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Characterization Of Genetic Resistance To Diclofop In Italian Ryegrass, R E. Barker, G W. Mueller-Warrant, S M. Griffith, G M. Banowetz Aug 2024

Characterization Of Genetic Resistance To Diclofop In Italian Ryegrass, R E. Barker, G W. Mueller-Warrant, S M. Griffith, G M. Banowetz

IGC Proceedings (1993-2023)

Diclofop ( (:t)-2-[4-(2,4 • dichlorophenoxy) phenoxy] propanoic acid} has been used to control annual grasses in cereals since 1980 in the Willamette Valley of Oregon, USA. Populations of Italian ryegms (Lolillm multiflorum Lam.) resistant to diclofop were recently discovered. Progenies from resistant plants crossed with plants from the susceptible cvs. Marshall and Gulf were sib-mated and backcrossed to Marshall or Gulf. Resultant F2 and backcross families were screened for survival when sprayed with 1.4 kg/ha diclofop-methyl. Segregation ratios of live to dead plants showed that resistance is determined by 2 genes when a dominant allele is present at each …


Managing Crop Weeds, Department Of Primary Industries And Regional Development, Western Australia Jan 2024

Managing Crop Weeds, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

In-crop weed competition causes losses costing around $1 billion per annum for Western Australia. There are effective strategic and tactical options available to manage weed competition that will increase crop yields and profitability.

Weeds with herbicide resistance are an increasing problem in grain cropping enterprises. Integrated weed management (IWM) is a system for managing weeds over the long term and is particularly useful for managing and minimising herbicide resistance.

Growers are advised to adopt integrated weed management (IWM) to reduce the damage caused by herbicide-resistant weeds.

Herbicide resistant weed populations are found throughout all cropping areas of Western Australia. The …


The Silver Bullet That Wasn’T: Rapid Agronomic Weed Adaptations To Glyphosate In North America, Christopher Landau, Kevin Bradley, Erin Burns, Michael Flessner, Karla Gage, Aaron Hager, Joseph Ikley, Prashant Jha, Amit Jhala, Paul O. Johnson, William Johnson, Sarah Lancaster, Travis Legleiter, Dwight Lingenfelter, Mark Loux, Eric Miller, Jason Norsworthy, Micheal Owen, Scott Nolte, Debalin Sarangi, Peter Sikkema, Christy Sprague, Mark Vangessel, Rodrigo Werle, Bryan Young, Martin M. Williamsii Oct 2023

The Silver Bullet That Wasn’T: Rapid Agronomic Weed Adaptations To Glyphosate In North America, Christopher Landau, Kevin Bradley, Erin Burns, Michael Flessner, Karla Gage, Aaron Hager, Joseph Ikley, Prashant Jha, Amit Jhala, Paul O. Johnson, William Johnson, Sarah Lancaster, Travis Legleiter, Dwight Lingenfelter, Mark Loux, Eric Miller, Jason Norsworthy, Micheal Owen, Scott Nolte, Debalin Sarangi, Peter Sikkema, Christy Sprague, Mark Vangessel, Rodrigo Werle, Bryan Young, Martin M. Williamsii

Department of Agronomy and Horticulture: Faculty Publications

The rapid adoption of glyphosate-resistant crops at the end of the 20th century caused a simplification of weed management that relied heavily on glyphosate for weed control. However, the effectiveness of glyphosate has diminished. A greater understanding of trends related to glyphosate use will shed new light on weed adaptation to a product that transformed global agriculture. Objectives were to (1) quantify the change in weed control efficacy from postemergence (POST) glyphosate use on troublesome weeds in corn and soybean and (2) determine the extent to which glyphosate preceded by a preemergence (PRE) improved the efficacy and consistency of weed …


Survey And Prevalence Of Palmer Amaranth Herbicide Resistance In South Carolina, Mitchell Williams Aug 2023

Survey And Prevalence Of Palmer Amaranth Herbicide Resistance In South Carolina, Mitchell Williams

All Theses

Palmer amaranth is a troublesome weed for growers to control, not only due to its aggressive growth characteristics that limit row-crop production, but because of its resistance to different herbicide modes of action. The first case of herbicide resistance in Palmer amaranth was detected in 1989 and has since grown to nine different herbicide classes throughout the United States. New herbicide modes of action have not been developed since the 1980s, so proper stewardship of the remaining modes of action is important for effective control of Palmer amaranth. Increased herbicide resistance from states bordering South Carolina have been reported; therefore, …


