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Sample records for aquatic weed control

  1. 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…

  2. ECOLOGICAL IMPACT OF INTEGRATED CHEMICAL AND BIOLOGICAL AQUATIC WEED CONTROL

    Science.gov (United States)

    This final report presents results of a four-year study of the ecological impacts of chemical, biological, and integrated methods of aquatic weed control. Biological and water quality changes occurred as abundance of macrophytic vegetation was altered by natural factors or manage...

  3. Mechanical control of floating aquatic weed: Kainji Lake experience

    OpenAIRE

    Daddy, F.; Ladu, B.M.B.; Salzwedel, H.; Isa, A.U.

    2003-01-01

    The paper describes the uniqueness and invasiveness of water hyacinth (Eichhornia crassipes) on Lake Kainji (Nigeria). The mechanical blocking device design concept based on the Kainji Lake flooding regime is also highlighted. Water hyacinth coverage, that was over 23% at high water in level in 1994, was reduced to 0.75% in the same period in 2000. Although this feat cannot be wholly ascribed to mechanical control effort alone, the first year of the device's full operation more than 1.04 mill...

  4. PROCEEDINGS OF THE WORKSHOP ON AQUATIC WEEDS: CONTROL AND ITS ENVIRONMENTAL CONSEQUENCES HELD AT GULF BREEZE, FLORIDA ON FEBRUARY 25-26, 1980

    Science.gov (United States)

    The report reviews the state-of-the-art of the chemical, biological, mechanical, and integrated control of aquatic weeds. Participants discuss problems in the field of aquatic weed control and the role of EPA in working toward their solution. Guidelines are proposed for the evalu...

  5. Control of aquatic weeds through pollutant reduction and weed utilization: a weed management approach in the lower Kafue River of Zambia

    Science.gov (United States)

    Sinkala, Thomson; Mwase, Enala T.; Mwala, Mick

    The aquatic weed situation in the Kafue River in Zambia continues to be a major challenge to the sustainable utilization of the water resources of the river. The general methods for managing the weeds, especially the water hyacinth, include use of bio-agents, chemicals, mechanical and physical approaches. These have had very little impact. This paper reports on a project that is investigating weed management strategies which involve use of cleaner production (CP) approach and the utilization of the weed for economic purposes. In addition, the ecological implications of these methods are being assessed. Effluent assessments indicated that apart from nitrates and phosphates, other effluent parameters met the Environmental Council of Zambia standards. Results further show that all the 24 areas surveyed for CP have uncontrolled socio-economic activities which generate both point and non-point sources of pollution that enter the water bodies. To minimize pollution, efforts include devising policy and technical strategies with the involvement of the affected riparian community. Production of mushroom by the communities using the water hyacinth substrate has been demonstrated. Up to 2.1 kg of mushroom was harvested from a single flush over a period of 4-5 weeks. Vegetables grown on soils treated with water hyacinth manure performed better than those grown using commercial fertiliser. The economics of the production are however, yet to be confirmed. If weed usage is proven economically and ecologically viable, the riverine community is envisaged to play a big role in aquatic weed management. High numbers of invertebrates known to be sensitive to pollution have been recorded in the weed-infested Kafue River implying that the water is of “good” quality for these aquatic invertebrates. This observed quality of water may be due to water hyacinth playing a role by sieving pollutants from the river.

  6. Physical model of a floating trash boom to control aquatic weeds at the TVA Widows Creek Fossil Plant

    International Nuclear Information System (INIS)

    This paper reports that the Tennessee Valley Authority (TVA) Widows Creek Fossil plant seasonally encounters adverse accumulations of aquatic weeds at the intakes of the condenser cooling water pumps. To reduce the accumulations, a floating trash boom has been proposed for the intakes. To evaluate the hydraulic feasibility of a boom, a physical model of the intakes has been built at the TVA Engineering Laboratory. The model was used to determine the boom alignment and depth of skimming needed to successfully deflect weeds away from the intakes and provide self-cleaning

  7. 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).

  8. Aquatic Pest Control. Manual 99.

    Science.gov (United States)

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet the minimum EPA standards for certification as a commercial applicator of pesticides in the aquatic pest control category. The text discusses various water use situations; aquatic weed identification; herbicide use and effects; and aquatic insects and their control. (CS)

  9. Turfgrass Weed Control

    OpenAIRE

    Extension, USU

    2000-01-01

    Weeds in the lawn are one of the more noticeable pests of the landscape. They not only detract from the aesthetic value of the home, but also waste water and fertilizer, harbor insects, and reduce the overall health of the lawn. There are a number of cultural and mechanical practices to reduce weed populations. In severe and difficult cases, herbicides can be used to control some weeds.

  10. Mustard meal weed control

    Science.gov (United States)

    Weed control in organic production systems can be a labor intensive and expensive process. Mustard meal (MM) is phytotoxic and a potential pre-emergent and preplant-incorporated organic herbicide for controlling germinating and emerging weed seedlings. Unfortunately, MM may also adversely impact s...

  11. Weed Control in Organic Onion

    OpenAIRE

    Piazza, C.; Conti, M

    2008-01-01

    Weed control is a major management concern in extensive plantings of organic vegetables. We tested organic onion under conventional sowing with mechanical and flaming weed control against transplants. The parameters logged included weed number and species and bulb yield, size and storability. We found fewer weeds and higher yields in the transplanted than in the sown treatments.

  12. Selectivity of three aquatic weeds as diet for Nile tilapia (Oreochromis niloticus)

    OpenAIRE

    Agbede, S.A.; Akinyemi, O.; A. E. Falaye; Atsanda, N. N.; Adeyemo, A.O.; Adesina, A. A.

    2001-01-01

    A total of sixty juvenile Oreochromis niloticus (Nile tilapia) were fed three species of aquatic weed, namely Azolla filiculoides (water fern), Elodea sp. and Pistia stratiotes (water lettuce) to determine which of the weeds will be selectively consumed, and preferred of all. A control group of twenty Nile tilapia was fed compounded feed. The selectivity of the weeds was observed based on their utilization as food source, and Azolla filiculoides was found to be highly utilized, followed by El...

  13. Nonchemical weed control: New Directions

    OpenAIRE

    Melander, Bo

    2004-01-01

    The chapter reviews the most recent research on non-chemical weed control methods for field crops and highlights new technologies that might improve current physical weed control methods and probably lead to new and even better methods

  14. A Comparative Study of Bioethanol Production from Aquatic Weeds

    OpenAIRE

    Kodichetty Ramaiah Sunil; Merin John; Venkatachalapathi Girish; Sirangala Thimappa Girisha

    2015-01-01

    A greatest challenge for society in the 21st century is to meet energy demand, where biomass is subjected for pre-treatment and converted into biofuel (alcohol). Aquatic weeds are potential bio resources which are easily available for biofuel production. Aquatic weeds like Alternanthera sessilis, Typha latifolia, Eichhornia crassipes, Baccopa monnieri, Ipomoea aquatica and Pistia stratiotes are estimated for carbohydrates content. Highest content of reducing sugar was observed in Alternanther...

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

    Directory of Open Access Journals (Sweden)

    Jabran, Khawar

    2016-02-01

    Full Text Available 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. However, mechanical control and chemical control are the backbone of weed management plans in cotton crop. Use of allelopathy has also been found effective for suppressing weeds in cotton. Allelopathy used in several forms (such as intercropping, mulches, and crop rotation contributes to weed control in cotton crop. All of these weed management practices may be integrated to achieve economical and sustainable weed control in cotton with an ultimate result of improved weed control, productivity, quality of produce in cotton crop.

  16. Phytotoxicity of sesquiterpene lactone parthenin on aquatic weeds.

    Science.gov (United States)

    Pandey, D K

    1996-01-01

    The sesquiterpene lactone parthenin, one of the major toxins in an obnoxious weed, parthenium (Parthenium hysterophorus L.), was toxic at 50 ppm to the floating aquatic weeds pistia (Pistia stratiotes L.) and lemna (Lemna pausicostata Hegelm.) and at 100 ppm to water hyacinth (Eichhornia crassipes Mart Solmns.), salvinia (Salvinia molesta Mitchell), azolla (Azolla nilotica Decne.), and spirodella (Spirodella polyrhiza L. Schleid). The lethal dose for the submerged weeds najas (Najas graminea Del.), ceratophyllun (Ceratophyllum demersun L.), and hydrilla (Hydrilla verticillata L. f. Royle) was 25 ppm. The submerged aquatic weeds were more sensitive to parthenin. Water hyacinth was used as a representative for studying the phytotoxicity of parthenin on aquatic weeds. Inhibition of water hyacinth by parthenin was associated with decline in water use, root dysfunction, excessive leakage of solutes from roots indicative of massive damage to cellular membranes, loss of dehydrogenase activity in the roots, and loss of chlorophyll in the leaves. Plant death occurred in a period of one to two weeks. Parthenin phytotoxicity is gradually lost in an aquatic environment as a lethal dose became nonlethal in about 30 days under outdoor conditions. Possible buildup of a toxin concentration may affect population dynamics and a shift in the aquatic weed flora in the immediate area of parthenium stands. Accumulation of the toxin in an aquatic environment, however, at a level sufficient to produce such changes in a natural ecosystem as a consequence of rain washing parthenium plants and leaching of toxin from their residue appears to be unlikely. PMID:24226989

  17. Controlling Landscape Weeds.

    Science.gov (United States)

    Nuss, James Robert, Jr.

    This agriculture extension service publication from Pennsylvania State University discusses the control of common grass and broadleaf weeds through the use of mulches and herbicides. The section on mulches discusses the different types of mulching materials, their advantages and disadvantages, herbicide-mulch combinations, and lists source of…

  18. Aquatic weeds: their implications in Indian nuclear industry

    International Nuclear Information System (INIS)

    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)

  19. 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....

  20. 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. PMID:27145588

  1. 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…

  2. Utilização de chama para controle de plantas daninhas emersas em ambiente aquático Using flame for control of emerged aquatic weeds

    Directory of Open Access Journals (Sweden)

    S.R. Marchi

    2005-06-01

    Full Text Available Dois estudos foram conduzidos com o objetivo de avaliar os efeitos da aplicação de chama no controle de Eichhornia crassipes, Brachiaria subquadripara, Pistia stratiotes e Salvinia auriculata. No primeiro estudo foram utilizadas diferentes doses de chama, representadas pela quantidade de gás consumida durante a aplicação, e, no segundo, usaramse duas aplicações de chama em intervalo de 14 dias, uma aplicação seqüencial (intervalo de sete dias e aplicação única. As diferentes doses, tanto no primeiro quanto no segundo, foram comparadas com plantas que não receberam nenhum tratamento térmico. Avaliações de injúria foram realizadas aos 1, 3, 7, 10, 14, 17, 21 e 30 após a aplicação dos tratamentos, sendo realizadas também avaliações das biomassas secas das plantas aquáticas remanescentes em cada tratamento, ao final dos ensaios. No primeiro estudo foram observadas reduções significativas na produção da biomassa seca das espécies E. crassipes, B. subquadripara e P. stratiotes tratadas com as maiores doses referentes aos consumos de gás. Doses menores não diferiram estatisticamente da testemunha quanto à produção de biomassa seca, exceção feita para a espécie P. stratiotes. Todas as aplicações seqüenciais proporcionaram redução acima de 90% na produção da biomassa seca de E. crassipes e B. subquadripara. As aplicações seqüenciais e únicas proporcionaram reduções abaixo de 37% na produção da biomassa seca de S. auriculata. Os resultados demonstraram que existe a possibilidade de se utilizar o controle físico através da aplicação de chama como alternativa no manejo de plantas daninhas em ambientes aquáticos.Two trials were carried out to evaluate the effect of flame weeding on Eichhornia crassipes, Brachiaria subquadripara, Pistia stratiotes and Salvinia auriculata. In the first trial, different doses of flame were applied, according to the amount of gas consumed during application. In the second

  3. A Comparative Study of Bioethanol Production from Aquatic Weeds

    Directory of Open Access Journals (Sweden)

    Kodichetty Ramaiah Sunil

    2015-09-01

    Full Text Available A greatest challenge for society in the 21st century is to meet energy demand, where biomass is subjected for pre-treatment and converted into biofuel (alcohol. Aquatic weeds are potential bio resources which are easily available for biofuel production. Aquatic weeds like Alternanthera sessilis, Typha latifolia, Eichhornia crassipes, Baccopa monnieri, Ipomoea aquatica and Pistia stratiotes are estimated for carbohydrates content. Highest content of reducing sugar was observed in Alternanthera sessilis (296.8µg/ml, total sugar in Ipomoea aquatic (880.00mg/ml, starch in Alternanthera sessilis (57.13mg/ml, cellulose in Pistia stratiotes and Typha latifolia (280.00mg/ml, hemicellulose in Typha latifolia (26.85mg/ml; high cellulosic aquatic weeds were subjected to pre-treatment methods like physical, chemical and enzymatic method. Meanwhile different yeast strains from the fruits of Manilkara zapota, Cucumis melo, Musa paradisiaca, Citrullus lanatus, Punica granatum and Ananas comosus were isolated yeast of Citrullus lanatus shows highest amount of alcohol production (307µg/ml, which is inoculated to pre-treated hydrolysate, where Alternanthera sessilis and Typha latifolia shows high amount of alcohol in physical method (160.5 and 115.4µg/ml. In chemical method in acid hydrolysis it shows 387.1 and 69.63µg/ml and in alkali hydrolysis 62 and 170µg/ml, so these two weeds were taken for enzymatic method for alcohol production, on seventh day Alternanthera sessilis shows highest alcohol production (113.33µg/ml, hence among six weeds Alternanthera sessilis and the yeast of Citrullus lanatus produces more amount of alcohol than others and it also shows that enzymatic method of pre-treatment is best in hydrolysis of biomass than physical and chemical method. The study revealed the possibility of producing alcohol from locally available fruits using simple, cheap and adaptable technology with biochemically characterized yeast strains.

  4. Brassicas limited in weed control

    OpenAIRE

    Kristiansen, Mr P

    2006-01-01

    This article discusses the limitations of using brassica cover crops for weed control. A brief overview of the role of cover crops is provided, followed by a short review of research looking at brassica cover crops.

  5. [Alfalfa Planting as weed control

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a letter to farming cooperators regarding the stipulations surrounding alfalfa plantings in lieu of small grain plantings to provide weed control,...

  6. 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...

  7. Aquatic Pest Control. Sale Publication 4071.

    Science.gov (United States)

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    The information in this manual applies to control of aquatic pests in recreational waters, agricultural reservoirs, ornamental ponds, coastal bays, estuaries and channels, and drinking water reservoirs. Mechanical, cultural, biological, and chemical control methods are discussed. The majority of the material is devoted to weed control in static…

  8. Biogas production from the aquatic weed Pistia (Pistia stratiotes)

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, S.A.; Nipaney, P.C. (Pondicherry (Central) Univ. (IN). Salim Ali School of Ecology); Panholzer, M.B. (Institute for Environmental Research, Graz (AT))

    1991-01-01

    Pistia stratiotes, an aquatic weed, was investigated as a substrate for biogas production in batch digestion. An inoculum was necessary to obtain biogas production form the weed. With Pistia,only production of carbon dioxide alone was high during the first five days of digestion but began to level off thereafter. With inoculated Pistia, a high rate of biogas production was sustained for nearly 10 days and the average methane content was 58%-68%. The digesters charged with Pistia alone had significant concentrations of propionic, butyric, isobutyric, valeric, and isovaleric acids. These acids were not present in detectable concentrations, in the digesters running with inoculated Pistia, except during the first 4 days of the digestion when propionic acid was formed. When an inoculum was added to a 'soured' digester the performance of the latter improved dramatically. (author).

  9. Water hyacinth : the suitable aquatic weed for radioactive nuclide absorption in water

    International Nuclear Information System (INIS)

    The experiment was set up to determine the quantities of radioactive nuclides which were absorbed by aquatic weeds in Khon Kaen Province. The best aquatic weed would be used to be sampled for study of radioactive nuclide quantities in natural water resources. Seven kinds of aquatic weeds in the same site were corrected and pretreated by ovening to be ash at 450 οC. Gamma-ray spectra of the samples were detected and analyzed for comparing the quantities of radioactive nuclides. Gamma-ray spectrometry with a HPGe detector was set up to detect radioactive nuclides and their quantities in ashes of aquatic weeds. According to this study, water hyacinth, from seven aquatic weeds, had the most quantities of radioactive nuclides. The water hyacinth with 30 cm leaves in length can absorb the most quantities of radioactive nuclides

  10. Weed Control in Soybean (Glycine max)

    International Nuclear Information System (INIS)

    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

  11. Optimising woody-weed control

    OpenAIRE

    Zull, Andrew F.; Cacho, Oscar J.; Lawes, Roger A.

    2009-01-01

    Woody weeds pose significant threats to the 12.3 billion dollar Australian grazing industry. These weeds reduce stocking rate, increase mustering effort, and impede cattle access to waterways. Two major concerns of woody-weed management are the high cost of weed management with respect to grazing gross margins, and episodic seedling recruitments due to climatic conditions. This case study uses a Stochastic Dynamic Programming (SDP) model to determine the optimal weed management decisions for ...

  12. Herbicidal control of parthenium weed in maize

    International Nuclear Information System (INIS)

    Two years experiments were conducted using randomized complete block (RCB) design, having eight treatments, replicated four times to find their impact on maize, parthenium and associated weeds. The treatments consisted of 6 herbicides, viz., Aatrax (atrazine) at the rate 1.0, Buctril super (bromoxynil+MCPA) 60 EC at the rate 0.80, Dual gold (s-metolachlor) 960 EC at the rate 1.92, Sencor extra (metribuzin) at the rate 2.0, Primextra gold 720 SC (atrazine+s-metolachlor), at the rate 1.50 Stomp (pendimethalin) 330 EC at the rate 1.50 kg. a.i. ha/sub -1/, hand weeding and a control. Data showed that weed density was significantly influenced by application of various herbicides in maize. Fresh weed biomass (g m/sup -2/) was reduced in plots where Primextra gold and Dual gold were sprayed followed by hand weeding. Weed mortality (%) was significantly influenced by application of different herbicides, whereas year effect remained similar for weed mortality. Higher weed mortality was observed in Primextra gold treated plots, followed by hand weeding and Dual gold which were statistically at par. Long stature maize plants were recorded in hand weeding and Primextra gold treated plots, whereas short stature plants were found in control plots. Number of grains ear-1 was significantly increased by application of herbicides and higher numbers of grains were recorded in Primextra gold and hand weeded plots. Thousand grain weight was significantly increased by herbicides and hand weeding. Application of herbicides significantly influenced biological and grain yields of maize. The effect of year was found non-significant for both grain and biological yields. Control plots resulted in lower grain and biological yield. Overall results indicated that application of Primextra gold as pre-emergence could provide good control of parthenium weed and associated weeds in maize. (author)

  13. 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? PMID:24339388

  14. Development of tools for automated physical weed control

    OpenAIRE

    Nørremark, Michael; Melander, Bo

    2009-01-01

    Tools are being developed for automated physical weed control in the close to crop area. The most promising weed control concepts are the so-called high precision tillage solutions and thermal weed control by pulsed lasers.

  15. Scythe (pelargonic acid) weed control in squash

    Science.gov (United States)

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

  16. Post-directed weed control in squash

    Science.gov (United States)

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

  17. Residues and accumulation of molinate in rice crops and aquatic weeds in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Plant and soil residue levels and its accumulation in rice crops and rice aquatic weed plants were studied. Molinate residue levels in rice, weeds and soil were not significantly different between the recycled and the non-recycled area, even though they were higher in the non-recycled area. In the rice plant, the residue level at 10 DAT (days after treatment) was significantly higher than 30 DAT in the recycled area. In rice aquatic weed plants, the residue level was significantly higher at 10 DAT as compared to 30 DAT in the non-recycled area. Molinate residue levels in soil at 10 DAT and 30 DAT were similar. Molinate accumulated (ratio of molinate concentration in plant over soil) more in the rice crop as compared to rice aquatic weeds at 10 DAT, in both the recycled and the non-recycled areas. (Author)

  18. 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.

  19. Utilização de chama para controle de plantas daninhas emersas em ambiente aquático Using flame for control of emerged aquatic weeds

    OpenAIRE

    S.R. Marchi; E.D. Velini; E. Negrisoli; M.R Corrêa

    2005-01-01

    Dois estudos foram conduzidos com o objetivo de avaliar os efeitos da aplicação de chama no controle de Eichhornia crassipes, Brachiaria subquadripara, Pistia stratiotes e Salvinia auriculata. No primeiro estudo foram utilizadas diferentes doses de chama, representadas pela quantidade de gás consumida durante a aplicação, e, no segundo, usaramse duas aplicações de chama em intervalo de 14 dias, uma aplicação seqüencial (intervalo de sete dias) e aplicação única. As diferentes doses, tanto no ...

  20. Apply Pesticides Correctly, A Guide for Commercial Applicators: Aquatic Pest Control.

    Science.gov (United States)

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This guide presents information needed to meet the requirements for pesticide applicator certification. The first part deals with recognition and control of aquatic pests such as aquatic weeds, fish and other vertebrates. Environmental concerns in aquatic pest control are discussed in the second section. (CS)

  1. Controle químico de plantas daninhas aquáticas em condições controladas - caixa d'água Chemical aquatic weed control in resevoir

    Directory of Open Access Journals (Sweden)

    Dagoberto Martins

    1999-08-01

    Full Text Available Durante o ano de 1998 foram conduzidos quatro experimentos em Botucatu, Estado de São Paulo, Brasil, em condições de caixas d'água, com o objetivo de estudar o efeito de alguns herbicidas sobre Eicchornia crassipes, Pistia stratiotes, Thypha subulata e Salvinia molesta. Os herbicidas e doses utilizadas foram: imazapyr a 125, 250, 500, 1.000, 1.500 e 2.000 g e.a./ha; 2,4 D a 1.200 g e.a./ha; glyphosate a 3.360 g e.a./ha. Houve, ainda, uma testemunha sem aplicação de herbicidas. Os experimentos foram instalados no delineamento experimental em blocos ao acaso, com quatro repetições. As parcelas experimentais foram constituídas pelas caixas d'água com dimensões de 60x60x60 cm e colocadas a pleno sol no campo. Utilizou-se 3, 12, 25 e 60 plantas/caixa de T. subulata, P. stratiotes, E. crassipes e S. molesta, respectivamente. Os herbicidas foram aplicados com pulverizador costal a pressão constante de CO2 de 1,75 Bar, munido de barra com bicos Teejet 110.02 VS e com um consumo de calda de 200 l/ha. Foram efetuadas avaliações visuais de controle de sete em sete dias por 35 a 49 dias, dependendo da espécie. Todos os herbicidas testados foram eficientes no controle de E. crassipes e o imazapyr foi o único herbicida a promover morte total das plantas, independente da dose utilizada. Os herbicidas 2,4 D e glyphosate não foram eficientes no controle de P. stratiotes. O herbicida imazapyr foi eficiente no controle de P. stratiotes, exceto na dose de 125 g e.a./ha. Todos os herbicidas foram eficientes no controle de T. subulata, exceção ao imazapyr na dose de125 g e.a./ha. Houve rebrota de T. subulata nas parcelas aplicadas com 2,4 D. Nenhum tratamento químico foi eficiente no controle de S. molesta.In 1998 were carried out four trials in Brazil to studied the effect of herbicides on weed aquatic control in reservoir. The herbicides and dosis used were: imzapyr at 125, 250, 500, 1.000, 1.500 e 2.000 g /ha, 2,4 D at 1.200 g/ha, glyphosate at

  2. Absorption and degradation of 14C-2, 4-D by some free-floating aquatic weeds

    International Nuclear Information System (INIS)

    Plants of Salvinia, Lemna, Azolla and Limnobium, which are free-floating aquatic weeds, were grown separately in glass dishes containing initially 400 ml of nutrient solution and 2 μCi of 14C-2,4-D under controlled conditions of temperature, light and relative humidity. The total uptake of 2,4-D by these plant species increased with the increasing duration of exposure to herbicide. 2,4-D uptake, calculated on per unit dry weight of weed, was maximum in case of Limnobium, followed by Salvinia, Lemna and Azolla. After 20 days of treatment, the highest radioactivity (24%) was obtained in the organic fraction of the extracts of Limnobium and Azolla; followed by Salvinia (8%) and Lemna (6%). In a separate experiment, root uptake and subsequent translocation of 14C-2,4-D was also studied. At all the stages of sampling, more than half to 3/4th of the absorbed 14C-2,4-D was found in the roots, and the remaining was present in the shoot. (author)

  3. PHYSICAL AND CULTURAL WEED CONTROL IN MINOR CROPS

    OpenAIRE

    Melander, Bo; Barberi, Paolo

    2004-01-01

    This paper summarises the major European achievements with physical and cultural weed control methods in minor row crops. Minor crops, such as vegetables, sweet maize and potatoes, present two different situations for physical weed control of entirely different difficulty. Inter-row weeds are easily removed by inter-row cultivation while intra-row weeds, i.e. those growing between the crop plants in the rows, still constitute a major challenge aimed at minimising laborious hand weeding. Inves...

  4. Site Specific Weed Control Technologies

    DEFF Research Database (Denmark)

    Christensen, Svend; Søgaard, Henning Tangen; Kudsk, Per; Nørremark, Michael; Lund, Ivar; Shahrak Nadimi, Esmaeil; Jørgensen, Rasmus Nyholm

    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...... two decades, though barriers prevent their breakthrough. Most important among these is the lack of a truly robust weed recognition method, owing to mutual shading among plants and limitations in the capacity of highly accurate spraying and weeding apparatuses.   Another barrier is the lack of...

  5. 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...

  6. 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.

  7. 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.

  8. 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…

  9. Weed clearance in Hudiara Nallah by chemical weed control

    International Nuclear Information System (INIS)

    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

  10. Allelopathy, seed germination, weed control and bioassay methods

    OpenAIRE

    Dias, L.S.; Pereira, I.P.; A. S. Dias

    2016-01-01

    Even before its formal establishment as a scientific discipline, allelopathy has been intertwined with agriculture and the potential of allelopathy for weed control has been a permanent matter of interest. Therefore we investigate the importance of seeds and of permanent soil seed banks as a means for propagation of weed species as well as strategies for long-term weed control. Depleting seed banks is critical and encouraging weed seed germination prior to sowing crops is one of the most prom...

  11. A Non-Chemical System for Online Weed Control

    OpenAIRE

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

    2015-01-01

    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 ca...

  12. 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. PMID:12477000

  13. Benefits of Precision Farming Technologies for Mechanical Weed Control in Soybean and Sugar Beet—Comparison of Precision Hoeing with Conventional Mechanical Weed Control

    OpenAIRE

    Christoph Kunz; Jonas Felix Weber; Roland Gerhards

    2015-01-01

    Weed infestations and associated yield losses require effective weed control measures in soybean and sugar beet. Besides chemical weed control, mechanical weeding plays an important role in integrated weed management systems. Field experiments were conducted at three locations for soybean in 2013 and 2014 and at four locations for sugar beet in 2014 to investigate if automatic steering technologies for inter-row weed hoeing using a camera or RTK-GNSS increase weed control efficacy, efficiency...

  14. Utilization of cattail aquatic weed(Typha domingesis pers) for biogas energy production

    International Nuclear Information System (INIS)

    Cattail, Typha domingesis Pers, an aquatic emergent weed had seriously impacted the ecosystem of the lake Jipe in Northern Tanzania creating ecological-environmental and economic problems including shrinkage of the lake and reduction of fish yield. Two anaerobic digestion trial were carried out one based different parts and blends of cattail weed at 5, 15, 30 and 60% total solids (TS) in 0.5 L anaerobic batch bioreactors at ambient temperature of 33±1(deg)C. Gut contents from cockroaches (Periplaneta americana) was used as anaerobic inoculum (starter seed). The results showed that highest methane yields were obtained at 5% TS for both unmixed and mixed cattail weeds parts. In the first trial methane yield at 5% TS from five different cattail weed parts namely; spikes, leaves, stems rhizomes and roots ranged from 150-447 CH4 mL /gVS added. The highest and the lowest methane yields were obtained from leaves and spikes, respectively. In the second trial, methane yields at 5% TS from three different blends of cattail weed viz; spikes, leaves and stems (33.3%:33.3%:33.3%), rhizomes and roots (50%:50%), and whole cattail (spikes, leaves, stems, rhizomes and roots each 20%) ranged between 246 to 288 CH4 mL /gVS added. The highest and lowest methane yields were obtained from spikes, leaves, and stems and whole cattail blends, respectively. The overall average methane content in the biogas produced at 5 to 60% TS in two trials ranged from 68-83%. It was concluded, that anaerobic digestion of cattail weed is feasible and could serve the dual roles for producing biogas, a clean renewable energy and reducing the weed as part of its management as well as reduction of methane emission. (author)

  15. 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 to...

  16. The influence of soil tillage systems and weed control methods on weed infestation of potato (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Krystyna Zarzecka

    2012-12-01

    Full Text Available A field experiment was conducted in the years 2002- 2004 at the Zawady Agricultural Experimental Station (52o06' N; 22o06' E, belonging to the University of Podlasie in Siedlce, Poland. The investigated factors were two soil tillage systems (traditional and reduced and seven methods of weed control in potato canopies with herbicide application. The aim of the study was to determine the influence of tillage systems and weed control methods on the weed species composition and weed density. Tillage systems, weed control methods and atmospheric conditions prevailing in the study years significantly varied weed infestation of potato canopies at the beginning of vegetation and before tuber harvest. The lowest number of weeds, compared to the control treatment, was recorded in the treatments in which chemical and mechanical weed control had been applied. The treatments with the traditional tillage system also showed lower weed infestation than those in which simplifications had been applied.

  17. Training for Certification: Aquatic Pest Control.

    Science.gov (United States)

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This Cooperative Extension Service publication from Mississippi State University is a training guide for commercial applicators. Weed control, vertebrate pest control, and environmental considerations and restrictions are the three major parts of the document. The weed control section discusses non-pesticide, mechanical, and biological control as…

  18. Comparison of different mechanical weed control strategies in sugar beets

    Directory of Open Access Journals (Sweden)

    Kunz, Christoph

    2016-02-01

    Full Text Available In sugar beet (Beta vulgaris weed control is commonly performed by herbicide application applied broadcast at splitting during the cultivation period. Mechanical weeding can be an alternative to chemical weed control. The aim of this experiment was the estimation of weed control efficacy with the use of automatic steering technologies by camera guidance, the use of different intra row weed control implements in conservation tillage systems and the influence of these techniques to the number of uprooted sugar beets. A field experiment with a randomized complete plot design was conducted in 2015 at Ihinger Hof, Germany. Weed density ranged from 0 to 12 plants m-2 with Chenopodium album, Polygonum convolvulus, Polygonum aviculare as the most abundant weed species. Hoeing with the use of automatic steering technologies reduced the weed density by 82%. The use of finger weeders, rotary-harrow and torsion finger weeder reduced the weed density by 29% compared to common hoeing strategies. Differences in the number of uprooted sugar beets were not found across all treatments. We revealed the possibility of a more intense use of mechanical weeding technologies in combination with precision farming technologies in sugar beet.

  19. Site-specific herbicide applications based on weed maps provide effective control

    OpenAIRE

    Koller, Martina; Lanini, W. Thomas

    2005-01-01

    More-effective weed control in agricultural fields can be achieved by utilizing information about the spatial distribution of the previous year’s mature weeds. In our study, variable-rate herbicide applications based on weed infestation maps developed just before the previous year’s harvest provided effective weed control. The results showed that when information about the spatial distribution of the previous year’s weed seedlings or mature weeds was used, weed control was comparable to unifo...

  20. Restoring interventions: eco-sustainable weed control

    Directory of Open Access Journals (Sweden)

    Facciotto G

    2006-01-01

    Full Text Available The creation and enlargement of ecological networks is paramount to conserve plant biodiversity, to offer refuge to the local fauna and to improve the environment in general. Such networks intend to conserve areas of great natural value, to restore degraded areas and to link them physically through the creation of ecological corridors. The work described was carried out in order to improve and enlarge an ecological corridor within the experimental farm “Mezzi” of CRA-ISP at Casale Monferrato (AL - Italy. One of its bigger problems, weed control, was solved by increasing the planting density, by sowing herbaceous crops and mulching with woody chips.

  1. Avaliação da sensibilidade de diversas espécies de plantas daninhas aquáticas ao carfentrazone-ethyl, em ambiente controlado Assessment of sensitivity of several aquatic weeds to carfentrazone-ethyl under controlled environment

    Directory of Open Access Journals (Sweden)

    L.L. Foloni

    2005-06-01

    Full Text Available Plantas aquáticas, especialmente macrófitas, tornam-se sério problema em hidrelétricas, afetando a múltipla utilização dos corpos d'água, incluindo produção de peixes e atividades de pesca, perdas d'água por evapotranspiração, esportes aquáticos, canoagem, irrigação e produção de energia nas usinas hidrelétricas. Com o objetivo de analisar o potencial de uso do carfentrazone-ethyl no controle das principais plantas daninhas aquáticas no Brasil, foi instalado um experimento em vasos com água. Utilizaram-se os seguintes tratamentos herbicidas (g i.a. ha-1: carfentrazone-ethyl a 15, 30 e 60; glyphosate a 4.536; 2,4-D a 4.690; imazapyr a 1.250; e uma testemunha sem herbicida. Esses tratamentos foram testados nas seguintes espécies: Eichhornia crassipes, Salvinia auriculata, Pistia stratiotes, Myriophyllum aquaticum, Brachiaria arrecta, Hydrocotyle umbellata, Typha sp. e Echinochloa polystachya. As avaliações foram efetuadas aos 7, 14, 21 e 28 dias após os tratamentos. Os resultados mostraram que o carfentrazone-ethyl foi eficiente no controle de E. crassipes (maior dose e P. stratiotes (duas maiores doses, com efeito supressivo sobre S. auriculata. Foi observado que nas outras plantas daninhas estudadas não houve eficiência de controle.Aquatic weeds, especially macrophytes, are a serious problem in hydroelectric plant systems, affecting the multiple use of water, such as fish production and fishing activities, water losses by evapotranspiration, aquatic sports, boating, irrigation and hydroelectric power production. An experiment using boxes filled with water was carried out to analyze the potential use of carfentrazone-ethyl in the control of the main aquatic weeds in Brazil. The following herbicide treatments (g i.a. ha-1 were used: carfentrazone-ethyl at 15, 30 and 60; glyphosate at 4,536; 2,4D at 4,690; imazapyr at 1,250, and no herbicide. These treatments were tested on the species: Eichhornia crassipes, Salvinia

  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. PMID:26071767

  3. 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.

  4. Controlling weeds with fungi, bacteria and viruses: a review

    OpenAIRE

    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 comp...

  5. Corn gluten meal for weed control in cowpea

    Science.gov (United States)

    Cowpea, a major crop in Oklahoma, is produced for the fresh market and canning industry. Synthetic preemergence and postemergence herbicides are the primary weed control method in conventional (non-organic) production systems. Organic weed control in organic cowpea production includes obstacles wh...

  6. Post-directed weed control in bell peppers

    Science.gov (United States)

    Organic pepper (Capsicum annuum L.) producers need appropriate herbicides that can effectively provide post-emergent weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the impact of a potential organic herbicide on weed control efficacy, crop injury, an...

  7. 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…

  8. Critical Period of Weed Control in Aerobic Rice

    Directory of Open Access Journals (Sweden)

    M. P. Anwar

    2012-01-01

    Full Text Available 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.

  9. 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.

  10. Chemical weed control in barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    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)

  11. Dynamics of weed populations: spatial patter formation and implications for control.

    OpenAIRE

    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 control programme, herbicides are applied to the whole field only if the weed density exceeds a threshold value, otherwise there is no control at all. The dynamics of a weed population subjected to such a 'threshold control p...

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

    International Nuclear Information System (INIS)

    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

  13. Weed risk assessment for aquatic plants: modification of a New Zealand system for the United States.

    Directory of Open Access Journals (Sweden)

    Doria R Gordon

    Full Text Available We tested the accuracy of an invasive aquatic plant risk assessment system in the United States that we modified from a system originally developed by New Zealand's Biosecurity Program. The US system is comprised of 38 questions that address biological, historical, and environmental tolerance traits. Values associated with each response are summed to produce a total score for each species that indicates its risk of invasion. To calibrate and test this risk assessment, we identified 39 aquatic plant species that are major invaders in the continental US, 31 species that have naturalized but have no documented impacts (minor invaders, and 60 that have been introduced but have not established. These species represent 55 families and span all aquatic plant growth forms. We found sufficient information to assess all but three of these species. When the results are compared to the known invasiveness of the species, major invaders are distinguished from minor and non-invaders with 91% accuracy. Using this approach, the US aquatic weed risk assessment correctly identifies major invaders 85%, and non-invaders 98%, of the time. Model validation using an additional 10 non-invaders and 10 invaders resulted in 100% accuracy for the former, and 80% accuracy for the latter group. Accuracy was further improved to an average of 91% for all groups when the 17% of species with scores of 31-39 required further evaluation prior to risk classification. The high accuracy with which we can distinguish non-invaders from harmful invaders suggests that this tool provides a feasible, pro-active system for pre-import screening of aquatic plants in the US, and may have additional utility for prioritizing management efforts of established species.

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

    DEFF Research Database (Denmark)

    Bak, Thomas; Mathiassen, Solvejg K.; Christensen, Svend; Kudsk, Per

    2006-01-01

    for weed control, however, require a systematic investigation of the relationship between energy density and the biological effect on different weed species, growth stages, etc. This paper investigates the effect of laser treatment directed towards the apical meristems of selected weed species at the...... chickweed), Tripleurospermum inodorum (scentless mayweed) and Brassica napus (oilseed rape). The experiment showed that laser treatment of the apical meristems caused significant growth reduction and in some cases had lethal effects on the weed species. The biological efficacy of the laser control method...... 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...

  15. Aquatic plant control research

    Energy Technology Data Exchange (ETDEWEB)

    Pryfogle, P.A.; Rinehart, B.N. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Ghio, E.G. [Pacific Gas & Electric Company, San Francisco, CA (United States). Hydro Generation Engineering

    1997-05-01

    The Northwest region of the United States contains extensive canal systems that transport water for hydropower generation. Nuisance plants, including algae, that grow in these systems reduce their hydraulic capacity through water displacement and increased surface friction. Most control methods are applied in an ad hoc fashion. The goal of this work is to develop cost-effective, environmentally sound, long-term management strategies to prevent and control nuisance algal growth. This paper reports on a multi-year study, performed in collaboration with the Pacific Gas & Electric Company, to investigate algal growth in their canal systems, and to evaluate various control methodologies. Three types of controls, including mechanical, biological and chemical treatment, were selected for testing and evaluation. As part of this study, water quality data were collected and algal communities were sampled from numerous stations throughout the distribution system at regular intervals. This study resulted in a more comprehensive understanding of conditions leading to the development of nuisance algal growth, a better informed selection of treatment plans, and improved evaluation of the effectiveness for the control strategies selected for testing.

  16. Weed Control Sprayers: Calibration and Maintenance. Special Circular 81.

    Science.gov (United States)

    Myers, Arthur L.

    This manual covers aspects of calibration and maintenance of weed control sprayers including variables affecting application rate, the pre-calibration check, calculations, band spraying, nozzle tip selection, agitation, and cleaning. (BB)

  17. Weed control and selectivity of flumioxazin in eucalyptus

    Directory of Open Access Journals (Sweden)

    Rafael Augusto Soares Tiburcio

    2012-12-01

    Full Text Available Flumioxazin is a registered herbicide for agricultural crops what is an important fact concerning integrated management for weeds in eucalyptus plantations. This study evaluated the efficiency of weed control and the phytotoxicity in eucalyptus plants caused by the herbicide flumioxazin applied alone or in tank mixture with sulfentrazone and isoxaflutole. The aim was to extend the use of thisherbicide in eucalyptus. The herbicide was applied to eucalyptus plants using precision backpack sprayer. It was evaluated, visually,the intoxication percentage and measured height and diameter of eucalyptus trees, the control plants and dry mass of weeds. It wasconcluded that flumioxazin is selective to the eucalyptus at the 125 g.ha-1 dosage, and its efficiency in controlling weeds pre-emergencewas better when mixed in the tank with isoxaflutole and sulfentrazone.

  18. Benefits of Precision Farming Technologies for Mechanical Weed Control in Soybean and Sugar Beet—Comparison of Precision Hoeing with Conventional Mechanical Weed Control

    Directory of Open Access Journals (Sweden)

    Christoph Kunz

    2015-04-01

    Full Text Available Weed infestations and associated yield losses require effective weed control measures in soybean and sugar beet. Besides chemical weed control, mechanical weeding plays an important role in integrated weed management systems. Field experiments were conducted at three locations for soybean in 2013 and 2014 and at four locations for sugar beet in 2014 to investigate if automatic steering technologies for inter-row weed hoeing using a camera or RTK-GNSS increase weed control efficacy, efficiency and crop yield. Treatments using precision farming technologies were compared with conventional weed control strategies. Weed densities in the experiments ranged from 15 to 154 plants m−2 with Chenopodium album, Polygonum convolvulus, Polygonum aviculare, Matricaria chamomilla and Lamium purpureum being the most abundant species. Weed hoeing using automatic steering technologies reduced weed densities in soybean by 89% and in sugar beet by 87% compared to 85% weed control efficacy in soybean and sugar beet with conventional weeding systems. Speed of weed hoeing could be increased from 4 km h−1 with conventional hoes to 7 and 10 km·h−1, when automatic steering systems were used. Precision hoeing technologies increased soybean yield by 23% and sugar beet yield by 37%. After conventional hoeing and harrowing, soybean yields were increased by 28% and sugar beet yield by 26%.

  19. Economics of supplemental weed control applications on spring-transplanted onions

    Science.gov (United States)

    Field research conducted to determine the relative benefits among alternative herbicides for weed control in onions (Allium cepa L.) measured weed control efficacy, impact of herbicides on crop injury, and the resulting weed competition on crop yields and marketable bulb size. Weed competition produ...

  20. Changes in species composition of weeds and their number in potato under the influence of different of weed control method

    Directory of Open Access Journals (Sweden)

    Katarzyna Zarzecka

    2013-12-01

    Full Text Available In a strict field experiment we have studied the influence of different weed control method on the species composition and the number on weeds occurring in a field of four potato cultivars. The application of herbicides decreased the number of weeds, as compared with the number obtained for mechanical control by 1,9-5,1 times at the beginning ofthe vegetation and by 1,5-3,7 times prior to tubers harvest. The herbicides considerably reduced the composition of weed species, moreover.

  1. Changes in species composition of weeds and their number in potato under the influence of different of weed control method

    OpenAIRE

    Katarzyna Zarzecka

    2013-01-01

    In a strict field experiment we have studied the influence of different weed control method on the species composition and the number on weeds occurring in a field of four potato cultivars. The application of herbicides decreased the number of weeds, as compared with the number obtained for mechanical control by 1,9-5,1 times at the beginning ofthe vegetation and by 1,5-3,7 times prior to tubers harvest. The herbicides considerably reduced the composition of weed species, moreover.

  2. Green synthesis of silver nanoparticles using cellulose extracted from an aquatic weed; water hyacinth.

    Science.gov (United States)

    Mochochoko, Tanki; Oluwafemi, Oluwatobi S; Jumbam, Denis N; Songca, Sandile P

    2013-10-15

    As part of the desire to save the environment through "green" chemistry practices, we herein report an environmentally benign synthesis of silver nanoparticles (Ag-NPs) using cellulose extracted from an environmentally problematic aquatic weed, water hyacinth (WH), as both reducing and capping agent in an aqueous medium. By varying the pH of the solution and reaction time, the temporal evolutions of the optical and morphological properties of the as-synthesised Ag-NPs were investigated. The as-synthesised cellulose capped silver nanoparticles (C-Ag-NPs) were characterised using Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). The maximum surface plasmon resonance (SPR) peak decreased as the pH increased indicating that an increase in the pH of the solution favoured the formation of smaller particles. In addition, instantaneous change in the colour of the solution from colourless to brown within 5 min at pH 11 showed that the rate of reduction is faster at this pH compared to those at lower pH. The TEM micrographs showed that the materials are small, highly monodispersed and spherical in shape. The average particle mean diameters were calculated to be 5.69±5.89 nm, 4.53±1.36 nm and 2.68±0.69 nm nm at pH 4, 8 and 11 respectively. The HRTEM confirmed the crystallinity of the material while the FTIR spectra confirmed the capping of the as-synthesised Ag-NPs by the cellulose. It has been shown therefore that based on this synthetic method, this aquatic plant can be used to the advantage of mankind. PMID:23987347

  3. Lawn Weeds and Their Control. North Central Regional Extension Publication No. 26.

    Science.gov (United States)

    Purdue Univ., Lafayette, IN. Cooperative Extension Service.

    This publication discusses lawn weed control for the twelve state north central region of the country. Written for use by homeowners, the publication focuses on weed identification and proper herbicide selection and application. Identification of weeds and safe and appropriate herbicide use are emphasized. Forty-six weed and turf plants are…

  4. 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.

  5. Organic and weed control in water supply reservoirs of power plants

    International Nuclear Information System (INIS)

    Aquatic weeds and algal control in water supply reservoirs used for multipurpose use need specific attention, since they pose a lot of problem for the operating plants by affecting (a) the water quality of boiler and feed waters, (b) the performance of DM plants by reducing the efficiency of Anion beds, (c) the performance of Activated Carbon Filters (ACF) and (d) fouling induced corrosion problems in cooling water systems (Heat Exchangers and Piping materials) causing plant outages leading to production losses. The photosynthetic activity of planktonic plants which are growing abundantly in the open reservoir, sustained by the relatively high inorganic phosphate levels shoots up the pH of the reservoir water to very high levels. High pH, Total Dissolved Solids (TDS) and depleted plants can increase corrosion problems affecting plant performance. This paper focuses on the type of weeds prominent in the water supply reservoir at Kalpakkam and the associated problems in the Nuclear Power Plants (NPPs). (author)

  6. 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.

  7. Alternative surfacing materials for weed control at BC Hydro substations

    International Nuclear Information System (INIS)

    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. Unifying parameters in mechanical weed control research - report of the roundtable

    OpenAIRE

    Rasmussen, Jesper

    2009-01-01

    This report summarises (i) the introduction given at the initiation of the roundtable discussion about unifying parameters in mechanical weed control and (ii) the following discussion at the EWRS Physical and Cultural Weed Control Group meeting in Zaragoza 2009

  9. 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.

  10. A new weed control strategy in onion culture.

    Science.gov (United States)

    Thieron, M; Kerres, W; Schäffer, A

    2007-01-01

    A new strategy combining modem hoeing technique and spray application has been developed in order to reduce the amount of herbicides down to 20% compared to common practice. The effects on weed control have been investigated as well as the impact on qualitative and quantitative harvest. In two large scale field trials and two years of testing the authors evaluated different hoeing techniques combined with band spray application and standard spray application, the minimal lethal herbicide dose method (MLHD). All varieties have been calculated for environmental impact as well as practical and economical means. These studies reveal crop losses due to improper weed control as well as losses due to herbicide stress. Detailed information on concentration depending impact of several herbicides have been correlated to their control of different weeds and the achieved yield. Two contrary effects influencing the total yield have been identified. The novel strategy is based on the knowledge of these complex effects which finally led to a well practicable and highly economic strategy that enables onion farmers to control weeds while reducing the amounts of herbicides down to approximately 20%. PMID:18399447

  11. Corn gluten meal for weed control in cowpea, Spring 2008

    Science.gov (United States)

    Cowpea is a major vegetable crop within Oklahoma. It is utilized as both a processing crop by the canning industry and as a fresh market crop for farmer’s and roadside markets. Traditionally weed control in this crop is with preemergence and some postemergence herbicides, but recently fresh market...

  12. Effects of clearing on the succession of aquatic weeds along irrigation and drainage canals in the MUDA area

    International Nuclear Information System (INIS)

    The effects of clearing on the succession of aquatic weeds in five selected areas were studied for a six-month period. Overall Polygonum barbatum was found to be the most dominant species with an Importance Value (IV) of 60%. However, in terms of species succession, each site was different from the others and no determinable patterns were observed. In general, after major disturbances such as manual clearing, succession can happen in two ways; the re-establishment of the original species or invasion by new species. (Author)

  13. Control of Fish and Aquatic Plants.

    Science.gov (United States)

    Hesser, R. B.; And Others

    This agriculture extension service publication from Pennsylvania State University is a handbook for the water body manager. The bulk of the contents deals with aquatic plant control. The different types of aquatic plants, their reproduction and growth, and their role in the ecology of the water body are introduced in this main section. Also, the…

  14. AXXE® (pelargonic acid) and Racer® (ammonium nonanoate): Weed control comparisons

    Science.gov (United States)

    Organic vegetable producers need herbicides that can provide effective season-long weed control. The availability and use of effective post-emergence organic herbicides would increase the likelihood of season-long weed control, reduce crop loses, and decrease the introduction of additional weed seed...

  15. The Critical Period for Weed Control (CPWC) in Potato (Solanum tuberosum L.)

    OpenAIRE

    Dogan ISIK; Adem AKCA; KAYA ALTOP, Emine; TURSUN, Nihat; Husrev MENNAN

    2015-01-01

    Accurate assessment of crop-weed control period is an essential part for planning an effective weed management for cropping systems. Field experiments were conducted during the seasonal growing periods of potato in 2012 and 2013 in Kayseri, Turkey to assess critical period for weed control (CPWC) in potato. A four parameter log-logistic model was used to assist in monitoring and analysing two sets of related, relative crop yield. Data was obtained during the periods of increased weed interfer...

  16. Biodiversity of Segetal Weed Communities when Chlorsulfuron-Based Weed Control is Being Used on Continuous Winter Wheat

    OpenAIRE

    Pawlonka Zbigniew; Rymuza Katarzyna; Starczewski Krzysztof; Bombik Antoni

    2014-01-01

    The purpose of the study was to determine the relationship between herbicide rate and weed community biodiversity in continuous wheat. A six-year field experiment was conducted to examine the effect of four chlorsulfuron rates in comparison with untreated (the control) plots, on the status and severity of weed infestation - in successive study years of cultivating winter wheat in monoculture. In addition, the following indices were calculated: Shannon-Wiener and Simpson’s index of biodiversit...

  17. The effect of sowing date, stale seedbed, row width and mechanical weed control on weeds and yields of organic winter wheat

    OpenAIRE

    Rasmussen, Ilse A.

    2004-01-01

    Three field experiments were carried out in organically grown winter wheat in Denmark. The treatments were sowing time (normal or late sowing) and false seedbed, row width (12 cm and 24 cm) and weed control method (untreated, mechanical weed control (weed harrowing at 12 cm supplemented with inter-row hoeing at 24 cm), and herbicide weed control). Weed biomass in mid-summer was greatest on plots sown at the normal sowing time (compared to delayed sowing) and was reduced by mechanical or chemi...

  18. Weed Control in White Bean with Various Halosulfuron Tankmixes

    OpenAIRE

    Nader Soltani; Robert E. Nurse; Christy Shropshire; Peter H. Sikkema

    2014-01-01

    Four field trials were conducted over a three-year period (2011–2013) in southwestern Ontario to evaluate the level of weed control provided by various halosulfuron tankmixes applied preplant incorporated (PPI) in white bean. Trifluralin, s-metolachlor, halosulfuron, and imazethapyr applied alone or in combination caused 4% or less visible injury 1 and 4 weeks after emergence (WAE) in white bean. Trifluralin, s-metolachlor, halosulfuron, and imazethapyr applied PPI provided 80–96%, 84–95%, 83...

  19. Experience with GOLTIX® TITAN® controlling annual dicotyledonous weeds in beets

    Directory of Open Access Journals (Sweden)

    Fell, Martina

    2014-02-01

    Full Text Available The herbicide GOLTIX® TITAN® is the unique combination of two active ingredients, Metamitrone (525 g/L and Quinmerac (40 g/L. GOLTIX® TITAN® is used for the control of annual dicotyledonous weeds in sugar and fodder beets. Registration was granted for the post emergence splitting application with 3 x 2,0 L/ha (3 applications. This corresponds to the amount of 3150 g Metamitrone and 240 g Quinmerac per hectare at maximum application rate. The registration application for pre-emergence application has been submitted. Several field trials were carried out between 2009 and 2013. These trials revealed the optimized efficacy on important weeds in sugar beet production including Fool´s parsley (Aethusa cynapium, Cleavers (Gallium aparine and Fat-hen (Chenopodium album. Selectivity was examined in all of these trials and showed good results with all relevant mixtures at all application times. The two active ingredients have different modes of action; hence, the product plays an important role in resistance management. They can be applied flexibly and do not have any known negative influence on the environment. The successful formulation of this highly sophisticated sugar beet herbicide was confirmed by the available trial results. GOLTIX® TITAN® with its specified characteristics is the base for every weed control measure.

  20. Combinations of corn glutel meal, clove oil, and sweep cultivation are ineffective for weed control in organic peanut production

    Science.gov (United States)

    Weed control in organic peanut is difficult and lack of residual weed control complicates weed management efforts. Weed management systems using corn gluten meal in combination with clove oil and sweep cultivation were evaluated in a series of irrigated field trials. Corn gluten meal applied in a ...

  1. Agronomic Weeds.

    Science.gov (United States)

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University examines agronomic weed problems and control. Contents include a listing of the characteristics of weeds, a section on herbicides, and a section on the important weeds of agronomic crops in Pennsylvania. The herbicide section discusses systemic herbicides, contact…

  2. ANN Model for Predicting the Impact of Submerged Aquatic Weeds Existence on the Hydraulic Performance of Branched Open Channel System Accompanied by Water Structures

    International Nuclear Information System (INIS)

    The existence of hydraulic structures in a branched open channel system urges the need for considering the gradually varied flow criterion in evaluating the different hydraulic characteristics in this type of open channel system. Computations of hydraulic characteristics such as flow rates and water surface profiles in branched open channel system with hydraulic structures require tremendous numerical effort especially when the flow cannot be assumed uniform. In addition, the existence of submerged aquatic weeds in this branched open channel system adds to the complexity of the evaluation of the different hydraulic characteristics for this system. However, this existence of aquatic weeds can not be neglected since it is very common in Egyptian open channel systems. Artificial Neural Network (ANN) has been widely utilized in the past decade in civil engineering applications for the simulation and prediction of the different physical phenomena and has proven its capabilities in the different fields. The present study aims towards introducing the use of ANN technique to model and predict the impact of submerged aquatic weeds existence on the hydraulic performance of branched open channel system. Specifically the current paper investigates a branched open channel system that consists of main channel supplies water to two branch channels that are infested by submerged aquatic weeds and have water structures such as clear over fall weirs and sluice gates. The results of this study showed that ANN technique was capable, with small computational effort and high accuracy, of predicting the impact of different infestation percentage for submerged aquatic weeds on the hydraulic performance of branched open channel system with two different hydraulic structures

  3. Response of wheat (triticum aestivum) to herbicidal weed control

    International Nuclear Information System (INIS)

    This study was carried out with a view to determining the response of wheat cv. Sandal to herbicidal weed control. The plant height was influenced by various herbicidal treatments. But maximum height was obtained by bromoxynil - MCPA (Buctil-M) fallowed by isoproturon (TolKan). Similarly maximum number of fertile tillers per plant, flag leaf area, ear length, yield (Kg/ha) and number of spikelet per ear were observed at bromoxynil-MCPA, Isoproturon (Tolkan), hand weeding and 2-4-D (DMA-6) treatments. But the number of grains per ear did not vary much in response to various herbicidal treatments. However, maximum 1000 grain weight and herbicidal activity index (HAI) were obtained by brombromoxynil-MCPA. The results show that post-emergence herbicides applied as low as 1.3 Kg ai/ha and supplemented with one hand weeding can give optimum crop yield and will there fore be an ideal recommendation to farmers with little experience in the use of herbicides. (author)

  4. CHEMICAL WEED CONTROL IN OIL PUMPKIN (CUCURBITA PEPO L. VAR. OLEIFERA PIETSCH)

    OpenAIRE

    Zdenko Besek; Renata Baličević; Marija Ivezić; Emilija Raspudić; Marija Ravlić

    2012-01-01

    A two-year experiment (2002 – 2003) was conducted in oil pumpkin (Cucurbita pepo var. oleifera) at two localities (Vranjevo and Poljanice) to evaluate the effectiveness of chemical weed control through application of herbicides, and to compare it with mechanical weed control. Main weeds were Amaranthus retroflexus, Setaria viridis and Echinochloa crus-galli. All herbicide treatments, except combination of prometrine + fluazifop-p butyl36, in 2002 appeared to be acceptable to high efficacy in ...

