.C. NASEBY, J.A. PASCUAL and J.M. LYNCH.2000.Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 8% respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the Plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced Plant Damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved Plant growth in the absence of Pythium and reduced Plant Damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of Plant pathogens.
J A Pascual - One of the best experts on this subject based on the ideXlab platform.
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effect of biocontrol strains of trichoderma on Plant growth pythium ultimum populations soil microbial communities and soil enzyme activities
Journal of Applied Microbiology, 2001Co-Authors: D C Naseby, J A Pascual, J M LynchAbstract:D.C. NASEBY, J.A. PASCUAL and J.M. LYNCH.2000.Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 8% respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the Plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced Plant Damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved Plant growth in the absence of Pythium and reduced Plant Damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of Plant pathogens.
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effect of biocontrol strains of trichoderma on Plant growth pythium ultimum populations soil microbial communities and soil enzyme activities
Journal of Applied Microbiology, 2001Co-Authors: D C Naseby, J A Pascual, J M LynchAbstract:D.C. NASEBY, J.A. PASCUAL and J.M. LYNCH.2000.Five strains of Trichoderma with known biocontrol activities were assessed for their effect upon pea growth and their antagonistic activity against large Pythium ultimum inocula. The effect of Trichoderma inocula upon the indigenous soil microflora and soil enzyme activities in the presence and absence of Pythium is assessed. In the absence of Pythium, Trichoderma strain N47 significantly increased the wet shoot weight by 15% but did not significantly affect the dry weight, whilst strains T4 and N47 significantly increased the root weights by 22% and 8% respectively. Strains TH1 and N47 resulted in significantly greater root lengths. Pythium inoculation significantly reduced the root length and the number of lateral roots and nodules, and significantly increased the root and rhizosphere soil fungal populations. Pythium inoculation significantly reduced the Plant wet and dry shoot weights and significantly increased the wet and the dry shoot/root ratio. All the Trichoderma strains reduced the number of lesions caused by Pythium and increased the number of lateral roots. The effect of the Pythium on emergence and shoot growth was significantly reduced by all the Trichoderma strains except strain To10. Inoculation with Trichoderma strains TH1 and T4 resulted in significantly greater wet root weights (62% and 57%, respectively) in the presence of Pythium compared to the Pythium control. Strain N47 significantly increased the shoot/root ratio compared to the Pythium control. Inoculation with Trichoderma strains T4, T12 and N47 significantly reduced Pythium populations. Pythium increased the activity of C, N and P cycle enzymes, whilst four Trichoderma strains reduced this effect, indicating reduced Plant Damage and C leakage. Overall, strains T4 and N47 had the greatest beneficial characteristics, as both these strains improved Plant growth in the absence of Pythium and reduced Plant Damage in the presence of Pythium. The dual properties of these strains improve the commercial application, giving them an advantage over single action inocula, especially in the absence of Plant pathogens.
Terri L. Randolph - One of the best experts on this subject based on the ideXlab platform.
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Damage and Yield Response of Wheat Lines with Dn4 and Dn7 Genes Resistant to Russian Wheat Aphid Biotype RWA21
Southwestern Entomologist, 2020Co-Authors: Darren M. Cockrell, Terri L. Randolph, Cynthia B. Walker, Rachael A. Sitz, Scott D. Haley, Frank B. PeairsAbstract:Plant Damage and yield responses to three infestation levels (0, 1, and 10x) of biotype RWA2 Russian wheat aphid, Diuraphis noxia (Kurdjumov), were compared in winter wheat, Triticum aestivum L., during the 2010-11, 2011-12, and 2012-13 growing seasons at two sites in eastern Colorado. Wheat lines contained either no resistance gene (Yuma), Dn4 resistance (Yumar), or the Dn7 resistance gene (CO08RWA050). Fewer Russian wheat aphids and symptomatic tillers were on CO08RWA050 at any infestation. Yuma and Yumar tillers had an average of seven times more aphids present than CO08RWA050. Yields decreased as infestation increased in Yuma and Yumar, but yield was not less in CO08RWA050 at any infestation level. Kernel weights of Yuma and Yumar, but not CO08RWA050, were less with greater infestation. Data from the study suggested that resistance conferred by the Dn7 gene would be effective in reducing Russian wheat aphid abundance, and ultimately benefit wheat producers during outbreak years.
