WorldWideScience

Sample records for rangeland noxious weeds

  1. Introducing cattle grazing to a noxious weed-dominated rangeland shifts plant communities

    Directory of Open Access Journals (Sweden)

    Josh S. Davy

    2015-10-01

    Full Text Available Invasive weed species in California's rangelands can reduce herbaceous diversity, forage quality and wildlife habitat. Small-scale studies (5 acres or fewer have shown reductions of medusahead and yellow starthistle using prescribed grazing on rangelands, but little is published on the effects of pasture-scale (greater than 80 acres prescribed grazing on weed control and plant community responses. We report the results of a 6-year collaborative study of manager-applied prescribed grazing implemented on rangeland that had not been grazed for 4 years. Grazing reduced medusahead but did not alter yellow starthistle cover. Medusahead reductions were only seen in years that did not have significant late spring rainfall, suggesting that it is able to recover from heavy grazing if soil moisture is present. Later season grazing appears to have the potential to suppress medusahead in all years. In practice, however, such grazing is constrained by livestock drinking water availability and forage quality, which were limited even in years with late spring rainfall. Thus, we expect that grazing treatments under real-world constraints would reduce medusahead only in years with little late spring rainfall. After 10 years of grazing exclusion, the ungrazed plant communities began to shift, replacing medusahead with species that have little value, such as ripgut and red brome.

  2. Guidelines for management of noxious weeds at Hanford

    International Nuclear Information System (INIS)

    Roos, R.C.; Malady, M.B.

    1995-01-01

    Integrated Pest Management Services is responsible for management and control of noxious weeds on the Hanford Site. Weed species and populations are prioritized and objective defined, according to potential site and regional impact. Population controls are implemented according to priority. An integrated approach is planned for noxious weed control in which several management options are considered and implemented separately or in coordination to best meet management objectives. Noxious weeds are inventories and monitored to provide information for planning and program review

  3. 7 CFR 201.52 - Noxious-weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 64499, Dec. 14, 1994] germination tests in the administration of the act ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT...

  4. 7 CFR 201.65 - Noxious weed seeds in interstate commerce.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious weed seeds in interstate commerce. 201.65 Section 201.65 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.65 Noxious weed seeds in interstate commerce...

  5. Puncturevine (Tribulus terrestris L.: noxious weed or powerful medical herb

    Directory of Open Access Journals (Sweden)

    Zvonko Pacanoski

    2014-03-01

    Full Text Available Tribulus terrestris L., an annual dicot species of the family Zygophyllaceae, is a common herb that is often found in disturbed habitats and agricultural areas in many parts of the temperate, tropical and desert regions of the world. T. terrestris is an aggressive species that has the potential to injure livestock, reduce hay and wool values, detour recreationists and reduces plant biodivesity. The species may become troublesome because of its weedy potential. It has been declared a weed in at least 37 countries and in at least 21 crops (cotton, maize, vineyards, orchards, etc.. It is adapted to a wide range of climatic conditions and grows on a wide variety of soil types. The management of T. terrestris can be achieved by herbicide application, mechanical (hand pulling, hoeing, mulching and biological control methods. Beside its invasive potential as a noxious and troublesome weed, T. terrestris is considered highly useful herb which is used for various purposes in folk and modern medicine and sport, as well.

  6. Allelopathic potential of a noxious weed on mung bean

    Directory of Open Access Journals (Sweden)

    Parthapratim Maiti

    2013-10-01

    Full Text Available Eupatorium odoratum have invaded the waste lands of South West Bengal, India. A field study indicated a gradual and also significant increase in Eupatorium odoratum accompanied with significant decrease in other coexisting species. Considering the above in mind, a study was undertaken to evaluate the existence of inhibitory effect of leaf extracts and leaf leachates noxious weed Eupatorium odoratum using fully viable seeds of mung bean (Vigna radiata as the bioassay material. The study showed the reduced the percentage germination and TTC stainability along with extended T50 values of mung bean seeds. The levels of protein, DNA and RNA, activities of dehydrogenase and catalase enzymes were significantly retarded in pretreated seed samples. Amino acid and sugar levels were increased in the leachates of seeds pretreated with leaf extracts and leaf leachates. Thus, from the overall results it can be concluded that various inhibitors present in E. odoratum can impart strong inhibitory effect on mung bean. The study suggests that the leaves of E. odoratum possess phytotoxic or allelopathic chemicals which potentially rendered the inhibitory action on mung bean seeds.

  7. Early Detection Rapid Response Program Targets New Noxious Weed Species in Washington State

    Science.gov (United States)

    Andreas, Jennifer E.; Halpern, Alison D.; DesCamp, Wendy C.; Miller, Timothy W.

    2015-01-01

    Early detection, rapid response is a critical component of invasive plant management. It can be challenging, however, to detect new invaders before they become established if landowners cannot identify species of concern. In order to increase awareness, eye-catching postcards were developed in Washington State as part of a noxious weed educational…

  8. 76 FR 39811 - International Center for Technology Assessment and the Center for Food Safety; Noxious Weed...

    Science.gov (United States)

    2011-07-07

    ... dated July 18, 2002, the International Center for Technology Assessment and the Center for Food Safety... Inspection Service [Docket No. APHIS-2011-0081] International Center for Technology Assessment and the Center for Food Safety; Noxious Weed Status of Kentucky Bluegrass Genetically Engineered for Herbicide...

  9. 76 FR 43706 - Final Supplementary Rules To Require the Use of Certified Noxious-Weed-Free Forage and Straw on...

    Science.gov (United States)

    2011-07-21

    ... projects also will be required to use weed-free straw bales and mulch for project work. This action is a... days a week, to leave a message or question with the above individual. You will receive a reply during...): ``Certified noxious-weed-free compressed forage bales are identified with yellow binding (strapping) material...

  10. Forage seeding in rangelands increases production and prevents weed invasion

    Directory of Open Access Journals (Sweden)

    Josh Davy

    2017-07-01

    Full Text Available Increasing forage productivity in the Sierra foothill rangelands would help sustain the livestock industry as land availability shrinks and lease rates rise, but hardly any studies have been done on forage selections. From 2009 to 2014, in one of the first long-term and replicated studies of seeding Northern California's Mediterranean annual rangeland, we compared the cover of 22 diverse forages to determine their establishment and survivability over time. Among the annual herbs, forage brassica (Brassica napus L. and chicory (Cichorium intybus L. proved viable options. Among the annual grasses, soft brome (Bromus hordeaceus and annual ryegrass (Lolium multiflorum performed well. However, these species will likely require frequent reseeding to maintain dominance. Long-term goals of sustained dominant cover (> 3 years are best achieved with perennial grasses. Perennial grasses that persisted with greater than 50% cover were Berber orchardgrass (Dactylis glomerata, Flecha tall fescue (Lolium arundinaceum and several varieties of hardinggrass (Phalaris aquatica L., Perla koleagrass, Holdfast, Advanced AT. In 2014, these successful perennials produced over three times more dry matter (pounds per acre than the unseeded control and also suppressed annual grasses and yellow starthistle (Centaurea solstitialis L. cover.

  11. Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent

    Science.gov (United States)

    González, Eduardo; Sher, Anna A.; Anderson, Robert M.; Bay, Robin F.; Bean, Daniel W.; Bissonnete, Gabriel J.; Cooper, David J.; Dohrenwend, Kara; Eichhorst, Kim D.; El Waer, Hisham; Kennard, Deborah K.; Harms-Weissinger, Rebecca; Henry, Annie L.; Makarick, Lori J.; Ostoja, Steven M.; Reynolds, Lindsay V.; Robinson, W. Wright; Shafroth, Patrick B.; Tabacchi, Erich

    2017-01-01

    Control of invasive species within ecosystems may induce secondary invasions of non-target invaders replacing the first alien. We used four plant species listed as noxious by local authorities in riparian systems to discern whether 1) the severity of these secondary invasions was related to the control method applied to the first alien; and 2) which species that were secondary invaders persisted over time. In a collaborative study by 16 research institutions, we monitored plant species composition following control of non-native Tamarix trees along southwestern U.S. rivers using defoliation by an introduced biocontrol beetle, and three physical removal methods: mechanical using saws, heavy machinery, and burning in 244 treated and 79 untreated sites across six U.S. states. Physical removal favored secondary invasions immediately after Tamarix removal (0–3 yrs.), while in the biocontrol treatment, secondary invasions manifested later (> 5 yrs.). Within this general trend, the response of weeds to control was idiosyncratic; dependent on treatment type and invader. Two annual tumbleweeds that only reproduce by seed (Bassia scoparia and Salsola tragus) peaked immediately after physical Tamarix removal and persisted over time, even after herbicide application. Acroptilon repens, a perennial forb that vigorously reproduces by rhizomes, and Bromus tectorum, a very frequent annual grass before removal that only reproduces by seed, were most successful at biocontrol sites, and progressively spread as the canopy layer opened. These results demonstrate that strategies to control Tamarix affect secondary invasions differently among species and that time since disturbance is an important, generally overlooked, factor affecting response.

  12. Phytotoxins produced by pathogenic fungi for the integrated management of noxious weeds

    OpenAIRE

    Cimmino, Alessio

    2008-01-01

    Weeds infest economically important crops causing marked losses in agrarian production, forests, and ornamental heritages. Weed pests, including parasitic plants, have always being recognised as one of the most serious agricultural and environmental problems due to competition with the growth of agrarian crops and forest plants by subtraction of water, nutrients, light and by the serious obstacles they represent for agronomic activities. A number of weed management strategies have been fo...

  13. 75 FR 57496 - Notice of Proposed Supplementary Rule To Require the Use of Certified Noxious-Weed-Free Forage...

    Science.gov (United States)

    2010-09-21

    ... mulch for project work. This action is a cooperative effort between the BLM, the U.S. Forest Service... enemies to keep their populations in balance. Consequently, depending on the circumstances (e.g., weed(s... rules would be implemented by including a standard stipulation in all Special Recreation Permits and...

  14. Biology and management of Avena fatua and Avena ludoviciana: two noxious weed species of agro-ecosystems.

    Science.gov (United States)

    Bajwa, Ali Ahsan; Akhter, Muhammad Javaid; Iqbal, Nadeem; Peerzada, Arslan Masood; Hanif, Zarka; Manalil, Sudheesh; Hashim, Saima; Ali, Hafiz Haider; Kebaso, Lynda; Frimpong, David; Namubiru, Halima; Chauhan, Bhagirath Singh

    2017-08-01

    Avena fatua and Avena ludoviciana are closely related grass weed species infesting a large number of crops around the world. These species are widely distributed in diverse agro-ecosystems from temperate to sub-tropical regions due to their unique seed traits, successful germination ecology, high competitive ability, and allelopathic potential. A. fatua is more widespread, adaptable, and problematic than A. ludoviciana. Both these species infest major winter and spring crops, including wheat, oat, barley, canola, maize, alfalfa, and sunflower, causing up to 70% yield losses depending on crop species and weed density. Chemical control has been challenged by large-scale herbicide resistance evolution in these weed species. A. fatua is the most widespread herbicide-resistant weed in the world, infesting about 5 million hectares in 13 countries. The use of alternative herbicides with different modes of action has proved effective. Several cultural practices, including diverse crop rotations, cover crops, improved crop competition (using competitive cultivars, high seed rates, narrow row spacing, altered crop geometry), and allelopathic suppression, have shown promise for controlling A. fatua and A. ludoviciana. The integrated use of these cultural methods can reduce the herbicide dose required, and lower dependency on herbicides to control these grasses. Moreover, integrated management may successfully control herbicide-resistant populations of these weed species. The use of integrated approaches based on the knowledge of biology and ecology of A. fatua and A. ludoviciana may help to manage them sustainably in the future.

  15. A nature-based approach for managing the invasive weed species Gutenbergia cordifolia for sustainable rangeland management.

    Science.gov (United States)

    Ngondya, Issakwisa B; Munishi, Linus K; Treydte, Anna C; Ndakidemi, Patrick A

    2016-01-01

    The invasive weed species Gutenbergia cordifolia has been observed to suppress native plants and to dominate more than half of the entire crater floor (250 km 2 ) in the Ngorongoro Conservation Area (NCA). As this species has been found to be toxic to ruminants it might strongly impact animal populations in this ecologically diverse ecosystem. Hence, a nature-based approach is urgently needed to manage its spread. We tested two Desmodium spp extracts applied to G. cordifolia and assessed the latter's germination rate, height, fresh weight and leaf total chlorophyll content after 30 days in both laboratory and screen house experiments. Seedling germination rate was halved by Desmodium uncinatum leaf extract (DuL), particularly under higher concentrations (≥75 %) rather than lower concentrations (≤62.5 %). Likewise, in both laboratory and screen house experiments, germination rate under DuL treatments declined with increasing concentrations. Seedling height, fresh weight and leaf total chlorophyll content (Chl) were also most strongly affected by DuL treatments rather than D. uncinatum root extract, Desmodium intortum leaf extract or D. intortum root extract treatments. Generally, seedlings treated with higher DuL concentrations were half as tall, had one-third the weight and half the leaf Chl content compared to those treated with lower concentrations. Our study shows a novel technique that can be applied where G. cordifolia may be driving native flora and fauna to local extinction. Our data further suggest that this innovative approach is both ecologically safe and effective and that D. uncinatum can be sustainably used to manage invasive plants, and thus, to improve rangeland productivity.

  16. Common garden comparisons of reproductive, forage and weed suppression potential of rangeland rehabilitation grasses of the Great Basin

    Science.gov (United States)

    Common garden experiments are a means to remove environmental effects. Using 8 species of perennial rangeland grasses, we established a common garden (3 reps x28 plants = 84 plants/species). We found that ‘Hycrest’ crested wheatgrass (Agropyron cristatum) and bluebunch wheatgrass (Pseudoroegneria sp...

  17. Fire effects on noxious weeds

    Science.gov (United States)

    Robin Innes

    2012-01-01

    The Fire Effects Information System (FEIS, www.fs.fed.us/database/feis/) has been providing reviews of scientific knowledge about fire effects since 1986. FEIS is an online collection of literature reviews on more than 1,100 species and their relationships with fire. Reviews cover plants and animals throughout the United States, providing a wealth of information for...

  18. 77 FR 3729 - Notice of Request for Extension of Approval of an Information Collection; Plant Pest, Noxious...

    Science.gov (United States)

    2012-01-25

    ... Collection; Plant Pest, Noxious Weed, and Garbage Regulations AGENCY: Animal and Plant Health Inspection... with plant pest, noxious weed, and garbage regulations. DATES: We will consider all comments that we... pest, noxious weed, and garbage regulations, contact Dr. Shirley Wager- Pag[eacute], Chief, Pest Permit...

  19. Weather-centric rangeland revegetation planning

    Science.gov (United States)

    Semiarid rangelands in the western United States have been or are being invaded by introduced annual weeds that negatively impact ecosystem services and pose a major conservation threat. Rehabilitation and restoration of these rangelands are challenging due to inter-annual climate and sub-seasonal ...

  20. Meeting wild bees' needs on rangelands

    Science.gov (United States)

    Some arid rangeland regions, notably those with warm dry climates of the temperate zones, host great diversities of native bees, primarily non-social species among which are many floral specialists. Rangeland bee faunas are threatened indirectly by invasive exotic weeds wherever these displace nat...

  1. Book title: Rangelands systems: Processes, management and challenges - Chapter title: Invasive plant species and novel ecosystems

    Science.gov (United States)

    Rangelands represent the dominant land use systems in many countries of the world and provide sociological and cultural benefits to millions of people in both rural and urban areas. The undesirable impacts of rangeland weeds have been recognized for well over 100 years and infest between 41 and 51 ...

  2. Weather-centric rangeland revegetation planning

    Science.gov (United States)

    Hardegree, Stuart P.; Abatzoglou, John T.; Brunson, Mark W.; Germino, Matthew; Hegewisch, Katherine C.; Moffet, Corey A.; Pilliod, David S.; Roundy, Bruce A.; Boehm, Alex R.; Meredith, Gwendwr R.

    2018-01-01

    Invasive annual weeds negatively impact ecosystem services and pose a major conservation threat on semiarid rangelands throughout the western United States. Rehabilitation of these rangelands is challenging due to interannual climate and subseasonal weather variability that impacts seed germination, seedling survival and establishment, annual weed dynamics, wildfire frequency, and soil stability. Rehabilitation and restoration outcomes could be improved by adopting a weather-centric approach that uses the full spectrum of available site-specific weather information from historical observations, seasonal climate forecasts, and climate-change projections. Climate data can be used retrospectively to interpret success or failure of past seedings by describing seasonal and longer-term patterns of environmental variability subsequent to planting. A more detailed evaluation of weather impacts on site conditions may yield more flexible adaptive-management strategies for rangeland restoration and rehabilitation, as well as provide estimates of transition probabilities between desirable and undesirable vegetation states. Skillful seasonal climate forecasts could greatly improve the cost efficiency of management treatments by limiting revegetation activities to time periods where forecasts suggest higher probabilities of successful seedling establishment. Climate-change projections are key to the application of current environmental models for development of mitigation and adaptation strategies and for management practices that require a multidecadal planning horizon. Adoption of new weather technology will require collaboration between land managers and revegetation specialists and modifications to the way we currently plan and conduct rangeland rehabilitation and restoration in the Intermountain West.

  3. Soil Properties and Plant Biomass Production in Natural Rangeland Management Systems

    Directory of Open Access Journals (Sweden)

    Romeu de Souza Werner

    Full Text Available ABSTRACT Improper management of rangelands can cause land degradation and reduce the economic efficiency of livestock activity. The aim of this study was to evaluate soil properties and quantify plant biomass production in four natural rangeland management systems in the Santa Catarina Plateau (Planalto Catarinense of Brazil. The treatments, which included mowed natural rangeland (NR, burned natural rangeland (BR, natural rangeland improved through the introduction of plant species after harrowing (IH, and natural rangeland improved through the introduction of plant species after chisel plowing (IC, were evaluated in a Nitossolo Bruno (Nitisol. In the improved treatments, soil acidity was corrected, phosphate fertilizer was applied, and intercropped annual ryegrass (Lolium multiflorum, velvet grass (Holcus lanatus, and white clover (Trifolium repens were sown. Management systems with harrowed or chisel plowed soil showed improved soil physical properties; however, the effect decreased over time and values approached those of burned and mowed natural rangelands. Natural rangeland systems in the establishment phase had little influence on soil organic C. The mowed natural rangeland and improved natural rangeland exhibited greater production of grazing material, while burning the field decreased production and increased the proportion of weeds. Improvement of the natural rangelands increased leguminous biomass for pasture.

  4. 7 CFR 361.6 - Noxious weed seeds.

    Science.gov (United States)

    2010-01-01

    ... aciculatus (Retzius) Trinius Commelina benghalensis L. Crupina vulgaris Cassini Cuscuta spp. Digitaria...), nightshade (Solanaceae), and sunflower (Asteraceae). (5) Dodder (Cuscuta spp.) seeds devoid of embryos and...

  5. 75 FR 68945 - Update of Noxious Weed Regulations

    Science.gov (United States)

    2010-11-10

    ...: Cause impacts on ecosystem processes (alteration of hydrology, sedimentation rates, a fire regime... for ``Caulerpa taxifolia (Mediterranean clone)'', ``Eichornia azurea (Swarth) Kunth'', and ``Melaleuca...

  6. 7 CFR 201.16 - Noxious-weed seeds.

    Science.gov (United States)

    2010-01-01

    ... following species on which no tolerance will be applied: Aeginetia spp. Ageratina adenophora (Spreng.) King.... Prosopis elata (Burkart) Burkart Prosopis farcta (Russell) Macbride Prosopis ferox Griseb. Prosopis...

  7. 7 CFR 360.200 - Designation of noxious weeds.

    Science.gov (United States)

    2010-01-01

    ... mantegazzianum Sommier & Levier (giant hogweed) Homeria spp. Imperata brasiliensis Trinius (Brazilian satintail) Imperata cylindrica (Linnaeus) Raeuschel (cogongrass) Ischaemum rugosum Salisbury (murainograss) Leptochloa...

  8. Wallowa Canyonlands Weed Partnership : Completion Report November 19, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Mark C.; Ketchum, Sarah

    2008-12-30

    Noxious weeds threaten fish and wildlife habitat by contributing to increased sedimentation rates, diminishing riparian structure and function, and reducing forage quality and quantity. Wallowa Resources Wallowa Canyonlands Partnership (WCP) protects the unique ecological and economic values of the Hells Canyon grasslands along lower Joseph Creek, the lower Grande Ronde and Imnaha Rivers from invasion and degradation by noxious weeds using Integrated Weed Management techniques. Objectives of this grant were to inventory and map high priority weeds, coordinate treatment of those weeds, release and monitor bio-control agents, educate the public as to the dangers of noxious weeds and how to deal with them, and restore lands to productive plant communities after treatment. With collaborative help from partners, WCP inventoried {approx} 215,000 upland acres and 52.2 miles of riparian habitat, released bio-controls at 23 sites, and educated the public through posters, weed profiles, newspaper articles, and radio advertisements. Additionally, WCP used other sources of funding to finance the treatment of 1,802 acres during the course of this grant.

  9. RANGELAND SEQUESTRATION POTENTIAL ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Lee Spangler; George F. Vance; Gerald E. Schuman; Justin D. Derner

    2012-03-31

    Rangelands occupy approximately half of the world's land area and store greater than 10% of the terrestrial biomass carbon and up to 30% of the global soil organic carbon. Although soil carbon sequestration rates are generally low on rangelands in comparison to croplands, increases in terrestrial carbon in rangelands resulting from management can account for significant carbon sequestration given the magnitude of this land resource. Despite the significance rangelands can play in carbon sequestration, our understanding remains limited. Researchers conducted a literature review to identify sustainably management practices that conserve existing rangeland carbon pools, as well as increase or restore carbon sequestration potentials for this type of ecosystem. The research team also reviewed the impact of grazing management on rangeland carbon dynamics, which are not well understood due to heterogeneity in grassland types. The literature review on the impact of grazing showed a wide variation of results, ranging from positive to negative to no response. On further review, the intensity of grazing appears to be a major factor in controlling rangeland soil organic carbon dynamics. In 2003, researchers conducted field sampling to assess the effect of several drought years during the period 1993-2002. Results suggested that drought can significantly impact rangeland soil organic carbon (SOC) levels, and therefore, carbon sequestration. Resampling was conducted in 2006; results again suggested that climatic conditions may have overridden management effects on SOC due to the ecological lag of the severe drought of 2002. Analysis of grazing practices during this research effort suggested that there are beneficial effects of light grazing compared to heavy grazing and non-grazing with respect to increased SOC and nitrogen contents. In general, carbon storage in rangelands also increases with increased precipitation, although researchers identified threshold levels of

  10. Rangeland and water resources

    African Journals Online (AJOL)

    Session B3 Management for sustainable use — Rangeland and water resources. ... The theme of optimsing integrated catchment management will be treated ... land system, catchment, basin), with a focus on law, policy and implementation.

  11. Robotic weeding and automated weed measurements

    DEFF Research Database (Denmark)

    Christensen, S.; Søgaard, H.T.; Jørgensen, R.N.

    2003-01-01

    The goal of decreasing herbicide usage has so far focused on reducing the herbicide dosage or replacing chemical weed control by hoeing and harrowing. The conventional weed control strategy is to apply the same dose of herbicide or the same intensity of hoeing and harrowing in the whole field. Th...... the state-of-the-art of automated weed measurement methods and the research projects concerning autonomous platform and information system for crop and weed monitoring and robotic weeding....

  12. Earth observation for rangeland monitoring

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2012-10-01

    Full Text Available .kashan.co.za] INTRODUCTION Grass nitrogen (N), as an indicator of rangeland quality, plays a crucial role in understanding the distribution, densities and feeding patterns of both wild herbivores and livestock. Zebras and livestock in the grazing and agricultural lands... ? How can grass nitrogen be mapped for assessing and monitoring of rangeland quality at wider or regional scales? ? Conventional point-based techniques for assessing rangeland quality proved to be expensive, laborious and time consuming...

  13. A RANGELAND GRASSHOPPER INSURANCE PROGRAM

    OpenAIRE

    Skold, Melvin D.; Davis, Robert M.

    1995-01-01

    The incidence of benefits and costs from controlling rangeland grasshoppers on public grazing lands poses problems of economic efficiency and distributional equity. Public grasshopper control programs operate like public disaster assistance. However, grasshopper infestations are an insurable risk. This article proposes a rangeland grasshopper insurance program which reduces the economic inefficiencies and distributional inequities of the existing program.

  14. De novo transcriptome assembly analysis of weed Apera spica-venti from seven tissues and growth stages

    DEFF Research Database (Denmark)

    Babineau, Marielle; Mahmood, Khalid; Mathiassen, Solvejg Kopp

    2017-01-01

    Background Loose silky bentgrass (Apera spica-venti) is an important weed in Europe with a recent increase in herbicide resistance cases. The lack of genetic information about this noxious weed limits its biological understanding such as growth, reproduction, genetic variation, molecular ecology ...

  15. Long-term effects of weed control with picloram along a gradient of spotted knapweed invasion

    Science.gov (United States)

    Yvette K. Ortega; Dean E. Pearson

    2011-01-01

    Broadleaf herbicides are commonly used in rangelands to suppress exotic weeds and release native communities from negative impacts of invasion. However, few studies have comprehensively evaluated treatment effects on differing community components across a gradient of initial invasion levels.We conducted a 6-yr experiment within grasslands of western Montana to measure...

  16. Weed-Species Abundance and Diversity Indices in Relation to Tillage Systems and Fertilization

    Directory of Open Access Journals (Sweden)

    Ilias S. Travlos

    2018-04-01

    Full Text Available Weeds pose a major threat to world agriculture by reducing detrimentally crop yield and quality. However, at the same time, weeds are major interacting components of the agroecosystems. Abundance and diversity of weeds vary significantly among the several communities. In order to evaluate each community's structure and the interactions among them, several population indices are used as key tools. In parallel, various cultivation and land management strategies, such as tillage and fertilization, are commonly used in terms of integrated weed management. Estimating the response of weed species on those practices is crucial for both biodiversity maintenance and alternative weed control methods. Many experiments have confirmed the fundamental role of tillage intensity and nutrition supply in weed species' abundance and diversity. For instance, in some studies, the abundance of perennial weeds was doubled under reduced tillage intensity. In addition, higher values of Shannon-Weiner and Pielou indices were reported in the PK fertilization treatment compared to the control and NK fertilization treatments. The objective of this paper is to provide a brief overview of the key results of these experiments and summarize the part of the literature related to the effect of tillage systems and fertilization on weed species abundance and diversity. Such knowledge could contribute to the sound design and implementation of integrated weed management programs which in turn may lead to a decrease in the density of serious and noxious weeds and an increase in the overall balance of agroecosystems.

  17. Use of biosolids to enhance rangeland forage quality.

    Science.gov (United States)

    McFarland, Michael J; Vasquez, Issaak Romero; Vutran, MaiAnh; Schmitz, Mark; Brobst, Robert B

    2010-05-01

    Biosolids land application was demonstrated to be a potentially cost-effective means for restoring forage productivity and enhancing soil-moisture-holding capacity on disturbed rangelands. By land-applying aerobically digested, anaerobically digested, composted, and lime-stabilized biosolids on rangeland test plots at rates of up to 20 times (20X) the estimated nitrogen-based agronomic rate, forage yields were found to increase from 132.8 kg/ha (118.2 lb/ac) (control plots) to 1182.3 kg/ha (1052.8 lb/ac). Despite the environmental benefits associated with increased forage yield (e.g., reduced soil erosion, improved drainage, and enhanced terrestrial carbon sequestration), the type of forage generated both before and after biosolids land application was found to be dominated by invasive weeds, all of which were characterized as having fair to poor nutritional value. Opportunistic and shallow rooting invasive weeds not only have marginal nutritional value, they also limit the establishment of native perennial grasses and thus biodiversity. Many of the identified invasive species (e.g., Cheatgrass) mature early, a characteristic that significantly increases the fuel loads that support the increased frequency and extent of western wildfires.

  18. Testing an Invasive Weed Prediction Model for Leafy Spurge using Hyperspectral Remote Sensing

    Science.gov (United States)

    Leafy spurge (Euphorbia esula L.) is a noxious invasive weed that infests over 1.2 million hectares of land in North America. One of the fundamental needs in leafy spurge management is cost-effective, large-scale, and long-term documentation and monitoring of plant populations. Leafy spurge is a g...

  19. Ecologically sustainable weed management

    NARCIS (Netherlands)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne; Childs, Dylan; Christensen, Svend; Cousens, Roger; Eizenberg, Hanan; Heijting, Sanne; Loddo, Donato; Merotto, Aldo; Renton, Michael; Riemens, Marleen

    2016-01-01

    Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade, and

  20. Horny Goat Weed

    Science.gov (United States)

    Horny goat weed is an herb. The leaves are used to make medicine. As many as 15 horny goat weed species are known as “yin yang huo” in Chinese medicine. Horny goat weed is used for weak back and knees, ...

  1. Rangeland monitoring and assessment: a review

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2018-04-01

    Full Text Available Rangelands provide vast landscapes for grazing and foraging for livestock and wildlife. Services of rangelands are diverse and generally provide food for millions of the world’s population, especially the rural and sometimes poor communities...

  2. 30 CFR 75.322 - Harmful quantities of noxious gases.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Harmful quantities of noxious gases. 75.322... quantities of noxious gases. Concentrations of noxious or poisonous gases, other than carbon dioxide, shall... Governmental Industrial Hygienists in “Threshold Limit Values for Substance in Workroom Air” (1972). Detectors...

  3. Conserving biodiversity on native rangelands: Symposium proceedings

    Science.gov (United States)

    Daniel W. Uresk; Greg L. Schenbeck; James T. O' Rourke

    1997-01-01

    These proceedings are the result of a symposium, "Conserving biodiversity on native rangelands" held on August 17, 1995 in Fort Robinson State Park, NE. The purpose of this symposium was to provide a forum to discuss how elements of rangeland biodiversity are being conserved today. We asked, "How resilient and sustainable are rangeland systems to the...

  4. Carbon fluxes on North American rangelands

    Science.gov (United States)

    Tony Svejcar; Raymond Angell; James A. Bradford; William Dugas; William Emmerich; Albert B. Frank; Tagir Gilmanov; Marshall Haferkamp; Douglas A. Johnson; Herman Mayeux; Pat Mielnick; Jack Morgan; Nicanor Z. Saliendra; Gerald E. Schuman; Phillip L. Sims; Kereith Snyder

    2008-01-01

    Rangelands account for almost half of the earth's land surface and may play an important role in the global carbon (C) cycle. We studied net ecosystem exchange (NEE) of C on eight North American rangeland sites over a 6-yr period. Management practices and disturbance regimes can influence NEE; for consistency, we compared ungrazed and undisturbed rangelands...

  5. Crop–weed competition

    DEFF Research Database (Denmark)

    Gallandt, Eric R.; Weiner, Jacob

    2015-01-01

    importantly, weed density and time of emergence relative to the crop. Practices that (1) reduce the density of weeds, (2) maximise occupation of space or uptake of resources by the crop or (3) establish an early-season size advantage of the crop over the weeds will minimise the competitive effects of weeds...... on crops. Longer term management of crop–weed competition can be achieved through crop rotations, specifically crop sequences that reduce the weed seed bank, and therefore seedling density, and prevent proliferation of perennial weeds. Key ConceptsKey Concepts * Plant growth requires sunlight, water...... an early-season competitive advantage to the crop and (3) maximising resource capture by the crop using competitive species, competitive cultivars, high sowing densities, optimal spatial arrangement, intercropping complimentary species or transplanting....

  6. Criterion III: Maintenance of rangeland productive capacity [Chapter 4

    Science.gov (United States)

    G. R. Evans; R. A. Washmgton-Allen; R. D. Child; J. E. Mitchell; B. R. Bobowskl; R. V. Loper; B. H. Allen-Diaz; D. W. Thompson; G. R. Welling; T. B. Reuwsaat

    2010-01-01

    Maintenance of rangeland productive capacity is one of five criteria established by the Sustainable Rangelands Roundtable (SRR) to monitor and assess rangeland sustainable management. Within this criterion, six indicators were developed through the Delphi Process and the expert opinions of academicians, rangeland scientists, rangeland management agency personnel, non-...

  7. Controlled maritime storage of noxious materials

    International Nuclear Information System (INIS)

    1984-01-01

    The invention relates to an accommodation for the controlled storage of noxious material, especially of radioactive material packed in vessels. The invention provides a storage accommodation far from populated regions, in which this material may be stored during a long period in a safe and controlled way and from which it may be winned back in a simple and cheap way. For that purpose, a floating and submersible construction is designed that may be let down to the sea-bottom at least partially and that is fitted with a closable entrance. (Auth.)

  8. RANGELAND DEGRADATION: EXTENT, IMPACTS, AND ALTERNATIVE RESTORATION TECHNIQUES IN THE RANGELANDS OF ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Mohammed Mussa Abdulahi

    2016-12-01

    Full Text Available Rangeland degradation remains a serious impediment to improve pastoral livelihoods in the lowlands of Ethiopia. This review paper presents an overview of the extent of rangeland degradation, explores its drivers, discusses the potential impacts of rangeland degradation and also suggests alternative rangeland restoration techniques. It is intended to serve as an exploratory tool for ensuing more detailed quantitative analyses to support policy and investment programs to address rangeland degradation in Ethiopia. The extent of rangeland degradation increases with time, and the productivity of rangelands are losing if not given due attention. The major drivers leading to rangeland degradation includes climate change, overgrazing, bush encroachment, population pressure, drought, and government policy, encroachment of rain fed agriculture and decline of traditional resource management institution. Degradation of rangeland has resulted in substantial declines in rangeland condition, water potential, soil status, and animal performance, livestock holding at the household level and community become destitute. Another consequence of rangeland degradation is linked to food insecurity, poverty to the extent of food aid, expansion of aridity and the need for alternative livelihood and income diversification. Moreover, it has increasingly become a threat to the pastoral production systems, and has contributed towards increases in poverty and tribal conflicts over grazing land and water resources. In spite of these impacts, the adoption of alternative restoration techniques in the country is highly insufficient. To address rangeland degradation problems, there is a strong need to substantially increase the investments and strengthen the policy support for sustainable land management.

  9. Ecologically sustainable weed management

    DEFF Research Database (Denmark)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne

    2016-01-01

    Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade, and gre......Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade...... to influence learning, decision-making, and actions by farmers and land managers. We offer examples of how these impediments are being addressed in different parts of the world, but note that there is no clear formula for determining which sets of policies, market mechanisms, and educational activities...... will be effective in various locations. Implementing new approaches for weed management will require multidisciplinary teams comprised of scientists, engineers, economists, sociologists, educators, farmers, land managers, industry personnel, policy makers, and others willing to focus on weeds within whole farming...

  10. Eco-distribution Mapping of Invasive Weed Limnocharis flava (L. Buchenau Using Geographical Information System: Implications for Containment and Integrated Weed Management for Ecosystem Conservation

    Directory of Open Access Journals (Sweden)

    P. C. Abhilash

    2008-03-01

    Full Text Available Exotic weed invasion has been identified as one of the serious environmental problem impacting the structure, composition and function of biological diversity. They are aggressive colonizers, which have flexible habitat requirement and ability to outcompete native species. The present paper describes the distribution and autecology of an exotic weed Limnocharis flava (L. Buchenau (an emergent aquatic weed of ‘Limnocharitaceae’ in Kumarakom Grama Panchayat, one of the well known tourist spot of South India famous for its vast stretches of paddy fields, wetlands and backwaters. The mapping of L. flava in the entire study area has been done using Geographical Information System (Arc-info 8.3 version. The growth and distribution pattern of L. flava were studied quantitatively. Data on distribution, abundance, biomass, ecological associations and root zone nutrient quality of water and sediment samples were collected from different sampling points of Kumarakom. The study reflected that nutrients, water depth and land use patterns were the major factors responsible for the growth and proliferation of this exotic weed. The strategies for controlling L. flava invasion are discussed in detail. If early steps are not taken to eradicate this weed, it will become a problematic weed in the same way as other noxious aquatic weeds like Salvinia molesta D. Mitch and Eichhornia crassipes (C. Martius Solms-Laub.

  11. Weed flora, yield losses and weed control in cotton crop

    OpenAIRE

    Jabran, Khawar

    2016-01-01

    Cotton (Gossypium spp.) is the most important fiber crop of world and provides fiber, oil, and animals meals. Weeds interfere with the growth activities of cotton plants and compete with it for resources. All kinds of weeds (grasses, sedges, and broadleaves) have been noted to infest cotton crop. Weeds can cause more than 30% decrease in cotton productivity. Several methods are available for weed control in cotton. Cultural control carries significance for weed control up to a certain extent....

  12. Weed ecology and population dynamics

    Science.gov (United States)

    A global rise in herbicide resistant weed genotypes, coupled with a growing demand for food produced with minimal external synthetic inputs, is driving producer interest in reducing reliance on herbicides for weed management. An improved understanding of weed ecology can support the design of weed s...

  13. A Dynamic Model of California's Hardwood Rangelands

    Science.gov (United States)

    Richard B. Standiford; Richard E. Howitt

    1991-01-01

    Low profitability of hardwood rangeland management, and oak tree harvesting for firewood markets and forage enhancement has led to concern about the long-term sustainability of the oak resource on rangelands. New markets for recreational hunting may give value to oaks for the habitat they provide for game species, and broaden the economic base for managers. A ranch...

  14. Current situation of rangelands in Mexico

    Science.gov (United States)

    Alicia Melgoza-Castillo

    2006-01-01

    Rangelands are natural areas with certain characteristics that make them unsuitable for agriculture. They include several types of vegetation such as deserts, grasslands, shrubs, forests, and riparian areas. Cattle ranching, along with the products and services it engenders, is a prime activity that rangelands have traditionally supported.

  15. Remote sensing applications for monitoring rangeland vegetation ...

    African Journals Online (AJOL)

    Remote sensing techniques hold considerable promise for the inventory and monitoring of natural resources on rangelands. A significant lack of information concerning basic spectral characteristics of range vegetation and soils has resulted in a lack of rangeland applications. The parameters of interest for range condition ...

  16. Measuring ecological function on California's rangelands

    Science.gov (United States)

    Porzig, E.

    2016-12-01

    There is a need for a better understanding of ecosystem processes on rangelands and how management decisions influence these processes on scales that are both ecologically and socially relevant. Point Blue Conservation Science's Rangeland Monitoring Network is a coordinated effort to collect standardized data on birds, vegetation, and soils on rangelands throughout California. We work with partners, including private landowners, land trusts, state and federal agencies, and others, to measure bird and plant abundance and diversity and three soil dynamic properties (water infiltration, bulk density, and organic carbon). Here, we present data from our first two years of monitoring on over 50 ranches in 17 counties. By collecting data on the scope and scale of variation in ecological function across rangelands and the relationship with management practices, we aim to advance rangeland management, restoration, and conservation.

  17. 76 FR 70954 - Idaho Panhandle National Forests, Idaho; Idaho Panhandle National Forest Noxious Weed Treatment...

    Science.gov (United States)

    2011-11-16

    ... and other ecological, social or economic values. DATES: Comments concerning the scope of the analysis... into areas where the potential to harm ecological, social or economic values is high; (3) rapidly... the undesirable impacts that these NNIP species have on native plant communities and other ecological...

  18. Population genetic structure of the noxious weed Amaranthus retroflexus in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Mandák, Bohumil; Zákravský, Petr; Dostál, Petr; Plačková, Ivana

    2011-01-01

    Roč. 206, č. 8 (2011), s. 697-703 ISSN 0367-2530 R&D Projects: GA AV ČR IAA600050707 Institutional research plan: CEZ:AV0Z60050516 Keywords : allozyme * inbreeding * invasion Subject RIV: EF - Botanics Impact factor: 1.639, year: 2011

  19. 7 CFR 201.17 - Noxious-weed seeds in the District of Columbia.

    Science.gov (United States)

    2010-01-01

    ...), Canada thistle (Cirsium arvense), field bindweed (Convolvulus arvensis), bermudagrass (Cynodon dactylon), giant bermudagrass (Cynodon dactylon var. aridus), annual bluegrass (Poa annua), and wild garlic or wild...

  20. Valuation of rangeland ecosystem services

    Science.gov (United States)

    Gascoigne, W.R.

    2011-01-01

    Economic valuation lends itself well to the anthropocentric orientation of ecosystem services. An economic perspective on ecosystems portrays them as natural assets providing a flow of goods and services valuable to individuals and society collectively. A few examples include the purification of drinking water, reduced risk from flooding and other extreme events, pollination of agricultural crops, climate regulation, and recreation opportunities from plant and animal habitat maintenance, among many others. Once these goods and services are identified and quantified, they can be monetized to complete the valuation process. The monetization of ecosystem goods and services (in the form of dollars) provides a common metric that allows for cross-comparison of attributes and evaluation of differing ecological scenarios. Complicating the monetization process is the fact that most of these goods and services are public and non-market in nature; meaning they are non-rival and non-exclusive and are typically not sold in a traditional market setting where monetary values are revealed. Instead, one must employ non-market valuation techniques, with primary valuation methods typically being very time and resource consuming, intimidating to non-economists, and often impractical. For these reasons, benefit transfer methods have gained popularity. This methodology harnesses the primary collection results of existing studies to make inferences about the economic values of non-market goods and services at an alternative policy site (in place and/or in time). For instance, if a primary valuation study on oak reestablishment on rangelands in southern California yielded a value of $30 per-acre associated with water regulation, this result can be transferred, with some adjustments, to say something about the value of an acre of oaks on rangelands in northern portions of the state. The economic valuation of rangeland ecosystem services has many roles. Economic values may be used as input

  1. Non-chemical weed management

    DEFF Research Database (Denmark)

    Melander, Bo; Liebman, Matt; Davies, Adam S.

    2017-01-01

    Non-chemical weed management covers all management practices that influence weeds except herbicides. This chapter summarises the major achievements in European research, as well as work undertaken in North America. Research groups from both continents have interacted strongly on the topic over...... and in some cases amenity areas as well. Preventive methods reduce weed germination, cultural methods improve crop competition and direct physical weed control reduces weed survival. Non-chemical weed management is mainly adopted in organic crop production, as conventional growers still perceive it as more...

  2. The neurologic effects of noxious marine creatures.

    Science.gov (United States)

    Southcott, R V

    1975-01-01

    The concept of the sea as a source of noxious agents is perhaps not a familiar one to clinical neurologists, judging by the lack of reference to these agents in standard textbooks. Chemical, physiologic, and pharmacologic laboratories are increasingly investigating the properties of marine toxins, finding in them compounds with interesting and novel structures or unusual physiologic effects. Such substances are seen as possible agents for biologic and, more particularly, physiologic research, and as possible sources of new pharmaceuticals. These include hormone-like substances and antiviral or antitumor agents. Despite these specialized developments, which are in large measure a consequence of the technological advances of the present century, the clinician is at times directly concerned with the effects of marine toxic substances. For example, in Japan, puffer fish or tetrodotoxic poisoning is one of the major causes of deaths from food poisoning. Another marine toxin that has caused many explosive outbreaks of food poisoning. with many deaths in various parts of the world, comes from clams or mussels. This toxin, saxitoxin, is produced by species of marine protozoa including Gonyaulax, and is concentrated in filter-feeding molluscs. These two examples were of significant interest in medicine long before the technologic developments of the twentieth century. In the last few decades, entirely new problems of marine intoxication have arisen as a result of marine pollution from the disposal of industrial wastes in the sea. The most striking example of a man-made marine intoxication has been the outbreak of Minamata disease. In Minamata, Japan, the disposal of mercury-contaminated industrial wastes from a plastics factory into an enclosed bay, followed by human consumption of the contaminated fishes, crabs, or shellfish, led to many instances of acute cerebral degeneration. With the increasing exploration of the sea for both pleasure and economic exploitation, which

  3. Effect of plant spacing and weeding frequency on weed infestation ...

    African Journals Online (AJOL)

    Common bean is an important food and cash crop in eastern Ethiopia. However, its yield is constrained by weeds. Therefore, this study was conducted in 2012 main cropping season at Haramaya and Hirna research fields, eastern Ethiopia, to determine the effect of plant spacing and weeding frequency on weeds, yield ...

  4. Weeds and Wildlife: Perceptions and Practices of Weed Managers

    Directory of Open Access Journals (Sweden)

    Emma H Carlos

    2014-01-01

    Full Text Available Negative impacts of invasive plants or weeds on biodiversity have been well established yet their role in providing key habitats and resources for wildlife has been little understood. Weed removal thus has the potential to adversely affect wildlife but whether this is considered during weed management is poorly known. To determine the extent of this knowledge, we examined the perceptions of weed managers regarding wildlife and weed management in Victoria, Australia. We surveyed 81 weed managers of varying levels of experience from different types of organisations, including state and local government, community groups and private companies. We found 90% of managers had observed wildlife-weed interactions and that most (70% adjusted management programmes to accommodate wildlife. Despite this, few (19% had adopted the recommended practice of combining gradual weed removal with re-vegetation. While management programmes included monitoring of native vegetation, consideration of wildlife monitoring in weed management was rare. This highlights the need for management to better understand and respond to wildlife-weed relationships. If the improvement of wildlife habitat is included in the objectives of weed programmes, as it should be, then wildlife should also be incorporated in project monitoring. This would lead to a greater understanding of the role weeds and their management have in each situation and, ultimately, more informed decision making.

  5. Grass and weed killer poisoning

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002838.htm Grass and weed killer poisoning To use the sharing features on this page, please enable JavaScript. Many weed killers contain dangerous chemicals that are harmful if ...

  6. Integrated Weed Control for Land Stewardship at Legacy Management's Rocky Flats Site in Colorado - 13086

    International Nuclear Information System (INIS)

    Nelson, Jody K.

    2013-01-01

    Land stewardship is one of nine sustainability programs in the U.S. Department of Energy's Environmental Management System. Land stewardship includes maintaining and improving ecosystem health. At the Rocky Flats Site near Westminster, Colorado, land stewardship is an integral component of the Office of Legacy Management's post-closure monitoring and management at the site. Nearly 263 hectares (650 acres) were disturbed and re-vegetated during site cleanup and closure operations. Proactive management of revegetation areas is critical to the successful reestablishment of native grasslands, wetlands, and riparian communities. The undisturbed native plant communities that occur at the site also require active management to maintain the high-quality wetlands and other habitats that are home to numerous species of birds and other wildlife such as elk and deer, rare plant communities, and the federally listed threatened Preble's meadow jumping mouse. Over the past several decades, an increase of Noxious weeds has impacted much of Colorado's Front Range. As a result, weed control is a key component of the land stewardship program at Rocky Flats. Thirty-three species of state-listed Noxious weeds are known to occur in the Central and Peripheral Operable Units at Rocky Flats, along with another five species that are considered invasive at the site. Early detection and rapid response to control new invasive species is crucial to the program. An integrated weed control/vegetation management approach is key to maintaining healthy, sustainable plant communities that are able to resist Noxious weed invasions. Weed mapping, field surveys, and field-staff training sessions (to learn how to identify new potential problem species) are conducted to help detect and prevent new weed problems. The integrated approach at Rocky Flats includes administrative and cultural techniques (prevention), mechanical controls, biological controls, and chemical controls. Several species of biocontrol

  7. WEED INTERFERENCE IN EGGPLANT CROPS

    Directory of Open Access Journals (Sweden)

    LUIZ JUNIOR PEREIRA MARQUES

    2017-01-01

    Full Text Available Uncontrolled weed growth interferes with the growth eggplants and crop yields. To control weeds, the main weed species must be identified in crop growing areas and during weed control periods, as weed species might vary in relation to management practices. Therefore, this study aimed to identify the main weed species and determine the periods of weed interference in the eggplant cultivar Nápoli when grown under certain cultural practices, including plant staking and sprout thinning. The experiment was carried out in 2014 using a randomized complete block design, with 3 replications. The treatments consisted of 11 periods of (1 increasing weed control and (2 increasing coexistence of eggplant with weeds from the first day of transplanting (0-14, 0-28, 0-42, 0-56, 0-70, 0-84, 0-98, 0-112, 0-126, 0-140, and up do day 154. Eggplant staking and sprout thinning were performed 42 days after transplanting (DAT. Weed identification and crop yield assessments were performed to determine the Period Before Interference (PBI, Total Period of Interference Prevention (TPIP, and the Critical Period of Interference Prevention (CPIP. The major weeds found in the eggplant cultivar Nápoli were Eleusine indica, Portulaca oleracea, and Cyperus rotundus. Coexistence between the weed community and the eggplant throughout the entire crop production cycle reduced eggplant fruit yield by 78%. The PBI was 29 DAT and the TPIP was 48 DAT, resulting in 19 days of CPIP.

  8. Management of Collective Rangelands in Rhamna (Morocco ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Management of Collective Rangelands in Rhamna (Morocco) ... reduce the pressure on natural resources and promote sustainable management. ... Project status ... IDRC congratulates first cohort of Women in Climate Change Science Fellows ... and adaptive water management: Innovative solutions from the Global South”.

  9. Water conservation for semi-arid rangelands

    International Nuclear Information System (INIS)

    Willis, W.O.