  5. The role of plant-microbiome interactions in weed establishment and control.

    Science.gov (United States)

    Trognitz, Friederike; Hackl, Evelyn; Widhalm, Siegrid; Sessitsch, Angela

    2016-10-01

    The soil microbiome plays an important role in the establishment of weeds and invasive plants. They associate with microorganisms supporting their growth and health. Weed management strategies, like tillage and herbicide treatments, to control weeds generally alter soil structure going alongside with changes in the microbial community. Once a weed population establishes in the field, the plants build up a close relationship with the available microorganisms. Seeds or vegetative organs overwinter in soil and select early in the season their own microbiome before crop plants start to vegetate. Weed and crop plants compete for light, nutrition and water, but may differently interact with soil microorganisms. The development of new sequencing technologies for analyzing soil microbiomes has opened up the possibility for in depth analysis of the interaction between 'undesired' plants and crop plants under different management systems. These findings will help us to understand the functions of microorganisms involved in crop productivity and plant health, weed establishment and weed prevention. Exploitation of the knowledge offers the possibility to search for new biocontrol methods against weeds based on soil and plant-associated microorganisms. This review discusses the recent advances in understanding the functions of microbial communities for weed/invasive plant establishment and shows new ways to use plant-associated microorganisms to control weeds and invasive plants in different land management systems. PMID:27387910

  6. Biodiversity of segetal weed community in continuous potato cultivated with metribuzin-based weed control

    OpenAIRE

    Pawlonka Zbigniew; Rymuza Katarzyna; Starczewski Krzysztof; Bombik Antoni

    2015-01-01

    The objective of the work reported here was to determine the relationship between herbicide rate and the biodiversity of weed communities in potato cultivated in continuous cropping. A seven-year field experiment was conducted to examine the effect of 4 metribuzin rates and an uncontrol on weed infestation in successive years of continuous potato cultivation. The following indices were calculated: the Shannon-Wiener and Simpson’s indices of species diversity and the Simpson’s index of dominat...

  7. Broadcast application of Matran for broadleaf weed control in spring-transplanted onions

    Science.gov (United States)

    Weed competition can cause serious yield reductions if not controlled throughout the growing season. Corn gluten meal can provide early season control, but additional organic herbicides need to be evaluated for mid to late season weed control. Research was conducted in southeast Oklahoma to determ...

  8. Chemical control of curled dock (Rumex crispus L.) and other weeds in noncropped areas

    OpenAIRE

    Tsvetanka Dimitrova; Plamen Marinov-Serafimov

    2008-01-01

    Rumex crispus L. is an invasive species widespread in our country and in particular in the region of North Bulgaria. It is characterized by high biological and ecological plasticity. Owing to its great reproductive potential, the weed has been assigned to the list of economically most important weeds in the country. With the purpose of studying the possibility of chemical weed control in noncropped areas with heavy natural background infestation with R. crispus L. and other dicotyledonous wee...

  9. Nematode, Fungi, and Weed Control using Telone C35 and Colored Plastic Mulches

    Science.gov (United States)

    Methyl bromide fumigation controls weeds, fungi, and nematodes. An alternative treatment system was investigated that used various colored plastic mulches with Telone C35 (65% 1,3- dichloropropene plus 35% chloropicrin). These mulches controlled weeds by a thickness that prevented nutsedge penetrati...

  10. Laboratory tests to assess optimal agricultural residue traits for an abrasive weed control system

    Science.gov (United States)

    One of the biggest challenges to organic agricultural production and herbicide resistant crops in industrialized countries today is the non-chemical control of weed plants. Studies of new tools and methods for weed control have been motivated by an increased consumer demand for organic produce and c...

  11. Impact of broadcast applications of acetic acid on onion injury and weed control

    Science.gov (United States)

    Interest in organic onion production is growing throughout the areas now producing onions with conventional methods, but weed control continues to be a primary obstacle. Weed control is ranked as the number one research priority by organic vegetable producers. The few organic herbicides cleared for ...

  12. Impact of over-the-top broadcast applications of Racer® on onion weed control

    Science.gov (United States)

    The weed control challenges for onion production are formidable; however, these challenges are even greater for those considering organic crop production. Organic onion producers need organic herbicides that can effectively provide post-emergent weed control. Racer (registered trademark) is a poten...

  13. Onion weed control with post-directed applications of pelargonic acid

    Science.gov (United States)

    Organic onion producers need appropriate herbicides that can effectively provide post-emergent weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the impact of a potential organic herbicide on weed control efficacy, crop injury, and yields. The experim...

  14. Broadcast application of scythe for broadleaf weed control in spring-transplanted onions

    Science.gov (United States)

    Producers using organic methods for onion production need organic herbicides that will effectively provide post-emergent weed control. In 2008, a second year of field research was conducted to determine the effect of broadcast over-the-top application of Scythe (57% pelargonic acid) on weed control...

  15. Pelargonic acid formulations, application rates, and sequential applications for weed control in squash

    Science.gov (United States)

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

  16. PRECISION FARMING TECHNOLOGIES FOR WEED CONTROL IN THE MISSISSIPPI DELTA MANAGEMENT SYSTEMS EVALUATION AREA

    Science.gov (United States)

    Studies were conducted to evaluate two precision farming technologies for weed control in the Mississippi Delta Management systems Evaluation Area (MDMSEA). A sensor-controlled hooded sprayer that utilized spectral reflectance type sensors to detect and spray only where weeds were present was evalu...

  17. EVALUATION OF METRIBUZIN IN COMBINATION WITH CLODINAFOP, SULFOSULFURON AND PINOXADEN FOR WEED CONTROL IN WHEAT

    Directory of Open Access Journals (Sweden)

    A P SINGH

    2015-03-01

    Full Text Available A field experiment was conducted during winter season in two consecutive years 2010-11 and 2011-12 at Indira Gandhi Krishi Vishwavidyalaya, Raipur to test the efficacy of metribuzin alone and in combination with other herbicides for the control of mixed weed flora of wheat crop. Out of a total of ten treatments, four consisted of Clodinafop, Sulfosulfuron ,Metribuzin and Pinoxaden applied as alone, another four consisted of combinations of these and one each of weed free and weedy check. During both the years, minimum weed density was recorded in weed free plots at 28DAS. However, similar weed density was observed in sulfosulfuron and metribuzin treated plots at 60DAS and at harvest where the herbicides were applied @25g and 105g ha-1, respectively. Lowest biomass of weeds was observed in weed free plots at 60DAS, whereas at harvest application of sulfosulfuron and metribuzin (25 and 105g ha-1, respectively showed their highest efficacy to reduce the biomass of weeds. Hence, above treatment combination was proved best with respect to weed control efficacy i.e.56.84 and 60.8 per cent in two respective years. The data of weed index (00 and 00 also supported the efficacy of above treatment. The data on yield and yield attributing characters showed significance of the combination of sulfosulfuron and metribuzin for getting higher yield over weedy check which was however found statistically comparable with weed free condition. The supremacy of above treatment was proved by increment of grain yield with the tune of 48 and 52 per cent in two consecutive years, respectively. Thus it can be concluded that metribuzin in combination with sulfosulfuron is effective to control mixed weed flora of wheat when applied @25g and 105g ha-1, respectively.

  18. Biodiversity of Segetal Weed Communities when Chlorsulfuron-Based Weed Control is Being Used on Continuous Winter Wheat

    Directory of Open Access Journals (Sweden)

    Pawlonka Zbigniew

    2014-07-01

    Full Text Available The purpose of the study was to determine the relationship between herbicide rate and weed community biodiversity in continuous wheat. A six-year field experiment was conducted to examine the effect of four chlorsulfuron rates in comparison with untreated (the control plots, on the status and severity of weed infestation - in successive study years of cultivating winter wheat in monoculture. In addition, the following indices were calculated: Shannon-Wiener and Simpson’s index of biodiversity, and Simpson’s index of domination. A total of 36 weedy species were identified in the experimental plots. The richest segetal communities were established in the control plots. An application of herbicide reduced the biodiversity of the agrophytocensosis. A short-term monoculture did not impoverish the species richness of the weed community established in winter wheat. The average number of species in the community was significantly greater in the second study year. In the initial study years of monoculture, the biodiversity of the segetal community increased markedly compared with rotation-based cultivation. The calculated indices of biodiversity were not significantly affected by herbicide rate or monoculture but the indices confirmed the trends outlined by an analysis of the status and level of weed infestation.

  19. Weed control in distress – can all weeds still be controlled with herbicides in future?

    Directory of Open Access Journals (Sweden)

    Drobny, Hans G.

    2016-02-01

    Full Text Available The introduction and availability of highly active and selective herbicides in all important field crops, in the last decades, enabled the simplification and money saving in crop rotations and agronomic measures. This resulted in respective specialized and adapted weed populations, and consequently an increasing selection of resistant populations. Since the introduction of the ALS-inhibitors (starting 1985 and the 4-HPPD-inhibitors (2001, no new MoA-Classes were registered, and there are none in the registration process. Several established herbicides were not registered or re-registered in the EU, or were severely restricted in their application. The cost and the risk to develop and register a new selective herbicide in the EU are hardly justified, in relation to their market potential. The only solution on problem fields, with resistant populations, is to change the agronomic practices, like crop rotation, soil tillage, seeding time, etc., as a precautionary principle also on still „normal“ fields. The different advising institutions have to integrate these aspects into their recommendations, besides the proper herbicide management.

  20. CONTENT AND UPTAKE OF SELECTED TRACE ELEMENTS BY WEEDS IN POTATO TO CULTIVATION UNDER DIFFERENT CONDITIONS OF SOIL TILLAGE AND WEED CONTROL METHODS

    OpenAIRE

    Krystyna Zarzecka; Marek Gugała; Alicja Baranowska

    2014-01-01

    The study utilized data from a field experiment carried out at the Experimental Station in Zawady owned by the University of Natural Sciences and Humanities in Siedlce in the years 2005–2007. The experimental factors included two soil tillage systems and seven weed control methods in potato. Iron, copper and zinc in weeds were determined with the AAS method. The trace element content in weed dry matter before row closure of potato depended significantly on soil tillage methods (excluding Cu),...

  1. The Critical Period for Weed Control (CPWC in Potato (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Dogan ISIK

    2015-12-01

    Full Text Available Accurate assessment of crop-weed control period is an essential part for planning an effective weed management for cropping systems. Field experiments were conducted during the seasonal growing periods of potato in 2012 and 2013 in Kayseri, Turkey to assess critical period for weed control (CPWC in potato. A four parameter log-logistic model was used to assist in monitoring and analysing two sets of related, relative crop yield. Data was obtained during the periods of increased weed interference and as a comparison, during weed-free periods. In both years, the relative yield of potato decreased with a longer period of weed-interference whereas increased with increasing length of weed free period. In 2012, the CPWC ranged from 112 to 1014 GDD (Growing Degree Days which corresponded to 8 to 66 days after crop emergence (DAE and between 135-958 GDD (10 to 63 DAE in the following year based on a 5% acceptable yield loss. Weed-free conditions needed to be established as early as the first week after crop emergence and maintained as late as ten weeks after crop emergence to avoid more than 5% yield loss in the potato. The results suggest that CPWC could well assist potato producers to significantly reduce the expense of their weed management programs as well as improving its efficacy.

  2. EFFECT OF HERBICIDES ON WEED CONTROL AND YIELD OF WET SEEDED RICE (ORYZA SATIVA L.

    Directory of Open Access Journals (Sweden)

    MALLIKARJUN

    2014-06-01

    Full Text Available To study effect of herbicides on weed control and yield of wet seeded rice which involves three pre-emergent herbicides viz., butachlor, anilophos and oxyflurofen applied as alone and each these followed by two post emergent herbicides 2, 4- sodium salt, bispyribac sodium and one hand weeding at 25 days. The results revealed that sequential application of butachlor and anilophos fb bispyribac sodium, 2, 4-D sodium salt and one hand weeding at 25 days was recorded significantly lower weed population and dry weight of weeds viz., monocots, dicots and sedges in equal manner which ultimately indicates that higher weed control efficiency over rest of the treatments except weed free check and hand weeding thrice. further, grain and straw yield of rice was followed the same trend as well influenced by yield parameters like number of panicles per sq.m and number of seeds/ panicle ultimately sequential application butachlor and anilophos fb 2, 4-D sodium salt and bispyribac sodium and one hand weeding at 25 DAS resulted higher grain yield and profitable rice production.

  3. Physical Weed Control in Organic Carrot in Sicily (Italy)

    OpenAIRE

    Peruzzi, A.; Raffaelli, M.; M. Fontanelli; C. Frasconi; Ginanni, M.; Lulli, L.

    2008-01-01

    Weeds are the major biotic factor that negatively affects organic carrot yield. As a matter of fact, weeds can reduce carrot growth from early stages to harvest because of the low competitive attitude of this vegetable. Innovative and conventional crop and weed managements were compared in an experiment carried out on farm in the Catania Plain (Sicily, Italy) in 2005-2006. Innovative planting pattern, operative machines (rolling harrow, flaming machine, precision hoe) and crop management incr...

  4. Tine cultivation effects on weed control, productivity, and economics of peanut under organic management

    Science.gov (United States)

    Identifying effective weed control regimes for organic peanut has become paramount for improving the feasibility of organic production. Tine cultivation is a proven effective method at reducing in-row weed populations in several crops. Field trials were therefore conducted in 2008 and 2009 to asse...

  5. Precision placement of corn gluten meal for weed control in organic vegetable production

    Science.gov (United States)

    Producers of organic vegetables continue to rank weeds as one of their most troublesome, time consuming, and costly production problems. As a result of the limited number of organically approved weed control herbicides, the precision placement of these materials increases their potential usefulness...

  6. Biodiversity of segetal weed community in continuous potato cultivated with metribuzin-based weed control

    Directory of Open Access Journals (Sweden)

    Pawlonka Zbigniew

    2015-01-01

    Full Text Available The objective of the work reported here was to determine the relationship between herbicide rate and the biodiversity of weed communities in potato cultivated in continuous cropping. A seven-year field experiment was conducted to examine the effect of 4 metribuzin rates and an uncontrol on weed infestation in successive years of continuous potato cultivation. The following indices were calculated: the Shannon-Wiener and Simpson’s indices of species diversity and the Simpson’s index of domination. A total of 33 species were recorded in the experimental plots. Echinochoa crus-galli was the dominant species. The most abundant segetal communities were observed in untreated plots. An application of the herbicide reduced the biodiversity of the agrophytocenosis. Cultivation in continuous cropping increased the species number of the weed community in potato. The herbicide and cultivation in continuous cropping did not significantly affect the biodiversity indices but their values, to a great extent, confirmed the trends revealed by the analysis of weed infestation

  7. UTILIZATION OF Limnocharis flava, AN INVASIVE AQUATIC WEED FROM KUTTANAD WETLAND ECOSYSTEM, KERALA, INDIA AS A POTENTIAL FEEDSTOCK FOR LIVESTOCK

    Directory of Open Access Journals (Sweden)

    S. SMITHA CHANDRAN

    2016-01-01

    Full Text Available The chemical composition, nutritive value and trace element profiles of Limnocharis flava, an emergent aquatic weed during its different growth stages was determined to evaluate as possible cattle feed. Samples were analyzed at three progressive morphological stages of the plant, pre-flowering, flowering and post-flowering. The moisture content, dry matter (DM, ash content, crude protein (CP, ether extract (EE, crude fiber (CF, nitrogen free extract (NFE and mineral constituents like sodium (Na+ potassium (K+, calcium (Ca2+, phosphorous (P and trace elements like iron (Fe2+, copper (Cu2+, manganese (Mn2+, zinc (Zn2+, lead (Pb2+, chromium (Cr2+ nickel (Ni+ and cadmium (Cd+ contents were analyzed. The moisture content, organic matter (OM, acid detergent fiber content increased during maturation, while CP and EE were found decreased with increased growth stage. Only slight fluctuations occurred in Calcium, Potassium, Phosphorous and Sodium contents. The highest values for crude protein, fiber content, NFE and EE were observed at the flowering stage. These plant posses several characteristics which makes it a nutritious feed suitable for domestic livestock, and is recommended to use L.flava, particularly at the flowering stage of growth.

  8. Characterization of Anaerobic Degradability and Kinetics of Harvested Submerged Aquatic Weeds Used for Nutrient Phytoremediation

    Directory of Open Access Journals (Sweden)

    Takuro Kobayashi

    2014-12-01

    Full Text Available In this study, eight different submerged aquatic species were screened by batch biochemical methane potential and anaerobic degradability tests to identify a promising/suitable feedstock. Kinetics of the best-screened substrate were studied in a mesophilic semi-continuous experiment. The aquatic species Myriophyllum aquaticum, Egeria densa and Potamogeton perfoliatus showed relatively higher methane yields of over 400 NmL/g-VS (volatile solids. Semi-continuous operation was carried out by feeding E. densa for over 400 days. The achieved results were 33%–53% chemical oxygen demand (COD reduction and methane yield of 126–231 NmL/g-VS with a short hydraulic retention time (HRT. Additionally, the NH4+ and PO43− releases from the biomass to water were found to be low (18%–27% and 2.5%–3.9% throughout the experiment. Hydrolysis was the limiting step in the digestion of E. densa, regardless of changes in HRT (15–45 days. The acid-phase model indicated that the hydrolysis rate constant (kh of E. densa was 0.058 one/day, which was one third lower the kh value of food waste, but quite similar to cow manure.

  9. 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...

  10. Organic weed control with vinegar: Application volumes and adjuvants

    Science.gov (United States)

    Preliminary results have indicated that vinegar has potential as an organic herbicide, but further research is needed to increase our understanding of the relationship between acetic acid concentrations, application volumes, adjuvants, weed species, and weed maturity on effectiveness of vinegar to c...

  11. Effects of allelopathic chemicals extracted from various plant leaves on weed control and wheat crop productivity

    International Nuclear Information System (INIS)

    A study on allelopathic effect of leaf water extracts of Eucalyptus, Acacia, Sorghum, Shishum, Sunflower, Poplar, Tobacco and Congress grass on weeds control and growth of wheat cv. Hashim-8 was conducted at Faculty of Agriculture, Gomal University, Dera Ismail Khan during 2012-2013. The findings of this study revealed that allelopathic chemicals in leaf water extracts of these plants significantly suppressed weeds growth by reducing weed density, fresh and dry weed biomass, and encouraged wheat yield and yield components such as days to 50% heading, plant height, tillers m-2, grain spike-1, 1000-gain weight, biological and grain yield. Even though minimum fresh and dry weed biomass and highest wheat grain yield and yield related components were observed in twice hand weeding treatment which is economically less feasible on large scale. However, our findings showed an alternative allelopathic technique to minimize weed infestation and boost wheat growth and yield using natural plant material. On the basis of present results, it is recommended that leaf water extracts of Sorghum, Sunflower and Congress grass can be applied twice (30 and 60 DAS) during the growing season to control weeds and to enhance wheat grain yield. (author)

  12. Cultivation of macroscopic marine algae and freshwater aquatic weeds. Progress report, May 1--December 31, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J. H.

    1977-01-01

    Research was divided between basic physiological studies of the growth and nutrient-uptake kinetics of macroscopic marine algae and the more applied problems involved in the selection of species and the development of inexpensive, non-energy intensive culture methods for growing seaweeds and freshwater plants as a biomass source for conversion to energy. Best growth of the seaweeds occurs at low (0.1 to 1.0 ..mu..molar) concentration of major nutrients, with ammonia as a nitrogen source, with rapid exchange of the culture medium (residence time of 0.05 days or less). Of 43 species of seaweeds evaluated, representatives of the large red alga genus Gracilaria appear most promising with potential yields, in a highly intensive culture system under optimal conditions, of some 129 metric dry tons per hectare per year (about half of which is organic). Non-intensive culture methods have yielded one-third to one-half that figure. Unexplained periodicity of growth and overgrowth by epiphytes remain the most critical constraint to large-scale seaweed culture. Freshwater weed species in culture include water hyacinth (Eichhornia crassipes), duckweed (Lemna minor), and Hydrilla vertecillata, with yields to date averaging 15, 4, and 8 g dry wt/m/sup 2//day, respectively. However, these plants have not yet been grown through the winter, so average annual yields are expected to be lower. In contrast to the seaweeds, the freshwater plants grow well at high nutrient concentrations and slow culture volume exchange rates (residence time ca. 20 days or more). Experiments were initiated on the recycling of digester residues from the fermentation of the freshwater and marine plants as a possible nutrient source for growth of the same species.

  13. Accumulation of 241Am by suspended matter, diatoms and aquatic weeds of the Yenisei River

    International Nuclear Information System (INIS)

    In this work we experimentally estimated the capacities of the key components of the Yenisei River (Russia): particulate suspended matter (seston), diatom microalgae, and submerged macrophytes for accumulating 241Am from water. In our experiments large particles of seston (>8 μm), comparable in size with diatoms, took up most of americium from water. The accumulation of americium by isolated diatom algae (Asterionella formosa and Diatoma vulgare) was lower than by total seston. The concentration factors (CFs) of 241Am for seston of the Yenisei River in our experiments were (2.8-6.9).105; for diatoms - (1.5-4.2).104. The CFs for aquatic plant Elodea canadensis were within the same order of magnitude as those for diatoms. Activity concentration and CFs of 241Am were nearly the same in experiments under dark and light conditions. This is indicative of an energy independent mechanism of americium uptake from the water by diatoms and submerged macrophytes.

  14. New weed control strategies in maize considering narrow crop rotations with maize, greater ALSresistance in common weeds and application restrictions with regard to active substance

    Directory of Open Access Journals (Sweden)

    Ewert, Katrin

    2014-02-01

    Full Text Available Many herbicides with different HRAC-groups are available for weed control in maize. Because of narrow maize crop rotation summer weeds and warmth loving weeds are encouraged. On the other hand the new confirmed cases of an ALS target site resistance in the weed species Echinochloa crus-galli and Amaranthus retroflexus in Brandenburg, Stellaria media in Saxony and Matricaria recutita and Tripleurospermum perforatum in Brandenburg and Thuringia, warn that in the future the sulfonylureas must be used only according to the management of herbicide resistance. In this way the selection of resistant weed biotypes will be prevented. Moreover in protected water areas it may be a requirement to reduce and to substitute the input of some active substances, for example terbuthylazine and bentazon. The control of E. crus-galli and P. convolvulus with non-sulfonylurea or/and non-terbuthylazine herbicides according to management of herbicide resistance will be discussed.

  15. Evaluation of yield quality and weed infestation of common valerian (Valeriana officinalis L. in dependence on weed control method and forecrop.

    Directory of Open Access Journals (Sweden)

    Cezary Kwiatkowski

    2012-12-01

    Full Text Available A field experiment involving the cultivation of common valerian was conducted on loess soil in Abramów (Lublin region in the period 2007-2009. Qualitative parameters of herbal raw material obtained from this plant as well as in-crop weed infestation were evaluated depending on the protection method and forecrop. Hand-weeded plots, in which a hand hoe was used, were the control. In the other treatments, weeds were controlled using various herbicides and a mechanical implement (brush weeder. Potato and winter wheat + field pea cover crop were the forecrops for common valerian crops. A hypothesis was made that the use of a brush weeder and herbicides not registered for application in valerian crops would have a positive effect on this plant's productivity and weed infestation in its crops. It was also assumed that the introduction of a cover crop would allow the elimination of differences in the forecrop value of the crop stands in question. The best quantitative and qualitative parameters of common valerian raw material as well as the largest reduction of incrop weed infestation were recorded after the application of the herbicides which were not type approved. The use of the brush weeder in the interrows also had a beneficial effect on productivity of the plant in question, but secondary weed infestation at the end of the growing season of common valerian turned out to be its disadvantage. Traditional crop protection methods used in common valerian crops were less effective in weed infestation reduction and they resulted in lower plant productivity and raw material quality. Potato proved to be a better forecrop for common valerian than winter wheat + field pea; however, this positive effect was not confirmed statistically. The following annual weeds: Chenopodium album, Galinsoga parviflora, Stellaria media, were predominant in the common valerian crop. Traditional weed control methods resulted in the dominance of some dicotyledonous weeds, such

  16. Weed Control and Crop Production Practices in Cotton Production in Diyarbakır Province of Turkey

    OpenAIRE

    ÖZASLAN, Cumali; AKIN, Songül; GÜRSOY, Songül

    2015-01-01

    Cotton agriculture is very important in South Eastern Anatolia Region of Turkey. Weeds are major problems in cotton farming systems. In this study, a survey was conducted in Diyarbakır Province of Turkey to evaluate weed management practices being opted, crop production methods in use, most important weed species and major production problems in the region. Moreover, effect of agricultural extension activities on weed control was investigated. For this purpose, over 75 cotton growers were sur...

  17. Mapping invasive weeds and their control with spatial information technologies

    Science.gov (United States)

    We discuss applications of airborne multispectral digital imaging systems, imaging processing techniques, global positioning systems (GPS), and geographic information systems (GIS) for mapping the invasive weeds giant salvinia (Salvinia molesta) and Brazilian pepper (Schinus terebinthifolius) and fo...

  18. FruitGrowth - Gasburning in Orchards - Environment friendly weed control

    DEFF Research Database (Denmark)

    Bertelsen, Keld Kjærhus; Duzel, Jasmin; Nielsen, Søren Hundevadt;

    Gas burning makes treatment of weed organic. The new ENVO-DAN burner saves 40% gas and treats ½ meter in width. It can be mounted on a standard lawn tractor, orchard tractor or a mobile robot.......Gas burning makes treatment of weed organic. The new ENVO-DAN burner saves 40% gas and treats ½ meter in width. It can be mounted on a standard lawn tractor, orchard tractor or a mobile robot....

  19. Arsenic removal in solution using non living bio masses of aquatic weed

    International Nuclear Information System (INIS)

    Arsenic is a metalloid considered among the most dangerous to health. The As maximum level allowed of drinkable water is 0.01 mg/L established by the Who. Several techniques have been proposed to remove arsenic from water, among which are the sorption processes in economic biological materials, which has advantages for its high efficiency in dilute toxic removing from contaminated water, for these reason it is necessary to study new bio sorbents materials which are economic, simple and easy to apply in the treatment of contaminated areas. The aim of this project was evaluate the removal of As (V) in solution using two non living aquatic plants: water hyacinth (Eichhornia crassipes) and lesser duckweed (Lemna minor), characterize these materials and compare the efficiency between both; the parameters evaluated were the As (V) initial concentration in solution, contact time, ph value and the amount of biomass in contact with them. It describes the method to prepare the non living plants. The physicochemical characterization by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis was made. The results shown that cellulose is the main component confirmed by the techniques above mentioned. Surface characterization of Eichhornia crassipes and Lemna minor by specific surface area, shown 1.3521 m2/g and 0.6395 m2/g respectively, the hydration kinetic indicates that 24 h was the maximum hydration time for both plants; the point of zero charge determination by mass titration gives a ph=6.1 for the first plant and ph=7.1 for the second plant, finally the active site density obtained for the plants were of 8.57 sites/nm2 and 12.47 sites/nm2. The point of zero charge was analyzed for know the ph from which the As (V) species are removal preferably. Tested contact processes between bio sorbent-As (V) were performed to assess the ability of bio masses to removal As (V) from aqueous solutions, investigated parameters

  20. CHEMICAL WEED CONTROL IN OIL PUMPKIN (CUCURBITA PEPO L. VAR. OLEIFERA PIETSCH

    Directory of Open Access Journals (Sweden)

    Zdenko Besek

    2012-06-01

    Full Text Available A two-year experiment (2002 – 2003 was conducted in oil pumpkin (Cucurbita pepo var. oleifera at two localities (Vranjevo and Poljanice to evaluate the effectiveness of chemical weed control through application of herbicides, and to compare it with mechanical weed control. Main weeds were Amaranthus retroflexus, Setaria viridis and Echinochloa crus-galli. All herbicide treatments, except combination of prometrine + fluazifop-p butyl36, in 2002 appeared to be acceptable to high efficacy in control of annual grass- and broad-leaved weeds. The efficacy of all herbicide treatments in 2003 was lower. The best results of herbicide effectiveness were achieved with combination of linuron + dimethenamid (91.3%, trifluralin (90.1% + napropamide and clomazone + linuron (89%.

  1. Seawater: an alternative grassy weed control method for post emergence herbicides in tropical turfgrass

    International Nuclear Information System (INIS)

    Research was designed to reduce herbicide use by replacing post emergence herbicides with readily available sea water to control tropical turfgrass weeds. In studies evaluating the use of saline solutions for weed control, four salinity levels (0, 24, 48 and 72 dS m/sup -1/) were applied once to 30 grassy weed species, along with seashore paspalum (Paspalum vaginatum Swartz) (as a control) during December, 2007 to March, 2008. The results on injury ratings for salt tolerant weeds were categorized as highly susceptible, moderately susceptible and extremely tolerant. C. dactylon, E. indica, E. virescense, E. unioloides and I. globosa were very susceptible and found to be effectively controlled (100%) at 72 dS m/sup -1/ salinity treatment. However, two most serious weeds viz. wiry eragrostis (E. atrovirens) and lesser dropseed (S. diander), were found to be extremely tolerant, and were not controlled even at the highest salinity level of 72 dS m/sup -1/. P. vaginatum and E. atrovirens did not show significant decrease in shoot and root dry weight at highest salinity levels (72 dS m/sup -1/). The results indicate that sea water has excellent potential for sustainable control of several common grassy weeds in tropical turf. (author)

  2. Critical period of weed control in chickpea under non-irrigated conditions

    OpenAIRE

    TEPE, Işık; Erman, Murat; YERGİN, Reyyan; BÜKÜN, Bekir

    2011-01-01

    The present study was conducted during the growing seasons of 2005, 2006, and 2007 to determine the critical period of weed control (CPWC) in chickpea (cv. Aziziye 94). In order to evaluate the beginning of CPWC, weeds were allowed to compete at weekly intervals for 1 to 8 weeks after emergence (WAE) and, at the end of CPWC, plots were kept weed-free at weekly intervals for 1 to 8 WAE by periodic hand hoeing. The beginning and the end of CPWC were based on 5% acceptable yield loss (AYL) level...

  3. Field sprayer for inter and intra-row weed control: performance and labor savings

    OpenAIRE

    Carballido, J; A. Rodríguez-Lizana; Agüera, J.; M. Pérez-Ruiz

    2013-01-01

    Studies of new tools and methods for weed control have been motivated by increased consumer demand for organic produce, consumer and regulatory demands for a reduction in environmentally harmful herbicide use, and the decreased availability of farm workers willing to perform manual tasks, such as hand weeding. This study describes the performance of a new sprayer system for commercial production that integrates two herbicide applications in a single pass, selective herbicide (SH) application ...

  4. Efficient soil solarization for weed control in the rain-fed upland rice ecosystem

    Directory of Open Access Journals (Sweden)

    Singh S.R.

    2003-09-01

    Full Text Available Weed competition causes significant damage (up to 90% to crop yields. Weed control through chemical means in the form of herbicide is commonly used to kill weeds or inhibit their growth throughout the world. However, the use of herbicides has increased toxic residues dangerously, indiscriminately targeting organisms, the environment, and ground water and creating serious upheaval in the ecosystem. Studies were conducted through a series of experiments for five consecutive wet seasons with a variety of alternative biological solutions to control the weeds. These solutions are benign, harmless, pollution free, non - hazardous and eco - friendly and control the pre-emergence of weeds in the rain-fed, upland rice ecosystem whereas in the high rainfall coastal region of eastern India, control was effected through soil solarization. This is a method of heating the soil's surface by using transparent low-density polyethylene (LDPE film sheets placed on the soil's surface to trap solar radiation. This raises the soil temperature to a level which is lethal for many soil borne pathogens and weed seeds, thus killing weeds before they even begin to grow. The rise in soil temperature due to solarization by using LDPE film was significantly correlated to the soil temperature under normal conditions (uncovered and the cumulative solar radiation (Wm-2 of that day but the effect of the air temperature was found to be insignificant. A quadratic relationship was developed between temperature difference (DT and soil temperature (ST and the cumulative solar radiation (SR for that day. The use of transparent and black LDPE sheets reduces weed growth and increases rice yield. Higher yields were found in treatments using transparent LDPE films of 200 gauges and 400 gauges for 30 days followed by black LDPE film. However, lower yields were recorded from the fields which were covered with LDPE films (both 200 and 400 gauge beyond 30 days.

  5. Effect of Different Control Methods on Weeds, Yield Components and Nodulation in the Spring Lentil

    OpenAIRE

    TEPE, Işık

    2004-01-01

    This study was conducted on the lentil cultivar Malazgirt 89 during 1999 and 2000 to determine the most appropriate method for controlling weeds. In the experiments, hand hoeing, trifluralin, imazethapyr, linuron, prometryn, phenmedipham + desmediphame, trifluralin + hand hoeing and linuron + hand hoeing which should be used as an alternative to hand weeding, were tested. The effects of herbicides on nodulation in lentils were also investigated. Centaurea depressa in the first year, and Ranun...

  6. Damage and Control of Poisonous Weeds in Western Grassland of China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bao-yu; SHI Zhi-cheng; LIU Zhong-yan; LU Hao; WANG Zhan-xin; SUN Li-sha; WAN Xue-pan; GUO Xi; ZHAO Yan-tao; WANG Jian-jun

    2010-01-01

    Western grassland is the main source of living and means of production of western inhabitants. For many years,desertification and poisonous-weeds growth in grassland were resulted from over-grazing, over-reclaiming, over-spading and population growth. Western natural ecological environment is destroyed severly. Meanwhile, it has restricted the sustainable development of animal husbandry. The fast spreading poisonous-weeds, which caused grassland ecology unbalance, is one of the considerable bioecology problems and an important index of grassland degeneration. Based on analysis and induction of previous data, this article introduced the situation of poisonous-weeds disaster of western grassland in recent decades, category and distribution of poisonous-weeds, integrated control and reasonable utilization.

  7. Cultivation of macroscopic marine algae and freshwater aquatic weeds. Progress report, May 1-December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J. H.

    1979-01-01

    Studies were continued during 1977 to 1978 on the growth and yields in culture of the red seaweed Gracilaria tikvahiae. Partial control of epiphytes was achieved by nutrient removal, shading, and/or biological agents. For the first time, a single clone of the alga was grown continuously throughout the year without replacement. Yields in large (2600 1) aluminum tanks averaged 21.4 g dry weight/m/sup 2/.day, equivalent to 31 tons/acre.year (15.5 ash-free dry wt tons/acre.year). Growth of Gracilaria and other seaweeds in Vexar-mesh baskets in natural habitats and in the oceanic waters of a power plant cooling water intake canal were unsuccessful. Productivity of the freshwater macrophytes Lemna minor (common duckweed), Eichhornia crassipes (water hyacinth), and Hydrilla verticillata have now been measured throughout the year with mean yields of 3.7, 24.2 and 4.2 g dry weight/m/sup 2/.day (5.4, 35.3, and 6.1 dry tons/acre.year) respectively. Yields of duckweed and water hyacinths in the Harbor Branch Foundation culture units have averaged roughly three times those of the same species growing in highly-eutrophic natural environments. The yields of several other species of freshwater plants were investigated. Only the pennywort (Hydrocotyle umbellata) appears to approach the productivity of water hyacinth on the basis of preliminary measurements. Chopped water hyacinths and unprocessed Gracilaria have both been successfully fermented to methane in anaerobic digesters and the liquid digester residues recycled to produce more of the same plants.

  8. Effects of cultural methods and physical weed control on intrarow weed numbers, manual weeding and marketable yield in direct-sown leek and bulb onion

    OpenAIRE

    Melander, Senior scientist Bo; Rasmussen, Scientist Gitte

    2001-01-01

    Manual weeding of intrarow weeds in seeded leek and bulb onion grown organically can be very labour-intensive. Four field experiments, two in direct-sown leek (Allium porrum L.) and two in direct-sown bulb onion (Allium cepa L.), were made in this investigation to study the effects of physical and cultural methods on intrarow weed numbers, time consumption for hand-weeding and marketable yield parameters. The physical methods considered were: pre-emergence flaming and harrowing, and post-emer...

  9. Efficacy of the alginate controlled-release formulation (CRF) of thiobencarb herbicide for weed control in transplanted rice

    International Nuclear Information System (INIS)

    Field trial was conducted during the summer season of 1992 at the Agriculture Research Station, Alexandria University to determine the effect of thiobencarb formulations (alginate controlled-release formulation and granular formulation), their combination, application times and rates of application on weed control and on economics of transplanted rice. Thioberncarb at 0.75 or 1.5 kg/ha was applied twice, 1 day before transplanting and 6 days after transplanting. The differences in response among weeds and rice to thiobencarb formulations, their combinations, application times and rates were variable. All of the herbicidal treatments as well as the hand weeded one gave superior yields over un-weeded control. Controlled release thiobencarb formulation applied 6 days after transplanting at 1.5 kg/ha was the most effective treatment up to 40 days after transplanting, followed by the same formulation applied 1 day before transplanting, based on weed density, weed height and weed dry weight and it provided the highest grain yield. (author). 11 refs, 5 tabs

  10. Biology and Biological Control of Mile-a-Minute Weed

    Science.gov (United States)

    Mile-a-minute weed (MAM), Persicaria perfoliata (L.) H. Gross (Fig. 1), is a member of the family Polygonaceae. It is an annual vine that can grow up to 6 meters long over the course of a season. It is widely distributed throughout east Asia, including Japan, China, Korea, India, Indonesia, Banglade...

  11. Corn gluten meal application equipment evaluations for organic weed control

    Science.gov (United States)

    Corn gluten meal (CGM) produces an inhibitory effect and reduces root formation in several weed species. One limitation to further use of CGM in vegetable production is the difficulty in achieving a uniform application to the soil surface and detrimental impact of CGM on direct-seeded vegetables. ...

  12. Introduction to Weeds and Herbicides.

    Science.gov (United States)

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University is an introduction to weed control and herbicide use. An initial discussion of the characteristics of weeds includes scientific naming, weed competition with crops, weed dispersal and dormancy, and conditions affecting weed seed germination. The main body of the…

  13. Robotic weeding and automated weed measurements

    DEFF Research Database (Denmark)

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

    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. The...... strategy may be changed in the coming years because experiments in Germany, USA, Australia, and Denmark have shown that site-specific weed management can reduce herbicide usage significantly. One of the promising technologies for site specific weed management is robotic weeding. This paper reviews 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....

  14. Weed control in sunflower (helianthus annuus L.) with post-emergent herbicides.

    Science.gov (United States)

    Béres, I; Szente, D; Gyenes, V; Somlyay, I

    2005-01-01

    Sunflower is the most important oil crop in Hungary, is the base of the production of cooking oil and moreover takes an important part in production of margarine too. Extracted sunflower groats as a secondary product origining from the mentioned procedure can be used in forage successfully. The amount of harvested sunflower reaches the 20-25% of the EU's yield. The sowing area approaches 500 thousand hectares. The essential condition of successful crop production is the perfect weed control. Sowing areas are infected with monocotyledon and dicotyledonous weeds too. Annual dicotyledonous weeds are the most troublesome. The worst species is the Ambrosia artemisiifolia L. Many other weed species as Abutilon theophrasti MEDIC., Datura stramonium L. and Xanthium strumarium L. can cause serious damages. In our model experiments we examined the herbicide sensibility of two commercial sunflower cultivars as "Iregi szürke csikos", "Marica II" and a sulfonylurea-urea tolerant new hybrid "PR63E82". The experiment was set up under greenhouse conditions with the use of four important weed and different post-emergent herbicide as Modown 4F (bifenox), Pledge 50 WP (flumioxazin) and Granstar 75 DF (tribenuron-methyl). We applied normal and double doses too. Sunflower was cultivated to 4-6 leaf stage. Post-emergent herbicides were sprayed out when weeds were in 2, 2-4 and 4-6 leaf stage. Weed killer and phytotoxic effects of post-emergent herbicides were examined. We declared that development of weeds had significally effect on the effectiveness of different herbicides. PMID:16637218

  15. Weed Control and Corn (Zea mays) Response to Planting Pattern and Herbicide Program with High Seeding Rates in North Carolina

    OpenAIRE

    Williams, Mitchell K.; Ronnie W. Heiniger; Everman, Wesley J.; David L. Jordan

    2014-01-01

    Effective weed control in corn (Zea mays L.) is important to optimize yield. Concern over environmental impact of atrazine and selection for glyphosate resistance has increased the need to develop alternative strategies that use herbicides other than atrazine and glyphosate and appropriate cultural practices to control weeds. Research was conducted during 2011 and 2012 to determine weed and corn response to herbicide programs containing dicamba, glufosinate, and glyphosate applied postemergen...

  16. Research on the weed control degree and glyphosate soil biodegradation in apple plantations (Pioneer variety

    Directory of Open Access Journals (Sweden)

    Ersilia ALEXA

    2010-05-01

    Full Text Available In this study we follow control degree of glyphosate herbicide on weeds in apple plantations (Pioneer variety of the Research Station Timisoara. It was also followed glyphosate biodegradation capacity in the soil by determining the amount of CO2 released by the action of microorganisms on C14 glyphosate marked isotope. Laboratory analysis of glyphosate residues in soil was made using a Liquid Scintillation TRIATHLER. Glyphosate biodegradation ability in the presence of soil microorganisms is high, so glyphosate residues remaining in soil, in terms of its use in weed combating, are minimal. Study of glyphosate biodegradation capacity in the experimental field indicates that the CO2 fraction accumulated after 50 days is 28.02% for samples exposed in the experimental field. Weather conditions, especially temperature variations between day and night, influences the activity of soilmicroorganisms and affect biodegraded glyphosate percentage.Chemical method of weed control consisted in: herbicide used was Roundup 3 l/ha (glyphosate isopropyl amine salt 360 g/l and are based on chemical application on weeds, on the rows of trees, on their uptake and translocation in their organs having as principal scope the total destruction of weeds. The experimental results obtained reveal a weed combat degree of 82.98% , in the case of chemical variant, compared with control variant. The species combated mainly due to glyphosate herbicide, which is no longer found in the final mapping are: Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Plantago major, Polygonum aviculare. Total combated weeds /m2 with glyphosate is 126.67.

  17. Effect of chemical and mechanical weed control on cassava yield, soil quality and erosion under cassava cropping system

    Science.gov (United States)

    Islami, Titiek; Wisnubroto, Erwin; Utomo, Wani

    2016-04-01

    Three years field experiments were conducted to study the effect of chemical and mechanical weed control on soil quality and erosion under cassava cropping system. The experiment were conducted at University Brawijaya field experimental station, Jatikerto, Malang, Indonesia. The experiments were carried out from 2011 - 2014. The treatments consist of three cropping system (cassava mono culture; cassava + maize intercropping and cassava + peanut intercropping), and two weed control method (chemical and mechanical methods). The experimental result showed that the yield of cassava first year and second year did not influenced by weed control method and cropping system. However, the third year yield of cassava was influence by weed control method and cropping system. The cassava yield planted in cassava + maize intercropping system with chemical weed control methods was only 24 t/ha, which lower compared to other treatments, even with that of the same cropping system used mechanical weed control. The highest cassava yield in third year was obtained by cassava + peanuts cropping system with mechanical weed control method. After three years experiment, the soil of cassava monoculture system with chemical weed control method possessed the lowest soil organic matter, and soil aggregate stability. During three years of cropping soil erosion in chemical weed control method, especially on cassava monoculture, was higher compared to mechanical weed control method. The soil loss from chemical control method were 40 t/ha, 44 t/ha and 54 t/ha for the first, second and third year crop. The soil loss from mechanical weed control method for the same years was: 36 t/ha, 36 t/ha and 38 t/ha. Key words: herbicide, intercropping, soil organic matter, aggregate stability.

  18. Growth and competition model for organic weed control

    OpenAIRE

    Anon.

    2002-01-01

    There is a more detailed Executive Summary at the top of the attached document, which is the final report for Defra Project OF0177. The project aimed to examine the organic extension of a simple mechanistically-based growth and competition model, calibrated to data originally gained from conventional vegetable production. Essentially the model simulation follows the growth of each crop and weed plant as they compete for space and light during and after canopy closure. The growth and compet...

  19. Studies on the performance of glyphosate in the control of graminaceous weeds in rice fields

    International Nuclear Information System (INIS)

    Absorption and translocation of 14C-labelled glyphosate was studied from the commercial formulation 'Roundup' to which three different surfactants, singly or in combination, four different oil adjuvants and ammonium sulfate were added. Increased penetration of the herbicide was observed after 1, 2 and 24 h by the addition of Triton X-100, ammonium sulfate and coconut oil. Addition of Neem oil instead of coconut oil also showed increased penetration after 24 h. Addition of Tween 80 and diesel oil increased the penetration with or without ammonium sulfate; whereas, Tween 20 with the added peanut oil or coconut oil and Tween 80 with Neem oil increased penetration only in the presence of ammonium sulfate. Therefore, the absorption of glyphosate seems to be dependent on the nature of surfactant and the oil (adjuvant) used. Field tests were carried out to study the effect of hand weeding, one dose of unamended and three different doses of amended (0.5, 0.75 and 1.5 kg a.i. ha-1) 'Roundup' on weed control. The herbicide was applied at 9 am and 4 pm in cropped and uncropped plots. Visual rating, after 15 days suggested better control in hand weeded plots. However, this may be due to the fact that the hand weeding, was performed later than the herbicide application. Herbicide treatment with unamended Roundup resulted in significantly better weed control than the amended Roundup plots. (author)

  20. Direct control of perennial weeds between crops - Implication for organic farming

    DEFF Research Database (Denmark)

    Melander, Bo; Holst, Niels; Rasmussen, Ilse Ankjær;

    2012-01-01

    Perennial weeds can be a major constraint to organic crop production and direct control actions applied between crops can then be necessary to reduce the problems. We conducted two experiments, one on a sandy loam and one on a sandy soil in Denmark, with the aim of studying the efficacy of...... ending the strategy with mouldboard ploughing in the succeeding spring. Grain yields did not differ among the treatments in the two experiments as a result of the generally high effectiveness exerted by the control strategies. Especially post-harvest control strategies based on rotating weed devices and...... mouldboard ploughing appear to be effective solutions against mixed stands of perennials on sandy soils but they do not comply with optimal nutrient management in organic cropping. Therefore, intensive autumn cultivation is only relevant where a perennial weed problem is uncontrollable by other means....

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    Brookes, Graham

    2014-01-01

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

  3. Effect of sprayer output volume and adjuvants on efficacy of clove oil for weed control in organic Vidalia sweet onion

    Science.gov (United States)

    Timely cultivation with a tine weeder is the primary tool for successful weed control in organic Vidalia® sweet onion, but conditions frequently arise that delay the initial cultivation. Weeds that emerge during the delay are not effectively controlled by cultivation and herbicides derived from nat...

  4. CONVISO® SMART – a new solution to control monocotyledonous and dicotyledonous weeds in ALStolerant sugar beets

    Directory of Open Access Journals (Sweden)

    Balgheim, Natalie

    2016-02-01

    Full Text Available CONVISO SMART is a new system to control monocotyledonous and dicotyledonous weeds in ALS-inhibitor tolerant sugar beets. This system consists of an ALS-inhibiting herbicide and a sugar beet variety which is tolerant against the complementary herbicide due to classic breeding mechanisms. The herbicide CONVISO is a combination of the two active ingredients foramsulfuron and thiencarbazonemethyl. Whereas foramsulfuron is the leaf active compound, thiencarbazone-methyl is leaf as well as soil active. The product will be formulated as an oily dispersion (OD. The registration was requested with an application rate of 1 x 1 l/ha or 2 x 0.5 l/ha in ALS-inhibitor tolerant sugar beets. Application should be done from BBCH 10 – 14 of the weeds, especially of Chenopodium album as well as from BBCH 12 – 18 of the sugar beet. The estimated introduction of this system on the German market will be 2018. CONVISO is well active against the most important weeds in sugar beets, including Polygonum and Chenopodium species. Furthermore several difficult to control weeds as Aethusa cynapium and Mercurialis annua will be controlled by CONVISO. The addition of special herbicides to control those difficult weeds will no longer be necessary. The tolerance of the variety against CONVISO is very strong, which will be shown by the results of the weed free selectivity trials. Due to the high tolerance of the variety against CONVISO and the not occurring of negative herbicide effects, the full yield potential can be utilized.

  5. Use of multicopy transposons bearing unfitness genes in weed control: four example scenarios.

    Science.gov (United States)

    Gressel, Jonathan; Levy, Avraham A

    2014-11-01

    We speculate that multicopy transposons, carrying both fitness and unfitness genes, can provide new positive and negative selection options to intractable weed problems. Multicopy transposons rapidly disseminate through populations, appearing in approximately 100% of progeny, unlike nuclear transgenes, which appear in a proportion of segregating populations. Different unfitness transgenes and modes of propagation will be appropriate for different cases: (1) outcrossing Amaranthus spp. (that evolved resistances to major herbicides); (2) Lolium spp., important pasture grasses, yet herbicide-resistant weeds in crops; (3) rice (Oryza sativa), often infested with feral weedy rice, which interbreeds with the crop; and (4) self-compatible sorghum (Sorghum bicolor), which readily crosses with conspecific shattercane and with allotetraploid johnsongrass (Sorghum halepense). The speculated outcome of these scenarios is to generate weed populations that contain the unfitness gene and thus are easily controllable. Unfitness genes can be under chemically or environmentally inducible promoters, activated after gene dissemination, or under constitutive promoters where the gene function is utilized only at special times (e.g. sensitivity to an herbicide). The transposons can be vectored to the weeds by introgression from the crop (in rice, sorghum, and Lolium spp.) or from planted engineered weed (Amaranthus spp.) using a gene conferring the degradation of a no longer widely used herbicide, especially in tandem with an herbicide-resistant gene that kills all nonhybrids, facilitating the rapid dissemination of the multicopy transposons in a weedy population. PMID:24820021

  6. Modeling and optimization of anaerobic codigestion of potato waste and aquatic weed by response surface methodology and artificial neural network coupled genetic algorithm.

    Science.gov (United States)

    Jacob, Samuel; Banerjee, Rintu

    2016-08-01

    A novel approach to overcome the acidification problem has been attempted in the present study by codigesting industrial potato waste (PW) with Pistia stratiotes (PS, an aquatic weed). The effectiveness of codigestion of the weed and PW was tested in an equal (1:1) proportion by weight with substrate concentration of 5g total solid (TS)/L (2.5gPW+2.5gPS) which resulted in enhancement of methane yield by 76.45% as compared to monodigestion of PW with a positive synergistic effect. Optimization of process parameters was conducted using central composite design (CCD) based response surface methodology (RSM) and artificial neural network (ANN) coupled genetic algorithm (GA) model. Upon comparison of these two optimization techniques, ANN-GA model obtained through feed forward back propagation methodology was found to be efficient and yielded 447.4±21.43LCH4/kgVSfed (0.279gCH4/kgCODvs) which is 6% higher as compared to the CCD-RSM based approach. PMID:27155267

  7. Weed Control in Maize-Cowpea Intercropping System Related to Environmental Resources Consumption

    Directory of Open Access Journals (Sweden)

    Hamdollah ESKANDARI

    2011-03-01

    Full Text Available A field experiment was carried out in Ramhormoz, Iran during the 2008-2009 growing season to investigate the effects of different planting pattern of intercropping on environmental resource consumption and weed biomass. A randomized complete block design (RCBD with three replications was employed to compare the treatments. Treatments included maize sole crop (M, cow pea sole crop (C, within row intercropping (I1, row intercropping (I2 and mix cropping (I3. The density of intercropping was according to replacement design (one maize replaced by three cow pea plants. The results showed that environmental resource consumption was significantly (P?0.05 affected by cropping system, where PAR interception, moisture and nutrients uptake were higher in intercropping systems compared to sole crop systems. Regarding to weed control, intercrops were more effective than sole crops and it was related to lower availability of environmental resources for weeds in intercropping systems.

  8. Chemical Control of Curled Dock (Rumex crispus L. and Other Weeds in Noncropped Areas

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2008-01-01

    Full Text Available Rumex crispus L. is an invasive species widespread in our country and in particular in the region of North Bulgaria. It is characterized by high biological and ecological plasticity. Owing to its great reproductive potential, the weed has been assigned to the list of economically most important weeds in the country. With the purpose of studying the possibility of chemical weed control in noncropped areas with heavy natural background infestation with R. crispus L. and other dicotyledonous weeds, two field trials were carried out. A ready-to-use herbicide mixture 2,4-D 140.2 g/l-1 + Triclopyr 144 g/l-1, trade product Genoxon 3X (X0050, was tested at two doses of active ingredient, 3552 and 2842 ml/ha-1. It was found that: (1 population density of Rumex crispus L. can be successfully reduced by treatment at the stage of early stem formation; herbicideefficacy with 3552 and 2882 ml/ha-1 doses on the 21st day after treatment was 100% and 90.5%, respectively, at the end of vegetation 94.4 and 85.7%, respectively; (2 herbicidal efficacy was lower when R. crispus L. was treated at the 5 - 6 leaf stage, being 100 – 94.1%and 80 – 76.5% respectively for the indicated doses and time of recording; (3 at the studied doses the herbicide controlled both annual dicotyledonous weeds (Amaranthus spp., Chenopodium album L., Portulaca oleracea L. and perennial dicotyledonous ones (Cirsiumarvense L., Sonchus arvensis L., Convolvulus arvensis L., Carduus acanthoides L., but it was not toxic to monocotyledonous weeds.

  9. Diversifying cereal-based rotations to improve weed control. Evaluation with the AlomySys model quantifying the effect of cropping systems on a grass weed

    Directory of Open Access Journals (Sweden)

    Colbach Nathalie

    2010-09-01

    Full Text Available Simplified rotations often select weed flora consisting of one or several dominant species. In rotations consisting mainly of winter cereals, one of the most frequent weeds in Atlantic European countries is blackgrass (Alopecurus myosuroides Huds.. In order to reduce environmental impacts and avoid the selection of herbicide-resistant populations, alternative weed management strategies are necessary. The objective of the present study was to develop a methodology for using a weed dynamics model called ALOMYSYS for evaluating prospective diversified crop rotations based on expert opinion. These prospective rotations were developed for a particular region aiming at reducing herbicide use while keeping weed infestation similar to that in current cropping systems. The prospective systems were also evaluated economically by calculating costs and margins for the farmer. The simulations showed that the more diverse the rotation, the better blackgrass was controlled and the less herbicides (rates and frequencies were necessary. Optimal herbicide spraying conditions and mouldboard ploughing were also less essential in diverse rotations. It was though essential to reason herbicide programs over the whole rotation and not simply as function of the preceding crop. The economic evaluation identified the interest of spring or winter pea either replacing or preceding oilseed rape (OSR in OSR/wheat/barley rotations.

  10. Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems

    Directory of Open Access Journals (Sweden)

    Vincenzo Tabaglio

    2013-02-01

    Full Text Available The allelopathic potential of rye (Secale cereale L. is mainly due to phytotoxic benzoxazinones, compounds that are produced and accumulated in young tissues to different degrees depending on cultivar and environmental influences. Living rye plants exude low levels of benzoxazinones, while cover crop residues can release from 12 to 20 kg ha–1. This paper summarizes the results obtained from several experiments performed in both controlled and field environments, in which rye was used as a cover crop to control summer weeds in a following maize crop. Significant differences in benzoxazinoid content were detected between rye cultivars. In controlled environments, rye mulches significantly reduced germination of some broadleaf weeds. Germination and seedling growth of Amaranthus retroflexus and Portulaca oleracea were particularly affected by the application of rye mulches, while Chenopodium album was hardly influenced and Abutilon theophrasti was advantaged by the presence of the mulch. With reference to the influence of agronomic factors on the production of benzoxazinoids, nitrogen fertilization increased the content of allelochemicals, although proportionally less than dry matter. The field trial established on no-till maize confirmed the significant weed suppressiveness of rye mulch, both for grass and broadleaf weeds. A significant positive interaction between nitrogen (N fertilization and notillage resulting in the suppression of broadleaf weeds was observed. The different behavior of the weeds in the presence of allelochemicals was explained in terms of differential uptake and translocation capabilities. The four summer weeds tested were able to grow in the presence of low amounts of benzoxazolin-2(3H-one (BOA, between 0.3 and 20 mmol g–1 fresh weight. Although there were considerable differences in their sensitivity to higher BOA concentrations, P. oleracea, A. retroflexus, and Ch. album represented a group of species with a consistent

  11. Effect of reduced doses of mesosulfuron + iodosulfuron to control weeds in no-till wheat under Mediterranean conditions

    Energy Technology Data Exchange (ETDEWEB)

    Barros, J. F. C.; Basch, G.; Freixial, R.; Carvalho, M.

    2009-07-01

    Field experiments were carried out over three years (2004-05, to 2006-07) to study the efficacy of a post-emergence dual-purpose herbicide (mesosulfuron - methyl (3%) + iodosulfuron - methyl - sodium (0.6%) + mefenpyr - diethyl (9%) to control Lolium rigidum Gaud. and broad-leaved weeds in no-till wheat (Triticum aestivum L.). A ready herbicide mixture was used at three doses (6+1.2, 9+1.8 and 12+2.4 g a.i. ha{sup 1}) on two dates (beginning of tillering for L. rigidum and 2-3 pair of leaves for broad-leaved weeds, and complete tillering for L. rigidum and 5-6 pair of leaves for broad-leaved weeds) with three different application volumes (100, 200 and 300 L ha{sup -}1). The results of the present study reveal that using lower than the recommended dose (12+2.4 g ha{sup -}1), the herbicide mixture controls L. rigidum better than it controls some broad-leaved weeds. Effective weed control, which was achieved mainly through the application at the first weed development stage, provided higher grain yields. The lower control efficacy of more developed L. rigidum and broad-leaved weeds and a longer period of competition between crop and weeds are responsible for the significantly lower crop yields for the delayed application. Within each application timing significant differences were obtained among the dose/volume combinations, with the exception of the first application regarding L. rigidum control, indicating that a reduction in herbicide dose is possible, but only for certain dose/volume combinations. Nonetheless, weed control was maintained across an array of dose/volume combinations, especially with L. rigidum, thus, our results demonstrate that reduced doses can effectively control weeds if applied early. (Author) 31 refs.

