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A S Csinos - One of the best experts on this subject based on the ideXlab platform.
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Effect of application timing and method on efficacy and phytotoxicity of 1,3‐D, chloropicrin and Metam‐Sodium combinations in squash plasticulture
Pest Management Science, 2020Co-Authors: Johan Desaeger, Kenneth W Seebold, A S CsinosAbstract:BACKGROUND: Metam-Sodium, 1,3-dichloropropene (1,3-D) and chloropicrin are widely used soil fumigants. Combined application of Metam-Sodium and 1,3-D + chloropicrin is intended to improve efficacy and broaden spectrum of control, but little is known about the effect on crop safety. This study aimed to evaluate the effects of application timing of fumigant combinations on soilborne pest and disease control (nematodes, soil fungi and weeds) and growth of squash. Two separate tests with chisel-injected and drip-applied fumigant combinations and plant-back times ranging from 1 to 4 weeks were conducted in Tifton, GA, USA, in spring and fall 2002. RESULTS: Fumigant combinations using 1,3-D, chloropicrin and Metam-Sodium were as effective as methyl bromide in controlling Meloidogyne incognita (Kofoid & White) Chitwood, Pythium irregulare Buis., Rhizoctonia solani Kuhn and Cyperus esculentus L. Chisel-applied combinations were more effective in terms of root-knot nematode control than drip-applied combinations. Root-knot nematode reduced squash yields by up to 60%. Phytotoxicity problems and lower yields were observed during spring, especially following 1,3-D + chloropicrin and when plant-back periods were shorter. CONCLUSION: The main problem with fumigant alternatives to methyl bromide may not be reduced efficacy but, in particular for 1,3-D products, loss of flexibility in terms of longer plant-back periods. Copyright © 2008 Society of Chemical Industry
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effect of application timing and method on efficacy and phytotoxicity of 1 3 d chloropicrin and Metam Sodium combinations in squash plasticulture
Pest Management Science, 2008Co-Authors: Johan Desaeger, Kenneth W Seebold, A S CsinosAbstract:BACKGROUND: Metam-Sodium, 1,3-dichloropropene (1,3-D) and chloropicrin are widely used soil fumigants. Combined application of Metam-Sodium and 1,3-D + chloropicrin is intended to improve efficacy and broaden spectrum of control, but little is known about the effect on crop safety. This study aimed to evaluate the effects of application timing of fumigant combinations on soilborne pest and disease control (nematodes, soil fungi and weeds) and growth of squash. Two separate tests with chisel-injected and drip-applied fumigant combinations and plant-back times ranging from 1 to 4 weeks were conducted in Tifton, GA, USA, in spring and fall 2002. RESULTS: Fumigant combinations using 1,3-D, chloropicrin and Metam-Sodium were as effective as methyl bromide in controlling Meloidogyne incognita (Kofoid & White) Chitwood, Pythium irregulare Buis., Rhizoctonia solani Kuhn and Cyperus esculentus L. Chisel-applied combinations were more effective in terms of root-knot nematode control than drip-applied combinations. Root-knot nematode reduced squash yields by up to 60%. Phytotoxicity problems and lower yields were observed during spring, especially following 1,3-D + chloropicrin and when plant-back periods were shorter. CONCLUSION: The main problem with fumigant alternatives to methyl bromide may not be reduced efficacy but, in particular for 1,3-D products, loss of flexibility in terms of longer plant-back periods. Copyright © 2008 Society of Chemical Industry
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Effect of application timing and method on efficacy and phytotoxicity of 1,3‐D, chloropicrin and Metam‐Sodium combinations in squash plasticulture
Pest Management Science, 2008Co-Authors: Johan Desaeger, Kenneth W Seebold, A S CsinosAbstract:BACKGROUND: Metam-Sodium, 1,3-dichloropropene (1,3-D) and chloropicrin are widely used soil fumigants. Combined application of Metam-Sodium and 1,3-D + chloropicrin is intended to improve efficacy and broaden spectrum of control, but little is known about the effect on crop safety. This study aimed to evaluate the effects of application timing of fumigant combinations on soilborne pest and disease control (nematodes, soil fungi and weeds) and growth of squash. Two separate tests with chisel-injected and drip-applied fumigant combinations and plant-back times ranging from 1 to 4 weeks were conducted in Tifton, GA, USA, in spring and fall 2002. RESULTS: Fumigant combinations using 1,3-D, chloropicrin and Metam-Sodium were as effective as methyl bromide in controlling Meloidogyne incognita (Kofoid & White) Chitwood, Pythium irregulare Buis., Rhizoctonia solani Kuhn and Cyperus esculentus L. Chisel-applied combinations were more effective in terms of root-knot nematode control than drip-applied combinations. Root-knot nematode reduced squash yields by up to 60%. Phytotoxicity problems and lower yields were observed during spring, especially following 1,3-D + chloropicrin and when plant-back periods were shorter. CONCLUSION: The main problem with fumigant alternatives to methyl bromide may not be reduced efficacy but, in particular for 1,3-D products, loss of flexibility in terms of longer plant-back periods.
