Glyphosate-Resistant Common Ragweed (Ambrosia artemisiifolia) in Nebraska: Confirmation and Response to Postemergence Corn and Soybean Herbicides

2017 ◽  
Vol 31 (2) ◽  
pp. 225-237 ◽  
Author(s):  
Zahoor A. Ganie ◽  
Amit J. Jhala
Keyword(s):  
United States ◽  
Dose Response ◽  
Acetolactate Synthase ◽  
Ambrosia Artemisiifolia ◽  
Effective Control ◽  
Common Ragweed ◽  
Agronomic Crops ◽  
Whole Plant ◽  
And Control ◽  
Biomass Reduction

Common ragweed is an important broadleaf weed in agronomic crops in the northcentral United States. A common ragweed biotype in glyphosate-resistant (GR) soybean production field in southeast Nebraska was not controlled after sequential applications of glyphosate at the labeled rate. The objectives of this study were to confirm GR common ragweed in Nebraska by quantifying the level of resistance in greenhouse and field whole-plant dose-response studies and to evaluate the response of the putative GR common ragweed to POST corn and soybean herbicides. Greenhouse whole-plant dose-response studies confirmed 7- and 19-fold resistance to glyphosate compared to the known glyphosate-susceptible (GS) biotype based on biomass reduction and control estimates, respectively. Field dose-response studies conducted in 2015 and 2016 at the putative GR common ragweed research site suggested that glyphosate doses equivalent to 15- and 40-times the labeled rate (1,260 gaeha–1) were required for 90% control and biomass reduction, respectively. Response of GR common ragweed to POST soybean herbicides in greenhouse studies indicated ≥89% control with acifluorfen, fomesafen, fomesafen plus glyphosate, glyphosate plus dicamba or 2,4-D choline, glufosinate, imazamox plus acifluorfen, and lactofen. POST corn herbicides, including 2,4-D, bromoxynil, diflufenzopyr plus dicamba, glufosinate, halosulfuron-methyl plus dicamba, mesotrione plus atrazine, and tembotrione provided ≥87% control, indicating that POST herbicides with distinct modes of action are available in corn and soybean for effective control of GR common ragweed. Results also suggested a reduced efficacy of the acetolactate synthase (ALS)-inhibiting herbicides tested in this study for control of GR and GS biotypes, indicating further research is needed to determine whether this biotype has evolved multiple herbicide resistance.

A Biotype of Annual Bluegrass (Poa annua) in Tennessee Is Resistant to Inhibitors of ALS and Photosystem II

Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 321-328 ◽  
Author(s):  
James T. Brosnan ◽  
Gregory K. Breeden ◽  
Jose J. Vargas ◽  
Logan Grier
Keyword(s):  
United States ◽  
Photosystem Ii ◽  
Herbicide Resistance ◽  
Dose Response ◽  
Southeastern United States ◽  
Acetolactate Synthase ◽  
Poa Annua ◽  
Annual Bluegrass ◽  
Leaf Stage ◽  
Whole Plant

Annual bluegrass resistance to inhibitors of acetolactate synthase (ALS) and photosystem II (PSII) in managed turf has been confirmed in the southeastern United States. A biotype of annual bluegrass that had developed resistance (R) to the PSII inhibitor simazine was not controlled by POST applications of foramsulfuron or trifloxysulfuron in 2011 or 2012. In whole plant dose-response experiments, trifloxysulfuron, simazine, and indaziflam controlled a susceptible (S) population of annual bluegrass > 91% when applied POST to nontillering plants. However, trifloxysulfuron applications at 3.5 to 223 g ai ha−1only controlled R annual bluegrass ≤ 40%. Similarly, simazine at 140 to 9,000 g ai ha−1only controlled R annual bluegrass ≤ 20%. R annual bluegrass plants were more tolerant to indaziflam applied POST to leaf stage plants prior to tillering, as rates > 100 g ai ha−1were needed to control R annual bluegrass ≥ 96%. No differences in the activity of ALS in R and S plants exposed to increasing foramsulfuron concentrations from 0 to 100 µM were detected suggesting that nontarget mechanisms could explain reduced efficacy of POST herbicide applications in whole plant dose-response experiments. Applications of indaziflam (35 to 70 g ha−1) and oxadiazon (2,240 to 4,500 g ai ha−1) effectively controlled R annual bluegrass when applied PRE. This biotype of R annual bluegrass is the first reported instance of a weed developing resistance to multiple modes of action in managed turf. Education is needed among turf managers regarding the consequences of exclusive use of the same herbicides for annual bluegrass control leading to the onset of herbicide resistance.

