Enhanced Atrazine Degradation: Evidence for Reduced Residual Weed Control and a Method for Identifying Adapted Soils and Predicting Herbicide Persistence

Weed Science ◽  
2009 ◽  
Vol 57 (4) ◽  
pp. 427-434 ◽  
Author(s):  
L. Jason Krutz ◽  
Ian C. Burke ◽  
Krishna N. Reddy ◽  
Robert M. Zablotowicz ◽  
Andrew J. Price
Keyword(s):  
Weed Control ◽  
Diagnostic Test ◽  
Residual Activity ◽  
Field Conditions ◽  
Published Data ◽  
Planting Dates ◽  
Prickly Sida ◽  
Persistence Model ◽  
Enhanced Degradation ◽  
Atrazine Degradation

Soilborne bacteria with novel metabolic abilities have been linked with enhanced atrazine degradation and complaints of reduced residual weed control in soils with ans-triazine use history. However, no field study has verified that enhanced degradation reduces atrazine's residual weed control. The objectives of this study were to (1) compare atrazine persistence and prickly sida density ins-triazine-adapted and nonadapted field sites at two planting dates; (2) utilize original and published data to construct a diagnostic test for identifyings-triazine-adapted soils; and (3) develop and validate ans-triazine persistence model based on data generated from the diagnostic test, i.e., mineralization of ring-labeled14C-s-triazine. Atrazine half-life values ins-triazine-adapted soil were at least 1.4-fold lower than nonadapted soil and 5-fold lower than historic estimates (60 d). At both planting dates atrazine reduced prickly sida density in the nonadapted soils (P ≤ 0.0091). Conversely, in thes-triazine-adapted soil, prickly sida density was not different between no atrazine PRE and atrazine PRE at the March 15 planting date (P = 0.1397). A lack of significance in this contrast signifies that enhanced degradation can reduce atrazine's residual control of sensitive weed species. Analyses of published data indicate that cumulative mineralization in excess of 50% of C0after 30 d of incubation is diagnostic for enhanceds-triazine degradation. Ans-triazine persistence model was developed and validated; model predictions for atrazine persistence under field conditions were within the 95% confidence intervals of observed values. Results indicate that enhanced atrazine degradation can decrease the herbicide's persistence and residual activity; however, coupling the diagnostic test with the persistence model could enable weed scientists to identifys-triazine-adapted soils, predict herbicide persistence under field conditions, and implement alternative weed control strategies in affected areas if warranted.

Field Dissipation of Atrazine and Metribuzin in Organic Soils in Florida

2014 ◽  
Vol 28 (4) ◽  
pp. 578-586 ◽  
Author(s):  
Dennis C. Odero ◽  
Dale L. Shaner
Keyword(s):  
Weed Control ◽  
Residual Activity ◽  
Field Studies ◽  
South Florida ◽  
Field Conditions ◽  
Agricultural Area ◽  
Organic Soils ◽  
Bioavailable Fraction ◽  
Rate Of Dissipation ◽  
Atrazine Degradation

Sugarcane growers have observed reduced residual activity of atrazine on organic soils in the Everglades Agricultural Area (EAA) of south Florida. Field studies were conducted between 2011 and 2012 to determine the rate of dissipation of atrazine at 2.24, 4.48, and 8.96 kg ha−1and metribuzin at 0.56, 1.12, and 2.24 kg ha−1in the top 10 cm of soil in sugarcane fields in the EAA. The bioavailable fraction of atrazine dissipated more rapidly than the total amount of atrazine in the soil. Half-lives of the total and bioavailable fraction of atrazine ranged between 3.9 to 12.1 d and 1.0 to 7.5 d, respectively. Metribuzin dissipated much more slowly than atrazine on organic soils. Similarly, dissipation of the bioavailable fraction of metribuzin was more rapid than was the dissipation of the total amount of metribuzin in the soil. Half-lives of the total and bioavailable fraction of metribuzin ranged between 16.2 and 24.8 d and 6.0 and 14.3 d, respectively. These results indicate that enhanced atrazine degradation occurs on organic soils under field conditions in the EAA, resulting in shorter residual atrazine activity. This implies that metribuzin is a better option for weed control in sugarcane grown on organic soils of the EAA exhibiting enhanced atrazine degradation.