    1983-01-01

    Water deficiency is most often the cause for low forage production on rangelands in semi-arid and arid regions. Water conservation methods have been developed but additional research is needed to develop the best management practices for various climatic regions. Poor management is another major cause of low rangeland production. Better management, including the application of research findings, depends on attitudes, policies, adaptability of findings, resources for implementation and a good understanding of the governing biotic and abiotic factors. (author)

  10. USDA internet tool to estimate runoff and soil loss on rangelands: rangelands hydrology and erosion model

    Science.gov (United States)

    Rangelands are the most dominant land cover type in the United States (770 million acres) with approximately 53% of the nation’s rangelands owned and managed by the private sector, while approximately 43% are managed by the federal government. Information on the type, extent, and spatial location of...

  11. The Rangeland Hydrology and Erosion Model: A dynamic approach for predicting soil loss on rangelands

    Science.gov (United States)

    In this study we present the improved Rangeland Hydrology and Erosion Model (RHEM V2.3), a process-based erosion prediction tool specific for rangeland application. The article provides the mathematical formulation of the model and parameter estimation equations. Model performance is assessed agains...

  12. Biotechnology in weed control

    Science.gov (United States)

    Biotechnology can be used to enhance the management of weeds in several ways. Crops have been made resistant to herbicides by inserting transgenes that impart herbicide resistance into the plant genome. Glyphosate and glufosinate-resistant crops are commercialized in North America and crops made res...

  13. Conserving rangeland resources. | Mentis | African Journal of Range ...

    African Journals Online (AJOL)

    ... goal-attainment, (5) try to correct departures, and (6) align individual and societal interests by manipulating market-forces. Keywords: altruism; conservation; Conservation implementation; Conservation properties; human activity; Human values; philosophy; Range resources; rangeland; Rangelands; Science philosophy

  14. Rangelands: Where Anthromes Meet Their Limits

    Directory of Open Access Journals (Sweden)

    Nathan F. Sayre

    2017-05-01

    Full Text Available Defining rangelands as anthromes enabled Ellis and Ramankutty (2008 to conclude that more than three-quarters of Earth’s land is anthropogenic; without rangelands, this figure would have been less than half. They classified all lands grazed by domestic livestock as rangelands, provided that human population densities were low; similar areas without livestock were excluded and classified instead as ‘wildlands’. This paper examines the empirical basis and conceptual assumptions of defining and categorizing rangelands in this fashion. Empirically, we conclude that a large proportion of rangelands, although used to varying degrees by domesticated livestock, are not altered significantly by this use, especially in arid, highly variable environments and in settings with long evolutionary histories of herbivory by wild animals. Even where changes have occurred, the dynamics and components of many rangelands remain structurally and functionally equivalent to those that preceded domestic livestock grazing or would be found in its absence. In much of Africa and Asia, grazing is so longstanding as to be inextricable from ‘natural’ or reference conditions for those sites. Thus, the extent of anthropogenic biomes is significantly overstated. Conceptually, rangelands reveal the dependence of the anthromes thesis on outdated assumptions of ecological climax and equilibrium. Coming to terms with rangelands—how they can be classified, understood, and managed sustainably—thus offers important lessons for understanding anthromes and the Anthropocene as a whole. At the root of these lessons, we argue, is not the question of human impacts on ecosystems but property relations among humans.

  15. Weed Dynamics and Management in Wheat

    DEFF Research Database (Denmark)

    Jabran, Khawar; Mahmood, Khalid; Melander, Bo

    2017-01-01

    ) chemical weed control; and (vi) integrated weed management strategy in wheat. A critical analysis of recent literature indicated that broadleaved weeds are the most common group of weeds in wheat fields followed by grass weeds, while sedges were rarely noted in wheat fields. Across the globe, the most...

  16. Weed Identification and Control in Vegetable Crops.

    Science.gov (United States)

    Ferretti, Peter A., Comp.

    This agriculture extension service publication from Pennsylvania State University examines weed control and identification in vegetable crops. Contents include: (1) Types of weeds; (2) Reducing losses caused by weeds, general control methods and home garden weed control; (3) How herbicides are used; (4) Specific weeds in vegetable plantings; and…

  17. INTEGRATED WEED CONTROL IN MAIZE.

    Science.gov (United States)

    Latré, J; Dewitte, K; Derycke, V; De Roo, B; Haesaert, G

    2015-01-01

    Integrated pest management has been implemented as a general practice by EU legislation. As weed control actually is the most important crop protection measure in maize for Western Europe, the new legislation will have its impact. The question is of course which systems can be successfully implemented in practice with respect to labour efficiency and economical parameters. During 3 successive growing seasons (2007, 2008, 2009) weed control in maize was evaluated, the main focus was put on different techniques of integrated weed control and was compared with chemical weed control. Additionally, during 4 successive growing seasons (2011, 2012, 2013 and 2014) two objects based on integrated weed control and two objects based on mechanical weed control were compared to about twenty different objects of conventional chemical weed control. One of the objects based on mechanical weed control consisted of treatment with the flex-tine harrow before and after emergence in combination with chemical weed control at a reduced rate in 3-4 leave stage. The second one consisted of broadcast mechanical treatments before and after emergence followed by a final in-row application of herbicides and an inter-row cultivation at 6-7(8) leave stage. All trials were conducted on the Experimental farm of Bottelare HoGent-UGent on a sandy loam soil. Maize was growing in 1/3 crop rotation. The effect on weed growth as well as the economic impact of the different applications was evaluated. Combining chemical and mechanical weed control is a possible option in conventional farming but the disadvantages must be taken into account. A better planned weed control based on the real present weed-population in combination with a carefully thought-out choice of herbicides should also be considered as an IPM--approach.

  18. WeedML: a Tool for Collaborative Weed Demographic Modeling

    OpenAIRE

    Holst, Niels

    2010-01-01

    WeedML is a proposed standard to formulate models of weed demography, or maybe even complex models in general, that are both transparent and straightforward to re-use as building blocks for new models. The paper describes the design and thoughts behind WeedML which relies on XML and object-oriented systems development. Proof-of-concept software is provided as open-source C++ code and executables that can be downloaded freely.

  19. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Science.gov (United States)

    2010-02-23

    ... DEPARTMENT OF AGRICULTURE Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest... Rangeland Project area. The analysis will determine if a change in management direction for livestock grazing is needed to move existing resource conditions within the Monitor-Hot Creek Rangeland Project area...

  20. A systematic review of US rangeland social science

    Science.gov (United States)

    Rangeland science aims to create knowledge to sustain rangeland social-ecological systems over the long term. Range science has made substantial progress on understanding ecological dynamics of rangeland systems and the management practices that sustain them, and these findings have been systematica...

  1. Using remotely sensed imagery to monitor savanna rangeland deterioration through woody plant proliferation: a case study from communal and biodiversity conservation rangeland sites in Mokopane, South Africa

    CSIR Research Space (South Africa)

    Munyati, C

    2011-05-01

    Full Text Available rangeland, whereas the communal rangelands were getting more opened up by livestock trampling. Rangeland management practices of fire utilisation, stocking levels and stock concentration account for the differing trends. Lightly grazed and heavily grazed...

  2. Robotic weed monitoring

    DEFF Research Database (Denmark)

    Bochtis, Dionysis; Sørensen, Claus Aage Grøn; Jørgensen, R N

    2011-01-01

    Abstract: In this paper, an integrated management system for the planning and activation of thefield monitoring task is presented. The architecture of the system is built around a mobile roboticunit. The internet based architecture of the system includes a station unit that works as a mobileon-fa...... of the weed monitoring operation.Key words: autonomous vehicles, farm management, mission planning, route planning,sampling....

  3. Selective weed control using laser techniques

    OpenAIRE

    Marx, Christian; Pastrana-Perez, Julio; Hustedt, Michael; Barcikowski, Stephan; Haferkamp, Heinz; Rath, Thomas

    2012-01-01

    This contribution discusses technical and growth relevant aspects of using laser techniques for weed control. The research on thermal weed control via laser first focused on the interaction of laser beams and weed plants. Due to preliminary studies, a CO2-laser was selected for further studies with regard to the process factors laser energy, laser spot area, coverage of the weeds meristem, weed species (Amaranthus retroflexus), and weed growth stage. Thereby, the laser damage was modeled in o...

  4. Effect of ploughing frequency and weeding methods on weeds and ...

    African Journals Online (AJOL)

    User

    Five tillage practices ... 2.5 l ha-1, Duplosan plus one hand weeding at 30 days after emergence (DAE); ... weed on time, is one of the major constraints in wheat ... management factors and soil type (Yohannes, 1982). .... The finding at ICARDA (1984) shows that ..... selling price of the crop changes, the farmer can still get a.

  5. PERSPECTIVES ON RANGELAND ECOLOGY AND MANAGEMENT

    OpenAIRE

    Heady, Harold F.

    2011-01-01

    This paper reviews changes in rangeland ecology and management in the U.S.A. over the last 65 years and speculates on future changes. Emphasis has shifted from livestock management to ecological and environmental concerns, hence "rangeland ecology." The term "range management" may have outlived its usefulness and may also be detrimental to our image. The vision that we have of ourselves is not the same as others have of us. Many members of the Society for Range Management (SRM) and most of ou...

  6. Favorable fragmentation: river reservoirs can impede downstream expansion of riparian weeds.

    Science.gov (United States)

    Rood, Stewart B; Braatne, Jeffrey H; Goater, Lori A

    2010-09-01

    River valleys represent biologically rich corridors characterized by natural disturbances that create moist and barren sites suitable for colonization by native riparian plants, and also by weeds. Dams and reservoirs interrupt the longitudinal corridors and we hypothesized that this could restrict downstream weed expansion. To consider this "reservoir impediment" hypothesis we assessed the occurrences and abundances of weeds along a 315-km river valley corridor that commenced with an unimpounded reach of the Snake River and extended through Brownlee, Oxbow, and Hells Canyon reservoirs and dams, and downstream along the Snake River. Sampling along 206 belt transects with 3610 quadrats revealed 16 noxious and four invasive weed species. Ten weeds were upland plants, with Canada thistle (Cirsium arvense) restricted to the upstream reaches, where field morning glory (Convolvulus arvensis) was also more common. In contrast, St. John's wort (Hypericum perforatum) was more abundant below the dams, and medusahead wildrye (Taeniatherum caput-medusae) occurred primarily along the reservoirs. All seven riparian species were abundant in the upstream zones but sparse or absent below the dams. This pattern was observed for the facultative riparian species, poison hemlock (Conium maculatum) and perennial pepperweed (Lepidium latifolium), the obligate riparian, yellow nut sedge (Cyperus esculentus), the invasive perennial, reed canary grass (Phalaris arundinacea), and three invasive riparian trees, Russian olive (Elaeagnus angustifolia), false indigo (Amorpha fruticosa), and tamarisk (Tamarix spp.). The hydrophyte purple loosestrife (Lythrum salicaria) was also restricted to the upstream zone. These longitudinal patterns indicate that the reservoirs have impeded the downstream expansion of riparian weeds, and this may especially result from the repetitive draw-down and refilling of Brownlee Reservoir that imposes a lethal combination of drought and flood stress. The dams and

  7. Investigation of weed species diversity and community structure in saffron fields of Khorasan

    Directory of Open Access Journals (Sweden)

    Surur Khorramdel

    2017-09-01

    Full Text Available Weedy flora of agroecosystems is composed of many species that have evolved in response to cropping system practices by occupying the niches left available in agroecosystems. In order to study weed species diversity and community structure in the saffron fields of Khorasan province, a survey trial was carried out in seven counties (including Mashhad, Neyshabur, Birjandn, Ghaen, Gonabad, Torbat-e Jam and Torbat-e Heydari during 2014 and 2015 from vegetative growth, dormant to flowering stages of saffron randomly dropped 1×1 m2 quadrates in 50 fields based on a systematic method as W pattern. The counties were clustered by the hierarchical complete linkage method based on Euclidean. Biodiversity indices such as stability coefficient, Simpson, Shannon–Wiener, Margalef and Menhinick were computed. The results indicated that the dominant weeds in saffron fields belong to 19 families and 50 species. Poaceae, Brassicaceae, Asteraceae and Fabaceae were dominant families with 11, 9, 8 and 6 species, respectively. The majority of weed species were dicotyledonous, C3, noxious and annual plants. The highest stability coefficients in the stages of growth of saffron were calculated in Alhagi camelorum, Avena fatua and Achillea millefolium to be 30.81, 24.11 and 12.14, respectively. All weed species except for Alhagi camelorum (sustainable species and Avena fatua (temporary species were recognized as causal species. The maximum diversity indices for weed species were recorded at the vegetative phase of saffron. Correlation coefficient between weed density and yield loss of saffron was computed as R2=0.98. Based on diversity indices for weed species, different counties were clustered in three groups at 75% similarity level.

  8. Integrated Weed Control for Land Stewardship at Legacy Management's Rocky Flats Site in Colorado - 13086

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Jody K. [Stoller LMS Team, Contractor to the U.S. Department of Energy Office of Legacy Management, 11025 Dover Street, Suite 1000, Westminster, Colorado 80021 (United States)

    2013-07-01

    Land stewardship is one of nine sustainability programs in the U.S. Department of Energy's Environmental Management System. Land stewardship includes maintaining and improving ecosystem health. At the Rocky Flats Site near Westminster, Colorado, land stewardship is an integral component of the Office of Legacy Management's post-closure monitoring and management at the site. Nearly 263 hectares (650 acres) were disturbed and re-vegetated during site cleanup and closure operations. Proactive management of revegetation areas is critical to the successful reestablishment of native grasslands, wetlands, and riparian communities. The undisturbed native plant communities that occur at the site also require active management to maintain the high-quality wetlands and other habitats that are home to numerous species of birds and other wildlife such as elk and deer, rare plant communities, and the federally listed threatened Preble's meadow jumping mouse. Over the past several decades, an increase of Noxious weeds has impacted much of Colorado's Front Range. As a result, weed control is a key component of the land stewardship program at Rocky Flats. Thirty-three species of state-listed Noxious weeds are known to occur in the Central and Peripheral Operable Units at Rocky Flats, along with another five species that are considered invasive at the site. Early detection and rapid response to control new invasive species is crucial to the program. An integrated weed control/vegetation management approach is key to maintaining healthy, sustainable plant communities that are able to resist Noxious weed invasions. Weed mapping, field surveys, and field-staff training sessions (to learn how to identify new potential problem species) are conducted to help detect and prevent new weed problems. The integrated approach at Rocky Flats includes administrative and cultural techniques (prevention), mechanical controls, biological controls, and chemical controls. Several

  9. Site-specific weed control technologies

    DEFF Research Database (Denmark)

    Christensen, Svend; Søgaard, Henning Tangen; Kudsk, Per

    2009-01-01

    Site-specific weed control technologies are defined as machinery or equipment embedded with technologies that detect weeds growing in a crop and, taking into account predefined factors such as economics, takes action to maximise the chances of successfully controlling them. In the article, we...... describe the basic parts of site specific weed control technologies, comprising of weed sensing systems, weed management models and precision weed control implements. A review of state-of-the-art technologies shows that several weed sensing systems and precision implements have been developed over the last...... of knowledge about the economic and environmental potential for increasing the resolution of weed control. The integration of site-specific information on weed distribution, weed species composition and density, and the effect on crop yield, is decisive for successful site-specific weed management.   Keywords...

  10. Brain mediators of the effects of noxious heat on pain.

    Science.gov (United States)

    Atlas, Lauren Y; Lindquist, Martin A; Bolger, Niall; Wager, Tor D

    2014-08-01

    Recent human neuroimaging studies have investigated the neural correlates of either noxious stimulus intensity or reported pain. Although useful, analyzing brain relationships with stimulus intensity and behavior separately does not address how sensation and pain are linked in the central nervous system. In this study, we used multi-level mediation analysis to identify brain mediators of pain--regions in which trial-by-trial responses to heat explained variability in the relationship between noxious stimulus intensity (across 4 levels) and pain. This approach has the potential to identify multiple circuits with complementary roles in pain genesis. Brain mediators of noxious heat effects on pain included targets of ascending nociceptive pathways (anterior cingulate, insula, SII, and medial thalamus) and also prefrontal and subcortical regions not associated with nociceptive pathways per se. Cluster analysis revealed that mediators were grouped into several distinct functional networks, including the following: somatosensory, paralimbic, and striatal-cerebellar networks that increased with stimulus intensity; and 2 networks co-localized with "default mode" regions in which stimulus intensity-related decreases mediated increased pain. We also identified "thermosensory" regions that responded to increasing noxious heat but did not predict pain reports. Finally, several regions did not respond to noxious input, but their activity predicted pain; these included ventromedial prefrontal cortex, dorsolateral prefrontal cortex, cerebellar regions, and supplementary motor cortices. These regions likely underlie both nociceptive and non-nociceptive processes that contribute to pain, such as attention and decision-making processes. Overall, these results elucidate how multiple distinct brain systems jointly contribute to the central generation of pain. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  11. Spatial analysis of weed patterns

    NARCIS (Netherlands)

    Heijting, S.

    2007-01-01

    Keywords: Spatial analysis, weed patterns, Mead’s test, space-time correlograms, 2-D correlograms, dispersal, Generalized Linear Models, heterogeneity, soil, Taylor’s power law. Weeds in agriculture occur in patches. This thesis is a contribution to the characterization of this patchiness, to its

  12. Structural and Functional Diversity of Weed Species in Organic and Conventional Rice Agro-Ecosystems

    Directory of Open Access Journals (Sweden)

    S. Y. Mousawi Toghani

    2016-02-01

    -Wilson included two clusters in 83% and 82%, respectively. Range of similarity index was between 1.89% and 83.96%. Weed grouping based on relative frequency during the sampling stages showed two clusters in 78% and four clusters in 85% similarity. Clustering weeds centered on relative frequency during sampling stages, according to the family, showed different results. It might be the reason that the relative abundance of weeds, sedge family (79% were in two clusters. However, sampling stages grouping based on weed density, induced two clusters in 39% similarity. Both conventional and organic systems, are included 10 species of 8 genera of four families. The 75 percent of families based on the vegetative form were monocots and 25% of them were dicots, so monocots had more diversity. Perhaps the presence of Alismaplantagoin the conventional system could be as a unique species and its absence in the organic system, attributable to duck existence in it. Based on life-cycle, 6 species were annual and 4 were perennial. While, according to the photosynthetic pathway, 50 percent species were C3 and others had C4 pathway. Based on the characteristics of the interference, 4 species were noxious and 6 species were non-noxious. Poaceae were the most diversity of weeds in monocotyledon and C4 pathway (three species. Two species of noxious weeds and herbicide resistant belong to Poaceae too. The Cyperaceae consist of two species from four perennial ones. The weeds of Poaceae and Cyperaceae families include 70% of total weed. Generally, weeds in ecosystems usually change thehabitat conditions or impact on the resources availability for other species. Conclusions Due to repeated or severe disturbances, agro-ecosystems are limited to the early stages of succession. Thus, the widespread destruction of agro-ecosystems during consecutive years, by changing the succession, weed population dynamics was affected as well. It should be noted that the differences of weed distribution in the various stages

  13. Managing the livestock– Wildlife interface on rangelands

    Science.gov (United States)

    du Toit, Johan T.; Cross, Paul C.; Valeix, Marion

    2017-01-01

    On rangelands the livestock–wildlife interface is mostly characterized by management actions aimed at controlling problems associated with competition, disease, and depredation. Wildlife communities (especially the large vertebrate species) are typically incompatible with agricultural development because the opportunity costs of wildlife conservation are unaffordable except in arid and semi-arid regions. Ecological factors including the provision of supplementary food and water for livestock, together with the persecution of large predators, result in livestock replacing wildlife at biomass densities far exceeding those of indigenous ungulates. Diseases are difficult to eradicate from free-ranging wildlife populations and so veterinary controls usually focus on separating commercial livestock herds from wildlife. Persecution of large carnivores due to their depredation of livestock has caused the virtual eradication of apex predators from most rangelands. However, recent research points to a broad range of solutions to reduce conflict at the livestock–wildlife interface. Conserving wildlife bolsters the adaptive capacity of a rangeland by providing stakeholders with options for dealing with environmental change. This is contingent upon local communities being empowered to benefit directly from their wildlife resources within a management framework that integrates land-use sectors at the landscape scale. As rangelands undergo irreversible changes caused by species invasions and climate forcings, the future perspective favors a proactive shift in attitude towards the livestock–wildlife interface, from problem control to asset management.

  14. Invasive Plants on Rangelands: a Global Threat

    Science.gov (United States)

    Invasive plant species are spreading and invading rangelands at an unprecedented rate costing ranchers billions of dollars to control invasive plants each year. In its simplest form, the invasion process has four primary stages, including introduction, establishment, spread and colonization. Th...

  15. 7 CFR 201.15 - Weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation or...

  16. Applicator Training Manual for: Aquatic Weed Control.

    Science.gov (United States)

    Herron, James W.

    The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

  17. of different weed control methods on Weed infestation, growth

    African Journals Online (AJOL)

    thinkexploitsint'l

    This weed control method also resulted in significantly better growth and ... proper management, it is possible to obtain 2,500 kg ha-1 (Onwueme and Sinha, 1991). ... however, time consuming, labour – intensive, strenuous and generally ...

  18. Burning Cold: Involvement of TRPA1 in Noxious Cold Sensation

    OpenAIRE

    Kwan, Kelvin Y.; Corey, David P.

    2009-01-01

    Soon after its discovery ten years ago, the ion channel TRPA1 was proposed as a sensor of noxious cold. Evidence for its activation by painfully cold temperatures (below ~15° C) has been mixed, however. Some groups found that cold elicits a nonselective conductance in cells expressing TRPA1; others found no activation, or argued that activation is an indirect effect of elevated \\(Ca^{ 2+}\\) . Sensory cells from the trigeminal and dorsal root ganglia that are activated by cold were sometimes c...

  19. Guide Of Treatment On Noxious Waste Of Experiment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-05-15

    This book deals with environmental safe management and smooth driving of facilities, which indicates purpose of this guide, responsibility of environmental safe management, division of collect of starting point treatment, batch processing system, treatment of noxious waste of experiment, regulation of harmful waste such as medicine, corrosivity liquid, and treatment of cleaning solution of chrome-sulfuric acid, and regulation of Kyungpook National University Department Environmental Engineering Research Center, environmental protection law and the other related law.

  20. Guide Of Treatment On Noxious Waste Of Experiment

    International Nuclear Information System (INIS)

    1987-05-01

    This book deals with environmental safe management and smooth driving of facilities, which indicates purpose of this guide, responsibility of environmental safe management, division of collect of starting point treatment, batch processing system, treatment of noxious waste of experiment, regulation of harmful waste such as medicine, corrosivity liquid, and treatment of cleaning solution of chrome-sulfuric acid, and regulation of Kyungpook National University Department Environmental Engineering Research Center, environmental protection law and the other related law.

  1. Pastoral Decision-Making: An Empirical Investigation of Rangeland Use

    International Nuclear Information System (INIS)

    MacPeak, J.

    1999-01-01

    Recent research in range ecology suggests that the process of resource degradation in African arid and semi-arid rangelands may be less reliant on how many animals are kept on the rangeland than on where these animals are kept. Analysis of pastoralist land use decisions indicated that rangeland condition influences livestock keeping. However, it was found that food and income production strategies, herd characteristics play critical roles in livestock keeping decisions

  2. Ecological Weed Management by Cover Cropping: Effect on Winter Weeds and Summer Weeds Establishment in Potato

    Directory of Open Access Journals (Sweden)

    M Ghaffari

    2012-07-01

    Full Text Available Now a day winter cover crops planting has been attended to reduce herbicide application. An experiment was carried out at the Research Farm of Agriculture Faculty, Bu- Ali Sina, University, in 2009. The experiment was a randomized complete block design with three replications. The trial included of five treatments consists of no cover crop, rye, winter oilseed rape, barley and triticale. The results showed that winter cereals were produced more biomass than winter oilseed rape. living mulch of rye, barley, oilseed rape and triticale reduced winter weeds biomass 89, 86, 82 and 70 percent respectively, in compare to control. Cover crop treatments showed significant different weeds control of potato at 3 time (15, 45 and 75 DAPG compare to control treatment. Residues mixed to soil of oilseed rape and rye had the most inhibition affects on summer weeds. These treatments, average weeds biomass decreased 61 and 57 percent respectively, in compare to control. Oilseed rape and rye in compare to control reduced weeds density in potato 36 and 35 percent, respectively. Significant negation correlations of weeds plant population, weeds dry matter with average tuber weight and potato yield. The treatments, oilseed rape and rye in compare to control increased tuber yield of potato 54 and 50 percent, respectively. These treatments, the average tuber weight increased 74 and 38 percent in compare with control, respectively.

  3. Weed clearance in Hudiara Nallah by chemical weed control

    International Nuclear Information System (INIS)

    Dhillon, G.S.

    1981-01-01

    Hudiara Nallah is a flood stream in West Punjab. It has a length of about 45km and breadth of nearly 25 metres. About 20 subsidiary drains join with the Nallah. These drains have a length of about 270km. The Nallah has a discharge capacity of 1248 cusecs. Most of the subsidiary drains start from ponds which are generally infected with Eichhornia plants. These plants enter into the subsidiary drains and finally into Hudiara Nallah. The plants float freely on the surface of water and multiply at a high rate. One plant of the weed propagates to 24 plants in a period of one month. The plants thus cover the whole drain in a few months. The weed also originates from seeds. Their heavy growth forms a mat-like surface. The weeds also choke bridges and sometimes cause damage to their structures. These obstruct the flow of water and decrease the carrying capacity of the drain. Their infestation thus causes floods and the very purpose of the drains gets lost. Thus the Nallah is heavily infested with Eichhornia crassipes (water hyacinth weed). Due to its fast propagation and heavy infestation it was not possible to clear the weed manually. The problem was, therefore, referred to the Chemistry Division of the Irrigation and Power Research Institute, Amritsar, by the Drainage Circle of the Irrigation Department in June 1978 when weed propagation was in full swing. A chemical treatment method of eradication was attempted

  4. Integrated weed management in wheat

    International Nuclear Information System (INIS)

    Marwat, K.B.; Khan, M.A.; Nawab, K.; Khattak, A.M.

    2011-01-01

    The paper summarizes the results of an experiment conducted on wheat at Kohat, Khyber Pakhtunkhwa, Pakistan during winter 2004-05. Randomized complete block design with split-split-plot arrangement was used where wheat line and broadcast sowing were kept in main plots. Seed rates (100 and 150 kg ha-1) were assigned as sub-plots, while four herbicides (Topik, Isoproturon, Puma super and Buctril super) and weed check were assigned to sub-sub-plots. Results revealed that higher biological yield was recorded in line sowing. However, higher wheat seed rate decreased weed biomass and increased biological yield. Herbicides proved to be effective in decreasing weed biomass and enhancing grain yield and its contributing traits. It was suggested that line sowing in combination with higher seeding rate and Buctril super should be used in an integrated weed management fashion. However further studies are required to investigate various ranges of seeding rate and herbicides doses. (author)

  5. Can global weed assemblages be used to predict future weeds?

    Directory of Open Access Journals (Sweden)

    Louise Morin

    Full Text Available Predicting which plant taxa are more likely to become weeds in a region presents significant challenges to both researchers and government agencies. Often it is done in a qualitative or semi-quantitative way. In this study, we explored the potential of using the quantitative self-organising map (SOM approach to analyse global weed assemblages and estimate likelihoods of plant taxa becoming weeds before and after they have been moved to a new region. The SOM approach examines plant taxa associations by analysing where a taxon is recorded as a weed and what other taxa are recorded as weeds in those regions. The dataset analysed was extracted from a pre-existing, extensive worldwide database of plant taxa recorded as weeds or other related status and, following reformatting, included 187 regions and 6690 plant taxa. To assess the value of the SOM approach we selected Australia as a case study. We found that the key and most important limitation in using such analytical approach lies with the dataset used. The classification of a taxon as a weed in the literature is not often based on actual data that document the economic, environmental and/or social impact of the taxon, but mostly based on human perceptions that the taxon is troublesome or simply not wanted in a particular situation. The adoption of consistent and objective criteria that incorporate a standardized approach for impact assessment of plant taxa will be necessary to develop a new global database suitable to make predictions regarding weediness using methods like SOM. It may however, be more realistic to opt for a classification system that focuses on the invasive characteristics of plant taxa without any inference to impacts, which to be defined would require some level of research to avoid bias from human perceptions and value systems.

  6. Sustaining working rangelands: Insights from rancher decision making

    Science.gov (United States)

    Grazed rangeland ecosystems encompass diverse global land resources, and are complex social-ecological systems from which society demands both goods (e.g., livestock and forage production) and services (e.g., abundant and high quality water). In the dialogue on rangeland conservation and sustainable...

  7. Developing an operational rangeland water requirement satisfaction index

    Science.gov (United States)

    Senay, Gabriel B.; Verdin, James P.; Rowland, James

    2011-01-01

    Developing an operational water requirement satisfaction index (WRSI) for rangeland monitoring is an important goal of the famine early warning systems network. An operational WRSI has been developed for crop monitoring, but until recently a comparable WRSI for rangeland was not successful because of the extremely poor performance of the index when based on published crop coefficients (K c) for rangelands. To improve the rangeland WRSI, we developed a simple calibration technique that adjusts the K c values for rangeland monitoring using long-term rainfall distribution and reference evapotranspiration data. The premise for adjusting the K c values is based on the assumption that a viable rangeland should exhibit above-average WRSI (values >80%) during a normal year. The normal year was represented by a median dekadal rainfall distribution (satellite rainfall estimate from 1996 to 2006). Similarly, a long-term average for potential evapotranspiration was used as input to the famine early warning systems network WRSI model in combination with soil-water-holding capacity data. A dekadal rangeland WRSI has been operational for east and west Africa since 2005. User feedback has been encouraging, especially with regard to the end-of-season WRSI anomaly products that compare the index's performance to ‘normal’ years. Currently, rangeland WRSI products are generated on a dekadal basis and posted for free distribution on the US Geological Survey early warning website at http://earlywarning.usgs.gov/adds/

  8. Managing climate change risks in rangeland systems [Chapter 15

    Science.gov (United States)

    Linda A. Joyce; Nadine A. Marshall

    2017-01-01

    The management of rangelands has long involved adapting to climate variability to ensure that economic enterprises remain viable and ecosystems sustainable; climate change brings the potential for change that surpasses the experience of humans within rangeland systems. Adaptation will require an intentionality to address the effects of climate change. Knowledge of...

  9. Adaptive management for complex communal rangelands in South ...

    African Journals Online (AJOL)

    Many of the intransigent problems facing the world arise in complex systems. In this paper, I propose that communal rangelands in South Africa be recognised as complex social–ecological systems and that one of the reasons that development initiatives have had little impact on improving livelihoods and rangeland ...

  10. A description of rangeland on commercial and communal land ...

    African Journals Online (AJOL)

    Analysis of a Landsat TM image from a rangeland near Peddie, Eastern Cape, revealed differences in two vegetation indices (normalised difference vegetation index, NDVI, and moving standard deviation index, MSDI) between communal and commercial rangeland. It was suggested that the difference in the MSDI reflected ...

  11. Meeting wild bees' needs on Western US rangelands

    Science.gov (United States)

    James H. Cane

    2011-01-01

    Rangelands are areas that are too arid, or with soils too shallow, to support either forests or cultivated agriculture, but that nonetheless produce enough vegetation for livestock grazing. Some arid rangeland regions, notably those with warm, dry climates in temperate zones (e.g., the warm deserts of the United States and adjacent Mexico, parts of Australia, South...

  12. Race, ethnicity, and noxious facilities: Environmental racism re- examined

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, A.L. [Wheaton Coll., IL (United States)]|[Argonne National Lab., IL (United States); Nieves, L.A. [Argonne National Lab., IL (United States)

    1992-10-01

    The charge has been made that hazardous facilities tend to be located in proximity to minority populations. This study uses a facility density measure for three categories of noxious facilities to examine the relationship between facilities and minority population concentrations. County-level data are used in a correlation analysis for African Americans, Hispanics, and Asians in the four major regions of the US. Even controlling for income and housing value, and limiting the data set to urban areas, consistent patterns of moderate to strong association of facility densities with minority population percentages are found.

  13. New Tools to Estimate Runoff, Soil Erosion, and Sustainability of Rangeland Plant Communities

    Science.gov (United States)

    Rangelands are the largest land cover type in the world. Degradation from mismanagement, desertification, and drought impact more than 50% of rangelands across the globe. The USDA Agricultural Research Service has been evaluating sustainability of rangeland for over 40-years by conducted rangeland r...

  14. Sustainable rangeland management, economic growth, and a cautious role for the SRM

    Science.gov (United States)

    Interest in the art and science of rangeland management increased dramatically during the 20th century and it was out of this interest that the profession of rangeland management was born. As public interest in rangeland management grew, so did the number, breadth, and depth of rangeland management ...

  15. An Integrated Social, Economic, and Ecologic Conceptual (ISEEC) framework for considering rangeland sustainability

    Science.gov (United States)

    William E. Fox; Daniel W. McCollum; John E. Mitchell; Louis E. Swanson; Urs P. Kreuter; John A. Tanaka; Gary R. Evans; H. Theodore Heintz; Robert P. Breckenridge; Paul H. Geissler

    2009-01-01

    Currently, there is no standard method to assess the complex systems in rangeland ecosystems. Decision makers need baselines to create a common language of current rangeland conditions and standards for continued rangeland assessment. The Sustainable Rangeland Roundtable (SRR), a group of private and public organizations and agencies, has created a forum to discuss...

  16. Climate change effects on rangelands and rangeland management: Affirming the need for monitoring

    Science.gov (United States)

    Daniel W. Mccollum; John A. Tanaka; Jack A. Morgan; John E. Mitchell; William E. Fox; Kristie A. Maczko; Lori Hidinger; Clifford S. Duke; Urs P. Kreuter

    2017-01-01

    Uncertainty as to the extent and magnitude of changes in conditions that might occur due to climate change poses a problem for land and resource managers as they seek to adapt to changes and mitigate effects of climate variability. We illustrate using scenarios of projected future conditions on rangelands in the Northern Great Plains and Desert Southwest of the United...

  17. 7 CFR 201.50 - Weed seed.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Purity Analysis in the Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or... sieve are considered weed seeds. For wild onion and wild garlic (Allium spp.) bulblets classed as inert...

  18. Rangeland dynamics in South Omo Zone of Southern Ethiopia: Assessment of rangeland condition in relation to altitude and Grazing types

    NARCIS (Netherlands)

    Terefe, A.; Ebro, A.; Tessema, Z.K.

    2010-01-01

    A study was undertaken in Hamer and Benna-Tsemay districts of the Southern Ethiopia with the objective to determine the condition of the rangelands for grazing animals as influenced by altitude and grazing types. The rangelands in each of the study districts were stratified based on altitude and

  19. Maintaining ecosystem services through continued livestock production on California rangelands

    Science.gov (United States)

    Barry, S.; Becchetti, T.

    2015-12-01

    Nearly 40% of California is rangeland comprising the largest land type in California and providing forage for livestock, primarily beef cattle. In addition to forage, rangelands provide a host of ecosystem systems services, including habitat for common and endangered species, fire fuels management, pollination services, clean water, viewsheds, and carbon sequestration. Published research has documented that most of these ecosystem services are positively impacted by managed livestock grazing and rancher stewardship. Ranchers typically do not receive any monetary reimbursement for their stewardship in providing these ecosystem services to the public. Markets have been difficult to establish with limited ability to adequately monitor and measure services provided. At the same time, rangelands have been experiencing rapid conversion to urbanization and more profitable and intensive forms of agriculture such as almond and walnut orchards. To prevent further conversion of rangelands and the loss of the services they provide, there needs to be a mechanism to identify and compensate landowners for the value of all products and services being received from rangelands. This paper considers two methods (opportunity cost and avoided cost) to determine the value of Payment for Ecosystem Services (PES) for rangelands. PES can raise the value of rangelands, making them more competitive financially. Real estate values and University of California Cooperative Extension Cost Studies, were used to demonstrate the difference in value (lost opportunity cost) between the primary products of rangelands (livestock production) and the products of the converted rangelands (almond and walnut orchards). Avoided costs for vegetation management and habitat creation and maintenance were used to establish the value of managed grazing. If conversion is to be slowed or stopped and managed grazing promoted to protect the ecosystem services rangelands provide, this value could be compensated through

  20. Noxious facility impact projection: Incorporating the effects of risk aversion

    International Nuclear Information System (INIS)

    Nieves, L.A.

    1993-01-01

    Developing new sites for noxious facilities has become a complex process with many potential pitfalls. In addition to the need to negotiate conditions acceptable to the host community, siting success may depend on the facility proposer's ability to identify a candidate site that not only meets technical requirements, but that is located in a community or region whose population is not highly averse to the risks associated with the type of facility being proposed. Success may also depend on the proposer accurately assessing potential impacts of the facility and offering an equitable compensation package to the people affected by it. Facility impact assessments, as typically performed, include only the effects of changes in population, employment and economic activity associated with facility construction and operation. Because of their scope, such assessments usually show a short-run, net economic benefit for the host region, making the intensely negative public reaction to some types and locations of facilities seem unreasonable. The impact component excluded from these assessments is the long-run economic effect of public perceptions of facility risk and nuisance characteristics. Recent developments in psychological and economic measurement techniques have opened the possibility of correcting this flaw by incorporating public perceptions in projections of economic impacts from noxious facilities

  1. Prospects for site specific weed management

    DEFF Research Database (Denmark)

    Christensen, Svend; Rasmussen, Jesper; Pedersen, Søren Marcus

    2014-01-01

    Research on Site Specific Weed Management (SSWM) started in the late 80's. Since that moment, considerable research has been conducted on different aspects of SSWM, from fundamental studies on the spatial ecology of weeds to the applied development and testing of new technologies for weed detection...

  2. Weed Recognition Framework for Robotic Precision Farming

    DEFF Research Database (Denmark)

    Kounalakis, Tsampikos; Triantafyllidis, Georgios; Nalpantidis, Lazaros

    2016-01-01

    using advanced encoding and machine learning algorithms. The resulting system can be applied in a variety of environments, plantation or weed types. This results in a novel and generic weed control approach, that in our knowledge is unique among weed recognition methods and systems. For the experimental...

  3. A Regional Guidebook for Applying the Hydrogeomorphic Approach to Assessing the Functions of Tidal Fringe Wetlands Along the Mississippi and Alabama Gulf Coast

    Science.gov (United States)

    2007-04-01

    philoxeroides Alligatorweed Alabama Class C noxious weed Imperata cylindrica Cogongrass Alabama Class A noxious weed; Mississippi noxious weed Ipomoea...Invasive Species Alternanthera philoxeroides Phragmites australis Cuscuta spp. Imperata cylindrica...weed Cuscuta spp. Dodder Alabama Class A noxious weed Imperata cylindrica Cogongrass Alabama Class A noxious weed; MS noxious weed Ipomoea

  4. Are weeds hitchhiking a ride on your car? A systematic review of seed dispersal on cars.

    Directory of Open Access Journals (Sweden)

    Michael Ansong

    Full Text Available When traveling in cars, we can unintentionally carry and disperse weed seed; but which species, and where are they a problem? To answer these questions, we systematically searched the scientific literature to identify all original research studies that assess seed transported by cars and listed the species with seed on/in cars. From the 13 studies that fit these criteria, we found 626 species from 75 families that have seed that can be dispersed by cars. Of these, 599 are listed as weeds in some part of the world, with 439 listed as invasive or naturalized alien species in one or more European countries, 248 are invasive/noxious weeds in North America, 370 are naturalized alien species in Australia, 167 are alien species in India, 77 are invasive species in China and 23 are declared weeds/invaders in South Africa. One hundred and one are classified as internationally important environmental weeds. Although most (487 were only recorded once, some species such as Chenopodium album, Poa pratensis and Trifolium repens were common among studies. Perennial graminoids seem to be favoured over annual graminoids while annual forbs are favoured over perennial forbs. Species characteristics including seed size and morphology and where the plants grew affected the probability that their seed was transported by cars. Seeds can be found in many different places on cars including under the chassis, front and rear bumpers, wheel wells and rims, front and back mudguards, wheel arches, tyres and on interior floor mats. With increasing numbers of cars and expanding road networks in many regions, these results highlight the importance of cars as a dispersal mechanism, and how it may favour invasions by some species over others. Strategies to reduce the risk of seed dispersal by cars include reducing seed on cars by mowing road verges and cleaning cars.

  5. Weed Control in Soybean (Glycine max)

    International Nuclear Information System (INIS)

    Kipkemoi, P.L.

    2002-01-01

    Weed Compete for limited growth factors with crop plants. This result in loss of crop vigour and hence reduces crop yields. A study was conducted in 1997 and 2001 to evaluate the use of herbicides and hand hoeing for weed control in soybeans. Crop establishment was by hand planting. The herbicides were applied using CP3 Knap sack sprayer calibrated to deliver a spray volume of 150l/ha. Hand weeding treatment were done as appropriate. The trial layout was randomised complete block design with four replications in both years. The tested herbicides did not satisfactorily control the weeds present at the experimental site in both years. Hand weeding on the other hand gave good control of the weeds which were reflected in high soybean yields. In these trials yields were negatively correlated with the number of weeds present. The tested herbicides alone appeared to be inadequate in controlling weeds in soybean. Compared with the weed-free treatment a single application of soil-applied or post-emergence herbicides did not control a broad spectrum of weeds and reduced soybean yields. It can also be inferred that soybean yield losses are minimised if they are kept weed free for at most 6 weeks after emergence

  6. Rounding Up the Astrophysical Weeds

    Science.gov (United States)

    McMillan, James P.

    2016-09-01

    New instruments used for astronomy such as ALMA, Herschel, and SOFIA have greatly increased the quality of available astrophysical data. These improved data contain spectral lines and features which are not accounted for in the quantum mechanical (QM) catalogs. A class of molecules has been identified as being particularly problematic, the so-called "weeds". These molecules have numerous transitions, of non-trivial intensity, which are difficult to model due to highly perturbed low lying vibrational states. The inability to properly describe the complete contribution of these weeds to the astrophysical data has led directly to the misidentification of other target molecules. Ohio State's Microwave Laboratory has developed an alternative approach to this problem. Rather than relying on complex QM calculations, we have developed a temperature dependent approach to laboratory based terahertz spectroscopy. We have developed a set of simple packages, in addition to traditional line list catalogs, that enable astronomers to successfully remove the weed signals from their data. This dissertation will detail my laboratory work and analysis of three keys weeds: methanol, methyl formate and methyl cyanide. Also, discussed will be the analytical technique I used to apply these laboratory results to astrophysical data.

  7. Device for the elimination of noxious components of exhaust gases

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, A

    1975-04-24

    A device for the removal of noxious components from the exhaust gases of an internal combustion engine is described. It consists of a chemical reactor installed in the tail-pipe. Behind the reactor, in the flow direction of the exhaust gases, there is a catalytic temperature sensor whose electrical output is transmitted to an analyzer which provides a signal if the reactor fails. The temperature sensor is situated directly in the waste gas duct or in a branch of the tail-pipe which is supplied with air. There is also another, catalytically inactive, temperature sensor. A failure is signalled (a) if the chemical reactor has failed, and (b) if there is not enough oxygen in the exhaust gas to keep up a chemical reaction.

  8. THE USE OF BIOFILTERS FOR DEODORISATION OF THE NOXIOUS GASES

    Directory of Open Access Journals (Sweden)

    Monika Wierzbińska

    2015-01-01

    Full Text Available One of the methods of deodorization of noxious gases is biofiltration. This method consists of pollutants biodegradation by using micro-organisms, what leads to the formation of nontoxic and innoxious compounds. In comparison with conventional techniques, bio-filtration requires lower investments and exploitation costs, moreover it is nature friendly. This technique is still developing. Scientists have carried out research on the optimization of biofiltration process, biofilters and selecting parameters of purified gases or improving the method of efficiency. However, industrial application of biofilters is still difficult for many reasons. In this paper we present the mechanism of biofiltration process, the parameters and conditions which have to be fulfilled by purified gases, installation structure for gases biofiltration, application field of this method and specific example of exploited biofilters, including practical operational guidelines.

  9. Management of communal rangelands - the dialogue between science and indigenous knowledge: the case of the Eastern Cape

    CSIR Research Space (South Africa)

    Dube, S

    2010-07-01

    Full Text Available Communal area rangeland resource users are an important part of the rangeland ecosystem; rangeland management policies and practice should, therefore, accommodate their socio-cultural practices and knowledge. Indigenous knowledge (IK) is often...

  10. Botanical Criteria of Baharkish Rangeland in Quchan, Khorasan ...

    African Journals Online (AJOL)

    ADOWIE PERE

    University of Mashhad International Campus, Mashhad, I.R of IRAN ... ABSTRACT: Rangelands are natural ecosystems containing a range of resources of genetic ..... Ecology of world vegetation. .... Science Journal of Islamic Azad University,.

  11. A comparison of the effects of different rangeland management ...

    African Journals Online (AJOL)

    A comparison of the effects of different rangeland management systems on ... Three management systems exploit these areas: commercial livestock ranching, communal livestock ranching and game ranching. ... AJOL African Journals Online.

  12. Forests, rangelands and climate change in Southern Africa

    CSIR Research Space (South Africa)

    Naidoo, Sasha

    2013-09-01

    Full Text Available This paper provides an analysis of the implications of climate change for forests and rangelands in southern Africa. The extent of the resources and their economic and social functions and drivers of change is outlined. The vulnerability...

  13. Future scenarios of impacts to ecosystem services on California rangelands

    Science.gov (United States)

    Byrd, Kristin; Alvarez, Pelayo; Flint, Lorraine; Flint, Alan

    2014-01-01

    The 18 million acres of rangelands in the Central Valley of California provide multiple benefits or “ecosystem services” to people—including wildlife habitat, water supply, open space, recreation, and cultural resources. Most of this land is privately owned and managed for livestock production. These rangelands are vulnerable to land-use conversion and climate change. To help resource managers assess the impacts of land-use change and climate change, U.S. Geological Survey scientists and their cooperators developed scenarios to quantify and map changes to three main rangeland ecosystem services—wildlife habitat, water supply, and carbon sequestration. Project results will help prioritize strategies to conserve these rangelands and the ecosystem services that they provide.

  14. Ecological evaluation of rangeland quality in dry subtropics of Azerbaijan

    Science.gov (United States)

    Gasanova, A. F.

    2014-12-01

    The results of ecological evaluation of soil-landscape complexes of winter rangelands of Gobustan with the use of energy criteria are discussed. The diagnostic characteristics of soil fertility and correction coefficients for the thickness of texture of soil horizons, soil salinization, soil erosion, and microelemental composition of soils have been used to separate the soils of winter rangelands into several quality groups. A larger part of the soils belongs to the medium quality group with the mean weighted quality factor (bonitet) of 52. Special assessment scales have been suggested for the differential ecological assessment and monitoring of the rangelands. In the past 40 years, the area of steppe landscapes has decreased from 22.7 to 12%, whereas the area of semideserts has increased up to 64%. The area of best-quality soils within the studied rangelands had decreased by three times, and their average quality factor has decreased from 92 to 86.

  15. Effect of management on rangeland phytomass, cover and condition ...

    African Journals Online (AJOL)

    similarity of management effects on rangeland condition and forage provision across major dryland biomes. Taking a macro-ecological perspective, we analysed if management effects differed between South Africa's central grassland and ...

  16. Overview of glyphosate-resistant weeds worldwide.

    Science.gov (United States)

    Heap, Ian; Duke, Stephen O

    2018-05-01

    Glyphosate is the most widely used and successful herbicide discovered to date, but its utility is now threatened by the occurrence of several glyphosate-resistant weed species. Glyphosate resistance first appeared in Lolium rigidum in an apple orchard in Australia in 1996, ironically the year that the first glyphosate-resistant crop (soybean) was introduced in the USA. Thirty-eight weed species have now evolved resistance to glyphosate, distributed across 37 countries and in 34 different crops and six non-crop situations. Although glyphosate-resistant weeds have been identified in orchards, vineyards, plantations, cereals, fallow and non-crop situations, it is the glyphosate-resistant weeds in glyphosate-resistant crop systems that dominate the area infested and growing economic impact. Glyphosate-resistant weeds present the greatest threat to sustained weed control in major agronomic crops because this herbicide is used to control weeds with resistance to herbicides with other sites of action, and no new herbicide sites of action have been introduced for over 30 years. Industry has responded by developing herbicide resistance traits in major crops that allow existing herbicides to be used in a new way. However, over reliance on these traits will result in multiple-resistance in weeds. Weed control in major crops is at a precarious point, where we must maintain the utility of the herbicides we have until we can transition to new weed management technologies. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. The future for weed control and technology.

    Science.gov (United States)

    Shaner, Dale L; Beckie, Hugh J

    2014-09-01

    This review is both a retrospective (what have we missed?) and prospective (where are we going?) examination of weed control and technology, particularly as it applies to herbicide-resistant weed management (RWM). Major obstacles to RWM are discussed, including lack of diversity in weed management, unwillingness of many weed researchers to conduct real integrated weed management research or growers to accept recommendations, influence or role of agrichemical marketing and governmental policy and lack of multidisciplinary research. We then look ahead to new technologies that are needed for future weed control in general and RWM in particular, in areas such as non-chemical and chemical weed management, novel herbicides, site-specific weed management, drones for monitoring large areas, wider application of 'omics' and simulation model development. Finally, we discuss implementation strategies for integrated weed management to achieve RWM, development of RWM for developing countries, a new classification of herbicides based on mode of metabolism to facilitate greater stewardship and greater global exchange of information to focus efforts on areas that maximize progress in weed control and RWM. There is little doubt that new or emerging technologies will provide novel tools for RMW in the future, but will they arrive in time? © 2013 Her Majesty the Queen in Right of Canada Pest Management Science © 2013 Society of Chemical Industry.