Characterization of a Common Ragweed (Ambrosia artemisiifolia) Population Resistant to ALS- and PPO-Inhibiting Herbicides

Weed Science ◽  
2012 ◽  
Vol 60 (3) ◽  
pp. 335-344 ◽  
Author(s):  
Stephanie L. Rousonelos ◽  
Ryan M. Lee ◽  
Murilo S. Moreira ◽  
Mark J. VanGessel ◽  
Patrick J. Tranel
Keyword(s):  
Dose Response ◽  
Sequence Data ◽  
Resistance Mechanism ◽  
Nuclear Gene ◽  
Acetolactate Synthase ◽  
Ambrosia Artemisiifolia ◽  
Common Ragweed ◽  
Dna Sequence Data ◽  
Molecular Marker Analysis ◽  
Dose Response Study

A population of common ragweed from Delaware was not controlled in the field by herbicides that inhibit acetolactate synthase (ALS) or protoporphyrinogen oxidase (PPO). Research was conducted to ascertain if this population was resistant to these herbicidal modes of action and, if so, to determine the resistance mechanism(s). Resistance was confirmed by dose-response studies on greenhouse-grown plants with multiple ALS- and PPO-inhibiting herbicides. DNA sequence data revealed that resistance to ALS-inhibiting herbicides was due to the previously reported W574L ALS mutation. To assist in determining the mechanism of resistance to PPO-inhibiting herbicides, an F2population was derived from a cross between the resistant biotype (Del-R) and a sensitive biotype (DV1-S). This population segregated in the ratio of three resistant : one sensitive when treated with fomesafen, indicating that resistance to PPO-inhibiting herbicides was conferred by a single, (incompletely) dominant, nuclear gene. Sequences of the target-site genes,PPX1andPPX2, for PPO-inhibiting herbicides were obtained through the screening of a common ragweed cDNA library and subsequent cDNA extension (5′-RACE). Molecular marker analysis with the F2population revealed that thePPX2gene cosegregated with resistance to PPO-inhibiting herbicides. A mutation substituting an arginine codon for a leucine codon at a conserved location (R98L) of thePPX2gene was suspected of being responsible for resistance. By using a transgenicEscherichia colisystem, it was demonstrated that the R98L mutation was sufficient to confer resistance to PPO-inhibiting herbicides. The level of resistance to acifluorfen conferred by the R98L mutation in theE. colisystem was about 31-fold, similar to the level of resistance seen in the whole-plant dose-response study. Last, a DNA-based assay was developed to identify the presence or absence of the common ragweedPPX2R98L mutation. The R98LPPX2mutation is the second mechanism identified for evolved resistance to PPO-inhibiting herbicides.

scholarly journals Interaction of dicamba, fluthiacet-methyl, and glyphosate for control of velvetleaf (Abutilon theopharsti) in dicamba/glyphosate-resistant soybean

2021 ◽  
pp. 1-21
Author(s):  
Jose H. S. de Sanctis ◽  
Amit J. Jhala
Keyword(s):  
United States ◽  
Field Experiments ◽  
The United States ◽  
Application Rate ◽  
Herbicide Application ◽  
Soybean Yield ◽  
Agronomic Crops ◽  
Split Plot ◽  
Main Plot ◽  
Biomass Reduction

Abstract Velvetleaf is an economically important weed in agronomic crops in Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when velvetleaf is greater than 15 cm tall. The objectives of this experiment were to evaluate the interaction of dicamba, fluthiacet-methyl, and glyphosate applied alone or in a mixture in two- or three-way combinations for velvetleaf control in dicamba/glyphosate-resistant (DGR) soybean and to evaluate whether velvetleaf height (≤ 12 cm or ≤ 20 cm) at the time of herbicide application influences herbicide efficacy, velvetleaf density, biomass, and soybean yield. Field experiments were conducted near Clay Center, Nebraska in 2019 and 2020. The experiment was arranged in a split-plot with velvetleaf height (≤ 12 cm or ≤ 20 cm) as the main plot treatment and herbicides as sub-plot treatment. Fluthiacet provided ≥ 94% velvetleaf control 28 d after treatment (DAT) and ≥ 96% biomass reduction regardless of application rate or velvetleaf height. Velvetleaf control was 31% to 74% at 28 DAT when dicamba or glyphosate was applied alone to velvetleaf ≤ 20 cm tall compared with 47% to 100% control applied to ≤ 12 cm tall plants. Dicamba applied alone to ≤ 20 cm tall velvetleaf provided < 75% control and < 87% biomass reduction 28 DAT compared with ≥ 90% control with dicamba at 560 g ae ha−1 + fluthiacet at 7.2 g ai ha−1 or glyphosate at 1,260 g ae ha−1. Dicmaba at 280 g ae ha−1 + glyphosate at 630 g ae ha−1 applied to ≤ 20 cm tall velvetleaf resulted in 86% control 28 DAT compared with the expected 99% control. The interaction of dicamba + fluthiacet + glyphosate was additive for velvetleaf control and biomass reduction regardless of application rate and velvetleaf height.

