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Dimitrios G. Karpouzas - One of the best experts on this subject based on the ideXlab platform.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation
Science of the Total Environment, 2019Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing ( NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and C-14-Oxamyl mineralization assays. Oxamyl was rapidlymineralized by the indigenous microorganisms reaching > 70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes ina-diversity indices in response to Oxamyl exposure. Analysis of the beta-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation.
The Science of the total environment, 2018Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Abstract Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing (NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and 14 C-Oxamyl mineralization assays. Oxamyl was rapidly mineralized by the indigenous microorganisms reaching >70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes in α-diversity indices in response to Oxamyl exposure. Analysis of the β-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
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Distribution and function of carbamate hydrolase genes cehA and mcd in soils: the distinct role of soil pH.
FEMS microbiology ecology, 2016Co-Authors: Constantina Rousidou, Maria Tourna, Emmanuel A. Tzortzakakis, Dionysis Karaiskos, Despoina Myti, Evangelos Karanasios, Panagiotis A. Karas, Dimitrios G. KarpouzasAbstract:Synthetic carbamates constitute a significant pesticide group with Oxamyl being a leading compound in the nematicide market. Oxamyl degradation in soil is mainly microbially mediated. However, the distribution and function of carbamate hydrolase genes (cehA, mcd, cahA) associated with the soil biodegradation of carbamates is not yet clear. We studied Oxamyl degradation in 16 soils from a potato monoculture area in Greece where Oxamyl is regularly used. Oxamyl showed low persistence (DT50 2.4-26.7 days). q-PCR detected the cehA and mcd genes in 10 and three soils, respectively. The abundance of the cehA gene was positively correlated with pH, while both cehA abundance and pH were negatively correlated with Oxamyl DT50. Amongst the carbamates used in the study region, Oxamyl stimulated the abundance and expression only of the cehA gene, while carbofuran stimulated the abundance and expression of both genes. The cehA gene was also detected in pristine soils upon repeated treatments with Oxamyl and carbofuran and only in soils with pH ≥7.2, where the most rapid degradation of Oxamyl was observed. These results have major implications regarding the maintenance of carbamate hydrolase genes in soils, have practical implications regarding the agricultural use of carbamates, and provide insights into the evolution of cehA.
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Isolation of Oxamyl-degrading Bacteria and Identification of cehA as a Novel Oxamyl Hydrolase Gene.
Frontiers in microbiology, 2016Co-Authors: Konstantina Rousidou, Eleni Chanika, Dafne Georgiadou, Eftychia Soueref, Demetra Katsarou, Panagiotis Kolovos, Spyridon Ntougias, Maria Tourna, Emmanuel A. Tzortzakakis, Dimitrios G. KarpouzasAbstract:Microbial degradation is the main process controlling the environmental dissipation of the nematicide Oxamyl. Despite that, little is known regarding the microorganisms involved in its biotransformation. We report the isolation of four Oxamyl-degrading bacterial strains from an agricultural soil exhibiting enhanced biodegradation of Oxamyl. Multilocus sequence analysis (MLSA) assigned the isolated bacteria to different subgroups of the genus Pseudomonas. The isolated bacteria hydrolyzed Oxamyl to Oxamyl oxime, which was not further transformed, and utilized methylamine as a C and N source. This was further supported by the detection of methylamine dehydrogenase in three of the four isolates. All Oxamyl-degrading strains carried a gene highly homologous to a carbamate-hydrolase gene cehA previously identified in carbaryl- and carbofuran-degrading strains. Transcription analysis verified its direct involvement in the hydrolysis of Oxamyl. Selected isolates exhibited relaxed degrading specificity and transformed all carbamates tested including the oximino carbamates aldicarb and methomyl (structurally related to Oxamyl) and the aryl-methyl carbamates carbofuran and carbaryl which share with Oxamyl only the carbamate moiety.
Fabrice Martin-laurent - One of the best experts on this subject based on the ideXlab platform.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation
Science of the Total Environment, 2019Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing ( NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and C-14-Oxamyl mineralization assays. Oxamyl was rapidlymineralized by the indigenous microorganisms reaching > 70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes ina-diversity indices in response to Oxamyl exposure. Analysis of the beta-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation.