scholarly journals Enhanced degradation of atrazine under field conditions correlates with a loss of weed control in the glasshouse

2006 ◽  
Vol 63 (1) ◽  
pp. 23-31 ◽  
Author(s):  
L Jason Krutz ◽  
Robert M Zablotowicz ◽  
Krishna N Reddy ◽  
Clifford H Koger III ◽  
Mark A Weaver
Keyword(s):  
Weed Control ◽  
Field Conditions ◽  
Enhanced Degradation

MON-37500 for Weed Control and Alfalfa Seed Production

2004 ◽  
Vol 18 (3) ◽  
pp. 810-815 ◽  
Author(s):  
Clayton D. Myhre ◽  
Heather A. Loeppky ◽  
F. Craig Stevenson
Keyword(s):  
Weed Control ◽  
Seed Yield ◽  
Organic Matter Content ◽  
Residual Activity ◽  
Matter Content ◽  
Management Tool ◽  
Early Season ◽  
Perennial Weed ◽  
Herbicide Treatments ◽  
Alfalfa Seed

Alfalfa seed producers have a limited number of herbicide options to manage weed problems. MON-37500 (proposed name sulfosulfuron) is a sulfonylurea herbicide that controls dandelion and quackgrass, two common weeds in alfalfa fields. A study was conducted in two alfalfa fields at Valparaiso and Carrot River, Saskatchewan, Canada, from 1999 to 2001 to evaluate perennial weed control and alfalfa production responses with 0.5×, 1×, and 1.5× label-recommended rates of MON-37500 and also 2,4-DB and hexazinone. MON-37500 applied at the 1× and 1.5× rates at both locations reduced mid-May alfalfa vigor from 100% to between 80 and 90% and increased early-season control of dandelion and quackgrass by about 10 to 40 percentage units, when compared with other herbicide treatments. Improved weed control with 1× and 1.5× MON-37500 rates was sustained into mid-June only at Carrot River and was completely eliminated (100% vigor and 0% weed control), or almost so, by mid-July. MON-37500 did not control Canada thistle. Improved early-season weed control with the 1× MON-37500 rate apparently compensated for the loss of alfalfa vigor at Valparaiso, thus resulting in 27% (57 kg/ha) greater seed yield than with the other herbicide treatments. At Carrot River, hexazinone generally provided levels of weed control similar to MON-37500 but did not injure alfalfa. Consequently, alfalfa yields were highest and the proportion of dead (decaying) seed was least with this treatment. The 0.5× MON-37500 rate often resulted in inferior weed control relative to the 1× and 1.5× rates and never was among the herbicide treatments providing the greatest seed yield. Managing the residual activity of MON-37500 and its negative effect on alfalfa growth, especially at locations with soils having coarse texture and low organic matter content, represents the greatest challenge in making MON-37500 a reliable weed management tool for alfalfa seed producers.

Evaluation of Imazethapyr for Weed Control in Leafy Vegetable Crops

1996 ◽  
Vol 10 (2) ◽  
pp. 253-257 ◽  
Author(s):  
Joan A. Dusky ◽  
William M. Stall
Keyword(s):  
Regression Analysis ◽  
Weed Control ◽  
Crop Yield ◽  
Relative Sensitivity ◽  
Leafy Vegetable ◽  
Field Conditions ◽  
Vegetable Crops ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Common Purslane