  18. Rangeland degradation in two watersheds of Lebanon

    International Nuclear Information System (INIS)

    Darwish, T; Faour, G.

    2008-01-01

    A complex and rugged nature characterizes the Lebanese mountains.The climatic pattern prevailing in the country, deforestation and man made erosion caused increased rangeland degradation. The purpose of this study was to monitor two contrasting watersheds, representing the Lebanese agro-ecological zones, to analyze the vegetation dynamics and trace the state of rangeland degradation. The Kfarselouane (205 km2) and Aarsal (316.7 km2) watersheds are located in the Lebanon and Anti-Lebanon mountain chain and characterized by sub humid and semi-arid climate respectively.Using multitemporal spot vegetation images between 1999 and 2005 to analyze the normalized differential vegetation index (NDVI) revealed some improvement of the vegetation cover over recent years in Kfaselouane with a steady state in Aarsal. The NDVI trend curve inclines in spring and declines in summer and fall. Judging by the time scale amplitude change and highest magnitude between the peak and lower NDVI level in Aarsal, an increased vulnerability to drought is observed in the dry Lebanese areas. Comparing land cover/use in Aarsal area between 1962 and 2000 using aerial photos and large resolution Indian satellite images (IRS) showed wood fragmentation and slight increase of the degenerated forest cover from 1108 ha to 1168 ha. Landuse change was accompanied by a simultaneous increase of cultivated lands (mostly fruit trees) from 932 ha to 4878 ha with absence of soil conservation and water harvesting practices. On the contrary, grasslands decreased from 29581 ha to 25000 ha. In Kfarselouane, the area of grassland was invaded by forestland where rangeland decreased from 8073 ha to 3568 ha and woodland increased from 5766 ha to 11800 ha. Forest expansion occurred even at the account of unproductive land which decreased from 2668 ha to 248 ha, while cultivated lands did not reveal any substantial change. Based on animals' seasonal feeding pattern, a mismatch between land carrying capacity and grazing

  19. WEED CONTROL EFFECTS ON SOIL CHEMICAL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    2008-01-01

    Full Text Available The weed control procedures are known to affect the soil physical attributes and the nutrient amount taken up by weed roots. This work hypothesis is that weed control methods might also affect soil chemical attributes. Four experiments were carried out, three with maize (E-1, E-2 and E-3 and one with cotton (E-4, in randomized complete blocks design arranged in split-plots, with five replications. In E-1 experiment, the plots consisted of two weed control treatments: no-weed control and weed shovel-digging at 20 and 40 days after sowing; and the subplots consisted of six maize cultivars. In the three other experiments, the plots consisted of plant cultivars: four maize cultivars (E-2 and E-3 and four cotton cultivars (E-4. And, the subplots consisted of three weed control treatments: (1 no-weed control; (2 weed shovel-digging at 20 and 40 days after sowing; and (3 intercropping with cowpea (E-2 or Gliricidia sepium (Jacq. Walp. (E-3 and E-4. In all experiments, after harvest, eight soil samples were collected from each subplot (0-20 cm depth and composed in one sample. Soil chemical analysis results indicated that the weed control by shovel-digging or intercropping may increase or decrease some soil element concentrations and the alterations depend on the element and experiment considered. In E-2, the weed shovel-dug plots showed intermediate soil pH, lower S (sum of bases values and higher soil P concentrations than the other plots. In E-4, soil K and Na concentrations in plots without weed control did not differ from plots with intercropping, and in both, K and Na values were higher than in weed shovel-dug plots. Maize and cotton cultivars did not affect soil chemical characteristics.

  20. Restoring Degraded Rangelands in Jordan: Optimizing Mechanized Micro-Water Harvesting Technique Using Rangeland Hydrology and Erosion Model (RHEM)

    Science.gov (United States)

    Continuous population growth, recent refugee movement and migration as well as boundary restrictions and their implications on the nomadic lifestyle are additive pressure on rangelands throughout the Middle East. In particular, overgrazing through increased livestock herds threatens the Jordanian ra...

  1. Principles of optimizing animal production from rangeland

    International Nuclear Information System (INIS)

    Stubbendieck, J.; Waller, S.S.

    1983-01-01

    Increasing world population is one of the dominant factors escalating demands for the world's natural resources. Range and forage resources, which are used primarily for food and fibre, could be more efficiently used if management techniques were improved. The principles of managing forage resources are directly associated with both the growth and development of plants and the actions and needs of the grazing animal. An understanding of the effects of environmental factors and herbage removal (frequency, intensity and season of defoliation) on growth and regrowth of plants is the first step towards optimizing animal productivity from rangelands. Most potential changes will fit into three categories: (1) increase the quantity of forage, (2) improve the quality of forage, and (3) improve use of forage. The principles of grazing management can be separated into four intricately related categories: (1) proper degree of grazing, (2) proper season of grazing, (3) proper kind of livestock, and (4) proper distribution of grazing. Grazing management is affected by the manner in which both improvements and manipulation of vegetation affect forage yield and quality. The adaptation and application of existing knowledge to individual locations will be one step towards optimizing animal production from rangeland. Some of the problems may be solved through better dissemination of present knowledge through existing educational programmes, while others will require expanded programmes of information dissemination. A third group of problems may also be solved with present technology, but the solutions are not currently economical. Some of the problems will be solved only through expanded research. These research efforts need to be directed towards grazing or browsing animals, plant resources and the interaction between plants and animals. Application of nuclear techniques will be an integral part of this research. (author)

  2. Precise tillage systems for enhanced non-chemical weed management

    NARCIS (Netherlands)

    Kurstjens, D.A.G.

    2007-01-01

    Soil and residue manipulation can assist weed management by killing weeds mechanically, interfering in weed lifecycles, facilitating operations and enhancing crop establishment and growth. Current tillage systems often compromise these functions, resulting in heavy reliance on herbicides,

  3. About the value of species diversity in arable weeds for weed management

    Directory of Open Access Journals (Sweden)

    Gerowitt, Bärbel

    2016-02-01

    Full Text Available Arable weeds accompany arable land use – we define them based on their affiliation to ar able systems. They are adapted to such a degree that most of them cannot exist without arable land use. Weeds are part of the total biodiversity on arable fields, as primary producers they are basic for important functions within the ecosystem. This paper elaborates the relevance of species diversity in arable weeds for their management. Arable systems can be regarded for the number of different methods for preventive and direct weed control which are realized. Historical arable land use is roughly divided into three periods, which differ concerning the diversity of weed management and the occurring diversity in weed species. Obviously divers weed management in arable systems and diversity in weed species depend on each other, this is illustrated with a simple abstract picture. Arable systems, which are characterised by simpleness, favor the domination of few species which ensure an effective use of the resources within the ecosystem. One consequence under continuous pressure of an overused tool in weed management is that the genetic diversity within a dominating weed population is exploited to ensure this resource use. Current herbicides represent this tool – the results are herbicide resistant biotypes within the weed populations. Species diversity in arable weeds as a rationale within arable production can assist to prevent this development.

  4. Combining a weed traits database with a population dynamics model predicts shifts in weed communities

    DEFF Research Database (Denmark)

    Storkey, Jonathan; Holst, Niels; Bøjer, Ole Mission

    2015-01-01

    A functional approach to predicting shifts in weed floras in response to management or environmental change requires the combination of data on weed traits with analytical frameworks that capture the filtering effect of selection pressures on traits. A weed traits database (WTDB) was designed, po...

  5. Effect of Weed Management on Weeds and Grain Yield of Haricot ...

    African Journals Online (AJOL)

    Weeds are one of the major constraints limiting haricot bean productivity and production. Field experiments were conducted on the effect of weed managements on weeds and grain yield of haricot bean (Phaseolus Vulgaris L.) at Melkassa Agricultural Research Center from 2011 - 2013. The objective was to determine the ...

  6. Weeds of onion fields and effects of some herbicides on weeds in ...

    African Journals Online (AJOL)

    Weeds are one of the most important problems in onion (Allium cepa L.) production areas, since onion plants are poor competitors. This study was conducted in order to identify the weed species in onion fields in Cukurova Region, establish the effects of some herbicides on weeds and the yield of onion in reducing the ...

  7. Effect of weed management on weeds and grain yield of haricot bean

    African Journals Online (AJOL)

    Weeds are one of the major constraints limiting haricot bean productivity and production. Field experiments were conducted on the effect of weed managements on weeds and grain yield of haricot bean (Phaseolus Vulgaris L.) at Melkassa Agricultural Research Center from 2011 - 2013. The objective was to determine the ...

  8. Linking Farmer Weed Management Behavior with Weed Pressure: More than Just Technology

    NARCIS (Netherlands)

    Riemens, M.M.; Groeneveld, R.M.W.; Kropff, M.J.; Lotz, L.A.P.; Renes, R.J.; Sukkel, W.; Weide, van der R.Y.

    2010-01-01

    Most studies on weed population dynamics in farming systems have focused on the effects of different weed control strategies. Those studies usually assume that farmers, operating within a particular system, have a uniform management style. However, it is likely that weed management decision making

  9. 1-14 Effect of Plant Spacing and Weeding Frequency on Weed ...

    African Journals Online (AJOL)

    user

    2College of Agriculture and Environmental Sciences, Haramaya University, ... pod, hundred seed weight, grain yield, aboveground dry biomass, and ... an infestation by weeds and the performance of crop ... frequencies affect weed management in common bean .... including broad-leaved, sedge and grass weeds (Table.

  10. Effect of stale seedbed preparations and subsequent weed control in lettuce (cv. Iceboll) on weed densities

    NARCIS (Netherlands)

    Riemens, M.M.; Weide, van der R.Y.; Bleeker, P.O.; Lotz, L.A.P.

    2007-01-01

    The effects of stale seedbed preparations and several weed control methods on the emergence of weeds in lettuce were studied. The specific goal was to evaluate the use of a stale seedbed in combination with chemical or mechanical weed control methods in the field. Depending on location and year,

  11. A STUDY ON WEED CONTROL IN SOYBEAN

    Directory of Open Access Journals (Sweden)

    S. TJITROSEMITO

    1991-01-01

    Full Text Available Two field experiments on weed control in soybeans were carried out at BIOTROP, Bogor, Indonesia from February to June, 1989. The critical period for weed control was found to be between 20 - 40 days after planting of soybean (c. v. Wilis grown at a planting distance of 40 x 10 cm. It did not coincide with the fastest growth in terms of trifoliate leaf number. Further studies were suggested to understand the physiological growth of soybean related to weed control. Pendimethalin at 660- 1320 g a.e./ha applied one day after sowing did not cause any phytotoxic effect to soybean and had good weed control performance.

  12. Very High Resolution Panoramic Photography to Improve Conventional Rangeland Monitoring 1994

    Science.gov (United States)

    Rangeland monitoring often includes repeat photographs as a basis for documentation and although photographic equipment and electronics have been evolving rapidly, basic rangeland photo monitoring methods have changed little over time. Ground based digital photography is underutilized, especially s...

  13. The effect of sowing strategy, row distance and mechanical weed control on weeds and yield in organic winter wheat

    OpenAIRE

    Rasmussen, Ilse A.

    2002-01-01

    A series of field experiments were carried out in winter wheat grown under organic conditions in Denmark on fields with different weed pressure. The treatments were sowing strategy (normal sowing time, late sowing and false seedbed), row distance (12 cm and 24 cm row distance) and weed control method (untreated, mechanical weed control (weed harrowing at 12 cm supplemented with row hoeing at 24 cm), and herbicide weed control). Weed biomass was largest at the normal sowing time and was reduce...

  14. Ecological weed management by cover cropping : effects on weed growth in autumn and weed establishment in spring

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2008-01-01

    Cover crops grown in the period between two main crops have potential as an important component of a system-oriented ecological weed management strategy. In late summer and autumn, the cover crop can suppress growth and seed production of weeds, whereas the incorporation of cover crop residues in

  15. Weeds in a Changing Climate: Vulnerabilities, Consequences, and Implications for Future Weed Management.

    Science.gov (United States)

    Ramesh, Kulasekaran; Matloob, Amar; Aslam, Farhena; Florentine, Singarayer K; Chauhan, Bhagirath S

    2017-01-01

    Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim that recent changes observed throughout the world within the weed spectrum in different cropping systems which were ostensibly related to climate change, warrant a deeper examination of weed vulnerabilities before a full understanding is reached. For example, the uncontrolled establishment of weeds in crops leads to a mixed population, in terms of C 3 and C 4 pathways, and this poses a considerable level of complexity for weed management. There is a need to include all possible combinations of crops and weeds while studying the impact of climate change on crop-weed competitive interactions, since, from a weed management perspective, C 4 weeds would flourish in the increased temperature scenario and pose serious yield penalties. This is particularly alarming as a majority of the most competitive weeds are C 4 plants. Although CO 2 is considered as a main contributing factor for climate change, a few Australian studies have also predicted differing responses of weed species due to shifts in rainfall patterns. Reduced water availability, due to recurrent and unforeseen droughts, would alter the competitive balance between crops and some weed species, intensifying the crop-weed competition pressure. Although it is recognized that the weed pressure associated with climate change is a significant threat to crop production, either through increased temperatures, rainfall shift, and elevated CO 2 levels, the current knowledge of this effect is very sparse. A few models that have attempted to predict these interactions are discussed in this paper, since these models could play an

  16. Bioherbicides: Current knowledge on weed control mechanism.

    Science.gov (United States)

    Radhakrishnan, Ramalingam; Alqarawi, Abdulaziz A; Abd Allah, Elsayed Fathi

    2018-04-17

    Weed control is a challenging event during crop cultivation. Integrated management, including the application of bioherbicides, is an emerging method for weed control in sustainable agriculture. Plant extracts, allelochemicals and some microbes are utilized as bioherbicides to control weed populations. Bioherbicides based on plants and microbes inhibit the germination and growth of weeds; however,few studies conducted in weed physiology. This review ascribes the current knowledge of the physiological changes in weeds that occur during the exposure to bioherbicides. Plant extracts or metabolites are absorbed by weed seeds, which initiates damage to the cell membrane, DNA, mitosis, amylase activity and other biochemical processes and delays or inhibits seed germination. The growth of weeds is also retarded due to low rates of root-cell division, nutrient uptake, photosynthetic pigment synthesis, and plant growth hormone synthesis, while the productions of reactive oxygen species (ROS) and stress-mediated hormones increase, including irregular antioxidant activity. However, lytic enzymes and toxic substances secreted from microbes degrade the weed seed coat and utilize the endosperm for survival, which inhibits seed germination. The microbes grow through the intercellular spaces to reach the root core, and the deposition of toxins in the cells affects cell division and cellular functions. Some of the metabolites of deleterious microbes cause disease, necrosis and chlorosis,which inhibit the germination and growth of weed seeds by suppressing photosynthesis and gibberellin activities and enhancing ROS, abscisic acid and ethylene. This review explains the effects of bioherbicides (derived from plants and microbes) on weed-plant physiology to elucidate their modes of action. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Step-down vs. step-up noxious stimulation: differential effects on pain perception and patterns of brain activation.

    Science.gov (United States)

    Choi, J C; Kim, J; Kang, E; Choi, J-H; Park, W Y; Choi, Y-S; Cha, J; Han, C; Park, S K; Kim, M H; Lee, G H; Do, H-J; Jung, S W; Lee, J-M

    2016-01-01

    We hypothesize that pain and brain responses are affected by changes in the presentation sequence of noxious stimuli that are, overall, identical in intensity and duration. During functional magnetic resonance imaging (fMRI) scanning, 21 participants experienced three patterns of noxious stimulation: Up-type (step-up noxious stimulation, 15 s), Down-type (step-down noxious stimulation, 15 s), and Down-up-type (decreasing and increasing pattern of noxious stimulation, 15 s). The total intensity and duration of the three noxious stimulation patterns were identical, but the stimulation sequences were different. Pain and unpleasantness ratings in the Down- and Down-up-type noxious stimulations were lower than in the Up-type noxious stimulation. The left prefrontal cortex [(PFC, BA (Brodmann area) 10, (-45, 50, 1)] was more highly activated in the Down- and Down-up-type noxious stimulations than in the Up-type noxious stimulation. The S1, S2, insula, bilateral PFC (BA 46), and midcingulate cortex were more highly activated in the Up-type noxious stimulation than in the Down-type noxious stimulation. PFC BA 10 was located at an inferior level compared to the bilateral PFC BA 46 (Z axis = 1 for BA 10, compared to 22 and 25 for the right and left BA 46, respectively). When cortisol level was increased, the left hippocampal cortex, along with the left parahippocampal cortex, was greatly activated for the Up-type noxious stimulation. When pain cannot be avoided in clinical practice, noxious stimuli should be applied to patients in a step-down pattern that delivers the most intense pain first and the least intense pain last. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  18. Regional Standards for Rangeland Health and Guidelines for Livestock Grazing Management ... A Progress Report

    OpenAIRE

    1996-01-01

    In August 1995, new BLM regulations for rangeland administration went into effect. The new regulations require BLM to establish regional standards for rangeland health and guidelines for grazing management. This publication is a report on the alternatives being considered for the Montana/Dakotas Rangeland Health Standards and Guidelines process.

  19. State-and-transition model archetypes: a global taxonomy of rangeland change

    Science.gov (United States)

    State and transition models (STMs) synthesize science-based and local knowledge to formally represent the dynamics of rangeland and other ecosystems. Mental models or concepts of ecosystem dynamics implicitly underlie all management decisions in rangelands and thus how people influence rangeland sus...

  20. Criterion IV: Social and economic indicators of rangeland sustainability (Chapter 5)

    Science.gov (United States)

    Daniel W. McCollum; Louis E. Swanson; John A. Tanaka; Mark W. Brunson; Aaron J. Harp; L. Allen Torell; H. Theodore Heintz

    2010-01-01

    Social and economic systems provide the context and rationale for rangeland management. Sustaining rangeland ecosystems requires attention to the social and economic conditions that accompany the functioning of those systems. We present and discuss economic and social indicators for rangeland sustainability. A brief conceptual basis for each indicator is offered,...

  1. Ecohydrologic impacts of rangeland fire on runoff and erosion: A literature synthesis

    Science.gov (United States)

    Frederick B. Pierson; C. Jason Williams

    2016-01-01

    Fire can dramatically influence rangeland hydrology and erosion by altering ecohydrologic relationships. This synthesis presents an ecohydrologic perspective on the effects of fire on rangeland runoff and erosion through a review of scientific literature spanning many decades. The objectives are: (1) to introduce rangeland hydrology and erosion concepts necessary for...

  2. Ecologic, Economic, and Social Considerations for Rangeland Sustainability: An Integrated Conceptual Framework

    Science.gov (United States)

    Daniel W. McCollum; H. Theodore Jr. Heintz; Aaron J. Harp; John A. Tanaka; Gary R. Evans; David Radloff; Louis E. Swanson; William E. III Fox; Michael G. Sherm Karl; John E. Mitchell

    2006-01-01

    Use and sustainability of rangelands are inherently linked to the health and sustainability of the land. They are also inherently linked to the social and economic infrastructures that complement and support those rangelands and rangeland uses. Ecological systems and processes provide the biological interactions underlying ecosystem health and viability. Social and...

  3. WEED SURVEYING OF PHACELIA (PHACELIA TANACETIFOLIA L.) AND EVALUATING THE EFFICIENCY OF THE WEED CONTROL.

    Science.gov (United States)

    Horváth, E; Szabó, R

    2014-01-01

    The experiment was set up in an area of 9 ha that was split into 4 plots: in plot 1 the row spacing was 12 cm and the seeding rate was 10 kg; in plot 2 the row spacing was 24 cm and the seeding rate was 10 kg; in plot 3 the row spacing was 24 cm and the seeding rate was 8 kg; in plot 4 the row spacing was 12 cm and the seeding rate was 8 kg. After the weed surveying, the total weed coverage was established as follows: in plot 1 the total weed coverage was 11.34%, in plot 2 it was 12.3%, in plot 3 it was 18%, and in plot 4 the total weed coverage was 15%. Based on the weed survey, on the test area the following dicotyledon weeds belonging to the T4 Raunkiaer plant life-form category occupied the highest percentage: heal-all, black-bindweed, goosefoot. The proportion of the perennial dicotyledons: field bindweed (G3), tuberous pea (G1), white campion (H3) was negligible. In all four cases the weed control was executed using the same herbicide in the same doses and with regard to the weed species it showed the same level of efficiency. The smaller row spacing and higher seeding rate has a beneficial effect on the weed suppressing capacity of the crop, the crop's weed suppressing capacity is better and the development of the weeds becomes worse.

  4. Parthenium weed (Parthenium hysterophorus L.) and climate change: the effect of CO2 concentration, temperature, and water deficit on growth and reproduction of two biotypes.

    Science.gov (United States)

    Nguyen, Thi; Bajwa, Ali Ahsan; Navie, Sheldon; O'Donnell, Chris; Adkins, Steve

    2017-04-01

    Climate change will have a considerable impact upon the processes that moderate weed invasion, in particular to that of parthenium weed (Parthenium hysterophorus L.). This study evaluated the performance of two Australian biotypes of parthenium weed under a range of environmental conditions including soil moisture (100 and 50% of field capacity), atmospheric carbon dioxide (CO 2 ) concentration (390 and 550 ppm), and temperature (35/20 and 30/15 °C/day/night). Measurements were taken upon growth, reproductive output, seed biology (fill, viability and dormancy) and soil seed longevity. Parthenium weed growth and seed output were significantly increased under the elevated CO 2 concentration (550 ppm) and in the cooler (30/15 °C) and wetter (field capacity) conditions. However, elevated CO 2 concentration could not promote growth or seed output when the plants were grown under the warmer (35/20 °C) and wetter conditions. Warm temperatures accelerated the growth of parthenium weed, producing plants with greater height biomass but with a shorter life span. Warm temperatures also affected the reproductive output by promoting both seed production and fill, and promoting seed longevity. Dryer soil conditions (50% of field capacity) also promoted the reproductive output, but did not retain high seed fill or promote seed longevity. Therefore, the rising temperatures, the increased atmospheric CO 2 concentration and the longer periods of drought predicted under climate change scenarios are likely to substantially enhance the growth and reproductive output of these two Australian parthenium weed biotypes. This may facilitate the further invasion of this noxious weed in tropical and sub-tropical natural and agro-ecosystems.

  5. An autonomous weeding robot for organic farming

    NARCIS (Netherlands)

    Bakker, T.; Asselt, van C.J.; Bontsema, J.; Müller, J.; Straten, van G.

    2006-01-01

    The objective of this research is the replacement of hand weeding in organic farming by a device working autonomously at ¯eld level. The autonomous weeding robot was designed using a structured design approach, giving a good overview of the total design. A vehicle was developed with a diesel engine,

  6. Weeds as important vegetables for farmers

    NARCIS (Netherlands)

    Cruz Garcia, G.S.; Price, L.L.

    2012-01-01

    The objective of this study was to investigate the multiple uses and cognitive importance of edible weeds in Northeast Thailand. Research methods included focus group discussions and freelistings. A total of 43 weeds consumed as vegetable were reported, including economic, naturalized, agricultural

  7. Weed management strategies for castor bean crops

    Directory of Open Access Journals (Sweden)

    Augusto Guerreiro Fontoura Costa

    2014-04-01

    Full Text Available Castor bean crops are agriculturally relevant due to the quality and versatility of their oil, both for the chemical industry and for biodiesel production. Proper weed management is important for both the cultivation and the yield of castor bean crops; therefore, the intention of the present work is to review pertinent information regarding weed management, including the studies regarding weed interference periods, chemical controls for use in different crop production systems and herbicide selectivity, for castor bean crops. Weed science research for castor bean crops is scarce. One of the main weed management challenges for castor bean crops is the absence of herbicides registered with the Ministry of Agriculture, Livestock and Food Supply (MALFS. Research for viable herbicides for weed control in castor bean crops should be directed by research and/or rural extension institutions, associations and farmers cooperatives, as well as by manufactures, for the registration of these selective herbicides, which would be primarily used to control eudicotyledons in castor bean crops. New studies involving the integration of weed control methods in castor bean also may increase the efficiency of weed management, for both small farmers using traditional crop methods in the Brazilian Northeast region, as well as for areas with the potential for large scale production, using conservation tillage systems, such as the no-tillage crop production system.

  8. Effectiveness of weed control methods on pavement

    NARCIS (Netherlands)

    Vermeulen, G.D.; Verwijs, B.R.; Kempenaar, C.

    2007-01-01

    The policy in the Netherlands is to signifiantly reduce the use of herbicides, also on pavements. Existing non-chemical methods to control weeds are much less effective than spot spraying, the usual method at this moment. Therefore, the cost of non-chemical weed management is often estimated to be 4

  9. A comparison of noxious facilities' impacts for home owners versus renters

    International Nuclear Information System (INIS)

    Clark, D.E.; Nieves, L.A.

    1995-01-01

    The siting of noxious facilities, such as hazardous waste facilities, is often vigorously opposed by local residents, and thus it is now common for local residents to be compensated for the presence of the facility. One technique that has been employed to implicitly value noxious facilities is the intercity hedonic approach, which examines the wage and land rent premia between cities that result from the presence of the facility. However, most of the focus has been on the behavior of home owners as opposed to renters. Since these two groups of residents vary on numerous dimensions such as marital status, age, sex, and personal mobility, it would not be surprising to find different marginal valuations of local site characteristics. The authors use 1980 Census data to derive separate estimates for owners and renters of the implicit value placed on eight different types of noxious facilities. They find that renters and owners differ in their response to noxious facilities, although the differences are not systematic. Furthermore, the differences between owners and renters are not primarily due to differential mobility or socio-demographic factors. Controlling those factors decreases the differences between renters' and owners' implicit valuations of noxious facilities by less than 10%. Unmeasured differences between the two groups, such as tastes, risk aversion, or commitment to the community, must account for the remaining difference in valuations. These findings suggest that policymakers should separately consider the responses of owners and renters when estimating noxious facility impacts

  10. Risk assessment and implications of common crupina rust disease for biological control

    Science.gov (United States)

    Common crupina is listed as a Federal noxious weed infesting rangelands and pastures in the states of Idaho, Washington, Oregon, and California. Because there is no practical control measure for this plant, and considering its potential to spread extensively at least within the region, an evaluatio...

  11. Effect of Cultural Practices in Night on Weed Density and Weed Dry Matter

    Directory of Open Access Journals (Sweden)

    M.H Rashed Mohasel

    2011-01-01

    Full Text Available Abstract In order to evaluate the response of weed seeds to light, two experiments, at two different locations were conducted at Ferdowsi university of Mashhad in 2009. At the first experiment, field was ploughed in day and night. Weed density was evaluated 70 d after plough, with 1×1 quadrate. At the second experiment, at night treatment, ploughing, potato planting and weeding with cultivator were done at night. Weed sampling was done twice at 43 and 130 days after planting with 1×1 quadrate and weeds were identified and counted. Result showed pigweed (Amaranthus retroflexus L., sowthistle (Sonchus oleraceus L., crabgrass (Digitaria sanguinalis (L. scop, jimsonweed (Datura stramonium L. and mallow (Hibiscus trionum L. did not observed at night plough, in contrast, night plough has no significance influence on common lambsquarters (Chenopodium album L., and black nightshade (Solanum nigrum L.. Only common lambsquarters had similar appearance in two treatments, indicating insusceptibility of this weed to time of plough. Interestingly, at the second experiment, result was very similar. Potato yield was higher at night treatment, but not significant. This research showed that some cultural practice like plough, planting and weeding with cultivator in night can reduce weed density and weed dry matter. Keywords: Germination, Time of plough, Sustainable weeds management, Light

  12. EVALUATION AND MAPPING OF RANGELANDS DEGRADATION USING REMOTELY SENSED DATA

    Directory of Open Access Journals (Sweden)

    Majid Ajorlo

    2005-05-01

    Full Text Available The empirical and scientifically documents prove that misuse of natural resource causes degradation in it. So natural resources conservation is important in approaching sustainable development aims. In current study, Landsat Thematic Mapper images and grazing gradient method have been used to map the extent and degree of rangeland degradation. In during ground-based data measuring, factors such as vegetation cover, litter, plant diversity, bare soil, and stone & gravels were estimated as biophysical indicators of degradation. The next stage, after geometric correction and doing some necessary pre-processing practices on the study area’s images; the best and suitable vegetation index has been selected to map rangeland degradation among the Normalized Difference Vegetation Index (NDVI, Soil Adjusted Vegetation Index (SAVI, and Perpendicular Vegetation Index (PVI. Then using suitable vegetation index and distance parameter was produced the rangelands degradation map. The results of ground-based data analysis reveal that there is a significant relation between increasing distance from critical points and plant diversity and also percentage of litter. Also there is significant relation between vegetation cover percent and distance from village, i.e. the vegetation cover percent increases by increasing distance from villages, while it wasn’t the same around the stock watering points. The result of analysis about bare soil and distance from critical point was the same to vegetation cover changes manner. Also there wasn’t significant relation between stones & gravels index and distance from critical points. The results of image processing show that, NDVI appears to be sensitive to vegetation changes along the grazing gradient and it can be suitable vegetation index to map rangeland degradation. The degradation map shows that there is high degradation around the critical points. These areas need urgent attention for soil conservation. Generally, it

  13. Climate impacts on agriculture: Implications for forage and rangeland production

    Energy Technology Data Exchange (ETDEWEB)

    Izaurralde, Roberto C.; Thomson, Allison M.; Morgan, Jack; Fay, Philip; Polley, Wayne; Hatfield, Jerry L.

    2011-04-19

    Projections of temperature and precipitation patterns across the United States during the next 50 years anticipate a 1.5 to 2°C warming and a slight increase in precipitation as a result of global climate change. There have been relatively few studies of climate change impacts on pasture and rangeland (grazingland) species compared to those on crop species, despite the economic and ecological importance of the former. Here we review the literature on pastureland and rangeland species to rising CO2 and climate change (temperature, and precipitation) and discuss plant and management factors likely to influence pastureland and rangeland responses to change (e.g., community composition, plant competition, perennial growth habit, seasonal productivity, and management methods). Overall, the response of pasture species to increased [CO2] is consistent with the general response of C3 and C4 type vegetation, although significant exceptions exist. Both pastureland and rangeland species should exhibit an acceleration of metabolism and development due to earlier onset of spring green-up and longer growing seasons. However, in the studies reviewed here, C3 pasture species increased their photosynthetic rates by up to 40% while C4 species exhibited no increase in photosynthesis. In general, it is expected that increases in [CO2] and precipitation would enhance rangeland net primary production (NPP) while increased air temperatures would either increase or decrease NPP. Much of this uncertainty in response is due to uncertain future projections of precipitation, both globally and regionally. For example, if annual precipitation changes little or declines, rangeland plant response to warming temperatures and rising [CO2] may be neutral or may decline due to increased water stress. This review reveals the need for comprehensive studies of climate change impacts on the pasture ecosystem including grazing regimes, mutualistic relationships (e.g., plant roots-nematodes; N

  14. The changing role of agriculture and tomorrow's weed research agenda

    NARCIS (Netherlands)

    Kropff, M.J.; Bastiaans, L.; Kempenaar, C.; Weide, van der R.Y.

    2008-01-01

    With the changing position of agriculture in the world the challenges for weed management and weed science are changing as well. In this paper recent developments in weed science with respect to several aspects of weed management are discussed in relation to those changes. Developments in cultural

  15. Seeding method and rate influence on weed suppression in aerobic ...

    African Journals Online (AJOL)

    High weed pressure is amongst the major constraints to the extensive adoption of aerobic rice system as a water-wise technique. Towards developing a sustainable weed management strategy, seeding method and rate may substantially contribute to weed suppression and reduce herbicide use and weeding cost. A trough ...

  16. Influence of cowpea and melon populations on weed infestation and ...

    African Journals Online (AJOL)

    Small farmers in the humid regions of tropical Africa spend 30–42% of their total farm labour input in controlling weeds. Chemical weed control is normally recommended but high cost of herbicides and environmental pollution are specific problems with chemical weed control. A three year bio-weed control system with three ...

  17. Adapting weed management in rice to changing climates

    NARCIS (Netherlands)

    Rodenburg, J.; Meinke, H.B.

    2011-01-01

    This paper provides some of the scientific background on how projected environmental conditions could affect weeds and weed management in rice in Africa. Elevated CO2 levels may have positive effects on rice competitiveness with C4 weeds, but these are generally outnumbered by C3 species in weed

  18. Weed Garden: An Effective Tool for Extension Education

    Science.gov (United States)

    Beck, Leslie; Patton, Aaron J.

    2015-01-01

    A weed garden was constructed to quantify and improve identification skills among clientele. The garden was planted with over 100 weed species based on surveys on problematic weeds. The weed garden proved useful for introducing additional hands-on learning activities into traditional lecture-based seminars. Through seminar and field day attendee…

  19. Soil solarization for weed control in carrot

    Directory of Open Access Journals (Sweden)

    MARENCO RICARDO ANTONIO

    2000-01-01

    Full Text Available Soil solarization is a technique used for weed and plant disease control in regions with high levels of solar radiation. The effect of solarization (0, 3, 6, and 9 weeks upon weed populations, carrot (Daucus carota L. cv. Brasília yield and nematode infestation in carrot roots was studied in São Luís (2º35' S; 44º10' W, MA, Brazil, using transparent polyethylene films (100 and 150 mm of thickness. The maximum temperature at 5 cm of depth was about 10ºC warmer in solarized soil than in control plots. In the study 20 weed types were recorded. Solarization reduced weed biomass and density in about 50% of weed species, including Cyperus spp., Chamaecrista nictans var. paraguariensis (Chod & Hassl. Irwin & Barneby, Marsypianthes chamaedrys (Vahl O. Kuntze, Mitracarpus sp., Mollugo verticillata L., Sebastiania corniculata M. Arg., and Spigelia anthelmia L. Approximately 40% of species in the weed flora were not affected by soil mulching. Furthermore, seed germination of Commelina benghalensis L. was increased by soil solarization. Marketable yield of carrots was greater in solarized soil than in the unsolarized one. It was concluded that solarization for nine weeks increases carrot yield and is effective for controlling more than half of the weed species recorded. Mulching was not effective for controlling root-knot nematodes in carrot.

  20. Biological weed control with soil fungi? Antagonistic effects of arbuscular mycorrhizal fungi on the growth of weeds

    NARCIS (Netherlands)

    Veiga, R.

    2012-01-01

    Excessive weed growth represents one of the major threats to crop production especially when reliance on herbicides is reduced. Biological weed control is an alternative, environmentally-sound method that, combined with other weed control practices, can contribute to an effective weed management in

  1. Weed suppression ability of spring barley varieties

    DEFF Research Database (Denmark)

    Christensen, Svend

    1995-01-01

    , Grit. Ranking varietal responses to weed competition in terms of grain yield loss corresponded well to ranking weed dry matter produced in crop weed mixtures. There was no correspondence between the varietal grain yields in pure stands and their competitiveness, suggesting that breeding to optimize...... both yielding and competitive ability may be possible. Non-linear regression models were fitted to canopy height and light interception data for each variety in all three years. The canopy height model provided a precise description of development and maximum canopy height of the varieties. A light...

  2. Weeds in Organic Fertility-Building Leys: Aspects of Species Richness and Weed Management

    Directory of Open Access Journals (Sweden)

    Thomas F. Döring

    2017-02-01

    Full Text Available Legume-based leys (perennial sod crops are an important component of fertility management in organic rotations in many parts of Europe. Despite their importance, however, relatively little is known about how these leys affect weed communities or how the specific composition of leys may contribute to weed management. To determine whether the choice of plant species in the ley affects weeds, we conducted replicated field trials at six locations in the UK over 24 months, measuring weed cover and biomass in plots sown with monocultures of 12 legume and 4 grass species, and in plots sown with a mixture of 10 legume species and 4 grass species. Additionally, we monitored weed communities in leys on 21 organic farms across the UK either sown with a mixture of the project species or the farmers’ own species mix. In total, 63 weed species were found on the farms, with the annuals Stellaria media, Sonchus arvensis, and Veronica persica being the most frequent species in the first year after establishment of the ley, while Stellaria media and the two perennials Ranunculus repens and Taraxacum officinale dominated the weed spectrum in the second year. Our study shows that organic leys constitute an important element of farm biodiversity. In both replicated and on-farm trials, weed cover and species richness were significantly lower in the second year than in the first, owing to lower presence of annual weeds in year two. In monocultures, meadow pea (Lathyrus pratensis was a poor competitor against weeds, and a significant increase in the proportion of weed biomass was observed over time, due to poor recovery of meadow pea after mowing. For red clover (Trifolium pratense, we observed the lowest proportion of weed biomass in total biomass among the tested legume species. Crop biomass and weed biomass were negatively correlated across species. Residuals from the linear regression between crop biomass and weed biomass indicated that at similar levels of crop

  3. Advances in modeling soil erosion after disturbance on rangelands

    Science.gov (United States)

    Research has been undertaken to develop process based models that predict soil erosion rate after disturbance on rangelands. In these models soil detachment is predicted as a combination of multiple erosion processes, rain splash and thin sheet flow (splash and sheet) detachment and concentrated flo...

  4. Session B1 Management for sustainable use — Rangeland auditing ...

    African Journals Online (AJOL)

    We need to monitor the capacity of healthy rangeland to support a broad suite of ecosystem services for a wide range of stakeholders — in a fair, objective and representative way. ... A hybrid session structure will be utilised: distilling wisdom from relevant posters; formal presentations; and stimulating structured debate.

  5. Rangeland restoration for Hirola, the world's most endangered antelope

    Science.gov (United States)

    Rangeland restoration can improve habitat for threatened species such as the hirola antelope (Beatragus hunteri) that inhabit savannas of eastern Kenya. However, restoration success likely varies across soil types and target restoration species, as well as according to restoration approach. We teste...

  6. A conceptual tool for improving rangeland management decision ...

    African Journals Online (AJOL)

    ... the LLM concept should be seen as a continuous and evolving learning process that will be updated over the long term through decision support to include several other components essential to implement effective and sustainable rangeland management practices by local land users. Keywords: desertification; indicators ...

  7. Yield Response of Mediterranean Rangelands under a Changing Climate

    NARCIS (Netherlands)

    Daliakopoulos, Ioannis N.; Panagea, Ioanna S.; Tsanis, Ioannis K.; Grillakis, Manolis G.; Koutroulis, Aristeidis G.; Hessel, Rudi; Mayor, Angeles G.; Ritsema, Coen J.

    2017-01-01

    Understanding the Mediterranean rangelands degradation trends is a key element of mitigating their vulnerability and enhancing their resilience. Climate change and its inherent effects on mean temperature and the precipitation variability can regulate the magnitude, frequency and duration of

  8. Runoff and soil erosion from two rangeland sites

    Science.gov (United States)

    Historically over 50 years of rainfall/runoff research using rainfall simulators has been conducted at various rangeland sites in the West, however these sites rarely have consecutive yearly measurements. This limits the understanding of dynamic annual conditions and the interactions of grazing, pla...

  9. Session B1 Management for sustainable use — Rangeland auditing ...

    African Journals Online (AJOL)

    Social, economic and cultural needs, values and expectations will be examined together with the biophysical technologies and approaches which underlie auditing in rangeland science. Adaptive frameworks which enhance sustainable strategic responses, and the state of art in scale dilemmas will be addressed. A hybrid ...

  10. Presidential address - 1999 Towards a national rangeland policy ...

    African Journals Online (AJOL)

    There are some problems with the publication of the journal, but Council hopes to have our ... The first is that all agencies funded through DACST will be reviewed ... to improve our understanding of management issues in communal rangeland. ... All current programmes to rehabilitate degraded land contain budgets for the ...

  11. Ecology and Conservation of Acacia senegal in the Rangelands ...

    African Journals Online (AJOL)

    Ecology and Conservation of Acacia senegal in the Rangelands ofLuwero and Nakasongola Districts. Jacob Godfrey Agea, Joseph Obua, Sara Namirembe, Mukadasi Buyinza, Daniel Waiswa. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  12. Agroforestry potential of Acacia senegal in the rangelands of luwero ...

    African Journals Online (AJOL)

    Agroforestry potential of Acacia senegal in the rangelands of luwero and Nakasongola districts. Jacob Godfrey Agea, Joseph Obua, Sara Namirembe, Mukadasi Buyinza, Daniel Waiswa. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  13. Impact of Rangeland Degradation on Soil Physical, Chemical

    African Journals Online (AJOL)

    major threats to enhance a sustainable pastoral-livestock production in Ethiopia. ... overall negative impact on the soil physical and chemical characteristics, demanding ... chemical properties (Gemedo et al., 2006) as well as the rangeland .... parameters such as life forms (annuals and perennials), plant forms (woody plant,.

  14. A review of climate change effects on terrestrial rangeland birds

    Science.gov (United States)

    D. M. Finch; K. E. Bagne; M. M. Friggens; D. M. Smith; K. M. Brodhead

    2011-01-01

    We evaluated existing literature on predicted and known climate change effects on terrestrial rangeland birds. We asked the following questions: 1) How does climate change affect birds? 2) How will birds respond to climate change? 3) Are species already responding? 4) How will habitats be impacted?

  15. The challenge of integrated rangeland monitoring: synthesis address

    African Journals Online (AJOL)

    The utility of monitoring and its guiding principles will only work effectively where good environmental governance is practiced by users and producers affecting rangeland ecosystems. Keywords: adaptive management, complex, environmental governance, human impacts, multi-scale, socio-ecological. African Journal of ...

  16. Ranch business planning and resource monitoring for rangeland sustainability

    Science.gov (United States)

    Kristie A. Maczko; John A. Tanaka; Michael Smith; Cindy Garretson-Weibel; Stanley F. Hamilton; John E. Mitchell; Gene Fults; Charles Stanley; Dick Loper; Larry D. Bryant; J. K. (Rooter) Brite

    2012-01-01

    Aligning a rancher's business plan goals with the capability of the ranch's rangeland resources improves the viability and sustainability of family ranches. Strategically monitoring the condition of soil, water, vegetation, wildlife, livestock production, and economics helps inform business plan goals. Business planning and resource monitoring help keep...

  17. Determining termite diversity in arid Namibian rangelands – a ...

    African Journals Online (AJOL)

    Three methods of sampling termite diversity in arid rangelands were tested in Namibia during the wet (March) and dry (October) seasons of 1998. Six sites were chosen: one pair on each of three farms representing a gradient of land use intensity. At each site, two adjacent plots of 1 ha each were sampled: one plot by a ...

  18. Session A6 Rangelands as dynamic systems — Fragmentation of ...

    African Journals Online (AJOL)

    Biological complexity in rangelands arises from spatially-linked ecological states and processes. Herbivores, humans and other agents integrate distinct spatial units into complex systems by moving among and exploiting these units. Spatial heterogeneity plays a central role in the structure and function of grazed ...

  19. Parameterization of erodibility in the Rangeland Hydrology and Erosion Model

    Science.gov (United States)

    The magnitude of erosion from a hillslope is governed by the availability of sediment and connectivity of runoff and erosion processes. For undisturbed rangelands, sediment is primarily detached and transported by rainsplash and sheetflow (splash-sheet) processes in isolated bare batches, but sedime...

  20. Ecology and utilization of desert shrub rangelands in Iraq

    NARCIS (Netherlands)

    Thalen, Derk Catharinus Peter

    1979-01-01

    When grazing is the accepted land use, vegetation is the key resource. The present study deals with the desert shrub rangelands of lraq, which contain the major characteristics of such an area, having been under grazing for many centuries. Emphasis is given to the ecology and utilization of the

  1. Vulnerability of amphibians to climate change: implications for rangeland management

    Science.gov (United States)

    Karen E. Bagne; Deborah M. Finch; Megan M. Friggens

    2011-01-01

    Many amphibian populations have declined drastically in recent years due to a large number of factors including the emerging threat of climate change (Wake 2007). Rangelands provide important habitat for amphibians. In addition to natural wetlands, stock tanks and other artificial water catchments provide habitat for many amphibian species (Euliss et al. 2004).

  2. Exploring the invasion of rangelands by Acacia mearnsii (black ...

    African Journals Online (AJOL)

    Reducing A. mearnsii canopy could promote grass production while encouraging carbon sequestration. Given the high AGB and clearing costs, it may be prudent to adopt the 'novel ecosystems' approach in managing infested landscapes. Keywords: grassland, invasive plants, landscape ecology, rangeland condition ...

  3. Rangeland Ecosystem Services: Nature's Supply and Humans' Demand

    Science.gov (United States)

    Ecosystem services are the benefits that society receives from nature and they include the regulation of climate, the pollination of crops, the provisioning of intellectual inspiration and recreational environment, as well as many essential goods such as food, fiber, and wood. Rangeland ecosystem se...

  4. Opportunities for biological weed control in Europe

    NARCIS (Netherlands)

    Scheepens, P.C.; Müller-Schärer, H.; Kempenaar, C.

    2001-01-01

    The development and application of biological weed control offer greatopportunities not only for farmers, nature conservationists and othervegetation managers but also for institutions and companies that wish tosell plant protection services and products, and for the general publicthat demands safe

  5. Bioenergy potential of eight common aquatic weeds

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, S.A.; Nipaney, P.C.; Schaumberg, G.D. (Pondicherry (Central) Univ. (IN). Salim Ali School of Ecology)

    1990-01-01

    Eight common aquatic weeds Salvinia molesta, Hydrilla verticillata, Nymphaea stellata, Azolla pinnata, Ceratopteris sp. Scirpus sp. Cyperus sp, and Utricularia reticulata were digested anaerobically to produce methane. The carbon to nitrogen (C/N) ratio, carbon to phosphorus (C/P) ratio, and the volatile solids (VS) content of the weeds varied widely. No trend between these factors and the methane yield was discernable; the possible reasons are discussed. The energy potential of the weeds per unit area of the weed crop was worked out. Natural stands of salvinia, such as the one employed in the present investigation, would yield energy (methane) of the order of 10{sup 8} Kcal/ha/yr. (author).

  6. Alien species in the Finnish weed flora

    Directory of Open Access Journals (Sweden)

    T. HYVÖNEN

    2008-12-01

    Full Text Available The present study aimed at assessing the invasion of alien weed species in Finland based on a review of their occurrence in the Finnish weed flora. The evaluation was conducted for the three phases of the invasion process, i.e. introduction, naturalization and invasion. The literature review revealed that 815 alien weed species occur in Finland of which 314 are regarded as naturalized. Based on their occurrence in different climate zones, the risk of naturalization of new harmful alien weed species was deemed low for those species not currently found in Finland, but higher for species occurring as casual aliens in Finland. In the latter group, 10 species of concern were detected. Exploration of the distribution patterns of naturalized species within Finland revealed species occupancy to be dependent on the residence time of the species. Established neophytes can be expected to extend their ranges and to increase occupation of agricultural habitats in the future.;

  7. WHITE BLISTER SPECIES (Albuginaceae ON WEEDS

    Directory of Open Access Journals (Sweden)

    Karolina Vrandečić

    2011-06-01

    Full Text Available The obligate fungi inside the family Albuginaceae are widespread world wide and cause white rust or white blister disease. Mycopopulation of weeds has been researched within the project „The role of weeds in epidemiology of row-crop diseases“. The aim of this research was to identify white blister species occurring on weeds in Eastern Croatia. Weed plants with disease symptoms characteristic for white blister species have been collected since 2001 on location Slavonia and Baranja country. Determination of white blister species was based on morphological characters of pathogen and the host. Wilsoniana bliti was determined on Amaranthus retroflexus and Amaranthus hybridus leaves. Capsella bursa pastoris is a host for Albugo candida. Ambrosia artemisiifolia is a host for Pustula sp. and Cirsium arvense was found to be host for Pustula spinulosa. Wilsoniana portulaceae was determined on Portulaca oleracea.

  8. Impact of fungicides on weed growth

    Directory of Open Access Journals (Sweden)

    Nordmeyer, Henning

    2014-02-01

    Full Text Available The study has shown that fungicides influence the growth of weeds. The competition against crops will be substantially reduced. Bioassays in a climate chamber variation in temperature as well as different lightning phases and microplot trials under semi field levels were carried out to investigate the influence of fungicides on weed growth. Selected weed species (Alopecurus myosuroides, Viola arvensis, Galium aparine, Stellaria media, Lamium purpureum have been examined with different dose rates of fungicides (Adexar, Bravo 500, Diamant, Crupozin flüssig. Weed species showed a different sensitivity. There were leaf discoloration, contractions and growth inhibition. In some cases using common practise dose rates of fungicides more than 70% growth inhibition could be estimated 14 days after application in comparison to the untreated control. Effects were much stronger in bioassays than in semi field trials.

  9. Viruses in weeds in Dioscorea yam

    African Journals Online (AJOL)

    ACSS

    East, Central and Southern Africa (FAOSTAT,. 2009) ... This study was conducted in the Guinea Savanna zone, which is the ... Weed hosts of yam viruses in the wet season of 2009 in northern Nigeria .... be due to differences in the surrounding.

  10. The economic impacts of noxious facilities on wages and property values: An exploratory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Hemphill, R.C.; Clark, D.E.

    1991-05-01

    Recent assessments of socioeconomic impacts resulting from the location of potentially hazardous facilities have concentrated on the issue of negative public perceptions and their resulting economic consequences. This report presents an analysis designed to answer the question: Can economic impacts resulting from negative perceptions of noxious facilities'' be identified and measured To identify the impacts of negative perceptions, data on noxious facilities sited throughout the United States were compiled, and secondary economic and demographic data sufficient to analyze the economic impacts on the surrounding study areas were assembled. This study uses wage rate and property value differentials to measure impacts on social welfare so that the extent to which noxious facilities and their associated activities have affected surrounding areas can be determined.