  12. Potential Use of Abrasive Air-Propelled Agricultural Residues for Weed Control

    Science.gov (United States)

    A new postemergence weed control tactic is proposed for organic production systems that results in plant abrasion and death upon assault from abrasive grits propelled by compressed air. Grit derived from granulated walnut shells was delivered by a sand blaster at 517 kPa at distances of 30 to 60 cm ...

  13. Status of biological control projects on terrestrial invasive alien weeds in California

    Science.gov (United States)

    In cooperation with foreign scientists, we are currently developing new classical biological control agents for five species of invasive alien terrestrial weeds. Cape-Ivy. A gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae, have been favorably reviewed by TAG...

  14. Weed Control and Peanut Tolerance with Ethalfluralin-Based Herbicide Systems

    OpenAIRE

    Grichar, W. J.; Dotray, P. A.

    2012-01-01

    Field studies were conducted from 2007 through 2009 to determine weed efficacy and peanut (Arachis hypogaea L.) response to herbicide systems that included ethalfluralin applied preplant incorporated. Control of devil's claw (Proboscidea louisianica (Mill.) Thellung), yellow nutsedge (Cyperus esculentus L.), Palmer amaranth (Amaranthus palmeri S. Wats.), and puncturevine (Tribulus terrestris L.) was most consistent with ethalfluralin followed by either imazapic or imazethapyr applied postemer...

  15. Impact and legacy of R. Charudattan in biological control of weeds

    Science.gov (United States)

    Raghavan “Charu” Charudattan is highly regarded internationally as a scientist, professor, mentor, and friend. Charu has authored four books, more than 100 refereed manuscripts, 24 book chapters, and hundreds of other publications. He holds 11 patents in the area of biological control of weeds and s...

  16. Impact and Legacy of Raghavan Charudattan in Biological Control of Weeds

    Science.gov (United States)

    Dr. Raghavan Charudattan has worked in the area of biological control of weeds with plant pathogenic fungi for nearly four decades. He has maintained his research program in this line throughout his career. The excellent scientific discoveries and contributions that he has made have been recognize...

  17. Enhanced s-triazine Degradation and Sugar Cane Weed Control Options

    Science.gov (United States)

    Soil borne bacteria on all continents except Antarctica have developed the ability to rapidly degrade the herbicide atrazine. Reduced residual weed control with atrazine in soils exhibiting enhanced degradation was confirmed under Mississippi Delta corn production and is expected to be occurring in...

  18. A sterile-female technique proposed for control of Striga hermonthica and other intractable weeds: Advantages, shortcomings, and risk management

    Science.gov (United States)

    Weeds have posed intractable challenges to farmers since the dawn of agriculture. This article describes in detail a proposed control strategy based on the introduction of genes conferring female-sterility into the genomes of intractable target weeds. Spread of these genes through target populations...

  19. EVALUATION OF TWO METHODS OF THERMAL WEED CONTROL IN FRUIT TREE ORCHARDS, PESTICIDE SPECIAL STUDY, COLORADO STATE UNIVERSITY

    Science.gov (United States)

    Research Objectives: 1) Compare the efficiency of two different types of thermal flamers: a direct flamer (Red Dragon, Inc., LaCrosse, Kansas) and a prototype infrared weed flamer (Sunburst, Inc., Eugene Oregon) in controlling weed populations in an apple orchard. 2) Determine ...

  20. Effects of Elimination of Alligator Weed on Certain Aquatic Plants and the Value of these Plants as Waterfowl Foods

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The effects of elimination of alligatorweed by granular silvex on the abundance of 12 species of aquatic plants were studied on the Santee National Wildlife Refuge,...

  1. Use of Essential Oils of Cinnamon, Lavender and Peppermint for Weed Control

    Directory of Open Access Journals (Sweden)

    Enio Campiglia

    Full Text Available The indiscriminate use of synthetic chemical compounds for weed control has been often responsible of damage to both the environment and the human health. To challenge these problems, in the last years research has increased its effort to find out alternative farming strategies. A feasible alternative could be the identification of natural substances with allelopathic effects for the realization of natural herbicides. Some research has already highlighted the possibility of using essential oils, extracted from aromatic plants, for weed control. The advantage in the utilization of such natural compounds is the quickly breaking down process into the environment and so the possible application in sustainable agriculture like organic farming. Objective of this research was the evaluation of the inhibition effect exerted by the essential oils of cinnamon, peppermint and lavender on seeds germination of some of the most common weeds species of the Mediterranean environment (pigweed, wild mustard and ryegrass. The results have highlighted a control in the weeds germination. Among the essential oils tested, cinnamon oil has exerted the highest inhibition effect compared with lavender and peppermint ones. The dicotyledonous species have been more susceptible compared with the monocotyledonous, even if it has been recorded only for redroot pigweed a dose able to inhibit totally the seed germination.

  2. Humic substances and its distribution in coffee crop under cover crops and weed control methods

    Directory of Open Access Journals (Sweden)

    Bruno Henrique Martins

    2016-08-01

    Full Text Available ABSTRACT Humic substances (HS comprise the passive element in soil organic matter (SOM, and represent one of the soil carbon pools which may be altered by different cover crops and weed control methods. This study aimed to assess HS distribution and characteristics in an experimental coffee crop area subjected to cover crops and cultural, mechanical, and chemical weed control. The study was carried out at Londrina, in the state of Paraná, southern Brazil (23°21’30” S; 51°10’17” W. In 2008, seven weed control/cover crops were established in a randomized block design between two coffee rows as the main-plot factor per plot and soil sampling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm as a split-plot. HS were extracted through alkaline and acid solutions and analyzed by chromic acid wet oxidation and UV-Vis spectroscopy. Chemical attributes presented variations in the topsoil between the field conditions analyzed. Cover crop cutting and coffee tree pruning residues left on the soil surface may have interfered in nutrient cycling and the humification process. Data showed that humic substances comprised about 50 % of SOM. Although different cover crops and weed control methods did not alter humic and fulvic acid carbon content, a possible incidence of condensed aromatic structures at depth increments in fulvic acids was observed, leading to an average decrease of 53 % in the E4/E6 ratio. Humin carbon content increased 25 % in the topsoil, particularly under crop weed-control methods, probably due to high incorporation of recalcitrant structures from coffee tree pruning residues and cover crops.

  3. Organic weed conrol and cover crop residue integration impacts on weed control, quality, and yield and economics in conservation tillage tomato - A case study

    Science.gov (United States)

    The increased use of conservation tillage in vegetable production requires more information be developed on the role of cover crops in weed control, tomato quality and yield. Three conservation-tillage systems utilizing crimson clover, brassica and cereal rye as winter cover crops were compared to ...

  4. Organic weed conrol and cover crop residue integration impacts on weed control, quality, and yield and economics in conservation tillage tomato- A case study

    Science.gov (United States)

    The increased use of conservation tillage in vegetable production requires more information be developed on the role of cover crops in weed control, tomato quality and yield. Three conservation-tillage systems utilizing crimson clover, brassica and cereal rye as winter cover crops were compared to ...

  5. Evaluation of the Use of Rice Bran Compost for Eco-friendly Weed Control in Organic Farming Systems

    OpenAIRE

    Khan, M. A. I.; Ueno, K; S. Horimoto; F. Komai; Tanaka, K; Ono, Y

    2007-01-01

    Rice bran compost (RC) was evaluated under greenhouse and field conditions for eco-friendly weed control of vegetable crops in organic farming systems. RC was applied 7 days before spinach seed sowing, at the rate of 0% (control), 10%, 20% and 30% of soil (v/v) in the greenhouse and 2 kg m-2 under field conditions. RC significantly controlled the number and dry weight of weeds, and the weed control potentiality was increased by the increased application of RC in both years. The efficacy of RC...

  6. Weed Control and Grain Sorghum (Sorghum bicolor) Tolerance to Pyrasulfotole plus Bromoxynil

    OpenAIRE

    Dan D. Fromme; Peter A. Dotray; W. James Grichar; Fernandez, Carlos J.

    2012-01-01

    Field studies were conducted during the 2008 and 2009 growing seasons at five locations in the Texas grain sorghum producing regions to evaluate pyrasulfotole plus bromoxynil combinations for weed control and grain sorghum response. All pyrasulfotole plus bromoxynil combinations controlled Amaranthus palmeri, Cucumis melo, and Proboscidea louisianica at least 94% while control of Urochloa texana was never better than 69%. Pyrasulfotole plus bromoxynil combinations did result in early season c...

  7. Reduced Chemical Weed Control Options in Virginia for Corn and Turfgrass and Characterization of Sorghum halepense Expressing Multiple Resistance to Nicosulfuron and Glyphosate

    OpenAIRE

    Smith, Adam N.

    2014-01-01

    Sustainable weed control in managed agricultural systems requires the judicious use of multiple weed control tactics and prevents over-reliance on any one tactic. In this context, sustainable weed management plays a critical role in the mitigation of one of agriculture's most pressing problems- herbicide resistance. Research conducted in Virginia sought to explore the effects of integrating multiple weed management tactics in corn and cool-season turfgrass. Additionally, research was conducte...

  8. The effects of cover crop on weed control in collard (Brassica olerecea var acephala) and lettuce (Lactuca sativa L.).

    Science.gov (United States)

    Mennan, H; Ngouajio, M; Isik, D; Kose, B; Kaya, E

    2006-01-01

    Leafy vegetables are not very competitive and weed interference can cause considerable yield losses in collard (Brassica olerecea var acephala) and lettuce (Lactuca sativa L.). Currently there are no pre or post emergence herbicides registered for weed control in these vegetables in Turkey. For this reason, alternative weed control strategies need to be developed. Cover crop residue could represent an alternative method of weed management in these crops. Field studies were conducted in 2004 at the Black Sea Agricultural Research Institute experimental field in Samsun, Turkey. The cover crop treatments consisted of Sorghum bicolor (L.) Moench, Sorghum vulgare Pers., Vicia villosa L., Amaranthus cruentus L., Pisum sativum L. and the bare ground with no cover crop. All cover crops were seeded by hand and incorporated into the soil on 11 May, 2004. Each plot was 10 m2 (2 x 5 m) and arranged in a randomized complete block design with four replications. All cover crops were incorporated into the soil by discing on 1 September 2004 at flowering stage of the cover crops. Broadleaved weed species were dominant in the experimental area. Most cover crops established well and S. bicolor biomass was the highest. The number of weed species emerging in all treatments was different at 14 DAD (days after desiccation). Similar results were observed at 28 and 56 DAD. Treatments with Vicia villosa residues had fewer weed species and lower total weed densities than other treatments. PMID:17390812

  9. Integrated control of annual weeds by inter-row hoeing and intra-row herbicide treatment in spring oilseed rape

    Directory of Open Access Journals (Sweden)

    Nilsson, Anders

    2014-02-01

    Full Text Available The aim of this project is to develop an integrated weed control strategy against annual weeds in spring oilseed rape by means of a combined mechanical and chemical weed control which will be performed concurrently and separately. The project encompasses field experiments in which different combinations of inter-row hoeing and intra-row herbicide treatments will be evaluated and compared to conventional weed control treatments with broadcast spraying of herbicides, and experiments in which an implement for concurrent inter-row hoeing and intra-row herbicide treatment will be refined and evaluated. In 2012, an implement for intra-row spraying combined with row hoeing was developed and evaluated in two field experiments in spring oilseed rape in the southern part of Sweden. The effects of inter-row hoeing, intra row spraying, and combination of the two methods were compared with conventional broadcast spraying. Preliminary results showed that the best weed control effects were obtained with the combination of inter-row hoeing and intra-row spraying in both experiments. Regarding crop yield, the yield was significantly higher in the combined treatment in one of the experiments while no effects on the yields were obtained in the other experiment. We envisage that the inter-row hoeing and intra-row herbicide treatment will diminish the overall use of herbicides to less than one third in comparison with the more conventional chemical weed control methods, while having the same weed control effect.

  10. Strip Tillage and Early-Season Broadleaf Weed Control in Seeded Onion (Allium cepa

    Directory of Open Access Journals (Sweden)

    Sarah Gegner-Kazmierczak

    2016-03-01

    Full Text Available Field experiments were conducted in 2007 and 2008 near Oakes, North Dakota (ND, USA, to evaluate if strip tillage could be incorporated into a production system of seeded onion (Allium cepa to eliminate the standard use of a barley (Hordeum vulgare companion crop with conventional, full width tillage, yet support common early-season weed control programs. A split-factor design was used with tillage (conventional and strip tillage as the main plot and herbicide treatments (bromoxynil, DCPA, oxyfluorfen, and pendimethalin as sub-plots. Neither tillage nor herbicide treatments affected onion stand counts. Common lambsquarters (Chenopodium album densities were lower in strip tillage compared to conventional tillage up to three weeks after the post-emergence applied herbicides. In general, micro-rate post-emergence herbicide treatments provided greater early-season broadleaf weed control than pre-emergence herbicide treatments. Onion yield and grade did not differ among herbicide treatments because the mid-season herbicide application provided sufficient control/suppression of the early-season weed escapes that these initial weed escapes did not impact onion yield or bulb diameter. In 2007, onion in the strip tillage treatment were larger in diameter resulting in greater total and marketable yields compared to conventional tillage. Marketable onion yield was 82.1 Mg ha−1 in strip tillage and 64.9 Mg ha−1 in conventional tillage. Results indicate that strip tillage use in direct-seeded onion production was beneficial, especially when growing conditions were conducive to higher yields and that the use of strip tillage in onion may provide an alternative to using a companion crop as it did not interfere with either early-season weed management system.

  11. Foliar Potassium Fertilizer Additives Affect Soybean Response and Weed Control with Glyphosate

    Directory of Open Access Journals (Sweden)

    Kelly A. Nelson

    2012-01-01

    Full Text Available Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S, 0-0-25-17, 3-18-18-0, and 5-0-20-13 and additive rates (2.2, 8.8, and 17.6 kg K ha−1 on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1 in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1 in a low-yield year (2005 depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1 compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K (P=0.03, S (P=0.03, B (P=0.0001, and Cu (P=0.008 concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.

  12. Manejo de plantas daninhas na cultura do mamoeiro Weed control in papaya

    Directory of Open Access Journals (Sweden)

    C.P. Ronchi

    2008-01-01

    Full Text Available Apesar de o controle de plantas daninhas na cultura do mamoeiro representar um dos componentes de grande importância do custo de produção, no mundo e no Brasil, a disponibilidade de informações sobre esse tema é escassa, o que reflete a pouca importância que tem sido dada ao assunto nas últimas décadas. Neste texto são discutidos alguns avanços no manejo integrado de plantas daninhas que têm sido alcançados em vários países, particularmente no tocante à manutenção da vegetação natural ou à introdução de leguminosas na entrelinha de cultivo. Não obstante, várias espécies de plantas daninhas foram identificadas como hospedeiras de vetores de importantes viroses à cultura, com destaque para Commelina benghalensis e Solanum americanum. Isso se reveste de grande importância para o manejo (seletivo das plantas daninhas, sobretudo na produção integrada de mamão. Também são discutidos, em especial para a região norte do Estado do Espírito Santo, a seletividade de herbicidas, os períodos de controle e as principais características e aspectos práticos sobre o manejo de plantas daninhas na cultura do mamoeiro.Despite the fact that weed control entails high costs to crop production, the availability of national and international papers regarding papaya weed control is scarce, showing that little importance has been given to this subject in the last decades. Some integrated weed management advances attamed in several countries are discussed, particularly in the use of both natural groundcover or leguminous plants in the crop interrows. However, several weed species have been identified as host plants of major virus vectors to the crop, such as C. benghalensis and S. americanum. Such information is of major importance for selective weed control, particularly in the integrated system of papaya production. The present review also examined herbicide selectivity, weedy periods as well as the main characteristics and practical

  13. Long-term benefits to the growth of ponderosa pines from controlling southwestern pine tip moth (Lepidoptera: Tortricidae) and weeds.

    Science.gov (United States)

    Wagner, Michael R; Chen, Zhong

    2004-12-01

    The southwestern pine tip moth, Rhyacionia neomexicana (Dyar) (Lepidoptera: Tortricidae), is a native forest pest that attacks seedlings and saplings of ponderosa pine, Pinus ponderosa Dougl. ex Laws, in the southwestern United States. Repeated attacks can cause severe deformation of host trees and significant long-term growth loss. Alternatively, effective control of R. neomexicana, vegetative competition, or both in young pine plantations may increase survival and growth of trees for many years after treatments are applied. We test the null hypothesis that 4 yr of R. neomexicana and weed control with insecticide, weeding, and insecticide plus weeding would not have any residual effect on survival and growth of trees in ponderosa pine plantation in northern Arizona 14 yr post-treatment, when the trees were 18 yr old. Both insecticide and weeding treatment increased tree growth and reduced the incidence of southwestern pine tip moth damage compared with the control. However, weeding alone also significantly increased tree survival, whereas insecticide alone did not. The insecticide plus weeding treatment had the greatest tree growth and survival, and the lowest rate of tip moth damage. Based on these results, we rejected our null hypothesis and concluded that there were detectable increases in the survival and growth of ponderosa pines 14 yr after treatments applied to control R. neomexicana and weeds. PMID:15666752

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

    Directory of Open Access Journals (Sweden)

    Michele Perniola

    2008-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Vittorio Filì

    2011-02-01

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

  16. Studies on the efficacy of the controlled-release formulations of herbicides against weeds in transplanted rice

    International Nuclear Information System (INIS)

    Weed control efficacy of controlled-release (CR) formulations of thiobencarb and butachlor were compared with the commercial formulations of these herbicides in transplanted rice field experiments during 1990, 1991 and 1992. The controlled-release formulations comprised i) herbicides uniformly dispersed in a mixture of calcium alginate and kaolin and ii) herbicides absorbed on corn cob granules which were then coated with a mixture of polyvinyl acetate (PVA) and polyoxyethylene glycol (PEG). Some of the alginate formulations also contained sand. The herbicides were applied at three different rates of 1.50, 1.05 and 0.75 kg a.i/ha 3-4 days after transplanting. The weed control efficacy was directly related to the rate of application of the herbicide and this in turn resulted into relevant increase in the grain yield. The control of weeds by hand weeding or by the application of the herbicides resulted in significantly higher yield of the rice grain than the control plots. On the other hand, there was no significant difference in the yield of the rice grain from hand weeding or the use of herbicides. There was also no significant difference between the increase in the grain yield resulting from the use of the commercial or the controlled-release formulations and both type of formulations provided equally good weed control. (author). Abstract only

  17. Influences of different control periods and coexistence with weed in eucalyptus

    Directory of Open Access Journals (Sweden)

    Eduardo Kneipp Londero

    2012-09-01

    Full Text Available This work studied the periods of control and coexistence of weeds with eucalyptus culture. The experiment was led in Candiota, RS, in the period from January to December, 2006. The treatments consisted of different control times and coexistence of the culture, these periods were divided in two groups; one was to determine the Period Previous to the Interference (PPI and the other to define the Total Period of Prevention of the Interference (TPFI. In the two groups the tested periods were: 00, 28, 56, 84, 112, 140, 168, 210, 252, 294 and 336 days. The young trees of eucalyptus were susceptible to weed, presenting a period previous to the interference of 56 days. In order to guarantee its largest production, the total period of prevention of the interference was 140 days and the period previous to the interference was of 56 days.

  18. WEED CONTROL IN GENETICALLY MODIFIED GLYPHOSATE-TOLERANT SOYBEAN MANEJO DE PLANTAS DANINHAS EM SOJA GENETICAMENTE MODIFICADA TOLERANTE AO GLYPHOSATE

    OpenAIRE

    Júlio Cezar Durigan; Núbia Maria Correia; Melina Espanhol

    2011-01-01

    The transgenic production systems, as well as conventional systems, require, in addition to chemical control, the adoption of other weed management strategies. This study was developed to evaluate the weed chemical control in glyphosate tolerant soybean, associated to cover crops cultivated in the autumn/winter. The experiment was carried out under field conditions at the FCAV/Unesp, Jaboticabal, São Paulo State, Brazil. A randomized split-plot block design was used, with four replications. S...

  19. The use of desalinated-dried jellyfish and rice bran for controlling weeds and rice yield

    OpenAIRE

    Hossain, Shaikh Tanveer; Sugimoto, Hideki; Asagi, N.; Araki, T; Ueno, H; Morokuma, M.; Kato, H.

    2013-01-01

    To achieve higher rice production, rice-growing countries have used great amounts of synthetic chemical compounds (chemical fertilizers and pesticides) that can have adverse effects on the environment and humans. Organic products and organic farming technologies are friendlier to the environment and more conducive to sustainable agriculture but require different inputs, knowledge and skills. Weed control is one of the major challenges in organic rice cultivation. The present study proposes an...

  20. Chemigation for Control of Black Shank-Root-knot Complex and Weeds in Tobacco

    OpenAIRE

    Johnson, A. W.; Csinos, A.S.; Golden, A. M.; Glaze, N. C.

    1992-01-01

    Tank mixes of a fungicide (metalaxyl) and a nematicide (fenamiphos) with herbicides (isopropalin or pendimethalin) and an insecticide (chlorpyrifos) were applied by soil incorporation or irrigation to control the black shank-root knot complex and weeds on four tobacco cultivars. The disease complex was more severe on cultivars McNair 944, NC-2326, and K-326 than on Speight G-70. The disease complex was reduced (P ≤ 0.05) on all cultivars with the pesticide combinations containing metalaxyl + ...

  1. Research on the weed control degree and glyphosate soil biodegradation in apple plantations (Pioneer variety)

    OpenAIRE

    Alexa, Ersilia; Roxana MICU; Monica NEGREA; Renata SUMALAN; Olimpia IORDANESCU

    2010-01-01

    In this study we follow control degree of glyphosate herbicide on weeds in apple plantations (Pioneer variety) of the Research Station Timisoara. It was also followed glyphosate biodegradation capacity in the soil by determining the amount of CO2 released by the action of microorganisms on C14 glyphosate marked isotope. Laboratory analysis of glyphosate residues in soil was made using a Liquid Scintillation TRIATHLER. Glyphosate biodegradation ability in the presence of soil microorganisms is...

  2. Strip Tillage and Early-Season Broadleaf Weed Control in Seeded Onion (Allium cepa)

    OpenAIRE

    Sarah Gegner-Kazmierczak; Harlene Hatterman-Valenti

    2016-01-01

    Field experiments were conducted in 2007 and 2008 near Oakes, North Dakota (ND), USA, to evaluate if strip tillage could be incorporated into a production system of seeded onion (Allium cepa) to eliminate the standard use of a barley (Hordeum vulgare) companion crop with conventional, full width tillage, yet support common early-season weed control programs. A split-factor design was used with tillage (conventional and strip tillage) as the main plot and herbicide treatments (bromoxynil, DCPA...

  3. Tree shelters and weed control enhance growth and survival of natural blue oak seedlings

    OpenAIRE

    McCreary, Douglas D.; Tietje, William; Davy, Josh; Larsen, Royce E.; Doran, Morgan; Flavell, Dustin; Garcia, Sergio

    2011-01-01

    Blue oak is regenerating poorly in portions of its range. Techniques to artificially regenerate trees by collecting acorns, growing seedlings in a nursery and then planting them are effective but costly. Improving the growth and survival rate of existing volunteer seedlings in woodlands could be more cost efficient and therefore more widely used. We tested tree shelters and weed control treatments over 3 years at six woodland sites to evaluate whether they helped blue oak seedlings grow into ...

  4. Field plot test of efficacy of thiobencarb formulations for weed control in direct seeded rice

    International Nuclear Information System (INIS)

    Experiments were conducted in field plots in Tanjung Karang rice growing are to study the effect of the timing of application and type of formulation of thiobencarb herbicide on the control of weeds, especially Echinochloa crusgalli. The area selected has a history of heavy weed infestation in farmers fields. In these tests the performance of a commonly used commercial thiobencarb formulation, SaturnR was compared with that of a controlled-release (CR) formulation. These contained 5.0 and 7.56% thiobencarb, respectively. The CR formulation had the herbicide uniformly dispersed in a mixture of calcium alginate and kaolin. The herbicide was applied at 6 and 1 day before direct sowing (DBS) of the rice seeds at 60 kg/ha rate. The herbicide formulations were applied singly or as a 50/50 mixture to deliver 0.75 or 1.50 kg a.i./ha. The effect of the treatments on the number and growth of weed plants, the growth parameters of the rice plants and the rice grain yield was determined. SaturnR at 1.5 kg/ha, CR formulation at 0.75 kg/ha and hand weeding were most effective in controlling the number of E. crusgalli plants. There was no significant difference between the formulations or the rates used regarding their effect on the growth of the rice plants. The highest rice grain yield was recorded from the plots treated with the CR formulation at 1.5 kg/ha. The CR formulation was also very effective at 0.75 kg/ha rate and the rice grain yield was recorded from the plots receiving this treatment was much greater than those treated with a similar rate of the commercial formulation. (author). 5 tabs

  5. Controle de plantas daninhas na cultura da batata Potato weed control by application of herbicides

    Directory of Open Access Journals (Sweden)

    Jeferson Zagonel

    1999-03-01

    Full Text Available O experimento foi conduzido na Fazenda Escola da UEPG, em Ponta Grossa-PR, em Latossolo Vermelho Escuro de textura média argilosa, com o objetivo de verificar a praticabilidade e a eficiência agronômica dos herbicidas metolachlor e metribuzin + metolachlor no controle de plantas daninhas na cultura da batata. O delineamento experimental foi de blocos ao acaso com nove tratamentos e quatro repetições, quais sejam: metolachlor (1,92; 2,88 e 3,84 kg i.a./ha; metribuzin + metolachlor (0,24 + 1,68; 0,36 + 2,52 e 0,48 + 3,36 kg i.a./ha; metribuzin (0,48 kg i.a./ha; testemunha capinada e testemunha sem capina. O plantio foi realizado em outubro/95 utilizando-se a cultivar Elvira, no espaçamento 0,70 x 0,35 m. As plantas daninhas predominantes foram Brachiaria plantaginea (capim-papuã, Digitaria horizontalis (capim-milhã e Galinsoga parviflora (fazendeiro. As avaliações foram efetuadas aos 15, 30 e 45 dias após a aplicação dos tratamentos onde verificou-se que foram eficientes os seguintes herbicidas: metolachlor no controle sobre capim-papuã e capim-milhã nas doses de 2,88 e 3,84 kg i.a./ha; a mistura metribuzin + metolachlor no controle sobre capim-papuã e capim-milhã nas doses 0,36 + 2,52 e 0,48 + 3,36 kg i.a./ha; metolachlor (1,92; 2,88 e 3,84 kg i.a./ha e metribuzin + metolachlor (0,24 + 1,68; 0,36 + 2,52 e 0,48 + 3,36 kg i.a./ha no controle sobre fazendeiro. Não foram observados efeitos fitotóxicos dos produtos sobre as plantas de batata.The presented field trial was conducted at the Universidade Estadual de Ponta Grossa, Paraná State, Brazil, on a Dark Red Latossoil, to evaluate the availability and efficiency of herbicides metolachlor and metribuzin + metolachlor in the control of weeds in the potato crop. The experiment was laid out in a randomized block design with nine treatments and four replications as follows: metolachlor (1.92; 2.88 and 3.84 kg a.i/ha; metribuzin + metolachlor (0.24 + 1.68; 0.36 + 2.52 and 0.48 + 3

  6. Control of an Autonomous Vehicle for Registration of Weed and Crop in Precision Agriculture

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Mølgaard; Andersen, Palle; Pedersen, Tom Søndergaard;

    2002-01-01

    The paper describes the development of an autonomous electrical vehicle to be used for weed mapping in precision agriculture with special focus on the conceptual framework of the control system. The lowest layer of the control system is the propulsion and steering control, the second layer...... coordinates the movements of the wheel units, the third layer is path execution and perception and the upper layer performs planning and reasoning. The control system is implemented on an autonomous vehicle. The vehicle has been tested for path following and position accuracy. Based on the results a new...... vehicle is under construction....

  7. Phytotoxic potential of Drimys brasiliensis Miers for use in weed control

    Directory of Open Access Journals (Sweden)

    Simoni Anese

    2015-10-01

    Full Text Available This study aims to evaluate the phytotoxicity potential of leaf and root extracts of Drimys brasiliensis on the germination and seedling growth of Panicum maximum and Euphorbia heterophylla and its influence on metaxylem cell size in the seedling roots of the latter specie. The leaf and root extracts were fractionated by partition chromatography, and the hexane and ethyl acetate fractions obtained from each organ were evaluated at different concentrations for phytotoxic activity in several bioassays. In seedling growth tests, we compared the effects of these fractions with the herbicide oxyfluorfen. The hexane fraction of the root extracts showed a higher inhibitory potential on the germination and growth of weeds and reduced the average size of the metaxylem cells of E. heterophylla roots by more than 50%.The inhibitory effects of the root hexane fraction on seedling growth was similar to the herbicide, indicating that D. brasiliensis is a possible alternative form of control for the weed species examined.

  8. Field sprayer for inter and intra-row weed control: performance and labor savings

    Directory of Open Access Journals (Sweden)

    J. Carballido

    2013-07-01

    Full Text Available Studies of new tools and methods for weed control have been motivated by increased consumer demand for organic produce, consumer and regulatory demands for a reduction in environmentally harmful herbicide use, and the decreased availability of farm workers willing to perform manual tasks, such as hand weeding. This study describes the performance of a new sprayer system for commercial production that integrates two herbicide applications in a single pass, selective herbicide (SH application in narrow bands over the crop row, and a non-selective herbicide (NSH application between crop rows. A real-time kinematic (RTK global positioning system (GPS was used for auto-guidance in seeding and spraying operations. Conventional broadcast SHs and experimental treatments were applied at a constant nominal speed of 5.5 km h-1 for comparison. Trials in commercial sugar beet fields demonstrated the following: (i average hand-weeding time can be reduced by 53% (ii the new sprayer system reduced SH use by 76%, and (iii sugar beet density did not change significantly during treatment. These results demonstrate the feasibility of using the new RTK-GPS controller sprayer system for differential and efficient herbicide application in inter- and intra-row zones in row crop production.

  9. Investigation of uranium accumulation potential and biochemical responses of an aquatic weed Hydrilla verticillata (L.f.) Royle.

    Science.gov (United States)

    Srivastava, Sudhakar; Bhainsa, K C; D'Souza, S F

    2010-04-01

    The uranium (U) accumulation potential and ensuing biochemical responses were studied in Hydrilla verticillata (L.f.) Royle upon exposure to U (0, 20 and 100 mg L(-1)). There was a concentration-duration dependent increase in U accumulation with the maximum being 78 mg g(-1) DW at 100 mg L(-1) U after 24 h. Plants experienced an initial phase of the maximum toxicity (within 30 min) followed by almost complete recovery after 24 h. The recovery was attributed to an integrated modulation in the level of both enzymatic and molecular antioxidants (viz., guaiacol peroxidase, ascorbate peroxidase, catalase, proline, total phenolics) and also the constituents of thiol metabolism (viz., cysteine and glutathione). Thus, plants were found to be able to accumulate significant amount of U in a short time and to tolerate it efficiently. Hence, they may find application in U phytoremediation considering there accumulation ability, fast growth due to weed-like habit and world-wide distribution. PMID:19939677

  10. Evaluation of the Use of Rice Bran Compost for Eco-friendly Weed Control in Organic Farming Systems

    Directory of Open Access Journals (Sweden)

    M. A.I. Khan

    2007-01-01

    Full Text Available Rice bran compost (RC was evaluated under greenhouse and field conditions for eco-friendly weed control of vegetable crops in organic farming systems. RC was applied 7 days before spinach seed sowing, at the rate of 0% (control, 10%, 20% and 30% of soil (v/v in the greenhouse and 2 kg m-2 under field conditions. RC significantly controlled the number and dry weight of weeds, and the weed control potentiality was increased by the increased application of RC in both years. The efficacy of RC in reducing weed emergence and dry weight of broadleaf species was higher than grass weeds. Among the broad leaf weeds, Lamium amplexicaule L was the most sensitive to RC and was drastically reduced by the increased application of RC. Under field conditions, the total number of weeds and the dry weight of weeds were also significantly reduced with the application of RC, compared with the untreated control. The growth inhibition potentiality of water soluble fractions of RC was also tested with seed germination and radicle elongation of test species (barley, oat, tomato and lettuce. The concentration response curves for the test species were drawn by plotting the percentage of germination against the logarithm of the concentration. Considering the I25 value (defined as 25% inhibition of control both for seed germination and radicle elongation, it was indicated that water soluble fractions of RC was more effective in the suppression of dicotyledonous species (tomato and lettuce than monocotyledonous species (barley and oat. The results of the preliminary experiment with fresh rice bran under greenhouse conditions showed that fresh bran suppressed spinach seed germination when applied as 10% rice bran in soil but RC did not show a significantly negative effect up to 20% RC application, compared with the control. Moreover, RC enhanced spinach growth. Considering both the weed control potentiality and spinach growth enhancing ability of RC, the effective

  11. Spring-Interseeded Winter Rye Seeding Rates Influence Weed Control and Organic Soybean Yield

    Directory of Open Access Journals (Sweden)

    Kelly A. Nelson

    2011-01-01

    Full Text Available Field research in 2002 and 2003 evaluated spring-interseeded winter rye (Secale cereale L. at 67, 134, or 200 kg ha−1 at two soybean (Glycine max (L. Merr. row spacings (19- and 76-cm on weed control, yield, and gross margins. Based on regression analysis, wide-row (76-cm soybean grain yield and gross margins were greatest when winter rye was interseeded at 114 and 106 kg ha−1, respectively. Yields and gross margins for wide-row soybean were 8 to 55% greater than narrow-row (19-cm soybean seeded at 494,000 or 742,000 seeds ha−1 which was probably due to flexibility for implementing cultivation. As interseeded rye rates increased from 67 to 200 kg ha−1, yields and gross margins for narrow-rows decreased. Soybean row spacing had minimal impacts on specific weed species and total weed biomass or density. The use of wide-row soybean and spring-interseeded rye at 67 kg ha−1 was more cost-effective compared to narrow rows.

  12. Herbicides as weed control agents: state of the art: II. Recent achievements.

    Science.gov (United States)

    Kraehmer, Hansjoerg; van Almsick, Andreas; Beffa, Roland; Dietrich, Hansjoerg; Eckes, Peter; Hacker, Erwin; Hain, Ruediger; Strek, Harry John; Stuebler, Hermann; Willms, Lothar

    2014-11-01

    In response to changing market dynamics, the discovery of new herbicides has declined significantly over the past few decades and has only seen a modest upsurge in recent years. Nevertheless, the few introductions have proven to be interesting and have brought useful innovation to the market. In addition, herbicide-tolerant or herbicide-resistant crop technologies have allowed the use of existing nonselective herbicides to be extended into crops. An increasing and now major challenge is being posed by the inexorable increase in biotypes of weeds that are resistant to herbicides. This problem is now at a level that threatens future agricultural productivity and needs to be better understood. If herbicides are to remain sustainable, then it is a must that we adopt diversity in crop rotation and herbicide use as well as increase the use of nonchemical measures to control weeds. Nevertheless, despite the difficulties posed by resistant weeds and increased regulatory hurdles, new screening tools promise to provide an upsurge of potential herbicide leads. Our industry urgently needs to supply agriculture with new, effective resistance-breaking herbicides along with strategies to sustain their utility. PMID:25104721

  13. Herbicides as Weed Control Agents: State of the Art: II. Recent Achievements[C

    Science.gov (United States)

    Kraehmer, Hansjoerg; van Almsick, Andreas; Beffa, Roland; Dietrich, Hansjoerg; Eckes, Peter; Hacker, Erwin; Hain, Ruediger; Strek, Harry John; Stuebler, Hermann; Willms, Lothar

    2014-01-01

    In response to changing market dynamics, the discovery of new herbicides has declined significantly over the past few decades and has only seen a modest upsurge in recent years. Nevertheless, the few introductions have proven to be interesting and have brought useful innovation to the market. In addition, herbicide-tolerant or herbicide-resistant crop technologies have allowed the use of existing nonselective herbicides to be extended into crops. An increasing and now major challenge is being posed by the inexorable increase in biotypes of weeds that are resistant to herbicides. This problem is now at a level that threatens future agricultural productivity and needs to be better understood. If herbicides are to remain sustainable, then it is a must that we adopt diversity in crop rotation and herbicide use as well as increase the use of nonchemical measures to control weeds. Nevertheless, despite the difficulties posed by resistant weeds and increased regulatory hurdles, new screening tools promise to provide an upsurge of potential herbicide leads. Our industry urgently needs to supply agriculture with new, effective resistance-breaking herbicides along with strategies to sustain their utility. PMID:25104721

  14. Biological control of weeds release sites : Kulm Wetland Management District

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Table of release sites of insects for biological control of invasive plants at Kulm Wetland Management District (WMD). Insects were released on Kulm WMD to...

  15. Root growth potential and weed control effects on the first year growth of pitch x loblolly pine (Pinus ridiga x P. taeda L.) and loblolly pine

    OpenAIRE

    Barnes, Andrew D.

    1989-01-01

    The study was initiated to determine the effects of RGP and three levels on weed control: no weed control (control), herbaceous weed control (Oust), and woody and herbaceous weed control (Oust-Garlon) on three pine seedlots: pitch x loblolly pine hybrid (pxL-F2), Virginia Department of Forestry loblolly pine (VDF-Iob), and westvaco loblolly pine (WCO-Iob). Lateral roots had the greatest response to the Oust treatment compared to all other seedling parts. All seedlot and treatment interacti...

  16. Studies on weeds and their control possibilities of second crop soybean fields in Mediterranean Region.

    OpenAIRE

    Uluğ, E.; Kadıoğlu, İ.

    2009-01-01

    In 1984-1986, a survey was carried out to determine weed species, density and widespread in second crop soybean  fields in Adana, Antalya, Hatay, İçel, Kahramanmaraş provinces. The possibilities of the most effective control measures were also studied with various chemical and mechanical control methods; and then studied on soybean yield and rotation crop wheat. According to the results of survey; in the second crop soybean fields in desity in Adana, nudsedge species (Cyperus rotundus L...

  17. VALIDATION OF EMBRYO TESTS FOR DETERMINING EFFECTS OF FUNGAL PEST CONTROL AGENTS ON NONTARGET AQUATIC ANIMALS

    Science.gov (United States)

    Developing embryos of the inland silverside fish Menidia beryllina and grass shrimp Palaemonetes pugio were exposed to conidiospores of the fungal weed control agent, Colletotrichum gloeosporioides, f. sp. aeschynomene, and the entomopathogen, Metarhizium anisopliae. nly Metarhiz...

  18. Safe, Effective Use of Pesticides, A Manual for Commercial Applicators: Aquatic Pest Control.

    Science.gov (United States)

    Extension Service (USDA), Washington, DC.

    This manual is intended to assist pesticide applicators in the area of aquatic pest control meet the requirements of the Michigan Department of Agriculture for certification. The Environmental Protection Agency (EPA) Aquatic Pest Control Guide served as a basis for this manual. The six sections presented describe: (1) Aquatic pest control; (2)…

  19. Weed Control and Grain Yield in Double-Cropped Soybean

    Directory of Open Access Journals (Sweden)

    Milena Simić

    2008-01-01

    Full Text Available The effects of different herbicide combinations: control (1, alachlor+linuron (2, and alachlor+linuron+imazethapyr (3 were investigated in double-cropped soybean grown in two row spacing variants, 38 cm and 76 cm, under conventional tillage (CT or no-tillage (NT. In trials conducted on a sandy loam soil at Zemun Polje, high weediness had a negative effect of on the yield of double-cropped soybean, especially at the higher row spacing tested and with no-tillage.Regression and correlation data revealed a dependence of weediness in double-cropped soybean on tillage system and herbicide combination, and dependence of soybean yield on tillage system.

  20. Weed control by direct injection of plant protection products according to specific situations

    Directory of Open Access Journals (Sweden)

    Krebs, Mathias

    2016-02-01

    Full Text Available Precision Farming in agriculture allows a site-specific management of the crop. The aim of plant protection is to apply plant protection products (PPP according to the site specific requirements on the field. Within the context of a research program to promote innovation, a sprayer with direct injection of plant protection products was developed. The direct injection offers site specific spraying of different individual PPP in a single pass. The sprayer prototype is equipped with a special spray boom combining three nozzle lines. In order to prevent delay times, the nozzle lines are preloaded before spraying. First results for weed control from test stand measurements and field trials showed that the injection pumps work with high accuracy. The prototype can be used without delay times site specific with up to three different herbicides. Field trials for site-specific weed control in winter wheat demonstrate the applicability of the system under practical conditions. By treatment of subareas herbicides and therefore costs could be saved. A reduction in yield compared with the conventionally treated field areas could not be ascertained. Also an efficacy reduction through washout of active ingredient from target surfaces due to simultaneous use of all three nozzle lines with up to 1050 l/ha application rate could not be detected. At high water spray rates, the efficacy effect occurs delayed. Overall, the newly developed direct injection system proved fieldabillity during the first tests. So weed control can be carried out situation-responsive, which can save herbicides and environmental impacts are reduced.

  1. Spring-Interseeded Winter Rye Seeding Rates Influence Weed Control and Organic Soybean Yield

    OpenAIRE

    Kelly A. Nelson; Smeda, Reid J.; Smoot, Randall L.

    2011-01-01

    Field research in 2002 and 2003 evaluated spring-interseeded winter rye (Secale cereale L.) at 67, 134, or 200 kg ha−1 at two soybean (Glycine max (L.) Merr.) row spacings (19- and 76-cm) on weed control, yield, and gross margins. Based on regression analysis, wide-row (76-cm) soybean grain yield and gross margins were greatest when winter rye was interseeded at 114 and 106 kg ha−1, respectively. Yields and gross margins for wide-row soybean were 8 to 55% greater than narrow-row (19-cm) soybe...

  2. Weed control and persistence of two oxyfluorfen formulations in olive groves under non tillage conditions.

    Science.gov (United States)

    Martínez, M J; Farsaoui, K; de Prado, R

    2004-01-01

    To obtain profitable yields in olive groves, residual preemergence herbicides are applied in October or November before the winter rains, and before the winter annual weeds germinate. Simazine, one of the herbicides most used for weed control in olive groves, has recently been banned. Oxyfluorfen is presented as a good alternative to simazine in olive fields. Experiments were carried out in 2002 and 2003 to evaluate the behaviour of two oxyfluorfen formulations, 2XL and G4F, at 480 g a.i. ha(-1) for three different soil management systems with three replications (1. bare soil; 2. bare soil and grassed buffer strips, chemically controlled and 3. bare soil and grassed buffer strips with controlled mowing; under non tillage conditions in all three cases). The most important species that survived 2XL and G4F treatments was Sagina apetala ARD. Oxyfluorfen residues were evaluated throughout 158 days after the applications. Three soil samples from each plot were collected, mixed and air dried. The herbicide extractions were made with methanol and the residues were analyzed by HPLC. We found no differences between the two formulations, but results showed that recoveries of oxyfluorfen were higher in plots with chemically controlled buffer grassed strips than in the other soil management types. PMID:15765564

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

    Science.gov (United States)

    Agricultural Research Service (USDA), Washington, DC.

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

  4. Estudo da degradação da biomassa de três espécies de plantas aquáticas no reservatório da UHE de Americana-SP Study on the degradation of three aquatic weeds at the Americana-SP reservoir in Brazil

    Directory of Open Access Journals (Sweden)

    E. Negrisoli

    2006-06-01

    Full Text Available O estudo de decomposição de plantas aquáticas foi realizado na UHE de Americana-CPFL, com o objetivo de avaliar a taxa de degradação de plantas na própria água do reservatório. Foram consideradas como variáveis a profundidade (superfície, 3,5 e 7,0 m, as espécies de plantas aquáticas (Eichhornia crassipes, Brachiaria subquadripara e Pistia stratiotes e o tipo de processamento a que estas foram submetidas (planta inteira, planta picada manualmente e com aplicação de fogo. Este estudo indicou que as espécies E. crassipes e P. stratiotes foram rapidamente decompostas no reservatório, ao contrário de B. subquadripara. Um outro fator importante observado foi a similaridade na decomposição das plantas, independentemente da profundidade testada. Essas diferenças devem ser consideradas na elaboração de planos de manejo e na previsão do impacto ambiental de programas de controle de plantas aquáticas.A study on aquatic weed decomposition was carried out at the Americana-SP reservoir in Brazil, to compare degradation rate of the plants in the reservoir's water itself. Three variables were considered as treatments: depth (surface, 3.5 and 7.0 m; aquatic weed species (Eichhornia crassipes, Brachiaria subquadripara, and Pistia stratiotes and type of handling the aquatic weeds (whole plant, hand cut plant, and burnt plant. The results indicated that the species E. crassipes and P. stratiotes had a fast decomposition in the reservoir, unlike B. subquadripara. These differences must be considered in the elaboration of management plans and prediction of environmental impact of aquatic plant control programs. The most positive aspect of the study was to demonstrate that decomposition at 3.5m and 7.0 m of depth had practically the same speed observed on the surface.

  5. Seed preferences by rodents in the agri-environment and implications for biological weed control.

    Science.gov (United States)

    Fischer, Christina; Türke, Manfred

    2016-08-01

    Post-dispersal seed predation and endozoochorous seed dispersal are two antagonistic processes in relation to plant recruitment, but rely on similar preconditions such as feeding behavior of seed consumers and seed traits. In agricultural landscapes, rodents are considered important seed predators, thereby potentially providing regulating ecosystem services in terms of biological weed control. However, their potential to disperse seeds endozoochorously is largely unknown. We exposed seeds of arable plant species with different seed traits (seed weight, nutrient content) and different Red List status in an experimental rye field and assessed seed removal by rodents. In a complementary laboratory experiment, consumption rates, feeding preferences, and potential endozoochory by two vole species (Microtus arvalis and Myodes glareolus) were tested. Seed consumption by rodents after 24 h was 35% in the field and 90% in the laboratory. Both vole species preferred nutrient-rich over nutrient-poor seeds and M. glareolus further preferred light over heavy seeds and seeds of common over those of endangered plants. Endozoochory by voles could be neglected for all tested plant species as no seeds germinated, and only few intact seeds could be retrieved from feces. Synthesis and applications. Our results suggest that voles can provide regulating services in agricultural landscapes by depleting the seed shadow of weeds, rather than facilitating plant recruitment by endozoochory. In the laboratory, endangered arable plants were less preferred by voles than noxious weeds, and thus, our results provide implications for seed choice in restoration approaches. However, other factors such as seed and predator densities need to be taken into account to reliably predict the impact of rodents on the seed fate of arable plants. PMID:27547355

  6. 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

  7. Hygrophila polysperma (Acanthaceae, una maleza acuática registrada por primera vez para la flora mexicana First record in the Mexican flora of Hygrophila polysperma (Acanthaceae, an aquatic weed

    Directory of Open Access Journals (Sweden)

    Arturo Mora-Olivo

    2008-06-01

    Full Text Available Se registra por primera vez la presencia de la maleza acuática Hygrophila polysperma en México. Se proporcionan datos sobre su historia en América, morfología y distribución en Tamaulipas. Se incluye una clave para distinguirla de H. costata, una planta nativa de México. Finalmente, se discute la amenaza que representa esta planta introducida para los ambientes acuáticos artificiales y naturales en nuestro país.The presence in Mexico of the aquatic weed Hygrophila polysperma is reported for the fi rst time. Data regarding history in America, morphology, and distribution in Tamaulipas are provided. A key is included to distinguish this species from the Mexican native, H. costata. Finally, the threat that this introduced plant represents for artificial and natural aquatic ecosystems in Mexico is discussed.

  8. Controls on metal exposure to aquatic organisms in urban streams.

    Science.gov (United States)

    Turpin-Nagel, Katelyn; Vadas, Timothy M

    2016-08-10

    Streams in urban ecosystems receive metal inputs primarily from stormwater runoff and wastewater effluent. The relative contribution of these metal sources to stream impairment is difficult to discern based on simple water characteristics and biological surveys. Stream impairment in these systems is often indicated by reduced abundance and diversity of aquatic insects, which tend to be more sensitive to chronic metal exposures. Metal species and controls on metal species in both the waterborne and dietborne exposure pathways to aquatic organisms are reviewed here. In addition, ecological changes that can control dietborne species are discussed. A main focus is on how organic matter from different anthropogenic sources may control both aqueous metal speciation as well as interaction with various inorganic or microbiological surfaces in streams. Most of the reviewed research focuses on Cu, Zn or Pb as those are the primary metals of concern in developed systems and Cu and Pb have unique and strong interactions with organic matter. Recommendations for further research are described in the context of exposure species, dynamics of exposure, stoichiometry, or advanced analytical tools, and regulatory implications are discussed. PMID:27170052

  9. Controle pós-emergente de plantas daninhas em cenoura Post-emergence weed control in carrot crop

    Directory of Open Access Journals (Sweden)

    Jeferson Zagonel

    1999-03-01

    Full Text Available O experimento foi conduzido em Piraí do Sul-PR no ano de 1995 em solo de textura argilo arenosa, tendo como objetivo avaliar a eficiência e a seletividade do herbicida propaquizafop no controle pós-emergente de plantas daninhas na cultura da cenoura. O delineamento experimental utilizado foi de blocos ao acaso com seis tratamentos e quatro repetições, quais sejam: propaquizafop (100, 125 e 150 g i.a./ha; fluazifop-p-butil (188 g i.a./ha; testemunha capinada e testemunha sem capina. A cultivar de cenoura utilizada foi Nantes Tim Tom semeada em 15 de junho, com espaçamento de 0,25 x 0,05 m, em parcelas com área útil de 5,00 x 1,00 m. As plantas daninhas predominantes foram Brachiaria plantaginea (capim-papuã, Digitaria horizontalis (capim-milhã e Eleusine indica (capim pé-de-galinha. As avaliações foram efetuadas aos 15, 30 e 45 dias após a aplicação dos tratamentos. Observou-se que o herbicida propaquizafop, nas doses de 100, 125 e 150 g i.a./ha foi eficiente no controle sobre capim-papuã, capim-milhã e capim pé-de-galinha. O controle de plantas daninhas realizado através de herbicidas proporcionou a mesma produção obtida com o controle manual. A perda na produção ocasionada pela presença de plantas daninhas foi da ordem de 76,4%. Não foram observados efeitos fitotóxicos nas plantas de cenoura que pudessem ser atribuídos aos produtos utilizados.The presented field trial was conducted in 1995 in Piraí do Sul, Paraná State, Brazil, on a sand-clay texture soil, to evaluate the efficiency and selectivity of propaquizafop on carrot crop weed control. The experiment was laid out in a randomized block design with six treatments and four replications, and 5.00 x 1.00 m plots. The treatmens were: propaquizafop (100, 125 and 150 g a.i/ha; fluazifop-p-butil (188 g a.i/ha; control with weeding and control without weeding. The carrot cultivar Nantes Tim Tom was sown on June 15 with plants spaced 0.25 x 0.05 m. The prevalent weeds

  10. Tanaris® – the new herbicide for weed control in pre and post emergence in oilseed rape

    OpenAIRE

    Bessai, Johannes; Bremer, Hagen; Schläfer, Sascha; Schjönhammer, Alfons; Vantieghem, Herve

    2016-01-01

    With the Product Tanaris® BASF introduces a broadly effective herbicide for weed control in winter oilseed rape. Tanaris® is used at a dose rate of 1.5 l/ha and contains the active substances Dimethenamid-P (333 g/l) and Quinmerac (167 g/l). With the combination of both actives, the product is delivering high activity on most oilseed rape key weeds such as mayweeds, deadnettles and speedwell. Especially the high effectivity on cleavers and cranesbill species needs to be emphasized. Further Ta...

  11. Effect of weed control and fertilization on early growth of Gmelina arborea Roxb. at department of Tolima, Colombia

    International Nuclear Information System (INIS)

    This study was conducted to generate knowledge about silvicultural management in the establishment of Gmelina arborea plantations located at department of Tolima, Colombia. The objective was to quantify the individual and combined effects of weed control and fertilization with N-PK-Mg on the growth of individual trees of G. arborea. The evaluation used analysis of variance (ANOVA) considering a block design with split plots arrangement, being the response variables: periodic annual increment (PAI) in diameter, total height, basal area and total volume inside the bark. ANOVA allowed to infer that there are no significant response differences among the application of one to three chemical weed control per year. However, the absence of weed control reduced the PAI in diameter by 22% and 3% in total volume inside bark. Fertilization was the main factor influencing the PAI in diameter, total height, basal area and total volume inside bark. To conclude, the best treatment consisted of a combination of two weed controls per year and the use of a high dose of fertilizer (N = 60 g = 30 g P2O5, K2O = 120 g, Mg = 68 g). This combination increased the PAI in diameter by 29%, total height by 15% , area basal by 30% and total volume inside bark by 15% when compared with control plots.

  12. Occurence, spread and possibilities of invasive weeds control in sugar beet

    OpenAIRE

    Konstantinović Branko I.; Meseldžija Maja U.

    2006-01-01

    Floristically rich and diverse weed comunity of sugar beet is in our country represented by 150 weed species. They are not all equaly significant in weediness of this crop. Only a limited number of them participate in weed comunity composition. These are: Abuthilon theophrasti Medic., Ambrosia artemisiifolia L., Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense (L) Scop., Convolvulus arvensis L., Cynodon dactylon (L) Pers. Digitaria sanguinalis (L) Scop., Hibiscus trionum L., R...

  13. Avaliação da sensibilidade de diversas espécies de plantas daninhas aquáticas ao carfentrazone-ethyl, em ambiente controlado Assessment of sensitivity of several aquatic weeds to carfentrazone-ethyl under controlled environment

    OpenAIRE

    L.L. Foloni; R.A. Pitelli

    2005-01-01

    Plantas aquáticas, especialmente macrófitas, tornam-se sério problema em hidrelétricas, afetando a múltipla utilização dos corpos d'água, incluindo produção de peixes e atividades de pesca, perdas d'água por evapotranspiração, esportes aquáticos, canoagem, irrigação e produção de energia nas usinas hidrelétricas. Com o objetivo de analisar o potencial de uso do carfentrazone-ethyl no controle das principais plantas daninhas aquáticas no Brasil, foi instalado um experimento em vasos com água. ...

  14. Efficacy of various pre and post-emergence herbicides to control weeds in wheat

    International Nuclear Information System (INIS)

    The efficacy of various pre and post-emergence herbicides viz. pyroxasulfone at the rate 0.15 kg a.i. ha/sup -1/, terbutryn + triasulfuron at the rate 0.18 kg a.i. ha/sup -1/ and flufenacet + pyroxasulfone at the rate 0.24 + 0.15 kg a.i. ha-1 as pre-emergence while flufenacet at the rate 0.24 kg a.i. ha/sup -1/, carfentrazone ethyl + isoproturon at the rate 0.018 kg a.i. ha/sup -1/, bromoxynil + MCPA at the rate 0.49 kg a.i. ha/sup -/ as post-emergence and hand weeding at (20 and 40 DAS) with a weedy check were tested against narrow and broad leaved weeds in wheat during Rabi season 2008-09. The results revealed that Fumaria indica, Melilotus indica and Rumex dentatus density significantly decreased by all the herbicides compared with control. Bromoxynil + MCPA at the rate 0.49 kg a.i. ha/sup -1/ as post-emergence application was most effective in controlling F. indica, M. indica and R. dentatus with maximum mortality at both (30 and 60 DAS) without being phytotoxic to wheat. Bromoxynil + MCPA at the rate 0.49 kg a.i. ha/sup -1/ as post-emergence spray proved significantly better than other herbicide treatments as it severely reduced the weeds biomass as compared to weedy check. Spike bearing tillers (355.75), spike length (15.07 cm), number of grains spike-1 (52.00) and 1000-grain weight (54.00 g) were maximum in bromoxynil + MCPA at the rate 0.49 kg a.i. ha/sup -1/ as post-emergence treated plots, which ultimately enhanced the yield up to 39.13% over control. Bromoxynil + MCPA at the rate 0.49 kg a.i. ha/sup -1/ as post-emergence gave the maximum net income of Rs. 97345 ha/sup -1/. However, maximum MRR (%) of 191730 was obtained with the use of bromoxynil + MCPA followed by flufenacet with the MRR (%) of 67590. (author)

  15. The Effect of Nozzle Types and Time of Herbicide Incorporation in Soil on Corn (Zea mays L. Weed Control

    Directory of Open Access Journals (Sweden)

    K Gerami

    2012-09-01

    Full Text Available This experiment was conducted to study the effect of nozzle types and the time of herbicide incorporation in soil on weed control, using split plot design by randomized block design. The main plots were soil and herbicide mixing time and the subplots were nozzle types with three replications. This study was performed in Karaj station of Seed and Plant Improvement Institute, located 25 km west of Tehran, in 2008. Treatments were including: T-Jet standard nozzle, Flood-Jet nozzle and Air induction nozzle as well as mixing with the soil immediately, three, six and nine hours after spraying. The parameters were measured includes: the number of weeds before spraying, 15 days and 30 days after spraying; dry weed at two stages of 15 and 30 days after the spraying; and yield of corn. The results revealed that the spraying quality coefficient was greater for T-jet nozzle compared to the other types. However Flood-jet nozzle had a wide range of corn weeds control in comparison to other treatments. Regardless of the nozzle type, the immediate incorporation of herbicide in soil after spraying significantly increased the yield. The time of herbicide incorporation in soil and poison intermixture with soil, from zero to 4.5 hours after spraying was superior to the other times. This was mainly due to different weeds reactions to the times of herbicide incorporation in soil after spraying, and also treatments effect on yield and weed dry weight. Combined data analysis showed that treatment combination of T-Jet nozzle (with time of herbicide incorporation in soil immediately and three hours after spraying, Flood-jet nozzle (with time of herbicide incorporation in soil immediately after spraying and air induction nozzle (with time of herbicide incorporation in soil immediately, three and six hours after spraying produced the highest yield than the other treatment combinations.

