The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
A E Olness - One of the best experts on this subject based on the ideXlab platform.
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herbicide banding and tillage system interactions on runoff losses of alachlor and Cyanazine
Journal of Environmental Quality, 2001Co-Authors: Neil C Hansen, J F Moncrief, Satish C Gupta, Paul D Capel, A E OlnessAbstract:: Herbicides transported to surface waters by agricultural runoff are partitioned between solution and solid phases. Conservation tillage that reduces upland erosion will also reduce transport of herbicides associated with the solid phase. However, transport of many herbicides occurs predominantly in solution. Conservation tillage practices may or may not reduce transport of solution-phase herbicides, as this depends on the runoff volume. Reducing herbicide application rate is another approach to minimize off-site transport. Herbicide banding can reduce herbicide application rates and costs by one-half or more. Our objective was to compare herbicide losses in runoff from different tillage practices and with band- or broadcast-applied herbicides. The herbicides alachlor [2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide] and Cyanazine [2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile] were broadcast- or band-applied to plots managed in a moldboard plow, chisel plow, or ridge till system. Herbicide concentration in runoff was largest for the first runoff event occurring after application and then decreased in subsequent events proportional to the cumulative rain since the herbicide application. When herbicides were broadcast-applied, losses of alachlor and Cyanazine in runoff followed the order: moldboard plow > chisel plow > ridge till. Conservation tillage systems reduced runoff loss of herbicides by reducing runoff volume and not the herbicide concentration in runoff. Herbicide banding reduced the concentration and loss of herbicides in runoff compared with the broadcast application. Herbicide losses in the water phase averaged 88 and 97% of the total loss for alachlor and Cyanazine, respectively. Cyanazine was more persistent than alachlor in the soil.
Robert M Zablotowicz - One of the best experts on this subject based on the ideXlab platform.
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Effect of organic amendments on the bioremediation of Cyanazine and fluometuron in soil
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 1997Co-Authors: Stephen C Wagner, Robert M ZablotowiczAbstract:Abstract Biostimulation may offer a viable approach to remediate soils containing high concentrations of herbicides. We determined the effects of cornmeal, ryegrass and poultry litter on the degradation of Cyanazine and fluometuron (250 μmol kg‐1) in a Dundee silt loam. All three amendments enhanced Cyanazine degradation with half lives of 18.2 d in ryegrass‐, and 21 d in cornmeal‐ or poultry litter‐amended soil, compared to 28.3 d in unamended soil. The amendments differentially affected patterns of metabolite accumulation. After 42 d, 45% of the 14C was recovered as dechlorinated (hydroxy Cyanazine) metabolites in ryegrass‐amended soil compared to
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supercritical fluid extraction from soil and hplc analysis of Cyanazine herbicide
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Deepa M Goli, Martin A Locke, Robert M ZablotowiczAbstract:Efficacy of supercritical fluid extraction (SFE) for the recovery of Cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile) from soil was investigated. A reverse-ph...
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soil type and tillage effects on sorption of Cyanazine and degradation products
Weed Science, 1997Co-Authors: Krishna N Reddy, Martin A Locke, Robert M ZablotowiczAbstract:Martin A. Locke Robert M. Zablotowicz Southern Weed Science Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Stoneville, MS 38776 The hydrolytic and dealkylation products of Cyanazine have been detected in soils, but the sorption of these products in soil has not been well studied. We examined sorption characteristics of five Cyanazine degradation products in relation to Cyanazine in Norfolk loamy sand, Tunica silty clay, and Dundee silt loam soils. Sorption was determined using a batch equilibrium method. Air-dried soil (3 g) was shaken in 6 ml of solution containing Cyanazine or one of its degradation products for 48 h at 4 C. Five concentrations (2.04 to 54.67 ,umol L-1) of each chemical were evaluated. The Cyanazine Freundlich coefficient (K1) ranged from 0.64 in Norfolk soil to 4.75 in Dundee no-tillage (NT) soil, and was higher in Dundee NT than in Dundee conventional-tillage (CT) soil. The Freundlich exponent (N) values for Cyanazine were less than 0.85 in all soils, indicating nonlinearity of the sorption isotherm. In general, Cyanazine sorption among the soils increased in the order of Norfolk desmethylpropanenitrile Cyanazine > hydroxyacid Cyanazine > desethyl Cyanazine > Cyanazine amide >> chloroacid Cyanazine. The Kf for chloroacid Cyanazine ranged from 0.21 in Norfolk soil to 0.42 in Dundee NT soil. Sorption patterns of five degradation products among the soils were generally similar to that of Cyanazine. Our data indicate that under field conditions, Cyanazine degradation products (especially Cyanazine amide and chloroacid Cyanazine) are more likely to remain in the aqueous phase and thus have a greater potential to move with water compared to Cyanazine.
