18 results
Ethofumesate-resistant annual bluegrass (Poa annua) in grass seed production systems
- Vera Vukovic, Clint M. Mattox, Alec R. Kowalewski, Brandon C. McNally, Cale A. Bigelow, Stephen L. Meyers, James T. Brosnan, Aaron J. Patton
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- Journal:
- Weed Technology / Volume 37 / Issue 6 / December 2023
- Published online by Cambridge University Press:
- 13 October 2023, pp. 628-636
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The prolific seed production and polyploidy of annual bluegrass allow for the rapid development of herbicide resistance. Ethofumesate-resistant annual bluegrass plants were identified in the 1990s in grass seed production in Oregon, but their prevalence and distribution are not well documented. Therefore a dose–response experiment was initiated to determine the potential level of ethofumesate resistance in seed production systems. Seeds from 55 annual bluegrass populations were obtained from three sources: seed production fields (31 populations), the seed cleaning process (6 populations), and seed testing lots prior to retail distribution (18 populations). Additionally, two populations, one with known ethofumesate resistance and one with known susceptibility, were identified in preliminary testing and used as controls in this experiment. Seed from each collected population was increased. Individual seedlings were then transplanted into separate cone-tainers, grown to a size of 2 to 3 tillers in the greenhouse, and then sprayed using a compressed air track spray chamber with 10 doses of ethofumesate at 0, 0.56, 1.1, 2.8, 5.6, 8.4, 11.2, 16.8, 22.4, and 44.8 kg ai ha−1, with 0.84 to 2.2 kg ha−1 as the label application rate for perennial ryegrass. The resistant to susceptible ratio of populations across all sources ranged from 0.5 to 5.5. The most resistant populations found in production fields, seed cleaning, and seed testing lots had the effective dose necessary to kill 50% of the population (ED50) of 12.1, 9.4, and 13.1 kg ha−1, respectively. Furthermore, 68% of the populations found in production fields had ED50 higher than 6 kg ha−1, indicating common annual bluegrass resistance in grass seed production. As such, growers should implement integrated weed management strategies, as herbicides alone will likely be ineffective at controlling annual bluegrass.
Extension event attendance increases adoption of weed management practices by sports field managers
- George B. Frisvold, Chandrakant Agme, David Ervin, Jennifer Allen, Shawn Askew, Rebecca Grubbs Bowling, James Brosnan, Matthew Elmore, Travis Gannon, John Kaminski, Lambert McCarty, James D. McCurdy, Aaron J. Patton, Jacob Taylor, J. Bryan Unruh, Muthukumar Bagavathiannan
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- Journal:
- Weed Technology / Volume 37 / Issue 5 / October 2023
- Published online by Cambridge University Press:
- 20 September 2023, pp. 578-587
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Data from a national survey of 348 U.S. sports field managers were used to examine the effects of participation in Cooperative Extension events on the adoption of turfgrass weed management practices. Of the respondents, 94% had attended at least one event in the previous 3 yr. Of this 94%, 97% reported adopting at least one practice as a result of knowledge gained at an Extension turfgrass event. Half of the respondents had adopted four or more practices; a third adopted five or more practices. Nonchemical, cultural practices were the most-adopted practices (65% of respondents). Multiple regression analysis was used to examine factors explaining practice adoption and Extension event attendance. Compared to attending one event, attending three events increased total adoption by an average of one practice. Attending four or more events increased total adoption by two practices. Attending four or more events (compared to one event) increased the odds of adopting six individual practices by 3- to 6-fold, depending on the practice. This suggests that practice adoption could be enhanced by encouraging repeat attendance among past Extension event attendees. Manager experience was a statistically significant predictor of the number of Extension events attended but a poor direct predictor of practice adoption. Experience does not appear to increase adoption directly, but indirectly, via its impact on Extension event attendance. In addition to questions about weed management generally, the survey asked questions specifically about annual bluegrass management. Respondents were asked to rank seven sources of information for their helpfulness in managing annual bluegrass. There was no single dominant information source, but Extension was ranked more than any other source as the most helpful (by 22% of the respondents) and was ranked among the top three by 53%, closely behind field representative/local distributor sources at 54%.
