Persistence and Bioavailability of Aminocyclopyrachlor and Clopyralid in Turfgrass Clippings: Recycling Clippings for Additional Weed Control

Weed Science ◽  
2014 ◽  
Vol 62 (3) ◽  
pp. 493-500 ◽  
Author(s):  
Dustin F. Lewis ◽  
Matthew D. Jeffries ◽  
Travis W. Gannon ◽  
Robert J. Richardson ◽  
Fred H. Yelverton
Keyword(s):  
Weed Control ◽  
White Clover ◽  
Tall Fescue ◽  
Golf Courses ◽  
Synthetic Auxin ◽  
Normalized Difference Vegetative Index ◽  
Athletic Fields ◽  
Previously Treated ◽  
Auxin Herbicides ◽  
Regression Pattern

The synthetic auxin herbicides, aminocyclopyrachlor and clopyralid, control dicotyledonous weeds in turf. Clippings of turfgrass treated with synthetic auxin herbicides have injured off-target plants exposed to herbicide-laden clippings. Labels of aminocyclopyrachlor and clopyralid recommend that clippings of treated turfgrass remain on the turf following a mowing event. Alternative uses for synthetic auxin-treated turfgrass clippings are needed because large quantities of clippings on the turf surface interfere with the functionality and aesthetics of golf courses, athletic fields, and residential turf. A white clover bioassay was conducted to determine the persistence and bioavailability of aminocyclopyrachlor and clopyralid in turfgrass clippings. Aminocyclopyrachlor and clopyralid were each applied at 79 g ae ha−1 to mature tall fescue at 56, 28, 14, 7, 3.5, and 1.75 d before clipping collection (DBCC). Clippings were collected, and the treated clippings were recycled onto adjacent white clover plots to determine herbicidal persistence and potential for additional weed control. Clippings of tall fescue treated with aminocyclopyrachlor produced a nonlinear regression pattern of response on white clover. Calculated values for 50% response (GR50) for visual control, for normalized difference vegetative index (NDVI), and for reduction in harvested biomass were 20.5, 17.3, and 18.7 DBCC, respectively, 8 wk after clippings were applied. Clippings of tall fescue treated with clopyralid did not demonstrate a significant pattern for white clover control, presumably because clopyralid was applied at a less-than-label rate. The persistence and bioavailability of synthetic auxin herbicides in clippings harvested from previously treated turfgrass creates the opportunity to recycle clippings for additional weed control.

Effect of Ambient Moisture on Aminocyclopyrachlor Efficacy

2013 ◽  
Vol 27 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Dustin F. Lewis ◽  
Matthew D. Jeffries ◽  
Harry J. Strek ◽  
Robert J. Richardson ◽  
Fred H. Yelverton
Keyword(s):  
Shallow Water ◽  
Weed Control ◽  
Golf Courses ◽  
Synthetic Auxin ◽  
Normalized Difference Vegetative Index ◽  
Herbicide Treatments ◽  
Turfgrass Quality

Aminocyclopyrachlor (AMCP) is a newly developed synthetic auxin herbicide for broadleaf weed control in turfgrass systems. AMCP has been observed to undergo rapid photodecomposition in shallow water when exposed to sunlight. Most herbicide applications on golf courses occur during the morning when dew is still present on the turfgrass canopy. These conditions could result in efficacy loss if photolysis occurred while AMCP is suspended in dew droplets. Research was conducted to determine the effect of ambient moisture on AMCP efficacy. AMCP (79 and 105 g ae ha−1), aminopyralid (280 g ae ha−1), and two AMCP granular formulations (84 g ha−1) were applied to dew-covered (WET) and dew-excluded (DRY) ‘Tifway' bermudagrass plots. Herbicide treatments applied to WET plots had greater visually rated bermudagrass injury than respective treatments applied to DRY plots at 7 and 21 d after treatment (DAT), with the exception of aminopyralid at 21 DAT. Normalized difference vegetative index on turfgrass quality complemented visual ratings, indicating greater turfgrass quality reductions when applied to WET vs. DRY plots. These results indicate that AMCP applications made to dew-covered turfgrass can increase herbicidal efficacy, and no significant losses due to photodegradation were observed.

