Auxinic Herbicide Mixtures for Controlling Multiple Herbicide-Resistant Kochia in Fallow

ABSTRACT Use of herbicide mixtures has been advocated as most effective strategy for avoidance and management of herbicide resistant weeds. Effect of twelve selected treatments of four herbicides (clodinafop-propargil, metribuzin, pinoxaden and sulfosulfuron) two-way mixtures at different doses was investigated against fenoxaprop-p-ethyl resistant and susceptible populations of P. minor grown along the wheat plants. In repeated experiment, herbicides mixtures were applied at 3 to 4 leaf stage of P. minor under greenhouse conditions. All the herbicide mixtures were effective to control resistant as well as susceptible P. minor. Mixtures having 75% lethal dose of each mixture component provided best control against P. minor. Mixtures with 50% lethal dose of each herbicide also provided more than 80% control of P. minor. Surviving P. minor plants after exposure to herbicide mixtures showed reduced growth and seed production potential. No mixture combination produced phytotoxic effects on wheat plant up to 75% of lethal dose of each mixture component. Mixtures including clodinafop-propargil + metribuzin, pinoxaden + sulfosulfuron and pinoxaden + metribuzin at 100% dose of each mixture component produced minor phytotoxic effects on wheat plants and caused no reduction in terms of ultimate growth and grain yield. However, mixture of sulfosulfuron + clodinafop-propargil at 100% dose of each component was phytotoxic to wheat and caused significant reduction in term of growth and grain yield. So, farmers can use these mixtures even at 75% of recommended dose of mixture component to control susceptible and resistant P. minor in wheat.

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CONTROL OF HERBICIDE RESISTANT BLACK-GRASS WITH HERBICIDE MIXTURES CONTAINING TRIDIPHANE

Herbicide Resistance in Weeds and Crops ◽

10.1016/b978-0-7506-1101-5.50039-5 ◽

1991 ◽

pp. 429-430

Author(s):

J.C. Caseley ◽

L. Copping ◽

D. Mason

Keyword(s):

Herbicide Resistant ◽

Herbicide Mixtures

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Herbicide mixtures control glyphosate-resistant kochia (Bassia scoparia) in chemical fallow, but their longevity warrants careful stewardship

Canadian Journal of Plant Science ◽

10.1139/cjps-2020-0205 ◽

2020 ◽

Author(s):

Alysha T Torbiak ◽

Robert Blackshaw ◽

Randall N Brandt ◽

Linda M Hall ◽

Bill Hamman ◽

...

Keyword(s):

Weed Management ◽

Integrated Weed Management ◽

Group 14 ◽

Herbicide Resistant ◽

Group 4 ◽

Synthetic Auxins ◽

Auxin Transport Inhibitor ◽

Herbicide Mixtures ◽

Chemical Fallow ◽

Herbicide Programs

Glyphosate-resistant kochia [Bassia scoparia (L.) A.J. Scott], the first known glyphosate-resistant weed in western Canada, was confirmed initially in chemical fallow fields located in Warner County, Alberta in 2011. Further selection, lack of control, and rampant spread of this biotype contributed to its increased incidence, now present in about 50% of kochia populations sampled in Alberta. In 2014 and 2015, herbicide mixtures were evaluated based on control of glyphosate-resistant and susceptible kochia in chemical fallow fields near Lethbridge and Coalhurst, Alberta. The most consistent control (≥ 80% visual control in all environments with ≥ 80% biomass reduction in 2014) was observed with glyphosate + dicamba (450 + 580 g ae ha-1), glyphosate + dicamba/diflufenzopyr (450 + 150/50 g ai/ae ha-1), glyphosate + saflufenacil (450 + 50 g ai/ae ha-1), and glyphosate + carfentrazone + sulfentrazone (450 + 9 + 105 g ai/ae ha-1). Reduced efficacy was observed for several herbicide mixtures when they were applied to glyphosate-resistant compared with glyphosate-susceptible kochia accessions. Effective modes of action mixed with glyphosate include synthetic auxins (group 4), a combination of a synthetic auxin and an auxin transport inhibitor (group 19), or protoporphyrinogen oxidase inhibitors (group 14). In response to glyphosate-resistant kochia, many farmers in this region shifted their herbicide programs resulting in greater reliance on synthetic auxins; likely contributing to the recent discovery of auxinic herbicide-resistant kochia biotypes in Alberta in 2017. Careful herbicide stewardship is warranted to mitigate further selection of multiple herbicide-resistant kochia, suggesting an important role for integrated weed management.