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effect of application timing and method on efficacy and phytotoxicity of 1 3 d chloropicrin and Metam Sodium combinations in squash plasticulture
Pest Management Science, 2008Co-Authors: Johan Desaeger, Kenneth W Seebold, A S CsinosAbstract:BACKGROUND: Metam-Sodium, 1,3-dichloropropene (1,3-D) and chloropicrin are widely used soil fumigants. Combined application of Metam-Sodium and 1,3-D + chloropicrin is intended to improve efficacy and broaden spectrum of control, but little is known about the effect on crop safety. This study aimed to evaluate the effects of application timing of fumigant combinations on soilborne pest and disease control (nematodes, soil fungi and weeds) and growth of squash. Two separate tests with chisel-injected and drip-applied fumigant combinations and plant-back times ranging from 1 to 4 weeks were conducted in Tifton, GA, USA, in spring and fall 2002. RESULTS: Fumigant combinations using 1,3-D, chloropicrin and Metam-Sodium were as effective as methyl bromide in controlling Meloidogyne incognita (Kofoid & White) Chitwood, Pythium irregulare Buis., Rhizoctonia solani Kuhn and Cyperus esculentus L. Chisel-applied combinations were more effective in terms of root-knot nematode control than drip-applied combinations. Root-knot nematode reduced squash yields by up to 60%. Phytotoxicity problems and lower yields were observed during spring, especially following 1,3-D + chloropicrin and when plant-back periods were shorter. CONCLUSION: The main problem with fumigant alternatives to methyl bromide may not be reduced efficacy but, in particular for 1,3-D products, loss of flexibility in terms of longer plant-back periods.
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concentrations in soil and efficacy of drip applied 1 3 d chloropicrin and Metam Sodium in plastic mulched sandy soil beds
Crop Protection, 2007Co-Authors: B L Candole, A S Csinos, Dong WangAbstract:Abstract Concentrations in soil and efficacy of 1,3-dichloropropene (1,3-D)+chloropicrin and methyl isothiocyanate (MITC) against the survival of Phytophthora capcisi , Rhizoctonia solani and yellow nutsedge ( Cyperus esculentus L.) were studied in plastic-mulched Southern Georgia sandy soil beds. Beds were treated with InLine (60.8% 1,3-D+33.3% chloropicrin) at 93.5, 187, and 280.5 l ha −1 and Vapam (42% Metam Sodium) 233.8, 467.5 and 701.3 l ha −1 . 1,3-D+chloropicrin and MITC concentrations in soil were monitored after drip application for 7 d and 240 h, respectively, from pre-selected sites in beds. 1,3-D+chloropicrin and MITC concentrations decreased with time and distance from the emitter. Survival of P. capsici , R. solani and yellow nutsedge in treated beds was higher with distance from the emitter. These methyl bromide alternatives did not diffuse laterally at effective concentrations beyond the point of application. Improved application techniques are required to improve the lateral distribution of these alternatives.
Neil C Gudmestad - One of the best experts on this subject based on the ideXlab platform.
