scholarly journals Confirmation and Control of Annual Bluegrass (Poa annua) with Resistance to Prodiamine and Glyphosate

2017 ◽  
Vol 31 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Shane M. Breeden ◽  
James T. Brosnan ◽  
Thomas C. Mueller ◽  
Gregory K. Breeden ◽  
Brandon J. Horvath ◽  
...  
Keyword(s):  
Dose Response ◽  
Shikimic Acid ◽  
Golf Course ◽  
Multiple Resistance ◽  
Post Dose ◽  
Annual Bluegrass ◽  
Resistant Phenotype ◽  
Dry Biomass ◽  
Herbicide Mixtures ◽  
And Control

Poor annual bluegrass control was reported in golf course roughs following treatment with prodiamine (1120 gaiha−1) and glyphosate (840 gaeha−1) during hybrid bermudagrass dormancy. Research was conducted to determine if this annual bluegrass phenotype was resistant to both prodiamine and glyphosate and to determine the efficacy of herbicide mixtures for controlling this phenotype in the field. In PRE or POST dose-response experiments, 9 to 31 times more prodiamine or glyphosate was needed to control (or reduce dry biomass of) this resistant phenotype by 50% compared to an herbicide-susceptible phenotype. Moreover, glyphosate-susceptible plants accumulated 50% more shikimic acid (898 mgkg−1) 6 d after treatment than those resistant to glyphosate (394 mgkg−1). October (fall) applications of herbicide mixtures containing trifloxysulfuron, simazine,S-metolachlor, or mesotrione controlled this resistant annual bluegrass phenotype 84 to 98% in April (spring), with no differences detected among treatments. Our findings document the second instance of annual bluegrass evolving multiple resistance in a managed turfgrass system. However, several herbicide mixtures can be used to effectively manage this resistant phenotype.

scholarly journals Multiple Resistance to Glyphosate and 2,4-D in Carduus acanthoides L. from Argentina and Alternative Control Solutions

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1735
Author(s):  
Candelario Palma-Bautista ◽  
Pablo Belluccini ◽  
Valentin Gentiletti ◽  
José G. Vázquez-García ◽  
Hugo E. Cruz-Hipolito ◽  
...  
Keyword(s):  
Dose Response ◽  
Shikimic Acid ◽  
Multiple Resistance ◽  
Response Curves ◽  
Retention Capacity ◽  
Carduus Acanthoides ◽  
Action Mechanisms ◽  
North And South America ◽  
North And South ◽  
Different Doses

Carduus acanthoides L. is an invasive species native to Europe and distributed in other parts of the world, including North and South America. In Cordoba, Argentina, control failures of this species have been reported in Roundup Ready (RR) soybean crops where glyphosate and 2,4-D have frequently been applied, although there are no confirmed reports worldwide of resistance to glyphosate and 2,4-D in this species. Dose–response tests showed multiple-resistance to both active principles. The resistant population (R) had LD50 values of 1854.27 and 1577.18 g ae ha−1 (grams of acid equivalent per hectare), while the susceptible (S) population had LD50 values of 195.56 and 111.78 g ae ha−1 for glyphosate and 2,4-D, respectively. Low accumulations of shikimic acid (glyphosate) and ethylene (2,4-D) at different doses in the R population compared to the S population support the results observed in the dose–response curves. No significant differences in leaf retention were observed for glyphosate and 2,4-D in the R and S populations. However, the use of adjuvants increased the retention capacity of herbicides in both populations. Ten alternative herbicides with seven different action mechanisms (MOAs) were evaluated and the most effective active principles were dicamba, bromoxynil, atrazine, tembotrione, flazasulfuron, glufosinate, and paraquat. These findings are the first evidence of glyphosate and 2,4 D resistance in C. acanthoides.

scholarly journals First Report of Amaranthus hybridus with Multiple Resistance to 2,4-D, Dicamba, and Glyphosate

Agronomy ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 140 ◽  
Author(s):  
Ignacio Dellaferrera ◽  
Eduardo Cortés ◽  
Elisa Panigo ◽  
Rafael De Prado ◽  
Pedro Christoffoleti ◽  
...  
Keyword(s):  
Dose Response ◽  
Shikimic Acid ◽  
Multiple Resistance ◽  
Agricultural Systems ◽  
Amaranthus Hybridus ◽  
First Report ◽  
Resistant Population ◽  
Acid Accumulation ◽  
Invasive Capacity

In many countries, Amaranthus hybridus is a widespread weed in agricultural systems. The high prolificacy and invasive capacity as well as the resistance of some biotypes to herbicides are among the complications of handling this weed. This paper reports on the first A. hybridus biotypes with resistance to auxinic herbicides and multiple resistance to auxinic herbicides and the EPSPs inhibitor, glyphosate. Several dose response assays were carried out to determine and compare sensitivity of six population of A. hybridus to glyphosate, 2,4-D, and dicamba. In addition, shikimic acid accumulation and piperonil butoxide effects on 2,4-D and dicamba metabolism were tested in the same populations. The results showed four populations were resistant to dicamba and three of these were also resistant to 2,4-D, while only one population was resistant to glyphosate. The glyphosate-resistant population also showed multiple resistance to auxinic herbicides. Pretreatment with piperonil butoxide (PBO) followed by 2,4-D or dicamba resulted in the death of all individual weeds independent of herbicide or population.

