The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Ioannis O. Giannakou - One of the best experts on this subject based on the ideXlab platform.
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the effect of soil fumigants methyl bromide and metham sodium on the microbial degradation of the Nematicide cadusafos
Soil Biology & Biochemistry, 2005Co-Authors: Dimitrios G. Karpouzas, Ioannis O. Giannakou, Athena Georgiadou, Evangelos Karanasios, Urania MenkissogluspiroudiAbstract:Abstract Rapid biodegradation of Cadusafos in a soil from a previously treated greenhouse site from the area of Vasilika in Northern Greece was observed using both incubation and bioassay studies with nematodes. The slow rates of Cadusafos degradation observed in soils from the previously treated site after sterilization with chloroform and also in soils from an adjacent previously untreated site suggested that soil microorganisms adapted to metabolize Cadusafos were responsible for its rapid dissipation. Fumigation of the soil from the previously treated site with methyl bromide (MB) 9 months prior to the experimental addition of Cadusafos (4 μg g −1 ) only temporarily inhibited degradation of Cadusafos, unlike metham sodium (MS) whose application significantly hampered degradation of the Nematicide. However, when the time interval between fumigation of soil from the previously treated greenhouse with MB and MS and the experimental application of Cadusafos was minimized to 20 d, both fumigants halted the rapid degradation of the Nematicide. The transient inhibitory effect of MB on the microbial degradation of subsequent Cadusafos applications was attributed to the recovery of the soil microflora within 9 months. In contrast, the persistent inhibitory effect of MS on the microbial degradation of Cadusafos might have been caused by the adverse effects of the fumigant on the microorganisms, which were responsible for the rapid degradation of Cadusafos in the specific soil, although this was not tested in this study. According to these findings, the combined application of MS as a pre-planting treatment with a post-planting application of Cadusafos would maximize the biological efficacy of the non-fumigant Nematicide by extending its persistence and preventing the development of enhanced biodegradation for organophosphorus Nematicides such Cadusafos.
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Factors affecting the efficacy of non-fumigant Nematicides for controlling root-knot nematodes.
Pest management science, 2005Co-Authors: Ioannis O. Giannakou, Dimitrios G. Karpouzas, Ioannis Anastasiades, Nicholas G Tsiropoulos, Athena GeorgiadouAbstract:Second-stage juveniles (J2) and egg masses of root-knot nematodes as well as root debris heavily infected by the latter were exposed for different periods of time to six different doses of the Nematicides cadusafos and fenamiphos. The efficacy of the Nematicides increased significantly with increasing exposure time. Both Nematicides were more effective against J2, although they could not provide acceptable control of J2 inside egg masses or heavily galled root debris. The effect of different application strategies on the efficacy and persistence of certain Nematicides was also assessed in a field study. Cadusafos, fenamiphos, fosthiazate and oxamyl were applied in field micro-plots either as a single full dose at the time of crop establishment or as multiple reduced-rate applications at 14-day intervals throughout the cropping period, and their efficacy and persistence were determined using bioassays and analytical studies. Fosthiazate was the most efficient Nematicide studied, and this was mainly attributed to its long soil persistence. Oxamyl also provided adequate nematode control for the first 48-56 days after its application, regardless of the application method used and its relatively rapid field dissipation. Fenamiphos and cadusafos failed to provide adequate nematode control, although cadusafos was the most persistent of the Nematicides tested. The failure of fenamiphos to provide adequate nematode control was mainly attributed to its rapid degradation by soil micro-organisms, which were stimulated after its repeated low-rate application at 14-day intervals. In contrast cadusafos failure was attributed to the inability of the Nematicide to reduce nematode populations even at relatively high concentrations in soil.