Imazethapyr was evaluated PRE and POST in five lettuce types and chicory under Florida field conditions. The relative sensitivity of leafy crop vigor (most sensitive to most tolerant) to imazethapyr PRE, based on 20% inhibition determined using regression analysis, was as follows: Boston > bibb > crisphead > romaine > leaf > escarole > endive. Leafy crop injury increased as the rate of imazethapyr applied POST increased, with all leafy crops responding in a similar manner. Surfactant addition increased imazethapyr phytotoxicity. Imazethapyr PRE treatments at 0.067 kg ai/ha provided greater than 80% control of livid amaranth, common purslane, flatsedge, and common lambsquarters. Imazethapyr POST at 0.067 kg/ha, with surfactant provided control greater than 85% of all weed species. Greater than 85% spiny amaranth control was provided by imazethapyr POST at 0.017 kg/ha. Use of surfactant with imazethapyr did not improve spiny amaranth control over imazethapyr with no surfactant. POST treatments did not decrease leafy crop yield compared with the hand-weeded check. Imazethapyr applied PRE reduced crop yield compared to the POST treatments and the hand-weeded control.

A Comparison of Symmetrical and Asymmetrical Triazine Herbicides for Enhanced Degradation in Three Midwestern Soils

Weed Science ◽  
2018 ◽  
Vol 66 (5) ◽  
pp. 673-679
Author(s):  
Ethan T. Parker ◽  
Micheal D. K. Owen ◽  
Mark L. Bernards ◽  
William S. Curran ◽  
Lawrence E. Steckel ◽  
...  
Keyword(s):  
Weed Control ◽  
Herbicide Resistance ◽  
Microbial Degradation ◽  
Scientific Literature ◽  
Corn Belt ◽  
Triazine Herbicides ◽  
History Of ◽  
Enhanced Degradation

AbstractThe triazines are one of the most widely used herbicide classes ever developed and are critical for managing weed populations that have developed herbicide resistance. These herbicides are traditionally valued for their residual weed control in more than 50 crops. Scientific literature suggests that atrazine, and perhaps others-triazines, may no longer remain persistent in soils due to enhanced microbial degradation. Experiments examined the rate of degradation of atrazine and two other triazine herbicides, simazine and metribuzin, in both atrazine-adapted and non-history Corn Belt soils, with similar soils being used from each state as a comparison of potential triazine degradation. In three soils with no history of atrazine use, thet1/2of atrazine was at least four times greater than in three soils with a history of atrazine use. Simazine degradation in the same three sets of soils was 2.4 to 15 times more rapid in history soils than non-history soils. Metribuzin in history soils degraded at 0.6, 0.9, and 1.9 times the rate seen in the same three non-history soils. These results indicate enhanced degradation of the symmetrical triazine simazine, but not of the asymmetrical triazine metribuzin.

scholarly journals Globe fringerush (Fimbristylis miliacea) cross resistance to als-inhibitor herbicides under field conditions in irrigated rice in the south of Brazil

2013 ◽  
Vol 31 (4) ◽  
pp. 893-902 ◽  
Author(s):  
C.E. Schaedler ◽  
J.A. Noldin ◽  
D.S. Eberhardt ◽  
D. Agostinetto ◽  
N.R. Burgos
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Rice Fields ◽  
Field Conditions ◽  
Cross Resistance ◽  
Herbicide Application ◽  
The South ◽  
Santa Catarina ◽  
Irrigated Rice ◽  
South Of Brazil

