Herbicide Resistance in Weed Management

A special issue of Agronomy (ISSN 2073-4395). This special issue belongs to the section "Weed Science and Weed Management".

Deadline for manuscript submissions: closed (31 August 2020) | Viewed by 44981

Special Issue Editors

Department of Plant Pathology and Weed Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel
Interests: non-chemical weed control; remote sensing; precise weed management; integrated weed management

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Guest Editor
Department of Plant Pathology and Weed Research, Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay 30095, Israel
Interests: herbicide resistance; weed physiology; weed management under changing climate

E-Mail Website
Guest Editor
The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
Interests: herbicide resistance; weed control under changing environment; weed genetics

Special Issue Information

Dear Colleagues,

The agriculture community, farmers, and researchers are facing major challenges as our ability to secure food production for future world population is impaired by rapid environmental changes. These extensive changes directly and indirectly endanger crop yield by accelerating excessive fluctuations in weed communities and thus hastening the evolution of herbicide-resistant weed biotypes. Currently, over 500 unique cases of herbicide-resistant weeds have been reported worldwide. These weed populations cause massive yield losses and are hazardous to human health and the environment. Our ability to develop new integrated weed management practices will be one of the most important tools to combat herbicide-resistant weeds. This Special Issue will focus on various aspects of “Herbicide Resistance in Weed Management” following the keywords listed below.

Dr. Ran Lati
Dr. Maor Matzrafi
Prof. Dr. Zvi Peleg
Guest Editor

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Keywords

  • Herbicide-resistant cases (species, modes of action)
  • Mechanisms of herbicide resistance
  • Studies exploring the effects of environmental conditions on herbicide efficacy
  • Alternative methods for herbicide resistance management
  • Novel methods and sensors for the detection of herbicide-resistant weeds (quick tests, molecular, imaging technologies)
  • Invasive herbicide-resistant weeds (origin, population genetics)
  • New herbicide application technologies and non-chemical means for the prevention and management of resistance weeds.

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Published Papers (12 papers)

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Editorial

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4 pages, 203 KiB  
Editorial
Herbicide Resistance in Weed Management
by Maor Matzrafi, Zvi Peleg and Ran Lati
Agronomy 2021, 11(2), 280; https://doi.org/10.3390/agronomy11020280 - 3 Feb 2021
Cited by 12 | Viewed by 4000
Abstract
Herbicides are the most efficient and cost-effective means of weed management [...] Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)