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characterization of eight russian wheat aphid hemiptera aphididae biotypes using two category resistant susceptible Plant responses
Journal of Economic Entomology, 2014Co-Authors: Gary J Puterka, Frank B. Peairs, Scott J Nicholson, M J Brown, W R Cooper, Terri L. RandolphAbstract:ABSTRACT Eight biotypes of the Russian wheat aphid, Diuraphis noxia (Kurdjumov), have been discovered in the United States since 2003. Biotypes are identified by the distinct feeding Damage responses they produce on wheat carrying different Russian wheat aphid resistance genes, namely, from Dn1 to Dn9. Each Russian wheat aphid biotype has been named using Plant Damage criteria and virulence categories that have varied between studies. The study was initiated to compare the Plant Damage caused by all the eight known Russian wheat aphid biotypes, and analyze the results to determine how Russian wheat aphid virulence should be classified. Each Russian wheat aphid biotype was evaluated on 16 resistant or susceptible cereal genotypes. Plant Damage criteria included leaf roll, leaf chlorosis, and Plant height. The distribution of chlorosis ratings followed a bimodal pattern indicating two categories of Plant responses, resistant or susceptible. Correlations were significant between chlorosis ratings and leaf ro...
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occurrence of a new russian wheat aphid biotype in colorado
Crop Science, 2004Co-Authors: Scott D. Haley, Cynthia B. Walker, Frank B. Peairs, J B Rudolph, Terri L. RandolphAbstract:Russian wheat aphid [RWA, Diuraphis noxia (Mordvilko)] is a serious pest of wheat (Triticum aestivum L.) in the western USA Great Plains region. While variation in virulence among different RWA isolates has been reported elsewhere, no such variation has been documented among North American RWA isolates. Our objective was to confirm observations in spring 2003 suggesting that a new biotype of RWA was present in southeastern Colorado. The new biotype induced greater injury (leaf rolling and overall Plant Damage) than the original biotype in standard greenhouse seedling screening tests with a limited collection of resistant and susceptible cultivars. A second experiment with a broader collection of known RWA resistance sources identified only one accession, 94M370 (Dn7 gene), with resistance to the new biotype. Development of wheat cultivars with resistance to this new biotype will depend on rapid identification and deployment of new resistance sources.
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Plant Damage and yield response to the russian wheat aphid homoptera aphididae on susceptible and resistant winter wheats in colorado
Journal of Economic Entomology, 2003Co-Authors: Terri L. Randolph, Cynthia B. Walker, Frank B. Peairs, Robert W Hammon, M K Kroening, John S Armstrong, J. S. QuickAbstract:Plant Damage and yield response to the Russian wheat aphid, Diuraphis noxia (Mordvilko), were evaluated on a susceptible (TAM 107) and a resistant (RWA E1) winter wheat, Triticum aestivum L., in three Colorado locations in the 1993 and 1994 crop years. Russian wheat aphid was more abundant on TAM 107 than on RWA E1. Russian wheat aphid days per tiller were greater at the higher infestation levels. Yield losses as a result of Russian wheat aphid infestation occurred most of the time with TAM 107 but rarely with RWA E1. Seed densities were reduced at higher infestation levels in TAM 107 at two locations. Russian wheat aphids per tiller had a negative relationship to yield in TAM 107 but not in RWA E1. In TAM 107 yield decreased as aphid densities increased, but yield remained constant regardless of initial aphid abundance on RWA E1 in all environments. Seed densities were reduced at higher infestation levels in TAM 107 at two locations. The resistance conferred by the Dn4 gene seems to be an effective management approach across a range of field conditions.
Frank B. Peairs - One of the best experts on this subject based on the ideXlab platform.
