Growth and Seed Production of Horseweed (Conyza canadensis) Populations Resistant to Glyphosate, ALS-Inhibiting, and Multiple (Glyphosate + ALS-Inhibiting) Herbicides

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 494-504 ◽  
Author(s):  
Vince M. Davis ◽  
Greg R. Kruger ◽  
Jeff M. Stachler ◽  
Mark M. Loux ◽  
William G. Johnson

Horseweed populations with mixtures of biotypes resistant to glyphosate and acetolactate synthase (ALS)–inhibiting herbicides as well as biotypes with multiple resistance to glyphosate + ALS-inhibiting herbicides have been documented in Indiana and Ohio. These biotypes are particularly problematic because ALS-inhibiting herbicides are commonly tank mixed with glyphosate to improve postemergence horseweed control in soybean. The objective of this research was to characterize the growth and seed production of horseweed populations with resistance to glyphosate or ALS-inhibiting herbicides, and multiple resistance to glyphosate + ALS-inhibiting herbicides. A four-herbicide by four-horseweed population factorial field experiment was conducted in the southeastern region of Indiana in 2007 and repeated in 2008. Four horseweed populations were collected from Indiana or Ohio and confirmed resistant to glyphosate, ALS inhibitors, both, or neither in greenhouse experiments. The four herbicide treatments were untreated, 0.84 kg ae ha−1glyphosate, 35 g ai ha−1cloransulam, and 0.84 kg ae ha−1glyphosate + 35 g ai ha−1cloransulam. Untreated plants from horseweed populations that were resistant to glyphosate, ALS-inhibiting, or multiple glyphosate + ALS-inhibiting herbicides produced similar amounts of biomass and seed compared to populations that were susceptible to those herbicides or combination of herbicides. Furthermore, aboveground shoot mass and seed production did not differ between treated and untreated plants.

2017 ◽  
Vol 31 (3) ◽  
pp. 470-476 ◽  
Author(s):  
James T. Brosnan ◽  
Jose J. Vargas ◽  
Gregory K. Breeden ◽  
Sarah L. Boggess ◽  
Margaret A. Staton ◽  
...  

Methiozolin is an isoxazoline herbicide being investigated for selective POST annual bluegrass control in managed turfgrass. Research was conducted to evaluate methiozolin efficacy for controlling two annual bluegrass phenotypes with target-site resistance to photosystem II (PSII) or enolpyruvylshikimate-3-phosphate synthase (EPSPS)-inhibiting herbicides (i.e., glyphosate), as well as phenotypes with multiple resistance to microtubule and EPSPS or PSII and acetolactate synthase (ALS)-inhibiting herbicides. All resistant phenotypes were established in glasshouse culture along with a known herbicide-susceptible control and treated with methiozolin at 0, 125, 250, 500, 1000, 2000, 4000, or 8000 g ai ha−1. Methiozolin effectively controlled annual bluegrass with target-site resistance to inhibitors of EPSPS, PSII, as well as multiple resistance to EPSPS and microtubule inhibitors. Methiozolin rates required to reduce aboveground biomass of these resistant phenotypes 50% (GR50 values) were not significantly different from the susceptible control, ranging from 159 to 421 g ha−1. A phenotype with target-site resistance to PSII and ALS inhibitors was less sensitive to methiozolin (GR50=862 g ha−1) than a susceptible phenotype (GR50=423 g ha−1). Our findings indicate that methiozolin is an effective option for controlling select annual bluegrass phenotypes with target-site resistance to several herbicides.


2019 ◽  
Vol 37 ◽  
Author(s):  
A. FRANCISCHINI ◽  
J. CONSTANTIN ◽  
R.S. OLIVEIRA JR ◽  
H.K. TAKANO ◽  
R.R. MENDES

ABSTRACT: Herbicide resistance in Amaranthus genus occurs frequently around the word and has become a big problem in cotton producing areas. The objective of this work was to evaluate cross-and multiple-resistance of redroot pigweed (A. retroflexus) to herbicides used in preemergence in cotton fields in Brazil. Seven dose-response experiments were conducted with herbicides atrazine, prometryn, diuron, S-metolachlor, trifluralin, trifloxysulfuron-sodium and pyrithiobac-sodium, and the treatments consisted of application rates of 0, ¼, ½, 1, 2 and 4 times the recommended label rate. Eight A. retroflexus byotipes with suspect of resistance were sampled for experiments in three brazilian states of cotton producing. Resistance to prometryn was confirmed for one biotype in Goiás (GO), and one biotype from Mato Grosso (MT) showed cross-resistance to atrazine and prometryn. One byotipe from GO was identified with cross-resistance to trifloxysulfuron-sodium and pyrithiobac-sodium. One of the GO samples was identified with multiple resistance to prometryn and ALS inhibitors, another one to atrazine and ALS inhibitors, while MT byotipe was confirmed with multiple resistance to triazines and pyrithiobac. The herbicides S-metolachlor, diuron, and trifluralin were efficient for control of this species, therefore, they can be used as managment alternative in those regions.