Simulated controlled-release mesotrione for turfgrass tolerance and weed control

2021 ◽  
pp. 1-25
Author(s):  
Matthew J. R. Goddard ◽  
Clebson G. Gonçalves ◽  
Shawn D. Askew
Keyword(s):  
Controlled Release ◽  
Weed Control ◽  
White Clover ◽  
Tall Fescue ◽  
Standard Treatment ◽  
Creeping Bentgrass ◽  
Control Efficacy ◽  
Stepwise Change

Abstract Mesotrione typically requires multiple applications to control emerged weeds in turfgrass. Since it is absorbed by both foliage and roots, a controlled-release (CR) formulation could eliminate the need for multiple applications. Research was conducted evaluate simulated-release scenarios that mimic a potential CR mesotrione formulation. A soluble concentrate formulation of mesotrione was titrated to produce a stepwise change in mesotrione rates, which were applied daily to mimic predetermined release scenarios over a three-wk period. CR scenarios were compared to a broadcast treatment of mesotrione at 280 g ai ha-1 applied twice at three-wk intervals, and a nontreated. Mesotrione applied in three temporal release scenarios controlled creeping bentgrass, goosegrass, nimblewill, smooth crabgrass, and white clover equivalent to the standard sprayed mesotrione treatment in every comparison. However, each CR scenario injured tall fescue 2 to 7 times more than the standard treatment. Soil- and foliar-initiated repeat treatments were equivalent in most comparisons. Data indicates that mesotrione applied in a temporal range to simulate controlled release scenarios can deliver desired weed control efficacy comparable to sequential broadcast applications. More research is needed to elucidate proper timings and release scenarios to minimize turfgrass injury.

Weed Control with Halauxifen-Methyl Applied Alone and in Mixtures with 2,4-D, Dicamba, and Glyphosate

2018 ◽  
Vol 32 (5) ◽  
pp. 597-602 ◽  
Author(s):  
Marcelo Zimmer ◽  
Bryan G. Young ◽  
William G. Johnson
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Common Ragweed ◽  
Synthetic Auxin ◽  
Redroot Pigweed ◽  
Giant Ragweed ◽  
Auxin Herbicides ◽  
Control Spectrum

AbstractSynthetic auxin herbicides such as 2,4-D and dicamba are often utilized to control broadleaf weeds in preplant burndown applications to soybean. Halauxifen-methyl is a new synthetic auxin herbicide for broadleaf weed control in preplant burndown applications to corn, cotton, and soybean at low use rates (5 g ae ha–1). Field experiments were conducted to evaluate efficacy and weed control spectrum of halauxifen-methyl applied alone and in mixtures with 2,4-D (560 g ae ha–1), dicamba (280 g ae ha–1), and glyphosate (560 g ae ha–1). Glyphosate-resistant (GR) horseweed was controlled with halauxifen-methyl applied alone (90% control) and in mixtures (87% to 97% control) 35 d after treatment (DAT). Common ragweed was controlled 93% with halauxifen-methyl applied alone and 91% to 97% in mixtures 35 DAT. Halauxifen-methyl applied alone resulted in poor giant ragweed control 21 DAT (73% control); however, mixtures of halauxifen-methyl with 2,4-D, dicamba, or glyphosate controlled giant ragweed (86% to 98% control). Halauxifen-methyl alone resulted in poor redroot pigweed control (62% control) 21 DAT; however, mixtures of halauxifen-methyl with dicamba, 2,4-D, or glyphosate controlled redroot pigweed (89% to 98% control). Halauxifen-methyl controls GR horseweed and common ragweed applied alone and in mixtures with other synthetic auxin herbicides and glyphosate. Furthermore, mixing 2,4-D or dicamba with halauxifen-methyl can increase the weed control spectrum in preplant burndown applications.

Aminocyclopyrachlor Enhances Fenoxaprop Efficacy for Smooth Crabgrass Control

2011 ◽  
Vol 25 (3) ◽  
pp. 506-510 ◽  
Author(s):  
Patrick E. McCullough ◽  
Stephen E. Hart ◽  
James T. Brosnan ◽  
Gregory K. Breeden
Keyword(s):  
New Jersey ◽  
Weed Control ◽  
White Clover ◽  
Tall Fescue ◽  
Field Experiments ◽  
Treatment Results