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effect of soil temperature injection depth and rate of Metam Sodium efficacy in fine textured soils with high organic matter on the management of verticillium wilt of potato
American Journal of Potato Research, 2018Co-Authors: S K R Yellareddygari, Neil C GudmestadAbstract:Metam Sodium is a widely used soil fumigant for Verticillium wilt management in most potato production regions of the United States. Environmental concerns regarding volatilization losses have led to restrictions on the use of Metam Sodium. The potato industry adapted to these restrictions by replacing Metam Sodium applications through sprinkler irrigation with shank injection applications of the fumigant. Previous research established parameters for effective shank application of Metam Sodium based on soil temperature, injection depth and rate of fumigation. However, these recommendations were based on research conducted under coarse-textured soil conditions with a low organic matter (OM) content ( 2.5%. Therefore, it is important to know whether Metam Sodium fumigation recommendations for coarse-textured soils can be adapted to fine-textured soils. Two field trials were conducted using a split strip-block design for studying Metam Sodium efficacy in managing wilt. In both years, Metam Sodium injection depth and soil temperature at the time of injection did not result in significant differences in any study variable evaluated. All Metam Sodium fumigation rates significantly (P < 0.05), lowered Verticillium microsclerotia, reduced wilt severity, and improved tuber yield compared to non-treated plots. However, significant differences among fumigation rates were not observed across any variable evaluated. A relatively low rate of 373 l/ha is as effective as higher Metam Sodium rates for effective control of Verticillium wilt. Results presented here suggest that current Metam Sodium recommendations for shank injection applications in coarse-textured soils can be implemented in field soils with a fine texture and higher OM content.
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effect of soil temperature injection depth and Metam Sodium rate on the management of verticillium wilt of potato
American Journal of Potato Research, 2014Co-Authors: Julie S Pasche, Raymond J Taylor, N L David, Neil C GudmestadAbstract:Verticillium wilt, caused by Verticillium dahliae Kleb., is a primary component of the early dying complex of potato (Solanum tuberosum L.) in the United States. Although genetic resistance to V. dahliae exists and has been incorporated into several potato cultivars, the commercial potato industry is still dominated by cultivars susceptible to the pathogen. As a result, soil fumigation with Metam Sodium remains an important means by which Verticillium wilt is controlled, despite its expense and potentially negative environmental impact. Recent restrictions on Metam Sodium use by the Environmental Protection Agency directed at reducing exposure to vapor emissions have increased the need to improve shank injection of the soil fumigant. In studies reported here, the application of Metam Sodium reduced the severity of Verticillium wilt, however, soil temperature at the time of injection, Metam Sodium injection depth, and application rate had little overall effect. In 2011, temperature at the time of Metam Sodium injection did not result in significant differences in any parameter evaluated. However, in 2012, soil populations of V. dahliae, wilt severity and host colonization were significantly reduced when Metam Sodium was applied at 4 °C compared to 13 or 15 °C. No significant differences were observed between a single or two Metam Sodium injection depths in any parameter evaluated across the 2 years the study was conducted. While all rates of Metam Sodium significantly reduced soil populations of V. dahliae compared to the non-treated control, significant differences across rates were rarely observed. Improved control of Verticillium wilt and increased yield can be achieved as a result of these studies. The effective control of Verticillium wilt can be obtained by using Metam Sodium at a comparatively low rate of 373 l/ha, particularly when applied at a relatively cold soil temperature of 4 °C using a single injection depth of 25 cm. The potential impact of these application modifications of Metam Sodium in reducing emissions and non-target exposure is discussed.