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The enhanced biodegradation of fenamiphos in soils from previously treated sites and the effect of soil fumigants
Environmental toxicology and chemistry, 2004Co-Authors: Dimitrios G. Karpouzas, Polydoros Hatziapostolou, Euphemia Papadopoulou-mourkidou, Ioannis O. Giannakou, Athena GeorgiadouAbstract:The application of fenamiphos either alone or in combination with soil fumigants is a common practice in greenhouses and potato-cultivation areas in Greece. However, repeated applications of fenamiphos in the same field for a number of years can lead to the development of enhanced biodegradation of the Nematicide. Studies in previously treated greenhouse sites and potato field sites in Greece were employed in order to investigate the development of enhanced biodegradation of fenamiphos and the respective effect of soil fumigants on the development of the phenomenon. Enhanced biodegradation of fenamiphos in a soil from a previously treated greenhouse site from the area of Aggelohori in Northern Greece was observed using both incubation and bioassay studies with nematodes. Fumigation of the enhanced soil with methyl bromide (MeBr) only temporarily inhibited degradation of fenamiphos unlike metham sodium (MS) whose application significantly reduced microbial degradation of fenamiphos. Similarly, enhanced biodegradation of fenamiphos was evident in soil from potato fields that had a history of previous exposure to fenamiphos. The slow rates of fenamiphos degradation observed in soils from the previously treated sites after sterilization with broad-spectrum antibiotics and also in soils from previously untreated sites suggested that soil microorganisms were responsible for its rapid degradation. The inhibition of enhanced biodegradation of fenamiphos in soil from the previously treated greenhouse site caused by the antibiotic penicillin probably indicates that Gram+ or other bacteria sensitive to penicillin are responsible for the rapid degradation of fenamiphos in this soil. No cross-adaptation was observed between fenamiphos and other Nematicides registered in Greece for the control of root-knot and potato cyst nematodes, including cadusafos, ethoprophos, and oxamyl. According to our results, applications of MS followed by fenamiphos or in rotation with other registered Nematicides are the most promising means for minimizing the risk of development of enhanced biodegradation of fenamiphos in soils.
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A novel non-chemical Nematicide for the control of root-knot nematodes
Applied Soil Ecology, 2004Co-Authors: Ioannis O. Giannakou, Dimitrios G. Karpouzas, D.a. Prophetou-athanasiadouAbstract:Abstract The efficacy of a novel bio-Nematicide based on a strain of Bacillus firmus was investigated in a series of field and laboratory studies. The efficacy of this bio-Nematicide was compared with standard fumigant Nematicides and the bio-control agent Pasteuria penetrans. The impact of the application of this bio-Nematicide on the size and activity of the soil microflora was also tested by measuring ninhydrin reactive N and FDA hydrolytic activity, respectively. The bio-Nematicide was applied as powder at three dose levels 50, 70 and 90 g walking m−1 and incorporated into the top 0–20 cm of soil, which was naturally infected with Meloidogyne spp. In field studies, 1,3-dichloropropene and dazomet + sodium tetrathiocarbonate applications were generally superior to the bio-Nematicide treatment. However, the recommended dose of the bio-Nematicide (70 g walking m−1) significantly suppressed the numbers of second stage juveniles at the end of the cropping season in comparison with 1,3-dichloropropene. The broadcast application of the bio-Nematicide was more efficient than the banded application, regardless of the dose levels, and as efficient as the oxamyl + sodium tetrathiocarbonate combined application for the control of root-knot nematodes. In pot-experiments, the bio-Nematicide was generally more efficient in controlling root-knot nematodes than the bio-control agent P. penetrans. Application of the bio-Nematicide increased both the size and the activity of the soil microbial biomass, especially at the higher dose rates of 70 and 90 g walking m−1. This was probably due mainly to the stimulation of the indigenous soil microflora caused by the addition of animal and plant extracts contained in the bio-Nematicide formulation and partly to the added spores of B. firmus. Overall, the results indicate that the novel bio-Nematicide offers a satisfactory and environmentally friendly solution for the control of root-knot nematodes.
Ka Evans - One of the best experts on this subject based on the ideXlab platform.
