Biological control of plant parasitic nematodes with antagonistic bacteria on different host plants
Biological control of plant parasitic nematodes with antagonistic bacteria on different host plants
View/Type of Scholarly Publication
DissertationDate of Exam
17.04.2002Date of Publication
2002Advisor
Sikora, Richard A.Co-Referee
Skowronek, ArminMetadata
Show full item record
Citable Links 
Abstract
Root-knot nematodes, Meloidogyne spp., are recognized as the most economically important genus of plant parasitic nematodes worldwide. The nematode causes severe damage and yield loss to a large number of cultivated plants and especially on vegetable crops in the tropics and subtropics. In the investigations conducted in this study, the potential control of plant parasitic nematodes using different antagonistic bacteria was studied with particular reference to the control of species of Meloidogyne on tomato.
The results obtained from the research are presented in four chapters. The first chapter gives a: comprehensive
introduction to the problems associated with root-knot nematode attack, outlines the major control methods being used and and gives an insite into integrated pest management now as well as the potential use of biological control in future integrated strategies for nematode management.
In the second chapter the results of experiments on the biological control activity of the plant health promoting rhizobacterium Bacillus cereus strain S18 for biocontrol of the three major species of Meloidogyne are discussed. The results showed that B. cereus introduced either as a soil drench or as a root dip, reduced the number of galls and egg masses of M. incognita on tomato significantly. B. cereus applied 10 days before nematode inoculation caused significant reductions in root galling and number of galls. No differences, however, were detected between the different application times in the number of egg masses produced. It was also shown that B. cereus does not control all three major species of Meloidogyne to the same degree. B. cereus had little to no biological control activity toward M. arenaria, but gave significant control of M. incognita and M. javanica. Furthermore, the results demonstrated that B. cereus is an effective biological control agent of M. incognita on a broad spectrum of host plants.
In the third chapter the plant health promoting rhizobacterium Rhizobium etli strain G12 was tested for control of different genera of plant parasitic nematodes on a broad spectrum of crops. R. etli exhibited strong biocontrol activity towards M. incognita on different host plants. The reduction rates varied however between crops. Results showed that R. etli had the ability to control three economically important species of Meloidogyne. The highest reduction was against M. incognita and M. javanica, whereas it had little effect on M. arenaria. It was also demonstrated that increasing inoculum densities of R. etli caused increased reductions in nematode infection. Reduction in the number of galls occurred at 1010 cfu/ml whereas reductions in egg mass number were detected at 106 to 1010 cfu/ml. R. etli also caused significant reductions in sugar beet cyst nematode, Heterodera schachtii infection. R. etli reduced significantly the number of cysts/plant and number of eggs and juveniles/plant. The bacteria, however, did not affect the number of eggs and juveniles/cyst. The experimental data also showed that R. etli can reduce infection of the cyst nematode Globodera pallida on potato, but had no activity towards the migratory endoparasitic root-lesion nematode Pratylenchus zeae on maize.
In the fourth chapter the spore-forming endoparasitic bacterium Pasteuria penetrans (Pp3) was used as a biocontrol agent for the biological control of M. javanica on tomato. The results revealed abiotic factors affect attachment. Culture filtrates of the two antagonistic rhizobacteria B. cereus S18 and R. etli G12 reduced attachment of Pp3 spores to the cuticle of M. javanica juveniles at 100 strength and dilutions of 10 percent of the original fermentation broth. The experiments also demonstrated that percolates of chicken manure compost treated soil had a strong negative effect on the attachment of Pp3 spores to M. javanica juveniles. In greenhouse tests P. penetrans multiplied quickly and within 6 months and gave good biological control of M. javanica when initially introduce into the planting soil during seedling production. The seedlings with P. penetrans in the potting soil were then grown for two additional tomato cropping cycles in a sand substrate previously infested with root-knot nematodes, at temperatures above 25 C. The overall results of these studies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditionsstudies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditions. Biologische Bekämpfung pflanzenparasitärer Nematoden mit antagonistischen Bakterien an verschiedenen Wirtspflanzen
Wurzelgallennematoden der Gattung Meloidogyne zählen weltweit zu den wirtschaftlich wichtigsten pflanzenparasitären Nematoden. Nematoden dieser Gattung verursachen hohe Schäden und Ertragsausfälle an den meisten landwirtschaftlichen Kulturpflanzen, vor allem aber an Gemüse in tropischen/subtropischen Regionen. In der vorliegenden Arbeit wurden Möglichkeiten zur biologischen Bekämpfung von Meloidogyne mit antagonistischen Bakterien an verschiedenen Kulturpflanzen untersucht.