Fenoxaprop effectively controls crabgrass in tall fescue turf, but antagonism with growth-regulating herbicides reduces potential to apply fenoxaprop in combination with many herbicides registered for broadleaf weed control. Aminocyclopyrachlor is a new broadleaf weed control herbicide that has not been evaluated in combination with fenoxaprop. Field experiments were conducted in Georgia, New Jersey, and Tennessee to investigate tank mixtures of fenoxaprop with aminocyclopyrachlor for smooth crabgrass and white clover control. Fenoxaprop alone exhibited substantial activity on smooth crabgrass but control was greater with fenoxaprop + aminocyclopyrachlor treatments. By 4 and 6 wk after treatment (WAT), approximately 22 and 44% less fenoxaprop was required to achieve 80% smooth crabgrass control when the herbicide was tank-mixed with aminocyclopyrachlor at 52.5 and 79 g ai ha−1, respectively. Fenoxaprop did not reduce white clover control with aminocyclopyrachlor because 97% control was achieved by 4 WAT for all aminocyclopyrachlor + fenoxaprop treatments. Tall fescue was not injured by any treatment. Results suggest aminocyclopyrachlor enhances fenoxaprop efficacy for smooth crabgrass control in tall fescue.

Impact of Herbicides and Application Timing on Weed Control, Yield, and Nutritive Value of Tall Fescue Pastures and Hayfields

2010 ◽  
Vol 24 (4) ◽  
pp. 515-522 ◽  
Author(s):  
Kristin K. Payne ◽  
Byron B. Sleugh ◽  
Kevin W. Bradley
Keyword(s):  
Weed Control ◽  
White Clover ◽  
Tall Fescue ◽  
Field Experiments ◽  
Stem Density ◽  
Total Biomass ◽  
Common Ragweed ◽  
Herbicide Treatments ◽  
Nutritive Values ◽  
Biomass Yields

Field experiments were conducted from 2007 through 2009 at four locations in Missouri to evaluate the effect of May and August herbicide applications on weed control, total biomass yield, and forage nutritive values. Experiments were conducted in established tall fescue pastures that contained natural infestations of common ragweed and tall ironweed. Treatments consisted of 2,4-D, metsulfuron, aminopyralid, 2,4-D + dicamba, 2,4-D + picloram, aminopyralid + 2,4-D, and 2,4-D + dicamba + metsulfuron. All herbicide treatments provided > 76% control of common ragweed 1 mo after treatment (MAT), except metsulfuron alone which provided ≤ 62% control. August applications provided greater reductions in common ragweed density than May applications the following spring. Few differences in tall ironweed density were observed, but metsulfuron-containing herbicides tended to provide the lowest reduction in tall ironweed stem density the following spring. Biomass yields were generally greater in nontreated compared to herbicide-treated plots. Crude protein (CP) concentration and relative feed value (RFV) were higher in nontreated compared with herbicide-treated biomass. Overall, the poorer nutritive values and lower biomass yields in the herbicide-treated compared with the nontreated biomass may be partially explained by the removal of common ragweed, tall ironweed, and legumes with the herbicide treatments. Pure samples of common ragweed and white clover were greater in nutritive values than pure samples of tall fescue at all June harvests. Results indicate that common ragweed offers nutritive values equivalent to or greater than tall fescue and white clover when harvested in June at the vegetative stage of growth and that the removal of common ragweed and tall ironweed with herbicide applications is not likely to improve forage nutritive values of the total harvested biomass of tall fescue pastures, at least by the season after treatment.

Physiological Basis for Differential Selectivity of Four Grass Species to Aminocyclopyrachlor

Weed Science ◽  
2015 ◽  
Vol 63 (4) ◽  
pp. 788-798 ◽  
Author(s):  
Ethan T. Parker ◽  
Glenn R. Wehtje ◽  
J. Scott McElroy ◽  
Michael L. Flessner ◽  
Peter Panizzi
Keyword(s):  
Weed Control ◽  
Tall Fescue ◽  
The Other ◽  
Grass Species ◽  
Target Area ◽  
Physiological Basis ◽  
Synthetic Auxin ◽  
Differential Selectivity

Aminocyclopyrachlor (AMCP) is a synthetic auxin herbicide used for broadleaf weed control in pasture and rangeland. The tolerance and fate of AMCP within pertinent grass species is not well understood. Research was conducted to establish the tolerance of four grass species to AMCP application and observe their absorption, translocation, and metabolism. Results indicate that tall fescue is the most tolerant of AMCP at rates required for weed control. Bahiagrass and bermudagrass are marginally tolerant, and cogongrass is the most sensitive. Tall fescue and bahiagrass absorbed more AMCP than bermudagrass and cogongrass, but cogongrass absorption is the most rapid and complete within 2 days after treatment (DAT). Cogongrass and bermudagrass translocated the least amount out of the target area, whereas bahiagrass and tall fescue translocated the most. Radioisotope imaging revealed that tall fescue may sequester absorbed AMCP in leaf tips. This sequestering may be the basis of the greater tolerance to AMCP by tall fescue relative to the other species evaluated. No metabolism of AMCP was detected in any grass species out to 42 DAT.

