WorldWideScience

Sample records for university silvicultural herbicide

  1. Silvicultural madness

    DEFF Research Database (Denmark)

    Basnyat, Bijendra; Treue, Thorsten; Pokharel, R.K.

    2018-01-01

    Following a case study approach, this paper explains how scientific forest management plans were developed and implemented in community forests of a mid-hill district in Nepal. Field observations were carried over a period of two years (December 2014 to December 2016) in two community forests. User...... guidelines with little reference to the actual site quality, management objectives, and forest stand conditions. Apart from harvesting of trees, users hardly implemented the plans‘ silvicultural prescriptions and forest restoration activities. Moreover forest officials administratively reduced the number...... of trees that users could harvest to around half of what the plans allow. Accordingly, forest user groups face a paradoxical forest administration that promotes timber harvesting according to so-called scientific principles, which it then brushes aside to satisfy bureaucratic demands. The study concludes...

  2. Free selection: a silvicultural option

    Science.gov (United States)

    Russell T. Graham; Theresa B. Jain; Jonathan Sandquist

    2007-01-01

    Forest management objectives continue to evolve as the desires and needs of society change. The practice of silviculture has risen to the challenge by supplying silvicultural methods and systems to produce desired stand and forest structures and compositions to meet these changing objectives. For the most part, the practice of silviculture offers a robust set of...

  3. Herbicide options for hardwood management

    Science.gov (United States)

    Andrew W. Ezell; A. Brady Self

    2016-01-01

    The use of herbicides in hardwood management presents special problems in that many of the most effective herbicides are either designed to control hardwoods or the product is not labeled for such applications. Numerous studies involving herbicide application in hardwoods have been completed at Mississippi State University. This paper is a compilation of results from...

  4. Selecting a silvicultural system

    Science.gov (United States)

    Richard M. Godman

    1992-01-01

    Sometimes a name creates a problem. The name of a silvicultural system usually refers to the way a stand is cut to get regeneration-"single tree selection"-for example. Trouble is, the name suggests that the regeneration cut will be the first treatment applied to the stand. Not so. We are now mostly making "intermediate" cuts in our Lake States...

  5. Simulating Silvicultural Treatments Using FIA Data

    Science.gov (United States)

    Christopher W. Woodall; Carl E. Fiedler

    2005-01-01

    Potential uses of the Forest Inventory and Analysis Database (FIADB) extend far beyond descriptions and summaries of current forest resources. Silvicultural treatments, although typically conducted at the stand level, may be simulated using the FIADB for predicting future forest conditions and resources at broader scales. In this study, silvicultural prescription...

  6. Proceedings of the 15th biennial southern silvicultural research conference

    Science.gov (United States)

    James M. Guldin

    2013-01-01

    Sixty-eight papers and seventeen posters address a range of issues affecting southern forests. Papers are grouped in 12 sessions that include pine silviculture session I, hardwood silviculture - intermediate treatment and stand development, longleaf pine; quantitative silviculture and economics, pine silviculture session II, hardwood regeneration, carbon and bioenergy...

  7. The sound bases of systemic silviculture

    Directory of Open Access Journals (Sweden)

    Nocentini S

    2009-11-01

    Full Text Available Following recent critiques on systemic silviculture, the author examines the principles, scientific consequences and practical implications of this theory. Systemic silviculture is based on the assumption that the forest is a complex biological system. This means abandoning the reductive, mechanistic and deterministic paradigm that has characterized forest science until the last century. If the forest is a complex biological system then its properties cannot be reduced to those of its components. According to this assumption, the author analyzes the concepts of forest structure, predictability and unpredictability of forest ecosystem processes, intrinsic value and rights of the forest. Systemic silviculture is characterized by an adaptive approach which has the flexibility and the capacity to respond to environmental retroactions which are fundamental for the governance of complex and adaptive systems. The author concludes that the bases of systemic silviculture are unassailable and surely much sounder than those of “naturalistic” silviculture, or at least of that type of silviculture which, trying to define “natural structural models” for forest ecosystems, is still anchored to the old, classic, paradigm of natural resource management and conservation.

  8. Getting to the future through silviculture - Workshop proceedings

    Science.gov (United States)

    Dennis Murphy

    1992-01-01

    Includes 19 papers documenting presentations at the 1991 Forest Service National Silviculture Workshop. Discussions focus on the role of silviculture in New Perspectives (ecosystem management), new approaches to the practice of silviculture, and examples of successful integration of practices into multi resource management.

  9. The management system of silvicultural practices

    Directory of Open Access Journals (Sweden)

    Carbone F

    2012-02-01

    Full Text Available The coexistence of public and private interests on forest ecosystems makes the silvicultural interventions the most thorny moment of their management. In this paper the author analyzes the characteristics of forest firms and logging companies usually involved in forest management. The relations between their legitimate interests, expectations and strategies, the ways by which forest firm may entrust the execution of the silvicultural intervention, etc. are aspects strongly connected with the public interests, which is protected by forestry institutions. Silvicultural system of management interventions is the context where public interests are coordinated with the private interests. The output are qualitative and quantitative standards for the use of forest resources. Moving on from this preliminary to the executive phase, the case study has highlighted the crucial role played by foresters, who have to guarantee the coexistence of public and private interests on forests.

  10. Communicating the role of silviculture in managing the national forests: Proceedings of the National Silviculture Workshop

    Science.gov (United States)

    Northeastern Forest Experiment Station

    1997-01-01

    Contains 32 articles on communicating the values and benefits of silviculture in managing the national forests. Specific topics addressed are how communications affect: policymakers, inventory and monitoring, resource management, research, education and demonstration, and partnerships.

  11. Efficient silvicultural practices for eastern hardwood management

    Science.gov (United States)

    Gary W. Miller; John E. Baumgras

    1994-01-01

    Eastern hardwood forests are now managed to meet a wide range of objectives, resulting in the need for silvicultural alternatives that provide timber, wildlife, aesthetics, recreation, and other benefits. However, forest management practices must continue to be efficient in terms of profiting from current harvests, protecting the environment, and sustaining production...

  12. Forest management practices and silviculture. Chapter 12.

    Science.gov (United States)

    Donald A. Perala; Elon S. Verry

    2011-01-01

    This chapter is an overview of forest management and silviculture practices, and lessons learned, on the Marcell Experimental Forest (MEF). The forests there are a mosaic of natural regeneration and conifer plantations. Verry (1969) described forest-plant communities in detail for the study watersheds (Sl through S6) on the MEF. The remaining area is described in...

  13. Silvicultural systems for southern bottomland hardwood forests

    Science.gov (United States)

    James S. Meadows; John A. Stanturf

    1997-01-01

    Silvicultural systems integrate both regeneration and intermediate operations in an orderly process for managing forest stands. The clearcutting method of regeneration favors the development of species that are moderately intolerant to intolerant of shade. In fact, clearcutting is the most proven and widely used method of successfully regenerating bottomland oak...

  14. Photosensitized herbicidal action

    Energy Technology Data Exchange (ETDEWEB)

    Zweig, A; Nachtigall, G W [American Cyanamid Co., Stamford, Conn.

    1975-12-01

    The herbicidal action produced by the colorless hydrocarbon fluoranthene sprayed on the leaves of growing plants did not occur when uv radiation was removed from the light to which the plants are exposed. If the uv component of the light under which the plants were grown was augmented, the herbicidal effect of fluoranthene was increased. The mechanism of this photodynamic action is discussed.

  15. History of silviculture on public lands

    Science.gov (United States)

    James M. Guldin

    2014-01-01

    There are many instances in scholarly activity where the writing of a colleague is made more vivid when one knows him or her personally—and Eric Zenner’s essay is certainly no exception! I can see Eric at a podium of a forestry school in the United States or Europe, emphatically proclaiming that “Silviculture is the pen with which our profession writes, but too often...

  16. Near-natural forests in southern Sweden. Palaeoecological and silvicultural aspects on nature-based silviculture

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerse, Gisela [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden). Southern Swedish Forest Research Centre

    2000-07-01

    Timber production and protection of biodiversity are two main issues in south Swedish forestry. This thesis explores the possibilities of combining the two issues in a nature-based silviculture. Different branches of science, palaeoecology, silviculture and forest vegetation ecology, were combined to give a multidisciplinary approach to the subject. Mimicking the historical forest composition and processes in the silvicultural measures for the benefit of both biodiversity protection and timber production was identified as one possible way of developing a nature-based silviculture. The long period of human influence on the landscape in southern Sweden has effectively removed all the remnants of natural forest that could have been used as references in the mimicking procedure. Consequently, historical references were searched. A method to describe former forest conditions was developed using palaeoecological data and methods. It was found that the historical deciduous dominance was pronounced. Over 2000 years southern Sweden has been transformed from a deciduous to a coniferous landscape. Human activities were shown to be a major driving force in this change. Several detected historical forest types were possible as references for the mimicking approach, but forest types common in the past and rare today were suggested for maximal efficiency in obtaining high biodiversity. Mixed nemoral deciduous forests were pointed out as a historically widespread forest type with very little resemblance in the present landscape. The small fragments left are important for present biodiversity and from many other aspects. Development of a nature-based silvicultural system for the management of mixed nemoral forest stands based on the theory of mimicking was begun. A silvicultural experiment was established in a near-natural, mixed nemoral forest stand in southern Sweden and the early effects of the silvicultural treatments tested were evaluated with regard to floristic diversity

  17. Structural and functional effects of herbicides on non-target organisms in aquatic ecosystems with an emphasis on atrazine

    Science.gov (United States)

    Fairchild, James; Kortekamp, Andreas

    2011-01-01

    Herbicide use has increased dramatically around the world over the past 6 decades (Gianessi and Reigner, 2007). Few herbicides were in use in the 1950s. However, by 2001 approximately 1.14 billion kilograms of herbicides were applied globally for the control of undesireable vegetation in agricultural, silvicultural, lawncare, aquacultural, and irrigation/recreational water management activities (Kiely et al., 2004). Twenty-eight percent of the total mass of herbicides is applied in the United States, with the remaining 72 percent being applied elsewhere around the globe (Kiely et al., 2004). Herbicides represent 36% of global pesticide use, followed by insecticides (25%), fungicides (10%) and other chemical classes (Kiely et al., 2004). Agricultural production accounts for approximately 90% of herbicide use in the U.S. (Kiely et al., 2004). Gianessi and Reigner (2007) indicated that herbicides are routinely used on more than 90% of the area designated for large commercial crops including corn, soybeans, cotton, sugar beets, peanuts, and rice. Increased farm mechanization, technological advancements in production of inexpensive sources of inorganic nitrogen fertilizer (e.g., anhydrous ammonia), and conversion of forest, grassland, and wetland habitats to cropland has led to a tremendous increase in global food production over the past half-century. Herbicides have augmented advances in large-scale agricultural systems and have largely replaced mechanical and hand-weeding control mechanisms (Gianessi and Reigner, 2007). The wide-spread use of herbicides in agriculture has resulted in frequent chemical detections in surface and groundwaters (Gilliom, 2007). The majority of herbicides used are highly water soluble and are therefore prone to runoff from terrestrial environments. In additon, spray drift and atmospheric deposition can contribute to herbicide contamination of aquatic environments. Lastly, selected herbicides are deliberately applied to aquatic environments

  18. A transportation-scheduling system for managing silvicultural projects

    Science.gov (United States)

    Jorge F. Valenzuela; H. Hakan Balci; Timothy McDonald

    2005-01-01

    A silvicultural project encompasses tasks such as sitelevel planning, regeneration, harvestin, and stand-tending treatments. an essential problem in managing silvicultural projects is to efficiently schedule the operations while considering project task due dates and costs of moving scarce resources to specific job locations. Transportation costs represent a...

  19. Silvicultural guide for northern hardwoods in the northeast

    Science.gov (United States)

    William B. Leak; Mariko Yamasaki; Robbo. Holleran

    2014-01-01

    This revision of the 1987 silvicultural guide includes updated and expanded silvicultural information on northern hardwoods as well as additional information on wildlife habitat and the management of mixed-wood and northern hardwood-oak stands. The prescription methodology is simpler and more field-oriented. This guide also includes an appendix of familiar tables and...

  20. Silviculture of southwestern ponderosa pine: The status of our knowledge

    Science.gov (United States)

    Gilbert H. Schubert

    1974-01-01

    Describes the status of our knowledge of ponderosa pine silviculture in the southwestern States of Arizona, Colorado, New Mexico, and Utah. Economic value, impact on other uses, and the timber resource are discussed first, followed by ecological background, site quality, growth and yield, and silviculture and management. Relevant literature is discussed along with...

  1. Use of expert systems for integrated silvicultural planning

    Science.gov (United States)

    Chris B. LeDoux

    1997-01-01

    The use of silvicultural treatments in hardwood stands presents opportunities for increasing the growth and yield of quality sawtimber and enhancing the suitability of the site for use by numerous species of wildlife. Planners, loggers, and managers must consider multiple aspects of the ecosystem when making silvicultural decisions. In this paper we demonstrate an...

  2. Forest regulation methods and silvicultural systems: what are they?

    Science.gov (United States)

    Ivan L. Sander; Burnell C. Fischer

    1989-01-01

    "Forest regulation methods" and "silvicultural systems" are important forest resource management concepts but there is much confusion about them. They often mean different things to different individuals. Confusion exists in part because "forest regulation methods" and "silvicultural systems" often use the same terminology. Also...

  3. How applicable is even-aged silviculture in the northeast?

    Science.gov (United States)

    Ralph H. Griffin

    1977-01-01

    The applicability of even-aged silviculture in the management of forest stands in the Northeast is examined through consideration of the forest stand, stand development, intermediate cuttings, and regeneration methods. It is concluded that even-aged silviculture is quite applicable in the management of forest stands in the Northeast.

  4. Shifting conceptions of complexity in forest management and silviculture

    Science.gov (United States)

    Robert T. Fahey; Brandon C. Alveshere; Julia I. Burton; Anthony W. D' Amato; Yvette L. Dickinson; William S. Keeton; Christel C. Kern; Andrew J. Larson; Brian J. Palik; Klaus J. Puettmann; Michael R. Saunders; Christopher R. Webster; Jeff W. Atkins; Christopher M. Gough; Brady S. Hardiman

    2018-01-01

    In the past several decades, a trend in forestry and silviculture has been toward promoting complexity in forest ecosystems, but how complexity is conceived and described has shifted over time as new ideas and terminology have been introduced. Historically, ecologically-focused silviculture has focused largely on manipulation of structural complexity, but often with...

  5. Annual Herbicide Loadings

    Data.gov (United States)

    U.S. Environmental Protection Agency — Pesticides, Herbicides, Fungicides...etc, are used for a variety of purposes, including control of household, lawn, and garden pests; for control of mosquitoes and...

  6. Proceedings of the National Silviculture Workshop: Silviculture for All Resources; Sacramento, CA; May 11-14, 1987

    Science.gov (United States)

    Melanie Malespin Woolever; Mike Smith; Elizabeth McGraw; Mike Lanasa; Arthur C. Zack; Chris Reichert; Robert MacWhorter; Michael R. Lennartz; Richard A. Lancia; Marc G. Rounsaville; James R. Sedell; Fred H. Everest; David R. Gibbons; Stephen R. Shifley; Melinda Moeur; David A. Marquis; Richard O. Fitzgerald; Nelson Loftus; Thomas C. Turpin; William R. Terrill; Glenn L. Crouch; Wayne D. Shepperd; Edith W. Petrick; John J. Petrick; Roger W. Dennington; Allan W. Ashton; Hubertus J. Mittmann; Gary Thompson; Ken Sonksen; David A. Stark; Michael A. Ware; Allan J. West; Patrick D. Jackson; Richard L. Bassett; Jimmie D. Chew; William B. White; Bruce W. Morse; Mike Znerold; Russell T. Graham; Peyton W. Owston; Richard G. Miller; John R. Nesbitt; Gaston Porterie; Ernest Del Rio

    1987-01-01

    The 1987 National Silviculture Workshop was held in Sacramento, California, and the Eldorado National Forest. The purpose of the workshop was to discuss, review, and share information and experiences regarding how silviculture can serve as the tool to help accomplish the objectives of many resources.

  7. Proceedings of the National Silviculture Workshop: Economics Of Silvicultural Investments; Eugene, OR; May 16-20, 1983

    Science.gov (United States)

    Clark Row; Charles Palmer; Robert M. Randall; Tom Ortman; James P. Merzenich; Gary Manning; George Howe; Jim McDivitt; Chris Hansen; Willard R. Fey; Vernon L. Robinson; K. E. Sleavin; K. N. Johnson; Roger D. Fight; L. O. (Pete) Stanger; Lee Medema; Christopher D. Risbrudt; Richard W. Guldin; Richard Greenhalgh; Mike Skinner; John Fiske; Thomas J. Mills; John H. Beuter

    1983-01-01

    The 1983 Silviculture Workshop was held in Eugene, Oregon, and the Willamette National Forest. The purpose of the workshop was to review and discuss the requirements by laws, regulations, and Forest Service policy of the need for and uses of economic analyses in silvicultural program planning and development.

  8. Proceedings of the National Silviculture Workshop: Silvicultural Examination, Prescription, and Related Activities; Missoula, Montana; September 26-28, 1978

    Science.gov (United States)

    Norman E. Gould; Don Potter; Ray Johnston; Jim Loton; Donald Pierce; Ronald C. Hamilton; George E. Gruell; Victor DeKalb; Dav Wright; Bill Beaufait; Dan Schroeder; Bob Blomquist; John C. Tappeiner; Carl Puuri; Dav Terry; R. E. Stewart; Walter H. Knapp

    1978-01-01

    The 1978 Silviculture Workshop was held in Missoula, Montana, September 26-28, 1978. The objective of the meeting was to discuss Silvicultural prescriptions, standards of certification for silviculturists, certification of planting and thinning projects, and other related items of interest. These proceedings includes the presentations that were available for...

  9. [Silvicultural treatments and their selection effects].

    Science.gov (United States)

    Vincent, G

    1973-01-01

    Selection can be defined in terms of its observable consequences as the non random differential reproduction of genotypes (Lerner 1958). In the forest stands we are selecting during the improvements-fellings and reproduction treatments the individuals surpassing in growth or in production of first-class timber. However the silvicultural treatments taken in forest stands guarantee a permanent increase of forest production only in such cases, if they have been taken with respect to the principles of directional (dynamic) selection. These principles require that the trees determined for further growing and for forest regeneration are selected by their hereditary properties, i.e. by their genotypes.For making this selection feasible, our study deals with the genetic parameters and gives some examples of the application of the response, the selection differential, the heritability in the narrow and in the broad sense, as well as of the genetic and genotypic gain. On the strength of this parameter we have the possibility to estimate the economic success of several silvicultural treatments in forest stands.The mentioned examples demonstrate that the selection measures of a higher intensity will be manifested in a higher selection differential, in a higher genetic and genotypic gain and that the mentioned measures show more distinct effects in the variable populations - in natural forest - than in the population characteristic by a smaller variability, e.g. in many uniform artificially established stands.The examples of influences of different selection on the genotypes composition of population prove that genetics instructs us to differentiate the different genotypes of the same species and gives us at the same time a new criterions for evaluating selectional treatments. These criterions from economic point of view is necessary to consider in silviculture as advantageous even for the reason that we can judge from these criterions the genetical composition of forest stands

  10. Effects of herbicides on fish

    DEFF Research Database (Denmark)

    Solomon, Keith R.; Dalhoff, Kristoffer; Volz, David

    2013-01-01

    Herbicides are used to control weeds and are usually targeted to processes and target sites that are specific to plants. As a result, most herbicides are not acutely toxic to fish. Exceptions to this general rule are uncouplers of oxidative phosphorylation and some herbicides that interfere...... with cell division. Chronic and sublethal effects have been studied for some herbicides, but fewer data are available for these effects than for acute effects. The sublethal effects of herbicides that have been studied include reproduction, stress, olfaction, and behavior. Although some of these responses......, and reproduction. As with all pesticides, herbicides may have indirect effects in fish. These effects are mediated by herbicide-induced changes in food webs or in the physical environment. Indirect effects can only occur if direct effects occur first and would be mediated by the killing of plants by herbicides...

  11. Silviculture and forest protection: results and prospects from third Italian National Congress of Silviculture

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available This paper summarizes the topics discussed during the session “Silviculture, Forest Protection” of the Third Italian National Congress of Silviculture. The health of Italian forests is often depending on irrational forest exploitation schemes and is threatened by the arrival of invasive species, the strengthening of native pests and diseases, and the increase of stress related to changing environment (both climate and pollution. The climate change is considered as a major complication in forest protection, as it is related to increasing outbreaks both directly and indirectly, through changes in tree physiology. Drawbacks are observed on biodiversity, forest growth and productivity, and protective function of forests. Ecosystems with high biodiversity may show a high degree of resilience to the changes. It is important to address these issues in the framework of the systemic silviculture approach to the management of Italian forests. Important requisites are availability of trained staff, funding for research and monitoring projects, access to the most uptodated scientific knowledge and methodologies. An integration of different types of available expertise (entomologists, plant pathologists, pollution scientists is also envisaged.

  12. The Effect of Silvicultural Management on Regeneration, Growth ...

    African Journals Online (AJOL)

    improved management, including protection from interference, culm yield of ... silvicultural measure helped boosting up of bamboo productivity (Midmore 2009). .... experiment was replicated three times, making the total number of plots ( ...

  13. Basic principles, mosaic of knowledges and adaptive silviculture

    Directory of Open Access Journals (Sweden)

    Borghetti M

    2012-07-01

    Full Text Available Achievements of ecological science and direct experience are of great help for the interpretation of forest ecosystem dynamics and the definition of adaptive procedures for forest manipulation, i.e. adaptive silviculture.

  14. A Review of Relationships Between Wood Quality and Silvicultural Practices

    Directory of Open Access Journals (Sweden)

    Tomy Listyanto

    2009-07-01

    Full Text Available The effect of silviculture on wood quality has been approached from different perspectives. This relationship is being a critical concern of forest managers, landowners, and also researchers. Reliable information is needed to support forest managers in predicting the consequences of various silvicultural practices in terms of quantity and wood quality. Wood has beed used for a variety of products. Each product has particular requirements regarding quality. The variation of wood quality requirement allows industries to decide to use timber resource appropriate for their products. Silvicultural practives cover all treatments applied in forest stand management especially to improve the quality of stand, including manipulation of the availability of sunlight, nutrient and water by using several treatments such as thinning, control of spacing, fertilizing, and pruning. The quality of stand is aimed to achieve particular forest management objectives including higher wood quality. There is no broad generalization regarding the relation between silvicultural practice and wood quality. Many investigators showed positive results in relation to producing high quality of wood products, while other researchers revealed negative effects. Reliable information is needed to support forest managers in predicting the consequences of various silvicultural practices in relation to the wood quantity and quality. Continuous research is needed to find methods of producing wood of high quality based on silvicultural practices and genetic improvement which can be used in wider area by considering limitation including environment and geographic variation.

  15. selective herbicide glyphosate

    African Journals Online (AJOL)

    Aghomotsegin

    2016-05-04

    May 4, 2016 ... concentrations of the test chemical at 0.625, 1.25, 2.5, 5 and 10 mg/L, respectively. The percentage growth rate ... production, processing, storage, transport or marketing of ... Herbicides commonly known as weed-killers are.

  16. ORGEST: Regional guidelines and silvicultural models for sustainable forest management

    Energy Technology Data Exchange (ETDEWEB)

    Piqué, Míriam; Vericat, Pau; Beltrán, Mario

    2017-11-01

    Aim of the study: To develop regional guidelines for sustainable forest management. Area of the study: Forests of Catalonia (NE Spain). Material and methods: The process of developing the forest management guidelines (FMG) started by establishing a thorough classification of forest types at stand level. This classification hinges on two attributes: tree species composition and site quality based on ecological variables, which together determine potential productivity. From there, the management guidelines establish certain objectives and silvicultural models for each forest type. The forest type classifications, like the silvicultural models, were produced using both existing and newly-built growth models based on data from the National Forest Inventory (NFI) and expert knowledge. The effort involved over 20 expert working groups in order to better integrate the expertise and vision of different sectorial agents. Main results: The FMG consist in quantitative silvicultural models that include typical silvicultural variables, technical descriptions of treatments and codes of good practice. Guidelines now cover almost all forest types in Catalonia (spanning up to 90% of the Catalan forest area). Different silvicultural models have been developed for pure and mixed stands, different site quality classes (2–3 classes per species), and even- and multi-aged stands. Research highlights: FMG: i) orient the management of private and public forests, (ii) provide a technical scaffold for efficient allocation/investment of public subsidies in forest management, and (iii) bridge forest planning instruments at regional (strategic-tactical) and stand (operational) level.

  17. ORGEST: Regional guidelines and silvicultural models for sustainable forest management

    International Nuclear Information System (INIS)

    Piqué, Míriam; Vericat, Pau; Beltrán, Mario

    2017-01-01

    Aim of the study: To develop regional guidelines for sustainable forest management. Area of the study: Forests of Catalonia (NE Spain). Material and methods: The process of developing the forest management guidelines (FMG) started by establishing a thorough classification of forest types at stand level. This classification hinges on two attributes: tree species composition and site quality based on ecological variables, which together determine potential productivity. From there, the management guidelines establish certain objectives and silvicultural models for each forest type. The forest type classifications, like the silvicultural models, were produced using both existing and newly-built growth models based on data from the National Forest Inventory (NFI) and expert knowledge. The effort involved over 20 expert working groups in order to better integrate the expertise and vision of different sectorial agents. Main results: The FMG consist in quantitative silvicultural models that include typical silvicultural variables, technical descriptions of treatments and codes of good practice. Guidelines now cover almost all forest types in Catalonia (spanning up to 90% of the Catalan forest area). Different silvicultural models have been developed for pure and mixed stands, different site quality classes (2–3 classes per species), and even- and multi-aged stands. Research highlights: FMG: i) orient the management of private and public forests, (ii) provide a technical scaffold for efficient allocation/investment of public subsidies in forest management, and (iii) bridge forest planning instruments at regional (strategic-tactical) and stand (operational) level.

  18. CADDIS Volume 2. Sources, Stressors and Responses: Herbicides

    Science.gov (United States)

    Introduction to the herbicides module, when to list herbicides as a candidate cause, ways to measure herbicides, simple and detailed conceptual diagrams for herbicides, herbicides module references and literature reviews.

  19. Herbicides in environmental pollution

    International Nuclear Information System (INIS)

    Qureshi, M.J.; Haq, A.; Maqbool, U.

    1997-01-01

    Herbicide effectiveness on the most pernicious weeds including cyperus rotundus may be limited because spray droplets are not well retained or because penetration and/or translocation is restricted. As a result, chemical pollute the environment and is hazardous to the human health. Monitoring studies ad undertaken to check that the flate and environmental effects of herbicides under field condition are consistent with prediction. Studies on /sup 14/-glyphosate in Cyperus rotundus using radiotracer methods indicated that out of five formulations studies formulation No.3 was the best from penetration point of view of the chemical whereas formulation No. 4 with the high dose showed effective retention and uniform translocation of the chemical after five days of the treatment. Cuticular penetration and translocation of glyphosate in the formulations with or without surfactants have also been studied in C. rotundus. It is also concluded that synperonic surfactants, diesel oil or glycerol did not influence the translocation of glyphosate within the weed. The translocation mainly occurred down swards and accumulated in the plant parts located below the treated zone. (author)

  20. Adjusting slash pine growth and yield for silvicultural treatments

    Science.gov (United States)

    Stephen R. Logan; Barry D. Shiver

    2006-01-01

    With intensive silvicultural treatments such as fertilization and competition control now commonplace in today's slash pine (Pinus elliottii Engelm.) plantations, a method to adjust current growth and yield models is required to accurately account for yield increases due to these practices. Some commonly used ad-hoc methods, such as raising site...

  1. Combining Silviculture and Landscape Architecture to Enhance the Roadside View

    Science.gov (United States)

    Philip M. McDonald; R. Burton Litton Jr.

    1998-01-01

    On a high-quality site in the mixed conifer forest of northern California, understory and overstory vegetation along a 3-mile paved county road were manipulated to enhance the view for the traveler. Traditional silvicultural cutting methods and landscape architectural techniques were blended to give contrast and variability to the vegetation along both sides of the...

  2. Plantation Forestry in Sub Saharan Africa: Silvicultural, Ecological ...

    African Journals Online (AJOL)

    This paper discusses the potentials of meeting the wood demand and achieving SFM in Sub-Saharan Africa (SSA) through the establishment of forest plantations. The paper reviews forest plantation ownership and distribution patterns in SSA and the factors –silvicultural, ecological, and economic that affect supply and ...

  3. A financial evaluation of two contrasting silvicultural systems ...

    African Journals Online (AJOL)

    The Loblolly pine (Pinus taeda L.) plantation area in north-east Uruguay was 108 000 ha in 2008. Recent industrial capacity developments have resulted in major structural changes. Silvicultural system selection depends on site productivity, costs, timber prices and public policies. This study aimed to assess economic ...

  4. Silviculture: what is it like, and where have we journeyed?

    Science.gov (United States)

    Ralph D. Nyland

    1997-01-01

    The philosophy of ecosystem management calls for a new way of doing business. It represents an evolution of thinking and acting that began during the era of dominant use, and continued through the time of multiple use. As such, ecosystem management represents a maturing of thought about silviculture and other aspects of natural resources management and use. It stresses...

  5. Effect of Silviculture on the Yield and Quality of Veneers

    Science.gov (United States)

    Leslie H. Groom; Ray Newbold; Jim Guldin

    2002-01-01

    The structural and aesthetic value of wood is typically sacrificed in an attempt to meet demand. This paper addresses the financial and quality aspects of silvicultural choices as it relates to wood veneers. Five trees each were harvested from an uneven-aged stand and from the following even- aged stands: intensive plantation, conventional plantation, and natural...

  6. Resistance and resilience: A conceptual framework for silviculture

    Science.gov (United States)

    Robert J. DeRose; James N. Long

    2014-01-01

    Increasingly, forest management goals include building or maintaining resistance and/or resilience to disturbances in the face of climate change. Although a multitude of descriptive definitions for resistance and resilience exist, to evaluate whether specific management activities (silviculture) are effective, prescriptive characterizations are necessary. We introduce...

  7. Silvicultural approaches to animal damage management in Pacific Northwest forests.

    Science.gov (United States)

    Hugh C. Black

    1992-01-01

    This book examines the potential of Silvicultural approaches for managing animal damage in forests at two levels: management of free-to-grow stands and sitespecific practices that foster prompt and successful regeneration. Introductory chapters provide a historical perspective of animal damage management in the Pacific Northwest, describe the elements of an integrated...

  8. Proceedings of the 12th biennial southern silvicultural research conference

    Science.gov (United States)

    Kristina F. Connor; [Editor

    2004-01-01

    Ninety-two papers and thirty-six poster summaries address a range of issues affecting southern forests. Papers are grouped in 15 sessions that include wildlife ecology; fire ecology; natural pine management; forest health; growth and yield; upland hardwoods - natural regeneration; hardwood intermediate treatments; longleaf pine; pine plantation silviculture; site...

  9. Proceedings of the 14th biennial southern silvicultural research conference

    Science.gov (United States)

    John A. Stanturf

    2010-01-01

    A range of issues affecting southern forests are addressed in 113 papers. Papers are grouped into 12 sessions that include carbon; pine silviculture; invasive species; site preparation; hardwood artificial regeneration; longleaf pine; forest health and fire; growth and yield; hardwood intermediate treatments; hardwood natural regeneration; wildlife; and posters.

  10. Evolution of silvicultural thinning: from rejection to transcendence

    Science.gov (United States)

    Boris Zeide

    2006-01-01

    Our views on a main tool of forestry, silvicultural thinning, have changed greatly since the beginning of forestry over 200 years ago. At first, thinning was rejected as something unnatural and destructive. It was believed that the densest stands were the most productive and any thinning only detracted from maximum growth produced by nature. This philosophy was still...

  11. Large-scale silviculture experiments of western Oregon and Washington.

    Science.gov (United States)

    Nathan J. Poage; Paul D. Anderson

    2007-01-01

    We review 12 large-scale silviculture experiments (LSSEs) in western Washington and Oregon with which the Pacific Northwest Research Station of the USDA Forest Service is substantially involved. We compiled and arrayed information about the LSSEs as a series of matrices in a relational database, which is included on the compact disc published with this report and...

  12. Use of microcomputers for planning and managing silviculture habitat relationships.

    Science.gov (United States)

    B.G. Marcot; R.S. McNay; R.E. Page

    1988-01-01

    Microcomputers aid in monitoring, modeling, and decision support for integrating objectives of silviculture and wildlife habitat management. Spreadsheets, data bases, statistics, and graphics programs are described for use in monitoring. Stand growth models, modeling languages, area and geobased information systems, and optimization models are discussed for use in...

  13. Natural compounds as next-generation herbicides.

    Science.gov (United States)

    Dayan, Franck E; Duke, Stephen O

    2014-11-01

    Herbicides with new modes of action (MOAs) are badly needed due to the rapidly evolving resistance to commercial herbicides, but a new MOA has not been introduced in over 20 years. The greatest pest management challenge for organic agriculture is the lack of effective natural product herbicides. The structural diversity and evolved biological activity of natural phytotoxins offer opportunities for the development of both directly used natural compounds and synthetic herbicides with new target sites based on the structures of natural phytotoxins. Natural phytotoxins are also a source for the discovery of new herbicide target sites that can serve as the focus of traditional herbicide discovery efforts. There are many examples of strong natural phytotoxins with MOAs other than those used by commercial herbicides, which indicates that there are molecular targets of herbicides that can be added to the current repertoire of commercial herbicide MOAs. © 2014 American Society of Plant Biologists. All Rights Reserved.

  14. Cloud based, Open Source Software Application for Mitigating Herbicide Drift

    Science.gov (United States)

    Saraswat, D.; Scott, B.

    2014-12-01

    The spread of herbicide resistant weeds has resulted in the need for clearly marked fields. In response to this need, the University of Arkansas Cooperative Extension Service launched a program named Flag the Technology in 2011. This program uses color-coded flags as a visual alert of the herbicide trait technology within a farm field. The flag based program also serves to help avoid herbicide misapplication and prevent herbicide drift damage between fields with differing crop technologies. This program has been endorsed by Southern Weed Science Society of America and is attracting interest from across the USA, Canada, and Australia. However, flags have risk of misplacement or disappearance due to mischief or severe windstorms/thunderstorms, respectively. This presentation will discuss the design and development of a cloud-based, free application utilizing open-source technologies, called Flag the Technology Cloud (FTTCloud), for allowing agricultural stakeholders to color code their farm fields for indicating herbicide resistant technologies. The developed software utilizes modern web development practices, widely used design technologies, and basic geographic information system (GIS) based interactive interfaces for representing, color-coding, searching, and visualizing fields. This program has also been made compatible for a wider usability on different size devices- smartphones, tablets, desktops and laptops.

  15. Geographical information systems (GIS), a great tool for urban silviculture

    International Nuclear Information System (INIS)

    Otaya Burbano, Leodan Andres; Sanchez Zapata, Robinson de Jesus; Morales Soto, Leon; Botero Fernandez, Veronica

    2006-01-01

    As a pilot phase, to acquire experience, define methodologies and determine the advantages of Geographical Information Systems (GIS) for applying to urban silviculture and inventory, diagnosis, management plan and economic appraisal were made for the urban forest in the Magnolia neighborhood of the Envigado municipality, department of Antioquia, Colombia. for the management and analysis of the data collected in field, a database was designed using the software microsoft Access. The species inventoried were mapped digitally and the conditions there were analyzed using some tools and extensions of technological architecture ArcGIS 8.3 such as: characteristics, silviculture practices required, and environmental conflicts. It was determined that the GIS analysis of the urban forest conducted for a specific neighborhood can be a tool that permits environmental authorities and interested researchers to have agile and easy access to the information stored in it; it permits programming of required silviculture activities; it also permits having a general vision of the urban forest according to the infrastructure of the neighborhood, complemented by photographs of the area for improved illustration; it permits the inclusion or elimination of information in a rapid and simple manner, thus facilitating decision making with relation to management of the urban woodland and for comparison with other similar studies

  16. Spot Spraying Reduces Herbicide Concentrations in Runoff.

    Science.gov (United States)

    Melland, Alice R; Silburn, D Mark; McHugh, Allen D; Fillols, Emilie; Rojas-Ponce, Samuel; Baillie, Craig; Lewis, Stephen

    2016-05-25

    Rainfall simulator trials were conducted on sugar cane paddocks across dry-tropical and subtropical Queensland, Australia, to examine the potential for spot spraying to reduce herbicide losses in runoff. Recommended rates of the herbicides glyphosate, 2,4-D, fluoroxypyr, atrazine, and diuron were sprayed onto 0, 20, 40, 50, 70, or 100% of the area of runoff plots. Simulated rainfall was applied 2 days after spraying to induce runoff at one plant cane and three ratoon crop sites. Over 50% of all herbicides were transported in the dissolved phase of runoff, regardless of the herbicide's sediment-water partition coefficient. For most sites and herbicides, runoff herbicide concentrations decreased with decreasing spray coverage and with decreasing herbicide load in the soil and cane residues. Importantly, sites with higher infiltration prior to runoff and lower total runoff had lower runoff herbicide concentrations.

  17. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Mariano Fracchiolla

    2007-12-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  18. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Pasquale Montemurro

    2011-02-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  19. Variable-retention harvesting as a silvicultural option for lodgepole pine

    Science.gov (United States)

    Christopher R. Keyes; Thomas E. Perry; Elaine K. Sutherland; David K. Wright; Joel M. Egan

    2014-01-01

    Bark beetle-induced mortality in forested landscapes of structurally uniform, even-aged lodgepole pine stands has inspired a growing interest in the potential of silvicultural treatments to enhance resilience by increasing spatial and vertical complexity. Silvicultural treatments can simulate mixed-severity disturbances that create multiaged lodgepole pine stands,...

  20. Habitat use by bats in two Indiana forests prior to silvicultural treatments for oak regeneration

    Science.gov (United States)

    Jeremy J. Sheets; Joseph E. Duchamp; Megan K. Caylor; Laura D' Acunto; John O. Whitaker; Virgil Jr. Brack; Dale W. Sparks

    2013-01-01

    As part of a study examining the effects of silvicultural treatments for oak regeneration on habitat use by bats, we surveyed forest stands prior to the implementation of treatments in two state forests in Indiana. Interior forest sites corresponding to areas designated for silvicultural treatments were surveyed for 2 nights each during the summers of 2007 and 2008....

  1. Ecology and silviculture of the spruce-fir forests of eastern North America

    Science.gov (United States)

    Marinus. Westveld

    1953-01-01

    Using the climax forest as a guide to growing the species best suited to the climate and the site, the author offers a silvicultural system for managing the spruce-fir forests of eastern North America. Based on ecological principles, such silviculture is aimed to bring about forests that are inherently healthy and have a natural resistance to insects and disease.

  2. Putting out fire with gasoline: pitfalls in the silvicultural treatment of canopy fuels

    Science.gov (United States)

    Christopher R. Keyes; J. Morgan Varner

    2007-01-01

    There is little question that forest stand structure is directly related to fire behavior, and that canopy fuel structure may be altered using silvicultural methods to successfully modify forest fire behavior and reduce susceptibility to crown fire initiation and spread. Silvicultural treatments can remediate hazardous stand structures that have developed as a result...

  3. A special issue of the Journal of Forestry---proceedings of the 2013 National Silviculture Workshop

    Science.gov (United States)

    James M. Guldin; Marilyn A. Buford

    2014-01-01

    This special issue of the Journal of Forestry presents the Proceedings of the 2013 National Silviculture Workshop (NSW), which was held as one of the concurrent sessions of the 2013 national convention of the Society of American Foresters (SAF) and sponsored by the D-2 Silviculture Working Group. This marks the first time the NSW has been held in conjunction with the...

  4. Silviculture guide for the mahogany forests of Quintana Roo, Mexico – Criteria and recommendations

    Science.gov (United States)

    P. Negreros-Castillo; L. Cámara-Cabrales; Margaret Devall; M.A. Fajvan; M.A. Mendoza Briseño; C.W. Mize

    2014-01-01

    Silviculture is the art, science and practice of controlling the establishment, composition, health, quality and growth of forests to accomplish a set of management objectives. This publication offers an approach to silviculture of the forests of Quintana Roo in which mahogany (Swietenia macrophylla King), the commercially most important tree species in Latin America,...

  5. Silviculture of the mahogany forest of Quintana Roo, Mexico: criteria and recommendations

    Science.gov (United States)

    P. ​​Negreros-Castillo; L. Camara-Cabrales; MS Devall; Mary Ann Fajvan; M.A. Mendoza Briseno; C.W. Mize; A. Navarro-Martinez

    2014-01-01

    Silviculture is the art, science and practice of controlling the establishment, composition, health, quality and growth of forests to accomplish a set of management objectives. This publication offers an approach to silviculture of the forests of Quintana Roo in which mahogany (Swietenia macrophylla King), the commercially most important tree...

  6. Age structure of a southern pine stand following 72 years of uneven-aged silviculture

    Science.gov (United States)

    Don C. Bragg

    2012-01-01

    Work on uneven-aged silviculture in southern pine stands on the Crossett Experimental Forest (CEF) began in the 1930s, when a number of 16.2-ha compartments were placed into a series of demonstration projects and studies (Reynolds 1980). Two of these compartments, the Good and Poor Farm Forestry Forties, have been maintained continuously in this silvicultural regime...

  7. Using Live-Crown Ratio to Control Wood Quality: An Example of Quantitative Silviculture

    Science.gov (United States)

    Thomas J. Dean

    1999-01-01

    Quantitative silviculture is the application of biological relationships in meeting specific, quantitative management objectives. It is a two-sided approach requiring the identification and application of biological relationships. An example of quantitative silviculture is presented that uses a relationship between average-live crown ratio and relative stand density...

  8. The Ecology and Silviculture of Oaks, Second Edition: A new book

    Science.gov (United States)

    Paul S. Johnson; Stephen R. Shifley; Robert. Rogers

    2011-01-01

    The second edition of The Ecology and Silviculture of Oaks was recently published (Johnson and others 2009). The approach of the book is fundamentally silvicultural, but the content is based on the premise that eff ective and environmentally sound management and protection of oak forests and associated landscapes must be grounded in ecological...

  9. Vegetation structure, logging damage and silviculture in a tropical rain forest in Suriname

    NARCIS (Netherlands)

    Jonkers, W.B.J.

    1987-01-01

    In the first publication in this series, a polycyclic forest management system was formulated, in which three silvicultural treatments (refinements) were scheduled in a cutting cycle of twenty years. This system, which is referred to as the Celos Silvicultural System, is developed further

  10. Comparisons of Herbicide Treated and Cultivated Herbicide-Resistant Corn

    Directory of Open Access Journals (Sweden)

    H. Arnold Bruns

    2010-01-01

    Full Text Available Four glyphosate resistant corn (Zea mays L. hybrids, a glufosinate-ammonium resistant hybrid, and a conventional atrazine resistant hybrid gown at Stoneville, MS in 2005, 2006, and 2007 with furrow irrigation were treated with their respective herbicides and their growth, yield, and mycotoxin incidence were compared with untreated cultivated plots. Leaf area index (LAI and dry matter accumulation (DMA were collected on a weekly basis beginning at growth stage V3 and terminating at anthesis. Crop growth rates (CRGs and relative growth rates (RGRs were calculated. Plots were later harvested, yield and yield component data collected, and kernel samples analyzed for aflatoxin and fumonisin. Leaf area index, DMA, CRG, and RGR were not different among the herbicide treated plots and from those that were cultivated. Curves for LAI and DMA were similar to those previously reported. Aflatoxin and fumonisin were relatively low in all plots. Herbicide application or the lack thereof had no negative impact on the incidence of kernel contamination by these two mycotoxins. Herbicides, especially glyphosate on resistant hybrids, have no negative effects on corn yields or kernel quality in corn produced in a humid subtropical environment.

  11. Biotechnology: herbicide-resistant crops

    Science.gov (United States)

    Transgenic, herbicide-resistant (HR) crops are planted on about 80% of the land covered by transgenic crops. More than 90% of HR crios are glyphosate-resistant (GR) crops, the others being resistant to glufosinate. The wide-scale adoption of HR crops, largely for economic reasons, has been the mos...

  12. Are herbicide-resistant crops the answer to controlling Cuscuta?

    Science.gov (United States)

    Nadler-Hassar, Talia; Shaner, Dale L; Nissen, Scott; Westra, Phill; Rubin, Baruch

    2009-07-01

    Herbicide-resistant crop technology could provide new management strategies for the control of parasitic plants. Three herbicide-resistant oilseed rape (Brassica napus L.) genotypes were used to examine the response of attached Cuscuta campestris Yuncker to glyphosate, imazamox and glufosinate. Cuscata campestris was allowed to establish on all oilseed rape genotypes before herbicides were applied. Unattached seedlings of C. campestris, C. subinclusa Durand & Hilg. and C. gronovii Willd. were resistant to imazamox and glyphosate and sensitive to glufosinate, indicating that resistance initially discovered in C. campestris is universal to all Cuscuta species. Glufosinate applied to C. campestris attached to glufosinate-resistant oilseed rape had little impact on the parasite, while imazamox completely inhibited C. campestris growth on the imidazolinone-resistant host. The growth of C. campestris on glyphosate-resistant host was initially inhibited by glyphosate, but the parasite recovered and resumed growth within 3-4 weeks. The ability of C. campestris to recover was related to the quality of interaction between the host and parasite and to the resistance mechanism of the host. The parasite was less likely to recover when it had low compatibility with the host, indicating that parasite-resistant crops coupled with herbicide resistance could be highly effective in controlling Cuscuta. (c) 2009 by John Wiley & Sons, Ltd.

  13. Herbicide Persistence in Seawater Simulation Experiments.

    Directory of Open Access Journals (Sweden)

    Philip Mercurio

    Full Text Available Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR. The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities. Very little degradation was recorded over the standard 60 d period (Experiment 1 so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated

  14. Herbicide Persistence in Seawater Simulation Experiments

    Science.gov (United States)

    Mercurio, Philip; Mueller, Jochen F.; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P.

    2015-01-01

    Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

  15. Multifunctional natural forest silviculture economics revised: Challenges in meeting landowners’ and society's wants. A review

    International Nuclear Information System (INIS)

    Campos, P.; Caparrós, A.; Cerdá, E.; Diaz-Balteiro, L.; Herruzo, A.C.; Huntsinger, L.; Martín-Barroso, D.; Martínez-Jauregui, M.; Ovando, P.; Oviedo, J.L.; Pasalodos-Tato, M.; Romero, C.; Soliño, M.; Standiford, R.B.

    2017-01-01

    Aim of study: This paper objective focuses on the contribution of multifunctional natural forest silviculture, incorporating both private and public product managements, to forest and woodland economics. Area of study: Spain and California (USA). Material and methods: This conceptual article has developed a critical revision of the existing literature on the main economic issues about the multifunctional natural forest silviculture in the last decades. Main results: Multifunctional natural silviculture has secular roots as a local practice, but as a science of the natural environment applied to the economic management of forest lands it is still in the process of maturation. Timber silviculture remains the central concern of forest economics investment in scientific publications. By contrast, silvicultural modeling of the natural growth of firewood, browse and other non-timber forest products of trees and shrubs receives scant attention in scientific journals. Even rarer are publications on multifunctional natural silviculture of forest and woodland managements, including environmental services geared to people’s active and passive consumption. Under this umbrella, private environmental self-consumption is represented by the amenities enjoyed by private non-industrial landowners. As for environmental public products, the most relevant are carbon, water, mushrooms, recreation, landscape and threatened biodiversity. Research highlights: This paper is a good example about the conceptual research on forestry techniques and economic concepts applied to multifunctional silviculture in Mediterranean areas of Spain and California. The combination of technical knowledge and private and public economic behaviors definitively contributes to the multifunctional management of natural forest systems.

  16. Comparisons of Herbicide Treated and Cultivated Herbicide-Resistant Corn

    OpenAIRE

    H. Arnold Bruns; Hamed K. Abbas

    2010-01-01

    Four glyphosate resistant corn (Zea mays L.) hybrids, a glufosinate-ammonium resistant hybrid, and a conventional atrazine resistant hybrid gown at Stoneville, MS in 2005, 2006, and 2007 with furrow irrigation were treated with their respective herbicides and their growth, yield, and mycotoxin incidence were compared with untreated cultivated plots. Leaf area index (LAI) and dry matter accumulation (DMA) were collected on a weekly basis beginning at growth stage V3 and terminating at anthesi...

  17. Sensor-based assessment of herbicide effects

    DEFF Research Database (Denmark)

    Streibig, Jens Carl; Rasmussen, Jesper; Andújar, D.

    2014-01-01

    Non-destructive assessment of herbicide effects may be able to support integrated weed management. To test whether effects of herbicides on canopy variables could be detected by sensors, two crops were used as models and treated with herbicides at BBCH 20 using a logarithmic sprayer. Twelve days...... after spraying at BBCH 25 and 42 days after sowing, nine sensor systems scanned a spring barley and an oilseed rape field experiment sown at different densities and sprayed with increasing field rates of glyphosate and tribenuron-methyl. The objective was to compare ED50s for crops and weeds derived...... by the different sensors in relation to crop density and herbicides. Although sensors were not directly developed to detect herbicide symptoms, they all detected changes in canopy colours or height and crop density. Generally ED50s showed the same pattern in response to crop density within herbicide...

  18. Sorption behaviour of herbicides in soils

    International Nuclear Information System (INIS)

    Luchini, L.C.; Wiendl, F.M.; Ruegg, E.F.; Instituto Biologico, Sao Paulo

    1988-01-01

    Environmental contamination by herbicides is related with the sorption phenomenon of these compounds in the soils. The behaviour of paraquat, 2,4-D and diuron was studied in soils with different physico-chemical properties, through the Freundlich adsorption and desorption isotherms, using 14 C-radiolabeled herbicides. Results of the range of the adsorption-desorption of each herbicide was related mainly with the chemical characteristics of these compounds. (author) [pt

  19. Delivery of calibration workshops covering herbicide application equipment : final report.

    Science.gov (United States)

    2014-03-31

    Proper herbicide sprayer set-up and calibration are critical to the success of the Oklahoma Department of Transportation (ODOT) herbicide program. Sprayer system set-up and calibration training is provided in annual continuing education herbicide wor...

  20. CADDIS Volume 2. Sources, Stressors and Responses: Herbicides - Detailed Conceptual Diagram

    Science.gov (United States)

    Introduction to the herbicides module, when to list herbicides as a candidate cause, ways to measure herbicides, simple and detailed conceptual diagrams for herbicides, herbicides module references and literature reviews.

  1. CADDIS Volume 2. Sources, Stressors and Responses: Herbicides - Simple Conceptual Diagram

    Science.gov (United States)

    Introduction to the herbicides module, when to list herbicides as a candidate cause, ways to measure herbicides, simple and detailed conceptual diagrams for herbicides, herbicides module references and literature reviews.

  2. Physiology and silviculture of black walnut for combined timber and nut production

    Science.gov (United States)

    J. W. Van Sambeek; George Rink

    1981-01-01

    Research literature was reviewed for evidence supporting the management of black walnut plantations for combined timber and nut production. The silviculture of the species is discussed in relation to dual cropping. Stimulation and phenology of flowering and fruiting are reviewed.

  3. Biotechnology approaches to developing herbicide tolerance ...

    African Journals Online (AJOL)

    The use of herbicides has revolutionized weed control in many crop production systems. However, with the increasing development of weed resistances to many popular selective herbicides, the need has arisen to rethink the application of chemical weed control. Approaches to maintain the efficiency of chemical weed ...

  4. FLAMMABILITY OF HERBICIDE-TREATED GUAVA FOLIAGE

    Science.gov (United States)

    Guava leaves treated with herbicide were found to be less flammable than untreated green leaves or dead leaves . Differences in flammability were...determined by small-scale laboratory fires, differential thermal analysis, and thermogravimetric analysis. The herbicide-treated leaves had a higher ash

  5. Response of Saw Palmetto to Three Herbicides

    Science.gov (United States)

    J.L. Michael; D.G. Neary

    1985-01-01

    Saw palmetto [Serona repens (Bartram) Small] can be controlled with herbicides. Garion® 4E1/2 and Brush Killer® 800 were evaluated for effectiveness againest saw palmetto when they were applied at three rates in April, June, and August. Oust® was tested at three rates in April only. Herbicides were not effective with April...

  6. SELECTIVITY OF DIFFERENT HERBICIDES TO COWPEA

    Directory of Open Access Journals (Sweden)

    Francisco Aires Sizenando Filho2

    2013-12-01

    1.5 = recommended rate + half the recommended rate. At the end of the experiment it was found that: the cowpea showed phytotoxicity to use herbicide among 14 and 21 AAD; the herbicides diuron and metolachlor showed a rate "middle" in control weed, while the pendimethalin wasn't efficient for those function.

  7. Herbicide residues in grapes and wine.

    Science.gov (United States)

    Ying, G G; Williams, B

    1999-05-01

    The persistence of several common herbicides from grapes to wine has been studied. Shiraz, Tarrango and Doradillo grapes were separately sprayed with either norflurazon, oxyfluorfen, oxadiazon or trifluralin-persistent herbicides commonly used for weed control in vineyards. The dissipation of the herbicides from the grapes was followed for 28 days following treatment. Results showed that norflurazon was the most persist herbicide although there were detectable residues of all the herbicides on both red and white grapes at the end of the study period. The penetration of herbicides into the flesh of the grapes was found to be significantly greater for white grapes than for red grapes. Small-lot winemaking experiments showed that norflurazon persisted at levels close to the initial concentration through vinification and into the finished wine. The other herbicides degraded, essentially via first-order kinetics, within the period of "first fermentation" and had largely disappeared after 28 days. The use of charcoal together with filter pads, or with diatomaceous earth was shown to be very effective in removing herbicide residues from the wine. A 5% charcoal filter removed more than 96% of the norflurazon persisting in the treated wine.

  8. Control of Butterfly Bush with Postemergence Herbicides

    Science.gov (United States)

    Butterfly bush (Buddleja davidii) is classified as invasive in several parts of the United States. Two experiments were conducted to evaluate the effectiveness of four herbicides and two application methods on postemergence butterfly bush control. The four herbicides included: Roundup (glyphosate)...

  9. Imazapyr (herbicide) seed dressing increases yield, suppresses ...

    African Journals Online (AJOL)

    from damage. In 1998/99 season, a trial was initiated at Chitedze Research Station under artificial infection, to evaluate the effects of seed dressing with imazapyr (an acetolactate synthase {ALS} inhibiting herbicide) using three seed treatment methods (coating, priming or drenching) and three herbicide rates (15, 30 and 45 ...

  10. Environmental toxicology: Degradation of herbicides

    International Nuclear Information System (INIS)

    Corbin, F.T.; Monaco, T.J.; Bjelk, L.A.

    1991-01-01

    This chapter focuses on the advances that have been made for the quantitative analysis of radiotracers in thin-layer chromatography through the development of computer controlled imaging proportional counters (IPC). IPC has been developed to give high sensitivity digital data from an entire TLC separation in one measurement. The imaging capability provides a 100 percent improvement over mechanical scanners. Sensitivity is 100 DPM or less with 14 C and higher energy isotopes. Investigations of herbicide metabolism in plant cell suspension cultures are presented with procedures for the use of this technique

  11. Rice Transcriptome Analysis to Identify Possible Herbicide Quinclorac Detoxification Genes

    Directory of Open Access Journals (Sweden)

    Wenying eXu

    2015-09-01

    Full Text Available Quinclorac is a highly selective auxin-type herbicide, and is widely used in the effective control of barnyard grass in paddy rice fields, improving the world’s rice yield. The herbicide mode of action of quinclorac has been proposed and hormone interactions affect quinclorac signaling. Because of widespread use, quinclorac may be transported outside rice fields with the drainage waters, leading to soil and water pollution and environmental health problems.In this study, we used 57K Affymetrix rice whole-genome array to identify quinclorac signaling response genes to study the molecular mechanisms of action and detoxification of quinclorac in rice plants. Overall, 637 probe sets were identified with differential expression levels under either 6 or 24 h of quinclorac treatment. Auxin-related genes such as GH3 and OsIAAs responded to quinclorac treatment. Gene Ontology analysis showed that genes of detoxification-related family genes were significantly enriched, including cytochrome P450, GST, UGT, and ABC and drug transporter genes. Moreover, real-time RT-PCR analysis showed that top candidate P450 families such as CYP81, CYP709C and CYP72A genes were universally induced by different herbicides. Some Arabidopsis genes for the same P450 family were up-regulated under quinclorac treatment.We conduct rice whole-genome GeneChip analysis and the first global identification of quinclorac response genes. This work may provide potential markers for detoxification of quinclorac and biomonitors of environmental chemical pollution.

  12. Multifunctional natural forest silviculture economics revised: Challenges in meeting landowners’ and society's wants. A review

    Directory of Open Access Journals (Sweden)

    Pablo Campos

    2017-10-01

    Full Text Available Aim of study: This paper objective focuses on the contribution of multifunctional natural forest silviculture, incorporating both private and public product managements, to forest and woodland economics. Area of study: Spain and California (USA. Material and methods: This conceptual article has developed a critical revision of the existing literature on the main economic issues for multifunctional natural forest silviculture in the last decades. Main results: Multifunctional natural silviculture has secular roots as a local practice, but as a science of the natural environment applied to the economic management of forest lands it is still in the process of maturation. Timber silviculture remains the central concern of forest economics investment in scientific publications. By contrast, silvicultural modeling of the natural growth of firewood, browse and other non-timber forest products from trees and shrubs receives scant attention in scientific journals. Even rarer are publications on multifunctional natural silviculture for forest and woodland managements, including environmental services geared to people’s active and passive consumption. Under this umbrella, private environmental self-consumption is represented by the amenities enjoyed by private non-industrial landowners. As for environmental public products, the most relevant are carbon, water, mushrooms, recreation, landscape and threatened biodiversity. Research highlights: This paper is a good example for the conceptual research on forestry techniques and economic concepts applied to multifunctional silviculture in Mediterranean areas of Spain and California. The combination of technical knowledge and private and public economic behaviors definitively contributes to the multifunctional management of natural forest systems.

  13. Beyond 2001: a silvicultural odyssey to sustaining terrestrial and aquatic ecosystems? Proceedings of the 2001 national silviculture workshop, May 6-10, Hood River, Oregon.

    Science.gov (United States)

    Sharon Parker; Susan Stevens. Hummel

    2002-01-01

    The 2001 National Silviculture Workshop was held in Hood River, Oregon, and hosted by the Mt. Hood National Forest, the Gifford Pinchot National Forest, and the Pacific Northwest Research Station. The Washington Office Vegetation Management and Protection Research and Forest and Grassland staffs are ongoing sponsors of the biennial workshop, which began in 1973 in...

  14. Nonnative invasive plants in the Penobscot Experimental Forest in Maine, USA: influence of site, silviculture, and land use history

    Science.gov (United States)

    Elizabeth Olson; Laura S. Kenefic; Alison C. Dibble; John C. Brissette

    2011-01-01

    We investigated the occurrence of nonnative invasive plants on approximately 175 ha comprising a long-term, 60-year-old U.S. Forest Service silvicultural experiment and old-field stands in the Penobscot Experimental Forest (PEF) in central Maine. Stands in the silvicultural experiment were never cleared for agriculture, but have been repeatedly partially cut. Our...

  15. Large-scale, long-term silvicultural experiments in the United States: historical overview and contemporary examples.

    Science.gov (United States)

    R. S. Seymour; J. Guldin; D. Marshall; B. Palik

    2006-01-01

    This paper provides a synopsis of large-scale, long-term silviculture experiments in the United States. Large-scale in a silvicultural context means that experimental treatment units encompass entire stands (5 to 30 ha); long-term means that results are intended to be monitored over many cutting cycles or an entire rotation, typically for many decades. Such studies...

  16. Silvicultural Attempts to Induce Browse Resistance in Conifer Seedlings

    Directory of Open Access Journals (Sweden)

    Bruce A. Kimball

    2011-01-01

    Full Text Available A multiyear study was conducted to determine if soil amendment combined with topical application of elemental sulfur could be employed to reduce deer browse damage to four conifer species. Fertilizer and sulfur were applied to conifer seedlings at seven sites near Corvallis, OR. Growth and browse damage data were collected for all seedlings over a period of 17 months. Additionally, foliar concentrations of monoterpenes and simple carbohydrates were assessed in western redcedar (Thuja plicata seedlings over a period of three years. Fertilization and sulfur treatments had a moderate impact on growth and no influence on browse damage or the chemical responses. Over the course of the study, browse damage diminished while foliar monoterpene concentrations increased in redcedar. It appears that silvicultural manipulation via sulfur application and/or soil amendment cannot accelerate or alter the ontogenetical changes that may naturally defend seedlings against mammalian herbivores. In a brief trial with captive deer, redcedar browse resistance was influenced by seedling maturation, but not monoterpene content. Other maturation effects may yield significant browse protection to young seedlings.