Die Ergebnisse der Arbeit wurden in vier Kapiteln dargestellt. Im ersten Kapitel wurde eine kritische Darstellung der schädigende Wirkung von Wurzelgallennematoden und deren Bekämpfungsmöglichkeiten vorgenommen, sowie die Bedeutung eines integrierten Pflanzenschutzes dargestellt und mögliche Strategien zum Einsatz biologischer Bekämpfungsverfahren für die Zukunft entwickelt.
Im zweiten Kapitel sind die Ergebnisse zur biologischen Bekämpfung der drei wichtigsten Meloidogyne-Arten mit dem pflanzengesundheitsfördernden Bakterium Bacillus cereus S18 dargestellt. Die Ergebnisse zeigen, dass eine Gieß- oder Tauchbehandlung von Tomaten mit B. cereus S18 zu einer signifikanten Reduzierung der Anzahl Gallen und Eiermassen von Meloidogyne spp. führt. Eine besonders gute Wirkung wurde erzielt, wenn B. cereus S18 10 Tage vor den Nematoden appliziert wurde. Keine Unterschiede zeigten sich im Applikationszeitpunkt auf die Anzahl gebildeter Eiermassen. Die antagonistische Wirkung von B. cereus S18 war nicht gegen alle drei Meloidogyne-Arten gleich gut ausgeprägt. Im Gegensatz zu M. incognita und M. javanica, zeigte B. cereus S18 nur eine geringe Wirkung gegen M. arenaria. Weiterhin zeigten die Ergebnisse eine gute Bekämpfung von M. incognita mit B. cereus S18 an einem breiten Spektrum von Wirtspflanzen.
Im dritten Kapitel wurde die antagonistische Wirkung des Rhizosphärebakteriums Rhizobium etli Isolat G12 gegen verschiedene Nematodenarten an unterschiedlichen Wirtspflanzen untersucht. R. etli G12 zeigt eine hohe Wirksamkeit gegen M. incognita an verschiedenen Wirtspflanzen, wobei die Wirkung in Abhängigkeit der Wirtspflanze variierte. R. etli G12 zeigte eine sehr gute Wirkung gegen M. incognita und M. javanica und eine geringer Wirkung gegen M. arenaria. Mit Erhöhung der Inokulumdichte von R. etli G12 bis auf 1010 cfu/m war eine Steigerung der Wirksamkeit verbunden. R. etli G12 zeigte weiterhin eine gute Wirkung gegen Heterodera schachtii an Zuckerrübe. Die Anzahl Zysten/Pflanze und Anzahl Eier + Larven/Pflanze war signifikant reduziert. R. etli G12 hatte jedoch keine Wirkung auf die Anzahl Eier + Larven pro Zyste. An Kartoffeln führte R. etli G12 zu einer Reduzierung des Befalls mit Globodera pallida. Demgegenüber zeigte das Bakterium keine Wirkung gegen den wandernden Endoparasiten Pratylenchus zeae an Mais.
Im vierten Kapitel wurde der obligate Endoparasit Pasteuria penetrans (Pp3) zur biologischen Bekämpfung von M. javanica an Tomate eingesetzt. Die Ergebnisse zeigten, dass die Anhaftung der P. penetrans-Sporen an die Nematodenlarven durch abiotische Faktoren beeinflusst wird. Eine Behandlung der P. penetrans-Sporen mit Kulturfiltraten der beiden antagonistischen Bakterien B. cereus S18 und R. etli G12 führte zu einer verringerten Anhaftung. Auch das Perkolat eines mit 5 % und 20 % Hühnermistkompost behandelten Bodens führte zu einer Verringerung der Sporenanhaftung an M. javanica. In Gewächshausversuchen mit Tomaten konnte sich P. penetrans gut vermehren. Bei Behandlung der Sämlinge mit P. penetrans war nach 6 Monaten eine gute Bekämpfung von M. javanica gegeben.