Reducing Populations of Annual Bluegrass and Roughstalk Bluegrass in Creeping Bentgrass Fairways: A Nutritional Approach

1999 ◽  
Vol 13 (4) ◽  
pp. 829-834 ◽  
Author(s):  
Gregory E. Bell ◽  
Edward Odorizzi ◽  
T. Karl Danneberger
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Creeping Bentgrass ◽  
Field Studies ◽  
Golf Course ◽  
Irrigation Regime ◽  
Annual Bluegrass ◽  
Putting Green ◽  
And Control

Two field studies, a seeded study and a golf course study, were conducted to compare competition among creeping bentgrass, annual bluegrass, and roughstalk bluegrass when subjected to common weed control practices and foliar applications of iron and magnesium. A research site was selected for the seeded study and divided into 10 whole plots receiving irrigation at either 50 or 100% evapotranspiration deficit. Each whole plot was further divided into subplots receiving one of seven treatments: bensulide, ethofumesate, trinexapac-ethyl, foliar Mg, foliar Fe, foliar Mg plus foliar Fe, and control. The site was seeded to a mixture of creeping bentgrass, annual bluegrass, and roughstalk bluegrass in September 1995, and treatments began in March 1996. Annual bluegrass was reduced 29% in plots treated with foliar Fe and 65% in plots treated with foliar Fe plus foliar Mg. Roughstalk bluegrass was significantly reduced in seeded plots treated with foliar iron (50%), plant growth regulator (75%), and foliar iron plus foliar magnesium (100%). Annual bluegrass and roughstalk bluegrass proportions were not affected by irrigation regime. In a second study, the most effective treatment, foliar magnesium plus foliar iron, was tested on a working golf course fairway and on a practice putting green beginning April 1997 and ending November 1997. Treatments on the golf course fairway and practice putting green were ineffective due to the established, perennial nature of the annual bluegrass biotypes on these sites. Further research is required to improve the efficacy of nutritional treatments on these perennials.

scholarly journals Confirmation of Multiple Resistant Chloris radiata Population, Harvested in Colombian Rice Fields

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 496
Author(s):  
Verónica Hoyos ◽  
Guido Plaza ◽  
José G. Vázquez-Garcia ◽  
Candelario Palma-Bautista ◽  
Antonia M. Rojano-Delgado ◽  
...  
Keyword(s):  
Dose Response ◽  
Weed Management ◽  
Shikimic Acid ◽  
Lethal Dose ◽  
Dry Weight ◽  
Integrated Weed Management ◽  
Cross Resistance ◽  
Multiple Resistance ◽  
Visual Evaluation ◽  
Acid Accumulation

This paper reports the first C. radiata population with resistance to glyphosate and multiple resistance to the acetolactate synthase (ALS) inhibitor, imazamox. Two populations, one putative resistant (R) and one susceptible (S), were used in the studies. Dose–response experiments were performed to evaluate the resistance factor (RF). Shikimic acid accumulation, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) and ALS enzyme activities were studied together with chemical integrated weed management (adjuvants and alternative herbicides). The resistance to glyphosate and imazamox was confirmed based on the dry weight reduction, visual evaluation and survival. The results of dose–response curve assays showed for the R population intermedium RF for glyphosate (5.1 and 9.7 for amount of herbicide needed to reduce the dry weight by 50% GR50 and lethal dose of 50% LD50, respectively) and high RF for imazamox (34.9 and 37.4, respectively). The low shikimic acid accumulation in R population confirmed the glyphosate resistance. The glyphosate concentration which inhibited the EPSPS enzyme in 50% (I50) was approximately 20 times higher for R population than the S population, while the imazamox I50 in ALS enzyme for the R plants was 89 times greater than the S plants. In the chemical integrated weed management, the foliar retention and effectivity assays showed that the use of adjuvants improves the retention of glyphosate and imazamox, and the reduction in dry weight of weeds. The alternative herbicides study showed that the acetyl-CoA carboxylase (ACCase) inhibitors, paraquat and glufosinate, had better results for control in this species. However, poor control was observed with bispyribac-sodium, metsulfuron-methyl and quinclorac, indicating possible cross-resistance for ALS-inhibitors and also multiple resistance for auxinic herbicides (quinclorac). Nevertheless dose–response experiments are required to confirm this assumption.