  17. Potential organic herbicides for squash production: Pelargonic acid herbicides AXXE (registered trademark) and Scythe (registered trademark)

    Science.gov (United States)

    Organic squash (Cucurbita pepo L.) producers need appropriate herbicides that can effectively provide season- long weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the impact of potential organic herbicides on weed control efficacy, crop injury, and y...

  18. Genetically Modified Herbicide-Tolerant Crops, Weeds, and Herbicides: Overview and Impact

    Science.gov (United States)

    Bonny, Sylvie

    2016-01-01

    Genetically modified (GM) crops have been and continue to be a subject of controversy despite their rapid adoption by farmers where approved. For the last two decades, an important matter of debate has been their impact on pesticide use, particularly for herbicide-tolerant (HT) crops. Some claim that these crops bring about a decrease in herbicide use, while others claim the opposite. In fact, since 1996, most cultivated GMOs have been GMHT crops, which involve the use of an associated herbicide, generally glyphosate. In their very first years of adoption, HT crops often led to some decrease in herbicide use. However, the repetition of glyphosate-tolerant crops and of glyphosate only applications in the same fields without sufficient alternation and herbicide diversity has contributed to the appearance of glyphosate-resistant weeds. These weeds have resulted in a rise in the use of glyphosate and other herbicides. This article explores this situation and the impacts of herbicide-resistant weeds, using an interdisciplinary approach and drawing on recent data. The paper analyzes the spread of GMHT crops worldwide and their consequences on herbicide use in the USA in particular. It then addresses the global development of glyphosate-resistant weeds and their impact, particularly focusing on the USA. Finally, the last section explores how industry, farmers, and weed scientists are coping with the spread of resistant weeds. The concluding comments deal more widely with trends in GM crops.

  19. Herbicide resistance and biodiversity: agronomic and environmental aspects of genetically modified herbicide-resistant plants.

    Science.gov (United States)

    Schütte, Gesine; Eckerstorfer, Michael; Rastelli, Valentina; Reichenbecher, Wolfram; Restrepo-Vassalli, Sara; Ruohonen-Lehto, Marja; Saucy, Anne-Gabrielle Wuest; Mertens, Martha

    2017-01-01

    Farmland biodiversity is an important characteristic when assessing sustainability of agricultural practices and is of major international concern. Scientific data indicate that agricultural intensification and pesticide use are among the main drivers of biodiversity loss. The analysed data and experiences do not support statements that herbicide-resistant crops provide consistently better yields than conventional crops or reduce herbicide amounts. They rather show that the adoption of herbicide-resistant crops impacts agronomy, agricultural practice, and weed management and contributes to biodiversity loss in several ways: (i) many studies show that glyphosate-based herbicides, which were commonly regarded as less harmful, are toxic to a range of aquatic organisms and adversely affect the soil and intestinal microflora and plant disease resistance; the increased use of 2,4-D or dicamba, linked to new herbicide-resistant crops, causes special concerns. (ii) The adoption of herbicide-resistant crops has reduced crop rotation and favoured weed management that is solely based on the use of herbicides. (iii) Continuous herbicide resistance cropping and the intensive use of glyphosate over the last 20 years have led to the appearance of at least 34 glyphosate-resistant weed species worldwide. Although recommended for many years, farmers did not counter resistance development in weeds by integrated weed management, but continued to rely on herbicides as sole measure. Despite occurrence of widespread resistance in weeds to other herbicides, industry rather develops transgenic crops with additional herbicide resistance genes. (iv) Agricultural management based on broad-spectrum herbicides as in herbicide-resistant crops further decreases diversity and abundance of wild plants and impacts arthropod fauna and other farmland animals. Taken together, adverse impacts of herbicide-resistant crops on biodiversity, when widely adopted, should be expected and are indeed very hard

  20. Multifunctional natural forest silviculture economics revised: Challenges in meeting landowners’ and society's wants. A review

    Energy Technology Data Exchange (ETDEWEB)

    Campos, P.; Caparrós, A.; Cerdá, E.; Diaz-Balteiro, L.; Herruzo, A.C.; Huntsinger, L.; Martín-Barroso, D.; Martínez-Jauregui, M.; Ovando, P.; Oviedo, J.L.; Pasalodos-Tato, M.; Romero, C.; Soliño, M.; Standiford, R.B.

    2017-11-01

    Aim of study: This paper objective focuses on the contribution of multifunctional natural forest silviculture, incorporating both private and public product managements, to forest and woodland economics. Area of study: Spain and California (USA). Material and methods: This conceptual article has developed a critical revision of the existing literature on the main economic issues about the multifunctional natural forest silviculture in the last decades. Main results: Multifunctional natural silviculture has secular roots as a local practice, but as a science of the natural environment applied to the economic management of forest lands it is still in the process of maturation. Timber silviculture remains the central concern of forest economics investment in scientific publications. By contrast, silvicultural modeling of the natural growth of firewood, browse and other non-timber forest products of trees and shrubs receives scant attention in scientific journals. Even rarer are publications on multifunctional natural silviculture of forest and woodland managements, including environmental services geared to people’s active and passive consumption. Under this umbrella, private environmental self-consumption is represented by the amenities enjoyed by private non-industrial landowners. As for environmental public products, the most relevant are carbon, water, mushrooms, recreation, landscape and threatened biodiversity. Research highlights: This paper is a good example about the conceptual research on forestry techniques and economic concepts applied to multifunctional silviculture in Mediterranean areas of Spain and California. The combination of technical knowledge and private and public economic behaviors definitively contributes to the multifunctional management of natural forest systems.

  1. The benefits of herbicide-resistant crops.

    Science.gov (United States)

    Green, Jerry M

    2012-10-01

    Since 1996, genetically modified herbicide-resistant crops, primarily glyphosate-resistant soybean, corn, cotton and canola, have helped to revolutionize weed management and have become an important tool in crop production practices. Glyphosate-resistant crops have enabled the implementation of weed management practices that have improved yield and profitability while better protecting the environment. Growers have recognized their benefits and have made glyphosate-resistant crops the most rapidly adopted technology in the history of agriculture. Weed management systems with glyphosate-resistant crops have often relied on glyphosate alone, have been easy to use and have been effective, economical and more environmentally friendly than the systems they have replaced. Glyphosate has worked extremely well in controlling weeds in glyphosate-resistant crops for more than a decade, but some key weeds have evolved resistance, and using glyphosate alone has proved unsustainable. Now, growers need to renew their weed management practices and use glyphosate with other cultural, mechanical and herbicide options in integrated systems. New multiple-herbicide-resistant crops with resistance to glyphosate and other herbicides will expand the utility of existing herbicide technologies and will be an important component of future weed management systems that help to sustain the current benefits of high-efficiency and high-production agriculture. Copyright © 2012 Society of Chemical Industry.

  2. studies on transition metal complexes of herbicidal compounds. ii

    African Journals Online (AJOL)

    a

    derivative of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, atrazine (ATZ) --- a well known herbicide has ... development while the other is the metal ion associated degradation or deactivation of the herbicides .... Colour M.p./decomp.

  3. Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

    International Nuclear Information System (INIS)

    Gonzalez-Barreiro, O.; Rioboo, C.; Herrero, C.; Cid, A.

    2006-01-01

    The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides

  4. Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Barreiro, O. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Rioboo, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Herrero, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Cid, A. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain)]. E-mail: cid@udc.es

    2006-11-15

    The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides.

  5. Effects of silviculture on neotropical migratory birds in central and southeastern oak pine forests

    Science.gov (United States)

    James G. Dickson; Frank R. Thompson; Richard N. Conner; Kathleen E. Franzreb

    1993-01-01

    Avian communities that are associated with forest habitat attributes are affected by silvicultural and other stand influences. Some species have specific habitat requirements, whereas others occupy a broad range of vegetative conditions. In general, bird species richness and density are positively related to stand foliage volume and diversity. Bird density and...

  6. Silvicultural treatments for converting loblolly pine to longleaf pine dominance: Effects on planted longleaf pine seedlings

    Science.gov (United States)

    Huifeng Hu; G.Geoff Wang; Joan L. Walker; Benjamin O. Knapp

    2012-01-01

    A field study was installed to test silvicultural treatments for establishing longleaf pine (Pinus palustris Mill) in loblolly pine (P. taeda L.) stands. Harvesting was used to create seven canopy treatments, four with uniformly distributed canopies at different residual basal areas [Control (16.2 m2/ha),...

  7. Subdivide or silviculture: choices facing family forest owners in the redwood region

    Science.gov (United States)

    William Stewart; Shasta Ferranto; Gary Nakamura; Christy Getz; Lynn Huntsinger; Maggi. Kelly

    2012-01-01

    Families or family businesses own nearly all of the private redwood forestland in California. Family forest owners have practiced both subdivision and silviculture for decades but the dominant theme for most family owners is environmental stewardship. Parcel size is more important than expressed values as a predictor of resource management activities. All landowners...

  8. Nonnative plant response to silvicultural treatments: A model based on disturbance, propagule pressure, and competitive abilities

    Science.gov (United States)

    Steve Sutherland; Cara R. Nelson

    2010-01-01

    Invasion by nonnative plants can result in substantial adverse effects on the functions of native forest ecosystems, including nutrient cycling and fire regimes. Thus, forest managers need to be aware of the potential impacts of management activities, including silvicultural treatments, on nonnative vegetation. To aid in that effort, we created a conceptual model of...

  9. Regeneration of red oak (Quercus rubra L.) using shelterwood systems: Ecophysiology, silviculture and management recommendations

    Science.gov (United States)

    Daniel C. Dey; William C. parker

    1996-01-01

    There is considerable interest in developing relaible methods for regenerating red oak (Quercus rubra) in Ontario. Traditional silviculture methods have not been successful in maintaining the curent levels of oak growing stock. In this paper, we review the ecology, physiology and reproductive biology of red oak. This discussion stresses the...

  10. Silviculture and the assessment of climate change genetic risk for southern Appalachian forest tree species

    Science.gov (United States)

    Kevin M. Potter; Barbara S. Crane

    2012-01-01

    Changing climate conditions and increasing insect and pathogen infestations will increase the likelihood that forest trees could experience population-level extirpation or species-level extinction during the next century. Gene conservation and silvicultural efforts to preserve forest tree genetic diversity present a particular challenge in species-rich regions such as...

  11. State survey of silviculture nonpoint source programs: a comparison of the 2000 northeastern and national results

    Science.gov (United States)

    Pamela J. Edwards; Gordon W. Stuart

    2002-01-01

    The National Association of State Foresters conducts surveys of silviculture nonpoint source (NPS) pollution control programs to measure progress and identify needs. The 2000 survey results are summarized here for the nation and for the 20-state northeastern region. Current emphasis of NPS pollution programs is on education, training, and monitoring. Educational...

  12. Silviculture-ecology of forest-zone hardwoods in the Sierra Nevada

    Science.gov (United States)

    Philip M. McDonald; John C. Tappeiner

    1996-01-01

    Although the principal hardwood species in the forest zone of the Sierra Nevada (California black oak, tanoak, Pacific madrone, and canyon live oak) are key components of many ecosystems, they have received comparatively little study. Currently they are underutilized and unmanaged. This paper brings together what is known on the silviculture-ecology of these species...

  13. Comparing Floristic Diversity between a Silviculturally Managed Arboretum and a Forest Reserve in Dambulla, Sri Lanka

    Directory of Open Access Journals (Sweden)

    B. D. Madurapperuma

    2014-01-01

    Full Text Available Repeated slash and burn cultivation creates wasteland with thorny shrubs, which then takes a long time to become secondary forests through serial stages of succession. Assisted natural regeneration through silvicultural management is a useful restoration method to accelerate succession. This survey evaluates the effectiveness of a simple silvicultural method for the rehabilitation of degraded lands to productive forest, thereby increasing floristic wealth. Field-based comparative analyses of floristic composition were carried out at a silviculturally managed forest (Popham Arboretum and a primary forest (Kaludiyapokuna Forest Reserve which is located in Dambulla in Sri Lanka. Floristic analysis was used to examine the effectiveness of silvicultural techniques for successful restoration of degraded forest in the dry zone. Nine 20 m × 20 m plots in each forest were enumerated and the vegetation ≥ 10 cm girth at breast height was quantitatively analyzed. Cluster analysis resulted in five distinguishable clusters (two from Popham Arboretum and three from Kaludiyapokuna Forest Reserve. Similarity indices were generated to compare the plots within and between sites. Floristic similarity was higher in forest reserve plots compared to arboretum plots. A total of 72 plant species belonging to 60 genera and 26 families were recorded from the study sites. Of the recorded species, Grewia damine and Syzygium cumini (Importance Value Index, IVI = 24 and 23 respectively were the ecologically co-dominant taxa at the Popham Arboretum. In contrast, Mischodon zeylanicus (IVI = 31, Schleichera oleosa (IVI = 25 and Diospyros ebenum (IVI = 21 were the abundant taxa in the forest reserve.

  14. Changes in down dead wood volume across a chronosequence of silvicultural openings in southern Indiana forests

    Science.gov (United States)

    Michael A. Jenkins; George R. Parker

    1997-01-01

    The volume and decay stages of down dead wood were evaluated across a chronosequence of 46 silvicultural openings and 10 uncut control stands to determine how down dead wood volume changes with stand development. Openings ranged in age from 8 to 26 years and were divided into three age groups: (1) 16 years. Individual logs...

  15. Suitability of close-to-nature silviculture for adapting temperate European forests to climate change

    NARCIS (Netherlands)

    Brang, P.; Spathelf, P.; Larsen, J.B.; Bauhus, J.; Boncina, A.; Mohren, G.M.J.

    2014-01-01

    In many parts of Europe, close-to-nature silviculture (CNS) has been widely advocated as being the best approach for managing forests to cope with future climate change. In this review, we identify and evaluate six principles for enhancing the adaptive capacity of European temperate forests in a

  16. Restoring old-growth southern pine ecosystems: strategic lessons from long-term silvicultural research

    Science.gov (United States)

    Don C. Bragg; Michael G. Shelton; James M. Guldin

    2008-01-01

    The successful restoration of old-growth-like loblolly (Pinus taeda) and shortleaf (Pinus echinata) pine-dominated forests requires the integration of ecological information with long-term silvicultural research from places such as the Crossett Experimental Forest (CEF). Conventional management practices such as timber harvesting or competition control have supplied...

  17. Silvicultural research and the evolution of forest practices in the Douglas-fir region.

    Science.gov (United States)

    Robert O. Curtis; Dean S. DeBell; Richard E. Miller; Michael Newton; J. Bradley St. Clair; William I. Stein

    2007-01-01

    Silvicultural practices in the Douglas-fir region evolved through a combination of formal research, observation, and practical experience of forest managers and silviculturists, and changing economic and social factors. This process began more than a century ago and still continues. It has had a great influence on the economic well-being of the region and on the...

  18. The Effects of Silvicultural Treatment on Sirex noctilio Attacks and Tree Health in Northeastern United States

    Directory of Open Access Journals (Sweden)

    Kevin J. Dodds

    2014-11-01

    Full Text Available The invasive woodwasp Sirex noctilio (Hymenoptera: Siricidae is established in east-central North America. A replicated case study testing the effectiveness of silvicultural treatments for reducing the number of S. noctilio attacked trees in a stand was conducted in New York, USA. Silvicultural treatments reduced S. noctilio attacked trees by approximately 75% over the course of the study. There was no tree growth response to silvicultural treatments in the four years after thinning, but targeted removal of weakened trees removed potential S. noctilio habitat from treated stands. Two spectral vegetation indices were used to determine tree health in each treatment and potentially provide guidance for detection efforts. Silvicultural treatment significantly influenced the Red Edge Inflection Point, a strong indicator of chlorophyll content, and the Moisture Stress Index, a reflectance measurement sensitive to changes in foliar leaf water content, with the greatest differences occurring between control and treated blocks. Vegetation indices showed promise as a tool for aiding in stand prioritization for S. noctilio surveys or management activities.

  19. Short-term response of small mammals following oak regeneration silviculture treatments.

    Science.gov (United States)

    Amy L. Raybuck; Christopher E. Moorman; Christopher S. DePerno; Kevin Gross; Dean M. Simon; Gordon S. Warburton

    2012-01-01

    Upland, mixed-oak forests in the eastern United States have experienced widespread oak regeneration failure, largely due to cessation of anthropogenic disturbance. Silvicultural practices used to promote advance oak regeneration may affect ground-dwelling mammals. From May to August 2008 (pre-treatment), 2010 (first year post-treatment), and 2011 (second year post-...

  20. Using silviculture to influence carbon sequestration in southern Appalachian spruce-fir forests

    Science.gov (United States)

    Patrick T. Moore; R. Justin DeRose; James N. Long; Helga. van Miegroet

    2012-01-01

    Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C) sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled....

  1. Silvicultural treatments enhance growth rates of future crop trees in a tropical dry forest

    NARCIS (Netherlands)

    Villegas, Z.; Peña-Claros, M.; Mostacedo, B.; Alarcón, A.; Licona, J.C.; Leaño, C.; Pariona, W.; Choque, U.

    2009-01-01

    Silvicultural treatments are often needed in selectively logged tropical forest to enhance the growth rates of many commercial tree species and, consequently, for recovering a larger proportion of the initial volume harvested over the next cutting cycle. The available data in the literature suggest,

  2. Herbicide-resistant crops: utilities and limitations for herbicide-resistant weed management.

    Science.gov (United States)

    Green, Jerry M; Owen, Micheal D K

    2011-06-08

    Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effectiveness of glyphosate. Unfortunately, the introduction of GR crops and the high initial efficacy of glyphosate often lead to a decline in the use of other herbicide options and less investment by industry to discover new herbicide active ingredients. With some exceptions, most growers can still manage their weed problems with currently available selective and HR crop-enabled herbicides. However, current crop management systems are in jeopardy given the pace at which weed populations are evolving glyphosate resistance. New HR crop technologies will expand the utility of currently available herbicides and enable new interim solutions for growers to manage HR weeds, but will not replace the long-term need to diversify weed management tactics and discover herbicides with new modes of action. This paper reviews the strengths and weaknesses of anticipated weed management options and the best management practices that growers need to implement in HR crops to maximize the long-term benefits of current technologies and reduce weed shifts to difficult-to-control and HR weeds.

  3. Tribal lands provide forest management laboratory for mainstream university students

    Science.gov (United States)

    Serra J. Hoagland; Ronald Miller; Kristen M. Waring; Orlando Carroll

    2017-01-01

    Northern Arizona University (NAU) faculty and Bureau of Indian Affairs (BIA) foresters initiated a partnership to expose NAU School of Forestry (SoF) graduate students to tribal forest management practices by incorporating field trips to the 1.68-million acre Fort Apache Indian Reservation as part of their silviculture curriculum. Tribal field trips were contrasted and...

  4. Discovery of new herbicide modes of action with natural phytotoxins

    Science.gov (United States)

    About 20 modes of action (MOAs) are utilized by commercial herbicides, and almost 30 years have passed since the last new MOA was introduced. Rapidly increasing evolution of resistance to herbicides with these MOAs has greatly increased the need for herbicides with new MOAs. Combinatorial chemistry ...

  5. Universe

    CERN Document Server

    2009-01-01

    The Universe, is one book in the Britannica Illustrated Science Library Series that is correlated to the science curriculum in grades 5-8. The Britannica Illustrated Science Library is a visually compelling set that covers earth science, life science, and physical science in 16 volumes.  Created for ages 10 and up, each volume provides an overview on a subject and thoroughly explains it through detailed and powerful graphics-more than 1,000 per volume-that turn complex subjects into information that students can grasp.  Each volume contains a glossary with full definitions for vocabulary help and an index.

  6. Surface plasmon resonance application for herbicide detection

    Science.gov (United States)

    Chegel, Vladimir I.; Shirshov, Yuri M.; Piletskaya, Elena V.; Piletsky, Sergey A.

    1998-01-01

    The optoelectronic biosensor, based on Surface Plasmon Resonance (SPR) for detection of photosynthesis-inhibiting herbicides in aqueous solutions is presented. The pesticide capability to replace plastoquinone from its complex with D1 protein is used for the detection. This replacement reaction results in the changes of the optical characteristics of protein layer, immobilized on the gold surface. Monitoring of these changes with SPR-technique permit to determine 0.1 - 5.0 mkg/ml herbicide in solution within one hour.

  7. Herbicide Orange Site Characterization Study, Eglin AFB

    Science.gov (United States)

    1987-01-01

    F THIS PAGE Availabilit o this r is sp f o.n" the reverse of fo cove* . - .’.r. 717 CSAT CO ES ’SU JEC TE MS Coninu onrevrseif ece~ar an idntiy b...of Hardstand 7 and Surface Water Drainages ......... 4 3 Hardstand 7 Herbicide Oran&e Storage Locations .............. 5 4 Concentrations (in ppb) of...insoluble in water . The formula contained an approximate 50/50 mixture of the herbicides 2,4-dichlorophenoxyacetic acid (2,4,-D) and 2,4,5

  8. Response of Transplanted Aman Rice Varieties to Herbicides in Strip-Tilled Non-Puddled Soil

    Directory of Open Access Journals (Sweden)

    Taslima Zahan1

    2017-12-01

    Full Text Available BACKGROUND: Sensitivity of crop cultivars may vary to commonly used herbicides resulting in potential yield loss and reduce farm profit. Transplanting of rice seedlings in strip-tilled non-puddled field is a new practice for which herbicide tolerant varieties need to select. Therefore, a study was executed at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh during 2013 to evaluate the response of some popular transplanted aman rice varieties to different herbicides at their recommended rate and to select most tolerant aman rice variety or varieties for strip-tilled non-puddled transplanting. METHODOLOGY: Twelve aman rice varieties (BR11, BRRI dhan33, BRRI dhan39, BRRI dhan44, BRRI dhan46, BRRI dhan49, BRRI dhan51, BRRI dhan52, BRRI dhan56, BRRI dhan57, BRRI hybrid dhan-4 and BINA dhan7 were examined in the study against six herbicides (2 pre-emergence: pyrazosulfuron-ethyl and butachlor; 1 early post-emergence: orthosulfamuron and 3 late post-emergence: acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine along with one untreated manually weed-free control. KEY FINDINGS: The study revealed that aman rice varieties responded differentially to different herbicides. All rice varieties performed better in pyrazosulfuron-ethyl treated plots relative to the other herbicide treated plots and even than the control plots. Pyrazosulfuron-ethyl increased grain yield of all aman rice varieties by 0.6-32.6% over control and butachlor + propanil provided increased grain yield in all rice varieties by 2.0-25.5% except BRRI hybrid dhan-4. The study also disclosed that BRRI dhan57 and BRRI hybrid dhan-4 gone through the yield loss by application of 2,4-D amine and BRRI dhan56 by application of butachlor and orthosulfamuron. Moreover, acetochlor + bensulfuron methyl produced shorter plants and caused yield loss by 7.8-27.1% in all aman rice varieties compared to the control and BRRI dhan39 was the most susceptible

  9. Proceedings of the National Silviculture Workshop: Density of Stocking Control; Eugene, Oregon; October 13-15, 1976

    Science.gov (United States)

    Jack H. Usher; Daniel B. Jones; A. R. Stage; Benjamin A. Roach; Gilbert B. Schubert; Darrell W. Crawford; Gilbert H. Schubert; Walter Fox; Edward A. Smith; Richard E. Lowrey Sofes; Richard F. Watt

    1976-01-01

    The 1976 National Silviculture Workshop was held in Eugene, Oregon, on October 13-15, 1976. The objectives were to discuss second growth management of individual stands, with particular emphasis on the control of stand density.

  10. EFFECT OF POST-LOGGING SILVICULTURAL TREATMENT ON GROWTH RATES OF RESIDUAL STAND IN A TROPICAL FOREST

    Directory of Open Access Journals (Sweden)

    Haruni Krisnawati

    2010-12-01

    Full Text Available Post-logging silvicultural treatments are generally performed to improve yields of the remaining tree species by increasing their growth rate. In this study the effects of silvicultural treatment on the growth rates of commercial (dipterocarps and non-dipterocarps as well as non- commercial tree species in a tropical forest in West Kalimantan were examined and were compared to a control treatment. Silvicultural treatment applied was liberation of future crop trees from lianas and neighbouring competing trees. Treatments were applied to six plots of 80 m x 80 m each. The plots comprised 64 quadrats of 10 m x 10 m to allow better control of measurements. The treatment and control plots were established 6 years after logging. Effects were measured 2,4 and 7 years after treatment application. In all obser vation periods, the growth rates increased with silvicultural treatment. Overall, commercial dipterocarps, commercial non-dipterocarps and non-commercial tree species groups differed in response to silvicultural treatment. The growth rates of commercial tree species in plots that received silvicultural treatment were 62–97% higher than in the control plots. For non-commercial tree species, the increase of growth rates was 20–58%, compared to the control plots. These results indicate that the application of silvicultural treatments after logging could help improve the growth of the residual stands. These provide quantitative information that silvicultural treatments in logged-over forest should be considered as a viable management option and may guide the choice of cutting cycle.

  11. Methods for Rapid Screening in Woody Plant Herbicide Development

    Directory of Open Access Journals (Sweden)

    William Stanley

    2014-07-01

    Full Text Available Methods for woody plant herbicide screening were assayed with the goal of reducing resources and time required to conduct preliminary screenings for new products. Rapid screening methods tested included greenhouse seedling screening, germinal screening, and seed screening. Triclopyr and eight experimental herbicides from Dow AgroSciences (DAS 313, 402, 534, 548, 602, 729, 779, and 896 were tested on black locust, loblolly pine, red maple, sweetgum, and water oak. Screening results detected differences in herbicide and species in all experiments in much less time (days to weeks than traditional field screenings and consumed significantly less resources (<500 mg acid equivalent per herbicide per screening. Using regression analysis, various rapid screening methods were linked into a system capable of rapidly and inexpensively assessing herbicide efficacy and spectrum of activity. Implementation of such a system could streamline early-stage herbicide development leading to field trials, potentially freeing resources for use in development of beneficial new herbicide products.

  12. A Rapid and Simple Bioassay Method for Herbicide Detection

    Directory of Open Access Journals (Sweden)

    Xiu-Qing Li

    2008-01-01

    Full Text Available Chlamydomonas reinhardtii, a unicellular green alga, has been used in bioassay detection of a variety of toxic compounds such as pesticides and toxic metals, but mainly using liquid culture systems. In this study, an algal lawn--agar system for semi-quantitative bioassay of herbicidal activities has been developed. Sixteen different herbicides belonging to 11 different categories were applied to paper disks and placed on green alga lawns in Petri dishes. Presence of herbicide activities was indicated by clearing zones around the paper disks on the lawn 2-3 days after application. The different groups of herbicides induced clearing zones of variable size that depended on the amount, mode of action, and chemical properties of the herbicides applied to the paper disks. This simple, paper-disk-algal system may be used to detect the presence of herbicides in water samples and act as a quick and inexpensive semi-quantitative screening for assessing herbicide contamination.

  13. Effect of herbicides on microbiological properties of soil

    Directory of Open Access Journals (Sweden)

    Milošević Nada A.

    2002-01-01

    Full Text Available Microorganisms decompose herbicides and they may serve as bioindicators of soil changes following herbicide application. Certain microbial species may be used as bioherbicides. This study has shown that Azotobacter is most sensitive to herbicide application; it is, therefore, a reliable indicator of the biological value of soil. The numbers of this group of nitrogen-fixing bacteria decrease considerably in the period of 7-14 days after herbicide application. Simultaneously, the numbers of Actinomycetes and less so of fungi increase, indicating that these microorganisms use herbicides as sources of biogenous elements. Rate of herbicidal decomposition depends on the properties of the preparation applied herbicide dose as well as on the physical and chemical soil properties, soil moisture and temperature, ground cover, agrotechnical measures applied and the resident microbial population.

  14. Glycerine associated molecules with herbicide for controlling ...

    African Journals Online (AJOL)

    ciganinha”, belongs to the family Bignoniaceae. The only way to control this plant species in crop fields is by the application of herbicides on the stump or directly on the stem. The present study aimed to analyze the effect of glycerine in controlling A.

  15. Fondurile cinegetice ale Universității ”Ștefan cel Mare” Suceava – Facultatea de Silvicultură: o retrospectivă a activității [Hunting Funds of Ștefan cel Mare University of Suceava - Faculty of Forestry: a retrospective of work

    Directory of Open Access Journals (Sweden)

    Dănilă G

    2016-12-01

    Full Text Available Ștefan cel Mare University’s Hunting Funds, through the Faculty of Forestry, consists of three hunting territories (HT: HT no. 55 Mitoc, HT no. 69 Râșca, HT no. 56 Salcea. The first two have a high hunting potential for major hunting sedentary game species (wild boar, roe buck, roe deer, hare, wolf, bear. In over 15 years of hunting management, USV has overcome the difficulties imposed by different legislations. Also, USV, along with the University of Brașov, managed to amend Law 407/2006 and to return to free hunting use of the public lands. The teaching and research activities in the hunting territories have resulted in over 15 diploma projects, over 20 scientific articles published in specialized reviews, of which 7 ISI, over 10 scientific papers of which two were the students’ work, two research contracts and a book. The management coherence driven by the specialized staff is reflected in the higher number of top quality trophies, which started to be harvested after about 10 years of management.

  16. Forest structure of oak plantations after silvicultural treatment to enhance habitat for wildlife

    Science.gov (United States)

    Twedt, Daniel J.; Phillip, Cherrie-Lee P.; Guilfoyle, Michael P.; Wilson, R. Randy; Schweitzer, Callie Jo; Clatterbuck, Wayne K.; Oswalt, Christopher M.

    2016-01-01

    During the past 30 years, thousands of hectares of oak-dominated bottomland hardwood plantations have been planted on agricultural fields in the Mississippi Alluvial Valley. Many of these plantations now have closed canopies and sparse understories. Silvicultural treatments could create a more heterogeneous forest structure, with canopy gaps and increased understory vegetation for wildlife. Lack of volume sufficient for commercial harvest in hardwood plantations has impeded treatments, but demand for woody biomass for energy production may provide a viable means to introduce disturbance beneficial for wildlife. We assessed forest structure in response to prescribed pre-commercial perturbations in hardwood plantations resulting from silvicultural treatments: 1) row thinning by felling every fourth planted row; 2) multiple patch cuts with canopy gaps of gaps appear likely to be filled by regenerating saplings.

  17. Forest adaptation to global climate change through silvicultural treatments and genetic improvement

    International Nuclear Information System (INIS)

    Farnum, P.

    1991-01-01

    The research being conducted by one forest products company into silviculture and plant genetics as a response to future problems caused by the greenhouse effect is reviewed. The company's research priorities have been adjusted to be technologically prepared for greenhouse-effect warming, including the effects of fire, shorter planting seasons, insect problems, and drought-related mortality. The review focuses on research into improving drought-related mortality by developing drought-resistant trees and then growing such trees by making use of biotechnological techniques such as somatic embryogenesis. In silvicultural research, emphasis is placed on quantifying how thinning can mitigate the effects of drought by stand density control. In genetics and physiology research, the applicability of greenhouse studies of drought resistance to stands of older trees was tested. This research led to an examination of the role of root systems and identification of possible characteristics to screen for in genetic tests. 2 refs

  18. The weed composition in an orchard as a result of long-term foliar herbicide application

    Directory of Open Access Journals (Sweden)

    Maria Licznar-Małańczuk

    2016-09-01

    Full Text Available The weed composition and the dominance of individual species occurring in an orchard were assessed at the Research Station of the Wrocław University of Environmental and Life Sciences, Poland, during the first 10 years after orchard establishment. ‘Ligol’ apple trees were planted in the spring of 2004 (3.5 × 1.2 m. Foliar herbicides were applied in 1 m wide tree rows twice or three times per each vegetation period. In the inter-row spaces, perennial grass was maintained. Ten years of maintenance of herbicide fallow contributed to a change in the weed composition in the orchard. It changed as a result of different responses of the most important weed species to the foliar herbicides. Total suppression of Elymus repens was observed in the first year after planting the trees. Convolvulus arvensis, Cirsium arvense, and other perennial weeds, completely disappeared in the succeeding periods. The maintenance of herbicide fallow did not affect the abundance of Taraxacum officinale. The percentage of the soil surface covered by Trifolium repens and Epilobium adenocaulon, perennial weeds with considerable tolerance to post-emergence herbicides, increased during the fruit-bearing period of the trees. The abundance of these weeds was significantly reduced only in the rows with the stronger growing trees on the semi-dwarf P 2 rootstock. Stellaria media was the dominant annual weed. Senecio vulgaris, Poa annua, Capsella bursa-pastoris, and Lamium spp. were also frequently observed. A significant increase in the abundance of annual and perennial weeds was found in the tree rows as a result of improved water availability after a period of high precipitation.

  19. Maize, switchgrass, and ponderosa pine biochar added to soil increased herbicide sorption and decreased herbicide efficacy.

    Science.gov (United States)

    Clay, Sharon A; Krack, Kaitlynn K; Bruggeman, Stephanie A; Papiernik, Sharon; Schumacher, Thomas E

    2016-08-02

    Biochar, a by-product of pyrolysis made from a wide array of plant biomass when producing biofuels, is a proposed soil amendment to improve soil health. This study measured herbicide sorption and efficacy when soils were treated with low (1% w/w) or high (10% w/w) amounts of biochar manufactured from different feedstocks [maize (Zea mays) stover, switchgrass (Panicum vigatum), and ponderosa pine (Pinus ponderosa)], and treated with different post-processing techniques. Twenty-four hour batch equilibration measured sorption of (14)C-labelled atrazine or 2,4-D to two soil types with and without biochar amendments. Herbicide efficacy was measured with and without biochar using speed of seed germination tests of sensitive species. Biochar amended soils sorbed more herbicide than untreated soils, with major differences due to biochar application rate but minor differences due to biochar type or post-process handling technique. Biochar presence increased the speed of seed germination compared with herbicide alone addition. These data indicate that biochar addition to soil can increase herbicide sorption and reduce efficacy. Evaluation for site-specific biochar applications may be warranted to obtain maximal benefits without compromising other agronomic practices.

  20. Bio stimulation for the Enhanced Degradation of Herbicides in Soil

    International Nuclear Information System (INIS)

    Kanissery, R.G; Sims, G.K

    2011-01-01

    Cleanup of herbicide-contaminated soils has been a dire environmental concern since the advent of industrial era. Although microorganisms are excellent degraders of herbicide compounds in the soil, some reparation may need to be brought about, in order to stimulate them to degrade the herbicide at a faster rate in a confined time frame. Bio stimulation through the appropriate utilization of organic amendments and nutrients can accelerate the degradation of herbicides in the soil. However, effective use of bio stimulants requires thorough comprehension of the global redox cycle during the microbial degradation of the herbicide molecules in the soil. In this paper, we present the prospects of using bio stimulation as a powerful remediation strategy for the rapid cleanup of herbicide-polluted soils.

  1. Hazard and risk of herbicides for marine microalgae.

    Science.gov (United States)

    Sjollema, Sascha B; Martínezgarcía, Gema; van der Geest, Harm G; Kraak, Michiel H S; Booij, Petra; Vethaak, A Dick; Admiraal, Wim

    2014-04-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol(®)1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Electrochemical degradation and mineralization of glyphosate herbicide.

    Science.gov (United States)

    Tran, Nam; Drogui, Patrick; Doan, Tuan Linh; Le, Thanh Son; Nguyen, Hoai Chau

    2017-12-01

    The presence of herbicide is a concern for both human and ecological health. Glyphosate is occasionally detected as water contaminants in agriculture areas where the herbicide is used extensively. The removal of glyphosate in synthetic solution using advanced oxidation process is a possible approach for remediation of contaminated waters. The ability of electrochemical oxidation for the degradation and mineralization of glyphosate herbicide was investigated using Ti/PbO 2 anode. The current intensity, treatment time, initial concentration and pH of solution are the influent parameters on the degradation efficiency. An experimental design methodology was applied to determine the optimal condition (in terms of cost/effectiveness) based on response surface methodology. Glyphosate concentration (C 0  = 16.9 mg L -1 ) decreased up to 0.6 mg L -1 when the optimal conditions were imposed (current intensity of 4.77 A and treatment time of 173 min). The removal efficiencies of glyphosate and total organic carbon were 95 ± 16% and 90.31%, respectively. This work demonstrates that electrochemical oxidation is a promising process for degradation and mineralization of glyphosate.

  3. Phytotoxicity of Four Photosystem II Herbicides to Tropical Seagrasses

    Science.gov (United States)

    Flores, Florita; Collier, Catherine J.; Mercurio, Philip; Negri, Andrew P.

    2013-01-01

    Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50) over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zostera muelleri and Halodule uninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m ′), indicating reduced photosynthesis and maximum effective yields (Fv/Fm) corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect seagrass meadows

  4. Phytotoxicity of four photosystem II herbicides to tropical seagrasses.

    Science.gov (United States)

    Flores, Florita; Collier, Catherine J; Mercurio, Philip; Negri, Andrew P

    2013-01-01

    Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50) over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zosteramuelleri and Haloduleuninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m '), indicating reduced photosynthesis and maximum effective yields (Fv/Fm ) corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect seagrass meadows of

  5. Phytotoxicity of Four Photosystem II Herbicides to Tropical Seagrasses

    OpenAIRE

    Flores, Florita; Collier, Catherine J.; Mercurio, Philip; Negri, Andrew P.

    2013-01-01

    Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identi...

  6. Phytotoxicity of four photosystem II herbicides to tropical seagrasses.

    Directory of Open Access Journals (Sweden)

    Florita Flores

    Full Text Available Coastal waters of the Great Barrier Reef (GBR are contaminated with agricultural pesticides, including the photosystem II (PSII herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50 over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zosteramuelleri and Haloduleuninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m ', indicating reduced photosynthesis and maximum effective yields (Fv/Fm corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect

  7. Occurrence of dichloroacetamide herbicide safeners and co-applied herbicides in midwestern U.S. streams

    Science.gov (United States)

    Woodward, Emily; Hladik, Michelle; Kolpin, Dana W.

    2018-01-01

    Dichloroacetamide safeners (e.g., AD-67, benoxacor, dichlormid, and furilazole) are co-applied with chloroacetanilide herbicides to protect crops from herbicide toxicity. While such safeners have been used since the early 1970s, there are minimal data about safener usage, occurrence in streams, or potential ecological effects. This study focused on one of these research gaps, occurrence in streams. Seven Midwestern U.S. streams (five in Iowa and two in Illinois), with extensive row-crop agriculture, were sampled at varying frequencies from spring 2016 through summer 2017. All four safeners were detected at least once; furilazole was the most frequently detected (31%), followed by benoxacor (29%), dichlormid (15%), and AD-67 (2%). The maximum concentrations ranged from 42 to 190 ng/L. Stream detections and concentrations of safeners appear to be driven by a combination of timing of application (spring following herbicide application) and precipitation events. Detected concentrations were below known toxicity levels for aquatic organisms.

  8. Uses of thaxtomin and thaxtomin compositions as herbicides

    Energy Technology Data Exchange (ETDEWEB)

    Koivunen, Marja; Marrone, Pamela

    2016-12-27

    There is a need for a selective, low-risk herbicide that can be used to control weeds in cereal cultures and turf. The present invention discloses that a bacterial secondary metabolite, thaxtomin and optionally another herbicide is an effective herbicide on broadleaved, sedge and grass weeds. Thaxtomin A and structurally similar compounds can be used as natural herbicides to control the germination and growth of weeds in cereal, turf grass, Timothy grass and pasture grass cultures with no phytotoxicity to these crops. As a natural, non-toxic compound, thaxtomin can be used as a safe alternative for weed control in both conventional and organic farming and gardening systems.

  9. Herbicide injury induces DNA methylome alterations in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Gunjune Kim

    2017-07-01

    Full Text Available The emergence of herbicide-resistant weeds is a major threat facing modern agriculture. Over 470 weedy-plant populations have developed resistance to herbicides. Traditional evolutionary mechanisms are not always sufficient to explain the rapidity with which certain weed populations adapt in response to herbicide exposure. Stress-induced epigenetic changes, such as alterations in DNA methylation, are potential additional adaptive mechanisms for herbicide resistance. We performed methylC sequencing of Arabidopsis thaliana leaves that developed after either mock treatment or two different sub-lethal doses of the herbicide glyphosate, the most-used herbicide in the history of agriculture. The herbicide injury resulted in 9,205 differentially methylated regions (DMRs across the genome. In total, 5,914 of these DMRs were induced in a dose-dependent manner, wherein the methylation levels were positively correlated to the severity of the herbicide injury, suggesting that plants can modulate the magnitude of methylation changes based on the severity of the stress. Of the 3,680 genes associated with glyphosate-induced DMRs, only 7% were also implicated in methylation changes following biotic or salinity stress. These results demonstrate that plants respond to herbicide stress through changes in methylation patterns that are, in general, dose-sensitive and, at least partially, stress-specific.

  10. Joint action of some usable important broadleaf herbicides in sugar beet

    Directory of Open Access Journals (Sweden)

    AliAsghar Chitband

    2018-01-01

    Full Text Available Introduction: The assessment of the effect of mixtures could be based on various concepts whether we work within toxicology, pharmacology or weed control. Combinations of certain herbicides can give better weed control than use of the individual herbicide alone and/or loss of weed control when use of certain other herbicides in combination. Predicting the joint action of mixtures is extremely difficult, unless the compounds are known to interact at the same site of action. These most common methods to analyze the joint action of herbicide mixtures are the Additive Dose Model (ADM or the Multiplicative Survival Model (MSM. The ADM assumes the two compounds have similar modes of action (do not interact in the receiver plant, i.e. effective doses of each component will not change by mixing. ADM has been widely accepted as a valid method to estimate joint action of mixtures sharing the same or similar action mechanisms in the receiver plant. MSM has been reported to yield more accurate results for mixture toxicity than ADM do when the components exhibited different or dissimilar modes of action in the receiver plant. ADM or Concentration Addition (CA is used here to test for deviation of additivity of doses using the ADM isoboles as reference; any deviation from the ADM is characterized by antagonism when the efficacy of a mixture is lower than predicted by the reference model and synergistic when the efficacy is higher than predicted. Materials and Methods: In order to determine joint action of some usable important broadleaf herbicides in sugar beet, six experiments were conducted at the research glasshouse in Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. The plants were sprayed with seven doses of commercial formulation of desmedipham + phenmedipham + ethofumesate (Betanal Progress- OF®, 427 g a.i. L-1, Tragusa, Spain, chloridazon (Pyramin®, 1361 g a.i. L-1, BASF, Germany, clopyralid (Lontrel®, 149 g a.i. L-1, Golsam, Gorgan

  11. DNA analysis of herbarium Specimens of the grass weed Alopecurus myosuroides reveals herbicide resistance pre-dated herbicides.

    Science.gov (United States)

    Délye, Christophe; Deulvot, Chrystel; Chauvel, Bruno

    2013-01-01

    Acetyl-CoA carboxylase (ACCase) alleles carrying one point mutation that confers resistance to herbicides have been identified in arable grass weed populations where resistance has evolved under the selective pressure of herbicides. In an effort to determine whether herbicide resistance evolves from newly arisen mutations or from standing genetic variation in weed populations, we used herbarium specimens of the grass weed Alopecurus myosuroides to seek mutant ACCase alleles carrying an isoleucine-to-leucine substitution at codon 1781 that endows herbicide resistance. These specimens had been collected between 1788 and 1975, i.e., prior to the commercial release of herbicides inhibiting ACCase. Among the 734 specimens investigated, 685 yielded DNA suitable for PCR. Genotyping the ACCase locus using the derived Cleaved Amplified Polymorphic Sequence (dCAPS) technique identified one heterozygous mutant specimen that had been collected in 1888. Occurrence of a mutant codon encoding a leucine residue at codon 1781 at the heterozygous state was confirmed in this specimen by sequencing, clearly demonstrating that resistance to herbicides can pre-date herbicides in weeds. We conclude that point mutations endowing resistance to herbicides without having associated deleterious pleiotropic effects can be present in weed populations as part of their standing genetic variation, in frequencies higher than the mutation frequency, thereby facilitating their subsequent selection by herbicide applications.

  12. Adsorption of chloroacetanilide herbicides on soil and its components. III. Influence of clay acidity, humic acid coating and herbicide structure on acetanilide herbicide adsorption on homoionic clays.

    Science.gov (United States)

    Liu, Wei-ping; Fang, Zhuo; Liu, Hui-jun; Yang, Wei-chun

    2002-04-01

    Adsorption of chloroacetanilide herbicides on homoionic montmorillonite, soil humic acid, and their mixtures was studied by coupling batch equilibration and FT-IR analysis. Adsorption isotherms of acetochlor, alachlor, metolachlor and propachlor on Ca(2+)-, Mg(2+)-, Al(3+)- and Fe(3+)-saturated clays were well described by the Freundlich equation. Regardless of the type of exchange cations, Kf decreased in the order of metolachlor > acetolachlor > alachlor > propachlor on the same clay. FT-IR spectra showed that the carbonyl group of the herbicide molecule was involved in binding, probably via H-bond with water molecules in the clay interlayer. The type and position of substitutions around the carbonyl group may have affected the electronegativity of oxygen, thus influencing the relative adsorption of these herbicides. For the same herbicide, adsorption on clay increased in the order of Mg2+ < Ca2+ < Al3+ < or = Fe3+ which coincided with the increasing acidity of homoionic clays. Acidity of cations may have affected the protonation of water, and thus the strength of H-bond between the clay water and herbicide. Complexation of clay and humic acid resulted in less adsorption than that expected from independent adsorption by the individual constituents. The effect varied with herbicides, but the greatest decrease in adsorption occurred at a 60:40 clay-to-humic acid ratio for all the herbicides. Causes for the decreased adsorption need to be characterized to better understand adsorption mechanisms and predict adsorption from soil compositions.

  13. Controlled Release Formulations of Auxinic Herbicides

    Science.gov (United States)

    Kowalski, Witold J.; Siłowiecki, Andrzej.; Romanowska, Iwona; Glazek, Mariola; Bajor, Justyna; Cieciwa, Katarzyna; Rychter, Piotr

    2013-04-01

    Controlled release formulations are applied extensively for the release of active ingredients such as plant protection agents and fertilizers in response to growing concern for ecological problems associated with increased use of plant protection chemicals required for intensive agricultural practices [1]. We synthesized oligomeric mixtures of (R,S)-3-hydroxy butyric acid chemically bonded with 2,4-D, Dicamba and MCPA herbicides (HBA) respectively, and determined their molecular structure and molecular weight dispersion by the size exclusion chromatography, proton magnetic resonance spectrometry and electro-spray ionization mass spectrometry. Further we carried out bioassays of herbicidal effectiveness of the HBA herbicides vs. series of dicotyledonous weeds and crop injury tests [2, 3, 4]. Field bioassays were accomplished according to the EPPO standards [5]. Groups of representative weeds (the development stages in the BCCH scale: 10 - 30) were selected as targets. Statistical variabilities were assessed by the Fisher LSD test for plants treated with the studied herbicides in form of HBA oligomers, the reference herbicides in form of dimethyl ammonium salts (DMA), and untreated plants. No statistically significant differences in the crop injuries caused by the HBA vs. the DMA reference formulation were observed. The effectiveness of the HBA herbicides was lower through the initial period (ca. 2 weeks) relative to the DMA salts, but a significant increase in the effectiveness of the HBA systems followed during the remaining fraction of each assay. After 6 weeks all observed efficiencies approached 100%. The death of weeds treated with the HBA herbicides was delayed when compared with the DMA reference herbicides. The delayed uptake observed for the HBA oligomers relative to the DMA salts was due to controlled release phenomena. In case of the DMA salts the total amount of active ingredients was available at the target site. By contrast, the amount of an active

  14. Sarmentine, a natural herbicide from Piper species with multiple herbicide mechanisms of action

    Science.gov (United States)

    Sarmentine, 1-(1-pyrrolidinyl)-(2E,4E)-2,4-decadien-1-one, is a natural amide isolated from the fruits of Piper species. The compound has a number of interesting biological properties, including its broad-spectrum activity on weeds as a contact herbicide. Initial studies highlighted a similarity in ...

  15. Predicting herbicidal plant mortality with mobile photosynthesis meters

    NARCIS (Netherlands)

    Kempenaar, C.; Lotz, L.A.P.; Snel, J.F.H.; Smutny, V.; Zhang, H.J.

    2011-01-01

    Herbicide dose optimisation, i.e. maximising weed control and crop yield with herbicide dose, is an important part of integrated weed management strategies. However, the adoption of optimised dose technology and variable rate application has been limited because of the relatively long period between

  16. Herbicide volatilization trumps runoff losses, a multi-year investigation

    Science.gov (United States)

    Surface runoff and volatilization are two processes critical to herbicide off-site transport. To determine the relevance of these off-site transport mechanisms, runoff and turbulent vapor fluxes were simultaneously monitored on the same site for eight years. Site location, herbicide formulations, ...

  17. In vitro screening of selected herbicides on rhizosphere mycoflora ...

    African Journals Online (AJOL)

    In vitro screening of five selected herbicides at different concentrations on rhizosphere mycoflora from yellow pepper (capsicum annum L var. Nsukka yellow) seedlings at Nsukka were investigated. The herbicides employed for this study were Paraquat, Glyphosate, Primextra, Atrazine and Linuron. The isolated rhizosphere ...

  18. Effects of acetochlor (herbicide) on the survival and avoidance ...

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... These results suggested that acetochlor residues had negligible effects on P. birmanica and L. terrestris. Michalkova and Pekar (2009) and Yardim and Edwards (1998) also reported negligible effects of herbicide (glyphosate) on Pardosa agrestis. Although, we also observed negligible effects of herbicide.

  19. Estimation of herbicide bioconcentration in sugarcane (Saccharum officinarum L.

    Directory of Open Access Journals (Sweden)

    Antonio Luiz Cerdeira

    2015-04-01

    Full Text Available Sugarcane is an important crop for sugar and biofuel production in Brazil. Growers depend greatly on herbicides to produce it. This experiment used herbicide physical-chemical and sugarcane plant physiological properties to simulate herbicide uptake and estimate the bioconcentration factor (BCF. The (BCF was calculated for the steady state chemical equilibrium between the plant herbicide concentration and soil solution. Plant-water partition coefficient (sugarcane bagasse-water partition coefficient, herbicide dilution rate, metabolism and dissipation in the soil-plant system, as well as total plant biomass factors were used. In addition, we added Tebuthiuron at rate of 5.0kg a.i. ha-1 to physically test the model. In conclusion, the model showed the following ranking of herbicide uptake: sulfentrazone > picloram >tebuthiuron > hexazinone > metribuzin > simazine > ametryn > diuron > clomazone > acetochlor. Furthermore, the highest BCF herbicides showed higher Groundwater Ubiquity Score (GUS index indicating high leaching potential. We did not find tebuthiuron in plants after three months of herbicide application

  20. Plant Community Diversity After Herbicide Control of Spotted Knapweed

    OpenAIRE

    United States Department of Agriculture, Forest Service

    1992-01-01

    Herbicides were applied to four west-central Montana sites with light to moderate spotted knapweed (Centaurea maculosa Lam.) infestations. Althought knapweed suppression was high, 2 years after the spraying the communities were not converted to grass monocultures. No large declines in plant diversity were caused by the herbicides, and small depressions were probably transitory. By the third year, diversity had increased.

  1. economics of herbicide weed management in wheat in ethiopia ...

    African Journals Online (AJOL)

    ACSS

    Effective use of herbicides for the control of annual grass and broadleaf weeds in wheat (Triticum aestivum L.) was not a reality in Ethiopia, until in recent years. This study aimed at evaluating different post-emergence herbicides against annual grasses and broadleaf weeds in wheat for selection and incorporation into an ...

  2. Expanding the eco-evolutionary context of herbicide resistance research.

    Science.gov (United States)

    Neve, Paul; Busi, Roberto; Renton, Michael; Vila-Aiub, Martin M

    2014-09-01

    The potential for human-driven evolution in economically and environmentally important organisms in medicine, agriculture and conservation management is now widely recognised. The evolution of herbicide resistance in weeds is a classic example of rapid adaptation in the face of human-mediated selection. Management strategies that aim to slow or prevent the evolution of herbicide resistance must be informed by an understanding of the ecological and evolutionary factors that drive selection in weed populations. Here, we argue for a greater focus on the ultimate causes of selection for resistance in herbicide resistance studies. The emerging fields of eco-evolutionary dynamics and applied evolutionary biology offer a means to achieve this goal and to consider herbicide resistance in a broader and sometimes novel context. Four relevant research questions are presented, which examine (i) the impact of herbicide dose on selection for resistance, (ii) plant fitness in herbicide resistance studies, (iii) the efficacy of herbicide rotations and mixtures and (iv) the impacts of gene flow on resistance evolution and spread. In all cases, fundamental ecology and evolution have the potential to offer new insights into herbicide resistance evolution and management. © 2014 Society of Chemical Industry.

  3. Efficacy and economics of different herbicides in aerobic rice system ...

    African Journals Online (AJOL)

    Aerobic rice system, the most promising irrigation water saving rice production technology, is highly impeded by severe weed pressure. Weed control through the use of same herbicide causes development of herbicide resistant weed biotypes and serious problem in weed management. This study was aimed at finding out ...

  4. Herbicide-resistant crop biotechnology: potential and pitfalls

    Science.gov (United States)

    Herbicide-resistant crops are an important agricultural biotechnology that can enable farmers to effectively control weeds without harming their crops. Glyphosate-resistant (i.e. Roundup Ready) crops have been the most commercially successful varieties of herbicide-resistant crops and have been plan...

  5. Effect of four herbicides on microbial population, soil organic matter ...

    African Journals Online (AJOL)

    The effect of four herbicides (atrazine, primeextra, paraquat and glyphosate) on soil microbial population, soil organic matter and dehydrogenase activity was assessed over a period of six weeks. Soil samples from cassava farms were treated with herbicides at company recommended rates. Soil dehydrogenase activity was ...

  6. Integrated Effect of Seeding Rate, Herbicide Dosage and ...

    African Journals Online (AJOL)

    yield reductions of 26 to 63% across four bread wheat cultivars at 90 weed seedlings m-2 in. Ethiopia. Before herbicides were widely available, farmers employed cultural measures to manage weed population. Wild oat management systems have evolved to the point that producers rely on herbicides to the virtual exclusion ...

  7. ACETANILIDE HERBICIDE DEGRADATION PRODUCTS BY LC/MS

    Science.gov (United States)

    Acetanilide herbicides are frequently applied in the U.S. on crops (corn, soybeans, popcorn, etc.) to control broadleaf and annual weeds. The acetanilide and acetamide herbicides currently registered for use in the U.S. are alachlor, acetochlor, metolachlor, propachlor, flufen...

  8. Evaluation of generic and branded herbicides : technical report.

    Science.gov (United States)

    2015-03-01

    As with other generic brand products in the marketplace, generic herbicides often have a lower initial product cost than : their brand-name counterparts. While the purchase price of herbicides is important to TxDOT, it is essential to look at : more ...

  9. Selective Herbicides for Cultivation of Eucalyptus urograndis Clones

    Directory of Open Access Journals (Sweden)

    Patrick J. Minogue

    2015-01-01

    Full Text Available Competition control is essential for successful eucalyptus plantation establishment, yet few selective herbicides have been identified. Five herbicides, flumioxazin, imazamox, imazapic, oxyfluorfen, and sulfometuron methyl, were evaluated for selective weed control in the establishment of genetically modified frost tolerant Eucalyptus urograndis clones. Herbicides were applied at two or three rates, either before or after weed emergence, and compared to a nontreated control and to near-complete weed control obtained with glyphosate directed sprays. Applications prior to weed emergence were most effective for weed control and, with the exception of imazapic, all resulted in enhanced eucalyptus growth relative to the nontreated control. Among postemergent treatments, only imazamox enhanced stem volume. Among selective herbicide treatments, preemergent 2240 g ha−1 oxyfluorfen produced the best growth response, resulting in stem volume index that was 860% greater than the nontreated control, although only 15% of the volume index obtained with near-complete weed control. Imazapic was the most phytotoxic of all herbicides, resulting in 40% mortality when applied preemergent. Survival was 100% for all other herbicide treatments. This research found the previously nontested herbicides imazamox and imazapic to be effective for selective weed control and refined application rate and timing of five herbicides for use in clonal plantations.

  10. Hazard and risk of herbicides for marine microalgae

    International Nuclear Information System (INIS)

    Sjollema, Sascha B.; MartínezGarcía, Gema; Geest, Harm G. van der; Kraak, Michiel H.S.; Booij, Petra; Vethaak, A. Dick; Admiraal, Wim

    2014-01-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol ® 1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. - Highlights: • The hazard of herbicides for microalgae is compound and species specific. • In general a low risk although occasional potential effect levels are reached. • Current legislation does not protect marine microalgae sufficiently. - The hazard of herbicides in the coastal waters is compound and species specific and although the general risk in the field is low, occasionally potential effect levels are reached

  11. Herbicidal cyanoacrylates with antimicrotubule mechanism of action.

    Science.gov (United States)

    Tresch, Stefan; Plath, Peter; Grossmann, Klaus

    2005-11-01

    The herbicidal mode of action of the new synthetic cyanoacrylates ethyl (2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA1) and its isopropyl ester derivative CA2 was investigated. For initial characterization, a series of bioassays was used indicating a mode of action similar to that of mitotic disrupter herbicides such as the dinitroaniline pendimethalin. Cytochemical fluorescence studies including monoclonal antibodies against polymerized and depolymerized tubulin and a cellulose-binding domain of a bacterial cellulase conjugated to a fluorescent dye were applied to elucidate effects on cell division processes including mitosis and microtubule and cell wall formation in maize roots. When seedlings were root treated with 10 microM of CA1 or CA2, cell division activity in meristematic root tip cells decreased within 4 h. The chromosomes proceeded to a condensed state of prometaphase, but were unable to progress further in the mitotic cycle. The compounds caused a complete loss of microtubular structures, including preprophase, spindle, phragmoplast and cortical microtubules. Concomitantly, in the cytoplasm, an increase in labelling of free tubulin was observed. This suggests that the herbicides disrupt polymerization and microtubule stability, whereas tubulin synthesis or degradation appeared not to be affected. In addition, cellulose labelling in cell walls of root tip cells was not influenced. The effects of CA1 and CA2 were comparable with those caused by pendimethalin. In transgenic Arabidopsis plants expressing a green fluorescent protein-microtubule-associated protein4 fusion protein, labelled arrays of cortical microtubules in living epidermal cells of hypocotyls collapsed within 160 min after exposure to 10 microM CA1 or pendimethalin. Moreover, a dinitroaniline-resistant biotype of goosegrass (Eleusine indica (L) Gaertn) with a point mutation in alpha-tubulin showed cross-resistance against CA1 and CA2. The results strongly indicate that the cyanoacrylates are

  12. Uneven-aged silviculture can enhance within stand heterogeneity and beetle diversity.

    Science.gov (United States)

    Joelsson, Klara; Hjältén, Joakim; Work, Timothy

    2018-01-01

    Uneven-aged silviculture may better maintain species assemblages associated with old-growth forests than clear felling in part due to habitat heterogeneity created by maintaining standing retention strips adjacent to harvest trails. Retention strips and harvest trails created at the time of tree removal will likely have different microclimate and may harbor different assemblages. In some cases, the resultant stand heterogeneity associated with uneven-aged silviculture may be similar to natural small-scale disturbances. For beetles, increased light and temperature as well as potential access to young vegetation and deadwood substrates present in harvset trails may harbor beetle assemblages similar to those found in natural gaps. We sampled saproxylic beetles using flight intercept traps placed in harvest corridors and retention strips in 9 replicated uneven-aged spruce stands in central Sweden. We compared abundance, species richness and composition between harvest corridors and retention strips using generalized linear models, rarefaction, permutational multivariate analysis of variance and indicator species analysis. Canopy openness doubled, mean temperature and variability in daily temperature increased and humidity decreased on harvest trails. Beetle richness and abundance were greater in harvests trails than in retention strips and the beetle species composition differed significantly between habitats. Twenty-five species were associated with harvest trails, including three old-growth specialists such as Agathidium discoideum (Erichson), currently red-listed. We observed only one species, Xylechinus pilosus (Ratzeburg) that strongly favored retention strips. Harvest trails foster both open habitat species and old-growth species while retention strips harbored forest interior specialists. The combination of closed canopy, stratified forest in the retention strips and gap-like conditions on the harvest trails thus increases overall species richness and maintains

  13. [Effects of herbicide on grape leaf photosynthesis and nutrient storage].