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Effect of Soil Temperature, Injection Depth, and Metam Sodium Rate on the Management of Verticillium Wilt of Potato
American Journal of Potato Research, 2014Co-Authors: Julie S Pasche, Raymond J Taylor, N L David, Neil C GudmestadAbstract:La marchitez por Verticillium, causada por Verticillium dahliae Kleb., es un componente primario del complejo de muerte temprana de papa ( Solanum tuberosum L.) en los Estados Unidos. Aun cuando existe resistencia genética a V. dahliae y se ha incorporado a varias variedades de papa, la industria de la papa comercial aún está dominada por variedades susceptibles al patógeno. Como resultado, la fumigación del suelo con Metam sodio permanece como un medio importante por el cual se controla la marchitez por Verticillium, a pesar de que es caro y de su impacto ambiental potencialmente negativo. Restricciones recientes en el uso de Metam sodio por la Agencia de Protección al Ambiente dirigidas a la reducción de la exposición a las emisiones de vapor, han aumentado la necesidad de mejorar las inyecciones del fumigante del suelo. En estudios aquí reportados, la aplicación del Metam sodio redujo la severidad de la marchitez por Verticillium, no obstante, la temperatura del suelo al momento de la inyección, la profundidad de ésta, y la dosis de aplicación, tuvieron poco efecto en general. En 2011, la temperatura al momento de la inyección del Metam sodio no resultó en diferencias significativas en cualquier parámetro. No obstante, en 2012, las poblaciones del suelo de V. dahliae , la severidad del marchitamiento y la colonización del hospedante se redujeron significativamente cuando el Metam sodio se aplicó a 4 °C comparado a 13º o 15 °C. No se observaron diferencias significativas entre una o dos profundidades de inyección de Metam sodio en cualquier parámetro evaluado a lo largo de los dos años de la conducción del estudio. Mientras todas las dosis de Metam sodio redujeron significativamente las poblaciones en el suelo de V. dahliae comparadas con el testigo sin tratar, raramente se observaron diferencias significativas entre los niveles. El mejoramiento en el control del marchitamiento por Verticillium y el incremento en el rendimiento se pueden lograr como resultado de estos estudios. El control efectivo de la marchitez por Verticillium se puede obtener mediante el uso de Metam sodio a una dosis comparativamente baja de 373 l/ha, particularmente cuando se aplica a una temperatura relativamente fría del suelo de 4 °C usando una sola profundidad de inyección de 25 cm. Se discute el impacto potencial de estas modificaciones de aplicación de Metam sodio en la reducción de emisiones y de exposición a no-objetivos. Verticillium wilt, caused by Verticillium dahliae Kleb., is a primary component of the early dying complex of potato ( Solanum tuberosum L.) in the United States. Although genetic resistance to V. dahliae exists and has been incorporated into several potato cultivars, the commercial potato industry is still dominated by cultivars susceptible to the pathogen. As a result, soil fumigation with Metam Sodium remains an important means by which Verticillium wilt is controlled, despite its expense and potentially negative environmental impact. Recent restrictions on Metam Sodium use by the Environmental Protection Agency directed at reducing exposure to vapor emissions have increased the need to improve shank injection of the soil fumigant. In studies reported here, the application of Metam Sodium reduced the severity of Verticillium wilt, however, soil temperature at the time of injection, Metam Sodium injection depth, and application rate had little overall effect. In 2011, temperature at the time of Metam Sodium injection did not result in significant differences in any parameter evaluated. However, in 2012, soil populations of V. dahliae , wilt severity and host colonization were significantly reduced when Metam Sodium was applied at 4 °C compared to 13 or 15 °C. No significant differences were observed between a single or two Metam Sodium injection depths in any parameter evaluated across the 2 years the study was conducted. While all rates of Metam Sodium significantly reduced soil populations of V. dahliae compared to the non-treated control, significant differences across rates were rarely observed. Improved control of Verticillium wilt and increased yield can be achieved as a result of these studies. The effective control of Verticillium wilt can be obtained by using Metam Sodium at a comparatively low rate of 373 l/ha, particularly when applied at a relatively cold soil temperature of 4 °C using a single injection depth of 25 cm. The potential impact of these application modifications of Metam Sodium in reducing emissions and non-target exposure is discussed.