Imiflex Evaluation At Two Kansas Locations In Igrowth Grain Sorghum, P. W. Geier, R. S. Currie, S. H. Lancaster, C. M. Weber Jan 2023

Imiflex Evaluation At Two Kansas Locations In Igrowth Grain Sorghum, P. W. Geier, R. S. Currie, S. H. Lancaster, C. M. Weber

Kansas Agricultural Experiment Station Research Reports

Herbicide-tolerant grain sorghums, such as Igrowth (imidazolinone-resistant) hybrids were recently commercialized in Kansas. Even though the active ingredient of the herbicide associated with these systems, imazamox, is used in other crops, data are needed to define best practices for use in grain sorghum. The objective of these studies was to evaluate ImiFlex (imazamox) herbicide in Igrowth grain sorghum at two Kansas locations in 2022. ImiFlex applied postemergence provided 93% volunteer corn control, and 90 to 95% johnsongrass control regardless of application timing at Garden City. At Manhattan, ImiFlex controlled Palmer amaranth 90 to 99%. Early season grain sorghum injury was …


Winter Cover Crop Impacts On Weed Dynamics In Eastern And Central Nebraska, Elizabeth Ann Oys Apr 2022

Winter Cover Crop Impacts On Weed Dynamics In Eastern And Central Nebraska, Elizabeth Ann Oys

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Reducing tillage in cropping systems causes weed management to be dependent on chemical and cultural methods for weed control. Over time, herbicide-resistant weeds have developed due to the continuous selection pressures from herbicides, particularly in the Midwest Corn Belt. Integrated weed management strategies, such as cover crops, can be used to mitigate some of these issues. Cover crops are primarily known for their soil health benefits, but there is evidence that cover crops can suppress weeds. However, less research has been done at the field-scale level to address cover crop impacts on the weed seedbank and aboveground weeds during the …


Impact And Liberty Rates And Mixtures For Efficacy In Corn, R. S. Currie, P. W. Geier Jan 2021

Impact And Liberty Rates And Mixtures For Efficacy In Corn, R. S. Currie, P. W. Geier

Kansas Agricultural Experiment Station Research Reports

The objective of the study was to compare Impact (topramezone), Liberty (glufosinate) and a premixture of the two herbicides (Sinate) for efficacy in corn. Rates for each herbicide were 0.75 and 1.0 oz/a for Impact, 22 and 30 oz/a for Liberty, and 21 and 28 oz/a for Sinate. Impact and Sinate, each at the high rates, and Status plus glyphosate provided the best kochia control for corn late in the season. These treatments, along with the low rate of Impact controlled crabgrass the best. Status was also the best treatment for Russian thistle, Palmer amaranth, and green foxtail control. The …


Fallow Weed Control With Liberty And Enlist One Tank Mixtures And Application Timings, R. S. Currie, P. W. Geier Jan 2021

Fallow Weed Control With Liberty And Enlist One Tank Mixtures And Application Timings, R. S. Currie, P. W. Geier

Kansas Agricultural Experiment Station Research Reports

This study evaluated Liberty (glufosinate) and Enlist One (2,4-D choline) at three application timings and with various tank mix partners for weed control in fallow. Most herbicides tested controlled 94% or more of volunteer sorghum 17 days after the late postemergence treatments in the season. Conversely, Palmer amaranth and crabgrass control was less than 90% with most herbicides. However, control of these species was good when Tricor, or Zidua plus OpTill were applied preemergence followed by Liberty or Liberty and Enlist One late postemergence.


