Herbicide residues of pre-harvest burndown in cowpea bean (Vigna unguiculata) grains

2020 ◽  
pp. 1-13
Author(s):  
G. Concenço ◽  
R. Vivian ◽  
F. S. Ikeda ◽  
I. R. Pizzutti ◽  
G.M.E. Vela ◽  
...  
Keyword(s):  
Vigna Unguiculata ◽  
Glufosinate Ammonium ◽  
Herbicide Residues ◽  
Brazilian Legislation ◽  
Herbicide Residue ◽  
Residue Levels ◽  
Early Harvest

Abstract Cowpea bean (Vigna unguiculata) is usually submitted to pre-harvest burndown with herbicides aiming to an early harvest. We aimed to quantify the residues of paraquat, diquat, glufosinate-ammonium and glyphosate in cowpea grains subjected to two timings of pre-harvest burndown. Three identical experiments were installed in Dourados (Lat. 22° S), Sinop (Lat. 11° S) and Teresina (Lat. 05° S), Brazil, comprising the pre-harvest burndown of cowpea bean with these herbicides, applied either with 50 or 75% of the pods dry and ready for harvest. As hotter and drier the location as slower the herbicide dissipation. Glyphosate should not be used for pre-harvest burndown of cowpea. Herbicide residues were above the maximum levels stated by the Brazilian legislation when applied with 50% dry pods. Burndown herbicides aiming to speed harvest should be applied with at least 75% dry pods in cowpea to ensure safe herbicide residue levels in grains.

Effect of application timing of glyphosate and saflufenacil as desiccants in dry edible bean (Phaseolus vulgaris L.)

2015 ◽  
Vol 95 (2) ◽  
pp. 369-375 ◽  
Author(s):  
Kristen E. McNaughton ◽  
Robert E. Blackshaw ◽  
Kristine A. Waddell ◽  
Robert H. Gulden ◽  
Peter H. Sikkema ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Crop Yield ◽  
Design Guidelines ◽  
Phaseolus Vulgaris L ◽  
Early Application ◽  
Application Timing ◽  
Herbicide Residue ◽  
Dry Edible Bean ◽  
Residue Levels ◽  
Crop Maturity

McNaughton, K. E., Blackshaw, R. E., Waddell, K. A., Gulden, R. H., Sikkema, P. H. and Gillard, C. L. 2015. Effect of application timing of glyphosate and saflufenacil as desiccants in dry edible bean (Phaseolus vulgaris L.). Can. J. Plant Sci. 95: 369–375. Early application of desiccants in dry edible bean may cause yield reductions and unacceptable herbicide residue levels, resulting in rejection of exported shipments. The effect of application timing of two registered desiccants, glyphosate and saflufenacil, was examined in 12 field trials conducted over a 4-yr period (2009–2012) at Exeter, Ontario, Carman, Manitoba, and Lethbridge, Alberta. Desiccants were applied alone and in combination at five crop maturation stages. When glyphosate or saflufenacil alone, or in combination, was applied at 100% crop maturity, herbicide residue levels were acceptable (less than 2.0 and 0.01 ppm for glyphosate and saflufenacil, respectively) and there was no reduction in yield or hundred seed weight. Glyphosate residues remained below 2.0 ppm when the desiccant was applied alone or with saflufenacil at 75% crop maturity, but crop yield decreased by 16% compared with the untreated control when glyphosate and saflufenacil were combined. Residue levels were unacceptable when glyphosate was applied at 0, 25, and 50% maturity; generally the earlier glyphosate was applied, the greater the residue concentration in the seeds at harvest. Although no application timing resulted in saflufenacil residues above 0.01 ppm, crop yield was reduced when the desiccant was applied at 0, 25, 50, and 75% crop maturity. This information will provide dry bean processors with the necessary information to design guidelines concerning the application timing of glyphosate and saflufenacil so that bean yield and quality remain unaffected and seed residues remain below accepted levels.