  11. The economic impacts of noxious facilities on wages and property values: An exploratory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Hemphill, R.C.; Clark, D.E.

    1991-05-01

    Recent assessments of socioeconomic impacts resulting from the location of potentially hazardous facilities have concentrated on the issue of negative public perceptions and their resulting economic consequences. This report presents an analysis designed to answer the question: Can economic impacts resulting from negative perceptions of ``noxious facilities`` be identified and measured? To identify the impacts of negative perceptions, data on noxious facilities sited throughout the United States were compiled, and secondary economic and demographic data sufficient to analyze the economic impacts on the surrounding study areas were assembled. This study uses wage rate and property value differentials to measure impacts on social welfare so that the extent to which noxious facilities and their associated activities have affected surrounding areas can be determined.

  12. Crop diversity prevents serious weed problems

    DEFF Research Database (Denmark)

    Melander, Bo

    2016-01-01

    Weed management in organic crop production could benefit from more diversification of today’s cropping systems. However, the potential of diversification needs better documentation and solid suggestions for employment in practise must be identified.......Weed management in organic crop production could benefit from more diversification of today’s cropping systems. However, the potential of diversification needs better documentation and solid suggestions for employment in practise must be identified....

  13. Vegetation restoration on degraded rangelands through the use of microcatchment and brush packs in the communal areas of the Eastern Cape

    CSIR Research Space (South Africa)

    Lesoli, MS

    2010-07-01

    Full Text Available Rangeland degradation results in declining functional capacity, increased poverty, and food insecurity. Major changes in rangeland surface morphology and soil characteristics have a drastic effect on the primary productivity of the rangeland...

  14. WEED MANAGEMENT AND CONTROL IN POTATOES

    Directory of Open Access Journals (Sweden)

    Marcelo Cleón de Castro Silva

    2011-07-01

    Full Text Available This review shows instructions to potatoes' farmer about behavior of the weeds and how to manage them so as to minimize loss of productivity through the use of control strategies for potato crop. The prevention consists in adoption of practices that prevents entry of unwanted species of weeds in the planting site. The control reduces the infestation of these species, but this practice does not eradicate them completely. However, it needs to control the weeds before the area preparation for planting the tubers until complete closure of the soil by shoots of potatoes during the critical period. After covering the soil, the potato crop does not suffer negative interference caused by weeds. The cultural practices include a good plane for harvest, plant crop rotation, the planting of appropriate plants for covering the soil, the ideal space to the planting and the correct time to potato planting. The control must be efficient to reduce the number of weeds in the area to avoid economic losses to farmers. It is necessary to establish weed management strategies in order to maintain sustainable farming systems, preserving the environment and quality of life of the farmer.

  15. Weed detection using unmanned aircraft vehicles

    Directory of Open Access Journals (Sweden)

    Pflanz, Michael

    2014-03-01

    Full Text Available In contrast to agricultural remote sensing technologies, which are based on images from satellites or manned aircrafts, photogrammetry at low altitude from unmanned aircraft vehicles lead to higher spatial resolution, real-time processing and lower costs. Moreover multicopter aircrafts are suitable vehicles to perform precise path or stationary flights. In terms of vegetation photogrammetry this minimises motion blur and provide better image overlapping for stitching and mapping procedures. Through improved image analyses and through the recent increase in the availability of powerful batteries, microcontrollers and multispectral cameras, it can be expected in future that spatial mapping of weeds from low altitudes will be promoted. A small unmanned aircraft vehicle with a modified RGB camera was tested taking images from agricultural fields. A microcopter with six rotors was applied. The hexacopter in particular is GPS controlled and operates within predefined areas at given altitudes (from 5 to 10 m. Different scenarios of photogrammetrically weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. First experiences with microcopter showed a high potential for site-specific weed control. Images analyses with regards to recognition of weed patches can be used to adapt herbicide applications to varying weed occurrence across a field.

  16. Livestock-rangeland management practices and community perceptions towards rangeland degradation in South Omo zone of Southern Ethiopia

    NARCIS (Netherlands)

    Admasu, T.; Abule, E.; Tessema, Z.K.

    2010-01-01

    A survey was conducted in Hamer and Benna-Tsemay districts of the South Omo zone of Ethiopia, with the objectives of assessing the range-livestock management practices and perceptions of the different pastoral groups (Hamer, Benna, and Tsemay) towards rangeland degradation. This information is

  17. Chemical weed control in Spinach (Spiniacia oleracea

    Directory of Open Access Journals (Sweden)

    A. Modhej

    2016-03-01

    Full Text Available Introduction Spinach (Spinacia oleracea is an annual plant of family Chenopodiaceae. It is cultivated in temperate and cold regions in Khouzestan in autumn and winter. Weeds are the main problems that limit the production of vegetables. Competition ability of spinach against weeds is very low and weeds cause the loss of quality and quantity in this plant. Weeds reduce germination and establishment and growth of spinach. Weed management in spinach should be done at the beginning of the season. Hand weeding is the best way to control weeds spinach, although due to the high cost it is not cost effective, but is steel common in large areas. Weed control spinach, using chemical methods, the number of weeds are kept below the threshold of economic damage. Materials and Methods The experiment was conducted in a randomized complete block design with 15 treatments and three replications. Treatments included pre-plant application of EPTC at 5 and 6 lit ha-1, pre-plant application of Trifluralin at 2 lit ha-1, pre-plant and pre-emergence application of Pendimethalin at 3 lit ha-1, pre-emergence and post-emergence application of Meteribouzin at 300 g ha-1, pre-emergence and post-emergence application of Meteribouzin at 400 g ha-1, pre-emergence and post-emergence application of Imazethapyr at 0.7 lit ha-1, pre-emergence and post-emergence application of Imazethapyr at 1 lit ha-1, weedy and weed free checks. Each plot the size of 2.5 × 2 meters and 10 row cultivation with distances between rows of 15 cm and the distance between the plants 25 cm and the sowing depth was 3 cm. The herbicide treatments were applied to the back sprayer with Flat fan nozzle with volume of consumption of 240 lit ha-1 solution. The final harvest was about 50 days after emergence. Sampling of weeds 10 days before harvest was performed with using quadrate 0.5 ×0.5. Results Discussion Important broad-leaf and narrow leaf weeds observed in the field, included field bindweed

  18. On weed competition and population dynamics : considerations for crop rotations & organic farming

    NARCIS (Netherlands)

    Mertens, S.K.

    2002-01-01

    Key words: organic farming, weeds, weed management, weed ecology, weed diversity, matrix population model, elasticity analysis, neighbourhood model, survey, crop row spacing, mechanical hoe, harrow, Polygonum convolvulus ,

  19. Combining a weed traits database with a population dynamics model predicts shifts in weed communities.

    Science.gov (United States)

    Storkey, J; Holst, N; Bøjer, O Q; Bigongiali, F; Bocci, G; Colbach, N; Dorner, Z; Riemens, M M; Sartorato, I; Sønderskov, M; Verschwele, A

    2015-04-01

    A functional approach to predicting shifts in weed floras in response to management or environmental change requires the combination of data on weed traits with analytical frameworks that capture the filtering effect of selection pressures on traits. A weed traits database (WTDB) was designed, populated and analysed, initially using data for 19 common European weeds, to begin to consolidate trait data in a single repository. The initial choice of traits was driven by the requirements of empirical models of weed population dynamics to identify correlations between traits and model parameters. These relationships were used to build a generic model, operating at the level of functional traits, to simulate the impact of increasing herbicide and fertiliser use on virtual weeds along gradients of seed weight and maximum height. The model generated 'fitness contours' (defined as population growth rates) within this trait space in different scenarios, onto which two sets of weed species, defined as common or declining in the UK, were mapped. The effect of increasing inputs on the weed flora was successfully simulated; 77% of common species were predicted to have stable or increasing populations under high fertiliser and herbicide use, in contrast with only 29% of the species that have declined. Future development of the WTDB will aim to increase the number of species covered, incorporate a wider range of traits and analyse intraspecific variability under contrasting management and environments.

  20. Mechanical weed control in organic winter wheat

    Directory of Open Access Journals (Sweden)

    Euro Pannacci

    2017-12-01

    Full Text Available Three field experiments were carried out in organic winter wheat in three consecutive years (exp. 1, 2005-06; exp. 2, 2006- 07; exp. 3, 2007-08 in central Italy (42°57’ N - 12°22’ E, 165 m a.s.l. in order to evaluate the efficacy against weeds and the effects on winter wheat of two main mechanical weed control strategies: i spring tine harrowing used at three different application times (1 passage at T1, 2 passages at the time T1, 1 passage at T1 followed by 1 passage at T1 + 14 days in the crop sowed at narrow (traditional row spacing (0.15 m; and ii split-hoeing and finger-weeder, alone and combined at T1, in the crop sowed at wider row spacing (0.30 m. At the time T1 winter wheat was at tillering and weeds were at the cotyledons-2 true leaves growth stage. The experimental design was a randomized block with four replicates. Six weeks after mechanical treatments, weed ground cover (% was rated visually using the Braun-Blanquet coverabundance scale; weeds on three squares (0.6×0.5 m each one per plot were collected, counted, weighed, dried in oven at 105°C to determine weed density and weed above-ground dry biomass. At harvest, wheat ears density, grain yield, weight of 1000 seeds and hectolitre weight were recorded. Total weed flora was quite different in the three experiments. The main weed species were: Polygonum aviculare L. (exp. 1 and 2, Fallopia convolvulus (L. Á. Löve (exp. 1 and 3, Stachys annua (L. L. (exp. 1, Anagallis arvensis L. (exp. 2, Papaver rhoeas L. (exp.3, Veronica hederifolia L. (exp. 3. In the winter wheat sowed at narrow rows, 2 passages with spring-tine harrowing at the same time seems to be the best option in order to reconcile a good efficacy with the feasibility of treatment. In wider rows spacing the best weed control was obtained by split hoeing alone or combined with finger-weeder. The grain yield, on average 10% higher in narrow rows, the lower costs and the good selectivity of spring-tine harrowing

  1. Developments in physical weed control in Northwest Europe

    Directory of Open Access Journals (Sweden)

    Riemens, Marieen

    2016-02-01

    Full Text Available In North West Europe there is an increasing need for advanced weed control methods. This paper gives an overview of the developments in physical weed control methods. Current innovations in interrow weeding focus on systems that take over the steering function of the driver in order to make them more precise and reduce crop losses. The latest developments in intrarow weeding techniques involve technologies that automatically detect and classify crop and weed plants and use this information to guide a weeding device. Several commercially available examples are presented.

  2. Ecological Intensification Through Pesticide Reduction: Weed Control, Weed Biodiversity and Sustainability in Arable Farming.

    Science.gov (United States)

    Petit, Sandrine; Munier-Jolain, Nicolas; Bretagnolle, Vincent; Bockstaller, Christian; Gaba, Sabrina; Cordeau, Stéphane; Lechenet, Martin; Mézière, Delphine; Colbach, Nathalie

    2015-11-01

    Amongst the biodiversity components of agriculture, weeds are an interesting model for exploring management options relying on the principle of ecological intensification in arable farming. Weeds can cause severe crop yield losses, contribute to farmland functional biodiversity and are strongly associated with the generic issue of pesticide use. In this paper, we address the impacts of herbicide reduction following a causal framework starting with herbicide reduction and triggering changes in (i) the management options required to control weeds, (ii) the weed communities and functions they provide and (iii) the overall performance and sustainability of the implemented land management options. The three components of this framework were analysed in a multidisciplinary project that was conducted on 55 experimental and farmer's fields that included conventional, integrated and organic cropping systems. Our results indicate that the reduction of herbicide use is not antagonistic with crop production, provided that alternative practices are put into place. Herbicide reduction and associated land management modified the composition of in-field weed communities and thus the functions of weeds related to biodiversity and production. Through a long-term simulation of weed communities based on alternative (?) cropping systems, some specific management pathways were identified that delivered high biodiversity gains and limited the negative impacts of weeds on crop production. Finally, the multi-criteria assessment of the environmental, economic and societal sustainability of the 55 systems suggests that integrated weed management systems fared better than their conventional and organic counterparts. These outcomes suggest that sustainable management could possibly be achieved through changes in weed management, along a pathway starting with herbicide reduction.

  3. Weed control in rose-scented geranium (Pelargonium spp).

    Science.gov (United States)

    Kothari, Sushil K; Singh, Chandra P; Singh, Kamla

    2002-12-01

    Abstract: Field investigations were carried out during 1999 and 2000 to identify effective chemical/ cultural methods of weed control in rose-scented geranium (Pelargonium spp). The treatments comprised pre-emergence applications of oxyfluorfen (0.15, 0.20 and 0.25 kg AI ha(-1)) and pendimethalin (0.50, 0.75 and 1.00kg AI ha(-1)), successive hand weeding, hoeing and mulching using spent of lemon grass (at 5 tonnes ha(-1)) 45 days after planting (DAP), three hand-weedings 30, 60 and 90 DAP, weed-free (frequent manual weeding) and weedy control. Broad-leaf weeds were more predominant than grass and sedge weeds, accounting for 85.8% weed density and 93.0% weed dry weight in 1999 and 77.2% weed density and 93.9% weed dry weight in 2000. Unrestricted weed growth significantly reduced geranium oil yield, by 61.6% and 70.6% in 1999 and 2000, respectively. Pre-emergence application of pendimethalin (0.75-1.00 kgAI ha(-1)) or oxyfluorfen (0.25 kg AI ha(-1)), successive hand-weeding, hoeing and mulching and three hand-weedings were highly effective in reducing weed density and dry weight and gave oil yield comparable to the weed-free check. Application of oxyfluorfen (0.15 or 0.20 kg AI ha(-1)) and pendimethalin (0.50 kg AI ha(-1)) were less effective in controlling the weed species in geranium. None of the herbicides impaired the quality of rose-scented geranium oil measured in terms of citronellol and geraniol content.

  4. Noxious heat and scratching decrease histamine-induced itch and skin blood flow.

    Science.gov (United States)

    Yosipovitch, Gil; Fast, Katharine; Bernhard, Jeffrey D

    2005-12-01

    The aim of this study was to assess the effect of thermal stimuli or distal scratching on skin blood flow and histamine-induced itch in healthy volunteers. Twenty-one healthy volunteers participated in the study. Baseline measurements of skin blood flow were obtained on the flexor aspect of the forearm. These measurements were compared with skin blood flow after various stimuli: heating the skin, cooling the skin, noxious cold 2 degrees C, noxious heat 49 degrees C, and scratching via a brush with controlled pressure. Afterwards histamine iontophoresis was performed and skin blood flow and itch intensity were measured immediately after the above-mentioned stimuli. Scratching reduced mean histamine-induced skin blood flow and itch intensity. Noxious heat pain increased basal skin blood flow but reduced histamine-induced maximal skin blood flow and itch intensity. Cold pain and cooling reduced itch intensity, but neither affected histamine-induced skin blood flow. Sub-noxious warming the skin did not affect the skin blood flow or itch intensity. These findings suggest that heat pain and scratching may inhibit itch through a neurogenic mechanism that also affects skin blood flow.

  5. Optical Sensing of Weed Infestations at Harvest.

    Science.gov (United States)

    Barroso, Judit; McCallum, John; Long, Dan

    2017-10-19

    Kochia ( Kochia scoparia L.), Russian thistle ( Salsola tragus L.), and prickly lettuce ( Lactuca serriola L.) are economically important weeds infesting dryland wheat ( Triticum aestivum L.) production systems in the western United States. Those weeds produce most of their seeds post-harvest. The objectives of this study were to determine the ability of an optical sensor, installed for on-the-go measurement of grain protein concentration, to detect the presence of green plant matter in flowing grain and assess the potential usefulness of this information for mapping weeds at harvest. Spectra of the grain stream were recorded continuously at a rate of 0.33 Hz during harvest of two spring wheat fields of 1.9 and 5.4 ha. All readings were georeferenced using a Global Positioning System (GPS) receiver with 1 m positional accuracy. Chlorophyll of green plant matter was detectable in the red (638-710 nm) waveband. Maps of the chlorophyll signal from both fields showed an overall agreement of 78.1% with reference maps, one constructed prior to harvest and the other at harvest time, both based on visual evaluations of the three green weed species conducted by experts. Information on weed distributions at harvest may be useful for controlling post-harvest using variable rate technology for herbicide applications.

  6. SHIFTING WEED COMPOSITIONS AND BIOMASS PRODUCTION IN SWEET CORN FIELD TREATED WITH ORGANIC COMPOSTS AND CHEMICAL WEED CONTROLS

    Directory of Open Access Journals (Sweden)

    Marulak Simarmata

    2015-10-01

    Full Text Available The objectives of the research were to study the shift of weed compositions in sweet corn field treated with organic compost and chemical weed controls and to compare the effect of treatment combinations on weed growth, weed biomass and sweet corn biomass. The research was conducted in Bengkulu, Indonesia, from April to July 2014. Results showed that the number of weed species decreased after the trials from 14 to 13. There was a shift in weed compositions because 5 species of weeds did not emerge after the trials, but 4 new species were found. Chemical weed control used a herbiside mixture of atrazine and mesotrione applied during postemergence was the most effective method to control weeds, which was observed on decreased weed emergence and weed biomass down to 22.33 and 25.00 percent of control, respectively. Subsequently, biomass production of sweet corn increased up to 195.64 percent at the same trials. Biomass of weeds and sweet corn were also affected by the organic composts. Weed biomass was inhibited by treatment of composted empty fruith bunches of oil palm, whereas significantly increased of sweet corn biomass were observed in the plots of organic manure.

  7. Weed seed germination in winter cereals under contrasting tillage systems

    DEFF Research Database (Denmark)

    Scherner, Ananda

    2015-01-01

    to accumulate in the top soil layer and timing of herbicide applications sometimes seems to target the emergence pattern of these weeds poorly. In contrast to the management of most diseases and pests, weed management should be considered in a time frame. The abilities to produce above and below ground...... of weeds. An important component in IWM is to understand and ultimately predict weed emergence patterns in relation to the cropping system and the tillage method applied. A better understanding of the cumulative emergence patterns of weed species in winter crops under different tillage regimes will help......Grass weeds and Gallium aparine are major weed problems in North European arable cropping systems with high proportions of winter crops, especially winter wheat (Clarke et al., 2000; Melander et al., 2008). Problems are accentuated where inverting tillage is omitted, as weed seeds tend...

  8. An ultrasonic system for weed detection in cereal crops.

    Science.gov (United States)

    Andújar, Dionisio; Weis, Martin; Gerhards, Roland

    2012-12-13

    Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index) computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were

  9. Weed Control in Clean Agriculture: A Review1

    OpenAIRE

    ABOUZIENA,H.F.; HAGGAG,W.M.

    2016-01-01

    ABSTRACT Weed control is consider the major obstacle for the growers in the organic farming. Lower plant productivity in organic farming mainly related to the poor weed control. It is widely known, in most cases, that losses caused by weeds exceeded the losses from any category of agricultural pests. Under water-stress condition, weeds can reduce crop yields more than 50% through moisture competition alone. In the light of the environmental and toxicological problems created by herbicides, it...

  10. Controlling grass weeds on hard surfaces

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Kristoffersen, Palle; Andreasen, Christian

    2012-01-01

    An experiment was conducted on a specially designed hard surface to study the impact of time interval between flaming treatments on the regrowth and flower production of two grass weeds. The goal of this experiment was to optimize the control of annual bluegrass and perennial ryegrass, both species...... that are very difficult to control without herbicides. Aboveground biomass from 72 plants per treatment was harvested and dry weights were recorded at regular intervals to investigate how the plants responded to flaming. Regrowth of the grasses was measured by harvesting aboveground biomass 2 wk after......, as they did not increase the reduction of aboveground biomass compared with the 7-d treatment interval. Knowledge on the regrowth of grass weeds after flaming treatments provided by this study can help improve recommendations given to road keepers and park managers for management on these weeds. Nomenclature...

  11. Weeded Out? Gendered Responses to Failing Calculus.

    Science.gov (United States)

    Sanabria, Tanya; Penner, Andrew

    2017-06-01

    Although women graduate from college at higher rates than men, they remain underrepresented in science, technology, engineering, and mathematics (STEM) fields. This study examines whether women react to failing a STEM weed-out course by switching to a non-STEM major and graduating with a bachelor's degree in a non-STEM field. While competitive courses designed to weed out potential STEM majors are often invoked in discussions around why students exit the STEM pipeline, relatively little is known about how women and men react to failing these courses. We use detailed individual-level data from the National Educational Longitudinal Study (NELS) Postsecondary Transcript Study (PETS): 1988-2000 to show that women who failed an introductory calculus course are substantially less likely to earn a bachelor's degree in STEM. In doing so, we provide evidence that weed-out course failure might help us to better understand why women are less likely to earn degrees.

  12. Pest Control in Corn and Soybeans: Weeds - Insects - Diseases.

    Science.gov (United States)

    Doersch, R. E.; And Others

    This document gives the characteristics and application rates for herbicides used to control annual weeds in corn, annual and perennial broadleaf weeds in corn, quackgrass and yellow nutsedge in corn, and annual weeds in soybeans. It also gives insecticide use information for corn and soybeans. A brief discussion of disease control in corn and…

  13. Conservation implications of weed management of lake reservoirs ...

    African Journals Online (AJOL)

    Management of weeds around lake reservoirs is often implemented to reduce any possibility of siltation. However, machineries used in weed management have resulted in habitat degradation and geometrical multiplication of weeds by chopping rhizomes and scattering seeds. In general, the removal offers some feedbacks ...

  14. Descriptive and mechanistic models of crop–weed competition

    NARCIS (Netherlands)

    Bastiaans, L.; Storkey, J.

    2017-01-01

    Crop-weed competitive relations are an important element of agroecosystems. Quantifying and understanding them helps to design appropriate weed management at operational, tactical and strategic level. This chapter presents and discusses simple descriptive and more mechanistic models for crop-weed

  15. Effect of the Critical Period of Weed Interference on Optimum ...

    African Journals Online (AJOL)

    A field study was carried out at the National Root Crop Research Institute experimental farm to determine the critical period of weed interference and magnitude of yield loss caused by weed on turmeric in 2008 and 2009 cropping season. Turmeric was subjected to 13 weeding regimes using randomized complete block ...

  16. Focus on ecological weed management : what is hindering adoption?

    NARCIS (Netherlands)

    Bastiaans, L.; Paolini, R.; Baumann, D.T.

    2008-01-01

    Despite increased concerns regarding the heavy reliance of many cropping systems on chemical weed control, adoption of ecological weed management practices is only steadily progressing. For this reason, this paper reflects on both the possibilities and limitations of cultural weed control practices.

  17. Image-based thresholds for weeds in maize fields

    DEFF Research Database (Denmark)

    Asif, Ali; Streibig, Jens Carl; Christensen, Svend

    2015-01-01

    in some parts of the field and if late germinating weeds do not affect yield, it may not be necessary the spray such places from an economic point of view. Consequently, it makes sense to develop weed control thresholds for patch spraying, based on weed cover early in the growing season. In Danish maize...

  18. Evaluation of UAV imagery for mapping Silybum marianum weed patches

    Science.gov (United States)

    The invasive weed, milk thistle (Silybum marianum), has the tendency to grow in patches. In order to perform site-specific weed management, determining the spatial distribution of weeds is important for its eradication. Remote sensing has been used to perform species discrimination, and it offers pr...

  19. Onion and weed response to mustard (Sinapis alba) seed meal

    Science.gov (United States)

    Weed control in organic onion production is often difficult and expensive, requiring numerous cultivations and extensive hand-weeding. Onion safety and weed control with mustard seed meal (MSM) derived from Sinapis alba was evaluated in greenhouse and field trials. MSM applied at 110, 220, and 440 g...

  20. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa

    Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one

  1. A century of progress in weed control in hardwood seedbeds

    Science.gov (United States)

    David B. South

    2009-01-01

    Weeds have existed in nurseries since before the time Bartram grew hardwoods during the 18th century. Hand weeding was the primary method of weed control during the first part of the 20th century. From 1931 to 1970, advances in chemistry increased the use of herbicides, and advances in engineering increased the reliance on machines for cultivation. Many managers now...

  2. 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.

  3. Vegetation - Herbivory Dynamics in Rangeland Ecosystems: Geospatial Modeling for Savanna and Wildlife Conservation in California and Namibia

    OpenAIRE

    Tsalyuk, Miriam

    2014-01-01

    Rangelands cover about half of Earth's land surface, encompass considerable biodiversity, and provide pivotal ecosystem services. However, rangelands across the globe face degradation due to changes in climate, land use, and management. Moreover, since herbivory is fundamental to rangeland ecosystem dynamics, shifts in the distribution of herbivores lead to overgrazing and desertification. To better understand, predict, and prevent changes on rangelands it is important to monitor these landsc...

  4. Assessing the impacts of livestock production on biodiversity in rangeland ecosystems

    Science.gov (United States)

    Alkemade, Rob; Reid, Robin S.; van den Berg, Maurits; de Leeuw, Jan; Jeuken, Michel

    2013-01-01

    Biodiversity in rangelands is decreasing, due to intense utilization for livestock production and conversion of rangeland into cropland; yet the outlook of rangeland biodiversity has not been considered in view of future global demand for food. Here we assess the impact of future livestock production on the global rangelands area and their biodiversity. First we formalized existing knowledge about livestock grazing impacts on biodiversity, expressed in mean species abundance (MSA) of the original rangeland native species assemblages, through metaanalysis of peer-reviewed literature. MSA values, ranging from 1 in natural rangelands to 0.3 in man-made grasslands, were entered in the IMAGE-GLOBIO model. This model was used to assess the impact of change in food demand and livestock production on future rangeland biodiversity. The model revealed remarkable regional variation in impact on rangeland area and MSA between two agricultural production scenarios. The area of used rangelands slightly increases globally between 2000 and 2050 in the baseline scenario and reduces under a scenario of enhanced uptake of resource-efficient production technologies increasing production [high levels of agricultural knowledge, science, and technology (high-AKST)], particularly in Africa. Both scenarios suggest a global decrease in MSA for rangelands until 2050. The contribution of livestock grazing to MSA loss is, however, expected to diminish after 2030, in particular in Africa under the high-AKST scenario. Policies fostering agricultural intensification can reduce the overall pressure on rangeland biodiversity, but additional measures, addressing factors such as climate change and infrastructural development, are necessary to totally halt biodiversity loss. PMID:22308313

  5. Mechanical weed control in organic winter wheat

    OpenAIRE

    Euro Pannacci; Francesco Tei; Marcello Guiducci

    2017-01-01

    Three field experiments were carried out in organic winter wheat in three consecutive years (exp. 1, 2005-06; exp. 2, 2006- 07; exp. 3, 2007-08) in central Italy (42°57’ N - 12°22’ E, 165 m a.s.l.) in order to evaluate the efficacy against weeds and the effects on winter wheat of two main mechanical weed control strategies: i) spring tine harrowing used at three different application times (1 passage at T1, 2 passages at the time T1, 1 passage at T1 followed by 1 passage at T1 + 14 days) in t...

  6. Rangeland resource trends in the United States: A technical document supporting the 2000 USDA Forest Service RPA Assessment

    Science.gov (United States)

    John E. Mitchell

    2000-01-01

    This report documents trends in America's rangelands as required by the Renewable Resources Planning Act of 1974. The Forest Service has conducted assessments of the rangeland situation for 30 years. Over this period, rangeland values and uses have gradually shifted from concentrating upon forage production and meeting increasing demand for red meat to a more...

  7. Population dynamics of weeds in oil palm (Elaeis guineensis Jacq.) circle weeding area affected by herbicide application

    Science.gov (United States)

    Sidik, S.; Purba, E.; Yakub, E. N.

    2018-02-01

    Weed problems in oil palm field were mainly overcomed by herbicide application. The application certain herbicides may lead to rapid population dynamic of certain species due to their different response to herbicides. Some species may less susceptible to certain herbicide whereas other species more susceptible. The objective of this study was to determine the population dynamic of weed species in circle weeding of oil palm in Serdang Bedagai, North Sumatra. Six treatments using glyphosate singly and mixture compared with manual weeding were evaluated for weed control. The treatments were arranged in a randomized block design with four replicates. Each treatment consisted of four circle weedings. The results showed that glyphosate 720 g a.i/ha + indaziflam 50 g a.i/hareduced seedbank and regrowth of weeds. Up to 12 weeks after application glyphosate 720 g a.i/ha + indaziflam 50 g a.i/ha is 29.46% total weeds dry weight compared to manual weeding. The effect of herbicide application on changes on the weed composition and weed seedbank are affected by the characteristic of herbicides and weed response to herbicide application.

  8. Suppression of bulboreticular unit responses to noxious stimuli by analgesic mesencephalic stimulation.

    Science.gov (United States)

    Morrow, T J; Casey, K L

    1983-01-01

    The responses of 302 neurons in the medial medullary reticular formation (MRF) to a variety of noxious and innocuous somatic stimuli were studied in anesthetized and awake rats. In addition, the effects of analgesic electrical stimulation in the mesencephalon (MES) on unit responses were examined. Tail shock was the most effective stimulus, exciting more than 80% of all units recorded. This stimulus was considered separately during data analysis, since it could not be classified as noxious or innocuous. Noxious somatic stimuli (including pinch, firm pressure, pin prick, and radiant heating of the tail above 45 degrees C were especially effective in eliciting discharge in a significant fraction of all cells in both awake (123/205) and anesthetized (45/97) animals. Nociceptive neurons could be classified as nociceptive specific (NS) or wide dynamic range (WDR) depending on their responses to all somatic stimuli tested. Nociceptive neurons showed no preferential anatomical distribution. Most neurons, including those responsive to noxious inputs, exhibited large, often bilateral receptive fields which frequently covered the tail, one or more limbs, and extensive areas of the body or head. Electrical stimulation within or adjacent to the mesencephalic periaqueductal gray matter depressed the spontaneous and evoked discharge of MRF neurons in both acute and chronic preparations. This inhibition showed a significant preference (p less than 0.001, chi-square statistic) for units that were excited by somatic and especially noxious stimuli. No units were facilitated by MES stimulation. In the awake rat, unit suppression closely followed the time course and level of MES-induced analgesia. Excitability data from the acute experiments suggest that this response inhibition may be the result of a direct action on MRF neurons. Anesthesia severely depressed the spontaneous discharge of MRF neurons as well as the activity evoked by innocuous somatic stimulation. Our data suggest

  9. Virus infection of a weed increases vector attraction to and vector fitness on the weed.

    Science.gov (United States)

    Chen, Gong; Pan, Huipeng; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Fang, Yong; Shi, Xiaobin; Zhang, Youjun

    2013-01-01

    Weeds are important in the ecology of field crops, and when crops are harvested, weeds often become the main hosts for plant viruses and their insect vectors. Few studies, however, have examined the relationships between plant viruses, vectors, and weeds. Here, we investigated how infection of the weed Datura stramonium L. by tomato yellow leaf curl virus (TYLCV) affects the host preference and performance of the TYLCV vector, Bemisia tabaci (Gennadius) Q. The results of a choice experiment indicated that B. tabaci Q preferentially settled and oviposited on TYLCV-infected plants rather than on healthy plants. In addition, B. tabaci Q performed better on TYLCV-infected plants than on healthy plants. These results demonstrate that TYLCV is indirectly mutualistic to B. tabaci Q. The mutually beneficial interaction between TYLCV and B. tabaci Q may help explain the concurrent outbreaks of TYLCV and B. tabaci Q in China.

  10. BIOLOGICAL CONTROL OF WEEDS BY MEANS OF PLANT PATHOGENS

    Directory of Open Access Journals (Sweden)

    Marija Ravlić

    2014-06-01

    Full Text Available Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, conservation and augmentative (inoculative and inundated biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chemical herbicides are not allowed, if resistant weed species are present or in the integrated pest management against weeds with reduced herbicides doses and other non-chemical measures, but it has certain limitations and disadvantages.

  11. Bush encroachment dynamics and rangeland management implications in the Horn of Africa

    Science.gov (United States)

    Rangelands in the Horn of Africa have been undergoing a rapid shift from herbaceous to woody plant dominance in the past decades, threatening subsistence livestock herding and pastoral food security. Despite of significant rangeland management implications, quantification of the spatial extent of en...

  12. Rehabilitation of community-owned, mixed-use rangelands: Lessons from the Ewaso ecosystem in Kenya

    Science.gov (United States)

    Globally, 10-20% of arid and semi-arid rangelands have been classified as severely degraded (UNCCD 1994; MEA 2005), and in sub-Saharan Africa specifically, 70% of rangelands are considered moderately to severely degraded (Dregne 1992; UNCCD 1994). Given that these drylands make up 43% of Africa’s la...

  13. Bayesian estimation of shrubs diversity in rangelands under two management systems in northern Syria

    NARCIS (Netherlands)

    Niane, A.A.; Singh, M.; Struik, P.C.

    2014-01-01

    The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the rangeland grazing management treatments, two popular indices for diversity, the

  14. Heat dosage and oviposition depth influence egg mortality of two common rangeland grasshopper species

    Science.gov (United States)

    Rangeland fire is a common naturally occurring event and management tool, with the amount and structure of biomass controlling transfer of heat belowground. Temperatures grasshopper eggs are exposed to during rangeland fires are mediated by species specific oviposition traits. This experiment examin...

  15. Discussion of submitted posters for Section 2.3 (Rangeland Germplasm Resources)

    Science.gov (United States)

    As part of the IX International Rangeland Congress held in Rosario, Argentina, a total of 70 posters from 17 countries were submitted to Section 2.3 (Rangeland Germplasm Resources). These posters documented research conducted in five major regions of the world: South America, North America, Africa...

  16. Recovery of rangelands : the functioning of soil seed banks in a semi-arid African savanna

    NARCIS (Netherlands)

    Tessema, Z.K.

    2011-01-01

    Rangelands in Africa provide important forage resources for herbivores; particularly perennial grasses provide grazing for domestic and wild herbivores. However, semi-arid African rangelands experience severe vegetation and soil degradation due to heavy grazing, causing negative impacts

  17. Effects of climate change on rangeland vegetation in the Northern Rockies Region [Chapter 7

    Science.gov (United States)

    Matt C. Reeves; Mary E. Manning; Jeff P. DiBenedetto; Kyle A. Palmquist; William K. Lauenroth; John B. Bradford; Daniel R. Schlaepfer

    2018-01-01

    Rangelands are dominated by grass, forb, or shrub species, but are usually not modified by using agronomic improvements such as fertilization or irrigation (Lund 2007; Reeves and Mitchell 2011) as these lands would normally be considered pastures. Rangeland includes grassland, shrubland, and desert ecosystems, alpine areas, and some woodlands (box 7.1). This chapter...

  18. Earth stewardship on rangelands: Coping with ecological, economic, and political marginality

    Science.gov (United States)

    Rangelands encompass 30-40 percent of Earth's land surface and support 1-2 billion people. Their predominant use is extensive livestock production by pastoralists and ranchers. But rangelands are characterized by ecological, economic, and political marginality, and higher-value, more intensive land ...

  19. Global view of remote sensing of rangelands: Evolution, applications, future pathways [Chapter 10

    Science.gov (United States)

    Matt Reeves; Robert A. Washington-Allen; Jay Angerer; E. Raymond Hunt; Ranjani Wasantha Kulawardhana; Lalit Kumar; Tatiana Loboda; Thomas Loveland; Graciela Metternicht; R. Douglas. Ramsey

    2015-01-01

    The term "rangeland" is rather nebulous, and there is no single definition of rangeland that is universally accepted by land managers, scientists, or international bodies (Lund, 2007; Reeves and Mitchell, 2011). Dozens and possibly hundreds (Lund, 2007) of definitions and ideologies exist because various stakeholders often have unique objectives...

  20. China's Rangelands under Stress : A comparative study of pasture commons in the Ningxia Hui Autonomous Region

    NARCIS (Netherlands)

    Ho, P.P.S.

    2000-01-01

    China's economic reforms have exacerbated the problems of over-grazing and desertification in the country's pastoral areas. In order to deal with rangeland degradation, the Chinese government has resorted to nationalization, or semi-privatization. Since the implementation of rangeland policy has

  1. Hydrologic ramifications of an increased role of wildland fire across the rangeland-dry forest continuum

    Science.gov (United States)

    The increased role of wildland fire across the rangeland-dry forest continuum in the western United States (US) presents landscape-scale consequences relative runoff and erosion. Much of the Intermountain West now exists in a state in which rangeland and woodland wildfires stimulated by invasive che...

  2. Climate change and North American rangelands: Assessment of mitigation and adaptation strategies

    Science.gov (United States)

    Linda A. Joyce; David D. Briske; Joel R. Brown; H. Wayne Polley; Bruce A. McCarl; Derek W. Bailey

    2013-01-01

    Recent climatic trends and climate model projections indicate that climate change will modify rangeland ecosystem functions and the services and livelihoods that they provision. Recent history has demonstrated that climatic variability has a strong influence on both ecological and social components of rangeland systems and that these systems possess substantial...

  3. Integrating the Indigenous Knowledge of Borana Pastoralists into Rangeland Management Strategies in Southern Ethiopia

    OpenAIRE

    World Bank

    2005-01-01

    Pastoralists' indigenous knowledge (IK) about ecology and social organization led to rangeland-management strategies appropriate to deal with the erratic rainfall in African drylands. Herd mobility was traditionally practiced as the key strategy to make use of the scattered rangeland resources on a large scale.

  4. Agricultural, Runoff, Erosion and Salinity (ARES) Database to Better Evaluate Rangeland State and Sustainability

    Science.gov (United States)

    Rangelands comprise approximately 40% of the earth’s surface and are the largest land cover type in the world. Degradation from mismanagement, desertification, and drought impact more than 50% of rangelands across the globe. The USDA Agricultural Research Service (ARS) has been evaluating means of r...

  5. Plant/life form considerations in the rangeland hydrology and erosion model (RHEM)

    Science.gov (United States)

    Resilience of rangeland to erosion has largely been attributed to adequate plant cover; however, plant life/growth form, and individual species presence can have a dramatic effect on hydrologic and erosion dynamics on rangelands. Plant life/growth form refers to genetic tendency of a plant to grow i...

  6. Application of the Rangeland Hydrology and Erosion Model to Ecological Site Descriptions and Management

    Science.gov (United States)

    The utility of Ecological Site Descriptions (ESDs) and State-and-Transition Models (STMs) concepts in guiding rangeland management hinges on their ability to accurately describe and predict community dynamics and the associated consequences. For many rangeland ecosystems, plant community dynamics ar...

  7. Weed infestation of spring barley (Hordeum vulgare L. depending on the cover crop and weed control method

    Directory of Open Access Journals (Sweden)

    Dorota Gawęda

    2014-04-01

    Full Text Available The aim of this 3-year field study was to evaluate the effect of some stubble crops and weed control methods on the species composition, number and air-dry weight of weeds in a spring barley crop grown in short-term monoculture. The study was conducted in the period 2009–2011 at the Uhrusk Experimental Farm, on mixed rendzina soil classified as very good rye soil complex. It included stubble crops which were ploughed under in each year (control treatment without cover crop, white mustard, lacy phacelia, a mixture of legumes – narrow-leaf lupin + field pea and 3 weed control methods used in spring barley crops (mechanical, mechanical and chemical, chemical weed control. Veronica persica was the weed species that occurred in greatest numbers in the spring barley crop sown after stubble crops. All cover crops reduced the numbers of Avena fatua which was the dominant species in the control treatment. Chemical as well as chemical and mechanical weed control significantly reduced the numbers of Avena fatua compared to the treatment where only double harrowing was used for weed control. The stubble crops did not reduce weed infestation of spring barley. Compared to the control treatment, the ploughing-in of white mustard and the mixture of legumes reduced the dry weight of weeds by 49.1 and 22.7%, respectively. Mechanical weed management proved to be less effective in reducing the number and dry weight of weeds compared to the other weed control methods. A significant negative correlation was found between the dry weight of weeds in the spring barley crop and the dry weight of the ploughed-in white mustard cover crop under the conditions of chemical weed control as well as in the case of the mixture of legumes when complete mechanical and chemical weed control was used.

  8. Weed hosts of cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Vennila, S; Prasad, Y G; Prabhakar, M; Agarwal, Meenu; Sreedevi, G; Bambawale, O M

    2013-03-01

    The exotic cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) invaded India during 2006, and caused widespread infestation across all nine cotton growing states. P. solenopsis also infested weeds that aided its faster spread and increased severity across cotton fields. Two year survey carried out to document host plants of P. solenopsis between 2008 and 2010 revealed 27, 83, 59 and 108 weeds belonging to 8, 18, 10 and 32 families serving as alternate hosts at North, Central, South and All India cotton growing zones, respectively. Plant species of four families viz., Asteraceae, Amaranthaceae, Malvaceae and Lamiaceae constituted almost 50% of the weed hosts. While 39 weed species supported P. solenopsis multiplication during the cotton season, 37 were hosts during off season. Higher number of weeds as off season hosts (17) outnumbering cotton season (13) at Central over other zones indicated the strong carryover of the pest aided by weeds between two cotton seasons. Six, two and seven weed hosts had the extreme severity of Grade 4 during cotton, off and cotton + off seasons, respectively. Higher number of weed hosts of P. solenopsis were located at roadside: South (12) > Central (8) > North (3) zones. Commonality of weed hosts was higher between C+S zones, while no weed host was common between N+S zones. Paper furnishes the wide range of weed hosts of P. solenopsis, discusses their significance, and formulated general and specific cultural management strategies for nationwide implementation to prevent its outbreaks.

  9. Parthenium weed ( Parthenium hysterophorus L.) research in ...

    African Journals Online (AJOL)

    Parthenium is an exotic invasive weed that now occurs widely in Ethiopia. Surveys to determine the presence and distribution of pathogens associated with parthenium and further evaluation of the pathogens found as potential biocontrol agents were carried out in Ethiopia since 1998. Several fungal isolates of the genus ...

  10. Weed identification using an automated active shape matching (AASM) technique

    DEFF Research Database (Denmark)

    C. Swain, Kishore; Nørremark, Michael; Jørgensen, Rasmus Nyholm

    2011-01-01

    Weed identification and control is a challenge for intercultural operations in agriculture. As an alternative to chemical pest control, a smart weed identification technique followed by mechanical weed control system could be developed. The proposed smart identification technique works on the con......Weed identification and control is a challenge for intercultural operations in agriculture. As an alternative to chemical pest control, a smart weed identification technique followed by mechanical weed control system could be developed. The proposed smart identification technique works...... on the concept of ‘active shape modelling’ to identify weed and crop plants based on their morphology. The automated active shape matching system (AASM) technique consisted of, i) a Pixelink camera ii) an LTI (Lehrstuhlfuer technische informatik) image processing library, iii) a laptop pc with the Linux OS. A 2...

  11. Weeds optimally grow in peat swamp after burning

    Directory of Open Access Journals (Sweden)

    P.D. Susanti

    2014-07-01

    Full Text Available After clearing land by burning the peat, then the weeds and undergrowth will flourish. Even sometimes, the weeds are eventually burned again. Weed is known as a destroyer plant that has to be controlled. Through proper treatment, the existing weeds in peatlands can be potentiallly exploited. The purpose of this study was to determine the calorific value of briquettes as one of peatland weeds utilization. The results showed that the calorific value ranged from 2,492 cal/g to 5,230 cal/g. The lowest calorific value was on ‘teki kecil’ grass (Scirpus grossus Lf, while the highest calorific value was observed for ‘bantalaki grass’ (Hymenachne amplexicaulis Nees. The high calorific value of the peat weeds are potential for biomass briquettes raw materials. The utilization and use of peat weed briquettes as a raw materials expected can reduce land degradation due to peat swamp burning

  12. A method and apparatus for preparing the storage of noxious substances, in particular radioactive substances

    International Nuclear Information System (INIS)

    1974-01-01

    The invention relates to the storage of radioactive substances. It deals with a method for storing a substance, in particular a noxious or radioactive substance, comprising trapping said substance in a solid substance by bombarding said solid substance with ions of the above substance, so that the latter reaches a certain concentration level in the solid substance. This is applicable to the storage of radioactive wastes [fr

  13. Suramin affects capsaicin responses and capsaicin-noxious heat interactions in rat dorsal root ganglia neurones

    Czech Academy of Sciences Publication Activity Database

    Vlachová, Viktorie; Lyfenko, Alla; Vyklický st., Ladislav; Orkand, R. K.

    2002-01-01

    Roč. 51, č. 2 (2002), s. 193-198 ISSN 0862-8408 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Institutional research plan: CEZ:AV0Z5011922 Keywords : dorsal root ganglia neurones * vanilloid receptor * capsaicin-noxious heat Subject RIV: ED - Physiology Impact factor: 0.984, year: 2002

  14. Determining perception-based impacts of noxious facilities on wage rates and property values

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Clark, D.E.

    1992-02-01

    This document, written for the US Department of Energy, discusses current information and the need for future research on estimating the impacts on wages and property values that could result from people's perceptions of the risks associated with noxious facilities. Psychometric studies indicate that the US population is averse to living near noxious facilities, nuclear-related facilities in particular. Contingent valuation and hedonic studies find that the net economic impacts of proximity to noxious facilities are generally negative and often substantial. Most of these studies are limited in scope, and none estimate the impacts derived from public perceptions of such facilities. This study examines the mechanisms by which negative public perceptions result in economic impacts reflected in wages and property values. On the basis of these mechanisms, it develops a predictive model of perception-based impacts and identifies the data and methods needed to implement it. The key to predicting perception-based impacts lies in combining psychometric and hedonic methods. The reliability of psychometric measures as indicators of aversive stimuli that precipitate economic impacts can be empirically tested. To test the robustness of the findings, alternative estimation methods an be employed in the hedonic analysis. Contingent valuation methods can confirm the results.

  15. Determining perception-based impacts of noxious facilities on wage rates and property values

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Clark, D.E.

    1992-02-01

    This document, written for the US Department of Energy, discusses current information and the need for future research on estimating the impacts on wages and property values that could result from people`s perceptions of the risks associated with noxious facilities. Psychometric studies indicate that the US population is averse to living near noxious facilities, nuclear-related facilities in particular. Contingent valuation and hedonic studies find that the net economic impacts of proximity to noxious facilities are generally negative and often substantial. Most of these studies are limited in scope, and none estimate the impacts derived from public perceptions of such facilities. This study examines the mechanisms by which negative public perceptions result in economic impacts reflected in wages and property values. On the basis of these mechanisms, it develops a predictive model of perception-based impacts and identifies the data and methods needed to implement it. The key to predicting perception-based impacts lies in combining psychometric and hedonic methods. The reliability of psychometric measures as indicators of aversive stimuli that precipitate economic impacts can be empirically tested. To test the robustness of the findings, alternative estimation methods an be employed in the hedonic analysis. Contingent valuation methods can confirm the results.

  16. A leptin-regulated circuit controls glucose mobilization during noxious stimuli.

    Science.gov (United States)

    Flak, Jonathan N; Arble, Deanna; Pan, Warren; Patterson, Christa; Lanigan, Thomas; Goforth, Paulette B; Sacksner, Jamie; Joosten, Maja; Morgan, Donald A; Allison, Margaret B; Hayes, John; Feldman, Eva; Seeley, Randy J; Olson, David P; Rahmouni, Kamal; Myers, Martin G

    2017-08-01

    Adipocytes secrete the hormone leptin to signal the sufficiency of energy stores. Reductions in circulating leptin concentrations reflect a negative energy balance, which augments sympathetic nervous system (SNS) activation in response to metabolically demanding emergencies. This process ensures adequate glucose mobilization despite low energy stores. We report that leptin receptor-expressing neurons (LepRb neurons) in the periaqueductal gray (PAG), the largest population of LepRb neurons in the brain stem, mediate this process. Application of noxious stimuli, which often signal the need to mobilize glucose to support an appropriate response, activated PAG LepRb neurons, which project to and activate parabrachial nucleus (PBN) neurons that control SNS activation and glucose mobilization. Furthermore, activating PAG LepRb neurons increased SNS activity and blood glucose concentrations, while ablating LepRb in PAG neurons augmented glucose mobilization in response to noxious stimuli. Thus, decreased leptin action on PAG LepRb neurons augments the autonomic response to noxious stimuli, ensuring sufficient glucose mobilization during periods of acute demand in the face of diminished energy stores.

  17. RNAseq reveals weed-induced PIF3-like as a candidate target to manipulate weed stress response in soybean.

    Science.gov (United States)

    Horvath, David P; Hansen, Stephanie A; Moriles-Miller, Janet P; Pierik, Ronald; Yan, Changhui; Clay, David E; Scheffler, Brian; Clay, Sharon A

    2015-07-01

    Weeds reduce yield in soybeans (Glycine max) through incompletely defined mechanisms. The effects of weeds on the soybean transcriptome were evaluated in field conditions during four separate growing seasons. RNASeq data were collected from six biological samples of soybeans growing with or without weeds. Weed species and the methods to maintain weed-free controls varied between years to mitigate treatment effects, and to allow detection of general soybean weed responses. Soybean plants were not visibly nutrient- or water-stressed. We identified 55 consistently downregulated genes in weedy plots. Many of the downregulated genes were heat shock genes. Fourteen genes were consistently upregulated. Several transcription factors including a PHYTOCHROME INTERACTING FACTOR 3-like gene (PIF3) were included among the upregulated genes. Gene set enrichment analysis indicated roles for increased oxidative stress and jasmonic acid signaling responses during weed stress. The relationship of this weed-induced PIF3 gene to genes involved in shade avoidance responses in Arabidopsis provide evidence that this gene may be important in the response of soybean to weeds. These results suggest that the weed-induced PIF3 gene will be a target for manipulating weed tolerance in soybean. No claim to original US government works New Phytologist © 2015 New Phytologist Trust.