    Science.gov (United States)

    Tan, Wei; Wang, Hui; Zhai, Heng

    2011-09-01

    Selecting three adjacent vineyards as test objects, this paper studied the effects of applying herbicide in growth season on the leaf photosynthetic apparatus and branch nutrient storage of grape Kyoho (Vitis vinfrraxVitis labrusca). In the vineyards T1 and T2 where herbicide was applied in 2009, the net photosynthesis rate (Pa) of grape leaves had a significant decrease, as compared with that in vineyard CK where artificial weeding was implemented. The leaves at the fourth node in vineyard T1 and those at the sixth node in vineyard T2 had the largest decrement of Pn (40.5% and 32.1%, respectively). Herbicide had slight effects on the leaf stomatal conductance (Gs). In T1 where herbicide application was kept on with in 2010, the Pn, was still significantly lower than that in CK; while in T2 where artificial weeding was implemented in 2010, the Pn and Gs of top- and middle node leaves were slightly higher than those in T1, but the Pn was still lower than that in CK, showing the aftereffects of herbicide residual. The herbicide application in 2009 decreased the leaf maximum photochemical efficiency of PS II (Fv/Fm) and performance index (P1) while increased the relative variable fluorescence in the J step and K step, indicating the damage of electron transportation of PS II center and oxygen-evolving complex. Herbicide application decreased the pigment content of middle-node leaves in a dose-manner. Applying herbicide enhanced the leaf catalase and peroxidase activities significantly, increased the superoxide dismutase (SOD) activity of middle-node leaves, but decreased the SOD activity of top- and bottom node leaves. After treated with herbicide, the ascorbate peroxidase (APX) activity of middle- and bottom node leaves increased, but that of top-node leaves decreased. Herbicide treatment aggravated leaf lipid peroxidation, and reduced the soluble sugar, starch, free amino acids, and soluble protein storage in branches.

  14. Selectivity and stability of herbicides and herbicide combinations for the grain yield of maize (Zea Mays L.

    Directory of Open Access Journals (Sweden)

    T. Barakova

    2016-09-01

    Full Text Available Abstract. The research was conducted during 2012 - 2014 on pellic vertisol soil type. Under investigation was cycloxydim tolerant maize hybrid Ultrafox duo (Zea mays L.. Factor A included the years of investigation. Factor B included no treated check and 3 soil-applied herbicides – Adengo 465 SC (isoxaflutol + tiencarbazon – 440 ml/ha, Wing P (pendimethalin + dimethenamid – 4 l/ha and Lumax 538 SC (S-metolachlor + terbuthylazine + mesotrione – 4 l/ha. Factor C included no treated check and 5 foliar-applied herbicides – Stellar 210 SL (topramezon + dicamba – 1 l/ha, Principal plus (nicosulfuron + rimsulfuron + dicamba – 380 g/ha, Ventum WG (foramsulfuron + iodosulfuron – 150 g/ha, Monsun active OD (foramsulfuron + tiencarbazon – 1.5 l/ha and Laudis OD (tembotrione – 2 l/ha. In addition to these variants by conventional technology for maize growing one variant by Duo system technology is also included in the experiment. It includes soil-applied herbicide Merlin flex 480 SC (isoxaflutole – 420 g/ha and tank mixture of antigraminaceous herbicide Focus ultra (cycloxydim - 2 l/ha + antibroadleaved herbicide Kalam (tritosulfuron + dicamba – 300 g/ha. It is found that herbicide combination of soil-applied herbicide Merlin flex with tank mixture Focus ultra + Kalam by Duo system technology leads to obtaining high grain yield. High yields of maize grain are also obtained by herbicide combinations Lumax + Principal plus, Lumax + Laudis and Wing + Principal plus. The most unstable are the non-treated check and single use of soilapplied herbicides Adengo, Wing and Lumax. Technologically the most valuable are herbicide combination Merlin flex + Focus ultra + Kalam by Duo system technology, followed by combinations of foliar-applied herbicides Principal plus and Laudis with soil-applied herbicides Adengo, Wing and Lumax by conventional technology. Single use of herbicides has low estimate due to must to combine soil-applied with foliar

  15. Biotransformation and biomonitoring of phenylurea herbicide diuron.

    Science.gov (United States)

    Sharma, Priyanka; Suri, C Raman

    2011-02-01

    A Gram-positive, Micrococcus sp. strain PS-1 isolated from diuron storage site was studied for its capability of biotransformation of phenylurea herbicide diuron to a secondary metabolite, 1-(3,4-dichlorophenyl)urea (DCPU) for bioconjugation and antibody development applications. The metabolite formed associated with profound changes in bacterial cell morphology demonstrated increase in the degradation kinetics of diuron in presence of small quantity of a surfactant. The synthesized metabolite identified by chromatographic and mass spectrometry techniques was conjugated with carrier protein, and used as an immunogen for antibodies production. The generated antibody was highly specific, demonstrating excellent sensitivity against diuron. The antibody was used as receptor molecules in standard fluorescence immunoassay (FIA) format showing detection limit of 0.01 ng/mL in the optimum working concentration range of diuron with good signal precision (∼2%). The study presented first time the degradation pathway of herbicide by specific microorganism to synthesize hapten for bioconjugation and immunoassay development. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. Selectivity of herbicides in crambe crop

    Directory of Open Access Journals (Sweden)

    Guilherme Sasso Ferreira Souza

    2014-02-01

    Full Text Available The low productivity of crambe can be associated with many factors, among these, the competition with weeds, which reduces the yield, harvest affects and contributes to the increase in seed moisture. Therefore, this study aimed to evaluate the tolerance of crambe plants cv. FMS Brilhante to herbicides applied in preplant incorporated (PPI, preemergence (PRE, and postemergence (POST. The study was installed in a green-house and the treatments consisted of the herbicide application in: pre-plant incorporated ofdiclosulam, flumetsulam, metribuzin, and trifluralin;preemergence applicationof atrazine, diclosulam, diuron, flumetsulam, metribuzim, S-metolachlor, sulfentrazone, and trifluralin; and postemergence application ofbentazon, carfentrazone-ethyl, clefoxydim, cletodim + fenoxaprop-p-ethyl, ethoxysulfuron, fomesafen, fluazifop-p-butyl, flumioxazin, halosulfuron, imazamox, imazapic, lactofen, nicosulfuron, oxadiazon, quinclorac, and setoxydim. Visual evaluations of phytotoxicity on crambe plants were realized after applications, the seedlings were counted and the height and plant dry matter were determined in the end of the evaluation period. In conditions where the studies were conducted, we can conclude that only the trifluralin application in PRE and the application of clefoxidim+fenoxaprop-p-ethyl, fluazifop-p-butyl, quinclorac, setoxydim and clefoxydim in POST showed selectivity and potential use for FMS Brilhante crambe cultivar.

  17. Hormonal changes in spring barley after triazine herbicide treatment and its mixtures of regulators of polyamine biosynthesis

    Directory of Open Access Journals (Sweden)

    Pavol Trebichalský

    2017-01-01

    Full Text Available Plants adapt to abiotic stress by undergoing diverse biochemical and physiological changes that involve hormone-dependent signalling pathways. The effects of regulators of polyamine biosynthesis can be mimicked by exogenous chemical regulators such as herbicide safeners, which not only enhance stress tolerance but also confer hormetic benefits such as increased vigor and yield. The phytohormones, abscisic acid (ABA and auxin (IAA play key roles in regulating stress responses in plants. Two years pot trials at Slovak University of agriculture Nitra were carried out with analyses of contents of plant hormones in spring barley grain of variety Kompakt: indolyl-acetic acid (IAA and abscisic acid (ABA, after exposing of tested plants to herbicide stress, as well as the possible decrease of these stress factors with application of regulators of polyamine synthesis was evaluated. At 1st year in spring barley grain after application of solo triazine herbicide treatment in dose 0,5 L.ha-1 an increase of all analyzed plant hormones was observed and contrary, at 2nd year there was the decrease of their contents. From our work there is an obvious influence of herbicide stress induced by application of certain dose of triazine herbicide at 1st year. Expect of the variant with mixture of triazine herbicide (in amount of 0,5 L.ha-1 and 29,6 g.ha-1 DAB, at this year all by us applied regulators of polyamine synthesis reduced the level of both plant hormones. Higher affect of stress caused by enhanced content of soluble macroelements in soil where the plants of barley were grown was observed next year. Soil with increased contents of macronutrients (mg.kg-1: N30.7 + P108.3 + K261.5 + Mg604.2 had reducing effect on contents of plant hormones in barley grain at variant treated with solo triazine herbicide (in dose at 0,5 L.ha-1 in comparison to control variant. The mixtures of regulators of polyamine synthesis reduced the contents of IAA only in comparison to

  18. Research methods in weed science: herbicide absorption and translocation in plants using radioisotopes

    Science.gov (United States)

    Herbicide absorption and translocation in plants is a key component in the study of herbicide physiology, mode of action, selectivity, resistance mechanisms, and in the registration process. Radioactive herbicides have been in use for over half-a-century in the research and study of herbicide absorp...

  19. Ecology and silvicultural management for the rehabilitation in rain forests of low altitude on complex metamorphic

    Directory of Open Access Journals (Sweden)

    Gonzalo Cantos Cevallos

    2018-01-01

    Full Text Available In order to characterize ecology and silvicultural management for the rehabilitation of the low altitude rain forest on a metamorphic complex, Quibiján-Naranjal del Toa sector, a floristic inventory was carried out, 36 sample plots of 20 x 25 m in the forest in both sides of Toa's riverside. Tree species with d1,3 e» 5 cm were measured, a total of 1507 individuals represented in 52 species belonging to 49 genera and 24 families were identified and evaluated. Both forests were statistically compared in terms of richness, composition, structure, diversity and abundance, with a high alpha and beta diversity. The species with the highest value index of ecological importance were determined. The families Fabaceae, Moraceae, Lauraceae and Meliaceae are the most representative in terms of species and genera. The most important species are Hibiscus elatus, Calophyllum utile, Carapa guianensis, Buhenavia capitata, y Guarea guara, among others, which stand out as the most abundant. Economic occupation was adequate in a few plots and incomplete in most of the sampling units. Taking into account the results obtained, we propose silvicultural actions aimed at sustainable forest management through the application of improvement shorts and the method of enrichment in dense spaced-groups for the rehabilitation and the achievement of the expected multiethane forest.

  20. Response of the boreal forest ecosystem to climatic change and its silvicultural implications

    Energy Technology Data Exchange (ETDEWEB)

    Kellomaeki, S.; Haenninen, H.; Karjalainen, T. [Joensuu Univ. (Finland). Faculty of Forestry] [and others

    1996-12-31

    During the next 100 years, the mean annual temperature is expected to be 1-6 deg C higher than at present. It is also expected to be accompanied by a lengthening of the thermal growing season and increased precipitation. Consequently, climatic change will increase the uncertainty of the management of forest ecosystems in the future. In this context, this research project aimed to outline the ecological and silvicultural implications of climatic change with regard to (1) how the expected climatic change might modify the functioning and structure of the boreal forest ecosystem, and (2) how the silvicultural management of the forest ecosystem should be modified in order to maintain sustainable forest yield under changing climatic conditions. The experimental component of the project concerned first the effect that elevating temperature and elevating concentration of atmospheric carbon have on the ontogenetic development of Scots pine (Pinus sylvestris L) and on the subsequent increase in frost damage during winter. The second part of the study looked the effect of elevating temperature and elevating concentration of atmospheric carbon on the growth of Scots pine through photosynthesis, respiration, transpiration, nutrient supply, and changes in crown structure. This experiment was utilised in several subprojects of the overall project

  1. POTENTIAL OF MULTI-TEMPORAL UAV-BORNE LIDAR IN ASSESSING EFFECTIVENESS OF SILVICULTURAL TREATMENTS

    Directory of Open Access Journals (Sweden)

    U. Vepakomma

    2017-08-01

    Full Text Available Silvicultural treatments are practiced to control resource competition and direct forest stand development to meet management objectives. Effective tracking of thinning and partial cutting treatments help in timely mitigation and ensuring future stand productivity. Based on a study conducted in autumn 2015, our findings in a white pine dominant forest stand in Petawawa (Ontario, Canada showed that almost all individual trees were detectable, structure of individual trees and undergrowth was well pronounced and underlying terrain below dense undisturbed canopy was well captured with UAS based Riegl Vux-1 lidar even at a range of 150 m. Thereafter, the site was re-scanned the following summer with the same system. Besides understanding the difference in distribution patterns due to foliage conditions, co-registering the two datasets, in the current study, we tested the potential of quantifying effectiveness of a partial cutting silvicultural system especially in terms of filling of 3D spaces through vertical or lateral growth and mortality in a very short period of time.

  2. Silvicultural manipulation and site effect on above and belowground biomass equations for young Pinus radiata

    International Nuclear Information System (INIS)

    Rubilar, Rafael A.; Allen, H. Lee; Alvarez, Jose S.; Albaugh, Timothy J.; Fox, Thomas R.; Stape, Jose L.

    2010-01-01

    There is little understanding of how silvicultural treatments, during the early stages of tree development, affect allometric relationships. We developed and compared stem, branch, foliage, coarse and fine root biomass, and leaf area estimation equations, for four-year-old genetically improved radiata pine trees grown on three contrasting soil-site conditions. At each site, selected trees were destructively sampled from a control (shovel planted, no weed control, fertilized with 2 g of boron), a shovel planted + weed control (2 first years) + complete fertilization (nitrogen + phosphorus + boron 2 first years + potassium 2nd year), and a soil tillage (subsoil at 60 cm) + weed control (first 2 years) + complete fertilization treatment. Tissues were separated into foliage, branch, stem, fine and coarse roots (>2 mm). Regression equations for each tree biomass tissue versus leaf area were fit for each site and compared among treatments and sites with the same genetic material. Our results indicated that individual tree biomasses for young plantations are affected by silvicultural treatment and site growing conditions. Higher variability in estimates was found for foliage and branches due to the ephemeral nature of these components. Stem biomass equations vary less, but differences in biomass equations were found among sites and treatments. Coarse root biomass estimates were variable but less than expected, considering the gradient among sites. Similar to stem biomass, a simple positive general linear relationship between root collar diameter, or diameter at breast height with coarse roots biomass was developed across sites and treatments.

  3. Response of the boreal forest ecosystem to climatic change and its silvicultural implications

    Energy Technology Data Exchange (ETDEWEB)

    Kellomaeki, S; Haenninen, H; Karjalainen, T [Joensuu Univ. (Finland). Faculty of Forestry; and others

    1997-12-31

    During the next 100 years, the mean annual temperature is expected to be 1-6 deg C higher than at present. It is also expected to be accompanied by a lengthening of the thermal growing season and increased precipitation. Consequently, climatic change will increase the uncertainty of the management of forest ecosystems in the future. In this context, this research project aimed to outline the ecological and silvicultural implications of climatic change with regard to (1) how the expected climatic change might modify the functioning and structure of the boreal forest ecosystem, and (2) how the silvicultural management of the forest ecosystem should be modified in order to maintain sustainable forest yield under changing climatic conditions. The experimental component of the project concerned first the effect that elevating temperature and elevating concentration of atmospheric carbon have on the ontogenetic development of Scots pine (Pinus sylvestris L) and on the subsequent increase in frost damage during winter. The second part of the study looked the effect of elevating temperature and elevating concentration of atmospheric carbon on the growth of Scots pine through photosynthesis, respiration, transpiration, nutrient supply, and changes in crown structure. This experiment was utilised in several subprojects of the overall project

  4. Carbon rentals and silvicultural subsidies for private forests as climate policy instruments

    International Nuclear Information System (INIS)

    Uusivuori, J.; Laturi, J.

    2007-01-01

    The impacts of potential climate policy instruments on the carbon production of privately owned and operated forests were investigated. A forest model with an endogenous growth description and age-class structure was used to describe both the output supply and input demand decisions of a private non-industrial landowner with optimized consumption flow, harvest timing, and an intertemporal allocation of forest investments. Two scenarios were examined, notably (1) a scenario in which the landowner was granted periodic carbon rental payments; and (2) a scenario in which the government subsidized the costs of silvicultural investments. The intended and unintended effects of the policies were examined. Models were used to demonstrate that the effectiveness of the instruments was significantly influenced by the age-class structure of forests when future carbon benefits were discounted. It was concluded that carbon rental payments were a more effective policy for older age-class structured forests. Silvicultural subsidies were more beneficial for forests with younger age-class structures. 21 refs., 6 figs

  5. Adsorption of sugar beet herbicides to Finnish soils.

    Science.gov (United States)

    Autio, Sari; Siimes, Katri; Laitinen, Pirkko; Rämö, Sari; Oinonen, Seija; Eronen, Liisa

    2004-04-01

    Three sugar beet herbicides, ethofumesate, phenmedipham and metamitron, are currently used on conventional sugar beet cultivation, while new varieties of herbicide resistant (HR) sugar beet, tolerant of glyphosate or glufosinate-ammonium, are under field testing in Finland. Little knowledge has so far been available on the adsorption of these herbicides to Finnish soils. The adsorption of these five herbicides was studied using the batch equilibrium method in 21 soil samples collected from different depths. Soil properties like organic carbon content, texture, pH and partly the phosphorus and oxide content of the soils were tested against the adsorption coefficients of the herbicides. In general, the herbicides studied could be arranged according to their adsorption coefficients as follows: glyphosate>phenmedipham>ethofumesate approximately glufosinate-ammonium>metamitron, metamitron meaning the highest risk of leaching. None of the measured soil parameters could alone explain the adsorption mechanism of these five herbicides. The results can be used in model assessments of risk for leaching to ground water resulting from weed control of sugar beet in Finland.

  6. Studies on maize inbred lines susceptibility to herbicides

    Directory of Open Access Journals (Sweden)

    Stefanović Lidija

    2010-01-01

    Full Text Available This paper presents the analysis of results obtained during long- term studies on the response of maize inbred lines to herbicides. Under the agroecological conditions of Zemun Polje the response (reaction of maize inbred lines to herbicides of different classes was investigated. Biological tests were performed and some agronomic, morphological, physiological and biochemical parameters were determined when the response of maize inbred lines to herbicides was estimated. The use of active ingredients of herbicides from triazine, acetanilide, thiocarbamate to new chemical groups (sulfonylurea etc., have been resulted in changes in weed suppression and susceptibility of inbred lines. Obtained results show that effects of herbicides on susceptible maize genotypes can be different: they can slowdown the growth and development and affect the plant height; they can also affect the stages of the tassel and ear development and at the end they can reduced grain yield of the tested inbreds. Numerous studies confirmed the existence of differences in susceptibility level of maize genotypes in relation to herbicides. According to gained results the recommendations for growers are made on the possibility of the application of new herbicides in the hybrid seed production.

  7. Rationale for a natural products approach to herbicide discovery.

    Science.gov (United States)

    Dayan, Franck E; Owens, Daniel K; Duke, Stephen O

    2012-04-01

    Weeds continue to evolve resistance to all the known modes of herbicidal action, but no herbicide with a new target site has been commercialized in nearly 20 years. The so-called 'new chemistries' are simply molecules belonging to new chemical classes that have the same mechanisms of action as older herbicides (e.g. the protoporphyrinogen-oxidase-inhibiting pyrimidinedione saflufenacil or the very-long-chain fatty acid elongase targeting sulfonylisoxazoline herbicide pyroxasulfone). Therefore, the number of tools to manage weeds, and in particular those that can control herbicide-resistant weeds, is diminishing rapidly. There is an imminent need for truly innovative classes of herbicides that explore chemical spaces and interact with target sites not previously exploited by older active ingredients. This review proposes a rationale for a natural-products-centered approach to herbicide discovery that capitalizes on the structural diversity and ingenuity afforded by these biologically active compounds. The natural process of extended-throughput screening (high number of compounds tested on many potential target sites over long periods of times) that has shaped the evolution of natural products tends to generate molecules tailored to interact with specific target sites. As this review shows, there is generally little overlap between the mode of action of natural and synthetic phytotoxins, and more emphasis should be placed on applying methods that have proved beneficial to the pharmaceutical industry to solve problems in the agrochemical industry. Published 2012 by John Wiley & Sons, Ltd.

  8. Fire performance in traditional silvicultural and fire and fire surrogate treatments in Sierran mixed-conifer forests: a brief summary

    Science.gov (United States)

    Jason J. Moghaddas; Scott L. Stephens

    2007-01-01

    Mixed conifer forests cover 7.9 million acres of California’s total land base. Forest structure in these forests has been influenced by harvest practices and silvicultural systems implemented since the beginning of the California Gold Rush in 1849. Today, the role of fire in coniferous forests, both in shaping past stand structure and its ability to shape future...

  9. Physiological responses of eastern hemlock (Tsuga Canadensis) to biological control and silvicultural release: implications for hemlock restoration

    Science.gov (United States)

    Chelcy F. Miniat; David Zeitlow; Steven T. Brantley; Albert (Bud) Mayfield; Rusty Rhea; Robert Jetton; Paul.  Arnold

    2016-01-01

    The rapid loss of eastern hemlock (Tsuga canadensis) from riparian zones in the southern Appalachian Mountains due to Hemlock Woolly Adelgid (Adelgis tsugae, HWA) infestation has resulted in changes to watershed structure and function. Several restoration strategies have been proposed, including silvicultural treatments that increase incident light in forest...

  10. Modeling silviculture after natural disturbance to sustain biodiversity in the longleaf pine (Pinus palustris) ecosystem : balancing complexity and implementation

    Science.gov (United States)

    Brian J. Palik; Robert J. Mitchell; J. Kevin Hiers

    2002-01-01

    Modeling silviculture after natural disturbance to maintain biodiversity is a popular concept, yet its application remains elusive. We discuss difficulties inherent to this idea, and suggest approaches to facilitate implementation, using longleaf pine (Pinus palustris) as an example. Natural disturbance regimes are spatially and temporally variable. Variability...

  11. Mid-rotation silviculture timing influences nitrogen mineralization of loblolly pine plantations in the mid-south USA

    Science.gov (United States)

    Michael A. Blazier; D. Andrew Scott; Ryan Coleman

    2015-01-01

    Intensively managed loblolly pine (Pinus taeda L.) plantations often develop nutrient deficiencies near mid-rotation. Common silvicultural treatments for improving stand nutrition at this stage include thinning, fertilization, and vegetation control. It is important to better understand the influence of timing fertilization and vegetation control...

  12. Influence of residual basal area on longleaf pine (Pinus palustris Mill.) first year germination and establishment under selection silviculture

    Science.gov (United States)

    Ferhat Kara; Edward F. Loewenstein

    2015-01-01

    Even-aged silvicultural methods have been successfully used to manage longleaf pine (Pinus palustris Mill.) forests for wood production; however, successful use of uneven-aged methods to manage this ecosystem is less well documented. In this study, the effects of varying levels of residual basal area (RBA) (9.2, 13.8, and 18.4 m2...

  13. Development of the selection system in northern hardwood forests of the Lake States: an 80-year silviculture research legacy

    Science.gov (United States)

    Christel Kern; Gus Erdmann; Laura Kenefic; Brian Palik; Terry. Strong

    2014-01-01

    The northern hardwood research program at the Dukes Experimental Forest in Michigan and Argonne Experimental Forest in Wisconsin has been adapting to changing management and social objectives for more than 80 years. In 1926, the first northern hardwood silviculture study was established in old-growth stands at the Dukes Experimental Forest. In response to social...

  14. Post-harvesting silvicultural treatments in logging gaps: A comparison between enrichment planting and tending of natural regeneration

    NARCIS (Netherlands)

    Schwartz, G.; Lopes, J.C.A.; Mohren, G.M.J.; Peña-Claros, M.

    2013-01-01

    Despite greatly improved forest management in recent decades, long-term assessments show that if current harvesting volumes and cutting cycles are maintained, future volume yields of commercial species will decrease. A possible solution is to apply post-harvesting silvicultural treatments to

  15. Methanol production from Eucalyptus wood chips. Working document I. The Florida Eucalyptus energy farm: silvicultural methods and considerations

    Energy Technology Data Exchange (ETDEWEB)

    Fishkind, H.H.

    1982-04-01

    The silvicultural matrix within which the nation's first large scale wood energy plantation will develop is described in detail. The relevant literature reviewed is identified and distilled. The plantation history, site preparation, planting, species selection, maintenance and management, harvesting, and the Eucalyptus biomass production estimates are presented.

  16. Two-age silviculture: an innovative tool for enhancing species diversity and vertical structure in Appalachian hardwoods

    Science.gov (United States)

    Gary W. Miller; Petra B. Wood; Jeffrey V. Nichols; Jeffrey V. Nichols

    1995-01-01

    Silvicultural practices that promote a two-age stand structure provide an opportunity to maintain diversity of woody species and vertical structure for extended periods of time in Appalachian hardwoods. Data from four two-age stands initiated by deferment cutting in West Virginia are summarized for the first 10 to 15 years after treatment. Results indicated that 15...

  17. Disturbances and structural development of natural forest ecosystems with silvicultural implications, using Douglas-fir forests as an example.

    Science.gov (United States)

    J.F. Franklin; T.A. Spies; R.V. Pelt; A.B. Carey; D.A. Thornburgh; D.R. Berg; D.B. Lindenmayer; M.E. Harmon; W.S. Keeton; D.C. Shaw; K. Bible; J. Chen

    2002-01-01

    Forest managers need a comprehensive scientific understanding of natural stand development processes when designing silvicultural systems that integrate ecological and economic objectives, including a better appreciation of the nature of disturbance regimes and the biological legacies, such as live trees, snags, and logs, that they leave behind. Most conceptual forest...

  18. Development of silvicultural systems for maintaining old-growth conditions in the temperate rainforest of southeast Alaska.

    Science.gov (United States)

    Michael H. McClellan

    2004-01-01

    In the old-growth temperate rainforests of southeast Alaska, concerns over clearcutting effects on habitat, visual quality, slope stability, and biodiversity have created a demand for the use of other silvicultural systems. The forest vegetation and animal taxa of southeast Alaska appear to be well adapted to frequent, widespread, small-scale disturbance, suggesting...

  19. Proceedings of the National Silviculture Workshop: The Shelterwood Regeneration Method; Charleston, South Carolina September 17-21, 1979

    Science.gov (United States)

    Dan Cramsey; Carl Puuri; Dick Miller; Billy E. Page; David Smith; David Marquis; Jack Usher; Bob Naumann; William Beaufait; Robert Loomis; Edward Smith; David Loftis; Gordon Langdon; Thomas Croker; William Boyer; Jim Edgren; Douglas Roy; John Hughes; Charles Boldt; Glenn Jacobson; Dick Godman; Carl Tubbs; Ivan Sander; Bob Blomquist

    1979-01-01

    Historic Charleston, South Carolina was the site of the 1979 Silviculture Workshop. The objective of the meeting was to discuss state of the art application of the shelterwood regeneration method to forests of the United States. These proceedings include the presentations of the individuals on the program.

  20. 40 CFR 122.27 - Silvicultural activities (applicable to State NPDES programs, see § 123.25).

    Science.gov (United States)

    2010-07-01

    ... POLLUTANT DISCHARGE ELIMINATION SYSTEM Permit Application and Special NPDES Program Requirements § 122.27... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Silvicultural activities (applicable to State NPDES programs, see § 123.25). 122.27 Section 122.27 Protection of Environment...

  1. Acute and additive toxicity of ten photosystem-II herbicides to seagrass

    OpenAIRE

    Adam D. Wilkinson; Catherine J. Collier; Florita Flores; Andrew P. Negri

    2015-01-01

    Photosystem II herbicides are transported to inshore marine waters, including those of the Great Barrier Reef, and are usually detected in complex mixtures. These herbicides inhibit photosynthesis, which can deplete energy reserves and reduce growth in seagrass, but the toxicity of some of these herbicides to seagrass is unknown and combined effects of multiple herbicides on seagrass has not been tested. Here we assessed the acute phytotoxicity of 10 PSII herbicides to the seagrass Halophila ...

  2. Sarmentine, a natural herbicide from Piper species with multiple herbicide mechanisms of action

    Directory of Open Access Journals (Sweden)

    Franck Emmanuel Dayan

    2015-04-01

    Full Text Available Sarmentine, 1-(1-pyrrolidinyl-(2E,4E-2,4-decadien-1-one, is a natural amide isolated from the fruits of Piper species. The compound has a number of interesting biological properties, including its broad-spectrum activity on weeds as a contact herbicide. Initial studies highlighted a similarity in response between plants treated with sarmentine and herbicidal soaps such as pelargonic acid (nonanoic acid. However, little was known about the mechanism of action leading to the rapid desiccation of foliage treated by sarmentine. In cucumber cotyledon disc-assays, sarmentine induced rapid light-independent loss of membrane integrity at 100 µM or higher concentration, whereas 3 mM pelargonic acid was required for a similar effect. Sarmentine was between 10 and 30 times more active than pelargonic acid on wild mustard, velvetleaf, redroot pigweed and crabgrass. Additionally, the potency of 30 µM sarmentine was greatly stimulated by light, suggesting that this natural product may also interfere with photosynthetic processes. This was confirmed by observing a complete inhibition of photosynthetic electron transport at that concentration. Sarmentine also acted as an inhibitor of photosystem II on isolated thylakoid membranes by competing for the binding site of plastoquinone. This can be attributed in part to structural similarities between herbicides like sarmentine and diuron. While this mechanism of action accounts for the light stimulation of the activity of sarmentine, it does not account for its ability to destabilize membranes in darkness. In this respect, sarmentine has some structural similarity to crotonoyl-CoA, the substrate of enoyl-ACP reductase, a key enzyme in the early steps of fatty acid synthesis. Inhibitors of this enzyme, such as triclosan, cause rapid loss of membrane integrity in the dark. Sarmentine inhibited the activity of enoyl-ACP reductase, with an I50app of 18.3 µM. Therefore, the herbicidal activity of sarmentine appears to

  3. Correlations between chromatographic parameters and bioactivity predictors of potential herbicides.

    Science.gov (United States)

    Janicka, Małgorzata

    2014-08-01

    Different liquid chromatography techniques, including reversed-phase liquid chromatography on Purosphere RP-18e, IAM.PC.DD2 and Cosmosil Cholester columns and micellar liqud chromatography with a Purosphere RP-8e column and using buffered sodium dodecyl sulfate-acetonitrile as the mobile phase, were applied to study the lipophilic properties of 15 newly synthesized phenoxyacetic and carbamic acid derivatives, which are potential herbicides. Chromatographic lipophilicity descriptors were used to extrapolate log k parameters (log kw and log km) and log k values. Partitioning lipophilicity descriptors, i.e., log P coefficients in an n-octanol-water system, were computed from the molecular structures of the tested compounds. Bioactivity descriptors, including partition coefficients in a water-plant cuticle system and water-human serum albumin and coefficients for human skin partition and permeation were calculated in silico by ACD/ADME software using the linear solvation energy relationship of Abraham. Principal component analysis was applied to describe similarities between various chromatographic and partitioning lipophilicities. Highly significant, predictive linear relationships were found between chromatographic parameters and bioactivity descriptors. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Micellar electrokinetic chromatographic determination of triazine herbicides in water samples.

    Science.gov (United States)

    Li, Zhi; Zhang, Shuaihua; Yin, Xiaofang; Wang, Chun; Wang, Zhi

    2014-09-01

    Dispersive liquid-liquid microextraction combined with online sweeping preconcentration in micellar electrokinetic chromatography was developed for the simultaneous determination of five triazine herbicides (atrazine, simazine, propazine, prometon and simetryn) in water samples. Several experimental parameters affecting the extraction efficiencies such as the type and volume of both the extraction and dispersive solvents, the addition of salt to sample solution, the extraction time and the pH of the sample solution were investigated. Under optimum conditions, the linearity of the method was good in the range from 0.33 to 20 ng mL(-1) for simazine, propazine, atrazine and simetryn, and from 0.17 to 20 ng mL(-1) for prometon, respectively. The sensitivity enrichment factors were in the range from 1750 to 2100, depending on the compound. The limit of detection (S/N = 3) ranged from 0.05 to 0.10 ng mL(-1). The developed method was successfully applied to the analysis of the five triazines in river, ground and well waters. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Herbicide Glyphosate Impact to Earthworm (E. fetida

    Directory of Open Access Journals (Sweden)

    Greta Dajoraitė

    2016-10-01

    Full Text Available Glyphosate is a broad spectrum weed resistant herbicide. Glyphosate may pose negative impact on land ecosystems because of wide broad usage and hydrofilic characteristic. The aim of this study was to investigate negative effects of glyphosate on soil invertebrate organisms (earthworm Eisenia fetida. The duration of experiment was 8 weeks. The range of the test concentrations of glyphosate were: 0,1, 1, 5, 10, 20 mg/kg. To investigate the glyphosate impact on earthworm Eisenia fetida the following endpoints were measured: survival, reproduction and weight. The exposure to 20 mg/kg glyphosate has led to the 100% mortality of earthworms. Glyphosate has led to decreased E. fetida reproduction, the cocoons were observed only in the lowest concentration (0,1 mg/kg. In general: long-term glyphosate toxicity to earthworms (E. fetida may be significant.

  6. Dinitroaniline herbicide resistance and the microtubule cytoskeleton.

    Science.gov (United States)

    Anthony; Hussey

    1999-03-01

    Dinitroaniline herbicides have been used for pre-emergence weed control for the past 25 years in cotton, soybean, wheat and oilseed crops. Considering their long persistence and extensive use, resistance to dinitroanilines is fairly rare. However, the most widespread dinitroaniline-resistant weeds, the highly resistant (R) and the intermediate (I) biotypes of the invasive goosegrass Eleusine indica, are now infesting more than 1000 cotton fields in the southern states of the USA. The molecular basis of this resistance has been identified, and found to be a point mutation in a major microtubule cytoskeletal protein, alpha-tubulin. These studies have served both to explain the establishment of resistance and to reveal fundamental properties of tubulin gene expression and microtubule structure.

  7. Selectivity and stability of new herbicides and herbicide combinations for the seed yields of some field crops I. Effect at Coriander (Coriandrum Sativum L.)

    OpenAIRE

    G. Delchev

    2016-01-01

    Abstract. . The research was conducted during 2013 – 2015 on pellic vertisol soil type. Under investigation was Bulgarian coriander cultivar Lozen 1 (Coriandrum sativum L.). The purpose of the investigation was to establish the selectivity and stability of some herbicides, herbicide combinations and herbicide tank mixtures on the coriander. Factor A included the years of investigation. Factor B included no treated check, 6 soil-applied herbicides – Tendar EC, Silba SC, Sharpen 33 EC,...

  8. Efficacy and economics of different herbicides in aerobic rice system

    African Journals Online (AJOL)

    Jane

    2011-08-03

    Aug 3, 2011 ... options for effective and economic weed control in rice under aerobic system ... constraint to aerobic rice production and therefore, ... Herbicide has become an attractive alternative to manual ... MATERIALS AND METHODS.

  9. Herbicides effect on the nitrogen fertilizer assimilation by sensitive plants

    International Nuclear Information System (INIS)

    Ladonin, V.F.; Samojlov, L.N.

    1976-01-01

    It has been established in studying the effect of herbicides on pea plants that the penetration of the preparations into the tissues of leaves and stems results in a slight increase of the rate of formation of dry substance in the leaves of the treated plants within 24 hours after treatment as compared with control, whereas in the last period of the analysis the herbicides strongly inhibit the formation of dry substance in leaves. The applied herbicide doses have resulted in drastic changes of the distribution of the plant-assimilated nitrogen between the protein and non-protein fractions in the leaves and stems of pea. When affected by the studied herbicides, the fertilizer nitrogen supply to the pea plants changes and the rate of the fertilizer nitrogen assimilation by the plants varies noticeably. The regularities of the fertilizer nitrogen inclusion in the protein and non-protein nitrogen compounds of the above-ground pea organs have been studied

  10. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    Science.gov (United States)

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

  11. Biodegradation of glyphosate herbicide in vitro using bacterial ...

    African Journals Online (AJOL)

    USER

    2010-06-28

    Jun 28, 2010 ... Full Length Research Paper ... Glyphosate is a compound used as herbicide in the control and/or killing of grasses and herbaceous plants. ... Because of its toxicity to non-target organisms, there is need to decontaminate.

  12. Nitrogen dynamics across silvicultural canopy gaps in young forests of western Oregon

    Science.gov (United States)

    Thiel, A.L.; Perakis, S.S.

    2009-01-01

    Silvicultural canopy gaps are emerging as an alternative management tool to accelerate development of complex forest structure in young, even-aged forests of the Pacific Northwest. The effect of gap creation on available nitrogen (N) is of concern to managers because N is often a limiting nutrient in Pacific Northwest forests. We investigated patterns of N availability in the forest floor and upper mineral soil (0-10 cm) across 6-8-year-old silvicultural canopy gaps in three 50-70-year-old Douglas-fir forests spanning a wide range of soil N capital in the Coast Range and Cascade Mountains of western Oregon. We used extractable ammonium (NH4+) and nitrate (NO3-) pools, net N mineralization and nitrification rates, and NH4+ and NO3- ion exchange resin (IER) concentrations to quantify N availability along north-south transects run through the centers of 0.4 and 0.1 ha gaps. In addition, we measured several factors known to influence N availability, including litterfall, moisture, temperature, and decomposition rates. In general, gap-forest differences in N availability were more pronounced in the mineral soil than in the forest floor. Mineral soil extractable NH4+ and NO3- pools, net N mineralization and nitrification rates, and NH4+ and NO3- IER concentrations were all significantly elevated in gaps relative to adjacent forest, and in several cases exhibited significantly greater spatial variability in gaps than forest. Nitrogen availability along the edges of gaps more often resembled levels in the adjacent forest than in gap centers. For the majority of response variables, there were no significant differences between northern and southern transect positions, nor between 0.4 and 0.1 ha gaps. Forest floor and mineral soil gravimetric percent moisture and temperature showed few differences along transects, while litterfall carbon (C) inputs and litterfall C:N ratios in gaps were significantly lower than in the adjacent forest. Reciprocal transfer incubations of

  13. MEMORANDUM: Application of Best Management Practices to Mechanical Silvicultural Site Preparation Activities for the Establishment of Pine Plantations in the Southeast

    Science.gov (United States)

    Memorandum to the Field, November 28, 1995, clarifying the applicability of forested wetlands best management practices to mechanical silvicultural site preparation activities for the establishment of pine plantations in the Southeast.

  14. Changes in bacterial community after application of three different herbicides.

    Science.gov (United States)

    Moretto, Jéssica Aparecida Silva; Altarugio, Lucas Miguel; Andrade, Pedro Avelino; Fachin, Ana Lúcia; Andreote, Fernando Dini; Stehling, Eliana Guedes

    2017-07-06

    The native soil microbiota is very important to maintain the quality of that environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of large quantities of toxic waste were observed in soil, groundwater and surface water. Thereby, the goal of this study was to evaluate if the selective pressure exerted by the presence of the herbicides atrazine, diuron and 2,4-D changes the bacterial community structure of an agricultural soil, using denaturing gradient gel electrophoresis technique. According to PERMANOVA analysis, a greater effect of the herbicide persistence time in the soil, the effect of the herbicide class and the effect of interaction between these two factors (persistence time and herbicide class) were observed. In conclusion, the results showed that the selective pressure exerted by the presence of these herbicides altered the composition of the local microbiota, being atrazine and diuron that most significantly affected the bacterial community in soil, and the herbicide 2,4-D was the one that less altered the microbial community and that bacterial community was reestablished first. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Herbicidal treatments for control of Papaver somniferum L.

    Science.gov (United States)

    Horowitz, M

    1980-01-01

    Fifty-five commercially available herbicides were evaluated for possible use to destroy illicit opium poppy crops (Papaver somniferum). In the first stage, herbicides were sprayed on poppy plants grown in containers. The following compounds killed poppy plants: (a) herbicides with typical foliar activity--amitrole, bromoxynil, 2,4-D, glyphosate, ioxynil and paraquat; and (b) herbicides with root and foliar activity--the triazines ametryn, atrazine, metribuzin, prometryn, simazine and terbutryn; the substituted ureas benzthiazuron, chloroxuron, diuron, fluometuron, linuron, methabenzthiazuron, neburon and phenobenzuron; and the miscellaneous compounds karbutilate, methazole, oxadiazon and pyrazon. Severe but sublethal injury was caused by cycloate, EPTC, molinate, pobulate, cacodylate + MSMA, ethofumesate, perfluidone and phenmedipham. Abnormal development of vegetative or reproductive parts of the plant was induced by benefin, butralin, dinitramine, pendimethalin, trifluralin, diphenamid, napropamide, dalapon and propham. Efficient herbicides with negligible persistence in soil at the doses applied were evaluated on poppy plants in the field at various stages of growth. Small plants were severely injured by 2,4-D, killed rapidly by bromoxynil, ioxynil, paraquat (in mixture + diquat), and more slowly by glyphosate and metribuzin. The resistance to herbicides increased with the age of the poppy plant. Severe damage with partial kill of developed plants was obtained with bromoxynil, ioxynil, glyphosate, and paraquat + diquat; the last treatment produced the fastest effect.

  16. Selectivity of herbicides in Camelina (Camelina sativa (L. Crtz.

    Directory of Open Access Journals (Sweden)

    Scheliga, Maria

    2016-02-01

    Full Text Available Camelina (Camelina sativa (L. Crtz. is a cruciferous plant. As an oilseed crop camelina is mainly grown for oil production. After the 1960s, however, the cultivation has become less important. Only in recent years, interest in this culture was awakened in the search for new sources of omega 3 fatty acids, natural antioxidants and a potential crop for the production of biofuels. The use of camelina oil for different purposes within the framework of the material use of renewable raw materials is of particular interest due to the high levels of linoleic and linolenic acid. For the establishment of camelina as a crop in agricultural crop rotation systems weed control should not be disregarded despite the rather good competitive ability against weeds. Based on greenhouse experiments a field trial in 2015 with different herbicide strategies was carried out. Besides Butisan Top (metazachlor + quinmerac, Devrinol FL (napropamide and Stomp Aqua (pendimethalin and also Betasana SC (phenmedipham has been tested in various amounts and combinations. Using assessments to weed density and herbicide tolerance different herbicide strategies were compared with each other. Though, it is difficult to find a compromise between satisfactory herbicidal effect and a slight injury to the crop plant. The herbicide selection, the application rate and the combination of different herbicides have an effect on the crop. To confirm the data obtained further tests are necessary.

  17. Herbicides: A new threat to the Great Barrier Reef

    International Nuclear Information System (INIS)

    Lewis, Stephen E.; Brodie, Jon E.; Bainbridge, Zoe T.; Rohde, Ken W.; Davis, Aaron M.; Masters, Bronwyn L.; Maughan, Mirjam; Devlin, Michelle J.; Mueller, Jochen F.; Schaffelke, Britta

    2009-01-01

    The runoff of pesticides (insecticides, herbicides and fungicides) from agricultural lands is a key concern for the health of the iconic Great Barrier Reef, Australia. Relatively low levels of herbicide residues can reduce the productivity of marine plants and corals. However, the risk of these residues to Great Barrier Reef ecosystems has been poorly quantified due to a lack of large-scale datasets. Here we present results of a study tracing pesticide residues from rivers and creeks in three catchment regions to the adjacent marine environment. Several pesticides (mainly herbicides) were detected in both freshwater and coastal marine waters and were attributed to specific land uses in the catchment. Elevated herbicide concentrations were particularly associated with sugar cane cultivation in the adjacent catchment. We demonstrate that herbicides reach the Great Barrier Reef lagoon and may disturb sensitive marine ecosystems already affected by other pressures such as climate change. - Herbicide residues have been detected in Great Barrier Reef catchment waterways and river water plumes which may affect marine ecosystems.

  18. Antioxidant activity of rice plants sprayed with herbicides

    Directory of Open Access Journals (Sweden)

    Marcos André Nohatto

    2016-03-01

    Full Text Available Understanding the physiological defense behavior of plants subjected to herbicide application may help to identify products with higher or lower capacity to cause oxidative stress in crops. This study aimed at evaluating the effect of herbicides in the antioxidant activity of rice plants. The experimental design was completely randomized, with six replications. Treatments consisted of the herbicides bentazon (photosystem II inhibitor; 960 g ha-1, penoxsulam (acetolactate synthase inhibitor; 60 g ha-1, cyhalofop-butyl (acetyl coenzyme-A carboxylase inhibitor; 315 g ha-1 and a control. After the herbicides application, samples of rice shoots were collected at 12, 24, 48 and 96 hours after application (HAA. The components evaluated were hydrogen peroxide (H2O2, lipid peroxidation and activity of the antioxidant enzymes superoxide dismutase (SOD and catalase (CAT. Bentazon (up to 24 HAA and penoxsulam (48 and 96 HAA reduced the CAT activity. Moreover, these herbicides increased the levels of H2O2, lipid peroxidation and SOD activity, indicating a condition of oxidative stress in rice plants. The cyhalofop-butyl herbicide did not alter the antioxidant activity, showing that it causes less stress to the crop.

  19. Aquatic Plant Control Research Program: Aquatic Plant Identification and Herbicide Use Guide. Volume 2. Aquatic Plants and Susceptibility to Herbicides

    Science.gov (United States)

    1988-11-01

    Chronic >0.5 Daphnia Repeat exposure Chronic >0.2 reproduction 0 NOTE; Fluridone was not found to cause genetic mutations or cancer in tested lab...persists. REGISTERED HERBICIDES 95 REGISTERED HERBICIDES GLYPHOSATE A. Chemical Name and Formulation: Chemical name: N-(phosphonomethyl)glycine Formulation...RODEO (53.5% ai, isopropylamine salt of glyphosate , liquid) B. Mode of Action: Not definite. However, investigators have postulated that

  20. Using Silviculture to Influence Carbon Sequestration in Southern Appalachian Spruce-Fir Forests

    Directory of Open Access Journals (Sweden)

    Patrick T. Moore

    2012-06-01

    Full Text Available Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled. We explicitly considered C stored in standing forest stocks and the fate of forest products derived from harvesting. Over a 100-year simulation period the even-aged scenario (250 Mg C ha1 outperformed the no-action scenario (241 Mg C ha1 in total carbon (TC sequestered. The uneven-aged scenario approached 220 Mg C ha1, but did not outperform the no-action scenario within the simulation period. While the average annual change in C (AAC of the no-action scenario approached zero, or carbon neutral, during the simulation, both the even-aged and uneven-aged scenarios surpassed the no-action by year 30 and maintained positive AAC throughout the 100-year simulation. This study demonstrates that silvicultural treatment of forest stands can increase potential C storage, but that careful consideration of: (1 accounting method (i.e., TC versus AAC; (2 fate of harvested products and; (3 length of the planning horizon (e.g., 100 years will strongly influence the evaluation of C sequestration.

  1. Silviculture and biology of short-rotation woody crops in temperate regions: Then and now

    Energy Technology Data Exchange (ETDEWEB)

    Dickmann, Donald I. [Department of Forestry, Michigan State University, East Lansing, MI 48824-1222 (United States)

    2006-08-15

    Although its roots are in antiquity, the current concept of short-rotation woody crops (SRWC) for fiber and energy evolved scientifically from pioneering tree breeding work begun in the early 20th century. A natural outgrowth of this work was the culture of fast-growing trees on rotations of 1-15 years. Close-spaced tree culture received further impetus with the introduction of the 'silage sycamore' concept in the southeastern US in the mid-1960s and the OPEC oil embargo in 1973, leading to statistically designed trials at numerous locations in North America, Europe, and Scandinavia. Early silvicultural research focused on spacing and species trials, propagation methods, site preparation, weed management, nutrition, growth, and yield. Because these trials were based on small plots, and the importance of pest depredations or site variation were not fully recognized, early biomass yield predictions tended to be overly optimistic. Soon physiologists and ecologists began to unravel the biological characteristics of SRWC plantations and their responses to environment. Knowledge of the influence and diversity of pests-insects, diseases, and animals-provided a necessary reality check. Many hardwood tree species and a few conifers have been evaluated over the years for SRWC in temperate regions of the world. Clones of Populus and Salix, however, became the dominant plantation material because of their inherently rapid growth and ease of propagation by hardwood cuttings. Among conifers, loblolly pine (Pinus taeda) also shows promise. Because genetic variation is readily exploitable in the dominant SRWC taxa, strongly focused breeding programs began to provide highly productive genotypes and seed sources in the last decades of the 20th century. A new plateau, with significant practical potential, was reached in the late 20th century when biotechnological methods were applied to tree taxa. Recently, the DNA in the Populus genome was sequenced. Thus, the few current

  2. Medium-long term soil resilience against different disturbances: wildfires, silvicultural treatments and climate change

    Science.gov (United States)

    Hedo de Santiago, Javier; Borja, Manuel Esteban Lucas; de las Heras, Jorge

    2016-04-01

    Soils of semiarid Mediterranean forest ecosystems are very fragile and sensitive to changes due to different anthropogenic and natural disturbances. The increasing vulnerability of semiarid lands within this world framework has generated growing awareness in the field of research, with highly intensified study into soils properties. One of the main problems of Mediterranean forests is wildfire disturbance. Fire should be considered more an ecological factor but, in contrast to the role of fire, it is now a closely related factor to human action. On the other hand, to improve the recovery of forest communities after fire, silvicultural treatments are needed and, for that matter, another disturbance is added to the ecosystem. By last, climate change is also affecting the fire regime increasing fire frequency and burned area, enhancing the destructiveness to Mediterranean ecosystems. After all of these three disturbances, changes in vegetation dynamics and soil properties are expected to occur due to the plant-soil feedback. Soil plays an essential role in the forest ecosystem's fertility and stability and specifically soil microorganisms, which accomplish reactions to release soil nutrients for vegetation development, for that is essential to enlarge knowledge about soil properties resilience in semiarid forest ecosystems. Physico-chemical and microbiological soil properties, and enzyme activities have been studied in two Aleppo pine forest stands that have suffered three disturbances: 1) a wildfire event, 2) silvicultural treatments (thinning) and 3) an artificial drought (simulating climate change) and results showed that soil recovered after 15 years. Final results showed that soils have been recovered from the three disturbances at the medium-long term.

  3. Silviculture of eucaliptus plantations in the Paraiba do Sul basin, Brazil, and its potential implication on the basin ecohydrology.

    Science.gov (United States)

    Carriello, Felix; Andres Rodriguez, Daniel; Marques Neves, Otto; Vicens, Raul

    2014-05-01

    Silviculture of eucaliptus plantations is an important driver of the Mata Atlântica biome conversion into another land use in the Paraíba do Sul basin, in the southeastern of Brazil. This region is located in one of the most developed areas in Brazil, between Rio de Janeiro and São Paulo, the most important cities in Brazil, linked by Presidente Dutra highway. Between both cities there are another cities that produce a variety of goods - from meat to planes, cars and mobile phones. This area is, at the same time, one the most important hot spot for the Mata Atlântica biome. Here we have a large Mata Atlântica fragment protected by law and others fragments being conversed to pasture, agriculture, silviculture and urban areas. Paraiba do Sul river drains the region and runs into Rio de Janeiro State. The basin is highly anthropized, with multiple approaches of its waters resources. Its waters also serve Rio de Janeiro metropolitan area. Because land use and land cover changes impact the water yield in a basin, the study of its dynamic its of great importance for water resources management. We study the land use and land cover change in the region between 1986 and 2010, focusing in the development of silviculture of eucaliptus plantations. We used the HAND (Height Above Nearest Drainage) approach that uses the height above the nearest water body, acquired from SRTM Data and transformed into a Terrain Numeric Mode, to classify the landscape into three different ecohydrological environments: floodplain, mountain top and hillslope. This classes were intersected with 1986 and 2010 land use and cover change classification obtained from Landsat imagery. Results show that silviculture has increased in the region from 1986 to 2010. In both years, silviculture areas are mainly located at the hillslope (47%), while floodplain and mountain top share 28 % and 23 % respectively. Available census data from the Brazilian Institute of Geography and Statistics, IBGE, for 1995 and

  4. Regularity of mitosis in different varieties of winter bread wheat under the action of herbicides

    Directory of Open Access Journals (Sweden)

    Tatyana Eugenivna KOPYTCHUK

    2012-05-01

    Full Text Available The influence of the most widespread herbicides on winter wheat in Ukraine was studied by anaphase test. Treatment with herbicides reduced the germination of the seeds and disturbed the regularity of mitosis in all varieties of wheat. The range of violations of mitosis was demonstrated by the formation of chromosomal aberrations and dysfunctions of cell cytoskeleton which occurred while processing herbicides. Varietal differences between investigated wheat by sensitivity to herbicides were discovered. The most resistant to herbicides was variety Fantasya Odesskaya, and the most sensitive – Nikoniya, while the most harmful herbicide for wheat was Napalm.

  5. Soil microbial and faunal responses to herbicide tolerant maize and herbicide in two soils

    DEFF Research Database (Denmark)

    Griffiths, Bryan; Caul, Sandra; Thompson, J.

    2008-01-01

    using a tiered approach at laboratory, glasshouse and field scales. Soil for the experiment was taken from field sites where the same maize cultivars were grown to allow comparison between results under glasshouse and field conditions. The maize cultivars T25 (GM HT glufosinate-ammonium tolerant....... The main effects on all measured parameters were those of soil type and plant growth stage, with four categories of subsequent interaction: (1) there were no effects of herbicide on plant growth or soil microarthropods: (2) the maize cultivar (but not the GM HT trait) had effects on the decomposition...

  6. Weed infestation of a winter wheat canopy under the conditions of application of different herbicide doses and foliar fertilization

    Directory of Open Access Journals (Sweden)

    Piotr Kraska

    2012-12-01

    Full Text Available The present study was carried out in the years 2006-2008 in the Bezek Experimental Farm (University of Life Sciences in Lublin. A two-factor field experiment was set up according to a randomized block design, in three replications. The experimental field was situated on medium heavy mixed rendzina developed from chalk rock with medium dusty loam granulometric composition. The soil was characterised by neutral pH, a very high content of P (342.1 and K (278.9 along with a very low level of magnesium (16.0 mg × kg-1 of soil and organic carbon (over 3.5%. The aim of this research was to compare the effect of three herbicide doses and two foliar fertilizers applied in a winter wheat canopy on weed infestation. The herbicides Mustang 306 SE 0.4 l × ha-1 and Attribut 70 WG 60 g × ha-1 were applied at full recommended doses as well as at doses reduced to 75% and 50%. Foliar fertilizers Insol 3 (1 1 × ha-1 and FoliCare (20 kg × ha-1 were applied at full recommended doses twice in the growing season BBCH* development stage 23-25* and 33-35*. The control was not treated with the herbicides and foliar fertilizers. The weed infestation level was determined by means of the quantitative gravimetric method at two dates: the first one 6 weeks after herbicide application and the second one - before harvest. The number of weed individuals was counted; species composition and air-dry biomass of aboveground parts were estimated from randomly selected areas of 1 m × 0.25 m at four sites on each plot. Galium aparine and Apera spica-venti plants were sampled for molecular analysis 6 weeks after herbicide application (the treatments with the full herbicide dose, a 50% dose and the control without herbicides. The density of weeds and weed air-dry weight were statistically analysed by means of variance analysis, and the mean values were estimated with Tukey's confidence intervals (p=0.05. It was found that the number of weeds and air-dry weight of weeds in the

  7. Herbicides interfere with antigrazer defenses in Scenedesmus obliquus.

    Science.gov (United States)

    Zhu, Xuexia; Sun, Yunfei; Zhang, Xingxing; Heng, Hailu; Nan, Haihong; Zhang, Lu; Huang, Yuan; Yang, Zhou

    2016-11-01

    The extensive application of herbicides has led to a serious threat of herbicide contamination to aquatic ecosystem. Herbicide exposure affects aquatic communities not only by exerting toxicity on single species but also by changing interspecific interactions. This study investigated the antigrazer defenses of the common green alga Scenedesmus obliquus against different herbicides [glyphosate, 2,4-dichlorophenoxyacetic acid (2,4-D), and atrazine] at various concentrations (0-2.0 mg L(-1)). In the presence of grazer (Daphnia)-derived cues, S. obliquus populations without herbicides formed high proportions of multicelled (e.g., four- and eight-celled) colonies. This result confirms that S. obliquus exhibits a morphological defense against grazing risk. At the low concentration range of 0.002-0.02 mg L(-1), the three herbicides exerted no influence on the growth and photosynthetic efficiency of S. obliquus, and multicelled colonies showed constant proportions. At the high concentration range of 0.20-2.0 mg L(-1), atrazine significantly inhibited the algal growth and photosynthesis whereas glyphosate or 2,4-D did not. Nonetheless, these levels of glyphosate or 2,4-D remarkably decreased the proportion of multicelled colonies, with reduced numbers of cells per particle in Daphnia filtrate-treated population. No eight-celled colony was formed after treatment with atrazine at 0.20-2.0 mg L(-1) despite the addition of Daphnia filtrate. These results suggest that herbicide exposure impairs antigrazer colonial morphs in phytoplankton although it is not sufficient to hamper algal growth. This phenomenon can increase the risk of predation by herbivores, thereby disrupting the inducible phytoplankton community. Furthermore, the predator-prey interactions between herbivores and phytoplankton can be potentially changed more seriously than previously considered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Interactions between near-ground temperature and radiation, silvicultural treatments and frost damage to Norway spruce seedlings

    OpenAIRE

    Langvall, Ola

    2000-01-01

    Several different silvicultural treatments were studied in two experiments. In the first, mechanical scarification, slash removal, vegetation control, clear-cut age and seedling types were investigated with respect to frost injury to Norway spruce (Picea abies (L.) Karst.) seedlings. Frost damage was also related to near-ground minimum temperature. In the other experiment, the effects of Scots pine (Pinus sylvestris (L.)) shelterwood density gradients, ranging from dense, uncut forest to comp...

  9. Rapeseed with tolerance to the non selective herbicide glufosinate ammonium

    Energy Technology Data Exchange (ETDEWEB)

    Rasche, E. [Hoechst Schering AgrEvo GmbH, Frankfurt am Main (Germany)

    1998-12-31

    Weed control with herbicides is essential to grow rapeseed. Glufosinate Ammonium is used as a non selective herbicide successfully in many countries for over 10 years. It conforms well with ever increasing safety standards for human beings, animals and the environment. The tolerance of rapeseed and other crop plants was achieved by genetic modification. A resistance gene (PAT or BAR) was transfered into previously susceptible rapeseed plants. This new approach allowed the development of Glufosinate Ammonium as an almost ideal selective herbicide. In cooperation with major seed companies and by own breeding programmes new Glufosinate tolerant rapeseed varieties and hybrids are developed. Data on metabolism, toxicity, residues, efficacy etc. were generated to get registration for the selective herbicide use. In addition various studies were done for safety assessments of the PAT gene and the modified rapeseed. In spring 1995 Canadian authorities granted worldwide the first approvals for the selective use of Glufosinate Ammonium (trademark Liberty) and Glufosinate tolerant (trademark and logo Liberty Link) spring rapeseed (Canola). After a successful launch in 1995 about 150.000 ha of Liberty Link Canola were grown and treated with Liberty in 1996. The Liberty Link Canola growers were very well satisfied. In a grower survey 84% stated that they will definitely use the Liberty Link System again. In Europe registrations for Glufosinate Ammonium as a selective herbicide and for the first Glufosinate tolerant rapeseed varieties are expected in the course of 1997. The Liberty Link System will be launched in rapeseed most probably in 1998. (orig.)

  10. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs

    Science.gov (United States)

    Yahnke, Amy E.; Grue, Christian E.; Hayes, Marc P.; Troiano, Alexandra T.

    2013-01-01

    Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs.

  11. Combined thermal and herbicide stress in functionally diverse coral symbionts

    International Nuclear Information System (INIS)

    Dam, J.W. van; Uthicke, S.; Beltran, V.H.; Mueller, J.F.; Negri, A.P.