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Influence of tillage and method of Metam Sodium application on distribution and survival ofVerticillium dahliae in the soil and the development of verticillium wilt of potato
American Journal of Potato Research, 2005Co-Authors: Raymond J Taylor, Julie S Pasche, Neil C GudmestadAbstract:The effect of plowing and deep-rip tillage, in combination with chemigation or shank injection of Metam Sodium, on Verticillium dahliae populations and disease development was assessed in two fields with differing soil types and potato rotations. Soil samples were collected on a geo-referenced basis at depths of 0 to 10 cm and 10 to 20 cm before tillage, after tillage, after chemical application, and before planting and assayed for the presence of the pathogen. Propagules of V. dahliae were detected at 140 of 141 sites sampled prior to tillage. Most (74.4% in heavy, sandy loam; 63.1% in light, loamy sand) were concentrated in upper 10 cm of the soil profile. Plowing redistributed inoculum vertically while deep-rip tillage did not. In the non-chemical treated areas of both fields, the Verticillium population reached a maximum between 25 July and 8 August before declining to near pre-tillage levels. Overall, the population generally was lower in the field with heavy soil, higher organic matter content, and a 3-year crop rotation. Metam Sodium appeared to be most effective when shank injected, as the levels of inoculum in both fields declined by 60% to 80% following this application method. Chemigation was ineffective in the lighter soil, but the inoculum density in the deep-rip tillage area of the field with the heavier soil declined by nearly 20% in the upper and 60% in the lower strata following this treatment. The number of V. dahliae propagules at the 10- to 20-cm depth in the plowed area of the same field was reduced by 25% following chemigation, but remained unchanged in the upper strata. Wilt was reduced in both fields by as much as 50% with shank injection of Metam Sodium with concomitant increases in total yield, marketable yield and gross income. Increases in total yield were significant ( P
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Influence of Tillage and Method of Metam Sodium Application on Distribution and Survival of Verticillium dahliae in the Soil and the Development of Verticillium Wilt of Potato
American Journal of Potato Research, 2005Co-Authors: Raymond J Taylor, Julie S Pasche, Neil C GudmestadAbstract:The effect of plowing and deep-rip tillage, in combination with chemigation or shank injection of Metam Sodium, onVerticillium dahliae populations and disease development was assessed in two fields with differing soil types and potato rotations. Soil samples were collected on a geo-referenced basis at depths of 0 to 10 cm and 10 to 20 cm before tillage, after tillage, after chemical application, and before planting and assayed for the presence of the pathogen. Propagules ofV. dahliae were detected at 140 of 141 sites sampled prior to tillage. Most (74.4% in heavy, sandy loam; 63.1% in light, loamy sand) were concentrated in upper 10 cm of the soil profile. Plowing redistributed inoculum vertically while deep-rip tillage did not. In the non-chemical treated areas of both fields, theVerticillium population reached a maximum between 25 July and 8 August before declining to near pre-tillage levels. Overall, the population generally was lower in the field with heavy soil, higher organic matter content, and a 3-year crop rotation. Metam Sodium appeared to be most effective when shank injected, as the levels of inoculum in both fields declined by 60% to 80% following this application method. Chemigation was ineffective in the lighter soil, but the inoculum density in the deep-rip tillage area of the field with the heavier soil declined by nearly 20% in the upper and 60% in the lower strata following this treatment. The number ofV. dahliae propagules at the 10- to 20-cm depth in the plowed area of the same field was reduced by 25% following chemigation, but remained unchanged in the upper strata. Wilt was reduced in both fields by as much as 50% with shank injection of Metam Sodium with concomitant increases in total yield, marketable yield and gross income. Increases in total yield were significant (P
Dong Wang - One of the best experts on this subject based on the ideXlab platform.
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concentrations in soil and efficacy of drip applied 1 3 d chloropicrin and Metam Sodium in plastic mulched sandy soil beds
Crop Protection, 2007Co-Authors: B L Candole, A S Csinos, Dong WangAbstract:Abstract Concentrations in soil and efficacy of 1,3-dichloropropene (1,3-D)+chloropicrin and methyl isothiocyanate (MITC) against the survival of Phytophthora capcisi , Rhizoctonia solani and yellow nutsedge ( Cyperus esculentus L.) were studied in plastic-mulched Southern Georgia sandy soil beds. Beds were treated with InLine (60.8% 1,3-D+33.3% chloropicrin) at 93.5, 187, and 280.5 l ha −1 and Vapam (42% Metam Sodium) 233.8, 467.5 and 701.3 l ha −1 . 1,3-D+chloropicrin and MITC concentrations in soil were monitored after drip application for 7 d and 240 h, respectively, from pre-selected sites in beds. 1,3-D+chloropicrin and MITC concentrations decreased with time and distance from the emitter. Survival of P. capsici , R. solani and yellow nutsedge in treated beds was higher with distance from the emitter. These methyl bromide alternatives did not diffuse laterally at effective concentrations beyond the point of application. Improved application techniques are required to improve the lateral distribution of these alternatives.