  18. Changes in weed infestation of common bean (Phaseolus vulgaris L. under conditions of strip intercropping and different weed control methods

    Directory of Open Access Journals (Sweden)

    Aleksandra Głowacka

    2012-12-01

    Full Text Available The experiment was conducted in the years 2004-2006 in a private farm in the village of Frankamionka in Zamość district. There were two experimental factors: I. Cultivation methods - sole cropping and strip intercropping; and II. Tending methods - mechanical, mechanical-chemical, and chemical weed control. The subject of the study was weed infestation of the Mela variety of common bean. Beans were sown between 30 April and 5 May. Weed infestation was assessed in the last week before harvesting by determining its floristic composition and the frequency of occurrence of particular weed species, as well as the air-dry weight of weeds. The dominant weed species were Galinsoga parviflora, Echinochloa crus-galli, Chenopodium album, and Amaranthus retroflexus, which comprised 84.7% of the total number of weeds. Strip intercropping markedly reduced the number of weeds per unit area (by 50%, as well as the dry weight of their aerial parts. The most effective method of weed control was the mechanical-chemical method, which resulted in the lowest occurrence of weeds. It also significantly reduced the weight of weeds.

  19. Weed Biomass and Weed Species Diversity of Juvenile Citrus Trees Intercrop with some Arable Crops

    Directory of Open Access Journals (Sweden)

    Patience Mojibade OLORUNMAIYE

    2012-02-01

    Full Text Available A preliminary study was carried out to evaluate the performances of eight crops in the intercrop of citrus with arable crops at the National Horticultural Research Institute (NIHORT Ibadan, Nigeria. Eight arable crops: maize, cucumber, sweet potato, Corchorus olitorius, large green, grain amaranth, Mucuna pruriens var. utilis, and groundnut were intercropped with young citrus trees in the early planting season of 2010 with sole citrus as control. The experiment was laid out in a completely randomized block design with three replicates. Data were collected on weed flora, weed density and weed dry weight. Results showed that the relative frequencies of weeds in all the plots were less than 4% at both 6 and 9WAP. Gomphrena celosoides, Oldenlandia corymbosa and Tridax procumbens were most preponderant in appearing in all the plots. Tridax procumbens had a consistent relative frequency (2.34% in all the plots except in citrus/maize plot (0.78% at 9 WAP. Significantly lower broadleaf weed densities were obtained in citrus/sweet potato, citrus/large green, control plot and citrus/cucumber (28.67, 45.00, 50.00 and 76.33 m-2 respectively than in citrus/groundnut plot (143.00 m-2. Similarly, significantly lower grass weed densities were produced in citrus/Mucuna and citrus/sweet potato (0.33 m-2 each plots than the control plot (11.33 m-2. Whereas citrus/corchorus plot produced significantly lower broadleaf weed dry weight (37.59 g m-2 than citrus/Mucuna plot (126.47 g m-2 at 3WAP, citrus/large green plot (16.15 g m-2 and citrus/groundnut plot (123.25 g m-2 followed the same trend at 6 WAP. Sedges dry weights were less than 7 g m-2 in all the plots compared with control plot.

  20. Effect of Different Methods of Chemical Weed Control Irrigation Regimes on Weed Biomass and Safflower Yield

    Directory of Open Access Journals (Sweden)

    M. Matinfar

    2011-06-01

    Full Text Available In order to investigate the effects of different weed control methods and moisture regimes on safflower (Carthamus tinctorius, a field split plot experiment based on randomized complete block design with 4 replications was conducted in Takestan Iran, during growing seasons of 2007-8. Three irrigations regimes (normal irrigation, restricted irrigation at stem elongation and restricted irrigation at  flowering stage were assigned to the main plots and nine chemical weed control method (complete hand weeding, treflan with 2 L/ha as pre plant herbicide, sonalan with 3 L/ha ad pre plant herbicide, estomp with 3 L/ha as pre plant herbicide, gallant super with 0/75 L/ha as post emergence herbicide, treflan with 2 L/ha as pre plant herbicide+ gallant super with 0/75 L/ha as post emergence herbicide, sonalan with 3 L/ha as pre plant herbicide + gallant super with 0/75 L/ha as post emergence herbicide estomp with 3 L/ha as pre plant herbicide + gallant super with 0/75 L/ha as post emergence herbicide and without hand weeding to sub- plots. At the end of growing period traits like number of head   per plant, number of seed per head, 1000 grain weight, percent of seed oil, yield of seed oil and grain yield were measured. Results indicated that treflan + gallant super treatment in restricted irrigation at stem elongation stage had the lowest dry weight of weeds. In this study maximum grain yield (2927 Kg/ha was achieved from hand weeding + usual irrigation treatments. In general treflan + gallant super treatment was the most effective treatment on safflower yield and weed control.

  1. The benefits of using quantile regression for analysing the effect of weeds on organic winter wheat

    NARCIS (Netherlands)

    Casagrande, M.; Makowski, D.; Jeuffroy, M.H.; Valantin-Morison, M.; David, C.

    2010-01-01

    P>In organic farming, weeds are one of the threats that limit crop yield. An early prediction of weed effect on yield loss and the size of late weed populations could help farmers and advisors to improve weed management. Numerous studies predicting the effect of weeds on yield have already been

  2. High-residue cultivation timing impact on organic no-till soybean weed management

    Science.gov (United States)

    A cereal rye cover crop mulch can suppress summer annual weeds early in the soybean growing season. However, a multi-tactic weed management approach is required when annual weed seedbanks are large or perennial weeds are present. In such situations, the weed suppression from a cereal rye mulch can b...

  3. Weed Identification Distribution and Mapping at Njoro and Katumani

    International Nuclear Information System (INIS)

    Mwangi, H; Alembi, D.K

    1999-01-01

    The study was a response to the need from Katumani DFRC and Njoro (NPBC) Crop protection team request for support service in identification of weed spp. in their mandated areas. From their ongoing adaptive research they encountered ceratin weed spp. which were troublesome and they could not identify and their contact farmers had expressed concern over the weed constraint. A survey in the mentioned areas were carried out in the long/short rains 1997. In the fields, the sites were selected after every 10 km. The field selected was traversed and a quadrat measuring 1m 2 was placed randomly and weeds identified. General Position System (GPS) recorded the position. Two methods of identifying weeds thus on the spot in the field in situ and unidentified weed samples were carefully collected, labelled and preserved for identification in the laboratory of NARL herbarium. Weed distribution was determined using scale 1-4 where 1=1 plant/M 2 , 2=2-5 plants/m 2 , 3=6-20 plants/m 2 ,4=>20 plants m /2. The results show identified weeds in different categories; dominant, troublesome, indigenous and weed introduced within the ten years as percieved by farmers. Developed weed maps are presented for specific districts

  4. Weed infestation of onion in soil reduced cultivation system

    Directory of Open Access Journals (Sweden)

    Marzena Błażej-Woźniak

    2013-12-01

    Full Text Available Field experiment was conducted in the years 1998-2000 in GD Felin. The influence of no-tillage cultivation and conventional tillage with spring ploughing on weed infestation of onion was compared. In experiment four cover crop mulches (Sinapis alba L., Vicia sativa L., Phacelia tanacetifolia B., Avena sativa L. were applied. From annual weeds in weed infestation of onion in great number Matricaria chamomilla L., and Senecio vulgaris L. stepped out. and from perennial - Agropyron repens (L.P.B. Reduced soil cultivation system (no-tillage caused the significant growth of primary weed infestation of onion in comparison with conventional tillage. In all years of investigations the executed pre-sowing ploughing limited significantly the annual weeds' number in primary weed infestation. The applied mulches from cover plants limited in considerable degree the number of primary weed infestation. In all years of investigations the most weeds stepped out on control object. Among investigated cover crop mulches Vicia sativa L. and Avena sativa L. had a profitable effect on decrease of onion`s primary weed infestation. Soil cultivation system and cover crop mulches had no signi ficant residual influence on the secondary weed infestation of onion.

  5. A non-chemical system for online weed control.

    Science.gov (United States)

    Rueda-Ayala, Victor; Peteinatos, Gerassimos; Gerhards, Roland; Andújar, Dionisio

    2015-03-30

    Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with two consecutive passes. The plots presented from low to high weed infestation levels. Discriminant capabilities of an ultrasonic sensor were used to determine the crop and weed variability of the field. A controlling unit used ultrasonic readings to adjust the tine angle, producing an appropriate harrowing intensity. Thus, areas with high crop and weed densities were more aggressively harrowed, while areas with lower densities were cultivated with a gentler treatment; areas with very low densities or without weeds were not treated. Although the weed development was relatively advanced and the soil surface was hard, the weed control achieved by the system reached an average of 51% (20%-91%), without causing significant crop damage as a result of harrowing. This system is proposed as a relatively low cost, online, and real-time automatic harrow that improves the weed control efficacy, reduces energy consumption, and avoids the usage of herbicide.

  6. Nutrient changes and biodynamics of Eisenia fetida during vermicomposting of water lettuce (Pistia sp.) biomass: a noxious weed of aquatic system.

    Science.gov (United States)

    Suthar, Surindra; Pandey, Bhawna; Gusain, Rita; Gaur, Rubia Zahid; Kumar, Kapil

    2017-01-01

    This paper reports the results of vermicomposting of water lettuce biomass (WL) spiked with cow dung at ratios of 20, 40, 60, and 80 % employing Eisenia fetida. A total of four treatments were established and changes in chemical properties of mixtures were observed. Vermicomposting caused a decrease in pH, TOC, volatile solids, and C/N ratio by 1.01-1.08-fold, 0.85-0.92-fold, 0.94-0.96-fold, 0.56-0.70-fold, respectively, but increase in EC, tot N, tot P, tot K, tot Ca, tot Zn, tot Fe, and tot Cu, by 1.19-1.42-fold, 1.33-1.68-fold, 1.38-1.69-fold, 1.13-1.24-fold, 1.04-1.11-fold, 1.16-1.37-fold, 1.05-1.113-fold, 1.10-1.27-fold, respectively. Overall, the treatment with 60-80 % of WL showed the maximum decomposition and mineralization rates. The earthworm showed the growth and reproduction rate in considerable ranges in all treatment setups but setups with 60-80 % WL proportion exhibited the optimum results. Results reveal that biomass of water lettuce can be utilized effectively for production of valuable manure through vermicomposting system.

  7. Root-secreted allelochemical in the noxious weed Phragmites australis deploys a reactive oxygen species response and microtubule assembly disruption to execute rhizotoxicity.

    Science.gov (United States)

    Rudrappa, Thimmaraju; Bonsall, Justin; Gallagher, John L; Seliskar, Denise M; Bais, Harsh P

    2007-10-01

    Phragmites australis is considered the most invasive plant in marsh and wetland communities in the eastern United States. Although allelopathy has been considered as a possible displacing mechanism in P. australis, there has been minimal success in characterizing the responsible allelochemical. We tested the occurrence of root-derived allelopathy in the invasiveness of P. australis. To this end, root exudates of two P. australis genotypes, BB (native) and P38 (an exotic) were tested for phytotoxicity on different plant species. The treatment of the susceptible plants with P. australis root exudates resulted in acute rhizotoxicity. It is interesting to note that the root exudates of P38 were more effective in causing root death in susceptible plants compared to the native BB exudates. The active ingredient in the P. australis exudates was identified as 3,4,5-trihydroxybenzoic acid (gallic acid). We tested the phytotoxic efficacy of gallic acid on various plant systems, including the model plant Arabidopsis thaliana. Most tested plants succumbed to the gallic acid treatment with the exception of P. australis itself. Mechanistically, gallic acid treatment generated elevated levels of reactive oxygen species (ROS) in the treated plant roots. Furthermore, the triggered ROS mediated the disruption of the root architecture of the susceptible plants by damaging the microtubule assembly. The study also highlights the persistence of the exuded gallic acid in P. australis's rhizosphere and its inhibitory effects against A. thaliana in the soil. In addition, gallic acid demonstrated an inhibitory effect on Spartina alterniflora, one of the salt marsh species it successfully invades.

  8. The Role of Rural Communities in Conservation of Rangelands in Mahneshan Township

    Directory of Open Access Journals (Sweden)

    Kobra Karimi

    2016-05-01

    Full Text Available The aim of this study was to investigate the action of rangeland-depended livestock holders regarding rangeland conservation, including protection and rehabilitation activities and to analyse relevant influencing factors, using a mixed method of survey and case study. The data were collected through analysing existing documents, focus groups, semi-structured and structured interviews using questionnaires submitted to 204 rural livestock holders in the Mahneshan Township. The quantitative data were analysed using SPSS and AMOS software. According to the results farmers’ knowledge regarding the role, importance and factors affecting rangeland degradation was relatively high, however they had a low level of knowledge and action about mechanical conservation techniques. The action of livestock holders in terms of biological conservation activities and grazing management showed a positive and signifincat corrletaion with variables such as implementing of rangeland projects, their interaction with external institutions, participating in extension training courses, education level and irrigated and rainfed agricultural land size. Moreover, based on a path analysis, 37% of the variance of the farmers’ actions regarding the rangeland conservation was explained by the variables such as rangeland rehabilitation actions, farmers’ conservation knowledge, farmers’ interaction with natural resources experts, beekeeping, and participating in extension training courses. Promotional and extension activities and farmers’ interaction with experts have a positive effect in enhancing farmers’ knowledge and actions for sustainable rangeland use and conservation.

  9. The GEOGLAM Rangelands and Pasture Productivity Activity: Recent Progress and Future Directions

    Science.gov (United States)

    Guerschman, J. P.; Held, A. A.; Donohue, R. J.; Renzullo, L. J.; Sims, N.; Kerblat, F.; Grundy, M.

    2015-12-01

    Rangelands and pastures cover about a third of the world's land area and support livestock production which represents ~40% of global agricultural gross domestic product. The global consumption of animal protein shows a clear increasing trend, driven by both total population and per capita income increases, putting a growing pressure on the sustainability of grazing lands worldwide. Despite their relevance, rangelands have received less attention than croplands regarding global monitoring of the resource productivity and condition. The Rangelands and Pasture Productivity (RaPP) activity is a component within the Global Agricultural Monitoring initiative established under the Group on Earth Observations (GEOGLAM) in 2013. GEOGLAM RaPP is aimed at providing the global community with the means to monitor the world's rangelands and pastures on a routine basis, and the capacity to produce animal protein in real-time, at global, regional and national levels. Since its launch two years ago GEOGLAM RAPP has made progress in the four implementation elements. These include: 1- the establishment of community of practice; 2- the development of a global monitoring system for rangeland condition; 3- the establishment of pilot sites in main rangeland systems for satellite data products validation and model testing; and 4- integration with livestock production models. Three international workshops have been held building the community of practice. A prototype monitoring system that provides global visualisations and querying capability of vegetation cover data and anomalies has been established. Pilot sites, mostly in areas with long records of field measurements of rangeland condition and productivity have been proposed for nine countries. The link to global livestock models, including physical and economic components, have been established. Future challenges for GEOGLAM RaPP have also been identified and include: better representation of the areas occupied by rangelands

  10. Analysis reveals potential rangeland impacts if Williamson Act eliminated

    Directory of Open Access Journals (Sweden)

    William C. Wetzel

    2012-10-01

    Full Text Available California budget cuts have resulted in dramatic reductions in state funding for the Williamson Act, a land protection program that reduces property taxes for the owners of 15 million acres of California farms and rangeland. With state reimbursements to counties eliminated, the decision to continue Williamson Act contracts lies with individual counties. We investigated the consequences of eliminating the Williamson Act, using a geospatial analysis and a mail questionnaire asking ranchers for plans under a hypothetical elimination scenario. The geospatial analysis revealed that 72% of rangeland parcels enrolled in Williamson Act contracts contained habitat important for statewide conservation goals. Presented with the elimination scenario, survey respondents reported an intention to sell 20% of their total 496,889 acres. The tendency of survey participants to respond that they would sell land was highest among full-time ranchers with low household incomes and without off-ranch employment. A majority (76% of the ranchers who reported that they would sell land predicted that the buyers would develop it for nonagricultural uses, suggesting substantial changes to California's landscape in a future without the Williamson Act.

  11. Scales of snow depth variability in high elevation rangeland sagebrush

    Science.gov (United States)

    Tedesche, Molly E.; Fassnacht, Steven R.; Meiman, Paul J.

    2017-09-01

    In high elevation semi-arid rangelands, sagebrush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush ( Artemisia tridentata Nutt.) at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions (0.05 to 25 m) and extents (2 to 1000 m). Finer scale data were collected specifically for this study to examine the correlation between snow depth, sagebrush microtopography, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Variograms were used to identify the spatial structure and the Moran's I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

  12. Water management as a key component of integrated weed management

    Directory of Open Access Journals (Sweden)

    Antonio Berti

    2010-09-01

    Full Text Available Water management within the cropping system is a key factor for an integrated weed management. Soil moisture affects seed persistence and seed dormancy, thus influencing their germination, the establishment of seedlings as well as the competition at adult stage and the number, vitality and dormancy of the new seeds produced by the weeds. The interactions among water availability and competition are very complex and still not fully understood. A research effort in this sector should the be very relevant for the development of new approaches of weed management, such as “Ecological weed management”, aiming to reduce weed density and competitiveness and, in the medium term, to prevent undesired modifications of the weed flora.

  13. Comparison of LANDSAT-2 and field spectrometer reflectance signatures of south Texas rangeland plant communities

    Science.gov (United States)

    Richardson, A. J.; Escobar, D. E.; Gausman, H. W.; Everitt, J. H. (Principal Investigator)

    1982-01-01

    The accuracy was assessed for an atmospheric correction method that depends on clear water bodies to infer solar and atmospheric parameters for radiative transfer equations by measuring the reflectance signature of four prominent south Texas rangeland plants with the LANDSAT satellite multispectral scanner (MSS) and a ground based spectroradiometer. The rangeland plant reflectances produced by the two sensors were correlated with no significant deviation of the slope from unity or of the intercept from zero. These results indicated that the atmospheric correction produced LANDSAT MSS estimates of rangeland plant reflectances that are as accurate as the ground based spectroradiometer.

  14. The value of milk in rangelands in Mandera County, Kenya

    Science.gov (United States)

    Ngugi, Keziah; Ertsen, Maurits

    2015-04-01

    Lack of water over expansive regions in Greater Horn of Africa created the rangelands and rangelands created pastoralism. Pastoralism involve keeping of large livestock herds and movement in search of resources, mainly water, pasture, medicine and wild foods. Several studies have been done in the last century and findings pointed at pastoralism being primitive and unsustainable. It has been predicted it would die in the last century but in the rangelands, pastoralism lives on and it is resilient. This study is based in Mandera, a pastoralism county in Kenya that neighbors Ethiopia to the North and Somalia to the East. The study sought to investigate contribution of milk to pastoralism resilience. Interviews were conducted in the field among the pastoralists, women groups, transporters, traders, government officials and consumers of milk. These information was corroborated with actual field investigations in the expansive rangelands of Mandera County. Pastoralists rarely slaughter or sell their livestock even when the animals waste away during droughts. This is because they have been through such cycles before and observed livestock make tremendous recovery when the right conditions were restored. Rangelands lack infrastructure, there are no roads, schools, telephone or hospitals. Pastoralists diet is comprised of rice, wheat and milk. It was established milk was the main source of income among pastoralists in Mandera County. From milk, the pastoralists make income that is used to purchase the other foodstuffs. Milk is available on daily basis in large quantities owing to the large number of livestock. Unfortunately, every pastoralist household produce copious amounts of milk, thus no local demand and transport infrastructure is nonexistent, making sale of milk a near impossible task. The findings showed the pastoralists have established unique routes through which milk reach the markets in urban centers where demand is high. Urbanization sustain pastoralism. These

  15. Can Arbuscular Mycorrhizal Fungi Reduce the Growth of Agricultural Weeds?

    Science.gov (United States)

    Veiga, Rita S. L.; Jansa, Jan; Frossard, Emmanuel; van der Heijden, Marcel G. A.

    2011-01-01

    Background Arbuscular mycorrhizal fungi (AMF) are known for their beneficial effects on plants. However, there is increasing evidence that some ruderal plants, including several agricultural weeds, respond negatively to AMF colonization. Here, we investigated the effect of AMF on the growth of individual weed species and on weed-crop interactions. Methodology/Principal Findings First, under controlled glasshouse conditions, we screened growth responses of nine weed species and three crops to a widespread AMF, Glomus intraradices. None of the weeds screened showed a significant positive mycorrhizal growth response and four weed species were significantly reduced by the AMF (growth responses between −22 and −35%). In a subsequent experiment, we selected three of the negatively responding weed species – Echinochloa crus-galli, Setaria viridis and Solanum nigrum – and analyzed their responses to a combination of three AMF (Glomus intraradices, Glomus mosseae and Glomus claroideum). Finally, we tested whether the presence of a crop (maize) enhanced the suppressive effect of AMF on weeds. We found that the growth of the three selected weed species was also reduced by a combination of AMF and that the presence of maize amplified the negative effect of AMF on the growth of E. crus-galli. Conclusions/Significance Our results show that AMF can negatively influence the growth of some weed species indicating that AMF have the potential to act as determinants of weed community structure. Furthermore, mycorrhizal weed growth reductions can be amplified in the presence of a crop. Previous studies have shown that AMF provide a number of beneficial ecosystem services. Taken together with our current results, the maintenance and promotion of AMF activity may thereby contribute to sustainable management of agroecosystems. However, in order to further the practical and ecological relevance of our findings, additional experiments should be performed under field conditions. PMID

  16. BIOLOGICAL CONTROL OF WEEDS BY MEANS OF PLANT PATHOGENS

    OpenAIRE

    Marija Ravlić; Renata Baličević

    2014-01-01

    Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, conservation and augmentative (inoculative and inundated) biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides) or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chem...

  17. Establishment and Early Growth of Willow at Different Levels of Weed Competition and Nitrogen Fertilization

    DEFF Research Database (Denmark)

    Edelfeldt, Stina; Lundkvist, Anneli; Forkman, Johannes

    2016-01-01

    To evaluate the effects of weed competition and nitrogen fertilization on the early growth performance of willow, cuttings of the clone Tora (Salix schwerinii x S. viminalis) were planted in buckets together with model weeds (spring barley or white mustard) sown 15, 26, and 30 days after willow...... gave higher willow biomass production in willow with weeds sown after 26 or 30 days. Type of model weed had no effect on willow performance. Weed biomass and maximum shoot height were higher in weeds planted without willows compared to the willow-weed mixtures. A high nitrogen level gave more weed...... biomass when planted without willows and in the willow-weed mixture with weeds sown after 15 days. We conclude that for the given high density of willow, competition from weeds emerging soon after willow planting had strong effect on early production. Furthermore, if there is a risk of weed infestation...

  18. The mathematical method of studying the reproduction structure of weeds and its application to Bromus sterilis

    NARCIS (Netherlands)

    Wang, J.; Hansen, P.K.; Christensen, S.; Qi, G.Z.

    2004-01-01

    This article discusses the structure of weed reproduction incorporating the application of a mathematical model. This mathematical methodology enables the construction, testing and application of distribution models for the analysis of the structure of weed reproduction and weed ecology. The

  19. Weeds in spring cereal fields in Finland - a third survey

    Directory of Open Access Journals (Sweden)

    J. SALONEN

    2008-12-01

    Full Text Available A survey of weeds in spring cereal fields was conducted in 16 regions of southern and central Finland in 1997-1999. Data were collected from conventional and organic farms, both of which applied their normal cropping practices. A total of 690 fields were investigated by counting and weighing the weed species from ten sample quadrats 0.1 m2 in size in late July - early August. Altogether 160 weed species were found, of which 134 were broad-leaved and 26 grass species. The total number of weed species ranged from 41 to 84 between regions. In organically farmed fields, the average species number was 24 and in conventionally farmed fields 16. The most frequent weed species were Viola arvensis 84%, Stellaria media 76% and Galeopsis spp. 70%. Only 18 species exceeded the frequency level of 33%. The average density of weeds was 136 m-2 (median= 91 in sprayed conventional fields, 420 m-2 (374 in unsprayed conventional fields and 469 m-2 (395 in organic fields. The average air-dry above-ground biomass of weeds was 163 kg ha-1 (median=63, 605 kg ha-1 (413 and 678 kg ha-1 (567, respectively. Weed biomass accounted for 3% of the total biomass of the crop stand in sprayed conventional fields and for 17% in organic fields. Elymus repens, the most frequent grass species, produced the highest proportion of weed biomass.

  20. 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.

  1. Problems and achievements of cotton (Gossypium Hirsutum L. weeds control

    Directory of Open Access Journals (Sweden)

    T. Barakova

    2017-09-01

    Full Text Available Abstract. Weed control in the cultivation of cotton is critical to the yield and quality of production. The influence of economically important weeds was studied. Chemical control is the most effective method of weed control in cotton but much of the information on it relates to primary weed infestation. Problems with primary weed infestation in cotton have been solved to a significant extent. The question of secondary weed infestation with annual and perennial graminaceous weeds during the period of cotton vegetation is also determined largely by the use of antigraminaceous herbicides. The data related to herbicides to effectively control secondary germinated broadleaf weeds in conventional technology for cotton growing are quite scarce, even globally. We are still seeking effective herbicides for control of these weeds in cotton crops. Studies on their influence on the sowing characteristics of cotton seed and the quality of cotton fiber are still insufficient. In the scientific literature there is not enough information on these questions. The combinations of herbicides, as well as their tank mixtures with fertilizers or plant growth regulators are more efficient than autonomous application. Often during their combined application higher synergistic effect on yield is produced. There is information about cotton cultivars resistant to glyphosate. These cultivars are GMO and they are banned within the European Union, including Bulgaria.

  2. Weed control technology for environmentally, economically and socially sustainable agriculture

    International Nuclear Information System (INIS)

    Khan, A.R.; Srivastava, R.C.; Ghorai, A.K.; Singh, S.R.

    2001-04-01

    Studies were conducted through a series of experiments for five consecutive wet seasons with a variety of alternative biological weed control techniques by means of soil solarization. This is a method of heating soil surface by using transparent polyethylene sheets placed on soil surface to trap solar radiation. This raises soil temperature to a level lethal for many soil borne pathogens and weed seeds, thus killing weeds before crop emergence. The use of black low density polyethylene sheets reduces weed growth and increases rice yield

  3. Development of Weeds Density Evaluation System Based on RGB Sensor

    Science.gov (United States)

    Solahudin, M.; Slamet, W.; Wahyu, W.

    2018-05-01

    Weeds are plant competitors which potentially reduce the yields due to competition for sunlight, water and soil nutrients. Recently, for chemical-based weed control, site-specific weed management that accommodates spatial and temporal diversity of weeds attack in determining the appropriate dose of herbicide based on Variable Rate Technology (VRT) is preferable than traditional approach with single dose herbicide application. In such application, determination of the level of weed density is an important task. Several methods have been studied to evaluate the density of weed attack. The objective of this study is to develop a system that is able to evaluate weed density based on RGB (Red, Green, and Blue) sensors. RGB sensor was used to acquire the RGB values of the surface of the field. An artificial neural network (ANN) model was then used for determining the weed density. In this study the ANN model was trained with 280 training data (70%), 60 validation data (15%), and 60 testing data (15%). Based on the field test, using the proposed method the weed density could be evaluated with an accuracy of 83.75%.

  4. Weed control technology for environmentally, economically and socially sustainable agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, Phulwari Sharif, Patna, Bihar (India); [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Srivastava, R C [Water Technology Centre for Eastern Region (ICAR), Bhubaneswar (India); Ghorai, A K [CRIJAF (ICAR), Barrackpore, West Bengal (India); Singh, S R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, Phulwari Sharif, Patna, Bihar (India)

    2001-04-01

    Studies were conducted through a series of experiments for five consecutive wet seasons with a variety of alternative biological weed control techniques by means of soil solarization. This is a method of heating soil surface by using transparent polyethylene sheets placed on soil surface to trap solar radiation. This raises soil temperature to a level lethal for many soil borne pathogens and weed seeds, thus killing weeds before crop emergence. The use of black low density polyethylene sheets reduces weed growth and increases rice yield.

  5. 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.

  6. Weed Growth Stage Estimator Using Deep Convolutional Neural Networks

    DEFF Research Database (Denmark)

    Teimouri, Nima; Dyrmann, Mads; Nielsen, Per Rydahl

    2018-01-01

    This study outlines a new method of automatically estimating weed species and growth stages (from cotyledon until eight leaves are visible) of in situ images covering 18 weed species or families. Images of weeds growing within a variety of crops were gathered across variable environmental conditi...... in estimating the number of leaves and 96% accuracy when accepting a deviation of two leaves. These results show that this new method of using deep convolutional neural networks has a relatively high ability to estimate early growth stages across a wide variety of weed species....

  7. Critical Period of Weed Control in Aerobic Rice

    Science.gov (United States)

    Anwar, M. P.; Juraimi, A. S.; Samedani, B.; Puteh, A.; Man, A.

    2012-01-01

    Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interference and (b) increasing length of weed-free period, were imposed. Critical period was determined through Logistic and Gompertz equations. Critical period varied between seasons; in main season, it started earlier and lasted longer, as compared to off-season. The onset of the critical period was found relatively stable between seasons, while the end was more variable. Critical period was determined as 7–49 days after seeding in off-season and 7–53 days in main season to achieve 95% of weed-free yield, and 23–40 days in off-season and 21–43 days in main season to achieve 90% of weed-free yield. Since 5% yield loss level is not practical from economic view point, a 10% yield loss may be considered excellent from economic view point. Therefore, aerobic rice should be kept weed-free during 21–43 days for better yield and higher economic return. PMID:22778701

  8. Integrated Weed Management Strategies for Control of Hydrilla

    National Research Council Canada - National Science Library

    Nelson, Linda S; Shearer, Judy F

    2009-01-01

    ...), and the fungal pathogen Mycoleptodiscus terrestris (Gerd.) Ostazeski, applied alone and in combination with one another, as an integrated weed management strategy against the nuisance aquatic plant, hydrilla...

  9. Prediction of the competitive effects of weeds on crop yields based on the relative leaf area of weeds

    DEFF Research Database (Denmark)

    Lotz, L. A. P.; Christensen, Svend; Cloutier, D.

    1996-01-01

    . alba whereas the density model did not. A parameter that allows the maximum yield loss to be smaller than 100% was mostly not needed to describe the effects of weed competition. The parameter that denotes the competitiveness of the weed species with respect to the crop decreased the later the relative......For implementation of simple yield loss models into threshold-based weed management systems, a thorough validation is needed over a great diversity of sites. Yield losses by competition wsth Sinapis alba L. (white mustard) as a model weed, were studied in 12 experiments in sugar beet (Beta vulgaris...... L.) and in 11 experiments in spring wheat (Triticum aestivum L.). Most data sets were heller described by a model based on the relative leaf area of the weed than by a hyperbolic model based on weed density. This leaf area model accounted for (part of) the effect of different emerging times of the S...

  10. Determining treatment frequency for controlling weeds on traffic islands using chemical and non-chemical weed control

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Larsen, S.U.; Andreasen, Christian

    2013-01-01

    Many public authorities rely on the use of non-chemical weed control methods, due to stringent restrictions on herbicide use in urban areas. However, these methods usually require more repeated treatments than chemical weed management, resulting in increased costs of weed management. In order...... of treatments per year were required: glyphosate 2.5, hot water 3, flames 5, hot air/flames 5.5 and steam 5.5 treatments. The results demonstrate that the weed control should be adjusted to the prescribed quality for the traffic islands by regularly assessing the need for weed control. They also show...... to investigate the efficacy of four non-chemical weed control methods and glyphosate treatment, experiments were carried out on traffic islands in the growing seasons 2005 and 2006. Three trial sites were each divided into six treatment areas, which were either treated with glyphosate, flame, steam, hot air...

  11. Characterization of thoracic spinal neurons with noxious convergent inputs from heart and lower airways in rats.

    Science.gov (United States)

    Qin, Chao; Foreman, Robert D; Farber, Jay P

    2007-04-13

    Respiratory symptoms experienced in some patients with cardiac diseases may be due to convergence of noxious cardiac and pulmonary inputs onto neurons of the central nervous system. For example, convergence of cardiac and respiratory inputs onto single solitary tract neurons may be in part responsible for integration of regulatory and defensive reflex control. However, it is unknown whether inputs from the lungs and heart converge onto single neurons of the spinal cord. The present aim was to characterize upper thoracic spinal neurons responding to both noxious stimuli of the heart and lungs in rats. Extracellular potentials of single thoracic (T3) spinal neurons were recorded in pentobarbital anesthetized, paralyzed, and ventilated male rats. A catheter was placed in the pericardial sac to administer bradykinin (BK, 10 microg/ml, 0.2 ml, 1 min) as a noxious cardiac stimulus. The lung irritant, ammonia, obtained as vapor over a 30% solution of NH(4)OH was injected into the inspiratory line of the ventilator (0.5-1.0 ml over 20 s). Intrapericardial bradykinin (IB) altered activity of 58/65 (89%) spinal neurons that responded to inhaled ammonia (IA). Among those cardiopulmonary convergent neurons, 81% (47/58) were excited by both IA and IB, and the remainder had complex response patterns. Bilateral cervical vagotomy revealed that vagal afferents modulated but did not eliminate responses of individual spinal neurons to IB and IA. The convergence of pulmonary and cardiac nociceptive signaling in the spinal cord may be relevant to situations where a disease process in one organ influences the behavior of the other.

  12. Diffuse noxious inhibitory controls and nerve injury: restoring an imbalance between descending monoamine inhibitions and facilitations.

    Science.gov (United States)

    Bannister, Kirsty; Patel, Ryan; Goncalves, Leonor; Townson, Louisa; Dickenson, Anthony H

    2015-09-01

    Diffuse noxious inhibitory controls (DNICs) utilize descending inhibitory controls through poorly understood brain stem pathways. The human counterpart, conditioned pain modulation, is reduced in patients with neuropathy aligned with animal data showing a loss of descending inhibitory noradrenaline controls together with a gain of 5-HT3 receptor-mediated facilitations after neuropathy. We investigated the pharmacological basis of DNIC and whether it can be restored after neuropathy. Deep dorsal horn neurons were activated by von Frey filaments applied to the hind paw, and DNIC was induced by a pinch applied to the ear in isoflurane-anaesthetized animals. Spinal nerve ligation was the model of neuropathy. Diffuse noxious inhibitory control was present in control rats but abolished after neuropathy. α2 adrenoceptor mechanisms underlie DNIC because the antagonists, yohimbine and atipamezole, markedly attenuated this descending inhibition. We restored DNIC in spinal nerve ligated animals by blocking 5-HT3 descending facilitations with the antagonist ondansetron or by enhancing norepinephrine modulation through the use of reboxetine (a norepinephrine reuptake inhibitor, NRI) or tapentadol (μ-opioid receptor agonist and NRI). Additionally, ondansetron enhanced DNIC in normal animals. Diffuse noxious inhibitory controls are reduced after peripheral nerve injury illustrating the central impact of neuropathy, leading to an imbalance in descending excitations and inhibitions. Underlying noradrenergic mechanisms explain the relationship between conditioned pain modulation and the use of tapentadol and duloxetine (a serotonin, NRI) in patients. We suggest that pharmacological strategies through manipulation of the monoamine system could be used to enhance DNIC in patients by blocking descending facilitations with ondansetron or enhancing norepinephrine inhibitions, so possibly reducing chronic pain.

  13. Suicidal germination for parasitic weed control.

    Science.gov (United States)

    Zwanenburg, Binne; Mwakaboko, Alinanuswe S; Kannan, Chinnaswamy

    2016-11-01

    Parasitic weeds of the genera Striga and Orobanche spp. cause severe yield losses in agriculture, especially in developing countries and the Mediterranean. Seeds of these weeds germinate by a chemical signal exuded by the roots of host plants. The radicle thus produced attaches to the root of the host plant, which can then supply nutrients to the parasite. There is an urgent need to control these weeds to ensure better agricultural production. The naturally occurring chemical signals are strigolactones (SLs), e.g. strigol and orobanchol. One option to control these weeds involves the use of SLs as suicidal germination agents, where germination takes place in the absence of a host. Owing to the lack of nutrients, the germinated seeds will die. The structure of natural SLs is too complex to allow multigram synthesis. Therefore, SL analogues are developed for this purpose. Examples are GR24 and Nijmegen-1. In this paper, the SL analogues Nijmegen-1 and Nijmegen-1 Me were applied in the field as suicidal germination agents. Both SL analogues were formulated using an appropriate EC-approved emulsifier (polyoxyethylene sorbitol hexaoleate) and applied to tobacco (Nicotiana tabacum L.) fields infested by Orobanche ramosa L. (hemp broomrape), following a strict protocol. Four out of 12 trials showed a reduction in broomrape of ≥95%, two trials were negative, two showed a moderate result, one was unclear and in three cases there was no Orobanche problem in the year of the trials. The trial plots were ca 2000 m 2 ; half of that area was treated with stimulant emulsion, the other half was not treated. The optimal amount of stimulant was 6.25 g ha -1 . A preconditioning prior to the treatment was a prerequisite for a successful trial. In conclusion, the suicidal germination approach to reducing O. ramosa in tobacco fields using formulated SL analogues was successful. Two other options for weed control are discussed: deactivation of stimulants prior to action and

  14. THE EFFECT OF WINTER CATCH CROPS ON WEED INFESTATION IN SWEET CORN DEPENDING ON THE WEED CONTROL METHODS

    Directory of Open Access Journals (Sweden)

    Robert Rosa

    2015-02-01

    Full Text Available An experiment was carried out in east-central Poland (52°06’ N, 22°55’ E over 2008–2011 to study the effect of winter catch crops on the weed infestation, number, and fresh matter of weeds in sweet corn (Zea mays L. var. saccharata. The following winter catch crops were grown: hairy vetch (Vicia villosa Roth., white clover (Trifolium repens L., winter rye (Secale cereale L., Italian ryegrass (Lolium multiflorum L. and winter turnip rape (Brassica rapa var. typica Posp.. The catch crops were sown in early September and incorporated in early May. The effect of the catch crops was compared to the effect of FYM (30 t·ha-1 and control without organic manuring (NOM. Three methods of weed control were used: HW – hand weeding, twice during the growing period, GCM – the herbicide Guardian Complete Mix 664 SE, immediately after sowing of corn seeds, Z+T – a mixture of the herbicides Zeagran 340 SE and Titus 25 WG applied at the 3–4-leaf stage of sweet corn growth. Rye and turnip rape catch crops had least weeds in their fresh matter. Sweet corn following winter catch crops was less infested by weeds than corn following farmyard manure and non-manured corn. Least weeds and their lowest weight were found after SC, BRT and VV. LM and BRT reduced weed species numbers compared with FYM and NOM. The greatest weed species diversity, determined at the corn flowering stage, was determined after SC and FYM. The number and weight of weeds were significantly lower when chemically controlled compared with hand weeding. The best results were observed after a post-emergent application of the mixture Z+T. The weed species diversity on Z+T-treated plots was clearly lower compared with GCM and HW.

  15. Weed-cover versus weed-removal management in olive orchards: influence on the carbon balance at the ecosystem scale

    Science.gov (United States)

    Chamizo, Sonia; Serrano-Ortiz, Penélope; Vicente-Vicente, José Luis; Sánchez-Cañete, Enrique P.; López-Ballesteros, Ana; Kowalski, Andrew S.

    2016-04-01

    Agriculture plays an important role in the C budget at the global scale. Traditional practices based on soil tillage and applying herbicides to remove weeds have caused damage to soils and led to important losses of soil organic C and increased CO2 emissions to the atmosphere. Changing trends from traditional agriculture to conservation agriculture practices may have an important role in both C and water budgets and the transformation of agriculture from C source to C sink. The objective of this study was to analyse the effect of two treatments, weed removal by herbicides versus weed cover conservation, on the C balance in an irrigated olive orchard in SE Spain. Measurements of CO2 exchange were made from October 2014 to September 2015 using two eddy covariance towers, one for each olive crop treatment. Results show that CO2 fluxes at the ecosystem scale were similar in the two treatments during initial conditions, prior to weed growth in the soils without herbicide application (October). During the first week, daily net ecosystem exchange (NEE) was close to zero in both treatments, with values ranging from 1.06 to -0.41 g C m-2 in the weed cover treatment, and from 0.76 to -0.69 g C m-2 in the weed removal treatment. As weed growth increased, higher net CO2 assimilation was found in the treatment with weed cover. In both treatments, maximum net CO2 assimilation was found in March, with a monthly NEE of -72 and -28 g C m-2 in the treatment with and without weed cover, respectively. In May, after the weeds were cut and left on the soil, a strong increase was observed in NEE in the treatment with weed cover due to decreased CO2 assimilation and increased respiration compared to the treatment without weed cover. Therefore, soil chamber measurements showed average respiration rates of 2.57 and 1.57 μmol m-2 s-2 in the weed cover and weed removal treatment, respectively. Finally, the highest monthly NEE was registered during July, with both treatments showing a similar

  16. Reality of rangeland degradation mapping with remote sensing: the South African experience

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2008-09-01

    Full Text Available Globally there is an urgent need for standardized, quantitative measures rangeland degradation. Over the past 10 years in South Africa (SA), significant research efforts have been directed at this challenge, using diverse methods and data...

  17. Human-modified landscapes: patterns of fine-scale woody vegetation structure in communal savannah rangelands

    CSIR Research Space (South Africa)

    Fisher, T

    2011-11-01

    Full Text Available structure in five communal rangelands around 12 settlements in Bushbuckridge, a municipality in the Kruger to Canyons Biosphere Reserve (South Africa). The importance of underlying abiotic factors was evaluated by measuring size class distributions across...

  18. Success of seeding native compared with introduced perennial vegetation for revegetating medusahead-invaded sagebrush rangeland

    Science.gov (United States)

    Millions of hectares of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &Young) rangeland have been invaded by medusahead (Taeniatherum caput-medusae [L.] Nevski), an exotic annual grass that degrades wildlife habitat, reduces forage production, and decreases biodiversity....

  19. Separating the cows from the trees: toward development of national definitions of forest and rangeland

    Science.gov (United States)

    H. Gyde Lund

    2007-01-01

    This paper introduces issues surrounding the need for national definitions of forest and rangeland, and it review types of definitions in use, reviews past agreements and their status, and finally gives recommendations as to what should be done next.

  20. Multiscale sagebrush rangeland habitat modeling in southwest Wyoming

    Science.gov (United States)

    Homer, Collin G.; Aldridge, Cameron L.; Meyer, Debra K.; Coan, Michael J.; Bowen, Zachary H.

    2009-01-01

    Sagebrush-steppe ecosystems in North America have experienced dramatic elimination and degradation since European settlement. As a result, sagebrush-steppe dependent species have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, would improve the ability to maintain existing sagebrush habitats. However, current data only identify resource availability locally, with rigorous spatial tools and models that accurately model and map sagebrush habitats over large areas still unavailable. Here we report on an effort to produce a rigorous large-area sagebrush-habitat classification and inventory with statistically validated products and estimates of precision in the State of Wyoming. This research employs a combination of significant new tools, including (1) modeling sagebrush rangeland as a series of independent continuous field components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground-measured plot data on 2.4-meter imagery in the same season the satellite imagery is acquired; (3) effective modeling of ground-measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of an additional two spatial scales of imagery (30 meter and 56 meter) for optimal large-area modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution sensors; and (6) employing rigorous accuracy assessment of model predictions to enable users to understand the inherent uncertainties. First-phase results modeled eight rangeland components (four primary targets and four secondary targets) as continuous field predictions. The primary targets included percent bare ground, percent herbaceousness, percent shrub, and percent litter. The

  1. Analysis of the Heterogeneity of Weed Infestation in Cereal Stands

    Directory of Open Access Journals (Sweden)

    Jan Winkler

    2015-01-01

    Full Text Available The aim of this study was to evaluate the heterogeneity of the incidence of individual weed species on a selected experimental field. This field was situated in the cadastre of the village Žabčice (South Moravian Region, Czech Republic. To evaluate the intensity of weed infestation, a field experiment was established. In 2011, altogether 33 weed species were identified in a stand of spring barley. In the next year, the total number of weeds in a stand of winter wheat was 22. Basing on results of the evaluation of infestation heterogeneity it was possible to detect the following trends: The first one concerned the incidence of significantly dominant species Chenopodium album and Veronica hederifolia in stands of spring barley and winter wheat, respectively. The second one expressed the incidence of the so-called sub-dominant species. Regarding the character of the incidence of these weed species it would be suitable to kill them by means of a targeted application of herbicides. Finally, the third trend concerned the incidence of that group of weeds that occurred in the major part of the experimental plot but in low numbers only. The abundance of these species was minimal and the total number of weed plants did not exceed the limit of 100 specimens. This group of weeds involved also those species that were markedly more frequent on plots situated closer to the margin of the experimental field. The targeted application of herbicides can be performed on plots with a lower level of weed infestation; another possibility, however, seems to be a targeted intervention that helps to control the incidence of a certain weed species and/or that is performed along the margin of the field where the different weed species are more frequent.

  2. Freezing of enkephalinergic functions by multiple noxious foci: a source of pain sensitization?

    Directory of Open Access Journals (Sweden)

    François Cesselin

    Full Text Available BACKGROUND: The functional significance of proenkephalin systems in processing pain remains an open question and indeed is puzzling. For example, a noxious mechanical stimulus does not alter the release of Met-enkephalin-like material (MELM from segments of the spinal cord related to the stimulated area of the body, but does increase its release from other segments. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that, in the rat, a noxious mechanical stimulus applied to either the right or the left hind paw elicits a marked increase of MELM release during perifusion of either the whole spinal cord or the cervico-trigeminal area. However, these stimulatory effects were not additive and indeed, disappeared completely when the right and left paws were stimulated simultaneously. CONCLUSION/SIGNIFICANCE: We have concluded that in addition to the concept of a diffuse control of the transmission of nociceptive signals through the dorsal horn, there is a diffuse control of the modulation of this transmission. The "freezing" of Met-enkephalinergic functions represents a potential source of central sensitization in the spinal cord, notably in clinical situations involving multiple painful foci, e.g. cancer with metastases, poly-traumatism or rheumatoid arthritis.

  3. Rangeland Use Rights Privatisation Based on the Tragedy of the Commons: A Case Study from Tibet

    Directory of Open Access Journals (Sweden)

    Yonten Nyima Yundannima

    2017-01-01

    Full Text Available Rangeland use rights privatisation based on a tragedy of the commons assumption has been the backbone of state policy on rangeland management and pastoralism in China. Through an empirical case study from Pelgon county, Tibet Autonomous Region in China, this paper provides an empirical analysis of rangeland use rights privatisation. It shows that the tragedy of the commons is not the correct model to apply to Tibetan pastoralism because pasture use in Tibet has never been an open-access institution. Thus, when the tragedy of the commons model is applied as a rationale for rangeland use rights privatisation, the result is not what is intended by the policy, but rather a misfit to features of pastoralism and thus disruption of the essence of pastoralism, i.e. mobility and flexibility. The paper further shows that a hybrid institution combining household rangeland tenure with community-based use with user fees is a restoration of the pastoralist institution. This demonstrates the capacity of pastoralists to create adaptive new institutions congruent with the interdependent and integrated nature of pastoralism consisting of three components: pastoralists, livestock, and rangeland.

  4. Effect of weed control treatments and cutting frequency on weed dry ...

    African Journals Online (AJOL)

    Two experiments were conducted during the rainy seasons of 2012 and 2013 at the Teaching and Research Farm of the Department of Crop Science, University of Nigeria, Nsukka, to evaluate the growth and leaf yield of Telfairia occidentials Hook F. as influenced by weed control treatments and cutting frequencies.

  5. Remote sensing data in Rangeland assessment and monitoring

    International Nuclear Information System (INIS)

    Hamid, Amna Ahmed; Ali, Mohamed M.

    1999-01-01

    The main objective of the paper is to illustrate the potential of remote sensing data in the study and monitoring of environmental changes in western Sudan where considerable part of the area is under rangeland use. Data from NOAA satellite AVHRR sensor as well as thematic mapper Tm was used to assess the environment of the area during 1982-1997. The AVHRR data was processed into vegetation index (NDVI) images. Image analysis and classification was done using image display and analysis (IDA) GIS method to study vegetation condition in time series. The obtained information from field observations. The result showed high correlation between the information the work concluded the followings: NDVI images and thematic mapper data proved to be efficient in environment change analysis. NOAA AVHRR satellite data can provide an early-warning indicator of an approaching disaster. Remote sensing integrated into a GIS can contribute effectively to improve land management through better understanding of environment variability.(Author)

  6. Monitoring Forage Production of California Rangeland Using Remote Sensing Observations

    Science.gov (United States)

    Liu, H.; Jin, Y.; Dahlgren, R. A.; O'Geen, A. T.; Roche, L. M.; Smith, A. M.; Flavell, D.