Research

Jump to: Editorial

9 pages, 2023 KiB  
Article
Confirmation and Characterization of the First Case of Acetolactate Synthase (ALS)-Inhibitor—Resistant Wild Buckwheat (Polygonum convolvulus L.) in the United States
by Balaji Aravindhan Pandian, Abigail Friesen, Martin Laforest, Dallas E. Peterson, P. V. Vara Prasad and Mithila Jugulam
Agronomy 2020, 10(10), 1496; https://doi.org/10.3390/agronomy10101496 - 1 Oct 2020
Cited by 3 | Viewed by 3454
Abstract
Wild buckwheat (Polygonum convolvulus L.) is a problem weed and ALS-inhibitors (e.g., chlorsulfuron) are commonly used for its management. Recently, a population of wild buckwheat (KSW-R) uncontrolled with ALS-inhibitors was found in a wheat field in Kansas, USA. The objectives of this [...] Read more.
Wild buckwheat (Polygonum convolvulus L.) is a problem weed and ALS-inhibitors (e.g., chlorsulfuron) are commonly used for its management. Recently, a population of wild buckwheat (KSW-R) uncontrolled with ALS-inhibitors was found in a wheat field in Kansas, USA. The objectives of this research were to determine the level and mechanism of resistance to chlorsulfuron and cross resistance to other ALS-inhibitors in the KSW-R population. In response to chlorsulfuron rates ranging from 0 to 16x (x = 18 g ai/ha), the KSW-R wild buckwheat was found >100-fold more resistant compared to a known ALS-inhibitor susceptible (KSW-S) wild buckwheat. Also, >90% of KSW-R plants survived field recommended rates of sulfonylurea but not imidazolinone family of ALS-inhibitors. A portion of the ALS gene covering all previously reported mutations known to bestow resistance to ALS-inhibitors was sequenced from both KSW-R and KSW-S plants. The Pro-197-Ser substitution that confers resistance to the sulfonylurea herbicides was found in KSW-R plants. Our results support the evolution of high level of chlorsulfuron resistance as a result of a mutation in the ALS-gene in KSW-R buckwheat. This is the first case of resistance to any herbicides in wild buckwheat in the US. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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12 pages, 1180 KiB  
Article
Occurrence and Management of PSII-Inhibitor-Resistant Chenopodium album L. in Atlantic Canadian Potato Production
by Andrew McKenzie-Gopsill, Gavin Graham, Martin Laforest, Sebastian Ibarra, Sheldon Hann and Cameron Wagg
Agronomy 2020, 10(9), 1369; https://doi.org/10.3390/agronomy10091369 - 11 Sep 2020
Cited by 7 | Viewed by 2574
Abstract
Potato producers in the Atlantic Canadian provinces of New Brunswick (NB) and Prince Edward Island (PE) rely on the photosystem II-inhibiting herbicide metribuzin for weed management. Recently, potato producers in the region have reported unacceptable common lambsquarters control following an application of metribuzin. [...] Read more.
Potato producers in the Atlantic Canadian provinces of New Brunswick (NB) and Prince Edward Island (PE) rely on the photosystem II-inhibiting herbicide metribuzin for weed management. Recently, potato producers in the region have reported unacceptable common lambsquarters control following an application of metribuzin. Tissue and seed samples were collected from escaped common lambsquarters populations from across the potato producing regions of NB and PE and screened for the Ser264Gly mutation in psbA. Overall, 46% of sampled populations possessed the Ser264Gly mutation across the region. Cross-resistance testing to atrazine, metribuzin and linuron confirmed populations with the Ser264Gly were resistant to triazines and triazinones but remained susceptible to linuron. Dose response analysis determined a moderate level of resistance to metribuzin in common lambsquarters which would not be controlled in producers fields. A field experiment was conducted in Fredericton, NB and Harrington, PE, to determine if currently registered and unregistered products and tank-mixes would control PSII-inhibitor-resistant common lambsquarters in potato. All evaluated products, with the exception of S-metolachlor, provided control equivalent to the weed-free check without compromising potato yield or quality. This study demonstrates that PSII-inhibitor-resistant common lambsquarters are found in Atlantic Canadian potato production systems, but can be controlled with currently registered herbicides and rates with alternative modes of action. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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13 pages, 1767 KiB  
Article
First Report on Assessing the Severity of Herbicide Resistance to ACCase Inhibitors Pinoxaden, Propaquizafop and Cycloxydim in Six Avena fatua Populations in Ireland
by Vijaya Bhaskar Alwarnaidu Vijayarajan, Patrick D. Forristal, Sarah K. Cook, Jimmy Staples, David Schilder, Michael Hennessy and Susanne Barth
Agronomy 2020, 10(9), 1362; https://doi.org/10.3390/agronomy10091362 - 10 Sep 2020
Cited by 9 | Viewed by 4008
Abstract
In response to growers reports of poor weed control, resistance to ACCase inhibitors pinoxaden, propaquizafop and cycloxydim was investigated in populations of six wild oats, Avena fatua, collected from cereal-dominated crop rotations in Ireland. Glasshouse assays confirmed reduced sensitivity to all three [...] Read more.