A Behavioral Approach to Identify Barriers to Adoption of New Technology: A Case Study of Low-input Turfgrasses
- Chengyan Yue, Yufeng Lai, Eric Watkins, Aaron Patton, Ross Braun
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- Journal:
- Journal of Agricultural and Applied Economics / Volume 55 / Issue 1 / February 2023
- Published online by Cambridge University Press:
- 08 May 2023, pp. 72-99
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Adopting eco-friendly technologies, such as converting lawns to alternative low-input grass species, can reduce household expenditures and mitigate negative environmental impacts at the same time. However, the rate of adoption of these technologies has not been as high as expected. This study develops a behavioral framework to identify barriers to new technology adoption by incorporating both prospect theory and present bias. We apply the framework in a choice experiment to investigate the relative importance of several factors that shape decisions associated with adoption of low-input turfgrass. We find that loss aversion plays a significant role. Though consumers exhibit present bias, long-term benefits still matter to them. Insights from the behavior model suggest that marketing and government programs that promote cost–benefit-efficient technologies should focus on eliminating or reducing potential losses caused by product failure.
Audit of physical health monitoring during initiation and ongoing treatment with antipsychotic medication in a tier 3 outpatient CAMHS service, Belfast
- Pam Hamlyn, Aaron McMenamin, Hilary Boyd, Lara Patton
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- BJPsych Open / Volume 7 / Issue S1 / June 2021
- Published online by Cambridge University Press:
- 18 June 2021, pp. S323-S324
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Aims
To evidence that physical health monitoring during antipsychotic initiation and continued treatment within the Child and Family Clinic is current, as per the agreed Antipsychotic Medication Monitoring Schedule for Belfast Trust CAMHS (2015), supporting Quality Network for Community CAMHS(QNCC) accreditation.
BackgroundThe Antipsychotic Medication Monitoring Schedule CAMHS(2015) was agreed by a working group of consultant psychiatrists and pharmacists, based on evidence from The Canadian Alliance for Monitoring Effectiveness and Safety of Antipsychotics in Children (CAMSEA), NICE Guidelines CG 185(2014), CG155(2013) and Maudsley Guidelines, and was to be located on the electronic system (PARIS).
MethodIn January 2019, a list of all children/young people on antipsychotic medication was collated (n = 12). Presence of the monitoring schedule in the clinical notes or PARIS was recorded. The Electronic Care Record was reviewed for blood results and PARIS letters for documentation of physical health parameters (heart rate, blood pressure, height, weight, BMI, extrapyramidal side effects, ECG) and to identify documentation of risk/benefit review where monitoring was declined. Re-audit January 2020 (n = 9). Criteria:
All patients commenced on antipsychotic medication will have baseline blood investigations and other physical health parameters documented as per the monitoring schedule. If monitoring was declined, the reason for this and indications for prescribing must be documented as a risk/benefit analysis.
All patients on antipsychotic medication will be current with their physical health Monitoring Schedule.
All patients will have their Monitoring Schedule completed in clinical notes or on PARIS.
ResultFirst cycle results (n = 12):
Baseline bloods (or documented declined) = 92%, Baseline ECG (or documented declined) = 75%
Complete monitoring bloods = 33%, Physical health monitoring parameters complete = 42%
Monitoring schedule present in the notes and current = 42% (0% on PARIS).
Initial Recommendations: Standardised recording of monitoring using PARIS clinic letters and the schedule in front of clinical notes; Baseline ECG mandatory
Second cycle results (n = 9):
Baseline bloods (or declined) = 89%, Baseline ECG (or declined) = 67%
Complete monitoring bloods = 44%, Physical health monitoring parameters complete = 56%
Monitoring schedule present in notes and current = 38%, Present, not current = 50% (0% on PARIS).
ConclusionLower numbers at re-audit limit interpretation.
Further recommendations: Antipsychotic initiation checklist; Central bloods diary for clinicians; Antipsychotic care-pathway booklet, co-produced with young people, incorporating the monitoring schedule.