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Control of potato cyst nematodes and economic benefits of application of 1,3-dichloropropene and granular Nematicides
Annals of Applied Biology, 2004Co-Authors: S. Minnis, Patrick P.j. Haydock, Ka EvansAbstract:Summary The two species of the potato cyst nematodes (PCN) Globodera pallida and G rostochiensis are the most problematic pests of the potato crop in the UK. There are no commercially available cultivars with full resistance to G. pallida and both crop rotation and granular Nematicides are less effective at controlling this species than G. rostochiensis. In situations of very high PCN levels it may be possible to reduce populations and yield losses by using an autumn application of the soil fumigant 1,3-dichloropropene (1,3-D) followed by a spring application of a granular Nematicide. Two field experiments were done to look at the integration of methods for the control of PCN. The Common Field experiment (G. rostochiensis infested) compared the use of 1,3-D with the granular Nematicides aldicarb, oxamyl and fosthiazate when growing the susceptible cv. Estima. The Four Gates experiment (infested with both PCN species but mainly G rostochiensis) compared the performance of cv. Sante (partially resistant to G. pallida, fully resistant to G. rostochiensis) with that of the susceptible cv. Estima when treated with 1,3-D and oxamyl at full and half-rates. The results of the experiments show that an integrated approach to nematode control on heavily infested sites, including granular and fumigant Nematicides and cultivar resistance, can lead to significant decreases in nematode population densities and reduce yield losses. An economic evaluation of the experiments modelled the gross margins from the different Nematicide treatments. In Common Field, the highest gross margins were achieved with the combined use of fumigant and granular Nematicides. In Four Gates, there was a clear economic benefit for both cultivars from the use of 1,3-D. In this experiment, oxamyl was of economic value to Estima but not to Sante and full-rate oxamyl was of more benefit than half-rate to Estima.
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Mapping Infestations of Potato Cyst Nematodes and the Potential for Spatially Varying Application of Nematicides
Precision Agriculture, 2003Co-Authors: Ka Evans, R. Webster, A. Barker, P. Halford, M. Russell, J. Stafford, S. GriffinAbstract:The most important constraint to potato production in the UK is the damage caused by the potato cyst nematodes (PCN) Globodera pallida and Globodera rostochiensis . These are serious pests, capable of causing substantial yield loss. Modern management systems depend heavily on Nematicides which, at c . £360 ha^−1 for granular and c . £550 ha^−1 for fumigant Nematicides, are costly to use. Mapping field infestations of PCN gives growers the option of applying Nematicide variably across their fields. We intensively sampled a field, infested with G. pallida , before and after potatoes were grown and used the results to consider decisions the grower might have taken and to examine the consequences of various actions. Sampling intensity is important in generating accurate maps. In our results, spatial independence in PCN counts occurred at about 60 m, although there was also evidence of spatial independence at a range of 10–20 m in intensively sampled areas of the field. A strategic requirement to keep PCN population densities small, rather than the more tactical objective of avoiding yield loss, would mean blanket treatment of infested fields with granular Nematicide. Maps could then be used to target ‘hot spots’ of PCN infestation for additional treatment with fumigant. This procedure would avoid blanket treatment with both types of Nematicide, thereby diminishing the cost of chemicals applied and reducing possible environmental damage. However, the inverse relationship between pre-planting population density and multiplication rate of PCN makes it difficult to devise safe spatial application procedures, especially when the pre-planting population density is just less than the detection threshold.
Athena Georgiadou - One of the best experts on this subject based on the ideXlab platform.