    2015-01-01

    Most reef building corals rely on symbiotic microalgae (genus Symbiodinium) to supply a substantial proportion of their energy requirements. Functional diversity of different Symbiodinium genotypes, endorsing the host with physiological advantages, has been widely reported. Yet, the influence of genotypic specificity on the symbiont's susceptibility to contaminants or cumulative stressors is unknown. Cultured Symbiodinium of presumed thermal-tolerant clade D tested especially vulnerable to the widespread herbicide diuron, suggesting important free-living populations may be at risk in areas subjected to terrestrial runoff. Co-exposure experiments where cultured Symbiodinium were exposed to diuron over a thermal stress gradient demonstrated how fast-growing clade C1 better maintained photosynthetic capability than clade D. The mixture toxicity model of Independent Action, considering combined thermal stress and herbicide contamination, revealed response additivity for inhibition of photosynthetic yield in both tested cultures, emphasizing the need to account for cumulative stressor impacts in ecological risk assessment and resource management. - Highlights: • Water quality influences thermal stress thresholds in different Symbiodinium types. • Photosystem of clade D tested more sensitive than C1 to a common herbicide. • Increased thermal tolerance quickly countered in presence of herbicide. • Mixture toxicity approach demonstrated response additivity for combined stressors. • Symbiotic partnership may be compromised in areas subjected to terrestrial runoff. - Thermal-tolerant Symbiodinium type D tested especially vulnerable to a common herbicide, emphasizing the significance of cumulative stressors in ecological risk management

  12. Plant reproduction is altered by simulated herbicide drift to constructed plant communities

    Science.gov (United States)

    Herbicide drift may have unintended impacts on native vegetation, adversely affecting structure and function of plant communities. However, these potential effects have been rarely studied or quantified. To determine potential ecological effects of herbicide drift, we construct...

  13. Bioactivity of Several Herbicides on the Nanogram Level Under Different Soil Moisture Conditions.

    Science.gov (United States)

    Jung, S C; Kuk, Y I; Senseman, S A; Ahn, H G; Seong, C N; Lee, D J

    2015-01-01

    In this study, a double-tube centrifuge method was employed to determine the effects of soil moisture on the bioactivity of cafenstrole, pretilachlor, benfuresate, oxyfluorfen and simetryn. In general, the available herbicide concentration in soil solution (ACSS) showed little change as soil moisture increased for herbicides. The total available herbicide in soil solution (TASS) typically increased as soil moisture increased for all herbicides. The relationship between TASS and % growth rate based on dry weight showed strong linear relationships for both cafenstrole and pretilachlor, with r2 values of 0.95 and 0.84, respectively. Increasing TASS values were consistent with increasing herbicide water solubility, with the exception of the ionizable herbicide simetryn. Plant absorption and % growth rate exhibited a strong linear relationship with TASS. According to the results suggested that TASS was a better predictor of herbicidal bioactivity than ACSS for all herbicides under unsaturated soil moisture conditions.

  14. Determining the Optimum Concentration of Pretilachlor and Sunrice plus Herbicides for Weed control in Rice

    Directory of Open Access Journals (Sweden)

    A. Ebrahimpour Lish

    2017-02-01

    Full Text Available In order to determine the optimal rates of Pertilachlor and Sunrice­-plus herbicides for weed control of rice (Oryza sativa Var.Tarom Hashemi, a factorial experiment was conducted with a randomized complete block design with four replications in Rice Research Farm of Faculty of Agriculture, University of Guilan, Rasht, northern Iran. The first factor was weed control treatment which   consisted of lower than, equal, and more than recommended levels of Pertilachlor (i.e. 0.5, 0.75, 1 kg a.i ha-1 and Sun­rice plus (0.45, 0.9, 1.35 kg a.i ha-1 herbicides, along with unweeded and twice hand-weeded controls. The second factor consisted of two levels of nitrogen fertilizer (N application (i.e. 0 and 90 kg ha-1 of N. Barnyardgrass (Echinochloa crus-galli L. and Purple nutsedge (Cyperus rotandus L. were the most dominant weeds of the experimental plots. The highest number of filled panicles per plant, number of grains per panicle, and grain yield were found in recommended rate of Pertilachlor, Sun­rice plus and more than recommended rate of Sun­rice plus due to adequate weed control (>70% at the presence of 90 kg ha-1 of N. The lowest number of grains per panicle, number of panicles per plant and grain yield were observed in unweeded treatment, at both levels of nitrogen fertilizer application.  It was concluded that application of N is effective in increasing grain yield of the examined rice genotype only if weeds are effectively controlled by herbicides. Hence, application of N in the unweeded conditions does not lead to an increase in grain yield of rice, because the consumption of N by weeds decreased the effect of nitrogen on rice grain production.

  15. In vitro sensitivity of antagonistic Trichoderma atroviride to herbicides

    Directory of Open Access Journals (Sweden)

    Patricia Helena Santoro

    2014-04-01

    Full Text Available Trichoderma atroviride was tested in vitro for its sensitivity to different herbicides. The dosages tested were recommended dosage (RD, half dosage (½RD, and double dosage (2RD. Germination, colony-forming units (CFU, radial growth, and spore production were evaluated. Carfentrazone-ethyl and sulfentrazone inhibited the germination at RD and 2RD. A reduction in the CFU was observed for glufosinate-ammonium, atrazine, carfentrazone-ethyl, diuron + paraquat dichloride, imazapyr, oxyfluorfen, and sulfentrazone at each of the tested dosages. Radial growth was influenced by ametryn, atrazine, carfentrazone-ethyl, oxyfluorfen, and sulfentrazone herbicides, with an 80% reduction of the colonial area. Spore production was affected by carfentrazone-ethyl, oxyfluorfen, and sulfentrazone with colonial area reductions of over 70%. It was concluded that 2,4 D, clomazone, and imazapyr herbicides showed the least toxicity to T. atroviride and should be used in the crops where the fungus has been applied for phytopathogen control.

  16. Soil microbial activity in Aleppo pine stands naturally regenerated after fire: silvicultural management and induced drought

    Directory of Open Access Journals (Sweden)

    D. Moya

    2013-01-01

    Full Text Available In post-fire restoration, early monitoring is mandatory to check impacts and ecosystem responses to apply proper management according to social standards and ecological conditions. In areas where the natural regeneration was successful, excessive tree density can be found which induces to high intraspecific competence and assisted restoration management could be adequate. In addition, climatic changes will have large impacts on vegetation productivity and resilience since the regional models for south-eastern Spain predicts a rainfall decrease of about 20% and temperature increase of 4.5 ºC. The microbial biomass could be used as indicator of ecosystem recovery, since it is negatively affected by wildfires and depends on fire characteristics, vegetation and soil properties. Our aim is to determine how forest management may affect the ecosystem recovery in different climatic scenarios, included drought scenarios with and without forest management (thinning.We compared soil physicochemical properties and microbial activity in four scenarios: unmanaged and thinned stands in two rainfall scenarios (under induced drought. The study areas were set close to Yeste (Albacete where Aleppo pine forest were burned in summer 1994 (nearly 14000 ha. We set sixteen rectangular plots (150 m2; 15 m ×10 m implementing experimental silvicultural treatments: thinning eight plots in 2004, reducing the naturally recovered tree density from about 12000 to 1600 pine trees ha-1. In addition, in half the plots, we induced drought conditions from about 500 to 400 mm (20% from March 2009. In every plot, we monitored temperature at ground level (Ts, 10 cm depth (T10d and soil relative humidity (RH. Taking into account season of the year and canopy coverage, we collected soil samples in mid-winter (ending January 2011 and mid-spring (ending May 2011 under pine trees and in bare soil. The soil samples were used to evaluate soil physicochemical properties and soil microbial

  17. Intraregional and inter-regional variability of herbicide sensitivity in common arable weed populations

    DEFF Research Database (Denmark)

    de Mol, Friederike; Gerowitt, Bärbel; Kaczmarek, Sylwia

    2015-01-01

    The question on intraregional versus inter-regional variability in herbicide sensitivity for weed populations is of major importance, both in extrapolation of model parameters and in herbicide zonal approval procedures. We hypothesised that inter-regional variability in herbicide sensitivity for ...

  18. Agricultural herbicide transport in a first-order intermittent stream, Nebraska, USA

    Science.gov (United States)

    Vogel, J.R.; Linard, J.I.

    2011-01-01

    The behavior of herbicides in surface waters is a function of many variables, including scale of the watershed, physical and chemical properties of the herbicide, physical and chemical properties of the soil, rainfall intensity, and time of year. In this study, the transport of 6 herbicides and 12 herbicide degradates was examined during the 2004 growing season in an intermediate-scale agricultural watershed (146 ha) that is drained by a first-order intermittent stream, and the mass load for each herbicide in the stream was estimated. The herbicide load during the first week of storm events after application ranged from 17% of annual load for trifluralin to 84% of annual load for acetochlor. The maximum weekly herbicide load in the stream was generally within the first 3 weeks after application for those compounds that were applied within the watershed during 2004, and later for herbicides not applied within the watershed during 2004 but still detected in the stream. The apparent dominant mode of herbicide transport in the stream-determined by analysis amongst herbicide and conservative ion concentrations at different points in the hydrograph and in base flow samples-was either overland runoff or shallow subsurface flow, depending on the elapsed time after application and type of herbicide. The load as a percentage of use (LAPU) for the parent compounds in this study was similar to literature values for those compounds applied by the farmer within the watershed, but smaller for those herbicides that had rainfall as their only source within the watershed.

  19. Transcript markers of herbicide stress in Arabidopsis and their cross-species extrapolation to Brassica

    Science.gov (United States)

    Low concentrations and short environmental persistence times of some herbicides make it difficult to develop analytical methods to detect herbicide residues in plants or soils. In contrast, genomics may provide tools to identify herbicide exposure to plants in field settings. Usi...

  20. The role of herbicides for enhancing productivity and conserving land for biodiversity in North America

    Science.gov (United States)

    Robert G. Wagner; Michael Newton; Elizabeth C. Cole; James H. Miller; Barry D. Shiver

    2004-01-01

    Herbicide technology has evolved with forest management in North America over the past 60 years and has become an integral part of modern forestry practice. Forest managers have prescribed herbicides to increase reforestation success and long-term timber yields. Wildlife managers and others interested in conserving biodi- versity, however, have often viewed herbicide...

  1. Using a Hydrological Model to Determine Environmentally Safer Windows for Herbicide Application

    Science.gov (United States)

    J.L. Michael; M.C. Smith; W.G. Knisel; D.G. Neary; W.P. Fowler; D.J. Turton

    1996-01-01

    A modification of the GLEAMS model was used to determine application windows which would optimise efficacy and environmental safety for herbicide application to a forest site. Herbicide/soil partition coefficients were determined using soil samples collected from the study site for two herbicides (imazapyr, Koc=46, triclopyr ester, K

  2. Effect of herbicides on photosynthetic electron transport and on the growth of the alga Scenedesmus quadricauda

    Directory of Open Access Journals (Sweden)

    W. Hendrich

    2015-01-01

    Full Text Available The inhibitory effect of herbicides on the Hill reaction (with 2,6-dichloro-phenol-indophenol as acceptor and their influence on development of the alga Scenedesmus quadricauda was studied. The following herbicides were tested: 2,4-D, Gramoxone, Afalon, Kresamone, CIPC and Simazine. The results are discussed in terms of the mechanism of action of the investigated herbicides.

  3. 75 FR 17857 - Removal of Obsolete References to Herbicides Containing Dioxin

    Science.gov (United States)

    2010-04-08

    ... Herbicides Containing Dioxin AGENCY: Department of Veterans Affairs. ACTION: Final rule. SUMMARY: The... health effects of exposure to herbicides containing dioxin and radiation to remove the obsolete references to herbicides containing dioxin. This final rule reflects changes made by the Agent Orange Act of...

  4. Evaluation Effect of Adjuvant on Mesosulfuron+Iodosulfuron Herbicide Performance on Littleseed Canarygrass Control

    Directory of Open Access Journals (Sweden)

    M. kargar

    2016-02-01

    replications at 8 levels of adjuvants (0, 0.01, 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3 (% v/v. Moreover, the effects of surfactant and vegetable oil on the efficacy of mesosulfuron + iodosulfuron commercial mixture on littleseed canarygrass (Phalaris minor Retz. were investigated under greenhouse conditions in Agriculture Faculty of Ferdowsi University of Mashhad. Greenhouse study was conducted in 6 concentration levels of mesosulfuron-methyl+idiosulfuron (0, 5.62, 11.25, 22.5, 33.75, and 45 g ai ha-1. This herbicide was applied alone and with these adjuvants including: (i citogate (a nonionic surfactant, (ii castor oil and (iii rapeseed oil each one of them at two levels 0.1 and 0.2 %, the experiments were arranged in a completely randomize design with a factorial arrangement of treatments with four replications. Results and Discussion: When adjuvants alone were applied against littleseed canarygrass, none of them had not phytotoxic effect so that fresh weight and dry weight of plants did not decrease significantly as compared to the control. The results of lab experiment showed the lowest and highest surface tension belonged to Citogate and rapeseed oil, respectively. Also the results of greenhouse experiment indicated all adjuvant were able to increase the efficacy of mesosulfuron + iodosulfuron herbicide. Relatively potency (R of dry weight increased with usage of Citogate surfactant, castor and rapeseed oils to 1.4, 1.35 and 1.13 respectively. The Citogate surfactant leads to the greatest enhancement of herbicide efficacy. The foliar activity of the tested herbicide enhanced with increasing adjuvant concentration from 0.1 to 0.2 (% v/v. According to the accessible information, surfactants (nonionic Citogate are suitable for reduction surface tension. Previous studies showed that nonionic surfactant was too effective in decreasing surface tension of spray solution. Despite, it has been observed that vegetable-derived oils could not greatly decrease surface tension. For example

  5. Tropical forest recovery from logging: a 24 year silvicultural experiment from Central Africa.

    Science.gov (United States)

    Gourlet-Fleury, Sylvie; Mortier, Frédéric; Fayolle, Adeline; Baya, Fidèle; Ouédraogo, Dakis; Bénédet, Fabrice; Picard, Nicolas

    2013-01-01

    Large areas of African moist forests are being logged in the context of supposedly sustainable management plans. It remains however controversial whether harvesting a few trees per hectare can be maintained in the long term while preserving other forest services as well. We used a unique 24 year silvicultural experiment, encompassing 10 4 ha plots established in the Central African Republic, to assess the effect of disturbance linked to logging (two to nine trees ha⁻¹ greater than or equal to 80 cm DBH) and thinning (11-41 trees ha⁻¹ greater than or equal to 50 cm DBH) on the structure and dynamics of the forest. Before silvicultural treatments, above-ground biomass (AGB) and timber stock (i.e. the volume of commercial trees greater than or equal to 80 cm DBH) in the plots amounted 374.5 ± 58.2 Mg ha⁻¹ and 79.7 ± 45.9 m³ ha⁻¹, respectively. We found that (i) natural control forest was increasing in AGB (2.58 ± 1.73 Mg dry mass ha⁻¹ yr⁻¹) and decreasing in timber stock (-0.33 ± 1.57 m³ ha⁻¹ yr⁻¹); (ii) the AGB recovered very quickly after logging and thinning, at a rate proportional to the disturbance intensity (mean recovery after 24 years: 144%). Compared with controls, the gain almost doubled in the logged plots (4.82 ± 1.22 Mg ha⁻¹ yr⁻¹) and tripled in the logged + thinned plots (8.03 ± 1.41 Mg ha⁻¹ yr⁻¹); (iii) the timber stock recovered slowly (mean recovery after 24 years: 41%), at a rate of 0.75 ± 0.51 m³ ha⁻¹ yr⁻¹ in the logged plots, and 0.81 ± 0.74 m³ ha⁻¹ yr⁻¹ in the logged + thinned plots. Although thinning significantly increased the gain in biomass, it had no effect on the gain in timber stock. However, thinning did foster the growth and survival of small- and medium-sized timber trees and should have a positive effect over the next felling cycle.

  6. Decision Support System for Optimized Herbicide Dose in Spring Barley

    DEFF Research Database (Denmark)

    Sønderskov, Mette; Kudsk, Per; Mathiassen, Solvejg K

    2014-01-01

    Crop Protection Online (CPO) is a decision support system, which integrates decision algorithms quantifying the requirement for weed control and a herbicide dose model. CPO was designed to be used by advisors and farmers to optimize the choice of herbicide and dose. The recommendations from CPO...... as the Treatment Frequency Index (TFI)) compared to a high level of required weed control. The observations indicated that the current level of weed control required is robust for a range of weed scenarios. Weed plant numbers 3 wk after spraying indicated that the growth of the weed species were inhibited...

  7. Response of soil microbiota to selected herbicide treatments.

    Science.gov (United States)

    Roslycky, E B

    1977-04-01

    Recommended concentrations of paraquat alone and its combination with each of linuron, diuron, atrazine, simazine, and simazine plus diuron exerted little effect on total populations of bacteria, actinomycetes, and fungi in Fox sandy loam under laboratory and simulated field conditions in 66 and 77 days, respectively. Respiration of the total microbiota in soil suspension was afeected by the combinations as well as individual herbicides in various concentrations. Yet, the inhibition of the O2 uptake by any of these herbicides, including some extreme concentrations, was not permanent, indicating adaptation, or suppression of specific organisms. Only linuron in concentrations up to 20 microng/ml stimulated respiration of the soil.

  8. Residual herbicide study on selected Hanford Site roadsides

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.L.; Kemp, C.J.; Sackschewsky, M.R.

    1993-08-01

    Westinghouse Hanford Company routinely treats roadsides with herbicides to control undesirable plant growth. An experiment was conducted to test perennial grass germination in soils adjacent to roadways of the Hanford Site. The primary variable was the distance from the roadside. A simple germination test was executed in a controlled-environment chamber to determine the residual effects of these applications. As expected, the greatest herbicide activity was found directly adjacent to the roadway, approximately 0 to 20 ft (0 to 6.3 m) from the roadway.

  9. Silvicultural study of Sapindus saponaria L. (Jaboncillo), as foundation for its silvo-industrial use

    International Nuclear Information System (INIS)

    Sanchez Buitrago Jose Alejandro; Silva Herrera Luis Jairo

    2008-01-01

    A silvicultural study of Sapindus saponaria L. was carried out including sexual and asexual propagation tests, provenance test, phenological surveillance, and quantification of fruits production. The sexual propagation test was carried out using five source localities, being the best those seeds from Santa Cruz (Bolivia). The asexual propagation test had a negative result because the cuttings did not root, making it necessary to try different methods for asexual reproduction. The seedlings obtained from the sexual propagation test were used to establish a plantation in Otanche (Boyaca) in order to evaluate growth and mortality. After five months, the highest growth was found in those seeds from Santa Cruz (Bolivia). However, this result was not significant from a statistical point of view. The best results regarding mortality came from the seeds from Viota (Cundinamarca), while those from Palmira (Valle) showed the highest levels of mortality. Fruit production was measured and related to the DBH and the canopy wide. Flowering and fruiting periods as well as the harvest season of the fruits in Viota (Cundinamarca) were established. Some methods for fruit harvesting and planting of the species are proposed.

  10. COMPORTAMENTO DA ERVA-MATE (Ilex paraguariensis St. Hil. EM CONSÓRCIO SILVICULTURAL

    Directory of Open Access Journals (Sweden)

    Odilson dos Santos Oliveira

    1995-12-01

    Full Text Available O presente trabalho foi realizado no Campus da Universidade Federal de Santa Maria e teve por objetivo determinar o comportamento da erva-mate (Ilex paraguariensis St. Hil. cultivada em sistemas de consórcio silvicultural. A metodologia adotada constituiu-se da implantação de três tratamentos, cortes aos sistemas de consórcio erva-mate x Pinus sp., erva-mate x bracatinga e erva-mate x capoeira. A análise dos resultados levou às setes conclusões: os melhores resultados de desenvolvimento de erva-mate são obdos nos consórcios com bracatinga e Pinus sp. e, o pior, na capoeira; as vazes extremas dos fatores do meio são amenizadas pelas outras espécies do consórcio; índices elevados de luminosidade não promovem maior produção de matéria seca, nem os índices muito baixos.

  11. Comportamento da erva-mate (Ilex paraguariensis St. Hil. em consórcio silvicultural.

    Directory of Open Access Journals (Sweden)

    Luisilvio Pes

    2009-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 O presente trabalho foi realizado no Campus da Universidade Federal de Santa Maria e teve por objetivo determinar o comportamento da erva-mate (Ilex paraguariensis St. Hil. cultivada em sistema de consórcio silvicultural. A metodologia adotada constituiu-se da implantação de três tratamentos, correspondentes aos sistemas de consórcio erva-mata x Pinus sp., erva-mate x bracatinga e erva-mate x capoeira. A análise dos resultados levou às seguintes conclusões: os melhores resultados de desenvolvimento da erva-mate são obtidos nos consórcios com bracatinga e Pins sp. e, o pior, na caopeira; as variações externas dos fatores do meio são amenizadas pelas outras espécies do consórcio; índices elevados de luminosidade não promovem maior produção de matéria seca, nem os índices muito baixos.

  12. Proceedings. Larch genetics and breeding. Research findings and ecological-silvicultural demands

    Energy Technology Data Exchange (ETDEWEB)

    Martinsson, Owe [ed.

    1995-12-31

    The genus Larix Mill. (larch) represents a great part of the boreal and alpine forests. Larch species are the most common conifers in Siberia and they have an important role in European and North American forest ecosystems and forest economies. The value of these group of species are expected to increase in the future. There are at least three different reasons for that assumption: 1. Larch has highly appreciated technical wood properties., 2. Intensive cutting during the past three centuries has made larch a threatened group of species in some parts of the world., 3. Increasing access to Siberia will make forestry and forest harvest of larch an important part of the forest economy and ecology. In August 1995 a group of forest scientists gathered under the framework of IUFRO working group S2.02-07 in southern Sweden for exchange of experience in the fields of breeding and silviculture of larch. This proceedings was compiled on the basis of the presentations of this working group. Separate abstracts have been prepared for 12 of the 17 papers

  13. Proceedings. Larch genetics and breeding. Research findings and ecological-silvicultural demands

    Energy Technology Data Exchange (ETDEWEB)

    Martinsson, Owe [ed.

    1996-12-31

    The genus Larix Mill. (larch) represents a great part of the boreal and alpine forests. Larch species are the most common conifers in Siberia and they have an important role in European and North American forest ecosystems and forest economies. The value of these group of species are expected to increase in the future. There are at least three different reasons for that assumption: 1. Larch has highly appreciated technical wood properties., 2. Intensive cutting during the past three centuries has made larch a threatened group of species in some parts of the world., 3. Increasing access to Siberia will make forestry and forest harvest of larch an important part of the forest economy and ecology. In August 1995 a group of forest scientists gathered under the framework of IUFRO working group S2.02-07 in southern Sweden for exchange of experience in the fields of breeding and silviculture of larch. This proceedings was compiled on the basis of the presentations of this working group. Separate abstracts have been prepared for 12 of the 17 papers

  14. Effects of herbicides on Behr's metalmark butterfly, a surrogate species for the endangered butterfly, Lange's metalmark

    International Nuclear Information System (INIS)

    Stark, John D.; Chen Xuedong; Johnson, Catherine S.

    2012-01-01

    Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24–36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species. - Highlights: ► We evaluated the effects of three herbicides on the butterfly, Behr's metalmark. ► These herbicides are used to control invasive weeds in butterfly habitat. ► The herbicides reduced adult butterfly emergence. - Herbicides are used to remove invasive weeds from butterfly habitat. Certain herbicides may be having a negative effect on butterflies.

  15. Herbicide Safeners Decrease Sensitivity to Herbicides Inhibiting Acetolactate-Synthase and Likely Activate Non-Target-Site-Based Resistance Pathways in the Major Grass Weed Lolium sp. (Rye-Grass)

    OpenAIRE

    Duhoux, Arnaud; Pernin, Fanny; Desserre, Diane; D?lye, Christophe

    2017-01-01

    Herbicides are currently pivotal to control weeds and sustain food security. Herbicides must efficiently kill weeds while being as harmless as possible for crops, even crops taxonomically close to weeds. To increase their selectivity toward crops, some herbicides are sprayed in association with safeners that are bioactive compounds exacerbating herbicide-degrading pathways reputedly specifically in crops. However, exacerbated herbicide metabolism is also a key mechanism underlying evolved non...

  16. Analysis of the metabolic resistance of Ambrosia artemisiifolia L. to the herbicides action

    Directory of Open Access Journals (Sweden)

    Y.V. Lykholat

    2018-03-01

    Full Text Available Action and aftereffect of the herbicides with different modes of action on the common ragweed population were studied in the field and greenhouse experiments. Activation of glutathione S-transferase has been detected due to the action of herbicides Harness and Guardian-Tetra both in leaves of juvenile plants and in ragweed seeds, which indicates intensive detoxification of herbicides during weed ontogenesis. Electrophoretic analysis showed that four components in protein spectra of ragweed seeds were inherent in seeds collected from herbicides-treated plants only. Using the method of isoelectric focusing, three specific peroxidase isoforms associated with a certain mechanism of herbicidal action on the parent plants were found in leaves of the next generation plants. The results confirm the intensive adaptive changes in A. artemisiifolia population that could provide the metabolic resistance to different modes of the herbicide action. Keywords: Common ragweed, Metabolic resistance, Herbicide, Mode of action, Isoforms, Isoelectric

  17. Fourier transform of delayed fluorescence as an indicator of herbicide concentration.

    Science.gov (United States)

    Guo, Ya; Tan, Jinglu

    2014-12-21

    It is well known that delayed fluorescence (DF) from Photosystem II (PSII) of plant leaves can be potentially used to sense herbicide pollution and evaluate the effect of herbicides on plant leaves. The research of using DF as a measure of herbicides in the literature was mainly conducted in time domain and qualitative correlation was often obtained. Fourier transform is often used to analyze signals. Viewing DF signal in frequency domain through Fourier transform may allow separation of signal components and provide a quantitative method for sensing herbicides. However, there is a lack of an attempt to use Fourier transform of DF as an indicator of herbicide. In this work, the relationship between the Fourier transform of DF and herbicide concentration was theoretically modelled and analyzed, which immediately yielded a quantitative method to measure herbicide concentration in frequency domain. Experiments were performed to validate the developed method. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. How to test herbicides at forest tree nurseries.

    Science.gov (United States)

    Roger E. Sandquist; Peyton W. Owston; Stephen E. McDonald

    1981-01-01

    Procedures developed in a cooperative westwide study of weed control in forest tree nurseries are described in a form modified for use by nursery managers. The proven, properly designed test and evaluation methods can be used to generate data needed for evaluation and registration of herbicides.

  19. Epigenetic regulation – contribution to herbicide resistance in weeds?

    Czech Academy of Sciences Publication Activity Database

    Markus, C.; Pečinka, Aleš; Karan, R.; Barney, J. N.; Merotto, A.

    2018-01-01

    Roč. 74, č. 2 (2018), s. 275-281 ISSN 1526-498X Institutional support: RVO:61389030 Keywords : DNA methylation * epigenetic s * gene expression * gene regulation * herbicide detoxification * plant stress response Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 3.253, year: 2016

  20. Treating downy brome with herbicide and seeding with native shrubs

    Science.gov (United States)

    Suzanne Owen; Carolyn Sieg

    2011-01-01

    Downy brome or cheatgrass (Bromus tectorum L.) is one of the most invasive and widespread exotic plants in North America. Downy brome can reduce soil nutrient availability, alter native plant community composition, and increase fire frequencies. The effectiveness of Plateau® imazapic herbicide in reducing downy brome cover has been variable, and there is uncertainty...

  1. Selective isolation and screening of fungi with herbicidal potential ...

    African Journals Online (AJOL)

    The respective fungal isolates were cultivated in modified Fries media under standard condition. The mycelia and the filtrate were extracted with ethyl acetate and the concentrated extract was evaluated for the herbicidal activity adopting leaf necrosis assay. Among the different isolates, extract prepared from A. alternata and ...

  2. Biological Efficacy of Herbicides for Weed Control in Noncropped Areas

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2009-01-01

    Full Text Available An increasing problem facing agricultural producers is the invasion of weeds, perennial in particular, so that implementation of industrial technologies is impossible without their highly efficient and rational control. For the purpose of studying efficient herbicides for weed control in noncropped areas (stubbles, a biological study of five total systemic herbicides was conducted in areas under natural weed infestation and pressure from othersurrounding weeds at the Institute of Forage Crops in Pleven in 2005-2007. The trials were carried out in field conditions using the block method with plot size of 20 m². Treatment was conducted at the predominant stage of budding of perennial dicotyledonous weeds and earing of monocotyledonous weeds. Herbicidal efficacy was recorded on the EWRS 9-score scale (0-100% killed weeds = score 9-1. It was found that treatment of noncropped areas (stubbles with the total systemic herbicides Touchdown System 4 (360 g/l glyphosate; Cosmic (360 g/l glyphosate; Roundup Plus (441 g/l glyphosate potassium salt; Leon 36 SL (360 g/l glyphosate and Glyphos Super 45 SL (450 g/l glyphosate was highly efficient, so that it was a successful element of a strategy for controlling weeds of different biological groups, and was especially effective against perennial weeds.

  3. Synthesis of a tritiated herbicide with high activity: methyl thifensulfuron

    International Nuclear Information System (INIS)

    Bastide, J.; Ortega, F.

    1993-01-01

    In order to study the binding on acetolactate synthase, a tritiated herbicide sulfonylurea (thifensulfuron methyl) of high specific activity was synthesized. By use of C 3 H 3 I for esterification of an acid group, a rapid incorporation of tritium into this compound may be achieved. (Author)

  4. Efficacy of selected herbicide formulations on sugarcane field weeds ...

    African Journals Online (AJOL)

    In continuation for the search of appropriate weed control strategy for sugarcane field weeds at the Unilorin Sugar Research Institute (USRI), Ilorin located at 8o 030' N; 4o 32' E , Nigeria. Field trials were laid out in a randomized complete block design during 2012 and 2013 growing seasons to evaluate four herbicide ...

  5. Effect of atrazine (Herbicide) on blood parameters of common carp ...

    African Journals Online (AJOL)

    EJIRO

    could be used as an important tool for the assessment of pathological conditions of fish. ... agricultural or industrial areas have high probability of ... The use of herbicides to control aquatic weeds has ... Five hundred fish were stocked in a large cement tank (4 m × 6 m × 3 m) ..... Ecological risk assessment of atrazine in North.

  6. Ecological risks of pesticides in freshwater ecosystems; Part 1: herbicides

    NARCIS (Netherlands)

    Brock, T.C.M.; Lahr, J.; Brink, van den P.J.

    2000-01-01

    A literature review of freshwater model ecosystem studies with herbicides was performed to assess the NOEC[sub]ecosystem for individual compounds, to compare these threshold levels with water quality standards, and to evaluate the ecological consequences of exceeding these standards. Studies were

  7. Herbicide Trials on European Larch in Northern Wisconsin

    Science.gov (United States)

    Daniel A. Netzer

    1984-01-01

    Herbicides of 17 different rates and formulations were oversprayed on newly planted 1-0 European larch seedlings in teh spring of 1983 at the recommended rates. Simazine, bifenox, oxyfluorfen, promamide, and oryzalin provided adequate weed control with no damage to the larch. Height growth at the end of the first growing season was one-and-a-half times greater in the...

  8. Chromatographic determination of herbicide residues in various matrices

    Czech Academy of Sciences Publication Activity Database

    Cserháti, T.; Forgács, E.; Deyl, Zdeněk; Mikšík, Ivan; Eckhardt, Adam

    2004-01-01

    Roč. 18, č. 6 (2004), s. 350-359 ISSN 0269-3879 Institutional research plan: CEZ:AV0Z5011922 Keywords : herbicide residues * extraction methods * HPLC Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.069, year: 2004

  9. Vinegar as a broadcast herbicide for spring-transplanted onions

    Science.gov (United States)

    The weed control challenges for onion production are formidable; however, these challenges are even greater for those considering organic crop production. Organic onion producers need additional organic herbicides that can effectively provide post-emergent weed control. Field research was conducted...

  10. Herbicide-resistant weed management: focus on glyphosate.

    Science.gov (United States)

    Beckie, Hugh J

    2011-09-01

    This review focuses on proactive and reactive management of glyphosate-resistant (GR) weeds. Glyphosate resistance in weeds has evolved under recurrent glyphosate usage, with little or no diversity in weed management practices. The main herbicide strategy for proactively or reactively managing GR weeds is to supplement glyphosate with herbicides of alternative modes of action and with soil-residual activity. These herbicides can be applied in sequences or mixtures. Proactive or reactive GR weed management can be aided by crop cultivars with alternative single or stacked herbicide-resistance traits, which will become increasingly available to growers in the future. Many growers with GR weeds continue to use glyphosate because of its economical broad-spectrum weed control. Government farm policies, pesticide regulatory policies and industry actions should encourage growers to adopt a more proactive approach to GR weed management by providing the best information and training on management practices, information on the benefits of proactive management and voluntary incentives, as appropriate. Results from recent surveys in the United States indicate that such a change in grower attitudes may be occurring because of enhanced awareness of the benefits of proactive management and the relative cost of the reactive management of GR weeds. Copyright © 2011 Society of Chemical Industry.

  11. Hazard and risk of herbicides for marine microalgae

    NARCIS (Netherlands)

    Sjollema, S.B.; Martínez-García, G.; van der Geest, H.G.; Kraak, M.H.S.; Booij, P.; Vethaak, A.D.; Admiraal, W.

    2014-01-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects

  12. Cytogenetic studies of three triazine herbicides. I. In vitro studies

    Science.gov (United States)

    Atrazine, simazine, and cyanazine are widely used pre-emergence and post-emergence triazine herbicides that have made their way into the potable water supply of many agricultural communities. Because of this and the prevalence of contradictory cytogenetic studies in the literatur...

  13. Effect of sugarcane cropping systems on herbicide losses in surface runoff.

    Science.gov (United States)

    Nachimuthu, Gunasekhar; Halpin, Neil V; Bell, Michael J

    2016-07-01

    Herbicide runoff from cropping fields has been identified as a threat to the Great Barrier Reef ecosystem. A field investigation was carried out to monitor the changes in runoff water quality resulting from four different sugarcane cropping systems that included different herbicides and contrasting tillage and trash management practices. These include (i) Conventional - Tillage (beds and inter-rows) with residual herbicides used; (ii) Improved - only the beds were tilled (zonal) with reduced residual herbicides used; (iii) Aspirational - minimum tillage (one pass of a single tine ripper before planting) with trash mulch, no residual herbicides and a legume intercrop after cane establishment; and (iv) New Farming System (NFS) - minimum tillage as in Aspirational practice with a grain legume rotation and a combination of residual and knockdown herbicides. Results suggest soil and trash management had a larger effect on the herbicide losses in runoff than the physico-chemical properties of herbicides. Improved practices with 30% lower atrazine application rates than used in conventional systems produced reduced runoff volumes by 40% and atrazine loss by 62%. There were a 2-fold variation in atrazine and >10-fold variation in metribuzin loads in runoff water between reduced tillage systems differing in soil disturbance and surface residue cover from the previous rotation crops, despite the same herbicide application rates. The elevated risk of offsite losses from herbicides was illustrated by the high concentrations of diuron (14μgL(-1)) recorded in runoff that occurred >2.5months after herbicide application in a 1(st) ratoon crop. A cropping system employing less persistent non-selective herbicides and an inter-row soybean mulch resulted in no residual herbicide contamination in runoff water, but recorded 12.3% lower yield compared to Conventional practice. These findings reveal a trade-off between achieving good water quality with minimal herbicide contamination and

  14. Cross-resistance to herbicides in annual ryegrass (lolium rigidum)

    International Nuclear Information System (INIS)

    Christopher, J.T.; Powles, S.B.; Liljegren, D.R.; Holtum, J.A.M.

    1991-01-01

    Lolium rigidum Gaud. biotype SLR31 is resistant to the herbicide diclofop-methyl and cross-resistant to several sulfonylurea herbicides. Wheat and the cross-resistant ryegrass exhibit similar patterns of resistance to sulfonylurea herbicides, suggesting that the mechanism of resistance may be similar. Cross-resistant ryegrass is also resistant to the wheat-selective imidazolinone herbicide imazamethabenz. The cross-resistant biotype SLR31 metabolized [phenyl-U- 14 C]chlorsulfuron at a faster rate than a biotype which is susceptible to both diclofop-methyl and chlorsulfuron. A third biotype which is resistant to diclofop-methyl but not to chlorsulfuron metabolized chlorsulfuron at the same rate as the susceptible biotype. The increased metabolism of chlorsulfuron observed in the cross-resistant biotype is, therefore, correlated with the patterns of resistance observed in these L. rigidum biotypes. During high performance liquid chromatography analysis the major metabolite of chlorsulfuron in both susceptible and cross-resistant ryegrass coeluted with the major metabolite produced in wheat. The major product is clearly different from the major product in the tolerant dicot species, flax (Linium usitatissimum). The elution pattern of metabolites of chlorsulfuron was the same for both the susceptible and cross-resistant ryegrass but the cross-resistant ryegrass metabolized chlorsulfuron more rapidly. The investigation of the dose response to sulfonylurea herbicides at the whole plant level and the study of the metabolism of chlorsulfuron provide two independent sets of data which both suggest that the resistance to chlorsulfuron in cross-resistant ryegrass biotype SLR31 involves a wheat-like detoxification system

  15. Effect of Mycorrhizal Fungi and Trifluralin Herbicide on Emergence, Growth and Root Colonization of Clover (Trifolium repens L.

    Directory of Open Access Journals (Sweden)

    Hassan Shahgholi

    2016-09-01

    Full Text Available Introduction: Herbicides, despite of their control of weeds, have the potential to affect sensitive crops in rotation and also beneficial non-targeted soil microbes including vesicular arbuscular mycorrhiza (VAM fungi (6. AM fungi can increase the growth of crops through increasing uptake of phosphorus and insoluble micronutrients, and indirectly by improving soil quality parameters (30. However, several authors have reported different effects of herbicides on VAM symbiosis, which ranges from no adverse effects to slightly or highly toxic effects (6. Pesticides have also been reported to stimulate colonization of plant roots by AM fungi (27. Therefore, the objective of this study was to investigate the interaction effects of mycorrhizal fungi and Trifluralin herbicide on the growth and root colonization of clover. Materials and Methods: A factorial experiment was arranged in randomized complete block design with three replicates at the College of Agricultural, University of Shahrood during 2012. Treatments were included three levels of mycorrhiza inoculation, M1: non mycorrhiza (control, M2: Glommus mosseae and M3: Glommus intraradices and herbicide treatments were included four levels of Trifluralin(T1: 0, T2: 1000, T3: 1500 and T4: 2000 ml ha-1. In mycorrhizal treatments, 20 g inoculums were thoroughly mixed with soil. Seeds of clover (Trifolium repens L. were sown in the pots maintained near the field in order to provide normal environmental conditions. Seedlings were thinned to two plants per pot at three leaf stages. At the time of harvesting, the emergence and growth characteristics of clover and root colonization was also registered. Statistical analyses of data were performed with statistical software MSTATC. Significant differences between means refer to the probability level of 0.05 calculated by LSD test. Results and Discussion: The results showed that emergence, uniformity (EU values decreased and time to 10% (D10 and 90% (D90 of

  16. Influence of herbicide structure, clay acidity, and humic acid coating on acetanilide herbicide adsorption on homoionic clays.

    Science.gov (United States)

    Liu, Weiping; Gan, Jianying; Yates, Scott R

    2002-07-03

    Adsorption of chloroacetanilide herbicides on homoionic montmorillonite was studied by coupling batch equilibration and FT-IR analysis. Adsorption decreased in the order metolachlor > acetochlor > alachlor > propachlor on Ca(2+)- or Mg(2+)-saturated clays and in the order metolachlor > alachlor > acetachlor > propachlor on Al(3+)- or Fe(3+)-saturated clays. FT-IR spectra showed that the carbonyl group of the herbicide molecule was involved in bonding. For the same herbicide, adsorption of alachlor, acetachlor, and metolachlor on clay followed the order Ca(2+) approximately Mg(2+) < Al(3+) < or = Fe(3+), which coincided with the increasing acidity of homoionic clays. Adsorption of propachlor, however, showed an opposite dependence, suggesting a different governing interaction. In clay and humic acid mixtures, herbicide adsorption was less than that expected from independent additive adsorption by the individual constituents, and the deviation was dependent on the clay-to-humic acid ratio, with the greatest deviation consistently occurring at a 60:40 clay-to-humic acid ratio.

  17. Woodland salamander responses to a shelterwood harvest-prescribed burn silvicultural treatment within Appalachian mixed-oak forests

    Science.gov (United States)

    Ford, W. Mark; Mahoney, Kathleen R.; Russell, Kevin R.; Rodrigue, Jane L.; Riddle, Jason D.; Schuler, Thomas M.; Adams, Mary Beth

    2015-01-01

    Forest management practices that mimic natural canopy disturbances, including prescribed fire and timber harvests, may reduce competition and facilitate establishment of favorable vegetative species within various ecosystems. Fire suppression in the central Appalachian region for almost a century has contributed to a transition from oak-dominated to more mesophytic, fire-intolerant forest communities. Prescribed fire coupled with timber removal is currently implemented to aid in oak regeneration and establishment but responses of woodland salamanders to this complex silvicultural system is poorly documented. The purpose of our research was to determine how woodland salamanders respond to shelterwood harvests following successive burns in a central Appalachian mixed-oak forest. Woodland salamanders were surveyed using coverboard arrays in May, July, and August–September 2011 and 2012. Surveys were conducted within fenced shelterwood-burn (prescribed fires, shelterwood harvest, and fencing to prevent white-tailed deer [Odocoileus virginianus] herbivory), shelterwood-burn (prescribed fires and shelterwood harvest), and control plots. Relative abundance was modeled in relation to habitat variables measured within treatments for mountain dusky salamanders (Desmognathus ochrophaeus), slimy salamanders (Plethodon glutinosus), and eastern red-backed salamanders (Plethodon cinereus). Mountain dusky salamander relative abundance was positively associated with canopy cover and there were significantly more individuals within controls than either shelterwood-burn or fenced shelterwood-burn treatments. Conversely, habitat variables associated with slimy salamanders and eastern red-backed salamanders did not differ among treatments. Salamander age-class structure within controls did not differ from shelterwood-burn or fenced shelterwood-burn treatments for any species. Overall, the woodland salamander assemblage remained relatively intact throughout the shelterwoodburn

  18. Silvicultural evaluations on maritime pine (Pinus pinaster Aiton plantations in Istanbul

    Directory of Open Access Journals (Sweden)

    Safa Balekoğlu

    2016-07-01

    Full Text Available Industrial plantations have substantially reduced the pressure on natural forests. There are approximately 80.000 hectares of industrial plantations, established with fast growing coniferous species, 77.000 hectares of which are maritime pine plantations in Turkey. Furthermore, approximately 16.000 hectares of maritime pine plantations, which amount to about 20 percent of all maritime pine plantations in Turkey, occur in Istanbul. The aim of this study is to determine the growth pattern of maritime pine plantations located in Anatolian and European Istanbul: Kanlıca, Beykoz, Sultanbeyli and Şile-Sahilköy; and Bahçeköy-Bentler, Arnavutköy and Terkos-Durusu respectively. Specifically, the study examined individual trees within the above-mentioned sites to determine the first thinning age of the plantations. In addition, some specific silvicultural suggestions were offered for the plantations. The minimum and maximum recorded values for the trees’ age, DBH, height and stem volume were found in the range of 22-50 years, 26.6-46.8 cm, 14.0-23.0 m and 0.5150-1.8560 m3 respectively. In order to take advantage of the fast growing attributes of maritime pine which was found to grow fast within first 10 years, the first thinning should commence at the age of 11-12 years; thereafter, the second thinning should commence at the age of 18-20 years; finally, the final cut should be performed when the plantation is approximately 30 years of age. If rotation age is considered 40 years, the third thinning should commence at the age of 30 years.

  19. Effects of basal area on survival and growth of longleaf pine when practicing selection silviculture

    International Nuclear Information System (INIS)

    Kara, F.; Loewenstein, E.F.; Brockway, D.G.

    2017-01-01

    Aim of study: Uneven-aged (UEA) management systems can achieve multiple-use objectives, however, use of UEA techniques to manage longleaf pine (Pinus palustris Mill.) forests are still open to question, because of the species’ intolerance of competition. It was our aim to examine the influence of different levels (9.2, 13.8 and 18.4 m2 ha-1) of residual basal area (RBA) on longleaf pine seedling survival and growth following three growing seasons. Area of study: This study was conducted at the Escambia Experimental Forest, located on the Southern Coastal Plain of Alabama, in the southeastern United States. Material and Methods: Selection silviculture was implemented with the Proportional-Basal Area (Pro-B) method. Prescribed burning was conducted before seed dispersal and in the second year after germination. Photosynthetically active radiation (PAR) was measured under the canopy in the study plots. Survival and growth of longleaf pine seedlings were observed for three growing seasons. Main results: An inverse relationship was found between the number of germinants and RBA, but the mortality of germinants and planted seedlings was not affected by RBA. At age three, an inverse relationship was observed between root-collar diameter (RCD) growth of the germinants and RBA, but RCD growth of planted seedlings was not affected by RBA. Most of the study plots contained more than the projected number of seedlings needed to sustain the target diameter structure. Research highlights: Long-term continuous monitoring of seedling development and recruitment into canopy is required to determine the efficacy of UEA management. However, current data suggest that UEA methods may be a viable alternative to the use of even-aged (EA) methods in longleaf ecosystems.

  20. Effects of basal area on survival and growth of longleaf pine when practicing selection silviculture

    Energy Technology Data Exchange (ETDEWEB)

    Kara, F.; Loewenstein, E.F.; Brockway, D.G.

    2017-11-01

    Aim of study: Uneven-aged (UEA) management systems can achieve multiple-use objectives, however, use of UEA techniques to manage longleaf pine (Pinus palustris Mill.) forests are still open to question, because of the species’ intolerance of competition. It was our aim to examine the influence of different levels (9.2, 13.8 and 18.4 m2 ha-1) of residual basal area (RBA) on longleaf pine seedling survival and growth following three growing seasons. Area of study: This study was conducted at the Escambia Experimental Forest, located on the Southern Coastal Plain of Alabama, in the southeastern United States. Material and Methods: Selection silviculture was implemented with the Proportional-Basal Area (Pro-B) method. Prescribed burning was conducted before seed dispersal and in the second year after germination. Photosynthetically active radiation (PAR) was measured under the canopy in the study plots. Survival and growth of longleaf pine seedlings were observed for three growing seasons. Main results: An inverse relationship was found between the number of germinants and RBA, but the mortality of germinants and planted seedlings was not affected by RBA. At age three, an inverse relationship was observed between root-collar diameter (RCD) growth of the germinants and RBA, but RCD growth of planted seedlings was not affected by RBA. Most of the study plots contained more than the projected number of seedlings needed to sustain the target diameter structure. Research highlights: Long-term continuous monitoring of seedling development and recruitment into canopy is required to determine the efficacy of UEA management. However, current data suggest that UEA methods may be a viable alternative to the use of even-aged (EA) methods in longleaf ecosystems.

  1. A comparison of the herbicide tolerances of rare and common plants in an agricultural landscape.

    Science.gov (United States)

    Egan, J Franklin; Graham, Ian M; Mortensen, David A

    2014-03-01

    Declining plant biodiversity in agroecosystems has often been attributed to escalating use of chemical herbicides, but other changes in farming systems, including the clearing of seminatural habitat fragments, confound the influence of herbicides. The present study introduces a new approach to evaluate the impacts of herbicide pollution on plant communities at landscape or regional scales. If herbicides are in fact a key factor shaping agricultural plant diversity, one would expect to see the signal of past herbicide impacts in the current plant community composition of an intensively farmed region, with common, successful species more tolerant to widely used herbicides than rare or declining species. Data from an extensive field survey of plant diversity in Lancaster County, Pennsylvania, USA, were compared with herbicide bioassay experiments in a greenhouse to test the hypothesis that common species possess higher herbicide tolerances than rare species. Five congeneric pairs of rare and common species were treated with 3 commonly used herbicide modes of action in bioassay experiments, and few significant differences were found in the tolerances of rare species relative to common species. These preliminary results suggest that other factors beyond herbicide exposure may be more important in shaping the distribution and abundance of plant species diversity across an agricultural landscape. © 2014 SETAC.

  2. Transformation of the herbicide [14C]glufosinate in soils

    International Nuclear Information System (INIS)

    Smith, A.E.

    1989-01-01

    The degradation of 2 μg/g [ 14 C]glufosinate (DL-homoalan-4-ylmethylphosphinic acid) was studied in clay, clay loam, and sandy loam soils at 85% field capacity and at 20 degree C. Over a 4-week period the soils were extracted and analyzed for transformation products by radiochemical and gas chromatographic techniques. In all soils there was release of [ 14 C]carbon dioxide and formation of [ 14 C]-3-(hydroxymethylphosphinyl)propionic acid (MPPA) as major degradation products. Within 21 days, about 55% of the applied 14 C herbicide had been transformed to MPPA in the sandy loam and 19% to [ 14 C]carbon dioxide. After 28 days, approximately 45% of the 14 C herbicide had been transformed to MPPA in the clay and clay loam and 10% released as [ 14 C]carbon dioxide. At all samplings, other 14 C transformation products appeared to be insignificant

  3. Herbicide contamination in carrot grown in punjab, pakistan

    International Nuclear Information System (INIS)

    Amjad, M.; Ahmad, T.; Jahangir, M.M.

    2013-01-01

    Food safety and security is a burning issue of the time whereas vegetable production is an important aspect of agriculture. Use of herbicides for vegetable production is very common in Pakistan but no proper procedure has been planned to keep optimal level of doses of herbicide under permissible limit. To estimate the pesticide residues, samples from the leading carrot producing sites were collected along with the samples from the market. The samples were processed using standard procedures and qualitative and quantitative analysis was performed by Gas Chromatography-Mass Spectrometry (GC-MS). It was concluded that all the samples were contaminated with S-metolachlor in the range of 0.45 to 0.73 mg kg-1 which was above the permissible limit (0.40 mg kg-1). (author)

  4. Are post-fire silvicultural treatments a useful tool to fight the climate change threat in terms of plant diversity?

    Science.gov (United States)

    Hedo de Santiago, Javier; Esteban Lucasr Borja, Manuel; de las Heras, Jorge

    2016-04-01

    Adaptative forest management demands a huge scientific knowledge about post-fire vegetation dynamics, taking into account the current context of global change. We hypothesized that management practices should be carry out taking into account the climate change effect, to obtain better results in the biodiversity maintenance across time. All of this with respect to diversity and species composition of the post-fire naturally regenerated Aleppo pine forests understory. The study was carried out in two post-fire naturally regenerated Aleppo pine forests in the Southeastern of the Iberian Peninsula, under contrasting climatic conditions: Yeste (Albacete) shows a dry climate and Calasparra (Murcia) shows a semiarid climate. Thinning as post-fire silvicultural treatment was carried out five years after the wildfire event, in the year 1999. An experiment of artificial drought was designed to evacuate 15% of the natural rainfall in both sites, Yeste and Calasparra, to simulate climate change. Taking into account all the variables (site, silvicultural treatment and artificial drought), alpha diversity indices including species richness, Shannon and Simpson diversity indices, and plant cover, were analyzed as a measure of vegetation abundance. The results showed that plant species were affected by thinning, whereas induced drought affected total cover and species, with lower values at Yeste. Significant site variation was also observed in soil properties, species richness and total plant cover, conversely to the plant species diversity indices. We conclude that the plant community shows different responses to a simulated environment of climate change depending on the experimental site.

  5. Herbicide spring treatments for the control of brome grasses (Bromus spp. in winter cereals

    Directory of Open Access Journals (Sweden)

    Gehring, Klaus

    2014-02-01

    Full Text Available The efficacy of different ALS-inhibiting herbicides for the control of brome species (Bromus spp. was tested in three field trials in the year 2010 – 2012 in the region of North-West-Bavaria Franken. As a result of the trials the standard herbicide Attribut (Propoxycarbazone was confirmed for the control of brome. In case of infestation with brome and black grass the herbicide Broadway (Pyroxsulam offers a certain control of both problematic grass weeds. This illustrates the high dependency of sufficient brome control in winter cereals on the effectiveness of specific ALS-Inhibitor herbicides. Because of the high risk of herbicide resistance to ACCaseand ALS-inhibiting herbicides in brome, integrated weed management is essential for the sustainable control of brome in winter cereals, respectively winter wheat.

  6. Glyphosate herbicide affects belowground interactions between earthworms and symbiotic mycorrhizal fungi in a model ecosystem

    Science.gov (United States)

    Zaller, Johann G.; Heigl, Florian; Ruess, Liliane; Grabmaier, Andrea

    2014-01-01

    Herbicides containing glyphosate are widely used in agriculture and private gardens, however, surprisingly little is known on potential side effects on non-target soil organisms. In a greenhouse experiment with white clover we investigated, to what extent a globally-used glyphosate herbicide affects interactions between essential soil organisms such as earthworms and arbuscular mycorrhizal fungi (AMF). We found that herbicides significantly decreased root mycorrhization, soil AMF spore biomass, vesicles and propagules. Herbicide application and earthworms increased soil hyphal biomass and tended to reduce soil water infiltration after a simulated heavy rainfall. Herbicide application in interaction with AMF led to slightly heavier but less active earthworms. Leaching of glyphosate after a simulated rainfall was substantial and altered by earthworms and AMF. These sizeable changes provide impetus for more general attention to side-effects of glyphosate-based herbicides on key soil organisms and their associated ecosystem services. PMID:25005713

  7. Weed emergence on long years’ not herbicide treated fields - duration of the after-effects

    Directory of Open Access Journals (Sweden)

    Schwarz, Jürgen

    2016-02-01

    Full Text Available In a long-term field trial plots were not treated with herbicides for 12 years (from 1996 to 2007. Two different crop rotations with 50% or 66% of cereals in the rotation were tested. At the same time in each crop rotation two different plant protection strategies were established. Since autumn 2007 the former controls not sprayed with any herbicide have been treated with herbicides. The crop rotation was unified. In that long-term field trial plots always treated with herbicides exist also. Weeds were counted by number and species before herbicide treatments. The comparison of these two different plots (treated and untreated shows what after-effect exists on the formerly untreated plots even after eight years. The emergence of weeds is still higher. Also the different crop rotations are still perceptible. For the plant protection strategy with the lower herbicide amounts the differences blur now.

  8. Three-parameter modeling of the soil sorption of acetanilide and triazine herbicide derivatives.

    Science.gov (United States)

    Freitas, Mirlaine R; Matias, Stella V B G; Macedo, Renato L G; Freitas, Matheus P; Venturin, Nelson

    2014-02-01

    Herbicides have widely variable toxicity and many of them are persistent soil contaminants. Acetanilide and triazine family of herbicides have widespread use, but increasing interest for the development of new herbicides has been rising to increase their effectiveness and to diminish environmental hazard. The environmental risk of new herbicides can be accessed by estimating their soil sorption (logKoc), which is usually correlated to the octanol/water partition coefficient (logKow). However, earlier findings have shown that this correlation is not valid for some acetanilide and triazine herbicides. Thus, easily accessible quantitative structure-property relationship models are required to predict logKoc of analogues of the these compounds. Octanol/water partition coefficient, molecular weight and volume were calculated and then regressed against logKoc for two series of acetanilide and triazine herbicides using multiple linear regression, resulting in predictive and validated models.

  9. Herbicide contamination and the potential impact to seagrass meadows in Hervey Bay, Queensland, Australia.

    Science.gov (United States)

    McMahon, Kathryn; Bengtson Nash, Susan; Eaglesham, Geoff; Müller, Jochen F; Duke, Norman C; Winderlich, Steve

    2005-01-01

    Low concentrations of herbicides (up to 70 ng l(-1)), chiefly diuron (up to 50 ng l(-1)) were detected in surface waters associated with inter-tidal seagrass meadows of Zostera muelleri in Hervey Bay, south-east Queensland, Australia. Diuron and atrazine (up to 1.1 ng g(-1) dry weight of sediment) were detected in the sediments of these seagrass meadows. Concentration of the herbicides diuron, simazine and atrazine increased in surface waters associated with seagrass meadows during moderate river flow events indicating herbicides were washed from the catchment to the marine environment. Maximum herbicide concentration (sum of eight herbicides) in the Mary River during a moderate river flow event was 4260 ng l(-1). No photosynthetic stress was detected in seagrass in this study during low river flow. However, with moderate river flow events, nearshore seagrasses are at risk of being exposed to concentrations of herbicides that are known to inhibit photosynthesis.

  10. Leaching and residual activity of imidazolinone herbicides in lowland soils

    Directory of Open Access Journals (Sweden)

    João Paulo Refatti

    Full Text Available ABSTRACT: Herbicides used in the Clearfield® rice (Oryza sativa L. production system have a potential for leaching. This can result in contamination of underground water resources and cause injury to not tolerant crops that are sown in a succession and/or crop rotation. The objective of this study was to determine the leaching potential and the residual activity of the herbicides used in the Clearfield® rice system. The experiment was conducted over a period of two years and consisted of conducting a field test to be followed by two bioassays with a year of difference between their implementation. Initially an experiment was conducted in lowland area where it was planted the cultivar of rice ‘PUITA INTA CL’. Approximately one and two years thereafter, soil samples from each plot were collected at intervals of 5cm to a depth of 30cm (B factor for the bioassay to evaluate persistence of herbicides. Factor A was composed of mixtures formulated of imazethapyr + imazapic (75 + 25g a.i. L-1, imazapyr + imazapic (525 + 175g a.i. kg-1 in two doses, imazethapyr (100g a.i. L-1 and treatment control without application. Basing on results, it was concluded that the mixtures imazethapyr + imazapic, imazapyr + imazapic and imazethapyr leached into the soil, reaching depths of up to 25cm in lowland soil. Imidazolinone herbicides used today in the irrigated rice Clearfield® system are persistent in soil, and their phytotoxic activity can be observed up to two years after application.

  11. Linking fluorescence induction curve and biomass in herbicide screening.

    Science.gov (United States)

    Christensen, Martin G; Teicher, Harald B; Streibig, Jens C

    2003-12-01

    A suite of dose-response bioassays with white mustard (Sinapis alba L) and sugar beet (Beta vulgaris L) in the greenhouse and with three herbicides was used to analyse how the fluorescence induction curves (Kautsky curves) were affected by the herbicides. Bentazone, a photosystem II (PSII) inhibitor, completely blocked the normal fluorescence decay after the P-step. In contrast, fluorescence decay was still obvious for flurochloridone, a PDS inhibitor, and glyphosate, an EPSP inhibitor, which indicated that PSII inhibition was incomplete. From the numerous parameters that can be derived from OJIP-steps of the Kautsky curve the relative changes at the J-step [Fvj = (Fm - Fj)/Fm] was selected to be a common response parameter for the herbicides and yielded consistent dose-response relationships. Four hours after treatment, the response Fvj on the doses of bentazone and flurochloridone could be measured. For glyphosate, the changes of the Kautsky curve could similarly be detected 4 h after treatment in sugar beet, but only after 24 hs in S alba. The best prediction of biomass in relation to Fvj was found for bentazone. The experiments were conducted between May and August 2002 and showed that the ambient temperature and solar radiation in the greenhouse could affect dose-response relationships. If the Kautsky curve parameters should be used to predict the outcome of herbicide screening experiments in the greenhouse, where ambient radiation and temperature can only partly be controlled, it is imperative that the chosen fluorescence parameters can be used to predict accurately the resulting biomass used in classical bioassays.

  12. Environmental Statement. Disposition of Orange Herbicide by Incineration

    Science.gov (United States)

    1974-11-01

    remote as possible from both residential and industrial population centers and from land currently in agronomic pro- duction., Vegetation should be...sparse, of little agronomic value, and of species resistant to the phenoxyacetic acid herbicides contained in Orange or to the pyrolytic products of...each to induce intoxication . The above results are summarized in Table 11-7. b. Behavior in Humans: Gehring et al., (1973) studied the effects of 2,4,5-T

  13. Hydrolysis of benzonitrile herbicides by soil actinobacteria and metabolite toxicity

    Czech Academy of Sciences Publication Activity Database

    Veselá, Alicja Barbara; Franc, M.; Pelantová, Helena; Kubáč, David; Vejvoda, Vojtěch; Šulc, Miroslav; Bhalla, T. C.; Macková, M.; Lovecká, P.; Janů, P.; Demnerová, K.; Martínková, Ludmila

    2011-01-01

    Roč. 22, č. 6 (2011), s. 761-770 ISSN 0923-9820 R&D Projects: GA MPO FT-TA5/043; GA MŠk OC09046; GA MŠk(CZ) LC06010; GA AV ČR IAA500200708; GA ČR GD305/09/H008 Institutional research plan: CEZ:AV0Z50200510 Keywords : nitrilase * benzonitrile herbicides * chloroxynil Subject RIV: CE - Biochemistry Impact factor: 2.017, year: 2011

  14. Hydrolysis of benzonitrile herbicides by soil actinobacteria and metabolite toxicity

    Czech Academy of Sciences Publication Activity Database

    Veselá, Alicja Barbara; Franc, M.; Pelantová, Helena; Kubáč, David; Vejvoda, Vojtěch; Šulc, Miroslav; Bhalla, T. C.; Macková, M.; Lovecká, P.; Janů, P.; Demnerová, K.; Martínková, Ludmila

    2010-01-01

    Roč. 21, č. 5 (2010), s. 761-770 ISSN 0923-9820 R&D Projects: GA MPO FT-TA5/043; GA MŠk OC09046; GA MŠk(CZ) LC06010; GA AV ČR IAA500200708; GA ČR GD305/09/H008 Institutional research plan: CEZ:AV0Z50200510 Keywords : Benzonitrile herbicides * nitrilase * Chloroxynil Subject RIV: EE - Microbiology, Virology Impact factor: 2.012, year: 2010

  15. Eastern hemlock response to even- and uneven-age management in the Acadian forest: results from the Penobscot Experimental Forest long-term silviculture study

    Science.gov (United States)

    John C. Brissette; Laura S. Kenefic

    2000-01-01

    Eastern hemlock (Tsuga canadensis (L.) Carr.) is an important tree species in the mixed-species conifer forests of northern New England and adjacent Canada. Hemlock is very tolerant of understory conditions; consequently, it responds differently to various silvicultural treatments. In a long-term study at the Penobscot Experimental Forest in east-...