ALS-inhibiting herbicides usually provide adequate weed control in irrigated rice fields. After consecutive years of use, the Cyperaceae species, globe fringerush (Fimbristylis miliacea) began to show resistance to ALS (acetolactate synthase) inhibitors. Globe fringerush is one of the most problematic herbicide-resistant weeds in irrigated rice in the state of Santa Catarina in the South of Brazil. The objective of this research was to examine cross resistance of globe fringerush to ALS inhibitors, under field conditions. Two experiments were conducted in a rice field naturally infested with ALS-resistant globe fringerush in Santa Catarina, in the 2008/09 and 2009/10 cropping seasons. The experimental units were arranged in randomized complete block design, with five replicates, consisting of two factors (herbicide and dose) in a 4 x 5 factorial arrangement. ALS herbicides included bispyribac-sodium, ethoxysulfuron, pyrazosulfuron-ethyl and penoxsulam. Six-leaf globe fringerush was sprayed with herbicide doses of 0, 0.5, 1, 2 and 4X the recommended doses in a spray volume of 200 L ha-1. The number of rice culm, filled and sterile grains, plant height, dry shoot biomass and grain yield were recorded. Globe fringerush control was evaluated 28 and 70 days after herbicide application (DAA); shoots were harvested at 13 weeks after herbicide application and dry weight recorded. Competition with globe fringerush reduced the number of culm and rice grain yield. The globe fringerush biotype in this field was resistant to all ALS herbicides tested. Penoxsulam had the highest level of activity among treatments at 28 and 70 DAA, but the control level was only 50% and 42%, respectively, in the second year of assessment. This was not enough to prevent rice yield loss. Alternative herbicides and weed control strategies are necessary to avoid yield losses in rice fields infested with ALS-resistant biotypes of globe fringerush.

scholarly journals Residual Activity of ACCase-Inhibiting Herbicides on Monocot Crops and Weeds

2018 ◽  
Vol 32 (4) ◽  
pp. 364-370 ◽  
Author(s):  
Zachary D. Lancaster ◽  
Jason K. Norsworthy ◽  
Robert C. Scott
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Residual Activity ◽  
Sprinkler Irrigation ◽  
Grain Sorghum ◽  
Rainfall Event ◽  
Rice Grain ◽  
Acetyl Coa Carboxylase ◽  
Herbicide Treatments ◽  
Residual Control

AbstractField experiments were conducted in 2014 and 2015 in Fayetteville, Arkansas, to evaluate the residual activity of acetyl-CoA carboxylase (ACCase)–inhibiting herbicides for monocot crop injury and weed control. Conventional rice, quizalofop-resistant rice, grain sorghum, and corn crops were evaluated for tolerance to soil applications of six herbicides (quizalofop at 80 and 160 g ai ha–1, clethodim at 68 and 136 g ai ha–1, fenoxaprop at 122 g ai ha–1, cyhalofop at 313 g ai ha–1, fluazifop at 210 and 420 g ai ha–1, and sethoxydim at 140 and 280 g ai ha–1). Overhead sprinkler irrigation of 1.3 cm was applied immediately after treatment to half of the plots, and the crops planted into the treated plots at 0, 7, and 14 d after herbicide treatment. In 2014, injury from herbicide treatments increased with activation for all crops evaluated, except for quizalofop-resistant rice. At 14 d after treatment (DAT) in 2014, corn and grain sorghum were injured 19% and 20%, respectively, from the higher rate of sethoxydim with irrigation activation averaged over plant-back dates. Conventional rice was injured 13% by the higher rate of fluazifop in 2014. Quizalofop-resistant rice was injured no more than 4% by any of the graminicides evaluated in either year. In 2015, a rainfall event occurred within 24 h of initiating the experiment; thus, there were no differences between activation via irrigation or by rainfall. However, as in 2014, grain sorghum and corn were injured 16% and 13%, respectively, by the higher rate of sethoxydim, averaged over plant-back dates. All herbicides provided little residual control of grass weeds, mainly broadleaf signalgrass and barnyardgrass. These findings indicate the need to continue allowing a plant-back interval to rice following a graminicide application, unless quizalofop-resistant rice is to be planted. The plant-back interval will vary by graminicide and the amount of moisture received following the application.

scholarly journals Influence of prometryne (Gesagard 50) on pectic substances and calcium contents in the above-ground parts of the field pea (Pisum arvense L.)