Die Ergebnisse der vorliegenden Arbeit zeigen die Bedeutung von drei verschiedenen bakteriellen Antagonisten für die Bekämpfung von Wurzelgallennematoden an Gemüse. Weiterhin wurden Strategien entwickelt, wie eine Verbesserung der Wirksamkeit zu erzielen ist und wie sich die biologischen Bekämpfungsverfahren in ein integriertes Pflanzenschutzverfahren integrieren lassen, um eine nachhaltige Bekämpfung der Nematoden im Freiland zu erzielen.
The results obtained from the research are presented in four chapters. The first chapter gives a: comprehensive
introduction to the problems associated with root-knot nematode attack, outlines the major control methods being used and and gives an insite into integrated pest management now as well as the potential use of biological control in future integrated strategies for nematode management.
In the second chapter the results of experiments on the biological control activity of the plant health promoting rhizobacterium Bacillus cereus strain S18 for biocontrol of the three major species of Meloidogyne are discussed. The results showed that B. cereus introduced either as a soil drench or as a root dip, reduced the number of galls and egg masses of M. incognita on tomato significantly. B. cereus applied 10 days before nematode inoculation caused significant reductions in root galling and number of galls. No differences, however, were detected between the different application times in the number of egg masses produced. It was also shown that B. cereus does not control all three major species of Meloidogyne to the same degree. B. cereus had little to no biological control activity toward M. arenaria, but gave significant control of M. incognita and M. javanica. Furthermore, the results demonstrated that B. cereus is an effective biological control agent of M. incognita on a broad spectrum of host plants.
In the third chapter the plant health promoting rhizobacterium Rhizobium etli strain G12 was tested for control of different genera of plant parasitic nematodes on a broad spectrum of crops. R. etli exhibited strong biocontrol activity towards M. incognita on different host plants. The reduction rates varied however between crops. Results showed that R. etli had the ability to control three economically important species of Meloidogyne. The highest reduction was against M. incognita and M. javanica, whereas it had little effect on M. arenaria. It was also demonstrated that increasing inoculum densities of R. etli caused increased reductions in nematode infection. Reduction in the number of galls occurred at 1010 cfu/ml whereas reductions in egg mass number were detected at 106 to 1010 cfu/ml. R. etli also caused significant reductions in sugar beet cyst nematode, Heterodera schachtii infection. R. etli reduced significantly the number of cysts/plant and number of eggs and juveniles/plant. The bacteria, however, did not affect the number of eggs and juveniles/cyst. The experimental data also showed that R. etli can reduce infection of the cyst nematode Globodera pallida on potato, but had no activity towards the migratory endoparasitic root-lesion nematode Pratylenchus zeae on maize.
In the fourth chapter the spore-forming endoparasitic bacterium Pasteuria penetrans (Pp3) was used as a biocontrol agent for the biological control of M. javanica on tomato. The results revealed abiotic factors affect attachment. Culture filtrates of the two antagonistic rhizobacteria B. cereus S18 and R. etli G12 reduced attachment of Pp3 spores to the cuticle of M. javanica juveniles at 100 strength and dilutions of 10 percent of the original fermentation broth. The experiments also demonstrated that percolates of chicken manure compost treated soil had a strong negative effect on the attachment of Pp3 spores to M. javanica juveniles. In greenhouse tests P. penetrans multiplied quickly and within 6 months and gave good biological control of M. javanica when initially introduce into the planting soil during seedling production. The seedlings with P. penetrans in the potting soil were then grown for two additional tomato cropping cycles in a sand substrate previously infested with root-knot nematodes, at temperatures above 25 C. The overall results of these studies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditionsstudies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditions.
Wurzelgallennematoden der Gattung Meloidogyne zählen weltweit zu den wirtschaftlich wichtigsten pflanzenparasitären Nematoden. Nematoden dieser Gattung verursachen hohe Schäden und Ertragsausfälle an den meisten landwirtschaftlichen Kulturpflanzen, vor allem aber an Gemüse in tropischen/subtropischen Regionen. In der vorliegenden Arbeit wurden Möglichkeiten zur biologischen Bekämpfung von Meloidogyne mit antagonistischen Bakterien an verschiedenen Kulturpflanzen untersucht.