Weed Science ◽  
2008 ◽  
Vol 56 (4) ◽  
pp. 582-587 ◽  
Author(s):  
Travis R. Legleiter ◽  
Kevin W. Bradley

Field and greenhouse experiments were conducted to determine the level of glyphosate resistance in common waterhemp populations from Platte County (MO1) and Holt County, Missouri (MO2), and to determine the level and distribution of resistance to glyphosate, acetolactate synthase (ALS)–inhibiting herbicides, and protoporophyrinogen oxidase (PPO)–inhibiting herbicides across the MO1 site. Results from greenhouse experiments revealed that the MO1 and MO2 waterhemp populations were 19 and 9 times more resistant to glyphosate, respectively, than a susceptible waterhemp population. In field experiments, greater than 54% of waterhemp at the MO1 site survived 1.7 kg glyphosate ae ha−1(twice the labeled rate) 6 wk after treatment. Tank-mix combinations of ALS- and PPO-inhibiting herbicides with glyphosate also failed to provide complete control of the waterhemp population at the MO1 site. Collection and screening of seed from individual female waterhemp accessions revealed multiple resistance to glyphosate, ALS-, and PPO-inhibiting herbicides across the MO1 site. All 14 waterhemp accessions collected across the MO1 site exhibited greater than 65% survival to 2× rates of glyphosate and thifensulfuron, and these accessions were spread across a 5-km2(503-ha) area. Four waterhemp accessions collected across a 0.9-km2(87-ha) area also exhibited 26 to 38% survival to 2× rates of lactofen. The results from these experiments provide evidence and confirmation of the first glyphosate-resistant waterhemp population in the United States and reveal that multiple resistance to glyphosate, ALS-, and PPO-inhibiting herbicides can occur in waterhemp.


2016 ◽  
Vol 67 (11) ◽  
pp. 1208 ◽  
Author(s):  
Lang Pan ◽  
Haitao Gao ◽  
Han Wu ◽  
Liyao Dong

American sloughgrass (Beckmannia syzigachne Steud.) is a problematic grass that is widely distributed in wheat and oilseed rape fields in China. The herbicides fenoxaprop-P-ethyl and mesosulfuron-methyl failed to control B. syzigachne JCWJ-R populations collected from a wheat field in Jiangsu Province. Dose-response experiments showed that JCWJ-R was resistant to the acetyl-CoA carboxylase (ACCase) inhibitors fenoxaprop-P-ethyl (33.8-fold), haloxyfop-R-methyl (12.7-fold), clethodim (7.8-fold) and pinoxaden (11.6-fold), and to the acetolactate synthase (ALS) inhibitors mesosulfuron-methyl (15.9-fold), pyroxsulam (17.6-fold), flucarbazone-Na (10.7-fold) and imazethapyr (7-fold). Resistance to ALS inhibitors was due to a Pro-197-Ser mutation in the ALS gene and resistance to ACCase inhibitors was due to an Ile-1781-Leu mutation in the ACCase gene. A derived cleaved amplified polymorphic sequence method was developed to detect the ALS mutation in B. syzigachne. This was combined with a previously established method to detect Ile-1781-Leu, and the mutation frequency and homozygous mutation rates in the JCWJ-R population were determined. The evolution of multiple resistance to ACCase and ALS inhibitors in this B. syzigachne population indicated that alternative methods should be developed to control resistant weeds.


2019 ◽  
Vol 33 (2) ◽  
pp. 253-257
Author(s):  
Steven M. Martin ◽  
Jason K. Norsworthy ◽  
Robert C. Scott ◽  
Jarrod Hardke ◽  
Gus M. Lorenz ◽  
...  