    2016-12-01

    Pastures and rangeland cover more than 10 million hectares in California's coastal and inland foothill regions, providing feeds to livestock and important ecosystem services. Forage production in California has a large year-to-year variation due to large inter-annual and seasonal variabilities in precipitation and temperature. It also varies spatially due to the variability in climate and soils. Our goal is to develop a robust and cost-effective tool to map the near-real-time and historical forage productivity in California using remote sensing observations from Landsat and MODIS satellites. We used a Monteith's eco-physiological plant growth theory: the aboveground net primary production (ANPP) is determined by (i) the absorbed photosynthetically active radiation (APAR) and the (ii) light use efficiency (LUE): ANPP = APAR * LUEmax * f(T) * f(SM), where LUEmax is the maximum LUE, and f(T) and f(SM) are the temperature and soil moisture constrains on LUE. APAR was estimated with Landsat and MODIS vegetation index (VI), and LUE was calibrated with a statewide point dataset of peak forage production measurements at 75 annual rangeland sites. A non-linear optimization was performed to derive maximum LUE and the parameters for temperature and soil moisture regulation on LUE by minimizing the differences between the estimated and measured ANPP. Our results showed the satellite-derived annual forage production estimates correlated well withcontemporaneous in-situ forage measurements and captured both the spatial and temporal productivity patterns of forage productivity well. This remote sensing algorithm can be further improved as new field measurements become available. This tool will have a great importance in maintaining a sustainable range industry by providing key knowledge for ranchers and the stakeholders to make managerial decisions.

  7. Designing, modeling and controlling a novel autonomous laser weeding system

    DEFF Research Database (Denmark)

    Shahrak Nadimi, Esmaeil; Andersson, Kim Johan; Jørgensen, Rasmus Nyholm

    2009-01-01

      Abstract: in this paper, the process of designing and developing a novel laser weeding test setup is explained. The main purpose of designing this system was to simulate the dynamic field conditions of a mobile vehicle capable of targeting weeds. This system consists of a rig containing three...

  8. Distribution patterns of segetal weeds of cereal crops in tajikistan

    International Nuclear Information System (INIS)

    Nowak, A.; Nowak, S.

    2015-01-01

    Using the literature data and field research conducted in 2009-2013 the distribution patterns, habitat conditions, phytogeographical characterisation and endangerment of weeds occurring in cereal crops in Tajikistan were analysed. We found out that Tajik weed flora of cereal crops counts 686 taxa. The most species rich families include Asteraceae, Poaceae and Fabaceae. The highest number of cereal weeds were noted in large river valleys of Syr-Daria, Amu-Daria and their tributaries in south-western and northern Tajikistan. This subregions have the warmest climate conditions and extensive arable lands. The greatest weed species richness was observed in submontane and montane elevations between approx. 700 and 1,900 m a.s. Cereal weeds occur frequently outside segetal communities in Tajikistan. They were noted usually in screes, wastelands, xerothermophilous grasslands, river gravel beds and in steppes habitats. The assessment of threat status reveals that ca. 33% of total cereal weed flora in Tajikistan are disappearing or occur very rarely. According to the chorological data we find that in the cereals of Tajikistan, 35 endemic and 14 subendemic species occur. The most numerous chorological elements of threatened weed flora of Tajikistan are Irano-Turanian (55%), pluriregional (16%), cosmopolitan (14,5%), Mediterranean (9%) and Eurosiberian (5%) species. Further research is suggested to explore the distribution patterns of all weed species in Tajikistan as it should be useful for economy and effectiveness of crop production as well as conservation of most valuable species. (author)

  9. Effect of different weed management techniques on growth ...

    African Journals Online (AJOL)

    The weed management techniques included slashing at 8-weekly intervals, mulching alone, glyphosate + slashing, glyphosate + mulching, glyphosate alone and a weed-free control. Glyphosate + mulching proved to have the greatest positive influence on plant height, plant girth, leaf area and number of leaves throughout ...

  10. Aquatic weed control within an integrated water management framework

    NARCIS (Netherlands)

    Querner, E.P.

    1993-01-01

    Aquatic weed control, carried out by the water boards in the Netherlands, is required to maintain sufficient discharge capacity of the surface water system. Weed control affects the conditions of both surface water and groundwater. The physically based model MOGROW was developed to simulate

  11. How to Identify and Control Water Weeds and Algae.

    Science.gov (United States)

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…

  12. Evaluation of Selected Pre-Emergence Herbicides for Weed Control ...

    African Journals Online (AJOL)

    Pendimentalin had no significant effect on the plantlets across the rates tested. The best weed control was achieved with diuron applied at 25% and above, while the least weed control occurred on the control plot and these treated with 10% of atrazine and primextra Gold. However, there were no significant variations in the ...

  13. Weed management in banana production: The use of Nelsonia ...

    African Journals Online (AJOL)

    During a survey of weeds in the Tiko banana plantations, the plant Nelsonia canescens (Lam.) Spreng was found to have invaded large areas of the plantation with no visible adverse effects on the banana crop. The effects of this Acanthaceae on banana yield parameters, snails' population and weed species diversity and ...

  14. Effects of different crop associations and fertilizer types on weed ...

    African Journals Online (AJOL)

    Experiments were conducted at the Teaching and Research Farm of the University of Ibadan in 1998/1999 and 1999/2000 cropping seasons to determine the effects of different crop associations and fertilizer types on the weed biomass. The results showed that crop associations did not significantly affect weed density and ...

  15. Developing selection protocols for weed competitiveness in aerobic rice

    NARCIS (Netherlands)

    Zhao, D.L.; Atlin, G.N.; Bastiaans, L.; Spiertz, J.H.J.

    2006-01-01

    Aerobic rice production systems, wherein rice is dry-sown in non-puddled soil and grown as an upland crop, offer large water savings but are subject to severe weed infestation. Weed-competitive cultivars will be critical to the adoption of aerobic rice production by farmers. Breeding

  16. Critical Period for Weed Removal in Garden Egg (Solanum Incanum ...

    African Journals Online (AJOL)

    Field experiments were conducted at the Teaching and Research Farm, Adeyemi College of Education, Ondo during the 2004 and 2005 cropping seasons to determine the extent of yield loss due to weed infestation and the critical time for weed removal in garden egg (Solanum incanum). The experiment which was ...

  17. 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 ...

  18. Effect of weed management methods and nitrogen fertilizer rates on ...

    African Journals Online (AJOL)

    Inefficient weed management practices and the use of inappropriate nitrogen fertilizer rates are the major causes of low yield of wheat in Ethiopia. Therefore, field experiments were conducted at Bobicho and Faate in southern Ethiopia to determine the effect of weed management practices and N fertilizer rates on grain yield ...

  19. 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 ...

  20. Effect Of Weed On Oil Palm Inflorenscence Production: Implication ...

    African Journals Online (AJOL)

    Weed consistently depressed the performance of oil palm and this depressive effect was attributed to aggressive growth resources, smothering of the oil palm and preventing the palm from proper ventilation and solar radiation. Weed interference on inflorescence production of oil palm was assessed with the view of ...

  1. effect of fluazitopbutyl and atrazine/metolachlor for weed control

    African Journals Online (AJOL)

    COCOYAM

    also gave the highest yield and monetary gain when compares with manual weeding. This technique will be ... be a “back yard” crop or “gap filler”. Survey reports in .... Critical period of weed interference intercropped with maize and cocoyam.

  2. An Autonomous Robotic System for Mapping Weeds in Fields

    DEFF Research Database (Denmark)

    Hansen, Karl Damkjær; Garcia Ruiz, Francisco Jose; Kazmi, Wajahat

    2013-01-01

    The ASETA project develops theory and methods for robotic agricultural systems. In ASETA, unmanned aircraft and unmanned ground vehicles are used to automate the task of identifying and removing weeds in sugar beet fields. The framework for a working automatic robotic weeding system is presented...

  3. WEED FLORA OF CASSAVA IN WEST NILE ZONES OF UGANDA ...

    African Journals Online (AJOL)

    ACSS

    Information on weeds of cassava (Manihot esculenta Crantz) in eastern Africa is limited. The objective of this study was to establish the status of weed flora in selected cassava growing regions of Uganda. This study was conducted in 2013 at Abi Zonal Agricultural Research and Development Institute; (AbiZARDI) in Arua, ...

  4. UAV low-altitude remote sensing for precision weed management

    Science.gov (United States)

    Precision weed management, an application of precision agriculture, accounts for within-field variability of weed infestation and herbicide damage. Unmanned aerial vehicles (UAVs) provide a unique platform for remote sensing of field crops. They are more efficient and flexible than manned agricultur...

  5. A weed suppressive index for spring barley (Hordeum vulgare) varieties

    DEFF Research Database (Denmark)

    Hansen, P K; Kristensen, K; Willas, J

    2008-01-01

    A screening programme for crop variety competitiveness would ideally be based on only a few, non-destructive measurements of key growth traits. In this study we measured the weed suppressive ability of 79 varieties of spring barley in two ways: (i) directly, by weed coverage assessments under wee...

  6. Optimal weed management in crop rotations: incorporating economics is crucial

    NARCIS (Netherlands)

    Berg, van den F.; Gilligan, C.A.; Lemmen-Gerdessen, van J.C.; Gregoire, L.A.H.; Bosch, van den F.

    2010-01-01

    Although the effects of crop rotation sequence and length on weed population dynamics have been studied, it is not clear whether or not the best strategy, from a weed population dynamics point of view, is also the economic optimal strategy. It is also not clear which biological and economic

  7. Big Data for weed control and crop protection

    NARCIS (Netherlands)

    Evert, van F.K.; Fountas, S.; Jakovetic, D.; Crnojevic, V.; Travlos, I.; Kempenaar, C.

    2017-01-01

    Farmers have access to many data-intensive technologies to help them monitor and control weeds and pests. Data collection, data modelling and analysis, and data sharing have become core challenges in weed control and crop protection. We review the challenges and opportunities of Big Data in

  8. Cover crop residue management for optimizing weed control

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2009-01-01

    Although residue management seems a key factor in residue-mediated weed suppression, very few studies have systematically compared the influence of different residue management strategies on the establishment of crop and weed species. We evaluated the effect of several methods of pre-treatment and

  9. Weed biocontrol in the EU: from serendipity to strategy

    Science.gov (United States)

    Biological control of weeds is a globally-recognized approach to the management of the worst invasive plants in the world. Unfortunately, accidental introduction of agents account for most weed biocontrol in the EU, but do include a number of current or emerging successes. From the redistribution of...

  10. Managing invasive plants in natural areas: Moving beyond weed control

    Science.gov (United States)

    Dean Pearson; Yvette Ortega

    2009-01-01

    Exotic invasive plants present one of the greatest challenges to natural resource management. These weeds can alter entire communities and ecosystems, substantially degrading important ecosystem services such as forage for wild and domestic herbivores, water and soil quality, recreational values, and wildlife habitat. Traditionally, weed management in natural areas has...

  11. Resource analysis of the Chinese society 1980-2002 based on exergy-Part 4: Fishery and rangeland

    International Nuclear Information System (INIS)

    Chen, B.; Chen, G.Q.

    2007-01-01

    This fourth part is the continuation of the third part on agricultural products. The major fishery and rangeland products entering the Chinese society from 1980 to 2002 are calculated and analyzed in detail in this paper. The aquatic production, mainly relying on freshwater and seawater breeding, Enhancement policy of fishery resources, including closed fishing season system, construction of artificial fish reefs and ecological fish breeding, etc., is discussed in detail. The degradation of the major rangeland areas, hay yields and intake rangeland resources by the livestock, are also described associated with the strategic adjustment and comprehensive program to protect rangeland resources during the study period

  12. Team-up Crop Diversification and Weed Management: PRODIVA

    DEFF Research Database (Denmark)

    Gerowitt, B.; Melander, B.; Krawczyk, R.

    2015-01-01

    The research-network PRODIVA focuses on a better utilization of crop diversification for weed management in North European arable cropping systems. The goal is to maintain diverse arable weed vegetation that is manageable in the long-term and could fulfil other necessary systemfunctions including...... support of beneficial organisms. The partners in PRODIVA will synthesize knowledge from terminated and running research projects and set-up selected new experiments on cover crops and variety resp. crop mixtures. Moreover, we will interact with partners from farming practice and extension services...... in organic agriculture. Regional fields will be surveyed for weeds to safeguard the relevance of the experimental research. Current cropping practices and their influence on weed pressure and weed diversity will be identified. The project will involve relevant stakeholders from the participating countries...

  13. Weed Mapping with Co-Kriging Using Soil Properties

    DEFF Research Database (Denmark)

    Heisel, Torben; Ersbøll, Annette Kjær; Andreasen, Christian

    1999-01-01

    Our aim is to build reliable weed maps to control weeds in patches. Weed sampling is time consuming but there are some shortcuts. If an intensively sampled variable (e.g. soil property) can be used to improve estimation of a sparsely sampled variable (e.g. weed distribution), one can reduce weed...... sampling. The geostatistical estimation method co-kriging uses two or more sampled variables, which are correlated, to improve the estimation of one of the variables at locations where it was not sampled. We did an experiment on a 2.1 ha winter wheat field to compare co-kriging using soil properties......, with kriging based only on one variable. The results showed that co-kriging Lamium spp. from 96 0.25m2 sample plots ha-1 with silt content improved the prediction variance by 11% compared to kriging. With 51 or 18 sample plots ha-1 the prediction variance was improved by 21 and 15%....

  14. Allelopatic potential of weeds under the minimalization of soil treatment

    Directory of Open Access Journals (Sweden)

    Mikhail A. Mazirov

    2014-01-01

    Full Text Available The content of water-dispersible phenol substances in rhizosphere both of annual and perennial species of weeds (Cirsium arvense, Sonchus arvensis increases under soil treatment minimalization. The higher content of phenol substances of researched weeds is defined in rhizosphere of Common Couch (Agropyrum repens. The absence of intensive anthropogenic treatment of plowing layer which accumulates the significant mass of weed’s roots in the cause of much more higher allelopathic potential of some species’ of weeds. The high level of saturation by weeds in agrophytocoenosis under non-tillage soil treatment is defines the competitiveness between certain sepsis’ of weeds, especially, at the beginning of the vegetation. In this case, increasing the secretion of phenol substances is one of the physiological screenings of such competitiveness.

  15. Weed species diversity in organic and integrated farming systems

    Directory of Open Access Journals (Sweden)

    Magdalena Jastrzębska

    2013-10-01

    Full Text Available Phytosociological data were collected in 1994–1996 in plots (relevés at the Research Station for Organic Farming and Conservation Breeding of the Polish Academy of Sciences in Popielno included in a large-area experiment conducted according to the concept and method proposed by Prof. S. Nawrocki. In a four-field crop rotation (root crops – spring barley undersown with red clover and grasses – red clover/grass mixture – winter triticale, each field was divided into two management units, organic and integrated. Data were collected in relevés by the Braun-Blanquet method, each year at the peak of the growing season. Weed abundance (% cover in cultivated fields and the number of weed species (species richness in crops were determined, which provided a basis for calculating the Shannon-Wiener indices of species diversity and evenness, and the Rényi profiles. The qualitative (species and quantitative structure of weed communities was compared using the Sørensen index. A total of 115 weed taxa (species, subspecies and varieties were identified in the examined agro-phytocenoses. Echinochloa crus-galli, Chenopodium album, Matricaria maritima subsp. inodora, Capsella bursa-pastoris, Thlaspi arvense and Stellaria media were the most abundant. Weed infestation was slightly higher in the organic farming system than in the integrated system. Organic farming contributed to higher weed species diversity in root crops, red clover/grass mixtures and winter triticale. Weed species richness was reduced in red clover/grass stands, while root crops and – to a lesser degree – spring barley undersown with red clover and grasses decreased weed species diversity. The species composition and in particular the quantitative structure of weeds were affected by crop species and cultivation regime rather than by the farming system. Weed communities of crops grown under organic and integrated farming systems were more similar with regard to species composition

  16. RNAseq reveals weed-induced PIF3-like as a candidate target to manipulate weed stress response in soybean

    NARCIS (Netherlands)

    Horvath, David P; Hansen, Stephanie A; Moriles-Miller, Janet P; Pierik, Ronald; Yan, Changhui; Clay, David E; Scheffler, Brian; Clay, Sharon A

    Weeds reduce yield in soybeans (Glycine max) through incompletely defined mechanisms. The effects of weeds on the soybean transcriptome were evaluated in field conditions during four separate growing seasons. RNASeq data were collected from six biological samples of soybeans growing with or without

  17. Chemical weed control in barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    Sarwar, M.; Hassan, S.W.; Abid, A.A.

    2008-01-01

    Effect of two different pre-emergence herbicides i.e. Terbutryn (lgron-500FW) A, 1.01.25 kg a.t. ha/sup -1/ and Flurochloridone (Racer-25 CS) a 0.31, 0.37, 0.44, 0.50 and 0.56 Kg a.i. ha/sup -1/ on weeds and yield of barley wad studied under field conditions hb/sup -1/. All the herbicides significantly reduce the dry weight of weed Maximum reduction (70%) was observed in terbutryn a 1.0 Kg a.i. ha/sup -1/ Growth and yield parameters like number of spike lets per spike. Number of grams per spike. 1000-grain weight. Biological yield. Grain yield straw yield and harvest index showed significant response to various herbicides doses under study. Application of Flurochloridone (Racer-25 (CS) a 0.44 kg a.i. ha/sup -1/ and Terbutryn (lgran-500 FW) a 1.0 kg a.i). The data further revealed that in general all herbicide application treatments exhibited superior performance in respect of growth and yield over control. (author)

  18. The effect of soil tillage system and weeding time on the growth of weed and yield of soybean (Glycine max (L. Merril

    Directory of Open Access Journals (Sweden)

    Husni Thamrin Sebayang

    2018-04-01

    Full Text Available The growth and yield of soybeans can decrease due to competition from weeds. Various efforts have been made to control the growth of weeds such as land preparation and weeding periods. An experiment to study the effect of soil tillage systems and weeding time on the growth of weeds and soybean crop yield (Glycine max (L. Merril has been done in Wringinsongo Village, Tumpang Sub-District, Malang Regency from February to May 2017. The split-plot design with three replicates was used with the soil tillage system as the main plot consisting of three levels, T0: no tillage, T1: minimum tillage, and T2: conventional tillage, and weeding time as the sub plot consisting of 4 levels, P0: no weeding, P1: weeding 1 time, P2: weeding two times and P3: weeding three times. The results showed that the dominant weed species before treatment were Amaranthus spinosus (Spiny amaranth, Cynodon dactylon (Bermuda grass, Cyperus rotundus (Purple nutsedge, Ageratum conyzoides (Billygoat weed, and Portulaca oleracea (Common purslane. After treatment, the dominant weed species were Cyperus rotundus (Purple nutsedge, Amaranthus spinosus (Spiny amaranth, Ageratum conyzoides (Billygoat weed, Physalis peruviana (Cape gooseberry, and Eclipta alba (False daisy. There was no significant difference of the dry weight of weeds in conventional tillage followed by weeding 3 times at 15, 30 and 45 days after planting, and minimum tillage and no tillage. For the yield of soybeans, conventional tillage followed by weeding 3 times at 15, 30 and 45 days after planting were not significant with that of minimum tillage. The yield of soybeans was lower than that of with no tillage and no weeding.

  19. Distribution of parthenium weed in peshawar valley, khyber pakhtunkhwa- pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Khan, H.; Marwat, K. B.; Hassan, M. G.; Khan, M. A.; Hashim, S. [The University of Agriculture, Peshawar (Pakistan). Dept. of Weed Sciences

    2014-01-15

    Parthenium hysterophorus L. is a weed of national significance in Pakistan. Although infesting many districts of Khyber Pakhtunkhwa province, but more affected districts are Swabi, Mardan, Charsadda and Peshawar where it is highly invasive and invaded most of the open spaces roadsides, etc and threatening the local biodiversity. Field survey of four districts of the Peshawar valley, Khyber Pakhtunkhwa viz. Swabi, Mardan, Charsadda and Peshawar were carried out during May-June, 2009-2010 to study the distribution and invasion of parthenium weed. Twenty five locations were sampled from each district. Data regarding absolute and relative density, frequency, relative frequency, importance valve %, average importance value, constancy classes and importance value constancy index of parthenium weed and other weeds of the area were recorded by using (1x1 m2) quadrate. The mean data across the surveyed districts reveals that the flora is predominated by parthenium weed with the highest relative density of 42.68% among all species. It was followed by Cannabis sativa, Cynodon dactylon and Cyperus rotundus, with relative densities of 15.17, 13.49 and 5.96, respectively. At different locations, it was observed that parthenium weed is competing with Cannabis sativa which is not so aggressive and problematic weed. While in some areas parthenium weed has already replaced Cannabis sativa. Mean distribution data showed that parthenium weed infestation was abundant and almost not uniform in all districts, however highest relative frequency of 26.14% was recorded for parthenium weed followed by Cannabis sativa, Cynodon dactylon and Cyperus rotundus having relative frequency of 15.17, 13.49 and 9.14, respectively. Rumex crispus and Xanthium strumarium infatuated the smallest relative frequency at most of the locations studied thereby indicating them as insignificant among the weed flora of the study area. Importance value data revealed that P. hysterophorus, Cannabis sativa, Cynodon

  20. Distribution of parthenium weed in peshawar valley, khyber pakhtunkhwa- pakistan

    International Nuclear Information System (INIS)

    Khan, H.; Marwat, K.B.; Hassan, M.G.; Khan, M.A.; Hashim, S.

    2014-01-01

    Parthenium hysterophorus L. is a weed of national significance in Pakistan. Although infesting many districts of Khyber Pakhtunkhwa province, but more affected districts are Swabi, Mardan, Charsadda and Peshawar where it is highly invasive and invaded most of the open spaces roadsides, etc and threatening the local biodiversity. Field survey of four districts of the Peshawar valley, Khyber Pakhtunkhwa viz. Swabi, Mardan, Charsadda and Peshawar were carried out during May-June, 2009-2010 to study the distribution and invasion of parthenium weed. Twenty five locations were sampled from each district. Data regarding absolute and relative density, frequency, relative frequency, importance valve %, average importance value, constancy classes and importance value constancy index of parthenium weed and other weeds of the area were recorded by using (1x1 m2) quadrate. The mean data across the surveyed districts reveals that the flora is predominated by parthenium weed with the highest relative density of 42.68% among all species. It was followed by Cannabis sativa, Cynodon dactylon and Cyperus rotundus, with relative densities of 15.17, 13.49 and 5.96, respectively. At different locations, it was observed that parthenium weed is competing with Cannabis sativa which is not so aggressive and problematic weed. While in some areas parthenium weed has already replaced Cannabis sativa. Mean distribution data showed that parthenium weed infestation was abundant and almost not uniform in all districts, however highest relative frequency of 26.14% was recorded for parthenium weed followed by Cannabis sativa, Cynodon dactylon and Cyperus rotundus having relative frequency of 15.17, 13.49 and 9.14, respectively. Rumex crispus and Xanthium strumarium infatuated the smallest relative frequency at most of the locations studied thereby indicating them as insignificant among the weed flora of the study area. Importance value data revealed that P. hysterophorus, Cannabis sativa, Cynodon

  1. Dynamics of weed populations : spatial pattern formation and implications for control

    NARCIS (Netherlands)

    Wallinga, J.

    1998-01-01

    Modelling studies were carried out to analyse spatio-temporal dynamics of annual weed populations and to identify the key factors that determine the long-term herbicide use of weed control programmes. Three different weed control programmes were studied.

    In the first weed

  2. Weed Interference Effects on Leaves, Internode and Harvest Index of Dry Bean (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Hossein GHAMARI

    2015-03-01

    Full Text Available The development of appropriate weed management strategies and efficient use of herbicides relies upon understanding weed-crop interactions. A field study was carried out to assess the effect of weed interference on leaves, internode and harvest index of dry bean (Phaseolus vulgaris L.. The experiment was established under a randomized complete block design with two types of weed interference treatments: plots with weeds and plots without weeds at different time intervals (0, 10, 20, 30, 40 and 50 days after crop emergence. The sigmoid Boltzmann model was used to quantify the crop traits as influenced by weed interference. Prolonged delays in weed removal reduced gradually the number of leaves of the crop. Weed interference decreased dry weight of leaves as well, so that the lowest value of it (33.49 g plant-1 was observed in full season during weed-infested treatment. Infestation of weeds affected the length of the crop internodes. While the weed interference duration increased, the length of the internodes decreased. Harvest index was also sensitive to weed competition. As the crop was kept weed-infested from the emergence for increasing periods of time, harvest index decreased to a value of 28.01%. A significant negative correlation between total biomass of weeds and dry bean traits (number of leaves, leaves dry weight, internode length and harvest index was observed. Therefore, weeds are able to adversely affect dry bean growth through constraining environmental resources and impairing leaves as the photosynthetic areas.

  3. Effect of tillage on the efficacy of CGA362622 on weed control in maize

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... time and resources managing weeds. Tillage alone or in combination with good cropping methods is ... help in managing herbicide resistance weeds and may also increase weed density as well as reduce crop yield .... This change in weed compo- sition agrees with Richley et al. (1977) indicating shift.

  4. Integrating management techniques to restore sites invaded by mile-a-minute weed, Persicaria perfoliata

    Science.gov (United States)

    Ellen C. Lake; Judith Hough-Goldstein; Vincent. D' Amico

    2014-01-01

    Efforts to suppress an invasive weed are often undertaken with the goal of facilitating the recovery of a diverse native plant community. In some cases, however, reduction in the abundance of the target weed results in an increase in other exotic weeds. Mile-a-minute weed (Persicaria perfoliata (L.) H. Gross (Polygonaceae)) is an annual vine from...

  5. Introduced and invasive species in novel rangeland ecosystems: friends or foes?

    Science.gov (United States)

    Belnap, Jayne; Ludwig, John A.; Wilcox, Bradford P.; Betancourt, Julio L.; Dean, W. Richard J.; Hoffmann, Benjamin D.; Milton, Sue J.

    2012-01-01

    Globally, new combinations of introduced and native plant and animal species have changed rangelands into novel ecosystems. Whereas many rangeland stakeholders (people who use or have an interest in rangelands) view intentional species introductions to improve forage and control erosion as beneficial, others focus on unintended costs, such as increased fire risk, loss of rangeland biodiversity, and threats to conservation efforts, specifically in nature reserves and parks. These conflicting views challenge all rangeland stakeholders, especially those making decisions on how best to manage novel ecosystems. To formulate a conceptual framework for decision making, we examined a wide range of novel ecosystems, created by intentional and unintentional introductions of nonnative species and land-use–facilitated spread of native ones. This framework simply divides decision making into two types: 1) straightforward–certain, and 2) complex–uncertain. We argue that management decisions to retain novel ecosystems are certain when goods and services provided by the system far outweigh the costs of restoration, for example in the case of intensively managed Cenchrus pastures. Decisions to return novel ecosystems to natural systems are also certain when the value of the system is low and restoration is easy and inexpensive as in the case of biocontrol of Opuntia infestations. In contrast, decisions whether to retain or restore novel ecosystems become complex and uncertain in cases where benefits are low and costs of control are high as, for example, in the case of stopping the expansion of Prosopis and Juniperus into semiarid rangelands. Decisions to retain or restore novel ecosystems are also complex and uncertain when, for example, nonnative Eucalyptus trees expand along natural streams, negatively affecting biodiversity, but also providing timber and honey. When decision making is complex and uncertain, we suggest that rangeland managers utilize cost–benefit analyses

  6. Race, region and risk: An examination of minority proximity to noxious facilities

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, A.L. [Wheaton Coll., IL (United States)]|[Argonne National Lab., IL (United States); Nieves, L.A. [Argonne National Lab., IL (United States)

    1996-04-01

    The past decade has given rise to terms like environmental racism, eco-racism, and environmental inequities to characterize a disproportional distribution of environmental disamenities among minority communities. Much of the literature supports the contention that racial and ethnic minorities and low-income groups bear a disproportionate burden of risk from hazardous activities and substances in the environment. This study expands the scope of prior studies by employing county-level data for the entire nation and including a broad range of facility types associated with environmental disamenities. In addition, it addresses the issue of the distribution of noxious facilities among white and non-white populations in an attempt to determine the relative exposure to risk among different racial and ethnic groups. In addition, the authors also explore the relative importance of nonurban versus urban residence.

  7. Influence of noxious products of blasting in mine air on miners' health

    Energy Technology Data Exchange (ETDEWEB)

    Zemlyakova, L F; Sukhanov, V V

    1979-07-01

    Changes in the percentage of carbon monoxide and nitric oxide in mine air as a result of blasting is analyzed as measured in coal mines of the Donbass in coal seams located from 500 m to 1000 m underground. It is stated that 15 minutes after blasting the concentration of carbon monoxide and nitric oxide drops to a permissible level. Fifty minutes after blasting the percentage of nitric oxide in mine air drops to such a level that it can not be detected. Carbon monoxide can be detected until the blasted rocks and coal are removed from the heading. The percentage of nitric oxide in mine air falls with growing depth of workings. The interdependence between state of miners' health and their contact with noxious gases is also analyzed. The analysis shows that miners working where blasting is used are ill more frequently than other miners, and their absence due to illness is longer. (In Russian)

  8. Secondary hyperalgesia phenotypes exhibit differences in brain activation during noxious stimulation

    DEFF Research Database (Denmark)

    Asghar, Mohammad Sohail; Pereira, Manuel Pedro; Werner, Mads Utke

    2015-01-01

    of the burn-injury) (p right (p = 0.001) and left caudate nucleus (p = 0.01) was detected....... To study differences in the propensity to develop central sensitization we examined differences in brain activity and anatomy according to individual phenotypical expression of secondary hyperalgesia by magnetic resonance imaging. Forty healthy volunteers received a first-degree burn-injury (47 °C, 7 min......, 9 cm(2)) on the non-dominant lower-leg. Areas of secondary hyperalgesia were assessed 100 min after the injury. We measured neuronal activation by recording blood-oxygen-level-dependent-signals (BOLD-signals) during mechanical noxious stimulation before burn injury and in both primary and secondary...

  9. Identification of the visceral pain pathway activated by noxious colorectal distension in mice

    Directory of Open Access Journals (Sweden)

    Melinda eKyloh

    2011-02-01

    Full Text Available In patients with irritable bowel syndrome (IBS, visceral pain is evoked more readily following distension of the colorectum. However, the identity of extrinsic afferent nerve pathway that detects and transmits visceral pain from the colorectum to the spinal cord is unclear. In this study, we identified which extrinsic nerve pathway(s underlies nociception from the colorectum to the spinal cord of rodents. Electromyogram (EMG recordings were made from the transverse oblique abdominal muscles in anesthetized wild type (C57BL/6 mice and acute noxious intraluminal distension (100-120 mmHg applied to the terminal 15mm of rectum to activate visceromotor responses (VMRs. Cutting the lumbar colonic nerves in vivo had no detectable effect on the VMRs evoked by colorectal distension. Lesioning right or left hypogastric nerves also failed to reduce VMRs. However, lesioning left and right branches of the rectal nerves completely abolished the VMRs, regardless of whether the lumbar colonic or hypogastric nerves were severed. Electrical stimulation applied to either the lumbar colonic or hypogastric nerves in vivo, failed to elicit a VMR. In contrast, electrical stimulation (2-5Hz, 0.4ms, 60V applied to the rectum reliably elicited VMRs, which were abolished by selective lesioning of the rectal nerves. DiI retrograde labelling from the colorectum labelled sensory neurons only in dorsal root ganglia (DRG of the lumbosacral region of the spinal cord. In contrast, injection of DiI into the mid to proximal colon labelled sensory neurons in DRG primarily of the lower thoracic level (T8-L4 of the spinal cord. The visceral pain pathway activated by acute noxious distension of the terminal 15 mm of mouse rectum is transmitted predominantly, if not solely, through rectal/pelvic afferent nerve fibres to the spinal cord. The sensory neurons of this spinal afferent pathway lie in the lumbosacral region of the spinal cord, primarily at the level of S2 and S3.

  10. Regulation of body temperature and nociception induced by non-noxious stress in rat.

    Science.gov (United States)

    Vidal, C; Suaudeau, C; Jacob, J

    1984-04-09

    The effects of 3 different non-noxious stressors on body temperature (Tb) were investigated in the rat: (1) loose restraint in cylinders, (2) removal of the rats from cylinders, exposure to a novel environment and replacement in cylinders, a stressor called here 'novelty', and (3) gentle holding of the rats by the nape of the neck. Loose restraint and 'novelty' produced hyperthermia. On the contrary, holding induced hypothermia. Hypophysectomy (HX) reduced basal Tb, abolished restraint hyperthermia and reduced both 'novelty' hyperthermia and holding hypothermia. Dexamethasone ( DEXA ) had no effect upon either restraint or novelty hyperthermia but reduced the hypothermia. Naloxone (Nx) produced a slight fall in basal Tb accounting for its reduction of restraint and 'novelty' hyperthermias ; it did not affect holding hypothermia. The inhibitory effects of HX suggest a participation of the pituitary in the hyperthermias ; the neurointermediate lobe would be involved as the hyperthermias were not affected by DEXA , which is known to block the stress-induced release of pituitary secretions from the anterior lobe but not from the neurointermediate lobe. In contrast, substances from the anterior lobe might participate in hypothermia due to holding since it is reduced by HX and DEXA . As to the effects of Nx, endogenous opioids would not be significantly involved in the thermic effects of the stressors used in this study; they might play, if any, only a minor role in the regulation of basal Tb. These results are compared with those previously obtained on nociception using the same non-noxious stressors. It emerges that, depending on the stressor, different types of association between thermoregulation and nociception may occur, i.e. hyperthermia with analgesia, hyperthermia with hyperalgesia and hypothermia with hyperalgesia.

  11. Chronic Lateral Epicondylalgia Does Not Exhibit Mechanical Pain Modulation in Response to Noxious Conditioning Heat Stimulus.

    Science.gov (United States)

    Lim, Edwin Choon Wyn; Sterling, Michele; Vicenzino, Bill

    2017-10-01

    The impaired attenuation of pain by the application of a noxious conditioning stimulus at a segmentally distinct site, known as conditioned pain modulation (CPM), has been implicated in clinical pain states. Chronic lateral epicondylalgia (LE), which is characterized by lower pressure pain thresholds (PPTs) at sites remote to the affected elbow and spinal cord hyperexcitability, is a clinical pain state that might plausibly involve less efficacious CPM. This study aimed to determine whether LE exhibits a less efficacious CPM compared with that in pain-free controls. Results: Twenty participants with LE, aged 50.7 years (SD=7.05) and who had their condition for 10.2 months (range: 2 to 80 mo), were matched by age and sex to 22 pain-free participants. All participants indicated their PPT over the lateral epicondyle(s) before and during a conditioning noxious heat stimulus that was applied over the calf. A CPM score was calculated as the difference between the PPT before and during the heat pain-conditioning stimulus expressed as a percentage of PPT before the heat pain-conditioning stimulus. The condition (LE vs. control) by side (affected vs. unaffected) analysis of variance revealed a significant condition effect (P=0.001), but not side effect (P=0.192) or side-by-condition interaction effect (P=0.951). Follow-up tests for the effect of condition revealed a mean deficit in CPM of -24.5% (95% confidence interval, -38.0 to -11.0) in LE compared with that in pain-free participants. The results that suggest an impaired ability to modulate pain might be associated with the previously observed spinal cord hyperexcitability and the mechanical hyperalgesia that characterizes LE.

  12. Weed flora in organically grown spring cereals in Finland

    Directory of Open Access Journals (Sweden)

    J. SALONEN

    2008-12-01

    Full Text Available The weed flora in organically grown spring cereals was investigated in southern and central Finland in 1997-1999 with the primary purpose of determining the species composition and the level of weed infestation. Altogether 165 fields were surveyed in the middle of the growing season. A total of 126 weed species were found, of which 42 exceeded the frequency level of 10%. The most frequent weed species were Chenopodium album, Stellaria media, Galeopsis spp. and Viola arvensis. Elymus repens was the most frequent grass species. The average density of weeds was 469 plants m-2 (median 395, and the air-dry biomass was 678 kg ha-1 (median 567 which accounted for 17% of the total biomass of the crop stand. Infestation by Chenopodium album and the perennial species Elymus repens, Cirsium arvense and Sonchus arvensis is of major concern. Weed control strategies should include direct control measures to overcome weed problems related to the conversion period from conventional to organic growing.

  13. Interactions between pre- and post-emergence weed harrowing in spring cereals

    DEFF Research Database (Denmark)

    Brandsæter, L.O.; Mangerud, K.; Rasmussen, Jesper

    2012-01-01

    that pre- and post-emergence harrowing interact positively, that a combination gives more stable weed control effects than pre- and post-emergence weed harrowing used alone, and that a harrow type with bent tines is more aggressive and suitable on hard-packed soils than a harrow with strait tines...... the average effect of post-emergence harrowing was 47% on weed density and 41% on weed biomass. The combined effect of pre- and post-emergence weed harrowing was 61% on weed density and 54% on weed biomass. The combination did not give more stable weed control effects than pre- and post-emergence weed...... harrowing used alone. Pre-emergence harrowing increased the average crop yield by 6.2%, post-emergence harrowing by 4.0% and the combined effect was 10%. Crop yield was mainly increased on hard-packed soils. Weed and crop responses varied strongly among experiments, but the efficacy of pre- and post...

  14. Capabilities of unmanned aircraft vehicles for low altitude weed detection

    Science.gov (United States)

    Pflanz, Michael; Nordmeyer, Henning

    2014-05-01

    Sustainable crop production and food security require a consumer and environmental safe plant protection. It is recently known, that precise weed monitoring approaches could help apply pesticides corresponding to field variability. In this regard the site-specific weed management may contribute to an application of herbicides with higher ecologically aware and economical savings. First attempts of precision agriculture date back to the 1980's. Since that time, remote sensing from satellites or manned aircrafts have been investigated and used in agricultural practice, but are currently inadequate for the separation of weeds in an early growth stage from cultivated plants. In contrast, low-cost image capturing at low altitude from unmanned aircraft vehicles (UAV) provides higher spatial resolution and almost real-time processing. Particularly, rotary-wing aircrafts are suitable for precise path or stationary flight. This minimises motion blur and provides better image overlapping for stitching and mapping procedures. Through improved image analyses and the recent increase in the availability of microcontrollers and powerful batteries for UAVs, it can be expected that the spatial mapping of weeds will be enhanced in the future. A six rotors microcopter was equipped with a modified RGB camera taking images from agricultural fields. The hexacopter operates within predefined pathways at adjusted altitudes (from 5 to 10 m) by using GPS navigation. Different scenarios of optical weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. Our experiences showed high capabilities for site-specific weed control. Image analyses with regard to recognition of weed patches can be used to adapt herbicide application to varying weed occurrence across a field.

  15. Effects of propofol anesthesia on the processing of noxious stimuli in the spinal cord and the brain.

    Science.gov (United States)

    Lichtner, Gregor; Auksztulewicz, Ryszard; Kirilina, Evgeniya; Velten, Helena; Mavrodis, Dionysios; Scheel, Michael; Blankenburg, Felix; von Dincklage, Falk

    2018-05-15

    Drug-induced unconsciousness is an essential component of general anesthesia, commonly attributed to attenuation of higher-order processing of external stimuli and a resulting loss of information integration capabilities of the brain. In this study, we investigated how the hypnotic drug propofol at doses comparable to those in clinical practice influences the processing of somatosensory stimuli in the spinal cord and in primary and higher-order cortices. Using nociceptive reflexes, somatosensory evoked potentials and functional magnet resonance imaging (fMRI), we found that propofol abolishes the processing of innocuous and moderate noxious stimuli at low to medium concentration levels, but that intense noxious stimuli evoked spinal and cerebral responses even during deep propofol anesthesia that caused profound electroencephalogram (EEG) burst suppression. While nociceptive reflexes and somatosensory potentials were affected only in a minor way by further increasing doses of propofol after the loss of consciousness, fMRI showed that increasing propofol concentration abolished processing of intense noxious stimuli in the insula and secondary somatosensory cortex and vastly increased processing in the frontal cortex. As the fMRI functional connectivity showed congruent changes with increasing doses of propofol - namely the temporal brain areas decreasing their connectivity with the bilateral pre-/postcentral gyri and the supplementary motor area, while connectivity of the latter with frontal areas is increased - we conclude that the changes in processing of noxious stimuli during propofol anesthesia might be related to changes in functional connectivity. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Weed infestation of spring common wheat (Triticum aestivum L. grown in monoculture depending on the cover crop and weed control method

    Directory of Open Access Journals (Sweden)

    Dorota Gawęda

    2012-10-01

    Full Text Available The aim of this 3-year field study was to evaluate the effect of some stubble crops and in-crop weed control methods on the species composition, number and air-dry weight of weeds in a wheat crop grown in short-term monoculture. The study was conducted in the period 2009-2011 in the Uhrusk Experimental Farm on mixed rendzina soil classified as very good rye soil complex. It included various types of stubble crops ploughed in each year (control treatment without cover crop, white mustard, lacy phacelia, a mixture of legumes – narrow-leaf lupin + field pea and methods of weed control in spring wheat (mechanical, mechanical and chemical, chemical weed control. On average during the study period, all stubble crops used reduced the air-dry weight of weds in the treatments with mechanical weed management relative to the control treatment. Irrespective of the weed control method, the number of weeds in the wheat crop was significantly lower only after the ploughing in of white mustard. Mechanical weed management proved to be less effective in reducing the number and dry weight of weeds compared to other weed control methods. The white mustard and legume mixture cover crops had a reducing effect on the number of weed species in relation to the treatment without cover crops. The highest floristic diversity of weed communities was found in the spring wheat crop in which only mechanical weeding alone was used.

  17. Phenology of exotic invasive weeds associated with downy brome

    Science.gov (United States)

    The exotic and highly invasive annual grass downy brome (Bromus tectorum) has invaded millions of hectares of rangelands throughout the Intermountain West. Downy brome increases the chance, rate, season and spread of wildfires, resulting in the destruction of native plant communities and the wildli...

  18. A New Hoe Blade for Inter-Row Weeding

    DEFF Research Database (Denmark)

    Green, O.; Znova, L.; Melander, Bo

    2016-01-01

    and weeds are relatively small. The term ‘Ducksfoot’ covers a range of hoe blade configurations where all have some resemblance with the shape of a ducks foot. However, the ‘Ducksfoot’ blade is not an optimal solution for weed control in narrow inter-row spaces. Several disadvantages have been encountered...... and the draft forces needed to pull it were approx. half those measured for a ‘Ducksfoot’ blade. The weeding features of the new L-blade will be further studied under field conditions....

  19. Seasonal food habits of swift fox (Vulpes velox) in cropland and rangeland landscapes in western Kansas

    Science.gov (United States)

    Sovada, M.A.; Roy, C.C.; Telesco, D.J.

    2001-01-01

    Food habits of swift foxes (Vulpes velox) occupying two distinct landscapes (dominated by cropland versus rangeland) in western Kansas were determined by analysis of scats collected in 1993 and 1996. Frequencies of occurrence of prey items in scats were compared between cropland and rangeland areas by season. Overall, the most frequently occurring foods of swift foxes were mammals (92% of all scats) and arthropods (87%), followed by birds (24%), carrion (23%), plants (15%) and reptiles (4%). No differences were detected between landscapes for occurrence of mammals, arthropods or carrion in any season (P ≥ 0.100). Plants, specifically commercial sunflower seeds, were consumed more frequently in cropland than in rangeland in spring (P = 0.004) and fall (P = 0.001). Birds were more common in the swift fox diet in cropland than in rangeland during the fall (P = 0.008), whereas reptiles occurred more frequently in the diet in rangeland than in cropland during spring (P = 0.042). Variation in the diet of the swift fox between areas was most likely due to its opportunistic foraging behavior, resulting in a diet that closely links prey use with availability.

  20. Reorienting land degradation towards sustainable land management: linking sustainable livelihoods with ecosystem services in rangeland systems.

    Science.gov (United States)

    Reed, M S; Stringer, L C; Dougill, A J; Perkins, J S; Atlhopheng, J R; Mulale, K; Favretto, N

    2015-03-15

    This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case study analysis of the Kalahari rangelands in southwest Botswana. The paper first describes the socio-economic and ecological characteristics of the Kalahari rangelands and the types of land degradation taking place. It then focuses on bush encroachment as a way of exploring new economic instruments (e.g. Payments for Ecosystem Services) designed to enhance the flow of ecosystem services that support livelihoods in rangeland systems. It does this by evaluating the likely impacts of bush encroachment, one of the key forms of rangeland degradation, on a range of ecosystem services in three land tenure types (private fenced ranches, communal grazing areas and Wildlife Management Areas), before considering options for more sustainable land management in these systems. We argue that with adequate policy support, economic mechanisms could help reorient degraded rangelands towards more sustainable land management. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. A synoptic review of U.S. rangelands: a technical document supporting the Forest Service 2010 RPA Assessment

    Science.gov (United States)

    Matthew Clark Reeves; John E. Mitchell

    2012-01-01

    The Renewable Resources Planning Act of 1974 requires the USDA Forest Service to conduct assessments of resource conditions. This report fulfills that need and focuses on quantifying extent, productivity, and health of U.S. rangelands. Since 1982, the area of U.S. rangelands has decreased at an average rate of 350,000 acres per year owed mostly to conversion to...

  2. Scale effects on runoff and soil erosion in rangelands: observations and estimations with predictors of different availability

    Science.gov (United States)

    Runoff and erosion estimates are needed for rangeland management decisions and evaluation of ecosystem services derived from rangeland conservation practices. The information on the effect of scale on the runoff and erosion, and on the choice of runoff and erosion predictors, remains scarce. The obj...

  3. Multi-agency Oregon Pilot: Working towards a national inventory and assessment of rangelands using onsite data

    Science.gov (United States)

    Paul L. Patterson; James Alegria; Leonard Jolley; Doug Powell; J. Jeffery Goebel; Gregg M. Riegel; Kurt H. Riitters; Craig. Ducey

    2014-01-01

    Rangelands are lands dominated by grasses, forbs, and shrubs and are managed as a natural ecosystem. Although these lands comprise approximately 40 percent of the landmass of the continental United States, there is no coordinated effort designed to inventory, monitor, or assess rangeland conditions at the national scale. A pilot project in central Oregon with the U.S....

  4. State and transition models: Theory, applications, and challenges. In: Briske, D.D. Rangeland Systems: Processes, Management and Challenges

    Science.gov (United States)

    State and transition models (STMs) are used for communicating about ecosystem change in rangelands and other ecosystems, especially the implications for management. The fundamental premise that rangelands can exhibit multiple states is now widely accepted. The current application of STMs for managem...

  5. Assessment of Responsiveness to Everyday Non-Noxious Stimuli in Pain-Free Migraineurs With Versus Without Aura.

    Science.gov (United States)

    Granovsky, Yelena; Shor, Merav; Shifrin, Alla; Sprecher, Elliot; Yarnitsky, David; Bar-Shalita, Tami

    2018-03-27

    Migraineurs with aura (MWA) express higher interictal response to non-noxious and noxious experimental sensory stimuli compared with migraineurs without aura (MWoA), but whether these differences also prevail in response to everyday non-noxious stimuli is not yet explored. This is a cross-sectional study testing 53 female migraineurs (30 MWA; 23 MWoA) who underwent a wide battery of noxious psychophysical testing at a pain-free phase, and completed a Sensory Responsiveness Questionnaire and pain-related psychological questionnaires. The MWA group showed higher questionnaire-based sensory over-responsiveness (P = .030), higher magnitude of pain temporal summation (P = .031) as well as higher monthly attack frequency (P = .027) compared with the MWoA group. Overall, 45% of migraineurs described abnormal sensory (hyper- or hypo-) responsiveness; its incidence was higher among MWA (19 of 30, 63%) versus MWoA (6 of 23, 27%, P = .012), with an odds ratio of 3.58 for MWA. Sensory responsiveness scores were positively correlated with attack frequency (r = .361, P = .008) and temporal summation magnitude (r = .390, P = .004), both regardless of migraine type. MWA express higher everyday sensory responsiveness than MWoA, in line with higher response to experimental noxious stimuli. Abnormal scores of sensory responsiveness characterize people with sensory modulation dysfunction, suggesting possible underlying mechanisms overlap, and possibly high incidence of both clinical entities. This article presents findings distinguishing MWA, showing enhanced pain amplification, monthly attack frequency, and over-responsiveness to everyday sensations, compared with MWoA. Further, migraine is characterized by a high incidence of abnormal responsiveness to everyday sensation, specifically sensory over-responsiveness, that was also found related to pain. Copyright © 2018 The American Pain Society. Published by Elsevier Inc. All rights reserved.

  6. Differential induction of c-Fos and phosphorylated ERK by a noxious stimulus after peripheral nerve injury.

    Science.gov (United States)

    Tabata, Mitsuyasu; Terayama, Ryuji; Maruhama, Kotaro; Iida, Seiji; Sugimoto, Tomosada

    2018-03-01

    In this study, we compared induction of c-Fos and phosphorylated extracellular signal-regulated kinase (p-ERK) in the spinal dorsal horn after peripheral nerve injury. We examined the spinal dorsal horn for noxious heat-induced c-Fos and p-ERK protein-like immunoreactive (c-Fos- and p-ERK-IR) neuron profiles after tibial nerve injury. The effect of administration of a MEK 1/2 inhibitor (PD98059) on noxious heat-induced c-Fos expression was also examined after tibial nerve injury. A large number of c-Fos- and p-ERK-IR neuron profiles were induced by noxious heat stimulation to the hindpaw in sham-operated animals. A marked reduction in the number of c-Fos- and p-ERK-IR neuron profiles was observed in the medial 1/3 (tibial territory) of the dorsal horn at 3 and 7 days after nerve injury. Although c-Fos-IR neuron profiles had reappeared by 14 days after injury, the number of p-ERK-IR neuron profiles remained decreased in the tibial territory of the superficial dorsal horn. Double immunofluorescence labeling for c-Fos and p-ERK induced by noxious heat stimulation to the hindpaw at different time points revealed that a large number of c-Fos-IR, but not p-ERK-IR, neuron profiles were distributed in the tibial territory after injury. Although administration of a MEK 1/2 inhibitor to the spinal cord suppressed noxious heat-induced c-Fos expression in the peroneal territory, this treatment did not alter c-Fos induction in the tibial territory after nerve injury. ERK phosphorylation may be involved in c-Fos induction in normal nociceptive responses, but not in exaggerated c-Fos induction after nerve injury.