scholarly journals Confirmation and Control of HPPD-Inhibiting Herbicide–Resistant Waterhemp (Amaranthus tuberculatus) in Nebraska

2017 ◽  
Vol 31 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Maxwel C. Oliveira ◽  
Amit J. Jhala ◽  
Todd Gaines ◽  
Suat Irmak ◽  
Keenan Amundsen ◽  
...  
Keyword(s):  
Dose Response ◽  
Field Conditions ◽  
Effective Control ◽  
Herbicide Resistant ◽  
Greenhouse Experiments ◽  
Amaranthus Tuberculatus ◽  
Sites Of Action ◽  
And Control ◽  
Herbicide Programs

Field and greenhouse experiments were conducted in Nebraska to (1) confirm the 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting resistant-waterhemp biotype (HPPD-RW) by quantifying the resistance levels in dose-response studies, and (2) to evaluate efficacy of PRE-only, POST-only, and PRE followed by POST herbicide programs for control of HPPD-RW in corn. Greenhouse dose-response studies confirmed that the suspected waterhemp biotype in Nebraska has evolved resistance to HPPD-inhibiting herbicides with a 2- to 18-fold resistance depending upon the type of HPPD-inhibiting herbicide being sprayed. Under field conditions, at 56 d after treatment, ≥90% control of the HPPD-RW was achieved with PRE-applied mesotrione/atrazine/S-metolachlor+acetochlor, pyroxasulfone (180 and 270 g ai ha−1), pyroxasulfone/fluthiacet-methyl/atrazine, and pyroxasulfone+saflufenacil+atrazine. Among POST-only herbicide programs, glyphosate, a premix of mesotrione/atrazine tank-mixed with diflufenzopyr/dicamba, or metribuzin, or glufosinate provided ≥92% HPPD-RW control. Herbicide combinations of different effective sites of action in mixtures provided ≥86% HPPD-RW control in PRE followed by POST herbicide programs. It is concluded that the suspected waterhemp biotype is resistant to HPPD-inhibiting herbicides and alternative herbicide programs are available for effective control in corn. The occurrence of HPPD-RW in Nebraska is significant because it limits the effectiveness of HPPD-inhibiting herbicides.

Palmer Amaranth (Amaranthus palmeri) Control by Glufosinate plus Fluometuron Applied Postemergence to WideStrike®Cotton

2013 ◽  
Vol 27 (2) ◽  
pp. 291-297 ◽  
Author(s):  
Kelly A. Barnett ◽  
A. Stanley Culpepper ◽  
Alan C. York ◽  
Lawrence E. Steckel
Keyword(s):  
United States ◽  
Weed Control ◽  
Acetolactate Synthase ◽  
The United States ◽  
Palmer Amaranth ◽  
Effective Control ◽  
Yield Response ◽  
Amaranthus Palmeri ◽  
Cotton Yield ◽  
Cotton Cultivar

Glyphosate-resistant (GR) weeds, especially GR Palmer amaranth, are very problematic for cotton growers in the Southeast and Midsouth regions of the United States. Glufosinate can control GR Palmer amaranth, and growers are transitioning to glufosinate-based systems. Palmer amaranth must be small for consistently effective control by glufosinate. Because this weed grows rapidly, growers are not always timely with applications. With widespread resistance to acetolactate synthase-inhibiting herbicides, growers have few herbicide options to mix with glufosinate to improve control of larger weeds. In a field study using a WideStrike®cotton cultivar, we evaluated fluometuron at 140 to 1,120 g ai ha−1mixed with the ammonium salt of glufosinate at 485 g ae ha−1for control of GR Palmer amaranth 13 and 26 cm tall. Standard PRE- and POST-directed herbicides were included in the systems. Glufosinate alone injured the WideStrike® cotton less than 10%. Fluometuron increased injury up to 25% but did not adversely affect yield. Glufosinate controlled 13-cm Palmer amaranth at least 90%, and there was no improvement in weed control nor a cotton yield response to fluometuron mixed with glufosinate. Palmer amaranth 26 cm tall was controlled only 59% by glufosinate. Fluometuron mixed with glufosinate increased control of the larger weeds up to 28% and there was a trend for greater yields. However, delaying applications until weeds were 26 cm reduced yield 22% relative to timely application. Our results suggest fluometuron mixed with glufosinate may be of some benefit when attempting to control large Palmer amaranth. However, mixing fluometuron with glufosinate is not a substitute for a timely glufosinate application.

