Managing herbicide resistance in China

Weed Science ◽  
2020 ◽  
pp. 1-14
Author(s):  
Xiangying Liu ◽  
Austin Merchant ◽  
Shihai Xiang ◽  
Tao Zong ◽  
Xuguo Zhou ◽  
...  

Abstract Since its initial introduction in the late 1950s, chemical control has dominated weed management practices in China. Not surprisingly, the development of herbicide resistance has become the biggest threat to long-term, sustainable weed management in China. Given that China has followed the same laissez-faire approach toward resistance management that has been practiced in developed countries such as the United States, herbicide resistance has evolved rapidly and increased steadily over the years. Previously, we carried out a systematic review to quantitatively assess herbicide-resistance issues in China. In this review, our main objective is to focus on mechanistic studies and management practices to document the (1) history of herbicide application in China; (2) resistance mechanisms governing the eight most resistance-prone herbicide groups, including acetolactate synthase inhibitors, acetyl-CoA carboxylase inhibitors, synthetic auxin herbicides, 5-enolpyruvylshikimate-3-phosphate synthase inhibitors, protoporphyrinogen oxidase inhibitors, photosystem I electron diverters, photosystem II inhibitors, and long-chain fatty-acid inhibitors; and (3) herbicide-resistance management strategies commonly used in China, including chemical, cultural, biological, physical, and integrated approaches. At the end, perspectives and future research are discussed to address the pressing need for the development of integrated herbicide-resistance management in China.

1999 ◽  
Vol 13 (3) ◽  
pp. 647-652 ◽  
Author(s):  
Michael J. Christoffers

Weed populations develop herbicide resistance when they evolve due to selection pressure. Mutations and gene flow contribute to genetic variability and provide resistant alleles. The speed of resistance gene frequency increase is determined by the inheritance of resistance alleles relative to wild-type susceptibility and is influenced by the interaction between gene expression and selection. The goal of herbicide resistance management is to minimize selection pressure while maintaining adequate weed control. However, the specific nature of each herbicide, weed, and resistance combination determines the practices that optimize undesirable selection pressure. Therefore, generalized management strategies should be recommended with caution and must not be mandated without thorough evaluation on a case-by-case basis.


2020 ◽  
Vol 295 (30) ◽  
pp. 10307-10330 ◽  
Author(s):  
Todd A. Gaines ◽  
Stephen O. Duke ◽  
Sarah Morran ◽  
Carlos A. G. Rigon ◽  
Patrick J. Tranel ◽  
...  

The widely successful use of synthetic herbicides over the past 70 years has imposed strong and widespread selection pressure, leading to the evolution of herbicide resistance in hundreds of weed species. Both target-site resistance (TSR) and nontarget-site resistance (NTSR) mechanisms have evolved to most herbicide classes. TSR often involves mutations in genes encoding the protein targets of herbicides, affecting the binding of the herbicide either at or near catalytic domains or in regions affecting access to them. Most of these mutations are nonsynonymous SNPs, but polymorphisms in more than one codon or entire codon deletions have also evolved. Some herbicides bind multiple proteins, making the evolution of TSR mechanisms more difficult. Increased amounts of protein target, by increased gene expression or by gene duplication, are an important, albeit less common, TSR mechanism. NTSR mechanisms include reduced absorption or translocation and increased sequestration or metabolic degradation. The mechanisms that can contribute to NTSR are complex and often involve genes that are members of large gene families. For example, enzymes involved in herbicide metabolism–based resistances include cytochromes P450, GSH S-transferases, glucosyl and other transferases, aryl acylamidase, and others. Both TSR and NTSR mechanisms can combine at the individual level to produce higher resistance levels. The vast array of herbicide-resistance mechanisms for generalist (NTSR) and specialist (TSR and some NTSR) adaptations that have evolved over a few decades illustrate the evolutionary resilience of weed populations to extreme selection pressures. These evolutionary processes drive herbicide and herbicide-resistant crop development and resistance management strategies.


