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Johan Desaeger - One of the best experts on this subject based on the ideXlab platform.
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efficacy of nonfumigant nematicides against Meloidogyne Javanica as affected by soil temperature under pasteurized and natural soil conditions
Pest Management Science, 2021Co-Authors: Hung X Bui, Johan DesaegerAbstract:BACKGROUND Biotic and abiotic factors such as microbes and soil temperature can affect nematicide efficacy. Two experiments were conducted to test the effect of three soil temperatures on the efficacy of nonfumigant nematicides (fluopyram, fluensulfone, oxamyl and fluazaindolizine) against Meloidogyne Javanica in pasteurized and natural soil in planta. RESULTS The results showed that all tested nematicides were more efficacious in pasteurized than in natural soil. Temperature affected the nematicides differently with no effect of soil temperature on oxamyl and fluazaindolizine, whereas fluopyram and fluensulfone had greater efficacy at higher soil temperatures. CONCLUSION Temperature effects were noted for some but not all nonfumigant nematicides. Fluopyram and fluensulfone were less effective when applied in cold soil, whereas oxamyl and fluazaindolizine were not affected by soil temperature. Although all nematicides resulted in almost complete control of M. Javanica in pasteurized soil, this was not the case in natural soil, and much more root damage and nematode reproduction was noted in the latter. © 2021 Society of Chemical Industry.
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interactions between Meloidogyne Javanica treub chitwood and rhizobia on growth of sesbania sesban l merr
Applied Soil Ecology, 2005Co-Authors: Johan Desaeger, Joseph Machua, David W. Odee, Milton EsitubiAbstract:Abstract A screenhouse experiment was conducted to evaluate the effects of inoculation with Meloidogyne Javanica (uninoculated nematode control, low level [1000 eggs pot −1 ] and high level [10,000 eggs pot −1 ]) and rhizobial strains (uninoculated rhizobial control, strains KFR 647 and MBS1312) on nematode infection, nodulation and growth of Sesbania sesban (L.) Merr. (sesbania) provenances (Kisii and Kakamega). Heavy nematode infection of sesbania was noted for all three rhizobial inoculation treatments 2 months after sowing, and nodulation and plant growth were affected negatively at the high nematode inoculum level. Shoot dry weights showed negative and positive relationships with nematode infection (gall index) and number of effective rhizobium nodules, respectively. At 3 months, negative effects of the high nematode inoculum level on nodulation and plant growth were observed for rhizobial strain KFR 647 and the uninoculated control, but not for strain MBS 1312. Low nematode inoculum levels did not negatively affect nodulation or plant growth. The two sesbania provenances had similar growth at the high nematode inoculum level, but the Kisii provenance showed better growth than the Kakamega provenance at the low nematode inoculum level.
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infection and damage potential of Meloidogyne Javanica on sesbania sesban in different soil types
Nematology, 2000Co-Authors: Johan DesaegerAbstract:An experiment in western Kenya tested the effects of six inoculum levels (0, 80, 400, 800, 2000 and 4000 eggs per 100 cm3 soil) of Meloidogyne Javanica on nematode infection and growth of two Sesbania sesban provenences (Kakamega and Kisii) in six soils with sand contents of 26 to 82%. At 1 month after sowing, nematode infection, gall index and seedling mortality increased with inoculum level and sand/clay ratio. Gall index decreased and seedling growth improved with extractable cations, particularly calcium. At 3 months, nematode infection and damage were affected neither by soil texture nor by extractable cations. However, nodulation and plant growth decreased with increasing inoculum levels in all soils. Soils with higher cations and inherent fertility were less prone to nematode infestation and sustained better Sesbania growth irrespective of soil texture. It appears that as Sesbania grows it develops tolerance to M. Javanica, suggesting that nematode infection is important at seedling stage primarily in determining stand establishment and early growth. Kisii provenance was more tolerant to the nematode and more productive than Kakamega. There is a need for screening a wide range of Sesbania germplasm for nematode resistance to select appropriate provenances and exploring low cost methods to minimise nematode damage to Sesbania at establishment stage. In einem Versuch in Westkenia wurde die Wirkung von sechs