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the effect of soil fumigants methyl bromide and metham sodium on the microbial degradation of the Nematicide cadusafos
Soil Biology & Biochemistry, 2005Co-Authors: Dimitrios G. Karpouzas, Ioannis O. Giannakou, Athena Georgiadou, Evangelos Karanasios, Urania MenkissogluspiroudiAbstract:Abstract Rapid biodegradation of Cadusafos in a soil from a previously treated greenhouse site from the area of Vasilika in Northern Greece was observed using both incubation and bioassay studies with nematodes. The slow rates of Cadusafos degradation observed in soils from the previously treated site after sterilization with chloroform and also in soils from an adjacent previously untreated site suggested that soil microorganisms adapted to metabolize Cadusafos were responsible for its rapid dissipation. Fumigation of the soil from the previously treated site with methyl bromide (MB) 9 months prior to the experimental addition of Cadusafos (4 μg g −1 ) only temporarily inhibited degradation of Cadusafos, unlike metham sodium (MS) whose application significantly hampered degradation of the Nematicide. However, when the time interval between fumigation of soil from the previously treated greenhouse with MB and MS and the experimental application of Cadusafos was minimized to 20 d, both fumigants halted the rapid degradation of the Nematicide. The transient inhibitory effect of MB on the microbial degradation of subsequent Cadusafos applications was attributed to the recovery of the soil microflora within 9 months. In contrast, the persistent inhibitory effect of MS on the microbial degradation of Cadusafos might have been caused by the adverse effects of the fumigant on the microorganisms, which were responsible for the rapid degradation of Cadusafos in the specific soil, although this was not tested in this study. According to these findings, the combined application of MS as a pre-planting treatment with a post-planting application of Cadusafos would maximize the biological efficacy of the non-fumigant Nematicide by extending its persistence and preventing the development of enhanced biodegradation for organophosphorus Nematicides such Cadusafos.
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Factors affecting the efficacy of non-fumigant Nematicides for controlling root-knot nematodes.
Pest management science, 2005Co-Authors: Ioannis O. Giannakou, Dimitrios G. Karpouzas, Ioannis Anastasiades, Nicholas G Tsiropoulos, Athena GeorgiadouAbstract:Second-stage juveniles (J2) and egg masses of root-knot nematodes as well as root debris heavily infected by the latter were exposed for different periods of time to six different doses of the Nematicides cadusafos and fenamiphos. The efficacy of the Nematicides increased significantly with increasing exposure time. Both Nematicides were more effective against J2, although they could not provide acceptable control of J2 inside egg masses or heavily galled root debris. The effect of different application strategies on the efficacy and persistence of certain Nematicides was also assessed in a field study. Cadusafos, fenamiphos, fosthiazate and oxamyl were applied in field micro-plots either as a single full dose at the time of crop establishment or as multiple reduced-rate applications at 14-day intervals throughout the cropping period, and their efficacy and persistence were determined using bioassays and analytical studies. Fosthiazate was the most efficient Nematicide studied, and this was mainly attributed to its long soil persistence. Oxamyl also provided adequate nematode control for the first 48-56 days after its application, regardless of the application method used and its relatively rapid field dissipation. Fenamiphos and cadusafos failed to provide adequate nematode control, although cadusafos was the most persistent of the Nematicides tested. The failure of fenamiphos to provide adequate nematode control was mainly attributed to its rapid degradation by soil micro-organisms, which were stimulated after its repeated low-rate application at 14-day intervals. In contrast cadusafos failure was attributed to the inability of the Nematicide to reduce nematode populations even at relatively high concentrations in soil.
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The enhanced biodegradation of fenamiphos in soils from previously treated sites and the effect of soil fumigants
Environmental toxicology and chemistry, 2004Co-Authors: Dimitrios G. Karpouzas, Polydoros Hatziapostolou, Euphemia Papadopoulou-mourkidou, Ioannis O. Giannakou, Athena GeorgiadouAbstract:The application of fenamiphos either alone or in combination with soil fumigants is a common practice in greenhouses and potato-cultivation areas in Greece. However, repeated applications of fenamiphos in the same field for a number of years can lead to the development of enhanced biodegradation of the Nematicide. Studies in previously treated greenhouse sites and potato field sites in Greece were employed in order to investigate the development of enhanced biodegradation of fenamiphos and the respective effect of soil fumigants on the development of the phenomenon. Enhanced biodegradation of fenamiphos in a soil from a previously treated greenhouse site from the area of Aggelohori in Northern Greece was observed using both incubation and bioassay studies with nematodes. Fumigation of the enhanced soil with methyl bromide (MeBr) only temporarily inhibited degradation of fenamiphos unlike metham sodium (MS) whose application significantly reduced microbial degradation of fenamiphos. Similarly, enhanced biodegradation of fenamiphos was evident in soil from potato fields that had a history of previous exposure to fenamiphos. The slow rates of fenamiphos degradation observed in soils from the previously treated sites after sterilization with broad-spectrum antibiotics and also in soils from previously untreated sites suggested that soil microorganisms were responsible for its rapid degradation. The inhibition of enhanced biodegradation of fenamiphos in soil from the previously treated greenhouse site caused by the antibiotic penicillin probably indicates that Gram+ or other bacteria sensitive to penicillin are responsible for the rapid degradation of fenamiphos in this soil. No cross-adaptation was observed between fenamiphos and other Nematicides registered in Greece for the control of root-knot and potato cyst nematodes, including cadusafos, ethoprophos, and oxamyl. According to our results, applications of MS followed by fenamiphos or in rotation with other registered Nematicides are the most promising means for minimizing the risk of development of enhanced biodegradation of fenamiphos in soils.