In response to growers reports of poor weed control, resistance to ACCase inhibitors pinoxaden, propaquizafop and cycloxydim was investigated in populations of six wild oats, Avena fatua, collected from cereal-dominated crop rotations in Ireland. Glasshouse assays confirmed reduced sensitivity to all three ACCase inhibitors in four of the six populations, R2 to R5. R1 was cross-resistant to pinoxaden and propaquizafop and R6 was resistant to propaquizafop only. Dose-response studies confirmed significant differences in the severity of resistance amongst these populations (p < 0.05). For pinoxaden, the ED50 or GR50 resistance factor (RF) of R1, R3 and R5 were between 11.6 and 13.1 times or 25.1 and 30.2 times more resistant, respectively, compared with the susceptible populations. For propaquizafop, the ED50 and GR50 RF of R1, R2, R3, R5 and R6 were between >7.8 and >32 or 16.6 and 59 times more resistant, respectively. For cycloxydim, only R5 had both high ED50 and GR50 RF values of >43.2 and 98.4 respectively. In R2, although the ED50 values to both pinoxaden and cycloxydim and additionally, R3 to cycloxydim, were above recommended field rates, their GR50 values remained below, suggesting a shift towards cross-resistance. While R4 was the only population, where both ED50 and GR50 for all ACCase inhibitors remained below recommended field rates, they would not give effective control at these rates, strongly indicating evolving resistance. This is the first study reporting variable cross-resistance types and levels to ACCase inhibitors in A. fatua from Ireland. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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9 pages, 775 KiB  
Article
Recurrent Selection with Glufosinate at Low Rates Reduces the Susceptibility of a Lolium perenne ssp. multiflorum Population to Glufosinate
by Maor Matzrafi, Sarah Morran and Marie Jasieniuk
Agronomy 2020, 10(9), 1288; https://doi.org/10.3390/agronomy10091288 - 31 Aug 2020
Cited by 8 | Viewed by 2648
Abstract
Repeated applications of herbicides at the labelled rates have often resulted in the selection and evolution of herbicide-resistant weeds capable of surviving the labelled and higher rates in subsequent generations. However, the evolutionary outcomes of recurrent herbicide selection at low rates are far [...] Read more.
Repeated applications of herbicides at the labelled rates have often resulted in the selection and evolution of herbicide-resistant weeds capable of surviving the labelled and higher rates in subsequent generations. However, the evolutionary outcomes of recurrent herbicide selection at low rates are far less understood. In this study of a herbicide-susceptible population of Lolium perenne ssp. multiflorum, we assessed the potential for low glufosinate rates to select for reduced susceptibility to the herbicide, and cross-resistance to herbicides with other modes of action. Reduced susceptibility to glufosinate was detected in progeny in comparison with the parental population following three rounds of selection at low glufosinate rates. Differences were mainly observed at the 0.5X, 0.75X, and 1X rates. Comparing the parental susceptible population and progeny from the second and third selection cycle, the percentage of surviving plants increased to values of LD50 (1.31 and 1.16, respectively) and LD90 (1.36 and 1.26, respectively). When treated with three alternative herbicides (glyphosate, paraquat, and sethoxydim), no plants of either the parental or successive progeny populations survived treatment with 0.75X or higher rates of these herbicides. The results of this study provide clear evidence that reduced susceptibility to glufosinate can evolve in weed populations following repeated applications of glufosinate at low herbicide rates. However, the magnitude of increases in resistance levels over three generations of recurrent low-rate glufosinate selection observed is relatively low compared with higher levels of resistance observed in response to low-rate selection with other herbicides (three fold and more). Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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13 pages, 2144 KiB  
Article
A Trp574Leu Target-Site Mutation Confers Imazamox Resistance in Multiple Herbicide-Resistant Wild Poinsettia Populations from Brazil
by Rafael R. Mendes, Hudson K. Takano, Rubem S. Oliveira, Jr., Fernando S. Adegas, Todd A. Gaines and Franck E. Dayan
Agronomy 2020, 10(8), 1057; https://doi.org/10.3390/agronomy10081057 - 22 Jul 2020
Cited by 11 | Viewed by 3232
Abstract
Wild poinsettia (Euphorbia heterophylla L.) is an important weed species in southern Brazil, especially due to the evolution of multiple herbicide resistance (e.g., acetolactate synthase (ALS)- inhibitors, protoporphyrinogen oxidase inhibitors, and glyphosate). The mechanism of resistance to imazamox was investigated in two [...] Read more.