2014 ◽  
Vol 70 (12) ◽  
pp. 1924-1929 ◽  
Author(s):  
C Blake Edwards ◽  
David L Jordan ◽  
Michael DK Owen ◽  
Philip M Dixon ◽  
Bryan G Young ◽  
...  

Weed Science ◽  
2016 ◽  
Vol 64 (SP1) ◽  
pp. 627-640 ◽  
Author(s):  
Michael Barrett ◽  
Michael Barrett ◽  
John Soteres ◽  
David Shaw

Although the problem of herbicide resistance is not new, the widespread evolution of glyphosate resistance in weed species such as Palmer amaranth (Amaranthus palmeriS. Wats.), common waterhemp (Amaranthus rudisSauer), and kochia [Kochia scoparia(L.) Schrad.] raised awareness throughout the agricultural community of herbicide resistance as a problem. Glyphosate-resistant weeds resulted in the loss of a simple, single herbicide option to control a wide spectrum of weeds that gave efficacious and economical weed management in corn (Zea maysL.), soybean [Glycine max(L.) Merr.], and cotton (Gossypium hirsutumL.) crops engineered for tolerance to this herbicide and planted over widespread areas of the South and Midwest of the United States. Beyond these crops, glyphosate is used for vegetation management in other cropping systems and in noncrop areas across the United States, and resistance to this herbicide threatens its continued utility in all of these situations. This, combined with the development of multiple herbicide-resistant weeds and the lack of commercialization of herbicides with new mechanisms of action over the past years (Duke 2012), caused the weed science community to realize that stewardship of existing herbicide resources, extending their useful life as long as possible, is imperative. Further, while additional herbicide tolerance traits are being incorporated into crops, weed management in these crops will still be based upon using existing, old, herbicide chemistries.


2020 ◽  
pp. 1-11
Author(s):  
Maxwel C. Oliveira ◽  
Anelise Lencina ◽  
André R. Ulguim ◽  
Rodrigo Werle

Abstract A stakeholder survey was conducted from April through June of 2018 to understand stakeholders’ perceptions and challenges about cropping systems and weed management in Brazil. The dominant crops managed by survey respondents were soybean (73%) and corn (66%). Approximately 75% of survey respondents have grown or managed annual cropping systems with two to three crops per year cultivated in succession. Eighteen percent of respondents manage only irrigated cropping systems, and over 60% of respondents adopt no-till as a standard practice. According to respondents, the top five troublesome weed species in Brazilian cropping systems are horseweed (asthmaweed, Canadian horseweed, and tall fleabane), sourgrass, morningglory, goosegrass, and dayflower (Asiatic dayflower and Benghal dayflower). Among the nine species documented to have evolved resistance to glyphosate in Brazil, horseweed and sourgrass were reported as the most concerning weeds. Other than glyphosate, 31% and 78% of respondents, respectively, manage weeds resistant to acetyl-CoA carboxylase (ACCase) inhibitors and/or acetolactate synthase (ALS) inhibitors. Besides herbicides, 45% of respondents use mechanical, and 75% use cultural (e.g., no-till, crop rotation/succession) weed control strategies. Sixty-one percent of survey respondents adopt cover crops to some extent to suppress weeds and improve soil chemical and physical properties. Nearly 60% of survey respondents intend to adopt the crops that are resistant to dicamba or 2,4-D when available. Results may help practitioners, academics, industry, and policy makers to better understand the bad and the good of current cropping systems and weed management practices adopted in Brazil, and to adjust research, education, technologies priorities, and needs moving forward.


