WorldWideScience

Sample records for biological weed control

  1. Opportunities for biological weed control in Europe

    NARCIS (Netherlands)

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

    2001-01-01

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

  2. 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.

  3. Domestic geese: biological weed control in an agricultural setting.

    Science.gov (United States)

    Tricia L. Wurtz

    1995-01-01

    Vertebrate herbivores can be effective agents of biological weed control in certain applications. I compared the use of domestic geese for weed control in an agricultural field with the herbicide hexazinone and with hand control. Newly planted spruce seedlings acted as a prototype crop that would be unpalatable to the geese. Trampling by geese led to as much as 47%...

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

    NARCIS (Netherlands)

    Veiga, R.

    2012-01-01

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

  5. Funding needed for assessments of weed biological control

    Science.gov (United States)

    John L. Maron; Dean E. Pearson; Stephen M. Hovick; Walter P. Carson

    2010-01-01

    Invasive non-native plants are a serious economic and ecological problem worldwide, and major efforts are therefore devoted to reducing weed abundance in agricultural and natural settings. Effective options for reducing invasive abundance and spread are few, although one common approach is biological control - the introduction of specialist herbivores or pathogens from...

  6. Use of rhizobacteria and endophytes for biological control of weeds

    Directory of Open Access Journals (Sweden)

    Trognitz, Friederike

    2014-02-01

    Full Text Available Weeds cause severe yield losses in agriculture, with a maximum estimate of 34% of yield loss worldwide due to competition between the crops and the weeds for nutrition, light and humidity (OERKE, 2006. Invasive plants contribute partially to other problems. The pollen of common ragweed, Ambrosia artemisiifolia L., for example, is five times more allergenic than grass pollen; already ten pollen grains per m3 air can trigger allergy in sensitized patients, including rhinitis, conjunctivitis and asthma. This neophyte from America has extended the season of allergy in European patients to October. Common ragweed is currently most frequent in Hungary, France and Italy. In Austria, ragweed populations along roads have increased dramatically since 2000. The effective means to control this weed of the Asteraceae family are limited; a single plant can produce up to 6000 seeds which stay in the soil for 40 years. Control using selective herbicides is not possible within stands of the Asteraceae member sunflower. Efforts to use herbivore insects as biological control agents also failed due to the unavailability of insects specializing on this ragweed. The use of plant-associated rhizobacteria and endophytes as bio-herbicides offers a novel alternative to conventional methods. By analogy to experiences from other plant-microbe systems, the chances to find microbes of the desired characteristics are highest when isolating and testing specimens directly from ragweed plants. These organisms often have an extremely narrow host range that permits their use for the control of among several even closely related plant species growing together in a field.

  7. Releases of natural enemies in Hawaii since 1980 for classical biological control of weeds

    Science.gov (United States)

    P. Conant; J. N. Garcia; M. T. Johnson; W. T. Nagamine; C. K. Hirayama; G. P. Markin; R. L. Hill

    2013-01-01

    A comprehensive review of biological control of weeds in Hawaii was last published in 1992, covering 74 natural enemy species released from 1902 through 1980. The present review summarizes releases of 21 natural enemies targeting seven invasive weeds from 1981 to 2010. These projects were carried out by Hawaii Department of Agriculture (HDOA), USDA Forest Service (USFS...

  8. 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...

  9. Diapause in Abrostola asclepiadis (Lepidoptera: Noctuidae) may make for an ineffective weed biological control agent

    Science.gov (United States)

    Pale and black swallow-wort (Vincetoxicum rossicum and V. nigrum; Apocynaceae, subfamily Asclepiadoideae) are perennial vines from Europe that are invasive in various terrestrial habitats in the northeastern USA and southeastern Canada. A classical weed biological control program has been in develop...

  10. Proceedings of the XIII International Symposium on Biological Control of Weeds; September 11-16, 2011; Waikoloa, Hawaii, USA

    Science.gov (United States)

    Yun Wu; Tracy Johnson; Sharlene Sing; S. Raghu; Greg Wheeler; Paul Pratt; Keith Warner; Ted Center; John Goolsby; Richard Reardon

    2013-01-01

    A total of 208 participants from 78 organizations in 19 countries gathered at the Waikoloa Beach Marriott on the Big Island of Hawaii on September 11-16, 2011 for the XIII International Symposium on Biological Control of Weeds. Following a reception on the first evening, Symposium co-chairs Tracy Johnson and Pat Conant formally welcomed the attendees on the morning of...