The Science of the total environment, 2018Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Abstract Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing (NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and 14 C-Oxamyl mineralization assays. Oxamyl was rapidly mineralized by the indigenous microorganisms reaching >70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes in α-diversity indices in response to Oxamyl exposure. Analysis of the β-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
Konstantina Rousidou - One of the best experts on this subject based on the ideXlab platform.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation
Science of the Total Environment, 2019Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing ( NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and C-14-Oxamyl mineralization assays. Oxamyl was rapidlymineralized by the indigenous microorganisms reaching > 70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes ina-diversity indices in response to Oxamyl exposure. Analysis of the beta-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation.
The Science of the total environment, 2018Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Abstract Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing (NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and 14 C-Oxamyl mineralization assays. Oxamyl was rapidly mineralized by the indigenous microorganisms reaching >70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes in α-diversity indices in response to Oxamyl exposure. Analysis of the β-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
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Isolation of Oxamyl-degrading Bacteria and Identification of cehA as a Novel Oxamyl Hydrolase Gene.
Frontiers in microbiology, 2016Co-Authors: Konstantina Rousidou, Eleni Chanika, Dafne Georgiadou, Eftychia Soueref, Demetra Katsarou, Panagiotis Kolovos, Spyridon Ntougias, Maria Tourna, Emmanuel A. Tzortzakakis, Dimitrios G. KarpouzasAbstract:Microbial degradation is the main process controlling the environmental dissipation of the nematicide Oxamyl. Despite that, little is known regarding the microorganisms involved in its biotransformation. We report the isolation of four Oxamyl-degrading bacterial strains from an agricultural soil exhibiting enhanced biodegradation of Oxamyl. Multilocus sequence analysis (MLSA) assigned the isolated bacteria to different subgroups of the genus Pseudomonas. The isolated bacteria hydrolyzed Oxamyl to Oxamyl oxime, which was not further transformed, and utilized methylamine as a C and N source. This was further supported by the detection of methylamine dehydrogenase in three of the four isolates. All Oxamyl-degrading strains carried a gene highly homologous to a carbamate-hydrolase gene cehA previously identified in carbaryl- and carbofuran-degrading strains. Transcription analysis verified its direct involvement in the hydrolysis of Oxamyl. Selected isolates exhibited relaxed degrading specificity and transformed all carbamates tested including the oximino carbamates aldicarb and methomyl (structurally related to Oxamyl) and the aryl-methyl carbamates carbofuran and carbaryl which share with Oxamyl only the carbamate moiety.
Sara Gallego - One of the best experts on this subject based on the ideXlab platform.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation
Science of the Total Environment, 2019Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing ( NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and C-14-Oxamyl mineralization assays. Oxamyl was rapidlymineralized by the indigenous microorganisms reaching > 70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes ina-diversity indices in response to Oxamyl exposure. Analysis of the beta-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
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Assessment of the effects of Oxamyl on the bacterial community of an agricultural soil exhibiting enhanced biodegradation.
The Science of the total environment, 2018Co-Authors: Sara Gallego, Konstantina Rousidou, Dimitrios G. Karpouzas, Marion Devers-lamrani, Fabrice Martin-laurentAbstract:Abstract Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide Oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of Oxamyl through 16S rRNA amplicon next generation sequencing (NGS) and on the Oxamyl-degrading bacterial community through cehA q-PCR analysis and 14 C-Oxamyl mineralization assays. Oxamyl was rapidly mineralized by the indigenous microorganisms reaching >70% within a month. Concomitantly, a significant increase in the number of Oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes in α-diversity indices in response to Oxamyl exposure. Analysis of the β-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of Oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by Oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of Oxamyl exposure respectively. To conclude, Oxamyl induced changes in the abundance of Oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored.
Patrick P.j. Haydock - One of the best experts on this subject based on the ideXlab platform.