Wild poinsettia (Euphorbia heterophylla L.) is an important weed species in southern Brazil, especially due to the evolution of multiple herbicide resistance (e.g., acetolactate synthase (ALS)- inhibitors, protoporphyrinogen oxidase inhibitors, and glyphosate). The mechanism of resistance to imazamox was investigated in two wild poinsettia populations (R1 and R2) from southern Brazil and compared to a known susceptible (S) population. Imazamox dose-response experiments revealed high levels of resistance: 45-fold and 224.5-fold based on dry biomass reduction, for R1 and R2, respectively. Extremely high concentrations of imazamox (20,000 µM) were not sufficient to provide 50% inhibition of ALS enzyme activity (I50) for R1 or R2. Hence, resistance levels were estimated to be greater than 123-fold for both populations based on in vitro ALS assays. The ALS gene from all R1 and R2 plants had a Trp574Leu mutation. A genotyping assay was developed to discriminate resistant and susceptible alleles based on the Trp574Leu mutation. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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13 pages, 299 KiB  
Article
Efficacy of Different Herbicides on Echinochloa colona (L.) Link Control and the First Case of Its Glyphosate Resistance in Greece
by Ilias Travlos, Panagiotis Kanatas, Anastasia Tsekoura, Ioannis Gazoulis, Panayiota Papastylianou, Ioanna Kakabouki and Nikolaos Antonopoulos
Agronomy 2020, 10(7), 1056; https://doi.org/10.3390/agronomy10071056 - 21 Jul 2020
Cited by 19 | Viewed by 5117
Abstract
E. colona is a C4 annual summer grass which is troublesome to major summer annual and perennial crops. Due to recent complaints by the farmers, the objectives of the present study were to evaluate the efficacy of penoxsulam, profoxydim, cycloxydim, cyhalofop-butyl, florpyrauxifen-benzyl [...] Read more.
E. colona is a C4 annual summer grass which is troublesome to major summer annual and perennial crops. Due to recent complaints by the farmers, the objectives of the present study were to evaluate the efficacy of penoxsulam, profoxydim, cycloxydim, cyhalofop-butyl, florpyrauxifen-benzyl and glyphosate against six E. colona accessions, and also to evaluate the response of these accessions to different rates of glyphosate in a dose-response experiment. In the first experiment, herbicides were applied at their maximum recommended label rates, while in the dose-response experiment, glyphosate was applied at six doses corresponding to 0, 1/4X, 1/2X, X, 2X, and 4X of the recommended rate. The dry weight of the biotypes TH8 and TH7 treated with profoxydim was 66% and 68% of the untreated control, respectively. The efficacy of cyhalofop-butyl against three accessions was lower than 30%, while two accessions were susceptible to this herbicide. The efficacy of penoxsulam against the biotypes ET2 and ET4 was lower than 10%, while dry weight of FT5 and TH8 was only reduced by 23%–28% as compared to the control. Cycloxydim application provided control higher than 75% at 21 days after treatment (DAT) of three accessions, while the majority of E. colona accessions was adequately controlled by the application of florpyrauxifen-benzyl. The response of the different accessions to glyphosate varied. The results of the glyphosate dose-response experiment revealed that the GR50 values of the resistant E. colona accessions ET2 and ET4 were up to 1098 and 1220 g a.e. ha−1 of glyphosate, respectively, whereas the GR50 value of the susceptible accession (FT5) was only 98 g a.e. ha−1. The resistance indices of ET2 and ET4 were 12.4 and 11.2, respectively, indicating that they have already developed resistance to glyphosate. Three more accessions could be also of developing resistant to glyphosate. This is the first report of glyphosate resistance from E. colona accessions in Greece, with indications of multiple resistance also present. Further research is needed in order to evaluate the efficacy of several herbicides under different soil and climatic conditions, conduct baseline sensitivity studies, reveal the evolvement of resistance patterns to glyphosate from accessions of Echinochloa spp., and search for alternative options of weed management in annual and perennial crops due to the clear indications of multiple resistance situations. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
23 pages, 3168 KiB  
Article
The Impact of Herbicide Application and Defoliation on Barley Grass (Hordeum murinum subsp. glaucum) Management in Mixed Pasture Legumes
by Jane E. Kelly, Allison J. Chambers, Paul A. Weston, William B. Brown, Wayne A. Robinson, John C. Broster and Leslie A. Weston
Agronomy 2020, 10(5), 671; https://doi.org/10.3390/agronomy10050671 - 11 May 2020
Cited by 2 | Viewed by 3838
Abstract
Barley grass (Hordeum murinum subsp. glaucum.) is an annual weed associated with grain revenue loss and sheep carcass damage in southern Australia. Increasing herbicide resistance led to a recent investigation into effective integrated weed management strategies for barley grass in southern [...] Read more.