  16. CONTROL DE MALEZA EN DISTRITOS DE RIEGO CON EQUIPOS LIGEROS WEED CONTROL IN IRRIGATION DISTRICTS WITH LIGHT WEIGHT EQUIPMENT

    Directory of Open Access Journals (Sweden)

    José Ramón Lomelí Villanueva

    2010-12-01

    Full Text Available En México el control mecánico de maleza, tradicionalmente se realizaba con maquinaria inadecuada lo cual provocaba daños en los taludes y modificaciones de la sección hidráulica. Para resolver este problema, actualmente se utilizan los equipos ligeros que permiten el desarrollo de una cubierta vegetal, que no interfiere con el flujo del agua y su sistema radical retiene el suelo, lo cual reduce la erosión y mantiene en condiciones estables los taludes. El presente trabajo aborda los aspectos relativos a características y criterios para la selección de los implementos y la secuencia para su utilización. El costo de las operaciones para el control de maleza en canales, drenes y caminos se ha reducido un 39,21% con respecto a utilizar maquinaria inadecuada. La versatilidad de los equipos ligeros permite emplear el implemento más adecuado para cada tipo de maleza. En México, el inventario actual es de 263 equipos ligeros que tienen un potencial de aplicación para el control de la maleza, en la totalidad de los caminos, el 90% de canales y el 70% de drenes de los Distritos de Riego.In Mexico, the mechanical weed control was traditionally carried out with inadequate equipment which caused damage to the slopes and changes in the hydraulic section. In order to solve this problem, light weight equipment is currently being used to allow the development of a vegetation cover to retain soil with no interference with water flow, reducing erosion and maintaining stable conditions in the slopes. This paper addresses aspects related to characteristics and criteria for selecting and sequencing tools for use. The costs of weed control in irrigation channels, drains and roads have been reduced 39.21% compared to using inadequate equipment. The versatility of light weight equipment allows the use of the most appropriate implement for each weed. In Mexico, the current inventory includes 263 light weight devices with which a potential weed control of 90

  17. Relationship of weed shiner and young-of-year bluegill and largemouth bass abundance to submersed aquatic vegetation in Navigation Pools 4, 8, and 13 of the Upper Mississippi River, 1998-2012

    Science.gov (United States)

    DeLain, Steven A.; Popp, Walter A.

    2014-01-01

    Aquatic vegetation provides food resources and shelter for many species of fish. This study found a significant relationship between increases in submersed aquatic vegetation (SAV) in four study reaches of the Upper Mississippi River (UMR) and increases in catch-per-unit-effort (CPUE) of weed shiners (Notropis texanus) and age-0 bluegills (Lepomis macrochirus) and largemouth bass (Micropterus salmoides) when all of the study reaches were treated collectively using Long Term Resource Monitoring Program (LTRMP) vegetation and fish data for 1998–2012. The selected fishes were more abundant in study reaches with higher SAV frequencies (Pool 8 and Lower Pool 4) and less abundant in reaches with lower SAV frequencies (Pool 13 and Upper Pool 4). When each study reach was examined independently, the relationship between SAV frequency and CPUE of the three species was not significant in most cases, the primary exception being weed shiners in Lower Pool 4. Results of this study indicate that the prevalence of SAV does affect relative abundance of these vegetation-associated fish species. However, the poor annual relationship between SAV frequency and age-0 relative abundance in individual study reaches indicates that several other factors also govern age-0 abundance. The data indicate that there may be a SAV frequency threshold in backwaters above which there is not a strong relationship with abundance of these fish species. This is indicated by the high annual CPUE variability of the three selected fishes in backwaters of Pool 8 and Lower Pool 4 when SAV exceeded certain frequencies.

  18. A new invasive weed-feeding species of Polypedilum (Pentapedilum) Kieffer from South Africa (Diptera: Chironomidae, Chironominae).

    Science.gov (United States)

    Andersen, Trond; González, Orestes C Bello; Baars, Jan-Robert; Earle, William

    2015-01-01

    Polypedilum (Pentapedilum) tuburcinatum Andersen et Bello González sp. n. is described and figured as male, female, pupa and larva based on material collected in the Eastern Cape Province in South Africa, imported into quarantine in Ireland and reared in the laboratory. The species feeds on the aquatic weed Lagarosiphon major (Ridl.) Moss ex Wager and is regarded as a promising candidate agent for biological control of this invasive weed. PMID:26623746

  19. A new invasive weed-feeding species of Polypedilum (Pentapedilum) Kieffer from South Africa (Diptera: Chironomidae, Chironominae)

    OpenAIRE

    Andersen, Trond; Bello Gonzalez, Orestes C.; Baars, Jan-Robert; Earle, William

    2015-01-01

    Polypedilum (Pentapedilum) tuburcinatum Andersen et Bello González sp. n. is described and figured as male, female, pupa and larva based on material collected in the Eastern Cape Province in South Africa, imported into quarantine in Ireland and reared in the laboratory. The species feeds on the aquatic weed Lagarosiphon major (Ridl.) Moss ex Wager and is regarded as a promising candidate agent for biological control of this invasive weed

  20. Nitrogen topdressing and application ways of fluazifop-p-butyl + fomesafen in weed control and agronomic performance of common bean.

    Science.gov (United States)

    Silva, Matheus G; Arf, Orivaldo; Teodoro, Paulo E

    2015-01-01

    The objective of this study was to investigate the effect of interaction between nitrogen topdressing and different application ways (active ingredients) a.i. fluazifop-p-butyl + fomesafen in weed control and agronomic performance of common bean. The experiment was conducted during winter 2003 in Selvíria/MS. The experimental design used was a randomized block design with four replications in a factorial scheme 2 x 7. The first factor was composed by the absence or presence of nitrogen topdressing, while the second factor consisted of different application ways of fluazifop-p-butyl + fomesafen. The following variables were measured: leaf N content, dry matter of plants, yield components (number of pods plant(-1), number of grains plant(-1), the average number of grains pod(-1) and mass of 100 grains), grain yield, phytotoxicity and weed control percentage. The nitrogen topdressing with 75 kg ha(-1) provided higher dry matter of plants, higher weed control and higher common bean yield of irrigated winter. In the absence of nitrogen topdressing in the application of urea before or together to fluazifop-p-butyl + fomesafen increased their effectiveness in controlling weeds without interference in the agronomic performance of common bean. PMID:26628016

  1. Phytotoxicity and weed control of oxyfluorfen and napropamide on container-grown conifer seedlings. Research memo No. 123

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    Factsheet assessing the affects of oxyfluorfen and napropamide applications on the designated crop plants and evaluating how well the herbicides controlled typical weed species. The study used recently-seeded Douglas-fir, white spruce and lodgepole pine and one-year-old Douglas-fir and white spruce. The oxyfluorfen formulation used was Goal and the napropamide formulation was Devrinol.

  2. Development of a standard test procedure for devices on thermal weed control

    Directory of Open Access Journals (Sweden)

    Verschwele, Arnd

    2016-02-01

    Full Text Available In contrast to the standard evaluation of the efficacy of pesticides and the testing of spraying equipment there are no comparable testing procedure for equipment of thermal weed control. It is the aim of the investigations described here to develop a standard procedure for assessing temperature distribution and biological efficacy. This will be the basis for quality testing which can be directly used by practical users. Also it can help engineers to improve devices if constructive gaps will be identified by these tests. The results from testing a flaming device (Green-Flame 850 E demonstrated such a potential for technical improvement: The temperature decreased from 159 °C to 89 °C by increasing driving speed from 0.35 m/s to 0.81 m/s. The variation of the temperature related to the working width was extremely high: The range was 60 °C at highest speed and 79 °C at lowest speed, respectively. The biological efficacy against the test plant species Sinapis arvensis was also affected by the driving speed and the corresponding temperature. A driving speed not higher than 0.53 m/s resulted in efficacy rates of almost 95%. However, the efficacy was only 66% at the highest tested speed of 0.81 m/s. Thus, the needed effective temperature is between 89 °C und 106 °C. In contrast, Lolium perenne was controlled by only 72% under the tested conditions. Here a dose-response relationship was not observed. The variation of the temperature, as well as the biological efficacy, was extremely heterogeneous and not satisfying in terms of an economic and safe use. Similar results were found for other devices on thermal weed control.

  3. Efeito de diferentes períodos de controle das plantas daninhas na produtividade da cultura da cebola Effect of different weed control periods on onion crop yield

    Directory of Open Access Journals (Sweden)

    D.J. Soares

    2004-12-01

    Full Text Available Foi realizado um experimento em Monte Alto-SP, visando estudar os efeitos de diferentes períodos de controle das plantas daninhas sobre a produção de bulbos da cultura da cebola (Allium cepa, cultivar 'Mercedes', no sistema de transplantio. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições. Parte dos tratamentos experimentais foi disposta num esquema fatorial 4 x 6, em que constituíram variáveis quatro períodos em que se fez o controle (0-0, 0-7, 0-14 e 0-21 DAT e seis períodos em que se reiniciou o controle das plantas daninhas prolongando até a colheita: 28, 42, 56, 70, 84 e 98 DAT. Duas testemunhas foram adotadas: uma com controle e outra sem controle das plantas daninhas durante todo o ciclo da cultura. Lycopersicon esculentum, Portulaca oleracea, Eragrostis pilosa e Galinsoga parviflora foram as plantas daninhas mais importantes na área. Não houve interação entre os diferentes períodos de controle das plantas daninhas. O controle inicial destas plantas deve se prolongar até 14 DAT e ser reiniciado aos 28 DAT, a fim de prevenir reduções significativas na produtividade em relação à testemunha no limpo A convivência com as plantas daninhas durante todo o ciclo da cebola reduziu a produtividade em 94,5%.An experiment was carried out in Monte Alto, SP to study the effects of different of weed control periods on the yield of onion (Allium cepa bulb, 'Mercedes' cultivar, under the transplanting system. The experiment was arranged in a completely randomized block design, with four replications. The treatments were arranged in 4 x 6 factorial design with four initial weed removal periods (after transplanting until 0, 7, 14 and 21 days and six final weed removal periods (from 28, 42, 56, 70, 84 or 98 days after transplanting until harvest. Two controls were adapted with and without weed control throughout the onion cycle. Lycopersicon esculentum, Portulaca oleracea, Eragrostis pilosa and

  4. The development of a phosphite-mediated fertilization and weed control system for rice.

    Science.gov (United States)

    Manna, Mrinalini; Achary, V Mohan M; Islam, Tahmina; Agrawal, Pawan K; Reddy, Malireddy K

    2016-01-01

    Fertilizers and herbicides are two vital components of modern agriculture. The imminent danger of phosphate reserve depletion and multiple herbicide tolerance casts doubt on agricultural sustainability in the future. Phosphite, a reduced form of phosphorus, has been proposed as an alternative fertilizer and herbicide that would address the above problems to a considerable extent. To assess the suitability of a phosphite-based fertilization and weed control system for rice, we engineered rice plants with a codon-optimized ptxD gene from Pseudomonas stutzeri. Ectopic expression of this gene led to improved root growth, physiology and overall phenotype in addition to normal yield in transgenic plants in the presence of phosphite. Phosphite functioned as a translocative, non-selective, pre- and post-emergent herbicide. Phosphite use as a dual fertilizer and herbicide may mitigate the overuse of phosphorus fertilizers and reduce eutrophication and the development of herbicide resistance, which in turn will improve the sustainability of agriculture. PMID:27109389

  5. Scythe (57% pelargonic acid) broadcast application for broadleaf weed control in spring-transplanted onions

    Science.gov (United States)

    Although previous studies yielded important information concerning use of pelargonic acid as a potential organic herbicide, further research is indicated to increase the understanding of the relationship among application volumes, weed species, and weed maturity on herbicidal efficacy and crop injur...

  6. Weed control in tomato (lycopersicon esculentum mill.) through mulching and herbicides

    International Nuclear Information System (INIS)

    Experiments were conducted at the Agricultural Research Farm of the University of Agriculture, Peshawar during 2012 and 2013 to determine the impact of row spacing and weed management strategies on tomato (Lycopersicon esculantum Mill.). Variety 'Roma' was planted on a plot size of 4.8m x 3m using a randomized complete block (RCB) design in split plot arrangements, having four replications. The experiment comprised of row spacing in main plots and ten treatments in the subplots that included five mulches viz., white polyethylene, black polyethylene, wheat straw, newspaper and saw dust; three herbicide treatments i.e. fenoxaprop-p-ethyl, pendimethalin, s-metolachlor along with a hand weeding treatment and a weedy check. The data were recorded on weed density m-2 at 20 days after treatments, plant height, fruit yield (kg ha-1). All the studied parameters were significantly affected by the row spacing (factor A) and weed management treatments (factor B); however, the interaction effects were non-significant. An increase in weed density was observed with increase in row spacing, having weed density of 3.39, 4.19 and 4.53 weeds m-2 for 40, 60 and 80 row spacing, respectively. The overall weed density m-2 ranged between 3.24 to 4.30 m-2. A maximum plant height of 62.44cm was recorded in weedy check and minimum 53.31cm plant height was observed in hand weeding treatments. As regards the fruit yield, a highest yield of 2.51 t ha-1 was recorded at row spacing of 60 cm (factor A) and the application of poly ethylene black plastic resulted in significantly highest fruit yield (4.04 t ha-1) among factor B treatments. (author)

  7. THE EFFECT OF DIFFERENT TYPES OF STRAW MULCHES ON WEED-CONTROL IN VEGETABLES CULTIVATION

    OpenAIRE

    Edyta Kosterna

    2014-01-01

    The experiment was carried out in 2010–2012. The effect of different kinds of straw and its dose applied to soil mulching on the amount and fresh mass of weeds and yield level of broccoli and tomato was investigated. The type of straw mulch applied to the soil mulching influenced number and fresh mass of weeds. This effect could be the result of the properties of the mulch (colour, structure, etc.) or the allelopathic effect on the germination and growth of individual weed species. The most e...

  8. Mixed cropping systems for biological control of weeds and pests in organic oilseed crops

    OpenAIRE

    Paulsen, Hans Marten; Schochow, Martin; Ulber, B; Kühne, Stefan; Rahmann, Gerold

    2006-01-01

    Agricultural advantages of mixed cropping are gained by biological effects like light competition, offering weed-suppressing capacities or by diversification of plant covers to break development cycles of pests. In a two-year project on mixed cropping with organic oilseed crops these effects were measured. It was found that weeds can be efficiently suppressed in organic linseed (Linum usitatissivum) in crop combinations with wheat (Triticum aestivum) or false flax (Camelina sativa). But linse...

  9. Mixed cropping systems for control of weeds and pests in organic oilseed crops

    OpenAIRE

    Paulsen, H. M.; Schochow, M; Ulber, B; Kuhne, S; Rahmann, G

    2006-01-01

    Agricultural advantages of mixed cropping are gained from biological effects like light competition offering weed-suppressing capacities, or by diversification of plant covers to break development cycles of pests. These effects were measured in a two-year project on mixed cropping with organic oilseed crops. It was found that weeds can be efficiently suppressed in organic linseed (Linum usitatissivum) grown in combination with wheat (Triticum aestivum) or false flax (Camelina sativa). Linseed...

  10. Algal-bloom control by allelopathy of aquatic macrophytes——A review

    Institute of Scientific and Technical Information of China (English)

    Hongying HU; Yu HONG

    2008-01-01

    Algal-bloom control is an important issue for water environment protection as it induces several nega-tive impacts on the lives of aquatic organisms, aquacul-ture, landscaping, and human health. The development of an environment-friendly, cost-effective, and convenient alternative for controlling algal bloom has gained much concern. Using the allelopathy of aquatic macrophytes as a novel and safe method for algal-bloom control is a promising alternative. This paper reviews the develop-ment and potential application about allelopathy of aquatic plants on algae, including the allelopathic research history, the potential research problems, the research methodology, and the reported aquatic macro-phytes and their inhibitory allelochemicals. Potential modes of inhibition action of allelochemicals on algae, possible ways for application, and future development directions of research on algal-bloom control by aquatic macrophytes were also presented.

  11. Assessment of aquatic plants in the reservoirs of AES-tietê and development of an integrated control model for the most important species.

    Science.gov (United States)

    Velini, Edivaldo Domingues; Galo, Maria Lourdes B T; Carvalho, Fernando Tadeu; Martins, Dagoberto; Cavenaghi, Anderson Luis; Trindade, Maria Lúcia Bueno; Bravin, Luis Fernando N; Negrisoli, Eduardo; Antuniassi, Ulisses Rocha; Simionato, José L A; Santos, Silvio C A

    2005-01-01

    The general objective of this work was to develop a monitoring and management model for aquatic plants that could be used in reservoir cascades in Brazil, using the reservoirs of AES-Tietê as a study case. The investigations were carried out at the reservoirs of Barra-Bonita, Bariri, Ibitinga, Promissão, and Nova-Avanhandava, located in the Tietê River Basin; Agua Vermelha, located in the Grande River Basin; Caconde, Limoeiro, and Euclides da Cunha, which are part of the Pardo River Basin; and the Mogi-Guaçu reservoir, which belongs to the Mogi-Guaçu River basin. The main products of this work were: development of techniques using satellite-generated images for monitoring and planning aquatic plant control; planning and construction of a boat to move coating plant masses and an airboat equipped with a DGPS navigation and application flow control system. Results allowed to conclude that the occurrence of all types of aquatic plants is directly associated with sedimentation process and, consequently, with nutrient and light availability. Reservoirs placed at the beginning of cascades are more subject to sedimentation and occurrence of marginal, floating and emerged plants, and are the priority when it comes to controlling these plants, since they provide a supply of weeds for the other reservoirs. Reservoirs placed downstream show smaller amounts of water-suspended solids, with greater transmission of light and occurrence of submerged plants. PMID:15656166

  12. Design and realization of an innovative automatic machine able to perform site-specific thermal weed control in maize

    OpenAIRE

    Luisa Martelloni

    2014-01-01

    This PhD thesis contains a detailed introduction on the state of the art of precision agriculture. The introduction is a brief guide to the technologies used in precision agriculture such as global navigation satellite system (GNSS), computer vision, remote and proximal sensors, Geographic Information System (GIS), Variable-Rate Application (VRA) and yield monitoring systems. In the introduction are also described in details the techniques for site-specific weed control and focuses on the mos...

  13. Fall and spring broccoli yields and weed control under no-till and conventional tillage with overseeded legume living mulches

    OpenAIRE

    Infante, Michelle Louise

    1994-01-01

    Experiments were conducted with 'BigSur' broccoli (Brassica oleracea var. italica Plenck) at two sites in fall of 1993 and at two sites in the spring of 1994 on a Hayter loam in southwestern Virginia. Objectives were to determine the tillage main-plot (CT = conventional tillage, and NT = no-tillage) and weed-control subplot (C = no overseeding or preemergent herbicide; HB = oxyfluorfen; RC = red clover (Trifolium pratense L.); WC = Dutch white clover (Trifolium repens L.); and ...

  14. Evaluation of the Upland Weed Control Potentiality of Green Tea Waste-Rice Bran Compost and Its Effect on Spinach Growth

    OpenAIRE

    Khan, M. A. I.; Ueno, K; S. Horimoto; F. Komai; Tanaka, K; Ono, Y

    2007-01-01

    This study evaluated the upland weed control potentiality, germination inhibition ability and growth suppression efficiency of the five combinations of green tea waste rice bran compost (GRC). GRC was prepared by mixing green tea waste and rice bran at five ratios, and allowed to decompose for 5 mo. Application of GRC suppressed weed growth up to 93.4% in number and 95.4% in dry weight in 2004, and 80.7% in number and 73.4% in dry weight of weeds in 2005, as compared with the untreated contro...

  15. Weed Control and Peanut Tolerance with Ethalfluralin-Based Herbicide Systems

    Directory of Open Access Journals (Sweden)

    W. J. Grichar

    2012-01-01

    Full Text Available Field studies were conducted from 2007 through 2009 to determine weed efficacy and peanut (Arachis hypogaea L. response to herbicide systems that included ethalfluralin applied preplant incorporated. Control of devil's claw (Proboscidea louisianica (Mill. Thellung, yellow nutsedge (Cyperus esculentus L., Palmer amaranth (Amaranthus palmeri S. Wats., and puncturevine (Tribulus terrestris L. was most consistent with ethalfluralin followed by either imazapic or imazethapyr applied postemergence. Peanut stunting was 19% when paraquat alone was applied early-postemergence. Stunting increased to greater than 30% when ethalfluralin applied preplant incorporated was followed by S-metolachlor applied preemergence and paraquat applied early-postemergence. Stunting (7% was also observed when ethalfluralin was followed by flumioxazin plus S-metolachlor applied preemergence with lactofen applied mid-postemergence. Ethalfluralin followed by paraquat applied early-postemergence reduced peanut yield when compared to the nontreated check. Ethalfluralin applied preplant incorporated followed by imazapic applied mid-postemergence provided the greatest yield (6220 kg/ha. None of the herbicide treatments reduced peanut grade (sound mature kernels plus sound splits when compared with the nontreated check.

  16. Influence Of Low Gamma Irradiation Doses And Weed Control On Faba Bean (Vicia F ABA L.) Yield And Yield Attributes

    International Nuclear Information System (INIS)

    Two field experiments were carried out in an administration field at Belbees district, Sharkia Governorate, Egypt, during two successive winter seasons (2007/08 – 2008/09). The study aimed to investigate the effect of four gamma irradiation doses (un irradiated seeds as a control, 10, 20 and 30 Gy) and five treatments of weed management practices 1- Un weeded (control), 2-Two hand hoeings at 21 and 42 days after sowing, 3-Prometryn, commercially known as Giza gared, sprayed at pre-emergence with rate of 1 kg/ 300 liters/fad. 4- Bentazon 48%, commercially known as Basagran 48%, sprayed at pre-emergence with the rate of 500 cm3/200 liters water/fad. sprayed at pre-emergence. 5- both herbicides, Prometryn, sprayed at pre-emergence with the rate of 1 kg/ 300 liters/fad. + Bentazon 48% sprayed at pre-emergence with the rate of 500 cm3/ 200 liters water/fad., on yield and yield attributes of faba bean. Results indicate that: 1- Gamma irradiation with the lowest dose of 10 Gy, gave high values for plant height (112.54 cm) and number of pods/plant (12.22), while the highest gamma irradiation dose of 30 Gy, resulted in high values for number of seeds/pod (4.52), number of seeds/plant (52.3), seed weight(g)/plant, 100-seeds weight (79.79 g), seed yield (11.39 ardab/fad.) and straw yield (ton/fad.). The lowest values for each of the aforementioned traits were obtained in non irradiated treatment in the combined analysis, 2-Weed control by hand hoeing twice (after 21 and 42 DAS) gave the highest values for each of the aforementioned traits, followed by spraying both herbicides, Prometryn + Bentazon 48%, followed by sole herbicide Bentazon 48% and sole Prometryn, while un weeded treatment gave the lowest values for the respective order, in the combined analysis

  17. Survey of the Current Status of Weed Control and Herbicide Usage by the Small-Scale Commercial Vegetable Farmers in Kenya

    International Nuclear Information System (INIS)

    Vegetable production in Kenya is a market that has grown very rapidly in the decade due to increased demand in the local and international markets. This has led to an increase in hectarerage planted to vegetable thus leading in labour shortage due urban migration of potential casual labourers especially the youth. This has resulted to inadequate labour for weed control especially at the critical period. The objectives of this study were to find out the problems encountered by farmers in their bid to control weeds and whether they considered weeds as their major problem. The survey was conducted in Kikuyu, Lari and Kinango divisions where intensive vegetable farming is done by small-scale farmers for commercial purposes. The farmers were randomly selected and interviews conducted in their farms, based on Participatory Rural Appraisal (PRA) method. The results obtained showed that the farmers who previously relied on manual labour for weed control were increasingly using herbicides for weed control. The adoption of herbicide technology by these small scale farmers was out of their own initiative, either due to labour shortage or because one had a special weed problem that had defied other methods of control.From the information obtained it was clear that locally generated data information on herbicide use by small-scale farmers is seriously lacking for most if not all vegetable crops

  18. Occurence, spread and possibilities of invasive weeds control in sugar beet

    Directory of Open Access Journals (Sweden)

    Konstantinović Branko I.

    2006-01-01

    Full Text Available Floristically rich and diverse weed comunity of sugar beet is in our country represented by 150 weed species. They are not all equaly significant in weediness of this crop. Only a limited number of them participate in weed comunity composition. These are: Abuthilon theophrasti Medic., Ambrosia artemisiifolia L., Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense (L Scop., Convolvulus arvensis L., Cynodon dactylon (L Pers. Digitaria sanguinalis (L Scop., Hibiscus trionum L., Rubus caesius L. Echinochloa crus-gall L., Polygonum aviculare L., P. lapathifolium L., P. persicaria L., Setaria glauca (L P. B., S. viridis (L P. B., Solanum nigrum L. and Sorghum halepense (L Pers. In shooting period up to 4-8 weeks upon emergence, sugar beet is under the haviest harmfull inluence of weeds, especially invasive ones such as: Abuthilon theophrasti Medic. Ambrosia artemisiifolia L., Cirsium arvense (L Scop., Iva xanthifolia L. Sorghum halepense (L Pers. and Xanthium strumarium L. Sugar beet growing requires intensive cultural practices, i.e. basic and additional tillage and cultivation. Due to the widening of weed problems, frequent herbicide use in several applications is needed in the longer time period.

  19. Bio-control potential of Cladosporium sp. (MCPL-461), against a noxious weed Parthenium hysterophorus L.

    Science.gov (United States)

    Kumar, Anuj; Verma, V C; Gond, S K; Kumar, V; Kharwar, R N

    2009-03-01

    The phenological survey of Parthenium hysterophorus L., in and around the campus of Banaras Hindu University (BHU) was done for about two years (2004-06). During Nov 2004, a few Parthenium plants were found diseased, and symptoms were restricted to the flowers, buds, and inflorescences. The disease causes sterility and reduces seed viability, which was observed with seed germination test from infected and healthy plants. The fungal pathogen was isolated and identified as Cladosporium sp. (MCPL-461). The severity of pathogen to the reproductive organs led to serious damages of the Parthenium plants. Thus in vitro and in vivo experiments were conducted to determine the bio-control potential of Cladosporium sp. (MCPL 461) against Parthenium weed. A combinatorial effort of Cladosporium sp. (MCPL 461) bio-control potential was evaluated with different culture media, incubation periods and spores strength. Spore suspension of 10(5) to 10(12) spores ml(-1) were used to spray on healthy Parthenium plants, and it was found that severe infection symptoms were appeared at 10(10) to 10(12) spores ml(-1) suspension. LD50 was found at 10(7) spores ml(-1). To enhance the myco-herbicide activity 3% sucrose was added to the spore suspension, which further resolute the bio-control efficacy of the isolates. Only 20-30% seeds of infected plants could germinate. However the safety of non-targeted and wild plants was also tested with Lantana camera, Chromolaena odorata and found that suspension up to 10(12) spores ml(-1) were not sufficient for disease outbreak in them. PMID:20121037

  20. Control de malezas con cobertura vegetal en el cultivo de la Caraota negra (Phaseolus vulgaris L. Weed control with vegetal mulch in black beans (Phaseolus vulgaris L. crop.

    Directory of Open Access Journals (Sweden)

    Carlos Najul

    2006-08-01

    Full Text Available Con la finalidad de evaluar el nivel de control de malezas con el uso de coberturas vegetales en el cultivo de la caraota (Phaseolus vulgaris L. y determinar el efecto que sobre algunos componentes del rendimiento tienen estos métodos en comparación al control químico y manual, se condujo un ensayo bajo diseño de bloques al azar con ocho tratamientos y cuatro repeticiones. Los tratamientos de cobertura evaluados fueron: paja de Panicum maximum Jacq picada, entera, repicada y paja compostada, además de control químico (pendimetalin + linurón, dos tipos de control manual (desmalezado todo el ciclo y desmalezado a partir del inicio de la floración y un testigo siempre enmalezado. Se encontró que todos los métodos de cobertura alcanzaron más del 90% en el control de malezas a los 28 días después de la emergencia del cultivo, mientras que a 42 días sólo la paja picada mantuvo el nivel de control por encima del 90%. El mayor rendimiento del cultivo se obtuvo con el uso de la paja compostada con un valor de 2852,53 kg·ha-1, a pesar de que este tratamiento no produjo el mejor nivel de control de malezas, lo cual se atribuyó a los beneficios adicionales que habría producido la incorporación de este material orgánico al suelo. En el resto de los tratamientos de cobertura, así como en el control químico y desmalezado manual, se presentaron rendimientos similares entre sí y superiores al testigo.A trial was conducted to evaluate the effect of different kinds of weed control on the yield components of black beans (Phaseolus vulgaris L.. Eight treatments consisting in the use of soil mulches based on straw of Panicum maximum Jacq. besides chemical and manual methods of weed control were used as follows: chopped, whole, very finely chopped, and composted straw; a chemical control (pendimethalin+linuron, two types of manual control (weeding for the whole crop cycle, and weeding starting at flowering, and a control (always with weeds. A

  1. Effectiveness of the GAEC cross compliance standard Rational management of set aside (weed control through mowing) in assuring a minimum level of habitats maintenance

    OpenAIRE

    Marcello Raglione; Paolo Lorenzoni; Angelo Bonifazi; Roberto Nannelli; Elena Gagnarli; Paolo Bazzoffi; Roberta Gentile

    2011-01-01

    The cross compliance standard Rational management of set aside (weeds control through mowing) regards sowable lands subject to the withdrawal from production (set-aside) or voluntarily withdrawn from the production. The aim of this standard is: i) to ensure a minimum level of maintenance of habitats; ii) to allow the maintenance of the productive potential and fertility of the soil; iii) to prevent the uncontrolled spread of weeds. Experimental data demonstrated that rational management of s...

  2. Effect of Weeds and Some Methods for their Control in Seed Production Stands of Sainfoin (Onobrychis viciifolia Scop.

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2010-01-01

    Full Text Available During the 2007-2009 period in the experimental field of the Institute of Forage Cropsa study was conducted with the purpose of investigating the effect of weeds and somemethods for their control in seed production stands of sainfoin (Onobrychis viciifolia Scop..The trial was carried out on a slightly leached chernozem on an area with a natural backgroundof weed infestation. As a result of the study it was found:Establishment of very uniform and productive seed production stands of sainfoinrequired effective weed control concentrated mainly in the first year when the degree ofweed infestation was the highest and reached to a number of 245 plants/m2 and the freshweed biomass to 1311 g/m2.The chemical control method showed the highest efficacy had the highest efficiencywhen, in the year of stand establishment at the stage of second-fourth true leaf of sainfoin,the treatment was conducted with imazamox 40g/l (Pulsar 40 at the dose of 48 g a.i./haor with the system of Bentazon 600 g/l (Basagran 600 SL – 900 g a.i./ha – fluazifop-P-butylg/l (Fusilad Forte – 120 g a.i./ha. In the years of seed production in spring at the beginningof vegetation, the treatment was conducted with imazamox 40 g/l (Pulsar 40 at the doseof 20 g a.i./ha + adjuvant DESH at the dose of 1000 ml/ha.An alternative to the chemical method is to sow sainfoin under cover of spring barleyachieving more complete use of the area in the first year, a weed suppressive and ecologicaleffect, but some negative residual effect on the crop was also observed;The pure stands of sainfoin with chemical control of weeds had the highest seed productivity,exceeding the zero check by 24 to 28%, followed by the stands with spring barleyas a cover crop with an increase of 12% and the mixed stands of sainfoin with crestedwheatgrass had the lowest productivity.

  3. MaisTer® Power: a Terbuthylazin free new solution to control monocotyledonous and dicotyledonous weeds in maize.

    Directory of Open Access Journals (Sweden)

    Wegener, Martin

    2014-02-01

    Full Text Available MaisTer® power is a combination of the well-known active ingredients Foramsulfuron (31,5 g/L, Iodosulfuron (1,04 g/L and the new developed ai Thiencarbazone-methyl (10,0 g/L and the new safener Cyprosulfamide (15,0 g/L. All three active ingredients belong to the group of the ALS inhibitors. The product can be applied with a dose rate of 1,5 L/ha or 1,0 L/ha. Foramsulfuron and Iodosulfuron will be taken up via the leaves of the plants whereas Thiencarbazone-methyl can penetrate the plants via the roots and the leaves. By using a dose rate of 1,5 L/ha a very good residual activity against new flushes of grass or broadleaf weeds will be observed. All relevant grass and broadleaf weeds in maize will be controlled after the application of MaisTer power including Polygonum species. If a dose rate of 1,0 L/ha is used it could make sense to add a tank mix partner like Aspect to complete the spectrum against some weeds like Chenopodium album or Polygonum convolvulus.

  4. What's a Weed? Knowledge, Attitude and Behaviour of Park Visitors about Weeds.

    Directory of Open Access Journals (Sweden)

    Michael Ansong

    Full Text Available Weeds are a major threat to biodiversity globally degrading natural areas of high conservation value. But what are our attitudes about weeds and their management including weeds in national parks? Do we know what a weed is? Do we consider weeds a problem? Do we support their management? Are we unintentionally spreading weeds in parks? To answer these questions, we surveyed visitors entering a large popular national park near the city of Brisbane, Australia. Park visitors were knowledgeable about weeds; with >75% correctly defining weeds as 'plants that grow where they are not wanted'. About 10% of the visitors, however, provided their own sophisticated definitions. This capacity to define weeds did not vary with people's age, sex or level of education. We constructed a scale measuring visitors' overall concern about weeds in parks using the responses to ten Likert scale statements. Over 85% of visitors were concerned about weeds with older visitors, hikers, and those who could correctly define weeds more concerned than their counterparts. The majority think visitors unintentionally introduce seeds into parks, with many (63% having found seeds on their own clothing. However, over a third disposed of these seeds in ways that could facilitate weed spread. Therefore, although most visitors were knowledgeable and concerned about weeds, and support their control, there is a clear need for more effective communication regarding the risk of visitors unintentionally dispersing weed seeds in parks.

  5. Matran (50% clove oil) broadcast application for broadleaf weed control in spring-transplanted onions

    Science.gov (United States)

    Although corn gluten meal has shown promise as an early-season pre-emergent organic herbicide in sweet onion production, uncontrolled weeds can inflict serious yield reductions by the end of the growing season. Research was conducted in southeast Oklahoma to determine the effectiveness of Matran EC...

  6. AXXE® (Pelargonic acid) and Racer® (Ammonium Nonanoate): Weed control comparisons

    Science.gov (United States)

    Although corn gluten meal has shown promise as an early-season pre-emergent organic herbicide in squash (Cucurbita pepo L.) production, any uncontrolled weeds can inflict serious yield reductions by the end of the growing season. Organic vegetable producers need additional organic herbicides that c...

  7. Winter Cover Crops and Vinegar for Early-Season Weed Control in Sustainable Cotton.

    Science.gov (United States)

    Weeds in cotton may be suppressed by winter cover crops and the use of organic herbicides such as vinegar. Black oat (Avena strigosa), and hairy vetch (Vicia villosa), winter cover crops were planted in a sustainable production field in the Lower Rio Grande Valley of Texas and were tilled prior to ...

  8. A systematic review of nonrandomized controlled trials on the curative effects of aquatic exercise

    OpenAIRE

    Kamioka, Hiroharu; Tsutani, Kiichiro; Mutoh, Yoshiteru; Okuizum, Hiroyasu; Ohta, Miho; Handa, Shuichi; Okada, Shinpei; Kitayuguchi, Jun; Kamada, Masamitsu; Shiozawa, Nobuyoshi; Park, Sang-Jun; Honda, Takuya; Moriyama, Shoko

    2011-01-01

    Background: The objectives of this review were to integrate the evidence of curative effects through aquatic exercise and assess the quality of studies based on a review of nonrandomized controlled trials (nRCTs). Methods: Study design was a systematic review of nonrandomized controlled trials. Trials were eligible if they were nonrandomized clinical trials. Studies included one treatment group in which aquatic exercise was applied. We searched the following databases from 2000 up to July 20,...

  9. Chemicals with a natural reference for controlling water hyacinth, Eichhornia crassipes (Mart.) Solms

    OpenAIRE

    El-Shahawy Tarek Abd El-Ghafar

    2015-01-01

    Life cannot exist without water. Appropriate management of water, from the water’s source to its utilization, is necessary to sustain life. Aquatic weeds pose a serious threat to aquatic environments and related eco-environments. Short- and long-term planning to control aquatic weeds is extremely important. Water hyacinth, Eichhornia crassipes (Mart.) Solms, is one of the world’s worst pests with a bad reputation as an invasive weed. In this study we are seeking the possibility of using certa...

  10. Short-term and long-term effects of weed control and fertilization on growth and wood anatomy of a Populus deltoides clone

    Directory of Open Access Journals (Sweden)

    Silvia Estela Monteoliva

    2015-04-01

    Full Text Available Aims of study: The short- and long-term effects of weed control and fertilization on growth and wood anatomy of 10-y-old Populus deltoides were investigated. Weed control and fertilization usually leads to an increase the growth rate of trees, and consequently, a possible modification in the quality of produced wood. Area of study: We analyzed trees from an experimental plantation in Buenos Aires, Argentina (34° 50’ S Lat; 60° 30’ W Long. Methods: 32 trees from three treatments: mechanical weed control (M, chemical and mechanical weed control (CHM and fertilized plus chemical and mechanical weed control (CHM-F were analyzed. Basal area, fibre morphology, cell wall area and vessel size were measured in the growth ring 1, 3 and 10. Results: differences on wood anatomy among treatments were mainly observed at the third year (short-term effect. Long-term negative effects were not observed. Fertilized trees had greater proportion and quality of wood closer to pith. Research highlights: fibre and vessel differences seen in CHM and CHM-F compared to controls in year 3 could be interpreted as evidence of maturation in cambial development (thicker, longer and wider fibres and greater vessels. The CHM-F treatment had a greater proportion of wood that showed characteristics of more mature wood.

  11. Weed control based on real time patchy application of herbicides using image analysis as a non-destructive estimation method for weed infestation and herbicide effects

    DEFF Research Database (Denmark)

    Asif, Ali

    crop yield. The excessive use of spraying can potentially be reduced by spraying only those parts of the field where it has economic importance. The competition relation between weeds and crop was ana-lyzed in context of real time patch spray. A non-destructive image analysis method was developed to...

  12. Screening of post emergence herbicides for weed control in cotton (GOSSYPIUM HIRSUTUM) and their effect on yield and yield components

    International Nuclear Information System (INIS)

    Response of varying herbicides at different levels: round up 490 G/L at the rate of 4.7 L ha/sup -1/ and 1.5 L ha/sup -1/ (Glyphosat) and Gramaxone 20 EC (Paraquat) at the rate of 2.5 L ha/sup -1/ against untreated (control, were investigated to cotton cultivar CIM-473 under field conditions during Kharif 2002 at Agronomic Research Area. Central Cotton Research Institute, Multan. Significant control of weeds and increase in yield and yield contributing factors were observed. It was indicated that maximum yield and weed control were obtained by using Round up (Glyphosate) at the rate of 4.7 L ha/sup -1/ as compared to other treatments including untreated (control). Average boll weight was not significant among treatments but significant against control. Maximum net profit was obtained from Round up 490 G/L when treated at the rate of 4.7 L ha/sup -1/ than all other treatments. (author)

  13. Influence of low Gamma Irradiation Doses And Weed Control On Faba Bean (VICIA FABA L.) Yield Attributes

    International Nuclear Information System (INIS)

    Two field experiments were carried out in an administration field at Belbees district, Sharkia Governorate, Egypt, during two successive winter seasons (2007⁄08-2008⁄09). The study aimed to investigate the effect of four gamma irradiation doses (un irradiated seeds as a control, 10,20 and 30 Gy)and five treatments of weed management practices 1- Un weeded (control), 2- Two hand hoeings at 21 and 42 days after sowing, 3- prometryn, commercially known as Gizagared,, sprayed at pre-emergence with rate of 1 Kg⁄300 liters⁄fad. 4-Bentazon 48⁒, commercially known as Basagran 48⁒ ,sprayed at pre-emergence with the rate of 500 Cm3⁄200 ;liters water⁄fad. Sprayed at pre-emergence. 5-48⁒ sprayed at pre-emergence with the rate of 500 cm3⁄200 liters water⁄fad. On yield and yield attributes of faba bean. Results indicate that :1- Gamma irradiation with the lowest dose of 10 Gy, gave high values for plant height (112.54 cm) and number of pods⁄plant (12.22), while the highest gamma irradiation dose of 30 Gy, resulted in high values for number of seeds⁄pod (4.52), number of seeds⁄plant (52.3) , seed weight (g)⁄plant, 100- seeds weight (79.79 g), seed yield (11.39 ardab⁄fad) and straw yield (ton⁄fad). The lowest values for each of the aforementioned traits were obtained in non irradiated treatment in the combined analysis 2- Weed control by hand hoeing twice (after 21 and 24 DAS) gave the highest values for each of the aforementioned traits, followed by spraying both herbicides., prometryn + bentazon 48⁒ followed by sole herbicide Bentazon 48⁒ and sole prometryn, while unweeded treatment gave the lowest values for the respective order, in the combined analysis.

  14. Effect of reduced doses of mesosulfuron + iodosulfuron to control weeds in no-till wheat under Mediterranean conditions

    OpenAIRE

    Barros, José; G. Basch; Freixial, Ricardo; Carvalho, Mário

    2009-01-01

    Field experiments were carried out over three years (2004-05, to 2006-07) to study the efficacy of a post-emergence dual-purpose herbicide (mesosulfuron – methyl (3%) + iodosulfuron – methyl – sodium (0.6%) + mefenpyr – diethyl (9%) to control Lolium rigidum Gaud. and broad-leaved weeds in no-till wheat (Triticum aestivum L.). A ready herbicide mixture was used at three doses (6+1.2, 9+1.8 and 12+2.4 g a.i. ha–1) on two dates (beginning of tillering for L. rigidum and 2-3 pair of ...

  15. 36 CFR 222.8 - Cooperation in control of estray or unbranded livestock, animal diseases, noxious farm weeds, and...

    Science.gov (United States)

    2010-07-01

    ... estray or unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. 222.8 Section... unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. (a) Insofar as it involves... farm weeds. (2) The Animal and Plant Health Inspection Service and other Federal or State agencies...

  16. Study on control techniques of weeds in Spinacia oleracea%菠菜田杂草防除技术

    Institute of Scientific and Technical Information of China (English)

    田志慧; 沈国辉; 张兆辉

    2015-01-01

    The efficacy and selectivity to Spinacia oleracea of five preemergence and two postemergence herbicides was e-valuated in a field study.Annual weeds were effectively controlled by 96% s-metolachlor at 75~100 mL/667 m2 and 90%thiobencarb at 1 500,1 875,and 2 250 mL/hm2 applied in preemergence to both the crop and the weeds.Broadleaf weeds were controlled without affecting crop by 160 g/L phenmedipham at 3 000,4 500,and 6 000 mL/hm2 at the 4~6 leaf growth stage.Both 33%pendimethalin at 1 500~1 875 mL/hm2 and 24%oxyfluorfen at 750~900 mL/hm2 were ef-fective at controlling weeds but decreased emergence and growth of Spinacia oleracea.Butachlor ( 60%) at 1 500 ~1 875 mL/hm2 was selective and effective on field weeds but 30% benazolin -ethyl at 750 mL/hm2 did not provide adequate weed control and was phytotoxic to Spinacia oleracea.%开展5种土壤处理除草剂和2种茎叶处理除草剂防除菠菜田杂草效果和安全性评价田间试验。结果表明,菠菜播后苗前、杂草出苗前使用96%精异丙甲草胺乳油1500 mL/hm2和90%高效禾草丹乳油2250 mL/hm2,可有效控制一年生杂草危害;菠菜生长期、阔叶杂草4~6叶期使用160 g/L甜菜宁乳油3000~4500 mL/hm2,能有效防除田间阔叶杂草危害,对菠菜出苗和生长均无不良影响。33%二甲戊灵乳油1500~1875 mL/hm2和24%乙氧氟草醚乳油750~900 mL/hm2除草效果好,但对菠菜出苗和生长有明显影响。60%丁草胺乳油1500~1875 mL/hm2对菠菜安全但除草效果一般。30%草除灵悬浮剂750 mL/hm2除草效果较差,且对菠菜生长不安全。

  17. An Expert System for Identification and Control of Weeds%杂草鉴别和防治对策计算机专家系统

    Institute of Scientific and Technical Information of China (English)

    唐乐尘

    2001-01-01

    Weed identification and control expert system consists of modules such as weed identification weed description and control herbicides herbicide properties weeding guidance data input and system maintenance. Results will be given based on the requirements of endusers. The system will list out descriptions and color images of the weed for comparison and confirmation. An integrated weed control can be based on the growth traits of weeds herbicides and their descriptions derived from the expert system. It was designed and encoded on Visual FoxPro 6.0. Object-oriented design and the friendly interface enhanced the system function. This system is easy for use trial running and maintenance. Fuzzy technique builds up the ignorance function. The intelligence capacity and practicability were enhanced by the database connective technique.%系统包括杂草鉴别、杂草信息、除草处方、除草指南、农药性能和系统维护等模块。用户可采用多种鉴别方式, 系统给出鉴别结果并列出其性状描述以及彩色模式图, 供对照确认。查询各种杂草的生长特性、除草处方和除草剂信息可为杂草综合防治提供依据。软件在Visual FoxPro 6.0支撑下开发, 使用可视化与面向对象编程技术,拥有良好的界面, 系统操作简单,调试和维护方便。依靠模糊查询技术提高系统的性能,使用数据库关联技术,增强智能性和实用性。

  18. Potential new tool for weed control in organically grown agronomic crops

    Directory of Open Access Journals (Sweden)

    Knežević Stevan

    2007-01-01

    Full Text Available Field experiments were conducted during summer 2007 to determine a baseline information on crop and weed tolerance to broadcast flaming utilizing different rates of propane. The species evaluated were: maize (Zea mays, sorghum (Sorghum halepense, soybean (Glycine max, sunflower (Helianthus annuus, barnyardgrass (Echinocloa crus-galli, green foxtail (Setaria viridis, velvetleaf (Abutilon theophrasti and redroot pigweed (Amaranthus retroflexus. The propane rates applied were 0, 12.1, 30.9, 49.7, 68.5 and 87.22 kg/ha. The response of the plants to propane rates were described by log-logistic models. Plant response to flame varied depending on the species, growth stage and propane rate. Broadleaf weeds were more susceptible to flames than grasses. Field maize and sorghum were less susceptible, while soybean and sunflower were severely injured. Of all crops tested, broadcast flaming has the most potential for use in field maize.

  19. Milestone – a selective herbicide for the control of important grasses and broadleaved weeds in winter oilseed rape

    Directory of Open Access Journals (Sweden)

    Zotz, Agnes

    2016-02-01

    Full Text Available MilestoneTM herbicide contains the active substance propyzamide (500 g/L and aminopyralid (5.3 g a.e./L and is formulated as a suspension concentrate (SC. Registration for Milestone for the use in winter oilseed rape was granted in Germany in July 2014. The active substance propyzamide is well known from the product KerbTM FLO (containing 500 g/L propyzamide, suspension concentrate, SC which is widely used in winter oilseed rape (WITTROCK et al., 2008. Aminopyralid is formulated in the commercial product Runway (clopyralid + picloram + aminopyralid. Milestone is applied with a use rate of 1.5 L/ha as a post-emergence herbicide from growth stage BBCH 14 of the crop at the beginning of November until February. Kerb FLO is applied with a use rate of 1.875 L/ha at the same timing. The efficacy of Milestone and Kerb FLO was tested in randomised and replicated plot trials in Germany, France and the United Kingdom. Milestone and Kerb FLO showed comparable and very high control levels against monocotyledonous species such as Alopecurus myosuroides, Apera spica-venti, Bromus species and volunteer cereals. Milestone shows a broader spectrum of activity vs. Kerb FLO against dicotyledonous weeds such as Matricaria chamomilla, Papaver rhoeas and Centaurea cyanus. The use of Milestone in dense crops (as the situation was in autumn 2014 for many areas in Germany shows very high efficacy levels as well. The comparison of various application timings between end of October until beginning of December confirms the application date early November for best results. Milestone controls herbicide-resistant weed populations and can be considered an important part of a resistance management program not only in winter oilseed rape but as a component of an integrated weed management strategy in cropping systems.

  20. Effects of pollutant accumulation by the invasive weed saltcedar (Tamarix ramosissima) on the biological control agent Diorhabda elongata (Coleoptera: Chrysomelidae)

    International Nuclear Information System (INIS)

    Hydroponic greenhouse studies were used to investigate the effect of four anthropogenic pollutants (perchlorate (ClO4-), selenium (Se), manganese (Mn), and hexavalent chromium (Cr (VI))) on the biological control agent Diorhabda elongata Brulle. Contaminant concentrations were quantified for experimental Tamarix ramosissima Ledab. plants and D. elongata beetles. Growth of larvae was significantly reduced by Se contamination, but was not affected by the presence of perchlorate, Mn, or Cr (VI). All of the contaminants were transferred from plants to D. elongata beetles. Only Cr (VI) was accumulated at greater levels in beetles than in their food. Because T. ramosissima grows in disturbed areas, acquires salts readily, and utilizes groundwater, this plant is likely to accumulate anthropogenic pollutants in contaminated areas. This study is one of the first to investigate the potential of an anthropogenic pollutant to influence a weed biological control system. - The presence of Se, but not perchlorate, Mn, or Cr (VI), in foliage of the invasive weed saltcedar was shown to reduce growth of the biological control agent Diorhabda elongata

  1. Effects of pollutant accumulation by the invasive weed saltcedar (Tamarix ramosissima) on the biological control agent Diorhabda elongata (Coleoptera: Chrysomelidae)

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, Mary A. [Department of Entomology, University of California, Riverside, CA 92521 (United States)], E-mail: mary.sorensen@ucr.edu; Parker, David R. [Department of Environmental Science, University of California, Riverside, CA 92521 (United States); Trumble, John T. [Department of Entomology, University of California, Riverside, CA 92521 (United States)

    2009-02-15

    Hydroponic greenhouse studies were used to investigate the effect of four anthropogenic pollutants (perchlorate (ClO{sub 4}{sup -}), selenium (Se), manganese (Mn), and hexavalent chromium (Cr (VI))) on the biological control agent Diorhabda elongata Brulle. Contaminant concentrations were quantified for experimental Tamarix ramosissima Ledab. plants and D. elongata beetles. Growth of larvae was significantly reduced by Se contamination, but was not affected by the presence of perchlorate, Mn, or Cr (VI). All of the contaminants were transferred from plants to D. elongata beetles. Only Cr (VI) was accumulated at greater levels in beetles than in their food. Because T. ramosissima grows in disturbed areas, acquires salts readily, and utilizes groundwater, this plant is likely to accumulate anthropogenic pollutants in contaminated areas. This study is one of the first to investigate the potential of an anthropogenic pollutant to influence a weed biological control system. - The presence of Se, but not perchlorate, Mn, or Cr (VI), in foliage of the invasive weed saltcedar was shown to reduce growth of the biological control agent Diorhabda elongata.

  2. Weed Research in Mint

    Science.gov (United States)

    Weeds present in peppermint and spearmint reduce mint oil yield and quality. Flumioxazin combinations with clomazone and pendimethalin applied to dormant peppermint controlled prickly lettuce and flixweed without significant injury to the crop. Low rates of flumioxazin and sulfentrazone applied imm...

  3. Azafenidin: novo herbicida para o controle de plantas daninhas em Eucalyptus camaldulensis Azafenidin: a new herbicide for weed control in Eucalyptus camaldulensis

    Directory of Open Access Journals (Sweden)

    J. Constantin

    2000-01-01

    Full Text Available Um experimento de campo foi conduzido em Presidente Castelo Branco-PR, com o objetivo de avaliar a seletividade do herbicida azafenidin para a cultura de Eucalyptus camaldulensis, assim como sua eficácia no controle de algumas plantas daninhas infestantes nessa cultura. Azafenidin foi aplicado nas doses de 300, 400, 500 600 e 800 g i.a. ha-1, em pré-emergencia das plantas daninhas. Tratamentos adicionais, incluindo oxyfluorfen (720 g i.a. ha-1, uma testemunha capinada e outra testemunha sem capina, foram também incluídos. Tanto azafenidin quanto oxyfluorfen provocaram sintomas de toxicidade na cultura; no primeiro, as injúrias foram mais intensas em doses ³ 600 g i.a. ha-1. Em relação ao controle de plantas daninhas, doses de azafenidin a partir de 500 g i.a. ha-1 foram efetivas no controle de Brachiaria decumbens, Commelina benghalensis, Richardia brasiliensis e Sida santaremnensis, mesmo 180 dias após a aplicação. Doses menores de azafenidin resultaram em controle suficiente da maioria das plantas daninhas, mas com menor efeito residual.A field experiment was conducted at Presidente Castelo Branco, PR, Brazil, to evaluate the selectivity of the herbicide azafenidin to the crop Eucalyptus camaldulensis, as well as its efficacy to control some infesting weeds in this crop. Azafenidin was applied under pre-emergence conditions, at rates of 300, 400, 500, 600 and 800 g a.i. ha-1. Additional treatments, including oxyfluorfen (720 g a.i. ha-1, a weed free and a weeded check plots were also included. Both azafenidin and oxyflluorfen caused crop symptoms of phytotoxicity, with injuries being more intense for azafenidin at rates ³ 600 g a.i. ha-1. For weed control, rates of azafenidin at 500 g a.i. ha-1 or higher were effective in controlling Brachiaria decumbens, Commelina benghalensis, Richardia brasiliensis and Sida santaremnensis, even at 180 days after application. Lower rates of azafenidin provided enough control of most weeds, but

  4. Controle de plantas daninhas em cultivos orgânicos de soja por meio de descarga elétrica Weed control in organic soybean using electrical discharge

    Directory of Open Access Journals (Sweden)

    Alexandre Magno Brighenti

    2009-11-01

    Full Text Available Dois experimentos foram instalados em semeadura direta, em área de cultivo orgânico de soja, no município de São Miguel do Iguaçu, Paraná (PR, com o objetivo de avaliar o controle de plantas daninhas na cultura da soja (BRS 232 por meio de descarga elétrica. O delineamento experimental foi blocos casualizados, com quatro repetições. No experimento 1, fixou-se a voltagem de 4400V e, no experimento 2, de 6800V. Em ambos os experimentos, os tratamentos consistiram das variações de rotação do motor do trator (i 2200rpm (rotações por minutos; (ii 2000rpm; (iii 1600rpm e as testemunhas (iv capinada e (v sem capina. O equipamento utilizado para aplicação dos tratamentos foi o Eletroherb (Sayyou do Brasil. As plantas daninhas existentes na área experimental foram o amendoim-bravo (Euphorbia heterophylla, a corda-de-viola (Ipomoea spp., a guanxuma (Sida spp., o capim-marmelada (Brachiaria plantaginea e o capim-colchão (Digitaria spp.. O emprego de descarga elétrica é eficiente no controle das plantas daninhas da cultura da soja. A rotação 2200rpm proporcionou o melhor controle e, consequentemente, a maior produtividade da soja.Two experiments were carried out in no-till organic soybean area in São Miguel do Iguaçu, Paraná State, Brazil, in order to evaluate the weed control using electrical discharge. The experiments were arranged in a complete block design, with four replicates. The voltages were fixed in 4400V (experiment 1 and 6800V (experiment 2. In both experiments, the treatments consisted by different revolution tractor: (i 2200rpm (revolutions per minute; (ii 2000rpm; (iii 1600rpm; and two checks [(iv unweeded control and (v weeded control]. The equipment Eletroherb (Sayyou do Brasil was used to apply the electrical discharges. The weeds presented in the experimental area were wild poinsettia (Euphorbia heterophylla, morningglory (Ipomoea spp., prickly Sida (Sida spp., alexandergrass (Brachiaria plantaginea and crabgrass

  5. WEEDS AND WEED CONTROL TECHNOLOGY FOR ALFALFA FIELD IN BEIJING AREA%北京地区大田苜蓿地杂草及其防治技术

    Institute of Scientific and Technical Information of China (English)

    吕世海

    2001-01-01

    本文在调研、分析北京地区大田苜蓿地杂草种类、发生规律及危害特性基础上,采用土壤耕作、刈割和化学药剂相结合的措施,对苜蓿幼苗地和大田杂草进行综合防治,取得良好效果。%On base of investigating and analyzing,the species,occuring ruleand disserve characteristics of alfalfa field weeds in Beijing area were discussed.And put forward weed control methods of alfalfa seedlings were put forward.