Inokulumstufen (0, 80, 400, 800, 2000 und 4000 Eier je 100 ml Boden) von Meloidogyne Javanica auf die Nematodeninfektion und auf das Wachstum von zwei Herkunften von Sesbania sesban (Kakamega und Kisii) in sechs verschiedenen Boden mit Sandanteilen zwischen 26 und 82% untersucht. Einen Monat nach der Aussaat stiegen die Nematodeninfektion, der Vergallungsindex und die Keimlingssterblichkeit mit der Inokulumsgrosse und dem Sand/Lehm-Verhaltnis an. Der Vergallungsindex nahm ab, und das Keimlingswachstum verbesserte sich mit dem Gehalt an extrahierbaren Kationen, insbesondere Kalzium. Nach 3 Monaten wurden Nematodeninfektion und Schaden weder durch die Bodentextur noch durch die extrahierbaren Kationen beeinflusst. Die Gallbildung und das Pflanzenwachstum nahmen jedoch in allen Boden mit steigenden Inokulumsstufen ab. Boden mit einem boheren Gehalt an Kationen und naturlicher Fruchtbarkeit neigten weniger zu Nematodeninfektionen und unterstutzten das Wachstum von Sesbania unabhangig von der Bodentextur. Anscheinend entwickelt Sesbania mit zunehmendem Wachstum eine Toleranz gegenuber M. Javanica. Das weist daraufhin, dass eine Nematodeninfektion im Keimlingsstadium in erster Linie wichtig ist fur die Entwicklung des Standplatzes und fur das fruhe Wachstum. Die Herkunft Kisii war toleranter gegenuber den Nematoden und auch produktiver als Kakamega. Es muss eine breite Palette von Sesbania-Genplasmen auf Nematodenresistenz gepruft werden, um geeignete Herkunfte zu selektieren und preiswerte Methoden zur Minimierung des Nematodenschadens an Sesbania im fruhen Entwicklungsstadium auszuprobieren.
Navazallah Sahebani - One of the best experts on this subject based on the ideXlab platform.
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potential biocontrol activity of arthrobotrys oligospora and trichoderma harzianum bi against Meloidogyne Javanica on tomato in the greenhouse and laboratory studies
Archives of Phytopathology and Plant Protection, 2013Co-Authors: V Jamshidnejad, Navazallah Sahebani, Hasan Reza EtebarianAbstract:In this investigation, the biological control activity of Arthrobotrys oligospora and Trichoderma harzinum BI against the root-knot nematode, Meloidogyne Javanica, infecting tomato, was assessed both in in vitro and in in vivo experiments. In greenhouse experiments, tomato seedlings at six-leaf stage were inoculated with 106 spores/ml of A. oligospora and T. harzianum BI and number of 2000 nematode eggs per individual seedling. In in vitro assays, the per cent inhibition of nematode eggs hatching, the death per cent of second-stage juvenile (J2) and proteolytic activity on casein hydrolysis was evaluated. Results showed that A. oligospora and T. harzianum BI decreased the mean numbers of galls, eggmasses and egg per eggmass significantly (p < 0.05) compared with control. Percentage hatching inhibition of M. Javanica treated with A. oligospora and T. harzianum BI was 25 and 52%, respectively. Moreover, A. oligospora and T. harzianum BI significantly increased (p < 0.05) the mortality rate of M. Javanica (J...
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biological control of Meloidogyne Javanica by trichoderma harzianum bi and salicylic acid on tomato
African Journal of Food Science, 2011Co-Authors: Fatemeh Naserinasab, Navazallah Sahebani, Hasan Reza EtebarianAbstract:In this study, Trichoderma harzianum BI was evaluated for its capacity to reduce the incidence and pathogenicity of the root-knot nematode Meloidogyne Javanica on tomato. Culture filtrates of T. harzianum BI at different concentrations, (standard, 1:1, 1:10, and 1:100) were studied. In vitro studies revealed that hatching of M. Javanica eggs were inhibited by the culture filtrates and this inhibition was positively correlated with increase in the concentration of culture filtrates. Parasitism of M. Javanica eggs by T. harzianum BI ranged from 21% in control to 84% in antagonistic fungi. T. harzianum BI reduced nematode damage to tomato in vivo, too. Treatment of the soil with the antagonistic fungi and salicylic acid clearly improved nematode control when applied jointly or alone. The antagonistic fungi and salicylic acid were further tested for their ability to induce production of defense related enzymes in tomato. Earlier and increased activities of soluble peroxidase (SPOX) was observed in T. harzianum BI and salicylic acid treated tomato inoculated with M. Javanica. Thus, the present study shows that in addition to direct antagonism, induction of defense-related enzymes involved in peroxidase pathway contributed to enhance resistance against invasion of M. Javanica in tomato. Key words: Biological control, Meloidogyne Javanica, Trichoderma harzianum BI, peroxidase.