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effect of organic amendments on the bioremediation of Cyanazine and fluometuron in soil
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 1997Co-Authors: Stephen C Wagner, Robert M ZablotowiczAbstract:Abstract Biostimulation may offer a viable approach to remediate soils containing high concentrations of herbicides. We determined the effects of cornmeal, ryegrass and poultry litter on the degradation of Cyanazine and fluometuron (250 μmol kg‐1) in a Dundee silt loam. All three amendments enhanced Cyanazine degradation with half lives of 18.2 d in ryegrass‐, and 21 d in cornmeal‐ or poultry litter‐amended soil, compared to 28.3 d in unamended soil. The amendments differentially affected patterns of metabolite accumulation. After 42 d, 45% of the 14C was recovered as dechlorinated (hydroxy Cyanazine) metabolites in ryegrass‐amended soil compared to <16% in other treatments. Significantly less 14C was extracted from cornmeal‐amended soil than the other treatments, suggesting a relationship between Cyanazine dissipation and incorporation into unextractable bound residues. Ryegrass had the greatest stimulatory effect on fiuometuron degradation. Half lives for fiuometuron were 41.0, 57.3, 27.7, and 66.4 d fo...
David R Shaw - One of the best experts on this subject based on the ideXlab platform.
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runoff losses of Cyanazine and metolachlor effects of soil type and precipitation timing
Weed Science, 2006Co-Authors: David R Shaw, Stephen M Schraer, Joby M Prince, Michele Boyette, William L KingeryAbstract:Abstract The effects of time of precipitation and soil type on runoff losses of Cyanazine and metolachlor were studied using a tilted-bed, microplot system. Two silt loam soils, Bosket and Dubbs, and a Sharkey silty clay were evaluated. Rainfall (22 mm h−1) was simulated at 0, 2, and 14 days after treatment (DAT). Time of precipitation did not impact herbicide losses or any of the runoff parameters evaluated in this study. Water runoff occurred sooner and in greater quantities from the surfaces of Bosket and Dubbs silt loam soils than from the surface of Sharkey silty clay. Runoff losses of Cyanazine did not vary by soil type. Soil drying produced large cracks in Sharkey silty clay, which greatly reduced runoff in this soil. Combined runoff and leachate losses were highest from Dubbs silt loam. Runoff losses of metolachlor were not affected by soil type. However, regression analyses indicated that time of precipitation and soil type interacted to affect initial metolachlor concentration. At 14 DAT, initia...
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sorption desorption of Cyanazine in three mississippi delta soils
Weed Science, 2003Co-Authors: Stephen M Schraer, David R Shaw, Michelle Boyette, William L Kingery, Cliff H KogerAbstract:for the Bosket silt loam, Dubbs silt loam, and Sharkey silty clay soils, respectively. Differences in sorption and Kd values were attributed to clay content. At a given initial Cyanazine concentration, Cyanazine was desorbed more readily from the silt loam soils than from the Sharkey clay after the first 4-h desorption cycle. Desorption from the Sharkey clay continued for a longer period than that from the silt loam soils, with up to 6% Cyanazine desorption from the Sharkey clay after a 16-h desorption cycle compared with 0% for the silt loam soils. Cyanazine losses increased with decreasing clay content, Dubbs 5 Bosket . Sharkey. This implies a potential relationship between Cyanazine desorption and surface runoff losses of Cyanazine.
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comparison of enzyme linked immunosorbent assay and gas chromatography procedures for the detection of Cyanazine and metolachlor in surface water samples
Journal of Agricultural and Food Chemistry, 2000Co-Authors: S M Schraer, David R Shaw, Michael D Boyette, R H Coupe, E M ThurmanAbstract:Enzyme-linked immunosorbent assay (ELISA) data from surface water reconnaissance were compared to data from samples analyzed by gas chromatography for the pesticide residues Cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile) and metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide). When ELISA analyses were duplicated, Cyanazine and metolachlor detection was found to have highly reproducible results; adjusted R2s were 0.97 and 0.94, respectively. When ELISA results for Cyanazine were regressed against gas chromatography results, the models effectively predicted Cyanazine concentrations from ELISA analyses (adjusted R2s ranging from 0.76 to 0.81). The intercepts and slopes for these models were not different from 0 and 1, respectively. This indicates that Cyanazine analysis by ELISA is expected to give the same results as analysis by gas chromatography. However, regressing ELISA analyses for metolachlor against gas chromatography data p...
Neil C Hansen - One of the best experts on this subject based on the ideXlab platform.