Influence of hard water on 2,4-D formulations for the control of dandelion
- Geoffrey P. Schortgen, Aaron J. Patton
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- Journal:
- Weed Technology / Volume 35 / Issue 3 / June 2021
- Published online by Cambridge University Press:
- 09 December 2020, pp. 371-379
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The herbicide 2,4-D is used in a variety of cropping systems, especially in grasses because it is a selective postemergence broadleaf herbicide. However, the most common formulation (2,4-D dimethylamine) is antagonized when mixed in hard water. The objective of this research was to determine which formulations of 2,4-D or premixes of various formulations of synthetic auxin herbicides are subject to hard water antagonism. Formulations surveyed for hard water antagonism in the first experiment included 2,4-D dimethylamine, 2,4-D diethanolamine, 2,4-D monomethylamine, 2,4-D isopropylamine salt, 2,4-D choline salt, 2,4-D isooctyl ester, and 2,4-D ethylhexyl ester. Synthetic auxin formulation types in the second experiment included water-soluble, emulsifiable concentrates and emulsion-in-water. All formulations were mixed with both soft and hard water (600 mg CaCO3 L−1) and applied to dandelions to determine whether antagonism occurred in hard water. Water-soluble (amine and choline) 2,4-D formulations were antagonized by hard water, but water-insoluble (ester) 2,4-D formulations were not antagonized. Similar results were found by formulation type with water-soluble synthetic auxin premixes antagonized but emulsifiable concentrates not antagonized. Furthermore, water-soluble salt formulations were not antagonized when formulated in premixes with other synthetic auxin herbicides as an emulsion-in-water. This research demonstrates that all 2,4-D water-soluble formulations and water-soluble premixes with phenoxycarboxylic acid herbicides are subject to hard water antagonism. Formulations of 2,4-D containing emulsifying agents protect against antagonism by the water-insoluble nature of ingredients in their formulation.
Weed control by 2,4-D dimethylamine depends on mixture water hardness and adjuvant inclusion but not spray solution storage time
- Geoffrey P. Schortgen, Aaron J. Patton
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- Weed Technology / Volume 34 / Issue 1 / February 2020
- Published online by Cambridge University Press:
- 14 November 2020, pp. 107-116
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Herbicides are an important tool in managing weeds in turf and agricultural production. One of the earliest selective herbicides, 2,4-D, is a weak acid herbicide used to control broadleaf weeds. Water-quality parameters, such as pH and hardness, influence the efficacy of weak acid herbicides. Greenhouse experiments were conducted to evaluate how varying water hardness level, spray solution storage time, and adjuvant inclusion affected broadleaf weed control by 2,4-D dimethylamine. The first experiment evaluated a range of water-hardness levels (from 0 to 600 mg calcium carbonate [CaCO3] L−1) on efficacy of 2,4-D dimethylamine applied at 1.60 kg ae ha−1 for dandelion and horseweed control. A second experiment evaluated dandelion control from spray solutions prepared 0, 1, 4, 24, and 72 h before application. Dandelion and horseweed control by 2,4-D dimethylamine was reduced when the CaCO3 level in water was at least 422 or at least 390 mg L−1, respectively. Hard-water antagonism was overcome by the addition of 20 g L−1 ammonium sulfate (AMS) into the mixture. When AMS was included in spray mixtures, no differences were observed at 600 mg CaCO3 L−1, compared with distilled water. Spray solution storage time did not influence dandelion control, regardless of water-hardness level or adjuvant inclusion. To prevent antagonism, applicators should use a water-conditioning agent such as AMS when applying 2,4-D dimethylamine in hard water.