Barley grass (Hordeum murinum subsp. glaucum.) is an annual weed associated with grain revenue loss and sheep carcass damage in southern Australia. Increasing herbicide resistance led to a recent investigation into effective integrated weed management strategies for barley grass in southern Australia. Field studies in Wagga Wagga, New South Wales (NSW) during 2016 and 2017 examined the effect of post-emergent herbicide applications and strategic defoliation by mowing on barley grass survival and seed production in a mixed legume pasture. Statistically significant differences between herbicide-only treatments in both years showed propaquizafop to be more than 98% effective in reducing barley grass survival and seed production. Paraquat was not effective in controlling barley grass (58% efficacy), but led to a 36% and 63.5% decrease in clover and other weed biomass, respectively, after 12 months and increased lucerne biomass by over three-fold after 24 months. A single repeated mowing treatment resulted in a 46% decline in barley grass seedling emergence after 12 months and, when integrated with herbicide applications, reduced other weed biomass after 24 months by 95%. Resistance to acetyl-CoA carboxylase (ACCase)-inhibiting herbicides observed in local barley grass populations led to additional and more focused investigation comparing the efficacy of other pre- and post-emergent herbicides for barley grass management in legume pastures. Haloxyfop-R + simazine or paraquat, applied at early tillering stage, were most efficacious in reducing barley grass survival and fecundity. Impact of defoliation timing and frequency on barley grass seedlings was also evaluated at various population densities, highlighting the efficacy of repeated post-inflorescence defoliations in reducing plant survival and seed production. Results highlight the importance of optimal environmental conditions and application timing in achieving efficacious control of barley grass and improving pasture growth and biomass accumulation. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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11 pages, 1609 KiB  
Article
Target Site Resistance to Acetolactate Synthase Inhibitors in Diplotaxis erucoides and Erucaria hispanica–Mechanism of Resistance and Response to Alternative Herbicides
by Maor Matzrafi, Ofri Gerson, Moshe Sibony and Baruch Rubin
Agronomy 2020, 10(4), 471; https://doi.org/10.3390/agronomy10040471 - 29 Mar 2020
Cited by 3 | Viewed by 3067
Abstract
Diplotaxis erucoides and Erucaria hispanica are common weeds of the Mediterranean region; they infest various habitats including cultivated fields and roadsides. In several fields across Israel, farmers have reported on poor control of D. erucoides and E. hispanica plants using acetolactate synthase (ALS) [...] Read more.
Diplotaxis erucoides and Erucaria hispanica are common weeds of the Mediterranean region; they infest various habitats including cultivated fields and roadsides. In several fields across Israel, farmers have reported on poor control of D. erucoides and E. hispanica plants using acetolactate synthase (ALS) inhibitors. Greenhouse experiments were conducted to determine the effect of various ALS inhibitors on plants from two potentially resistant D. erucoides and E. hispanica populations. Additionally, alternative management strategies using auxinic herbicides were studied. Plants from both populations exhibited resistance to all tested ALS inhibitors, up to 20-fold the label field rate, as compared with ALS sensitive populations of D. erucoides and E. hispanica. Sequencing of the ALS gene revealed Trp574 to Leu substitution in ALS-resistant D. erucoides plants, whereas a Pro197 to Ser substitution was detected in ALS-resistant E. hispanica plants. Although high levels of resistance were observed in individuals from both putative resistant populations, sensitive individuals were also detected, suggesting the evolution of resistance in these two populations is still in progress. Auxinic herbicides, 2,4-D, and mecoprop-P, provided excellent control of plants from both ALS-resistant populations. This study documents and confirms the first case of evolution of resistance to ALS inhibitors in D. erucoides and E. hispanica populations. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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10 pages, 1227 KiB  
Article
Glyphosate-Resistant Italian Ryegrass (Lolium perenne L. spp. Multiflorum) Control and Seed Suppression in Mississippi
by Taghi Bararpour, Jason A. Bond, Gurbir Singh, Ralph R. Hale, Matt Edwards and Benjamin H. Lawrence
Agronomy 2020, 10(2), 162; https://doi.org/10.3390/agronomy10020162 - 23 Jan 2020
Cited by 5 | Viewed by 3370
Abstract
Italian ryegrass is a major weed problem in wheat (Triticum aestivum L.) production worldwide. Two separate studies were conducted in Stoneville, Mississippi to evaluate: (1) the efficacy of herbicides available to Mississippi producers for controlling glyphosate-resistant (GR) Italian ryegrass (control study), and [...] Read more.