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Modelling the Effectiveness of Herbicide Rotations and Mixtures as Strategies to Delay or Preclude Resistance

Weed Technology ◽

10.1017/s0890037x00025215 ◽

1990 ◽

Vol 4 (1) ◽

pp. 186-198 ◽

Cited By ~ 153

Author(s):

Jonathan Gressel ◽

Lee A. Segel

Keyword(s):

Enzyme System ◽

Acetolactate Synthase ◽

Cross Resistance ◽

Competitive Fitness ◽

Herbicide Resistant ◽

Target Site Resistance ◽

Herbicide Mixtures ◽

Als Inhibitors ◽

And Control ◽

Single Enzyme

Herbicide-resistant populations have evolved only in monoculture and/or monoherbicide conditions at predictable rates for each compound and weed. No populations of triazine-resistant weeds have appeared in corn where rotations of crops and herbicides or herbicide mixtures were used. This is due to the greatly reduced competitive fitness of the resistant individuals, which could be expressed only during rotational cycles, and also to the greater sensitivity of resistant individuals to other herbicides, pests, and control practices (“negative cross-resistance”). The model presented here describes how an understanding of all of these factors can provide strategies to decrease the frequency of the resistant individuals during rotation. Rotations or mixtures may not delay the rate of appearance of resistance to inhibitors of acetolactate synthase (ALS), where the fitness of resistant biotypes is claimed to be near normal. The best way to delay resistance to ALS inhibitors is to use those compounds with less persistence so that the selection pressure will be lowered. Too little is known about the frequency of resistance to other herbicides with target-site resistance–to dinitroanilines, to acetyl CoA carboxylase inhibitors, or to those situations where a single enzyme system confers resistance to a broad spectrum of seemingly unrelated herbicides.

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Quizalofop interactions when mixed with clomazone and pendimethalin in acetyl coenzyme A carboxylase–inhibiting herbicide-resistant rice

Weed Technology ◽

10.1017/wet.2019.59 ◽

2019 ◽

Vol 33 (6) ◽

pp. 778-784 ◽

Cited By ~ 1

Author(s):

Matthew J. Osterholt ◽

Eric P. Webster ◽

David C. Blouin ◽

Benjamin M. McKnight

Keyword(s):

Coenzyme A ◽

Rice Yield ◽

Research Station ◽

Red Rice ◽

Acetyl Coenzyme A ◽

Herbicide Resistant ◽

Leaf Stage ◽

Initial Application ◽

Herbicide Mixtures ◽

Acetyl Coenzyme A Carboxylase

AbstractA study was conducted in 2017 and 2018 at the H. Rouse Caffey Rice Research Station near Crowley, LA, to evaluate quizalofop at 120 g ai ha−1 applied independently or in a mixture with clomazone, pendimethalin, clomazone plus pendimethalin, or a prepackaged mixture of clomazone plus pendimethalin when PVLO1 rice reached the two- to three-leaf stage. A second application of quizalofop at 120 g ha−1 was applied 21 d after the initial application. At 7 days after treatment (DAT), antagonism of quizalofop occurred when mixed with clomazone at 334 g ai ha−1, clomazone at 334 g ai ha−1 plus pendimethalin at 810 g ai ha−1, or a prepackaged mixture of clomazone plus pendimethalin at 334 plus 810 g ai ha−1, respectively, when applied to barnyardgrass. At 7 DAT, a neutral interaction occurred with a mixture of quizalofop plus pendimethalin at 810 g ha−1. These data indicate the antagonism of quizalofop was overcome at 14, 28, and 42 DAT with a neutral interaction for barnyardgrass control, 94% to 98%, with all herbicide mixtures evaluated. A neutral interaction occurred for CL-111, CLXL-745, and red rice control when treated with all the herbicide mixtures evaluated across all evaluation dates. Rice yield decreased when not treated with the initial quizalofop application.