AbstractThe increased use of insecticide seed treatments in rice has raised many questions about the potential benefits of these products. In 2014 and 2015, a field experiment was conducted near Stuttgart and Lonoke, AR, to evaluate whether an insecticide seed treatment could possibly lessen injury from acetolactate synthase (ALS)–inhibiting herbicides in imidazolinone-resistant (IR) rice. Two IR cultivars were tested (a hybrid, ‘CLXL745’, and an inbred, ‘CL152’), with and without an insecticide seed treatment (thiamethoxam). Four different herbicide combinations were evaluated: a nontreated control, two applications of bispyribac-sodium (hereafter bispyribac), two applications of imazethapyr, and two applications of imazethapyr plus bispyribac. The first herbicide application was to two- to three-leaf rice, and the second immediately prior to flooding (one- to two-tiller). At both 2 and 4 wk after final treatment (WAFT), the sequential applications of imazethapyr or bispyribac plus imazethapyr were more injurious to CLXL745 than CL152. This increased injury led to decreased groundcover 3 WAFT. Rice treated with thiamethoxam was less injured than nontreated rice and had improved groundcover and greater canopy heights. Even with up to 32% injury, the rice plants recovered by the end of the growing season, and yields within a cultivar were similar with and without a thiamethoxam seed treatment across all herbicide treatments. Based on these results, thiamethoxam can partially protect rice from injury caused by ALS-inhibiting herbicides as well as increase groundcover and canopy height; that is, the injury to rice never negatively affected yield.


Weed Science ◽  
2019 ◽  
pp. 1-8
Author(s):  
Hao Wang ◽  
Hengzhi Wang ◽  
Ning Zhao ◽  
Baolin Zhu ◽  
Penglei Sun ◽  
...  

Abstract A redroot pigweed (Amaranthus retroflexus L.) population (HN-02) collected from Nenjiang County, Heilongjiang Province, exhibited multiple resistance to fomesafen and nicosulfuron. The purposes of this study were to characterize the herbicide resistance status of an HN-02 population for both acetolactate synthase (ALS) and protoporphyrinogen oxidase (PPO) inhibitors and the response to other herbicides and to investigate the target site-based mechanism governing fomesafen and nicosulfuron resistance. Three mutations, Ala-205-Val and Trp-574-Leu mutations in the ALS gene and an Arg-128-Gly mutation in the PPX2 gene, were identified in individual resistant plants. An HN-02F1-1 subpopulation homozygous for the Ala-205-Val and Arg-128-Gly mutations was generated, and whole-plant experiments confirmed multiple resistance to PPO inhibitors (fomesafen, fluoroglycofen-ethyl, and acifluorfen) and ALS inhibitors (imidazolinones [IMI], sulfonylureas [SU], and triazolopyrimidines [TP]) in the HN-02F1-1 plants, which presented resistance index values ranging from 8.3 to 110; however, these plants were sensitive to flumioxazin, fluroxypyr-meptyl, and 2,4-D butylate. In vitro ALS enzyme activity assays revealed that, compared with ALS from susceptible plants, ALS from the HN-02F1-1 plants was 15-, 28- and 320-fold resistant to flumetsulam, nicosulfuron, and imazethapyr, respectively. This study confirms the first case of multiple resistance to PPO and ALS inhibitors in A. retroflexus and determines that the target-site resistance mechanism was produced by Ala-205-Val and Arg-128-Gly mutations in the ALS gene and PPX2 gene, respectively. In particular, the Ala-205-Val mutation was found to endow resistance to three classes of ALS inhibitors: TP, SU, and IMI.


2019 ◽  
Vol 43 ◽  
Author(s):  
Rafael Romero Mendes ◽  
Fernando Storniolo Adegas ◽  
Hudson Kagueyama Takano ◽  
Vanessa Francieli Vital Silva ◽  
Fellipe Goulart Machado ◽  
...  

ABSTRACT Glyphosate has been widely used to control greater beggarticks populations that are resistant to acetolactate synthase (ALS) inhibitors in South America. However, herbicide control failures has been observed over the last three growing seasons in grain production areas of Paraguay. In this research, we report the first case of multiple resistance to glyphosate (EPSPs) and imazethapyr (ALS) in greater beggarticks (Bidens subalternans) population from Paraguay. This conclusion was supported by dose-response experiments conducted in two consecutive years (2018 and 2019) with a putative resistant (R) and a susceptible (S) population. Alternative herbicides were also tested for post-emergence control of R population. For glyphosate, the resistant factor (RF) values were 8.8- (2018) and 15.7-fold (2019). For imazethapyr, the RF values were 59- and 58-fold, in 2018 and 2019, respectively. Treatments with 2,4-D, dicamba, 2,4-D + glyphosate, dicamba + glyphosate, lactofen, fomesafen, ammonium-glufosinate, atrazine, and bentazon provided more than 80% control of the R population. This is the first case of multiple resistance to glyphosate and imazethapyr in greater beggarticks (Bidens subalternans) in the world. The mechanisms underlying resistance in this biotype should be evaluated in future research.