scholarly journals Quantifying herbicide dose–response and resistance in Echinochloa spp. by measuring root length in growth pouches

2015 ◽  
Vol 95 (6) ◽  
pp. 1181-1192 ◽  
Author(s):  
C. J. Zhang ◽  
S. H. Lim ◽  
J. W. Kim ◽  
J. S. Song ◽  
M. J. Yook ◽  
...  
Keyword(s):  
Dose Response ◽  
Root Length ◽  
Cost Savings ◽  
Acetolactate Synthase ◽  
Rapid Diagnosis ◽  
Response Curves ◽  
Whole Plant ◽  
Accurate Dose ◽  
Plant Assays ◽  
Als Inhibitors

Zhang, C. J., Lim, S. H., Kim, J. W., Song, J. S., Yook, M. J., Nah, G., Valverde, N. E. and Kim, D. S. 2015. Quantifying herbicide dose–response and resistance in Echinochloa spp. by measuring root length in growth pouches. Can. J. Plant Sci. 95: 1181–1192. The aim of the presented study was to develop a bioassay for rapid diagnosis of herbicide dose–response and resistance in Echinochloa. Pre-germinated seeds of Echinochloa spp. were incubated in growth pouches (18 cm×16.5 cm) containing herbicide solutions in a range of concentrations. Shoot and root lengths were measured after 6 d of incubation. Dose–responses estimated by measuring root lengths in the growth pouches were well-described by the log-logistic dose–response model and similar to those estimated by a whole-plant assay. Accurate dose–response curves were successfully generated for several herbicides with different modes of action, suggesting that the growth pouch method can be used for herbicide bioassays. The suitability of the growth pouch method for rapid diagnosis of acetyl coenzyme-A carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor resistance in Echinochloa spp. was also tested. For cyhalofop-butyl, resistant and susceptible biotypes were discriminated at 180–300 mg a.i. L−1 and 80–120 mg a.i. L−1 for barnyardgrass (E. crus-galli) and late watergrass (E. oryzicola), respectively. For penoxsulam, the discriminatory dosage was 350–500 mg a.i. L−1 for barnyardgrass and 650–1000 mg a.i. L−1 for late watergrass. The method was further used to identify late watergrass biotypes resistant and susceptible to two other ALS inhibitors, azimsulfuron and bispyribac-sodium. Our results show that the growth pouch method can be reliably used in herbicide dose–response studies and to diagnose herbicide resistance in Echinochloa spp., with significant time and cost savings compared with conventional whole-plant assays.

Imidazolinone-Resistant Wheat Acetolactate Synthase In Vivo Response to Imazamox

2005 ◽  
Vol 19 (3) ◽  
pp. 539-548 ◽  
Author(s):  
Curtis R. Rainbolt ◽  
Donald C. Thill ◽  
Robert S. Zemetra ◽  
Dale L. Shaner
Keyword(s):  
Winter Wheat ◽  
Spring Wheat ◽  
Dose Response ◽  
Wheat Cultivar ◽  
Single Gene ◽  
Acetolactate Synthase ◽  
Wheat Cultivars ◽  
Whole Plant ◽  
Wheat Lines

Several experiments were conducted to evaluate the utility of an in vivo acetolactate synthase (ALS) assay for comparing sensitivity to imazamox among imidazolinone-resistant wheat cultivars/lines. Ten single-gene imidazolinone-resistant winter wheat cultivars/lines, one two-gene and four single-gene imidazolinone-resistant spring wheat cultivars/lines, and three pairs of heterozygous and homozygous imidazolinone-resistant winter wheat lines were evaluated in the assay experiments. Additionally, a dose-response assay was conducted to evaluate the tolerance of several imidazolinone-resistant wheat cultivars to imazamox on a whole plant level. The I50value (i.e., the imazamox dose that inhibited ALS activity by 50%) of the winter wheat cultivar ‘Above’ was 54 to 84% higher than the I50values of 99-420, 99-433, and CV-9804. However, based on the results of this study, it is unclear whether genetic background or market class (hard red winter vs. soft white winter) influences the level of ALS inhibition by imazamox. Teal 15A, the two-gene imidazolinone-resistant spring wheat cultivar, had an I50value that was two to three times greater than the I50value of the single-gene imidazolinone-resistant spring wheat cultivars/lines. The heterozygous imidazolinone-resistant wheat lines had I50values that were 69 to 81% less than the I50values of the homozygous lines. In the whole plant dose response, theR50values (i.e., the imazamox dose that reduced biomass by 50%) of the susceptible cultivars Brundage 96 and Conan were 15 to 17 times less than the homozygous single-gene imidazolinone-resistant winter and spring cultivars/lines, whoseR50values were about 1.7 times less than theR50value of the two-gene imidazolinone-resistant spring wheat line, Teal 15A. The results of the in vivo ALS imazamox assays and the whole plant imazamox dose-response assay were similar, indicating that the in vivo assay can be used to accurately and quickly compare resistance between imidazolinone-resistant wheat cultivars/lines.