  16. Integrated management of carbon sequestration and biomass utilization opportunities in a changing climate: Proceedings of the 2009 National Silviculture Workshop; 2009 June 15-18; Boise, ID.

    Science.gov (United States)

    Theresa B. Jain; Russell T. Graham; Jonathan Sandquist

    2010-01-01

    Forests are important for carbon sequestration and how they are manipulated either through natural or human induced disturbances can have an effect on CO2 emissions and carbon sequestration. The 2009 National Silviculture Workshop presented scientific information and management strategies to meet a variety of objectives while simultaneously addressing carbon...

  17. The effect of the herbicide diuron on soil microbial activity.

    Science.gov (United States)

    Prado, A G; Airoldi, C

    2001-07-01

    The inhibitory effect of the herbicide diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] on microbial activity in red Latosol soil was followed using microcalorimetry. The activity of the micro-organisms in 1.50 g of soil sample was stimulated by addition of 6.0 mg of glucose and 6.0 mg of ammonium sulfate under 35% controlled humidity at 298.15 (+/- 0.02) K. This activity was determined by power-time curves that were recorded for increasing amounts of diuron, varying from zero to 333.33 micrograms g-1 soil. An increase in the amount of diuron in soil caused a decrease of the original thermal effect, to reach a null value above 333.33 micrograms g-1 of herbicide. The power-time curve showed that the lag-phase period and peak time increased with added herbicide. The decrease of the thermal effect evolved by micro-organisms and the increase of the lag-phase period are associated with the death of microbial populations caused by diuron, which strongly affects soil microbial communities.

  18. A glutathione s-transferase confers herbicide tolerance in rice

    Directory of Open Access Journals (Sweden)

    Tingzhang Hu

    2014-07-01

    Full Text Available Plant glutathione S-transferases (GSTs have been a focus of attention due to their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice (Oryza sativa L.. Transgenic rice plants over-expressing OsGSTL2 were generated from rice calli by the use of an Agrobacterium transformation system, and were screened by a combination of hygromycin resistance, PCR and Southern blot analysis. In the vegetative tissues of transgenic rice plants, the over-expression of OsGSTL2 not only increased levels of OsGSTL2 transcripts, but also GST and GPX expression, while reduced superoxide. Transgenic rice plants also showed higher tolerance to glyphosate and chlorsulfuron, which often contaminate agricultural fields. The findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crops for developing herbicide tolerance and for limiting herbicide contamination in the food chain.

  19. Fluridone: a combination germination stimulant and herbicide for problem fields?

    Science.gov (United States)

    Goggin, Danica E; Powles, Stephen B

    2014-09-01

    Problem weeds in agriculture, such as Lolium rigidum Gaud., owe some of their success to their large and dormant seed banks, which permit germination throughout a crop-growing season. Dormant weed seed banks could be greatly depleted by application of a chemical that stimulates early-season germination and then kills the young seedlings. Fluridone, a phytoene desaturase-inhibiting herbicide that can also break seed dormancy, was assessed for its efficacy in this regard. The germination of fluridone-treated Lolium rigidum seeds was stimulated on soils with low organic matter, and almost 100% seedling mortality was observed, while the treatment was only moderately effective on a high-organic-matter potting mix. Seedlings from wheat, canola, common bean and chickpea seeds sown on fluridone-treated sandy loam were bleached and did not survive, but lupins and field peas grew normally. This proof-of-concept study with fluridone suggests that it may be possible to design safe and effective molecules that act as germination stimulants plus herbicides in a range of crop and soil types: a potentially novel way of utilising herbicides to stimulate seed bank germination and a valuable addition to an integrated weed management system. © 2014 Society of Chemical Industry.

  20. Biodegradation of the acetanilide herbicides alachlor, metolachlor, and propachlor.

    Science.gov (United States)

    Stamper, D M; Tuovinen, O H

    1998-01-01

    Alachlor, metolachlor, and propachlor are detoxified in biological systems by the formation of glutathione-acetanilide conjugates. This conjugation is mediated by glutathione-S-transferase, which is present in microorganisms, plants, and mammals. Other organic sulfides and inorganic sulfide also react through a nucleophilic attack on the 2-chloro group of acetanilide herbicides, but the products are only partially characterized. Sorption in soils and sediments is an important factor controlling the migration and bioavailability of these herbicides, while microbial degradation is the most important factor in determining their overall fate in the environment. The biodegradation of alachlor and metolachlor is proposed to be only partial and primarily cometabolic, and the ring cleavage seems to be slow or insignificant. Propachlor biodegradation has been reported to proceed to substantial (> 50%) mineralization of the ring structure. Reductive dechlorination may be one of the initial breakdown mechanisms under anaerobic conditions. Aerobic and anaerobic transformation products vary in their polarity and therefore in soil binding coefficient. A catabolic pathway for chloroacetanilide herbicides has not been presented in the literature because of the lack of mineralization data under defined cultural conditions.

  1. Fate of herbicides in deep subsurface limestone and sandy aquifers

    DEFF Research Database (Denmark)

    Janniche, Gry Sander

    afgørende for at vurdere herbiciders skæbne i underjord og grundvandsmagasiner. PhD-projektet har undersøgt sorption og nedbrydning af fire model-herbicider (atrazin, acetochlor, mecoprop og isoproturon) i kalksten og sandede grundvands¬magasiner. Desuden er den rumlige småskala-variation af herbicidernes...... tydelig selv inden for få cm afstand over dybden, og betydningen af denne variation afhænger af den samlede udbredelse af lag med forhøjet sorption eller nedbrydning; 2) at kalk/kalksten yder ringe beskyttelse mod grundvands¬forurening med mecoprop, atrazin, isoproturon og acetochlor, da sorptionen er lav...... og mineraliseringen meget langsom for isoproturon, acetochlor og mecoprop, og atrazin ikke er nedbrydeligt; 3) at i sandede grundvands¬magasiner er sorptionen af de fire herbicider generelt lav, men kan under reducerede forhold være kraftig for især isoproturon og acetochlor. Mecoprop, isoproturon og...

  2. An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides. Volume I: 1997 Follow-up Examination Results

    National Research Council Canada - National Science Library

    Michalek, J

    2000-01-01

    ... attributable to exposure to herbicides exist in veterans of Operation Ranch Hand Operation. Ranch Hand was the unit responsible for the aerial spraying of herbicides, including Herbicide Orange, in Vietnam from 1961 to 1971...

  3. Vasogenic edema in striatum following ingestion of glufosinate-containing herbicide.

    Science.gov (United States)

    Lee, Hui-Young; Song, Seo-Young; Lee, Seung-Hwan; Lee, Seo-Young; Kim, Sung-Hun; Ryu, Sook-Won

    2009-10-01

    Glufosinate-ammonium (GLA) is a broad-spectrum herbicide used worldwide. We report a patient who attempted suicide by ingesting a liquid herbicide containing GLA. A diffusion-weighted MRI showed cytotoxic edema in the hippocampus as well as vasogenic edema in the striata. To our knowledge, vasogenic edema caused by GLA-containing herbicide involving the striatum has not been reported in association with cytotoxic edema in the hippocampus. We assume that this herbicide affected the central nervous system via different mechanisms to produce both cytotoxic and vasogenic edema in the same patient.

  4. Sensitivity to Glufosinate-ammonium herbicide in plants of Glycine max cultivar INCASoy-27

    Directory of Open Access Journals (Sweden)

    Jorge Liusvert Pérez Pérez

    2014-10-01

    Full Text Available This work had as objective to define the minimum concentration of herbicide Glufosinate-ammonium that inhibits the growth of the soybean plants in greenhouse condition. The soybean plants were tried with different concentrations of herbicide (5; 10; 1 5; 20; 25; 30 mg L-1 and a control without herbicide. The increase of the concentrations increased the necrosis of the plants and the use of 20 mgL-1 Glufosinato de amonio herbicide was sufficient to inhibit the plant growth. These results allow using this method of selection in programs of genetic improvement and selection of transgenic soybean plants

  5. Fate of 2,4-D herbicide in soil-plant ecosystems

    International Nuclear Information System (INIS)

    Onal, G.

    1983-01-01

    Herbicide was applied to wheat, barley and oat plants grown under laboratory, greenhouse and field conditions and the fate of the herbicide was investigated using carbon 14 radioisotope. Results of the investigation indicate that (1) under laboratory condition degradation of the herbicide was faster in the soil, rich in organic matter and was not influenced by humidity; (2) the absorption of the herbicide by the plants was low under greenhouse conditions and (3) the uptake of the chemical by the plants grown in the field was higher in the presence of fertilizer (diammonium phosphate)

  6. Effects Of Spring Herbicide Treatments On Winter Wheat Growth And Grain Yield*

    Directory of Open Access Journals (Sweden)

    Hamouz P.

    2015-03-01

    Full Text Available Herbicides provide a low-cost solution for protecting crops from significant yield losses. If weed infestations are below damage thresholds, however, then herbicide application is unnecessary and can even lead to yield loss. A small-plot field trial was conducted to examine the effect of herbicides on winter wheat yields. Weeds were removed manually from the trial area before herbicide application. Twenty-four treatments were tested in four replications. Treatment 1 consisted of an untreated weed-free control, whereas the other treatments comprised applications of the following herbicides and their combinations: metsulfuron-methyl + tribenuron-methyl (4.95 + 9.99 g ha−1, pinoxaden (30 g ha−1, fluroxypyr (175 g ha−1, and clopyralid (120 g ha−1. Water (250 l ha−1 or a urea-ammonium nitrate fertilizer solution (UAN, 120.5 l ha−1 was used as the herbicide carrier. Crop injury 30 days after treatment and yield loss were recorded. Results showed minor crop injury by herbicides and their combinations when applied without UAN and moderate injury caused by UAN in combination with herbicides. Yield losses reached 5.3% and 4.3% in those treatments where all of the tested herbicides were applied with and without UAN, respectively. The effect of all treatments on crop yield was, however, statistically insignificant (P = 0.934.

  7. Acute and additive toxicity of ten photosystem-II herbicides to seagrass.

    Science.gov (United States)

    Wilkinson, Adam D; Collier, Catherine J; Flores, Florita; Negri, Andrew P

    2015-11-30

    Photosystem II herbicides are transported to inshore marine waters, including those of the Great Barrier Reef, and are usually detected in complex mixtures. These herbicides inhibit photosynthesis, which can deplete energy reserves and reduce growth in seagrass, but the toxicity of some of these herbicides to seagrass is unknown and combined effects of multiple herbicides on seagrass has not been tested. Here we assessed the acute phytotoxicity of 10 PSII herbicides to the seagrass Halophila ovalis over 24 and/or 48 h. Individual herbicides exhibited a broad range of toxicities with inhibition of photosynthetic activity (∆F/F(m)') by 50% at concentrations ranging from 3.5 μg l(-1) (ametryn) to 132 μg l(-1) (fluometuron). We assessed potential additivity using the Concentration Addition model of joint action for binary mixtures of diuron and atrazine as well as complex mixtures of all 10 herbicides. The effects of both mixture types were largely additive, validating the application of additive effects models for calculating the risk posed by multiple PSII herbicides to seagrasses. This study extends seagrass ecotoxicological data to ametryn, metribuzin, bromacil, prometryn and fluometuron and demonstrates that low concentrations of PSII herbicide mixtures have the potential to impact ecologically relevant endpoints in seagrass, including ∆F/F(m)'.

  8. Acute and additive toxicity of ten photosystem-II herbicides to seagrass

    Science.gov (United States)

    Wilkinson, Adam D.; Collier, Catherine J.; Flores, Florita; Negri, Andrew P.

    2015-11-01

    Photosystem II herbicides are transported to inshore marine waters, including those of the Great Barrier Reef, and are usually detected in complex mixtures. These herbicides inhibit photosynthesis, which can deplete energy reserves and reduce growth in seagrass, but the toxicity of some of these herbicides to seagrass is unknown and combined effects of multiple herbicides on seagrass has not been tested. Here we assessed the acute phytotoxicity of 10 PSII herbicides to the seagrass Halophila ovalis over 24 and/or 48 h. Individual herbicides exhibited a broad range of toxicities with inhibition of photosynthetic activity (∆F/Fm‧) by 50% at concentrations ranging from 3.5 μg l-1 (ametryn) to 132 μg l-1 (fluometuron). We assessed potential additivity using the Concentration Addition model of joint action for binary mixtures of diuron and atrazine as well as complex mixtures of all 10 herbicides. The effects of both mixture types were largely additive, validating the application of additive effects models for calculating the risk posed by multiple PSII herbicides to seagrasses. This study extends seagrass ecotoxicological data to ametryn, metribuzin, bromacil, prometryn and fluometuron and demonstrates that low concentrations of PSII herbicide mixtures have the potential to impact ecologically relevant endpoints in seagrass, including ∆F/Fm‧.

  9. Herbicidal activity of pre and post emergent herbicide on control of Eleusine indica in aerobic rice system

    International Nuclear Information System (INIS)

    Selvarajh, G.; Zain, N.M.; Aminudin, A.; Seng, C.T.

    2018-01-01

    Aerobic rice system can be an alternate way to cultivate rice in less water conditions. However, weeds are a major constrain in aerobic rice field which decline its success. Weeds are being controlled by herbicides in aerobic rice but not all herbicides are effective in controlling various types of weeds. In this study, two pre-emergent (pretilachor and pendimethalin) and two post-emergent (cyhalofop-butyl and bispyribac-sodium) herbicides were evaluated for effective control of the bioassay species, Eleusine indica. It was found that pendimethalin at a higher application rate of 1.0 kg ai ha-1 strongly inhibit the emergence and shoot growth of E. indica by >75% with negligible effect on the rice growth with stimulation on the leaf greenness. Conversely, pretilachor, cyhalofop-butyl and bispyribac-sodium gave moderate inhibition (55-60% inhibition) on weed emergence and shoot growth at higher application rates of 0.44, 0.1 and 0.035 kg ai ha-1, respectively. Significant inhibitory effects on rice root growth were noticed at highest application rates of pretilachor, cyhalofop-butyl and bispyribac-sodium (40-50% inhibition) across the growth stage of rice seedlings. Great reduction in shoot height, shoot fresh weight, and greenness of rice plant also was evident at 0 DAS across herbicides rates. However, with increasing growth stages, the rice plant became less susceptible to the applied treatments. The finding suggested that pendimethalin at 1.0 kg ai ha-1 was the most suitable application rate for inhibiting E. indica without injuring the rice seedlings. (author)

  10. Glyphosate, other herbicides, and transformation products in Midwestern streams, 2002

    Science.gov (United States)

    Battaglin, W.A.; Kolpin, D.W.; Scribner, E.A.; Kuivila, K.M.; Sandstrom, M.W.

    2005-01-01

    The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre-emergence herbicides, after the application of post-emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre-emergence, 40 percent of post-emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre-emergence, 83 percent of post-emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre-emergence, 96 percent of post-emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre-emergence and 33 percent of post-emergence samples

  11. Glyphasate, other herbicides, and transformation products in midwestern streams, 2002

    Science.gov (United States)

    Battaglin, William A.; Koplin, Dana W.; Scribner, Elizabeth A.; Kuivila, Kathryn; Sandstrom, Mark W.

    2005-01-01

    The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre-emergence herbicides, after the application of post-emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre-emergence, 40 percent of post-emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre-emergence, 83 percent of post-emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre-emergence, 96 percent of post-emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre-emergence and 33 percent of post-emergence samples.

  12. Forest-food nexus: a topical opportunity for human well-being and silviculture

    Directory of Open Access Journals (Sweden)

    Piermaria Corona

    2016-07-01

    Full Text Available As population will reach over 9 billion by 2050, interest in the forest-food nexus is rising. Forests play an important role in food production and nutrition. Forests can provide nutritionally-balanced diets, woodfuel for cooking and a broad set of ecosystem services. A large body of evidence recommends multi-functional and integrated landscape approaches to reimagine forestry and agriculture systems. Here, after a commented discussion of the literature produced in the last decade about the role for forests with respect to the food security global emergency, we summarize the state of the art in Italy as a representative country-case-study. The aim is to increase awareness about the potential of silviculture in Italy for combining ecological resilience with economic resilience, and reducing the pressure over tropical and sub-tropical forests by means of a sustainable intensification of forest management at national level. Although a quantification of the Italian non-wood forest products is difficult, the potential of this sector for the Italian bioeconomy is relatively high. Italy is among the four top European exporters of cork stoppers, is one of the three top countries for chestnut seed processing, and is among the leading exporters of wild mushroom, while it is the only European country among the top five global importers of tannins. In order to develop this sector for the food industry, more research is needed on non-wood forest products, the scale of production, emerging markets, marketing and production innovation. On the other hand, chain-supply fragmentation, landowner inertia, and lack of governance and cooperation may hamper an effective exploitation of non-wood products. A renewed joint impulse for exploitation of wood and non-wood products may come from a sustainable intensification of forest management. The strategies to guarantee an effective supply of non-wood products require appropriate business skills and the presence of a

  13. A silvicultura e os recursos hídricos superficiais Superficial hydric resources and the silviculture

    Directory of Open Access Journals (Sweden)

    Rafael Zoboli Guimarães

    2010-03-01

    Full Text Available Realizou-se um monitoramento da qualidade da água superficial em áreas de reflorestamento com
    espécies de Pinus taeda e Pinus ellioti no Município de Joinville, Santa Catarina, Brasil, no período de setembro
    de 2005 a julho de 2006. Fez-se a comparação entre os resultados obtidos no monitoramento em talhões de
    diferentes idades de reflorestamento e comparou-se com áreas de mata nativa. Utilizaram-se no monitoramento
    os parâmetros de temperatura, pH, oxigênio dissolvido (OD, demanda bioquímica de oxigênio (DBO, sólidos
    dissolvidos totais, turbidez, e coliformes termotolerantes (CT. Os resultados mais significativos foram: aumento
    médio de 0,4 unidades de pH, de 42 NMP/100mL de CT, comparando a qualidade da água na entrada e saída do
    reflorestamento. Houve maior estabilidade na variação espacial e temporal do parâmetro pH nos reflorestamentos
    mais velhos. Preliminarmente, esta pesquisa mostrou que a atividade de silvicultura não interfere de forma
    considerável na qualidade das águas superficiais.Superficial water quality was monitored in plantation areas with exotic species (Pinus taeda e Pinus ellioti in Joinville coutry, Santa Catarina, Brazil, between September 2005 and July 2006. The results, obtained in the monitoring area through the comparison of different forested catchments of different forestry ages, were compared with the ones of the native forest. The parameters used in monitoring were temperature, pH, dissolved oxygen (DO, oxygen biochemist demand (OBD, total solids dissolved (TSD, turbidity, and thermo tolerant coliforms (TC. The most significant result was: an average increase of 0,4 units of pH, 42 NMP/100 mL of TC, comparing the water quality in the entrance and exit of the forestry. It had greater stability at temporal and spatial variation in pH values in the oldest forestry. Preliminary, this research showed that the silviculture does not considerably intervene

  14. Determination of Two Sulfonylurea Herbicides Residues in Soil Environment Using HPLC and Phytotoxicity of These Herbicides by Lentil Bioassay.

    Science.gov (United States)

    Mehdizadeh, Mohammad; Alebrahim, Mohammad Taghi; Roushani, Mahmoud

    2017-07-01

    A HPLC-UV detection system was used for determination of sulfosulfuron and tribenuron methyl residues from soils. The soils were fortified with sulfosulfuron and tribenuron methyl at rates of 26 and 15 g a.i. ha -1 respectively and samples were taken randomly on 0 (2 h), 1, 2, 4, 10, 20, 40, 60, 90 and 120 days after treatment. The final extracts were prepared for analysis by HPLC. The results showed that degradation of both herbicides in the silty loam soil was faster than sandy loam soil. Half-life of sulfosulfuron was ranged from 5.37 to 10.82 days however this value for tribenuron methyl was ranged from 3.23 to 5.72 days on different soils. The residue of both herbicides at 120 days after application in wheat field had no toxicitic effect on lentil. It was concluded that HPLC analysis procedure was an appropriate method for determination of these herbicides from soils.

  15. Herbicides as an alternative to prescribed burning for achieving wildlife management objectives

    Science.gov (United States)

    T. Bently Wigley; Karl V. Miller; David S. deCalesta; Mark W. Thomas

    2002-01-01

    Prescribed burning is used for many silvicultural and wildlife management objectives. However, the use of prescribed burning can be constrained due to difficulties in obtaining burning permits, concerns about liability, potential effects of scorch on growth and survival of crop trees, its sometimes ineffective results, limited burning days, and the costs of applying,...

  16. Degradation of Herbicides in the Tropical Marine Environment: Influence of Light and Sediment.

    Science.gov (United States)

    Mercurio, Philip; Mueller, Jochen F; Eaglesham, Geoff; O'Brien, Jake; Flores, Florita; Negri, Andrew P

    2016-01-01

    Widespread contamination of nearshore marine systems, including the Great Barrier Reef (GBR) lagoon, with agricultural herbicides has long been recognised. The fate of these contaminants in the marine environment is poorly understood but the detection of photosystem II (PSII) herbicides in the GBR year-round suggests very slow degradation rates. Here, we evaluated the persistence of a range of commonly detected herbicides in marine water under field-relevant concentrations and conditions. Twelve-month degradation experiments were conducted in large open tanks, under different light scenarios and in the presence and absence of natural sediments. All PSII herbicides were persistent under control conditions (dark, no sediments) with half-lives of 300 d for atrazine, 499 d diuron, 1994 d hexazinone, 1766 d tebuthiuron, while the non-PSII herbicides were less persistent at 147 d for metolachlor and 59 d for 2,4-D. The degradation of herbicides was 2-10 fold more rapid in the presence of a diurnal light cycle and coastal sediments; apart from 2,4-D which degraded more slowly in the presence of light. Despite the more rapid degradation observed for most herbicides in the presence of light and sediments, the half-lives remained > 100 d for the PS II herbicides. The effects of light and sediments on herbicide persistence were likely due to their influence on microbial community composition and its ability to utilise the herbicides as a carbon source. These results help explain the year-round presence of PSII herbicides in marine systems, including the GBR, but more research on the transport, degradation and toxicity on a wider range of pesticides and their transformation products is needed to improve their regulation in sensitive environments.

  17. Investigation of Sensitivity of Some Pulses and Agronomic Crops to Soil Residue of Idosulfuron-mesosulfurun Herbicide

    Directory of Open Access Journals (Sweden)

    E. Izadi-Darbandi

    2013-03-01

    Full Text Available To study the sensitivity of chick pea, bean, lentil, rapeseed, sugarbeet and tomato to soil residual concentration of Idosulfuron-mesosulfurun herbicide, an experiment was carried out under controlled conditions at the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2010. The studied factors were the 6 mentioned crops, and 7 levels of soil residual concentration of Idosulfuron-mesosulfurun herbicide (0, 0.0015, 0.0037, 0.0079, 0.015, 0.031 and 0.047 mg per kg of soil. The factorial experiment was carried out as a completely randomized design with three replications. Crops' emergence percentage was determined one week after their emergence. Plants' survival percentage and shoot and root biomass production were measured 30 days after their emergence. Results showed that all mentioned characteristics decreased significantly (P<0.01 in the presence of soil residue of the herbicide. Increasing Idosulfuron-mesosulfurun residual concentration in soil decreased emergence and shoot and root biomass production. Bean had the lowest shoot (44% and root (66.78% biomass loss and tomato had the highest shoot (96.38% and root (89.64% biomass loss. Based on ED50 index, pea (0.0079 mg/kg soil was the most tolerant and tomato (0.0003 mg/kg soil was the most susceptible crop to soil residues of Idosulfuron-mesosulfurun, and other crops ranked in between as: tomato< sugarbeet< rapeseed< lentil< bean< pea. In general, these results showed that soil residue of Idosulfuron-mesosulfurun can injure rotation crops and it is important to consider their sensitivity in rotation programming.

  18. Palmistichus elaeisis (Hymenoptera: Eulophidae as an indicator of toxicity of herbicides registered for corn in Brazil

    Directory of Open Access Journals (Sweden)

    Claubert W.G de Menezes

    2014-09-01

    Full Text Available The diversity of plants in agricultural systems benefits natural enemies. Herbicides are used in weed management in corn (Zea mays L. to reduce competition and productivity losses, but they can impact natural enemies and contaminate the environment. The objective was to evaluate toxicity of herbicides on pupae parasitoid Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae. The treatments were represented by the host pupae Tenebrio molitor L., 1785 (Coleoptera: Tenebrionidae and herbicides atrazine, nicosulfuron, paraquat, and tembotrione in commercial doses compared to a control treatment with water. Pupae of T. molitor were immersed in the solution of herbicides and exposed to parasitism by six females of P. elaeisis each. The herbicides atrazine and paraquat were highly toxic and, therefore, not selective to P. elaeisis. Nicosulfuron reduced the sex ratio of P. elaeisis (0.20 ± 0.03, which may affect subsequent generations. Moreover, the herbicide tembotrione was selective to P. elaeisis, showing results comparable to the control. Floristic diversity of weeds can increase food source, habitat, shelter, breeding places and microclimates for insect parasitoids but herbicides formulations can be toxic and these products can affect P. elaeisis or its hosts by direct or indirect contact, showing the importance of selectivity studies for this natural enemy. However, the herbicide tembotrione was selective to P. elaeisis and it can be recommended for programs of sustainable management of weeds in corn crop with this parasitoid.

  19. Histopathological study on the effect of rice herbicides on grass carp ...

    African Journals Online (AJOL)

    user

    2011-02-14

    Feb 14, 2011 ... observe the impact of herbicides on the histopathology of the fish, the fingerlings were collected from the field trenches ... is almost non-existent in India; the reasons being that increasing ... intensive rice-cum-fish culture offered the opportunity for ..... Toxicity of herbicides to Malaysian rice field fish. In: Proc.

  20. Dynamics of herbicide transport and partitioning under event flow conditions in the lower Burdekin region, Australia

    International Nuclear Information System (INIS)

    Davis, Aaron M.; Lewis, Stephen E.; Bainbridge, Zoë T.; Glendenning, Lionel; Turner, Ryan D.R.; Brodie, Jon E.

    2012-01-01

    This study examined the temporal variability in herbicide delivery to the Great Barrier Reef (GBR) lagoon (Australia) from one of the GBR catchment’s major sugarcane growing regions. Annual loads of measured herbicides were consistently in the order of 200+ kg. Atrazine, it’s degradate desethylatrazine, and diuron contributed approximately 90% of annual herbicide load, with early ‘first-flush’ events accounting for the majority of herbicide loads leaving the catchment. Assessment of herbicide water–sediment partitioning in flood runoff highlighted the majority of herbicides were transported in predominantly dissolved form, although a considerable fraction of diuron was transported in particulate-bound form (ca. 33%). Diuron was also the herbicide demonstrating the highest concentrations and frequency of detection in sediments collected from catchment waterways and adjacent estuarine–marine environments, an outcome aligning with previous research. Herbicide physico-chemical properties appear to play a crucial role in partitioning between water column and sediment habitat types in GBR receiving ecosystems.

  1. A composite transcriptional signature differentiates responses towards closely related herbicides in Arabidopsis thaliana and brassica napus

    Science.gov (United States)

    In this study, genome-wide expression profiling based on Affymetrix ATH1 arrays was used to identify discriminating responses of Arabidopsis thaliana to five herbicides, which contain active ingredients targeting two different branches of amino acid biosynthesis. One herbicide co...

  2. Limited fitness costs of herbicide-resistance traits in Amaranthus tuberculatus facilitate resistance evolution

    Science.gov (United States)

    The fitness cost of herbicide resistance (HR) in the absence of herbicide selection plays a key role in HR evolution. Quantifying the fitness cost of resistance, however, is challenging, and there exists a knowledge gap in this area. A synthetic Amaranthus tuberculatus population segregating for fiv...

  3. Effects of the herbicides linuron and S-metolachlor on Perez's frog embryos.

    Science.gov (United States)

    Quintaneiro, Carla; Soares, Amadeu M V M; Monteiro, Marta S

    2018-03-01

    Presence of pesticides in the environment and their possible effects on aquatic organisms are of great concern worldwide. The extensive use of herbicides in agricultural areas are one of the factors contributing to the known decline of amphibian populations. Thus, as non-target species, amphibians can be exposed in early life stages to herbicides in aquatic systems. In this context, this study aims to evaluate effects of increasing concentrations of two maize herbicides, linuron and S-metolachlor on embryos of the Perez' frog (Pelophylax perezi) during 192 h. Apical endpoints were determined for each herbicide: mortality, hatching rate, malformations and length. Frog embryos presented a LC 50 of 21 mg/l linuron and 37.5 mg/l S-metolachlor. Furthermore, sub-lethal concentrations of both herbicides affected normal embryonic development, delaying hatching, decreasing larvae length and causing several malformations. Length of larvae decreased with increasing concentrations of each herbicide, even at the lower concentrations tested. Malformations observed in larvae exposed to both herbicides were oedemas, spinal curvature and deformation, blistering and microphtalmia. Overall, these results highlight the need to assess adverse effects of xenobiotics to early life stages of amphibians regarding beside mortality the embryonic development, which could result in impairments at later stages. However, to unravel mechanisms involved in toxicity of these herbicides further studies regarding lower levels of biological organisation such as biochemical and genomic level should be performed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Investigation of 10 herbicides in surface waters of a horticultural production catchment in southeastern Australia.

    Science.gov (United States)

    Allinson, Graeme; Bui, AnhDuyen; Zhang, Pei; Rose, Gavin; Wightwick, Adam M; Allinson, Mayumi; Pettigrove, Vincent

    2014-10-01

    Herbicides are regularly applied in horticultural production systems and may migrate off-site, potentially posing an ecological risk to surface waterways. However, few studies have investigated the levels and potential ecotoxicological impact of herbicides in horticultural catchments in southern Australia. This study investigated the presence of 10 herbicides at 18 sites during a 5-month period in horticulturally important areas of the Yarra Valley in southeastern Australia. Seven of the 10 herbicides were detected in the streams, in 39 % of spot water samples, in 25 % of surface sediment samples, and in >70 % of the passive sampler systems deployed. Few samples contained residues of ≥2 herbicides. Simazine was the herbicide most frequently detected in water, sediment, and passive sampler samples and had the highest concentrations in water (0.67 μg/L) and sediment (260 μg/kg dry weight). Generally the concentrations of the herbicides detected were several orders of magnitude lower than reported ecotoxicological effect values, including those for aquatic plants and algae, suggesting that concentrations of individual chemicals in the catchment were unlikely to pose an ecological risk. However, little is known about the combined effects of simultaneous, low-level exposure of multiple herbicides of the same mode of action on Australian aquatic organisms nor their contribution when found in mixtures with other pesticides. Further research is required to adequately assess the risk of pesticides in Victorian aquatic environments.

  5. GLOBAL EXPRESSION PROFILING AS A TOOL TO DEVELOP MOLECULAR MARKERS LINKED TO HERBICIDE STRESS IN ARABIDOPSIS

    Science.gov (United States)

    Herbicide drift (unintentional physical movement from target to off-target plants) is a cause of crop loss in US. Low-dose, high-potency herbicides that have short environmental persistence times constrain efforts to develop or identify metabolite or biochemical markers of exposu...

  6. Dicotyledon Weed Quantification Algorithm for Selective Herbicide Application in Maize Crops

    DEFF Research Database (Denmark)

    Laursen, Morten Stigaard; Nyholm Jørgensen, Rasmus; Midtiby, Henrik Skov

    2016-01-01

    The stricter legislation within the European Union for the regulation of herbicides that are prone to leaching causes a greater economic burden on the agricultural industry through taxation. Owing to the increased economic burden, research in reducing herbicide usage has been prompted. High-resol...

  7. Incorporating seeds in activated carbon pellets limits herbicide effects to seeded bunchgrasses when controlling exotic annuals

    Science.gov (United States)

    Revegetation of exotic annual grass-invaded rangeland with pre-emergent herbicides is challenging because seeding is delayed until herbicide toxicity has diminished, but at this time, exotic annuals can be re-invading. Incorporating seeds into activated carbon pellets may allow seeding to occur at t...

  8. Using GLEAMS to Select Environmental Windows for Herbicide Application in Forests

    Science.gov (United States)

    M.C. Smith; J.L. Michael; W.G. Koisel; D.G. Nealy

    1994-01-01

    Observed herbicide runoff and groundwater data from a pine-release herbicide application study near Gainesville, Florida were used to validate the GLEAMS model hydrology and pesticide component for forest application. The study revealed that model simulations agreed relatively well with the field data for the one-year study. Following validation, a modified version of...

  9. Identification and discrimination of herbicide residues using a conducting polymer electronic nose

    Science.gov (United States)

    Alphus Dan Wilson

    2016-01-01

    The identification of herbicide residues on crop foliage is necessary to make crop-management decisions for weed pest control and to monitor pesticide residue levels on food crops. Electronic-nose (e-nose) methods were tested as a cheaper, alternative means of discriminating between herbicide residue types (compared with conventional chromatography methods), by...

  10. Predictive value of species sensitivity distributions for effects of herbicides in freshwater ecosystems

    NARCIS (Netherlands)

    Brink, van den P.J.; Blake, N.; Brock, T.C.M.; Maltby, L.

    2006-01-01

    In this article we present a review of the laboratory and field toxicity of herbicides to aquatic ecosystems. Single-species acute toxicity data and ( micro) mesocosm data were collated for nine herbicides. These data were used to investigate the importance of test species selection in constructing

  11. NOVEL CHROMATOGRAPHIC SEPARATION AND CARBON SOLID PHASE EXTRACTION OF ACETANILIDE HERBICIDE DEGRADATION PRODUCTS

    Science.gov (United States)

    Six acetanilide herbicides are currently registered for use in the U.S. Over the past several years, ethanesufonic acid (ESA) and oxanilic acid (OA) degradatoin products of these acetanilide herbicides have been found in U.S. ground waters and surface waters. "Alachlor ESA and ...

  12. METHOD DEVELOPMENT FOR ALACHLOR ESA AND OTHER ACENTANILIDE HERBICIDE DEGRADATION PRODUCTS

    Science.gov (United States)

    Introduction: Acetanilide herbicides are frequently applied in the U.S. on crops (corn, soybeans, popcorn, etc.) to control broadleaf and annual weeds. The acetanilide and acetamide herbicides currently registered for use in the U.S. are alachlor, acetochlor, metolachlor, propa...

  13. A herbicide structure-activity analysis of the antimalarial lead compound MMV007978 against Arabidopsis thaliana.

    Science.gov (United States)

    Corral, Maxime G; Leroux, Julie; Tresch, Stefan; Newton, Trevor; Stubbs, Keith A; Mylne, Joshua S

    2018-07-01

    To fight herbicide-resistant weeds, new herbicides are needed; particularly ones with new modes of action. Building on the revelation that many antimalarial drugs are herbicidal, here we focus on the Medicines for Malaria Venture antimalarial lead compound MMV007978 that has herbicidal activity against the model plant Arabidopsis thaliana. Twenty-two variations of the lead compound thiophenyl motif revealed that change was tolerated provided ring size and charge were retained. MMV007978 was active against select monocot and dicot weeds, and physiological profiling indicated that its mode of action is related to germination and cell division. Of interest is the fact that the compound has a profile that is currently not found among known herbicides. We demonstrate that the antimalarial compound MMV007978 is also herbicidal and that exploiting lead compounds that are often understudied could lead to the identification of interesting herbicidal scaffolds. Further structural investigation of MMV007978 could provide improved herbicidal chemistries with a potential new mode of action. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  14. Controlling herbicide-susceptible, -tolerant and -resistant weeds with microbial bioherbicides

    Science.gov (United States)

    The management of weeds is a necessary but expensive challenge. Public concerns of health, safety, and sustainability have increased interest in reducing the use of synthetic chemicals for weed control. Alternatives to chemical herbicides, such as bioherbicides, may offer an alternative to herbicide...

  15. Relationship between weed dormancy and herbicide rotations: implications in resistance evolution.

    Science.gov (United States)

    Darmency, Henri; Colbach, Nathalie; Le Corre, Valérie

    2017-10-01

    It is suggested that selection for late germinating seed cohorts is significantly associated with herbicide resistance in some cropping systems. In turn, it is conceivable that rotating herbicide modes of action selects for populations with mutations for increased secondary dormancy, thus partially overcoming the delaying effect of rotation on resistance evolution. Modified seed dormancy could affect management strategies - like herbicide rotation - that are used to prevent or control herbicide resistance. Here, we review the literature for data on seed dormancy and germination dynamics of herbicide-resistant versus susceptible plants. Few studies use plant material with similar genetic backgrounds, so there are few really comparative data. Increased dormancy and delayed germination may co-occur with resistance to ACCase inhibitors, but there is no clear-cut link with resistance to other herbicide classes. Population shifts are due in part to pleiotropic effects of the resistance genes, but interaction with the cropping system is also possible. We provide an example of a model simulation that accounts for genetic diversity in the dormancy trait, and subsequent consequences for various cropping systems. We strongly recommend adding more accurate and detailed mechanistic modelling to the current tools used today to predict the efficiency of prevention and management of herbicide resistance. These models should be validated through long-term experimental designs including mono-herbicide versus chemical rotation in the field. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. Phorate can reverse P450 metabolism-based herbicide resistance in Lolium rigidum.

    Science.gov (United States)

    Busi, Roberto; Gaines, Todd Adam; Powles, Stephen

    2017-02-01

    Organophosphate insecticides can inhibit specific cytochrome P450 enzymes involved in metabolic herbicide resistance mechanisms, leading to synergistic interactions between the insecticide and the herbicide. In this study we report synergistic versus antagonistic interactions between the organophosphate insecticide phorate and five different herbicides observed in a population of multiple herbicide-resistant Lolium rigidum. Phorate synergised with three different herbicide modes of action, enhancing the activity of the ALS inhibitor chlorsulfuron (60% LD 50 reduction), the VLCFAE inhibitor pyroxasulfone (45% LD 50 reduction) and the mitosis inhibitor trifluralin (70% LD 50 reduction). Conversely, phorate antagonised the two thiocarbamate herbicides prosulfocarb and triallate with a 12-fold LD 50 increase. We report the selective reversal of P450-mediated metabolic multiple resistance to chlorsulfuron and trifluralin in the grass weed L. rigidum by synergistic interaction with the insecticide phorate, and discuss the putative mechanistic basis. This research should encourage diversity in herbicide use patterns for weed control as part of a long-term integrated management effort to reduce the risk of selection of metabolism-based multiple herbicide resistance in L. rigidum. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Oxidative stress caused by the use of preemergent herbicides in rice crops

    Directory of Open Access Journals (Sweden)

    Ana Claudia Langaro

    Full Text Available ABSTRACT Among the methods of weed control, stands out chemical control. However, even selective, herbicides can trigger the production of reactive species of oxygen and cause oxidative stress. The aim of the study was to evaluate changes in photosynthetic parameters, oxidative damage, antioxidant enzyme activity and altered metabolism of rice plants after applying pre-emergent herbicides. The experiment was conducted in a greenhouse and herbicides used were oxadiazon, pendimethalin and oxyfluorfen, beyond the control without herbicide. There was a reduction of photosynthetic rate and efficiency of carboxylation, compared to the control, when applied herbicides oxyfluorfen and pendimethalin. The major lipid peroxidation and proline accumulation was observed for the herbicide oxyfluorfen. The oxyfluorfen and oxadiazon herbicides also resulted in increased activity of superoxide dismutase, compared to control. When evaluated ascorbate peroxidase activity, there was a higher enzyme activity in plants treated with oxadiazon and pendimethalin. Even selective herbicides registered for weed control in rice crops cause phytotoxicity, reduce height and alter the metabolism of plants, generating reactive oxygen species, which activate enzymatic and non-enzymatic defense systems and result in the degradation of photosynthetic pigments and in reduced protein content.

  18. Laboratory study on leachability of five herbicides in South Australian soils.

    Science.gov (United States)

    Ying, G G; Williams, B

    2000-03-01

    Norflurazon, oxadiazon, oxyfluorfen, trifluralin and simazine are herbicides widely used in the vineyards of the Barossa Valley, South Australia. The leaching behaviour of norflurazon, oxadiazon, oxyfluorfen and trifluralin was investigated on four key soils in the Barossa Valley. Leaching potential on packed soil columns and actual mobility using intact soil columns were investigated. On the packed soil columns, norflurazon was the most leachable herbicide. More of the herbicides were detected in the leachates from the sandy soils (Mountadam and Nuriootpa) than from the clayey soils (Lyndoch and Tanunda). Organic matter is generally low in soils in the Barossa region. Porosity and saturated conductivity significantly affect herbicide movement and in the sandy Mountadam and Nuriootpa soils, the water flux is greater than for the higher clay content Lyndoch and Tanunda soils. Increasing the time interval between herbicide application and the incidence of "rainfall" reduced the amounts of herbicides found in the leachates. The use of intact soil columns and including simazine for comparison showed that both norflurazon and simazine were present in the leachates. Simazine was the first herbicide to appear in leachates. Sectioning of the intact soil columns after leaching clearly demonstrated that norflurazon and simazine reached the bottom of the soil columns for all soils studied. Greater amounts of norflurazon were retained in the soil columns compared with simazine. The other herbicides were mostly retained in the initial sections of the soil columns.

  19. Integration of Agronomic Practices with Herbicides for Sustainable Weed Management in Aerobic Rice

    Science.gov (United States)

    Anwar, M. P.; Juraimi, A. S.; Mohamed, M. T. M.; Uddin, M. K.; Samedani, B.; Puteh, A.; Man, Azmi

    2013-01-01

    Till now, herbicide seems to be a cost effective tool from an agronomic view point to control weeds. But long term efficacy and sustainability issues are the driving forces behind the reconsideration of herbicide dependent weed management strategy in rice. This demands reappearance of physical and cultural management options combined with judicious herbicide application in a more comprehensive and integrated way. Keeping those in mind, some agronomic tools along with different manual weeding and herbicides combinations were evaluated for their weed control efficacy in rice under aerobic soil conditions. Combination of competitive variety, higher seeding rate, and seed priming resulted in more competitive cropping system in favor of rice, which was reflected in lower weed pressure, higher weed control efficiency, and better yield. Most of the herbicides exhibited excellent weed control efficiency. Treatments comprising only herbicides required less cost involvement but produced higher net benefit. On the contrary, treatments comprising both herbicide and manual weeding required high cost involvement and thus produced lower net benefit. Therefore, adoption of competitive rice variety, higher seed rate, and seed priming along with spraying different early-postemergence herbicides in rotation at 10 days after seeding (DAS) followed by a manual weeding at 30 DAS may be recommended from sustainability view point. PMID:24223513

  20. Lawn Weed Control with Herbicides. Home and Garden Bulletin No. 123.

    Science.gov (United States)

    Agricultural Research Service (USDA), Washington, DC.

    Information and diagrams are given for identification and treatment of weed grasses and broadleaf weeds. Herbicides are suggested for use against each weed and instructions are given for proper application. Information is given for buying herbicides, and applying sprays and cleaning sprayers. (BB)

  1. Grassland response to herbicides and seeding of native grasses 6 years posttreatment

    Science.gov (United States)

    Bryan A. Endress; Catherine G. Parks; Bridgett J. Naylor; Steven R. Radosevich; Mark. Porter

    2012-01-01

    Herbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We found the timing of picloram...

  2. Questions concerning the potential impact of glyphosate-based herbicides on amphibians.

    Science.gov (United States)

    Wagner, Norman; Reichenbecher, Wolfram; Teichmann, Hanka; Tappeser, Beatrix; Lötters, Stefan

    2013-08-01

    Use of glyphosate-based herbicides is increasing worldwide. The authors review the available data related to potential impacts of these herbicides on amphibians and conduct a qualitative meta-analysis. Because little is known about environmental concentrations of glyphosate in amphibian habitats and virtually nothing is known about environmental concentrations of the substances added to the herbicide formulations that mainly contribute to adverse effects, glyphosate levels can only be seen as approximations for contamination with glyphosate-based herbicides. The impact on amphibians depends on the herbicide formulation, with different sensitivity of taxa and life stages. Effects on development of larvae apparently are the most sensitive endpoints to study. As with other contaminants, costressors mainly increase adverse effects. If and how glyphosate-based herbicides and other pesticides contribute to amphibian decline is not answerable yet due to missing data on how natural populations are affected. Amphibian risk assessment can only be conducted case-specifically, with consideration of the particular herbicide formulation. The authors recommend better monitoring of both amphibian populations and contamination of habitats with glyphosate-based herbicides, not just glyphosate, and suggest including amphibians in standardized test batteries to study at least dermal administration. Copyright © 2013 SETAC.

  3. Histopathological study on the effect of rice herbicides on grass carp ...

    African Journals Online (AJOL)

    Grass carp (Ctenopharyngodan idella) fingerlings were exposed to rice herbicides butachlor 1.5 kg ha-1, oxyfluorfen 0.25 kg ha-1 and thiobencarb 1.5 kg ha-1, 12 days after their application in the respective fields. To observe the impact of herbicides on the histopathology of the fish, the fingerlings were collected from the ...

  4. Effect of the silvicultural treatment on canopy properties, litter and seed production in beech coppices under conversion to high forest.

    Directory of Open Access Journals (Sweden)

    Andrea Cutini

    2010-12-01

    Full Text Available European beech (Fagus sylvatica L. is widely distributed in Italy where it covers 1035103 ha, mainly concentrated in the mountainous areas at altitudes above 900 m. The major part is represented by high forest often issued from the conversion of coppice woods, which in the past was the silvicultural system most widely applied mainly to provide fire wood. The social changes occurred in the second half of the last century –fire wood market crisis and the increasing importance of environmental issues- enhanced the conversion into high forest of large areas previously managed as coppice by means of different silvicultural treatments and practices. Nevertheless, the environmental benefits of this choice were not adequately investigated. Results of annual measurements (1992-2009 made in a beech coppice stand aged 65 are here reported. The study area is located on the Alpe di Catenaia, a pre-Apennine outcrop close to Arezzo (Central Italy. Variables strictly related to stand productivity and dynamics such as annual litter and seed production, leaf area index (LAI and transmittance (PAR were measured in the research area of Buca Zamponi to estimate the effects of two theses, natural evolution (TEST and conversion into high forest (DIR. Three thinnings were undertaken in the latter thesis in 1972, 1987 and 2002. Additional theses of natural evolution (CONTR and advance seed cutting (TS were added in 2002 in a nearby study area (Eremo della Casella. Results showed the high productivity of coppice stands, under conversion to high forest, with mean values of annual total litter, leaf litter and leaf area index of 5 Mg ha-1, 3 Mg ha-1 and 6 m2m-2, respectively. These findings confirm both the prompt response of beech to intensive thinning cycles and the reliability of undertaking coppice conversion into high forest. Furthermore, the positive trend observed in the ecological parameters and the high consistency of leaf fraction, highlight the still juvenile

  5. BELVEDERE® Extra – a new high performance- herbicide in beets

    Directory of Open Access Journals (Sweden)

    Donati, Alexandra

    2014-03-01

    Full Text Available Common lambsquarters, cleavers, ladysthumb and wild buckwheat, chamomile, mercury, foolsparsleey and volunteer rapes are only some of the most important weeds in fooder and sugar beets. For the control of classical weed societies farmers can fall back on a limited number of active ingredients. Generally, Phenmedipham (PMP, Desmedipham (DMP and Ethofumesate are the basis of a spray sequence. They are complemented with other active ingredients depending on the specific weed situation. The newly formulated BELVEDERE® Extra combines the three mentioned active ingredients in an optimal ratio. Hence, the herbicide covers a very broad weed spectrum with an excellent efficacy on Common lambsquarters, cleavers, ladysthumb and wild buckwheat. BELVEDERE® EXTRA is a liquid, selective, and systemic herbicide. It is formulated as suspoemulsion so that a high efficacy is achieved while preserving a very good selectivity. The product allows for flexible control of leaf activity as an additive (e.g. OLEO FC is appended. Ethofumesate, which is mainly effective via the roots of the plant, belongs to a different HRAC group than Phenmedipham and Desmedipham. The high concentration of 200 g/L Ethofumesate leads to an effective resistance management especially regarding Fathen and other important weeds. Since 23rd of September 2013 BELVEDERE® extra is registered for post emergence splitting application (3 applications against annual dicotyledonous weeds. The maximum application rate per treatment is 1,3 L/ha. In combination with GOLTIX® TITAN® (Metamitron + Quinmerac or Goltix® Gold (Metamitron the weed spectrum is broadened. Basically, a timely application whose application rates are adapted to the location is essential for a good efficacy of beet herbicides.

  6. Downy Brome (Bromus tectorum L. and Broadleaf Weed Control in Winter Wheat with Acetolactate Synthase-Inhibiting Herbicides

    Directory of Open Access Journals (Sweden)

    Patrick W. Geier

    2013-04-01

    Full Text Available A study was conducted for three seasons in northwest Kansas, USA to evaluate acetolactate synthase (ALS-inhibiting herbicides for downy brome (Bromus tectorum L. and winter annual broadleaf weed control in winter wheat. Herbicides included pyroxsulam at 18.4 g ai ha−1, propoxycarbazone-Na at 44 g ai ha−1, premixed propoxycarbazone-Na & mesosulfuron-methyl at 27 g ai ha−1, and sulfosulfuron at 35 g ai ha−1. The herbicides were applied postemergence in fall and spring seasons. Averaged over time of application, no herbicide controlled downy brome more than 78% in any year. When downy brome densities were high, control was less than 60%. Pyroxsulam controlled downy brome greater than or similar to other herbicides tested. Flixweed (Descurainia sophia L., blue mustard [Chorispora tenella (Pallas DC.], and henbit (Lamium amplexicaule L. control did not differ among herbicide treatments. All herbicides tested controlled flixweed and blue mustard at least 87% and 94%, respectively. However, none of the herbicides controlled henbit more than 73%. Fall herbicide applications improved weed control compared to early spring applications; improvement ranged from 3% to 31% depending on the weed species. Henbit control was greatly decreased by delaying herbicide applications until spring compared to fall applications (49% vs. 80% control. Herbicide injury was observed in only two instances. The injury was ≤13% with no difference between herbicides and the injury did not impact final plant height or grain yield.

  7. Forest worker exposure to airborne herbicide residues in smoke from prescribed fires in the Southern United States

    Science.gov (United States)

    Charles K. McMahon; Parshall B. Bush

    1992-01-01

    Occupational safety and health concerns have been raised in a number of southern states by workers conducting prescribed burns on forested lands treated with herbicides. Modeling assessments coupled with laboratory experiments have shown that the risk of airborne herbicide residues to workers is insignificant, even if the fire occurs immediately after herbicide...

  8. Silviculture and economic benefits of producing wood energy from conventional forestry systems and measures to mitigate negative impacts

    International Nuclear Information System (INIS)

    Manley, A.; Richardson, J.

    1995-01-01

    Activity ''Forest Energy Production'' focused on the development and evaluation, in the context of conventional forestry systems, silvicultural and forest management practices which optimise productivity for traditional products and wood for energy, while safeguarding the forest ecosystem. A series of meetings, workshops, and review papers involving the three participating countries of Canada, Sweden, and the United Kingdom were planned and completed. An additional workshop in Switzerland was also held. Increasing production of biomass for energy is generally found to be positive, from silvicultural, economic, and environmental perspectives. Eight specific forest management systems were investigated and/or reported: five conventional systems involving multiple products in softwood and mixed wood, and three hardwood systems emphasising production of biomass for energy. Modifications in silvercultural practice to also produce biomass for energy included increased opportunities for thinnings, intermediate cuttings, and stand and site rehabilitation as well as more flexible and efficient harvesting systems. Economic benefits accrued from increased investment in harvesting and burning technology, improvements in stand quality and site utilisation, and substitution for more expensive fuels, especially if all costs are considered. Environmental effects were found to be generally positive, but negative effects of nutrient and organic matter removal on the overall sustainability of specific systems are possible. These need to be addressed. Harvest and management guidelines are being designed and put into practice. Social, institutional, and technical barriers to the increased use of biomass for energy are being addressed by specific strategies and initiatives involving programs and incentives for production, market development, research and education. Net positive effects indicate increased use of forest biomass for energy, in the short and long term. (Abstract Truncated)

  9. Weed control changes and genetically modified herbicide tolerant crops in the USA 1996-2012.

    Science.gov (United States)

    Brookes, Graham

    2014-01-01

    Crops that have been genetically modified (GM) to be tolerant to herbicides have been widely grown in the USA since 1996. The rapid and widespread adoption of this technology reflects the important economic and environmental benefits that farmers have derived from its use (equal to $21.7 billion additional farm income and a 225 million kg reduction in herbicide active ingredient use 1996-2012). During this time, weed control practices in these crops relative to the 'conventional alternative' have evolved to reflect experience of using the technology, the challenges that have arisen and the increasing focus in recent years on developing sustainable production systems. This paper examines the evidence on the changing nature of herbicides used with these crops and in particular how farmers addressed the challenge of weed resistance. The evidence shows that use of the technology has resulted in a net reduction in both the amount of herbicide used and the associated environmental impact, as measured by the EIQ indicator when compared to what can reasonably be expected if the area planted to GM HT crops reverted to conventional production methods. It also facilitated many farmers being able to derive the economic and environmental benefits associated with switching from a plough-based to a no tillage or conservation tillage production system. In terms of herbicide use, the technology has also contributed to a change the profile of herbicides used. A broad range of, mostly selective herbicides has been replaced by one or 2 broad-spectrum herbicides (mostly glyphosate) used in conjunction with one or 2 other (complementary) herbicides. Since the mid-2000s, the average amount of herbicide applied and the associated environmental load, as measured by the EIQ indicator, have increased on both GM HT and conventional crops. A primary reason for these changes has been increasing incidence of weed species developing populations resistant to herbicides and increased awareness of

  10. Economics of site-specific and variable-dose herbicide application

    DEFF Research Database (Denmark)

    Ørum, Jens Erik; Kudsk, Per; Jensen, Peter Kryger

    2017-01-01

    Site-specific application of pesticides has so far focused mainly on herbicides. The purpose of precision farming technologies in relation to herbicide use is to reduce herbicide cost and environmental impact from spraying, but at the same time to achieve acceptable weed control. Another purpose...... is to increase the spraying capacity, to reduce the number of sprayer refills, and finally to minimize time spent on weed monitoring. In this chapter the relevance and profitability of four precision herbicide application technologies, two weed detection technologies and a low dose decision support system (DSS......) is analysed. With a low dose herbicide, cost can be reduced by 20–50%. It requires, however, proper monitoring of weeds, which can be a time-consuming task that again requires that the farmer is able to identify the dominant weed species. The current development of high-speed camera and software systems can...

  11. Study of different herbicide molecules for the control of durum wheat weed

    Directory of Open Access Journals (Sweden)

    Michele Perniola

    2008-07-01

    Full Text Available In order to enhance the chances to rotate the herbicide molecules, the effectiveness of a new molecule, pinoxaden, was tested, comparing it with other herbicides used in wheat weed control. The trial was carried out comparing the following herbicide mixtures: 1 no weed control treatment; 2 Tribenuron Methyl (TM; 3 Clodinafop (C; 4 Tribenuron Methyl + Clodinafop (TM+C; 5 Pinoxaden + clodinafop + propargile (PCP; 6 Pinoxaden + clodinafop + propargile + Triasulfuron (PCP+T; 7 Pinoxaden + clodinafop + propargile + absolute Ioxinil and Mecoprop (PCP+IM. The new PCP+T herbicides mixture didn’t differ statistically from the traditional TMC treatment in terms of effectiveness, but the agronomic result of the new mixture was totally satisfactory, even taking into account that the marketing of this mixture is not aimed to compete with other existing herbicides but to widen the chance to rotate active principles in time and space, in order to control the onset of resistance phenomena.

  12. Study of different herbicide molecules for the control of durum wheat weed

    Directory of Open Access Journals (Sweden)

    Michele Perniola

    Full Text Available In order to enhance the chances to rotate the herbicide molecules, the effectiveness of a new molecule, pinoxaden, was tested, comparing it with other herbicides used in wheat weed control. The trial was carried out comparing the following herbicide mixtures: 1 no weed control treatment; 2 Tribenuron Methyl (TM; 3 Clodinafop (C; 4 Tribenuron Methyl + Clodinafop (TM+C; 5 Pinoxaden + clodinafop + propargile (PCP; 6 Pinoxaden + clodinafop + propargile + Triasulfuron (PCP+T; 7 Pinoxaden + clodinafop + propargile + absolute Ioxinil and Mecoprop (PCP+IM. The new PCP+T herbicides mixture didn’t differ statistically from the traditional TMC treatment in terms of effectiveness, but the agronomic result of the new mixture was totally satisfactory, even taking into account that the marketing of this mixture is not aimed to compete with other existing herbicides but to widen the chance to rotate active principles in time and space, in order to control the onset of resistance phenomena.

  13. Study of different herbicide molecules for the control of durum wheat weed

    Directory of Open Access Journals (Sweden)

    Vittorio Filì

    2011-02-01

    Full Text Available In order to enhance the chances to rotate the herbicide molecules, the effectiveness of a new molecule, pinoxaden, was tested, comparing it with other herbicides used in wheat weed control. The trial was carried out comparing the following herbicide mixtures: 1 no weed control treatment; 2 Tribenuron Methyl (TM; 3 Clodinafop (C; 4 Tribenuron Methyl + Clodinafop (TM+C; 5 Pinoxaden + clodinafop + propargile (PCP; 6 Pinoxaden + clodinafop + propargile + Triasulfuron (PCP+T; 7 Pinoxaden + clodinafop + propargile + absolute Ioxinil and Mecoprop (PCP+IM. The new PCP+T herbicides mixture didn’t differ statistically from the traditional TMC treatment in terms of effectiveness, but the agronomic result of the new mixture was totally satisfactory, even taking into account that the marketing of this mixture is not aimed to compete with other existing herbicides but to widen the chance to rotate active principles in time and space, in order to control the onset of resistance phenomena.

  14. Screening of photosynthetic pigments for herbicidal activity with a new computational molecular approach.

    Science.gov (United States)

    Krishnaraj, R Navanietha; Chandran, Saravanan; Pal, Parimal; Berchmans, Sheela

    2013-12-01

    There is an immense interest among the researchers to identify new herbicides which are effective against the herbs without affecting the environment. In this work, photosynthetic pigments are used as the ligands to predict their herbicidal activity. The enzyme 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase is a good target for the herbicides. Homology modeling of the target enzyme is done using Modeler 9.11 and the model is validated. Docking studies were performed with AutoDock Vina algorithm to predict the binding of the natural pigments such as β-carotene, chlorophyll a, chlorophyll b, phycoerythrin and phycocyanin to the target. β-carotene, phycoerythrin and phycocyanin have higher binding energies indicating the herbicidal activity of the pigments. This work reports a procedure to screen herbicides with computational molecular approach. These pigments will serve as potential bioherbicides in the future.