Resistance To Herbicides Conferred By Amaranthus Palmeri Protoporphyrinogen Ix Oxidase Mutations, Pamela Carvalho De Lima Dec 2020

Resistance To Herbicides Conferred By Amaranthus Palmeri Protoporphyrinogen Ix Oxidase Mutations, Pamela Carvalho De Lima

Graduate Theses and Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats.) is one of the most problematic agronomic weeds to control in fields across Arkansas. Thus far, this species has evolved resistance to several herbicides, including protoporphyrinogen IX oxidase (PPO) inhibitors. The majority of PPO-resistant Palmer amaranth populations harbor a target-site mutation (substitution or deletion of amino acids). The objective of this thesis was to identify the level of fomesafen resistance conferred by PPO2 mutations from Palmer amaranth. The experiments conducted aimed to (1) characterize the level of resistance conferred by the transgene Palmer amaranth ppo2 carrying ΔG210 mutation into the wild type rice (Oryza …


Vida Tank Mixtures For Postemergence Weed Control In Fallow, R. S. Currie, P. W. Geier Jan 2020

Vida Tank Mixtures For Postemergence Weed Control In Fallow, R. S. Currie, P. W. Geier

Kansas Agricultural Experiment Station Research Reports

The objective of the study was to compare Vida (pyraflufen ethyl) with various tank mix partners for weed control in fallow. All herbicides controlled flixweed and tansymustard 96% or more by 16 days after treatment. Treatments containing Spartan provided faster and better kochia control compared to other herbicides, and these treatments were the only ones to control kochia 95% or more late in the season.


Mitigating Herbicide Impacts To Soybean, Grant Lawson Priess Dec 2019

Mitigating Herbicide Impacts To Soybean, Grant Lawson Priess

Graduate Theses and Dissertations

The rapidity in evolution of herbicide-resistant weeds and the resulting cost to U.S. farmers demonstrate the need to responsibly steward the limited number of herbicides available in agricultural systems. To reduce weed emergence and likewise added selection pressures placed on herbicides, early-season crop canopy formation has been promoted. However, impacts to soybean following a potentially injurious herbicide application have not been thoroughly evaluated. Therefore, field experiments were conducted to determine whether: 1) soybean injury from metribuzin or flumioxazin delayed canopy formation or changed the incidence of pathogen colonization; 2) residual herbicides applied preplant reduced the potential for soybean injury and …


Use Of Harvest Weed Seed Control Strategies In Arkansas Soybean, Jeremy Kyle Green Dec 2019

Use Of Harvest Weed Seed Control Strategies In Arkansas Soybean, Jeremy Kyle Green

Graduate Theses and Dissertations

Today, most growers use chemical weed management programs; however, a sole reliance on herbicides will place more resistance selection pressure on the weeds to which the herbicide is being applied. As herbicide resistance continues to grow and rob growers of yield, alternative weed control options are being sought to create complex integrated weed management programs to prolong the use of effective herbicides. Harvest weed seed control (HWSC) is a non-chemical practice that has been widely adopted in Australia due to herbicide resistance problems. In most cases, herbicide-resistant weeds that survive applications of herbicides produce viable seed that pass through the …


Herbicide Drift Influence On Amaranthus Spp. Herbicide Resistance Evolution, Bruno Canella Vieira Jul 2019

Herbicide Drift Influence On Amaranthus Spp. Herbicide Resistance Evolution, Bruno Canella Vieira

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The adverse consequences of herbicide drift towards sensitive crops have been extensively reported in the literature. However, no information is available on the consequences of herbicide drift onto weed species inhabiting boundaries of agricultural fields. Exposure to herbicide drift could be detrimental to long-term weed management as several weed species have evolved herbicide resistance after recurrent selection with low herbicide rates. Despite the herbicide drift exposure and its potential implications on resistance evolution and weed management, resistance prone weed species such as Palmer amaranth (Amaranthus palmeri) and waterhemp (Amaranthus tuberculatus) are often neglected and not properly …


Liberty Compared To Glyphosate Products In Irrigated Corn, R. S. Currie, P. W. Geier Jan 2019

Liberty Compared To Glyphosate Products In Irrigated Corn, R. S. Currie, P. W. Geier

Kansas Agricultural Experiment Station Research Reports

Postemergence treatments of Liberty (glufosinate) were compared to Durango DMA and Roundup PowerMax (glyphosate) after various preemergence treatments for efficacy in corn. Control of common sunflower, green foxtail, Russian thistle, and quinoa exceeded 92% regardless of herbicide treatment or evaluation date. Similarly, all preemergence (PRE) treatments controlled Palmer amaranth, kochia, and crabgrass by 93% or more. Later in the season, control of kochia was slightly less when Verdict (saflufenacil/dimethenamid) and atrazine PRE was followed by Roundup PowerMax and atrazine postemergence (POST). Palmer amaranth and crabgrass control was less when Verdict and atrazine PRE was followed by Roundup PowerMax or Liberty …