2013 ◽  
Vol 37 (2) ◽  
pp. 169-177
Author(s):  
Renata Ciszewska ◽  
Anna Sykut ◽  
Jadwiga Szynal
Keyword(s):  
Weed Control ◽  
Growth And Development ◽  
Plant Cells ◽  
Calcium Content ◽  
Field Pea ◽  
Field Conditions ◽  
Total Calcium ◽  
Pisum Arvense ◽  
Pectic Substances

The content of pectic substances (soluble pectins and fraction of protopectins) and calcium (free and bound) in field pea (<i>Pisum arvense</i> L.) leaves and stems during budding and flowering in field conditions was determined. In this experiment Gesagard 50 (S. A. - 50% prometryne) was applied to the soil in a weed control dose (2 kg/ha). An insignificant decrease of the content of protopectins and total pectins in leaves of the investigated plants (about 3-7% in relation to control) after application of this herbicide was noted, hut analogous changes in all years of the experiment were not observed in field pea stems. The influence of prometryne on the distribution of pectic substances in above-ground parts of the field pea and the degree of protopectins methylation were not corroborated. Neither did the total calcium content in the investigated plants change after application ofthe herbicide. These results show that application of Gesagard 50 in a weed control dose (2 kg/ha) in cultivation of field pea does not evoke changes in the investigated components content which might be of significance in the growth and development of plant cells and immunity reactions of plants.

Enhanced Soil Degradation of Butylate and EPTC in Nebraska Fields

1989 ◽  
Vol 3 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Fred W. Roeth ◽  
Robert G. Wilson ◽  
Alex R. Martin ◽  
Patrick J. Shea
Keyword(s):  
Weed Control ◽  
Soil Degradation ◽  
Central Field ◽  
North Central ◽  
Herbicide Degradation ◽  
Accelerated Degradation ◽  
South Central ◽  
Field Soils ◽  
Enhanced Degradation

A survey to determine the frequency and weed control impact of enhanced degradation of butylate or EPTC in field soils receiving repeat applications of these herbicides was conducted in a sugarbeet and three corn growing areas of Nebraska. All seven of the sugarbeet field soils exhibited enhanced EPTC degradation. In the corn areas, none of the 13 north central and southeast field soils displayed accelerated degradation; however, 10 of the 16 south central field soils did. In south central Nebraska, 60% and 45% of the surveyed growers were dissatisfied with weed control from butylate or EPTC in 1983 and 1984, respectively, compared to 24% and none in other survey areas. Enhanced herbicide degradation and the presence of shattercane were the main reasons for the disparity among areas.

Postemergence AC 263,222 Systems for Weed Control in Peanut (Arachis hypogaea)

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 615-621 ◽  
Author(s):  
John W. Wilcut ◽  
John S. Richburg ◽  
Gerald L. Wiley ◽  
F. Robert Walls
Keyword(s):  
North Carolina ◽  
Weed Control ◽  
Arachis Hypogaea ◽  
Field Studies ◽  
Common Lambsquarters ◽  
Yellow Nutsedge ◽  
Crop Injury ◽  
Ac 263,222 ◽  
Prickly Sida

Field studies in 1990 and 1991 at six locations in Georgia and one location in North Carolina evaluated AC 263,222 for weed control, peanut tolerance, and yield. AC 263,222 applied early postemergence at 71 g ai ha−1controlled bristly starbur, coffee senna, common lambsquarters,Ipomoeaspecies, prickly sida, sicklepod, smallflower morningglory, and yellow nutsedge at least 91%. AC 263,222 controlled common cocklebur 77% and Florida beggarweed from 47 to 100%. Crop injury was 4% for AC 263,222 applied once and 12% or less from two applications. Mixtures of bentazon with AC 263,222 did not improve control compared to AC 263,222 alone. Imazethapyr did not improve control of AC 263,222 systems. In several locations, bentazon reduced control of Florida beggarweed with AC 263,222 when applied in a mixture compared to AC 263,222 alone. Weed control from the standard of paraquat plus bentazon applied early postemergence followed by paraquat, bentazon plus 2,4-DB applied POST did not provide the level or spectrum of weed control as AC 263,222 systems.

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