Quantification of Warm-Season Turfgrass Injury from Triclopyr and Aminocyclopyrachlor

2011 ◽  
Vol 25 (3) ◽  
pp. 367-373 ◽  
Author(s):  
Michael L. Flessner ◽  
J. Scott McElroy ◽  
Glenn R. Wehtje
Keyword(s):  
Weed Control ◽  
Warm Season ◽  
Effective Control ◽  
Synthetic Auxin ◽  
Green Cover ◽  
Herbicide Treatment ◽  
Auxin Herbicides ◽  
Turfgrass Quality

Synthetic auxin herbicides are widely used because of their effective control of broadleaf weeds and safety in many turfgrass species. However, two synthetic auxin herbicides, triclopyr and aminocyclopyrachlor (AMCP; DPX-KJM44), are known to injure warm-season turfgrasses. Our objective was to quantify this injury through evaluations of turfgrass quality and turfgrass green cover in response to herbicide treatment. The results of this study indicate that relative to the labeled use rates of triclopyr (0.56 to 1.12 kg ae ha−1) and AMCP (0.053 kg ai ha−1), zoysiagrass is the only turfgrass tested with sufficient tolerance to the respective compounds for their use as weed-control agents. Bermudagrass and centipedegrass may be injured by triclopyr and AMCP at labeled rates, characterized by a reduction in turfgrass quality and green cover. St. Augustinegrass is not tolerant of either triclopyr or AMCP at labeled rates.

scholarly journals Adjuvant interference on spray solution properties of 2,4-D and dicamba herbicides and their efficacy for Ipomoea SPP. control

2020 ◽  
Vol 36 ◽  
Author(s):  
Roberto Costa Avila Neto ◽  
Adriano Arrué Melo ◽  
André da Rosa Ulguim ◽  
Rafael Munhoz Pedroso ◽  
Geovana Facco Barbieri ◽  
...  
Keyword(s):  
Surface Tension ◽  
Weed Control ◽  
Biomass Accumulation ◽  
Solution Properties ◽  
Synthetic Auxin ◽  
Spray Solution ◽  
Droplet Sizes ◽  
Auxin Herbicides ◽  
Two Phases ◽  
Solution Parameters

Synthetic auxin herbicides constitute major alternatives for managing tough-to-kill weeds such as Ipomoea spp. Adjuvant use is known to positively affect the biological efficacy of pesticides by modifying key spraying solution and droplet properties. Determining to what extent the use of adjuvants could change spray solution parameters and affect synthetic auxin herbicides’ efficiency for Ipomoea spp. control were the research goals. The study was conducted in two phases: laboratory and field, respectively. In the laboratory, the pH, the surface tension, and the resources of the herbicide drops were measured. In the field, weed control was evaluated. All adjuvants modified spray solution properties, lowering surface tension values. Most adjuvants decreased pH values as well as number and density of droplets due to an increase in droplet size. Regardless of adjuvant usage, Ipomoea spp. control levels rose more rapidly following 2,4-D spraying rather than dicamba, resulting in lower biomass accumulation when the former was used. Dicamba-containing treatments displayed slightly but significantly lower Ipomoea spp. control levels at the end of the evaluation period. Herbicide efficacy for Ipomoea spp. control was not improved upon the addition to the spray solution of any of the tested adjuvants. Adjuvant use altered spraying solution and droplet properties. 2,4-D spraying allowed for lower Ipomoea spp. biomass and greater control levels relative to dicamba, suggesting it might constitute a better option for Ipomoea spp. control. Even though herbicide efficacy was not improved with adjuvants, their use should still be considered given favorable spraying solution alterations, mainly with some alteration in droplet sizes despite the use of similar spray nozzles tips - maintaining weed control efficacy.