Application Timing Efficacy Of Enlist Duo In Irrigated Corn, R. S. Currie, P. W. Geier Jan 2019

Application Timing Efficacy Of Enlist Duo In Irrigated Corn, R. S. Currie, P. W. Geier

Kansas Agricultural Experiment Station Research Reports

In this study, herbicides were tested to compare application timing for weed control in irrigated corn. All herbicides tested provided season-long control (90% or more) of Palmer amaranth, Russian thistle, quinoa, and common sunflower. The inclusion of Enlist Duo to SureStart II as an early postemergence (V2) treatment increased kochia and johnsongrass control compared to a preemergence treatment of SureStart II alone early in the season. However, by later in the year, control of kochia and johnsongrass was best when Enlist Duo application was delayed until the V4 stage. Enlist Duo provided equal control of all weeds when applied at …


Relative Contribution Of Physical Interference And Allelopathy To Weed Suppression By Winter Annual Cover Crop Mixtures, Alyssa D. Travlos Dec 2018

Relative Contribution Of Physical Interference And Allelopathy To Weed Suppression By Winter Annual Cover Crop Mixtures, Alyssa D. Travlos

MSU Graduate Theses

Cover cropping systems are widely used in crop production systems to prevent erosion, improve soil health, and suppress weeds. Common cover cropping systems include combinations of cereal rye (Secale cereale L.), Brassica species, legumes, and other winter annual species. Three cover crop mixtures (cereal rye alone, cereal rye plus winter pea, and cereal rye plus winter pea plus radish) were applied using three methods (fresh residue, dried leached residue, and leachate) to common waterhemp (Amaranthus tuberculatus var. rudis) and large crabgrass [Digitaria sanguinalis (L.) Scop.]. The experiment was conducted once in a greenhouse and once in a …


Managing Herbicide Resistance: Listening To The Perspectives Of Practitioners. Procedures For Conducting Listening Sessions And An Evaluation Of The Process, Jill Schroeder, Michael Barrett, David R. Shaw, Amy B. Asmus, Harold Coble, David Ervin, Raymond A. Jussaume Jr., Micheal D. K. Owen, Ian Burke, Cody F. Creech, A. Stanley Culpepper, William S. Curran, Darrin M. Dodds, Todd A. Gaines, Jeffrey L. Gunsolus, Bradley D. Hanson, Prashant Jha, Annie E. Klodd, Andrew R. Kniss, Ramon G. Leon, Sandra Mcdonald, Don W. Morishita, Brian J. Schutte, Christy L. Sprague, Phillip W. Stahlman, Larry E. Steckel, Mark J. Vangessel Aug 2018

Managing Herbicide Resistance: Listening To The Perspectives Of Practitioners. Procedures For Conducting Listening Sessions And An Evaluation Of The Process, Jill Schroeder, Michael Barrett, David R. Shaw, Amy B. Asmus, Harold Coble, David Ervin, Raymond A. Jussaume Jr., Micheal D. K. Owen, Ian Burke, Cody F. Creech, A. Stanley Culpepper, William S. Curran, Darrin M. Dodds, Todd A. Gaines, Jeffrey L. Gunsolus, Bradley D. Hanson, Prashant Jha, Annie E. Klodd, Andrew R. Kniss, Ramon G. Leon, Sandra Mcdonald, Don W. Morishita, Brian J. Schutte, Christy L. Sprague, Phillip W. Stahlman, Larry E. Steckel, Mark J. Vangessel

Plant and Soil Sciences Faculty Publications

Seven half-day regional listening sessions were held between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide-resistance management. The objective of the listening sessions was to connect with stakeholders and hear their challenges and recommendations for addressing herbicide resistance. The coordinating team hired Strategic Conservation Solutions, LLC, to facilitate all the sessions. They and the coordinating team used in-person meetings, teleconferences, and email to communicate and coordinate the activities leading up to each regional listening session. The agenda was the same across all sessions and included small-group discussions followed by reporting …