Comparative fate of glyphosate and triclopyr herbicides in the forest floor and mineral soil of an Acadian forest regeneration site

2000 ◽  
Vol 30 (11) ◽  
pp. 1808-1816 ◽  
Author(s):  
Dean G Thompson ◽  
Douglas G Pitt ◽  
Teresa M Buscarini ◽  
Bozena Staznik ◽  
David R Thomas
Keyword(s):  
New Brunswick ◽  
Forest Floor ◽  
Forest Regeneration ◽  
Mineral Soil ◽  
Dry Mass ◽  
Litter Fall ◽  
Herbicide Residues ◽  
Residue Levels ◽  
Acadian Forest ◽  
Glyphosate Formulations

Following applications of three different salt formulations of glyphosate (Vision®, Touchdown®, and Mon14420) and an ester formulation of triclopyr (Release®) to an Acadian forest regeneration site in New Brunswick, Canada, the fate and persistence of herbicide residues in the forest floor and underlying mineral soil were investigated. Within 14 days of treatment, maximal residue levels (average 8.3 µg·g dry mass–1) were observed in the forest floor matrix following application of the glyphosate formulations, with higher values (45.7 µg·g dry mass–1) observed for triclopyr. Residue maxima in the underlying mineral soil were, on average, 5.7-fold lower than those in the forest floor. In both matrices, glyphosate residues declined exponentially with time, irrespective of the formulation applied. Among the glyphosate treatments no significant differences (p = 0.16, p = 0.97, for forest floor and mineral soil respectively) were observed in the estimated times to 50% dissipation (DT50). Overall, average DT50 values for glyphosate were estimated as 12 ± 2 and 10 ± 3 days for the forest floor matrix and mineral soil, respectively. Triclopyr residues, particularly in the forest floor, were characterized by a series of transient increases, possibly reflecting temporally varying inputs from dew, rainwash, or litter fall from surrounding treated vegetation. Triclopyr residues also dissipated with time, with approximate DT50 values ranging from 39 to 69 days in the forest floor and mineral soil, respectively.

scholarly journals Moisture Affects Cowpea and Okra Seed Emergence and -Growth at Low Temperatures

HortScience ◽  
1993 ◽  
Vol 28 (8) ◽  
pp. 774-777 ◽  
Author(s):  
Lurline Marsh
Keyword(s):  
Moisture Content ◽  
Field Study ◽  
Vigna Unguiculata ◽  
Low Temperatures ◽  
Dry Weight ◽  
Abelmoschus Esculentus ◽  
High Moisture ◽  
Pod Yield ◽  
Root Dry Weight ◽  
Early Harvest

The effect of moisture content on the emergence and development of `Pinkeye Purple Hull' and MN 13 cowpea [Vigna unguiculata (L.) Walp.] and `Clemson Spineless' okra [Abelmoschus esculentus (L.) Moench] seeds was investigated in a 3-year field study. Moisture content, ranging from 8% to 52%, was obtained by combining seeds, vermiculite, and varying volumes of water in sealed polyethylene packets and incubating them at 22C for 3 days. High moisture promoted the emergence of MN 13, did not significantly affect that of `Pinkeye Purple Hull', and decreased that of `Clemson Spineless' seeds. Percent seed emergence 22 days after planting averaged 17 % for `Clemson Spineless' and 15% for `Pinkeye Purple Hull' seeds, but was 44% for MN 13. High moisture generally promoted early harvest of MN 13 and increased root dry weight but did not affect fresh-pod yield significantly.