  11. Herbicidal control of parthenium weed in maize

    International Nuclear Information System (INIS)

    Khan, H.; Khan, M.A.; Hashim, S.

    2014-01-01

    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)

  12. Biological Control Of Witch Weed In Fields Of Burkina Faso Using ...

    African Journals Online (AJOL)

    Fifteen Fusarium oxysporum isolates from diseased parasitic weeds (Striga hermonthica plants) were evaluated over two years (1997-98) to identify the most effective isolates for the control of the parasite in infested sorghum fields in Burkina Faso. In both years the fungus was found to reduce Striga infection in sorghum by ...

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

    African Journals Online (AJOL)

    thinkexploitsint'l

    importance of integrated weed management in enhancing weed control compared with the use of single weed control ... comparable significantly taller soybeans plants with other herbicides treatments and two hoe- weedings except ... the soyabean plants to utilize more nutrient, moisture and sunlight for better performance.

  14. 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....

  15. 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.

  16. 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)

    Sorensen, Mary A.; Parker, David R.; Trumble, John T.

    2009-01-01

    Hydroponic greenhouse studies were used to investigate the effect of four anthropogenic pollutants (perchlorate (ClO 4 - ), 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

  17. 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.

  18. 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…

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

    Science.gov (United States)

    Sorensen, Mary A; Parker, David R; Trumble, John T

    2009-02-01

    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 Brullé. 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.

  20. 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...

  1. Site-specific weed control technologies

    DEFF Research Database (Denmark)

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

    2009-01-01

    Site-specific weed control technologies are defined as machinery or equipment embedded with technologies that detect weeds growing in a crop and, taking into account predefined factors such as economics, takes action to maximise the chances of successfully controlling them. In the article, we...... describe the basic parts of site specific weed control technologies, comprising of weed sensing systems, weed management models and precision weed control implements. A review of state-of-the-art technologies shows that several weed sensing systems and precision implements have been developed over the last...... 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...

  2. Weeds and their control in cassava | Melifonwu | African Crop ...

    African Journals Online (AJOL)

    Appropriate weed control methods for resource-limited cassava farmers, namely, cultural and biological, as well as an integrated system which combines two or more weed control methods at low input levels are suggested as ways of ensuring sustained production of cassava in developing countries. Key Words: Manihot ...

  3. 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…

  4. Aspergillus alliaceus, a new potential biological control of the root parasitic weed Orobanche.

    Science.gov (United States)

    Aybeke, Mehmet; Sen, Burhan; Okten, Suzan

    2014-07-01

    During extensive surveys in fields heavily infested by broomrape in the Trakya Region-Turkey, a different new fungus, Aspergillus alliaceus, was isolated from the infected broomrape. It is aimed to investigate whether or not it is really a pathogen for Orobanche. The fungi was exposed to a greenhouse environment in order to assess its pathogenicity and virulence against Orobanche cernua. In addition, infection tests on Orobanche seeds were also performed under laboratory conditions. The fungus was subjected using two different methods, exposure to a liquid culture with conidial solution and a sclerotial solid culture with fungal mycelia. Cytological studies were carried out at light, TEM and SEM levels. The results show that the sclerotial solid culture with fungal mycelia quickly caused necrosis and was more effective than the other type. It also greatly diminished attachments, tubercles, and caused the emergence of shoots and an increase in the total shoot number of Orobanche. In addition, both when the fungi was exposed to both soil and used to contaminate sunflower seeds, its pathogenicity was more effective. Consequently, it was determined that A. alliaceus was an effective potential biological control of broomrape throughout its life cycle from dormant seed to mature plant. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Biology, ecology and management of the invasive parthenium weed (Parthenium hysterophorus L.).

    Science.gov (United States)

    Adkins, Steve; Shabbir, Asad

    2014-07-01

    Parthenium weed (Parthenium hysterophorus L.) is one of the most aggressive invasive weeds, threatening natural ecosystems and agroecosystems in over 30 countries worldwide. Parthenium weed causes losses of crops and pastures, degrading the biodiversity of natural plant communities, causing human and animal health hazards and resulting in serious economic losses to people and their interests in many countries around the globe. Several of its biological and ecological attributes contribute towards its invasiveness. Various management approaches (namely cultural, mechanical, chemical and biological control) have been used to minimise losses caused by this weed, but most of these approaches are ineffective and uneconomical and/or have limitations. Although chemical control using herbicides and biological control utilising exotic insects and pathogens have been found to contribute to the management of the weed, the weed nevertheless remains a significant problem. An integrated management approach is proposed here for the effective management of parthenium weed on a sustainable basis. © 2014 Society of Chemical Industry.