Comparison Of Soil-Applied And Postemergence Herbicides With Multiple Sites Of Herbicidal Activity On Two Populations Of Herbicide-Resistant Palmer Amaranth In Kentucky, Nicholas J. Fleitz Jan 2018

Comparison Of Soil-Applied And Postemergence Herbicides With Multiple Sites Of Herbicidal Activity On Two Populations Of Herbicide-Resistant Palmer Amaranth In Kentucky, Nicholas J. Fleitz

Theses and Dissertations--Plant and Soil Sciences

With the introduction of herbicide resistant Palmer amaranth into Kentucky during the past 10 years there has been an increasing concern for effective control measures in grain production. Field trials were performed in 2016 and 2017 near Barlow and Paris, KY to determine efficacy of chemical control programs targeting herbicide resistant Palmer amaranth. Percent visual control, effects on plant density and plant height were measured in 2016 to determine treatment effectiveness. Treatments containing four different sites of herbicide activity achieved an average of 98% control. Treatments containing only 3, 2 or 1 site of activity only achieved 64%, 45% and …


Managing Wicked Herbicide-Resistance: Lessons From The Field, Jill Schroeder, Michael Barrett, David R. Shaw, Amy B. Asmus, Harold Coble, David Ervin, Raymond A. Jussaume Jr., Michael D. K. Owen, Ian Burke, Cody F. Creech, A. Stanley Culpepper, William S. Curran, Darrin M. Dodds, Todd A. Gaines, Jeffrey L. Gunsolus, Bradley D. Hanson, Prashant Jha, Annie E. Klodd, Andrew R. Kniss, Ramon G. Leon, Sandra Mcdonald, Don W. Morishita, Brian J. Schutte, Christy L. Sprague, Phillip W. Stahlman, Larry E. Steckel, Mark J. Vangessel Jan 2018

Managing Wicked Herbicide-Resistance: Lessons From The Field, Jill Schroeder, Michael Barrett, David R. Shaw, Amy B. Asmus, Harold Coble, David Ervin, Raymond A. Jussaume Jr., Michael D. K. Owen, Ian Burke, Cody F. Creech, A. Stanley Culpepper, William S. Curran, Darrin M. Dodds, Todd A. Gaines, Jeffrey L. Gunsolus, Bradley D. Hanson, Prashant Jha, Annie E. Klodd, Andrew R. Kniss, Ramon G. Leon, Sandra Mcdonald, Don W. Morishita, Brian J. Schutte, Christy L. Sprague, Phillip W. Stahlman, Larry E. Steckel, Mark J. Vangessel

Department of Agronomy and Horticulture: Faculty Publications

Herbicide resistance is ‘wicked’ in nature; therefore, results of the many educational efforts to encourage diversification of weed control practices in the United States have been mixed. It is clear that we do not sufficiently understand the totality of the grassroots obstacles, concerns, challenges, and specific solutions needed for varied crop production systems. Weed management issues and solutions vary with such variables as management styles, regions, cropping systems, and available or affordable technologies. Therefore, to help the weed science community better understand the needs and ideas of those directly dealing with herbicide resistance, seven half-day regional listening sessions were held …


Dicamba-Tolerant Volunteer Soybean, Palmer Amaranth, And Green Foxtail Control In Irrigated Field Corn, R. S. Currie, P. W. Geier Jan 2018

Dicamba-Tolerant Volunteer Soybean, Palmer Amaranth, And Green Foxtail Control In Irrigated Field Corn, R. S. Currie, P. W. Geier

Kansas Agricultural Experiment Station Research Reports

Dicamba-tolerant soybean control was best when Armezon (topramezone) or Armezon Pro (topramezone + dimethenamid) was applied POST with atrazine and glyphosate, and when Status (dicamba + diflufenzopyr), atrazine, and glyphosate were applied POST. These treatments, along with PRE treatments of Armezon Pro and atrazine, completely controlled soybean. Similarly, control of Palmer amaranth and green foxtail was generally best with Armezon Pro and atrazine applied PRE or any herbicide combination applied POST. Corn receiving PRE treatments yielded 41 to 120 bu/a more grain than the weedy checks, whereas corn treated POST yielded 117 to 145 bu/a more grain than the untreated …