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distribution and efficacy of drip applied Metam Sodium against the survival of rhizoctonia solani and yellow nutsedge in plastic mulched sandy soil beds
Pest Management Science, 2007Co-Authors: B L Candole, A S Csinos, Dong WangAbstract:The effects of Metam-Sodium application rate on soil residence time, spatial and temporal distributions of methyl isothiocyanate and pest control efficacy were studied in a Georgia sandy soil. Metam-Sodium 420 g L−1 SL was drip applied at rates of 147 and 295 L ha−1 in plastic-mulched raised beds. Methyl isothiocyanate concentrations in soil air space were monitored from four preselected sites: 10 and 20 cm below the emitter, and 20 and 30 cm laterally away from the emitter at 3, 12, 24, 48, 72, 120 and 240 h after chemigation. A higher rate of Metam-Sodium application resulted in higher methyl isothiocyanate concentrations in the soil. Highest methyl isothiocyanate concentrations were found at 20 cm below the emitter, and lowest at 30 cm laterally away from the emitter. Methyl isothiocyanate concentrations decreased with time and distance from the emitter. Lower methyl isothiocyanate concentration × time product values at 20 and 30 cm away from the emitter resulted in lower mortalities of Rhizoctonia solani Kuhn and yellow nutsedge (Cyperus esculentus L.). The results demonstrated that methyl isothiocyanate can be delivered at lethal doses with drip-applied water downward within the beds. Lateral diffusion of methyl isothiocyanate from the point of application did not reach biologically active concentrations to affect the survival of R. solani or yellow nutsedge. Further studies on the lateral distribution of methyl isothiocyanate in sandy soils are needed to circumvent this limitation. Copyright © 2007 Society of Chemical Industry
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fumigant distribution in forest nursery soils under water seal and plastic film after application of dazomet Metam Sodium and chloropicrin
Pest Management Science, 2006Co-Authors: Dong Wang, Stephen W Fraedrich, Jennifer Juzwik, Kurt A Spokas, Yi Zhang, William C KoskinenAbstract:Adequate concentration, exposure time and distribution uniformity of activated fumigant gases are prerequisites for successful soil fumigation. Field experiments were conducted to evaluate gas phase distributions of methyl isothiocyanate (MITC) and chloropicrin (CP) in two forest-tree nurseries. Concentrations of MITC and CP in soil air were measured from replicated microplots that received dazomet, Metam-Sodium and CP. Half of the plots were covered with high-density polyethylene tarp immediately after fumigation; the other half were not covered but received daily sprinkler irrigation for 1week to create and maintain a water seal. The magnitude of MITC concentrations was similar between nurseries for Metam-Sodium in both tarp and water seal treatments and for dazomet in the tarp treatment. Consistently greater MITC and CP concentrations were found in the upper 30cm of soil in the tarped plots compared with the water-sealed plots. Despite potential environmental and economic benefits with the water seal method, tarp covers were more reliable for achieving and maintaining higher MITC and CP concentrations and less prone to variations due to irrigation/rain, soil bulk density and other environmental conditions. 2006 Society of Chemical Industry
Abraham Gamliel - One of the best experts on this subject based on the ideXlab platform.
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microbial aspects of accelerated degradation of Metam Sodium in soil
Phytopathology, 2010Co-Authors: Shachaf Trikydotan, Maya Ofek, Miriam Austerweil, B Steiner, Dror Minz, J Katan, Abraham GamlielAbstract:ABSTRACT Preplant soil fumigation with Metam Sodium is used worldwide to control soilborne diseases. The development of accelerated degradation of pesticides in soil, including Metam Sodium, results in reduced pesticide efficacy. Therefore, we studied microbial involvement in accelerated degradation of methyl isothiocyanate (MITC) following repeated soil applications of the parent compound, Metam Sodium. MITC degradation was reduced in soil with a history of Metam Sodium applications following sterilization, indicating the key role of microorganisms in accelerated degradation. Accelerated degradation of MITC was induced by inoculation of soil with no previous application of Metam Sodium with soil with a history of Metam Sodium applications. We developed a method to extract the active microbial fraction responsible for MITC degradation from soil with a history of Metam Sodium applications. This concentrated soil extract induced accelerated degradation of MITC when added to two different soils with no previ...