Die Ergebnisse der Arbeit wurden in vier Kapiteln dargestellt. Im ersten Kapitel wurde eine kritische Darstellung der schädigende Wirkung von Wurzelgallennematoden und deren Bekämpfungsmöglichkeiten vorgenommen, sowie die Bedeutung eines integrierten Pflanzenschutzes dargestellt und mögliche Strategien zum Einsatz biologischer Bekämpfungsverfahren für die Zukunft entwickelt.
Im zweiten Kapitel sind die Ergebnisse zur biologischen Bekämpfung der drei wichtigsten Meloidogyne-Arten mit dem pflanzengesundheitsfördernden Bakterium Bacillus cereus S18 dargestellt. Die Ergebnisse zeigen, dass eine Gieß- oder Tauchbehandlung von Tomaten mit B. cereus S18 zu einer signifikanten Reduzierung der Anzahl Gallen und Eiermassen von Meloidogyne spp. führt. Eine besonders gute Wirkung wurde erzielt, wenn B. cereus S18 10 Tage vor den Nematoden appliziert wurde. Keine Unterschiede zeigten sich im Applikationszeitpunkt auf die Anzahl gebildeter Eiermassen. Die antagonistische Wirkung von B. cereus S18 war nicht gegen alle drei Meloidogyne-Arten gleich gut ausgeprägt. Im Gegensatz zu M. incognita und M. javanica, zeigte B. cereus S18 nur eine geringe Wirkung gegen M. arenaria. Weiterhin zeigten die Ergebnisse eine gute Bekämpfung von M. incognita mit B. cereus S18 an einem breiten Spektrum von Wirtspflanzen.
Im dritten Kapitel wurde die antagonistische Wirkung des Rhizosphärebakteriums Rhizobium etli Isolat G12 gegen verschiedene Nematodenarten an unterschiedlichen Wirtspflanzen untersucht. R. etli G12 zeigt eine hohe Wirksamkeit gegen M. incognita an verschiedenen Wirtspflanzen, wobei die Wirkung in Abhängigkeit der Wirtspflanze variierte. R. etli G12 zeigte eine sehr gute Wirkung gegen M. incognita und M. javanica und eine geringer Wirkung gegen M. arenaria. Mit Erhöhung der Inokulumdichte von R. etli G12 bis auf 1010 cfu/m war eine Steigerung der Wirksamkeit verbunden. R. etli G12 zeigte weiterhin eine gute Wirkung gegen Heterodera schachtii an Zuckerrübe. Die Anzahl Zysten/Pflanze und Anzahl Eier + Larven/Pflanze war signifikant reduziert. R. etli G12 hatte jedoch keine Wirkung auf die Anzahl Eier + Larven pro Zyste. An Kartoffeln führte R. etli G12 zu einer Reduzierung des Befalls mit Globodera pallida. Demgegenüber zeigte das Bakterium keine Wirkung gegen den wandernden Endoparasiten Pratylenchus zeae an Mais.
Im vierten Kapitel wurde der obligate Endoparasit Pasteuria penetrans (Pp3) zur biologischen Bekämpfung von M. javanica an Tomate eingesetzt. Die Ergebnisse zeigten, dass die Anhaftung der P. penetrans-Sporen an die Nematodenlarven durch abiotische Faktoren beeinflusst wird. Eine Behandlung der P. penetrans-Sporen mit Kulturfiltraten der beiden antagonistischen Bakterien B. cereus S18 und R. etli G12 führte zu einer verringerten Anhaftung. Auch das Perkolat eines mit 5 % und 20 % Hühnermistkompost behandelten Bodens führte zu einer Verringerung der Sporenanhaftung an M. javanica. In Gewächshausversuchen mit Tomaten konnte sich P. penetrans gut vermehren. Bei Behandlung der Sämlinge mit P. penetrans war nach 6 Monaten eine gute Bekämpfung von M. javanica gegeben.