scholarly journals First case of Conyza canadensis from Hungary with multiple resistance to glyphosate and flazasulfuron

2018 ◽  
Author(s):  
Candelario Palma-Bautista ◽  
Behroz Khalil Tahmasebi ◽  
Pablo Tomás Fernández-Moreno ◽  
Antonia María Rojano-Delgado ◽  
Ricardo Alcántara de la Cruz ◽  
...  
Keyword(s):  
Dose Response ◽  
Shikimic Acid ◽  
Multiple Resistance ◽  
Conyza Canadensis ◽  
Herbicide Application ◽  
Susceptible Population ◽  
First Case ◽  
Acid Accumulation ◽  
Agricultural Areas ◽  
Als Inhibitor

Conyza canadensis is a species invading large agricultural areas throughout the world, mainly to its ability to evolve herbicide resistance. Specifically, in Hungary, extensive areas have been infested by this species due to the difficulty in controlling it with glyphosate. To corroborate this fact as resistance and not as an incorrect herbicide application, eight suspicious glyphosate-resistant C. canadensis populations from different Hungarian regions were studied. In dose-response assays with glyphosate, the LD50 and GR50 values indicated that populations 1 to 5 were resistant to this herbicide (H-5 population the most resistant). Besides, the shikimic acid accumulation tests corroborated the results observed in the dose-response assays. 11 alternative herbicides from 6 different mode of action (MOA) were applied at field doses as control alternatives on populations H-5 and H-6 (both in the same regions). The H-5 population showed an unexpected resistance to flazasulfuron (ALS-inhibitor). The ALS enzyme activity studies indicated that the I50 for H-5 was 63.3 fold higher compared to its correspondent susceptible population (H-6). Therefore, the H-5 population exhibited multiple-resistance to flazasulfuron and glyphosate, being the first case reported in Europe for this two MOA. For that reason, the other herbicides with different MOA have to be tested here.

scholarly journals First Case of Conyza canadensis from Hungary with Multiple Resistance to Glyphosate and Flazasulfuron

Agronomy ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 157 ◽  
Author(s):  
Candelario Palma-Bautista ◽  
Behroz Khalil Tahmasebi ◽  
Pablo Tomás Fernández-Moreno ◽  
Antonia M. Rojano-Delgado ◽  
Ricardo Alcántara de la Cruz ◽  
...  
Keyword(s):  
Dose Response ◽  
Shikimic Acid ◽  
Multiple Resistance ◽  
Conyza Canadensis ◽  
Poor Control ◽  
Susceptible Population ◽  
First Case ◽  
Whole Plant ◽  
Acid Accumulation ◽  
Als Inhibitor

Conyza canadensis is a species invading large areas throughout the world, mainly due to its ability to evolve herbicide resistance. In Hungary, extensive areas have been infested by this species due to the difficulty in controlling it with glyphosate. To determine whether poor control was a result of misapplication or glyphosate resistance, eight suspected glyphosate-resistant C. canadensis populations from different Hungarian regions were studied. In whole-plant dose-response assays with glyphosate, the LD50 and GR50 values (survival and fresh weight reduction at 50% relative to the untreated control, respectively) indicated that resistance was confirmed in five of the eight populations (H-5 population being the most resistant). Additionally, the shikimic acid accumulation tests corroborated the results observed in the dose–response assays. 11 alternative herbicides from six different modes of action (MOA) were applied at field doses as control alternatives on populations H-5 and H-6 (both in the same regions). The H-5 population showed an unexpected resistance to flazasulfuron (ALS-inhibitor). The ALS enzyme activity studies indicated that the I50 for H-5 with flazasulfuron was 63.3 times higher compared to its correspondent susceptible population (H-6). Therefore, the H-5 population exhibited multiple-resistance to flazasulfuron and glyphosate, being the first case reported in Europe for these two MOA.

Annual Bluegrass (Poa annua) Control with Methiozolin and Nutrient Tank-Mixtures

2017 ◽  
Vol 31 (5) ◽  
pp. 761-768 ◽  
Author(s):  
Michael L. Flessner ◽  
J. Scott McElroy ◽  
James D. McCurdy
Keyword(s):  
Ammonium Sulfate ◽  
Creeping Bentgrass ◽  
Poa Annua ◽  
Iron Sulfate ◽  
Golf Course ◽  
Putting Greens ◽  
Annual Bluegrass ◽  
And Control ◽  
Selective Herbicide