Factors in Examining Fate of Herbicides in Soil with Bioassays

Weed Science ◽  
1985 ◽  
Vol 33 (S2) ◽  
pp. 2-6 ◽  
Author(s):  
Arnold P. Appleby
Keyword(s):  
Environmental Factors ◽  
Potential Effect ◽  
Plant Response ◽  
Field Conditions ◽  
Primary Reason ◽  
Herbicide Residues ◽  
Quantitative Measurements ◽  
Factors Influencing ◽  
Herbicide Residue

A primary reason for studying the fate of a herbicide in soil is because of its potential effect, beneficial or detrimental, on plants. Herbicide concentrations in soil often can be accurately analyzed by chemical or physical procedures. But such quantitative measurements sometimes are not well correlated with plant response because of a number of interacting soil and environmental factors. If the question is not “How much herbicide residue is present in the soil?”, but rather “How much potential exists for herbicidal effects on plants?”, then the use of plants as one aspect of studies on herbicide persistence can be valuable. This paper addresses factors influencing the response of plants to herbicide residues under field conditions.

Effect of five desiccants applied alone and in combination with glyphosate in dry edible bean (Phaseolus vulgaris L.)

2015 ◽  
Vol 95 (6) ◽  
pp. 1235-1242 ◽  
Author(s):  
Kristen E. McNaughton ◽  
Robert E. Blackshaw ◽  
Kristine A. Waddell ◽  
Robert H. Gulden ◽  
Peter H. Sikkema ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Crop Yield ◽  
Seed Quality ◽  
Human Consumption ◽  
Phaseolus Vulgaris L ◽  
Dry Bean ◽  
Herbicide Residues ◽  
Dry Edible Bean ◽  
Residue Levels ◽  
Seed Pigmentation

McNaughton, K. E., Blackshaw, R. E., Waddell, K. A., Gulden, R. H., Sikkema, P. H. and Gillard, C. L. 2015. Effect of five desiccants applied alone and in combination with glyphosate in dry edible bean (Phaseolus vulgaris L.). Can. J. Plant Sci. 95: 1235–1242. Application of dry bean desiccants just prior to crop maturity is common practice by Canadian producers. As dry beans are grown for human consumption it is critical that producers pick desiccants that do not affect crop yield, seed quality, or result in desiccant seed residue levels above accepted levels. In this study the efficacy of glyphosate, diquat, glufosinate, carfentrazone, flumioxazin, and saflufenacil as desiccants was examined for navy, cranberry, pinto, and great northern dry bean. Seed herbicide residues were also tested for each of the dry bean classes tested. Navy, cranberry, pinto, and great northern dry bean yields were not impacted by use of the desiccants diquat, carfentrazone, flumioxazin, or saflufenacil when applied at labelled rates and application timings. Additionally, herbicide residues in seed following application remained lower than maximum residue limits (MRL) established by primary Canadian dry bean export partners. Generally, dry bean colour, irrespective of class, was not altered by desiccant use; diquat and flumioxazin caused minor increases in the degree of red and yellow seed pigmentation for cranberry bean only. Although colour differences were noted using a Chroma meter the differences were slight and would not likely be of economic importance. Application of glyphosate did not affect crop yield, and seed residue levels were below MRLs for navy, pinto, and great northern bean. However, seed glyphosate residue levels were above the MRL for cranberry bean when glyphosate was applied alone or tankmixed with carfentrazone, flumioxazin, or saflufenacil. Seed residue levels were also above listed MRLs for some export countries when glufosinate was applied to navy, cranberry, and pinto bean, although crop yield and seed quality remained unaffected. These findings suggest that growers and contractors should avoid using glufosinate as a dry bean desiccant at least for some markets and that care should be taken when selecting glyphosate as a desiccant, especially for cranberry bean. Across all market classes desiccation progress of bean leaf, stem, and pod tissue was slowest when glyphosate and carfentrazone were used.