Efficacy of triclopyr and synthetic auxin herbicide mixtures for common blue violet (Viola sororia) control
- Aaron J. Patton, Daniel V. Weisenberger, Wenwen Liu
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- Weed Technology / Volume 34 / Issue 4 / August 2020
- Published online by Cambridge University Press:
- 29 April 2020, pp. 475-481
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Common blue violet is a widely distributed, perennial broadleaf that is difficult to control in lawns. Two experiments were conducted to evaluate the efficacy of synthetic auxin herbicides and their mixtures or rate for common blue violet control. A herbicide comparison experiment was conducted with treatments including a nontreated check; 2,4-D dimethylamine; 2,4-D isooctyl ester (2,4-D ester); dichlorprop (2,4-DP) ethylhexyl ester, MCPA dimethylamine; mecoprop dimethylamine; triclopyr butoxyethyl ester; quinclorac; and mixtures of triclopyr + quinclorac; 2,4-D ester + 2,4-DP; 2,4-D ester + triclopyr; 2,4-D ester + 2,4-DP + triclopyr. All herbicides were applied at 1.12 kg ae ha−1 except quinclorac (0.84 kg ha−1). Additionally, a triclopyr dose-response experiment was conducted using rates of 0, 0.14, 0.28, 0.56, 0.84, and 1.12 kg ha−1. Epinasty ranged from 80% to 99% at 21 d after application for triclopyr-containing treatments and no more than 28% for all other treatments. Plant mass from harvest and regrowth data from the comparison experiment indicated triclopyr-containing treatments provided the highest common blue violet control. Mixtures containing triclopyr did not differ from triclopyr alone, indicating there was no added effect between herbicide mixtures. The triclopyr dose-response experiment confirmed triclopyr efficacy across data collection types. As triclopyr dose increased, violet epinasty increased and chlorophyll content and dry weight decreased. Triclopyr applied at 0.81 kg ha−1 or greater concentration provided 75% or greater control, as indicated by regrowth data. Many herbicides containing triclopyr are registered for use in turf, but most apply a concentration not greater than 0.56 kg ha−1 triclopyr when applied at the high label rate. Thus, to achieve good (75%) common blue violet control, turf managers should select products that contain triclopyr and apply doses of at least 0.81 kg ha−1 when used according to the label.
Nonchemical annual bluegrass (Poa annua) management in zoysiagrass via fraise mowing
- James T. Brosnan, Gregory K. Breeden, John M. Zobel, Aaron J. Patton, Quincy D. Law
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- Weed Technology / Volume 34 / Issue 4 / August 2020
- Published online by Cambridge University Press:
- 13 January 2020, pp. 482-488
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Continued reliance on chemical methods for controlling annual bluegrass has resulted in many populations evolving resistance to PRE and POST herbicides, particularly in warm-season turfgrass species such as zoysiagrass. Soil seedbank management is critically important when managing herbicide-resistant weeds. Fraise mowing (also spelled fraze, frase, and fraize) is a new turfgrass cultivation practice designed to remove aboveground biomass while allowing turf to regrow vegetatively. We hypothesized that this process would remove annual bluegrass seed and therefore be a mechanical means of controlling annual bluegrass in turfgrass. Zoysiagrass field plots were fraise-mowed in June 2015 only, June 2016 only, June 2015 and June 2016, or left untreated. The fraise mower was configured to remove the uppermost 25 mm of plot surface (i.e., 15-mm verdure and 10-mm soil). Annual bluegrass infestation was quantified in April following fraise mowing via grid count. Soil cores (10.8 cm diameter) were extracted from each plot after grid count data were collected to assess effects of fraise mowing on the soil seedbank. Moreover, replicated subsamples (7.6 L) of debris generated during fraise mowing were collected to better understand weed seed content removed during the fraise mowing process. Fraise mowing in June offered a slight reduction (24%) in annual bluegrass cover the following April. Whereas 28% of the seed in fraise-mowing debris consisted of annual bluegrass, there was no difference in the quantity of annual bluegrass seed remaining in the soil seedbank among fraise-mowed and non–fraise-mowed plots. Although fraise mowing may help to temporarily reduce existing annual bluegrass infestations via mechanical removal, the frequency and depth we studied did not effectively reduce the seedbank. Fraise mowing is a useful tool for providing mechanical suppression of annual bluegrass but it is not a replacement for properly timed herbicide applications.