  6. Evaluation of Pre-Emergence Herbicides for Weed Control in Cowpea (Vigna unguiculata (L.) Walp.) in a Forest - Savanna Transition Zone

    OpenAIRE

    Sunday, Omovbude; Udensi, Udensi Ekea

    2013-01-01

    Aims: To evaluate the efficacy and economic benefits of selected pre-emergence herbicides for weed control in cowpea. Study Design: Randomized complete block design with four replications was used. Place and Duration of Study: Research and Teaching Farm of Ambrose Alli University in Ekpoma (Lat. 6º 45’N, Long. 6º 8’E), in a forest-savanna transition zone of Nigeria, between August and December 2005 and August and December 2006. Methodology: Five weed control treatments e...

  7. Effects of organic manures and non-chemical weed control on wheat. II. Grain quality

    OpenAIRE

    BULUT, Sancar; ÖZTÜRK, Ali; KARAOĞLU, Mehmet Murat; YILDIZ, Nesrin

    2013-01-01

    Deficit plant nutrients, especially nitrogen, and weed competition are the most critical problems in organic farming. This research was carried out on research plots of the Agricultural Research and Extension Center of Atatürk University Agricultural Faculty during the cropping seasons of 2006-07, 2007-08, and 2008-09 under dry farming conditions. A factorial experimental design with 4 replications was used to set up the experimental plots. The factors were 2 wheat cultivars (Kırik and Doğu-8...

  8. Controle de plantas daninhas na cultura da batata Potato weed control by application of herbicides

    OpenAIRE

    Jeferson Zagonel; Marie Y. Reghin; Eloir Moresco

    1999-01-01

    O experimento foi conduzido na Fazenda Escola da UEPG, em Ponta Grossa-PR, em Latossolo Vermelho Escuro de textura média argilosa, com o objetivo de verificar a praticabilidade e a eficiência agronômica dos herbicidas metolachlor e metribuzin + metolachlor no controle de plantas daninhas na cultura da batata. O delineamento experimental foi de blocos ao acaso com nove tratamentos e quatro repetições, quais sejam: metolachlor (1,92; 2,88 e 3,84 kg i.a./ha); metribuzin + metolachlor (0,24 + 1,6...

  9. Ornamental and Turf Pest Control for Commercial Applicators: Pest Control of Ornamental Plants; NCR 12, Lawn Diseases in the Midwest; NCR 26, Lawn Weeds and their Control. Manual 89.

    Science.gov (United States)

    Craig, W. S., Comp.; And Others

    This training manual provides information needed to meet the minimum EPA standards for certification as a commercial applicator of pesticides in the ornamental and turf pest control category. The text discusses pest control of ornamental plants, lawn diseases, and lawn weeds and their control. (CS)

  10. A randomized controlled trial of aquatic and land-based exercise in patients with knee osteoarthritis

    DEFF Research Database (Denmark)

    Lund, H.; Weile, U.; Christensen, R.;

    2008-01-01

    patients reported adverse events (i.e. discomfort) in land-based exercise, while only 3 reported adverse events in the aquatic exercise. Conclusion: Only land-based exercise showed some improvement in pain and muscle strength compared with the control group, while no clinical benefits were detectable after......Objective: To compare the efficacy of aquatic exercise and a land-based exercise programme vs control in patients with knee osteoarthritis. Methods: Primary outcome was change in pain, and in addition Knee Injury and Osteoarthritis Outcome Score questionnaire (KOOS). Standing balance and strength...... was also measured after and at 3-month follow-up. Seventy-nine patients (62 women), with a mean age of 68 years (age range 40-89 years) were randomized to aquatic exercise (n = 27), land-based exercise (n = 25) or control (n = 27). Results: No effect was observed immediately after exercise cessation...

  11. Weed species shifts in glyphosate-resistant crops.

    Science.gov (United States)

    Owen, Micheal D K

    2008-04-01

    The adoption of glyphosate-based crop production systems has been one of the most important revolutions in the history of agriculture. Changes in weed communities owing to species that do not respond to current glyphosate-based management tactics are rapidly increasing. Clearly, glyphosate-resistant crops (GRCs) do not influence weeds any more than non-transgenic crops. For most crops, the trait itself is essentially benign in the environment. Rather, the weed control tactics imposed by growers create the ecological selection pressure that ultimately changes the weed communities. This is seen in the adoption of conservation tillage and weed management programs that focus on one herbicide mode of action and have hastened several important weed population shifts. Tillage (disturbance) is one of the primary factors that affect changes in weed communities. The intense selection pressure from herbicide use will result in the evolution of herbicide-resistant weed biotypes or shifts in the relative prominence of one weed species in the weed community. Changes in weed communities are inevitable and an intrinsic consequence of growing crops over time. The glyphosate-based weed management tactics used in GRCs impose the selection pressure that supports weed population shifts. Examples of weed population shifts in GRCs include common waterhemp [Amaranthus tuberculatus (Moq ex DC) JD Sauer], horseweed (Conyza canadensis L), giant ragweed (Ambrosia trifida L) and other relatively new weed problems. Growers have handled these weed population shifts with varying success depending on the crop. PMID:18232055

  12. Effects of different methods to control the parasitic weed Phelipanche ramosa (L. Pomel in processing tomato crops

    Directory of Open Access Journals (Sweden)

    Grazia Disciglio

    2016-03-01

    Full Text Available The root-parasitic weed Phelipanche ramosa (L. Pomel represents a major problem for processing tomato crops. The control of this holoparasitic plant is difficult, and better understanding of treatment methods is needed to develop new and specific control strategies. This study investigated 12 agronomic, chemical, biological and biotechnological strategies for the control of this parasitic weed, in comparison with the untreated situation. The trial was carried out in 2014 at the Department of Agriculture, Food and the Environment of the University of Foggia (southern Italy, using processing tomato plants grown in pots filled with soil from a field that was heavily infested with P. ramosa. After transplantation, top dressing was performed with 70 kg ha–1 nitrogen. A randomised block design with 3 replicates (pots was adopted. During the growing cycle of the tomato, at 70, 75, 81 and 88 days after transplantation, the number of parasitic shoots (branched plants that had emerged in each pot was determined, and the leaf chlorophyll of the plants was measured using a soil-plantanalysis- development meter. At harvesting on 8 August 2014, the major quanti-qualitative yield parameters were determined, including marketable yield, mean weight, dry matter, soluble solids, and fruit colour. The results show lower chlorophyll levels in the parasitised tomato plants, compared to healthy plants. None of the treatments provided complete control against P. ramosa. However, among the methods tested, Radicon® biostimulant (Radicon, Inc., Elk Grove Village, IL, USA, compost activated with Fusarium oxysporum, nitrogen and sulphur mineral fertilisers, EnzoneTM soil fumigant (Elliott Chemicals Ltd., Auckland, New Zealand, and a resistant tomato genotype mitigated the virulence of the attacks of this parasite. These effects should be improved by combining some of these treatments, especially for gradual and continued reduction in the seed bank of the parasite in the

  13. Weed control practices on Costa Rican coffee farms: is herbicide use necessary for small-scale producers?

    OpenAIRE

    Bellamy, Angelina Sanderson

    2010-01-01

    Abstract This paper presents research conducted during two coffee farming seasons in Costa Rica. The study examined coffee farmers? weed management practices and is presented in the form of a case study of small-scale farmers? use of labor and herbicides in weed management practices. Over 200 structured interviews were conducted with coffee farmers concerning their use of hired labor and family labor, weed management activities, support services, and expectations about the future o...

  14. Variação da competição interespecífica em milho em função do controle de plantas daninhas em faixas Variation of interspecific weed competition in corn as a function of banded weed control

    Directory of Open Access Journals (Sweden)

    A. Merotto Jr.

    2001-08-01

    Full Text Available O controle de plantas daninhas em faixas é mais uma estratégia que pode ser utilizada no manejo integrado de plantas daninhas (MIPD para aumentar a racionalização do uso do ambiente no cultivo de plantas. Os objetivos deste trabalho foram determinar o efeito do controle de plantas daninhas em faixas na linha ou na entrelinha e avaliar suas conseqüências sobre a competição interespecífica na cultura do milho. Os tratamentos constaram do estabelecimento de um gradiente de infestação de Brachiaria plantaginea, obtido com a variação da intensidade do controle em pré-emergência, e do controle de plantas daninhas em pós-emergência realizado em faixas na linha, na entrelinha ou em área total. O controle de plantas daninhas em pós-emergência em faixas não foi suficiente para reduzir os efeitos da competição interespecífica sobre o rendimento de grãos de milho, mesmo em baixas densidades de plantas daninhas. Os prejuízos causados pela presença de plantas daninhas na linha da cultura são duas a três vezes maiores em comparação com a presença destas plantas na entrelinha ou em área total da cultura. O controle de plantas daninhas na linha da cultura necessita de complementação com práticas culturais ou outros métodos de controle destas plantas na entrelinha.Banded weed control is one of the methods used for integrated weed management (IWM to increase the rationalization of environmental use in crop activities management. The aim of this work was to determine the effect of in-and between-row weed control and the effects of weed competition on corn. The treatments consisted in the establishment of a range of Brachiaria plantaginea densities by varying the intensity of weed control in pre-emergence, complemented with post-emergence weed control in-row, between row and broadcast. Banded weed control was not efficient in decreasing weed competition and reducing corn grain yield, even at low weed infestation. In-row weed

  15. Eficácia do herbicida oxyfluorfen com a cobertura de palha no controle de plantas daninhas Efficacy of oxyfluorfen with straw cover in controlling weeds

    Directory of Open Access Journals (Sweden)

    E. Negrisoli

    2009-03-01

    Full Text Available A palha pode alterar a dinâmica do herbicida oxyfluorfen no sistema de cana-crua; assim, este trabalho teve por objetivo avaliar a eficácia do oxyfluorfen em condições de casa de vegetação, com a cobertura de palha, no controle das plantas daninhas que ocorrem em cana-crua. Foram avaliadas as espécies de Brachiaria decumbens, Ipomoea grandifolia, Ipomoea quamoclit e Merremia cissoides. A dose utilizada do oxyfluorfen foi de 3 L ha-1 (720 g i.a. ha-1. Os tratamentos constaram de diferentes posicionamentos do herbicida e condições antes e após a aplicação. A porcentagem de controle das plantas daninhas foi avaliada aos 12, 20, 26, 33 e 38 DAA. Os maiores índices de controle aos 38 DAA, independentemente da planta daninha estudada, foram alcançados quando se aplicou oxyfluorfen em tratamentos com a presença de palha em cobertura, com ou sem umidade. No entanto, os resultados obtidos nos demais tratamentos mostraram-se eficientes no controle das diferentes espécies de plantas daninhas estudadas.Straw can change the dynamics of the herbicide oxyfluorfen in the raw sugarcane system. Thus, this study aimed to assess the effectiveness of oxyfluorfen with straw cover in controlling weeds in raw sugarcane under greenhouse conditions. The species Brachiaria decumbens, Ipomoea grandifolia, Ipomoea quamoclit and Merremia cissoids were evaluated and the dose used was oxyfluorfen 3 L ha-1 (720 g .i.a. ha-1. Treatments consisted of different herbicide positions and conditions before and after application. Weed control percentage was evaluated at 12, 20, 26, 33 and 38 DAA. The highest control rates at 38 DAA, regardless of the weed studied, were reached when oxyfluorfen was applied in treatments with the cover straw, with or without humidity. However, the results obtained in the other treatments were effective in controlling the different weed species studied.

  16. Weed control and green ear yield in maize Controle de plantas daninhas e rendimento de espigas verdes de milho

    Directory of Open Access Journals (Sweden)

    P.S.L. Silva

    2004-03-01

    Full Text Available The objective of this work was to evaluate the influence of weeding frequency on cultivar Centralmex green corn yield. Two experiments were conducted in Mossoró-RN (Brazil, with the use of sprinkler irrigation. A random block design with four replicates was used. It was observed that the total number and weight (TW of unhusked green ears, the number and weight of marketable unhusked ears and the number and weight of marketable husked ears were reduced under no weeding treatment. The number timing of weedings did not influence green corn yield, except for one weeding at 60 DAP, which was equivalent to the "no weeding" treatment, for TW. When maize is marketed considering the total number of green ears, higher net income is obtained when one weeding is carried out 45 days after planting.O objetivo deste trabalho foi avaliar as influências da freqüência de capinas sobre o rendimento de milho-verde do cultivar Centralmex. Dois experimentos foram realizados em Mossoró-RN, com irrigação por aspersão. Utilizou-se o delineamento de blocos ao acaso, com quatro repetições. Verificou-se que a ausência de capinas reduz o número e o peso (PT totais de espigas verdes empalhadas, o número e o peso de espigas empalhadas comercializáveis e o número e o peso de espigas despalhadas comercializáveis. O número e a época de realização das capinas não influenciaram o rendimento de milho-verde, exceto uma capina aos 60 DAP, que é equivalente ao tratamento "sem capina", para PT. Quando o milho é comercializado considerando-se o número total de espigas verdes, maior receita líquida é obtida com a realização de uma capina, aos 45 dias após o plantio.

  17. Weed discrimination using ultrasonic sensors

    OpenAIRE

    Andújar, Dionisio; Escolà i Agustí, Alexandre; Dorado, José; Fernández-Quintanilla, César

    2011-01-01

    A new approach is described for automatic discrimination between grasses and broad-leaved weeds, based on their heights. An ultrasonic sensor was mounted on the front of a tractor, pointing vertically down in the inter-row area, with a control system georeferencing and registering the echoes reflected by the ground or by the various leaf layers. Static measurements were taken at locations with different densities of grasses (Sorghum halepense) and broad-leaved weeds (Xanthium strumarium and D...

  18. Confirmation of irradiation processing doses for controlling microflora in frozen aquatic products

    International Nuclear Information System (INIS)

    Based on the research results and existing references in the hygienic standard and technique code of frozen aquatic products, a conclusion is made that the irradiation dose of 4-7 kGy could ensure bacteria count less than 5 x 104 cfu/g and no pathogen microbial detected when microbial count in the products is less than 5 x 106 cfu/g before irradiation. The irradiation dose of 4-7 kGy could be used in establishing irradiation sterilization practice for control microflora of frozen aquatic products. (authors)

  19. Crude oil derived petroleum products in the aquatic environment: priorities for control

    International Nuclear Information System (INIS)

    The available data on the environmental fate, behaviour and toxicity of five groups of petroleum products is reviewed and the information used to identify the priority of oil products for pollution control to protect the aquatic environment. The oil product groups comprise gasolines, kerosenes, other light fuel oil distillates, residual heavy fuel oils and lubricating oils. (author)

  20. A randomized controlled trial of aquatic and land-based exercise in patients with knee osteoarthritis

    DEFF Research Database (Denmark)

    Lund, Hans; Weile, Ulla; Christensen, Robin;

    2008-01-01

    patients reported adverse events (i.e. discomfort) in land-based exercise, while only 3 reported adverse events in the aquatic exercise. CONCLUSION: Only land-based exercise showed some improvement in pain and muscle strength compared with the control group, while no clinical benefits were detectable after...

  1. Preventing, controlling, and managing alien species introduction for the health of aquatic and marine ecosystems

    Science.gov (United States)

    Short, C.I.; Gross, S.K.; Wilkinson, D.

    2004-01-01

    The introduction and spread of invasive species is an emerging global problem. As economic and ecological impacts continue to grow, there will be an increasing need to develop innovative solutions and global partnerships to combat the increasing rate of invasions and their accompanying impacts. Threats to sustainable fisheries in North America associated with alien species come from many global directions and sources and can be deliberate or the unintended consequence of other actions. Decisions about the role of sustainable fisheries in protecting and restoring the health of aquatic ecosystems become even more complex when economic and social factors are considered along with environmental impacts, because many intentionally introduced species also have associated economic and community costs and benefits. Actions designed to prevent or control alien species in an aquatic ecosystem are often complicated by these nonenvironmental factors as well as public perception and opinion. Aquatic ecosystems are disturbed to varying degrees by alien species, including disease organisms. Prevention is the first and best line of defense. Determining likely pathways and effective countermeasures is more cost-effective than either eradication or control. Our ability to quickly identify new species and their associated risk to ecosystems is critical in designing and implementing effective control and management actions. Lack of infrastructure and necessary resources, clear-cut authority for regulation and action, and scientific information about the biology of alien species and effective control techniques are often limiting factors that prevent the needed action to protect aquatic ecosystems.

  2. Herbicidas no transplante de mudas de sisal (Agave sisalana perr. Weed control and herbicide selectivity to sisal (Agave sisalana perr.

    Directory of Open Access Journals (Sweden)

    Antonio Luiz de Barros Salgado

    1980-01-01

    Full Text Available Com o objetivo de verificar a eficiência de hebraicas no controle de plantas daninhas e sua seletividade à cultura do sisal, foi instalado, em setembro de 1976, um experimento de campo em solo argiloso, com os seguintes tratamentos (i.a./hectare trifluralin a 0,84 e 0,96kg em pré-plantio com incorporação; alachlor a 2,40 e 3,26kg; metribuzin a 0,70 e 0,84kg; bromacil a 1,60 e 2,40kg; terbacil a 1,60 e 2,40kg; diuron a 2,40 e 3,20kg; simazine a 3,20 e 4,00kg; fluometuron a 1,20 e 1,60kg, todos em pré-emergência; uma testemunha carpida e outra sem capina. Foram feitas avaliações de controle do mato aos 67 e 114 dias e da condição da cultura aos 600 dias após a aplicação. Aos 114 dias, o controle de gramíneas foi acima de 90% pelo trifluralin, bromacil e terbacil, em torno de 80% pelo simazine, e inferior a 75% pelos demais; para dícotiledôneas, o controle foi de 90 a 100% pelo bromacil e terbacil, e de 80 a 85%o pelo simazine. Nenhum dos tratamentos afetou a cultura durante o período considerado, que foi de 600 dias. Aos 550 dias, fez-se avaliação da área coberta por reinfestação do mato, tendo o terbacil controlado ainda 75 e 95% do total, respectivamente, para as doses menor e maior; o trifluralin, 60 e 70% e, os demais, abaixo de 45%. Na avaliação final da cultura, aos 600 dias, foram considerados: população de plantas, número de plantas com perfilhos e condição da cultura. Os tratamentos que realizaram melhor controle do mato apresentaram também os melhores índices de desenvolvimento da cultura, atestando sua seletividade.The weed control with herbicides and its selectivity to sisal were studied on a clay soil field trial. The treatments (in a.i./ha were: 0.84 and 0.96kg of pre-plant incorporated trifluralin; 2.40 and 3.26kg of alachlor; 0.70 and 0.84kg of metribuzin; 1.60 and 2.40kg of bromacil; 1.60 and 2.40kg of terbacil; 2.40 and 3.20k- of diuron; 3.20 and 4.00kg of simazine; 1.20 and 1.60kg of fluometuron

  3. Effect of different doses of post-emergence-applied iodosulfuron on weed control and grain yield of malt barley (Hordeum distichum L., under Mediterranean conditions

    Directory of Open Access Journals (Sweden)

    Barros José Calado

    2016-01-01

    Full Text Available A study was carried out over a two year period (2009/2010 and 2012/2013 on an experimental farm in the Alentejo region (Beja, in southern Portugal where rainfed malt barley (Hordeum distichum L. is sown at the end of autumn or beginning of winter (November- December. The aim of this experiment was to study the efficiency of the herbicide iodosulfuron-methyl-sodium to control post-emergence broadleaved weeds in this cereal crop. The malt barley crop was established using no-till farming. This technology provides the necessary machine bearing capacity of the soil to assure the post-emergence application of herbicides at two different weed development stages. The herbicide iodosulfuron-methyl-sodium was applied at three doses (5.0, 7.5, and 10.0 g a. i. · ha-1 and at two different broadleaved weed development stages (3 to 4 and 6 to 7 pairs of leaves, that also corresponded to two different crop development stages (beginning of tillering and complete tillering. The results indicated that early herbicide application timing provided a significantly higher efficiency for all the applied herbicide doses, but this better weed control was not reflected in a higher crop grain yield. The lack of a higher crop grain yield was probably due to a crop phytotoxicity of the herbicide, when used at an early application timing.

  4. Guidelines for management of noxious weeds at Hanford

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    Swain, Kishore; Nørremark, Michael; Jørgensen, Rasmus N.; Midtiby, Henrik S.; Green, Ole

    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 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 L...

  6. Arsenic removal in solution using non living bio masses of aquatic weed; Remocion de As en solucion empleando biomasas no vivas de maleza acuatica

    Energy Technology Data Exchange (ETDEWEB)

    Marin A, M. J.

    2010-07-01

    Arsenic is a metalloid considered among the most dangerous to health. The As maximum level allowed of drinkable water is 0.01 mg/L established by the Who. Several techniques have been proposed to remove arsenic from water, among which are the sorption processes in economic biological materials, which has advantages for its high efficiency in dilute toxic removing from contaminated water, for these reason it is necessary to study new bio sorbents materials which are economic, simple and easy to apply in the treatment of contaminated areas. The aim of this project was evaluate the removal of As (V) in solution using two non living aquatic plants: water hyacinth (Eichhornia crassipes) and lesser duckweed (Lemna minor), characterize these materials and compare the efficiency between both; the parameters evaluated were the As (V) initial concentration in solution, contact time, ph value and the amount of biomass in contact with them. It describes the method to prepare the non living plants. The physicochemical characterization by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis was made. The results shown that cellulose is the main component confirmed by the techniques above mentioned. Surface characterization of Eichhornia crassipes and Lemna minor by specific surface area, shown 1.3521 m{sup 2}/g and 0.6395 m{sup 2}/g respectively, the hydration kinetic indicates that 24 h was the maximum hydration time for both plants; the point of zero charge determination by mass titration gives a ph=6.1 for the first plant and ph=7.1 for the second plant, finally the active site density obtained for the plants were of 8.57 sites/nm{sup 2} and 12.47 sites/nm{sup 2}. The point of zero charge was analyzed for know the ph from which the As (V) species are removal preferably. Tested contact processes between bio sorbent-As (V) were performed to assess the ability of bio masses to removal As (V) from aqueous solutions

  7. Effectiveness of the GAEC cross compliance standard Rational management of set aside (weed control through mowing in assuring a minimum level of habitats maintenance

    Directory of Open Access Journals (Sweden)

    Marcello Raglione

    2011-08-01

    Full Text Available The cross compliance standard Rational management of set aside (weeds control through mowing regards sowable lands subject to the withdrawal from production (set-aside or voluntarily withdrawn from the production. The aim of this standard is: i to ensure a minimum level of maintenance of habitats; ii to allow the maintenance of the productive potential and fertility of the soil; iii to prevent the uncontrolled spread of weeds. Experimental data demonstrated that rational management of set aside according to GAEC standard 4.2 is very effective in increasing soil quality and stabilizing the edaphic animal community in terms of biodiversity. On the contrary minor improvement are made by the standard in the inland areas and high hills and mountain areas, where long crop rotations are adopted and soils are mainly used for long lasting natural or artificial meadow. The rule appears to be ineffective and even not suitable to prevent the spread of weeds, as the only one mowing or mulching of the natural vegetation, made mandatory by the standard, does not prevent the spreading of unwanted seeds to neighbouring cultivated fields. According to many authors, to leave a land uncultivated for a long period of time is not a good agricultural practice. Natural vegetation cover which persists for a long period during the year is detrimental to the subsequent crop, because of the abundant seed production and consequent spread of weeds. At least two or three cuttings per year are needed to effectively reduce the spread of weeds, particularly in the presence of perennial species. Moreover, in order to avoid the spread of a single biological group of weeds, it is necessary to use different types of mechanical work in the course the year. Furthermore, the cutting period should be carefully chosen. Another suggested weed control practice is the use of doses of systemic foliar-absorption herbicides lower than the minimum quantity recommended and approved. In fact, in

  8. Nonchemical weeding of medicinal and aromatic plants

    OpenAIRE

    Carrubba, Alessandra; Militello, Marcello

    2013-01-01

    Medicinal and aromatic plants are major crops of domestic and industrial interest. Medicinal and aromatic plants are increasingly organically grown to enhance profitability. However, the presence of weeds may lead to a decrease in both yield and quality. Therefore, nonchemical methods of weed control are needed. In this study, mechanical weeding, flaming, stale seedbed, and biodegradable mulch were tested from 2003/2004 to 2006/2007 on coriander, fennel, and psyllium. Biomass and seed yield w...

  9. Weed management strategies for castor bean crops

    OpenAIRE

    Augusto Guerreiro Fontoura Costa; Valdinei Sofiatti; Cleber Daniel de Góes Maciel; Juliana Parisotto Poletine; João Igor de Sousa

    2014-01-01

    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 s...

  10. Controle de plantas daninhas em soja com doses reduzidas de herbicidas Soybean weed control with reduced rates of herbicides

    Directory of Open Access Journals (Sweden)

    Nilson G. Fleck

    1995-01-01

    . It was obtained Alexandergrass control around 95% for all the treatments, with small but not significant variations among them. Soybean seed yield was equivalent for the hoeing check, haloxyfop-methvl at 90 and 60 g/ha and sethoxydim at 220, 110, and 55+55 g/ha. The additional treatments were equivalents among them, but all surpassed the weeded check, which produced the lowest yield. These results evidence the possibility of using reduced herbicides rates, which may reach yield levels as high as those attained with full rates.

  11. Weed management research in alfalfa seed production in Washington state

    Science.gov (United States)

    Weed control is an important component of producing high quality and high yielding alfalfa seed. Alfalfa seed is produced with wider row and lower plant populations than alfalfa forage requiring greater weed management inputs. Flumioxazin was evaluated for weed control in alfalfa seed and forage pro...

  12. Legume-cereal intercropping as a weed management tool

    OpenAIRE

    Hauggaard-Nielsen, Henrik; Jørnsgaard, Bjarne; Jensen, Erik Steen

    2003-01-01

    Weed density and biomass is often markedly reduced in intercrops (IC) compared to the respective sole crops (SC). Such IC-weed control advantages by either (i) Weed-suppression; a more effec-tive use of resources by IC or suppressing weed growth through allelopathy compared to SC or (ii) Weed-tolerance; use of resources that are not exploitable by weeds or convert resources to harvestable material more efficiently than SC. A higher degree of interspecific competition combined with a certain c...

  13. Sistemas de control de malezas en maiz (Zea mays L.: efecto de metodos de control, densidad y distribucion del cultivo Weed control systems in corn: effects of control methods, density and plant distribution

    Directory of Open Access Journals (Sweden)

    G. Martinez

    1982-12-01

    realización de una escarda adicional no mejora significativamente el control de malezas, no afectando tampoco la incidencia de enfermedades, ni el desarrollo del cultivo, por lo cual resulta innecesaria. Las escardas tienen como principal efecto eliminar la interfe rencia presentada por las malezas y si éstas son eliminadas de otra manera, la realización de aquéllas no apareja beneficios significativos.An experiment was conducted at the Research Station of the University of Chapingo (Mexico (2250 m above sea level, average annual rainfall 550 mm( loamy soil, 1,7% O.M., where different cultural practices were combined in order to design a weed control system for corn. The work was done under rainfed conditions and the variables included were: two population densities (44.400 and 66.600 pl/ha, two plant distributions (normal and equidistant and seven weed control methods (cyanazine + alachlor (1,2 + 1,92 kg/ha, atrazine + alachlor (1,2 + 1,44 kg/ha, one cultivation, two cultivations, a weeded check, a weeded check + two cultivations and a weedy check. The main weed species were: pigweed (Amaranthus sp., Lopezia mexicana Jacq., hairy galinsoga (Galin-soga parviflora Cay., Encelia mexicana Mart., Sporobulus poiretti (Roem. et Sch. Hich., and large crabgrass (Digitaria sanguinalis (L. Scop.. The increase in plant population had no effect on the degree of weed control, incidence of diseases and crop growth. The equidistant distribution improved weed control over the normal one, but it also had a nigher incidence of diseases; this, is turn, may have caused the lack of differences in vegetative growth, a lower amount of cobs per ha and the lack of difference in grain yield between the two distributions. Atrazine + alachlor was better than cyanazine + alachlor in terms of weed control, although the difference was statistically observed only for the visual ratings. There were no differences between both chemical treatments in terms of incidence of diseases or their effect on crop

  14. Vision-based weed identification with farm robots

    OpenAIRE

    Swain, Kishore C.; Nørremark, Michael; Bochtis, Dionysis; Sørensen, Claus Grøn; Green, Ole

    2010-01-01

    Robots in agriculture offer new opportunities for real time weed identification and quick removal operations. Weed identification and control remains one of the most challenging task in agriculture, particularly in organic agriculture practices. Considering environmental impacts and food quality, the excess use of chemicals in agriculture for controlling weeds and diseases is decreasing. The cost of herbercides and their field applications must be optimized. As an alternative, a smart weed i...

  15. Evaluation of the Upland Weed Control Potentiality of Green Tea Waste-Rice Bran Compost and Its Effect on Spinach Growth

    Directory of Open Access Journals (Sweden)

    M. A. I. Khan

    2007-01-01

    Full Text Available This study evaluated the upland weed control potentiality, germination inhibition ability and growth suppression efficiency of the five combinations of green tea waste rice bran compost (GRC. GRC was prepared by mixing green tea waste and rice bran at five ratios, and allowed to decompose for 5 mo. Application of GRC suppressed weed growth up to 93.4% in number and 95.4% in dry weight in 2004, and 80.7% in number and 73.4% in dry weight of weeds in 2005, as compared with the untreated control (only soil under the greenhouse condition. Among the five combinations of GRC, rice bran alone (RC showed the significantly highest and green tea waste alone (GC showed the lowest weed suppressing activity in both years. The weed control potentiality of GRC was increased by the increase of rice bran percentages in the mixture. The exudates of GRC inhibited the hypocotyl and radicle elongation of lettuce seedlings when examined by the sandwich method. The water extracts of GRC also inhibited the germination and radicle elongation of the test species in the seed germination tests. The growth inhibitory activity of RC was greater than that of GC, and radicle elongation was more sensitive than seed germination and hypocotyl elongation in all bioassays. The inhibitory activity of GRC water extract varied with the test species and was higher for the dicotyledonous species than monocotyledonous species. The inhibitory effect on seed germination and seedling growth increased as the extract concentration increased. The concentration dependent responses of test species to the water extract of GRC indicated that it might contain phytotoxic substances that were responsible for growth inhibition. Moreover, GRC promoted spinach growth significantly compared with the untreated control. These results suggest that the use of 30% green tea waste + 70% rice bran mixture compost (GRC-3 might be useful to control the upland weeds and enhance spinach growth among the five

  16. Corn yield response to weed and fall armyworm controls Rendimento do milho em resposta ao controle de plantas daninhas e da lagarta-do-cartucho

    Directory of Open Access Journals (Sweden)

    M.S. Lima

    2010-01-01

    Full Text Available The interference imposed the by weeds on corn decreases practically all vegetative characteristics. As consequence, the green ear and grain yield are also reduced. Losses due to the fall armyworm (Spodoptera frugiperda attack can reduce corn grain yield up to 34%. In general, weed and insect control issues are addressed separately in research papers. Nevertheless, interaction between weeds and insects may exist. This study aimed to evaluate green ear and corn grain yield response to weed and fall armyworm control. A completely randomized block design with split-plots and five replicates was adopted. Corn cultivar AG 1051 was grown under weedy conditions or with control by hand hoeings performed at 20 and 40 days after planting. Fall armyworm control (applied to subplots was performed with sprays of water (control, deltamethrin (5g active ingredient ha-1; neem oil, at 0.5% (diluted in water, and neem leaf extract at 5%. Each product was sprayed three times, at seven-day intervals, starting at the 7th day after planting, using 150 L ha-1 of the tank solution. Dry mass of the above-ground part, internode diameter, leaf length, leaf width, leaf area, green ear yield and grain yield of corn were reduced due to the lack of weed control. Fall armyworm control in the weeded plots did not influence green ear yield and grain yield, except green mass of marketable, husked ears, which was reduced when the caterpillar was not controlled. Without weed control, neem extracts and deltamethrin sprays provided highest yields of number and total weight of green ears with husks, number and weight of marketable ears with husks and number of marketable ears without husks. The best results for husked ear mass and for grain yield were obtained with neem extract and deltamethrin, respectively.A interferência imposta pelas plantas daninhas ao milho reduz praticamente todas as características vegetativas. Em conseqüência, os rendimentos de espigas verdes e degrãos s

  17. WEED CONTROL IN GENETICALLY MODIFIED GLYPHOSATE-TOLERANT SOYBEAN MANEJO DE PLANTAS DANINHAS EM SOJA GENETICAMENTE MODIFICADA TOLERANTE AO GLYPHOSATE

    Directory of Open Access Journals (Sweden)

    Júlio Cezar Durigan

    2011-04-01

    Full Text Available The transgenic production systems, as well as conventional systems, require, in addition to chemical control, the adoption of other weed management strategies. This study was developed to evaluate the weed chemical control in glyphosate tolerant soybean, associated to cover crops cultivated in the autumn/winter. The experiment was carried out under field conditions at the FCAV/Unesp, Jaboticabal, São Paulo State, Brazil. A randomized split-plot block design was used, with four replications. St. Lucia Grass (Brachiaria brizantha ‘Marandu’, forage millet (Pennisetum americanum ‘BN2’, and a treatment with spontaneous growth vegetation were evaluated for plots, and, for subplots, the herbicides glyphosate, chlorimuron - ethyl plus lactofen, and fluazifop-p-butyl, in a sequential spraying, and two controls without any application. Grass cover contributed to the chemical control, suppressing weeds, and the single application of 720 g a.e. ha-1 of glyphosate, independently of the cover crop cultivated in the autumn/winter, was sufficient for adequately controlling Acanthospermum hispidum, Alternanthera tenella, Amaranthus sp., Bidens pilosa, Xanthium strumarium, Cenchrus echinatus, Digitaria sp., and Eleusine indica, with results similar to the treatment (chlorimuron-ethyl + lactofen + fluazifop-p-buthyl. When compared to the weeded control, the herbicides did not affect plants height, dry matter of the aerial parts, mass of 100 grains, and grain yield. Soybean plants grown over St. Lucia Grass and forage millet presented a higher height, however, no other feature was influenced by the cover crop.

    KEY-WORDS: Brachiaria brizantha; Pennisetum americanum; no-tillage; Roundup Ready; spontaneous vegetation.

    Os sistemas de produção transgênicos, assim como os

  18. Antibiotic resistance in urban aquatic environments: can it be controlled?

    Science.gov (United States)

    Manaia, Célia M; Macedo, Gonçalo; Fatta-Kassinos, Despo; Nunes, Olga C

    2016-02-01

    Over the last decade, numerous evidences have contributed to establish a link between the natural and human-impacted environments and the growing public health threat that is the antimicrobial resistance. In the environment, in particular in areas subjected to strong anthropogenic pressures, water plays a major role on the transformation and transport of contaminants including antibiotic residues, antibiotic-resistant bacteria, and antibiotic resistance genes. Therefore, the urban water cycle, comprising water abstraction, disinfection, and distribution for human consumption, and the collection, treatment, and delivery of wastewater to the environment, is a particularly interesting loop to track the fate of antibiotic resistance in the environment and to assess the risks of its transmission back to humans. In this article, the relevance of different transepts of the urban water cycle on the potential enrichment and spread of antibiotic resistance is reviewed. According to this analysis, some gaps of knowledge, research needs, and control measures are suggested. The critical rationale behind the measures suggested and the desirable involvement of some key action players is also discussed. PMID:26649735

  19. Control of amphibious weed ipomoea (Ipomoea carnea by utilizing it for the extraction of volatile fatty acids as energy precursors

    Directory of Open Access Journals (Sweden)

    M. Rafiq Kumar

    2015-01-01

    Full Text Available Volatile fatty acids (VFAs, comprising mainly of acetic acid and lesser quantities of propionic and butyric acids, are generated when zoomass or phytomass is acted upon by acidogenic and acetogenic microorganisms. VFAs can be utilized by methanogens under anaerobic conditions to generate flammable methane–carbon dioxide mixtures known as ‘biogas’. Acting on the premise that this manner of VFA utilization for generating relatively clean energy can be easily accomplished in a controlled fashion in conventional biogas plants as well as higher-rate anaerobic digesters, we have carried out studies aimed to generate VFAs from the pernicious weed ipomoea (Ipomoea carnea. The VFA extraction was accomplished by a simple yet effective technology, appropriate for use even by laypersons. For this acid-phase reactors were set, to which measured quantities of ipomoea leaves were charged along with water inoculated with cow dung. The reactors were stirred intermittently. It was found that VFA production started within hours of the mixing of the reactants and peaked by the 10th or 11th day in all the reactors, effecting a conversion of over 10% of the biomass into VFAs. The reactor performance had good reproducibility and the process appeared easily controllable, frugal and robust.

  20. Allelopathy and Its Applications in Weed Control%化感作用及其在杂草防除中的应用

    Institute of Scientific and Technical Information of China (English)

    石旭旭; 王红春; 高婷; 娄远来

    2013-01-01

    Allelopathy is widely present in the plant kingdom and has great potential for weed control.We mainly discussed the determination of allelopathy,the release pathways of allelochemicals,the mechanism of action of allelopathic compounds,and the application and potential of allelopathy for weed control.%化感作用在植物界中广泛存在,在杂草防除方面潜力巨大.重点对化感作用的判定、化感物质的释放途径、化感作用的作用机制及其在杂草防除中的应用进行了讨论,并对化感作用在杂草防除中的应用方式和应用潜力进行了探讨.

  1. INTEGRATION OF MECHANICAL AND CULTURAL CONTROL TREATMENTS TO MANAGE INVASIVE SHRUB Chromolaena odorata AND OTHER WEEDS UNDER DROUGHT CONDITIONS IN PASTURE AREA

    OpenAIRE

    M. Rusdy; R.Sjahril; M. Riadi; Budiman

    2013-01-01

    A field experiment was conducted on Chromolaena odorata dominated pasture with the objectives of evaluating efficacy of integrated of mechanical and cultural control on weed suppression and determining botanical composition of plant species after treatment started. The treatments were, T1 slashing of Chromolaena every month, T2 digging up of Chromolanea, and exposed to dry (mulching), T3 digging up of Chromolaena followed by burning, T4 digging up of Chromolaena followed by burning and sowing...

  2. 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.

  3. Diferenciação de espécies daninhas aquáticas pela análise multivariada de caracteres estruturais foliares Differentiation of aquatic weeds by multivariate analysis of foliar structural characters

    Directory of Open Access Journals (Sweden)

    N.V. Costa

    2006-01-01

    Brachiaria mutica, Brachiaria subquadripara, Panicum repens, Eichhornia crassipes, Heteranthera reniformis, Typha subulata, and Enhydra anagallis. Leaf blade samples were collected, fixed in FAA 50, infiltrated in glycol metacrylate resin, cut transversally with 8 mm thickness, and stained with toluidine blue. Structural characters in vein and internerval regions were quantitatively evaluated (% for adaxial and abaxial epidermis, vascular bundle, vascular bundle sheath, esclerenchyma, parenchyma, and spongy aerenchyma. Leaf thickness, stomata and trichome number were determined at the internerval region. The quantitative structural characters of the leaf were submitted to Clusters Analysis and Principal Components Analysis. Three groups were formed according to similarity levels: group 1 - B. mutica, B. subquadripara, and P. repens (Poaceae; group 2 - E. crassipes and H. reniformis (Pontederiaceae, and E. anagallis (Asteraceae; group 3 - only for T. subulata (Typhaceae. The structural characters with high discriminatory degree were: adaxial epidermis (internerval region; abaxial epidermis, vascular bundle, vascular bundle sheath, esclerenchyma and spongy aerenchyma (middle vein and internerval region; leaf thickness; and stomata number. The quantitative structural characters allowed the differentiation of these aquatic weed species during the vegetative period.

  4. Weed management in tropical turfgrass areas: A review

    OpenAIRE

    Uddin Kamal M.D.; Juraimi Shukor Abdul; Ismail Razi Mohd

    2012-01-01

    Cultural practices promoting vigorous, environmentally friendly dense turf are discussed. These are the most important and least recognized means of preventing weed establishment and encroachment which includes appropriate propagation material selection, sanitation and cultivation, adjustment of planting time, manual weed control (hand pulling, hoeing and rouging), turfgrass selection to better compete with weed populations, applying physiological stresses, fertilizer management, moistu...

  5. Study of effective application of 2,4-D on corn in order to control of red root Pig weed and common lambs quarters, by using of 14 C labeled Herbicide Tracer technique

    International Nuclear Information System (INIS)

    One of the suitable way to control the perennial weeds in the corn production is the application of selective herbicides. In order to study the best application time of 2,4-D to control red root weed and common lambs quarters an experiments was carried out at the Nuclear Research Center for agriculture and medicine in Karaj (2001-2002). Based on our research study, different growth stages of corn and two weeds were produced under the activity of 0.05-0.12μCi (in each 10 ml of solution), through the ad axial surface. The plants were harvested 48 hours after the treatment and divided into inoculated leaf, plant above and under the inoculated leaf. This study shows that 2-3 leaf stages of corn is the best application time of selective control of red root pig weed and common lambs quarters

  6. Control Effects of Two-Batch-Duck Raising with Rice Framing on Rice Diseases, Insect Pests and Weeds in Paddy Field

    Directory of Open Access Journals (Sweden)

    Kai-ming Liang

    2012-10-01

    Full Text Available Rice-duck farming system is one of the means of organic rice farming, in which the weeds, diseases and insects could be effectively controlled with minimal or no pesticide and herbicide application. Whereas in conventional rice-duck farming system the controlling effect on diseases, insect pests and weeds was slowly disappeared after the rice heading stage at which ducks were driven out of the paddy field. To fill up the blank period of pasture activities of ducks, this study put forward two new rice-duck farming systems innovated from the conventional rice-duck farming system, in these new systems, two batches of ducks were raised with rice within one rice planting season. The results revealed that the overall controlling effect of ducks on rice diseases, insect pest and weeds was significantly enhanced in the two new rice-duck farming systems without agrochemicals application. It might be suggested that these two new systems have potential application as biocontrol agent for the organic rice agriculture.

  7. Research Progress on Weed-controlling by Using Allelochemicals%利用化感物质防除杂草研究进展

    Institute of Scientific and Technical Information of China (English)

    赵强; 董晓宁; 井伟龙; 赵海福

    2012-01-01

    该文阐述了化感作用的作用机理,国内外植物化感抑草的研究现状,进而指出了植物化感作用在抑制杂草方面的优越性及存在的问题,同时对其未来的发展进行了展望.%By elaborating the mechanism of action of allelopathy and the research status of weed-controlling of allelopathy at home and abroad,further pointing out superiority and existing problems of allelopathy in the management of weeds,at the same time looking into the future.

  8. Occurrence, genetic control and evolution of non-target-site based resistance to herbicides inhibiting acetolactate synthase (ALS) in the dicot weed Papaver rhoeas.

    Science.gov (United States)

    Scarabel, Laura; Pernin, Fanny; Délye, Christophe

    2015-09-01

    Non-target-site resistance (NTSR) to herbicides is a major issue for the chemical control of weeds. Whilst predominant in grass weeds, NTSR remains largely uninvestigated in dicot weeds. We investigated the occurrence, inheritance and genetic control of NTSR to acetolactate synthase (ALS) inhibitors in Papaver rhoeas (corn poppy) using progenies from plants with potential NTSR to the imidazolinone herbicide imazamox. NTSR to imazamox was inherited from parents over two successive generations. NTSR to tritosulfuron (a sulfonylurea) was observed in F1 generations and inherited in F2 generations. NTSR to florasulam (a triazolopyrimidine) emerged in F2 generations. Our findings suggest NTSR was polygenic and gradually built-up by accumulation over generations of loci with moderate individual effects in single plants. We also demonstrated that ALS alleles conferring herbicide resistance can co-exist with NTSR loci in P. rhoeas plants. Previous research focussed on TSR in P. rhoeas, which most likely caused underestimation of NTSR significance in this species. This may also apply to other dicot species. From our data, resistance to ALS inhibitors in P. rhoeas appears complex, and involves well-known mutant ALS alleles and a set of unknown NTSR loci that confer resistance to ALS inhibitors from different chemical families. PMID:26259184

  9. Application Technology of Chemical Weed Control for Newly Planted Woodland%新植林地化学除草应用技术研究

    Institute of Scientific and Technical Information of China (English)

    董培田; 李荣岐; 王韡烨

    2012-01-01

    Weed species and occurrence of abandoned lands, clearcutting blanks of Longshan & Tieshan Forest farm were investigated. Through application experiments of oxyfluorfen (goal) , sethoxydim, roundup, SYL granulated herbicide, result shows that: control effect of chemical weed is good and the cost is low in newly planted young woodland ;it have significance to change the forestry traditional farming methods and promote the development of modem forestry ; it proposed practical technical solutions and supporting measures for chemical weed control.%通过对七台河市龙山林场、铁山林场退耕地、人工林皆伐迹地幼林地杂草种类及发生规律调查,以割地草(果尔)、拿捕净、农达、撒益林颗粒剂等几种主要除草剂的应用试验,结果表明,新植幼林地化学除草效果好,成本低,对改变林业传统耕作方式,促进现代林业发展具有重要意义,同时提出了化学除草切实可行的技术方案和配套措施。

  10. A systematic review of nonrandomized controlled trials on the curative effects of aquatic exercise

    Directory of Open Access Journals (Sweden)

    Kamioka H

    2011-03-01

    Full Text Available Hiroharu Kamioka1, Kiichiro Tsutani2, Yoshiteru Mutoh3, Hiroyasu Okuizum4, Miho Ohta5, Shuichi Handa4, Shinpei Okada6, Jun Kitayuguchi7, Masamitsu Kamada7, Nobuyoshi Shiozawa8, Sang-Jun Park4, Takuya Honda4, Shoko Moriyama41Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, Japan; 2Department of Drug Policy and Management, Graduate School of Pharmaceutical Sciences, 3Department of Physical and Health Education, Graduate School of Education, The University of Tokyo, Tokyo, Japan; 4Mimaki Onsen (Spa Clinic, Tomi City, Japan; 5Laboratory of Aqua, Health, and Sports Medicine, 6Physical Education and Medicine Research Foundation, Nagano, Japan; 7Physical Education and Medicine Research Center Unnan, Unnan City, Japan; 8Department of Longevity and Social Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, JapanBackground: The objectives of this review were to integrate the evidence of curative effects through aquatic exercise and assess the quality of studies based on a review of nonrandomized controlled trials (nRCTs.Methods: Study design was a systematic review of nonrandomized controlled trials. Trials were eligible if they were nonrandomized clinical trials. Studies included one treatment group in which aquatic exercise was applied. We searched the following databases from 2000 up to July 20, 2009: MEDLINE via PubMed, CINAHL, and Ichushi-Web.Results: Twenty-one trials met all inclusion criteria. Languages included were English (N = 9, Japanese (N = 11, and Korean (N = 1. Target diseases were knee and/or hip osteoarthritis, poliomyelitis, chronic kidney disease, discomforts of pregnancy, cardiovascular diseases, and rotator cuff tears. Many studies on nonspecific disease (healthy participants were included. All studies reported significant effectiveness in at least one or more outcomes. However results of evaluations with the TREND and CLEAR-NPT checklists generally

  11. Attempts to control aquatic Crassula helmsii at Huis ter Heide (Tilburg, The Netherlands), with special reference to dye treatment

    OpenAIRE

    Denys, Luc; van Valkenburg, Johan; Packet, Jo; Scheers, Kevin; De Hoop, Erwin; Adriaens, Tim

    2014-01-01

    Several methods were deployed simultaneously to control, if not eradicate, the highly invasive Crassula helmsii (Australian swamp stonecrop, New Zealand pigmy weed) in a newly created shallow pond adjoining the heath and moorland pools of the Dutch nature reserve Huis ter Heide. Measures included mechanical removal of top soil after draining, followed by extensive covering of pond margins with non-transparent foil, regular manual removal of washed-up plants, and addition of non-toxic dyes. Th...

  12. GWN-3189 B – A new selective herbicide based on Triallate for control of herbicide resistant grass weed in cereals

    Directory of Open Access Journals (Sweden)

    Mühlschlegel, Friedrich

    2014-02-01

    Full Text Available With substantial work on the formulation, Gowan offers a new herbicide (GWN-3189 B based on Triallate for use on winter wheat, winter barley, winter rye, winter triticale and spring barley. GWN-3189B will be applied from pre-emergence to early post-emergence of the crop and offers a broad spectrum against grass-weeds. GWN-3189 B is selective on all cereal species. As soil herbicide GWN-3189 B offers interesting alternatives in grass-weed resistance management. The efficacy on grass weed, especially on Alopecurus myosuroides (blackgrass, Apera spica venti (silky bentgrass and Lolium multiflorum (italian ryegrass is demonstrated with results of field trials performed in France, Great Britain and Germany.

  13. The Identification, Types, Taxonomic Orders, Biodiversity and Importance of Aquatic Insects

    Directory of Open Access Journals (Sweden)

    J.F.N. Abowei

    2012-10-01

    Full Text Available The identification, types, taxonomic orders, biodiversity and importance of aquatic insects was reviewed to facilitate sustainable culture fisheries management and practice. Aquatic insects contribute significantly to fresh water ecosystems, one of many groups of organisms that, together, must be considered in the study of aquatic ecology. As such their study may be a significant part of understanding the ecological state of a given ecosystem and in gauging how that ecosystem will respond to stress. Aquatic insects and the larvae attack fish eggs and fry. They also compete for food and space in the pond. However, mosquito larvae are a food for fish. So, some insect larvae can serve to increase fish production. Insect bioagents can control the alligator weed, Alternanthera philloxeriodes. The flea beetle Agasilles hydrophila; alligator, Amnothrips andersonu and the alligator stem borer, Vegtia mallio can control the weed effectively. Other insects that can control water hyacinth are nevil (Nechetina circhbornae warmer (Atustache bruchi and hycinthmite (Orthoguma terebranths. Paropoynk alliondis and Litodactylus leucogaster can control the water milfoil, Myriophyllum spicatium. The article reviews and discusses the identification, economic importance, life cycle, biodiversity, roles and taxonomic orders of aquatic insects to facilitate sustainable culture fisheries management and practice.

  14. Extracts from Field Margin Weeds Provide Economically Viable and Environmentally Benign Pest Control Compared to Synthetic Pesticides.

    Directory of Open Access Journals (Sweden)

    Prisila Mkenda

    Full Text Available Plants with pesticidal properties have been investigated for decades as alternatives to synthetics, but most progress has been shown in the laboratory. Consequently, research on pesticidal plants is failing to address gaps in our knowledge that constrain their uptake. Some of these gaps are their evaluation of their efficacy under field conditions, their economic viability and impact on beneficial organisms. Extracts made from four abundant weed species found in northern Tanzania, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina and Lippia javanica offered effective control of key pest species on common bean plants (Phaseolus vulgaris that was comparable to the pyrethroid synthetic, Karate. The plant pesticide treatments had significantly lower effects on natural enemies (lady beetles and spiders. Plant pesticide treatments were more cost effective to use than the synthetic pesticide where the marginal rate of return for the synthetic was no different from the untreated control, around 4USD/ha, compared to a rate of return of around 5.50USD/ha for plant pesticide treatments. Chemical analysis confirmed the presence of known insecticidal compounds in water extracts of T. vogelii (the rotenoid deguelin and T. diversifolia (the sesquiterpene lactone tagitinin A. Sesquiterpene lactones and the saponin vernonioside C were also identified in organic extracts of V. amygdalina but only the saponin was recorded in water extracts which are similar to those used in the field trial. Pesticidal plants were better able to facilitate ecosystem services whilst effectively managing pests. The labour costs of collecting and processing abundant plants near farm land were less than the cost of purchasing synthetic pesticides.

  15. Extracts from Field Margin Weeds Provide Economically Viable and Environmentally Benign Pest Control Compared to Synthetic Pesticides

    Science.gov (United States)

    Mkenda, Prisila; Mwanauta, Regina; Stevenson, Philip C.; Ndakidemi, Patrick; Mtei, Kelvin; Belmain, Steven R.

    2015-01-01

    Plants with pesticidal properties have been investigated for decades as alternatives to synthetics, but most progress has been shown in the laboratory. Consequently, research on pesticidal plants is failing to address gaps in our knowledge that constrain their uptake. Some of these gaps are their evaluation of their efficacy under field conditions, their economic viability and impact on beneficial organisms. Extracts made from four abundant weed species found in northern Tanzania, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina and Lippia javanica offered effective control of key pest species on common bean plants (Phaseolus vulgaris) that was comparable to the pyrethroid synthetic, Karate. The plant pesticide treatments had significantly lower effects on natural enemies (lady beetles and spiders). Plant pesticide treatments were more cost effective to use than the synthetic pesticide where the marginal rate of return for the synthetic was no different from the untreated control, around 4USD/ha, compared to a rate of return of around 5.50USD/ha for plant pesticide treatments. Chemical analysis confirmed the presence of known insecticidal compounds in water extracts of T. vogelii (the rotenoid deguelin) and T. diversifolia (the sesquiterpene lactone tagitinin A). Sesquiterpene lactones and the saponin vernonioside C were also identified in organic extracts of V. amygdalina but only the saponin was recorded in water extracts which are similar to those used in the field trial. Pesticidal plants were better able to facilitate ecosystem services whilst effectively managing pests. The labour costs of collecting and processing abundant plants near farm land were less than the cost of purchasing synthetic pesticides. PMID:26599609

  16. 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, joint ...

  17. Weed exterminator and method of exterminating weed

    NARCIS (Netherlands)

    Van der Tempel, J.

    2010-01-01

    The invention relates to a method of exterminating weed, which method comprises the steps of: providing an extermination chamber (14, 14a, 14b, 14c) having at least one open side (14d), placing the open side (14d) over weed to be exterminated; substantially closing off the edge of the open side of t

  18. 苏州市麦田草害现状及防除对策%Current Status and Control Strategies of Weeds in Wheat Field of Suzhou City

    Institute of Scientific and Technical Information of China (English)

    张国彪; 沈晴

    2014-01-01

    加重江苏省苏州市麦田杂草发生的原因包括免耕栽培的推广、稻草全量还田、草相变化、除草剂使用不科学等。要实现控草目标,必须坚持综合治理,立足“一封一杀”的化除策略并科学把好麦田化除技术关。%Weed problems in wheat field of Suzhou City have become more serious in association with changes in the cul -tural practices , including the promotion of no -tillage cultivation , leaving all the straw in the field from rotational rice crop, weed population shifts , and improper use of herbicides .For effective weed control , farmers should adhere to inte-grated practices based on prevention and management , including the judicious use of chemical methods available in wheat .

  19. INTEGRATION OF MECHANICAL AND CULTURAL CONTROL TREATMENTS TO MANAGE INVASIVE SHRUB Chromolaena odorata AND OTHER WEEDS UNDER DROUGHT CONDITIONS IN PASTURE AREA

    Directory of Open Access Journals (Sweden)

    M. Rusdy

    2013-03-01

    Full Text Available A field experiment was conducted on Chromolaena odorata dominated pasture with the objectives of evaluating efficacy of integrated of mechanical and cultural control on weed suppression and determining botanical composition of plant species after treatment started. The treatments were, T1 slashing of Chromolaena every month, T2 digging up of Chromolanea, and exposed to dry (mulching, T3 digging up of Chromolaena followed by burning, T4 digging up of Chromolaena followed by burning and sowing with Centrosema pubescens and T5 digging up of Chromolaena followed by burning and planting with Brachiaria decumbens. Results of experiment showed that under drought conditions, digging up Chromolaena was very effective in suppressing regrowth of Chromolaena but it was not effective to other weeds. Among treatments, digging out of Chromolaena followed by burning and planting with Brachiaria decumbens was the most effective and slashing of Chromolaena every month was the least effective in suppressing weeds. Botanical composition was shifted with treatments. Stachytarpheta jamaicensis and Chromolaena were the dominant species in monthly slashed Chromolaena plots, Stachytarpheta and Calopogonium muconoides were the dominant species in mulched plots while Mimosa pudica, Brachiaria and Centrosema were the dominant species in burnt plots.