  15. Toxicological Effects of a Post Emergent Herbicide on Spirodela polyrhiza as a Model Macrophyte: A Comparison of the Effects of Pure and Nano-capsulated Form of the Herbicide

    Directory of Open Access Journals (Sweden)

    Samaneh Torbati *

    2018-02-01

    Full Text Available Background: One of the main reasons of environmental contaminations is the broad application of herbicides. Controlled release technologies such as encapsulation of herbicides are as an effective tool to reduce environmental contaminations. The aim of the present study was successful nanocapsulation of Gallant Super (GS, its characterization and compare the physiological responses of Spirodela polyrhiza L. upon exposure to GS and its encapsulated form. Methods: Nanocapsulation of GS in the poly (methyl methacrylate (PMMA was performed in the Department of Nanotechnology, Faculty of Sciences and biological effects of the contaminants on S. polyrhiza was investigated in Biotechnology Research Center, both in Urmia University, Urmia, Iran in 2016. The surface morphology of PMMA/GS nanocapsules was studied by SEM and TEM and their chemical characterization was determined by FT-IR spectroscopy. For assessment of the effects of the encapsulated Gallant Super (ECGS and GS on S. polyrhiza, some plant physiological parameters were investigated. Results: Direct treatment of GS had more and notable negative effects on the plant growth when compared with ECGS treatments. Moreover, different examined concentrations of the two contaminant groups led to the remarkable induction of the activities of the antioxidant enzymes such as SOD. Even though the enhancement of the antioxidant enzymes activities when the plant was treated with GS was notably more than the effects of ECGS. Conclusion: ECGS caused to the fewer changes in the plant physiological parameters and negative effects of the treatment of ECGs were less than when the plant had direct contact with GS.

  16. Delayed degradation in soil of foliar herbicides glyphosate and sulcotrione previously absorbed by plants: Consequences on herbicide fate and risk assessment

    OpenAIRE

    Doublet, Jeremy; Mamy, Laure; Barriuso Benito, Enrique

    2009-01-01

    Following application, pesticides can be intercepted and absorbed by weeds and/or crops. Plants containing pesticides residues may then reach the soil during the crop cycle or after harvest. However, the fate in soil of pesticides residues in plants is unknown. Two commonly used foliar herbicides, glyphosate and sulcotrione, 14C-labeled, were applied on leaves of oilseed rape and/or maize, translocation was studied, and then soil incubations of aerial parts of plants containing herbicides res...

  17. DSSHerbicide: Herbicide field trials in winter wheat. How to come to a decision

    Directory of Open Access Journals (Sweden)

    Sefzat, David

    2014-02-01

    Full Text Available Herbicide decision support systems can calculate efficient, economically optimized herbicide mixtures with reduced dosages, if field specific weed data are given. Thus, they can be a sensible tool for integrated weed control. However, advises of decision support systems have to be tested before introducing them into practical farming. In Mecklenburg-Vorpommern two herbicide field trials were installed with four different prototypes of decision support systems. An untreated plot and three expert advices, private advisors, official advisory service and a farmer decision, were included as additional test variables. Herbicide efficacies in autumn, weed dry matter after spring applications, herbicide costs and wheat yield were measured to evaluate the decision support system prototypes. In one field trial with low weed density before treatments efficacies were at least 85%. In two prototypes efficacies were lower than in the expert plots. No significant differences between decision variables were found regarding weed dry matter after spraying in spring. On this site, herbicide costs were higher when expert advises were used compared to decision support system advises. No significant differences were detected in yield. Even yield in “untreated” was not significantly different. The second field trial carried higher weed densities. Here herbicide efficacies were lower in all treatments. Poa annua and Matricaria recutita were significantly affected by the treatments resulting from the decision tools. However, these differences did not result in statistically different weed dry matter or wheat yield. Three of the prototypes advised solutions with very low herbicide costs in autumn, but high costs in spring. As a result, total weed costs in these plots were higher than in the plots advised by experts. It is concluded from the field trials, that different prototypes of decision support systems are giving sensible herbicide advice. In fields with low

  18. Herbicide monitoring in soil, runoff waters and sediments in an olive orchard.

    Science.gov (United States)

    Calderon, Maria Jesus; De Luna, Elena; Gomez, Jose Alfonso; Hermosin, M Carmen

    2016-11-01

    Occurrences of surface water contamination by herbicides in areas where olive orchards are established reveal a need to understand soil processes affecting herbicide fate at field scale for this popular Mediterranean crop. A monitoring study with two herbicides (terbuthylazine and oxyfluorfen) in the first 2cm of soil, runoff waters, and sediments, was carried out after under natural rainfall conditions following winter herbicide application. At the end of the 107day field experiment, no residues of the soil applied terbuthylazine were recovered, whereas 42% of the oxyfluorfen applied remained in the top soil. Very low levels of both herbicides were measured in runoff waters; however, concentrations were slightly higher for terbuthylazine (0.53% of applied) than for oxyfluorfen (0.03% of applied), relating to their respective water solubilities. Congruent with soil residue data, 38.15% of the applied oxyfluorfen was found in runoff-sediment, compared to only 0.46% for terbuthylazine. Accordingly, the herbicide soil distribution coefficients measured within runoff field tanks was much greater for oxyfluorfen (Kd=3098) than for terbuthylazine (Kd=1.57). The herbicide oxyfluorfen is co-transported with sediment in runoff, remaining trapped and/or adsorbed to soil particle aggregates, due in part to its low water solubility. In contrast, terbuthylazine soil dissipation may be associated more so with leaching processes, favored by its high water solubility, low sorption, and slow degradation. By comparing these two herbicides, our results reaffirm the importance of herbicide physico-chemical properties in dictating their behavior in soil and also suggest that herbicides with low solubility, as seen in the case oxyfluorfen, remain susceptible to offsite transport associated with sediments. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. ACCERBATIN, a small molecule at the intersection of auxin and reactive oxygen species homeostasis with herbicidal properties.

    Science.gov (United States)

    Hu, Yuming; Depaepe, Thomas; Smet, Dajo; Hoyerova, Klara; Klíma, Petr; Cuypers, Ann; Cutler, Sean; Buyst, Dieter; Morreel, Kris; Boerjan, Wout; Martins, José; Petrášek, Jan; Vandenbussche, Filip; Van Der Straeten, Dominique

    2017-07-10

    The volatile two-carbon hormone ethylene acts in concert with an array of signals to affect etiolated seedling development. From a chemical screen, we isolated a quinoline carboxamide designated ACCERBATIN (AEX) that exacerbates the 1-aminocyclopropane-1-carboxylic acid-induced triple response, typical for ethylene-treated seedlings in darkness. Phenotypic analyses revealed distinct AEX effects including inhibition of root hair development and shortening of the root meristem. Mutant analysis and reporter studies further suggested that AEX most probably acts in parallel to ethylene signaling. We demonstrated that AEX functions at the intersection of auxin metabolism and reactive oxygen species (ROS) homeostasis. AEX inhibited auxin efflux in BY-2 cells and promoted indole-3-acetic acid (IAA) oxidation in the shoot apical meristem and cotyledons of etiolated seedlings. Gene expression studies and superoxide/hydrogen peroxide staining further revealed that the disrupted auxin homeostasis was accompanied by oxidative stress. Interestingly, in light conditions, AEX exhibited properties reminiscent of the quinoline carboxylate-type auxin-like herbicides. We propose that AEX interferes with auxin transport from its major biosynthesis sites, either as a direct consequence of poor basipetal transport from the shoot meristematic region, or indirectly, through excessive IAA oxidation and ROS accumulation. Further investigation of AEX can provide new insights into the mechanisms connecting auxin and ROS homeostasis in plant development and provide useful tools to study auxin-type herbicides. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  20. Preemergence herbicides on weed control in elephant grass pasture

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    Alexandre Magno Brighenti

    Full Text Available ABSTRACT Elephant grass (Pennisetum purpureum Schum. is an important forage crop that has been proposed as a potential feedstock for bioenergy production. However, weed interference is a major factor limiting elephant grass production. Field experiments were conducted in 2014 and 2015 to evaluate preemergence herbicides for selective weed control in an elephant grass pasture. Herbicide treatments included atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, diuron + hexazinone, sulfentrazone, imazethapyr, and atrazine at label use rates. Weedy and weed-free treatments were included. Atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, sulfentrazone, and atrazine did not cause phytotoxicity on elephantgrass 35 days after treatment (DAT. However, diuron + hexazinone and imazethapyr were the most phytotoxic on elephantgrass, resulting in 81 and 70% phytotoxicity in 2014, and 7 and 6% phytotoxicity in 2015 respectively 35 DAT. All treatments provided effective weed control (>81% with the exception of ethoxysulfuron (0 and 11% in 2014 and 2015, respectively, and atrazine (59% in 2014. These results show that atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, sulfentrazone, and atrazine were selectives when applied in preemergence in elephant grass pasture.

  1. Progress in herbicide determination with the thylakoid bioassay.

    Science.gov (United States)

    Trapmann, S; Etxebarria, N; Schnabl, H; Grobecker, K H

    1998-01-01

    Chloroplast thylakoids are used as biological units to determine herbicides in different kinds of water samples as well as in aqueous extracts of compost, soil or food samples. The thylakoid bioassay shows clearly inhibition of fluorescence yield in the presence of photosystem II specific herbicides. Due to this method the ecotoxicological effect of samples with unknown pollutants can be tested fast and cost effective. It has been proven that all photosynthetic active compounds are recorded at the same time because only additive interactions occur. Therefore, the contamination level can be expressed as cumulative parameter for photosystem II active substances. Application was improved clearly by the addition of the radical scavenger sodium ascorbate to the isolation media and by a higher concentration of the measuring medium. A new data evaluation method is described yielding in a lower detection limit of 0.4 microg diuron/1. The guidelines for the quality of water for human consumption with an allowable concentration of pesticides in groups is 0,5 microg/1 and can be controlled with the thylakoid bioassay without performing any preconcentration steps.

  2. Herbicidal and Fungicidal Activities of Lactones in Kava (Piper methysticum).

    Science.gov (United States)

    Xuan, T D; Elzaawely, A A; Fukuta, M; Tawata, S

    2006-02-08

    This is the first report showing that kava lactones are plant and plant fungus growth inhibitors. Aqueous extract of kava roots showed high allelopathic potential and strongly suppressed germination and growth of lettuce, radish, barnyardgrass, and monochoria. Nine kava lactones were detected using GC-MS including desmethoxyyagonin, kavain, 7,8-dihydrokavain, hydroxykavain, yagonin, 5,6,7,8-tetrahydroxyyagonin, methysticin, dihydromethysticin, and 11-hydroxy-12-methoxydihydrokavain. Quantities of desmethoxyyagonin, kavain, 7,8-dihydrokavain, yagonin, methysticin, and dihydromethysticin detected were 4.3, 6.9, 18.6, 5.7, 1.4, and 5.4 mg/g of dry weight, respectively. These six major lactones in kava roots showed great herbicidal and antifungal activities. Growth of lettuce and barnyardgrass were significantly inhibited at 1-10 ppm, and four plant fungi including Colletotrichum gloeosporides, Fusarium solani, Fusarium oxysporum, and Trichoderma viride were significantly inhibited at 10-50 ppm. The biological activities of kava lactones were characterized by different double-bond linkage patterns in positions 5,6 and 7,8. The findings of this study suggest that kava lactones may be useful for the development of bioactive herbicides and fungicides.

  3. Developmental toxicity of diphenyl ether herbicides in nestling American kestrels.

    Science.gov (United States)

    Hoffman, D J; Spann, J W; LeCaptain, L J; Bunck, C M; Rattner, B A

    1991-11-01

    Beginning the day after hatching, American kestrel (Falco sparverius) nestlings were orally dosed for 10 consecutive days with 5 microliters/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorfen) at concentrations of 10, 50, 250, or 500 mg/kg in corn oil. At 500 mg/kg, nitrofen resulted in complete nestling mortality, bifenox in high (66%) mortality, and oxyfluorfen in no mortality. Nitrofen at 250 mg/kg reduced nestling growth as reflected by decreased body weight, crown-rump length, and bone lengths including humerus, radius-ulna, femur, and tibiotarsus. Bifenox at 250 mg/kg had less effect on growth than nitrofen, but crown-rump, humerus, radius-ulna, and femur were significantly shorter than controls. Liver weight as a percent of body weight increased with 50 and 250 mg/kg nitrofen. Other manifestations of impending hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity in all nitrofen-treated groups, and increased plasma enzyme activities for ALT, AST, and LDH-L in the 250-mg/kg group. Bifenox ingestion resulted in increased hepatic GSH peroxidase activity in the 50- and 250-mg/kg groups. Nitrofen exposure also resulted in an increase in total plasma thyroxine (T4) concentration. These findings suggest that altricial nestlings are more sensitive to diphenyl ether herbicides than young or adult birds of precocial species.

  4. Application of electrokinetic soil flushing to four herbicides: A comparison.

    Science.gov (United States)

    dos Santos, E Vieira; Souza, F; Saez, C; Cañizares, P; Lanza, M R V; Martinez-Huitle, C A; Rodrigo, M A

    2016-06-01

    In this work, four bench-scale plants containing soil spiked with four herbicides (2,4-Dichlorophenoxyacetic acid (2,4-D), oxyfluorfen, chlorsulfuron and atrazine) undergo treatment consisting of an electrokinetic soil flushing (EKSF). Results clearly demonstrate that efficiency of EKSF depends on the chemical characteristic of the pesticide used. The amount of pesticide collected in the anode well is more significant than that collected in the cathode wells, indicating that the electromigration is much more important than drainage by electro-osmotic flux for this application. After 15 d of treatment, the 2,4-D is the pesticide most efficiently removed (95% of removal), while chlorsulfuron is the pesticide more resilient to the treatment. Additionally, volatilization was found to be a process of the major significance in the application of electrokinetic techniques to soil polluted with herbicides and because of that it should always be taken into account in the future design of full-scale processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. PREVENTION AND CONTROL OF DIMETHYLAMINE VAPORS EMISSION: HERBICIDE PRODUCTION PLANT

    Directory of Open Access Journals (Sweden)

    Zorana Arsenijević

    2008-11-01

    Full Text Available The widely used herbicide, dimethylamine salt of 2,4-dichlorophenoxy acetic acid (2,4-D-DMA, is usually prepared by mixing a dimethylamine (DMA aqueous solution with a solid 2,4-dichlorophenoxy acetic acid (2,4-D. The vapors of the both, reactants and products, are potentially hazardous for the environment. The contribution of DMA vapors in overall pollution from this process is most significant, concerning vapor pressures data of these pollutants. Therefore, the control of the air pollution in the manufacture and handling of methylamines is very important. Within this paper, the optimal air pollution control system in preparation of 2,4-D-DMA was developed for the pesticides manufacturing industry. This study employed the simple pollution prevention concept to reduce the emission of DMA vapors at the source. The investigations were performed on the pilot plant scale. To reduce the emission of DMA vapors, the effluent gases from the herbicide preparation zone were passed through the packed bed scrubber (water - scrubbing medium, and the catalytic reactor in sequence. The end result is a substantially improved air quality in the working area, as well as in the urbanized areas located near the chemical plant.

  6. Weed supression by smother crops and selective herbicides

    Directory of Open Access Journals (Sweden)

    Severino Francisco José

    2004-01-01

    Full Text Available Using a smother crop is thought to suppress weed density and to add other beneficial effects in sustainable agricultural systems. Weed suppression ought to be considered an essential component of integrated weed management. However, very little is known about the effects of green manure plants on weeds. This study evaluated the influence of three green manure species on weed suppression and selectivity of herbicides. A field experiment was designed to determine the effect of the green manure species Crotalaria juncea, Arachis pintoi and pigeon pea on the weeds Brachiaria decumbens, guineagrass and hairy beggarticks, and on the natural weed infestation in the inter rows area of an avocado orchard. The weed species were suppressed differently by each green manure species. Soil samples collected from the field experiment presented a residual effect, of at least 30 d, in suppressing weed seed bank recruitment; this residual effect was caused by the residues of the green manure present in the soil. When the green manure was incorporated into the top 5 cm of soil or left on the surface, in a greenhouse experiment, the emergence of weed seeds was significantly inhibited, depending on the species, and on the amount and depth of green manure incorporation. Greenhouse experiments indicate that pre-emergence herbicides cause lower phytotoxicity than post-emergence Arachis pintoi. Smother crops using green manure species, when well established in an area, provide additional weed control to the cropping system and are effective and valuable tools in integrated weed management.

  7. The Effect of Herbicides on Hydrogen Peroxide Generation in Isolated Vacuoles of Red Beet Root (Beta vulgaris L.

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    E.V. Pradedova

    2015-12-01

    Full Text Available Influence of herbicides on the hydrogen peroxide generation in vacuolar extracts of red beet root (Beta vulgaris L. was investigated. Belonging to different chemical classes of herbicide compounds have been used. Herbicides differ from each other in the mechanism of effects on plants. Clopyralid (aromatic acid herbicide, derivative of picolinic acid and 2.4-D (phenoxyacetic herbicide, characterized by hormone-like effects, contributed to the formation of H2O2 in vacuolar extracts. Fluorodifen (nitrophenyl ether herbicide and diuron (urea herbicide also have increased contents H2O2. These compounds inhibit the electron transport, photosynthesis, and photorespiration in sensitive plants. Herbicidal effect of glyphosate (organophosphorus herbicide is due to the inhibition of amino acid synthesis in plant cells. Glyphosate did not affect the content of H2O2 in vacuolar extracts. Herbicide dependent H2O2-generation did not occur with oxidoreductase inhibitors, potassium cyanide and sodium azide. The results suggest that the formation of ROS in the vacuoles due to activity of oxidoreductases, which could interact with herbicides.

  8. Phytotoxicity of chiral herbicide bromacil: Enantioselectivity of photosynthesis in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Chen, Zunwei; Zou, Yuqin; Wang, Jia; Li, Meichao; Wen, Yuezhong

    2016-01-01

    With the wide application of chiral herbicides and the frequent detection of photosystem II (PSII) herbicides, it is of great importance to assess the direct effects of PSII herbicides on photosynthesis in an enantiomeric level. In the present study, the enantioselective phytotoxicity of bromacil (BRO), typical photosynthesis inhibition herbicide, on Arabidopsis thaliana was investigated. The results showed that S-BRO exhibited a greater inhibition of electron transmission in photosystem I (PSI) of A. thaliana than R-BRO by inhibiting the transcription of fnr 1. S-BRO also changed the chlorophyll fluorescence parameters Y (II), Y (NO), and Y (NPQ) to a greater extent than R-Bro. Transcription of genes psbO2, Lhcb3 and Lhcb6 was down-regulated in an enantioselective rhythm and S-BRO caused more serious influence, indicating that S-BRO did worse damage to the photosystem II (PSII) of A. thaliana than R-BRO. This study suggested that S-BRO disturbed the photosynthesis of plants to a larger extent than R-BRO and provided a new sight to evaluate the phytotoxicity of chiral herbicides. - Highlights: • It is necessary to assess the direct effects of PSII herbicides on photosynthesis. • Phytotoxicity of bromacil is investigated in an enantiomeric level. • Bromacil disturbed enantioselectively the photosystem II of Arabidopsis thaliana. • S-bromacil caused severer damage to photosynthesis of Arabidopsis than R-bromacil. • Photosynthesis should be considered for phytotoxicity assessment of herbicides.

  9. Efficacy of Maister OD (Foramsulfuron + Idosulfuron a New Herbicide in Controlling Weeds of Corn Fields

    Directory of Open Access Journals (Sweden)

    J. Abdi

    2012-07-01

    Full Text Available To evaluate the efficacy of a new herbicide Foramsulfuron +Idosulfuron (Maister OD against other herbicides in corn fields, this experiment was fulfielld in 2010 at Mahidasht, Research Center of Agriculture and Natural Resources of Kermanshah, Iran. It was concucted in randomized complete block design with four replications and 11 treatments. In this experiment, three doses of herbicides (38.75, 46.5 and 54.25 g/ha including foramsulfuron + idosulfuron along with Nicusulfuron, ForamSulfuron, Rimsulfuron, Foramsulfuron + Rimsulfuron , Bromicid + hand weeding narrow leaf weeds, Bromicid + Nicusulfuron and U46 + hand weeding of narrow leaf weeds and a complete weeding as the control treatments were investigated. Weeds present in the field were Xanthium stromarium,Chenopedium album, Portulaca oleracea, Sorgum halepense and Setaria virdis. The results of this study showed that doses 38.75 and 46.5 g/ha of herbicide foramsulfuron + idosulfuron after treatments of Bromicid + Nicusulfuron and, Bromicid + narrow leaf weed, hand weeding respectively could control 90 and 86 % of weeds in corn field and increase its yields significantly. Because there are presently few registered herbicide available in Iran, necessity of finding proper herbicides to control weeds in corn field and based on the results oblained from this experiment it seems using 46.5 and 38-75 grams per hectare respectively of foramsulfuron + idosulfuron could be a better option than other herbicides to control weeds in corn fields and increase its seed yield.

  10. Persistence of auxinic herbicides applied on pasture and toxicity for succeeding crops

    Directory of Open Access Journals (Sweden)

    ARNON H.C. ANÉSIO

    2018-04-01

    Full Text Available ABSTRACT The aim of this work was to determine the persistence of auxinic herbicides applied on tropical pasture and toxicity for succeeding crops. The herbicides were applied in an area of dystrophic red‒yellow latosol with pasture infested of weeds. At 40, 80, and 280 days after application of herbicide, the soil samples were collected at depths of 0 to 20 cm. Soil with residues of 2,4-D, 2,4-D + picloram, triclopyr, and a soil without herbicide application were analyzed with six replicates. Seven crops were cultivated in these soils: cucumber (Cucumis sativus L., velvet bean [Mucuna pruriens (L. DC.], pigeon pea [Cajanus cajan (L. Millsp.], alfalfa (Medicago sativa L., lablab bean [Lablab purpureus (L. Sweet], corn (Zea mays L., and sorghum [Sorghum bicolor (L. Moench]. The plants of cucumber, pigeon pea, and alfalfa were the most susceptible to the auxinic herbicide residues. However, the lablab bean was the only one among the dicot evaluated that showed tolerance to the 2,4-D + picloram residual when cultivated in soils at 280 days after application of herbicide. Corn and sorghum showed lower chlorophyll content in soils with 2,4-D + picloram residual up to 80 days after application of herbicide.

  11. Phytotoxicity of four herbicides on Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii.

    Science.gov (United States)

    Pan, Huiyun; Li, Xiaolu; Xu, Xiaohua; Gao, Shixiang

    2009-01-01

    The physiological effects of 4 herbicides (butachlor, quinclorac, bensulfuron-methyl and atrazine) on 3 submerged macrophytes (Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii) were tested in laboratory. The variables of the relative growth rate and the photosynthetic pigment content showed that all of the tested herbicides affected the growth of the plants obviously, even at the lowest concentration (0.0001 mg/L). Except for the C. demersum treated with quinclorac at 0.005 and 0.01 mg/L, the relative growth rates of the plants were inhibited significantly (p < 0.01). Statistical analysis of chlorophyll a (Chl-a) contents was carried out with both the t-test and one-way ANOVA to determine the difference between the treatment and control. The results showed that Chl-a contents of the plants in all treatment groups were affected by herbicides significantly, except for the C. demersum treated with bensulfuron-methyl at 0.0005 mg/L. The decrease in Chl-a content was positively correlated to the dosage of the herbicides in most treatment groups. It was suggested that herbicides in water bodies might potentially affect the growth of aquatic macrophytes. Since the Chl-a content of submerged macrophytes responded to the stress of herbicides sensitively and directly, it could be used as a biomaker in environmental monitoring or in the ecological risk assessment of herbicide contamination.

  12. Mechanism of sulfonylurea herbicide resistance in the broadleaf weed, Kochia scoparia

    International Nuclear Information System (INIS)

    Saari, L.L.; Cotterman, J.C.; Primiani, M.M.

    1990-01-01

    Selection of kochia (Kochia scoparia) biotypes resistant to the sulfonylurea herbicide chlorsulfuron has occurred through the continued use of this herbicide in monoculture cereal-growing areas in the United States. The apparent sulfonylurea resistance observed in kochia was confirmed in greenhouse tests. Fresh and dry weight accumulation in the resistance kochia was 2- to >350-fold higher in the presence of four sulfonylurea herbicides as compared to the susceptible biotype. Acetolactate synthase (ALS) activity isolated from sulfonylurea-resistant kochia was less sensitive to inhibition by three classes of ALS-inhibiting herbicides, sulfonylureas, imidazolinones, and sulfonanilides. The decrease in ALS sensitivity to inhibition (as measured by the ratio of resistant I 50 to susceptible I 50 ) was 5- to 28-fold, 2- to 6-fold, and 20-fold for sulfonylurea herbicides, imidazolinone herbicides, and a sulfonanilide herbicide, respectively. No differences were observed in the ALS-specific activities or the rates of [ 14 C]chlorsulfuron uptake, translocation, and metabolism between susceptible and resistant kochia biotypes. The K m values for pyruvate using ALS from susceptible and resistant kochia were 2.13 and 1.74 mM, respectively. Based on these results, the mechanism of sulfonylurea resistance in this kochia biotype is due solely to a less sulfonylurea-sensitive ALS enzyme

  13. Phytotoxicity of chiral herbicide bromacil: Enantioselectivity of photosynthesis in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zunwei; Zou, Yuqin; Wang, Jia [MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Li, Meichao [Research Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou 310032 (China); Wen, Yuezhong, E-mail: wenyuezhong@zju.edu.cn [MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2016-04-01

    With the wide application of chiral herbicides and the frequent detection of photosystem II (PSII) herbicides, it is of great importance to assess the direct effects of PSII herbicides on photosynthesis in an enantiomeric level. In the present study, the enantioselective phytotoxicity of bromacil (BRO), typical photosynthesis inhibition herbicide, on Arabidopsis thaliana was investigated. The results showed that S-BRO exhibited a greater inhibition of electron transmission in photosystem I (PSI) of A. thaliana than R-BRO by inhibiting the transcription of fnr 1. S-BRO also changed the chlorophyll fluorescence parameters Y (II), Y (NO), and Y (NPQ) to a greater extent than R-Bro. Transcription of genes psbO2, Lhcb3 and Lhcb6 was down-regulated in an enantioselective rhythm and S-BRO caused more serious influence, indicating that S-BRO did worse damage to the photosystem II (PSII) of A. thaliana than R-BRO. This study suggested that S-BRO disturbed the photosynthesis of plants to a larger extent than R-BRO and provided a new sight to evaluate the phytotoxicity of chiral herbicides. - Highlights: • It is necessary to assess the direct effects of PSII herbicides on photosynthesis. • Phytotoxicity of bromacil is investigated in an enantiomeric level. • Bromacil disturbed enantioselectively the photosystem II of Arabidopsis thaliana. • S-bromacil caused severer damage to photosynthesis of Arabidopsis than R-bromacil. • Photosynthesis should be considered for phytotoxicity assessment of herbicides.

  14. Runoff of the herbicides triclopyr and glufosinate ammonium from oil palm plantation soil.

    Science.gov (United States)

    Tayeb, M A; Ismail, B S; Khairiatul-Mardiana, J

    2017-10-11

    This study focused on the residue detection of the herbicides triclopyr and glufosinate ammonium in the runoff losses from the Tasik Chini oil palm plantation area and the Tasik Chini Lake under natural rainfall conditions in the Malaysian tropical environment. Triclopyr and glufosinate ammonium are post-emergence herbicides. Both herbicides were foliar-sprayed on 0.5 ha of oil palm plantation plots, which were individualized by an uneven slope of 10-15%. Samples were collected at 1, 3, 7, 15, 30, 45, 60, 90, and 120 days after treatment. The concentrations of both herbicides quickly diminished from those in the analyzed sample by the time of collection. The highest residue levels found in the field surface leachate were 0.031 (single dosage, triclopyr), 0.041 (single dosage, glufosinate ammonium), 0.017 (double dosage, triclopyr), and 0.037 μg/kg (double dosage, glufosinate ammonium). The chromatographic peaks were observed at "0" day treatment (2 h after herbicide application). From the applied active ingredients, the triclopyr and glufosinate losses were 0.025 and 0.055%, respectively. The experimental results showed that both herbicides are less potent than other herbicides in polluting water systems because of their short persistence and strong adsorption onto soil clay particles.

  15. Hygienic assessment of risk caused by application of graminis ke and rinkor vg herbicides

    Directory of Open Access Journals (Sweden)

    M.M. Vasileva

    2017-12-01

    Full Text Available Our research goal was to perform hygienic assessment of risks caused by Graminis KE and Rinkor VG herbicides for people working with them. We applied sanitary-hygienic and toxicological research techniques in our work in full conformity with valid technical regulatory documents and guidelines. We set the following research tasks: to analyze literature and information sources; to perform primary toxicological assessment of preparatory herbicides and study their acute toxicity together with sensitizing effects at intragastric introduction, cutaneous application, and inhalation exposure on laboratory animals; to examine herbicides cumulative effects and calculation their cumulation coefficient; to examine working conditions during a natural experiment when Graminis KE and Rinkor VG herbicides were applied and calculate risks for workers; to work out scientifically grounded recommendations on their safety application in agriculture. The examined herbicides, Graminis KE and Rinkor VG, are classified as substances with the 3rd hazard degree as per their toxicometric parameters (moderately hazardous substances. Calculated risks of complex (inhalant and dermal exposure to Gramins KE and Rinkor VG herbicides for workers (operators who refills them and those who spray plants with them when they are applied in agriculture don't exceed acceptable levels (are less than 1. Our work results allow to enrich a set of plant protectors which are applied in the country and to use such preparations in agriculture which are the least harmful for health and the environment. Application of Graminis KE and Rinkor VG herbicides will help to increase crops productivity.

  16. Early Identification of Herbicide Stress in Soybean (Glycine max (L.) Merr.) Using Chlorophyll Fluorescence Imaging Technology.

    Science.gov (United States)

    Li, Hui; Wang, Pei; Weber, Jonas Felix; Gerhards, Roland

    2017-12-22

    Herbicides may damage soybean in conventional production systems. Chlorophyll fluorescence imaging technology has been applied to identify herbicide stress in weed species a few days after application. In this study, greenhouse experiments followed by field experiments at five sites were conducted to investigate if the chlorophyll fluorescence imaging is capable of identifying herbicide stress in soybean shortly after application. Measurements were carried out from emergence until the three-to-four-leaf stage of the soybean plants. Results showed that maximal photosystem II (PS II) quantum yield and shoot dry biomass was significantly reduced in soybean by herbicides compared to the untreated control plants. The stress of PS II inhibiting herbicides occurred on the cotyledons of soybean and plants recovered after one week. The stress induced by DOXP synthase-, microtubule assembly-, or cell division-inhibitors was measured from the two-leaf stage until four-leaf stage of soybean. We could demonstrate that the chlorophyll fluorescence imaging technology is capable for detecting herbicide stress in soybean. The system can be applied under both greenhouse and field conditions. This helps farmers to select weed control strategies with less phytotoxicity in soybean and avoid yield losses due to herbicide stress.

  17. The Turkey oak high forests in the Molise region (central Italy. Analysis of past silvicultural system and current management choices.

    Directory of Open Access Journals (Sweden)

    Paolo Cantiani

    2010-12-01

    Full Text Available Normal 0 14 false false false MicrosoftInternetExplorer4 Aim of the work is to provide further knowledge on the silvicultural system applied to Quercus cerris hight forests in the Molise Region (Central Italy. An historical analysis, based on a number of forest management plans applied since 1940 referred to 19 municipalities and on other historical documents, is provided in the paper. Forest management has been traditionally applied in the Molise Region and therefore is at now possible to reconstruct in detail the management of the forests of Molise Region. The historical study has been integrated with the analysis of a chronosequence including four steps of stand development in a Turkey oak stand: the regeneration phase (1-2 yrs - the unthinned young stand (46 yrs - the unthinned adult stand (aged 60 to 100 - the mature stand (126 yrs. Mensurational surveys were carried out at each phase in order to characterize both stand structure and derive information on the silvicultural practices applied in the past, but not documented in the available papers. The stand age was determined by tree coring and count of annual rings. At the beginning of the last century, the silvicultural system to be applied in oak high forests wasn’t strictly defined and a particular kind of selection cutting was carried out. It was named taglio a salto per sezioni i.e. “compartment selection cutting”, partly leading back to a real selection cutting, partly to a shelterwood system. The use of the reported silvicultural system gave rise to irregular forest structures and led to management problems well-described in the management plans at the end of 1940s. Another consequence of the applied practices was the absence or the inadequate natural regeneration establishment. The contemporary unregulated practice of grazing the forest floor contributed to the unsuccessful regeneration and made the situation worse. The presence of an understorey layer made up by sproutings

  18. Selectivity and stability of vegetation-applied herbicides in cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    T. Barakova

    2016-06-01

    Full Text Available Abstract. An experiment was carried out during 2013 – 2015 in the experimental field of the Field Crops Institute, Chirpan, with two cotton cultivars − Helius and Darmi (Gossypium hirsutum L.. Herbicides: Goal 2 E, oxyfluorfen (80 ml/da; Linuron 45 SC, linuron (200 ml/da; Wing-P, pendimethalin + dimethenamid (400 ml/da; Merlin 750 WG, isoxaflutol (5 g/da; Bazagran 480 SL, bentazone (150 ml/da were investigated. They were treated separately or combined with growth regulator Amalgerol (500 ml/da or foliar fertilizer Lactofol O (500 ml/da in the budding stage of the cotton. It was established that selectivity is the lowest in the two cotton cultivars with herbicides Linuron 45 CK and Merlin 750 WG. The purpose of this investigation was to establish the selectivity and stability of some herbicides and their tank mixtures on the cotton by influence of different meteorological conditions. It has been found that the highest phytotoxicity on cotton is given the vegetation-applied herbicides Merlin and Linuron. Foliar fertilizer Laktofol O reduces phytotoxicity of herbicides Goal, Wing, Merlin and Bazagran in two cotton cultivars. Herbicides Wing and Bazagran have excellent selectivity for the two cotton cultivars – Helius and Darmi. The highest yield was obtained by vegetation treatment with herbicide Bazagran, followed by herbicides Wing and Goal. Tank mixtures of Goal, Bazagran and Wing with Laktofol, followed by those with Amalgerol are technologically the most valuable. They combine high yield with high stability over the years. Аlone application of herbicides Linuron and Merlin and their tank mixtures with Amalgerol and Laktofol have low estimate.

  19. Removal of glyphosate herbicide from water using biopolymer membranes.

    Science.gov (United States)

    Carneiro, Rafael T A; Taketa, Thiago B; Gomes Neto, Reginaldo J; Oliveira, Jhones L; Campos, Estefânia V R; de Moraes, Mariana A; da Silva, Camila M G; Beppu, Marisa M; Fraceto, Leonardo F

    2015-03-15

    Enormous amounts of pesticides are manufactured and used worldwide, some of which reach soils and aquatic systems. Glyphosate is a non-selective herbicide that is effective against all types of weeds and has been used for many years. It can therefore be found as a contaminant in water, and procedures are required for its removal. This work investigates the use of biopolymeric membranes prepared with chitosan (CS), alginate (AG), and a chitosan/alginate combination (CS/AG) for the adsorption of glyphosate present in water samples. The adsorption of glyphosate by the different membranes was investigated using the pseudo-first order and pseudo-second order kinetic models, as well as the Langmuir and Freundlich isotherm models. The membranes were characterized regarding membrane solubility, swelling, mechanical, chemical and morphological properties. The results of kinetics experiments showed that adsorption equilibrium was reached within 4 h and that the CS membrane presented the best adsorption (10.88 mg of glyphosate/g of membrane), followed by the CS/AG bilayer (8.70 mg of glyphosate/g of membrane). The AG membrane did not show any adsorption capacity for this herbicide. The pseudo-second order model provided good fits to the glyphosate adsorption data on CS and CS/AG membranes, with high correlation coefficient values. Glyphosate adsorption by the membranes could be fitted by the Freundlich isotherm model. There was a high affinity between glyphosate and the CS membrane and moderate affinity in the case of the CS/AG membrane. Physico-chemical characterization of the membranes showed low values of solubility in water, indicating that the membranes are stable and not soluble in water. The SEM and AFM analysis showed evidence of the presence of glyphosate on CS membranes and on chitosan face on CS/AG membranes. The results showed that the glyphosate herbicide can be adsorbed by chitosan membranes and the proposed membrane-based methodology was successfully used to

  20. A further evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2002-07-01

    This report summarises the findings of a project evaluating the safety and efficiency of eleven herbicides for controlling weeds in newly plated willow short rotation coppices, and provides growers with information on post-emergence herbicide options, control of problem weeds, and emergency treatments. Weed germination, crop safety, and the encouraging results obtained using Reflex T and Impuls are discussed. It is suggested that a Technical Register of herbicide applications with contributions by growers and advisers should be considered by the British Biogen trade industry body.

  1. Glufosinate herbicide intoxication causing unconsciousness, convulsion, and 6th cranial nerve palsy.

    Science.gov (United States)

    Park, Jae-seok; Kwak, Soo-Jung; Gil, Hyo-wook; Kim, So-Young; Hong, Sae-yong

    2013-11-01

    Although glufosinate ammonium herbicides are considered safe when used properly, ingestion of the undiluted form can cause grave outcomes. Recently, we treated a 34-yr-old man who ingested glufosinate ammonium herbicide. In the course of treatment, the patient developed apnea, mental deterioration, and sixth cranial nerve palsy; he has since been discharged with full recovery after intensive care. This case report describes the clinical features of glufosinate intoxication with a focus on sixth cranial nerve palsy. Our observation suggests that neurologic manifestations after ingestion of a "low-grade toxicity herbicide" are variable and more complex than that was previously considered.

  2. Ecological review of black-grass (Alopecurus myosuroides Huds. propagation abilities in relationship with herbicide resistance

    Directory of Open Access Journals (Sweden)

    Maréchal, PY.

    2012-01-01

    Full Text Available Alopecurus myosuroides Huds. (black-grass has always been a major concern for cereal growers, and the development of herbicide resistance does not improve the situation. This review article summarizes the different traits involved in the dispersal pattern of herbicide resistant black-grass individuals within a susceptible field population. Therefore, the whole life cycle of black-grass is depicted from the seed to the seed. From the early vegetative development to the seed falling, every stage is described, taking into account how herbicide resistance can influence or exert a different impact compared to susceptible plants.

  3. An evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2000-07-01

    The objective of the project was to evaluate the safety and efficacy of a range of herbicides and mixtures of herbicides, with both contact and residual activity, for the post-emergence control of weeds in newly planted willow short rotation coppice (SRC). This report provides growers and advisers of short rotation coppice with important (but still limited) information on how to achieve improved weed control of problem weeds increasingly prevalent in SRC fields. This may provide guidance towards often-essential emergency treatments when the crop establishment is under considerable pressure and the potential safety, or otherwise, of certain weed-specific herbicides. (author)

  4. Integration of row spacing, mulching and herbicides on weed management in tomato

    International Nuclear Information System (INIS)

    Bakht, T.; Khan, I.A.

    2014-01-01

    A field experiment was conducted at the Research Farm of The University of Agriculture, Peshawar during the year 2012 to determine the impact of row spacing and weed management strategies on tomato (Lycopersicon esculentum Mill.). The local variety 'Roma' was sown in a randomized complete block (RCB) design with split plot arrangements, having four replications. The main plots were row spacings while subplots of the experiment comprised of ten treatments including five mulches viz., white and black polyethylene, wheat straw, newspaper and saw dust, three herbicide treatments (fenoxaprop-p-ethyl, pendimethalin and s-metolachlor), hand weeding and a weedy check. The data were recorded on weed density m/sup -2/, fresh and dry weed biomass, number of branches plant-1, and fruit yield (kg ha/sup -1/). All these parameters were significantly affected by row spacing and weed management treatments. Increase in weed population was observed with increasing in row spacing. The competitiveness of tomato with weeds can be enhanced by using black plastic as mulch. In light of the results, the row spacing of 60 cm is the optimum one for tomato plants, as the fruit yields decreased at 40 cm and 80 cm row spacing. (author)

  5. Fungal phytotoxins with potential herbicidal activity: chemical and biological characterization.

    Science.gov (United States)

    Cimmino, Alessio; Masi, Marco; Evidente, Marco; Superchi, Stefano; Evidente, Antonio

    2015-12-19

    Covering: 2007 to 2015 Fungal phytotoxins are secondary metabolites playing an important role in the induction of disease symptoms interfering with host plant physiological processes. Although fungal pathogens represent a heavy constraint for agrarian production and for forest and environmental heritage, they can also represent an ecofriendly alternative to manage weeds. Indeed, the phytotoxins produced by weed pathogenic fungi are an efficient tool to design natural, safe bioherbicides. Their use could avoid that of synthetic pesticides causing resistance in the host plants and the long term impact of residues in agricultural products with a risk to human and animal health. The isolation and structural and biological characterization of phytotoxins produced by pathogenic fungi for weeds, including parasitic plants, are described. Structure activity relationships and mode of action studies for some phytotoxins are also reported to elucidate the herbicide potential of these promising fungal metabolites.

  6. [Poisonings with the herbicides glyphosate and glyphosate-trimesium].

    Science.gov (United States)

    Mortensen, O S; Sørensen, F W; Gregersen, M; Jensen, K

    2000-08-28

    Generally the herbicide glyphosate is considered harmless to humans. Glyphosate-trimesium is labelled harmful (Xn), whereas glyphosate-isopropylamine carries no warning sign. As cases of serious poisoning have emerged contacts to the Poison Information Centre have been reviewed. The persons exposed were mainly smaller children and adults 20 to 59 years of age. Oral exposure was recorded in 47 persons, inhalation exposure in 24 and topical contact in 42. About one fourth of the exposed persons were asymptomatic. Most of the symptomatic poisonings demonstrated complaints from the mouth, the gastrointestinal tract and the airways. Eleven patients were admitted to hospital. Two died, one of them having ingested the isopropylamine salt, the other the trimesium salt. Death ensued quickly in the latter patient. A similar fate was observed in a child--not included in the present material--who had also ingested the trimesium compound.

  7. Herbicide tolerance and seed survival of grain amaranth (Amaranthus sp.)

    DEFF Research Database (Denmark)

    Kudsk, Per; Taberner, Andreu; de Troiani, Rosa M.

    2012-01-01

    Amaranth is receiving increasing attention as an alternative crop to small grain cereals. From a weed control point of view cultivation of amaranth poses two problems. Firstly, amaranth grows slowly after emergence and hence is very susceptible to competition by weeds and secondly, seed losses...... herbicides examined only clomazone, clopyralid, phenmedipham and triflusulfuron were tolerated by amaranth. Applying clomazone early postemergent instead of pre-emergent provided full crop tolerance even at the highest doses (Pcaused less...... crop damage applied at the 4-6 leaf stage compared to the 2-4 leaf stage while clopyralid was selective at both growth stages. The seed survival studies revealed differences between the countries with higher viability in Spain (up to 18%) than in Argentina and Denmark (up to 6%). Our results showed...

  8. Glufosinate (phosphinothricin), a natural amino acid with unexpected herbicidal properties.

    Science.gov (United States)

    Hoerlein, G

    1994-01-01

    Glufosinate ammonium (phosphinothricin ammonium) (GLA) is the active ingredient of Basta and several other herbicides used worldwide. It is produced as part of the tripeptide L-phosphinothricyl-L-alanyl-L-alanin, which was first isolated from Streptomyces viridichromogenes or Streptomyces hygroscopicus. Its structure is confirmed by degradation and synthesis. Several processes for the preparation of D,L- and L-phosphinothricin are described. Glufosinate is a structural analog of glutamate and inhibits the glutamine synthetase. The result is a rapid build-up of a high ammonia level and a concomitant depletion of glutamine and several other amino acids in the plant. These effects are accompanied by a rapid decline of photosynthetic CO2-fixation and are followed by chlorosis and desiccation. The results of numerous toxicological studies show that glufosinate ammonium and its commercial formulations are safe for users and consumers under the conditions of recommended use. The fast and complete degradation in soil and surface water prevents movement of residues into groundwater. The toxicological threshold levels for all the nontarget organisms tested are well above the potential exposure levels and therefore do not reflect any hazard for nontarget organisms in the ecosystem. Basta is a nonselective foliar applied herbicide for the control of undesirable mono- and dicotyledonous plants in orchards, vineyards, and plantations for minimum tillage, and as a harvest aid. A synthetic phosphinothricin acetyltransferase (PAT) gene has been introduced via Agrobacterium tumefaciens into dicot crops, such as like tobacco, tomato, spring and winter rapeseed, alfalfa, and several horticultural crops. The PAT gene was also successfully introduced into maize protoplasts that could be regenerated into fertile plants. All transgenic crop plants tolerated a two- to threefold field dosage of Basta.

  9. Differential Growth Responses of Marine Phytoplankton to Herbicide Glyphosate.

    Directory of Open Access Journals (Sweden)

    Cong Wang

    Full Text Available Glyphosate is a globally popular herbicide to kill weeds and its wide applications may lead to accumulation in coastal oceans as a source of phosphorus (P nutrient or growth inhibitor of phytoplankton. We studied the physiological effects of glyphosate on fourteen species representing five major coastal phytoplankton phyla (haptophyta, bacillariophyta, dinoflagellata, raphidophyta, and chlorophyta. Based on growth responses to different concentrations of glyphosate under contrasting dissolved inorganic phosphorus (DIP conditions, we found that phytoplankton species could be classified into five groups. Group I (Emiliania huxleyi, Skeletonema costatum, Phaeodactylum tricornutum could utilize glyphosate as sole P-source to support growth in axenic culture, but in the presence of DIP, they were inhibited by both 36-μM and 360-μM glyphosate. Group II (Karenia mikimotoi, Prorocentrum minimum, Dunaliella tertiolecta, Symbiodinium sp., Heterosigma akashiwo and Alexandrium catenella could not utilize glyphosate as sole P-source to support growth, and in the presence of DIP growth was not affected by 36-μM but inhibited by 360-μM glyphosate. Glyphosate consistently enhanced growth of Group III (Isochrysis galbana and inhibited Group IV (Thalassiosira weissflogii, Thalassiosira pseudonana and Chattonella marina regardless of DIP condition. Group V (Amphidinium carterae exhibited no measurable response to glyphosate regardless of DIP condition. This grouping is not congruent with the phylogenetic relationships of the phytoplankton species suggesting functional differentiation driven by environmental pressure. We conclude that glyphosate could be used as P-source by some species while is toxic to some other species and yet has no effects on others. The observed differential effects suggest that the continued use of glyphosate and increasing concentration of this herbicide in the coastal waters will likely exert significant impact on coastal marine

  10. Differential Growth Responses of Marine Phytoplankton to Herbicide Glyphosate

    Science.gov (United States)

    Wang, Cong; Lin, Xin; Li, Ling; Lin, Senjie

    2016-01-01

    Glyphosate is a globally popular herbicide to kill weeds and its wide applications may lead to accumulation in coastal oceans as a source of phosphorus (P) nutrient or growth inhibitor of phytoplankton. We studied the physiological effects of glyphosate on fourteen species representing five major coastal phytoplankton phyla (haptophyta, bacillariophyta, dinoflagellata, raphidophyta, and chlorophyta). Based on growth responses to different concentrations of glyphosate under contrasting dissolved inorganic phosphorus (DIP) conditions, we found that phytoplankton species could be classified into five groups. Group I (Emiliania huxleyi, Skeletonema costatum, Phaeodactylum tricornutum) could utilize glyphosate as sole P-source to support growth in axenic culture, but in the presence of DIP, they were inhibited by both 36-μM and 360-μM glyphosate. Group II (Karenia mikimotoi, Prorocentrum minimum, Dunaliella tertiolecta, Symbiodinium sp., Heterosigma akashiwo and Alexandrium catenella) could not utilize glyphosate as sole P-source to support growth, and in the presence of DIP growth was not affected by 36-μM but inhibited by 360-μM glyphosate. Glyphosate consistently enhanced growth of Group III (Isochrysis galbana) and inhibited Group IV (Thalassiosira weissflogii, Thalassiosira pseudonana and Chattonella marina) regardless of DIP condition. Group V (Amphidinium carterae) exhibited no measurable response to glyphosate regardless of DIP condition. This grouping is not congruent with the phylogenetic relationships of the phytoplankton species suggesting functional differentiation driven by environmental pressure. We conclude that glyphosate could be used as P-source by some species while is toxic to some other species and yet has no effects on others. The observed differential effects suggest that the continued use of glyphosate and increasing concentration of this herbicide in the coastal waters will likely exert significant impact on coastal marine phytoplankton

  11. Antifouling herbicides in the coastal waters of western Japan.

    Science.gov (United States)

    Okamura, H; Aoyama, I; Ono, Y; Nishida, T

    2003-01-01

    Residue analyses of some antifouling herbicides (Diuron, Irgarol 1051 and the latter's degradation product M1, which is also known as GS26575), were conducted in waters collected along the coast of western Japan. In total, 142 water samples were collected from fishery harbours (99 sites), marinas (27 sites), and small ports (16 sites) around the Seto Inland Sea, the Kii Peninsula, and Lake Biwa, in August 1999. A urea-based herbicide, Diuron, was positively identified for the first time in Japanese aquatic environments. Diuron was detected in 121 samples (86%) up to a highest concentration of 3.05 microg/l, and was found in 86% of samples from fishery harbours, 89% from marinas, and 75% from ports. Four freshwater samples out of 11 collected at Lake Biwa contained Diuron. Neither Irgarol 1051 nor M1 was found in the lake waters, but both were found in many coastal waters. Irgarol 1051 was found in 84 samples (60%) at a highest concentration of 0.262 microg/l. The concentrations detected were of similar magnitude to those in our previous surveys, taken in 1997 and 1998. M1 was found in 40 samples (28%) up to a highest concentration of 0.080 microg/l. The concentrations detected were generally lower than those found in our previous surveys. The detection frequency among fishery harbours, marinas, and ports was 57-70% for Irgarol 1051 and 25-30% for M1. Ninety-five per cent of the coastal waters in which M1 was detected also contained Irgarol 1051, and 93% of the samples in which Irgarol 1051 was detected also contained Diuron. These results clearly suggest that commercial ship-bottom paints containing both Diuron and Irgarol 1051 are used extensively in the survey area.

  12. Triazine herbicides inhibit relaxin signaling and disrupt nitric oxide homeostasis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Si Eun; Lim, Sa Rang; Choi, Hyung-kyoon; Bae, Jeehyeon, E-mail: jeehyeon@cau.ac.kr

    2016-09-15

    Triazines are herbicides that are widely used worldwide, and we previously observed that the maternal exposure of mice to simazine (50 or 500 μg/kg) resulted in smaller ovaries and uteri of their female offspring. Here, we investigated the underlying mechanism that may account for the reproductive dysfunction induced by simazine. We found that following maternal exposure, simazine is transmitted to the offspring, as evidenced by its presence in the offspring ovaries. Analyses of the simazine-exposed offspring revealed that the expression of the relaxin hormone receptor, relaxin-family peptide receptor 1 (RXFP1), prominently decreased in their ovaries and uteri. In addition, downstream target genes of the relaxin pathway including nitric oxide (NO) synthase 2 (Nos2), Nos3, matrix metallopeptidase 9 (Mmp9), and vascular endothelial growth factor (Vegf) were downregulated in their ovaries. Moreover, AKT and extracellular signal-regulated kinases (ERK) levels and their phosphorylated active forms decreased in simazine-exposed ovaries. In vitro exposure of the human ovarian granulosa cells (KGN) and uterine endometrium cells (Hec-1A) to very low concentrations (0.001 to 1 nM) of triazines including atrazine, terbuthylazine, and propazine repressed NO production with a concurrent reduction in RXFP1, NOS2, and NOS3. The inhibitory action of triazines on NO release was dependent on RXFP1, phosphoinositol 3-kinase (PI3K)/AKT, and ERK. Radioligand-binding assay also confirmed that triazines competitively inhibited the binding of relaxin to its receptor. Therefore, the present study suggests that triazine herbicides act as endocrine disrupters by interfering with relaxin hormone signaling. Thus, further evaluation of their impact on human health is imperative. - Highlights: • Triazines downregulate critical molecules involved in the relaxin signaling pathway. • Triazines act as potent antagonists of binding of relaxin to its receptor. • Triazines disrupt nitric oxide

  13. Growth and yield of rain fed wheat as affected by different tillage system integrated with glyphosate herbicide

    International Nuclear Information System (INIS)

    Ali, S.; Malik, M.A.; Khan, M.A.

    2016-01-01

    In rainfed areas, tillage is primarily done for moisture conservation and weed control. However, excessive tilling not only harms the soil health but also increases the cost of production. To find out the sustainable and economical tillage combination, response of wheat was studied under different tillage systems integrated with glyphosate herbicide through field experiments conducted at University Research Farm of Pir Mehr Ali Shah, Arid Agriculture University Rawalpindi, Pakistan during 2012-2014 for two consecutive seasons. Principal component analysis proved that the plant height, biological yield, grain yield and harvest index of wheat were highest in treatment where one moldboard plowing was done followed by eight cultivations without using glyphosate in fallow period, which might be due to vigorous growth of wheat in this tillage system having enhanced root proliferation and moisture conservation, thus allowing plants to extract more nutrients and water from the deeper soil layers; whereas, the number of tillers per square meter, number of spikelets per spike, 1000 grain weight and number of grains per spike of wheat were maximum where one moldboard plowing was done followed by two applications of glyphosate herbicide in fallow period, which might be due to vigorous growth of wheat in this tillage system during 1st year of experiment when unexpected high rainfall was occurred during crop growth stage. Cluster analysis also categorized these two treatments into same category on the base of all agronomic parameters studied. The highest yield (3.5132 t ha-1) and (3.1242 t ha-1) was obtained from where one moldboard plowing was done following eight cultivations without using glyphosate followed by the treatment where one moldboard plowing was done following four cultivations without using glyphosate, respectively and were statistically at par with each other. Therefore one moldboard plowing following four cultivations is recommended for taking higher and

  14. The direct and indirect effects of a glyphosate-based herbicide and nutrients on Chironomidae (Diptera) emerging from small wetlands.

    Science.gov (United States)

    Baker, Leanne F; Mudge, Joseph F; Houlahan, Jeff E; Thompson, Dean G; Kidd, Karen A

    2014-09-01

    Laboratory and mesocosm experiments have demonstrated that some glyphosate-based herbicides can have negative effects on benthic invertebrate species. Although these herbicides are among the most widely used in agriculture, there have been few multiple-stressor, natural system-based investigations of the impacts of glyphosate-based herbicides in combination with fertilizers on the emergence patterns of chironomids from wetlands. Using a replicated, split-wetland experiment, the authors examined the effects of 2 nominal concentrations (2.88 mg acid equivalents/L and 0.21 mg acid equivalents/L) of the glyphosate herbicide Roundup WeatherMax, alone or in combination with nutrient additions, on the emergence of Chironomidae (Diptera) before and after herbicide-induced damage to macrophytes. There were no direct effects of treatment on the structure of the Chironomidae community or on the overall emergence rates. However, after macrophyte cover declined as a result of herbicide application, there were statistically significant increases in emergence in all but the highest herbicide treatment, which had also received no nutrients. There was a negative relationship between chironomid abundance and macrophyte cover on the treated sides of wetlands. Fertilizer application did not appear to compound the effects of the herbicide treatments. Although direct toxicity of Roundup WeatherMax was not apparent, the authors observed longer-term impacts, suggesting that the indirect effects of this herbicide deserve more consideration when assessing the ecological risk of using herbicides in proximity to wetlands. © 2014 SETAC.

  15. Leaching of the S-metolachlor herbicide associated with paraquat or glyphosate in a no-tillage system

    Directory of Open Access Journals (Sweden)

    Anderson Luis Nunes

    2016-09-01

    Full Text Available The combined use of desiccant and residual herbicides is a common management practice under no-tillage systems. However, the effect of desiccant herbicides and mulch on the leaching of residual herbicide is unknown. This study aimed at assessing the leaching of the S-metolachlor herbicide applied to ryegrass sequentially or in association with paraquat or glyphosate. A randomized blocks design was used, with four repetitions and treatments distributed over split-plots. The desiccant herbicides paraquat (600 g ha-1 or glyphosate (720 g ha-1 were used in the main plot, while S-metolachlor (2,800 g ha-1 was applied sequentially or in association with the desiccant herbicides in the subplots. There was also a control containing only desiccant herbicide, with no application of residual herbicide. The type of desiccant did not affect the leaching of the residual herbicide. In addition, the chosen method to apply the residual herbicide, sequentially or in association with the desiccant, did not impact the S-metolachlor behavior in the soil. The bioavailable concentration in the soil, 25 days after the application, was 90 g a.i. ha-1, at a depth of 18 cm.

  16. Alternatives to herbicides in an apple orchard, effects on yield, earthworms and plant diversity

    DEFF Research Database (Denmark)

    Andersen, L.; Kuehn, Birka Falk; Bertelsen, M.

    2013-01-01

    tIn a newly established apple orchard eight alternative methods to weed control in the tree row werecompared to a herbicide treatment with respect to effects on tree growth, first-quality fruit yield, earth-worms and flora. All treatments were tested at two irrigation schedules, with similar amount......, whereasmulching with paper wool reduced first-quality fruit yield compared to herbicide treatment. Cover cropas tagetes and weed harrowing had similar yield as herbicide treatment, whereas cover crops as grassand hop medick and weed cutting reduced first-quality yield compared to herbicide treatment. Earth......-worms thrived under rape straw contrary to under black polypropylene and plots with weed harrowing.Treatments had significant effects on species numbers of plants both years, and total vegetation covergenerally increased in the second year. Rape straw supported a high production of apples and a largestock...

  17. CHRONIC EFFECTS OF THE HERBICIDE DIURON ON FRESHWATER CLADOCERANS,AMPHIPODS,MIDGES,MINNOWS,WORMS, AND SNAILS

    Science.gov (United States)

    The chronic effects of the herbicide diuron on survival and reproduction of Daphnia pulex, and survival and growth of the amphipod Hyalella azteca, the midge Chironomus tentans, juvenile and embro/larval fathead minnows, Pimephales promelas, annelid worms, Lumbriculus variegatus,...

  18. Arabidopsis transcriptional responses differentiating closely related chemicals (herbicides) and cross-species extrapolation to Brassica

    Science.gov (United States)

    Using whole genome Affymetrix ATH1 GeneChips we characterized the transcriptional response of Arabidopsis thaliana Columbia 24 hours after treatment with five different herbicides. Four of them (chloransulam, imazapyr, primisulfuron, sulfometuron) inhibit acetolactate synthase (A...

  19. Microevolution of ALS inhibitor herbicide resistance in loose silky bentgrass (Apera spica-venti)

    DEFF Research Database (Denmark)

    Babineau, Marielle

    , the ALS resistant biotypes have a fitness advantage over the susceptible biotype in time to germination and time to flowering and seed production growth stages. This study increased the understanding of the spatial, phenotypic, genetic and ecological processes and consequences in ALS herbicide resistance......-neighborhood experiments were conducted with ALS resistant and susceptible populations with a randomized genetic background, vegetative and reproductive growth stages were compared. The results show a large variation in the response of neighboring populations to ALS herbicide. Multiple resistance is observed between ALS...... from known metabolic herbicide resistance pathways, such as cytochrome P450s, ABC-transporters, UDP-glycosyltransferase and glutathione S-transferase, are identified and quantified. Different gene families are up-regulated at different times after herbicide treatment. In low competition conditions...

  20. Crops with target-site herbicide resistance for Orobanche and Striga control.

    Science.gov (United States)

    Gressel, Jonathan

    2009-05-01

    It is necessary to control root parasitic weeds before or as they attach to the crop. This can only be easily achieved chemically with herbicides that are systemic, or with herbicides that are active in soil. Long-term control can only be attained if the crops do not metabolise the herbicide, i.e. have target-site resistance. Such target-site resistances have allowed foliar applications of herbicides inhibiting enol-pyruvylshikimate phosphate synthase (EPSPS) (glyphosate), acetolactate synthase (ALS) (e.g. chlorsulfuron, imazapyr) and dihydropteroate synthase (asulam) for Orobanche control in experimental conditions with various crops. Large-scale use of imazapyr as a seed dressing of imidazolinone-resistant maize has been commercialised for Striga control. Crops with two target-site resistances will be more resilient to the evolution of resistance in the parasite, if well managed.

  1. ANALYTICAL METHOD DEVELOPMENT FOR ALACHLOR ESA AND OTHER ACETANILIDE HERBICIDE DEGRADATION PRODUCTS

    Science.gov (United States)

    In 1998, USEPA published a Drinking Water Contaminant Candidate List (CCL) of 50 chemicals and 10 microorganisms. "Alachlor ESA and other acetanilide herbicide degradation products" is listed on the the 1998 CCL. Acetanilide degradation products are generally more water soluble...