Die Ergebnisse der vorliegenden Arbeit zeigen die Bedeutung von drei verschiedenen bakteriellen Antagonisten für die Bekämpfung von Wurzelgallennematoden an Gemüse. Weiterhin wurden Strategien entwickelt, wie eine Verbesserung der Wirksamkeit zu erzielen ist und wie sich die biologischen Bekämpfungsverfahren in ein integriertes Pflanzenschutzverfahren integrieren lassen, um eine nachhaltige Bekämpfung der Nematoden im Freiland zu erzielen.
Classification (DDC)
580 Pflanzen (Botanik)Mahdy, Magdy: Biological control of plant parasitic nematodes with antagonistic bacteria on different host plants. - Bonn, 2002. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-02036
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-02036
@phdthesis{handle:20.500.11811/1765,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-02036,
author = {{Magdy Mahdy}},
title = {Biological control of plant parasitic nematodes with antagonistic bacteria on different host plants},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2002,
note = {Root-knot nematodes, Meloidogyne spp., are recognized as the most economically important genus of plant parasitic nematodes worldwide. The nematode causes severe damage and yield loss to a large number of cultivated plants and especially on vegetable crops in the tropics and subtropics. In the investigations conducted in this study, the potential control of plant parasitic nematodes using different antagonistic bacteria was studied with particular reference to the control of species of Meloidogyne on tomato.
The results obtained from the research are presented in four chapters. The first chapter gives a: comprehensive
introduction to the problems associated with root-knot nematode attack, outlines the major control methods being used and and gives an insite into integrated pest management now as well as the potential use of biological control in future integrated strategies for nematode management.
In the second chapter the results of experiments on the biological control activity of the plant health promoting rhizobacterium Bacillus cereus strain S18 for biocontrol of the three major species of Meloidogyne are discussed. The results showed that B. cereus introduced either as a soil drench or as a root dip, reduced the number of galls and egg masses of M. incognita on tomato significantly. B. cereus applied 10 days before nematode inoculation caused significant reductions in root galling and number of galls. No differences, however, were detected between the different application times in the number of egg masses produced. It was also shown that B. cereus does not control all three major species of Meloidogyne to the same degree. B. cereus had little to no biological control activity toward M. arenaria, but gave significant control of M. incognita and M. javanica. Furthermore, the results demonstrated that B. cereus is an effective biological control agent of M. incognita on a broad spectrum of host plants.
In the third chapter the plant health promoting rhizobacterium Rhizobium etli strain G12 was tested for control of different genera of plant parasitic nematodes on a broad spectrum of crops. R. etli exhibited strong biocontrol activity towards M. incognita on different host plants. The reduction rates varied however between crops. Results showed that R. etli had the ability to control three economically important species of Meloidogyne. The highest reduction was against M. incognita and M. javanica, whereas it had little effect on M. arenaria. It was also demonstrated that increasing inoculum densities of R. etli caused increased reductions in nematode infection. Reduction in the number of galls occurred at 1010 cfu/ml whereas reductions in egg mass number were detected at 106 to 1010 cfu/ml. R. etli also caused significant reductions in sugar beet cyst nematode, Heterodera schachtii infection. R. etli reduced significantly the number of cysts/plant and number of eggs and juveniles/plant. The bacteria, however, did not affect the number of eggs and juveniles/cyst. The experimental data also showed that R. etli can reduce infection of the cyst nematode Globodera pallida on potato, but had no activity towards the migratory endoparasitic root-lesion nematode Pratylenchus zeae on maize.