Italian ryegrass is a major weed problem in wheat (Triticum aestivum L.) production worldwide. Two separate studies were conducted in Stoneville, Mississippi to evaluate: (1) the efficacy of herbicides available to Mississippi producers for controlling glyphosate-resistant (GR) Italian ryegrass (control study), and (2) fall burndown herbicide seed suppression study. Results of the control study showed that flufenacet/metribuzin EPOST followed by (fb) pinoxaden LPOST (standard treatment) provided 93% control of GR Italian ryegrass. Some other treatments provided comparable Italian ryegrass control (92% to 97%) as the standard treatment in 2017. Italian ryegrass control in the seed suppression study was 100%, 100%, 67.5%, 97%, and 99.5% from the application of the following treatments: (1) S-metolachlor + flumioxazin + paraquat in October–November fb glyphosate + clethodim in January–February fb gramoxone as needed (weed-free check); (2) S-metolachlor + flumioxazin + paraquat in October–November; (3) field cultivator (disk) in October–November; (4) glyphosate + clethodim in January–February; and (5) field cultivator in October–November fb glyphosate + clethodim in January–February, respectively. The remaining Italian ryegrass from the application of treatments 3, 4, and 5 produced 65,700; 1008; and 9 seeds m−2, respectively. Seed suppression study highlights the importance of 100% control that is required to manage GR Italian grass. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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18 pages, 1850 KiB  
Article
Glyphosate as a Tool for the Incorporation of New Herbicide Options in Integrated Weed Management in Maize: A Weed Dynamics Evaluation
by Iñigo Loureiro, Inés Santin-Montanyá, María-Concepción Escorial, Esteban García-Ruiz, Guillermo Cobos, Ismael Sánchez-Ramos, Susana Pascual, Manuel González-Núñez and María-Cristina Chueca
Agronomy 2019, 9(12), 876; https://doi.org/10.3390/agronomy9120876 - 11 Dec 2019
Cited by 7 | Viewed by 4239
Abstract
A farm-scale investigation was conducted to evaluate the potential impact of integrating glyphosate into different weed management programs when cultivating herbicide-tolerant maize in central Spain from 2012 to 2014. The weed management programs were (1) a conventional weed management with pre- and post-emergent [...] Read more.
A farm-scale investigation was conducted to evaluate the potential impact of integrating glyphosate into different weed management programs when cultivating herbicide-tolerant maize in central Spain from 2012 to 2014. The weed management programs were (1) a conventional weed management with pre- and post-emergent herbicide applications, (2) a weed management program in which the number and total amount of conventional herbicides applied were reduced, and (3) three weed management programs that comprised either two post-emergent applications of the herbicide glyphosate, or only one glyphosate application combined with pre- and/or post-emergent herbicides. Weed density throughout each cropping season was greater in those weed management programs that did not include a pre-emergence application of herbicides than those that did. Moreover, none of the weed management programs affected the richness and species diversity of the weeds or reduced yields. Although the impact of the different programs was similar in terms of weed species diversity, the composition of the weed community differed and this effect must be considered when providing agroecosystem services. Our results indicate that glyphosate-tolerant maize provides an additional tool that allows integrated weed control of the weed populations without reducing yields. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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13 pages, 434 KiB  
Article
Effect of Different Water Salinity Levels on the Germination of Imazamox-Resistant and Sensitive Weedy Rice and Cultivated Rice
by Silvia Fogliatto, Francesca Serra, Lorenzo Patrucco, Marco Milan and Francesco Vidotto
Agronomy 2019, 9(10), 658; https://doi.org/10.3390/agronomy9100658 - 19 Oct 2019
Cited by 19 | Viewed by 3932
Abstract
Weeds that have become resistant to herbicides may threaten rice production. Rice cultivation is mainly carried out in coastal and river delta areas that often suffer salinity problems. The aims of this study were to evaluate the effects of salinity upon germination and [...] Read more.
Weeds that have become resistant to herbicides may threaten rice production. Rice cultivation is mainly carried out in coastal and river delta areas that often suffer salinity problems. The aims of this study were to evaluate the effects of salinity upon germination and the root and shoot seedling growth of Italian weedy rice and cultivated rice (Oryza sativa), and to find a possible correlation between salinity and herbicide resistance. Seed germination tests were conducted in Petri dishes on four imazamox-sensitive and one resistant weedy rice populations and two rice varieties: Baldo (conventional) and CL80 (imidazolinone-resistant Clearfield® variety). Different salt concentrations were tested: 0, 50, 100, 150, 200, 250, 300, 350 and 400 mM NaCl. Germination percentage, germination speed, seedling root and shoot length were affected by increasing the salt concentration in all tested populations and varieties. The germination percentage was in general more affected in resistant weedy rice and CL80. In resistant weedy rice this was partially compensated by a faster germination up to 100 mM. In terms of seedling root and shoot length, CL80 and Baldo showed the highest tolerance to salt; resistant weedy rice was not able to produce seedling roots and shoots at concentrations > 300 mM. Full article
(This article belongs to the Special Issue Herbicide Resistance in Weed Management)
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