Responses of spring-seeded cover crop roots by herbicide residues and short-term influence in soil aggregate stability and N cycling

2018 ◽  
Vol 98 (5) ◽  
pp. 990-1004 ◽  
Author(s):  
María A. Rojas ◽  
Laura L. Van Eerd ◽  
Ivan P. O’Halloran ◽  
Peter H. Sikkema ◽  
Darren E. Robinson
Keyword(s):  
Root Growth ◽  
Spring Wheat ◽  
Cover Crop ◽  
Root Biomass ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
N Content ◽  
Herbicide Residues ◽  
Herbicide Residue ◽  
Sorghum Sudangrass

Cover crop (CC) prevalence between cash crop systems is contributing to long-term sustainable crop production systems. However, herbicide residue impact on CC root growth and its subsequent effect on soil aggregation and fertility are unknown. An untreated control plus preemergence (PRE) application of saflufenacil (at 67 and 134 g a.i. ha−1)/dimethenamid-P (at 668 and 1336 g a.i. ha−1) as well as S-metolachlor (at 1600 and 3200 g a.i. ha−1)/atrazine (at 1280 and 2560 g a.i. ha−1) + mesotrione at 140 and 280 g a.i. ha−1to sweet corn (Zea mays L. var. rugosa Bonaf.) and imazethapyr (100 and 200 g a.i. ha−1) to pea (Pisum sativum L.) were made in spring 2011 and spring 2012. One year later, ryegrass (Lolium multiflorum Lam.), buckwheat (Fagopyrum esculentum Moench), sorghum–sudangrass [Sorghum bicolor (L.) Moench × S. bicolor var. sudanese (L.)], and spring wheat (Triticum aestivum L.) were seeded. Root biomass and N content, wet aggregate stability (WAS), and aggregate size plus soil mineral N (SMN) were determined. Buckwheat root biomass declined in all herbicide treatments but root N declined in imazethapyr and S-metolachlor/atrazine + mesotrione at the 2× and 1× rates, respectively. Ryegrass root biomass decreased in S-metolachlor/atrazine + mesotrione but root N content declined only at the 2× rate. Sorghum–sudangrass and spring wheat roots decreased in imazethapyr and S-metolachlor/atrazine + mesotrione at the 2× rate, respectively. Despite the impact of herbicide residues on roots, differences in aggregate size, WAS, and SMN were not detected. Findings from this study add knowledge on herbicide residue effect on CC root growth and provide useful CC seeding guidelines for growers.

Soil Persistence of Trifluralin, Benefin, and Nitralin

Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 211-214 ◽  
Author(s):  
J. H. Miller ◽  
P. E. Keeley ◽  
C. H. Carter ◽  
R. J. Thullen
Keyword(s):  
Gossypium Hirsutum ◽  
Soil Samples ◽  
Herbicide Residues ◽  
Soil Persistence ◽  
Herbicide Residue ◽  
Repeated Applications

Trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline], and benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine) were applied at two rates for five consecutive years (1966 through 1970) as soil-incorporated treatments to cotton (Gossypium hirsutumL. ‘Acala SJ-1’) before the preplanting irrigation. Repeated applications did not significantly affect stand or yield of cotton. Soil samples taken to depth of 120 cm showed that herbicide residues were confined to the tilled zone of soil (upper 30 cm), and about 80% of the residue was in the upper 15 cm of soil. The amount of herbicide residue found annually in the upper 15 cm of soil varied with herbicide and with season. Residues 15 months after final application had been reduced markedly, but were still sufficient to injure sensitive crops. Residues at 30 months had been reduced to innocuous amounts.

Effect of Soil and Climate on Herbicide Dissipation

Weed Science ◽  
1969 ◽  
Vol 17 (2) ◽  
pp. 241-245 ◽  
Author(s):  
O. C. Burnside ◽  
C. R. Fenster ◽  
G. A. Wicks ◽  
J. V. Drew
Keyword(s):  
Soil Texture ◽  
Soil Profile ◽  
Sandy Loam ◽  
Silty Clay ◽  
Silt Loam ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Fine Sandy Loam ◽  
Herbicide Residues ◽  
Herbicide Residue