  20. Controle de plantas daninhas em milho em função de quantidades de palha de nabo forrageiro Weed control in corn as a function of amount of turnip crop residue

    Directory of Open Access Journals (Sweden)

    M.A. Rizzardi

    2006-06-01

    Full Text Available Objetivou-se com este experimento avaliar a influência da quantidade de palha de nabo forrageiro (Raphanus sativus var. oleiferus no controle de plantas daninhas em milho. O delineamento experimental foi o de parcelas subdivididas, em blocos casualizados, com quatro repetições. Os tratamentos constaram das quantidades de 0, 6 e 9 t ha-1 de palha de nabo forrageiro, além do pousio, dispostas na parcela principal e, ainda, de seis momentos de controle de plantas daninhas (milho com 1, 2, 4, 5, 6 e 7 folhas, mais duas testemunhas (sem a presença de plantas daninhas e sem o controle destas, dispostos nas subparcelas. Houve interação de quantidades de palha e momentos de controle em relação ao grau de controle de plantas daninhas; o melhor momento ocorreu entre os estádios de duas a quatro folhas do milho. Na ausência de controle químico, o rendimento de grãos de milho foi superior no tratamento com 9 t ha-1 de palha de nabo forrageiro. O controle químico não proporcionou aumento significativo no rendimento de grãos do milho quando a quantidade de palha de nabo forrageiro foi de 9 t ha-1.The objective of this study was to evaluate the effect of the amount of turnip (Raphanus sativus var. oleiferus crop residue on weed control in corn. The experimental design was a split-plot, in randomized blocks, with four replications. The treatments tested were 0, 6, and 9 t ha-1 of turnip crop residues, fallow period (the amount of residues was equivalent to the amount of natural vegetation residues, arranged as main plots, and six weed control periods (corn plants with 1, 2, 4, 5, 6, and 7 developed leaves, besides two controls (one without weeds and another without weed control, arranged as subplots. Interactions occurred between residue amounts and control periods in relation to the degree of weed control. The best control period was achieved when the corn plants presented from 2 to 4 developed leaves. Corn grain yield was higher in the control

  1. WEED CONTROL AND COTTON (GOSSYPIUM HIRSUTUM) INJURY WITH COMBINATIONS OF GLYPHOSATE AND TRIFLOXYSULFURON

    Science.gov (United States)

    Greenhouse and field studies were conducted to evaluate potential interactions between glyphosate and trifloxysulfuron on barnyardgrass, browntop millet, hemp sesbania, pitted morningglory, prickly sida, sicklepod, and velvetleaf control as well as cotton injury. Glyphosate was tested at 560 and 112...

  2. An Ultrasonic System for Weed Detection in Cereal Crops

    Directory of Open Access Journals (Sweden)

    Dionisio Andújar

    2012-12-01

    discrimination were assessed by discriminant analysis. The ultrasonic readings permitted the separation between weed infested zones and non-infested areas with up to 92.8% of success. This system will potentially reduce the cost of weed detection and offers an opportunity to its use in non-selective methods for weed control.

  3. 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.

  4. Developing a novel approach to analyse the regimes of temporary streams and their controls on aquatic biota

    OpenAIRE

    Gallart, F.; Prat, N.; Garcia-Roger, E.M.; Latron, J.; Rieradevall, M.; P. Llorens; Barbera, G.G.; J. Froebrich

    2011-01-01

    Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. The use of the aquatic fauna structural and functional characteristics to assess the ecological quality of a temporary stream reach can not therefore be made without taking into account the controls i...

  5. 杂草科学管理——理论基础与实施途径%Scientific Management of Weed:Theory and Implementation

    Institute of Scientific and Technical Information of China (English)

    涂修亮; 陈英明

    2002-01-01

    Scientific management of weeds is theoretically based on ecology.The implementation methods inclade:Intensifying the weed biology and ecology research, especially those of the heavy weeds;Intensifying the research of developing competition between the crop and the weed;Utilizing a allelopathy the gene engineering and breeding against the weeds;Utilizing allelopathy between the crop and the weed, and utilizing biological and agricultural measurements to control the weeds.

  6. Does phylogeny explain the host choice behaviour of potential biological control agents for Brassicaceae weeds?

    Science.gov (United States)

    Four invasive Brassicaceae are currently being studied for biological control at the CABI Centre in Switzerland. A phylogenetic approach to host testing has so far been hampered by the fact that the evolutionary relationships of taxa within the Brassicaceae were unclear. Recently, a new phylogeny of...

  7. Finalizing host range determination of a weed biological control pathogen with BLUPs and damage assessment

    Science.gov (United States)

    Colletotrichum gloeosporioides f. sp. salsolae (Penz.) Penz. & Sacc. in Penz. (CGS) is a facultative parasitic fungus being evaluated as a classical biological control agent of Russian thistle or tumbleweed (Salsola tragus L.). In initial host range determination tests, Henderson’s mixed model equat...

  8. 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

    Weed control thresholds have been used to reduce costs and avoid unacceptable yield loss. Estimation of weed infestation has often been based on counts of weed plants per unit area or measurement of their relative leaf area index. Various linear, hyperbolic, and sigmoidal regression models have...... been proposed to predict yield loss, relative to yield in weed free environment from early measurements of weed infestation. The models are integrated in some weed management advisory systems. Generally, the recommendations from the advisory systems are applied to the whole field, but weed control...... 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...

  9. Effect of soil solarization on weed emergencee

    International Nuclear Information System (INIS)

    In order to evaluate the effect of soil solarization over the reduction of the seed bank of annual weeds, a field experiment was carried out on clay soil conditions. The average maximum soil temperature was 44,79 C at 5 cm depth, while it reached 44, 48 C at 20 cm depth during 30 days in January. The average thermal gradient during the solarization between the solarized soil and the air was 14,8 C. Solarization was effective to control annual weeds up to 180 days post-solarization. Weed aerial biomass in solarized soil was significantly lower than in the control without solarization

  10. Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems

    OpenAIRE

    Vincenzo Tabaglio; Adriano Marocco; Margot Schulz

    2013-01-01

    The allelopathic potential of rye (Secale cereale L.) is mainly due to phytotoxic benzoxazinones, compounds that are produced and accumulated in young tissues to different degrees depending on cultivar and environmental influences. Living rye plants exude low levels of benzoxazinones, while cover crop residues can release from 12 to 20 kg ha–1. This paper summarizes the results obtained from several experiments performed in both controlled and field environments, in which rye was used as a co...

  11. Influence of Isoxaben Application timing on Dissipation and Broadleaf weed Control in Turf

    OpenAIRE

    Chandran, Rakesh Sarasamma

    1997-01-01

    Isoxaben is a preemergence (PRE) broadleaf herbicide used in turf and ornamentals. Field, greenhouse, and laboratory research evaluated this herbicide for PRE control of selected broadleaves in turf, suspected postemergence (POST) herbicidal effects, and the influence of application timings and rates on soil residual. During seed germination in moist filter paper, isoxaben concentrations required for 50% inhibition of radicle growth (GR50) were 0.013, 0.010, 0.008, 0.008, and 0.007 ppm for da...

  12. Vineyard weeds control practices impact on surface water transfers: using numerical tracer experiment coupled to a distributed hydrological model to manage agricultural practices spatial arrangements.

    Science.gov (United States)

    Colin, F.; Moussa, R.

    2009-04-01

    In rural basins, agricultural landscape management highly influences water and pollutants transfers. Landuse, agricultural practices and their spatial arrangements are at issue. Hydrological model are widely used to explore impacts of anthropogenic influences on experimental catchments. But planning all spatial arrangements leads to a possible cases count which cannot be considered. On the basis of the recent « numerical experiment » approach, we propose a « numerical tracer function » which had to be coupled to a distributed rainfall-runoff model. This function simulate the transfer of a virtual tracer successively spread on each distributed unit inside the catchment. It allows to rank hydrological spatial units according to their hydrological contribution to the surface flows, particularly at the catchment outlet. It was used with the distributed model MHYDAS in an agricultural context. The case study concerns the experimental Roujan vine-growing catchment (1km², south of France) studied since 1992. In this Mediterranean context, we focus on the soil hydraulic conductivity distributed parameter because it highly depends on weed control practices (chemical weeding induces a lot more runoff than mechanical weeding). We checked model sensitivity analysis to soil hydraulic conductivity spatial arrangement on runoff coefficient, peak discharge and catchment lag-time. Results show (i) the use of the tracer function is more efficient than a random approach to improve sensitivity to spatial arrangements from point of view of simulated discharge range, (ii) the first factor explaining hydrological simulations variability was practices area ratio, (iii) variability induced by practices spatial arrangements was significant on runoff coefficient and peak discharge for balanced practices area ratio and on lag-time for low area ratio of chemical weeding practices. From the actual situation on the experimental Roujan catchment (40% of tilled and 60% of non tilled vineyard

  13. Parasitic Weed Orobanche spp. and Perspective of Its Control Methods%列当杂草及其防除措施展望

    Institute of Scientific and Technical Information of China (English)

    马永清; 董淑琦; 任祥祥; 安雨; 郎明

    2012-01-01

    根寄生杂草列当Orobanche spp.每株可产生大量细小的种子,易于传播,且在出苗前已经对寄主作物造成危害,使列当的防除成为一个世界性难题。本文详述了列当的生活史、为害现状以及防除措施,并突出了生物防除的生态效益与经济效益。基于"诱捕"作物及"捕获"作物诱导列当种子"自杀发芽"理论的防除机制,本文提出了新型可持续生态防除思想,为列当科杂草防除提供参考。%Orobanche spp.can produce a large number of small seeds,which are easily spread by agricultural implements or animals.It has caused severe harm to host plants before emerging to ground.Controlling root parasitic weed Orobanche becomes a worldwide problem.This paper introduced life cycle of Orobanche,harm status and control measures.It highlighted the ecological and economic benefits of biological control.Based on "trap crop" and "catch crop" methods for stimulating Orobanche seeds germination,a new way of eliminating the seed bank within the infested soil for the weeds "suicidal germination" was pointed out.A novel sustaining way for controlling Orobanche weeds was also described.

  14. New genetic opportunities from legume intercrops for controlling Striga spp. parasitic weeds.

    Science.gov (United States)

    Hooper, Antony M; Hassanali, Ahmed; Chamberlain, Keith; Khan, Zeyaur; Pickett, John A

    2009-05-01

    In smallholder farming in East Africa, intercropping of maize with the cattle forage legume, Desmodium uncinatum Jacq., prevents parasitism by Striga hermonthica (Del.) Benth. (witchweed) through an allelopathic mechanism. Isoschaftoside, a di-C-glycosylflavone, isolated from the root extract and root exudate of Desmodium, interferes with in vitro radicle development of germinated Striga. The biosynthetic pathway of this class of compound is already mostly present in edible legumes and in cereals, so characterisation of the enzyme and genes that control C-glycosylflavone biosynthesis has the potential to create this protection mechanism in other agriculturally important plants. PMID:19266493

  15. MYCOPOPULATION OF WEEDS IN ARABLE CROPS

    Directory of Open Access Journals (Sweden)

    Karolina Vrandečić

    2004-06-01

    Full Text Available A large number of weeds are alternative hosts to numerous pathogenic agents of fungus diseases to arable crops and they represent inoculum source to cultivated plants. The aim of our investigation was to determine weed mycopopulation, to establish pathogenicity of some fungi to cultivated plants as well as to choose potential parasites for biological control of weeds. During a two year investigation of weed mycopopulation obtained from root crops at five localities in East Slavonia and Baranya 32 fungus species were established at 25 weeds that were characterized by disease symptoms. Seven fungi species were determined on roots of 18 weeds, although there were no obvious disease symptoms. Obligated parasites along with 21 determined fungi are of Oomycetes, Plectomycetes and Hemibasidiomycetes genus. Facultative parasites from 18 determined fungus species are of Discomycetes, Pyrenomycetes, Coelomycetes and Hyphomycetes genus. Isolates of Sclerotinia sclerotiorum were tested for their pathogenicity to soybean. The results showed that there were no significant differences in pathogenicity of isolates in artificial conditions in laboratory. In natural conditions isolates from soybean were more pathogenic to soybean than the isolates from weeds. Experiments done with sunflower showed that the isolates from weeds were more pathogenic than isolates from sunflower. The isolates of Phomopsis/Diaporthe complex affected the length of germ, the length of necrosis and seed disease differently. Results showed that the isolates from weeds of Phomopsis species are pathogenic to soybean representing an important source of inoculum to soybean. Isolates of Fusarium species isolated from weeds were pathogenic for popcorn seedlings. Artificial infection of Abutilon theophrasti by Colletotrichum coccodes showed that foliar mass wilted earlier and whole plants died. For the first time in Croatia the presence of 14 fungus species was determined on 27 new hosts.

  16. Eficácia de herbicidas no controle de plantas daninhas na cultura da cebola em semeadura direta Efficacy of herbicides on weed control in onion direct sowing

    Directory of Open Access Journals (Sweden)

    Lino R. Ferreira

    1999-04-01

    Full Text Available As plantas de cebola provenientes da semeadura direta no campo são mais danificadas pelo cultivo mecânico e são mais sensíveis aos herbicidas, principalmente os latifolicidas, do que quando transplantadas. Com o objetivo de avaliar a eficácia dos herbicidas oxyfluorfen, ioxynil-octanoato e fluazifop-p-butil, aplicados em pós-emergência, isoladamente ou em mistura no tanque, com ou sem aplicação de paraquat, antes da emergência das plantas de cebola, conduziu-se este trabalho no município de Monte Alto, SP. Nenhum dos herbicidas aplicados isoladamente foi eficiente no controle de todas as espécies daninhas presentes na área experimental. As misturas no tanque de fluazifop-p-butil com oxyfluorfen ou ioxynil-octanoato, independente da aplicação ou não de paraquat aos cinco dias após a semeadura, controlaram eficientemente Portulaca oleracea, Amaranthus lividus, Echinochloa crusgalli, Eragrostis pilosa, Digitaria horizontalis, Eleusine indica e Brachiaria plantaginea, com produção de bulbos semelhante à da testemunha capinada.Onion plants, from direct sowing to the field, are more damaged by mechanical cultivation and more sensitive to herbicides, especially to broadleaf herbicides, than transplanted onions. With the purpose of evaluating the efficacy of the herbicides oxyfluorfen, ioxynyl-octanoato and fluazifop-p-butyl, applied in post-emergence, alone or tank mix, with or without paraquat application, before onion plants emergence, this investigation was carried out at Monte Alto County, São Paulo State, Brazil. None of the herbicides sprayed alone were efficient in the control of all the weeds present in the experimental area. The tank mix of fluazifop-p-butyl plus oxyfluorfen or ioxynyl-octanoato, regardless of paraquat application, at five days after sowing, controlled efficiently Portulaca oleracea, Amaranthus lividus, Echinoclhoa crusgalli, Eragrostis pilosa, Digitaria horizontalis, Eleusine indica and Brachiaria

  17. Control of ALS resistant volunteer oil seed rape and other dicotyledonous weeds with GF-145, a new cereal herbicide product containing isoxaben and florasulam

    Directory of Open Access Journals (Sweden)

    Becker, Jörg

    2014-02-01

    Full Text Available GF-145 contains the active ingredients isoxaben (610 g ai/kg and florasulam (40 g ai/kg and is formulated as a Wettable Granule (WG. The active ingredients are found in commercial products such as Primus™2 (florasulam, Starane XL™ (fluroxypyr + florasulam, Ariane C™ (fluroxypyr + florasulam + clopyralid or Flexidor™ (isoxaben. While florasulam has been widely used in cereal crops in recent years, isoxaben offers a new mode of action (MOA for use in German cereal herbicides even when considering that Flexidor™ has had regulatory approval in 1988 to 1991. The MOA of isoxaben is inhibition of cellulose synthesis (HRAC class L, while florasulam inhibits Acetolactate Synthase (ALS and is a representative of the HRAC class B. It is known that florasulam works through uptake by green leaves. Isoxaben is a herbicide with soil activity and with a very low activity when foliar applied, except on some species in the cruciferae family. GF-145 is intended to be applied in the autumn in cereals (wheat, barley, rye, triticale for the control of ALS resistant volunteer oil seed rape and annual dicotyledonous weeds including Matricaria spp., Stellaria media, Papaver rhoeas, Capsella bursa-pastoris, Myosotis arvensis, Lamium spp., Galium aparine, Veronica spp. and others when applied at early post-emergence from BBCH 10 to 13 of the crop. The use rate in winter cereals is 95 g product/ha (58 g ai/ha isoxaben plus 3.75 g ai/ha florasulam. Field trials conducted in previous years confirmed excellent selectivity in all cereal crops and efficacy trials initiated in autumn 2012 show that GF-145 provides excellent and superior control to ALS resistant oil seed rape that was better than straight florasulam and other ALS active ingredients. GF-145 adds a new MOA to the cereal herbicide portfolio and controls volunteer oil seed rape, cruciferous weeds and broad-leaved weeds and is more robust than florasulam based products that do not contain isoxaben.

  18. Evaluation of Fluazifop-P-Butyl and Propanil for Weed Control in Sesame (Sesamum indicum L.) in Southern Guinea Savanna, Nigeria

    OpenAIRE

    Magani, E. I.; Shave, P. A.; Avav, T.

    2012-01-01

    Aims: To evaluate the effects of rates of the post-emergence herbicides Fluazifop and Propanil for weed control in sesame (Sesamum indicum L.) grown in Makurdi. Study Design: Randomized Complete Block Design. Place and Duration of Study: The trials were conducted in the growing seasons of 2009 and 2010 at the Teaching and Research Farm of the University of Agriculture, Makurdi (07º 41´N and 08º 37´E) in the Southern Guinea Savanna zone of Nigeria. Methodology: The eight ...

  19. Control Efficacy of Five Herbicides on Sweetpotato Field Weeds%5种除草剂对甘薯田间杂草的防除效果

    Institute of Scientific and Technical Information of China (English)

    杨育峰; 李君霞; 代小冬; 杨晓平; 王春义; 杨国红

    2013-01-01

    为了筛选适合甘薯田使用的高效、安全除草剂,比较了50%乙草胺乳油、33%二甲戊乐灵乳油、50%扑草净可湿性粉剂、24%乙氧氟草醚乳油和10%精喹禾灵乳油5种除草剂对甘薯田杂草的防除效果.结果表明,乙草胺、二甲戊乐灵和乙氧氟草醚对甘薯田杂草的防除效果较好,二甲戊乐灵、乙氧氟草醚和精喹禾灵对甘薯较为安全,而33%二甲戊乐灵乳油1 500 mL/hm2处理获得了最高的鲜薯产量26 548.27 kg/hm2.从杂草防除效果及对甘薯安全性和鲜薯产量的影响等综合因素考虑,使用33%二甲戊乐灵乳油1 500 mL/hm2在甘薯田防除杂草效果最好.%In order to select herbicides both highly effective and safe for sweetpotato fields,an experiment was carried out to compare the weed control efficacy of five herbicides of 50 % acetochlor EC,33% pendimethalin EC,50% prometryne WP,24% oxyfluorfen EC and 10% quizalofoppethyl EC in sweetpotato fields.The results showed that acetochlor,pendimethalin and oxyfluorfen had good control effects on weeds,pendimethalin,oxyfluorfen and quizalofop-p-ethyl had good safety to sweetpotato,and the treatment of 33 % pendimethalin EC with 1 500 mL/ha obtained the highest fresh root yield of 26 548.27 kg/ha.Considering the comprehensive factors of weed control effect as well as the safety and fresh root yield,33% pendimethalin EC with 1 500 mL/ha was recommended to use in sweetpotato fields for control of weeds.

  20. 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

  1. Experimental weed control of Najas marina ssp. intermedia and Elodea nuttallii in lakes using biodegradable jute matting

    Directory of Open Access Journals (Sweden)

    Markus A. Hoffmann

    2013-10-01

    Full Text Available The use of jute matting in managing the invasive aquatic macrophyte species Elodea nuttallii (Planch. H. St. John and Najas marina ssp. intermedia (Wolfg. ex Gorski Casper (Najas intermedia was studied in laboratory experiments and field trials. Four German lakes with predominant population of Najas intermedia or Elodea nuttalli were chosen for the experiment and areas between 150 and 300 m² were covered with jute textile. The effect of the matting on the growth of invasive and non-invasive macrophytes was determined through comparison with control transects. Biodegradable jute matting successfully suppressed the invasive macrophyte Najas intermedia and significantly reduced the growth of Elodea nuttalli in lakes. The results indicate that the capability of the matting to inhibit the growth of Elodea nuttallii and Najas intermedia depends on the mesh size of the jute weaving and that environmental conditions can affect its efficiency. Various indigenous species like Charales or Potamogeton pusillus L. were able to grow through the jute fabric and populate the treated areas. Until the end of the vegetation period, none of the invasive species were able to penetrate the covering and establish a stable population; in fact, in the subsequent year the jute matting affected only the spread of Najas intermedia. Jute matting proved to be an easy-to-use and cheap method to control the growth of Elodea nuttallii and Najas intermedia.

  2. Biodiversity and Importance of Floating Weeds of Dara Ismail, Khan District of KPK, Pakistan

    OpenAIRE

    Marwat, Sarfaraz Khan; Khan, Mir Ajab; Fazal-ur-Rehman; Ahmad, Mushtaq; Zafar, Muhammad

    2011-01-01

    The present paper is based on the results of taxonomic research work conducted in Dera Ismail Khan District of KPK, Pakistan, during 2005 – 2007. The area was extensively surveyed in order to collect floating aquatic weeds. From the study area 11 floating aquatic weed species belonging to 9 genera and 9 families were collected and identified in the light of available literature. These plants include Bryophytes: 1 species, Ricciocarpus natans (L.) Corda; Pteridophytes: 2 species, Azolla pinnat...

  3. Weed suppression and weed tolerance of wheat cultivars - relevant traits for Integrated Pest Management

    Directory of Open Access Journals (Sweden)

    Verschwele, Arnd

    2014-02-01

    Full Text Available An assortment of 10 winter wheat cultivars was tested for specific effects on weed suppression. Furthermore cultivar specific effects of weed infestation and weed control measures on the crop yield were investigated. Two trial series conducted from 2005 to 2010 demonstrated a wide cultivar specific range of shading capacity and weed suppression. Light penetration and the dry matter of the model weed Sinapis alba were highly correlated (r = 0.87 in trial series A (2005-2007. Consequently, the weed dry matter in the less competitive cultivar Dekan was 5 times higher compared to the weak competitor Cubus. Mechanical weed control by harrowing reduced ears density of all cultivars tested in trial series A. These reductions were significantly higher in the cultivars Bussard and Pegassos compared to the other cultivars. Since the weed infestation was low and negative crop effects by harrowing could be compensated by a higher number of kernels/ear, the yield effects were the same for all cultivars. Contrary to the hypothesis, a cultivar specific yield response by harrowing could not be assessed. Higher competition effects by sowing the model weed Sinapis alba could be realised in trial series B (2008-20120. Consequently, the control measures (a harrowing (b 50% herbicide (c 100% herbicide resulted in significantly higher crop yields ranging from 1.23 t*ha-1 (harrowing to 2.08 t*ha-1 (100% herbicide. The yield reduction caused by the model weed was not the same for all cultivars and was lower for the cultivars Cubus and Limes (6% and 7% compared to Boomer (15%. Thus, weed tolerance could be identified as a cultivar specific trait. There were significant interactions between cultivar and weed control measures: The yield increase (relative to model weed was 5% for Bussard, which was much lower compared to the treatment effects on the cultivar Impression (11%. The hypothesis that yield effects by mechanical and chemical weed control may be affected by the

  4. Aquatic plants clean wastewater lagoons

    Energy Technology Data Exchange (ETDEWEB)

    1980-09-01

    Water weeds that grow profusely in warm tropical and subtropical regions have always been considered a nuisance; current research is focusing on methods to cull benefits from such aquatic proliferations. Weeds, especially the water hyacinth, are proving to be useful in the purification of wastewater lagoons. The plants extract inorganic and organic toxicants from the effluent. Hyacinths employed in experiments conducted in Puerto Rico are removed from the lagoons to prevent overcrowding. This harvest is sent through a digester to produce methane. (2 diagrams, 3 photos)

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

    OpenAIRE

    Emma H Carlos; Maria Gibson; Weston, Michael A.

    2014-01-01

    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 manage...

  6. IAA Producing Enterobacter sp. I-3 as a Potent Bio-herbicide Candidate for Weed Control: A Special Reference with Lettuce Growth Inhibition.

    Science.gov (United States)

    Park, Jae-Man; Radhakrishnan, Ramalingam; Kang, Sang-Mo; Lee, In-Jung

    2015-06-01

    Development of bio-herbicides is an emerging method to weed management in agricultural field. Very few studies were conducted on identification of microbial bio-herbicides to weed control. The present study was aimed to isolate and identify the effective bio-herbicide potential bacterium from soil and assess their role on plant growth inhibition. Three-hundred and one rhizobacteria were isolated from agriculture field soil samples collected from various parts of Republic of Korea. Two bacterial strains, I-4-5 and I-3 were significantly reduced the seedling growth of radish when compared to their controls. The highest rate of seedling growth inhibition was observed in I-3 bacterial isolate treatment in lettuce and radish. The mechanism of an effective bio-herbicide I-3 to plant growth inhibition was determined by analyzing IAA in their culture medium. IAA biosynthesis pathway of Enterobacter sp. I-3 was identified as tryptophan-dependent pathway and its production was increased due to addition of tryptophan in culture medium as quantified by using GC-MS SIM. In an in vitro study revealed that I-3 bacterial culture exudate combined with tryptophan significantly decreased leaf length, leaf width, root length and increased the number of lateral roots of lettuce. Indeed, the genomic DNA of I-3 bacterium was isolated and 16S rDNA was sequenced to find out the name of the bacterium. Based on phylogenetic analysis, I-3 isolate was identified and named into Enterobacter sp. I-3. The results of this study suggest that the utilization of Enterobacter sp. I-3 to crop field can be act as a potential bio-herbicide against weed growth. PMID:25805908

  7. Growth analysis and yield of two varieties of groundnut (Arachis hypogaea L.) as influenced by different weed control methods

    OpenAIRE

    Olayinka, Bolaji U.; Etejere, Emmanuel O.

    2015-01-01

    Field trials were carried out to evaluate the effects of seven weed management strategies on the growth and yield of two groundnut varieties (Samnut 10 and MK 373) for two successive seasons (2010–2011). The experimental layout was a split plot complete randomized block design with three replications. The two groundnut varieties showed identical pattern of results for leaf area index, dry matter accumulation, relative growth rate, net assimilation rate and crop growth rate as well as yield. A...

  8. The Price Model of Aquatic Products Based on Predictive Control Theory

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper discusses a disequilibrium cobweb model of price of aquatic products, and applies predictive control theory, so that the system operates stably, and the deviation between supply and demand of aquatic products smoothly tracks the pre-given target. It defines the supply and demand change model, and researches the impact of parameter selection in this model on dynamic state and robustness of the system. I conduct simulation by Matlab software, to get the response curve of this model. The results show that in the early period of commodities coming into the market, affected by lack of market information and many other factors, the price fluctuates greatly in a short time. The market will gradually achieve balance between supply and demand over time, and the price fluctuations in the neighbouring two periods are broadly consistent. The increase in model parameter can decrease overshoot, to promote the stability of system, but the slower the dynamic response, the longer the deviation between supply and demand to accurately track a given target. Therefore, by selecting different parameters, the decision-makers can establish different models of supply and demand changes to meet the actual needs, and ensure stable development of market. Simulation results verify the excellent performance of this algorithm.

  9. Applying physicochemical approaches to control phosphogypsum heavy metal releases in aquatic environment.

    Science.gov (United States)

    Ammar, Rawaa; El Samrani, Antoine G; Kazpard, Véronique; Bassil, Joseph; Lartiges, Bruno; Saad, Zeinab; Chou, Lei

    2013-12-01

    One of the most important sources of solid waste in the Mediterranean Basin ecosystem originated from the phosphate fertilizer industries, which discharge phosphogypsum (PG) directly into aquatic environments or are stacked on stockpiles. The present study investigates metal release from PG under the influence of variable pH, increasing PG mass content, and complexing organic matter ligands. Major ions from PG leachates, grain size and charge, main functional groups along with metal leachability (Pb, Cd, Cr, Cu, and Zn) were determined using ion chromatography, laser diffraction, zetameter, Fourier transform infrared spectroscopy, and atomic absorption spectroscopy, respectively. The complete dissolution of PG recorded is at 2 g/L. Saturation and supersaturation with respect to PG may occur at concentrations of 3 and 4 g/L, respectively, revealing a clustering phenomenon leading to heavy metal encapsulation within the aggregates. Organic ligands such as citrate may trigger the cationic exchange within the PG suspension leading to ion release. As these factors are considered as specific process involving the release of contaminants from PG during storage under natural conditions, this study could set the foundations for PG remediation in aquatic environment. Organic ligands under controlled pH conditions could be utilized in treating fertilizer industrial wastes by taking into consideration the particularity of the receiving area, thus decreasing metal hazardous impact on natural media. PMID:23764982

  10. 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...... 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.......Competition from weeds is the most important of all biological factors that reduce agricultural crop yield. This occurs primarily because weeds use resources that would otherwise be available to the crop. The magnitude of yield loss is affected by numerous agronomic and environmental factors, most...

  11. Controle químico de plantas daninhas na semeadura direta de tomate (Lycopersicon esculentum Mill. Weed control on direct seeded tomato (Lycopersicon esculentum Mill.

    Directory of Open Access Journals (Sweden)

    L. R. Ferreira

    1982-12-01

    with metribuzin at the same dose ge were evaluated in two assays, one at Viçosa, MG and the other at Domingos Martins, ES. One third assay was carried out at Viçosa, MG to evaluate the effectiveness of chloramben, napropamide, diphenamid and metr ibuzin at the dose of 3.40; 3.00; 5.00 and .70 kg/ha respectively, and pebulate at the dose of 4.32 and 1.76 kg/ha applied separated and combined with pebulate at mentioned dosages. All compounds showed some control of weeds, although the efficiency of each product was weed species dependant. Only pebulate was efficient on Cyperus rotundus control. Bachiaria plantaginea and Digitaria sanguinalis were better controled by chloramben, napropamide, diphenamid and trifluralin. Metribuzin gave excelent control of Bidens pilosa and Galinsoga parviflora. The mixtures of metr ibuzin or pebula te wi th each herbicide sudied increased the efficience of control and the number of species controled. All compounds were tolerated by the tomato plants. No visible injury were observed at the doses studied.

  12. Hot foam for weed control-Do alkyl polyglucoside surfactants used as foaming agents affect the mobility of organic contaminants in soil?

    Science.gov (United States)

    Cederlund, H; Börjesson, E

    2016-08-15

    Use of alkyl polyglucosides (APGs) as a foaming agent during hot water weed control may influence the environmental fate of organic contaminants in soil. We studied the effects of the APG-based foaming agent NCC Spuma (C8-C10) on leaching of diuron, glyphosate, and polycyclic aromatic hydrocarbons (PAHs) in sand columns. We also examined how APG concentration affected the apparent water solubility and adsorption of the herbicides and of the PAHs acenaphthene, acenaphthylene and fluorene. Application of APGs at the recommended concentration of 0.3% did not significantly affect leaching of any of the compounds studied. However, at a concentration of 1.5%, leaching of both diuron and glyphosate was significantly increased. The increased leaching corresponded to an increase in apparent water solubility of diuron and a decrease in glyphosate adsorption to the sand. However, APG addition did not significantly affect the mobility of PAHs even though their apparent water solubility was increased. These results suggest that application of APG-based foam during hot water weed control does not significantly affect the mobility of organic contaminants in soil if used according to recommendations. Moreover, they suggest that APGs could be useful for soil bioremediation purposes if higher concentrations are used. PMID:27149400

  13. Allelopathy: A Natural Way towards Weed Management

    OpenAIRE

    Bhadoria, P. B. S.

    2010-01-01

    To meet the food requirement of the ever-growing population of the world the introduction of pesticides in agriculture was a welcome move to control obnoxious weeds below the threshold limit and thereby reduce the yield loss. But continuous use of synthetic herbicides in heavy doses creates environment pollution and increases the number of herbicide resistant weeds. Hence, researches should be done to find out some natural way for minimizing the dependency on synthetic herbicides. The objecti...

  14. Remote Sensing of Aquatic Vegetation Coverage in the Kafue River, Zambia and Comparison to Climatic Variables

    Science.gov (United States)

    Mischler, J. A.; Abdalati, W.; Hussein, K.; Townsend, A. R.

    2013-12-01

    The Kafue River is the longest river in Zambia and is a major tributary of the Zambezi River. It is a vital source of fish, transportation, drinking water, and hydropower for much of Zambia's population, over half of whom live in the Kafue River basin. Like many important water bodies in developing countries the Kafue and its ecosystems face pollution from industrial, mining, agricultural, and domestic/sewage discharge. The Kafue River forms a wide and shallow wetland (the Kafue Flats) during the rainy season (Nov. - Apr.) which serves as habitat for diverse groups of birds and mammals. In recent years the unprecedented emergence of invasive aquatic vegetation such as the water hyacinth (Eichhornia crassipes) and Salvinia molesta have choked the river, degrading its ability to provide adequate habitat to promote biodiversity, ecosystem services, and hydropower. In addition, these plants provide additional habitat for mosquitoes (vectors for malaria) and aquatic snails (vectors of schistosomiasis). Nutrient-rich effluents are widely believed to contribute to the proliferation and explosive growth of this floating aquatic vegetation. The general methods for managing these aquatic weeds have included mechanical and physical removal, herbicides, and bio-control agents which have had very little impact. However, as in neighboring Lake Victoria, total weed coverage has fluctuated dramatically from year to year making evaluation of the efficacy of management programs difficult. The objectives of this study were to (1) generate the first record of aquatic plant coverage for a section of the Kafue River which is immediately downstream of a sugar plantation (a major source of nitrogen and phosphorus to the river) and (2) determine if plant coverage is correlated with any major climatic (ENSO, temperature, rainfall) or management (introduction of bio-control agents) indices. We utilized remote sensing techniques in conjunction with Landsat 4-5 TM and Landsat 7 ETM imagery for

  15. 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

    Pre- and post-emergence weed harrowing were studied in spring cereals in different environments and with two types of harrows in Norway during 2004–2006. The objectives were to investigate interactions between pre- and post-emergence weed harrowing and the importance of harrow type. We hypothesised...... 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...... results only supported the last of these hypotheses. Post-emergence weed harrowing controlled a certain percentage of the present weeds, and this percentage was not dependent on pre-emergence weed harrowing. On average, pre-emergence harrowing reduced weed density by 26% and weed biomass by 22%, while the...

  16. Developing a novel approach to analyse the regimes of temporary streams and their controls on aquatic biota

    Directory of Open Access Journals (Sweden)

    F. Gallart

    2011-10-01

    Full Text Available Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. The use of the aquatic fauna structural and functional characteristics to assess the ecological quality of a temporary stream reach can not therefore be made without taking into account the controls imposed by the hydrological regime. This paper develops some methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: flood, riffles, connected, pools, dry and arid. We used the water discharge records from gauging stations or simulations using rainfall-runoff models to infer the temporal patterns of occurrence of these states using the developed aquatic states frequency graph. The visual analysis of this graph is complemented by the development of two metrics based on the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of the aquatic regimes of temporary streams in terms of their influence over the development of aquatic life is put forward, defining Permanent, Temporary-pools, Temporary-dry and Episodic regime types. All these methods were tested with data from eight temporary streams around the Mediterranean from MIRAGE project and its application was a precondition to assess the ecological quality of these streams using the current methods prescribed in the European Water Framework Directive for macroinvertebrate communities.

  17. RoboWeedSupport

    DEFF Research Database (Denmark)

    Dyrmann, Mads; Nyholm Jørgensen, Rasmus

    Information about the weed population in fields is important for determining the optimal herbicides for the fields. A system based on images is presented that can provide support in determining the species and density of the weeds. Firstly, plants are segmented from the soil. Plants that after the...

  18. 成都青城山高尔夫球场草坪杂草调查及化学防除%Weed species Survey and their Chemical Control in Chengdu Qingcheng Golf

    Institute of Scientific and Technical Information of China (English)

    王贵林; 杨世军

    2011-01-01

    2009年调查分析了成都青城山高尔夫球场百慕达草坪年度杂草发生种类、发生规律及危害程度;并于2010年采用“翠坪”系列草坪专用除草剂进行杂草化学防除.结果显示“翠坪”系列草坪专用除草剂对青城山高尔夫球场各时期的主要杂草如马唐、水蜈蚣、香附子、早熟禾、小飞蓬等均有较好的防除效果,防除效果在90%以上,显著优于人工除草,防除成本也远低于人工除草费用,且对草坪安全.%The weed species survey of Chengdu Qingcheng Golf in Bermuda was conducted, which includes the weed species, extent of occurrence and damage in 2009. And the " CuiPing" series of grass-specific herbicides for weed chemical control was used in golf course in 2010. The results show that " CuiPing" series of grass-specific herbicides have an excellent control on the golf courses during every period of major weeds occurrence, such as crabgrass, water centipede, Cyperus rotundus, bluegrass, Conyza canadensis and so on. The control effect of 90% above was significantly better than manual weeding, and the payment of chemical control costs far less than the cost of manual weeding, further the safety for lawn is good.

  19. Evaluation of an autonomous GPS-based system for intra-row weed control by assessing the tilled area

    DEFF Research Database (Denmark)

    Nørremark, Michael; Griepentrog, Hans W.; Nielsen, Jon;

    2012-01-01

    -rotor (cycloid hoe) with eight sigmoidshaped, vertically directed tines. The individual tines can be released for individual rotation in order to avoid collision with geo-referenced crop plants. The system navigated with reference to pre-defined waypoints for tillage parallel to crop rows and around individual...... to 20% for a single pass and up to 29% for a 2-way pass treatment both at the white thread to the twoleaf stage of weeds. The result of the prediction is of crucial importance for the considerations of tool designs at the current conceptual stage of the system....

  20. Automated intelligent rotor tine cultivation and punch planting to improve the selectivity of mechanical intra-row weed control

    DEFF Research Database (Denmark)

    Rasmussen, Jesper; Griepentrog, Hans W.; Nielsen, Jon; Henriksen, Christian Bugge

    2012-01-01

    -GPS relative to geo-referenced sugar beets. Tines were moved into the row when there was enough space between crop plants to cultivate and kept outside when they were predicted to strike a crop plant. The selectivity of the cycloid hoe was tested against two machine variants without intelligent guidance: the...... sugar beet and carrot crops showed no synergistic effects between plant establishment procedures and selectivity of post-emergence weed harrowing. Even if punch planting and automated intelligent rotor tine cultivation were not combined, the results indicated that there was no reason to believe that a...

  1. Weed control in young coffee plantations through post emergence herbicide application onto total area Controle de plantas daninhas em cafezais recém-implantados, com herbicidas aplicados em pós-emergência em área total

    OpenAIRE

    C.P. Ronchi; A.A. Silva

    2004-01-01

    This study was carried out to investigate the efficiency of several herbicides under field conditions, by post-emergence application onto the entire area, their effect on the control of weeds in young coffee plantations and commercial coffee and bean intercropping system, as well as on both crops. Seedlings of Coffea arabica cv. Red Catuaí with four to six leaf pairs were transplanted to the field and treated according to conventional agronomic practices. A bean and coffee intercropping syste...

  2. Controle de plantas daninhas com herbicidas na cultura do feijão (Phaseolus vulgaris L. Weed control in beans (Phaseolus vulgaris L. with herbicides

    Directory of Open Access Journals (Sweden)

    L.S.P. Cruz

    1981-12-01

    Full Text Available Foi realizada uma pesquisa em 1970, para se conhecer os efeitos de três herbicidas aplicados em pré-plantio incorporado (EPTC a 3,60 kg/ha, nitralin e trifluralin a 0,76 kg/ha e de um em pré-emergência (fluorodifen a 3,00 kg/ha na cultura de feijão comparados com uma testemunha sem herbicida. As duas gramíneas presentes no ensaio, Eleusine indica (L. Gaertn. e Digitaria sanguinalis (L. Scop. foram eficientemente controladas por todos os herbicidas, com indices de controle superiores a 87,00%, em contagem de plantas daninhas realizada 29 dias após a aplicação dos herbicidas. Dentre as dicotiledóneas presentes, Amaranthus viridis L. também foi eficientemente controlado por todos os herbicidas, com indices de controle superiores a 92,00%. Ageratum conyzoides L. foi eficientemente controlado por fluorodifen (91,60% e regularmente por EPTC (78,99% e por nitralin (79,83%. Trifluralin não foi eficiente contra A. conyzoides L. Nenhum dos herbicidas testados controlou Ipomoea sp e Chenopodium ambrosioides L., também presentes no experimento. EPTC e nitralin apresentaram as menores porcentagens de infestação geral de plantas daninhas, tendo, aos 51 dias da aplicação dos produtos, quando suas parcelas foram capinadas mecanicamente, 8,00 e 17,00% de infestação, respectivamente. Trifluralin e fluorodifen precisaram de limpeza aos 42 dias da aplicação, e a testemunha já aos 29 dias, pois apresentavam parcelas com 25,00%, ou mais, de infestação, naquelas épocas. Os herbicidas experimentados não foram prejudiciais à germinação e ao desenvolvimento vegetativo dos feijoeiros, assim como à sua produção de grãos.The weed control with herbicides in beans crop was studied during 1970 year, in Campinas-SP, on a sandy-loam soil. The treatments employed were EPTC at 3.60 kg/ha, nitralin and trifluralin at 0.76 kg/ha, all applied in preplant i •porated; fluorodifen in preemergence at 3.00 kg/ha and a hoed check. Among the weeds

  3. Adaptive genetic variation mediates bottom-up and top-down control in an aquatic ecosystem.

    Science.gov (United States)

    Rudman, Seth M; Rodriguez-Cabal, Mariano A; Stier, Adrian; Sato, Takuya; Heavyside, Julian; El-Sabaawi, Rana W; Crutsinger, Gregory M

    2015-08-01

    Research in eco-evolutionary dynamics and community genetics has demonstrated that variation within a species can have strong impacts on associated communities and ecosystem processes. Yet, these studies have centred around individual focal species and at single trophic levels, ignoring the role of phenotypic variation in multiple taxa within an ecosystem. Given the ubiquitous nature of local adaptation, and thus intraspecific variation, we sought to understand how combinations of intraspecific variation in multiple species within an ecosystem impacts its ecology. Using two species that co-occur and demonstrate adaptation to their natal environments, black cottonwood (Populus trichocarpa) and three-spined stickleback (Gasterosteus aculeatus), we investigated the effects of intraspecific phenotypic variation on both top-down and bottom-up forces using a large-scale aquatic mesocosm experiment. Black cottonwood genotypes exhibit genetic variation in their productivity and consequently their leaf litter subsidies to the aquatic system, which mediates the strength of top-down effects from stickleback on prey abundances. Abundances of four common invertebrate prey species and available phosphorous, the most critically limiting nutrient in freshwater systems, are dictated by the interaction between genetic variation in cottonwood productivity and stickleback morphology. These interactive effects fit with ecological theory on the relationship between productivity and top-down control and are comparable in strength to the effects of predator addition. Our results illustrate that intraspecific variation, which can evolve rapidly, is an under-appreciated driver of community structure and ecosystem function, demonstrating that a multi-trophic perspective is essential to understanding the role of evolution in structuring ecological patterns. PMID:26203004

  4. Eficiência do triclopyr no controle de plantas daninhas em gramado (Paspalum notatum Triclopyr efficiency in controlling weeds in the lawn (Paspalum notatum

    Directory of Open Access Journals (Sweden)

    F.C.L. Freitas

    2003-04-01

    Full Text Available As plantas daninhas interferem nos gramados, prejudicando a sua formação, qualidade e estética. O carrapicho-beiço-de-boi (Desmodium incanum e a zórnia (Zornia latifolia, quando não controlados, podem atingir níveis de infestação que chegam a dizimar o gramado. Dentre as diversas técnicas de manejo de plantas daninhas em gramados, destaca-se o emprego de herbicidas; todavia, as informações sobre a utilização desses produtos em gramados são escassas. O objetivo deste trabalho foi avaliar a eficiência do herbicida triclopyr no controle de Desmodium incanum e Zornia latifolia, infestantes da grama-batatais (Paspalum notatum. O trabalho foi desenvolvido em gramado estabelecido no campus da Universidade Federal de Viçosa, em Viçosa-MG, entre os meses de abril e maio de 2000. Os tratamentos avaliados foram seis doses do triclopyr (0,00; 0,24; 0,48; 0,72; 0,96; e 1,20 kg ha-1 e uma dose do 2,4-D + picloram (0,48 + 0,128 kg ha-1, dispostos em delineamento experimental com blocos ao acaso e quatro repetições. O tamanho de cada parcela foi de 12 m² (4,0 x 3,0 m, sendo os tratamentos aplicados em uma faixa de 2,0 m de largura, ficando 1,0 m como testemunha lateral, para auxiliar nas avaliações visuais. Foram realizadas avaliações de fitotoxicidade aos 10 e 20 DAT (Dias Após o Tratamento e nível de controle aos 15 e 30 DAT, ambos com base na testemunha lateral. Em nenhum dos tratamentos avaliados verificaram-se danos na qualidade do gramado. A partir das doses de 0,48 e 0,66 kg ha-1 de triclopyr foram obtidos controles iguais ou superiores a 90% de Desmodium incanum e Zornia latifolia, respectivamente. Esses resultados foram semelhantes ao do tratamento-padrão (2,4D + picloram a 0,48 + 0,128 kg ha-1. Concluiu-se que o triclopyr mostrou-se seletivo para grama-batatais, proporcionando excelente controle das plantas daninhas acima mencionadas.Weeds interfere in the formation, quality and aesthetics of the lawn. Desmodium incanum

  5. 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.

  6. Assessment of the impact of chlorophyll derivatives to control parasites in aquatic ecosystems.

    Science.gov (United States)

    Erzinger, Gilmar Sidnei; Souza, Suellen Carolina; Pinto, Luciano Henrique; Hoppe, Roberto; Del Ciampo, Lineu Fernando; Souza, Ozair; Correia, Cláudia Hack Gumz; Häder, Donat-Peter

    2015-05-01

    Several research groups have studied new biopesticides which are less toxic to the environment and capable of controlling the vectors of parasitic diseases, especially in aquatic ecosystems. Pest control by photodynamic substances is an alternative to chemical or other measures, with chlorophyll and its derivatives as the most studied substances supported by their easy availability and low production costs. The impact of chlorophyll derivatives on four different species, a small crustacean (Daphnia similis), a unicellular alga (Euglena gracilis) and two species of fish (Astyanax bimaculatus and Cyprynus carpio) were tested under short-term conditions. In addition, the effects of long-term exposure were evaluated in D. similis and E. gracilis. In short-term tests, mortality of D. similis (EC50 = 7.75 mg/L) was most strongly affected by chlorophyllin, followed by E. gracilis (EC50 = 12.73 mg/L). The fish species showed a greater resistance documented by their EC50 values of 17.58 and 29.96 mg/L in C. carpio and A. bimaculatus, respectively. A risk quotient is calculated by dividing an estimate of exposure by an estimate of effect. It indicated that chlorophyll derivatives can be applied in nature to control the vectors of parasitic diseases under short-term conditions, but long-term exposure requires new formulations. PMID:25750014

  7. Soil organic carbon stocks in coffee plantations under different weed control systemsEstoques de carbono orgânico do solo em cafezais sob diferentes sistemas de controle de plantas invasoras

    Directory of Open Access Journals (Sweden)

    Franciane Diniz Cogo

    2013-06-01

    Full Text Available Soil organic carbon (COS is an important indicator of soil quality, as its levels and stocks can change by soil preparation. This study aimed to evaluate COS stocks on a clayey Oxisol cultivated with coffee and subject to different weed control systems in southern Minas Gerais, Brazil. The experimental design was in randomized blocks, and weed control systems were: no weeding, manual weeding, pre-emergence herbicide, post-emergence herbicide, rotary tiller, rotary mowers and disk harrow. Undisturbed soil samples were collected at two positions in the coffee plantation (tire tracks and planting line, at depths of 0-3, 10-13, and 25-28 cm. A nearby native forest was sampled as a reference. A higher bulk density of soils under coffee plantations occurred compared to soil under the forest. There was little difference between COS concentrations in the plating line in relation to the native forest, but for the tire track position, the amount of COS was generally lower. After correction for soil compaction, it was estimated a loss of ca. 20% in SOC stock for te 0-30 cm depth for herbicide post-emergence, rotary tiller, manual weeding and disk barrow, and a 35% loss when using herbicide pre-emergence. SOC stocks under no weeding and rotary mowers did not differ from native forest (37 M-1g ha COS, indicating that the rotary mower, which allows temporary growth of weeds and does not disrupt soil structure, is the most appropriate weed control for the preservation of COS in coffee plantations.O carbono orgânico no solo (COS é um importante indicador da qualidade do solo, pois seus teores e estoques podem ser alterados conforme o sistema de preparo do solo. Objetivou-se neste trabalho avaliar os estoques de COS em um Latossolo Vermelho distroférrico argiloso cultivado com cafeeiros (Coffea arabica L e submetido a diferentes manejos de plantas invasoras no sul de Minas Gerais. O delineamento experimental foi em blocos ao acaso, sendo os tratamentos os

  8. Stratification Requirements for Seed Dormancy Alleviation in a Wetland Weed

    OpenAIRE

    Boddy, Louis G.; Bradford, Kent J.; Albert J Fischer

    2013-01-01

    Echinochloaoryzicola(syn.E. phyllopogon) is an exotic weed of California rice paddies that has evolved resistance to multiple herbicides. Elimination of seedlingsthroughcertain weed control methods can limit the spread of this weed, but is contingent on accurate predictions of germination and emergence timing, which are influenced by seed dormancy levels.In summer annuals, dormancy can often be relieved through stratification, a period of prolonged exposure to cold and moist conditions.We use...

  9. Weeds in Asparagus Plantations in Hainan and Their Control Techniques%海南芦笋园杂草种类调查及杂草防除技术研究

    Institute of Scientific and Technical Information of China (English)

    李晓霞; 黄乔乔; 易克贤; 范志伟; 沈奕德; 程汉亭

    2014-01-01

    A syste matica l investigation of weeds was conducted in asparagus plantation of Hainan Province, and the dominant weed populations were determined. Then, weed control experiments were conducted. The results showed that there were 106 weed species belonging to 23 families in the asparagus garden. Of them, nine species were considered as dominant weeds, including Melinis repens, Panicum maximum, Imperata cylindrica, Digitaria setigera, Chromolaena odorata, Praxelis clematidea, Tridax procumbens and Mimosa pudica. Of the weed control strategies, coverage control and chemical control could control weeds to a certain degree:after 60d covering of nine plants, the control effect reached more than 60%. Covering the weed by cocered Pueraria lobata, Calopogonium mucunoides, Eupatorium odoratum, Mikania micrantha and Tithonia diversifolia increased the shoot number and the diameter of new shoots of asparagus. After application of four kinds of herbicides 60 d, Haloxyfop and acetochlor could control the weeds to a higher extent and were also safe to asparagus plants. In actual production practices, combining the covering and chemical weed control could control weeds to the maximum extent in the asparagus plantation.%系统调查海南芦笋种植区的主要杂草种类,明确芦笋园的杂草优势种群,并以此为基础进行盆栽芦笋化学除草药效试验及覆盖控草试验。结果表明,海南芦笋园常见杂草有21科106种,其中优势种群由马齿苋、红尾翎、短颖马唐、龙爪茅、牛筋草、砖子苗、假臭草、伞房花耳草及鳢肠9种构成。采用覆盖控草和化学除草可在一定程度上控制杂草的发生:覆盖9种植物60 d后,防效可达60%以上,且覆盖葛藤、毛蔓豆、飞机草、薇甘菊、肿柄菊后,芦笋抽笋数和新笋径围都显著高于其余各处理;施用4种除草剂60 d后,盖草能和乙草胺对盆栽芦笋的防效较高且安全。因此,在实际生产中,通过

  10. INFORMATION VALUE IN WEED MANAGEMENT

    OpenAIRE

    Gillmeister, William J.; Moffitt, L. Joe; Bhowmik, Prasanta C.; Allen, P. Geoffrey

    1990-01-01

    Use of the economic threshold to improve the efficiency of preemergent-herbicide treatment decisions is limited by a lack of weed information. An economic model for assessing the expected value of weed information needed to implement a threshold decision rule is developed. Empirical results suggest that early season weed information can have value in cabbage weed management in Massachusetts.

  11. Cultivos intercalares e controle de plantas daninhas em plantios de maracujá-amarelo Intercropping and weed control in yellow passion fruit orchard

    Directory of Open Access Journals (Sweden)

    Adelise de Almeida Lima

    2002-12-01

    Full Text Available Objetivou-se identificar cultivos intercalares e métodos integrados de controle de plantas daninhas em maracujá-amarelo (Passiflora edulis Sims f. flavicarpa Deg. como fatores que viabilizem a sua produção e rentabilidade. O experimento foi instalado em maio de 1999, conduzido em espaldeira vertical com um fio de arame a 2,0m do solo, no espaçamento de 2,5m x 5,0m, em blocos casualizados, com seis tratamentos e quatro repetições, sendo T1: milho (Zea mays L. - BR 106 como cultura intercalar; T2: feijão (Phaseolus vulgaris L. - cultivar Pérola como cultura intercalar; T3: feijão-de-porco nas entrelinhas e capina com enxada nas linhas; T4: feijão-de-porco nas entrelinhas e controle químico nas linhas (glifosate a 1,5 kg/ha; T5: planta daninha controlada quimicamente (em toda a parcela com alachlor a 2,8 kg/ha + diuron a 1,2 kg/ha em pré-emergência e glifosate a 1,5 kg/ha em pós-emergência; e T6: testemunha (capina com enxada em área total. Os dados analisados, no período de produção (maio de 1999 a abril de 2000, mostraram que não houve diferenças estatísticas entre os tratamentos para produtividade (indústria, peso médio, comprimento e diâmetro dos frutos, sólidos solúveis totais e acidez. Contudo, houve significância para produtividade total e in natura, com destaque para a utilização do feijão como cultura intercalar, com produtividade do maracujazeiro de 12,82 t/ha. Tanto o milho como o feijão podem ser recomendados como culturas intercalares no primeiro ano de cultivo do maracujá-amarelo. Os herbicidas aplicados em pré e pós-emergência foram economicamente viáveis e não mostraram efeito tóxico sobre as plantas de maracujá-amarelo.This work aimed identifying crops for intercropping and integrated methods for weed control in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg. orchard, that will favor its production and profitability. The experiment was set up in May 1999, with the plants

  12. Weed management using goats: Effects on water infiltration rate

    Science.gov (United States)

    Goats are used increasingly for weed control, fire fuel reduction and ecological restoration. The high stocking rates typical of these applications have been reported to decrease the rate of water infiltration in goat pastures. The hypothesis that annual goat browsing for weed control decreases infi...

  13. Activity of mesotrione on resistant weeds in maize.

    Science.gov (United States)

    Sutton, Peter; Richards, Claire; Buren, Larry; Glasgow, Les

    2002-09-01

    Mesotrione is a new callistemone herbicide that inhibits the HPPD enzyme (p-hydroxyphenylpyruvate dioxygenase) and introduces a new naturally selective tool into weed-management programmes for use in maize. Mesotrione provides control of the major broad-leaved weeds, and it can be used in integrated weed-management programmes depending on the grower's preferred weed-control strategy. At post-emergence rates of 150 g AI ha-1 or less, mesotrione provides naturally selective control of key species that may show triazine resistance (TR), e.g. Chenopodium album L, Amaranthus species, Solanum nigrum L, as well as species of weed that show resistance to acetolactase synthase (ALS) inhibitors e.g. Xanthium strumarium L, Amaranthus spp and Sonchus spp. The data presented show that resistant and susceptible biotypes of these species with resistance to triazine herbicides, such as atrazine, simazine, terbutylazine and metribuzin, or ALS-inhibitor herbicides, such as imazethepyr, remain susceptible to mesotrione. These results confirm that there is no cross-resistance in biotypes with target site resistance to triazine or ALS-inhibiting herbicides. It is important that herbicide choice and rotation becomes an integral part of planning weed management, so as to minimise the risks of crop losses from weed competition, build-up of weed seed in the soil and the further development of weed resistance across a range of herbicide modes of action. PMID:12233193

  14. Weed management in transplanted lettuce with Pendimethalin and S-metolachlor

    Science.gov (United States)

    Few herbicides are available for use in lettuce and hand weeding is required for commercially acceptable weed control. More effective herbicides are needed. Here we report field evaluations of pendimethalin and S-metolachlor for weed control in transplanted lettuce. Pendimethalin was evaluated PRE a...

  15. Changes in grass-weed seedbanks in relation to crops and rotations

    OpenAIRE

    Belo, A.F.; Dias, L. S.

    1998-01-01

    Forage, chikpea, medics, wheat, oilseed rape, and sunflower were cultivated during four years as part of ten different types of rotation which always included wheat. Grass-weed seedbanks were evaluated annually before seeding. The single most important reason for the control of grass-weed seedbanks or its failure seems to be the effectiveness of above-groud grass-weed control.

  16. Influence of Weed Competition on Potato Growth, Production and Radiation Use Efficiency

    OpenAIRE

    Farzad MONDANI; Farid GOLZARDI; Godarz AHMADVAND; Ghorbani, Reza; Rooholla MORADI

    2011-01-01

    Weed management in potato production is one of the main cost and time consuming practices. Understanding the most effective time of weed control could reduce the costs and increase potato yield. Field study was conducted in the west region of Iran during 2006 to evaluate the effect of weeds damage in potato fields. Twelve treatments used consisted of six initial weed-free periods in which plots were kept free of weeds for 0, 10, 20, 30, 40 and 50 days after crop emergence (DAE), and then weed...