Dimitrios G. Karpouzas - One of the best experts on this subject based on the ideXlab platform.
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isolation and characterization of soil bacteria able to rapidly degrade the organophosphorus Nematicide fosthiazate
Letters in Applied Microbiology, 2019Co-Authors: S Lagos, Chiara Perruchon, A Katsoula, Dimitrios G. KarpouzasAbstract:Foshtiazate is an organophosphorus Nematicide commonly used in protected crops and potato plantations. It is toxic to mammals, birds and honeybees, it is persistent in certain soils and can be transported to water resources. Recent studies by our group demonstrated, for the first time, the development of enhanced biodegradation of fosthiazate in agricultural soils. However, the micro-organisms driving this process are still unknown. We aimed to isolate soil bacteria responsible for the enhanced biodegradation of fosthiazate and assess their degradation potential against high concentrations of the Nematicide. Enrichment cultures led to the isolation of two bacterial cultures actively degrading fosthiazate. Denaturating Gradient Gel Electrophoresis analysis revealed that they were composed of a single phylotype, identified via 16S rRNA cloning and phylogenetic analysis as Variovorax boronicumulans. This strain showed high degradation potential against fosthiazate. It degraded up to 100 mg l-1 in liquid cultures (DT50 = 11·2 days), whereas its degrading capacity was reduced at higher concentration levels (500 mg l-1 , DT50 = 20 days). This is the first report for the isolation of a fosthiazate-degrading bacterium, which showed high potential for use in future biodepuration and bioremediation applications. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reported for the first time the isolation and molecular identification of bacteria able to rapidly degrade the organophosphorus Nematicide fosthiazate; one of the few synthetic Nematicides still available on the global market. Further tests demonstrated the high capacity of the isolated strain to degrade high concentrations of fosthiazate suggesting its high potential for future bioremediation applications in contaminated environmental sites, considering high acute toxicity and high persistence and mobility of fosthiazate in acidic and low in organic matter content soils.
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the effect of soil fumigants methyl bromide and metham sodium on the microbial degradation of the Nematicide cadusafos
Soil Biology & Biochemistry, 2005Co-Authors: Dimitrios G. Karpouzas, Ioannis O. Giannakou, Athena Georgiadou, Evangelos Karanasios, Urania MenkissogluspiroudiAbstract:Abstract Rapid biodegradation of Cadusafos in a soil from a previously treated greenhouse site from the area of Vasilika in Northern Greece was observed using both incubation and bioassay studies with nematodes. The slow rates of Cadusafos degradation observed in soils from the previously treated site after sterilization with chloroform and also in soils from an adjacent previously untreated site suggested that soil microorganisms adapted to metabolize Cadusafos were responsible for its rapid dissipation. Fumigation of the soil from the previously treated site with methyl bromide (MB) 9 months prior to the experimental addition of Cadusafos (4 μg g −1 ) only temporarily inhibited degradation of Cadusafos, unlike metham sodium (MS) whose application significantly hampered degradation of the Nematicide. However, when the time interval between fumigation of soil from the previously treated greenhouse with MB and MS and the experimental application of Cadusafos was minimized to 20 d, both fumigants halted the rapid degradation of the Nematicide. The transient inhibitory effect of MB on the microbial degradation of subsequent Cadusafos applications was attributed to the recovery of the soil microflora within 9 months. In contrast, the persistent inhibitory effect of MS on the microbial degradation of Cadusafos might have been caused by the adverse effects of the fumigant on the microorganisms, which were responsible for the rapid degradation of Cadusafos in the specific soil, although this was not tested in this study. According to these findings, the combined application of MS as a pre-planting treatment with a post-planting application of Cadusafos would maximize the biological efficacy of the non-fumigant Nematicide by extending its persistence and preventing the development of enhanced biodegradation for organophosphorus Nematicides such Cadusafos.