False-green kyllinga (Kyllinga gracillima) control in cool-season turfgrass
- Matthew T. Elmore, Aaron J. Patton, Daniel P. Tuck, James A. Murphy, Jenny Carleo
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- Journal:
- Weed Technology / Volume 33 / Issue 2 / April 2019
- Published online by Cambridge University Press:
- 23 April 2019, pp. 329-334
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We conducted research to evaluate various herbicides for POST false-green kyllinga control in cool-season turfgrass (primarily creeping bentgrass). In a preliminary evaluation, single and sequential applications of halosulfuron-methyl (70 g ai ha−1), mesotrione (175 g ai ha−1), and sulfentrazone (140 g ai ha−1), as well as a single application of imazosulfuron (740 g ai ha−1), were evaluated in New Jersey. Imazosulfuron and sequential applications of halosulfuron-methyl controlled false-green kyllinga >93% at 9 and 18 wk after initial treatment (WAIT). Sulfentrazone and mesotrione controlled false-green kyllinga <50%. Additional experiments were conducted to evaluate single and sequential applications of halosulfuron-methyl (70 g ha−1), imazosulfuron (420 and 740 g ha−1), and sulfentrazone (140 g ha−1) in New Jersey and Indiana at two locations in each state. At 12 WAIT, imazosulfuron generally controlled false-green kyllinga more effectively than other treatments at all locations. Sequential applications of imazosulfuron controlled false-green kyllinga 100% at 12 WAIT. Halosulfuron-methyl was less effective in Indiana than in New Jersey. Sulfentrazone controlled false-green kyllinga <40% at 12 WAIT. This research demonstrates that imazosulfuron is more effective than halosulfuron-methyl and sulfentrazone for POST false-green kyllinga control in cool-season turf.
2,4-D–Resistant Buckhorn Plantain (Plantago lanceolata) in Managed Turf
- Aaron J. Patton, Daniel V. Weisenberger, Geoff P. Schortgen
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- Weed Technology / Volume 32 / Issue 2 / April 2018
- Published online by Cambridge University Press:
- 01 February 2018, pp. 182-189
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A population of buckhorn plantain with suspected resistance to 2,4-D was identified in central Indiana following 30 yr of 2,4-D–containing herbicide applications. Our objectives were to (1) confirm and quantify the level of herbicide resistance in the buckhorn plantain population using dose–response experiments and (2) find alternative herbicides that could be used to control this population. Greenhouse experiments were conducted to quantify the dose–response of resistant (R) and susceptible (S) biotypes of buckhorn plantain to both 2,4-D and triclopyr, two synthetic auxin herbicides from different chemical families. The R biotype was ≥6.2 times less sensitive to 2,4-D than the S biotype. The efficacy of triclopyr was similar on both the R and S biotypes of buckhorn plantain, suggesting the absence of cross-resistance to this herbicide. This is the first report of 2,4-D resistance in buckhorn plantain and the first report of 2,4-D resistance in turf. The resistance mechanism was limited to within a chemical family (phenoxycarboxylic acid) and did not occur across all WSSA Group 4 synthetic auxin herbicides, as the pyridinecarboxylic acid herbicides clopyralid and triclopyr and the arylpicolinate herbicide halauxifen-methyl provided control in our experiments.