Application of synthetic auxin herbicides to suppress seed viability of Italian ryegrass (Lolium perenne ssp. multiflorum) in tall fescue seed production

2020 ◽  
Vol 34 (4) ◽  
pp. 489-497
Author(s):  
Lucas K. Bobadilla ◽  
Andrew G. Hulting ◽  
Daniel W. Curtis ◽  
Carol Mallory-Smith
Keyword(s):  
Seed Production ◽  
Herbicide Resistance ◽  
Tall Fescue ◽  
Negative Impact ◽  
Seed Viability ◽  
Italian Ryegrass ◽  
Growth Stages ◽  
Management Options ◽  
Synthetic Auxin ◽  
Auxin Herbicides

AbstractItalian ryegrass is one of the most troublesome weeds worldwide because of the rapid evolution of herbicide resistance in this species. Oregon tall fescue seed production requires high seed purity, demanding good control of Italian ryegrass. The necessity to control herbicide-resistant Italian ryegrass and maintain tall fescue seed purity created interest in new chemical management options. The objectives of this study were to assess the effects of synthetic auxin herbicides on seed viability of Italian ryegrass biotypes and the feasibility of this management strategy for use in tall fescue seed production. Eight treatments of synthetic auxin herbicides were applied to Italian ryegrass and tall fescue at two growth stages (boot and anthesis): dicamba (1.0 and 2.2 kg ae ha−1), 2,4-D (1.1 and 2.2 kg ae ha−1), aminopyralid (0.5 kg ae ha−1), dicamba + 2.4-D (0.8 + 1.1 kg ae ha−1), 2.4-D + clopyralid (1.1 + 0.3 kg ae ha−1), and halauxifen-methyl + florasulam (0.4 kg ae ha−1 + 0.4 kg ai ha−1). Aminopyralid applied at boot and anthesis stages of Italian ryegrass reduced seed viability. Aminopyralid treatments reduced seed viability and weight of Italian ryegrass more than 50% compared to the control. Four biotypes from different locations in western Oregon with different types of herbicide resistance were sprayed, and differences in aminopyralid effect among Italian ryegrass biotypes were documented. Aminopyralid reduced the speed of germination by 1 to 2 d. Aminopyralid treatments had a greater effect when applied at the anthesis stage and had a greater negative impact on tall fescue. Tall fescue plants were more susceptible to aminopyralid, so this management practice is not feasible for tall fescue seed production. Future studies are needed to understand the physiological mechanisms involved in the reduced seed viability and to define an optimum aminopyralid rate for different Italian ryegrass biotypes.

Bioavailability of Aminocyclopyrachlor and Triclopyr plus Clopyralid from Turfgrass Clippings in Aquatic and Riparian Plants

Weed Science ◽  
2013 ◽  
Vol 61 (4) ◽  
pp. 594-600 ◽  
Author(s):  
Dustin F. Lewis ◽  
Robert J. Richardson ◽  
Fred H. Yelverton ◽  
Thomas R. Wentworth
Keyword(s):  
Management Practices ◽  
Growth Responses ◽  
Terrestrial Plants ◽  
Riparian Plants ◽  
Synthetic Auxin ◽  
Similar Chemical ◽  
Aqueous Environments ◽  
Lentic System ◽  
Previously Treated ◽  
Auxin Herbicides

Synthetic auxin herbicides are widely utilized in golf course settings for selective broadleaf weed control. Aminocyclopyrachlor (AMCP) is a newly registered pyrimidine carboxylic acid with similar chemical mode-of-action and structure to triclopyr (TRIC) and clopyralid (CLPY). Off-target injury on terrestrial plants has been documented following exposure to turfgrass clippings previously treated with TRIC and CLPY. Management practices on golf courses can distribute turfgrass clippings into water bodies; however, research has not evaluated the bioavailability of synthetic auxin residues from turfgrass clippings to aquatic and riparian plants within these environments. A bioassay study was conducted to determine the response of alligatorweed and parrotfeather to tall fescue clippings previously treated with synthetic auxin herbicides. Previously treated AMCP and TRIC + CLPY clippings were placed into growth containers mimicking a lentic system containing both alligatorweed and parrotfeather. Results indicated all herbicide treated clippings induced significant growth responses to alligatorweed and parrotfeather growth compared to a nontreated mulch and nontreated control. Alligatorweed control was greater from AMCP clippings treated 14, 7, 3, and 1 DBCC (49, 60, 90, and 80%, respectively) than comparative TRIC + CLPY clippings (33, 25, 37, and 64%, respectively) at 10 weeks after treatment (WAT). Parrotfeather control was greater from AMCP clippings (57 to 87%) than TRIC + CLPY clippings (9 to 63%) collected from all days before clipping collection (DBCC) timings when evaluated 6 WAT. At 10 WAT, greater parrotfeather control and shoot reduction was observed from AMCP than TRIC + CLPY clippings when treated 14, 7, and 3 DBCC. Based on these data, synthetic auxin residues can become bioavailable to aquatic and riparian plants within aqueous environments.

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