The persistence of five herbicides in six soils across Nebraska can be ranked from greatest to least as follows: 5-bromo-3-isopropyl-6-methyluracil (isocil) at 5 and 25 1b/A, 2-chloro-4,6-bis-(isopropylamino)-s-triazine (propazine) at 3 and 9 1b/A, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) at 3 and 9 1b/A, trichlorobenzyl chloride (hereinafter referred to as TCBC) at 7 and 49 1b/A, and 3-(3,4-dichlorophenyl)-1-methoxyl-1-methylurea (linuron) at 3 and 9 1b/A. Soil texture differences (sandy loam, very fine sandy loam, silt loam, and silty clay loam) had a greater influence on herbicide residue carryover than did climatic differences across Nebraska during 1962 to 1968. Soil carryover of herbicide residues was greater in coarse rather than fine-textured soils and in the drier regions of western than in eastern Nebraska. Leaching of herbicides into the soil profile was an avenue of herbicide dissipation.

scholarly journals Contaminants in aged pesticide grade dichloromethane interfering in herbicide residue analysis and a method for their removal

1969 ◽  
Vol 75 (4) ◽  
pp. 329-344
Author(s):  
James A. Singmaster, III
Keyword(s):  
Literature Review ◽  
Sodium Carbonate ◽  
Sodium Carbonate Solution ◽  
Residue Analysis ◽  
Soil Samples ◽  
Carbonate Solution ◽  
Careful Evaluation ◽  
Herbicide Residues ◽  
Herbicide Residue ◽  
Trace Organic

A procedure developed for analyses of persistant herbicide residues in soil samples was found to give poor recoveries and extra peaks in gas chromatograms from fortified samples after initial studies had shown acceptable recoveries and no extra peaks. The problem was also found in a "solvent only" sample fortified with prometryn and metribuzin. These two herbicides were then shown to be altered by merely mixing with an aged pesticide grade dichloromethane being used for extractions. Contaminant(s), apparently formed in aged solvent to cause the extra peaks, can be removed by extracting dichloromethane, immediately before it is used, with 10% sodium carbonate solution. Chromatograms are presented to illustrate the effects of the contaminant(s) and their removal by such extraction with recoveries of 0 to 50-percent raised to above 75 percent for the two herbicides when clean solvent is used for extractions. With one of the oldest bottles of dichloromethane in stock for 8 years, the odor of dichlormethane was masked by a pungent acidic odor, which was removed by the sodium carbonate extraction. The contaminant(s) may arise with time in the pesticide grade solvent because of lack or degradation of an additive present in some other grades of this solvent. A literature review for data to explain the contaminants revealed numerous inhibitors, stabilizers and preservatives added at varying levels in many grades of dichloromethane but little information available on how these additives function, or whether they or their altered products may interfere in analyses. The data herein reinforce the report that careful evaluation of dichloromethane for additives or degradation must be made before using this solvent for extractions in trace organic analyses.

Spray damage and residue levels in tobacco treated with various concentrations of 2,4-D at different stages of growth

1973 ◽  
Vol 13 (62) ◽  
pp. 328 ◽  
Author(s):  
KH Fung ◽  
RS Belcher ◽  
DM Whitfield
Keyword(s):  
Irrigation Water ◽  
Chemical Method ◽  
Accurate Determination ◽  
Obvious Effect ◽  
Herbicide Residues ◽  
Stages Of Growth ◽  
Residue Levels ◽  
High Concentrations ◽  
Considerable Damage

The effects of 2,4-D on tobacco at various stages of growth were investigated. Symptoms of damage were recorded and illustrated. The herbicide had no obvious effect on mature plants at any concentration used, but it caused considerable damage to plants at other phases of growth at moderate and high concentrations. A chemical method was developed for accurate determination of 2,4-D residues in tobacco. Investigation of the herbicide residues in irrigation water was necessary following the discovery of 2,4-D residues in control plants.

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