2018 ◽  
Vol 36 ◽  
Author(s):  
E. XAVIER ◽  
M.M. TREZZI ◽  
M.C. OLIVEIRA ◽  
R.A. VIDAL ◽  
A.P. BRUSAMARELLO

ABSTRACT: The characteristics of multiple resistance in Euphorbia heterophylla biotypes to herbicides that are inhibitors of ALS (Acetolactate synthase) and PPO (Protoporphyrinogen oxidase) and their responsible mechanisms are still not completely elucidated. The objectives of this study were to identify cross-resistance to herbicides from different chemical groups of ALS inhibitors (imidazolinones, sulfonylureas, pyrimidyl benzoates and sulfonanilides) and also PPO inhibitors (diphenylethers, phthalamides, oxadiazoles, triazolinones and pyrimidinediones) in E. heterophylla biotypes with multiple resistance to these herbicides; to analyze whether the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) constitute mechanisms that are responsible for the resistance to PPO inhibitors. Initially, the response to doses of herbicides from these different chemical groups was determined, using doses below and above the one recommended for the species. The control of E. heterophylla was determined, estimating the required doses for a 50 and 80% control reduction and calculating the resistance factors. The constitutive and induced activities of the SOD and POD enzymes were also determined. The results confirmed cross-resistance for all chemical groups of ALS and PPO inhibitors in the Bom Sucesso do Sul and Vitorino biotypes. The constitutive and induced activities of the SOD and POD enzymes were superior in plants from the E. heterophylla biotypes Vitorino and Bom Sucesso do Sul, contributing to their resistance to PPO inhibiting herbicides.


Weed Science ◽  
2009 ◽  
Vol 57 (6) ◽  
pp. 652-659 ◽  
Author(s):  
Greg R. Kruger ◽  
Vince M. Davis ◽  
Stephen C. Weller ◽  
J. M. Stachler ◽  
M. M. Loux ◽  
...  

Greenhouse studies were conducted to determine the prevalence of resistance to acetolactate synthase (ALS)-inhibiting herbicides in 266 Indiana horseweed populations, both glyphosate-susceptible and glyphosate-resistant, and to characterize the response of selected biotypes to combinations of glyphosate and cloransulam. Populations with individuals resistant to ALS inhibitors were more frequent in the northern half (38% of the populations in the NW and 50% of the populations in the NE) of Indiana than in the southern half (26% of the populations in the SW and 5% of the populations in the SE). Only 2% of the populations appeared to be resistant to both glyphosate and ALS inhibitors in an initial greenhouse study. Horseweed populations with resistance to ALS inhibitors exhibited herbicide doses required for 50% reduction in plant growth (GR50) values ranging from 14 to 255 g ai ha−1of cloransulam. The resistant : susceptible (R : S) ratio for four horseweed populations with suspected resistance to glyphosate and ALS inhibitors ranged from 0.3 to 50 and from 2.5 to 8.1 for cloransulam and glyphosate, respectively. The tank mixtures exhibited an antagonistic response to 3 of the 16 combinations of cloransulam and glyphosate on the susceptible population. The tank mixtures exhibited primarily an additive response to those same combinations in the multiple-resistant populations, but the response was occasionally synergistic for two of the four populations. The additive response between glyphosate and cloransulam indicates that, where the level of resistance is fairly low, combinations of these herbicides should be more effective for control of multiple-resistant populations compared with application of a single herbicide.


2013 ◽  
Vol 31 (4) ◽  
pp. 867-874 ◽  
Author(s):  
E. Xavier ◽  
M.C. Oliveira ◽  
M.M. Trezzi ◽  
R.A. Vidal ◽  
F. Diesel ◽  
...  

The objective of this study was to determine the activity of the enzyme acetolactate synthase in biotypes of wild poinsettia (Euphorbia heterophylla) with multiple resistance to ALS- and Protox- inhibitors in the presence and absence of imazapyr, imazethapyr and nicosulfuron. We conducted in vitro assay of ALS enzyme extracted from plants of Vitorino, Bom Sucesso do Sul and Medianeira biotypes (with multiple resistance) and a susceptible population in the absence and presence of imazapyr, imazethapyr and nicosulfuron. In the absence of herbicides, biotypes with multiple resistance showed higher affinity for the substrate of the enzyme compared with the susceptible population. The herbicides imazapyr, imazethapyr and nicosulfuron had little effect on the enzyme activity of ALS-resistant biotypes and, conversely, high inhibitory effect on ALS of the susceptible population. Resistance factors were very high, greater than 438, 963 and 474 for Vitorino, Bom Sucesso do Sul and Medianeira biotypes, respectively. The resistance to ALS inhibitors is due to the insensitivity of ALS to herbicides of both imidazolinone and sulfonylurea groups, characterizing a cross-resistance.


Sign in / Sign up

Export Citation Format

Share Document