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Degradation of the nematicide Oxamyl under field and laboratory conditions
Nematology, 2012Co-Authors: Patrick P.j. Haydock, Emma L. Ambrose, Andrew Wilcox, Thomas DeliopoulosAbstract:The persistence of nematicides such as Oxamyl can vary greatly in field conditions. The objectives of the present studies were: i) to compare Oxamyl degradation in soils with different properties; ii) to quantify and examine the influence of various abiotic factors on Oxamyl degradation; iii) to establish the validity of using simulated models to predict the degradation in the field; and iv) to examine if a second application of Oxamyl to the same soil 13 or 26 weeks after the first application enhances degradation. The first two studies included field measurements of Oxamyl concentration and parallel laboratory incubations. For the field measurements, soils were collected from each of ten potato (Solanum tuberosum) fields in Shropshire, UK, immediately after application of Oxamyl on the day of planting and then at weekly intervals for the duration of the two experiments. After each collection, Oxamyl was extracted and its concentration determined. For the laboratory incubations, soils were collected from the same ten sites immediately prior to field application and received one application of Oxamyl in the laboratory at the same day (day 0). The PERSIST model was then used to predict Oxamyl degradation in the field (modelled degradation). Modelled degradation was then compared with the measured degradation up to 91 days (study 1) or 56 days (study 2) after application. In study 3, an extra application of Oxamyl to that in the field at day 0 was made in the laboratory at 13 or 26 weeks after application. There were wide variations in the persistence of Oxamyl between the ten sites, with the field half-life ranging from 10 to 24 days. Degradation in the field was significantly greater at site 4, where it could not be detected 28 days after application. At other sites, the chemical persisted for 42-63 days and was still detectable at two sites 91 days following application. Soil temperatures had a greater impact on Oxamyl degradation than rainfall accounting for up to a maximum of 79% of the variation. The short persistence at site 4 was attributed to the combination of warm and moist conditions in a higher pH soil. The PERSIST model predicted the same rate of decline of Oxamyl as actually occurred in the field at only four (sites 5, 6, 7 and 8) sites. At the other sites, degradation in the field occurred at more rapid rates than predicted. This could be as a result of the model not allowing for the movement of nematicide by leaching, or because enhanced degradation of nematicides occurred at these latter sites, or due to a combination of these factors. The wide variation in half-lives and the behaviour of soils after subsequent additions of Oxamyl in study 3 were suggestive of complex microbial dynamics even under controlled conditions. Further studies would be required to establish the influence of soil microflora together with that of abiotic parameters on Oxamyl degradation.
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Isolation and identification of Oxamyl-degrading bacteria from UK agricultural soils
Soil Biology and Biochemistry, 2010Co-Authors: R.k. Osborn, Patrick P.j. Haydock, Simon G. EdwardsAbstract:Abstract Bacteria capable of utilising Oxamyl as the sole carbon source were isolated from seven different agricultural soils that had previously demonstrated enhanced Oxamyl degradation in a soil incubation study. Partial sequencing and alignment of the 16S rRNA gene showed little diversity amongst isolates, with 26 of the 27 isolates demonstrating similarity to the genus Aminobacter . The most common species isolated was Aminobacter aminovorans , while a number of the isolates demonstrated an equal degree of similarity to the species Aminobacter niigataensis and Chelatobacter heintzii . One isolate was identified as Mesorhizobium sp. This is the first time that organisms involved in the degradation of Oxamyl have been isolated and identified.
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Potential enhancement of degradation of the nematicides aldicarb, Oxamyl and fosthiazate in UK agricultural soils through repeated applications.
Pest management science, 2009Co-Authors: Rachel K. Osborn, Simon G. Edwards, Andrew Wilcox, Patrick P.j. HaydockAbstract:BACKGROUND: The potential for enhanced degradation of the carbamoyloxime nematicides aldicarb and Oxamyl and the organophosphate fosthiazate was investigated in 35 UK agricultural soils. Under laboratory conditions, soil samples received three successive applications of nematicide at 25 day intervals. RESULTS: The second and third applications of aldicarb were degraded at a faster rate than the first application in six of the 15 aldicarb-treated soils, and a further three soils demonstrated rapid degradation of all three applications. High organic matter content and low pH had an inhibitory effect on the rate of aldicarb degradation. Rapid degradation was observed in nine out of the ten soils treated with Oxamyl. In contrast, none of the fosthiazate-treated soils demonstrated enhanced degradation. CONCLUSION: The potential for enhanced degradation of aldicarb and Oxamyl was demonstrated in nine out of 15 and nine out of ten soils respectively that had previously been treated with these active substances. Degradation of fosthiazate occurred at a much slower rate, with no evidence of enhanced degradation. Fosthiazate may provide a useful alternative in cases where the efficacy of aldicarb and Oxamyl has been reduced as a result of enhanced degradation. Copyright © 2009 Society of Chemical Industry