  6. Weed control in conservation agriculture

    Science.gov (United States)

    Prior to the introduction of the selective herbicide, 2,4-D (2,4-dichlorophenoxyacetic acid), in the 1940’s, weed control in agricultural crops was primarily achieved through mechanical cultivation of the soil. Since that time, an increasing number of highly efficacious herbicide options, paired wi...

  7. Potential Use of Essential oils from Four Tunisian Species of Lamiaceae: Biological Alternative for Fungal and Weed Control

    Directory of Open Access Journals (Sweden)

    Mohsen Hanana

    2017-05-01

    Full Text Available The chemical composition of the essential oils (EOs of four Lamiaceae (Thymus capitatus Hoff. et Link. , Rosmarinus officinalis L., Origanum vulgare L. and Mentha pulegium L. growing wild in Tunisia was analyzed by gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS. Obtained results showed significant variations among the different species. The major constituents identified for each species were respectively carvacrol (69% and δ-terpinene (17% for T. capitatus, 1,8-cineole (41% and α-pinene (24% for R. officinalis, menthol (39% and 1.8-cineole (17% for M. pulegium , thymol (30%, p-cymene (30% and δ-terpinene (27% for O. vulgare . EO herbicidal effects were evaluated against three invasive weed species in most cultivated crops: Sinapis arvensis L., Phalaris paradoxa L. and Lolium rigidum Gaud. The study of herbicidal activity was carried out on seed germination and seedling vigor and growth. All tested EOs significantly inhibited the germination and growth of weeds in a dose dependent manner and their herbicidal activity could be attributed mainly to their high content in oxygenated monoterpenes. The antifungal ability of EOs was assessed by using disc agar diffusion against ten plant pathogenic fungi affecting crops and stored foods. The EOs displayed strong inhibitory effect on all tested fungi. Our results on EOs chemical composition and biological activities showed properties that could be valorized in managing biocontrol of weeds and plant fungi.

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

    International Nuclear Information System (INIS)

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

    2001-04-01

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

  9. Hybrid weeds! Agent biotypes!: Montana's ever-evolving toadflax biological control soap opera

    Science.gov (United States)

    S. E. Sing; D. K. Weaver; S. M. Ward; J. Milan; C. L. Jorgensen; R. A. Progar; A. Gassmann; I. Tooevski

    2013-01-01

    An exotic toadflax stem mining weevil conventionally identified as Mecinus janthinus Germar has become widely established on Dalmatian toadflax [Linaria dalmatica (Linnaeus) Miller] in western North America, although agent density and control efficacy are highly variable across release sites (De Clerck-Floate & Miller, 2002; McClay & Hughes, 2007; Van Hezewijk...

  10. Weed Control in Soybean (Glycine max)

    International Nuclear Information System (INIS)

    Kipkemoi, P.L.

    2002-01-01

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

  11. A STUDY ON WEED CONTROL IN SOYBEAN

    Directory of Open Access Journals (Sweden)

    S. TJITROSEMITO

    1991-01-01

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

  12. The future for weed control and technology.

    Science.gov (United States)

    Shaner, Dale L; Beckie, Hugh J

    2014-09-01

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

  13. 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 ...

  14. 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...

  15. Bioherbicides: Current knowledge on weed control mechanism.

    Science.gov (United States)

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

    2018-04-17

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

  16. 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.

  17. The initiation of a biological control programme against pompom weed Campuloclinium macrocephalum (LESS.)DC (Asteraceae)in South Africa

    Science.gov (United States)

    Pompom weed, Campuloclinium macrocephalum (Less.) DC. (Asteraceae), is a South American invasive that was first recorded in South Africa in the early 1960s. In the 1980s, C. macrocephalum started slowly extending its range and in the 1990s and 2000s it entered a dramatic expansion phase. It invade...

  18. Biological Control of the weed hemp sesbania (Sesbania exaltata) in rice (Oryza sativa) by the fungus Myrothecium verrucaria

    Science.gov (United States)

    In greenhouse and field experiments, a mycelial formulation of the fungus Myrothecium verrucaria (IMI 361690; henceforth designated MV) containing 0.20% Silwet L-77 surfactant exhibited high bioherbicidal efficacy against the problematic weed hemp sesbania. High infection and mortality (100%) of he...