Impact Of Automated Guidance For Mechanical Control Of Herbicide-Resistant Weeds In Corn, Terry Griffin, James M. Lowenberg-Deboer Oct 2017

Impact Of Automated Guidance For Mechanical Control Of Herbicide-Resistant Weeds In Corn, Terry Griffin, James M. Lowenberg-Deboer

Journal of Applied Farm Economics

This study evaluated the feasibility of reintroducing mechanical weed control as an alternative for herbicide-resistance weed infestations. The production practice tested included row cultivation with a separate banded spray application using high-accuracy automated guidance systems. A range of ground speeds were tested for the row cultivation operation, each with a different per acre cost and timeliness penalty. A typical eastern Corn Belt farm with a rotation of corn and soybean served as the base for the linear programming model. It was found that if the farmer was willing to reintroduce tillage, row cultivation conducted at higher operating speeds in conjunction …


The Biology And Management Of Palmer Amaranth (Amaranthus Palmeri S. Wats) In Indiana, Douglas J. Spaunhorst Dec 2016

The Biology And Management Of Palmer Amaranth (Amaranthus Palmeri S. Wats) In Indiana, Douglas J. Spaunhorst

Open Access Dissertations

Palmer amaranth is a pernicious summer annual weed that has evolved resistance to six herbicide sites of action in the U.S. and threatens agriculture production. In 2011, Palmer amaranth was identified in flood plains in two southern Indiana counties (Posey and Vanderburgh). Determining if Palmer amaranth can survive and reproduce in northern Indiana may provide insight if this weed will be problematic for northern row crop producers. The objectives of our research were to identify fields containing Palmer amaranth and determine the distribution of herbicide resistance traits in Indiana; determine the influence of tillage frequency and tillage intervals on Palmer …


Glyphosate-Resistant Weed Control And Soybean Injury In Response To Different Ppo-Inhibiting Herbicides, Jatinder S. Aulakh, P. S. Chahal, Amit J. Jhala Jan 2016

Glyphosate-Resistant Weed Control And Soybean Injury In Response To Different Ppo-Inhibiting Herbicides, Jatinder S. Aulakh, P. S. Chahal, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

In Nebraska, 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) as well as acetolactate synthase (ALS)-inhibitor-resistant weeds occur in many soybean fields where herbicides from these modes-of-action have been frequently used in the past. Currently, the protoporphyrinogen oxidase (PPO)-inhibitors are the only effective herbicides for POST control of both glyphosate- and ALS-inhibitor-resistant weeds in soybean. Greenhouse experiments were conducted in 2014 to evaluate the efficacy of PPO-inhibitors applied POST for the control of three glyphosate-resistant (GR) weeds and potential for soybean injury, when applied at two growth stages. All herbicide treatments controlled 10- and 20-cm tall GR common waterhemp ≥ 95% at 21 DAT. …


Assessing Multiple-Herbicide Resistance In A 2,4-D Resistant Waterhemp (Amaranthus Tuberculatus) Biotype From Nebraska – Student Research, Roberto Crespo Oct 2015

Assessing Multiple-Herbicide Resistance In A 2,4-D Resistant Waterhemp (Amaranthus Tuberculatus) Biotype From Nebraska – Student Research, Roberto Crespo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

A waterhemp biotype was recently reported resistant to 2,4-D in Nebraska. In addition to the repeated use of 2,4-D, atrazine and imazathapyr were reported to be frequently used to control broadleaf weeds. Greenhouse experiments were conducted to confirm 2,4-D resistance and test for resistance to growth regulator herbicides and other herbicide modes-of-action (MoA). A single dose-response experiment showed reduced sensitivity in all three waterhemp biotypes to atrazine, imazethapyr and lactofen; therefore, they were generally considered resistant to those three herbicide MoA. None of the biotypes contained the Ser264 target-site mutation. Since the ametryn dose-response experiment resulted in all susceptible biotypes, …


Biology And Control Of Glyphosate-Resistant Giant Ragweed., Simranpreet Kaur Mar 2015

Biology And Control Of Glyphosate-Resistant Giant Ragweed., Simranpreet Kaur

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Giant ragweed is a troublesome, early emerging, summer annual weed found throughout the eastern and midwestern corn and soybean growing regions of the United States. Since the emergence of giant ragweed varies at different locations, our first objective was to determine the emergence pattern of giant ragweed in Nebraska and how spring tillage influences emergence. Results of a two-year study suggested that giant ragweed emerged from late March until mid-June, with the majority of emergence ceasing by early May. Spring tillage could be used as an alternative method for managing glyphosate resistant giant ragweed.