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Factors affecting the efficacy of non-fumigant Nematicides for controlling root-knot nematodes.
Pest management science, 2005Co-Authors: Ioannis O. Giannakou, Dimitrios G. Karpouzas, Ioannis Anastasiades, Nicholas G Tsiropoulos, Athena GeorgiadouAbstract:Second-stage juveniles (J2) and egg masses of root-knot nematodes as well as root debris heavily infected by the latter were exposed for different periods of time to six different doses of the Nematicides cadusafos and fenamiphos. The efficacy of the Nematicides increased significantly with increasing exposure time. Both Nematicides were more effective against J2, although they could not provide acceptable control of J2 inside egg masses or heavily galled root debris. The effect of different application strategies on the efficacy and persistence of certain Nematicides was also assessed in a field study. Cadusafos, fenamiphos, fosthiazate and oxamyl were applied in field micro-plots either as a single full dose at the time of crop establishment or as multiple reduced-rate applications at 14-day intervals throughout the cropping period, and their efficacy and persistence were determined using bioassays and analytical studies. Fosthiazate was the most efficient Nematicide studied, and this was mainly attributed to its long soil persistence. Oxamyl also provided adequate nematode control for the first 48-56 days after its application, regardless of the application method used and its relatively rapid field dissipation. Fenamiphos and cadusafos failed to provide adequate nematode control, although cadusafos was the most persistent of the Nematicides tested. The failure of fenamiphos to provide adequate nematode control was mainly attributed to its rapid degradation by soil micro-organisms, which were stimulated after its repeated low-rate application at 14-day intervals. In contrast cadusafos failure was attributed to the inability of the Nematicide to reduce nematode populations even at relatively high concentrations in soil.
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The enhanced biodegradation of fenamiphos in soils from previously treated sites and the effect of soil fumigants
Environmental toxicology and chemistry, 2004Co-Authors: Dimitrios G. Karpouzas, Polydoros Hatziapostolou, Euphemia Papadopoulou-mourkidou, Ioannis O. Giannakou, Athena GeorgiadouAbstract:The application of fenamiphos either alone or in combination with soil fumigants is a common practice in greenhouses and potato-cultivation areas in Greece. However, repeated applications of fenamiphos in the same field for a number of years can lead to the development of enhanced biodegradation of the Nematicide. Studies in previously treated greenhouse sites and potato field sites in Greece were employed in order to investigate the development of enhanced biodegradation of fenamiphos and the respective effect of soil fumigants on the development of the phenomenon. Enhanced biodegradation of fenamiphos in a soil from a previously treated greenhouse site from the area of Aggelohori in Northern Greece was observed using both incubation and bioassay studies with nematodes. Fumigation of the enhanced soil with methyl bromide (MeBr) only temporarily inhibited degradation of fenamiphos unlike metham sodium (MS) whose application significantly reduced microbial degradation of fenamiphos. Similarly, enhanced biodegradation of fenamiphos was evident in soil from potato fields that had a history of previous exposure to fenamiphos. The slow rates of fenamiphos degradation observed in soils from the previously treated sites after sterilization with broad-spectrum antibiotics and also in soils from previously untreated sites suggested that soil microorganisms were responsible for its rapid degradation. The inhibition of enhanced biodegradation of fenamiphos in soil from the previously treated greenhouse site caused by the antibiotic penicillin probably indicates that Gram+ or other bacteria sensitive to penicillin are responsible for the rapid degradation of fenamiphos in this soil. No cross-adaptation was observed between fenamiphos and other Nematicides registered in Greece for the control of root-knot and potato cyst nematodes, including cadusafos, ethoprophos, and oxamyl. According to our results, applications of MS followed by fenamiphos or in rotation with other registered Nematicides are the most promising means for minimizing the risk of development of enhanced biodegradation of fenamiphos in soils.