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Herbicide efficacy on Borreria densiflora control in pre- and post-emergence conditions

Planta Daninha ◽

10.1590/s0100-83582014000400017 ◽

2014 ◽

Vol 32 (4) ◽

pp. 817-825 ◽

Cited By ~ 4

Author(s):

B.A.B. Martins ◽

P.J. Christoffoleti

Keyword(s):

Weed Control ◽

Weed Management ◽

Integrated Management ◽

Block Design ◽

Dry Weight ◽

Northeastern Brazil ◽

Weed Species ◽

Herbicide Resistant ◽

Randomized Block Design ◽

Herbicide Mixtures

The weed Borreria densiflora is a management issue in soybean and sugarcane crops from North and Northeastern Brazil. Knowledge upon chemical control of B. densiflora contributes to the integrated management of this weed species, especially when active ingredient options become reduced due to the selection of herbicide resistant or tolerant weed species. Experiments in pre- and post-emergence of B. densiflora were conducted in greenhouse, in a randomized block design and four replications. In pre-emergence, the dose-response curve methodology was used and 7 herbicides were tested. In post-emergence, 9 herbicides at the recommended rate and 4 herbicide mixtures were tested. For pre and post-emergence conditions, evaluations were conducted at 60 and 21 days after treatment (DAT), respectively, and the variables analyzed were weed control and dry weight (%). The results showed options of pre-emergent herbicides that can be used for controlling B. densiflora, especially in sugarcane, where chemical weed control is mainly based on pre-emergent applications. In the current glyphosate resistance scenario, one should consider the use of pre-emergent herbicides within an integrated management of B. densiflora. For satisfactory post-emergence control, B. densiflora plants should be sprayed at the phenological stage of up to three pairs of leaves. Herbicide mixtures have been and will continue to be an important tool in chemical weed management, broadening the spectrum of weed control, while diversifying herbicide mechanisms of action, which helps to prevent or delay the appearance of herbicide resistance.

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Cloning of New Herbicide Resistant Gene in Soil Metagenomics and Generation of Transgenic Rice Plants

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2014.01190 ◽

2014 ◽

Vol 40 (7) ◽

pp. 1190

Author(s):

Yun-Peng WANG ◽

Jing-Yong MA ◽

Rui MA ◽

Jian MA ◽

Wen-Guo LIU

Keyword(s):

Transgenic Rice ◽

Herbicide Resistant ◽

Rice Plants ◽

Resistant Gene ◽

Transgenic Rice Plants ◽

Soil Metagenomics

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Monarch butterfly and milkweed declines substantially predate the use of genetically modified crops

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1811437116 ◽

2019 ◽

Vol 116 (8) ◽

pp. 3006-3011 ◽

Cited By ~ 20

Author(s):

J. H. Boyle ◽

H. J. Dalgleish ◽

J. R. Puzey

Keyword(s):

Genetically Modified ◽

Danaus Plexippus ◽

Genetically Modified Crops ◽

Monarch Butterfly ◽

The United States ◽

Gm Crops ◽

Herbicide Resistant ◽

The Past ◽

Scientific Attention ◽

Herbicide Use

Monarch butterfly (Danaus plexippus) decline over the past 25 years has received considerable public and scientific attention, in large part because its decline, and that of its milkweed (Asclepias spp.) host plant, have been linked to genetically modified (GM) crops and associated herbicide use. Here, we use museum and herbaria specimens to extend our knowledge of the dynamics of both monarchs and milkweeds in the United States to more than a century, from 1900 to 2016. We show that both monarchs and milkweeds increased during the early 20th century and that recent declines are actually part of a much longer-term decline in both monarchs and milkweed beginning around 1950. Herbicide-resistant crops, therefore, are clearly not the only culprit and, likely, not even the primary culprit: Not only did monarch and milkweed declines begin decades before GM crops were introduced, but other variables, particularly a decline in the number of farms, predict common milkweed trends more strongly over the period studied here.