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Damage and Yield Response of Wheat Lines with Dn4 and Dn7 Genes Resistant to Russian Wheat Aphid Biotype RWA21
Southwestern Entomologist, 2020Co-Authors: Darren M. Cockrell, Terri L. Randolph, Cynthia B. Walker, Rachael A. Sitz, Scott D. Haley, Frank B. PeairsAbstract:Plant Damage and yield responses to three infestation levels (0, 1, and 10x) of biotype RWA2 Russian wheat aphid, Diuraphis noxia (Kurdjumov), were compared in winter wheat, Triticum aestivum L., during the 2010-11, 2011-12, and 2012-13 growing seasons at two sites in eastern Colorado. Wheat lines contained either no resistance gene (Yuma), Dn4 resistance (Yumar), or the Dn7 resistance gene (CO08RWA050). Fewer Russian wheat aphids and symptomatic tillers were on CO08RWA050 at any infestation. Yuma and Yumar tillers had an average of seven times more aphids present than CO08RWA050. Yields decreased as infestation increased in Yuma and Yumar, but yield was not less in CO08RWA050 at any infestation level. Kernel weights of Yuma and Yumar, but not CO08RWA050, were less with greater infestation. Data from the study suggested that resistance conferred by the Dn7 gene would be effective in reducing Russian wheat aphid abundance, and ultimately benefit wheat producers during outbreak years.
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characterization of eight russian wheat aphid hemiptera aphididae biotypes using two category resistant susceptible Plant responses
Journal of Economic Entomology, 2014Co-Authors: Gary J Puterka, Frank B. Peairs, Scott J Nicholson, M J Brown, W R Cooper, Terri L. RandolphAbstract:ABSTRACT Eight biotypes of the Russian wheat aphid, Diuraphis noxia (Kurdjumov), have been discovered in the United States since 2003. Biotypes are identified by the distinct feeding Damage responses they produce on wheat carrying different Russian wheat aphid resistance genes, namely, from Dn1 to Dn9. Each Russian wheat aphid biotype has been named using Plant Damage criteria and virulence categories that have varied between studies. The study was initiated to compare the Plant Damage caused by all the eight known Russian wheat aphid biotypes, and analyze the results to determine how Russian wheat aphid virulence should be classified. Each Russian wheat aphid biotype was evaluated on 16 resistant or susceptible cereal genotypes. Plant Damage criteria included leaf roll, leaf chlorosis, and Plant height. The distribution of chlorosis ratings followed a bimodal pattern indicating two categories of Plant responses, resistant or susceptible. Correlations were significant between chlorosis ratings and leaf ro...
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occurrence of a new russian wheat aphid biotype in colorado
Crop Science, 2004Co-Authors: Scott D. Haley, Cynthia B. Walker, Frank B. Peairs, J B Rudolph, Terri L. RandolphAbstract:Russian wheat aphid [RWA, Diuraphis noxia (Mordvilko)] is a serious pest of wheat (Triticum aestivum L.) in the western USA Great Plains region. While variation in virulence among different RWA isolates has been reported elsewhere, no such variation has been documented among North American RWA isolates. Our objective was to confirm observations in spring 2003 suggesting that a new biotype of RWA was present in southeastern Colorado. The new biotype induced greater injury (leaf rolling and overall Plant Damage) than the original biotype in standard greenhouse seedling screening tests with a limited collection of resistant and susceptible cultivars. A second experiment with a broader collection of known RWA resistance sources identified only one accession, 94M370 (Dn7 gene), with resistance to the new biotype. Development of wheat cultivars with resistance to this new biotype will depend on rapid identification and deployment of new resistance sources.
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Plant Damage and yield response to the russian wheat aphid homoptera aphididae on susceptible and resistant winter wheats in colorado
Journal of Economic Entomology, 2003Co-Authors: Terri L. Randolph, Cynthia B. Walker, Frank B. Peairs, Robert W Hammon, M K Kroening, John S Armstrong, J. S. QuickAbstract:Plant Damage and yield response to the Russian wheat aphid, Diuraphis noxia (Mordvilko), were evaluated on a susceptible (TAM 107) and a resistant (RWA E1) winter wheat, Triticum aestivum L., in three Colorado locations in the 1993 and 1994 crop years. Russian wheat aphid was more abundant on TAM 107 than on RWA E1. Russian wheat aphid days per tiller were greater at the higher infestation levels. Yield losses as a result of Russian wheat aphid infestation occurred most of the time with TAM 107 but rarely with RWA E1. Seed densities were reduced at higher infestation levels in TAM 107 at two locations. Russian wheat aphids per tiller had a negative relationship to yield in TAM 107 but not in RWA E1. In TAM 107 yield decreased as aphid densities increased, but yield remained constant regardless of initial aphid abundance on RWA E1 in all environments. Seed densities were reduced at higher infestation levels in TAM 107 at two locations. The resistance conferred by the Dn4 gene seems to be an effective management approach across a range of field conditions.