Weed Science ◽  
2014 ◽  
Vol 62 (4) ◽  
pp. 555-562 ◽  
Author(s):  
Meredith J. Ward ◽  
Matthew R. Ryan ◽  
William S. Curran ◽  
Jeffrey Law

The utility of biological control for weed management in agroecosystems will increase with a greater understanding of the relationships between common weed and granivore species. Giant foxtail is an introduced, summer annual grass weed that is common throughout the United States and problematic in numerous crops.Harpalus pensylvanicus(DeGeer) (Coleoptera: Carabidae) is a common, native, omnivorous carabid beetle with a range that overlaps giant foxtail. In 2004 and 2005,H. pensylvanicuswas captured from farm fields in Centre County, PA, and subjected to laboratory feeding trials to test the preference of giant foxtail and other species on predation byH. pensylvanicus. Weed species seed preference experiments that included “Choice” and “No Choice” treatments were conducted using giant foxtail, common lambsquarters, and velvetleaf. When given a choice amongst the three weed species,H. pensylvanicuspreferred giant foxtail and common lambsquarters seeds equally compared to velvetleaf seeds. When given the choice,H. pensylvanicuspreferred newly dispersed giant foxtail seeds over field-aged seeds. Phenology of giant foxtail seed shed relative toH. pensylvanicusactivity density was also quantified in field experiments in 2005 and 2006. Giant foxtail seed rain was determined by collecting shed seeds from August through October using pan traps. Activity density ofH. pensylvanicuswas monitored for 72-h periods using pitfall traps from June to October. Peak activity density ofH. pensylvanicusoccurred at the onset of giant foxtail seed shed in both years; however, giant foxtail seed shed peaked approximately 30 to 50 d afterH. pensylvanicusactivity density. Future research should focus on management practices that enhance and supportH. pensylvanicuspopulations later in the growing season to maximize suppression of giant foxtail and other weeds that shed palatable seeds later in the season.


Weed Science ◽  
2018 ◽  
Vol 67 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Eshagh Keshtkar ◽  
Roohollah Abdolshahi ◽  
Hamidreza Sasanfar ◽  
Eskandar Zand ◽  
Roland Beffa ◽  
...  

AbstractIn recent years, herbicide resistance has attracted much attention as an increasingly urgent problem worldwide. Unfortunately, most of that effort was focused on confirmation of resistance and characterization of the mechanisms of resistance. For management purposes, knowledge about biology and ecology of the resistant weed phenotypes is critical. This includes fitness of the resistant biotypes compared with the corresponding wild biotypes. Accordingly, fitness has been the subject of many studies; however, lack of consensus on the concept of fitness resulted in poor experimental designs and misinterpretation of the ensuing data. In recent years, methodological protocols for conducting proper fitness studies have been proposed; however, we think these methods should be reconsidered from a herbicide-resistance management viewpoint. In addition, a discussion of the inherent challenges associated with fitness cost studies is pertinent. We believe that the methodological requirements for fitness studies of herbicide-resistant weed biotypes might differ from those applied in other scientific disciplines such as evolutionary ecology and genetics. Moreover, another important question is to what extent controlling genetic background is necessary when the aim of a fitness study is developing management practices for resistant biotypes. Among the methods available to control genetic background, we suggest two approaches (single population and pedigreed lines) as the most appropriate methods to detect differences between resistant (R) and susceptible (S) populations and to derive herbicide-resistant weed management programs. Based on these two methods, we suggest two new approaches that we named the “recurrent single population” and “recurrent pedigreed lines” methods. Importantly, whenever the aim of a fitness study is to develop optimal resistance management, we suggest selecting R and S plants within a single population and evaluating all fitness components from seed to seed instead of measuring changes in the frequency of R and S alleles through multigenerational fitness studies.