Water stress can affect the growth …


Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith May 2013

Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith

Graduate Theses and Dissertations

Since 2000, there have been thirteen weed species confirmed resistant (R) to glyphosate in the United States, six of those resistant species are present in Arkansas. The goal of this research was to confirm and to determine the level of resistance in two R Palmer amaranth biotypes from Mississippi (MC-R) and Lincoln (LC-R) Counties, Arkansas, and one susceptible (S) biotype from Clarendon County, South Carolina, which had never been exposed to glyphosate. Shikimic acid concentration over time was significantly greater in the S biotype than both the MC-R and LC-R biotypes. The lethal dose required to kill 50% (LD50 …


Response Of Nebraska Horseweed (Conyza Canadensis) Populations To Dicamba, Roberto Crespo, Mark L. Bernards, Greg Kruger, Donald Lee, Robert Wilson Jr. Apr 2013

Response Of Nebraska Horseweed (Conyza Canadensis) Populations To Dicamba, Roberto Crespo, Mark L. Bernards, Greg Kruger, Donald Lee, Robert Wilson Jr.

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism-of-action for postemergence weed control in soybean. Numerous broadleaf species, including horseweed, have evolved resistance to glyphosate. It is anticipated that dicamba will be used by farmers as a primary tool to manage these weeds. Studying and understanding variability in horseweed response to dicamba will aid in developing appropriate risk management strategies to extend the utility of the dicamba-resistance technology. Horseweed plants from ten Nebraska populations were treated with one of nine doses of dicamba in greenhouse experiments. At 28 days after treatment (DAT) visual injury estimations were made and …


Herbicide Resistance Mechanism(S) In Italian Ryegrass (Lolium Perenne Ssp. Multiflorum) Populations In The Southern United States, Reiofeli Algodon Salas May 2012

Herbicide Resistance Mechanism(S) In Italian Ryegrass (Lolium Perenne Ssp. Multiflorum) Populations In The Southern United States, Reiofeli Algodon Salas

Graduate Theses and Dissertations

Italian ryegrass is a principal weed problem in wheat production fields in the Southern US. Resistance to herbicides diclofop, mesosulfuron, and pinoxaden among ryegrass populations has been reported. Glyphosate-resistant Italian ryegrass populations were identified in Desha County, Arkansas. This research aimed to 1) determine resistance patterns to ACCase (diclofop and pinoxaden) and ALS (imazamox, mesosulfuron, and pyroxsulam) herbicides among Italian ryegrass populations from the southern US; 2) determine if cytochrome P450-mediated enhanced herbicide metabolism contributed to resistance; and 3) elucidate the resistance mechanism to glyphosate in four Arkansas populations (Des03, Des05, Des14, and D8). For objective 1, 30 accessions from …


Crop Updates 2010 - Weeds, Lorinda Hunt, Andrew Blake, Catherine Borger, Glen Riethmuller, Abul Hashem, Harmohinder Dhammu, David Nicholson, Vince Lambert, Russell Quartermaine, Roberto Busi, Todd Gaines, Sudheesg Manalil, Stephen Powles, Aik Cheam, Siew Lee, Peter Newman, Greg Doncon, Steve Davies, Michael Walsh, John Moore, Murray Gillespie, Sally Peltzer, Alex Douglas Feb 2010

Crop Updates 2010 - Weeds, Lorinda Hunt, Andrew Blake, Catherine Borger, Glen Riethmuller, Abul Hashem, Harmohinder Dhammu, David Nicholson, Vince Lambert, Russell Quartermaine, Roberto Busi, Todd Gaines, Sudheesg Manalil, Stephen Powles, Aik Cheam, Siew Lee, Peter Newman, Greg Doncon, Steve Davies, Michael Walsh, John Moore, Murray Gillespie, Sally Peltzer, Alex Douglas