Sulfonylurea Herbicide Safety on Newly Sprigged Bermudagrass and Seashore Paspalum
- Aaron J. Patton, Jon M. Trappe, Ronald E. Strahan, Jeffrey S. Beasley
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- Weed Technology / Volume 24 / Issue 3 / September 2010
- Published online by Cambridge University Press:
- 20 January 2017, pp. 342-348
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Several sulfonylurea herbicides are labeled for use on established bermudagrass or seashore paspalum, but label recommendations for many of these chemicals vary for sprigged turf. The objective of this study was to determine the safety of various sulfonylurea herbicides on newly planted, ‘Tifway’ bermudagrass and ‘Aloha’ seashore paspalum sprigs in Arkansas and Louisiana. Treatments were arranged as a five by two by two factorial with five herbicides (foramsulfuron at 29 and 59 g ai ha−1, halosulfuron at 35 and 70 g ai ha−1, metsulfuron at 21 and 42 g ai ha−1, sulfosulfuron at 66 and 131 g ai ha−1, and trifloxysulfuron at 28 and 56 g ai ha−1), two herbicide rates (low and high), and two application timings at 2 or 4 wk after sprigging (WAS). There was no discernable herbicide injury to, or reduction in, Tifway bermudagrass coverage in Arkansas, regardless of herbicide, application timing, or application rate. Trifloxysulfuron and metsulfuron were more injurious than other herbicides in Louisiana when applied at 2 WAS to Tifway bermudagrass, but injury levels were acceptable (< 15%), and there was no long-term reduction in establishment. Metsulfuron or halosulfuron applied at 2 or 4 WAS and sulfosulfuron applied at 4 WAS allowed > 90% establishment of Aloha seashore paspalum at both locations. Both trifloxysulfuron and foramsulfuron were injurious to seashore paspalum and reduced its establishment. These results suggest that sulfonylurea herbicides can be safely applied shortly after sprigging to Tifway bermudagrass and that metsulfuron, halosulfuron, and sulfosulfuron could be useful herbicides for establishing Aloha seashore paspalum from sprigs.
Divalent Cations in Spray Water Influence 2,4-D Efficacy on Dandelion (Taraxacum officinale) and Broadleaf Plantain (Plantago major)
- Aaron J. Patton, Daniel V. Weisenberger, William G. Johnson
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- Weed Technology / Volume 30 / Issue 2 / June 2016
- Published online by Cambridge University Press:
- 20 January 2017, pp. 431-440
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2,4-dichlorophenoxyacetic acid (2,4-D) is a common ingredient in POST broadleaf herbicides labeled for use in turf, pastures, rangeland, and grain crops. The herbicide 2,4-D is a weak acid, and when dissociated can bind to cations present in hard-water spray solutions and/or fertilizer solutions. Experiments were conducted with 2,4-D dimethylamine to evaluate the effect of cation solutions on herbicide efficacy on the perennial broadleaf weeds dandelion and broadleaf plantain. The objectives of this research were to (1) determine if 2,4-D efficacy is influenced by the divalent cations, calcium (Ca), magnesium (Mg), manganese (Mn), and zinc (Zn) in spray solution; and (2) determine if adding the adjuvant ammonium sulfate (AMS) to the spray solution can overcome antagonism. Broadleaf plantain and dandelion control was reduced and plant size and mass increased when 2,4-D was applied in a Ca solution in comparison to deionized water. However, 2,4-D antagonism was overcome when AMS was added as an adjuvant to the spray solution. Magnesium caused 2,4-D antagonism on both weed species in one run of the experiment similar to Ca solution and AMS was successful at overcoming antagonism when added to the tank mixture. Some 2,4-D antagonism from Mn was noticed even when AMS was in the tank mix, but Zn fertilizer solutions did not antagonize 2,4-D activity on either weed species. Although divalent cations can antagonize 2,4-D dimethylamine and reduce perennial broadleaf weed control, adding AMS can overcome this antagonism when Ca and Mg are the primary cations in spray solution. Applicators should avoid using Mn fertilizers when applying 2,4-D dimethylamine because AMS did not successfully overcome antagonism.
Potential Damage to Sensitive Landscape Plants from Wood Chips of Aminocyclopyrachlor Damaged Trees
- Aaron J. Patton, Gail E. Ruhl, Tom C. Creswell, Ping Wan, David E. Scott, Joe D. Becovitz, Daniel V. Weisenberger
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- Journal:
- Weed Technology / Volume 27 / Issue 4 / December 2013
- Published online by Cambridge University Press:
- 20 January 2017, pp. 803-809
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Applications of aminocyclopyrachlor in 2011 to turf resulted in brown and twisted shoots, leaves, and needles; shoot dieback; and in some cases, death of trees and ornamental plants adjacent to treated turf areas. Our research objective was to determine if a sensitive plant could be injured from wood chips (mulch) obtained from aminocyclopyrachlor-damaged trees, and to quantify movement of aminocyclopyrachlor from contaminated wood chips into soil and its subsequent uptake by roots into landscape plant tissues. Tomatoes were grown under greenhouse conditions and mulched with chipped tree branches collected from honey locust and Norway spruce damaged 12 mo previously by aminocyclopyrachlor. Analysis of tomato tissue for aminocyclopyrachlor residues 32 d after mulching found aminocyclopyrachlor in all mulched tomato plants, which was consistent with observations of epinasty on tomato leaflets. Aminocyclopyrachlor residues ranged from 0.5 to 8.0 ppb in tomato plants while chipped tree branches contained 1.7 to 14.7 ppb. Aminocyclopyrachlor residues in the potting soil below the mulch ranged from below the quantifiable limit to 0.63 ppb, indicating that aminocyclopyrachlor can leach from wood chips into soil, causing plant injury. These results indicate that trees damaged by aminocyclopyrachlor should not be chipped and used for mulch or as an ingredient in compost.