2019 ◽  
Vol 34 (3) ◽  
pp. 351-356 ◽  
Author(s):  
Bruno de Lima Fruet ◽  
Aldo Merotto ◽  
André da Rosa Ulguim

AbstractIdentification of common weeds is fundamental in determining adequate recommendations for management practices. The aim of this study was to identify the patterns of weed management adopted by rice farmers and the perspectives of consultants who work in flooded rice areas in Rio Grande do Sul (RS) State, Brazil. Fifty-three public and 50 private consultants who worked with rice in RS in 2017 and 2018 were interviewed. Data were analyzed by descriptive statistics. Both weedy rice and Echinochloa sp. occurred and escaped more often from chemical control because they remained in the field until harvest in 59% of the area. According to consultants, the main reasons for reduced weed control were related to herbicide resistance and late herbicide application. Fifty-six percent of farmers used imidazolinone herbicides at rates that were greater than those indicated on the label for POST application. The consultants’ main challenges were weed escapes, resistance management, and guidelines on herbicide rates. Survey results show that the use of herbicide rates above label recommendations and consultants’ work on control of weed escapes are directly related to the high occurrence of herbicide resistance.


2013 ◽  
Vol 27 (3) ◽  
pp. 623-630 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Jason Bond ◽  
Robert C. Scott

Crop consultants in Arkansas and Mississippi were sent a direct-mail survey in fall of 2011 with questions concerning weed management in rice. The goal of the survey was to document the extent of imidazoline-resistant rice hectares, the herbicides most commonly recommended in rice, the weeds perceived to be most troublesome in rice including those resistant to herbicides, and suggested areas of research and educational focus that would improve weed management in rice. When appropriate, results from this survey were compared to a similar survey conducted in 2006. Completed rice surveys were returned by 43 consultants, accounting for 179,500 ha of scouted rice or 38% of the rice hectarage in Arkansas and Mississippi. Imidazolinone-resistant rice was grown on 64% of the hectares, and this technology was used continually for the past 5 yr on 11% of the rice hectares. Of the area planted to imidazolinone-resistant rice, 42% of this hectarage was treated solely with an acetolactate synthase (ALS)-inhibiting herbicide. Consultants listed improved control options for barnyardgrass and Palmer amaranth as the most important research and educational need in rice. The top five weeds in order of importance were (1) barnyardgrass, (2) sprangletops, (3) red rice, (4) northern jointvetch, and (5) Palmer amaranth. From a predetermined list of research and educational topics, consultants gave the highest ratings of importance to (1) control of herbicide-resistant weeds, (2) strategies to reduce the occurrence and spread of herbicide-resistant weeds, and (3) development of new economical herbicide-resistant rice varieties which was comparable to economical weed control options. Findings from this survey point to the overuse of imidazolinone-resistant rice and a lack of preemptive resistance management strategies such as crop rotation and use of multiple effective herbicide modes of action by some growers, which has likely contributed to selection for the ALS-resistant barnyardgrass and rice flatsedge recently confirmed in Arkansas and Mississippi rice.


2018 ◽  
Vol 32 (4) ◽  
pp. 475-488 ◽  
Author(s):  
Jill Schroeder ◽  
Michael Barrett ◽  
David R. Shaw ◽  
Amy B. Asmus ◽  
Harold Coble ◽  
...  

AbstractHerbicide resistance is ‘wicked’ in nature; therefore, results of the many educational efforts to encourage diversification of weed control practices in the United States have been mixed. It is clear that we do not sufficiently understand the totality of the grassroots obstacles, concerns, challenges, and specific solutions needed for varied crop production systems. Weed management issues and solutions vary with such variables as management styles, regions, cropping systems, and available or affordable technologies. Therefore, to help the weed science community better understand the needs and ideas of those directly dealing with herbicide resistance, seven half-day regional listening sessions were held across the United States between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide resistance management. The major goals of the sessions were to gain an understanding of stakeholders and their goals and concerns related to herbicide resistance management, to become familiar with regional differences, and to identify decision maker needs to address herbicide resistance. The messages shared by listening-session participants could be summarized by six themes: we need new herbicides; there is no need for more regulation; there is a need for more education, especially for others who were not present; diversity is hard; the agricultural economy makes it difficult to make changes; and we are aware of herbicide resistance but are managing it. The authors concluded that more work is needed to bring a community-wide, interdisciplinary approach to understanding the complexity of managing weeds within the context of the whole farm operation and for communicating the need to address herbicide resistance.


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