  7. Cutting weeds with a CO2 laser

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Christensen, S.

    2001-01-01

    Stems of Chenopodium album. and Sinapis arvensis. and leaves of Lolium perenne. were cut with a CO2 laser or with a pair of scissors. Treatments were carried out on greenhouse-grown pot plants at three different growth stages and at two heights. Plant dry matter was measured 2 to 5 weeks after...... treatment. The relationship between dry weight and laser energy was analysed using a non-linear dose-response regression model. The regression parameters differed significantly between the weed species. At all growth stages and heights S. arvensis was more difficult to cut with a CO2 laser than C. album....... When stems were cut below the meristems, 0.9 and 2.3 J mm(-1) of CO2 laser energy dose was sufficient to reduce by 90% the biomass of C. album and S. arvensis respectively. Regrowth appeared when dicotyledonous plant stems were cut above meristems, indicating that it is important to cut close...

  8. Fungal Phytotoxins in Sustainable Weed Management.

    Science.gov (United States)

    Vurro, Maurizio; Boari, Angela; Casella, Francesca; Zonno, Maria Chiara

    2018-01-01

    Fungal phytotoxins are natural secondary metabolites produced by plant pathogenic fungi during host-pathogen interactions. They have received considerable particular attention for elucidating disease etiology, and consequently to design strategies for disease control. Due to wide differences in their chemical structures, these toxic metabolites have different ecological and environmental roles and mechanisms of action. This review aims at summarizing the studies on the possible use of these metabolites as tools in biological and integrated weed management, e.g. as: novel and environmentally friendly herbicides; lead for novel compounds; sources of novel mechanisms of action. Moreover, the limiting factors for utilizing those metabolites in practice will also be briefly discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. The Effect of Laser Treatment as a Weed Control Method

    DEFF Research Database (Denmark)

    Mathiassen, Solvejg K; Bak, Thomas; Christensen, Svend

    2006-01-01

    at the cotyledon stage. Experiments were carried out under controlled conditions, using pot-grown weeds. Two lasers and two spot sizes were tested and different energy doses were applied by varying the exposure time. The biological efficacy was examined on three different weed species: Stellaria media (common...... was related to wavelength, exposure time, spot size and laser power. The efficacy also varied between the weed species. The results indicate that the efficacy of laser treatments can be improved by a more precise pointing of the laser beam towards the apical meristems and optimisation of the energy density...... (exposure time and spot size of the laser beam). The experiment also showed a significant difference between two wavelengths. In order to improve the performance and to validate the efficacy on a broader spectrum of weed species, further research and development is needed....

  10. Effects of Weed Control and Cow Dung Manure on Growth ...

    African Journals Online (AJOL)

    ISSN 0794-5698. Effects of Weed Control and Cow Dung Manure on Growth Performance of Quality Protein Maize in ... worldwide on over 159.5 million hectares in the year. 2010. ...... Fertilizer company of Nigeria, NAFCON, Port. Harcourt.

  11. Aquatic weeds: their implications in Indian nuclear industry

    International Nuclear Information System (INIS)

    Rao, T.S.; Anup Kumar, B.; Aruna Jyothi, K.; Satpathy, K.K.

    2000-01-01

    The aquatic weed infestation of KAPS cooling water system, MAPS open reservoir, and the growth of filamentous algae and bacteria in the feed water unit of HWP (Kota), was investigated. The aquatic weeds identified were: Ceratophyllum, Elodea, Hydrilla verticillata, Najas and Vallisneria species. However, at HWP (Kota) filamentous alga (Nostoc punchiformis) and bacteria (Sphaerotilus natans) were found in plenty. The metabolic products when assayed in the form of total carbohydrate content released by weeds was 3.7 mg gm -1 biomass. The metabolic products adsorb on to the resin matrix and impaired its performance at HWP (K), enhanced bacterial growth on the resin beads and furthered resin deterioration. Besides, the growth of aquatic weeds also influenced the pH of the cooling water, thereby vitiating the water treatment programme. (author)

  12. Weed biomass and economic yield of wheat (Triticum aestivum) as ...

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    154 ... to realize the maximum yield potential of the crop at lower input costs ... only acceptable way for effective weed management in future (Marwat et al., ..... Jarwar AD, Tunio SD, Majeedano HI, Kaisrani MA. (1999). Efficacy.

  13. Weed biomass and economic yield of wheat (Triticum aestivum) as ...

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... INTRODUCTION ... to control weeds in conjunction with cultural practices. Jarwar et al. (1999) .... Wheat grain yield is an interplay of yield components especially ... The biological yield expresses the overall growth of crop.

  14. Evaluation of Botanical Herbicides against Common Weed Species ...

    African Journals Online (AJOL)

    test the inhibitory potential of essential oils extracted from eight locally available plants and .... from C. citratus was in different as weed growth observed with standard ..... NB:-Con = Control, EC = Eucalyptus citrodora, CW = Cymbopogon ...

  15. Weed management in banana production: The use of Nelsonia ...

    African Journals Online (AJOL)

    EJIRO

    reduction in abundance was more pronounced during the dry season when cover crop growth was dense, than in ... The main method of weed control is by use of herbicides ..... with organic plastic and paper mulches in small-scale vegetable.

  16. Weed management practices in natural ecosystems: a critical overview

    Directory of Open Access Journals (Sweden)

    C.F. Reinhardt

    2000-07-01

    Full Text Available Increasing public pressure against the use of pesticides and other agricultural inputs has placed increased emphasis on the development of ecologically based pest management. One distinct reaction of the Weed Science discipline has been the swing away from herbicide research to increased research on the basic biology and ecology of weeds in hopes of reduced reliance on "technological crutches" such as herbicides and other practices that are potentially harmful to the environment. Biological control is the long-standing alternative to the use of herbicides and interest in the former practice has been boosted by the realization that the use of herbicides may lead to the development of herbicide resistance in weed populations, and that herbicide residues occur in surface and groundwater. Supporters of herbicide use would point out that biological control is generally not effective in crop production systems, and is basically slow-acting. Debates between protagonists for the exclusive use of one or the other weed management practice tend to obscure the benefits that integration of different techniques are likely to have. For natural ecosystems it is proposed that integration of the more subtle practice of biological control with the use of herbicides, which relatively quickly overwhelm a biological system with mortality, is likely to be the most effective weed management tool. Different weed management practices that could be considered in natural ecosystems are discussed in terms of three key performance rating criteria, viz. activity, selec- tivity and persistence In this concise review, general discussion is focussed on the fundamentals of weed management practices, with the view to promote concept-based approaches that are critical for the development of effective weed management strate- gies.

  17. Chemical Weed Control Increases Survival and Growth in Hardwood Plantings

    Science.gov (United States)

    Gayne G. Erdmann

    1967-01-01

    In a plantation of four hardwood species on a silt loam soil planted to 1-0 stock, 4 pounds of active atrazine or simazine controlled weeds effectively without injuring the trees. Chemical weed control was better on plowed and disked ground than on unprepared ground. Yellow-poplar and white ash grew faster on prepared ground. Black walnut and red oak did not respond...

  18. Crop characteristics and weed Interactions of diverse Rrecurrent Inbred Lines (RILs) from a weed-suppressive x non-suppressive rice mapping population

    Science.gov (United States)

    ndica rice genotypes with enhanced weed suppression traits have been previously identified as potentially useful in supplementing weed control efforts in drill-seeded systems in the southern USA. A particularly weed-suppressive indica genotype (PI 312777) that was also high tillering and high yield...

  19. Weeding method and pre-sowing tillage effects on weed growth and pearl millet yield in a sandy soil of the West African Sahelian zone.

    NARCIS (Netherlands)

    Klaij, M.C.; Hoogmoed, W.B.

    1996-01-01

    Weed control for the West African Sahel rainfed crops is done mainly manually, resulting in high labor requirements. Because of the seasonality of rainfed farming, weed control is often late and incomplete, resulting in considerable losses in crop yield. We examined the case of weed control in

  20. INFLUENCE OF CROPPING SYSTEM AND WEED MANAGEMENT PRACTICE ON EMERGENCE, GROWTH OF WEEDS, YIELD OF MAIZE (Zea mays L. AND COWPEA (Vigna unguiculata L.

    Directory of Open Access Journals (Sweden)

    Felix Ogar Takim

    2014-06-01

    Full Text Available The effects of cropping system and weed management practice on weed seedling emergence, weed biomass production and yield of maize and cowpea were examined at Ilorin, in the southern Guinea savanna (9°29' N, 4°35' E and 307 m ASL of Nigeria. Weed emergence occurred throughout the 3-15 weeks after planting (WAP. Forty-three weed species belonging to 38 genera within 20 families were encountered. Fimbristylis littoralis Gaudet, Tridax procumbens L and Eleusine indica Gaertn were the most prevalent weed species. Cropping system and weed management practice significantly affected weed emergence. Significantly (p≤0.05 lower number of weeds emerged in the intercropped and herbicide treated plots while higher weed densities and weed biomass were recorded in the uncropped and unweeded control plots than in the other plots. While aggregate crop yields were significantly higher in the intercropped than in the sole plots, component crop yields were higher under the sole cropping than in the intercrop. The implication of the results on weed management is discussed.

  1. Nitrogen availability in an apple orchard with weed management

    Directory of Open Access Journals (Sweden)

    Gustavo Brunetto

    2018-05-01

    Full Text Available ABSTRACT: Weed management in apple orchards (Malus domestica can affect the leaching of nitrogen (N in soil. The study aimed to evaluate the potential leaching of N forms in soil of an apple orchard with different weed management treatments. The experiment was conducted in an apple orchard implanted in 2008. In October 2011, 80 plants were selected and the following treatments were implemented: no weed management (NM, desiccation of weeds on the tree row with herbicide use (DR and mechanical mowing of weeds on the tree row (MR. Yield was evaluated in the 2011/2012, 2012/2013 and 2013/2014 crop seasons. In May 2012 porous cup lysimeters were installed in the NM, DR and MR treatments. In the solution collected at 0.20m, NH4 +-N and NO3 --N were analyzed sixteen times and mineral N concentration was calculated. The highest concentrations of NO3 --N and mineral N occurred in soil solution with DR, which increases availability of the nutrient to apple trees, but also enhances the potential losses. Weed management and N flow in the solution did not affect apple yield.

  2. Weeds Cause Losses in Field Crops through Allelopathy

    Directory of Open Access Journals (Sweden)

    Ali ZOHAIB

    2016-03-01

    Full Text Available A large number of weeds are known to be associated with crops and causing economic losses. Weeds interfere with crops through competition and allelopathy. They produce secondary metabolites known as allelochemicals, which belong to numerous chemical classes such as phenolics, alkaloids, fatty acids, indoles, terpens etc. However, phenolics are the predominant class of allelochemicals. The allelochemicals release from weed plants takes place through leaf leachates, decomposition of plant residues, volatilization and root exudates. Weeds leave huge quantities of their residues in field and affect the associated, as well as succeeding crops, in various cropping systems. Liberation of allelochemicals from weeds affects the germination, stand establishment, growth, yield and physiology of crop plants. They cause substantial reduction in germination and growth of the crop plants by altering various physiological processes such as enzyme activity, protein synthesis, photosynthesis, respiration, cell division and enlargement, which ultimately leads to a significant reduction in crop yield. In crux, allelopathic weeds represent a potential threat for crop plants and cause economic losses.

  3. The impact of stubble crop on spring barley weed infestation

    Directory of Open Access Journals (Sweden)

    Eleonora Wrzesińska

    2016-09-01

    Full Text Available The condition and degree of weed infestation were determined in a spring barely crop grown in a short-term monoculture after mulching the soil with plants grown as a stubble crop (the control treatment without cover crop – lacy phacelia, white mustard, sunflower. The field experiment was carried out in 2010–2013 on good rye soil complex using a split-block design in four replications. The obtained results (the mean from all years of the experiment showed that the stubble crop, especially sunflower, reduced the diversity of weed species without causing at the same time changes in weed species dominance. In all the control treatments of the experiment, Chenopodium album and Fallopia convolvulus were the dominant species. The degree of spring barley weed infestation depended on the species grown in the cover crop. White mustard and lacy phacelia slightly increased the number of weeds but their fresh matter significantly increased. However, the sunflower cover crop significantly increased the number of weeds without any substantial differentiation of their fresh mass.

  4. Robust Crop and Weed Segmentation under Uncontrolled Outdoor Illumination

    Directory of Open Access Journals (Sweden)

    Hong Y. Jeon

    2011-06-01

    Full Text Available An image processing algorithm for detecting individual weeds was developed and evaluated. Weed detection processes included were normalized excessive green conversion, statistical threshold value estimation, adaptive image segmentation, median filter, morphological feature calculation and Artificial Neural Network (ANN. The developed algorithm was validated for its ability to identify and detect weeds and crop plants under uncontrolled outdoor illuminations. A machine vision implementing field robot captured field images under outdoor illuminations and the image processing algorithm automatically processed them without manual adjustment. The errors of the algorithm, when processing 666 field images, ranged from 2.1 to 2.9%. The ANN correctly detected 72.6% of crop plants from the identified plants, and considered the rest as weeds. However, the ANN identification rates for crop plants were improved up to 95.1% by addressing the error sources in the algorithm. The developed weed detection and image processing algorithm provides a novel method to identify plants against soil background under the uncontrolled outdoor illuminations, and to differentiate weeds from crop plants. Thus, the proposed new machine vision and processing algorithm may be useful for outdoor applications including plant specific direct applications (PSDA.

  5. Analysis of weed flora in conventional and organic potato production

    Directory of Open Access Journals (Sweden)

    Nikolić, Lj.

    2013-12-01

    Full Text Available Composition of weed flora is highly dynamic and depends upon great number of factors, of which cultural practices that are applied by humans in certain crops are the most important. One of the most frequently grown plants in the world and in our country is potato (Solanum tuberosum L., Solanaceae, due to its high biological and nutritive value. Therefore, in the paper was presented taxonomic analysis of weed flora in potato grown conventionally and according to the principles of organic agricultural production, with the intention to point out to eventual differences between present weeds. Of the total number of identified species, from phylum Equisetophyta and class Equisetopsida, in organic potato crop, was determined only one, Equisetum arvense. Of remaining 38 weeds from phylum Magnoliophyta., classified into two classes, Magnoliopsida and Liliopsida. On both of potato growing systems, 39 weed species were found, classified into 16 families and 32 genus. Of the total number, 31 species was identified in conventional potato crop, and only 23 species in potato crop grown according to organic principles, which is for about quarter less. Biological spectrum of weed flora in both potato growing systems is pronouncedly of terrophytic – geophytic type. In the spectrum of area types were recorded differences, i.e. in the conventional potato crop represented are only widely distributed species, while in the organic crop, beside species of wide distribution are also present elements of Pontic group.

  6. Researches regarding glyphosate effectiveness on the degree of weed control in grape plantation

    Directory of Open Access Journals (Sweden)

    Monica NEGREA

    2010-11-01

    Full Text Available In this paper was determined the control degree of weeds in grape plantation, Burgund variety, when is using chemical treatments with herbicides and agro-technique measures. Herbicide used was Roundup 3 l/ha and 4l/ha (glyphosate isopropyl amine salt 360 g/l applied in 4 experimental variants. It was determined the weed presence degree, the type of weeds destroyed and the degree of their participation. Predominant weed species in studied grape plantation, were: Agropyron repens (20.15%, Geranium dissectum (17.91%, Capsella bursa pastoris (15.67% and Avena fatua (13.43%. Ephemeral weeds Veronica hederifolia and Stellaria media had a participation rate of 8.96%. Perennial weeds represented 40.30% while annual weeds are 59.70% . The herbicide Roundup provides most effective control in a dose of 3 or 4 l/ha, combined with mechanical weeding + 1 manual weeding, control rates being over 90%.

  7. Image analysis as a non-destructive method to assess regrowth of weeds after repeated flame weeding

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Kristoffersen, Palle; Andreasen, Christian

    2013-01-01

    picture of the long-term effect of repeated treatments. Image analysis was most useful for assessing the effect of repeated treatments when weed cover was relatively low (below 40%) and when plots contained relatively much withered plant material. However, when weed cover is close to 100%, dry weight......, and therefore it may influence the long-term effect of repeated treatments. Visual assessment of weed cover or image analysis do not affect the remaining parts of the weed plants after treatment, but the methods may have other disadvantages. In order to evaluate and compare three methods we measured changes...... in vegetation cover of perennial ryegrass after flaming by (1) a simple image analysis programme counting green pixels, (2) visual assessment of images and (3) by taking biomass samples. Plants were flame treated with eight different dosages (0, 20, 30, 35, 45, 60, 90 and 180 kg propane ha-1) and with various...

  8. [Spatial and temporal dynamics of the weed community in the Zoysia matrella lawn].

    Science.gov (United States)

    Liu, Jia-Qi; Li, You-Han; Zeng, Ying; Xie, Xin-Ming

    2014-02-01

    The heterogeneity of species composition is one of the main attributes in weed community dynamics. Based on species frequency and power law, this paper studied the variations of weed community species composition and spatial heterogeneity in a Zoysia matrella lawn in Guangzhou at different time. The results showed that there were 43 weed species belonging to 19 families in the Z. matrella lawn from 2007 to 2009, in which Gramineae, Compositae, Cyperaceae and Rubiaceae had a comparative advantage. Perennial weeds accounted for the largest proportion of weeds and increased gradually in the three years. Weed communities distributed in higher heterogeneity than in a random model. Dominant weeds varied with season and displayed regularity in the order of 'dicotyledon-monocotyledon-dicotyledon weeds' and 'perennial-annual-perennial weeds'. The spatial heterogeneity of weed community in Z. matrella lawn was higher in summer than in winter. The diversity and evenness of weed community were higher in summer and autumn than in winter and spring. The number of weed species with high heterogeneity in summer was higher than in the other seasons. The spatial heterogeneity and diversity of weed community had no significant change in the three years, while the evenness of weed community had the tendency to decline gradually.

  9. Effect of tillage system on yield and weed populations of soybean ( Glycin Max L.).

    Science.gov (United States)

    Hosseini, Seyed Z; Firouzi, Saeed; Aminpanah, Hashem; Sadeghnejhad, Hamid R

    2016-03-01

    Field experiment was conducted at Agricultural and Natural Resources Research Center of Golestan Province, Iran, to determine the effects of tillage system and weed management regime on yield and weed populations in soybean ( Glycin max L.). The experimental design was a split plot where the whole plot portion was a randomized complete block with three replicates. Main plots were tillage system: 1- No-till row crop seeding, 2- No-till seed drilling, 3- Tillage with disc harrow and drill planting, 4- Tillage with chisel packer and drill planting. The subplots were weed management regimes: 1-Weed control with herbicide application, 2- Hand weeding, 3- Herbicide application plus hand weeding, and 4- Non-weeding. Results indicated that the main effects of tillage system and weed management regime were significant for seed yield, pod number per plant, seed number per pod, weed density and biomass, while their interaction were significant only for weed density, weed biomass, and seed number per pod. The highest grain yields (3838 kg ha-1) were recorded for No-till row crop seeding. The highest seed yield (3877 kg ha-1) also was recorded for weed control with herbicide and hand weeding treatment, followed by hand weeding (3379 kg ha-1).

  10. Evaluating new SMAP soil moisture for drought monitoring in the rangelands of the US High Plains

    Science.gov (United States)

    Velpuri, Naga Manohar; Senay, Gabriel B.; Morisette, Jeffrey T.

    2016-01-01

    Level 3 soil moisture datasets from the recently launched Soil Moisture Active Passive (SMAP) satellite are evaluated for drought monitoring in rangelands.Validation of SMAP soil moisture (SSM) with in situ and modeled estimates showed high level of agreement.SSM showed the highest correlation with surface soil moisture (0-5 cm) and a strong correlation to depths up to 20 cm.SSM showed a reliable and expected response of capturing seasonal dynamics in relation to precipitation, land surface temperature, and evapotranspiration.Further evaluation using multi-year SMAP datasets is necessary to quantify the full benefits and limitations for drought monitoring in rangelands.

  11. DEVELOPMENTS IN MONITORING RANGELANDS USING REMOTELY-SENSED CROSS-FENCE COMPARISONS

    Directory of Open Access Journals (Sweden)

    A. D. Kilpatrick

    2012-07-01

    Full Text Available This paper presents a new method for the use of earth-observation images to assess relative land condition over broad regions, using a cross-fence comparison methodology. It controls for natural spatial and temporal variables (e.g. rainfall, temperature soils, ecosystem so that we can objectively monitor rangelands and other areas for the effects of management. The method has been tested with small and large scale theoretical models, as well as a case study in South Australian rangelands. This method can also be applied in other systems and experiments such as field trials of crop varieties as a robust spatial statistic.

  12. Isotopes in Weed Research. Proceedings of the Symposium on the Use of Isotopes in Weed Research

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-05-15

    The Symposium on the Use of Isotopes in Weed Research was convened jointly by the Food and Agriculture Organization of the United Nations and the International Atomic Energy Agency, and was held in Vienna at the Headquarters of IAEA from 25 to 29 October 1965. It was attended by 67 participants representing 18 countries. The Symposium provided an occasion for the exchange of information on recent advances in the subject. Additionally it gave an opportunity for investigators who had not used isotopes in their research to assess the potentialities and applications of this technique. Isotopes have already been extensively used in weed research, particularly for studying the comparative absorption of herbicides by different plant species and the movement and distribution of the herbicide within the plant. Radioisotopes have proved of particular value in these studies through the ability of autoradiographic techniques to detect even the trace amounts involved. The mode of action of herbicides has also been quite widely studied through the use of isotopes. It is probably a general rule that the practical selective herbicidal nature of a chemical compound is usually known some time before the actual metabolic mode of action is traced. Nevertheless the mode of action is of great importance, as its study may lead to the development of other herbicides; isotope techniques may be expected to play an increasing role here. Weed control is a continuing world agriculture problem of serious dimensions and there is constant effort both to develop and utilize herbicides. As part of the general widespread concern over the residual effects of chemicals applied to crop plants, the study of herbicide residues in plants and soil, and the detoxification of herbicides, has become essential. For these studies isotopic techniques can be usefully used to identify degradation products and trace the ultimate fate of the herbicide. Such studies are of growing importance. Features of the

  13. Isotopes in Weed Research. Proceedings of the Symposium on the Use of Isotopes in Weed Research

    International Nuclear Information System (INIS)

    1966-01-01

    The Symposium on the Use of Isotopes in Weed Research was convened jointly by the Food and Agriculture Organization of the United Nations and the International Atomic Energy Agency, and was held in Vienna at the Headquarters of IAEA from 25 to 29 October 1965. It was attended by 67 participants representing 18 countries. The Symposium provided an occasion for the exchange of information on recent advances in the subject. Additionally it gave an opportunity for investigators who had not used isotopes in their research to assess the potentialities and applications of this technique. Isotopes have already been extensively used in weed research, particularly for studying the comparative absorption of herbicides by different plant species and the movement and distribution of the herbicide within the plant. Radioisotopes have proved of particular value in these studies through the ability of autoradiographic techniques to detect even the trace amounts involved. The mode of action of herbicides has also been quite widely studied through the use of isotopes. It is probably a general rule that the practical selective herbicidal nature of a chemical compound is usually known some time before the actual metabolic mode of action is traced. Nevertheless the mode of action is of great importance, as its study may lead to the development of other herbicides; isotope techniques may be expected to play an increasing role here. Weed control is a continuing world agriculture problem of serious dimensions and there is constant effort both to develop and utilize herbicides. As part of the general widespread concern over the residual effects of chemicals applied to crop plants, the study of herbicide residues in plants and soil, and the detoxification of herbicides, has become essential. For these studies isotopic techniques can be usefully used to identify degradation products and trace the ultimate fate of the herbicide. Such studies are of growing importance. Features of the

  14. Influence of local noxious heat stimulation on sensory nerve activity in the feline dental pulp.

    Science.gov (United States)

    Ahlberg, K F

    1978-05-01

    The present investigation was undertaken to develop an experimental model in which noxious heat stimulation was used to produce increased intradental sensory nerve activity in canine teeth of anesthetized cats. Two techniques were evaluated in which both the method of recording and the nature of the stimulus varied. Slow heating (approx 1 degree C/s) to 47 degree C of the tooth surface (combined with recording from electrodes in open dentinal cavities) did not produce any persistent nerve activity. Repeated periods of brief intense heating (approx 60 degrees C/s) (combined with recording from amalgam electrodes placed on cavity floors) resulted in an immediate response and an afterdischarge (phase 3) generally persisting for 20--60 min. Maximum phase 3 activity was characteristic for the individual cat and ranged from 0.2 to 50.2 imp/s. mean value 10.6 imp/s (S.D. +/- 9.2). A systematically higher phase 3 activity was recorded in lower compared to upper canine teeth (p less than 0.05). The maximum phase 3 response generally occurred after 3-8 stimulations; the median number of required stimuli was 3. Repeated brief heat stimulations combined with the closed cavity recording technique may be used as an experimental model by which the mechanisms behind increases in intradental sensory nerve activity associated with tissue damage can be studied.

  15. Noxious substances in the air - traffic planning measures - traffic of the future

    Energy Technology Data Exchange (ETDEWEB)

    Koestenberger, H

    1985-01-01

    Necessary bundle of measures: Extension of public transport and restriction of individual traffic, extension and activation of large main roads (by-passes) to unload inhabited areas, building garages, creation of residential streets, pedestrian precincts and cycle paths. The best possible traffic system can only be achieved if all means of transport are used efficiently. It is the duty of traffic planners to develop an overall traffic system with the aims of benefiting the whole community. Due to wrong slowing down of traffic, the reduction of emitted quantities of noxious substances from private cars can be counteracted by general slowing down of traffic; frequent braking and restarting. The functional separation of residential areas for living, areas for working, supply, education and leisure pursuits which has been aimed at in recent decades must be slowly changed. This could reduce the traffic and mobility (mixed functions). The aims for traffic of the future are: suitability for the environment, economy, safety and capacity. In an integrated road network, the traffic must take over the correct purpose of traffic. (orig.).

  16. Does Acupuncture Needling Induce Analgesic Effects Comparable to Diffuse Noxious Inhibitory Controls?

    Directory of Open Access Journals (Sweden)

    Juerg Schliessbach

    2012-01-01

    Full Text Available Diffuse noxious inhibitory control (DNIC is described as one possible mechanism of acupuncture analgesia. This study investigated the analgesic effect of acupuncture without stimulation compared to nonpenetrating sham acupuncture (NPSA and cold-pressor-induced DNIC. Forty-five subjects received each of the three interventions in a randomized order. The analgesic effect was measured using pressure algometry at the second toe before and after each of the interventions. Pressure pain detection threshold (PPDT rose from 299 kPa (SD 112 kPa to 364 kPa (SD 144, 353 kPa (SD 135, and 467 kPa (SD 168 after acupuncture, NPSA, and DNIC test, respectively. There was no statistically significant difference between acupuncture and NPSA at any time, but a significantly higher increase of PPDT in the DNIC test compared to acupuncture and NPSA. PPDT decreased after the DNIC test, whereas it remained stable after acupuncture and NPSA. Acupuncture needling at low pain stimulus intensity showed a small analgesic effect which did not significantly differ from placebo response and was significantly less than a DNIC-like effect of a painful noninvasive stimulus.

  17. Possibilities of utilizing zeolites for the reduction of toxical noxious gases of combustion engines

    Directory of Open Access Journals (Sweden)

    Pandová Iveta

    2001-12-01

    Full Text Available Combustion engines produce exhalations that contribute by 50% to the contamination of the environment. The subject of this work is the research of zeolites´ as the adsorbent of toxical gases. The decisive influence on the adsorbing power has the capacity of porous in unit of volume of the sorbent and dimensions of canals. The active component of zeolite from the deposit Bystré is mineral clinoptilolite. Recently, there is an increased interest to utilize zeolites in the partial reduction of NOx, CO and hydrocarbons in the combustion products. The catalysts used to detoxication of exhalation combustion engines are less effective during periods of relatively low temperature operation, such as the initial cold-start period of engine operation. Some European, American and Japones patents are directed to the use of a zeolite catalyst for the reduction of hydrocarbons, CO and NOx. The noble metals and acid zeolites are used as a catalyst of noxious components. The adsorbent material, which may be a zeolite is part treatment system in order to adsorb gaseous pollutants during of cold start period of engine operation.

  18. Greenhouse Gas and Noxious Emissions from Dual Fuel Diesel and Natural Gas Heavy Goods Vehicles.

    Science.gov (United States)

    Stettler, Marc E J; Midgley, William J B; Swanson, Jacob J; Cebon, David; Boies, Adam M

    2016-02-16

    Dual fuel diesel and natural gas heavy goods vehicles (HGVs) operate on a combination of the two fuels simultaneously. By substituting diesel for natural gas, vehicle operators can benefit from reduced fuel costs and as natural gas has a lower CO2 intensity compared to diesel, dual fuel HGVs have the potential to reduce greenhouse gas (GHG) emissions from the freight sector. In this study, energy consumption, greenhouse gas and noxious emissions for five after-market dual fuel configurations of two vehicle platforms are compared relative to their diesel-only baseline values over transient and steady state testing. Over a transient cycle, CO2 emissions are reduced by up to 9%; however, methane (CH4) emissions due to incomplete combustion lead to CO2e emissions that are 50-127% higher than the equivalent diesel vehicle. Oxidation catalysts evaluated on the vehicles at steady state reduced CH4 emissions by at most 15% at exhaust gas temperatures representative of transient conditions. This study highlights that control of CH4 emissions and improved control of in-cylinder CH4 combustion are required to reduce total GHG emissions of dual fuel HGVs relative to diesel vehicles.

  19. Equipment to reduce the emission of noxious components in the exhaust gas of an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Tatsutomi, Y; Inoue, H

    1976-10-21

    The invention concerns an arrangement for the reduction of emission of noxious components in exhaust gas of an internal combustion engine with automatic drive. According to the invention, there is a further switch in parallel with the usual kickdown switch, which is actuated by a temperature sensor and/or choke. If the operating temperature of the engine is below a certain value, or if the choke is pulled out, then the switch is closed. This has the effect that the downstream valve is brought into the same position as that in which the closed kickdown switch would place it. The automatic drive therefore takes up that position, independently of the position of the accelerator pedal, which it would normally occupy only with the accelerator pedal fully pressed down. This guarantees that the engine is always kept at high speed during the hot running phase, which reduces the portion of the noxious gas components emitted.

  20. Tillage and residue burning affects weed populations and seed banks.

    Science.gov (United States)

    Narwal, S; Sindel, B M; Jessop, R S

    2006-01-01

    An integrated weed management approach requires alternative management practices to herbicide use such as tillage, crop rotations and cultural controls to reduce soil weed seed banks. The objective of this study was to examine the value of different tillage practices and stubble burning to exhaust the seed bank of common weeds from the northern grain region of Australia. Five tillage and burning treatments were incorporated in a field experiment, at Armidale (30 degrees 30'S, 151 degrees 40'E), New South Wales, Australia in July 2004 in a randomized block design replicated four times. The trial was continued and treatments repeated in July 2005 with all the mature plants from the first year being allowed to shed seed in their respective treatment plots. The treatments were (i) no tillage (NT), (ii) chisel ploughing (CP), (iii) mould board ploughing (MBP), (iv) wheat straw burning with no tillage (SBNT) and (v) wheat straw burning with chisel ploughing (SBC). Soil samples were collected before applying treatments and before the weeds flowered to establish the seed bank status of the various weeds in the soil. Wheat was sown after the tillage treatments. Burning treatments were only initiated in the second year, one month prior to tillage treatments. The major weeds present in the seed bank before initiating the trial were Polygonum aviculare, Sonchus oleraceus and Avena fatua. Tillage promoted the germination of other weeds like Hibiscus trionum, Medicago sativa, Vicia sp. and Phalaris paradoxa later in the season in 2004 and Convolvulus erubescens emerged as a new weed in 2005. The MBP treatment in 2004 reduced the weed biomass to a significantly lower level of 55 g/m2 than the other treatments of CP (118 g/m2) and NT plots (196 g/m2) (P < 0.05). However, in 2005 SBC and MBP treatments were similar in reducing the weed biomass. In 2004, the grain yield trend of wheat was significantly different between CP and NT, and MBP and NT (P < 0.05) with maximum yield of 5898

  1. Adjustment of Weed Hoeing to Narrowly Spaced Cereals

    Directory of Open Access Journals (Sweden)

    Jannis Machleb

    2018-04-01

    Full Text Available Weed hoeing can be successfully performed in wide row crops, such as sugar beet, maize, soybean and wide spaced cereals. However, little experience is available for hoeing in narrow cereal row spaces below 200 mm. Yet, mechanical weed control can pose an alternative to herbicide applications by reducing the herbicide resistant populations present in the field. In this experiment, it was investigated whether hoeing is feasible in cereals with 150 and 125 mm row spacings. The trial was set up at two locations (Ihinger Hof and Kleinhohenheim in southwest Germany. Three different conventional hoeing sweeps, a goosefoot sweep, a no-till sweep and a down-cut side knife were adjusted to the small row widths, and hoeing was performed once with a tractor and a standard hoeing frame which was guided by a second human operator. The average grain yield, crop and weed biomass, and weed control efficacy of each treatment were recorded. The goosefoot and no-till sweep were tested at driving speeds of 4 and 6 km·h−1. The down-cut side knife was applied at 4 km·h−1. The results indicate that hoeing caused no yield decrease in comparison to a conventional herbicide application or manual weeding. The highest yield with a mechanical treatment was recorded for the no-till sweeps at both trial locations. Hoeing was performed successfully in narrowly spaced cereals of 150 and 125 mm, and the weed control efficacy of the mechanical treatments ranged from 50.9% at Kleinhohenheim to 89.1% at Ihinger Hof. Future experiments are going to focus on more distinct driving speeds ranging from 2 to 10 km·h−1 and performing more than one pass with the hoe. Additionally, combining the mechanical weeding tools with a camera-steered hoeing frame could increase accuracy, allow for higher working speeds and substitute the second human operator guiding the hoe.

  2. Assessment of Corn Densities on Ecological Indices of Weed Species

    Directory of Open Access Journals (Sweden)

    G Mahmoodi

    2012-06-01

    Full Text Available Diversity, dominance, and stability of weeds are the most important ecological properties in agricultural systems, which influenced by management factors such as crop density, abundantly. This experiment was conducted in 2009 at Ferdowsi University of Mashhad Research Field. The experimental design was interval mapping with four levels of corn densities (5, 6, 7 and 9 plant.m-2 and four levels of weed control (full-control, without control, broad-leaves control and grasses control. Weed sampling was done at 3 stages included beginning and end of critical period weed control and harvesting time. The results showed that the effect of plant density on species diversity was significant; some how the amount of Shanon and Simpson Indices were lowest in the 9 plant.m-2 (0.39 and 0.45, respectively and greatest in 5 plant.m-2 (0.84. The results also showed that the maximum amount of dominance index was observed in 9 plant.m-2, that was seen in Echinochloa crus- galli and Convulvulus arvensis at the beginning of growing season, then in Solanum nigrum and Amaranthus retroflexus in the end of growing season. The amount of community dominance index in 9 plant.m-2 was higher than other densities, and it decreased with decline of densities. based on the results of present experiment the linear relationship between plant species and area was found. The calculated amount of Alpha and Beta diversities. in a θ and β scales based on coefficients of this relationship were 0.534 (four species per unit area and 0.29 (two species per unit area, respectively. In conclusion the result of this experiment pointed that the weeds diversity decreased with increasing of corn density, weed diversity decreased and therefore, having appropriate plant density is very efficient for sustainable weed management.

  3. Allelopathic assessment of selected common weeds in Malaysia

    Science.gov (United States)

    Nurul Ain, M. B.; Nornasuha, Y.; Ismail, B. S.

    2016-11-01

    A laboratory study was conducted to evaluate the allelopathic potential of eight common weed species in Malaysia, namely, Ageratum conyzoides, Tridax procumbens, Cyperus iria, Fimbristylis miliacea, Eleusine indica, Imperata cylindrica, Lygodium flexuosum and Nephrolepis biserrata of different morphological characteristics (broadleaves, sedges, grasses and ferns). The allelopathic study of these weeds was carried out by testing the leaf litter leachate through the Sandwich method and the volatile compounds of these weeds through the Dish pack method with three replicates for each donor species. The results obtained from both methods were statistically analyzed and the means had converted to percentage growth inhibition to determine the inhibition pattern on the radicle and hypocotyl growth of lettuce seedlings. Among the eight weed species tested, Ageratum conyzoides showed the strongest growth inhibition on lettuce radicle elongation (86%) in the sandwich bioassay compared to the control, followed by Tridax procumbens (71%), which both species being broadleaves weeds. In the dish pack bioassay Lygodium flexuosum (fern) demonstrated maximum inhibition on the growth the radicle and hypocotyl for each different distance from the source well. On the other hand, two weed species exhibited enhanced on the growth radicle and hypocotyl when compared to that of the control in dish pack bioassay. Nephrolepis biserrata and Fimbristylis miliacea were the species that showed the highest growth stimulatory effect. The results presented can be utilized as benchmark information for further research on the elucidation of leachates and volatile chemicals involved in allelopathy in nature. The information can also be helpful in the development of new bioactive chemicals from natural products in weed control strategies.

  4. Assessment of Caesium -137 accumulation from soil to autochthonous weeds

    International Nuclear Information System (INIS)

    Sreenivasa Chari, M.; Karuna Sagar, G.; Manjaiah, K.M.

    2017-01-01

    A study was conducted at Nuclear Research Laboratory (NRL), IARI, New Delhi to obtain radio cesium ( 137 Cs) Soil-to-plant transfer factors of autochthonous weeds at low level of contamination, where contamination is a legacy of experimental activities. Studied area is sporadically covered with autochthonous weeds mainly with Amaranthus viridis, Cynodon dactylon, Cassia auriculata, Brachiaria mutica, Parthenium hysterophorus, Bohervia diffusa and some taxonomically unidentified weeds. Extractability as well as bioavailability of 137 Cs was quantified by sequential extraction. In the representative plant and soil samples, 137 Cs activity was measured directly with the 2.5” × 2.5” NaI (TI) well type detector installed in 15 cm thick lead shield and single channel gamma analyzer. Transfer factors of grassy weeds were 0.143 to 0.310 (1.43 × 10 -2 to 3.1 × 10 -2 ), for broad leaved weeds 0.103 to 0.133 (1.03 × 10 -2 to 1.33 × 10 -2 ). Increase in the activity levels increased the transfer factors of weeds. Irrespective of activity levels higher transfer factors were observed in roots ranging from 0.13 to 0.28 (1. 3 × 10 -1 to 2.8 × 10 -1 ). At both the levels (40 and 80 µci) Cynodon dactylon recorded higher root and shoot transfer factor of 2.99 and 0.29 respectively, when compared to other weeds. Significantly lower transfer factors were observed in Parthenium hysterophorus. Geochemical partitioning shown that the reducible phase (56%) is the largest sink for 137 Cs in the studied soils

  5. Natural metabolites for parasitic weed management.

    Science.gov (United States)

    Vurro, Maurizio; Boari, Angela; Evidente, Antonio; Andolfi, Anna; Zermane, Nadjia

    2009-05-01

    Compounds of natural origin, such as phytotoxins produced by fungi or natural amino acids, could be used in parasitic weed management strategies by interfering with the early growth stages of the parasites. These metabolites could inhibit seed germination or germ tube elongation, so preventing attachment to the host plant, or, conversely, stimulate seed germination in the absence of the host, contributing to a reduction in the parasite seed bank. Some of the fungal metabolites assayed were very active even at very low concentrations, such as some macrocyclic trichothecenes, which at 0.1 microM strongly suppressed the germination of Orobanche ramosa L. seeds. Interesting results were also obtained with some novel toxins, such as phyllostictine A, highly active in reducing germ tube elongation and seed germination both of O. ramosa and of Cuscuta campestris Yuncker. Among the amino acids tested, methionine and arginine were particularly interesting, as they were able to suppress seed germination at concentrations lower than 1 mM. Some of the fungal metabolites tested were also able to stimulate the germination of O. ramosa seeds. The major findings in this research field are described and discussed.

  6. Control of invasive weeds with prescribed burning

    Science.gov (United States)

    DiTomaso, Joseph M.; Brooks, Matthew L.; Allen, Edith B.; Minnich, Ralph; Rice, Peter M.; Kyser, Guy B.

    2006-01-01

    Prescribed burning has primarily been used as a tool for the control of invasive late-season annual broadleaf and grass species, particularly yellow starthistle, medusahead, barb goatgrass, and several bromes. However, timely burning of a few invasive biennial broadleaves (e.g., sweetclover and garlic mustard), perennial grasses (e.g., bluegrasses and smooth brome), and woody species (e.g., brooms and Chinese tallow tree) also has been successful. In many cases, the effectiveness of prescribed burning can be enhanced when incorporated into an integrated vegetation management program. Although there are some excellent examples of successful use of prescribed burning for the control of invasive species, a limited number of species have been evaluated. In addition, few studies have measured the impact of prescribed burning on the long-term changes in plant communities, impacts to endangered plant species, effects on wildlife and insect populations, and alterations in soil biology, including nutrition, mycorrhizae, and hydrology. In this review, we evaluate the current state of knowledge on prescribed burning as a tool for invasive weed management.

  7. Weed Diversity Affects Soybean and Maize Yield in a Long Term Experiment in Michigan, USA.

    Science.gov (United States)

    Ferrero, Rosana; Lima, Mauricio; Davis, Adam S; Gonzalez-Andujar, Jose L

    2017-01-01

    Managing production environments in ways that promote weed community diversity may enhance both crop production and the development of a more sustainable agriculture. This study analyzed data of productivity of maize (corn) and soybean in plots in the Main Cropping System Experiment (MCSE) at the W. K. Kellogg Biological Station Long-Term Ecological Research (KBS-LTER) in Michigan, USA, from 1996 to 2011. We used models derived from population ecology to explore how weed diversity, temperature, and precipitation interact with crop yields. Using three types of models that considered internal and external (climate and weeds) factors, with additive or non-linear variants, we found that changes in weed diversity were associated with changes in rates of crop yield increase over time for both maize and soybeans. The intrinsic capacity for soybean yield increase in response to the environment was greater under more diverse weed communities. Soybean production risks were greatest in the least weed diverse systems, in which each weed species lost was associated with progressively greater crop yield losses. Managing for weed community diversity, while suppressing dominant, highly competitive weeds, may be a helpful strategy for supporting long term increases in soybean productivity. In maize, there was a negative and non-additive response of yields to the interaction between weed diversity and minimum air temperatures. When cold temperatures constrained potential maize productivity through limited resources, negative interactions with weed diversity became more pronounced. We suggest that: (1) maize was less competitive in cold years allowing higher weed diversity and the dominance of some weed species; or (2) that cold years resulted in increased weed richness and prevalence of competitive weeds, thus reducing crop yields. Therefore, we propose to control dominant weed species especially in the years of low yield and extreme minimum temperatures to improve maize yields

  8. Emerging Challenges and Opportunities for Education and Research in Weed Science

    Directory of Open Access Journals (Sweden)

    Bhagirath S. Chauhan

    2017-09-01

    Full Text Available In modern agriculture, with more emphasis on high input systems, weed problems are likely to increase and become more complex. With heightened awareness of adverse effects of herbicide residues on human health and environment and the evolution of herbicide-resistant weed biotypes, a significant focus within weed science has now shifted to the development of eco-friendly technologies with reduced reliance on herbicides. Further, with the large-scale adoption of herbicide-resistant crops, and uncertain climatic optima under climate change, the problems for weed science have become multi-faceted. To handle these complex weed problems, a holistic line of action with multi-disciplinary approaches is required, including adjustments to technology, management practices, and legislation. Improved knowledge of weed ecology, biology, genetics, and molecular biology is essential for developing sustainable weed control practices. Additionally, judicious use of advanced technologies, such as site-specific weed management systems and decision support modeling, will play a significant role in reducing costs associated with weed control. Further, effective linkages between farmers and weed researchers will be necessary to facilitate the adoption of technological developments. To meet these challenges, priorities in research need to be determined and the education system for weed science needs to be reoriented. In respect of the latter imperative, closer collaboration between weed scientists and other disciplines can help in defining and solving the complex weed management challenges of the 21st century. This consensus will provide more versatile and diverse approaches to innovative teaching and training practices, which will be needed to prepare future weed science graduates who are capable of handling the anticipated challenges of weed science facing in contemporary agriculture. To build this capacity, mobilizing additional funding for both weed research and

  9. Weed Competition and its Effects on Pwani Hybrid 1 Maize Grain Yields in Coastal Kenya

    International Nuclear Information System (INIS)

    Kamau, G.M.; Saha, H.M.

    1999-01-01

    Weed competition is a serious constraint to maize production in coastal Kenya. A trial to asses the effects of weed competition on performance of maize was planted at Regional Research Centre-Mtwapa and Msabaha Research Sub-centre-Malindi in 1992. Pwani hybrid 1 maize was used in the trials. Weeding was done at weekly intervals from germination up to the sixth week in an additive weed removal system and plots maintained weed free afterwards. A weedy and a weed free plot were used as checks. Data on plant counts plant heights, weed biomass, weed identification and maize grain yield at 15 % MC were all recorded. There was a significant difference between weed and weedy free plots for grain yield, plant height and weed biomass for both sites. A 53% maize grain yield reduction due to weed competition was recorded. A 3% grain yield reduction equivalent to 1.03 bags for every week's delay in weeding after the first to weeks was realised for both sites. There was a corresponding grain yield loss as delay in weeding increased

  10. Fear appeals and attitude change: effects of a threat's noxiousness, probability of occurrence, and the efficacy of coping responses.

    Science.gov (United States)

    Rogers, R W; Mewborn, C R

    1976-07-01

    Three factorial experiments examined the persuasive effects of the noxiousness of threatened event, its probability of occurrence, and the efficacy of recommended protective measures. A total of 176 students participated in separate studies on the topics of cigarette smoking, driving safety, and venereal disease. The results disclosed that increments in the efficacy variable increased intentions to adopt the efficacy variable increased intentions to adopt the recommended practices. Interaction effects revealed that when the preventive practices were effective, increments in the noxiousness and probability variables facilitated attitude change; however, when the coping responses were the preventive practices were effective, increments in the noxiousness and probability either had no effect or a deleterious effect, respectively. These interaction effects were discussed in terms of a defensive avoidance hypothesis, the crucial component of which was an inability to ward off the danger. Furthermore, the effect of the emotion of fear upon intentions was found to be mediated by the cognitive appraisal of severity of the threat. Finally, similarities with and extensions of previous studies were reviewed.

  11. Basin wildrye (Leymus cinereus) pooled tetraploid accessions for U.S. Intermountain rangeland reclamation

    Science.gov (United States)

    Stanford A. Young; Jason Vernon; Nancy Shaw

    2013-01-01

    Basin wildrye (Leymus cinereus [Scribn. & Merr.] A. Love) is an important perennial, hardy, long-lived, cool season C3 native grass of rangeland plant communities throughout much of western United States and Canada. All classes of livestock and wildlife, including large and small birds and mammals, utilise the grass year round for food and protection due to its 2-3...

  12. Analytical approaches to quality assurance and quality control in rangeland monitoring data

    Science.gov (United States)

    Producing quality data to support land management decisions is the goal of every rangeland monitoring program. However, the results of quality assurance (QA) and quality control (QC) efforts to improve data quality are rarely reported. The purpose of QA and QC is to prevent and describe non-sampling...

  13. Livestock systems and rangeland degradation in the new World Atlas of Desertification

    Science.gov (United States)

    Zucca, Claudio; Reynolds, James F.; Cherlet, Michael

    2015-04-01

    Livestock systems and rangeland degradation in the new World Atlas of Desertification Land degradation and desertification (LDD), which are widespread in global rangelands, are complex processes. They are caused by multiple (but limited) number of biophysical and socioeconomic drivers that lead to an unbalance in the capacity of the land to sustainably produce ecosystem services and economic value. Converging evidence indicates that the key biophysical and socioeconomic drivers include agricultural or pastoral land use and management practices, population growth, societal demands (e.g., urbanization), and climate change (e.g., increasing aridity and drought). The new World Atlas of Desertification (WAD) describes these global issues, documents their spatial change, and highlights the importance of these drivers in relation to land degradation processes. The impacts of LDD on the atmosphere, on water and on biodiversity are also covered. The WAD spatially illustrates relevant types of livestock and rangeland management systems, related (over-under) use of resources, various management activities, and some of the common features and transitions that contribute to LDD. For example, livestock grazing in marginal areas is increasing due to competition with agricultural encroachment and, hence, vulnerable lands are under threat. The integration of stratified global data layers facilitates identifying areas where stress on the land system can be linked to underlying causal issues. One of the objectives of the new WAD is to provide synthesis and tools for scientists and stakeholders to design sustainable solutions for efficient land use in global rangelands.