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accelerated degradation of Metam Sodium in soil and consequences for root disease management
Phytopathology, 2009Co-Authors: Shachaf Trikydotan, Miriam Austerweil, B Steiner, J Katan, Yitzhak Peretzalon, Abraham GamlielAbstract:ABSTRACT We studied the development of accelerated degradation (AD) of methyl isothiocyanate (MITC) following repeated applications of its parent compound, Metam-Sodium (MS). Laboratory studies and four sets of field experiments were conducted during 2002–04 in three commercial fields in Israel. Repeated applications of MS to the three soils in the laboratory under controlled conditions demonstrated AD of MITC in some soils. In a peanut field, MS significantly reduced the incidence of Pythium pod rot and improved pod quality after a single application but its effectiveness was greatly reduced after two applications. In a second experiment, MS was significantly effective after a single application in controlling Verticillium wilt in potato but its efficacy diminished after three consecutive applications. In an additional experiment, fumigation with MS following single or double applications was more effective in reducing Verticillium wilt severity of potato compared with triple applications. Soils which di...
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generation and dissipation of methyl isothiocyanate in soils following Metam Sodium fumigation impact on verticillium control and potato yield
Plant Disease, 2007Co-Authors: Shachaf Trikydotan, Miriam Austerweil, B Steiner, J Katan, Yitzhak Peretzalon, Abraham GamlielAbstract:ABSTRACT The fate of methyl isothiocyanate (MITC) was studied in agricultural soils following Metam Sodium (MS) application in a controlled system and under field conditions as it was related to disease control. Soil samples were collected from 34 field sites in Israel with no history of MS application. The generation and dissipation curves of MITC in these soils, under controlled conditions, varied significantly among the soils, as reflected by the concentration by time (C × T) product. This value was significantly related with the mortality level of Fusarium oxysporum f. sp. radicis-lycopersici as a test organism and sand content of the soils. Seven field experiments were conducted in potato fields from 2001 to 2004. The MS treatments significantly reduced Verticillium wilt incidence and severity in five and four experiments, respectively, out of seven. Combining MS with formalin was more effective for controlling disease than MS alone in most cases. A significant relationship was found between mortalit...
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accelerated degradation of Metam Sodium and dazomet in soil characterization and consequences for pathogen control
Crop Protection, 2003Co-Authors: Pietro Di Primo, Miriam Austerweil, B Steiner, Abraham Gamliel, Marina Beniches, Itzik Peretzalon, J KatanAbstract:Metam-Sodium (MS) and dazomet (DAZ) are soil fumigants that generate methyl-isothiocyanate (MITC) in soil. The latter effectively controls soilborne plant pathogens. Recently, we have found that repeated applications of MS yield less effective pathogen control. Soil samples collected from 12 field sites in Israel without (nonhistory) or with (history) previous applications of MS or DAZ were tested for MITC generation and dissipation. Accelerated MITC degradation in history soils, as reflected by a sharp reduction in the concentration×time (C×T) values and half-lives of MITC, was evident in most of the tested history soils. Exposure to MS and DAZ in those soils resulted in a significant reduction in Verticillium dahliae, Sclerotium rolfsii and Fusarium oxysporum f. sp. radicis-lycopersici mortality compared to exposure in nonhistory soils. The chemical and biological assays were well correlated. This is the first report of accelerated degradation of MITC resulting from repeated applications of DAZ. MITC was rapidly degraded in soils which had been previously treated with either MS or DAZ, indicating induced cross-accelerated degradation with both fumigants. In two field soils, accelerated degradation of MITC capacity was still evident for 18 to 30 months after treatment. This study suggests that accelerated degradation of MITC is a likely cause of the poor pathogen control observed in commercial potato and peanut fields upon repeated application of the fumigants MS and DAZ, and emphasizes the need for rational use of pesticides to maintain their efficacy.
Wei Zheng - One of the best experts on this subject based on the ideXlab platform.