In the fourth chapter the spore-forming endoparasitic bacterium Pasteuria penetrans (Pp3) was used as a biocontrol agent for the biological control of M. javanica on tomato. The results revealed abiotic factors affect attachment. Culture filtrates of the two antagonistic rhizobacteria B. cereus S18 and R. etli G12 reduced attachment of Pp3 spores to the cuticle of M. javanica juveniles at 100 strength and dilutions of 10 percent of the original fermentation broth. The experiments also demonstrated that percolates of chicken manure compost treated soil had a strong negative effect on the attachment of Pp3 spores to M. javanica juveniles. In greenhouse tests P. penetrans multiplied quickly and within 6 months and gave good biological control of M. javanica when initially introduce into the planting soil during seedling production. The seedlings with P. penetrans in the potting soil were then grown for two additional tomato cropping cycles in a sand substrate previously infested with root-knot nematodes, at temperatures above 25 C. The overall results of these studies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditionsstudies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditions. },
url = {https://hdl.handle.net/20.500.11811/1765}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-02036,
author = {{Magdy Mahdy}},
title = {Biological control of plant parasitic nematodes with antagonistic bacteria on different host plants},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2002,
note = {Root-knot nematodes, Meloidogyne spp., are recognized as the most economically important genus of plant parasitic nematodes worldwide. The nematode causes severe damage and yield loss to a large number of cultivated plants and especially on vegetable crops in the tropics and subtropics. In the investigations conducted in this study, the potential control of plant parasitic nematodes using different antagonistic bacteria was studied with particular reference to the control of species of Meloidogyne on tomato.
The results obtained from the research are presented in four chapters. The first chapter gives a: comprehensive
introduction to the problems associated with root-knot nematode attack, outlines the major control methods being used and and gives an insite into integrated pest management now as well as the potential use of biological control in future integrated strategies for nematode management.
In the second chapter the results of experiments on the biological control activity of the plant health promoting rhizobacterium Bacillus cereus strain S18 for biocontrol of the three major species of Meloidogyne are discussed. The results showed that B. cereus introduced either as a soil drench or as a root dip, reduced the number of galls and egg masses of M. incognita on tomato significantly. B. cereus applied 10 days before nematode inoculation caused significant reductions in root galling and number of galls. No differences, however, were detected between the different application times in the number of egg masses produced. It was also shown that B. cereus does not control all three major species of Meloidogyne to the same degree. B. cereus had little to no biological control activity toward M. arenaria, but gave significant control of M. incognita and M. javanica. Furthermore, the results demonstrated that B. cereus is an effective biological control agent of M. incognita on a broad spectrum of host plants.
In the third chapter the plant health promoting rhizobacterium Rhizobium etli strain G12 was tested for control of different genera of plant parasitic nematodes on a broad spectrum of crops. R. etli exhibited strong biocontrol activity towards M. incognita on different host plants. The reduction rates varied however between crops. Results showed that R. etli had the ability to control three economically important species of Meloidogyne. The highest reduction was against M. incognita and M. javanica, whereas it had little effect on M. arenaria. It was also demonstrated that increasing inoculum densities of R. etli caused increased reductions in nematode infection. Reduction in the number of galls occurred at 1010 cfu/ml whereas reductions in egg mass number were detected at 106 to 1010 cfu/ml. R. etli also caused significant reductions in sugar beet cyst nematode, Heterodera schachtii infection. R. etli reduced significantly the number of cysts/plant and number of eggs and juveniles/plant. The bacteria, however, did not affect the number of eggs and juveniles/cyst. The experimental data also showed that R. etli can reduce infection of the cyst nematode Globodera pallida on potato, but had no activity towards the migratory endoparasitic root-lesion nematode Pratylenchus zeae on maize.
In the fourth chapter the spore-forming endoparasitic bacterium Pasteuria penetrans (Pp3) was used as a biocontrol agent for the biological control of M. javanica on tomato. The results revealed abiotic factors affect attachment. Culture filtrates of the two antagonistic rhizobacteria B. cereus S18 and R. etli G12 reduced attachment of Pp3 spores to the cuticle of M. javanica juveniles at 100 strength and dilutions of 10 percent of the original fermentation broth. The experiments also demonstrated that percolates of chicken manure compost treated soil had a strong negative effect on the attachment of Pp3 spores to M. javanica juveniles. In greenhouse tests P. penetrans multiplied quickly and within 6 months and gave good biological control of M. javanica when initially introduce into the planting soil during seedling production. The seedlings with P. penetrans in the potting soil were then grown for two additional tomato cropping cycles in a sand substrate previously infested with root-knot nematodes, at temperatures above 25 C. The overall results of these studies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditionsstudies demonstrated the importance of three different bacterial antagonists for root-knot nematode control and supplied new information on how to improve activity of the bioloigcal control agents as well as ideas on their use in integrated management under field conditions. },
url = {https://hdl.handle.net/20.500.11811/1765}
}
The following license files are associated with this item:
