scholarly journals Confirmation of Glyphosate- and Acetolactate Synthase (ALS)-Inhibitor-Resistant Kochia (Kochia scoparia) in Nebraska

2016 ◽  
Vol 8 (10) ◽  
pp. 54
Author(s):  
Neha Rana ◽  
Amit J. Jhala
Keyword(s):  
Great Plains ◽  
Acetolactate Synthase ◽  
The United States ◽  
Future Research ◽  
Kochia Scoparia ◽  
Whole Plant ◽  
Fold Level ◽  
Evolution Of Resistance ◽  
Resistance To Herbicides ◽  
Als Inhibitor

<p>Kochia is an early emerging weed of increasing concern across the Great Plains region of the United States due to the evolution of resistance to herbicides. Greenhouse studies were conducted to confirm and characterize the level of glyphosate and acetolactate synthase (ALS)-inhibiting herbicide resistance in kochia biotype collected from a field in Sheridan County in Nebraska. The response of kochia biotype to 9 rates (0 to 16×) of tribenuron and glyphosate was evaluated in a whole plant dose-response bioassay. On the basis of the values at the 90% effective dose (ED<sub>90</sub>), the putative-resistant kochia biotype had a 6- and 15-fold level of resistance to glyphosate and tribenuron, respectively. Future research will evaluate strategies for the management of glyphosate- and ALS-resistant kochia under field conditions.</p>

Glyphosate- and acetolactate synthase inhibitor-resistant kochia (Bassia scoparia) control in field pea

2021 ◽  
Author(s):  
Alysha T Torbiak ◽  
Robert Blackshaw ◽  
Randall N Brandt ◽  
Bill Hamman ◽  
Charles M. Geddes
Keyword(s):  
Great Plains ◽  
Field Experiments ◽  
Rapid Evolution ◽  
Acetolactate Synthase ◽  
Field Pea ◽  
Visible Injury ◽  
Crop Harvest ◽  
Selection For ◽  
Synthase Inhibitor ◽  
Als Inhibitor

Kochia [Bassia scoparia (L.) A.J. Scott] is an invasive C4 tumbleweed in the Great Plains of North America, where it impedes crop harvest and causes significant crop yield losses. Rapid evolution and spread of glyphosate- and acetolactate synthase (ALS) inhibitor-resistant kochia in western Canada limit the herbicide options available for control of these biotypes in field pea (Pisum sativum L.); one of the predominant pulse crops grown in this region. Field experiments were conducted near Lethbridge, Alberta in 2013-2015 and Coalhurst, Alberta in 2013-2014 to determine which herbicide options effectively control glyphosate- and ALS inhibitor-resistant kochia in field pea. Visible injury of field pea was minor (0-4%) in all environments except for Lethbridge 2013, where pre-plant (PP) flumioxazin and all treatments containing post-emergence (POST) imazamox/bentazon resulted in unacceptable (14-23%) pea visible injury. Herbicide impacts on pea yield were minor overall. Carfentrazone + sulfentrazone PP and saflufenacil PP followed by imazamox/bentazon POST resulted in ≥80% visible control of kochia in all environments, while POST imazamox/bentazon alone resulted in ≥80% reduction in kochia biomass in all environments compared with the untreated control (albeit absent of statistical difference in Coalhurst 2014). These results suggest that layering the protoporhyrinogen oxidase-inhibiting herbicides saflufenacil or carfentrazone + sulfentrazone PP with the ALS- and photosystem II-inhibiting herbicide combination imazamox/bentazon POST can effectively control glyphosate- and ALS inhibitor-resistant kochia in field pea while also mitigating further selection for herbicide resistance through the use of multiple effective herbicide modes-of-action.

Imidazolinone and Sulfonylurea Resistance in a Biotype of Common Waterhemp (Amaranthus rudis)

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 789-794 ◽  
Author(s):  
Sarah Taylor Lovell ◽  
Loyd M. Wax ◽  
Michael J. Horak ◽  
Dallas E. Peterson
Keyword(s):  
Acetolactate Synthase ◽  
The United States ◽  
Cross Resistance ◽  
Common Waterhemp ◽  
Whole Plant ◽  
Amaranthus Rudis ◽  
Plant Level ◽  
High Degree ◽  
Selection Agent ◽  
Weed Resistance

The incidence of weed resistance to acetolactate synthase (ALS) inhibiting herbicides has increased in the United States. In 1993, a population of ALS-resistant common waterhemp was discovered after two confirmed applications of an imidazolinone herbicide. Following another imazethapyr application in the glasshouse, the resistant biotype demonstrated 130-fold resistance to imazethapyr at the whole plant level. The concentration of imazethapyr required to inhibit the ALS activity by 50% was 520 times greater for the resistant biotype than the susceptible. Plants also demonstrated cross-resistance to the sulfonylureas, chlorimuron and thifensulfuron, at the whole plant and enzyme levels. This particular discovery is of concern due to the low number of applications of the selection agent (imazaquin 1989, imazethapyr 1992, and imazethapyr in the greenhouse) and the high degree of cross-resistance eliminating several options for weed control.

scholarly journals Cold Climate Winegrape Cultivar Sensitivity to Sulfur in the Northern Great Plains Region of the United States

2017 ◽  
Vol 27 (2) ◽  
pp. 235-239
Author(s):  
Nagehan D. Köycü ◽  
John E. Stenger ◽  
Harlene M. Hatterman-Valenti
Keyword(s):  
United States ◽  
Great Plains ◽  
The United States ◽  
Organic Production ◽  
Cold Climate ◽  
Future Research ◽  
Northern Great Plains ◽  
Research Station ◽  
Injury Incidence ◽  
The North

Elemental sulfur is commonly applied for powdery mildew (Erysiphe necator) protection on winegrape (Vitis sp.). The product may be used in a diversified, integrated disease management system to help prevent fungicide resistance to products with other modes of action. Additionally, sulfur may be used as a control option in organic systems. Applications of sulfur have been known to cause phytotoxic injury to susceptible winegrape cultivars, particularly those stemming from fox grape (Vitis labrusca) parentage. To improve recommendations to producers in the northern Great Plains region of the United States, a comparison of injury incidence and severity, as well as effects on yield characteristics was undertaken for 13 regional cultivars exposed to three sulfur rates (0, 2.4, and 4.8 lb/acre a.i.) at a North Dakota State University Research Station near Absaraka, ND. Overall, four cultivars (Bluebell, Baltica, Sabrevois, and King of the North) of the 13 cultivars tested showed phytotoxic symptoms. Injury severity and incidence of these cultivars differed between years and across rates. ‘Bluebell’ showed consistent and severe sulfur injury symptoms. Injury to the other three susceptible cultivars tended to vary by the given environment, with King of the North generally showing the lowest injury response. Injury symptoms were not found to be associated with the overall yield or cluster weight. Results suggest that alternative spray programs that exclude sulfur-based fungicides should be recommended for ‘Bluebell’, ‘Baltica’, ‘Sabrevois’, and ‘King of the North’, whereas sulfur-based fungicides may be applied to ‘Alpenglow’, ‘ES 12-6-18’, ‘Frontenac’, ‘Frontenac Gris’, ‘La Crescent’, ‘Marquette’, ‘Somerset Seedless’, ‘St. Croix’, and ‘Valiant’. Observations on fruit ripening in 2014 suggest that future research is needed to determine if a reduction of fruit quality may occur in some seasons with repeated sulfur applications or with successive annual sulfur applications for susceptible cultivars if used in an organic production system.

Acetolactate Synthase Resistance in a Common Waterhemp (Amaranthus rudis) Population

1997 ◽  
Vol 11 (1) ◽  
pp. 13-18 ◽  
Author(s):  
John R. R. Hinz ◽  
Micheal D. K. Owen
Keyword(s):  
Plant Material ◽  
Resistance Mechanism ◽  
Acetolactate Synthase ◽  
Grain Amaranth ◽  
Common Waterhemp ◽  
Resistant Species ◽  
Whole Plant ◽  
Amaranthus Rudis ◽  
Inhibitor Resistance ◽  
Als Inhibitor

Research was initiated to determine (a) whether a common waterhemp population was resistant to acetolactate synthase (ALS) inhibiting herbicides, (b) the percentage of the population that was ALS-inhibitor resistant, (c) the resistance mechanism, and (d) the effectiveness of a whole plant assay to detect ALS-inhibitor resistance. ALS-inhibitor resistance was confirmed in a common waterhemp population near Davis City, IA. The Davis City common waterhemp population was cross resistant to both imidazolinone and sulfonylurea herbicides, but not to lactofen. Approximately 10% of the Davis City common waterhemp population was sensitive to a rate of imazaquin 4 times the normal field rate. Davis City common waterhemp isolated ALS was much less sensitive to imazaquin and primisulfuron inhibition than was grain amaranth or an ALS-sensitive common waterhemp isolated ALS. Imazaquin I50values were 366.4 and 3.4 μM for ALS isolated from Davis City common waterhemp and grain amaranth, respectively. Primisulfuron I50values were 3.6 and 0.007 μM for ALS isolated from Davis City common waterhemp and grain amaranth, respectively. A whole plant ALS assay was developed that allowed for much more rapid detection of an ALS-resistant species and used less plant material than a conventional ALS assay.

Negative Cross-Resistance of Acetolactate Synthase Inhibitor–Resistant Kochia (Kochia scoparia) to Protoporphyrinogen Oxidase– and Hydroxyphenylpyruvate Dioxygenase–Inhibiting Herbicides

2012 ◽  
Vol 26 (3) ◽  
pp. 570-574 ◽  
Author(s):  
Hugh J. Beckie ◽  
Eric N. Johnson ◽  
Anne Légère
Keyword(s):  
Growth And Development ◽  
Null Hypothesis ◽  
Acetolactate Synthase ◽  
Pleiotropic Effect ◽  
Cross Resistance ◽  
Kochia Scoparia ◽  
Protoporphyrinogen Oxidase ◽  
Synthase Inhibitor ◽  
Sites Of Action ◽  
Als Inhibitor

This greenhouse experiment examined the response of homozygous susceptible and acetolactate synthase (ALS) inhibitor–resistant plants from six Canadian kochia accessions with the Pro197 or Trp574 mutation to six alternative herbicides of different sites of action. The null hypothesis was ALS-inhibitor–resistant and –susceptible plants from within and across accessions would respond similarly to herbicides of different sites of action. This hypothesis was accepted for all accessions except that of MBK2 with the Trp574 mutation. Resistant plants of that accession were 80, 60, and 50% more sensitive than susceptible plants to pyrasulfotole, mesotrione (hydroxyphenylpyruvate dioxygenase [HPPD] inhibitors), and carfentrazone (protoporphyrinogen oxidase [PPO] inhibitor), respectively. However, no differential dose response between resistant and susceptible plants of this kochia accession to bromoxynil, fluroxypyr, or glyphosate was observed. A previous study had found marked differences in growth and development between resistant and susceptible plants of this accession, but not of the other accessions examined in this experiment. Negative cross-resistance exhibited by resistant plants of accession MBK2 to PPO and HPPD inhibitors in this experiment may be a pleiotropic effect related to the Trp574 mutation.

scholarly journals Triple-resistant kochia [Kochia scoparia (L.) Schrad.] in Alberta

2019 ◽  
Vol 99 (2) ◽  
pp. 281-285 ◽  
Author(s):  
Hugh J. Beckie ◽  
Linda M. Hall ◽  
Scott W. Shirriff ◽  
Elise Martin ◽  
Julia Y. Leeson
Keyword(s):  
Mode Of Action ◽  
Acetolactate Synthase ◽  
Kochia Scoparia ◽  
Synthetic Auxin ◽  
Als Inhibitor ◽  
Dicamba Resistance

A randomized stratified survey was conducted in Alberta in 2017 to determine the distribution and abundance of multiple-resistant [acetolactate synthase (ALS) inhibitor, glycine, and synthetic auxin] kochia. All populations were ALS inhibitor resistant, with glyphosate and dicamba resistance confirmed in 50% and 18% of populations, respectively. Ten percent of populations exhibited resistance to all three mode-of-action herbicides.

scholarly journals Sustaining Cross-Timbers Forest Resources: Current Knowledge and Future Research Needs

2019 ◽  
Vol 11 (17) ◽  
pp. 4703 ◽  
Author(s):  
Omkar Joshi ◽  
Rodney E. Will ◽  
Chris B. Zou ◽  
Gehendra Kharel
Keyword(s):  
Ecosystem Services ◽  
Great Plains ◽  
Tallgrass Prairie ◽  
Deciduous Forest ◽  
Current Knowledge ◽  
The United States ◽  
Future Research ◽  
Cross Timbers ◽  
Eastern Deciduous Forest ◽  
The Cross

The Cross-Timbers region of the United States, situated in the southern Great Plains along the western edge of the eastern deciduous forest, was historically Quercus-dominated open forest interspersed with tallgrass prairie and shrubs communities. The historical structure of the Cross- Timbers forests in this region has been altered, mainly due to fire exclusion, such that the current structure is closed-canopy and includes a midstory of fire-intolerant species. This change has reduced many of the important ecosystem services provided. This paper synthesizes existing literature on the Cross-Timbers with the aim of summarizing the current state of Cross-Timbers management related to sustaining ecosystem services and identifying potential research topics and directions needed. Specifically, we consider the ecological, management, and socio-economic issues. In addition, we theorize how the adoption of active forest management will affect ecosystem services and structure of the Cross-Timbers forests.

Herbicide diagnostics reveal multiple patterns of synthetic auxin resistance in kochia (Bassia scoparia)

2021 ◽  
pp. 1-28
Author(s):  
Charles M. Geddes ◽  
Mallory L. Owen ◽  
Teandra E. Ostendorf ◽  
Julia Y. Leeson ◽  
Shaun M. Sharpe ◽  
...  
Keyword(s):  
Great Plains ◽  
Dose Response ◽  
Weed Management ◽  
Acetolactate Synthase ◽  
The United States ◽  
Cross Resistance ◽  
Visible Injury ◽  
Synthetic Auxin ◽  
Auxin Resistance ◽  
Sites Of Action

Abstract Herbicide-resistant (HR) kochia is a growing problem in the Great Plains region of Canada and the United States (U.S.). Resistance to up to four herbicide sites of action, including photosystem II inhibitors, acetolactate synthase inhibitors, synthetic auxins, and the 5-enolpyruvylshikimate-3-phosphate synthase inhibitor glyphosate have been reported in many areas of this region. Despite being present in the U.S. since 1993/1994, auxinic-HR kochia is a recent and growing phenomenon in Canada. This study was designed to characterize (a) the level of resistance and (b) patterns of cross-resistance to dicamba and fluroxypyr in 12 putative auxinic-HR kochia populations from western Canada. The incidence of dicamba-resistant individuals ranged among populations from 0% to 85%, while fluroxypyr-resistant individuals ranged from 0% to 45%. In whole-plant dose-response bioassays, the populations exhibited up to 6.5-fold resistance to dicamba and up to 51.5-fold resistance to fluroxypyr based on visible injury 28 days after application. Based on plant survival estimates, the populations exhibited up to 3.7-fold resistance to dicamba and up to 72.5-fold resistance to fluroxypyr. Multiple patterns of synthetic auxin resistance were observed, where one population from Cypress County, Alberta was resistant to dicamba but not fluroxypyr, while another from Rocky View County, Alberta was resistant to fluroxypyr but not dicamba based on single-dose population screening and dose-response bioassays. These results suggest that multiple mechanisms may confer resistance to dicamba and/or fluroxypyr in Canadian kochia populations. Further research is warranted to determine these mechanisms. Farmers are urged to adopt proactive non-chemical weed management tools in an effort to preserve efficacy of the remaining herbicide options available for control of HR kochia.

scholarly journals Nontarget-Site Resistance to ALS Inhibitors in Waterhemp (Amaranthus tuberculatus)

Weed Science ◽  
2015 ◽  
Vol 63 (2) ◽  
pp. 399-407 ◽  
Author(s):  
Jiaqi Guo ◽  
Chance W. Riggins ◽  
Nicholas E. Hausman ◽  
Aaron G. Hager ◽  
Dean E. Riechers ◽  
...  
Keyword(s):  
Acetolactate Synthase ◽  
Enzyme Assays ◽  
Whole Plant ◽  
Site Of Action ◽  
Amaranthus Tuberculatus ◽  
Resistance Trait ◽  
Als Inhibitors ◽  
Moderate Resistance ◽  
Inhibitor Resistance ◽  
Als Inhibitor

A waterhemp population (MCR) previously characterized as resistant to 4-hydroxyphenylpyruvate dioxygenase and photosystem II inhibitors demonstrated both moderate and high levels of resistance to acetolactate synthase (ALS) inhibitors. Plants from the MCR population exhibiting high resistance to ALS inhibitors contained the commonly found Trp574Leu ALS amino acid substitution, whereas plants with only moderate resistance did not have this substitution. A subpopulation (JG11) was derived from the MCR population in which the moderate-resistance trait was isolated from the Trp574Leu mutation. Results from DNA sequencing and ALS enzyme assays demonstrated that resistance to ALS inhibitors in the JG11 population was not due to an altered site of action. This nontarget-site ALS-inhibitor resistance was characterized with whole-plant dose–response experiments using herbicides from each of the five commercialized families of ALS-inhibiting herbicides. Resistance ratios ranging from 3 to 90 were obtained from the seven herbicides evaluated. Nontarget-site resistance to ALS has been rarely documented in eudicot weeds, and adds to the growing list of resistance traits evolved in waterhemp.

Interspecific Hybridization: Potential for Movement of Herbicide Resistance from Wheat to Jointed Goatgrass (Aegilops cylindrica)

2005 ◽  
Vol 19 (3) ◽  
pp. 674-682 ◽  
Author(s):  
Bradley D. Hanson ◽  
Carol A. Mallory-Smith ◽  
William J. Price ◽  
Bahman Shafii ◽  
Donald C. Thill ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Great Plains ◽  
Herbicide Resistance ◽  
Field Experiments ◽  
Introgressive Hybridization ◽  
Acetolactate Synthase ◽  
The United States ◽  
Aegilops Cylindrica ◽  
Herbicide Resistant ◽  
Jointed Goatgrass

The transfer of herbicide resistance genes from crops to related species is one of the greatest risks of growing herbicide-resistant crops. The recent introductions of imidazolinone-resistant wheat in the Great Plains and Pacific Northwest regions of the United States and research on transgenic glyphosate-resistant wheat have raised concerns about the transfer of herbicide resistance from wheat to jointed goatgrass via introgressive hybridization. Field experiments were conducted from 2000 to 2003 at three locations in Washington and Idaho to determine the frequency and distance that imidazolinone-resistant wheat can pollinate jointed goatgrass and produce resistant F1hybrids. Each experiment was designed as a Nelder wheel with 16 equally spaced rays extending away from a central pollen source of ‘Fidel-FS4’ imidazolinone-resistant wheat. Each ray was 46 m long and contained three rows of jointed goatgrass. Spikelets were collected at maturity at 1.8-m intervals along each ray and subjected to an imazamox screening test. The majority of all jointed goatgrass seeds tested were not resistant to imazamox; however, 5 and 15 resistant hybrids were found at the Pullman, WA, and Lewiston, ID, locations, respectively. The resistant plants were identified at a maximum distance of 40.2 m from the pollen source. The overall frequency of imazamox-resistant hybrids was similar to the predicted frequency of naturally occurring acetolactate synthase resistance in weeds; however, traits with a lower frequency of spontaneous mutations may have a relatively greater risk for gene escape via introgressive hybridization.

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