  14. Dairy cattle on Norwegian alpine rangelands – grazing preferences and milk quality

    NARCIS (Netherlands)

    Sickel, H; Abrahamsen, R K; Eldegard, K; Lunnan, T; Norderhaug, A; Petersen, M.A.; Sickel, M.; Steenhuisen, F.; Ohlson, M.

    2014-01-01

    The results from the study ‘Effects of vegetation and grazing preferences on the quality of alpine dairy products’ will be presented. The main objective of the project was to investigate the connections bet - ween alpine rangeland vegetation, landscape use and grazing preferences of free ranging

  15. Vulnerability of cattle production to climate change on U.S. rangelands

    Science.gov (United States)

    Matt C. Reeves; Karen E. Bagne

    2016-01-01

    We examined multiple climate change effects on cattle production for U.S. rangelands to estimate relative change and identify sources of vulnerability among seven regions. Climate change effects to 2100 were projected from published models for four elements: forage quantity, vegetation type trajectory, heat stress, and forage variability. Departure of projections from...

  16. Assessing Rangeland Attributes On Semi-Arid Zone Of North Darfur State Sudan

    Directory of Open Access Journals (Sweden)

    Mohamed Almontasir A. M. Mohamed

    2015-08-01

    Full Text Available Abstract The study was conducted over a two years period of 2012 and 2013 at three sites of Alfashir locality Ummarahik 25km north of Alfashir Fashar in eastern part of Alfashir about 5km and Berka 30km west of Alfashir Western Sudan in semi-arid zone. The aim of this study was to assess rangeland attributes. Measurements of plant density vegetation cover range production and carrying capacity were assessed. Results showed that total forage production was low and inadequate to satisfy requirements of livestock for inhabiting the area average range production all over the area was found to be 50.68 kgha and 59.21 kgha for the seasons 2012 and 2013 respectively. The average ground cover was about 34.71 and 42.41 for two seasons. The average plant density for the first season was 27.1 plantm2 while the average plant density for the second season was 29.4 plantm2. The study concluded that unwise utilization and exploitation of the rangelands particularly by man causes range deterioration and serious reduction in range production in both quantity and quality so the study suggested that improvement and rehabilitation such lands rangelands should be done. Further research work is needed to assess rangeland attributes across different ecological zones in North Darfur State.

  17. Rangelands Vegetation under Different Management Systems and Growth Stages in North Darfur State, Sudan (Range Attributes

    Directory of Open Access Journals (Sweden)

    Mohamed AAMA Mohamed

    2014-09-01

    Full Text Available This study was conducted at Um Kaddada, North Darfur State, Sudan, at two sites (closed and open for two consecutive seasons 2008 and 2009 during flowering and seed setting stages to evaluate range attributes at the locality. A split plot design was used to study vegetation attributes. Factors studied were management systems (closed and open and growth stages (flowering and seed setting. Vegetation cover, plant density, carrying capacity, and biomass production were assessed. Chemical analyses were done for selected plants to determine their nutritive values. The results showed high significant differences in vegetation attributes (density, cover and biomass production between closed and open areas. Closed areas had higher carrying capacity compared to open rangelands. Crude protein (CP and ash contents of range vegetation were found to decrease while Crude fiber (CF and Dry matter yield (DM had increased with growth. The study concluded that closed rangelands are better than open rangelands because it fenced and protected. Erosion index and vegetation degradation rate were very high. Future research work is needed to assess rangelands characteristics and habitat condition across different ecological zones in North Darfur State, Sudan.DOI: http://dx.doi.org/10.3126/ije.v3i3.11093 International Journal of Environment Vol.3(3 2014: 332-343

  18. Rangeland livestock production: Developing the concept of sustainability on the Santa Rita Experimental Range

    Science.gov (United States)

    George B. Ruyle

    2003-01-01

    The Santa Rita Experimental Range (SRER) was established in 1903 at the behest of concerned stockmen and researchers as the first facility in the United States set aside to study range livestock production. At the time, severe overgrazing of the public domain had seriously reduced carrying capacities of Southwestern rangelands. Researchers on the SRER developed and...

  19. Estimating climate change effects on net primary production of rangelands in the United States

    Science.gov (United States)

    Matthew C. Reeves; Adam L. Moreno; Karen E. Bagne; Steven W. Running

    2014-01-01

    The potential effects of climate change on net primary productivity (NPP) of U.S. rangelands were evaluated using estimated climate regimes from the A1B, A2 and B2 global change scenarios imposed on the biogeochemical cycling model, Biome-BGC from 2001 to 2100. Temperature, precipitation, vapor pressure deficit, day length, solar radiation, CO2 enrichment and nitrogen...

  20. Composted manure application promotes long-term invasion of semi-arid rangeland by Bromus tectorum

    Science.gov (United States)

    Composted organic matter derived from sewage treatment facilities or livestock manure from feedlots is often applied to rangelands of western North America to increase soil fertility, forage production, forage quality, and soil carbon (C) storage. This practice can have a number of undesirable side ...

  1. Contrasting watershed-scale trends in runoff and sediment yield complicate rangeland water resources planning

    Science.gov (United States)

    Berg, Matthew D.; Marcantonio, Franco; Allison, Mead A.; McAlister, Jason; Wilcox, Bradford P.; Fox, William E.

    2016-06-01

    Rangelands cover a large portion of the earth's land surface and are undergoing dramatic landscape changes. At the same time, these ecosystems face increasing expectations to meet growing water supply needs. To address major gaps in our understanding of rangeland hydrologic function, we investigated historical watershed-scale runoff and sediment yield in a dynamic landscape in central Texas, USA. We quantified the relationship between precipitation and runoff and analyzed reservoir sediment cores dated using cesium-137 and lead-210 radioisotopes. Local rainfall and streamflow showed no directional trend over a period of 85 years, resulting in a rainfall-runoff ratio that has been resilient to watershed changes. Reservoir sedimentation rates generally were higher before 1963, but have been much lower and very stable since that time. Our findings suggest that (1) rangeland water yields may be stable over long periods despite dramatic landscape changes while (2) these same landscape changes influence sediment yields that impact downstream reservoir storage. Relying on rangelands to meet water needs demands an understanding of how these dynamic landscapes function and a quantification of the physical processes at work.

  2. Weight gain and behavior of Raramuri Criollo versus Corriente steers developed on Chihuahuan Desert rangeland

    Science.gov (United States)

    Ranchers that raise Criollo cattle must overcome the challenge of lack of markets for weaned calves. Raramuri Criollo (RC) steers are commonly raised for beef and finished on rangelands, while Corriente (CR) are often raised for rodeo sports. No data exist on weight gains and grazing behavior of ran...

  3. Movement and spatial proximity patterns of rangeland-raised Raramuri Criollo cow-calf pairs

    Science.gov (United States)

    The objective of this study was to compare movement patterns of nursing vs. nonnursing mature cows and to characterize cow-calf proximity patterns in two herds of Raramuri Criollo cattle. Herds grazed rangeland pastures in southern New Mexico (4355 ha) and west-central Chihuahua, Mexico (633 ha)'' A...

  4. Mother-Offspring Interactions in Raramuri Criollo Cattle on New Mexico and Chihuahua (Mexico) Rangelands

    Science.gov (United States)

    Rangeland beef cows spend approximately six months of a typical year raising their calf. This endeavor is known to significantly alter a dam’s grazing behavior and spatial distribution patterns. The objective of this study was to characterize cow-calf contact events in two herds of Raramuri Criollo ...

  5. Weight gain and behavior of Raramuri Criollo versus crossbred steers developed on Chihuahuan Desert rangeland

    Science.gov (United States)

    Ranchers that raise Raramuri Criollo (RC) cattle must overcome the challenge of lack of markets for weaned calves. Growing and finishing RC or RC-crossbred steers on rangeland pastures is increasingly common; however, no data exist on their weight gains or grazing behavior. We tracked the weight a...

  6. Influence of forest and rangeland management on anadromous fish habitat in Western North America: economic considerations.

    Science.gov (United States)

    William R. tech. ed. Meehan

    1985-01-01

    Although many effects of forest and rangeland management on anadromous fisheries are difficult to measure, economic methods for the evaluation of costs and benefits can be helpful. Such methods can be used to address questions of equity as well as efficiency. Evaluations of equity can show who bears the costs and who captures the benefits of management actions, but...

  7. A planning support system for rangeland allocation in Iran : case of Chadegan sub-region

    NARCIS (Netherlands)

    Farahpour, M.

    2002-01-01

    Rangelands, like other natural resources are subject to many changes. In Iran, one of the changes is the land tenure reform, that may have significant effects on both the land and the land user. Land tenure changes not only affect the life of the present, but also that of next generations,

  8. A review of concentrated flow erosion processes on rangelands: fundamental understanding and knowledge gaps

    Science.gov (United States)

    Concentrated flow erosion processes are distinguished from splash and sheetflow processes in their enhanced ability to mobilize and transport large amounts of soil, water and dissolved elements. On rangelands, soil, nutrients and water are scarce and only narrow margins of resource losses are tolera...

  9. Salinity mobilization and transport from rangelands: assessment, recommendations, and knowledge gaps

    Science.gov (United States)

    The purpose of the salinity project is to improve the understanding of sources and transport mechanisms in rangeland catchments that deliver dissolved solids (salts) to streams within the Upper Colorado River Basin (UCRB) through a review of relevant literature on what is known about the impact of r...

  10. The Role of Rangelands in Diversified Farming Systems: Innovations, Obstacles, and Opportunities in the USA

    Directory of Open Access Journals (Sweden)

    Nathan F. Sayre

    2012-12-01

    Full Text Available Discussions of diversified farming systems (DFS rarely mention rangelands: the grasslands, shrublands, and savannas that make up roughly one-third of Earth's ice-free terrestrial area, including some 312 million ha of the United States. Although ranching has been criticized by environmentalists for decades, it is probably the most ecologically sustainable segment of the U.S. meat industry, and it exemplifies many of the defining characteristics of DFS: it relies on the functional diversity of natural ecological processes of plant and animal (reproduction at multiple scales, based on ecosystem services generated and regenerated on site rather than imported, often nonrenewable, inputs. Rangelands also provide other ecosystem services, including watershed, wildlife habitat, recreation, and tourism. Even where non-native or invasive plants have encroached on or replaced native species, rangelands retain unusually high levels of plant diversity compared with croplands or plantation forests. Innovations in management, marketing, incentives, and easement programs that augment ranch income, creative land tenure arrangements, and collaborations among ranchers all support diversification. Some obstacles include rapid landownership turnover, lack of accessible U.S. Department of Agriculture certified processing facilities, tenure uncertainty, fragmentation of rangelands, and low and variable income, especially relative to land costs. Taking advantage of rancher knowledge and stewardship, and aligning incentives with production of diverse goods and services, will support the sustainability of ranching and its associated public benefits. The creation of positive feedbacks between economic and ecological diversity should be the ultimate goal.

  11. Grazing management, resilience and the dynamics of a fire driven rangeland system

    NARCIS (Netherlands)

    Anderies, J.M.; Janssen, M.A.; Walker, B.H.

    2002-01-01

    We developed a stylized mathematical model to explore the effects of physical, ecological, and economic factors on the resilience of a managed fire-driven rangeland system. Depending on grazing pressure, the model exhibits one of three distinct configurations: a fire-dominated, grazing-dominated, or

  12. Towards a remote sensing based indicator of rangeland ecosystem resistance and resilience

    Science.gov (United States)

    Understanding ecosystem resistance and resilience to disturbance and invasive species is critical to the sustainable management of rangeland systems. In this context, resistance refers to the inherent ability of an ecosystem to resist disturbance, while resilience refers to the capacity of an ecosys...

  13. Comparative Assessment of Goods and Services Provided by Grazing Regulation and Reforestation in Degraded Mediterranean Rangelands

    NARCIS (Netherlands)

    Papanastasis, Vasilios P.; Bautista, Susana; Chouvardas, Dimitrios; Mantzanas, Konstantinos; Papadimitriou, Maria; Garcia Mayor, Angeles; Koukioumi, Polina; Papaioannou, Athanasios; Vallejo, Ramon V.

    2017-01-01

    Several management actions are applied to restore ecosystem services in degraded Mediterranean rangelands, which range from adjusting the grazing pressure to the removal of grazers and pine plantations. Four such actions were assessed in Quercus coccifera L. shrublands in northern Greece: (i)

  14. Revolutionary land use change in the 21st century: Is (rangeland) science relevant?

    Science.gov (United States)

    Rapidly increasing demand for food, fiber and fuel together with new technologies and the mobility of global capital are driving revolutionary changes in land use throughout the world. Efforts to increase land productivity include conversion of millions of hectares of rangelands to crop production, ...

  15. Session A5 Rangelands as dynamic systems Role of wildlife in ...

    African Journals Online (AJOL)

    Rangelands in southern Africa are increasingly being used for conservation, ecotourism, game farming and hunting. This impacts people's livelihoods and the state of natural resources. Complimentarity and competition between wildlife and domestic livestock can be explored. Theme: This session focuses on ecosystem ...

  16. Searls prairie clover (Dalea searlsiae) for rangeland revegetation: Phenotypic and genetic evaluations

    Science.gov (United States)

    Kishor Bhattarai; Shaun Bushman; Douglas A. Johnson; John G. Carman

    2011-01-01

    Few North American legumes are available for use in rangeland revegetation in the western USA, but Searls prairie clover [Dalea searlsiae (A. Gray) Barneby] is one that holds promise. Commercial-scale seed production of this species could address the issues of unreliable seed availability and high seed costs associated with its wildland seed collection. To evaluate its...

  17. Multi-scale wind erosion monitoring and assessment for US rangelands

    Science.gov (United States)

    Wind erosion is a major resource concern for rangeland managers. Although wind erosion is a naturally occurring process in many drylands, land use activities, and land management in particular, can accelerate wind-driven soil loss – impacting ecosystem dynamics and agricultural production, air quali...

  18. Ecosystem water availability in juniper versus sagebrush snow-dominated rangelands

    Science.gov (United States)

    Western Juniper (J. occidentalis Hook.) now dominates over 3.6 million ha of rangeland in the Intermountain Western US. Critical ecological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as sage grouse, remain poorly und...

  19. Climate-change adaptation on rangelands: Linking regional exposure with diverse adaptive capacity

    Science.gov (United States)

    David D. Briske; Linda A. Joyce; H. Wayne Polley; Joel R. Brown; Klaus Wolter; Jack A. Morgan; Bruce A. McCarl; Derek W. Bailey

    2015-01-01

    The ecological consequences of climate change are predicted to vary greatly throughout US rangelands. Projections show warming and drying in the southern Great Plains and the Southwest, warmer and drier summers with reduced winter snowpack in the Northwest, and warmer and wetter conditions in the northern Great Plains. Primarily through their combined effects on soil...

  20. Deforestation of "degraded" rangelands: The Argentine Chaco enters the next stage of the Anthropocene

    Science.gov (United States)

    Twenty years ago I completed my Master’s work in the Chaco forests of northern Argentina. The native forests are, in fact, rangelands. In addition to livestock grazing, there is timber extraction, wildlife harvest (think tegu lizard cowboy boots), and charcoal production. I took part in a project co...

  1. Bridging Drought – Resilience in Rangeland Management in Times of Climate Change

    OpenAIRE

    Isele, Judith

    2014-01-01

    Organic livestock farming in semiarid regions greatly depends on the sustainable management of the natural rangeland as the resource for livestock sustenance. High stock density in combination with short grazing and long recovery periods achieve effective rainfall utilisation and considerably higher fodder production resulting in a high degree of resilience in drought situations.

  2. Mapping Erosion and Salinity Risk Categories Using GIS and the Rangeland Hydrology Erosion Model

    Science.gov (United States)

    Up to fifteen percent of rangelands in the state of Utah in the United States are classified as being in severely eroding condition. Some of these degraded lands are located on saline, erodible soils of the Mancos Shale formation. This results in a disproportionate contribution of sediment, salinity...

  3. Temperament affects rangeland use patterns and reproductive performance of beef cows

    Science.gov (United States)

    • The American beef industry is paying more attention to cattle temperament, but studies examining relationships between temperaments and grazing behavior or animal performance on rangelands are limited. • We studied range beef cow temperaments using the behavioral syndromes framework. Cows classifi...

  4. Applying a dryland degradation framework for rangelands: the case of Mongolia.

    Science.gov (United States)

    Jamsranjav, C; Reid, R S; Fernández-Giménez, M E; Tsevlee, A; Yadamsuren, B; Heiner, M

    2018-04-01

    Livestock-caused rangeland degradation remains a major policy concern globally and the subject of widespread scientific study. This concern persists in part because it is difficult to isolate the effects of livestock from climate and other factors that influence ecosystem conditions. Further, degradation studies seldom use multiple plant and soil indicators linked to a clear definition of and ecologically grounded framework for degradation assessment that distinguishes different levels of degradation. Here, we integrate two globally applicable rangeland degradation frameworks and apply them to a broad-scale empirical data set for the country of Mongolia. We compare our assessment results with two other recent national rangeland degradation assessments in Mongolia to gauge consistency of findings across assessments and evaluate the utility of our framework. We measured livestock-use impacts across Mongolia's major ecological zones: mountain and forest steppe, eastern steppe, steppe, and desert steppe. At 143 sites in 36 counties, we measured livestock-use and degradation indicators at increasing distances from livestock corrals in winter-grazed pastures. At each site, we measured multiple indicators linked to our degradation framework, including plant cover, standing biomass, palatability, species richness, forage quality, vegetation gaps, and soil surface characteristics. Livestock use had no effect on soils, plant species richness, or standing crop biomass in any ecological zone, but subtly affected plant cover and palatable plant abundance. Livestock effects were strongest in the steppe zone, moderate in the desert steppe, and limited in the mountain/forest and eastern steppes. Our results aligned closely with those of two other recent country-wide assessments, suggesting that our framework may have widespread application. All three assessments found that very severe and irreversible degradation is rare in Mongolia (1-18% of land area), with most rangelands

  5. The weeding handbook a shelf-by-shelf guide

    CERN Document Server

    Vnuk, Rebecca

    2015-01-01

    "No! We can't rid of that!" Vnuk, author of the popular "Weeding Tips" column on Booklist Online, is here to show you that yes, you can. A library is an ever-changing organism; when done the right way, weeding helps a library thrive by focusing its resources on those parts of the collection that are the most useful to its users. Her handbook takes the guesswork out of this delicate but necessary process, giving public and school library staff the knowledge and the confidence to effectively weed any collection, of any size. Going through the proverbial stacks shelf by shelf, Vnuk: Explains why weeding is important for a healthy library, demonstrating that a vibrant collection leads to robust circulation, which in turn affects library budgets Walks readers through a library's shelves by Dewey area, with recommended weeding criteria and call-outs in each area for the different considerations of large collections and smaller collections Features a chapter addressing reference, media, magazines and newspapers, e-b...

  6. Cruciferous weeds in oil seed rape – appearance and control

    Directory of Open Access Journals (Sweden)

    Klingenhagen, Günter

    2014-02-01

    Full Text Available Different cruciferous weeds were drilled in autumn 2011 and 2012 in a field near Münster. Beside common species like hedge mustard (Sisymbrium officinale Scop., shepherd`s purse (Capsella bursa-pastoris, pennycress (Thlaspiarvense, tall hedge mustard (Sisymbrium loeselii and flixweed (Descurainia sophia, we tried to establish weeds that are not common on arable land in Germany until now. These were: Yellow rocket (Barbarea vulgaris, hoary cress (Lepidium draba and Turkish rocket (Bunias orientalis. In autumn 2011 emergence of the sown weeds was poor. In the second year of experiment we got good emergence of the named weeds excluding hoary cress (Lepidium draba. In autumn 2011 and 2012 different herbicidecombinations were applied across the stripes. The best results were achieved with Colzor Trio (clomazone + dimethachlor + napropamid which was applied in pre-emergence state, a spray sequence Butisan Gold (metazachlor + quinmerac + dimethenamid-P applied in pre-emergence followed by Salsa (ethametsulfuronmethyl + Trend (adjuvant in post-emergence and Clearfield-Vantiga (metazachlor + quinmerac + imazamox + Dash (adjuvant, also applied in post-emergence state of the weeds.

  7. Weed Growth Stage Estimator Using Deep Convolutional Neural Networks.

    Science.gov (United States)

    Teimouri, Nima; Dyrmann, Mads; Nielsen, Per Rydahl; Mathiassen, Solvejg Kopp; Somerville, Gayle J; Jørgensen, Rasmus Nyholm

    2018-05-16

    This study outlines a new method of automatically estimating weed species and growth stages (from cotyledon until eight leaves are visible) of in situ images covering 18 weed species or families. Images of weeds growing within a variety of crops were gathered across variable environmental conditions with regards to soil types, resolution and light settings. Then, 9649 of these images were used for training the computer, which automatically divided the weeds into nine growth classes. The performance of this proposed convolutional neural network approach was evaluated on a further set of 2516 images, which also varied in term of crop, soil type, image resolution and light conditions. The overall performance of this approach achieved a maximum accuracy of 78% for identifying Polygonum spp. and a minimum accuracy of 46% for blackgrass. In addition, it achieved an average 70% accuracy rate in estimating the number of leaves and 96% accuracy when accepting a deviation of two leaves. These results show that this new method of using deep convolutional neural networks has a relatively high ability to estimate early growth stages across a wide variety of weed species.

  8. Controlling weeds with fungi, bacteria and viruses: a review

    Science.gov (United States)

    Harding, Dylan P.; Raizada, Manish N.

    2015-01-01

    Weeds are a nuisance in a variety of land uses. The increasing prevalence of both herbicide resistant weeds and bans on cosmetic pesticide use has created a strong impetus to develop novel strategies for controlling weeds. The application of bacteria, fungi and viruses to achieving this goal has received increasingly great attention over the last three decades. Proposed benefits to this strategy include reduced environmental impact, increased target specificity, reduced development costs compared to conventional herbicides and the identification of novel herbicidal mechanisms. This review focuses on examples from North America. Among fungi, the prominent genera to receive attention as bioherbicide candidates include Colletotrichum, Phoma, and Sclerotinia. Among bacteria, Xanthomonas and Pseudomonas share this distinction. The available reports on the application of viruses to controlling weeds are also reviewed. Focus is given to the phytotoxic mechanisms associated with bioherbicide candidates. Achieving consistent suppression of weeds in field conditions is a common challenge to this control strategy, as the efficacy of a bioherbicide candidate is generally more sensitive to environmental variation than a conventional herbicide. Common themes and lessons emerging from the available literature in regard to this challenge are presented. Additionally, future directions for this crop protection strategy are suggested. PMID:26379687

  9. New possibilities for weed control in conventional soybeans

    Directory of Open Access Journals (Sweden)

    Petersen, Jan

    2014-02-01

    Full Text Available In field trials in was investigated, if the use of the in Germany new active ingredient imazamox enlarge the possibilities of post emergence weed control in soybeans. Furthermore new herbicide strategies were tested on efficacy and selectivity in soybeans. The use of imazamox was very selective and showed a relative broad spectrum of controlled weed species. However, efficacy of imazamox must be supported by a pre-emergence treatment and in most cases by a tank mix partner. For example cleavers (Galium aparine can not be controlled by imazamox. Tankmixtures of imazamox and bentazon indicated an antagonism. Efficacy to some weed species was reduced compared to solo application. The low dose concept – three applications of low doses at cotyledon stage of weeds led to some success. However, these strategies must be further investigated, before they can be recommended to commercial farming practice. All herbicide strategies tested showed some surviving weed species. This indicates that choice of herbicides, dose rates and application strategies must be done very careful and site specific.

  10. Chemical Weed Control in Saffron (Crocus sativus Fields

    Directory of Open Access Journals (Sweden)

    majid abbaspoor

    2018-01-01

    Full Text Available Introduction Saffron is derived from the stigmas of the saffron (Crocus sativus L. It is the world’s most expensive spice and has been widely used in many countries. It is also increasingly used for medicinal purposes. Weed control in this perennial, small and low growing crop, needs a lot of labor work. Chemical approach is one of the most effective methods for weed control in saffron. Currently, some herbicide options are available for applications in saffron. For example, satisfactory broadleaved weed control would be achieved by post-emergence application of metribuzin and ioxynil after harvesting saffron flowers. Application of glyphosate and/or 2, 4-D / 2, 4-DB are used to clean up the beds prior to the new season’s flowering and growth of saffron in New Zealand. The selective weed control of weeds in saffron has not been widely reported elsewhere but some in Iran. The choice of herbicide(s depends on the kind of weeds present. In some literatures metribuzin showed promising results for weed control in saffron fields. It is selectively used for control of annual grasses and numerous broad-leaved weeds. The objective of this study was the evaluation of the efficacy of 15 herbicides with different mode of actions, selected on the basis of dominant weed flora and previous studies, on weeds grown in saffron fields. Materials and Methods A field study was conducted to evaluate the efficacy of herbicides for weed control in saffron (Crocus sativus in Agricultural and Natural Resources Research and Education Center of Khorasan Razavi Province, Mashhad, in 2014-2015 growing season. The experiment was conducted in a completely randomized block design with three replications. Treatments were consisted of metsulfuron-methyl + sulfosulfuron (Total® at dose of 40 g ha-1, sulfosulfuron (Apirus® at dose of 26.6 g ha-1, oxadiazon (Ronestar® at dose of 2 l ha-1, oxyflurofen (Goal® at dose of 2 l ha-1, mesosulfuron + idosulfuron + diflufenican

  11. Microwave Technologies as Part of an Integrated Weed Management Strategy: A Review

    Directory of Open Access Journals (Sweden)

    Graham Brodie

    2012-01-01

    Full Text Available Interest in controlling weed plants using radio frequency or microwave energy has been growing in recent years because of the growing concerns about herbicide resistance and chemical residues in the environment. This paper reviews the prospects of using microwave energy to manage weeds. Microwave energy effectively kills weed plants and their seeds; however, most studies have focused on applying the microwave energy over a sizable area, which requires about ten times the energy that is embodied in conventional chemical treatments to achieve effective weed control. A closer analysis of the microwave heating phenomenon suggests that thermal runaway can reduce microwave weed treatment time by at least one order of magnitude. If thermal runaway can be induced in weed plants, the energy costs associated with microwave weed management would be comparable with chemical weed control.

  12. Opportunities and obstacles for rangeland conservation in San Diego County, California, USA

    Directory of Open Access Journals (Sweden)

    Kathleen A. Farley

    2017-03-01

    Full Text Available Working landscapes such as rangelands are increasingly recognized as having high conservation value, providing a variety of ecosystem services, including food, fiber, habitat, recreation, open space, carbon storage, and water, in addition to a broad range of social benefits. However, conversion of rangelands to other land uses has been prevalent throughout the western United States, leading to greater attention in the conservation community to the importance of collaborating with private landowners. The level of interest in collaborative conservation among private landowners and the types of conservation programs they choose to participate in depend on the social, economic, and environmental context. We used GIS analysis and interviews with ranchers to evaluate rangeland conversion and participation in conservation programs among ranchers in San Diego County, California, USA, which is part of a biodiversity hotspot with high plant species richness and a large number of endemic and rare species. We found that > 25% of rangelands were converted to other uses, primarily urbanization, over the past 25 years while the area of public rangeland increased by 9%. Interviews revealed that ranchers in San Diego County have had limited involvement with most conservation programs, and a critical factor for nonparticipation was providing programs access to private land, along with other issues related to trust and social values. Among ranchers who had participated in conservation programs, the payment level and the agency or organization administering the program were key factors. Our results provide insight into factors influencing whether and when ranchers are likely to participate in conservation initiatives and illustrate that private and public land conservation are strongly linked and would be more effective if the two strategies were better integrated.

  13. Light spectrum regulates cell accumulation during daytime in the raphidophyte Chattonella antiqua causing noxious red tides.

    Science.gov (United States)

    Shikata, Tomoyuki; Matsunaga, Shigeru; Kuwahara, Yusuke; Iwahori, Sho; Nishiyama, Yoshitaka

    2016-07-01

    Most marine raphidophyte species cause noxious red tides in temperate coastal areas around the world. It is known that swimming abilities enable raphidophytes to accumulation of cells and to actively acquire light at surface layers and nutrients over a wide depth range. However, it remains unclear how the swimming behavior is affected by environmental conditions, especially light condition. In the present study, we observed the accumulation of the harmful red-tide raphidophyte Chattonella antiqua under various light conditions during the daytime in the laboratory. When exposed to ultraviolet-A/blue light (320-480nm) or red light (640-680nm) from above, cells moved downward. In the case of blue light (455nm), cells started to swim downward after 5-15min of irradiation at a photon flux density≥10μmolm(-2)s(-1). When exposed to monochromatic lights (400-680nm) from the side, cells moved away from the blue light source and then descended, but just moved downward under red light. However, mixing of green/orange light (520-630nm) diminished the effects of blue light. When exposed to a mixture of 30μmolm(-2)s(-1) of blue light (440nm) and ≥6μmolm(-2)s(-1) of yellow light (560nm) from above, cells did not move downward. These results indicate that blue light induces negative phototaxis and ultraviolet-A/blue and red lights induce descending, and green/orange light cancels out their effects in C. antiqua. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Evaluating the toxic effects of three priority hazardous and noxious substances (HNS) to rotifer Brachionus plicatilis.

    Science.gov (United States)

    Zheng, Lei; Pan, Luqing; Lin, Pengfei; Miao, Jingjing; Wang, Xiufen; Lin, Yufei; Wu, Jiangyue

    2017-12-01

    Hazardous and noxious substances (HNS) spill in the marine environment is an issue of growing concern, and it will mostly continue to do so in the future owing to the increase of high chemical traffic. Nevertheless, the effects of HNS spill on marine environment, especially on aquatic organisms are unclear. Consequently, it is emergent to provide valuable information for the toxicities to marine biota caused by HNS spill. Accordingly, the acute toxicity of three preferential HNS and sub-lethal effects of acrylonitrile on Brachionus plicatilis were evaluated. The median lethal concentration (LC 50 ) at 24 h were 47.2 mg acrylonitrile L -1 , 276.9 mg styrene L -1 , and 488.3 mg p-xylene L -1 , respectively. Sub-lethal toxicity effects of acrylonitrile on feeding behavior, development, and reproduction parameters of B. plicatilis were also evaluated. Results demonstrated that rates of filtration and ingestion were significantly reduced at 2.0, 4.0, and 8.0 mg L -1 of acrylonitrile. Additionally, reproductive period, fecundity, and life span were significantly decreased at high acrylonitrile concentrations. Conversely, juvenile period was significantly increased at the highest two doses and no effects were observed on embryonic development and post-reproductive period. Meanwhile, we found that ingestion rate decline could be a good predictor of reproduction toxicity in B. plicatilis and ecologically relevant endpoint for toxicity assessment. These data will be useful to assess and deal with marine HNS spillages.

  15. Activated platelets release sphingosine 1-phosphate and induce hypersensitivity to noxious heat stimuli in vivo

    Directory of Open Access Journals (Sweden)

    Daniela eWeth

    2015-04-01

    Full Text Available At the site of injury activated platelets release various mediators, one of which is sphingosine 1-phosphate (S1P. It was the aim of this study to explore whether activated human platelets had a pronociceptive effect in an in vivo mouse model and whether this effect was based on the release of S1P and subsequent activation of neuronal S1P receptors 1 or 3. Human platelets were prepared in different concentrations (105/µl, 106/µl, 107/µl and assessed in mice with different genetic backgrounds (WT, S1P1fl/fl, SNS-S1P1-/-, S1P3-/-. Intracutaneous injections of activated human platelets induced a significant, dose-dependent hypersensitivity to noxious thermal stimulation. The degree of heat hypersensitivity correlated with the platelet concentration as well as the platelet S1P content and the amount of S1P released upon platelet activation as measured with LC MS/MS. Despite the significant correlations between S1P and platelet count, no difference in paw withdrawal latency (PWL was observed in mice with a global null mutation of the S1P3 receptor or a conditional deletion of the S1P1 receptor in nociceptive primary afferents. Furthermore, neutralisation of S1P with a selective anti-S1P antibody did not abolish platelet induced heat hypersensitivity. Our results suggest that activated platelets release S1P and induce heat hypersensitivity in vivo. However, the platelet induced heat hypersensitivity was caused by mediators other than S1P.

  16. Motor cortex stimulation suppresses cortical responses to noxious hindpaw stimulation after spinal cord lesion in rats.

    Science.gov (United States)

    Jiang, Li; Ji, Yadong; Voulalas, Pamela J; Keaser, Michael; Xu, Su; Gullapalli, Rao P; Greenspan, Joel; Masri, Radi

    2014-01-01

    Motor cortex stimulation (MCS) is a potentially effective treatment for chronic neuropathic pain. The neural mechanisms underlying the reduction of hyperalgesia and allodynia after MCS are not completely understood. To investigate the neural mechanisms responsible for analgesic effects after MCS. We test the hypothesis that MCS attenuates evoked blood oxygen-level dependent signals in cortical areas involved in nociceptive processing in an animal model of chronic neuropathic pain. We used adult female Sprague-Dawley rats (n = 10) that received unilateral electrolytic lesions of the right spinal cord at the level of C6 (SCL animals). In these animals, we performed magnetic resonance imaging (fMRI) experiments to study the analgesic effects of MCS. On the day of fMRI experiment, 14 days after spinal cord lesion, the animals were anesthetized and epidural bipolar platinum electrodes were placed above the left primary motor cortex. Two 10-min sessions of fMRI were performed before and after a session of MCS (50 μA, 50 Hz, 300 μs, for 30 min). During each fMRI session, the right hindpaw was electrically stimulated (noxious stimulation: 5 mA, 5 Hz, 3 ms) using a block design of 20 s stimulation off and 20 s stimulation on. A general linear model-based statistical parametric analysis was used to analyze whole brain activation maps. Region of interest (ROI) analysis and paired t-test were used to compare changes in activation before and after MCS in these ROI. MCS suppressed evoked blood oxygen dependent signals significantly (Family-wise error corrected P cortex and the prefrontal cortex. These findings suggest that, in animals with SCL, MCS attenuates hypersensitivity by suppressing activity in the primary somatosensory cortex and prefrontal cortex. Copyright © 2014. Published by Elsevier Inc.

  17. Distribution Map and Community Characteristics of Weeds in Barley Fields of Ardabil Province

    OpenAIRE

    B. Soheili; M. Minbashi; D. Hasanpanah; N. Razmi

    2013-01-01

    Surveying weeds of irrigated barley fields is one of the most important practices in weed management. Based on cultivated areas irrigated barley in all counties of Ardabil province during six years (2000-2005), 46 sample barley fields were selected and weed species were counted in each sampling point and population indices were calculated with Thomas method. By using specific furmula the density, frequency and uniformity of each weed species in fields were calculated. In each field longitude,...

  18. Evaluation of mulching materials as integrated weed management component in maize crop

    International Nuclear Information System (INIS)

    Shah, F.U.

    2014-01-01

    Yield losses by weeds in maize crop and demonstrated efficacy of various mulches in weed management led to check the efficacy of various available mulches for suppressing weeds in maize crop at National Agricultural Research Centre (NARC), Islamabad during kharif (autumn) season 2011. The experiment was laid in Randomized Complete Block Design, (RBCD) having eight treatments and four replications. The treatments were black plastic, white plastic, sugarcane straw, wheat straw, live mulch, weeds as mulch, hand weeding and weedy check. Weed data included weed density m, fresh and dry weight g m, while crop data included crop density m, fresh and dry weight g m, number of plant plot, stover yield (g), plant height (cm), number of cobs plant, number of leaves plant, average grain number of five cobs and grain yield (t ha). With the exception of hand weeding, minimum number of weeds 128 m and 164 m were recorded in black plastic and weeds as mulch, respectively, compared to 595 min weedy check. Similarly, maximum grain yields (1.91 and 1.85 tha) were recorded in black plastic and weeds as mulch, while minimum grain yield (0.64 t ha) was recorded in weedy check plots. The economic net returns of black plastic mulch and weeds as mulch were Rs. 39,824 and Rs. 38,291, respectively as compared to Rs. 21431 for weedy check. Yield increased by 21.1 and 16.5% over hand weeding by plastic mulch and weeds as mulch, respectively. Black plastic followed by weeds as mulch, are recommended to control weeds and get maximum yield as well as net economic return. (author)

  19. Host Status of Seven Weed Species and Their Effects on Ditylenchus destructor Infestation of Peanut

    OpenAIRE

    De Waele, D.; Jordaan, Elizabeth M.; Basson, Selmaré

    1990-01-01

    The host suitability to Ditylenchus destructor of seven common weed species in peanut (Arachis hypogaea) fields in South Africa was determined. Based on the number of nematodes per root unit, white goosefoot (Chenopodium album), feathertop chloris (Chloris virgata), purple nutsedge (Cyperus rotundus), jimson weed (Datura stramonium), goose grass (Eleusine indica), khaki weed (Tagetes minuta), and cocklebur (Xanthium strumarium) were poor hosts. Ditylenchus destructor survived on all weed spec...

  20. Spatial correlation between weed species densities and soil properties

    DEFF Research Database (Denmark)

    Walter, Mette; Christensen, Svend; Simmelsgaard, Svend Erik

    2002-01-01

    The spatial cross-correlation between weed species densities and six soil properties within fields was analysed using cross-semivariograms. The survey was carried out in three successive years in two fields. The most consistent relationship between weed species density (numbers m−2) and soil...... properties was negative cross-correlation between the density of Viola arvensis Murray and clay content. This correlation was found in both fields; however, the range of spatial dependence varied between fields. In one of the fields, the density of Lamium purpureum L. was positively cross......-correlated with the phosphorus content in the soil in all years. The density of Veronica spp. and Poa annua L. was negatively cross-correlated with pH in all three years. Other spatial cross-correlations that were found in this study were inconsistent over time or field site. The densities of some of the weed species were...

  1. Weed control through crop rotation and alternative management practices

    Directory of Open Access Journals (Sweden)

    Böhm, Herwart

    2014-02-01

    Full Text Available Economic as well as agricultural and socio-political changes have an impact on crop management and thus also on crop rotation design and the related effects on the weed flora. Likewise other changes in cultivation such as reduced tillage practices, earlier sowing date, etc. cause an increase in weed infestation resp. an increased use of herbicides and if so contribute to herbicide resistance. The positive effects of crop rotation, but also of alternative management practices such as choice of varieties, catch crops, mixed cropping, green chop, and the share of predators, as well as methods of direct non-chemical weed control are presented and discussed for both, conventional and organic farming. If alternative management methods should be more practiced, especially trade-offs need to be broken, or incentives be offered.

  2. Development of an Autonomous Vehicle for Weed and Crop Registration

    DEFF Research Database (Denmark)

    Pedersen, Tom Søndergaard; Nielsen, Kirsten Mølgaard; Andersen, Palle

    The extension of information technology and computers on farming tools results in new possibilities for crop/weed handling. In this paper a system using an autonomous field robot (vehicle) able to make images in the field is described. In the recent farming has come to rely on intensive use...... degree of autonomy. The vehicle is part of an autonomous information system for crop and weed registration in fields which is developed at Aalborg University and The Danish Institute of Agricultural Science. The system consists of the vehicle and a stationary base station as well as a wireless...... be a solution but at present the image analysis technology does not have the capability for online analysis. An alternative way is to construct a weed map prior to the spraying. In order to avoid damage to the soil a light weight vehicle carrying a camera is an obvious choice. To minimize damage to the crop...

  3. Smoking the Other: marijuana and counterhegemony in Weeds.

    Science.gov (United States)

    Lavoie, Dusty

    2011-01-01

    Subverting suburban modernity, the SHOWTIME television series Weeds invites its audiences to situate their opinions about marijuana amid spheres of bourgeois soccer-moms, class politics, turf wars, raw economics, violent milieux, and multiculti heterogeneity. I argue that Weeds encourages us to "smoke the Other"; that is, to hesitantly accept difference, in line with many drug circles' etiquette. The phrase "smoking the Other" is a critical alteration of bell hooks' (1992, Black looks: Race and representation. Boston: South End Press) conception of whites' ethnic "devouring" as "eating the Other," a rather rigid schematic itself problematized by Weeds' transgressive self-conscious playfulness with stereotyped ethnicities, loopy plotlines, and counterhegemonic dialogue. Cultural/political implications follow. Copyright © 2011 Informa Healthcare USA, Inc.

  4. Weed management: a case study from north-west Pakistan

    International Nuclear Information System (INIS)

    Marwat, K.B.; Hashim, S.; Ali, H.

    2010-01-01

    Alien and exotic plant invasions are threatening the floral diversity around the globe and affect ecological processes. Weed invasion has been documented in North-West Pakistan. A total of 16 weeds were reported as invasive. These were Xanthium strumarium, Ipomoea eriocarpa, Alternanthera pungens, Trianthema portulacastrum, Tagetes minuta, Imperata cylindrica, Amaranthus hybridus subsp. hybridus, Robinia pseudo-acacia, Broussonetia papyrifera, Ailanthus altissima, Pistia stratiotes, Phragmites australis, Parthenium hysterophorus, Cannabis sativa, Galium aparine and Emex spinosus. Among these Robinia pseudo-acacia, Broussonetia papyrifera and Ailanthus altissima are trees and were purposely introduced as they later became invasive. They were aggressive in nature and replaced or suppressed the local vegetation. Their distribution, history of invasion and management has been discussed here. The behaviour and association of the 36 problem weeds with different crops has also been outlined as they perspired from the farmers. (author)

  5. Weed management: a case study from north-west Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Marwat, K B; Hashim, S; Ali, H [KPK Agriculture University, Peshawar (Pakistan). Dept. of Weed Science

    2010-12-15

    Alien and exotic plant invasions are threatening the floral diversity around the globe and affect ecological processes. Weed invasion has been documented in North-West Pakistan. A total of 16 weeds were reported as invasive. These were Xanthium strumarium, Ipomoea eriocarpa, Alternanthera pungens, Trianthema portulacastrum, Tagetes minuta, Imperata cylindrica, Amaranthus hybridus subsp. hybridus, Robinia pseudo-acacia, Broussonetia papyrifera, Ailanthus altissima, Pistia stratiotes, Phragmites australis, Parthenium hysterophorus, Cannabis sativa, Galium aparine and Emex spinosus. Among these Robinia pseudo-acacia, Broussonetia papyrifera and Ailanthus altissima are trees and were purposely introduced as they later became invasive. They were aggressive in nature and replaced or suppressed the local vegetation. Their distribution, history of invasion and management has been discussed here. The behaviour and association of the 36 problem weeds with different crops has also been outlined as they perspired from the farmers. (author)

  6. Weed seed predation in organic and conventional fields

    DEFF Research Database (Denmark)

    Navntoft, Søren; Wratten, S.D.; Kristensen, Kristian

    2009-01-01

    Enhanced biological control of weed seeds may improve sustainability of agricultural production. Biological control due to seed predation may be higher in organic fields because organic production generally supports more seed predators. To investigate such a difference, weed seed predation...... University and in two of the fields used for estimating seed predation. Recording of predators had therefore limited overlap with seed predation assays but was expected to give important information on key seed predators in the region. The mean seed removal rate was 17% in organic fields compared with 10...... edges. Overall, there was no consistent effect of distance from the field edge. Vegetation had a significant influence on the predation rates, with maximum rates at a medium-dense plant cover. Based on the video images, birds were the most important seed predators. The higher weed seed predation rate...

  7. Alternative surfacing materials for weed control at BC Hydro substations

    International Nuclear Information System (INIS)

    Wells, T.C.; Shrimpton, G.M.

    1997-01-01

    A two year study was conducted by BC Hydro in which a variety of surfacing materials were tested for their suitability for use in substations. Ideally, surfacing materials should have the following characteristics: high electrical resistivity in both dry and wet conditions, resistance to invasion by weeds, good driveability, good drainage, non-flammable, reasonably priced, no dust to foul conductors, and be aesthetically pleasing. Trials at Vernon Koksilah, and Ingledow substations were conducted to test the materials. A qualitative estimate of the amount of weed control provided by each material was recorded. The trials were meant to provide operational recommendations and screening information to allow for future testing of promising materials or combination of materials. Results showed that no single material meets all the desired criteria. The surfaces that best combined good weed control, electrical resistance and surface stability was a 15 cm deep layer of crushed gravel, especially if underlain by a layer of geotextile. 4 refs., 3 tabs., 1 fig

  8. Organic Highbush Blueberry Production Systems Research – Management of Plant Nutrition, Irrigation Requirements, and Weeds

    Science.gov (United States)

    A 0.4 ha planting of blueberry was established in October 2006 to evaluate the effects of cultivar (Duke and Liberty), bed type (flat versus raised beds), weed management (sawdust mulch and hand-weed control; sawdust+compost mulch with acetic acid, flaming, and hand control used as needed; and weed ...

  9. Economics of weed suppressive rice cultivars in flood- and furrow-irrigated systems

    Science.gov (United States)

    Weeds are a major constraint to rice production. In the U.S, weeds in rice are controlled primarily with synthetic herbicides. Intensive herbicide application in rice also has many potential drawbacks, resulting in environmental pollution, human health concerns, and development of weed resistance. B...

  10. Effect of weed control methods on some soil properties of a newly ...

    African Journals Online (AJOL)

    Weed control constitutes a high percentage of the total field maintenance cost of newly planted cocoa. Soil samples were collected from an experiment that was designed to evaluate some weed control methods during cocoa establishment. The objective of the experiment was to assess the effect of the weed control ...

  11. Yield loss prediction models based on early estimation of weed pressure

    DEFF Research Database (Denmark)

    Asif, Ali; Streibig, Jens Carl; Andreasen, Christian

    2013-01-01

    thresholds are more relevant for site-specific weed management, because weeds are unevenly distributed in fields. Precision of prediction of yield loss is influenced by various factors such as locations, yield potential at the site, variation in competitive ability of mix stands of weed species and emergence...

  12. Narrow rows reduce biomass and seed production of weeds and increase maize yield

    NARCIS (Netherlands)

    Mashingaidze, A.B.; Werf, van der W.; Lotz, L.A.P.; Chipomho, J.; Kropff, M.J.

    2009-01-01

    Smallholder farmers in southern African countries rely primarily on cultural control and hoe weeding to combat weeds, but often times, they are unable to keep up with the weeding requirements of the crop because of its laboriousness, causing them to incur major yield losses. Optimisation of crop

  13. The effect of environmental conditions on the seasonal dormancy pattern and germination of weed seeds

    NARCIS (Netherlands)

    Bouwmeester, H.J.

    1990-01-01

    Weeds cause considerable losses in horticultural and agricultural crops. Weeds are still predominantly controlled with herbicides. To reduce the use of chemicals, a better understanding of the biology of weeds is required. In this thesis the effect of environmental conditions on dormancy

  14. On the development, environmental effects and human dimension of weed management strategies

    NARCIS (Netherlands)

    Riemens, M.M.

    2009-01-01

    On the development, environmental effects and human dimension of weed management strategies. On farm weed management is influenced by many factors. These factors comprise the development and availability of weed management tools, the environmental impact of these tools and the attitude and

  15. Trade off between costs and environmental effects of weed control on pavements

    NARCIS (Netherlands)

    Kempenaar, C.; Lotz, L.A.P.; Horst, van der C.L.M.; Beltman, W.H.J.; Leemans, K.J.M.; Bannink, A.D.

    2007-01-01

    An actor-participative project on sustainable weed control on pavements was started in 2000 in the Netherlands. The aim of the project was to develop a new concept of weed management that provides cost-effective and environmentally sound weed control. Early in 2002, practical guidelines were drawn

  16. 7 CFR 205.206 - Crop pest, weed, and disease management practice standard.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Crop pest, weed, and disease management practice... Requirements § 205.206 Crop pest, weed, and disease management practice standard. (a) The producer must use management practices to prevent crop pests, weeds, and diseases including but not limited to: (1) Crop...

  17. Using a fully convolutional neural network for detecting locations of weeds in images from cereal fields

    DEFF Research Database (Denmark)

    Dyrmann, Mads; Skovsen, Søren; Sørensen, René A.

    2018-01-01

    been evaluated on an Nvidia Titan X, on which it is able to process a 5MPx image in 0.02s, making the method suitable for real-time field operation. For mechanical weed control, this network is sufficient. However, for chemical weed control, we also need to know the weed species in order to choose...

  18. Influence of maize herbicides on weed seed bank diversity in a ...

    African Journals Online (AJOL)

    Influence of maize herbicides on weed seed bank diversity in a humid forest ... at 2.0 +2.0kg ai ha-1 was more effective in reducing weed seeds (seed bank) than the ... pre-emergence weed control program in diverse arable cropping systems ...

  19. Weed control using ammonium nonanoate and cultivation in organic Vidalia sweet onion production

    Science.gov (United States)

    Ammonium nonanoate is registered for weed control in certified organic crop production and may be useful to control cool-season weeds in organic Vidalia® sweet onion. Cultivation with a tine weeder has been identified as a cost-effective means of weed control, but delays in cultivation cause some w...

  20. The Art and the Science of Cultivation for Weed Control in Organic Peanut

    Science.gov (United States)

    Cultural weed control is the basis on which an integrated system of weed management in organic peanut is based. The cultural practices evaluated for weed control were row patterns and seeding rates, integrated with cultivation intensity. Results showed that peanut seeded in wide rows (two rows, 91...