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A novel non-chemical Nematicide for the control of root-knot nematodes
Applied Soil Ecology, 2004Co-Authors: Ioannis O. Giannakou, Dimitrios G. Karpouzas, D.a. Prophetou-athanasiadouAbstract:Abstract The efficacy of a novel bio-Nematicide based on a strain of Bacillus firmus was investigated in a series of field and laboratory studies. The efficacy of this bio-Nematicide was compared with standard fumigant Nematicides and the bio-control agent Pasteuria penetrans. The impact of the application of this bio-Nematicide on the size and activity of the soil microflora was also tested by measuring ninhydrin reactive N and FDA hydrolytic activity, respectively. The bio-Nematicide was applied as powder at three dose levels 50, 70 and 90 g walking m−1 and incorporated into the top 0–20 cm of soil, which was naturally infected with Meloidogyne spp. In field studies, 1,3-dichloropropene and dazomet + sodium tetrathiocarbonate applications were generally superior to the bio-Nematicide treatment. However, the recommended dose of the bio-Nematicide (70 g walking m−1) significantly suppressed the numbers of second stage juveniles at the end of the cropping season in comparison with 1,3-dichloropropene. The broadcast application of the bio-Nematicide was more efficient than the banded application, regardless of the dose levels, and as efficient as the oxamyl + sodium tetrathiocarbonate combined application for the control of root-knot nematodes. In pot-experiments, the bio-Nematicide was generally more efficient in controlling root-knot nematodes than the bio-control agent P. penetrans. Application of the bio-Nematicide increased both the size and the activity of the soil microbial biomass, especially at the higher dose rates of 70 and 90 g walking m−1. This was probably due mainly to the stimulation of the indigenous soil microflora caused by the addition of animal and plant extracts contained in the bio-Nematicide formulation and partly to the added spores of B. firmus. Overall, the results indicate that the novel bio-Nematicide offers a satisfactory and environmentally friendly solution for the control of root-knot nematodes.
Robert J. Walker - One of the best experts on this subject based on the ideXlab platform.
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Anthelmintic drugs and Nematicides: studies in Caenorhabditis elegans.
WormBook : the online review of C. elegans biology, 2014Co-Authors: Lindy Holden-dye, Robert J. WalkerAbstract:Parasitic nematodes infect many species of animals throughout the phyla, including humans. Moreover, nematodes that parasitise plants are a global problem for agriculture. As such, these nematodes place a major burden on human health, on livestock production, on the welfare of companion animals and on crop production. In the 21st century there are two major challenges posed by the wide-spread prevalence of parasitic nematodes. First, many anthelmintic drugs are losing their effectiveness because nematode strains with resistance are emerging. Second, serious concerns regarding the environmental impact of the Nematicides used for crop protection have prompted legislation to remove them from use, leaving agriculture at increased risk from nematode pests. There is clearly a need for a concerted effort to address these challenges. Over the last few decades the free-living nematode Caenorhabditis elegans has provided the opportunity to use molecular genetic techniques for mode of action studies for anthelmintics and Nematicides. These approaches continue to be of considerable value. Less fruitful so far, but nonetheless potentially very useful, has been the direct use of C. elegans for anthelmintic and Nematicide discovery programmes. Here we provide an introduction to the use of C. elegans as a 'model' parasitic nematode, briefly review the study of nematode control using C. elegans and highlight approaches that have been of particular value with a view to facilitating wider-use of C. elegans as a platform for anthelmintic and Nematicide discovery and development.