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Establishing white clover (Trifolium repens) as a living mulch: weed control and herbicide tolerance

Weed Technology ◽

10.1017/wet.2021.45 ◽

2021 ◽

pp. 1-28

Author(s):

Nicholas T. Basinger ◽

Nicholas S. Hill

Keyword(s):

Weed Control ◽

White Clover ◽

Cover Crops ◽

Herbicide Tolerance ◽

Single Application ◽

Weed Species ◽

Living Mulch ◽

Herbicide Resistant ◽

Research And Education ◽

Weed Emergence

Abstract With the increasing focus on herbicide-resistant weeds and the lack of introduction of new modes of action, many producers have turned to annual cover crops as a tool for reducing weed populations. Recent studies have suggested that perennial cover crops such as white clover could be used as living mulch. However, white clover is slow to establish and is susceptible to competition from winter weeds. Therefore, the objective of this study was to determine clover tolerance and weed control in established stands of white clover to several herbicides. Studies were conducted in the fall and winter of 2018 to 2019 and 2019 to 2020 at the J. Phil Campbell Research and Education Center in Watkinsville, GA, and the Southeast Georgia Research and Education Center in Midville, GA. POST applications of imazethapyr, bentazon, or flumetsulam at low and high rates, or in combination with 2,4-D and 2,4-DB, were applied when clover reached 2 to 3 trifoliate stage. Six weeks after the initial POST application, a sequential application of bentazon and flumetsulam individually, and combinations of 2,4-D, 2,4-DB, and flumetsulam were applied over designated plots. Clover biomass was similar across all treatments except where it was reduced by sequential applications of 2,4-D + 2,4-DB + flumetsulam in the 2019 to 2020 season indicating that most treatments were safe for use on establishing living mulch clover. A single application of flumetsulam at the low rate or a single application of 2,4-D + 2,4-DB provided the greatest control of all weed species while minimizing clover injury when compared to the non-treated check. These herbicide options allow for control of problematic winter weeds during clover establishment, maximizing clover biomass and limiting canopy gaps that would allow for summer weed emergence.

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Effects of cereal rye seeding rate on waterhemp (Amaranthus tuberculatus) emergence and soybean growth and yield

Weed Technology ◽

10.1017/wet.2021.28 ◽

2021 ◽

pp. 1-25

Author(s):

Mandy Bish ◽

Brian Dintelmann ◽

Eric Oseland ◽

Jacob Vaughn ◽

Kevin Bradley

Keyword(s):

Crop Production ◽

Production Systems ◽

Soil Seed Bank ◽

Linear Regression Analysis ◽

Growth And Yield ◽

Seeding Rate ◽

Early Season ◽

Cereal Rye ◽

Herbicide Resistant ◽

Growing Seasons

Abstract The evolution of herbicide-resistant weeds has resulted in the necessity to integrate non-chemical control methods with chemicals for effective management in crop production systems. In soybean, control of the pigweed species, particularly herbicide-resistant waterhemp and Palmer amaranth, have become predominant concerns. Cereal rye planted as a winter cover crop can effectively suppress early-season weed emergence in soybean, including waterhemp, when planted at a rate of 123 kg ha−1. The objectives of this study were to determine the effects of different cereal rye seeding rates (0, 34, 56, 79, 110, and 123 kg ha−1) on early-season waterhemp suppression and soybean growth and yield. Soybean was planted into fall-seeded cereal rye, which was terminated within four days of soybean planting. The experiment was conducted over the 2018, 2019, and 2020 growing seasons in Columbia, Missouri. Effects of cereal rye on early-season waterhemp suppression varied by year and were most consistent at 56 kg ha−1 or higher seeding rates. Linear regression analysis of cereal rye biomass, height, or stand at soybean planting showed inverse relationships with waterhemp emergence. No adverse effects to soybean growth or yield were observed at any of the cereal rye seeding rates relative to plots that lacked cereal rye cover. Result differences among the years suggest that the successfulness of cereal rye on suppression of early-season waterhemp emergence is likely influenced by the amount of waterhemp seed present in the soil seed bank.

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