  17. Global perspective of herbicide-resistant weeds.

    Science.gov (United States)

    Heap, Ian

    2014-09-01

    Two hundred and twenty weed species have evolved resistance to one or more herbicides, and there are now 404 unique cases (species × site of action) of herbicide-resistant weeds globally. ALS inhibitor-resistant weeds account for about a third of all cases (133/404) and are particularly troublesome in rice and cereals. Although 71 weed species have been identified with triazine resistance, their importance has dwindled with the shift towards Roundup Ready® crops in the USA and the reduction of triazine usage in Europe. Forty-three grasses have evolved resistance to ACCase inhibitors, with the most serious cases being Avena spp., Lolium spp., Phalaris spp., Setaria spp. and Alopecurus myosuroides, infesting more than 25 million hectares of cereal production globally. Of the 24 weed species with glyphosate resistance, 16 have been found in Roundup Ready® cropping systems. Although Conyza canadensis is the most widespread glyphosate-resistant weed, Amaranthus palmeri and Amaranthus tuberculartus are the two most economically important glyphosate-resistant weeds because of the area they infest and the fact that these species have evolved resistance to numerous other herbicide sites of action, leaving growers with few herbicidal options for their control. The agricultural chemical industry has not brought any new herbicides with novel sites of action to market in over 30 years, making growers reliant on using existing herbicides in new ways. In addition, tougher registration and environmental regulations on herbicides have resulted in a loss of some herbicides, particularly in Europe. The lack of novel herbicide chemistries being brought to market combined with the rapid increase in multiple resistance in weeds threatens crop production worldwide. PMID:24302673

  18. Seletividade e controle de plantas daninhas com oxyfluorfen e sulfentrazone na implantação de lavoura de café Weed selectivity and control with oxyfluorfen and sulfentrazone in young arabica coffee plantations

    Directory of Open Access Journals (Sweden)

    C.E.O. Magalhães

    2012-09-01

    Full Text Available Este trabalho teve por objetivo avaliar a seletividade do oxyfluorfen e do sulfentrazone e o controle de plantas daninhas em diferentes épocas após o transplantio das mudas de café no campo. Foram realizados três ensaios no delineamento experimental de blocos casualizados com dez tratamentos e quatro repetições. No ensaio 1, aos 30 dias após o transplantio (DAT e, no ensaio 2, aos 90 DAT, testaram-se duas doses de oxyfluorfen (0,36 e 0,72 kg i.a. ha-1 e de sulfentrazone (0,4 e 0,6 kg i.a. ha-1, em jato dirigido ao solo (com proteção das mudas e em área total. No ensaio 3, os mesmos herbicidas e doses foram aplicados, porém aos 300 DAT e apenas em aplicação dirigida, testando-se duas pontas de pulverização de diferentes potenciais de deriva. Em todos os ensaios, acrescentaram-se as testemunhas capinada e sem capina. A entrelinha foi manejada com roçada. Foram identificadas as espécies de plantas daninhas e suas densidades. A eficácia dos herbicidas e suas seletividades também foram avaliadas. A principal planta daninha que ocorreu na área experimental foi Brachiaria decumbens. Sintomas visuais de toxicidade foram observados apenas quando os herbicidas foram aplicados em área total (ensaios 1 e 2, independentemente da dose e época de aplicação. No ensaio 3, independentemente do herbicida, da dose e da ponta utilizada, não houve sintomas visuais de toxicidade, nem redução no crescimento das plantas, em função da aplicação dirigida. Em todas as épocas o controle de plantas daninhas foi eficiente, porém a seletividade só foi alcançada na aplicação dirigida, para ambos os herbicidas.This study aimed to evaluate oxyfluorfen and sulfentrazone selectivity and weed control in young coffee plantations (Coffea arabica cv. Red Catuaí. Three trials were conducted in a randomized complete block design, with 10 treatments and four replicates. In the first and second trials, at 30 and 90 days after transplanting (DAT

  19. 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.

  20. Monitoring the aquatic toxicity of mosquito vector control spray pesticides to freshwater receiving waters.

    Science.gov (United States)

    Phillips, Bryn M; Anderson, Brian S; Voorhees, Jennifer P; Siegler, Katie; Denton, Debra; TenBrook, Patti; Larsen, Karen; Isorena, Philip; Tjeerdema, Ron S

    2014-07-01

    Pesticides are applied to state and local waterways in California to control insects such as mosquitoes, which are known to serve as a vector for West Nile Virus infection of humans. The California State Water Resources Control Board adopted a National Pollutant Discharge Elimination System General Permit to address the discharge to waters of the United States of pesticides resulting from adult and larval mosquito control. Because pesticides used in spray activities have the potential to cause toxicity to nontarget organisms in receiving waters, the current study was designed to determine whether toxicity testing provides additional, useful environmental risk information beyond chemical analysis in monitoring spray pesticide applications. Monitoring included a combination of aquatic toxicity tests and chemical analyses of receiving waters from agricultural, urban, and wetland habitats. The active ingredients monitored included the organophosphate pesticides malathion and naled, the pyrethroid pesticides etofenprox, permethrin, and sumithrin, pyrethrins, and piperonyl butoxide (PBO). Approximately 15% of the postapplication water samples were significantly toxic. Toxicity of half of these samples was attributed to the naled breakdown product dichlorvos. Toxicity of 2 other water samples likely occurred when PBO synergized the effects of pyrethroid pesticides that were likely present in the receiving system. Four of 43 postapplication sediment samples were significantly more toxic than their corresponding pre-application samples, but none of the observed toxicity was attributed to the application events. These results indicate that many of the spray pesticides used for adult mosquito control do not pose significant acute toxicity risk to invertebrates in receiving systems. In the case of naled in water, analysis of only the active ingredient underestimated potential impacts to the receiving system, because toxicity was attributed to the breakdown product, dichlorvos

  1. Aumento da população de plantas e uso de herbicidas no controle de plantas daninhas em milho Increase of plant population and use of herbicides to control weeds in corn

    Directory of Open Access Journals (Sweden)

    Aldo Merotto Junior

    1997-01-01

    Full Text Available O objetivo deste trabalho foi determinar a capacidade de controle de plantas daninhas efetuada pelo aumento da população de plantas de milho em associação com diferentes métodos de controle de plantas daninhas. O experimento foi conduzido em Lages (SC sob o delineamento de blocos ao acaso em parcelas subdivididas. Nas parcelas principais foram alocados os métodos de controle de plantas daninhas: 1 sem controle; 2 atrazine + metolachlor (1,4 + 2,1 kg/h a em pré emergência; 3 nicosulfuron (60 g/ ha em pós - emergência; 4 atrazine + metolachlor em pré emergência e nicosulfuron em pós-emergência; e 5 capina até o florescimento. Nas sub parcelas foram alocadas as populações de plantas: 35.000, 50.000, 68.000 e 80.000 plantas ha-1. O aumento da população de plantas foi mais efetivo na diminuição da matéria seca de plantas daninhas nos tratamentos sem controle e com herbicida em pré emergência. As plantas daninhas promoveram maiores decréscimos no rendimento de grão s de milho na população de 80000 plantas ha-1, onde a competição com plantas daninhas somou-se à competição intraespecífica que também é maior do que nas menores populações . O uso de altas populações de plantas diminui a competição com plantas daninhas , mas deve ser complementado com outros métodos de controle no início do desenvolvimento da cultura.The objective of this experiment was to evaluate the effectiveness of increasing corn plant population in association with differe nt methods to control weeds. The trial was conduted in Lages, SC, using a randomized complete block desing in a split plot arragement. Fiv e methods of weed control were located at the main plots: 1 check without control, 2 atrazine + metolachlor (1,4 + 2,1 kg/ha in pre-emergency, 3 nicosulfuron (60 g/ha in post emergency, 4 atrazine + metolachlor in pre-emergency and nicosulfuron in post emergency, and 5 hoeing up to flowerin g. Four plant population were tested at split

  2. 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. PMID:21548004

  3. Characterization of Rhizobacteria Associated with Weed Seedlings †

    OpenAIRE

    Kremer, Robert J.; Begonia, Maria Fatima T.; Stanley, Lynn; Lanham, Eric T.

    1990-01-01

    Rhizobacteria were isolated from seedlings of seven economically important weeds and characterized for potential phytopathogenicity, effects on seedling growth, and antibiosis to assess the possibility of developing deleterious rhizobacteria as biological control agents. The abundance and composition of rhizobacteria varied among the different weed species. For example, fluorescent pseudomonads represented from 11 to 42% of the total rhizobacterial populations from jimsonweed and lambsquarter...

  4. 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 and germina

  5. 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...

  6. Morphological traits associated with weed-suppressive ability of winter wheat against Italian ryegrass

    Science.gov (United States)

    Weed-suppressive wheat (Triticum aestivum L.) cultivars have been suggested as a complement to chemical and cultural methods of weed control. The objectives of this study were to assess the range of weed-suppressive ability against Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] ...

  7. Competition between crops and weeds in the Zanderij area of Suriname.

    OpenAIRE

    Everaarts, A.P.

    1991-01-01

    A weed flora rapidly built up with the cultivation of annual crops on two experimental farms in the Zanderij area of Suriname, despite the fact that the farms were newly established in forested areas. Studies indicated that without adequate weed control, significant yield losses occurred in groundnuts, sorghum and soybeans due to competition with weeds. Plant density of the crops was not affected, but competition with weeds reduced ground-cover and leaf area index. Competition affected growth...

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

    OpenAIRE

    Brandsæter, Lars O.; Mangerud, Kjell; Rasmussen, Jesper

    2012-01-01

    Pre- and post-emergence weed harrowing were studied in spring cereals in different environments and with two types of harrows in Norway during 2004–2006. The objectives were to investigate interactions between pre and post-emergence weed harrowing and the importance of harrow type. We hypothesised 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 typ...

  9. 海南剑麻园杂草种类调查及防除技术研究%Survey of Weeds in Sisal Plantation and Control Techniques in Hainan

    Institute of Scientific and Technical Information of China (English)

    李晓霞; 沈奕德; 黄乔乔; 范志伟; 易克贤; 黄东东

    2014-01-01

    A systematical investigation of weeds was taken in sisal plantation in Hainan province , and the dominant weed groups were determined.Then, weed control experiments were conducted.The results showed that there were 121 weed species belonging to 21 families in the plantation.Among them, eight species were considered as dominant weeds , including Melinis repens, Panicum maximum, Imperata cylindrica, Digitaria setigera, Chromolaena odorata, Praxelis clematidea, Tridax procumbens and Mimosa pudica.Leguminous crops as intercrops , perennial vines as covering plants could control the weeds to some extent.Arachis hypogaea and Macroptilium atropurpureum as intercrops could have evident effect on controlling the weeds, and leguminous plants could increase the soil fertility.Therefore, their application could be further extended in this area.%本文系统调查了海南剑麻主要种植区的杂草种类,确定了剑麻园的杂草优势种群,并以此为基础进行了剑麻园除草试验。结果表明,本区剑麻园杂草发生种类共有21科121种,其中优势种杂草主要为红毛草、大黍、白茅、短颖马唐、飞机草、假臭草、羽芒菊和含羞草8种杂草;采用间种豆科植物或多年生藤本植物覆盖控草可在一定程度上控制杂草的发生,其中间种花生、大翼豆处理具有明显的防除效果,且间种豆科植物能提高土壤肥力,可以在该地区进一步推广应用。

  10. Misturas de herbicidas para o controle de plantas daninhas do gênero Commelina Herbicide mixtures to control weeds of the genus Commelina

    Directory of Open Access Journals (Sweden)

    C.P. Ronchi

    2002-08-01

    metsulfuron methyl (4 g ha-1; oxyfluorfen combined to sulfentrazone (480 + 375 g ha-1; sequential 21 day-spaced applications of (paraquat + diuron / (carfentrazone-ethyl + glyphosate (200+400 /(30+720 and (paraquat + diuron / (paraquat + diuron (200+400 / (200+400; and no herbicide application as check control. The percentage of weed control and shoot fresh weight were evaluated. The best treatments to control both species were the sequential applications of (paraquat + diuron / (carfentrazone-ethyl + glyphosate and of (paraquat + diuron / (paraquat + diuron, followed by 2.4-D + glyphosate and carfentrazone-ethyl + glyphosate or glyphosate-potassium salt mixtures.

  11. Robotic intra-row weed hoeing in maize and sugar beet

    Directory of Open Access Journals (Sweden)

    Gerhards, Roland

    2016-02-01

    Full Text Available A prototype of robotic intra-row weed hoeing in maize and sugar beet is presented in this study. Weeds in the crop rows were identified using a bi-spectral image analysis system and shape analysis. Positions of weeds in the images were recorded. Selective weed control in the row was performed with a modified finger weeder driven by electrical motors. Speed of the finger weeder was increased at positions where only weeds were classified. The system was triggered by an encoder and controlled by a micro-controller.

  12. Disponibilidad de agua, nitrógeno y azufre en barbechos con y sin control de malezas en distintos niveles de residuos Water, nitrogen and sulphur availability in fallows with and without weed control and different residue levels

    Directory of Open Access Journals (Sweden)

    Romina Fernández

    2009-06-01

    presence, ten experiments with different levels of residue (A: 10,000 kg MS ha-1, M: 5,000 kg MS ha-1, B: less than 2,000 kg MS ha-1 were set up in Haplustolls of the tosca and dune plains in La Pampa and south of Córdoba. Each residue treatment was divided into sub-plots with different weed management: without weed control (malezas and with control (barbecho. Soil texture, bulk density, permanent wilting pint, and organic matter were determined in each site. At the beginning and end of fallow soil water contents, nitrate (N and soluble and adsorbed sulphates (S were measured in samples from 0 -0.2m depth. At all sites the water content at the beginning of fallow was high (between 51 and 100% available water. Despite this, our results showed a positive effect of residue level on water contents at the end of fallow, with a mean difference between A and B of 33%. In weed treatments no effect of residue was observed, and the difference between A and B was 10%. Water contents were more strongly affected by the presence of weeds than by residue level. Available N and S contents showed no effect of residue level, but were strongly affected by weed presence. In weed treatments sunflower seeding would be severely limited by lower available water contents, and the expectable yields would be diminished by 200 kg ha-1 or 600 kg ha-1 due to the lower availability of N and S respectively.

  13. Influence of plasma radiation on weed plants

    International Nuclear Information System (INIS)

    Results of the long-term experimental researches realized in the Republic of Belarus of the influence of the preplanting radiation of spring wheat (Triticum aestivum) seeds by helium plasma on quantity of weed plants before crop harvesting were presented. Application of the presowing irradiation of wheat seeds by plasma radiations caused the severe reduction of weed quantity and their weight decrease. Quantity of weeds (biting knotweed (Polygonum hydropiper), winterweed (Stellaria media), frost-blite (Chenopodium album), field sow thistle (Sonchus arvensis), blind-worm (Capsella bursa pastoris), corn mayweed (Matricaria inodora), meadow pine (Equisetum arvense), field pennycress (Thlaspi arvense) as well as total weed quantity and weight in plantings of spring wheat in the conditions of different backgrounds (biological (without chemical fertilizers (manure 30 t/ha); intensive (maximum fertilizer application – N90P90K90); moderate (N45P45K45); minimal (N30P30K30); control (no fertilizers)) were analysed. Schemes of arrangement devices for realization of plasma spectrum analysis were presented. Taking into consideration a long-term supervision of plasma influence on agricultural crops it was possible to make a conclusion about the possibility of application of new highly effective, economically and ecologically effective method which could be used both for the increasing of agricultural crops yields and for weed control

  14. Uso do novo sistema Clearfield® na cultura do girassol para o controle de plantas daninhas dicotiledóneas Use of the new Clearfield® system in sunflower culture to control dicotyledonous weeds

    Directory of Open Access Journals (Sweden)

    G. Santos

    2012-06-01

    Full Text Available A ocorrência de plantas daninhas dicotiledóneas tem limitado o aumento da área de cultivo de girassol no Brasil, devido ao seu impacto sobre a produtividade. Isso se deve à escassez de produtos registrados para a cultura com amplo espectro de ação. Em razão disso, desenvolveram-se dois experimentos com o objetivo de avaliar a eficácia e seletividade de herbicidas do grupo das imidazolinonas aplicados em pós-emergência de plantas daninhas dicotiledôneas na cultura do girassol Clearfield®. Os experimentos foram instalados no campo, em Iguatemi, distrito de Maringá-PR. Os tratamentos constituíram-se de duas testemunhas sem aplicação de herbicida, sendo uma sem capina e outra capinada, sulfentrazone (200,00 g ha-1 aplicado em pré-emergência e imazapic+imazapyr aplicados em pós-emergência nas doses de [36,75+12,25], [52,5+17,5], [12,25+36,75] e [17,5+52,5] g ha-1. Foram feitas avaliações de controle para Euphorbia heterophylla, Conyza bonariensis, Raphanus raphanistrum, Bidens pilosa, Ipomoea grandifolia e Portulaca oleracea. Também foram realizadas avaliações de intoxicação do girassol Clearfield®, estande e produtividade em kg ha-1. De acordo com os resultados, verificou-se que o uso do sistema Clearfield® mostrou-se uma ótima opção para áreas com infestação de plantas daninhas dicotiledôneas, pois possibilita a aplicação de herbicidas inibidores da enzima acetolactato sintase (ALS; os controles obtidos variaram de medianos a excelentes, além de ele não provocar injúrias à cultura e manter o estande inicial e a produtividade.The occurrence of dicotyledonous weeds has limited the increase of the area of sunflower cultivation in Brazil, due to their impact on crop yield. This is a result of a shortage of products registered for the crop with broad-spectrum control. Thus, two experiments were installed to evaluate the efficacy and selectivity of the imidazolinone herbicides applied on post

  15. 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.

  16. 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 swallowed. ...

  17. Eficácia do carfentrazone-ethyl no controle de plantas aquáticas latifoliadas em caixas-d'água Efficiency of carfentrazone-ethyl in controlling large-leafed aquatic plants using boxes of water

    Directory of Open Access Journals (Sweden)

    F.T. Carvalho

    2005-06-01

    Full Text Available Atualmente, alguns herbicidas estão sendo desenvolvidos para o controle de plantas daninhas aquáticas. O objetivo deste trabalho foi avaliar a eficácia do carfentrazone-ethyl em ambiente aquático para o controle pós-emergente de aguapé, alface-d'água e salvínia. O trabalho foi desenvolvido em caixas-d'água, no período de julho a setembro de 2004, no NUPAM - FCA/UNESP, em Botucatu. O delineamento experimental adotado foi o de blocos ao acaso, com sete tratamentos e quatro repetições, sendo as unidades experimentais constituídas pelas caixasd'água. Os tratamentos foram os seguintes: testemunha sem herbicida; Aurora 400 CE (75, 150 e 300 mL ha-1; Roundup (3,0 L ha-1, Aurora 400 CE + Roundup (75 mL + 3,0 L ha-1 e Aurora 400 CE + Arsenal N.A. (75 mL + 2,0 L ha-1. Observou-se que o tratamento Aurora 400 CE (300 mL ha-1 é altamente eficaz no controle de alface-d'água (Pistia stratiotes; o tratamento Roundup (3,0 L ha-1 é altamente eficaz no controle de aguapé (Eichhornia crassipes; o tratamento Aurora 400 CE + Roundup (75 mL + 3,0 L ha-1 é eficaz no controle de aguapé (E. crassipes, alface-d'água (P. stratiotes e salvínia (Salvinia auriculata; e o tratamento Aurora 400 CE + Arsenal (75 mL + 2,0 L ha-1 é eficaz no controle de aguapé (E. crassipes e alface-d'água (P. stratiotes. A mistura Aurora 400 CE + Roundup (75 mL + 3,0 L ha-1 apresentou-se viável e foi o único tratamento eficaz no controle das três espécies estudadas.Some herbicides are being currently developed for the control of aquatic weeds.The objective of this work was to evaluate the efficiency of Aurora 400 CE in aquatic environment for the post-emergence control of Eichhornia crassipes, Pistia stratiotes and Salvinia auriculata. The experiment was developed in boxes of water, from 22/07 to 20/09/2004, at NUPAM-FCA/UNESP, Botucatu, SP, Brazil. The experimental design was in randomized blocks with seven treatments and four repetitions, with the units consisting

  18. Aplicação de diethatyl para o controle de plantas daninhas em cultura de algodoeiro herbáceo Use of diethatyl to control weeds in herbaceus cotton crop

    Directory of Open Access Journals (Sweden)

    L.S.P. Cruz

    1980-06-01

    Full Text Available Para conhecer a ação do herbicida diethatyl [N-cloroacetil -N-(2,6-dietilfenil glicine] no controle de plantas infestantes de cultura de algodão herbáceo foram conduzidos sete experimentos de campo nos anos de 1974 e 1975. Os ensaios foram instalados em diversos tipos de solos onde diethatyl foi aplicado em pré-plantio incorporado e em pré-emergência e foi comparado com herbicidas já conhecidos e comumente empregados em algodoeiros e, ainda, com alguns novos herbicidas. Esse produto mostrou-se eficiente no controle de gramíneas e de algumas plantas daninhas de folhas largas e não foi prejudicial às plantas de algodão e à sua produção.Seven field trials were conducted in 1974 and 1975 to determine the efficiency of the herbicide diethatyl for weed control in herbaceus cotton. Trials were carried out on various types of soil, and diethatyl was applied in pre -plant incorporated and preemergence. Standard herbicides normally used in cotton and some new herbicides were also included. This compound showed efficacy in controll ing gramineae and also some broad leaves weeds and did not cause damage to the crop nor affected yield.

  19. A New Hoe Blade for Inter-Row Weeding

    DEFF Research Database (Denmark)

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

    2016-01-01

    New camera-based systems for automatic steering of inter-row cultivators have made it possible to conduct inter-row weeding in small inter-row spaces at reasonable work rates. This has motivated organic growers to shift from full-width weed harrowing of small grain cereals to inter-row hoeing. The...... aim is mainly to improve weeding effectiveness against tall-growing and tap-rooted weed species. The ‘Ducksfoot’ hoe blade is commonly used for traditional inter-row weeding in row crops such as sugar beets and maize. This blade usually provides satisfactory weed control, if soils are not too wet 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...

  20. USE OF WATER HYACINTH AQUATIC TREATMENT SYSTEMS FOR AMMONIA CONTROL AND EFFLUENT POLISHING

    Science.gov (United States)

    A pilot investigation conducted at the City of Roseville, California evaluated the use of water hyacinth aquatic plants as a post-secondary wastewater treatment process. These systems substantially reduced ammonia concentrations during warm seasons by more than 70% in nonaerated ...

  1. Control of breathing in African lungfish (Protopterus dolloi): A comparison of aquatic and cocooned (terrestrialized) animals

    DEFF Research Database (Denmark)

    Perry, S.F.; Euverman, R.; Wang, Tobias;

    2008-01-01

    African lungfish, Protopterus dolloi exhibited constant rates of O2 consumption before (0.95 ± 0.07 mmol kg-1 h-1), during (1.21 ± 0.32 mmol kg-1 h-1) and after (1.14 ± 0.14 mmol kg-1 h-1) extended periods (1-2 months) of terrestrialization while cocooned. Although a breathing event...... in terrestrialized fish consisted of multiple bouts of inspiration and expiration in rapid succession, the mean frequency of pulmonary breathing events was unaltered in the terrestrialized fish (16.7 ± 1.4 h-1 versus 20.1 ± 4.9 h-1 in the aquatic and terrestrialized fish, respectively). Hypoxia ( 20 mmHg) increased...... the frequency of breathing events by 16 and 23 h-1 in the aquatic and terrestrialized fish, respectively. Hyperoxia ( 550 mmHg) decreased breathing event frequency by 10 and 15 h-1 in the aquatic and terrestrialized animals. Aquatic hypercapnia ( 37.5 mmHg) increased pulmonary breathing frequency (from 15...

  2. 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.

  3. Controle de plantas daninhas através da palha de cana-de-açúcar associada à mistura dos herbicidas trifloxysulfuron sodium + ametrina Weed control through green cane harvesting residue combined with the herbicide mixture trifloxysulfuron sodium + ametryne

    Directory of Open Access Journals (Sweden)

    R. Gravena

    2004-09-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da palha de cana-de-açúcar resultante da colheita sem queima e da mistura comercial dos herbicidas trifloxysulfuron sodium + ametrina, na emergência e no acúmulo de biomassa seca de nove espécies de plantas daninhas. Os tratamentos foram distribuídos em esquema fatorial 3 x 3, sendo três quantidades de palha resultantes da colheita da cana-de-açúcar sem queima (0, 10 e 15 t ha-1, e três doses da mistura formulada dos herbicidas trifloxysulfuron sodium + ametrina (0, 1,75 e 2,00 kg ha-1, aplicados em condições de pós-emergência das plantas daninhas. As densidades das plantas daninhas foram avaliadas aos 15, 60 e 90 dias após a aplicação (DAA da mistura dos herbicidas, e a biomassa seca das plantas daninhas, aos 90 DAA. A presença de palha sobre o solo suprimiu as densidades das populações de Brachiaria plantaginea, Digitaria horizontalis, Panicum maximum, Sida glaziovii e Amaranthus hybridus a níveis de infestação considerados satisfatórios de controle. A palhada também reduziu as populações de Senna obtusifolia, Ipomoea hederifolia, I. grandifolia e I. nil, porém em níveis insatisfatórios de controle. A mistura de herbicidas nas doses estudadas controlou todas as espécies de plantas daninhas avaliadas. Na presença da palha, o controle das plantas de S. obtusifolia, I. nil, I. hederifolia e I. grandifolia somente foi satisfatório quando foi aplicada a mistura de herbicidas. Para o controle de P. maximum, houve vantagem na integração dos dois métodos de controle, em relação à aplicação isolada da menor quantidade de palha estudada ou à aplicação da mistura de herbicidas.This work aimed to evaluate the effects of green cane harvesting residue and of the herbicide mixture trifloxysulfuron sodium + ametryne on the emergence and dry biomass accumulation of nine weed species. The treatments were arranged in a 3 x 3 factorial design, with three green cane

  4. Combining physical, cultural and biological methods: prospects for integrated non-chemical weed management strategies

    OpenAIRE

    Hatcher, Lecturer Paul; Melander, Senior scientist Bo

    2003-01-01

    Physical, cultural and biological methods for weed control have developed largely independently and are often concerned with weed control in different systems: physical and cultural control in annual crops and biocontrol in extensive grasslands. We discuss the strengths and limitations of four physical and cultural methods for weed control: mechanical, thermal, cutting, and intercropping, and the advantages and disadvantages of combining biological control with them. These physical and cult...

  5. Deposição de glyphosate aplicado para controle de plantas daninhas em soja transgênica Glyphosate deposition for weed control in transgenic soybean

    Directory of Open Access Journals (Sweden)

    D.L.P. Gazziero

    2006-01-01

    , corresponding to 17; 24; 31; 38 and 45 days after soybean emergence. The targets, soybean plants, wild poinsettias, and Petri dishes on the soil surface, were collected after spraying and the tracer solution was later recovered by washing and stirring in distilled water. Samples of recovered solutions were submitted to spectrophotometer analysis, and the absorption data were converted in µL cm-2 and µL per plant. The accumulated frequencies of the original deposit data were adequately adjusted to the Gompertz model, showing high precision (R² > 0.95. The results showed that the spraying solution deposition on soybean plants and wild poinsettia reduced progressively with crop development and weed infestation, suggesting that control efficiency can be obtained with early applications.

  6. Efeito de períodos de controle de plantas daninhas sobre o desenvolvimento inicial de plantas de eucalipto Effects of weed control periods on initial growth and development of eucalypt

    Directory of Open Access Journals (Sweden)

    R.E.B. Toledo

    2000-01-01

    Full Text Available O objetivo deste trabalho foi estudar os efeitos dos períodos de convivência e de controle de Brachiaria decumbens sobre o desenvolvimento inicial de clones de Eucalyptus grandis x Eucalyptus urophylla. Para isso, um ensaio foi conduzido, no município de Três Lagoas-MS, no período de janeiro a dezembro de 1997. Os tratamentos experimentais consistiram de diferentes épocas e períodos de convivência das plantas daninhas na cultura do eucalipto. As épocas foram divididas em dois grupos. No primeiro, a convivência se iniciava no transplante das mudas e era estendida até 28, 56, 84, 112, 140, 168, 224, 252 e 364 dias após. No segundo grupo, a convivência se iniciava aos 0, 28, 56, 84, 112, 140, 168, 224 e 252 dias após o transplante e era estendida até o final de um ano. As principais plantas daninhas que ocorreram na área experimental foram Brachiaria decumbens e Spermacocea latifola. As plantas jovens de eucalipto foram bastante suscetíveis à interferência das plantas daninhas, apresentando um período anterior à interferência inferior a 14-28 dias. Para assegurar o desenvolvimento da cultura, o período total de prevenção à interferência foi de 140 dias, e o período crítico de prevenção à interferência, de 14-28 a 140 dias após o transplante, considerando o índice de 5% de redução em diâmetro.A field trial was carried out in Três Lagoas-MS, Brazil, from January to December of 1997, to study the effects of control and coexistence period of Brachiaria decumbens on the growth of Eucalyptus grandis x Eucalyptus urophylla clones. The experimental design was a complete randomized block design, with four replications. The treatments consisted of different periods of weed-eucalypt association. The periods were divided in two groups. In the first one, the weed-eucalypt coexistence initiated during the eucalypt transplanting, continuing up to 28, 56, 112, 140, 168, 224, 252 and 364 days after it. In the second group, the

  7. Evaluation of mulching materials as integrated weed management component in maize crop

    International Nuclear Information System (INIS)

    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)

  8. Experiment of 30%Glyphosate Oil Miscible Flowable Concentrate Against Weeds Control in Citrus Garden%30%草甘膦油悬浮剂防治柑橘园杂草药效试验

    Institute of Scientific and Technical Information of China (English)

    王平

    2013-01-01

    30%草甘膦油悬浮剂防治柑橘园杂草药效试验结果表明,30%草甘膦油悬浮剂相比较于50%草甘膦可溶性粉剂,对柑橘园杂草鼠麴草、繁缕、看麦娘等有很好的防治效果。%The experiment of 30% glyphosate oil miscible flowable concentrate agarinst weed control in citrus garden showed that ,30%glyphosate oil miscible flowable concentrate had good control effect compared to 50% glyphosate soluble powder on the weeds in citrus garden , including Herba Gnaphaii Affinis,Stellaria media(Linn.) Cyrill.,Alopecurus aequalis etc.

  9. List of Threatened Weeds in the Continental Part of Croatia and their Possible Conservation

    Directory of Open Access Journals (Sweden)

    Nada Hulina

    2005-06-01

    Full Text Available List of threatened weed species in terms of IUCN categories of endangerment is presented. This list provides a general insight into problems involved in endangerment of weed flora in the continental part of Croatia. It contains a total of 78 species as follows: 6 of them are extinct, 42 endangered, 12 vulnerable and 18 are rare. Extinct and the majority of threatened weeds are companions of flax crop and cereals. The intensified soil cultivation, an abundant fertilization, seed cleaning and chemical weed control (herbicides are universally recognized as causes for a decline on floristic diversity in weed communities. The possibilities of preventing further endangerment of weed species and effective manners of conservation are: to promote organic farming and in conventional production to use less fertilization and the field edges not treated with herbicides. The measures of nature conservation include botanical and weed gardens. Botanical gardens with their systematic fields, can make a significant contribution to the weed conservation on the rang of species. In weed gardens weeds grow with belonging crops and on condition of traditional agrotechniques. Further chance is an inclusion of attractive and suitable weed species in the concept of esthetic-paysage planning (e.g. in flower garden beds, making green of rockeries, road verges and etc. Nature, by itself, protects segetal weeds, which, owing to the seed bank and dormancy, are ready to survive in the soil waiting favourable time and space.

  10. Weed Science and Technology. MP-17.

    Science.gov (United States)

    Alley, Harold P.; Lee, Gary A.

    This document is one in a series distributed by the Agricultural Extension Service of the University of Wyoming-Laramie. It presents the principles and methods of weed control especially as it relates to the use of herbicides. The factors influencing the effectiveness of both foliar-applied and soil-applied herbicides are discussed. A listing of…

  11. Métodos de controle de plantas daninhas e seus impactos na qualidade microbiana de solo sob cafeeiro Methods of weed control and their impacts on microbial quality of soil under coffee

    Directory of Open Access Journals (Sweden)

    Rogério Melloni

    2013-02-01

    empregado para o controle de plantas daninhas em cafeeiro.Minas Gerais stands out as the largest coffee-producing state of Brazil. This crop is extremely susceptible to weeds, which can be handled by manual, mechanized and/or chemical methods, which strongly affect production costs and soil quality. In this sense, the objective of this study was to evaluate the effect of different weed control methods in and between coffee rows on the soil microbiota and its processes. For this purpose, soil samples were taken in April 2010 from an Oxisol on the experimental farm of the Agricultural Research Company of Minas Gerais (EPAMIG, in São Sebastião do Paraíso, MG, at a depth of 0-10 cm in the middle of the track (interrow of coffee and 20 cm away from the stem of the coffee trees (row, to determine the following properties: total density of bacteria and fungi, phosphate solubilizers, cellulolytic and ammonifying microorganisms, non-symbiotic diazotrophic bacteria, carbon biomass and microbial activity, metabolic quotient (qCO2 and enzymatic activity by the hydrolysis of fluorescein diacetate. The coffee plants were subjected to seven methods of weed control: mowing, coffee tandem disk harrow (grid, rotary tiller, post-emergence herbicide, pre-emergence herbicide, manual weeding, and no weed control. The results showed the complexity of the effects of these different methods on soil and its processes, with lowest impacts of manual weeding and rotary hoe. Mowing, coffee tandem disk harrow, no weed control and pre-emergence herbicide caused intermediate impacts, while the application of post-emergence herbicides in-between coffee rows caused the most negative impacts on the evaluated properties. It is suggested that these impacts must be considered when evaluating and selecting the method for weed control in coffee plants.

  12. Application of vascular aquatic plants for pollution removal, energy and food production in a biological system

    Science.gov (United States)

    Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.

    1975-01-01

    Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

  13. Influence of weed mat and surface sawdust mulch on soil nutrient availability and soil chemical properties under organic blueberry production

    Science.gov (United States)

    Weed control represents one of the most important cultural management aspects for organic blueberry production. Two of the most common ways to control weeds in blueberries is by the use of surface sawdust mulch or by landscape fabric, often referred to as weed mat. Soil temperature and soil moisture...

  14. Robotic weed monitoring

    DEFF Research Database (Denmark)

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

    2011-01-01

    -farm operating console, the mobile robotic unit, and a field server for generating and storingmaps. The hypothesis is that it is possible to automate the planning and execution of theoperation of monitoring of the in-field weed density and species distribution. The developedplanning system includes the automatic...

  15. 30%丁草胺·乙氧氟草醚水乳剂防除甘蔗田杂草药效试验%Effects of 30%Mixed Butachlor and Oxyfluorfen EW on Controlling Weeds in Sugarcane Fields

    Institute of Scientific and Technical Information of China (English)

    邓延岗; 易芬远; 韦茂春; 赖开平; 叶一强

    2014-01-01

    以a.i.360~900 g/hm2用量,30%丁草胺·乙氧氟草醚水乳剂芽前土壤处理防除甘蔗田间杂草。试验结果表明,药后30天、60天对一年生禾本科杂草和阔叶杂草表现出良好防效,在a.i.450~540 g/hm2剂量下,对蔗田杂草防效大于86%,且对甘蔗安全。%The aim of the present study was to determine the pre-emergence application of 30%mixed butachlor and oxyfluorfen EW at a.i. 360~900 g/hm2 on controlling weeds in sugarcane fields. The results showed good control effect on annual weeds in Gramineae and broad-leaved weeds after 30 and 60 days of spraying. The control efficacy of 30%mixed butachlor and oxyfluorfen EW at dosages of a.i. 450~540 g/hm2 were more than 86%. It was safe to sugarcane at such dosages.

  16. Influence of Weed Competition on Potato Growth, Production and Radiation Use Efficiency

    Directory of Open Access Journals (Sweden)

    Farzad MONDANI

    2011-08-01

    Full Text Available Weed management in potato production is one of the main cost and time consuming practices. Understanding the most effective time of weed control could reduce the costs and increase potato yield. Field study was conducted in the west region of Iran during 2006 to evaluate the effect of weeds damage in potato fields. Twelve treatments used consisted of six initial weed-free periods in which plots were kept free of weeds for 0, 10, 20, 30, 40 and 50 days after crop emergence (DAE, and then weeds were allowed to grow until harvest, and six initial weed-infested periods in which, weeds were allowed to grow for 0, 10, 20, 30, 40 and 50 DAE, then the plots were kept free of weeds until harvest. Experiment was arranged as a randomized complete block design with three replications. The results showed effect of weed competition on crop dry matter started about 40 DAE and about 90 DAE reached its maximum. The weeds competition decreased dry matter accumulation, leaf area index, crop growth rate, leaf area index duration, light absorption, light extinction coefficient and radiation use efficiency (RUE of potato. Weeds reduced the potato yield 54.8 percent. The beginning and the end of the critical period of weed control in potato (CPWC was based on 5% and 10% tuber yield loss. The onset of the CPWC ranged from 486 to 572 GDD, at 5% and 10% yield loss level corresponding to 11 and 19 days after crop emergence, respectively. The end of the CPWC varied from 1372 to 1164 GDD, at 5% and 10% yield loss level corresponding to 65 and 51 days after crop emergence, respectively. RUE in the weed infestation treatment in comparison to the weed free treatment, reduced 11.8 percent.

  17. Water Hyacinths and Alligator Weeds for Final Filtration of Sewage

    Science.gov (United States)

    Wolverton, B. C.; Mcdonald, R. C.; Gordon, J.

    1976-01-01

    The potential of water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxerides) (Mart.) Griesb. as secondary and tertiary filtration systems for domestic sewage was demonstrated. These two vascular aquatic plants reduced the suspended solids, total Kjeldahl nitrogen, total phosphorus, BOD sub 5, and total organic carbon levels in domestic sewage from 60 percent to 98 percent within a two week period. These plants grown in domestic sewage were also free of toxic levels of trace heavy metals.

  18. Controle de plantas daninhas na produção de mudas de plantas ornamentais Weed control in ornamental plant seedling production

    Directory of Open Access Journals (Sweden)

    F.C.L. Freitas

    2007-09-01

    g ha-1 de oxyfluorfen, para plantas de copo-de-leite, estrelítzia e palmeira-australiana, respectivamente, na aplicação em área total, e nas concentrações superiores a 0,0018%, na aplicação dirigida, aos 30 DAA.This study aimed to evaluate efficacy of oxyfluorfen in controlling Pilea microphylla for the production of ornamental plant shoots. Two experiments were carried out in a randomized block design, arranged in a factorial scheme 2 x 7, with three replicates. One trial was composed by three ornamental plant species (Zantedeschia aethiopica, Strelitzia reginae and Archontophoenix cunninghamiana and seven oxyfluorfen rates (0, 24, 72, 144, 216, 288 and 360 g ha-1, sprayed in a total area; the other trial was composed by the same species and seven oxyfluorfen concentrations (0.00000, 0.00036, 0.00072, 0.00144, 0.00288, 0.00576 and 0.01152% of a.i. applied directly as spray, without reaching the ornamental plant leaves. Each experimental unit was represented by a pot with an ornamental plant shoot, infested with Pilea microphylla. At 15, 30 and 60 days after application (DAA visual evaluations of the control on P. microphylla and toxicity on ornamental plants were carried out. For the total area spray, the A. cunninghamiana plant pots demanded high herbicide doses due to this species' larger foliar area, during application, making the herbicide contact with weeds difficult. Still in this application modality,light intoxication symptoms were observed in the ornamental plants, being more evident in the A. cunninghamiana plants. For the direct spray modality, no interaction among the factors, species and herbicide concentration, nor herbicide behavior differences were observed for the characteristics evaluated. Intoxication was not observed in the ornamental plants in none of the treatments evaluated, for the direct spray modality. Efficient P. microphylla control was verified for rates above 90% at 300, 320 and 340 kg ha-1 of oxyfluorfen, plants of Z

  19. 50%吡氟酰草胺水分散粒剂对春小麦田阔叶杂草的防效%Control Effect of Diflufenican 50%WG on Broad-leaved Weeds in Spring Wheat Field

    Institute of Scientific and Technical Information of China (English)

    程亮

    2015-01-01

    通过田间药效试验明确50%吡氟酰草胺水分散粒剂对春小麦田阔叶杂草的防除效果和田间推荐使用剂量,结果表明,50%吡氟酰草胺水分散粒剂对小麦田杂草密花香薷、野油菜和酸模叶蓼的防除效果稍差,施药后40 d对杂草株数总体防效为53.01%~61.75%,鲜重总体防效为54.30%~58.03%。该药剂对小麦安全,较空白对照增产6.44%~8.52%。建议该药剂于春小麦3叶期前,杂草2叶期前进行茎叶喷雾处理。%Based on the field trials,the efficacy and recommended dosage of diflufenican 50% WG are determined for controlling broad-leaf weeds in spring wheat field. The result shows that diflufenican 50% WG had not good control effect to broad-leaved weeds. The integrated plant and fresh weight control effects are 53.01%~61.75% and 54.30%~58.03% on weeds respectively after 40 days after spaying. Diflufenican 50% WG had no significant effect on spring wheat growth and the yield increasing rate of spring wheat is 6.44%~8.52%after sparing. The proper period of spraying is 2 leaves in weeds(3 leaves in wheat).

  20. First establishment of the planthopper Megamelus scutellaris Berg 1883 (Hemiptera: Delphacidae) released for biological control of water hyacinth in California.

    Science.gov (United States)

    Water hyacinth (Eichhornia crassipes (Martius) Solms-Laubach) is a non-native, invasive floating aquatic weed in the Sacramento San Joaquin Delta and associated river watersheds of northern California. Prior efforts to control water hyacinth biologically in this region have not led to sustained cont...

  1. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  2. Avaliação de herbicidas no controle de plantas daninhas na cultura da soja Evaluation of herbicides in the control of weeds in the soybean crop

    Directory of Open Access Journals (Sweden)

    A.C. De Barros

    1992-01-01

    Full Text Available Foi conduzido em Serranópolis, GO, um ensaio objetivando avaliar a eficiência e a seletividade de herbicidas no controle de plantas daninhas na cultura da soja (Glycine max (L. Merril, utilizando-se os seguintes tratamentos: A 100 g/ha de imazethapyr (ácido 2-[4,5-dihidro-4-metil-4(1-metiletil-5-oxo-1H-imidazol-2-ilo]-5-etil-3-piridinacarboxilico + surfactante, a 0,25% v/v; B tratamento A e 15 dias após, 230 g/ha de sethoxydim (2-1-etoximino-butil-5-2(etiltio-propil-3-hidroxi-2-ciclohexeno-1-ona + óleo mineral, a 0,25% v/v; C 230 g/ha de sethoxydim + óleo mineral, a 0,25% v/v; D 480 + 200 + 230 g/ha de bentazon (3-isopropil-2,1,3-benzotiadiazinona-(4-2,2-dióxido + fomesafen (5-2-cloro-4-(trifluorometil-fenoxiN-metilsulfonil-2-nitrobenzamida + sethoxydim + óleo mineral, 0,25% v/v; E 150 g/ha de imazaquim (2-[4,5-dihidro-4-metil-4-(1-metiletil-5-oxo-1H-imidazol-2-ilo]-3-quinolinacarboxílico pré-e e 230 g/ha de sethoxydim + óleo mineral, 0,25% v/v; F 250 g/ha de fomesafen + 187 g/ha de fluazipop-p-butil (butil-(R-2-(4-(5-trifluorometil-2-piridiloxi-fenoxi-propionato + surfactante a 0,2% v/v; G 120 g/ha de imazethapyr + surfactante a 0,2% v/v; H testemunha capinada; I testemunha não capinada. O delineamento experimental foi de blocos ao acaso, com quatro repetições. O capim-custódio (Pennisetum setosum (Swartz L. Rich foi eficientemente controlado por todos os tratamentos químicos, enquanto a falsa-serralha (Emilia sonchifolia DC. foi somente pelo tratamento D. O capim-carrapicho (Cenchrus echinatus L. por C, D, E e F. O joá-de-capote (Nicandra physaloides (L. Pers. por D.F. e G. Ocorreram injúrias iniciais às plantas de soja, nos tratamentos D, E. e F. As alturas de plantas e de inserção da primeira vagem, além do rendimento de grãos, não foram influenciados significativamente pelos herbicidas.An experiment was carried out in Serranópolis, State of Goiás, Brazil, aiming to evaluate herbicides efficiency in weeds control

  3. 冀西北马铃薯田间杂草化学防治研究%Study on Chemical Controlling Weed in the Potato fields in Northwest Hebei

    Institute of Scientific and Technical Information of China (English)

    王宝地

    2011-01-01

    [ Objective ] In order to search the effective chemical control method on weed in the potato fields in Northwest Hebei. [ Method ] Weed control experiment was carried out by 15% Fluazifop emulsifiable concentrate ( EC ) and 24% oxyfluorfen emulsifiable concentrate (EC) in potato fields which were treated by 48% Trifluralin EC and 50% Acetochlor EC formerly. [ Result] The result showed that 50% Aeetochlor EC got better effect in germination rate of potato on pre-sowing treatments of soil than 48% Trifluralin EC. Weed could effective controlled by 24% oxyfluorfen EC (300,450 ml/hm2 ) in pre-sowing treatments of soil by 50% Acetochlor EC. The application time of 24% oxyfluorfen EC was at seedling stage. Using of chemical weed control in potato field, the expenditure could lower and reach to 1050 - 1080 Yuan/hm2 in northwest in Hebei province. [ Conclusion] Pre-sowing treatments of soil with chemicals combining with chemical control at seed ling stage is a effective way of controlling weed in the potato fields in Northwest Hebei.%[目的]寻找控制冀西北地区马铃薯田间杂草的有效化学防除方法.[方法]在经48%氟乐灵乳油和50%乙草胺乳油处理过的马铃薯田间使用15%精稳杀得乳油和24%果尔乳油进行除草试验.[结果]研究结果表明,50%乙草胺乳油在播前进行土壤处理比48%氟乐灵乳油具有不影响出苗率的优点,效果更好;播种前用50%乙草胺乳油2 625 mL/hm2处理过的土壤,苗期用24%果尔乳油300、450ml/hm2可以很好地防治田间杂草.在冀西北地区马铃薯生产中使用化学除草可以节省成本1 050~1 080元/hm2.[结论]播种前药剂处理土壤结合苗期化学防治是控制冀西北地区马铃薯田间杂草的有效途径.

  4. ArylexTM active – new herbicide active and base for new cereals herbicides: ZyparTM and Pixxaro™ EC to control wide range of broadleaf weeds in cereals in Europe

    Directory of Open Access Journals (Sweden)

    Dzikowski, Marcin

    2016-02-01

    Full Text Available Arylex™ active is a new auxinic herbicide for postemergence control of a range of important broadleaf weeds in cereals. It has been discovered and developed by Dow AgroSciences globally as a first member of the new ‘arylpicolinate‘ structural class. Arylex applied together with safener brings excellent crop safety and due to the rapid degradation in soil and plant tissue it does not limit the following crop choice. In Europe the first two herbicides containing this active are Zypar™ and Pixxaro™ EC. Zypar is a premix of Arylex and florasulam, delivering at the 1 L/ha maximum use rate 6 g ae/ha of Arylex and 5 g/ha of florasulam. It can be applied to all cereals, apart from oats, in autumn and spring. Spring application is allowed from BBCH 13 till BBCH 45, however the best performance is reached up to BBCH 32. Zypar’s spectrum of controlled weeds is very wide. Pixxaro EC is a combination of Arylex and fluroxypyr and at 0.5 l/ha dose rate delivers 6 g ae/ha of Arylex and 140 g ae/ha of fluroxypyr. It can be applied in all cereals, apart from oats, in spring from BBCH 13 till BBCH 45, while the best performance is observed between BBCH 30 and 45. Pixxaro EC shows excellent efficacy against key weeds, especially Galium aparine and at all growth stages. This herbicide brings a novel non-ALS solution and will be a key component of anti-resistance strategies for broadleaf weeds in cereals.

  5. Evaluation of control effects of glyphosate potassium salt 30% as against weeds in non-crop land%30%草甘膦钾盐水剂防除非耕地杂草田间药效评价

    Institute of Scientific and Technical Information of China (English)

    高生; 阚晓君

    2011-01-01

    Glyphosate is a no selective herbicide that has many advantages such as high effect,low dosage,low toxicity,wide weed control spectrum,free application stage and so on.The widely used glyphosate formulations are mainly isopropylamine salt and ammonium salt in China.The study aimed to explore the control effect of 30% glyphosate potassium salt AS against weeds.For this reason,glyphosate potassium salt 30% AS was applied to control weeds in non-crop land.Spraying method was leaf spraying and experimental design was the randomized block arrangement.The results showed that glyphosate potassium salt 30% AS had a good weed control effects in non-crop land.After spraying the herbicide 15 d,the total of the weed control effect was over 95%.The use of active ingredients dose which recommended was 1 000~2 000 g/hm2.%草甘膦是一种灭生性除草剂,具有高效、用量少、低毒、杀草谱广、使用时期灵活等优点.目前我国广泛使用的草甘膦制剂主要以异丙胺盐和铵盐为主,为探明草甘膦钾盐水剂的除草效果,用30%草甘膦钾盐水剂进行了非耕地杂草防除试验,试验设计采用随机区组排列,施药方法为茎叶处理.试验结果表明,30%草甘膦钾盐水剂对非耕地杂草有很好的防治效果,用药后15 d,对杂草的总防效在95%以上,推荐使用剂量为1 000~2 000 g/hm2.

  6. Effects of inlake application of glyphoste and 2, 4‐D to control shoreline water hyacinth on diversity and abundance of associated macrofauna

    OpenAIRE

    Twongo, T.

    1997-01-01

    The purpose of inlake herbicide trials was to assess on the aquatic environment and resources, of in-lake of weeder 64 (2,4-0 amine) and Rodio (Glyphosate) water hyacinth the effects application to control water hyacinth. The experiments reported here specifically studied the effects of the herbicides on the diversity and abundance of aquatic macrofauna associated with the water weed. Results from this and similar experiments which assessed herbicide efficacy on water hyacinth; dissi...

  7. Controlling and maintaining exposure of hydrophobic organic compounds in aquatic toxicity tests by passive dosing

    International Nuclear Information System (INIS)

    The risk assessment of hydrophobic organic compounds (HOCs) in aquatic toxicity or bioconcentration tests is a challenge due to their low aqueous solubilities, sorption and losses leading to poorly defined exposure and reduced test sensitivity. Passive dosing overcomes these problems via the continual partitioning of HOCs from a dominating reservoir loaded in a biocompatible polymer such as silicone, providing defined and constant freely dissolved concentrations and eliminating spiking with co-solvents. This study characterised the performance of a passive dosing format for aquatic tests with small organism such as invertebrates and algae, consisting of PDMS silicone cast into the base of the glass test vessel. The PDMS silicone was loaded by partitioning from a methanol solution containing PAHs (log KOW 3.56-6.63) as model compounds, followed by removal of the methanol with water. This resulted in highly reproducible PDMS silicone HOC concentrations. When shaking, release of PAHs into aqueous solution was rapid and reproducible, and equilibrium partitioning was reached within 5 h for all compounds. The buffering capacity was sufficient to maintain stable concentrations over more than 10 weeks. This format was applied in a 48 h Daphnia magna immobilisation assay to test the toxicity of a range of PAHs at their aqueous solubility. D. magna immobilisation did not show a trend with aqueous solubility or hydophobicity (KOW) of the PAHs. However, the immobilisation data for all compounds could be fitted with one maximum chemical activity response curve. Those PAHs with the lowest maximum chemical activities resulted in no immobilisation. Naphthalene and phenanthrene showed full toxicity at aqueous solubility, and passive dosing was also used for the concentration-response testing of these compounds. The freely dissolved aqueous concentrations causing 50% immobilisation (EC-50) were 1.96 mg L-1 for naphthalene and 0.48 mg L-1 for phenanthrene. Therefore, passive dosing

  8. A Case Study of Allelopathic Effect on Weeds in Wheat

    OpenAIRE

    Slaveya T. Petrova; Ekaterina G. Valcheva; Iliana G. Velcheva

    2015-01-01

    Most powerful and effective method of weed control is by chemical substances called herbicides. In recent years, they were published quite data on different side effects of herbicides on humans, animals, crops and the environment as a whole. Therefore, the increased interest for biological weed control lately is reasonable, since its improvement and expansion will contribute to limiting excessive use of herbicides, respectively their harmful effects and will support the successful implementat...

  9. Weed management in conventional, no-till, and transgenic corn with mesotrione combinations and other herbicides

    OpenAIRE

    Armel, Gregory Russell

    2002-01-01

    Weed management programs in corn typically include herbicides applied both preemergence (PRE) and postemergence (POST) for season-long weed control. Mesotrione is a new triketone herbicide registered for PRE and POST control of broadleaf weeds in corn. Triketone herbicides function through inhibition of the enzyme p-hydroxyphenylpyruvate dioxygenase. Mesotrione applied PRE did not adequately control common lambsquarters (Chenopodium album L.), smooth pigweed (Amaranthus hybridus L.), commo...

  10. 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.

  11. A novel approach to analysing the regimes of temporary streams in relation to their controls on the composition and structure of aquatic biota

    Directory of Open Access Journals (Sweden)

    F. Gallart

    2012-09-01

    Full Text Available Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The structure and composition of biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. Therefore, the structural and functional characteristics of aquatic fauna to assess the ecological quality of a temporary stream reach cannot be used without taking into account the controls imposed by the hydrological regime. This paper develops methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the transient sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: Hyperrheic, Eurheic, Oligorheic, Arheic, Hyporheic and Edaphic. When the hydrological conditions lead to a change in the aquatic state, the structure and composition of the aquatic community changes according to the new set of available habitats. We used the water discharge records from gauging stations or simulations with rainfall-runoff models to infer the temporal patterns of occurrence of these states in the Aquatic States Frequency Graph we developed. The visual analysis of this graph is complemented by the development of two metrics which describe the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of temporary streams in four aquatic regimes in terms of their influence over the development of aquatic life is updated from the existing classifications, with stream aquatic regimes defined as Permanent, Temporary-pools, Temporary-dry and Episodic. While aquatic regimes describe the long-term overall variability of the hydrological conditions of the river section and have been used for many years by hydrologists and ecologists, aquatic states describe the

  12. Evaluation of pre and post-emergence herbicides for weed management in lentil (lens culinaris medik.)

    International Nuclear Information System (INIS)

    The weeds in lentil are one of the major constraints in obtaining maximum yield. The manual weed control is simply not feasible because it is time consuming and costly. The chemical weed control is the effective method of weed management.A field study was conducted to evaluate pre and post-emergence herbicides for weed control in lentil. The experiment comprised eight treatments including three herbicides, manual weeding and check (no weeding). The yield was higher in manual weeding but in herbicide treatments Isoproturon as pre-emergence at the rate 2kg/sup -1/ha produced statistically at par grain yield to that of manual weeding followed by Isoproturon after one month of planting at the rate 2kg ha. Both the treatments showed 193.9% and 109.2% yield increase, respectively, over the check. It indicates that Isoproturon at the rate 2 kg ha can be used pre or post-emergence in lentil fields to control the weeds without causing injury to lentil plants. (author)

  13. Establishment of mixed reforestation with typical Atlantic forest species as a function of minimum or intensive soil cultivation and weed control; Estabelecimento de reflorestamentos mistos com especies tipicas da mata Atlantica, em funcao do cultivo minimo ou intensivo do solo e do controle de plantas invasoras

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Jose Leonardo de Moraes; Gandara, Flavio [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Dept. de Ciencias Florestais]. E-mail: jlmgonca@carpa.ciagri.usp.br; Goncalves, Janio Carlos; Oliveira, Donizete Barbosa de; Simionato, Jose Luiz do Amaral [Companhia Energetica de Sao Paulo (CESP), SP (Brazil); Cenci, Silvia [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ)

    1999-07-15

    The objectives of this research were: to study the effect of different methods of site cleaning and soil preparation on the reforestation growths established with typical species of the Atlantic Forest; and to evaluate the efficiency of different methods of weed control from planting time to canopy closure. The trial was installed (from Feb to May 1995) around the reservoir of Mario Lopes Leao hydroelectric plant owned by the Electric Power of Sao Paulo (CESP), municipal district of Promissao, SP. The climate of the area is tropical with dry winter (Cwa, classification of Koeppen). The soil was characterized as an Red-Dark Latosol, medium texture. Six treatments arranged in a randomized block design with four replications were tested: 1) herbicide application over total area, planting in furrows (PF), manual weeding in the planting row (MWR) and herbicide application inter rows (HAI); 2) slashing in total area (STA), planting hole (Ph), MW R and slashing inter rows: 3) STA, slash burning (SB), heavy and light harrowing (HLH), PF, MWR and HAI; 4) STA, SB, PF, MWR and HAI; 5) STA, SB, PF, HLH, MWR and HAI; and 6) SAT, SB, two heavy harrowing, PH, selective weed control in the rows and inter rows. The plantation was accomplished with a composition of nine species: pioneers - Trema micrantha, Guazuma ulmifolia and Croton urucurana; secondary - Peltophorum dubium, Gallesia integrifolia and Ormosia arborea and climax - Tabebuia avellanedae, Hymenaea courbaril and Genipa americana. The pioneer and secondary species presented the highest results to the applied treatments. In all treatments where weed control was made with herbicide (glyphosate), the occurrence of Panicum maximum, common species in the area, was very restricted. The growth rates were intensified and the under story presented more diversified composition of weed species, with predominance of broad leaves. Opposite results were observed when weed controlled was manually or mechanically. The largest

  14. 株间除草装置横向偏移量识别与作物行跟踪控制%Side-shift offset identification and control of crop row tracking for intra-row mechanical weeding

    Institute of Scientific and Technical Information of China (English)

    胡炼; 罗锡文※; 张智刚; 陈雄飞; 林潮兴

    2013-01-01

      株间机械除草技术与装置能有效摆脱田间除草的繁重体力劳动并消除化学除草方法所带来的危害,株间机械除草装置的牵引拖拉机在跟踪作物行时总会产生航向偏差,导致除草装置出现横向偏移,甚至无法进入除草的株间区域,同时还会增加伤苗率。为增大株间机械除草的作用区域和降低伤苗率,该文提出了通过作物行信息识别出株间机械除草装置与作物行横向偏移量的方法,并设计了株间机械除草作物行跟踪机构和控制器,实现了株间机械除草跟随作物行。采用正弦波和三角波2种标准信号作为横向偏移补偿量信号,对作物行跟踪控制器的性能进行了测试,试验结果表明:作物行跟踪控制器能较好地控制除草装置跟随横向偏移补偿信号,前进速度为0.5 m/s时正弦波信号跟踪最大误差10 mm,平均误差0.8 mm,三角波信号跟踪最大误差11 mm,平均误差1.2 mm。除草试验表明,作物行跟踪控制系统能较好地控制株间除草装置跟踪作物行,在0.5 m/s前进速度下跟踪最大误差为20.8 mm,平均误差2.5 mm;作物行跟踪控制明显减少了除草爪齿未进入株间区域的比例,在300 mm株距下,可保证93.3%的株间区域有除草爪齿进行除草作业,在200 mm株距下为85.9%;作物行跟踪控制降低了除草爪齿对作物的损伤,伤苗率从20%以上降到了12%以内,提高了株间机械除草的作业效果。%  Intra-row mechanical weeding technique and device can free strenuous labor and eliminate the detriment of using chemical weed. The yaw error is barely avoidable when running a tracked crop-row tractor. It can result in an inconstant side-shift between the intra-row mechanical weed device and crop row and the increasing of crop damage and untreated weeds in intra-row area. The objective of this research is to develop a crop row tracking control algorithm

  15. Real-time weed detection, decision making and patch spraying in maize, sugarbeet, winter wheat and winter barley

    DEFF Research Database (Denmark)

    Gerhards, R; Christensen, Svend

    2003-01-01

    with weed infestation levels higher than the economic weed threshold; a review of such work is provided. This paper presents a system for site-specific weed control in sugarbeet (Beta vulgaris L.), maize (Zea mays L.), winter wheat (Triticum aestivum L.) and winter barley (Hordeum vulgare L...