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biological control of the root knot nematode Meloidogyne Javanica by trichoderma harzianum
Soil Biology & Biochemistry, 2008Co-Authors: Navazallah Sahebani, N HadaviAbstract:Abstract The filamentous fungi Trichoderma spp. is currently developed as biocontrol agents against many plant pathogens. Recent studies have shown that these fungi are able to infect nematode eggs and juveniles. In this research, biological control of root-knot nematode (Meloidogyne Javanica) by Trichoderma harzianum BI was investigated in greenhouse and laboratory experiments. Results showed that different concentrations (102–108 spores/ml) of T. harzianum BI decreased nematode infection and other parameters significantly, compared to control. T. harzianum BI was able to penetrate nematode egg mass matrix and significantly decreased nematode egg hatching level. Specific activities of resistance-related enzymes, namely peroxidase (POX), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) increased significantly in T. harzianum BI inoculated plants. Maximum activities of POX, PPO and PAL were observed at the 5, 5 and 6 days after inoculation, respectively. Chitinase activity was also increased in culture filtrates of T. harzianum BI grown on wheat bran moistened with salt solution supplemented with colloidal chitin or nematode eggs. Maximum activity of chitinase was recorded at the 4 days after inoculation, in media supplemented with colloidal chitin (1.15 U/min per ml) and nematode eggs (0.85 U/min per ml). Results suggested that direct parasitism of eggs through the increase in extracellular chitinase activity, which would be indicator of eggs infection capability, and inducing plant defense mechanisms leading to systemic resistance are two main suppression mechanisms used by T. harzianum BI against nematode.
Hasan Reza Etebarian - One of the best experts on this subject based on the ideXlab platform.
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potential biocontrol activity of arthrobotrys oligospora and trichoderma harzianum bi against Meloidogyne Javanica on tomato in the greenhouse and laboratory studies
Archives of Phytopathology and Plant Protection, 2013Co-Authors: V Jamshidnejad, Navazallah Sahebani, Hasan Reza EtebarianAbstract:In this investigation, the biological control activity of Arthrobotrys oligospora and Trichoderma harzinum BI against the root-knot nematode, Meloidogyne Javanica, infecting tomato, was assessed both in in vitro and in in vivo experiments. In greenhouse experiments, tomato seedlings at six-leaf stage were inoculated with 106 spores/ml of A. oligospora and T. harzianum BI and number of 2000 nematode eggs per individual seedling. In in vitro assays, the per cent inhibition of nematode eggs hatching, the death per cent of second-stage juvenile (J2) and proteolytic activity on casein hydrolysis was evaluated. Results showed that A. oligospora and T. harzianum BI decreased the mean numbers of galls, eggmasses and egg per eggmass significantly (p < 0.05) compared with control. Percentage hatching inhibition of M. Javanica treated with A. oligospora and T. harzianum BI was 25 and 52%, respectively. Moreover, A. oligospora and T. harzianum BI significantly increased (p < 0.05) the mortality rate of M. Javanica (J...