  2. Responses of reniform nematode and browntop millet to tillage, cover crop, and herbicides in cotton

    Science.gov (United States)

    Cropping practices that reduce competition from reniform nematode (Rotylenchulus reniformis) and browntop millet (Urochlora ramosum) may help minimize losses in cotton (Gossypium hirsutum). The impacts of tillage, rye cover crop, and preemergence and postemergence herbicides on cotton yields, renifo...

  3. CYTOGENETIC STUDIES OF THREE TRIAZINE HERBICIDES II. IN VIVO MICRONUCLEUS STUDIES IN MOUSE BONE MARROW

    Science.gov (United States)

    Atrazine, simazine, and cyanazine are widely used preemergence and postemergence triazine herbicides that have made their way into the potable water supply of many agricultural communities. There are several contradictory studies in the literature. Our previous in vitro studies...

  4. Glyphosate em mistura com herbicidas alternativos para o manejo de plantas daninhas Glyphosate combined with alternative herbicides for vegetation management

    Directory of Open Access Journals (Sweden)

    P.A. Monquero

    2001-12-01

    mixtures of glyphosate combined with alternative mechanism of action herbicides. An experiment was developed in a randomized complete design, using 12 treatments and four replications, under greenhouse conditions at University of São Paulo - USP/ESALQ - Piracicaba-SP, Brazil, with the weeds Richardia brasiliensis, Commelina benghalensis, Amaranthus hybridus, Galinsoga parviflora and Ipomoea grandifolia and applying glyphosate combined with the herbicides chlorimuron-ethyl, carfentrazone, bentazon, sulfentrazone and flumioxazin. The interactions were additive for the weeds I. grandifolia and C. benghalensis but the herbicides flumioxazin, sulfentrazone and carfentrazone sprayed alone and in mixture with glyphosate gave better control results. The interaction of glyphosate with sulfentrazone was antagonic in R. brasiliensis, whereas the glyphosate mixed with other herbicides was additive; however, the treatments using glyphosate and chlorimuron-ethyl or flumioxazin were more efficient in weed control. In A. hybridus, the best control results were glyphosate and carfentrazone alone and glyphosate mixed with flumioxazin, sulfentrazone, chlorimuron-ethyl and bentazon, all additives. In the case of G. parviflora, flumioxazin, sulfentrazone, chlorimuron and bentazon with glyphosate and flumioxazin and sulfentrazone gave excellent control.

  5. Photostabilization of the herbicide norflurazon microencapsulated with ethylcellulose in the soil-water system

    Energy Technology Data Exchange (ETDEWEB)

    Sopena, Fatima, E-mail: fsopenav@irnase.csic.es [Institute of Natural Resources and Agrobiology (CSIC), Reina Mercedes 10, Apdo 1052, 41080 Seville, ES (Spain); Villaverde, Jaime; Maqueda, Celia; Morillo, Esmeralda [Institute of Natural Resources and Agrobiology (CSIC), Reina Mercedes 10, Apdo 1052, 41080 Seville, ES (Spain)

    2011-11-15

    Highlights: {yields} Herbicide photodegradation studies using ethylcellulose-microencapsulated formulations (ECF) in soil and water. {yields} Greater herbicide photo-protection observed from EFC than from its commercial form. {yields} Photo-protective effect due to the gradual herbicide release and the presence of ethylcellulose. {yields} Herbicide photo-stability conditioned by soil colloidal components, especially by goethite and humic acids. {yields} EFC could reduce the field herbicide losses by photolysis. - Abstract: Ethylcellulose-microencapsulated formulations (ECFs) of norflurazon have been shown to reduce leaching, maintaining a threshold concentration in the topsoil than the commercial formulation (CF). Since photodegradation contributes to field dissipation of norflurazon, the objective of the present work was to study if such formulations can also protect from its photodescomposition. For this purpose, aqueous solutions of CF and ECFs, containing the most important soil components (goethite, humic and fulvic acids and montmorillonite) were tested. To get a more realistic approach, studies in soil were also performed. The results were well explained by a simple first order model. DT{sub 50} value was 3 h for CF under irradiation, which was considerably lower than those corresponding to the systems where ECF was used (35 h for ECF; 260 h for ECF-goethite; 53 h for ECF-humic acids; 33 h for ECF-montmorillonite; and 28 h for ECF-fulvic acids). ECF protected against photodegradation in both aqueous solution and soil due to the gradual release of the herbicide, which reduced the herbicide available to be photodegraded. These lab-scale findings proved that ECF could reduce the herbicide dosage, minimizing its photolysis, which would be especially advantageous during the first hours after foliar and soil application.

  6. An identification of potential new herbicides for short rotation coppice (Task 4). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This report summarises the findings of a project to identify potential new herbicides and their suitability for weed control in commercial short rotation coppice (SRC) crops, and to establish the safety of the crops. The arrangements for the use of 'off-label' pesticides, which are permitted for use on other crops, on SRC are discussed along with the importance of the use of laboratory pot trials and field trials. Several herbicides are proposed for larger scale field trials.

  7. Glufosinate Herbicide Intoxication Causing Unconsciousness, Convulsion, and 6th Cranial Nerve Palsy

    OpenAIRE

    Park, Jae-seok; Kwak, Soo-Jung; Gil, Hyo-wook; Kim, So-Young; Hong, Sae-yong

    2013-01-01

    Although glufosinate ammonium herbicides are considered safe when used properly, ingestion of the undiluted form can cause grave outcomes. Recently, we treated a 34-yr-old man who ingested glufosinate ammonium herbicide. In the course of treatment, the patient developed apnea, mental deterioration, and sixth cranial nerve palsy; he has since been discharged with full recovery after intensive care. This case report describes the clinical features of glufosinate intoxication with a focus on six...

  8. Impact of Grassland Reseeding, Herbicide spraying and Ploughing on Diversity and Abundance of Soil Arthropods.

    OpenAIRE

    Wei Liu; Wei Liu; Wei Liu; Junling Zhang; Stuart L Norris; Phil Murray

    2016-01-01

    In order to determine the interactive effect of reseeding, herbicide spraying and ploughing on soil fauna communities, we conducted a grassland reseeding experiment combined with pre-reseed management to examine how with the whole reseeding process affects soil faunal composition. Sampling occasions and exact treatments were as follows: 1) before chemical herbicide spray; 2) after spray but before ploughing; 3) after ploughing but before reseeding; and 4) after one year of recovery. Our resul...

  9. Identification and ecotoxicity of degradation products of chloroacetamide herbicides from UV-treatment of water

    DEFF Research Database (Denmark)

    Souissi, Yasmine; Bouchonnet, Stéphane; Bourcier, Sophie

    2013-01-01

    The widespread occurrence of chlorinated herbicides and their degradation products in the aquatic environment raises health and environmental concerns. As a consequence pesticides, and to a lesser degree their degradation products, are monitored by authorities both in surface waters and drinking...... waters. In this study the formation of degradation products from ultraviolet (UV) treatment of the three chloroacetamide herbicides acetochlor, alachlor and metolachlor and their biological effects were investigated. UV treatment is mainly used for disinfection in water and wastewater treatments. First...

  10. Dinitroaniline herbicide resistance in a multiple-resistant Lolium rigidum population.

    Science.gov (United States)

    Chen, Jinyi; Yu, Qin; Owen, Mechelle; Han, Heping; Powles, Stephen

    2018-04-01

    The pre-emergence dinitroaniline herbicides (such as trifluralin and pendimethalin) are vital to Australian no-till farming systems. A Lolium rigidum population collected from the Western Australian grain belt with a 12-year trifluralin use history was characterised for resistance to dinitroaniline, acetyl CoA carboxylase (ACCase)- and acetolactate synthase (ALS)-inhibiting herbicides. Target-site resistance mechanisms were investigated. This L. rigidum population exhibited 32-fold resistance to trifluralin, as compared with the susceptible population. It also displayed 12- to 30-fold cross-resistance to other dinitroaniline herbicides (pendimethalin, ethalfluralin and oryzalin). In addition, this population showed multiple resistance to commonly used post-emergence ACCase- and ALS-inhibiting herbicides. Two target-site α-tubulin gene mutations (Val-202-Phe and Thr-239-Ile) previously documented in other dinitroaniline-resistant weed species were identified, and some known target-site mutations in ACCase (Ile-1781-Leu, Asp-2078-Gly and Cys-2088-Arg) and ALS (Pro-197-Gln/Ser) were found in the same population. An agar-based Petri dish screening method was established for the rapid diagnosis of resistance to dinitroaniline herbicides. Evolution of target-site resistance to both pre- and post-emergence herbicides was confirmed in a single L. rigidum population. The α-tubulin mutations Val-202-Phe and Thr-239-Ile, documented here for the first time in L. rigidum, are likely to be responsible for dinitroaniline resistance in this population. Early detection of dinitroaniline herbicide resistance and integrated weed management strategies are needed to maintain the effectiveness of dinitroaniline herbicides. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Comparative sensitivity of Selenastrum capricornutum and Lemna minor to sixteen herbicides

    Science.gov (United States)

    Fairchild, J.F.; Ruessler, D.S.; Haverland, P.S.; Carlson, A.R.

    1997-01-01

    Aquatic plant toxicity tests are frequently conducted in environmental risk assessments to determine the potential impacts of contaminants on primary producers. An examination of published plant toxicity data demonstrates that wide differences in sensitivity can occur across phylogenetic groups of plants. Yet relatively few studies have been conducted with the specific intent to compare the relative sensitivity of various aquatic plant species to contaminants. We compared the relative sensitivity of the algae Selenestrum capricornutum and the floating vascular plant Lemna minor to 16 herbicides (atrazine, metribuzin, simazine, cyanazine, alachlor, metolachlor, chlorsulfuron, metsulfuron, triallate, EPTC, trifluralin, diquat, paraquat, dicamba, bromoxynil, and 2,4-D). The herbicides studied represented nine chemical classes and several modes of action and were chosen to represent major current uses in the United States. Both plant species were generally sensitive to the triazines (atrazine, metribuzin, simazine, and cyanazine), sulfonureas (metsulfuron and chlorsulfuron), pyridines (diquat and paraquat), dinitroaniline (trifluralin), and acetanilide (alachlor and metolachlor) herbicides. Neither plant species was uniformly more sensitive than the other across the broad range of herbicides tested. Lemna was more sensitive to the sulfonureas (metsulfuron and chlorsulfuron) and the pyridines (diquat and parequat) than Selenastrum. However Selenastrum was more sensitive than Lemna to one of two thiocarbamates (triallate) and one of the triazines (cyanazine). Neither species was sensitive to selective broadleaf herbicides including bromoxynil, EPTC, dicamba, or 2,4-D. Results were not always predictable in spite of obvious differences in herbicide modes of action and plant phylogeny. Major departures in sensitivity of Selenastrum occurred between chemicals within individual classes of the triazine, acetanilide, and thiocarbamate herbicides. Results indicate that neither

  12. Selectable tolerance to herbicides by mutated acetolactate synthase genes integrated into the chloroplast genome of tobacco.

    Science.gov (United States)

    Shimizu, Masanori; Goto, Maki; Hanai, Moeko; Shimizu, Tsutomu; Izawa, Norihiko; Kanamoto, Hirosuke; Tomizawa, Ken-Ichi; Yokota, Akiho; Kobayashi, Hirokazu

    2008-08-01

    Strategies employed for the production of genetically modified (GM) crops are premised on (1) the avoidance of gene transfer in the field; (2) the use of genes derived from edible organisms such as plants; (3) preventing the appearance of herbicide-resistant weeds; and (4) maintaining transgenes without obstructing plant cell propagation. To this end, we developed a novel vector system for chloroplast transformation with acetolactate synthase (ALS). ALS catalyzes the first step in the biosynthesis of the branched amino acids, and its enzymatic activity is inhibited by certain classes of herbicides. We generated a series of Arabidopsis (Arabidopsis thaliana) mutated ALS (mALS) genes and introduced constructs with mALS and the aminoglycoside 3'-adenyltransferase gene (aadA) into the tobacco (Nicotiana tabacum) chloroplast genome by particle bombardment. Transplastomic plants were selected using their resistance to spectinomycin. The effects of herbicides on transplastomic mALS activity were examined by a colorimetric assay using the leaves of transplastomic plants. We found that transplastomic G121A, A122V, and P197S plants were specifically tolerant to pyrimidinylcarboxylate, imidazolinon, and sulfonylurea/pyrimidinylcarboxylate herbicides, respectively. Transplastomic plants possessing mALSs were able to grow in the presence of various herbicides, thus affirming the relationship between mALSs and the associated resistance to herbicides. Our results show that mALS genes integrated into the chloroplast genome are useful sustainable markers that function to exclude plants other than those that are GM while maintaining transplastomic crops. This investigation suggests that the resistance management of weeds in the field amid growing GM crops is possible using (1) a series of mALSs that confer specific resistance to herbicides and (2) a strategy that employs herbicide rotation.

  13. Perspectives on transgenic, herbicide-resistant crops in the United States almost 20 years after introduction.

    Science.gov (United States)

    Duke, Stephen O

    2015-05-01

    Herbicide-resistant crops have had a profound impact on weed management. Most of the impact has been by glyphosate-resistant maize, cotton, soybean and canola. Significant economic savings, yield increases and more efficacious and simplified weed management have resulted in widespread adoption of the technology. Initially, glyphosate-resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate-resistant crops over broad areas facilitated the evolution of glyphosate-resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate-resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl-CoA carboxylase and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive effects (reduced cost, simplified weed management, lowered environmental impact and reduced tillage) that glyphosate-resistant crops had initially. In the more distant future, other herbicide-resistant crops (including non-transgenic ones), herbicides with new modes of action and technologies that are currently in their infancy (e.g. bioherbicides, sprayable herbicidal RNAi and/or robotic weeding) may affect the role of transgenic, herbicide-resistant crops in weed management. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  14. Photostabilization of the herbicide norflurazon microencapsulated with ethylcellulose in the soil-water system

    International Nuclear Information System (INIS)

    Sopena, Fatima; Villaverde, Jaime; Maqueda, Celia; Morillo, Esmeralda

    2011-01-01

    Highlights: → Herbicide photodegradation studies using ethylcellulose-microencapsulated formulations (ECF) in soil and water. → Greater herbicide photo-protection observed from EFC than from its commercial form. → Photo-protective effect due to the gradual herbicide release and the presence of ethylcellulose. → Herbicide photo-stability conditioned by soil colloidal components, especially by goethite and humic acids. → EFC could reduce the field herbicide losses by photolysis. - Abstract: Ethylcellulose-microencapsulated formulations (ECFs) of norflurazon have been shown to reduce leaching, maintaining a threshold concentration in the topsoil than the commercial formulation (CF). Since photodegradation contributes to field dissipation of norflurazon, the objective of the present work was to study if such formulations can also protect from its photodescomposition. For this purpose, aqueous solutions of CF and ECFs, containing the most important soil components (goethite, humic and fulvic acids and montmorillonite) were tested. To get a more realistic approach, studies in soil were also performed. The results were well explained by a simple first order model. DT 50 value was 3 h for CF under irradiation, which was considerably lower than those corresponding to the systems where ECF was used (35 h for ECF; 260 h for ECF-goethite; 53 h for ECF-humic acids; 33 h for ECF-montmorillonite; and 28 h for ECF-fulvic acids). ECF protected against photodegradation in both aqueous solution and soil due to the gradual release of the herbicide, which reduced the herbicide available to be photodegraded. These lab-scale findings proved that ECF could reduce the herbicide dosage, minimizing its photolysis, which would be especially advantageous during the first hours after foliar and soil application.

  15. Structural Complexity and Ecosystem Functions in a Natural Mixed Forest under a Single-Tree Selection Silviculture

    Directory of Open Access Journals (Sweden)

    Toshiya Yoshida

    2017-11-01

    Full Text Available The objective of forest management has become broader, and it is essential to harmonize timber production with conservation of the forest ecosystem. Selection cutting is recognized as a major alternative of clear-cutting, because it can maintain the complexity and heterogeneity of a natural forest; however, its long-term evaluations are limited. This study compared various attributes of stand structures, which are indicators of biodiversity and ecosystem carbon stock between managed and unmanaged blocks (12.6 ha area in total in a natural mixed forest in Hokkaido, the northernmost island of Japan. We found that 30 years’ implementation of single-tree selection did not affect the volume, size structure, species diversity nor spatial distribution of overstory trees in the managed stands. Also, the total carbon stock in the managed stands was almost equal to that of the unmanaged stands. In contrast, several structural attributes and indicator elements that are significant for biodiversity (such as large-diameter live trees, dead trees, cavities, epiphytic bryophytes, and some avian guilds showed marked decrease in the managed stands. We conclude that it is required to leave these structures and elements to some extent for deriving the merit of the management as an alternative silvicultural regime in the region.

  16. The role of herbicides in the erosion of salt marshes in eastern England

    International Nuclear Information System (INIS)

    Mason, C.F.; Underwood, G.J.C.; Baker, N.R.; Davey, P.A.; Davidson, I.; Hanlon, A.; Long, S.P.; Oxborough, K.; Paterson, D.M.; Watson, A.

    2003-01-01

    Herbicide run-off stresses saltmarsh diatoms and higher plants and may increase erosion. - Laboratory studies and field trials were conducted to investigate the role of herbicides on saltmarsh vegetation, and their possible significance to saltmarsh erosion. Herbicide concentrations within the ranges present in the aquatic environment were found to reduce the photosynthetic efficiency and growth of both epipelic diatoms and higher saltmarsh plants in the laboratory and in situ. The addition of sublethal concentrations of herbicides resulted in decreased growth rates and photosynthetic efficiency of diatoms and photosynthetic efficiency of higher plants. Sediment stability also decreased due to a reduction in diatom EPS production. There was qualitative evidence that diatoms migrated deeper into the sediment when the surface was exposed to simazine, reducing surface sediment stability by the absence of a cohesive biofilm. Sediment loads on leaves severely reduced photosynthesis in Limonium vulgare. This, coupled with reduced carbon assimilation from the effects of herbicides, could have large negative consequences for plant productivity and over winter survival of saltmarsh plants. The data support the hypothesis that sublethal herbicide concentrations could be playing a role in the increased erosion of salt marshes that has occurred over the past 40 years

  17. Photochemical oxidation processes for the elimination of phenyl-urea herbicides in waters

    International Nuclear Information System (INIS)

    Benitez, F. Javier; Real, Francisco J.; Acero, Juan L.; Garcia, Carolina

    2006-01-01

    Four phenyl-urea herbicides (linuron, chlorotoluron, diuron, and isoproturon) were individually photooxidized by monochromatic UV radiation in ultra-pure aqueous solutions. The influence of pH and temperature on the photodegradation process was established, and the first-order rate constants and quantum yields were evaluated. The sequence of photodecomposition rates was: linuron > chlorotoluron > diuron > isoproturon. The simultaneous photooxidation of mixtures of the selected herbicides in several types of waters was then performed by means of UV radiation alone, and by UV radiation combined with hydrogen peroxide. The types of waters used were: ultra-pure water, a commercial mineral water, a groundwater, and a lake water. The influence of the independent variables in these processes - the presence or absence of tert-butyl alcohol, types of herbicide and waters, and concentration of hydrogen peroxide - were established and discussed. A kinetic study was performed using a competitive kinetic model that allowed various rate constants to be evaluated for each herbicide. This kinetic model allows one to predict the elimination of these phenyl-urea herbicides in contaminated waters by the oxidation systems used (UV alone and combined UV/H 2 O 2 ). The herbicide concentrations predicted by this model agree well with the experimental results that were obtained

  18. Herbicide effects on the growth and photosynthetic efficiency of Cassiopea maremetens.

    Science.gov (United States)

    Rowen, David J; Templeman, Michelle A; Kingsford, Michael J

    2017-09-01

    Herbicides from agricultural run-off have been measured in coastal systems of the Great Barrier Reef over many years. Non-target herbicide exposure, especially photosystem II herbicides has the potential to affect seagrasses and other marine species. The symbiotic benthic jellyfish Cassiopea maremetens is present in tropical/sub-tropical estuarine and marine environments. Jellyfish (n = 8 per treatment) were exposed to four separate concentrations of agricultural formulations of diuron or hexazinone to determine their sensitivity and potential for recovery to pulsed herbicide exposure. Jellyfish growth, symbiont photosynthetic activity and zooxanthellae density were analysed for herbicide-induced changes for 7 days followed by a 7 day recovery period. Both the jellyfish and endosymbiont were more sensitive to diuron than hexazinone. The 7-day EC 50 for jellyfish growth was 0.35 μg L -1 for Diuron and 17.5 μg L -1 for Hexazinone respectively. Diuron exposure caused a significant decrease (p diuron and hexazinone caused significant decreases in photosynthetic efficiency (effective quantum yield) in all treatment concentrations (0.1 μg L -1 and above) and this effect continued in the post-exposure period. As this species is frequently found in near-shore environments, they may be particularly vulnerable to herbicide run-off. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Contribution of transformation products towards the total herbicide toxicity to tropical marine organisms.

    Science.gov (United States)

    Mercurio, Philip; Eaglesham, Geoff; Parks, Stephen; Kenway, Matt; Beltran, Victor; Flores, Florita; Mueller, Jochen F; Negri, Andrew P

    2018-03-19

    The toxicity of herbicide degradation (transformation) products is rarely taken into account, even though these are commonly detected in the marine environment, sometimes at concentrations higher than the parent compounds. Here we assessed the potential contribution of toxicity by transformation products of five photosystem II herbicides to coral symbionts (Symbiodinium sp.), the green algae Dunaliella sp., and prawn (Penaeus monodon) larvae. Concentration-dependent inhibition of photosynthetic efficiency (∆F/F m ') was observed for all herbicides in both microalgal species. The toxicity of solutions of aged diuron solutions containing transformation products to Symbiodinium sp. and Dunaliella sp. was greater than could be explained by the concentrations of diuron measured, indicating transformation products contributed to the inhibition of ∆F/F m '. However, the toxicity of aged atrazine, simazine, hexazinone, and ametryn solutions could be explained by the concentration of parent herbicide, indicating no contribution by transformation products. Prawn larval metamorphosis was not sensitive to the herbicides, but preliminary results indicated some toxicity of the transformation products of atrazine and diuron. Risk assessments should take into account the contribution of herbicide transformation products; however, further studies are clearly needed to test the toxicity of a far wider range of transformation products to a representative diversity of relevant taxa.

  20. Crystal structure of plant acetohydroxyacid synthase, the target for several commercial herbicides.

    Science.gov (United States)

    Garcia, Mario Daniel; Wang, Jian-Guo; Lonhienne, Thierry; Guddat, Luke William

    2017-07-01

    Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) is the first enzyme in the branched-chain amino acid biosynthesis pathway. Five of the most widely used commercial herbicides (i.e. sulfonylureas, imidazolinones, triazolopyrimidines, pyrimidinyl-benzoates and sulfonylamino-cabonyl-triazolinones) target this enzyme. Here we have determined the first crystal structure of a plant AHAS in the absence of any inhibitor (2.9 Å resolution) and it shows that the herbicide-binding site adopts a folded state even in the absence of an inhibitor. This is unexpected because the equivalent regions for herbicide binding in uninhibited Saccharomyces cerevisiae AHAS crystal structures are either disordered, or adopt a different fold when the herbicide is not present. In addition, the structure provides an explanation as to why some herbicides are more potent inhibitors of Arabidopsis thaliana AHAS compared to AHASs from other species (e.g. S. cerevisiae). The elucidation of the native structure of plant AHAS provides a new platform for future rational structure-based herbicide design efforts. The coordinates and structure factors for uninhibited AtAHAS have been deposited in the Protein Data Bank (www.pdb.org) with the PDB ID code 5K6Q. © 2017 Federation of European Biochemical Societies.

  1. Stress-physiological reactions of the green alga Scenedesmus opoliensis to water pollution with herbicides

    Directory of Open Access Journals (Sweden)

    Zsolt Gyula KERESZTES

    2009-05-01

    Full Text Available The freshwater green alga Scenedesmus opoliensis proves to be a suitable bioindicator of water pollution with different herbicides. One of the best molecular markers of stress condition imposed by herbicides is overproduction of malondialdehyde resulting from lipid peroxidation in the damaged membranes. Methylviologen, a largely used pre-emergence herbicide which generates reactive oxygen species in the illuminated chloroplasts, triggers the accumulation of ascorbic acid and enhances the enzymatic activity of catalase, both of these substances being involved in the antioxidative protection of algal cells. Diuron, a herbicide that inhibits photosynthetic electron transport on the acceptor side of photosystem II, causes a decline in oxygen production and in biomass accumulation of algae. Glufosinate induces accumulation of toxic ammonia and leads to enhanced net oxygen production, associated with a low rate of carbon assimilation. Long-term exposure to micromolar concentrations of herbicides results in significant changes in the rate of cell division, in hotosynthetic parameters and in the intensity of antioxidative defense. A proper bioindication of toxic effects of herbicides on algae requires a selected combination of different physiological and biochemical parameters which reflect the degree of stress exerted on living organisms by water pollution with xenobiotic organic compounds.

  2. Resistance risk assessment within herbicide authorisation--a call for sensitivity data.

    Science.gov (United States)

    Ulber, Lena; Nordmeyer, Henning; Zwerger, Peter

    2013-02-01

    In most European countries, the risk of herbicide resistance is assessed as part of the authorisation of herbicides in accordance with EPPO Standard PP 1/213(2). Because the susceptibility of weed populations to a certain herbicide may vary greatly, one part of resistance risk assessment is the testing for sensitivity variation among different populations of target weed species with a high resistance risk. This paper emphasises the importance of sensitivity data provision with regard to the recent EU Regulation (EC) 1107/2009 concerning the placing of plant protection products on the market and outlines the main technical requirements for sensitivity data. A useful principle is that sensitivity data should be provided for all herbicides with a high resistance risk regardless of whether resistance has already evolved against the herbicidal substance. Methodical details regarding the generation of sensitivity data are discussed, together with remaining questions that will need to be addressed if a harmonised assessment of herbicide resistance risk is to be achieved. Copyright © 2012 Society of Chemical Industry.

  3. Toxicity of herbicides used in the sugarcane crop to diazotrophic bacterium Herbaspirillum seropedicae

    Directory of Open Access Journals (Sweden)

    Sergio de Oliveira Procópio

    2014-10-01

    Full Text Available The objective of this work was to identify herbicides used in the sugarcane crop that affects neither the growth, the development, of nor the process of biological nitrogen fixation (BNF by the diazotrophic bacterium Herbaspirillum seropedicae. Eighteen herbicides (paraquat, ametryne, tebuthiuron, amicarbazone, diuron, metribuzin, [hexazinone + diuron], [hexazinone + clomazone], clomazone, isoxaflutole, sulfentrazone, oxyfluorfen, imazapic, imazapyr, [trifloxysulfuron sodium + ametryne], glyphosate, MSMA e 2,4-D were tested in their respective commercial doses regarding their impact on the growth of the bacteria in liquid medium DIGs. For this, we determined the duration of lag phase, generation time and maximum cell density of H. seropedicae, calculated from optical density data obtained at regular intervals during the incubation of cultures for 33 h at 32oC. We also evaluated the impact of herbicides on nitrogenase activity of H. seropedicae grown in semi-solid N-free JNFb medium. The effects of herbicides on the growth variables and the ARA were compared with the untreated control by Dunnett test. A completely randomized design was used. The herbicides paraquat, imazapyr, ametryne, glyphosate and oxyfluorfen inhibited the growth of H. seropedicae in vitro. Ametryne, oxyfluorfen and glyphosate caused a small reduction in the duration of the lag phase of diazotrophic bacteria H. seropedicae. Oxyfluorfen, ametryne and imazapyr resulted in increased the generation time by H. seropedicae. Glyphosate promoted drastic reduction in biological nitrogen fixation in vitro by H. seropedicae. The other tested herbicides did not affect the growth or the same BNF by H. seropedicae.

  4. Photochemical oxidation processes for the elimination of phenyl-urea herbicides in waters

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, F. Javier [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)]. E-mail: javben@unex.es; Real, Francisco J. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain); Acero, Juan L. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain); Garcia, Carolina [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2006-11-16

    Four phenyl-urea herbicides (linuron, chlorotoluron, diuron, and isoproturon) were individually photooxidized by monochromatic UV radiation in ultra-pure aqueous solutions. The influence of pH and temperature on the photodegradation process was established, and the first-order rate constants and quantum yields were evaluated. The sequence of photodecomposition rates was: linuron > chlorotoluron > diuron > isoproturon. The simultaneous photooxidation of mixtures of the selected herbicides in several types of waters was then performed by means of UV radiation alone, and by UV radiation combined with hydrogen peroxide. The types of waters used were: ultra-pure water, a commercial mineral water, a groundwater, and a lake water. The influence of the independent variables in these processes - the presence or absence of tert-butyl alcohol, types of herbicide and waters, and concentration of hydrogen peroxide - were established and discussed. A kinetic study was performed using a competitive kinetic model that allowed various rate constants to be evaluated for each herbicide. This kinetic model allows one to predict the elimination of these phenyl-urea herbicides in contaminated waters by the oxidation systems used (UV alone and combined UV/H{sub 2}O{sub 2}). The herbicide concentrations predicted by this model agree well with the experimental results that were obtained.

  5. Built for the future: New directions in silviculture research and demonstration at Montana's Lubrecht Experimental Forest

    Science.gov (United States)

    Christopher R. Keyes; Thomas E. Perry

    2010-01-01

    Manipulative experiments at the University of Montana’s Lubrecht Experimental Forest have long been set aside as permanent research and demonstration areas (RDA’s) to communicate the tradeoffs among different stand management strategies. However, most of these have either degraded over time or have diminished relevance to contemporary forest management issues. An...

  6. Evaluation the Effect of Corn (Zea mays L. Sowing Pattern and Nitrogen Application Method on Herbicide Optimizing and Reducing Foramsulfuron (Equip® Dose

    Directory of Open Access Journals (Sweden)

    E. Izadi Darbandi

    2016-06-01

    used repeatedly as the primary mechanism of weed control. These herbicides exert strong selection pressure because of their high activity on sensitive biotypes at the rates used and because of their soil residual activity. So, the primary objective of this study was to determine the effect of some crop management strategies including sowing pattern and fertilizer application methods on herbicide optimizing and reducing foramsulfuron dose. Materials and Methods: In order to evaluate the effects of corn sowing pattern and nitrogen application methods on optimizing and reducing of foramsulfuron dose, a field experiment was conducted as split factorial, based on randomized complete block design with three replications at the Research Station, of Faculty of Agriculture, Ferdowsi University of Mashhad, in 2012. Treatments included, corn sowing methods (single-row with 75 cm distance, twine row as parallel on 75 cm width ridges sides and double row as zigzag on 75 cm width ridges sides as main plots, factorial of nitrogen application methods (broadcast and band application, nitrogen source for fertilization was urea (400 kg ha-1, and foramsulfuron doses (100, 75, 50 and 0% of recommended dose (2 liter of commercial doses applied at 4th corn leaf stage as sub plots.Weed density and frequency were recorded 10 days before corn harvesting and total weed biomass, corn biomass and seed yield were recorded at the end of the experiments per 1 m-2. Analysis of variance of data was carried out with SAS software and for means comparisons LSD (p≤0.05 test was used. Also The rectangular hyperbolic equation to describe the relationship between density and weed biomass and biomass and grain yield of maize was used Results and Discussion: Evaluation of weed flora indicated that 6 weed species (including 5 dicot. and 1 monocot. including red root pigweed (Amaranthus retroflexus L., black nightshade (Solanum nigrum L., lambsquarters (Chenopodium album L., field bindweed (Convolvolus arvensis

  7. Selectivity and stability of new herbicides and herbicide combinations for the seed yields of some field crops II. Effect at milk thistle (Silybum Marianum Gaertn.)

    OpenAIRE

    G. Delchev

    2016-01-01

    Abstract. During 2013 – 2015 on pellic vertisol soil type was conducted a field experiment. Under investigation was Bulgarian milk thistle cultivar Silmar (Silybum marianum Gaertn.). Factor A included the years of investigation. Factor B included no treated check, 6 soil-applied herbicides – Tendar EC, Sharpen 33 EC, Merlin flex 480 SC, Smerch 24 ЕC, Raft 400 SC, Eagle 75 DF and 5 foliar-applied herbicides – Kalin flo, Eclipse 70 DWG, Sultan 500 SC, Granstar super 50 SG, Starane 250 ...

  8. Fate of the herbicides glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron in two Finnish arable soils.

    Science.gov (United States)

    Laitinen, Pirkko; Siimes, Katri; Eronen, Liisa; Rämö, Sari; Welling, Leena; Oinonen, Seija; Mattsoff, Leona; Ruohonen-Lehto, Marja

    2006-06-01

    The fate of five herbicides (glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron) was studied in two Finnish sugar beet fields for 26 months. Soil types were sandy loam and clay. Two different herbicide-tolerant sugar beet cultivars and three different herbicide application schedules were used. Meteorological data were collected throughout the study and soil properties were thoroughly analysed. An extensive data set of herbicide residue concentrations in soil was collected. Five different soil depths were sampled. The study was carried out using common Finnish agricultural practices and represents typical sugar beet cultivation conditions in Finland. The overall observed order of persistence was ethofumesate > glyphosate > phenmedipham > metamitron > glufosinate-ammonium. Only ethofumesate and glyphosate persisted until the subsequent spring. Seasonal variation in herbicide dissipation was very high and dissipation ceased almost completely during winter. During the 2 year experiment no indication of potential groundwater pollution risk was obtained, but herbicides may cause surface water pollution. Copyright (c) 2006 Society of Chemical Industry

  9. Spatial variability of herbicide mobilisation and transport at catchment scale: insights from a field experiment

    Directory of Open Access Journals (Sweden)

    T. Doppler

    2012-07-01

    Full Text Available During rain events, herbicides can be transported from their point of application to surface waters, where they may harm aquatic organisms. Since the spatial pattern of mobilisation and transport is heterogeneous, the contributions of different fields to the herbicide load in the stream may vary considerably within one catchment. Therefore, the prediction of contributing areas could help to target mitigation measures efficiently to those locations where they reduce herbicide pollution the most.

    Such spatial predictions require sufficient insight into the underlying transport processes. To improve the understanding of the process chain of herbicide mobilisation on the field and the subsequent transport through the catchment to the stream, we performed a controlled herbicide application on corn fields in a small agricultural catchment (ca. 1 km2 with intensive crop production in the Swiss Plateau. Water samples were collected at different locations in the catchment (overland flow, tile drains and open channel for two months after application in 2009, with a high temporal resolution during rain events. We also analysed soil samples from the experimental fields and measured discharge, groundwater level, soil moisture and the occurrence of overland flow at several locations. Several rain events with varying intensities and magnitudes occurred during the study period. Overland flow and erosion were frequently observed in the entire catchment. Infiltration excess and saturation excess overland flow were both observed. However, the main herbicide loss event was dominated by infiltration excess.

    Despite the frequent and wide-spread occurrence of overland flow, most of this water did not reach the channel directly, but was retained in small depressions in the catchment. From there, it reached the stream via macropores and tile drains. Manholes of the drainage system and storm drains for road and farmyard runoff acted as

  10. The herbicide Glyphosate affects nitrification in the Elbe estuary, Germany

    Science.gov (United States)

    Sanders, Tina; Lassen, Stephan

    2015-04-01

    The Elbe River is one of the biggest European rivers discharging into the North Sea. It also transports high amounts of nutrients and pollutants like pesticides. Important source regions of both nutrients and pollutants are located within the river catchment, which is dominated by agricultural land-use. From these agricultural soils, pesticides can be carried via the river and estuary into the North Sea. Glyphosate (N-(phosphonomethyl) glycine) is the most commonly used herbicide worldwide and mainly used to regulate unwanted plant growth and for the expedition of crop ripening. In Germany, ~ 6000 tons of glyphosate are applied yearly in agriculture and private use. Glyphosate is degradable by microorganisms and has a half-life in water of 35 to 60 days. This herbicide specifically inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme that catalyzes the biosynthesis of essential aromatic amino acids in plants, fungi, and bacteria. Nitrifying bacteria, which play an important role in the internal nitrogen cycling in the Elbe estuary, also possess this enzyme. The aim of our study was to quantify the concentration of glyphosate in water and sediment samples of the Elbe to get an overview about relevant environmental levels and to assess the impact of glyphosate on inhibition of nitrifying activities. To quantify the effect of glyphosate on nitrification activity, natural samples as well as pure cultures of Nitrosomonas europea (strain Nm50) were incubated with different concentrations of glyphosate over a period of some weeks. The nitrifying activity was determined according to changes of the nitrite and nitrate concentration as well as the cell number. Glyphosate was detectable in water and sediment samples in the Elbe estuary with up to 5 ppb mainly in the Port of Hamburg region. In both incubation experiments an inhibiting effect of glyphosate on nitrification could be shown. The incubated natural water sample was affected by a glyphosate

  11. Plant breeding by using radiation mutation - Selection of herbicide-resistant cell lines by using {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyo Yeon [Sunchun University, Sunchun (Korea); Seo, Yong Weon [Korea University, Seoul (Korea)

    2000-04-01

    In order to develop the herbicide resistant cell lines, micro calli derived from rice anther culture and mature seed of wheat cultivars were irradiated with gamma rays. 1) The callus was dedifferentiated by 7 or 21 day pretreatment at 7 deg. C in two rice cultivars, Ilpumbyeo ad Dongjinbyeo. 2) To check the optimum concentration of herbicide, three herbicides were tested with micro calli. 3) The optimum dose of gamma ray to seeds of wheat seemed to be from 100 to 150 Gy. 4) AFLP and RAPD technique were established to develope herbicide resistant molecular marker in rice. 34 refs., 10 figs., 5 tabs. (Author)

  12. Economic Evaluation for Integrated Use of Glyphosate Herbicide and Tillage Combinations Applied before Sowing of Rain-Fed Wheat (Triticum Aestivum L.)

    International Nuclear Information System (INIS)

    Ali, S.; Malik, M. A.; Ansar, M.; Qureshi, R.

    2016-01-01

    Low average yield, scarce soil moisture and less soil fertility are major problems of rain-fed wheat. Economic feasibility of different tillage systems integrated with glyphosate herbicide and wheat crop productivity was determined through field experiments conducted at the University Research Farm of Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan during summer and winter seasons of 2012-13 and 2013-14. Different combinations of tillage and glyphosate herbicide were used in the fallow period (summer season) that were consisted of following treatments viz. T1 = 1 Mould board Plowing + 8 Cultivations, T2 = No-Till + Glyphosate, T3 = 1 Mould board Plowing + Glyphosate, T4 = 1 MB Plowing + 4 Cultivations, T5 = 1 Disc Harrowing + Glyphosate, T6 = 1 Disc Harrowing + 4 Cultivations and T7 = 1 Chiseling + Glyphosate. Results showed that the highest yield viz. 3.5132, 3.1242 t ha-1 were obtained in the case of conventional tillage (T1) and reduced tillage (T4), respectively with a net profit of 888.92 and 839.35 $ ha-1. The yield was positively affected by tillage intensity. In conclusion, T1 is recommended for getting maximum net return from wheat grown in rain-fed areas of Pakistan. (author)

  13. In-field frequencies and characteristics of oilseed rape with double herbicide resistance.

    Science.gov (United States)

    Dietz-Pfeilstetter, Antje; Zwerger, Peter

    2009-01-01

    When growing different transgenic herbicide-resistant oilseed rape cultivars side by side, seeds with multiple herbicide resistance can arise, possibly causing problems for the management of volunteer plants. Large-scale field experiments were performed in the years 1999/2000 and 2000/2001 in order to investigate the frequencies and the consequences of the transfer of herbicide resistance genes from transgenic oilseed rape to cultivars grown on neighboring agricultural fields. Transgenic oilseed rape with resistance to glufosinate-ammonium (LibertyLink, LL) and with glyphosate resistance (RoundupReady, RR), respectively, was sown in adjacent 0.5 ha plots, surrounded by about 8 ha non-transgenic oilseed rape. The plots and the field were either in direct contact (0.5 m gap width) or they were separated by 10 m of fallow land. Seed samples taken during harvest in the transgenic plots at different distances were investigated for progeny with resistance to the respective other herbicide. It was found that outcrossing frequencies were reduced to different extents by a 10 m isolation distance. In addition to pollen-mediated transgene flow as a result of outcrossing, we found considerable seed-mediated gene flow by adventitious dispersal of transgenic seeds through the harvesting machine. Volunteer plants with double herbicide resistance emerging in the transgenic plots after harvest were selected by suitable applications of the complementary herbicides Basta and Roundup Ultra. In both years, double-resistant volunteers were largely restricted to the inner edges of the plots. Expression analysis under controlled laboratory conditions of double-resistant plants generated by manual crosses revealed stability of transgene expression even at elevated temperatures. Greenhouse tests with double-resistant oilseed rape plants gave no indication that the sensitivity to a range of different herbicides is changed as compared to non-transgenic oilseed rape.

  14. Using Bioassays and Species Sensitivity Distributions to Assess Herbicide Toxicity towards Benthic Diatoms

    Science.gov (United States)

    Larras, Floriane; Bouchez, Agnès; Rimet, Frédéric; Montuelle, Bernard

    2012-01-01

    Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD) could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC5) and the Effective Concentration 50 (EC50) for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC5) and 50 (HC50). Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII) herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and “motile” guild species were more tolerant of PSII inhibitors, while N-autotroph and “low profile” guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron. PMID:22952981

  15. Structure effect on the interaction of phenylurea herbicides with model biomembrane as an environmental mobility parameter.

    Science.gov (United States)

    Librando, Vito; Forte, Stefano; Sarpietro, Maria G

    2004-01-15

    During recent years, intensive use of herbicides has raised increasing concern mainly due to their massive pollution of the environment. As these herbicides are directly or indirectly toxic to a wide range of organisms, their potential for contaminating soil, surface water, and groundwater makes these xenobiotics of special interest from a health and environmental point of view. Knowledge of the mechanisms by which they exert their toxic effects is becoming a need. Because of the herbicides' lipophilicity, a possible site of interaction in the cell is represented by biomembranes. The interaction of four herbicides, difenoxuron, diuron, linuron, and metoxuron, with model membranes constituted of dimyristoylphosphatidylcholine multilamellar vesicles was investigated by the differential scanning calorimetry technique. The aim was to study the effects exerted by an increasing amount of the examined compounds on thermotropic behavior of the model phospholipid membranes and to correlate the obtained results with structural features of the herbicides due to their environmental mobility. Among the herbicides studied, linuron is the most effective in perturbing the ordinate structure of vesicles forming phospholipids, whereas metoxuron is the least effective and the others exert an intermediate effect. Linuron exerts its effect both on the transition temperature of the gel to the liquid crystalline phase and on the enthalpy change. Difenoxuron, diuron, and metoxuron cause a change in the transition temperature but have an insignificant effect on the enthalpy change. The calorimetric results, correlated with the structural features of the herbicides, are consistent with their partition coefficient, log K(ow), suggesting that the more hydrophobic compound character causes a greater liposolubility and consequential cellular absorption with more effectiveness on the membrane order.

  16. Herbicide micropollutants in surface, ground and drinking waters within and near the area of Zagreb, Croatia.

    Science.gov (United States)

    Fingler, Sanja; Mendaš, G; Dvoršćak, M; Stipičević, S; Vasilić, Ž; Drevenkar, V

    2017-04-01

    The frequency and mass concentrations of 13 herbicide micropollutants (triazines, phenylureas, chloroacetanilides and trifluralin) were investigated during 2014 in surface, ground and drinking waters in the area of the city of Zagreb and its suburbs. Herbicide compounds were accumulated from water by solid-phase extraction using either octadecylsilica or styrene-divinylbenzene sorbent cartridges and analysed either by high-performance liquid chromatography with UV-diode array detector or gas chromatography with mass spectrometric detection. Atrazine was the most frequently detected herbicide in drinking (84 % of samples) and ground (61 % of samples) waters in mass concentrations of 5 to 68 ng L -1 . It was followed by metolachlor and terbuthylazine, the former being detected in 54 % of drinking (up to 15 ng L -1 ) and 23 % of ground (up to 100 ng L -1 ) waters, and the latter in 45 % of drinking (up to 20 ng L -1 ) and 26 % of ground (up to 25 ng L -1 ) water samples. Acetochlor was the fourth most abundant herbicide in drinking waters, detected in 32 % of samples. Its mass concentrations of 107 to 117 ng L -1 in three tap water samples were the highest of all herbicides measured in the drinking waters. The most frequently (62 % of samples) and highly (up to 887 ng L -1 ) detected herbicide in surface waters was metolachlor, followed by terbuthylazine detected in 49 % of samples in mass concentrations of up to 690 ng L -1 , and atrazine detected in 30 % of samples in mass concentrations of up to 18 ng L -1 . The seasonal variations in herbicide concentrations in surface waters were observed for terbuthylazine, metolachlor, acetochlor, chlortoluron and isoproturon with the highest concentrations measured from April to August.

  17. Effect of Rimsulfuron, Imazapic and Imazamox Herbicides on Broomrape (Orobanche aegyptiaca in Tomato (Lycopersicum esculentum

    Directory of Open Access Journals (Sweden)

    E. Kazerooni Monfared

    2016-01-01

    Full Text Available Experiments, in Petri dish and greenhouse, were carried out to investigate the efficiency of three herbicides (rimsulfuron, imazapic and imazamox in controling broomrape. In Petri dish study, herbicides were applied at 0.05, 0.25, 1.25, 6.25 and 31.25 micro-mole doses to broomrape seeds at germination stage without a host plant and adding GR24 as stimulator. In the greenhouse experiments, the efficiency of these herbicides to control broomrape in two varieties of tomato (Viva and Hyb.Petopride II was investigated. Treatments were four doses of rimsulfuron (25, 50, 75 and 100 g ai/ha, imazapic (5, 10, 15 and 20 g ai/ha and imazamox (0.4, 0.8, 1.2 and 1.6 g ai/ha at one, two and three applications. Results of Petri-dish experiments showed that rimsulfuron and imazapic significantly reduced radicle elongation of seedlings as compared to the control, while, imazamox did not have any effect on broomrape seed. Each dose was applied for one, two and three times with in 15, 29 and 43 days after within transplanting tomato seedlings. Results of pot experiments indicated that the responses of two tomato varieties herbicides were different. Viva was responsive to herbicidal effect and produced higher biomass than Hyb.Petopride II. Rimsulfuron was a suitable herbicide in tomato to control broomrape. Rimsulfuron at doses of 25, 50 and 75 g ai/ha (three times of application were the best doses, specially in viva were the best treatments for broomrape control and producing tomato biomass. Imazapic also, at 5 g ai/ha (two times of application and 10 g ai/ha (single application was an effective treatments in variety of viva. Imazamox treatments did not appear to be suitable herbicides in this study.

  18. Using bioassays and species sensitivity distributions to assess herbicide toxicity towards benthic diatoms.

    Directory of Open Access Journals (Sweden)

    Floriane Larras

    Full Text Available Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC(5 and the Effective Concentration 50 (EC(50 for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC(5 and 50 (HC(50. Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and "motile" guild species were more tolerant of PSII inhibitors, while N-autotroph and "low profile" guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron.

  19. Soil microbial communities and glyphosate decay in soils with different herbicide application history.

    Science.gov (United States)

    Guijarro, Keren Hernández; Aparicio, Virginia; De Gerónimo, Eduardo; Castellote, Martín; Figuerola, Eva L; Costa, José Luis; Erijman, Leonardo

    2018-04-11

    This study evaluates the glyphosate dissipation under field conditions in three types of soil, and aims to determine the importance of the following factors in the environmental persistence of herbicide: i) soil bacterial communities, ii) soil physicochemical properties, iii) previous exposure to the herbicide. A soil without previous record of GP application (P0) and two agricultural soils, with 5 and >10years of GP exposure (A5 and A10) were subjected to the application of glyphosate at doses of 3mg·kg -1 . The concentration of GP and AMPA was determined over time and the dynamics of soil bacterial communities was evaluated using 16S ARN ribosomal gene amplicon-sequencing. The GP exposure history affected the rate but not the extent of GP biodegradation. The herbicide was degraded rapidly, but P0 soil showed a dissipation rate significantly lower than soils with agricultural history. In P0 soil, a significant increase in the relative abundance of Bacteroidetes was observed in response to herbicide application. More generally, all soils displayed shifts in bacterial community structure, which nevertheless could not be clearly associated to glyphosate dissipation, suggesting the presence of redundant bacteria populations of potential degraders. Yet the application of the herbicide prompted a partial disruption of the bacterial association network of unexposed soil. On the other hand, higher values of linear (Kd) and nonlinear (Kf) sorption coefficient in P0 point to the relevance of cation exchange capacity (CEC), clay and organic matter to the capacity of soil to adsorb the herbicide, suggesting that bioavailability was a key factor for the persistence of GP and AMPA. These results contribute to understand the relationship between bacterial taxa exposed to the herbicide, and the importance of soil properties as predictors of the possible rate of degradation and persistence of glyphosate in soil. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Serial ammonia measurement in patients poisoned with glufosinate ammonium herbicide.

    Science.gov (United States)

    Moon, J M; Chun, B J

    2016-05-01

    This study investigated whether ammonia concentrations can predict delayed neurotoxicity development and neurotoxicity latency in glufosinate ammonium (GLA) herbicide-poisoned patients presenting with an alert mental state and stable hemodynamics. This retrospective observational case study included 26 patients divided into 2 groups: neurotoxicity during hospitalization (complicated group) and without neurotoxicity (noncomplicated group). Thirteen patients (50.0%) experienced neurotoxicity at 16 h post-ingestion. Although ammonia concentrations at presentation did not differ significantly between the two groups, the ammonia level in the complicated group increased significantly at the next measurement and remained significantly higher than that in the noncomplicated group until 48 h after ingestion. The peak ammonia concentration before neurotoxicity development was an independent predictor of neurotoxicity (odds ratio: 1.047, 95% confidence interval: 1.010-1.087, p value = 0.014), and the optimal cutoff value of peak ammonia concentration for predicting neurotoxicity was 101.5 μg/dL. The rate of ammonia increase was not associated with the time latency from ingestion to neurotoxicity development. This study showed that serial ammonia measurements in GLA-poisoned patients may identify those who are at high risk of developing neurotoxicity. However, as this study enrolled few patients, further qualified trials are required to confirm our results and to reveal the etiology of hyperammonemia and its causality in neurotoxicity. © The Author(s) 2015.

  1. Aquatic risk assessment of the new rice herbicide profoxydim

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Paloma [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta De La Coruna Km 7, 28040 Madrid (Spain)]. E-mail: arguello@inia.es; Kubitza, Johanna [BASF-AG, Agricultural Center Limburgerhof, P.O. Box 120, D-67114 Limburgerhof (Germany); Peter Dohmen, G. [BASF-AG, Agricultural Center Limburgerhof, P.O. Box 120, D-67114 Limburgerhof (Germany); Tarazona, Jose V. [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta De La Coruna Km 7, 28040 Madrid (Spain)

    2006-07-15

    A tiered protocol for assessing ecological risks has been applied to the rice pesticide profoxydim. The initial assessment (Tier I) was based on toxicity exposure ratio (TER) calculations based on laboratory data using a worst-case rice scenario. The first refinement (Tier II) was based on direct toxicity assessment (DTA) of water samples collected during a field-mesocosm study. Finally, a higher-tier assessment on the in situ assessment of paddy community responses (field-mesocosm-Tier III) was performed. A successive application of three pesticides, the herbicides azimsulfuron, propanil and the insecticide malathion, was used as reference controls. The refined assessments indicated a lower risk than that predicted from TER estimations. DTA-based Tier II showed toxicity effects only for concentrations above the recommended dose of profoxydim. Effects for reference controls were observed in DTA which were not expected from Tier I. The field-mesocosm study confirmed these effects but also showed that they were transient and of low relevance. - Risk refinement assessment of rice pesticides starting with DTA and moving to community studies is a cost-effective approach, only if required.

  2. Hydroxyl radical induced transformation of phenylurea herbicides: A theoretical study

    International Nuclear Information System (INIS)

    Mile, Viktória; Harsányi, Ildikó; Kovács, Krisztina; Földes, Tamás; Takács, Erzsébet; Wojnárovits, László

    2017-01-01

    Aromatic ring hydroxylation reactions occurring during radiolysis of aqueous solutions are studied on the example of phenylurea herbicides by Density Functional Theory calculations. The effect of the aqueous media is taken into account by using the Solvation Model Based on Density model. Hydroxyl radical adds to the ring because the activation free energies (0.4–47.2 kJ mol −1 ) are low and also the Gibbs free energies have high negative values ((−27.4) to (−5.9) kJ mol −1 ). According to the calculations in most of cases the ortho- and para-addition is preferred in agreement with the experimental results. In these reactions hydroxycyclohexadienyl type radicals form. In a second type reaction, when loss of chlorine atom takes place, OH/Cl substitution occurs without cyclohexadienyl type intermediate. - Highlights: • Attack of • OH to aniline, phenol, fenuron, monuron, diuron was studied by DFT. • Ortho-para directing is suggested with –NH 2 , –OH and –NHCON(CH 3 ) 2 groups. • • OH addition to the ring gives hydroxycyclohexadienyl radical. • Attack at C-Cl leads to • OH/Cl substitution without cyclohexadienyl intermediate.

  3. Phototransformation of the herbicide sulcotrione on maize cuticular wax.

    Science.gov (United States)

    Ter Halle, Alexandra; Drncova, Daniela; Richard, Claire

    2006-05-01

    Vegetation plays a key role in environmental cycling and the fate of many organic pollutants. This is especially the case for pesticides because plant leaves are their first reaction environment after application. It is commonly accepted that photochemical reactions of pollutants on plants predominantly take place in the cuticular wax coating of the leaves. Thus, we used films made of either cuticular wax extracted from maize or carnauba gray wax as a model support. Under simulated sunlight irradiation, sulcotrione (a new class of triketone herbicides) sorbed on cuticular wax films was photolyzed and mainly underwent an intramolecular cyclization. The photoproduct is a chromone derivative which was isolated and fully characterized. It is reported for the first time as a sulcotrione degradation product. The photoreactivity of formulated sulcotrione at the surface of cuticular waxes was investigated too. It photodegraded more rapidly than nonformulated sulcotrione. This study also shows that the rate of sulcotrione photolysis was much faster than the rate of penetration into the wax; photolysis should be, thus, a relevant process in real conditions.

  4. Seedling Performance Associated with Live or Herbicide Treated Tall Fescue

    Directory of Open Access Journals (Sweden)

    Jonathan J. Halvorson

    2015-01-01

    Full Text Available Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L, or an herbicide killed (K tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E− or legumes (alfalfa, red clover, and white clover. After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover and tall fescue (especially MaxQ were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions.

  5. Herbicidal potential of ophiobolins produced by Drechslera gigantea.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Cimmino, Alessio; Vurro, Maurizio; Fracchiolla, Mariano; Charudattan, Raghavan

    2006-03-08

    Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds.

  6. Surface retention and photochemical reactivity of the diphenylether herbicide oxyfluorfen.

    Science.gov (United States)

    Scrano, Laura; Bufo, Sabino A; Cataldi, Tommaso R I; Albanis, Triantafyllos A

    2004-01-01

    The photochemical behavior of oxyfluorfen [2-chloro-1-(3-etoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene] on two Greek soils was investigated. Soils were sampled from Nea Malgara and Preveza regions, characterized by a different organic matter content. Soils were spiked with the diphenyl-ether herbicide and irradiation experiments were performed either in the laboratory with a solar simulator (xenon lamp) or outside, under natural sunlight irradiation; other soil samples were kept in the dark to control the retention reaction. Kinetic parameters of both retention and photochemical reactions were calculated using zero-, first- and second- (Langmuir-Hinshelwood) order equations, and best fit was checked through statistical analysis. The soil behaviors were qualitatively similar but quantitatively different, with the soil sampled from the Nea Malgara region much more sorbent as compared with Preveza soil. All studied reactions followed second-order kinetics and photochemical reactions were influenced by retaining capability of the soils. The contributions of the photochemical processes to the global dissipation rates were also calculated. Two main metabolites were identified as 2-chloro-1-(3-ethoxy-4-hydroxyphenoxy)-4-(trifluoromethyl)benzene and 2-chloro-1- (3-hydroxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene.

  7. Aquatic risk assessment of the new rice herbicide profoxydim

    International Nuclear Information System (INIS)

    Sanchez, Paloma; Kubitza, Johanna; Peter Dohmen, G.; Tarazona, Jose V.

    2006-01-01

    A tiered protocol for assessing ecological risks has been applied to the rice pesticide profoxydim. The initial assessment (Tier I) was based on toxicity exposure ratio (TER) calculations based on laboratory data using a worst-case rice scenario. The first refinement (Tier II) was based on direct toxicity assessment (DTA) of water samples collected during a field-mesocosm study. Finally, a higher-tier assessment on the in situ assessment of paddy community responses (field-mesocosm-Tier III) was performed. A successive application of three pesticides, the herbicides azimsulfuron, propanil and the insecticide malathion, was used as reference controls. The refined assessments indicated a lower risk than that predicted from TER estimations. DTA-based Tier II showed toxicity effects only for concentrations above the recommended dose of profoxydim. Effects for reference controls were observed in DTA which were not expected from Tier I. The field-mesocosm study confirmed these effects but also showed that they were transient and of low relevance. - Risk refinement assessment of rice pesticides starting with DTA and moving to community studies is a cost-effective approach, only if required

  8. Biomaterials based on photosynthetic membranes as potential sensors for herbicides.

    Science.gov (United States)

    Ventrella, Andrea; Catucci, Lucia; Placido, Tiziana; Longobardi, Francesco; Agostiano, Angela

    2011-08-15

    In this study, ultrathin film multilayers of Photosystem II-enriched photosynthetic membranes (BBY) were prepared and immobilized on quartz substrates by means of a Layer by Layer procedure exploiting electrostatic interactions with poly(ethylenimine) as polyelectrolyte. The biomaterials thus obtained were characterized by means of optical techniques and Atomic Force Microscopy, highlighting the fact that the Layer by Layer approach allowed the BBYs to be immobilized with satisfactory results. The activity of these hybrid materials was evaluated by means of optical assays based on the Hill Reaction, indicating that the biosamples, which preserved about 65% of their original activity even ten weeks after preparation, were both stable and active. Furthermore, an investigation of the biochips' sensitivity to the herbicide terbutryn, as a model analyte, gave interesting results: inhibition of photosynthetic activity was observed at terbutryn concentrations higher than 10(-7)M, thus evidencing the potential of such biomaterials in the environmental biosensor field. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Toxic reactivity of wheat (Triticum aestivum) plants to herbicide isoproturon.

    Science.gov (United States)

    Yin, Xiao Le; Jiang, Lei; Song, Ning Hui; Yang, Hong

    2008-06-25

    The herbicide isoproturon is widely used for controlling weed/grass in agricultural practice. However, the side effect of isoproturon as contaminants on crops is unknown. In this study, we investigated isoproturon-induced oxidative stress in wheat ( Triticum aestivum). The plants were grown in soils with isoproturon at 0-20 mg/kg and showed negative biological responses. The growth of wheat seedlings with isoproturon was inhibited. Chlorophyll content significantly decreased at the low concentration of isoproturon (2 mg/kg), suggesting that chlorophyll was rather sensitive to isoproturon exposure. The level of thiobarbituric acid reactive substances (TBARS), an indicator of cellular peroxidation, showed an increase, indicating oxidative damage to plants. The isoproturon-induced oxidative stress resulted in a substantial change in activities of the majority of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Activities of the antioxidant enzymes showed a general increase at low isoproturon concentrations and a decrease at high isoproturon concentrations. Activities of CAT in leaves showed progressive suppression under the isoproturon exposure. Analysis of nondenaturing polyacrylamide gel electrophoresis (PAGE) confirmed these results. We also tested the activity of glutathione S-transferase (GST) and observed the activity stimulated by isoproturon at 2-10 mg/kg.