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conversion of Metam Sodium and emission of fumigant from soil columns
Atmospheric Environment, 2006Co-Authors: Scott R. Yates, Sharon K Papiernik, Wei Zheng, J J NunezAbstract:Metam Sodium is the most widely used soil fumigant in the United States. The primary breakdown product of Metam Sodium in soil is methyl isothiocyanate (MITC), an active pesticidal agent with a high toxicity and a great potential for volatilization. Reducing atmospheric emissions of MITC is therefore critical to maintain air quality. The objective of this study was to examine the rate and efficiency of conversion of Metam Sodium to MITC in soil and to investigate the potential of using surface water sealing to reduce MITC emissions. The conversion of Metam Sodium to MITC was a rapid abiotic decomposition process. At typical field application rates, the conversion efficiency depended on the initial content of Metam Sodium in soil, but was independent of soil moisture, soil type, and soil atmospheric conditions. A soil column system was used to measure the emission and distribution of MITC after subsurface and surface application of Metam Sodium. Volatilization flux and cumulative emission loss of MITC was substantially reduced with surface water sealing compared to uncovered soil columns after subsurface application of Metam Sodium. When Metam Sodium was surface applied in simulated chemigation, surface water sealing was ineffective, suggesting the need for additional emissions reduction practices when Metam Sodium is broadcast. Overall, the results of the column experiment indicate that surface water sealing with subsurface application of Metam Sodium may be an effective and economical strategy to reduce MITC emissions while maintaining pest control efficacy.
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incompatibility of Metam Sodium with halogenated fumigants
Pest Management Science, 2005Co-Authors: Scott R. Yates, Sharon K Papiernik, Wei ZhengAbstract:Metam Sodium (Metam) is a widely used soil fumigant. Combined application of Metam and other available fumigants is intended to produce synergic pesticidal effects for a broad spectrum of pest control in soil fumigation. This study aimed to test the compatibility of Metam with the halogenated fumigants 1,3-dichloropropene (1,3-D), chloropicrin, methyl bromide, methyl iodide and propargyl bromide. Halogenated fumigants and Metam were spiked simultaneously into organic solvents, water and moist soils, and Metam-induced degradation of these halogenated chemicals was evaluated. In all three media, the halogenated fumigants were incompatible with Metam and degraded via rapid chemical reactions. The degradation rate varied with halogenated fumigant species and increased as the amount of Metam present was increased. In moist soil, 15-95% of the halogenated fumigants were decomposed within 72h by Metam at a 1:1 molar ratio. Combined application of Telone C-35 (62.5% 1,3-D + 35% chloropicrin) at 265mgkg −1 and Vapam (42% Metam) at 567mgkg −1 in soil resulted in complete disappearance of the applied chloropicrin and 20-38% of the 1,3-D within 8h. The results suggest that simultaneous application of halogenated fumigants and Metam at the same soil depth will not maximize pest control. In practice, sequential treatment of soil or application at different soil depths is recommended when these two types of fumigants are used in combination. 2004 Society of Chemical Industry
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transformation of chloropicrin and 1 3 dichloropropene by Metam Sodium in a combined application of fumigants
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Scott R. Yates, Wei Zheng, Sharon K PapiernikAbstract:Combined application of fumigants is a potential strategy to replace methyl bromide in the control of soil-borne pests. Unfortunately, abiotic and biotic interactions among fumigants restrict some combined application approaches. In this study, the kinetics and mechanisms of reaction between Metam Sodium (Sodium methyldithiocarbamate) and the halogenated fumigants chloropicrin (trichloronitromethane) and 1,3-dichloropropene (1,3-D) were investigated in aqueous solution. For chloropicrin, an extremely rapid oxidation−reduction process occurred in the presence of Metam Sodium. The second-order rate constant for the reaction between chloropicrin and Metam Sodium was approximately 2 orders of magnitude greater than that for the reaction between 1,3-D isomers and Metam Sodium. Transformation of 1,3-D by Metam Sodium was associated with an aliphatic SN2 nucleophilic substitution process. The nucleophilic reaction of cis-1,3-D with Metam Sodium was significantly faster than that of the trans isomer and was corre...