Methiozolin is a selective herbicide that has been reported to control annual bluegrass in creeping bentgrass putting greens. Golf course managers frequently tank-mix fertilizers with herbicides to reduce time and labor, but no information is available regarding such mixtures with methiozolin. Research was conducted to evaluate methiozolin for annual bluegrass control and creeping bentgrass safety when tank-mixed with ammonium sulfate or iron sulfate. Mixtures with ammonium sulfate did not influence annual bluegrass control while they did reduce creeping bentgrass injury in some instances. Mixtures with iron sulfate varied by experimental run but annual bluegrass control was either similar or increased while creeping bentgrass injury did not vary. Paclobutrazol was included as an alternative agrochemical comparison for annual bluegrass management; its application resulted in similar control and injury with and without iron sulfate addition, and injury and control were similar to methiozolin at appropriate rates. While some differences were observed, overall annual bluegrass and creeping bentgrass response to methiozolin was not affected by tank-mix nutrient partner relative to methiozolin applied alone.

scholarly journals A Monte Carlo Determination of Dose and Range Uncertainties for Preclinical Studies with a Proton Beam

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1889
Author(s):  
Arthur Bongrand ◽  
Charbel Koumeir ◽  
Daphnée Villoing ◽  
Arnaud Guertin ◽  
Ferid Haddad ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Proton Beam ◽  
Dose Response ◽  
Small Animal ◽  
Absorbed Dose ◽  
Normal Tissue Damage ◽  
Dose Homogeneity ◽  
And Control ◽  
The Impact

Proton therapy (PRT) is an irradiation technique that aims at limiting normal tissue damage while maintaining the tumor response. To study its specificities, the ARRONAX cyclotron is currently developing a preclinical structure compatible with biological experiments. A prerequisite is to identify and control uncertainties on the ARRONAX beamline, which can lead to significant biases in the observed biological results and dose–response relationships, as for any facility. This paper summarizes and quantifies the impact of uncertainty on proton range, absorbed dose, and dose homogeneity in a preclinical context of cell or small animal irradiation on the Bragg curve, using Monte Carlo simulations. All possible sources of uncertainty were investigated and discussed independently. Those with a significant impact were identified, and protocols were established to reduce their consequences. Overall, the uncertainties evaluated were similar to those from clinical practice and are considered compatible with the performance of radiobiological experiments, as well as the study of dose–response relationships on this proton beam. Another conclusion of this study is that Monte Carlo simulations can be used to help build preclinical lines in other setups.

scholarly journals Validation study on urinary biomarkers of exposure for aflatoxin B1, ochratoxin A, fumonisin B1, deoxynivalenol and zearalenone in piglets

2013 ◽  
Vol 6 (3) ◽  
pp. 299-308 ◽  
Author(s):  
S. Gambacorta ◽  
H. Solfrizzo ◽  
A. Visconti ◽  
S. Powers ◽  
A.M. Cossalter ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Dose Response ◽  
Fumonisin B1 ◽  
Correlation Coefficients ◽  
Urinary Biomarkers ◽  
Post Dose ◽  
Toxigenic Fungi ◽  
Biomarkers Of Exposure ◽  
Commission Recommendation ◽  
Aflatoxin B

The multi-biomarker approach was used to validate urinary biomarkers in piglets administered boluses contaminated with mixtures of deoxynivalenol (DON), aflatoxin B1 (AFB1), fumonisin B1 (FB1), zearalenone (ZEA) and ochratoxin A (OTA) at different concentrations. Boluses contaminated with mycotoxins were prepared by slurrying and freezedrying feed material fortified with culture extracts of selected toxigenic fungi. Piglets were individually placed in metabolic cages to collect urine before gavage and 24 h post dose. Urine samples were hydrolysed with β-glucuronidase and analysed by a multi-biomarker LC-MS/MS method developed and validated to identify and measure biomarkers of FB1, OTA, DON, ZEA and AFB1. Urinary levels of FB1, OTA, DON + de-epoxy-deoxynivalenol, ZEA + alphazearalenol and aflatoxin M1 were selected as biomarkers of FB1, OTA, DON, ZEA and AFB1, respectively. Mean percentages of dietary mycotoxins excreted as biomarkers in 24 h post dose urine were 36.8% for ZEA, 28.5% for DON, 2.6% FB1, 2.6% for OTA and 2.5% for AFB1. A good correlation was observed between the amount of mycotoxins ingested and the amount of relevant biomarkers excreted in 24 h post dose urine. Linear dose-response correlation coefficients ranged between 0.68 and 0.78 for the tested couples of mycotoxin/biomarker. The good sensitivity of the LC-MS/MS method and the good dose-response correlations observed in this study permitted to validate the selected mycotoxin biomarkers in piglets at dietary levels close to the maximum permitted levels reported in Commission Directive 2003/100/EC for AFB1 and the guidance values reported in Commission Recommendation 2006/576/EC for DON, ZEA, OTA and FB1.

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