  10. Forest fire occurrence and silvicultural-economic prerequisites for protection improvement in forest regions of Krasnoyarsk Krai

    Directory of Open Access Journals (Sweden)

    V. V. Furyaev

    2017-10-01

    Full Text Available The territory of the Krasnoyarsk Krai is substantially diverse in terms of climatic, silvicultural and economic conditions owing to its sufficient spread from the North to the South. These differences were to some extent taken into account when the forest fund of the Krasnoyarsk Krai was divided into seven forest regions: forest tundra of Central Siberia, highland taiga of Central Siberia, plain taiga of West Siberia, Angara region, subtaiga forest steppe of Central Siberia, Altai-Sayanskiy highland, Altai-Sayanskiy highland forest steppe. The regions show different levels of fire occurrence and different fire effects that require different levels of protection from forest fires. Optimization of the protection is based on activities that combine prevention and timely detection of fires depending on development of forest regions and intensity of forest management. The main focus of the paper is on possibility or inadvisability of prescribed fires, fire-use fires (fires that started naturally but were then managed for their beneficial effects and the system of activities increasing fire resistance of the most valuable forests. It is justified that taking into account the effects of forest fires, selective protection of forests is expedient in forest-tundra Middle Siberia and highland taiga of Middle Siberia regions. The whole area of plain taiga of West Siberia region should be subject to protection but with various levels of intensity in different parts of it. The forest fund of Angara, subtaiga forest steppe of Middle Siberia, Altai-Sayanskiy highland, Altai-Sayanskiy highland forest steppe regions should be protected on the whole area. Application of prescribed fires is relevant in the subzone of South taiga, in the forest steppe zone as well as in the submontane and lowland taiga belts. Fire-use fires are admissible on limited areas in the subzones of Middle and North taiga.

  11. Discovery of Putative Herbicide Resistance Genes and Its Regulatory Network in Chickpea Using Transcriptome Sequencing

    Directory of Open Access Journals (Sweden)

    Mir A. Iquebal

    2017-06-01

    Full Text Available Background: Chickpea (Cicer arietinum L. contributes 75% of total pulse production. Being cheaper than animal protein, makes it important in dietary requirement of developing countries. Weed not only competes with chickpea resulting into drastic yield reduction but also creates problem of harboring fungi, bacterial diseases and insect pests. Chemical approach having new herbicide discovery has constraint of limited lead molecule options, statutory regulations and environmental clearance. Through genetic approach, transgenic herbicide tolerant crop has given successful result but led to serious concern over ecological safety thus non-transgenic approach like marker assisted selection is desirable. Since large variability in tolerance limit of herbicide already exists in chickpea varieties, thus the genes offering herbicide tolerance can be introgressed in variety improvement programme. Transcriptome studies can discover such associated key genes with herbicide tolerance in chickpea.Results: This is first transcriptomic studies of chickpea or even any legume crop using two herbicide susceptible and tolerant genotypes exposed to imidazoline (Imazethapyr. Approximately 90 million paired-end reads generated from four samples were processed and assembled into 30,803 contigs using reference based assembly. We report 6,310 differentially expressed genes (DEGs, of which 3,037 were regulated by 980 miRNAs, 1,528 transcription factors associated with 897 DEGs, 47 Hub proteins, 3,540 putative Simple Sequence Repeat-Functional Domain Marker (SSR-FDM, 13,778 genic Single Nucleotide Polymorphism (SNP putative markers and 1,174 Indels. Randomly selected 20 DEGs were validated using qPCR. Pathway analysis suggested that xenobiotic degradation related gene, glutathione S-transferase (GST were only up-regulated in presence of herbicide. Down-regulation of DNA replication genes and up-regulation of abscisic acid pathway genes were observed. Study further reveals

  12. Weed control in tomato (lycopersicon esculentum mill.) through mulching and herbicides

    International Nuclear Information System (INIS)

    Bakht, T.; Khan, I.A.

    2014-01-01

    Experiments were conducted at the Agricultural Research Farm of the University of Agriculture, Peshawar during 2012 and 2013 to determine the impact of row spacing and weed management strategies on tomato (Lycopersicon esculantum Mill.). Variety 'Roma' was planted on a plot size of 4.8m x 3m using a randomized complete block (RCB) design in split plot arrangements, having four replications. The experiment comprised of row spacing in main plots and ten treatments in the subplots that included five mulches viz., white polyethylene, black polyethylene, wheat straw, newspaper and saw dust; three herbicide treatments i.e. fenoxaprop-p-ethyl, pendimethalin, s-metolachlor along with a hand weeding treatment and a weedy check. The data were recorded on weed density m-2 at 20 days after treatments, plant height, fruit yield (kg ha-1). All the studied parameters were significantly affected by the row spacing (factor A) and weed management treatments (factor B); however, the interaction effects were non-significant. An increase in weed density was observed with increase in row spacing, having weed density of 3.39, 4.19 and 4.53 weeds m-2 for 40, 60 and 80 row spacing, respectively. The overall weed density m-2 ranged between 3.24 to 4.30 m-2. A maximum plant height of 62.44cm was recorded in weedy check and minimum 53.31cm plant height was observed in hand weeding treatments. As regards the fruit yield, a highest yield of 2.51 t ha-1 was recorded at row spacing of 60 cm (factor A) and the application of poly ethylene black plastic resulted in significantly highest fruit yield (4.04 t ha-1) among factor B treatments. (author)

  13. A further evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2002-07-01

    This report describes a study of the safety and efficacy of a range of herbicides and mixtures of herbicides (with both contact and residual activity) for the post-emergence control of weeds in newly planted willow short rotation coppice (SRC). Severe competition from weeds that have not been controlled adequately by pre-emergence herbicide application is one of the commonest causes of SRC crop failure. In the study, the effects of 11 herbicide treatments currently recommendation for weed control with cereals, legumes or potatoes were compared with an untreated control. There was minimal crop death from any treatment, though most of the treatments caused varying degrees of phytotoxicity. Two commercial products, Reflex T and Impuls, gave the best overall crop safety and weed control results. The report provides growers of SRC and their advisors with some information on how to achieve improved weed control in SRC fields, and recommends that British Biogen (the trade industry body) should consider the compilation of a technical register of herbicide applications based on information supplied by growers and advisers, including field treatment details.

  14. Two roles of thylakoid lipids in modifying the activity of herbicides which inhibit photosystem II

    International Nuclear Information System (INIS)

    Kupatt, C.C. Jr.

    1985-01-01

    Thylakoid lipids may modify the activity of herbicides which inhibit electron transport at the Q/sub B/ protein of photosystem II in two ways: (1) lipids can act as a hydrophobic barrier to a binding site localized close to the loculus of the membrane, and (2) changes in lipid composition can reduce the ability of inhibitors to block electron transport, possibly due to a change in the conformation of the Q/sub B/ protein. The herbicide binding site was localized close to the locular side of the thylakoid membrane by determining the activity of a number of substituted phenylurea and s-triazine herbicides in inverted and non-inverted thylakoids. Quantitative structure-activity relationship analysis showed that inversion of thylakoids reduced the requirement of molecular lipophilicity deemed necessary for phenylurea activity in non-inverted membranes, whereas s-triazines exhibited no differences in the lipophilicity requirement in thylakoid membranes of either orientation. The binding affinity of 14 C-diuron was reduced in bicarbonate-depleted thylakoids relative to reconstituted or control membranes, as is the case with atrazine binding. These observations support a model of the herbicide binding site containing both common and herbicide family specific binding domains. Thylakoids isolated either from detached lambs quarters (Chenopodium album L.) leaves, treated with SAN 6706, or from soybean (Glycine max L.), with norflurazon or pyrazon applied preemergence, exhibited decreased susceptibility to atrazine. The ability of lipid-modifying treatments to decrease the atrazine susceptibility of field-grown soybeans was also investigated

  15. Effect of herbicide and soil amendment on growth and photosynthetic responses in olive crops.

    Science.gov (United States)

    Redondo-Gómez, Susana; Mateos-Naranjo, Enrique; Cox, Lucía; Cornejo, Juan; Figueroa, Enrique

    2007-01-01

    Diuron [3-(3,4-dichlorophenyl)- = 1,1-dimethylurea] and simazine (6-chloro-N(2), N(4)-diethyl-1,3,5-triazine-2,4-diamine) are soil-applied herbicides used in olive crops. The objective of this study is to investigate the combined effect of these herbicides and the amendment of soil with an organic waste (OW) from the olive oil production industry on the growth and photosynthetic apparatus of adult olive trees and to compare the results with those obtained by Redondo-Gómez et al. for two-year-old trees. For this purpose, growth rate, gas exchange and chlorophyll fluorescence parameters were measured in 38-year-old olive trees, after one and two months of soil herbicide treatment and/or OW amendment. Soil co-application of OW and herbicide increases the quantum efficiency of Photosystem II (PSII) and the assimilation of CO(2) in olive trees, which led to a higher relative growth rate of the branches and leaves in length. Herbicide treatment reduced the photosynthetic efficiency in olive trees after two months of soil application, while this reduction is evident from week one in younger trees.

  16. Glyceria maxima as new test species for the EU risk assessment for herbicides: a microcosm study.

    Science.gov (United States)

    Mohr, S; Schott, J; Hoenemann, L; Feibicke, M

    2015-03-01

    In its recent guidance document on tiered risk assessment for plant protection products for aquatic organisms, the European Food Safety Authority (EFSA) proposed to use Glyceria maxima as monocotyledonous grass species for the testing of special herbicide groups. However, published toxicity data for this species is very limited and there is no test guideline for Glyceria sp. For this reason a microcosm study was conducted in order to gain experience on the degree of sensitivity of G. maxima to the herbicidal substances clodinafop-propargyl (grass herbicide) and fluroxypyr (auxin) in comparison to the already established test organism water milfoil Myriophyllum spicatum and the duckweed species Landoltia punctata. Five concentrations without replicates were tested for each test substance using 10 microcosms and three microcosms served as controls. The experiment was run for 8 weeks. Morphological endpoints were used to determine growth and EC50 values. The results show that M. spicatum was most sensitive to fluroxypyr (37 days EC50 for roots: 62 µg/L) and G. maxima most sensitive to clodinafop-propargyl (22 days EC50 for total shoot length: 48 µg/L) whereas the duckweed species was considerable less sensitive. Hence, G. maxima turns out to be a good candidate for testing grass specific herbicides, supporting its inclusion as an additional macrophyte test for the risk assessment of herbicides as proposed by the EFSA.

  17. Resistência de plantas daninhas aos herbicidas Weed resistance to herbicides

    Directory of Open Access Journals (Sweden)

    Pedro J. Christoffoleti

    1994-01-01

    Full Text Available A resistência de plantas daninhas aos herbicidas ocorre em função de um processo evolutivo. O desenvolvimento de biótipos de plantas daninhas resistentes é imposto pela agricultura moderna, através da pressão de seleção causada pelo uso intensivo dos herbicidas. O conhecimento dos mecanismos e fatores que favorecem o aparecimento de biótipos de plantas daninhas resistentes é fundamental para que técnicas de manejo sejam utilizadas no sentido de evitar ou retardar o aparecimento de plantas resistentes em uma área. São poucos os relatos ou citações de literatura no Brasil. Sendo assim, este trabalho de revisão procura relatar os principais avanços e descobertas na área de plantas daninhas resistentes aos herbicidas.Weed herbicide resistance has evolved from weed evolution. The modern agriculture is responsible for this evolution because of the intensive use of herbicides. The knowledge of mechanisms and factors that influence the weed herbicide resistance play an important role in the weed manegement techniques used to avoid or delay herbicide resistance appearence. There are not many report or scientific papers about herbi cide resistance in Brasil. Therefore, this literature review aims to provide information about the main advances and discoveries in the field of weed herbicide resistance.

  18. Non-target-site resistance to ALS-inhibiting herbicides in a Sagittaria trifolia L. population.

    Science.gov (United States)

    Zhao, Bochui; Fu, Danni; Yu, Yang; Huang, Chengtian; Yan, Kecheng; Li, Pingsheng; Shafi, Jamil; Zhu, He; Wei, Songhong; Ji, Mingshan

    2017-08-01

    Sagittaria trifolia L. is one of the most competitive weeds in rice fields in northeastern China. The continuous use of acetolactate synthase (ALS)-inhibitors has led to the evolution of herbicide resistant S. trifolia. A subpopulation BC1, which was derived from the L1 population, was analyzed using DNA sequencing and ALS enzyme activity assays and levels of resistance to five ALS-inhibiting herbicides was determined. DNA sequencing and ALS enzyme assays revealed no amino acid substitutions and no significant differences in enzyme sensitivity between susceptible and resistant populations. Whole-plant dose-response experiments showed that the BC1 population exhibited different levels of resistance (resistance ratios ranging from 2.14 to 51.53) to five ALS herbicides, and the addition of malathion (P450 inhibitor) to bensulfuron-methyl, penoxsulam and bispyribac-sodium strongly reduced the dry weight accumulation of the BC1 population compared with the effects of the three herbicides alone. The results of the present study demonstrated that the BC1 population has evolved non-target-site resistance to ALS-inhibiting herbicides. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Herbicide and pesticide occurrence in the soils of children's playgrounds in Sarajevo, Bosnia and Herzegovina.

    Science.gov (United States)

    Sapcanin, Aida; Cakal, Mirsada; Imamovic, Belma; Salihovic, Mirsada; Pehlic, Ekrem; Jacimovic, Zeljko; Jancan, Gordan

    2016-08-01

    Pesticide pollution in Sarajevo public playgrounds is an important health and environmental issue, and the lack of information about it is causing concerns amongst the general population as well as researchers. Since children are in direct contact with surface soils on children's playgrounds, such soils should be much more carefully examined. Furthermore, herbicides and pesticides get transmitted from soil surfaces brought from outside the urban areas, or they get dispersed following their direct applications in urban areas. Infants' and children's health can be directly affected by polluted soils because of the inherent toxicity and widespread use of the different pesticides in urban environments such as playgrounds. In addition to that, the presence of chromated copper arsenate (CCA) wood preservative pesticide found as soil pollutant in playing equipment was also documented. Soil samples from playgrounds were collected and analyzed for triazines, carbamates, dithiocarbamates, phenolic herbicides and organochlorine pesticides. Samples for the determination of heavy metals Cu, Cr and As were prepared by microwave-assisted acid digestion, and the findings were determined by using an inductively coupled plasma optical emission spectrometer. Triazines, carbamates, dithiocarbamates, chlorphenoxy compounds, phenolic herbicides, organochlorine pesticides and organotin compounds were detected in playground soils and their determined concentrations (mg/kg) were respectively found as follows: herbicides and pesticides on human health, which strengthens the case for a more preventative and protective approach to the uncontrolled presence of herbicides and pesticides in Sarajevo's playground soils.

  20. Effect of Butachlor Herbicide on Earthworm Eisenia fetidaIts Histological Perspicuity

    International Nuclear Information System (INIS)

    Gobi, M.; Gunasekaran, P.

    2010-01-01

    With the advent of the Green Revolution, there has been a quantum leap in the use of synthetic herbicides and pesticides throughout the world to sustain high yielding crop varieties. Continuous use of these synthetic chemicals leads to loss of soil fertility and soil organisms. To explore the effect of exposure to commercial herbicide (Butachlor) on the life history parameters (biomass, clitellum development, and cocoon production) and the histological changes in the earthworm Eisenia fetida over 60 days, the dried cow dung was contaminated with 0.2575 mg/ kg -1 , 0.5150 mg/ kg -1 , and 2.5750 mg/ kg -1 of butachlor based on the LC 50 value, and a control was maintained. The mean earthworm biomass was found to be decreased with increasing herbicide concentration. Similarly, cocoon production was also reduced by the increasing herbicide concentration. A possible explanation is an increased demand for energy, needed for the regulation and detoxification of herbicide. All earthworms in the exposed group were found to have glandular cell enlargement and to be vacuolated

  1. Development and characterization of mutant winter wheat (Triticum aestivum L.) accessions resistant to the herbicide quizalofop.

    Science.gov (United States)

    Ostlie, Michael; Haley, Scott D; Anderson, Victoria; Shaner, Dale; Manmathan, Harish; Beil, Craig; Westra, Phillip

    2015-02-01

    New herbicide resistance traits in wheat were produced through the use of induced mutagenesis. While herbicide-resistant crops have become common in many agricultural systems, wheat has seen few introductions of herbicide resistance traits. A population of Hatcher winter wheat treated with ethyl methanesulfonate was screened with quizalofop to identify herbicide-resistant plants. Initial testing identified plants that survived multiple quizalofop applications. A series of experiments were designed to characterize this trait. In greenhouse studies the mutants exhibited high levels of quizalofop resistance compared to non-mutant wheat. Sequencing ACC1 revealed a novel missense mutation causing an alanine to valine change at position 2004 (Alopecurus myosuroides reference sequence). Plants carrying single mutations in wheat's three genomes (A, B, D) were identified. Acetyl co-enzyme A carboxylase in resistant plants was 4- to 10-fold more tolerant to quizalofop. Populations of segregating backcross progenies were developed by crossing each of the three individual mutants with wild-type wheat. Experiments conducted with these populations confirmed largely normal segregation, with each mutant allele conferring an additive level of resistance. Further tests showed that the A genome mutation conferred the greatest resistance and the B genome mutation conferred the least resistance to quizalofop. The non-transgenic herbicide resistance trait identified will enhance weed control strategies in wheat.

  2. Potential environmental impacts associated with large-scale herbicide-tolerant GM oilseed rape crops

    Directory of Open Access Journals (Sweden)

    Fellous Marc

    2004-07-01

    Full Text Available The Biomolecular Engineering Commission considers that the knowledge acquired in the last three years has provided significant information in reply to the points raised in its review dated 16 February 2001. The Commission has studied the potential environmental impacts associated with large-scale herbicidetolerantGMoilseed rape crops, making a distinction between direct and indirect impacts. Direct impacts stem from the intrinsic properties of herbicide-tolerant GM oilseed rape crops whereas indirect impacts result from practices associated with the farming of these crops. The Commission considers that, in the absence of the use of the herbicide in question in and outside of farmed land, there is no direct environmental risk (development of invasive crops per se associated with the presence of a herbicide-tolerance gene in oilseed rape (or related species. Nevertheless, since the interest of these tolerant crops lies in the use of the herbicide in question, indirect effects, to varying extents, have been identified and must be taken into account: the use of the herbicide in question, applied to agricultural fields containing the herbicide-tolerant crop could lead to an increase in oilseed rape volunteer populations in crop rotations; the selective pressure exerted by non-specific herbicides (to which the crops have been rendered tolerant may be very high in cases of continuous and uncontrolled use of these herbicides, and may result in the persistence of rare events such as the reproduction of fertile interspecies hybrids; the change to the range of herbicides used should be conveyed by more effective weed control and, like any change in farming practices, induce indirect effects on the agri-ecosystem, particularly in terms of changes to weeds and the associated animal life. Accordingly, the Biomolecular Engineering Commission recommends a global approach in terms of the large-scale farming of herbicide-tolerant crops that: accounts for the

  3. Performance of Different Herbicides in Dry-Seeded Rice in Bangladesh

    Science.gov (United States)

    Ahmed, Sharif; Chauhan, Bhagirath Singh

    2014-01-01

    A field study was conducted in the boro season of 2011-12 and aman season of 2012 at Jessore, Bangladesh, to evaluate the performance of sequential applications of preemergence herbicides (oxadiargyl 80 g ai ha−1, pendimethalin 850 g ai ha−1, acetachlor + bensulfuranmethyl 240 g ai ha−1, and pyrazosulfuron 15 g ai ha−1) followed by a postemergence herbicide (ethoxysulfuron 18 g ai ha−1) in dry-seeded rice. All evaluated herbicides reduced weed density and biomass by a significant amount. Among herbicides, pendimethalin, oxadiargyl, and acetachlor + bensulfuranmethyl performed very well against grasses; pyrazosulfuron, on the other hand, was not effective. The best herbicide for broadleaf weed control was oxadiargyl (65–85% control); pendimethalin and acetachlor + bensulfuraonmethyl were not effective for this purpose. The best combination for weed control was oxadiargyl followed by ethoxysulfuron in the boro season and oxadiargyl followed by a one-time hand weeding in the aman season. Compared with the partial weedy plots (hand weeded once), oxadiargyl followed by ethoxysulfuron (4.13 t ha−1) provided a 62% higher yield in the boro season while oxadiargyl followed by a one-time hand weeding (4.08 t ha−1) provided a 37% higher yield in the aman season. PMID:24688423

  4. Herbicidal Spectrum, Absorption and Transportation, and Physiological Effect on Bidens pilosa of the Natural Alkaloid Berberine.

    Science.gov (United States)

    Wu, Jiao; Ma, Jing-Jing; Liu, Bo; Huang, Lun; Sang, Xiao-Qing; Zhou, Li-Juan

    2017-08-02

    Berberine is a natural herbicidal alkaloid from Coptis chinensis Franch. Here we characterized its herbicidal spectrum and absorption and transportation in the plant, along with the possible mechanism. Berberine showed no effect on the germination of the 10 tested plants. The IC 50 values of berberine on the primary root length and fresh weight of the 10 tested plants ranged from 2.91 to 9.79 mg L -1 and 5.76 to 35.07 mg L -1 , respectively. Berberine showed a similar herbicidal effect on Bidens pilosa as the commercial naturally derived herbicide cinmethylin. HPLC and fluorescence analysis revealed that berberine was mainly absorbed by B. pilosa root and transported through vascular bundle acropetally. Enzyme activity studies, GC-MS analysis, and SEM and TEM observations indicated that berberine might first function on the cell membrane indicated by variation of the IUFA percent and then cause POD, PPO, and SOD activity changes and cellular structure deformity, which was eventually expressed as the decrease of cell adaptation ability and abnormal cell function and may even result in cell death. Environmental safety evaluation tests revealed that berberine was low in toxicity to Brachydanio rerio. These indicate that berberine has the potential to be a bioherbicide and/or a lead molecule for new herbicides.

  5. Effect of Butachlor Herbicide on Earthworm Eisenia fetida—Its Histological Perspicuity

    Directory of Open Access Journals (Sweden)

    Muthukaruppan Gobi

    2010-01-01

    Full Text Available With the advent of the Green Revolution, there has been a quantum leap in the use of synthetic herbicides and pesticides throughout the world to sustain high yielding crop varieties. Continuous use of these synthetic chemicals leads to loss of soil fertility and soil organisms. To explore the effect of exposure to commercial herbicide (Butachlor on the life history parameters (biomass, clitellum development, and cocoon production and the histological changes in the earthworm Eisenia fetida over 60 days, the dried cow dung was contaminated with 0.2575 mg kg−1, 0.5150 mg kg−1, and 2.5750 mg kg−1 of butachlor based on the LC50 value, and a control was maintained. The mean earthworm biomass was found to be decreased with increasing herbicide concentration. Similarly, cocoon production was also reduced by the increasing herbicide concentration. A possible explanation is an increased demand for energy, needed for the regulation and detoxification of herbicide. All earthworms in the exposed group were found to have glandular cell enlargement and to be vacuolated.

  6. Seasonal variability in irradiance affects herbicide toxicity to the marine flagellate Dunaliella tertiolecta

    Directory of Open Access Journals (Sweden)

    Sascha eSjollema

    2014-06-01

    Full Text Available Photosynthetically Active Radiation (PAR and Ultraviolet Radiation (UVR of the solar spectrum affect microalgae directly and modify the toxicity of phytotoxic compounds present in water. As a consequence seasonal variable PAR and UVR levels are likely to modulate the toxic pressure of contaminants in the field. Therefore the present study aimed to determine the toxicity of two model contaminants, the herbicides diuron and Irgarol®1051, under simulated irradiance conditions mimicking different seasons. Irradiance conditions of spring and autumn were simulated with a set of Light Emitting Diodes (LEDs. Toxicity of both herbicides was measured individually and in a mixture by determining the inhibition of photosystem II efficiency (ΦPSII of the marine flagellate Dunaliella teriolecta using Pulse Amplitude Modulation (PAM fluorometry. Toxicity of the single herbicides was higher under simulated spring irradiance than under autumn irradiance and this effect was also observed for mixtures of the herbicides. This irradiance dependent toxicity indicates that herbicide toxicity in the field is seasonally variable. Consequently toxicity tests under standard light conditions may overestimate or underestimate the toxic effect of phytotoxic compounds.

  7. Evaluation of six pesticides leaching indexes using field data of herbicide application in Casablanca Valley, Chile.

    Science.gov (United States)

    Kogan, M; Rojas, S; Gómez, P; Suárez, F; Muñoz, J F; Alister, C

    2007-01-01

    A field study was performed to evaluate the accuracy of six pesticide screening leaching indexes for herbicide movement. Adsorption, dissipation and soil movement were studied in a vineyard in a sandy loam soil during 2005 season. Simazine, diuron, pendimethalin, oxyfluorfen and flumioxazin were applied to bare soil at rates commonly used, and their soil concentrations throughout soil profile were determined at 0, 10, 20, 40 and 90 days after application (DAA). Herbicides were subjected to two pluviometric regimens, natural field condition and modified conditions (plus natural rainfall 180 mm). Leaching indexes utilized were: Briggs's Rf, Hamaker's Rf, LEACH, LPI, GUS and LIX. Simazine reached 120 cm, diuron 90 cm, flumioxazin 30 cm soil depth respectively. Pendimethalin and oxyfluorfen were retained up to 5 cm. None of the herbicides leaching was affected by rainfall regimen. Only flumioxazin field dissipation was clearly affected by pluviometric condition. The best representation of the herbicide soil depth movement and leaching below 15 cm soil depth were: Hamaker's Rf < Briggs's Rf < GUS < LPI, < LEACH < LIX. Field results showed a good correlation between herbicides K(d) and their soil depth movement and mass leached below 15 cm soil depth.

  8. Controle de plantas daninhas em soja com doses reduzidas de herbicidas Soybean weed control with reduced rates of herbicides

    Directory of Open Access Journals (Sweden)

    Nilson G. Fleck

    1995-01-01

    Full Text Available doses reduzidas dos herbicidas haloxyfop-methyl e sethoxydim para controlar papuã [Brachiaria plantaginea (Link Hitchc.] na cultura da soja [Glycine max (L. Merrill. Haloxyfop-methyl foi testado nas doses de 120, 90, 60 e 30+30 g/ha; já sethoxydim o foi nas doses de 220, 165, 110 e 55+55 g/ha. A pulverização dos herbicidas ocorreu 15 dias após a semeadura da soja; nesta ocasião, a maioria das plantas de papuã encontravam-se no estádio de três a quatro folhas. Os tratamentos herbicidas com doses reduzidas em aplicações seqüenciais, tiveram a segunda pulverização realizada 11 dias após a primeira aplicação. Foi obtido controle ao redor de 95% para todos os tratamentos, com pequenas variações não significativas. O rendimento de grãos de soja foi equivalente entre a testemunha capinada e os tratamentos haloxyfop-methyl a 90 e 60 g/ha, sethoxydim a 220, 110 e 55+55 g/ha. Os demais tratamentos foram semelhantes entre si, superando a testemunha infestada, a qual apresentou o menor rendimento de grãos. Os resultados evidenciam a viabilidade da utilização de doses reduzidas, as quais podem alcançar patamares de produtividade tão elevados quanto aqueles obtidos com doses plenas.During the 1993/94 growing season, it was carried out a field experiment at the Agronomic Experimental Station of Federal University of Rio Grande do Sul, in Eldorado do Sul, RS, Brazil, in order to evaluate the possibility of using reduced rates of the herbicides haloxyfop-methyl and sethoxydim for Alexandergrass [Brachiaria plafitaginea (Link Hitchc.] control in soybeans. Haloxyfop-methyl was tested at 120, 90, 60, and 30+30 g/ha, where as sethoxydim was at rates, of 220, 165, 110, and 55+55 g/ha. Herbicide spraying occurred 15 days after soybean sowing; at this time Alexandergrass plants ranged from one leaf to one tiller. Herbicide treatments using reduced rates in sequential applications had the second spraying accomplished 11 days after the first one

  9. Environmental and health effects of the herbicide glyphosate.

    Science.gov (United States)

    Van Bruggen, A H C; He, M M; Shin, K; Mai, V; Jeong, K C; Finckh, M R; Morris, J G

    2018-03-01

    The herbicide glyphosate, N-(phosphonomethyl) glycine, has been used extensively in the past 40years, under the assumption that side effects were minimal. However, in recent years, concerns have increased worldwide about the potential wide ranging direct and indirect health effects of the large scale use of glyphosate. In 2015, the World Health Organization reclassified glyphosate as probably carcinogenic to humans. A detailed overview is given of the scientific literature on the movement and residues of glyphosate and its breakdown product aminomethyl phosphonic acid (AMPA) in soil and water, their toxicity to macro- and microorganisms, their effects on microbial compositions and potential indirect effects on plant, animal and human health. Although the acute toxic effects of glyphosate and AMPA on mammals are low, there are animal data raising the possibility of health effects associated with chronic, ultra-low doses related to accumulation of these compounds in the environment. Intensive glyphosate use has led to the selection of glyphosate-resistant weeds and microorganisms. Shifts in microbial compositions due to selective pressure by glyphosate may have contributed to the proliferation of plant and animal pathogens. Research on a link between glyphosate and antibiotic resistance is still scarce but we hypothesize that the selection pressure for glyphosate-resistance in bacteria could lead to shifts in microbiome composition and increases in antibiotic resistance to clinically important antimicrobial agents. We recommend interdisciplinary research on the associations between low level chronic glyphosate exposure, distortions in microbial communities, expansion of antibiotic resistance and the emergence of animal, human and plant diseases. Independent research is needed to revisit the tolerance thresholds for glyphosate residues in water, food and animal feed taking all possible health risks into account. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Glyphosate and dicamba herbicide tank mixture effects on native plant and non-genetically engineered soybean seedlings

    Science.gov (United States)

    Weed species are becoming resistant to intensive and extensive use of specific herbicides associated with the production of herbicide resistant crops, e.g., the use of glyphosate for weed management with glyphosate resistant soybeans. To counter this resistance, crops engineered ...

  11. Non-target effects of broadleaf herbicide on a native perennial forb: a demographic framework for assessing and minimizing impacts

    Science.gov (United States)

    Elizabeth E. Crone; Marilyn Marler; Dean E. Pearson

    2009-01-01

    Invasive species are one of the leading threats to biodiversity worldwide. Therefore, chemical herbicides are increasingly used to control invasive plants in natural and semi-natural areas. Little is known about the non-target impacts of these chemicals on native species. We conducted an experiment to test the demographic effects of the herbicide picloram on a native...

  12. RESPONSES OF MOLECULAR INDICATORS OF EXPOSURE IN MESOCOSMS: COMMON CARP (CYPRINUS CARPIO) EXPOSED TO THE HERBICIDES ALACHLOR AND ATRAZINE

    Science.gov (United States)

    Common carp (Cyprinus carpio) were treated in aquatic mesocosms with a single pulse of the herbicides atrazine or alachlor to study the bioavailability and biological activity of these herbicides using molecular indicators: Liver vitellogenin gene expression in male fish for estr...

  13. Evaluating grass strips trapping efficiency of sediments and herbicides

    Science.gov (United States)

    Burguet, Maria; Guzmán, Gema; de Luna, Elena; Taguas, Encarnación V.; Gómez, José Alfonso

    2016-04-01

    Water erosion and associated offsite contamination are major environmental risks in many Mediterranean crops such as olives or vineyards (Beaufoy, 2001; Gómez et al., 2011). The use of cover crops has been prescribed as a mitigation measure for both problems because permanent cover crops have demonstrated to reduce sediment and agrochemical loads (e.g. Gómez, 2009a, b). However, large uncertainty remains about its effectiveness degree to reduce sediment and agrochemical contribution to streams due to the limited number of available studies, and the large variability observed under field conditions (Taguas et al., 2012). Furthermore, the determination of sediment and herbicide sources using suitable sediment tracing/fingerprinting properties has been noted as one tool to evaluate the effectiveness and functioning of vegetated filters at the catchment scale (Koiter et al., 2013). The objectives of the present study were twofold: [1] to explore the combined use of natural and simulated rainfall and magnetic iron oxide in understanding the performance of vegetation strips on runoff and soil and herbicide losses at plot scale and, [2] to evaluate the effectiveness degree of vegetation strips in buffering sediment and herbicide from bare soil areas under different conditions compared to a control situation with no strips. This study encompasses six rainfall simulations under four different soil managements combining the use of a magnetic iron oxide as a sediment tracer to obtain a better understanding of the vegetation strips trapping efficiency. Three runoff plots of 6 m × 14 m were established in a 20% hillslope under a Fluvisol alluvial terrace. Each of the plots contained three bare strips tagged with magnetic iron oxide and three strips with Lolium multiflorum L. The soil management simulated scenarios were: immediately after sowing the vegetation cover (June 2011cover crop), with settled vegetation cover (June 2012cover crop), after 5 cm of deep ploughing

  14. Modified cellulose synthase gene from Arabidopsis thaliana confers herbicide resistance to plants

    Science.gov (United States)

    Somerville, Chris R [Portola Valley, CA; Scheible, Wolf [Golm, DE

    2007-07-10

    Cellulose synthase ("CS"), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl)phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  15. Sensitivity of Phaseolus vulgaris cv. `CIAP 7247F' plants to Glufosinate ammonium herbicide in greenhouse

    Directory of Open Access Journals (Sweden)

    Idalmis Bermúdez-Caraballoso

    2014-01-01

    Full Text Available Genetic breeding in Phaseolus by genetic transformation requires an efficient selection system. The present investigation was aimed to determine the minimum lethal concentration of glufosinate-ammonium (Finale ® in beans plants cv. `CIAP 7247F' grown in greenhouse. Different concentrations of the herbicide were applied to the foliage of plants in acclimatization phase (20, 30 y 40 mg l-1 and the control. Results showed that the minimum lethal concentration in plants in acclimatization phase was 30 mg l-1. Results also demonstrated that is possible the use of the herbicide as a selective agent of beans transformants cv. `CIAP 7247F' carrying the bar gene. Keywords: genetic transformation, herbicide, selective agent, tissue culture

  16. Chemically functionalized ZnS quantum dots as new optical nanosensor of herbicides

    Science.gov (United States)

    Masteri-Farahani, M.; Mahdavi, S.; Khanmohammadi, H.

    2018-03-01

    Surface chemical functionalization of ZnS quantum dots (ZnS-QDs) with cysteamine hydrochloride resulted in the preparation of an optical nanosensor for detection of herbicides. Characterization of the functionalized ZnS-QDs was performed with physicochemical methods such as x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive x-ray (EDX) analysis, ultraviolet-visible (UV–vis) and photoluminescence (PL) spectroscopies. The optical band gap of the functionalized ZnS-QDs was determined by using Tauc plot as 4.1 eV. Addition of various herbicides resulted in the linearly fluorescence quenching of the functionalized ZnS-QDs according to the Stern-Volmer equation. The functionalized ZnS-QDs can be used as simple, rapid, and inexpensive nanosensor for practical detection and measurement of various herbicides.

  17. REDUCTION OF HERBICIDE AND WATER STRESS IN SPRING BARLEY BY REGULATORS OF POLYAMINE BIOSYNTHESIS

    Directory of Open Access Journals (Sweden)

    Pavol Trebichalský

    2014-02-01

    Full Text Available The experiment was carried out under artificial light of fluorescent lamps starting with 60 % full water capacity which was afterwards decreased on 40 % and finally the plants of barley were not watered. 30 plants of this cereal after plant emergence were thinned on 22 pieces. Experiment was treated by triazine herbicide, as well as its mixtures of regulators of polyamine synthesis: γ-aminobutyric acid, 1.3-propylenediamine dihydrochloride and salicyl acid. Solo application of triazine herbicide during water stress had negative balance on formation of root and above ground biomass. Addition of regulators of polyamine synthesis had positive effects on mentioned parameters, but not in comparison to control variant. These stress factors were eliminated most significantly only the application of GABA (100 g.ha-1 in mixture with herbicide.

  18. Biotransformation of benzonitrile herbicides via the nitrile hydratase-amidase pathway in rhodococci.

    Science.gov (United States)

    Veselá, Alicja B; Pelantová, Helena; Sulc, Miroslav; Macková, Martina; Lovecká, Petra; Thimová, Markéta; Pasquarelli, Fabrizia; Pičmanová, Martina; Pátek, Miroslav; Bhalla, Tek Chand; Martínková, Ludmila

    2012-12-01

    The aim of this work was to determine the ability of rhodococci to transform 3,5-dichloro-4-hydroxybenzonitrile (chloroxynil), 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil), 3,5-diiodo-4-hydroxybenzonitrile (ioxynil) and 2,6-dichlorobenzonitrile (dichlobenil); to identify the products and determine their acute toxicities. Rhodococcus erythropolis A4 and Rhodococcus rhodochrous PA-34 converted benzonitrile herbicides into amides, but only the former strain was able to hydrolyze 2,6-dichlorobenzamide into 2,6-dichlorobenzoic acid, and produced also more of the carboxylic acids from the other herbicides compared to strain PA-34. Transformation of nitriles into amides decreased acute toxicities for chloroxynil and dichlobenil, but increased them for bromoxynil and ioxynil. The amides inhibited root growth in Lactuca sativa less than the nitriles but more than the acids. The conversion of the nitrile group may be the first step in the mineralization of benzonitrile herbicides but cannot be itself considered to be a detoxification.

  19. Biomass, Leaf Area, and Resource Availability of Kudzu Dominated Plant Communities Following Herbicide Treatment

    Energy Technology Data Exchange (ETDEWEB)

    L.T. Rader

    2001-10-01

    Kudzu is an exotic vine that threatens the forests of the southern U.S. Five herbicides were tested with regard to their efficacy in controlling kudzu, community recover was monitored, and interactions with planted pines were studied. The sites selected were old farm sites dominated by kudzu.These were burned following herbicide treatment. The herbicides included triclopyr, clopyralid, metsulfuron, tebuthiuron, and picloram plus 2,4-D. Pine seedlings were planted the following year. Regression equations were developed for predicting biomass and leaf area. Four distinct plant communities resulted from the treatments. The untreated check continued to be kudzu dominated. Blackberry dominated the clopyradid treatment. Metsulfron, trychlopyr and picloram treated sites resulted in herbaceous dominated communities. The tebuthiuron treatment maintained all vegetation low.

  20. COMPARATIVE STUDY CONCERNING THE INFLUENCE OF DIFFERENT HERBICIDE TREATMENT IN ONION CULTURE

    Directory of Open Access Journals (Sweden)

    Ioan OROIAN

    2009-06-01

    Full Text Available A comparative study was performed concerning the action of three herbicides (Pantera 40 CE, Fusilade Super and Agil 100 EC on onion culture. The Amstrong onion hybrid was used on clay - aluviovertic chernosem, with NPK fertilization (N80P80K80 during the preparation of the germinative bed. The unfavorable climatic conditions infl uence the effi cacy of the post-emergent applied herbicides, but signifi cant differences were recorded between variants treated with different products. When Pantera 40 CE was used, phytotoxicity phenomena materialized by temporary discoloration of the plants were not recorded, compared to the results obtained when the other herbicides were used. The use of Pantera 40 CE led to the most important production gain, with 9.8% compared to Fusilade super and 4.8% with Agil 100 EC.

  1. Effect of soil herbicides on the antioxidant system of maize vegetative organs during ontogenesis

    Directory of Open Access Journals (Sweden)

    I.P. Grigoryuk

    2016-06-01

    Full Text Available The impact of soil herbicides Harnes, Frontier and Merlin on the activity of enzymes superoxid dismutase (SOD, EC 1.15.1.1, catalase (CAT, EC 1.11.1.6, and benzidine peroxidase (POD, EC 1.11.1.7 in maize (Zea mays L.; cultivar Kadr 267 MV roots and leaves was studied in the field experiment. It was established that the adaptation of maize plants to the herbicides treatment was accompanied by significant activation of antioxidant enzymes both in roots (39%, 57%, and 67% above control level and leaves (50%, 64%, and 77% above control, respectively during different vegetation stages (shoots emergence; 3–5 leaves phase; florescence. The herbicides-induced changes of enzymes activity high correlated with ontogenetic dynamics of control plants activity: r = 0.98 for SOD; r = 0.96 for POD; r = 0.98 for CAT.

  2. Chemoproteomic Profiling of Acetanilide Herbicides Reveals Their Role in Inhibiting Fatty Acid Oxidation.

    Science.gov (United States)

    Counihan, Jessica L; Duckering, Megan; Dalvie, Esha; Ku, Wan-Min; Bateman, Leslie A; Fisher, Karl J; Nomura, Daniel K

    2017-03-17

    Acetanilide herbicides are among the most widely used pesticides in the United States, but their toxicological potential and mechanisms remain poorly understood. Here, we have used chemoproteomic platforms to map proteome-wide cysteine reactivity of acetochlor (AC), the most widely used acetanilide herbicide, in vivo in mice. We show that AC directly reacts with >20 protein targets in vivo in mouse liver, including the catalytic cysteines of several thiolase enzymes involved in mitochondrial and peroxisomal fatty acid oxidation. We show that the fatty acids that are not oxidized, due to impaired fatty acid oxidation, are instead diverted into other lipid pathways, resulting in heightened free fatty acids, triglycerides, cholesteryl esters, and other lipid species in the liver. Our findings show the utility of chemoproteomic approaches for identifying novel mechanisms of toxicity associated with environmental chemicals like acetanilide herbicides.

  3. Drazepinone, a trisubstituted tetrahydronaphthofuroazepinone with herbicidal activity produced by Drechslera siccans.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Vurro, Maurizio; Fracchiolla, Mariano; Zonno, Maria Chiara; Motta, Andrea

    2005-03-01

    When grown in a minimal-defined medium, a strain of Drechslera siccans, a pathogenic fungus isolated from seeds of Lolium perenne, produced phytotoxic metabolites. This strain is one of the best toxin producers among several grass pathogenic fungal strains collected and tested to find phytotoxins to be used as natural herbicides of monocot weeds. From the culture filtrates of D. siccans, we isolated a new phytotoxic trisubstituted naphthofuroazepinone, named drazepinone, and characterised it as a 3,5,12a-trimethyl-2,5,5a,12a-tetrahydro-1H-naphtho[2',3':4,5]furo[2,3-b]azepin-2-one. Assayed at 2 microg microl(-1) solution the novel metabolite proved to have broad-spectrum herbicidal properties, without antibacterial and antifungal activities, and low zootoxic activity. Its original chemical structure and the interesting biological properties make drazepinone a potential natural herbicide.

  4. Herbicide and fertilizers promote analogous phylogenetic responses but opposite functional responses in plant communities

    DEFF Research Database (Denmark)

    Pellissier, Loïc; Wisz, Mary S.; Strandberg, Beate

    2014-01-01

    on long-term experiment we show that fertilizer and herbicides (glyphosate) have contrasting effects on functional structure, but can increase phylogenetic diversity in semi-natural plant communities. We found that an increase in nitrogen promoted an increase in the average specific leaf area and canopy...... height at the community level, but an increase in glyphosate promoted a decrease in those traits. Phylogenetic diversity of plant communities increased when herbicide and fertilizer were applied together, likely because functional traits facilitating plant success in those conditions were......Throughout the world, herbicides and fertilizers change species composition in agricultural communities, but how do the cumulative effects of these chemicals impact the functional and phylogenetic structure of non-targeted communities when they drift into adjacent semi-natural habitats? Based...

  5. Cumulative effects analysis of the water quality risk of herbicides used for site preparation in the Central North Island, New Zealand

    Science.gov (United States)

    Dan Neary; Brenda R. Baillie

    2016-01-01

    Herbicide use varies both spatially and temporally within managed forests. While information exists on the effects of herbicide use on water quality at the site and small catchment scale, little is known about the cumulative effects of herbicide use at the landscape scale. A cumulative effects analysis was conducted in the upper Rangitaiki catchment (118,345...

  6. Effect of buctril super (Bromoxynil herbicide on soil microbial biomass and bacterial population

    Directory of Open Access Journals (Sweden)

    Zafar Abbas

    2014-02-01

    Full Text Available The present study aimed to evaluate the effect of bromoxynil herbicide on soil microorganisms, with the hypothesis that this herbicide caused suppression in microbial activity and biomass by exerting toxic effect on them. Nine sites of Punjab province (Pakistan those had been exposed to bromoxynil herbicide for about last ten years designated as soil 'A' were surveyed in 2011 and samples were collected and analyzed for Microbial Biomass Carbon (MBC, Biomass Nitrogen (MBN, Biomass Phosphorus (MBP and bacterial population. Simultaneously, soil samples from the same areas those were not exposed to herbicide designated as soil 'B' were taken. At all the sites MBC, MBN and MBP ranged from 131 to 457, 1.22 to 13.1 and 0.59 to 3.70 µg g-1 in the contaminated soils (Soil A, which was 187 to 573, 1.70 to 14.4 and 0.72 to 4.12 µg g-1 in the soils without contamination (soil B. Bacterial population ranged from 0.67 to 1.84x10(8 and 0.87 to 2.37x10(8 cfu g-1 soil in the soils A and B, respectively. Bromoxynil residues ranged from 0.09 to 0.24 mg kg-1 at all the sites in soil A. But no residues were detected in the soil B. Due to lethal effect of bromoxynil residues on the above parameters, considerable decline in these parameters was observed in the contaminated soils. Results depicted that the herbicide had left toxic effects on soil microbial parameters, thus confirmed that continuous use of this herbicide affected the quality of soil and sustainable crop production.

  7. A geographic information system for characterizing exposure to Agent Orange and other herbicides in Vietnam.

    Science.gov (United States)

    Stellman, Jeanne Mager; Stellman, Steven D; Weber, Tracy; Tomasallo, Carrie; Stellman, Andrew B; Christian, Richard

    2003-03-01

    Between 1961 and 1971, U.S. military forces dispersed more than 19 million gallons of phenoxy and other herbicidal agents in the Republic of Vietnam, including more than 12 million gallons of dioxin-contaminated Agent Orange, yet only comparatively limited epidemiologic and environmental research has been carried out on the distribution and health effects of this contamination. As part of a response to a National Academy of Sciences' request for development of exposure methodologies for carrying out epidemiologic research, a conceptual framework for estimating exposure opportunity to herbicides and a geographic information system (GIS) have been developed. The GIS is based on a relational database system that integrates extensive data resources on dispersal of herbicides (e.g., HERBS records of Ranch Hand aircraft flight paths, gallonage, and chemical agent), locations of military units and bases, dynamic movement of combat troops in Vietnam, and locations of civilian population centers. The GIS can provide a variety of proximity counts for exposure to 9,141 herbicide application missions. In addition, the GIS can be used to generate a quantitative exposure opportunity index that accounts for quantity of herbicide sprayed, distance, and environmental decay of a toxic factor such as dioxin, and is flexible enough to permit substitution of other mathematical exposure models by the user. The GIS thus provides a basis for estimation of herbicide exposure for use in large-scale epidemiologic studies. To facilitate widespread use of the GIS, a user-friendly software package was developed to permit researchers to assign exposure opportunity indexes to troops, locations, or individuals.

  8. Herbicide on Weed Composition, Diversity and Density in Silage Corn (cv. Sc 704

    Directory of Open Access Journals (Sweden)

    M. Zafarian

    2012-07-01

    Full Text Available In order to study the effect of plant density, planting pattern and herbicide dosage of nicosulfuron, a field experiment was arranged in a factorial split plot treatments based on RCBD with three replications in Chenaran, Khorasan Razavi, in 2010. The experimental treatments consisted of a factorial plant density (100000, 120000 and 140000 plants ha-1 in the planting pattern (single and double row as main plot and herbicide dosage of nicousulforon in four levels (0, 1, 1/5 and 2, l.ha-1 as sub-plot. Samplings were made at in five stages (37days after the emergence of corn and it was repeated once per 20 days. The results indicated reducing the weed density and dry matter of weeds in the first stage after the herbicide treatment. Moreover, it was observed a significant interaction effect between plant density with planting pattern and between planting pattern with herbicides dosages during growth season on reducing weed density and dry matter. Also results indicated that in between of this experiment's treatments, nicosulfuron herbicide reduced weed density at the beginning of growth season and double row planting pattern suppressed weed density during growing season, and resulted in lowest Jacard similarity index (Sj of weed species. Results also indicated that with increasing of plant density and herbicide dosage especially in composition of double row planting pattern, according to Shannon- Wiener index, sensitive population such as common purslane (Portulaca oleracea L., buckhorn plantain (Plantago lanceolata L., prostrate knotweed (Polygonum aviculareL., black nightshade (Solanum nigrum L. and Johnson grass (Sorghum halepens L. was reduced in during growing season. Simpson dominance index, showed that some low populated weeds such as redroot pigweed (Amaranthus retroflexus L., common lambsquarters (Chenopodium album L., field bindweed (Convolvulus arvensis L. and Canada thistle (Circum arvensis L. persisted their growth up to the end of

  9. Regulation of Microbial Herbicide Transformation by Coupled Moisture and Oxygen Dynamics in Soil

    Science.gov (United States)

    Marschmann, G.; Pagel, H.; Uksa, M.; Streck, T.; Milojevic, T.; Rezanezhad, F.; Van Cappellen, P.

    2017-12-01

    The key processes of herbicide fate in agricultural soils are well-characterized. However, most of these studies are from batch experiments that were conducted under optimal aerobic conditions. In order to delineate the processes controlling herbicide (i.e., phenoxy herbicide 2-methyl-4-chlorophenoxyacetic acid, MCPA) turnover in soil under variable moisture conditions, we conducted a state-of-the-art soil column experiment, with a highly instrumented automated soil column system, under constant and oscillating water table regimes. In this system, the position of the water table was imposed using a computer-controlled, multi-channel pump connected to a hydrostatic equilibrium reservoir and a water storage reservoir. The soil samples were collected from a fertilized, arable and carbon-limited agricultural field site in Germany. The efflux of CO2 was determined from headspace gas measurements as an integrated signal of microbial respiration activity. Moisture and oxygen profiles along the soil column were monitored continuously using high-resolution moisture content probes and luminescence-based Multi Fiber Optode (MuFO) microsensors, respectively. Pore water and solid-phase samples were collected periodically at 8 depths and analyzed for MCPA, dissolved inorganic and organic carbon concentrations as well as the abundance of specific MCPA-degrading bacteria. The results indicated a clear effect of the water table fluctuations on CO2 fluxes, with lower fluxes during imbibition periods and enhanced CO2 fluxes after drainage. In this presentation, we focus on the results of temporal changes in the vertical distribution of herbicide, specific herbicide degraders, organic carbon concentration, moisture content and oxygen. We expect that the high spatial and temporal resolution of measurements from this experiment will allow robust calibration of a reactive transport model for the soil columns, with subsequent identification and quantification of rate limiting processes of

  10. Using fluorescent dyes as proxies to study herbicide removal by sorption in buffer zones.

    Science.gov (United States)

    Dollinger, Jeanne; Dagès, Cécile; Voltz, Marc

    2017-04-01

    The performance of buffer zones for removing pesticides from runoff water varies greatly according to landscape settings, hydraulic regime, and system design. Evaluating the performance of buffers for a range of pesticides and environmental conditions can be very expensive. Recent studies suggested that the fluorescent dyes uranine and sulforhodamine B could be used as cost-effective surrogates of herbicides to evaluate buffer performance. However, while transformation mechanisms in buffers have been extensively documented, sorption processes of both dyes have rarely been investigated. In this study, we measured the adsorption, desorption, and kinetic sorption coefficients of uranine and sulforhodamine B for a diverse range of buffer zone materials (soils, litters, plants) and compared the adsorption coefficients (Kd) to those of selected herbicides. We also compared the global sorption capacity of 6 ditches, characterized by varying proportions of the aforementioned materials, between both dyes and a set of four herbicides using the sorption-induced pesticide retention indicator (SPRI). We found that both the individual Kd of uranine for the diverse buffer materials and the global sorption capacity of the ditches are equivalent to those of the herbicides diuron, isoproturon, and metolachlor. The Kd of sulforhodamine B on plants and soils are equivalent to those of glyphosate, and the global sorption capacities of the ditches are equivalent for both molecules. Hence, we demonstrate for the first time that uranine can be used as a proxy of moderately hydrophobic herbicides to evaluate the performance of buffer systems, whereas sulforhodamine B can serve as a proxy for more strongly sorbing herbicides.

  11. iMAR: An Interactive Web-Based Application for Mapping Herbicide Resistant Weeds.

    Directory of Open Access Journals (Sweden)

    Silvia Panozzo

    Full Text Available Herbicides are the major weed control tool in most cropping systems worldwide. However, the high reliance on herbicides has led to environmental issues as well as to the evolution of herbicide-resistant biotypes. Resistance is a major concern in modern agriculture and early detection of resistant biotypes is therefore crucial for its management and prevention. In this context, a timely update of resistance biotypes distribution is fundamental to devise and implement efficient resistance management strategies. Here we present an innovative web-based application called iMAR (interactive MApping of Resistance for the mapping of herbicide resistant biotypes. It is based on open source software tools and translates into maps the data reported in the GIRE (Italian herbicide resistance working group database of herbicide resistance at national level. iMAR allows an automatic, easy and cost-effective updating of the maps a nd provides two different systems, "static" and "dynamic". In the first one, the user choices are guided by a hierarchical tree menu, whereas the latter is more flexible and includes a multiple choice criteria (type of resistance, weed species, region, cropping systems that permits customized maps to be created. The generated information can be useful to various stakeholders who are involved in weed resistance management: farmers, advisors, national and local decision makers as well as the agrochemical industry. iMAR is freely available, and the system has the potential to handle large datasets and to be used for other purposes with geographical implications, such as the mapping of invasive plants or pests.

  12. Auxin molecular field maps define AUX1 selectivity: many auxin herbicides are not substrates

    Czech Academy of Sciences Publication Activity Database

    Hoyerová, Klára; Hošek, Petr; Quareshy, M.; Li, J.; Klíma, Petr; Kubeš, Martin; Yemm, A. A.; Neve, P.; Tripathi, A.; Bennett, M.J.; Napier, R. M.

    2018-01-01

    Roč. 217, č. 4 (2018), s. 1625-1639 ISSN 0028-646X R&D Projects: GA ČR(CZ) GA16-19557S; GA MŠk LD15137 Grant - others:OPPK(XE) CZ.2.16/3.1.00/21519 Institutional support: RVO:61389030 Keywords : auxin transport * cheminformatics * herbicide * herbicide resistance * molecular field maps * pharmacophore * structure–activity relationship * uptake carrier Subject RIV: ED - Physiology OBOR OECD: Cell biology Impact factor: 7.330, year: 2016

  13. Development of herbicide resistance in black-grass (Alopecurus myosuroides in Bavaria

    Directory of Open Access Journals (Sweden)

    Gehring, Klaus

    2016-02-01

    Full Text Available Black-grass (Alopecurus myosuroides is one of the most important grass weeds in Bavaria. Chemical weed control with high efficacy is very important in crops like winter cereals, oilseed rape and maize. Crop rotations with more winter cereals, reduced soil cultivation and e.g. contract harvesting enhanced distribution of blackgrass in arable farming regions. Effects of herbicide resistance were observed since the last 20 years. The blackgrass herbicide resistance is well observed by the official plant protection service of Bavaria. A wide experience of resistance tests shows the development of resistant black-grass and provides an opportunity for future prospects in resistance dynamics.

  14. Multi photon ionization mass spectrometry of carbamate pesticides, herbicides and fungicides

    International Nuclear Information System (INIS)

    Grun, Carsten; Koenig, Marcelle; Grotemeyer, Juergen

    2001-01-01

    Pesticides and herbicides are useful for a wide range of applications today. The determination of these substances either in the pure form or in complex matrices is of high analytical interest. Especially since these substances can by found in every day products. The combination of multi photon ionization (MUPI) and time of flight laser mass spectrometry may be a powerful tool for achieving fast well interpretable mass spectra for analytical purposes. In this paper we will discuss the mass spectra of several pesticides and herbicides accessed by MUPI-time-of-flight mass spectrometry. The influence of the laser pulse duration on the mass spectra are discussed

  15. Synthesis and Herbicidal Activity of Novel Sulfonylureas Containing 1,2,4-Triazolinone Moiety

    Institute of Scientific and Technical Information of China (English)

    LIU Zhuo; PAN Li; LI Yong-hong; WANG Su-hua; LI Zheng-ming

    2013-01-01

    A series of new sulfonylureas incorporating 1,2,4-triazolinone moiety was synthesized,which were further bio-assayed for the herbicidal activity against four herbs,representative of monocotyledons and dicotyledons.Some of them exhibited high potency to inhibit the growth of dicotyledons(Bassica napus and Amaranthus retroflexus) in the pot experiment.Compounds 9a and 9b also displayed an excellent herbicidal activity against Bassica napus at a concentration of 15 g/hectare,which were comparable with commercial triasulfuron.

  16. Effects of biotechnology on biodiversity: herbicide-tolerant and insect-resistant GM crops.

    Science.gov (United States)

    Ammann, Klaus

    2005-08-01

    Biodiversity is threatened by agriculture as a whole, and particularly also by traditional methods of agriculture. Knowledge-based agriculture, including GM crops, can reduce this threat in the future. The introduction of no-tillage practices, which are beneficial for soil fertility, has been encouraged by the rapid spread of herbicide-tolerant soybeans in the USA. The replacement of pesticides through Bt crops is advantageous for the non-target insect fauna in test-fields. The results of the British Farm Scale experiment are discussed. Biodiversity differences can mainly be referred to as differences in herbicide application management.

  17. Assessing the extent and effects of herbicide drift into Danish hedgerows

    DEFF Research Database (Denmark)

    Pedersen, Marianne Bruus; Andersen, H. V.; Strandberg, M. T.

    Very low dosages of herbicides are known to cause effects on bird cherry (Prunus avium) and hawthorn (Crataegus monogyna). It is not yet known whether other hedgerow trees and shrubs are equally sensitive to herbicide drift, to which extent spray drift into hedges and other habitats close to fiel...... were assessed. Metsulfuron methyl effects on Sambucus nigra (elder) and Sorbus intermedia were studied in separate experiments and will include second year effects. Methods and preliminary results are presented and discussed in relation to pesticide regulation....

  18. Inducible hydroxylation and demethylation of the herbicide isoproturon by Cunninghamella elegans.

    Science.gov (United States)

    Hangler, Martin; Jensen, Bo; Rønhede, Stig; Sørensen, Sebastian R

    2007-03-01

    A screening of 27 fungal strains for degradation of the phenylurea herbicide isoproturon was performed and yielded 15 strains capable of converting the herbicide to polar metabolites. The zygomycete fungus Cunninghamella elegans strain JS/2 isolated from an agricultural soil converted isoproturon to several known hydroxylated metabolites. In addition, unknown metabolites were produced in minor amounts. Inducible degradation was indicated by comparing resting cells pregrown with or without isoproturon. This shows that strain JS/2 is capable of partially degrading isoproturon and that one or more of the enzymes involved are inducible upon isoproturon exposure.

  19. Hydroxylation of the Herbicide Isoproturon by Fungi Isolated from Agricultural soil

    DEFF Research Database (Denmark)

    Rønhede, S.; Jensen, Bo; Rosendahl, Søren

    2005-01-01

    Several asco-, basidio-, and zygomycetes isolated from an agricultural field were shown to be able to hydroxylate the phenylurea herbicide isoproturon [N-(4-isopropylphenyl)-N',N'-dimethylurea] to N-(4-(2-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea and N-(4-(1-hydroxy-1-methylethyl)phenyl)-N......Several asco-, basidio-, and zygomycetes isolated from an agricultural field were shown to be able to hydroxylate the phenylurea herbicide isoproturon [N-(4-isopropylphenyl)-N',N'-dimethylurea] to N-(4-(2-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea and N-(4-(1-hydroxy-1-methylethyl...

  20. The Effect of Organic and Bio Fertilizers on Maize (Zea mays, and HydroMax Adjuvants Application on Optimizing of Nicosulfuron Herbicide Efficacy

    Directory of Open Access Journals (Sweden)

    ebrahim Mamnoie

    2017-06-01

    Full Text Available In order to study the effect of adjuvant on nicosulfuron herbicide efficacy improvement in maize weed control under organic fertilizers application, field study was conducted during 2013- 2014 at research field of Ferdowsi University of Mashhad, Iran. Experiment was arranged in completely randomized design with factorial arrangement of treatments with 16 treatments and three replications. Factors in this experiment were application of organic fertilizers (cow manure and vermicompost and bio fertilizer mycorrhiza, and a plot without fertilizer as control, nicosulfuron dose at 40, and 80 g a.i ha-1 (Cruz®,4% SC with and without the adjuvant of HydroMax™. Common purslane (Portulaca oleracea, black nightshade (Solanum nigrum L., and redroot pigweed (Amaranthus retroflexus L were the dominant weeds in the experimental fields. Black nightshade and common purslane had the highest relative density 20 and 45 days after spraying (DAS. Results showed that application of hydromax adjuvant increased herbicide efficiency, significantly. However dry weight of common purslane, black nightshade and redroot pigweed decreased 84, 71, 86 and 71, 79, 100 %, when nicosulfuron applied at reduced dose (40 g a.i. ha-1 with adjuvant 20 and 45 DAS, respectively. On the other hand, seed yield and dry weight of maize increased 49 and 60 % respectively, when nicosulfuron applied at 40 g a.i. ha-1 with Hydromax pulse cow manure.