scholarly journals Grain trade between China and the United States shapes the spatial genetic pattern of common ragweed populations in East China cities

2021 ◽  
Author(s):  
Siran lu ◽  
Xiangyu Luo ◽  
Hongfang Wang ◽  
Rodolfo Gentili ◽  
Sandra Citterio ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
East China ◽  
Effective Control ◽  
Common Ragweed ◽  
Control Programs ◽  
Grain Trade ◽  
Genetic Pattern ◽  
Spatial Genetic Pattern ◽  
Occurrence Records

Abstract Common ragweed (Ambrosia artemisiifolia L.) is an invasive alien species (IAS) that can cause severe allergies among urban residents. Understanding its invasion pathways is critical for designing effective control programs. However, studies on the invasion of common ragweed normally skip urban areas. Results from a few studies based on analyzing occurrence records contain high uncertainties. We attempted to address this knowledge gap through a case study in East China cities by combining the population genetic method with the occurrence records. We first collected leaf samples of 37 common ragweed populations from 15 cities. We then quantified the spatial genetic pattern of common ragweed populations by analyzing genomic and chloroplast DNA extracted from the leaf samples. Combined with the analysis of occurrence data and trade data, we discovered that multiple introductions have impacted the spatial genetic pattern of common ragweed populations in East China Cities. We inferred that the modern-day grain trade between the United States and China could be the primary invasion source while the bridgehead introduction passage through Japan played a minor role. Among the studied cities, Nanjing and Shenyang dispersed more gene flows than other cities. The two cities' central roles in transportation and grain importation might explain the observed pattern. Based on our findings, we suggest that invasive species control programs should consider the potential role of cities as landing points and dispersal hubs of common ragweed in invaded countries.

Association of the W574L ALS substitution with resistance to cloransulam and imazamox in common ragweed (Ambrosia artemisiifolia)

Weed Science ◽  
2005 ◽  
Vol 53 (4) ◽  
pp. 424-430 ◽  
Author(s):  
Danman Zheng ◽  
William L. Patzoldt ◽  
Patrick J. Tranel
Keyword(s):  
Acetolactate Synthase ◽  
Dry Weight ◽  
Ambrosia Artemisiifolia ◽  
Target Site ◽  
Common Ragweed ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Allele Specific ◽  
Treated Plant ◽  
Als Inhibitors

Previous research revealed that resistance to cloransulam in at least one population of common ragweed was conferred by an altered herbicide target site, specifically, by a tryptophan-to-leucine amino acid substitution at position 574 (W574L) of acetolactate synthase (ALS). In this study, 22 common ragweed populations, several of which were suspected cloransulam resistant, were assayed to determine if the W574L ALS substitution was correlated with resistance to ALS inhibitors. From each population, 16 greenhouse-grown plants were treated with cloransulam, and another 16 were treated with imazamox. Plant dry weights were recorded 20 d after treatment and individual plants were considered resistant if their dry weight exceeded 50% of that of nonherbicide-treated controls. For each herbicide-treated plant, allele-specific primers were used in polymerase chain reactions to determine whether the ALS alleles contained leucine or tryptophan codons at position 574. Of the 352 plants treated with cloransulam, 70 were determined to be resistant, and all but two contained one or more Leu574alleles. The frequency of imazamox resistance was much higher than that of cloransulam in the populations, with 149 of 352 plants identified as imazamox resistant. However, only about half (80) of the imazamox-resistant plants contained one or more Leu574alleles. Correlation of imazamox resistance and Leu574alleles was population dependent. ALS activity assays confirmed that imazamox resistance in plants from at least one population was due to an altered target site, even though plants from that population did not have a W574L substitution. These results lead to the conclusion that a Leu574allele is the predominant basis for cloransulam resistance in common ragweed; however, other mechanisms of resistance to ALS inhibitors exist in some populations.

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