Mesotrione Activity on Crabgrass (Digitaria spp.) as Influenced by Nitrogen Fertilization Rate, Source, and Timing
- Leslie L. Beck, Aaron J. Patton, Quincy D. Law, Daniel V. Weisenberger, James T. Brosnan, José J. Vargas Almodóvar, Gregory K. Breeden, Dean A. Kopsell
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- Weed Technology / Volume 29 / Issue 2 / June 2015
- Published online by Cambridge University Press:
- 20 January 2017, pp. 263-273
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Mesotrione, a 4-hydroxyphenylpyruvate dioxygenase-inhibiting herbicide, is labeled for PRE and POST crabgrass control. It has enhanced efficacy on smooth and large crabgrass when applied in conjunction with soil-applied nitrogen (N). The objectives of this study, using crabgrass as the weed species, were to (1) determine the influence of N rate and tissue N concentration on mesotrione activity, (2) determine the influence of N source on mesotrione activity, and (3) determine the influence of N application timing on mesotrione activity. Large crabgrass plants that received 12 kg N ha−1 or more before mesotrione application had more bleached and necrotic leaves compared with plants that received 0 kg N ha−1 7 d after treatment (DAT) in the greenhouse. Although N application rates as high as 98 kg N ha−1 were tested, 90% leaf bleaching and necrosis were observed with rates of 8.9 or 10.1 kg N ha−1 in Tennessee and Indiana, respectively. Nitrogen concentration in large crabgrass leaf and stem tissue on the day of the mesotrione application was closely related to the bleaching and necrosis symptoms observed 7 DAT. Although N rate influenced mesotrione activity, N source did not. Nitrogen application timing was also important, with N applications 3, 1, and 0 d before a mesotrione application having the highest percentage of bleached and necrotic leaves in greenhouse experiments. Both greenhouse and field trials support the finding that N applications in proximity to the mesotrione application enhance herbicide activity. Thus, practitioners can pair N and POST mesotrione applications together or in proximity to enhance crabgrass control.
Zoysiagrass Seedhead Suppression with Imidazolinone Herbicides
- James T. Brosnan, Greg K. Breeden, Matthew T. Elmore, Aaron J. Patton, Dan V. Weisenberger
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- Weed Technology / Volume 26 / Issue 4 / December 2012
- Published online by Cambridge University Press:
- 20 January 2017, pp. 708-713
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Options for suppressing zoysiagrass seedheads in managed turfgrass systems are limited. Experiments were conducted in 2010 and 2011 evaluating the use of imazamox (26, 52, and 70 g ai ha−1) or imazapic (52 g ai ha−1) for ‘Zenith' and ‘Meyer' zoysiagrass seedhead suppression. Imazamox and imazapic at ≥ 52 g ai ha−1 suppressed Zenith zoysiagrass seedheads ≥ 95% at 2 to 6 wk after initial treatment (WAIT) each year. Slight injury (< 10%) was observed with these treatments; however, effective seedhead suppression resulted in increased (i.e., darker) green color from 8 to 15 WAIT each year. Relative chlorophyll index values for imazamox- and imazapic-treated plots ranged from 100 to 147% of the nontreated control in 2010 and 89 to 125% of the nontreated in 2011. On Meyer zoysiagrass, imazamox and imazapic at ≥ 52 g ha−1 reduced seedhead counts greater than 90% in both Tennessee and Indiana. However, significant (> 25%) injury was reported with these treatments at one experimental location. Although imazamox and imazapic have efficacy for zoysiagrass seedhead suppression, additional studies are needed to determine factors affecting zoysiagrass injury potential from imazamox and imazapic applications.