Crop Updates

This session covers eighteen papers from different authors:

Herbicides

1. Herbicide control of slender iceplant, Lorinda Hunt, and Andrew Blake Department of Agriculture and Food

2. Herbicide tolerance of saltbush and bluebush, Lorinda Hunt, and Andrew Blake Department of Agriculture and Food

3. Chemical control of windmill grass, Catherine Borger, Glen Riethmuller and Abul Hashem, Department of Agriculture and Food

4. Use high water rates when applying pre-seeding herbicides to fields with high stubble density, Catherine Borger and Abul Hashem, Department of Agriculture and Food

5. Herbicide tolerance of lupins – influence of soil type and …


Crop Updates 2010 - Crop Specific, Hugh J. Beckie, Wallace Cowling, T. N. Khan, K. Adhikari, K. Siddique, J. Garlinge, L. Smith, S. Morgan, C. Boyd, Ian Pritchard, Chris Veitch, Alan Harris, Tony Leonforts, Murray Blyth, Shari Dougal, Kristy Hobson, Ben Curtis, Doug Sawkins, D. Stephens, Ciara Beard, Kith Jayasena, Kazue Tanaka, Anne Smith, Brenda Coutts, Roger Jones, Jean Galloway, Pip Payne, Tess Humphreys, William Macleod, Ravjit Khangura, M. Aberra, H. Mian, Geoff Thomas, Dusty Severtson, Peter Mangano, Monica Kehoe, Madeline A. Tucker, Neil Barker, Robert Loughman, Larisa Cato, Ken Quail, Mohammad Amjad, Mark Seymour, Justin Kudnig, Mark Thompson, Anton Mannes, Michael Uttley, Chris Fletcher, Andrew Etherton, Nick Joyce, Kate Light, Peter Hamblin, Michael Lamond, Alan Meldrum, Wayne Parker, Steve Penny Jr, Sarah Ellis, Brenda Shackley, Christine Zaicou, Shajahan Miyan, Darshan Sharma, Ben Curtis, Greg Shea, Bevan Buirchell, David Harris, Bob French Feb 2010

Crop Updates 2010 - Crop Specific, Hugh J. Beckie, Wallace Cowling, T. N. Khan, K. Adhikari, K. Siddique, J. Garlinge, L. Smith, S. Morgan, C. Boyd, Ian Pritchard, Chris Veitch, Alan Harris, Tony Leonforts, Murray Blyth, Shari Dougal, Kristy Hobson, Ben Curtis, Doug Sawkins, D. Stephens, Ciara Beard, Kith Jayasena, Kazue Tanaka, Anne Smith, Brenda Coutts, Roger Jones, Jean Galloway, Pip Payne, Tess Humphreys, William Macleod, Ravjit Khangura, M. Aberra, H. Mian, Geoff Thomas, Dusty Severtson, Peter Mangano, Monica Kehoe, Madeline A. Tucker, Neil Barker, Robert Loughman, Larisa Cato, Ken Quail, Mohammad Amjad, Mark Seymour, Justin Kudnig, Mark Thompson, Anton Mannes, Michael Uttley, Chris Fletcher, Andrew Etherton, Nick Joyce, Kate Light, Peter Hamblin, Michael Lamond, Alan Meldrum, Wayne Parker, Steve Penny Jr, Sarah Ellis, Brenda Shackley, Christine Zaicou, Shajahan Miyan, Darshan Sharma, Ben Curtis, Greg Shea, Bevan Buirchell, David Harris, Bob French

Crop Updates

This session covers twenty four papers from different authors:

PLENARY

1. Challenges facing western Canadian cropping over the next 10 years, Hugh J Beckie, Research Centre, Agriculture and Agri-Food Canada, Saskatoon,

Saskatchewan

CROP SPECIFIC

Breeding

2. The challenge of breeding canola hybrids – new opportunities for WA growers, Wallace Cowling, Research Director, Canola Breeders Western Australia Pty Ltd

3. Chickpea 2009 crop variety testing of germplasm developed by DAFWA/CLIMA/ICRISAT/COGGO alliance. Khan, TN1,3, Adhikari, K1,3, Siddique, K2, Garlinge, J1, Smith, L1, Morgan, S1 and Boyd, C1 1Department …