  16. Effect of Establishment Methods and Weed Management Practices on Some Growth Attributes of Rice

    Institute of Scientific and Technical Information of China (English)

    Mohammad Safdar BALOCH; Inayat Ullah AWAN; Gul HASSAN; Abdul Aziz KHAKWANI

    2006-01-01

    Studies were carried out for two years to evaluate the effect of methods of sowing and weed control practices on the productivity of transplanted and direct wet-seeded rice in Dera Ismail Khan, NWFP, Pakistan. The experiment was laid out in a randomized complete block design with a split plot arrangement. The planting techniques viz. transplanting and direct seeding were maintained in main plots while weed control practices included the use of granular herbicide Sunstar 15WG (ethoxy sulfuron),Machete 60EC (butachlor), conventional hand weeding, and the weedy check (control) were assigned to the sub-plots. Data were recorded on weed parameters like weed density and dry weed biomass 60 and 90 days after sowing (DAS); agronomic parameters including plant population, number of panicles and paddy yield and physiological parameters like leaf area index and net assimilation rate 45 and 90 DAS. The planting methods and weed management significantly influenced most of the parameters studied. The data revealed that the paddy yield and its components were significantly higher in the transplanted method than that in direct-seeded method, while the weed density and biomass were lower in the transplanted plots than the direct-seeded plots.Among weed management tools, the maximum paddy yield was obtained in hand weeding, closely followed by herbicide application Machete 60EC during both cropping seasons.

  17. Palha de sorgo associada ao herbicida imazamox no controle de plantas daninhas na cultura da soja em sucessão Sorghum mulch combined with imazamox for weed control in soybeans planted in succession

    Directory of Open Access Journals (Sweden)

    N.M. Correia

    2005-09-01

    Full Text Available Os resíduos vegetais de uma cultura de cobertura de outono/inverno podem interferir na infestação das plantas daninhas das culturas de verão subseqüentes. Dessa forma, com o objetivo de avaliar o efeito da palha de híbridos de sorgo (Sorghum bicolor, associada ao uso do herbicida imazamox, no controle de plantas daninhas na cultura da soja (Glycine max, cv. 'Conquista', em sucessão, foi conduzido no ano agrícola 2000/2001 um experimento em Uberlândia-MG. Foram utilizados quatro tipos de cobertura: três provenientes de resíduos culturais de híbridos de sorgo (Sara, DKB 860 e Ambar e uma sem restos vegetais (anteriormente sob pousio. Aos 24 dias após aplicação do herbicida, o controle das espécies Leonotis nepetifolia, Alternanthera tenella, Amaranthus hibridus, A. retroflexus, A. spinosus, Ipomoea grandifolia, Commelina benghalensis e Nicandra physaloides foi mais eficaz nas palhas dos híbridos Sara e Ambar, na ausência de imazamox, com porcentagens de controle de 40 e 41%, respectivamente. Quando associada a 15 g ha-1 de imazamox, a palha do Ambar resultou em melhor controle dessas espécies de plantas daninhas, com controle de 76%; e a 30 g ha-1 a palha do DKB 860 foi a mais eficaz, promovendo 85% de controle. Sem cobertura do solo, com 30 g ha-1 de imazamox obteve-se controle de 62,5%, e 47,5% com metade da dosagem. Os resultados indicaram variabilidade de controle em relação ao híbrido de sorgo estudado e a possibilidade de redução de dosagens do herbicida imazamox quando associado aos resíduos vegetais de sorgo.Plant residues of a fall/winter coverage crop can influence weed infestation of the subsequent summer crops. This research was carried out to evaluate the effects of mulch from several sorghum (Sorghum bicolor hybrids plus the herbicide imazamox on the control of the subsequent weed infestation of soybean crop (Glycine max cv. 'Conquista'. The experiment was carried out in the 2000/2001 crop year in Uberl

  18. 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 was...... at distances of 0, 3, 9 and 50 m from the field edge. The weed seeds were placed at the above distances on small dishes of finely sieved soil and sunk into the ground. Removal rates were recorded after 48 h. Seed predators were identified using video recording at an organically grown husbandry unit...... losses at organic field 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...

  19. Incorporating the Experimental Herbicide CGA 362622 into Cotton Weed Management Programs in Virginia

    OpenAIRE

    Richardson, Robert Jeryl

    2002-01-01

    Incorporating the Experimental Herbicide CGA 362622 into Cotton Weed Management Programs in Virginia Robert J. Richardson (ABSTRACT) As the importance of cotton (Gossypium hirsutum L.) to Virginia crop growers has increased, so has the need for more efficient weed control programs. Current cotton herbicides do not control all broadleaf weeds over the entire growing season, and many cotton herbicides must be applied at specific growth stages in order to reduce crop injury. CGA ...

  20. Study on Application of Chemical Control Techniques for Worst Weeds in Landscape Plant Nurseries in Jianghuai Region%江淮地区园林苗圃地恶性杂草化学防除技术应用研究

    Institute of Scientific and Technical Information of China (English)

    王新洋; 周根土; 张均

    2015-01-01

    In this paper the integrated control techniques regarding the main weed species, herbicides and the times,concentrations, methods of their applications for chemical weeding and artificial weeding in landscape plant nurseries were introduced. Chemical and artificial weeding techniques for 6 worst weeds in pre-emergence and seedling stages were elaborated in detail including Alternanthera philoxeroides, Commelina communis, Cyperus rotundus, Artemisia Selengensis, Cirsium setosum and Imperata cylindrica,so were the chemical weeding methods for difficult-to-control weed species Digitaria sanguinalis, Acalypha australis, Amaranthus tricolor, Eclipta prostrata, Chenopodium quinoa,Convolvu arvensis,Celosia cristata, Portulaca oleracea and Abutilon theophrasti. The study could provide practical chemical weeding operation techniques for landscape plant nurseries.%本文叙述了园林苗圃地主要杂草、除草剂,化学除草施用时间、浓度、方法,以及人工除草等综合防除技术,详细叙述了芽前、苗期化学和人工除草技术及苗圃地空心莲子草、鸭跖草、香附子、芦蒿、刺儿菜、白茅6种恶性杂草,以及防除难度较大的杂草马唐、铁苋菜、苋菜、醴肠、藜、田旋花、野鸡冠花、马齿苋、茼麻等化学除草方法,为园林苗木培育提供实用的苗圃化学除草操作技术。

  1. Floristic and phytosociology of weeds in pastures in Maranhão State, Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Jaílson Penha Costa

    2016-06-01

    Full Text Available ABSTRACT Knowledge of weed floristic composition and phytosociology are key factors for improving weed management in pastures. Information on weed species that occur in pastures in Northeast Brazil, particularly in Maranhão State is very limited. It is, therefore, important, to search for information to help farmers to control weeds in livestock farming. This paper describes the weed flora diversity and community structure parameters, including density, frequency, abundance and importance value for each weed species found in five pastures of same age and management in Maranhão State, Northeast Brazil. The weed survey was carried out using a wooden frame (80 cm x 30 cm placed randomly on the soil surface 30 times in each pasture (n = 150. Weeds were pulled out, separated by species and counted. The weed flora was represented by 996 individuals, from nine families, 15 genera and 19 species. Weed density within pastures was of 44.3 plants m-2. The weed flora was dominated by species of the Cyperaceae and Poaceae families. The most important weed species based on Importance Value were Eragrostis ciliaris (IV = 32.97, Cyperus rotundus (IV = 31,95, Cyperus luzulae (IV = 27,50, Cyperus sphacelatus (IV = 27,42, Pycreus lanceolatus (IV = 27,33 Cyperus haspan (IV = 25,72 and Eleusine indica (IV = 23,49. Weed diversity, based on Shannon Diversity Index was very high (H' = 4.37 nats ind-1. Our results could lead to improved weed management in pastures in Maranhão State, Northeast Brazil.

  2. 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.

  3. Controle de dez espécies daninhas em cana-de-açúcar com o herbicida mesotrione em mistura com ametryn e metribuzin Control of ten weed species in sugarcane using mesotrione mixed with ametryn and metribuzin

    Directory of Open Access Journals (Sweden)

    F.T. Carvalho

    2010-01-01

    -emergence control is the great challenge. The objective of this work was to evaluate the efficiency of the herbicide mesotrione in mixture with ametryn and metribuzin in the post-emergence control of ten weeds sown in sugarcane, variety RB86-7515. The weeds used in the experiment were: Brachiaria decumbens, Brachiaria plantaginea, Cenchrus echinatus, Digitaria horizontalis, Panicum maximum, Amaranthus deflexus, Bidens pilosa, Euphorbia heterophylla, Ipomoea nil and Sida glaziovii, sown in between the rows after crop emergence. The herbicides were applied on the 45th day after sugarcane planting when the monocotyledon weeds reached the third tiller phase and the dicotyledon weeds completed three to four leaves. The following treatments were carried out: mesotrione (120 g ha-1; ametryn (2,000 g ha-1; metribuzin (1,920 g ha-1; mesotrione + ametryn (120 g + 2,000 g ha-1; mesotrione + metribuzin (120 g + 1,920 g ha-1 and control with and without weeds. It was concluded that the herbicides, isolated or in mixture, were selective to sugarcane. Regarding control efficiency, it was observed that the herbicide mesotrione was efficient in the control of A. deflexus; ametryn was efficient in the control of A. deflexus, B. pilosa and I. nil; metribuzin was efficient in the control of A. deflexus, B. pilosa and S. glaziovii; mesotrione + ametryn were efficient in the control of B. decumbens, B. plantaginea, D. horizontalis, P. maximum, A. deflexus, B. pilosa, I. nil and S. glaziovii, and mesotrione + metribuzin was efficient in the control of B. plantaginea, D. horizontalis, P. maximum, A. deflexus, B. pilosa and S. glaziovii. A high synergistic effect of mesotrione was verified with the tested herbicides, with the mixture with ametryn being the most prominent.

  4. Weed emergence as influenced by soil moisture and air temperature

    OpenAIRE

    Calado, José; G. Basch; Carvalho, Mário

    2009-01-01

    Abstract Emergence of weed seedlings depends on soil environmental conditions; mainly temperature and moisture, with the latter being fundamental and particularly important in environments which are characterised by irregular amounts and distribution of rainfall throughout the year. Thus, this study looks at the influence of soil moisture and air temperature on the emergence of weed seedlings. The experiment was carried out under controlled environmental conditions, using rings filled with s...

  5. A Case Study of Allelopathic Effect on Weeds in Wheat

    Directory of Open Access Journals (Sweden)

    Slaveya T. Petrova

    2015-06-01

    Full Text Available Most powerful and effective method of weed control is by chemical substances called herbicides. In recent years, they were published quite data on different side effects of herbicides on humans, animals, crops and the environment as a whole. Therefore, the increased interest for biological weed control lately is reasonable, since its improvement and expansion will contribute to limiting excessive use of herbicides, respectively their harmful effects and will support the successful implementation of complex weed control. The purpose of this study was to investigate the effect of selected plant species, containing allelopathic active substances, on germination, growth and biomass of some widespread weeds in wheat. Experiments were carried out at laboratory conditions using seeds of wheat (Triticum aestivum L., sort Sadovo 1 and most common weeds therein: Johnson grass (Sorghum halepense (L Pers, white pigweed (Chenopodium album L., twitch (Cynodon dactylon L. and curly dock (Rumex crispus L.. Allelopathic substances were extracted with distilled water from flowers of lavender (Lavandula angustifolia Mill., leaves of basil (Ocimum basilicum L., leaves of spearmint (Mentha longifolia (L Huds., and leaves of peppermint (Mentha piperita L.. Of the tested active allelopathic plants, the most negative impact on germination of all weeds seeds (including wheat, as well as on the development of plants exhibited the water extract of lavender. Lavender and basil had a stronger negative effect on white pigweed and twitch compared with both mint species. A significant inhibitory effect of spearmint even at low concentrations was recorded on the germination of all weed species tested while the wheat was slightly affected, which manifests this plant as a potential effective species in strategies for weed control management.

  6. Biodiversity Of Weed Communities In Organic And Conventional Orchards

    OpenAIRE

    Lisek Jerzy; Sas-Paszt Lidia

    2015-01-01

    The aim of the study was to analyze the occurrence of segetal and ruderal weeds in young apple and cherry organic orchards, where weeds under tree canopies were controlled mechanically with a rototiller, and in conventional orchards, where post-emergence herbicides were used. The research material consisted of phytosociological relevés recorded according to the Braun-Blanquet method, in three organic and three conventional orchards, situated near Skierniewice (central Poland), in 2010-2013. O...

  7. Effect of Biofumigation on Typical Weeds of Strawberry Fields

    OpenAIRE

    González Zamora, José Enrique; López Martínez, Nuria; Aguirre Jiménez, Itziar; Avilla Hernández, Carlos; Lopez Medina, Jose

    2006-01-01

    This research was conducted to evaluate the effect of biofumigation using fresh organic matter on typical weeds present in strawberry fields of southern Spain. Field experiments consisted of biofumigation (BF) treatment over 45 days, at two locations, with hen droppings or horse manure at a dose of 3 kg m-2, alone or in combination with solarization (BF+S) in an experimental randomized block design. Results showed good control of the main weed species, Poa annua, Portulaca oleracea and Lolium...

  8. 28%丁草胺·吡嘧磺隆WP防除水稻移栽田杂草效果%Effects of Wettable Powder Mixed with Butachlor and Pyrazosulfuron for Control of Weeds in Transplanted Rice Fields

    Institute of Scientific and Technical Information of China (English)

    李宏; 朱文达; 张雷雷; 邱玉兰; 张均

    2012-01-01

    通过田间试验研究28%丁草胺·吡嘧磺隆WP对水稻移栽田杂草的控制效果和对水稻产量的影响.结果表明,28%丁草胺·吡嘧磺隆WP 226.8~525.0 g(a.i)/hm2对水稻移栽田的稗草、鸭舌草、节节草、异型莎草均具有良好的防治效果,综合密度防效和综合鲜重防效优于对照药剂60%丁草胺EC和10%吡嘧磺隆WP;并能有效降低杂草对田间氮、磷、钾和水分的吸收,增产效果明显.%To provide guidance for chemical weed management in broadcasted rice fields, trials were conducted to evaluate the effects on weed control and crop yield of a fertilizer formulation mixed with 28% butachlor and pyrazosulfuron WP. The results showed that 28% butachlor and pyrazosulfuron WP 226.8~525.0 g (a.I)/hm2 had good control effects on Echinochloa crusgalli(h.) Beauv, Monochoria vaginalis(hurm.F.), Rotala indica, Cyperus dijformis L. In transplanted rice fields. The overall fresh control effects and density control effects were significantly higher than 60% butachlor EC and 10% pyrazosulfuron WP. The application of 28% butachlor + pyrazosulfuron WP significantly reduced the weeds absorption of nutrition and water, resulting in prominent yield enhancing.

  9. An image analysis and classification system for automatic weed species identification in different crops for precision weed management

    OpenAIRE

    Weis, Martin

    2010-01-01

    A system for the automatic weed detection in arable fields was developed in this thesis. With the resulting maps, weeds in fields can be controlled on a sub-field level, according to their abundance. The system contributes to the emerging field of Precision Farming technologies. Precision Farming technologies have been developed during the last two decades to refine the agricultural management practise. The goal of Precision Farming is to vary treatments within fields, according to the local ...

  10. 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.

  11. Weed Identification Field Training Demonstrations.

    Science.gov (United States)

    Murdock, Edward C.; And Others

    1986-01-01

    Reviews efforts undertaken in weed identification field training sessions for agriprofessionals in South Carolina. Data over a four year period (1980-1983) revealed that participants showed significant improvement in their ability to identify weeds. Reaffirms the value of the field demonstration technique. (ML)

  12. 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 i

  13. Remoção mecânica de plantas aquáticas: análise econômica e operacional Mechanical removal of aquatic weeds: operational and economic analysis

    OpenAIRE

    U.R. Antuniassi; E.D. Velini; Martins, D.

    2002-01-01

    A remoção de plantas aquáticas tem sido utilizada como opção ao controle químico e biológico, em razão de restrições ambientais em algumas regiões brasileiras. O objetivo deste trabalho foi desenvolver um modelo para análise econômica e operacional da remoção mecânica de plantas aquáticas, visando realizar estudo econômico comparativo com o controle químico. A operação foi estudada num reservatório de uma usina de bombeamento em Barra do Piraí-RJ. O sistema consiste de retroescavadeiras insta...

  14. INVASIVE WEEDS IN BOGOR BOTANIC GARDENS, INDONESIA AND ITS IMPLICATION ON SURROUNDING LANDSCAPES

    Directory of Open Access Journals (Sweden)

    Edi Santosa

    2014-07-01

    Full Text Available Conservation areas with the objective for collection and exchange plant materials have been speculated as weed bank for surrounding areas. Objective of this study was to identify and characterize ruderal invasive weeds in the Bogor Botanic Gardens (BBG. Observations were conducted in all vak (collection blocks in the BBG in order to identify the weeds species, determine their invasiveness, dominance and distribution. Weeds associations with host plants were observed. Current weed control program and data of dead trees collection were analyzed in relevant to weed. Distribution of weeds outside BBG was observed by transects method following river and road directions. Results showed that there were seven invasive weeds, i.e., Cecropia adenopus (Cecropiaceae, Cissus nodosa Blume (Vitaceae, Cissus sicyoides Blume (Vitaceae, Dioscorea bulbifera L. (Dioscoreaceae, Ficus elastica Roxb. (Moraceae, Mikania micrantha H.B.K. (Asteraceae and Paraserianthes falcataria (L. Nielsen (Fabaceae. These seven weeds species invaded 41 out of 215 plant families in BBG. Six species of weeds, i.e., C. adenopus, C. nodosa Blume., C. sicyoides Blume., D. bulbifera L., M. micrantha H.B.K. and P. falcataria (L. Nielsen, were introduced as BBG collections for the first time while the F. elastica Roxb was considered as native. It is most likely that the weeds dispersal agents are the wind, birds, bats, visitors, and waters. All of these weeds existed in surrounding areas outside BBG. Given the detrimental impact of invasive weeds on the plant collection in BBG, it is necessary to develop long–term comprehensive control measures both inside and neighboring areas by involving other government authorities beyond BBG.

  15. Controle de plantas daninhas na cultura do milho-pipoca com herbicidas aplicados em pós-emergência Weed control in popcorn maize using post emergence herbicide

    Directory of Open Access Journals (Sweden)

    A. Jakelaitis

    2005-09-01

    Full Text Available Objetivou-se avaliar a eficiência de controle de plantas daninhas, a tolerância e a produção de milho-pipoca UFVM2 aos herbicidas atrazine (1.500 g ha-1, foramsulfuron + iodosulfuron methyl sodium + atrazine (15+1+1.500 e 30+2+1.500 g ha-1, foramsulfuron + iodosulfuron methyl sodium (15+1, 30+2, 45+3 e 60+4 g ha-1, nicosulfuron + atrazine (8+1.500 e 16+1.500 g ha-1 e nicosulfuron (16 g ha-1. A aplicação dos herbicidas foi realizada aos 25 dias após a emergência da cultura. As plantas daninhas predominantes na área foram Brachiaria plantaginea, Brachiaria decumbens e Ipomoea spp. Os herbicidas foramsulfuron + iodosulfuron methyl sodium, em todas as doses testadas, proporcionaram maiores índices de toxidez à cultura, aos 7, 14 e 28 dias após a aplicação dos tratamentos (DAA. Todas as combinações de herbicidas proporcionaram controle acima de 90% para B. plantaginea e B. decumbens, aos 28 DAA. O nicosulfuron aplicado isoladamente proporcionou controle de apenas 80% e o atrazine não controlou essas espécies daninhas. Para Ipomoea spp., nenhum tratamento herbicida proporcionou controle equivalente ao da testemunha capinada. A competição das plantas daninhas resultou em menores teores de clorofila total, N, P e K no tecido foliar das plantas de milho-pipoca e menor rendimento de grãos. Para o cultivar UFVM2, as sulfoniluréias isoladas ou associadas ao atrazine não afetaram o estado nutricional da cultura, o rendimento e a capacidade de expansão dos grãos de milho-pipoca.The efficiency of different herbicide combinations for weed control and tolerance and yield of UFVM2 popcorn maize were evaluated. The herbicide treatments and respective doses were: atrazine (1.500 g ha-1; foramsulfuron + iodosulfuron methyl sodium + atrazine (15+1+1.500 and 30+2+1.500 g ha-1; foramsulfuron + iodosulfuron methyl sodium (15+1, 30+2, 45+3, and 60+4 g ha-1; nicosulfuron + atrazine (8+1.500 and 16+1.500 g ha-1 and nicosulfuron (16 g ha-1. The

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

    Directory of Open Access Journals (Sweden)

    M. P. Anwar

    2013-01-01

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

  17. Métodos de controle de plantas daninhas no cafeeiro afetam os atributos químicos do solo Effects of weed control methods on coffee crop on soil chemical attributes

    Directory of Open Access Journals (Sweden)

    Elifas Nunes de Alcântara

    2009-06-01

    Full Text Available Nos ecossistemas agrícolas sob cafeeiro, nos quais o manejo do solo se resume, basicamente, à aplicação de corretivos, fertilizantes e controle de plantas daninhas, faz com que alternativas de manejo que preservam ou aumentam os teores de matéria orgânica no solo, a exemplo de alguns métodos de controle de plantas daninhas, sejam consideradas, quando se busca a sustentabilidade da cultura. Neste estudo o objetivo foi avaliar o efeito de alguns métodos comumente utilizadas na cultura do cafeeiro sobre os atributos químicos de um Latossolo Vermelho distroférrico sob cafeeiro, durante 15 anos. Os tratamentos avaliados consistiram de sete métodos de controle, envolvendo o uso de roçadora (RC, grade (GR, enxada rotativa (ER, herbicida de pré-emergência (HPRE, herbicida de pós-emergência (HPOS, capina manual (CM e uma testemunha sem capina (TEST. Foram determinados, nas profundidades de 0-0,15m e 0,15-0,30m, os teores de P, K+, Ca2+ + Mg2+, soma de bases (SB, saturação por bases (V, CTC efetiva (t e potencial (T. Os resultados mostraram que o tratamento sem capina (TEST influenciou, positivamente, os teores de P, K+, Ca2+ + Mg2+, valores de CTC efetiva, potencial e V, enquanto o HPRE exerceu um efeito contrário, ou seja, de redução nos valores das variáveis analisadas. Demais métodos RC, GR, ER, HPOS e CM apresentam um comportamento intermediário entre os métodos TEST e HPRE sobre as condições de fertilidade do solo.In agricultural ecosystems under coffee cultivation, soil management is based on liming, fertilizers and weed control. Alternatives that preserve or increase soil organic matter content are considered when the sustainability is the goal. This study was conducted to evaluate the chemical attributes of a dystroferric Red Latosol (Oxisols under coffee cultivation submitted to 15 years of weed control methods. Seven interrows coffee plant weed control methods were used; a mower (RC, tanden disk harrow (GR, rotative

  18. Eficiência do herbicida oxyfluorfen, quando veiculado ao papel, no controle de algumas espécies daninhas Effect of the herbicide oxyfluorfen using paper as a vehicle on the weed control

    Directory of Open Access Journals (Sweden)

    Alexandre J. Bezutte

    1995-01-01

    Full Text Available Com o objetivo de encontrar um método alternativo de aplicação de herbicidas, estudou-se a eficiência do oxyfluorfen aplicado em três doses (0, 480 e 960g/ha sob duas formas (pulverizado e veiculado em folha de papel no controle em pré-emergência de Bidens pilosa, Desmodium tortuosum, Eleusine indica, Sida rhombifolia Amaranthus retroflexus, Acanthospermum hispidum e Digitaria horizontalis. A pulverização do oxyfluorfen foi realizada com o auxílio de um pulverizador, e sua veiculação foi feita através da determinação prévia da capacidade de embebição do papel. Obteve-se a concentração necessária da calda quando o papel atingiu completa embebição e então, escorrido o excesso, foi posto a secar na sombra. O delineamento experimental foi o inteiramente casualizado, com cinco repetições. Foram realizadas avaliações aos 30, 45 e 60 dias após a aplicação (DAA, e os resultados indicaram que os métodos de aplicação utilizados, assim como as doses, apresentaram excelente controle de B. pilosa, D. tortuosum, E. indica S. rhombifolia, D. horizontalis e A. retroflexus até 60 DAA, reduzindo tanto a densidade como o acúmulo de matéria seca. Quanto ao A. hispidum, ambos os métodos e doses não proporcionaram bom controle. Foi observado também que o papel utilizado como veículo do oxyfluorfen proporcionou redução na densidade de B. pilosa, E. indica, D. horizontalis e A. retroflexus e promoveu a germinação de S. rhombifolia e A. hispidum quando da avaliação aos DAA. Estes resultados demonstram a viabilidade de utilização de papel como veículo de aplicação do oxyfluorfen.A greenhouse assay was conducted to evaluate na alternative method for applying oxyfluorfen to control annual weeds. The experiment was in 3 x 2 factorial, in a completely randomized design, with three replications. The factors were: three doses of oxyfluorfen (0, 480 and 960g/ha and two methods to apply the herbicide to the soil surface

  19. Weed control in young coffee plantations through post emergence herbicide application onto total area Controle de plantas daninhas em cafezais recém-implantados, com herbicidas aplicados em pós-emergência em área total

    Directory of Open Access Journals (Sweden)

    C.P. Ronchi

    2004-12-01

    Full Text Available This study was carried out to investigate the efficiency of several herbicides under field conditions, by post-emergence application onto the entire area, their effect on the control of weeds in young coffee plantations and commercial coffee and bean intercropping system, as well as on both crops. Seedlings of Coffea arabica cv. Red Catuaí with four to six leaf pairs were transplanted to the field and treated according to conventional agronomic practices. A bean and coffee intercropping system was established by sowing three lines of beans in the coffee inter-rows. At the time the herbicides were sprayed, the coffee plants had six to ten leaf pairs; the bean plants, three leaflets; and the weeds were at an early development stage. Fluazifop-p-butyl and clethodim were selective for coffee plants and controlled only Brachiaria plantaginea and Digitaria horizontalis efficiently. Broad-leaved weeds (Amaranthus retroflexus, Bidens pilosa, Coronopus didymus, Emilia sonchifolia, Galinsoga parviflora, Ipomoea grandifolia, Lepidium virginicum, and Raphanus raphanistrum were controlled with high efficiency by sole applications of fomesafen, flazasulfuron, and oxyfluorfen, except B. pilosa, C. didymus, and R. raphanistrum for oxyfluorfen. Sequential applications in seven-day intervals of fomesafen + fluazifop-p-butyl, or clethodim, and two commercial mixtures of fomesafen + fluazifop-p-butyl simultaneously controlled both types of weed. Cyperus rotundus was only controlled by flazasulfuron. Except for fluazifop-p-butyl and clethodim, all herbicide treatments caused only slight injuries on younger coffee leaves. However, further plant growth was not impaired and coffee plant height and stem diameter were therefore similar in the treatments, as evaluated four months later. Fomesafen, fluazifop-p-butyl, and clethodim, at sole or sequential application, and the commercial mixtures of fomesafen + fluazifop-p-butyl were also highly selective for bean crop; thus

  20. Optimizing the width of strip weeding in arabica coffee in relation to crop age Largura da faixa de controle de plantas daninhas em café arábica em função da idade do cafeeiro

    Directory of Open Access Journals (Sweden)

    FC. Araújo

    2012-03-01

    Full Text Available The aim of this study was to determine the weed strip control (WSC required for adequate coffee growth after transplanting. A non-irrigated, field-planted (spaced 3.80 x 0.70 m crop was used. The experimental design was a randomized block, with four replicates. The treatments were arranged in a 9 x 18 split-plot design to test the WSC of 0, 15, 30, 45, 60, 90, 120, 150, and 190 cm, which involved continuously hand-weeding at each side of the coffee row, and 18 coffee growth measurements. Multiple regression analyses were carried out relating to growth-variables as a function of both WSC and growth-evaluation times. Brachiaria decumbens was the main weed accomplishing 88.5% of the total weed dry mass. The minimum width of the WSC increases as the crop ages after transplanting. Assuming reductions of 2% and 5% in the maximum coffee growth, the recommended WSC was 75 and 52 cm at 4 months after transplanting (MAT, 104 and 85 cm at 6 MAT, 123 and 105 cm at 9 MAT, 134 and 116 cm at 12 MAT, 142 and 124 cm at 15 MAT, and 148 and 131 cm at 18 MAT, respectively. It was concluded that integrated weed management in young coffee crops must focus on the weed control only in a minimum range along coffee rows, which increases with coffee plant age, keeping natural vegetation in the inter-rows.O objetivo deste estudo consistiu em determinar a faixa ideal de controle de plantas daninhas (FCPD necessária para um crescimento adequado do cafeeiro após o transplantio. Foi utilizada uma lavoura não irrigada, implantada no espaçamento de 3,80 x 0,70 m, em dezembro de 2008. O delineamento experimental foi em blocos casualizados, com quatro repetições. Os tratamentos foram dispostos em um esquema de parcelas subdivididas (9 x 18 para testar as FCPDs de 0, 15, 30, 45, 60, 90, 120, 150 e 190 cm, mantidas com capina contínua em cada lado da linha de café, bem como seus efeitos ao longo de 18 meses após o transplantio (MAT. Efetuaram-se análises de regressão m

  1. Effect of eight herbicides on weed control and seedling safety in forest nursery%8种除草剂对林业苗圃杂草的防除效果和苗木安全性试验

    Institute of Scientific and Technical Information of China (English)

    邓华平; 朱秀红; 杨桂娟; 陈国海; 夏丹; 谢宁宁

    2012-01-01

    通过盆栽和大田试验进行除草剂的筛选试验.结果表明,10%农得时可湿性粉剂(150~ 750 g·hm-2)、20%盖杰乳油(2 250~3 150 mL·hm-2)、33%施田补乳油(1 200 ~90 000 mL·hm-2)、24%惠尔乳油(600~3 000 mL·hm-2)、坪绿1号(900~1 500 mL·hm-2)、50%异丙隆可湿性粉剂(2250~2 700 mL· hm-2)、50%丁草胺乳油(900~2 700 mL·hm-2)、30%苄丁可湿性粉剂(900 ~1 500 mL·hm-2)等8种除草剂的除草效果、控草时间各不相同,其中24%惠尔乳油(1 200 mL· hm-2)的除草效果可达100%,且控草时间在45 d以上;其他几种除草剂的除草效果和控草时间均低于24%惠尔乳油(1 200 mL·hm-2)相应指标.苗木安全性试验结果表明,24%惠尔乳油(1 200 mL·hm-2)对参试的播种苗出苗、早期生长和根系的影响是有限和短暂的,既使在苗木速生前期(出苗30 d前后)进行药剂处理,对苗木周年生长量影响也不大.%Experiment was carried out on the herbicide selection under the condition of basin cultivation and field. The results showed that these herbicides, 10% Bensulfuron-methyl ( 150 -750 g · hm-2) , 20% Oxyfluorfen · Pendimethalin(2 250 -3 150 mL · hm-2) ,33% Pendimethalin(1 200 -90 000 mL · hm-2) , 24% Oxyfluorfen (600 ~ 3 000 mL · hm-2) , Pinglil 1 (900 - 1 500 mL · hn-2),50% Isoproturon(2 250 -2 700 mL · hm-2),50% Butachlor(900 -2 700 mL · hm- 2), 30% Bensulfuron-methyl · Butachlor(900 - 1 500 mL · hm-2 ) ,had different weeding effect and weed control time, among which weeding effect of 24% Oxyfluorfen ( 1 200 mL · hm-2 ) could amount to 100% and its weed control time could maintain over 45 days. For the other seven kinds of herbicides, their weed control effect and weed control time were lower than the corresponding value of Oxyfluorfen. Furthermore, the seedling safety experiment indicated that 24% Oxyfluorfen(1 200 mL · hm-2) had little effect on emergence rate, early growth and root growth

  2. Development and appraisal of economical and sustainable approach for weed management in drill seeded aerobic rice (oryza sativa l.)

    International Nuclear Information System (INIS)

    Conventional rice cultivation by puddling and transplanting is a labor intensive activity. Water scarcity is a threat for the sustain ability of transplanted rice. In many areas of Asia, rice transplantation of rice is being replaced by direct seeding as farmers tried to solve the problems of labor cost and water scarcity but weed control is one of the major constraints to direct seeding. So, to control weeds in direct seeded rice present studies were designed. A two years study was conducted to develop sustainable and economical methods for managing weeds in aerobic rice grown by dry direct-seeding at Student's Farm, Department of Agronomy, University of Agriculture, Faisalabad during the years 2008 and 2009. Experiment was laid out in RCBD with five weed management strategies: hand weeding, hoeing with kasula, inter-row cultivation with tine cultivator, inter-row cultivation with spike hoe and chemical control with Nominee 100 SC along with control (no weeding). Weed dry weight was 300 g m/sup -2/, 257 g m/sup -2/, 225 g m/sup -2/ and 157 g m/sup -2/ less in hand weeding, hoeing, tine cultivator and Nominee 100 SC respectively than no weeding. Paddy yield was 221%, 203%, 181% and 105% more in hand weeding, hoeing, tine cultivator and Nominee 100 SC respectively than no weeding. (author)

  3. Distribution of the most common weeds from fam. Asteraceae in Srem

    OpenAIRE

    Igić Ružica S.; Konstantinović Branko; Polić Dubravka; Anačkov Goran T.

    2002-01-01

    Weeds fall into a specific ecological group of plants and man should play the key role in controlling the process of their formation and the rate of their spreading. Damage caused by weeds is significant in both the agricultural and natural ecosystems. Therefore, special care should be paid to the current rate of their spreading, ensuring that the caused environmental changes do not become irreversible. The paper summarizes the locations in which the most common weed types of the Asteraceae f...

  4. Efeito do eptc + r 25788 em combinação com o diuron no controle de plantas daninhas e seletividade para a cultura da batata-doce Weed control in sweet potato

    Directory of Open Access Journals (Sweden)

    Maurílio F. de Oliveira

    1997-01-01

    Full Text Available Com o objetivo de avaliar o efeito das doses de EPTC + R 25788 combinadas com doses de diuron no controle de plantas daninhas na cultura de batata-doce, realizou-se um ensaio sob condições de campo num Podzólico Vermelho Amarelo, fase terraço, argiloso, com 3,5 % de matéria orgânica. Foram avaliadas quatro doses de EP TC + R 25 78 8 aplicado em pré-plantio incorporado: 0,0; 1,6; 3,2 e 4,8 kg/ha por quatro doses dediuron : 0,0 ; 0,8 ; 1,2 e 1,6 kg/ha, em quatro repetições. O EPTC + R25788 apresentou bom controle das plantas de tiririca quando aplicado nas maiores doses, principalmente na ausência do diuron. As maiores doses de EPTC + R 25788 aplicadas isoladamente, apresentaram significativos aumentos na população de plantas de folhas largas. As maiores doses de diuron promoveram melhor controle das plantas de folhas largas, na presença das maiores doses de EPTC + R 25788. A combinação das maiores doses dos herbicidas não refletiram em maiores produções. A maior produção de batata-doce ocorreu quando se aplicou 6 L/ha de Eradicane e 1,32 kg/ha de Karmex 800.Four levels of EPTC + R 25788 (0.0; 1.6; 3.2 e 4.8 kg/ha and diuron (0.0; 0.8; 1.2 and 1.6 kg/ha with four replications were evaluated in a fatorial field experiment in a Utisol containg 3.5 % organic matter. Better control of nutsedge was obtained with the highest dosage of EPTC + R 25788, mainly in the absence of diuron. However, when the highest eradicane levels were applied as single treatments there was a marked increase in the broadleaf weed population. The best control of broadleaf weed population was achieved when the highest diuron levels were combined with the highest EPTC + R 25788 levels although this condition have not resulted in highest productions. The greatest sweet potato production was obtained with the combination of 6 1/ha of Eradicane plus 1.32 kg/ha of Karmex 800.

  5. 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...

  6. Managing weeds in potato rotations without herbicides

    Science.gov (United States)

    Managing weeds without herbicides requires an integration of methods and strategies and a change in how weeds are perceived. Weeds should be managed in a holistic, intentional and proactive manner. Successful weed management in organic systems attempts to understand the interactions between the crop...

  7. 秋豌豆田杂草的发生消长及其防除技术研究%Study on the occurrence and control techniques of weeds in autumn pea field

    Institute of Scientific and Technical Information of China (English)

    田志慧; 沈国辉; 张兆辉

    2015-01-01

    The occurrence and control techniques of weeds in pea field were studied in 2014—2015.The results indicated that broadleaf weeds began sprouting after pea sowed 9 days,and reached peak at about 30 days after pea sowed.The annual weeds damage could be effectively controlled by using 33% pendimethalin EC 2 250—3 000 mL?hm2 ,96% s-metolachlor EC 1 125—1 500 mL?hm2 ,24% oxyfluorfen EC 750 mL?hm2 and 50% napropamide WDG 1 500—2 250 mL?hm2 before pea sprouting.The broadleaf weeds damage could be effectively controlled by using 480 g?L bentazone AS 1500—3000 mL?hm2 in the pea growth period,Stellaria media 2—4 branching stage,Capsella bursa-pastoris and Chenopodium serotinum 3—4 leaves stage.The use of these herbicides had no adverse effect on the sprouting and growth of pea.%于2014—2015年对豌豆田杂草的发生消长及其防除技术进行了研究。结果表明,豌豆播种后9 d,田间阔叶杂草开始陆续出苗,至豌豆播种后30 d 左右发生量达到峰值。豌豆播后苗前使用33%二甲戊灵 EC 2250—3000 mL?hm2、96%精异丙甲草胺 EC 1125—1500 mL?hm2、24%乙氧氟草醚 EC 750 mL?hm2和50%敌草胺 WDG 1500—2250 mL?hm2可有效控制一年生杂草的为害;豌豆生长期、繁缕2—4分枝、荠菜和小藜3—4叶期使用480 g?L 灭草松 AS 1500—3000 mL?hm2能有效防除田间阔叶杂草的为害,且对豌豆出苗和生长均无不良影响。

  8. Evaluation and Modeling of Camel Thorn (Alhagi Maurorum Weed Cutting by Water Jet

    Directory of Open Access Journals (Sweden)

    M Naghipour Zade Mahani

    2016-04-01

    Full Text Available Due to the importance of weed control and the limitations of mechanical methods in some places, in this research the water jet cutting for weed control was investigated. The cutting tests were performed on camel thorn weed in Shahid Bahonar university of Kerman. The water jet pressure of 90 bars was achieved with the aid of a suitable pump. The cutting time was studied in a completely randomized factorial design experiment (CRD with five replications. Factors of experiments are: stem diameter in 2 levels (smaller and larger than 5 mm, distance of spraying jet from weeds in 3 levels (10, 20 and 30 cm and two types of plant holders: blade and plate. The results showed that stem diameter and jet distance from the weed stem had significant effects on cutting time (at the 1%. The mean comparison of parameters showed that with increase of stem diameter the cutting time increased and any increase in jet distance from the weeds decreased the cutting time linearly with R2=0.96 and R2=0.99 for small and large diameter weeds, respectively. The minimum cutting time was measured at 30 cm of the jet from small diameter of stems. A multivariate linear regression model was also proposed for cutting weed parameters. It can be concluded that due to the flexibility of water jet cutting for restricted places, hydrodynamic control of weeds is proposed as a complementary method and sometimes a competing substitute method.

  9. Taxonomic and life history bias in herbicide resistant weeds: implications for deployment of resistant crops.

    Directory of Open Access Journals (Sweden)

    Jodie S Holt

    Full Text Available Evolved herbicide resistance (EHR is an important agronomic problem and consequently a food security problem, as it jeopardizes herbicide effectiveness and increases the difficulty and cost of weed management. EHR in weeds was first reported in 1970 and the number of cases has accelerated dramatically over the last two decades. Despite 40 years of research on EHR, why some weeds evolve resistance and others do not is poorly understood. Here we ask whether weed species that have EHR are different from weeds in general. Comparing taxonomic and life history traits of weeds with EHR to a control group ("the world's worst weeds", we found weeds with EHR significantly over-represented in certain plant families and having certain life history biases. In particular, resistance is overrepresented in Amaranthaceae, Brassicaceae and Poaceae relative to all weeds, and annuality is ca. 1.5 times as frequent in weeds with EHR as in the control group. Also, for perennial EHR weeds, vegetative reproduction is only 60% as frequent as in the control group. We found the same trends for subsets of weeds with EHR to acetolactate synthase (ALS, photosystem II (PSII, and 5-enolpyruvylshikimate-3-phosphate (EPSP synthase-inhibitor herbicides and with multiple resistance. As herbicide resistant crops (transgenic or not are increasingly deployed in developing countries, the problems of EHR could increase in those countries as it has in the USA if the selecting herbicides are heavily applied and appropriate management strategies are not employed. Given our analysis, we make some predictions about additional species that might evolve resistance.

  10. 40%乙草胺·乙氧氟草醚乳油防除花生田杂草的效果%Control Effect of Acetochlor · Oxyfluorfen 40 % EC on Weed in Peanut Field

    Institute of Scientific and Technical Information of China (English)

    张田田; 路兴涛; 孔繁华; 张勇; 马士仲

    2011-01-01

    为明确40%乙草胺·乙氧氟草醚乳油防除花生田杂草的效果和对花生的安全性,进行了田间小区试验,观察其对花生田杂草的防效和对花生产量的影响.结果表明,40%乙草胺·乙氧氟草醚乳油660 ~720 ga.i./hm2对马唐、牛筋草、反枝苋、马齿苋等花生田杂草具有较好的防除效果,药后40d鲜重防效达90%以上,对花生安全.%Small - sized trail is conducted to evaluate the effects of acetochlor and oxyfluorfen 40% EC on weed control, yield potential and production safety in peanut field. The results show that acetochlor and oxyfluorfen 40% EC has good effect in peanut field on weeds control including species Digitaria sanguinalis, Eleusine indica, Amarardhus retroflexus, Portulaca oleracea, and so on with a dosage of 660 ~ 720g a. I. /hm2. The weight control effect is over 90% after treatment for 40 days, which can be safe to peanut growth.

  11. Uptake and release kinetics of 134Cs by goldfish (Carassius auratus) and 137Cs by zebra fish (Brachydanio rerio) in controlled aquatic environment

    International Nuclear Information System (INIS)

    The uptake and release kinetics of 134Cs by Goldfish (Carassius auratus) and 137Cs by Zebra Fish (Brachydanio rerio) from aquatic media of different ionic compositions and temperature was studied in controlled laboratory conditions. The accumulation of radiocesium in the case of Brachydanio rerio is observed to be strongly dependent on the potassium ion concentration of the aquatic medium, but in the case of Carassius auratus this dependence is quite weak. The biological half-lives of the cesium isotopes incorporated into the fish investigated in the present work vary from 19 to 80 days and are influenced by the temperature and the ionic composition of the aquatic medium. (author) 19 refs.; 1 fig.; 3 tabs

  12. Tolerance and selectivity of cereal species and cultivars to postemergence weed harrowing

    DEFF Research Database (Denmark)

    Rasmussen, Jesper; Nielsen, Helle Højland; Gundersen, Hanne

    2009-01-01

    POST weed harrowing and other cultivation methods to control weeds in early crop growth stages may result in crop damage due to low selectivity between crop and weeds. Crop tolerance to cultivation plays an important role but it has not been clearly defined and analyzed. We introduce a procedure...... for analyzing crop tolerance on the basis of digital image analysis. Crop tolerance is defined as the ability of the crop to avoid yield loss from cultivation in the absence of weeds, and it has two components: resistance and recovery. Resistance is the ability of the crop to resist soil covering and...... different abilities to suppress weeds. The order of species' tolerance to weed harrowing was triticale > wheat > barley > oat and the differences were mainly caused by different abilities to recover from soil covering. At 25% soil covering, grain yield loss in triticale was 0.5%, in wheat 2.5%, in barley 3...

  13. Biodiversity Of Weed Communities In Organic And Conventional Orchards

    Directory of Open Access Journals (Sweden)

    Lisek Jerzy

    2015-06-01

    Full Text Available The aim of the study was to analyze the occurrence of segetal and ruderal weeds in young apple and cherry organic orchards, where weeds under tree canopies were controlled mechanically with a rototiller, and in conventional orchards, where post-emergence herbicides were used. The research material consisted of phytosociological relevés recorded according to the Braun-Blanquet method, in three organic and three conventional orchards, situated near Skierniewice (central Poland, in 2010-2013. On the basis of the collected source material, species composition for the synanthropic flora, as well as phytosociological stability, the cover factor, and weed infestation rate for the analysed species were determined. The total number of the recorded weeds and the average number of weed species in a single relevé were for each of the three organic orchards greater than for the conventional orchards. The organic orchard situated in the same location as the conventional orchard was characterized by a greater biodiversity of flora. Systematic shallow cultivation of the soil, without herbicide treatments, resulted in the proliferation of perennial weeds.

  14. Taxonomic diversity and distinctness indices in assessment of weed communities

    Directory of Open Access Journals (Sweden)

    Magdalena Jastrzębska

    2012-12-01

    Full Text Available This paper contains an analysis of taxonomic weed biodiversity in the cultivation of spring barley in the period of 1990-2004, grown in crop rotation after potato with a 25% share of this cereal (potato - spring barley - field pea - winter triticale as well as in crop rotation with its 75% share (potato - spring barley - spring barley - spring barley in which barley was grown once and twice after the same barley crop. No weed control was used in the present experiment. Every year in the spring (at full emergence of the cereal crop and before harvest, the species composition and the numbers of individual weed species were determined, as well as weed biomass before harvest. On this basis, the taxonomic diversity and distinctness indices were calculated. Potato/barley crop rotation with a 25% share of this cereal and growing spring barley once and twice after the same barley crop did not differentiate taxonomic weed biodiversity. However, it was positively correlated with rainfall abundance during the growing season and negatively correlated with mean temperature. The taxonomic diversity indices were positively correlated with species richness and species diversity, whereas the taxonomic distinctness indices did not generally show any relationship with these measures. Spring barley grain yield did not depend on taxonomic biodiversity of weed communities.

  15. A Measurement System for On-line Estimation of Weed Coverage

    OpenAIRE

    Pirola, Marco; Parvis, Marco

    1999-01-01

    This paper describes two different solutions for the estimation of weed coverage. Both measuring systems discriminate the weed from the ground by means of the color difference between the weed and ground and can be used to on-line control tractor sprayers in order to reduce weedkiller use. The solutions differ with respect to the sensor type: one solution is based on a digital camera and a computer that analyzes the images and determines the weed amount, while the other simpler solution makes...

  16. Controle de plantas daninhas na cultura do algodoeiro (Gossypium hirsutum L. em solo anteriormente ocupado por vegetação de Cerrado Weed control on the cotton crop (Gossypium hirsutum L. in a soil previously occuped by Cerrado vegetation

    Directory of Open Access Journals (Sweden)

    J.G. Machado Neto

    1991-01-01

    Full Text Available Estudou-se os efeitos de herbicidas, isolados ou combinados, na cultura do algodão (Gossypium hirsutum L. e eficiência no controle das plantas daninhas. O experimento foi conduzido na Fazenda de Ensino e Pesquisa da Faculdade de Engenharia de Ilha Solteira - UNESP em solo Latossolo Vermelho Escuro franco argilo-arenoso, localizada no município de Selvíria, Estado de Mato Grosso do Sul, Brasil. Os tratamentos testados com as doses em kg i.a/ha foram: alachlor a 2,15 e 2,58 em pré-emergência (pré, trifluralina a 0,96 em pré-plantio incorporado ao solo (ppi isolada ou combinada com MSMA a 1,89, ou bentazon a 0,72 ou diuron a 1,20 em pós-emergência (pós em jato dirigido, MSMA a 2,52 em pós, linuron a 1,0 em pré diuron a 1,6 em pré ou pós e testemunhas com e sem capina. O delineamento experimental utilizado foi o de blocos ao acaso com doze tratamentos e quatro repetições. As aplicações em ppi e a semeadura foram realizadas dia 11. 12.81 e as em pré dia 18.12.81, com um pulverizador costal de pressão constante (CO2 de 30 1b/pol2, com barra de quatro bicos tipo leque Albuz verde e consumo de calda de 250 l/ha. As aplicações em pós foram realizadas. no dia 27.12.81, com o mesmo pulverizador com um bico tipo defletor, polijet azul, com protetor de jato, com pressão de 40 1b/pol2 e consumo de 500 I/ha. As espécies dominantes foram capim - colchão (Digitaria sangnalis (L. Scop e caruru (Amaranthus viridis L. que foram excelentemente controladas, até 90 dias após a semeadura, por alachlor, diuron em pré, trifluralina + diuron, que reduziram mais de 80% do peso da biomassa seca da parte aérea destas. Os herbicidas não causaram fitotoxicidade à cultura. A presença das plantas daninhas reduziu em 58,9% a produção de algodão em caroço.It was conduced field trial with the objective to study the effects of herbicides, isolated or combined, in cotton crop (Gossypium hirsutum L. and weeds control, in a soil previously occuped

  17. Avaliação de herbicidas de pós-emergência na cultura da batata Evaluation of herbicides on post emergent weed control in potato crops

    Directory of Open Access Journals (Sweden)

    Jeferson Zagonel

    1999-03-01

    Full Text Available O experimento foi instalado na Fazenda Escola da UEPG, Ponta Grossa-PR, em solo Latossolo Vermelho Escuro de textura média argilosa, tendo como objetivo avaliar a eficiência e a seletividade do herbicida propaquizafop no controle pós-emergente de plantas daninhas na cultura da batata. O delineamento experimental foi de blocos ao acaso com seis tratamentos: propaquizafop (100, 125 e 150 g i.a./ha; fluazifop-p-butil (188 g i.a./ha; testemunha capinada e testemunha sem capina, em quatro repetições. O plantio foi realizado em 26 de outubro com a cultivar Elvira, usando-se o espaçamento de 0,70 x 0,35 m. As plantas daninhas presentes foram: Brachiaria plantaginea (capim-papuã, Digitaria horizontalis (capim-milhã e Eleusine indica (capim pé-de-galinha. As avaliações foram efetuadas aos 15, 30 e 45 dias após a aplicação dos tratamento. Observou-se que a aplicação de herbicidas pós-emergentes após a amontoa, permite controle adequado de plantas daninhas desde a emergência até a colheita; o herbicida propaquizafop mostrou-se eficiente no controle sobre capim-papuã e capim pé-de-galinha nas doses de 100, 125 e 150 g i.a./ha e sobre capim-milhã nas doses de 125 e 150 g i.a./ha. As perdas na produção causadas pela competição com plantas daninha foram da ordem de 57,4 %. Não foram observados efeitos fitotóxicos nas plantas de batata que pudessem ser atribuídos aos tratamentos aplicados.The presented field experiment was conducted at the Universidade Estadual de Ponta Grossa, Paraná State, Brazil, on Dark Red Latossoil, to evaluate the efficiency and selectivity of herbicides on post emergence weed control in potato crops. The experiment was laid out in a randomized block design with six treatments and four replications: propaquizafop (100, 125 and 150 g a.i/ha; fluazifop-p-butil (188 g a.i/ha, weed free and weedy. Planting was conducted on October 26, using the cultivar Elvira. Potato plants were spaced 0.70 x 0.35 m. The

  18. Aquatic Sediments.

    Science.gov (United States)

    Sanville, W. D.; And Others

    1978-01-01

    Presents a literature review of aquatic sediments and its effect upon water quality, covering publications of 1976-77. This review includes: (1) sediment water interchange; (2) chemical and physical characterization; and (3) heavy water in sediments. A list of 129 references is also presented. (HM)

  19. Cultivation of macroscopic marine algae and fresh water aquatic weeds

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J.H.

    1982-02-01

    The ORCA clone of the red seaweed Gracilaria tikvahiae has been in culture continuously for over two years. Yield for the past year has averaged 12 g ash-free dry wt/m/sup 2/ .day (17.5 t/a.y) in suspended 2600-1 aluminum tank cultures with four exchanges of enriched seawater per day and continuous aeration. Yields from nonintensive pond-bottom culture, similar to commercial Gracilaria culture methods in Taiwan, averaged 3 g afdw/m/sup 2/.day in preliminary experiments. Rope and spray cultures were not successful. Yields of water hyacinths from March 1978 to March 1979 averaged 25 g afdw/m/sup 2/.day (37 t/a.y). Season, nutrient availability (form and quantity) and stand density were found to affect the relative proportions of structural and nonstructural tissue in water hyacinths and thereby significantly affect digestibility of and methane production by the plants. Pennywort (Hydrocotyle) grew poorly in winter and its annual yield averaged only one-third that of water hyacinth. Water lettuce (Pistia) appears more comparable to hyacinths in preliminary studies and its yields will be monitored throughout a complete year. Stable, continuous anaerobic digestion of both water hyacinths and Gracilaria has been maintained with an average gas production from both species of 0.4 1/g volatile solids at 60% methane.

  20. Development of remote sensing based site specific weed management for Midwest mint production

    Science.gov (United States)

    Gumz, Mary Saumur Paulson

    Peppermint and spearmint are high value essential oil crops in Indiana, Michigan, and Wisconsin. Although the mints are profitable alternatives to corn and soybeans, mint production efficiency must improve in order to allow industry survival against foreign produced oils and synthetic flavorings. Weed control is the major input cost in mint production and tools to increase efficiency are necessary. Remote sensing-based site-specific weed management offers potential for decreasing weed control costs through simplified weed detection and control from accurate site specific weed and herbicide application maps. This research showed the practicability of remote sensing for weed detection in the mints. Research was designed to compare spectral response curves of field grown mint and weeds, and to use these data to develop spectral vegetation indices for automated weed detection. Viability of remote sensing in mint production was established using unsupervised classification, supervised classification, handheld spectroradiometer readings and spectral vegetation indices (SVIs). Unsupervised classification of multispectral images of peppermint production fields generated crop health maps with 92 and 67% accuracy in meadow and row peppermint, respectively. Supervised classification of multispectral images identified weed infestations with 97% and 85% accuracy for meadow and row peppermint, respectively. Supervised classification showed that peppermint was spectrally distinct from weeds, but the accuracy of these measures was dependent on extensive ground referencing which is impractical and too costly for on-farm use. Handheld spectroradiometer measurements of peppermint, spearmint, and several weeds and crop and weed mixtures were taken over three years from greenhouse grown plants, replicated field plots, and production peppermint and spearmint fields. Results showed that mints have greater near infrared (NIR) and lower green reflectance and a steeper red edge slope than