Safety of Herbicides on ‘zenith’ Zoysiagrass Seedlings
- Aaron J. Patton, Daniel V. Weisenberger, Glenn A. Hardebeck, Zachary J. Reicher
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- Weed Technology / Volume 21 / Issue 1 / March 2007
- Published online by Cambridge University Press:
- 20 January 2017, pp. 145-150
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Improved cultivars of zoysiagrass established by seed are now available, but little is known about the safety of herbicides on zoysiagrass seedlings. Our objective was to determine the turf safety of various herbicides when applied from emergence to 4 wk after emergence (WAE) of ‘Zenith’ zoysiagrass. Oxadiazon (3.4 kg ai/ha), MSMA (2.3 kg ai/ha), and pronamide (1.1 kg ai/ha) did not reduce coverage 7 WAE when applied at emergence or later and caused only temporary discoloration of seedlings. Foramsulfuron (0.03 kg ai/ha) injured seedling zoysiagrass both years of testing and reduced cover in the final year. Fluazifop (0.07 kg ai/ha) caused significant injury in all 3 yr of the study and reduced coverage in the final year. Fenoxaprop (0.14 kg ai/ha) caused visible injury and reduction in zoysiagrass coverage in all 3 yr of the study. Our studies indicate pronamide, MSMA, or oxadiazon are the safest herbicides to use over Zenith zoysiagrass seedlings, and selection among these three depends on the primary weed species present.
Mesotrione, Topramezone, and Amicarbazone Combinations for Postemergence Annual Bluegrass (Poa annua) Control
- Matthew T. Elmore, James T. Brosnan, Gregory K. Breeden, Aaron J. Patton
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- Journal:
- Weed Technology / Volume 27 / Issue 3 / September 2013
- Published online by Cambridge University Press:
- 20 January 2017, pp. 596-603
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Selective annual bluegrass (ABG) control with mesotrione is often inconsistent, and sequential applications might be required for complete control. The complementary nature of p-hydroxyphenylpyruvate dioxygenase (HPPD)- and photosystem II (PSII)-inhibiting herbicides is well documented. The HPPD-inhibiting herbicide mesotrione and the PSII-inhibiting herbicide amicarbazone both have efficacy against annual bluegrass and safety on certain cool-season turfgrasses. Topramezone is a HPPD-inhibiting herbicide being investigated for use in turfgrass. Field and greenhouse experiments were conducted to examine single applications of topramezone and mesotrione alone or in combination with amicarbazone for POST ABG control in spring. In greenhouse experiments, the combination of mesotrione (280 g ai ha−1) and amicarbazone (75 g ai ha−1) controlled ABG 70% by 21 d after treatment, > 29% more than either herbicide applied alone; these combinations were determined to be synergistic. Amicarbazone combined with topramezone (14.5 g ai ha−1) provided < 10% ABG control and was not synergistic. When combined with mesotrione, increasing amicarbazone rate to 150 or 255 g ha−1 did not increase ABG control compared to 75 g ha−1in field experiments. Combining mesotrione with amicarbazone resulted in a synergistic increase in POST ABG control at 1 and 2 wk after treatment (WAT). When applied alone or in combination with amicarbazone, increasing the mesotrione rate from 90 to 280 g ha−1 increased efficacy on ABG in field experiments. The combination of mesotrione at 280 g ha−1 and amicarbazone at 75 g ha−1 provided > 90% ABG control in field experiments. Future research should focus on sequential applications of mesotrione–amicarbazone combinations for ABG control in locations where ABG is historically more difficult to control.
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- Book:
- The Cambridge Dictionary of Philosophy
- Published online:
- 05 August 2015
- Print publication:
- 27 April 2015, pp ix-xxx
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