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biological control of Meloidogyne Javanica by trichoderma harzianum bi and salicylic acid on tomato
African Journal of Food Science, 2011Co-Authors: Fatemeh Naserinasab, Navazallah Sahebani, Hasan Reza EtebarianAbstract:In this study, Trichoderma harzianum BI was evaluated for its capacity to reduce the incidence and pathogenicity of the root-knot nematode Meloidogyne Javanica on tomato. Culture filtrates of T. harzianum BI at different concentrations, (standard, 1:1, 1:10, and 1:100) were studied. In vitro studies revealed that hatching of M. Javanica eggs were inhibited by the culture filtrates and this inhibition was positively correlated with increase in the concentration of culture filtrates. Parasitism of M. Javanica eggs by T. harzianum BI ranged from 21% in control to 84% in antagonistic fungi. T. harzianum BI reduced nematode damage to tomato in vivo, too. Treatment of the soil with the antagonistic fungi and salicylic acid clearly improved nematode control when applied jointly or alone. The antagonistic fungi and salicylic acid were further tested for their ability to induce production of defense related enzymes in tomato. Earlier and increased activities of soluble peroxidase (SPOX) was observed in T. harzianum BI and salicylic acid treated tomato inoculated with M. Javanica. Thus, the present study shows that in addition to direct antagonism, induction of defense-related enzymes involved in peroxidase pathway contributed to enhance resistance against invasion of M. Javanica in tomato. Key words: Biological control, Meloidogyne Javanica, Trichoderma harzianum BI, peroxidase.
Fatemeh Naserinasab - One of the best experts on this subject based on the ideXlab platform.
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biological control of Meloidogyne Javanica by trichoderma harzianum bi and salicylic acid on tomato
African Journal of Food Science, 2011Co-Authors: Fatemeh Naserinasab, Navazallah Sahebani, Hasan Reza EtebarianAbstract:In this study, Trichoderma harzianum BI was evaluated for its capacity to reduce the incidence and pathogenicity of the root-knot nematode Meloidogyne Javanica on tomato. Culture filtrates of T. harzianum BI at different concentrations, (standard, 1:1, 1:10, and 1:100) were studied. In vitro studies revealed that hatching of M. Javanica eggs were inhibited by the culture filtrates and this inhibition was positively correlated with increase in the concentration of culture filtrates. Parasitism of M. Javanica eggs by T. harzianum BI ranged from 21% in control to 84% in antagonistic fungi. T. harzianum BI reduced nematode damage to tomato in vivo, too. Treatment of the soil with the antagonistic fungi and salicylic acid clearly improved nematode control when applied jointly or alone. The antagonistic fungi and salicylic acid were further tested for their ability to induce production of defense related enzymes in tomato. Earlier and increased activities of soluble peroxidase (SPOX) was observed in T. harzianum BI and salicylic acid treated tomato inoculated with M. Javanica. Thus, the present study shows that in addition to direct antagonism, induction of defense-related enzymes involved in peroxidase pathway contributed to enhance resistance against invasion of M. Javanica in tomato. Key words: Biological control, Meloidogyne Javanica, Trichoderma harzianum BI, peroxidase.
N Hadavi - One of the best experts on this subject based on the ideXlab platform.
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biological control of the root knot nematode Meloidogyne Javanica by trichoderma harzianum
Soil Biology & Biochemistry, 2008Co-Authors: Navazallah Sahebani, N HadaviAbstract:Abstract The filamentous fungi Trichoderma spp. is currently developed as biocontrol agents against many plant pathogens. Recent studies have shown that these fungi are able to infect nematode eggs and juveniles. In this research, biological control of root-knot nematode (Meloidogyne Javanica) by Trichoderma harzianum BI was investigated in greenhouse and laboratory experiments. Results showed that different concentrations (102–108 spores/ml) of T. harzianum BI decreased nematode infection and other parameters significantly, compared to control. T. harzianum BI was able to penetrate nematode egg mass matrix and significantly decreased nematode egg hatching level. Specific activities of resistance-related enzymes, namely peroxidase (POX), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) increased significantly in T. harzianum BI inoculated plants. Maximum activities of POX, PPO and PAL were observed at the 5, 5 and 6 days after inoculation, respectively. Chitinase activity was also increased in culture filtrates of T. harzianum BI grown on wheat bran moistened with salt solution supplemented with colloidal chitin or nematode eggs. Maximum activity of chitinase was recorded at the 4 days after inoculation, in media supplemented with colloidal chitin (1.15 U/min per ml) and nematode eggs (0.85 U/min per ml). Results suggested that direct parasitism of eggs through the increase in extracellular chitinase activity, which would be indicator of eggs infection capability, and inducing plant defense mechanisms leading to systemic resistance are two main suppression mechanisms used by T. harzianum BI against nematode.