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herbicide banding and tillage system interactions on runoff losses of alachlor and Cyanazine
Journal of Environmental Quality, 2001Co-Authors: Neil C Hansen, J F Moncrief, Satish C Gupta, Paul D Capel, A E OlnessAbstract:: Herbicides transported to surface waters by agricultural runoff are partitioned between solution and solid phases. Conservation tillage that reduces upland erosion will also reduce transport of herbicides associated with the solid phase. However, transport of many herbicides occurs predominantly in solution. Conservation tillage practices may or may not reduce transport of solution-phase herbicides, as this depends on the runoff volume. Reducing herbicide application rate is another approach to minimize off-site transport. Herbicide banding can reduce herbicide application rates and costs by one-half or more. Our objective was to compare herbicide losses in runoff from different tillage practices and with band- or broadcast-applied herbicides. The herbicides alachlor [2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide] and Cyanazine [2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile] were broadcast- or band-applied to plots managed in a moldboard plow, chisel plow, or ridge till system. Herbicide concentration in runoff was largest for the first runoff event occurring after application and then decreased in subsequent events proportional to the cumulative rain since the herbicide application. When herbicides were broadcast-applied, losses of alachlor and Cyanazine in runoff followed the order: moldboard plow > chisel plow > ridge till. Conservation tillage systems reduced runoff loss of herbicides by reducing runoff volume and not the herbicide concentration in runoff. Herbicide banding reduced the concentration and loss of herbicides in runoff compared with the broadcast application. Herbicide losses in the water phase averaged 88 and 97% of the total loss for alachlor and Cyanazine, respectively. Cyanazine was more persistent than alachlor in the soil.
Martin A Locke - One of the best experts on this subject based on the ideXlab platform.
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tillage and cover crop effects on Cyanazine adsorption and desorption kinetics
Soil Science, 1997Co-Authors: Krishna N Reddy, Martin A Locke, Lewis A GastonAbstract:Accumulation of partially decomposed plant residues under no-tillage (NT) and cover crop management systems can affect herbicide fate in the soil. This study evaluated adsorption and desorption of Cyanazine {2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino] -2-methylpropanenitrile} in soils and herbicide-killed Italian ryegrass (Lolium multiflorum Lam.) residues collected from a long-term conventional tillage (CT) and NT cotton field. The four cotton production systems included were CT and NT, each with and without ryegrass as a cover crop. Adsorption was determined by reacting 0.5 g of soil or ryegrass residue with 8 mL of 14 C-Cyanazine solution (five concentrations: 0.13 to 15.68 μmol L -1 ) for 48 h. The Freundlich K f values were higher in NT than in CT soils and higher in soils from ryegrass cover crop than in soils from no cover crop. The K f was higher in ryegrass residue (13.33) than in soils (1.77 to 2.94). The N values for soils (>0.90) and ryegrass residue (>0.95) indicated nearly linear adsorption. Time-course adsorption data analyzed by an equilibrium/kinetic model indicated that adsorption was rapid initially (within 1 h), followed by a slow increase in CT and NT soils from ryegrass plots. In contrast, adsorption achieved equilibrium within 48 h of reaction time in ryegrass residue. Cyanazine adsorption increased with increased decomposition of plant residues. The K f for ryegrass residues sampled at 5 weeks after cotton planting was 17% higher than the residues sampled at 3 weeks before planting. The CaCl 2 -desorbable Cyanazine in two consecutive 24-h cycles ranged from 77 to 88% in soils and from 46 to 47% ofthat adsorbed in ryegrass residues. Two additional 24-h desorptions with methanol removed most of the remaining Cyanazine. Under field conditions, the plant residues on the soil surface in NT and cover crop systems can apparently intercept and temporarily retain Cyanazine.
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supercritical fluid extraction from soil and hplc analysis of Cyanazine herbicide
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Deepa M Goli, Martin A Locke, Robert M ZablotowiczAbstract:Efficacy of supercritical fluid extraction (SFE) for the recovery of Cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile) from soil was investigated. A reverse-ph...
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soil type and tillage effects on sorption of Cyanazine and degradation products
Weed Science, 1997Co-Authors: Krishna N Reddy, Martin A Locke, Robert M ZablotowiczAbstract:Martin A. Locke Robert M. Zablotowicz Southern Weed Science Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Stoneville, MS 38776 The hydrolytic and dealkylation products of Cyanazine have been detected in soils, but the sorption of these products in soil has not been well studied. We examined sorption characteristics of five Cyanazine degradation products in relation to Cyanazine in Norfolk loamy sand, Tunica silty clay, and Dundee silt loam soils. Sorption was determined using a batch equilibrium method. Air-dried soil (3 g) was shaken in 6 ml of solution containing Cyanazine or one of its degradation products for 48 h at 4 C. Five concentrations (2.04 to 54.67 ,umol L-1) of each chemical were evaluated. The Cyanazine Freundlich coefficient (K1) ranged from 0.64 in Norfolk soil to 4.75 in Dundee no-tillage (NT) soil, and was higher in Dundee NT than in Dundee conventional-tillage (CT) soil. The Freundlich exponent (N) values for Cyanazine were less than 0.85 in all soils, indicating nonlinearity of the sorption isotherm. In general, Cyanazine sorption among the soils increased in the order of Norfolk desmethylpropanenitrile Cyanazine > hydroxyacid Cyanazine > desethyl Cyanazine > Cyanazine amide >> chloroacid Cyanazine. The Kf for chloroacid Cyanazine ranged from 0.21 in Norfolk soil to 0.42 in Dundee NT soil. Sorption patterns of five degradation products among the soils were generally similar to that of Cyanazine. Our data indicate that under field conditions, Cyanazine degradation products (especially Cyanazine amide and chloroacid Cyanazine) are more likely to remain in the aqueous phase and thus have a greater potential to move with water compared to Cyanazine.