  19. An overview of plant volatile metabolomics, sample treatment and reporting considerations with emphasis on mechanical damage and biological control of weeds.

    Science.gov (United States)

    Beck, John J; Smith, Lincoln; Baig, Nausheena

    2014-01-01

    The technology for the collection and analysis of plant-emitted volatiles for understanding chemical cues of plant-plant, plant-insect or plant-microbe interactions has increased over the years. Consequently, the in situ collection, analysis and identification of volatiles are considered integral to elucidation of complex plant communications. Due to the complexity and range of emissions the conditions for consistent emission of volatiles are difficult to standardise. To discuss: evaluation of emitted volatile metabolites as a means of screening potential target- and non-target weeds/plants for insect biological control agents; plant volatile metabolomics to analyse resultant data; importance of considering volatiles from damaged plants; and use of a database for reporting experimental conditions and results. Recent literature relating to plant volatiles and plant volatile metabolomics are summarised to provide a basic understanding of how metabolomics can be applied to the study of plant volatiles. An overview of plant secondary metabolites, plant volatile metabolomics, analysis of plant volatile metabolomics data and the subsequent input into a database, the roles of plant volatiles, volatile emission as a function of treatment, and the application of plant volatile metabolomics to biological control of invasive weeds. It is recommended that in addition to a non-damaged treatment, plants be damaged prior to collecting volatiles to provide the greatest diversity of odours. For the model system provided, optimal volatile emission occurred when the leaf was punctured with a needle. Results stored in a database should include basic environmental conditions or treatments. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Non-woody weed control in pine plantations

    Science.gov (United States)

    Phillip M. Dougherty; Bob Lowery

    1986-01-01

    The cost and benefits derived from controlling non-woody competitors in pine planations were reviewed. Cost considerations included both the capital cost and biological cost that may be incurred when weed control treatments are applied. Several methods for reducing the cost of herbicide treatments were explored. Cost reduction considerations included adjustments in...

  1. Molecular biology approaches to weed management

    Science.gov (United States)

    Global climate change appears to be favorable for invasive weed development and spread because invasive species in general are proficient at succeeding in new environments. To worsen matters, herbicide-resistant weeds have become a severe threat in modern agricultural systems due to the extensive us...

  2. Chemical weed control in barley (hordeum vulgare)

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  3. WEED MANAGEMENT AND CONTROL IN POTATOES

    Directory of Open Access Journals (Sweden)

    Marcelo Cleón de Castro Silva

    2011-07-01

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

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  5. Integrated Biological Control

    International Nuclear Information System (INIS)

    JOHNSON, A.R.

    2002-01-01

    Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects; and microorganisms such as molds that adversely affect the quality of the workplace environment). Biological control activities may be either preventive (apriori) or in response to existing contamination spread (aposteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and apriori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, aposteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response

  6. Mechanical weed control in organic winter wheat

    Directory of Open Access Journals (Sweden)

    Euro Pannacci

    2017-12-01

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

  7. Female sex pheromone secreted by Carmenta mimosa (Lepidoptera: Sesiidae), a biological control agent for an invasive weed in Vietnam.

    Science.gov (United States)

    Vang, Le Van; Khanh, Chau Nguyen Quoc; Shibasaki, Hiroshi; Ando, Tetsu

    2012-01-01

    Larvae of the clearwing moth, Carmenta mimosa (Lepidoptera: Sesiidae), bore into the trunk of Mimosa pigra L., which is one of the most invasive weeds in Vietnam. GC-EAD and GC-MS analyses of a pheromone gland extract revealed that the female moths produced (3Z,13Z)-3,13-octadecadienyl acetate. A lure baited with the synthetic acetate alone successfully attracted C. mimosa males in a field test. While the addition of a small amount of the corresponding alcohol did not strongly diminish the number of captured males, a trace of the aldehyde derivative or the (3E,13Z)-isomer markedly inhibited the attractiveness of the acetate. The diurnal males were mainly attracted from 6:00 am to 12:00 am.

  8. Integration of herbicides with manual weeding for controlling the weeds in rice under saline environment.

    Science.gov (United States)

    Hakim, M A; Juraimi, Abdul Shukor; Hanafi, M M; Rafii, Mohd Y; Ismail, Mohd Razi; Karim, S M Rezaul; Kausar, H

    2015-11-01

    The pot experiment was conducted to select appropriate integrated weed management method in rice under different salinity levels (0, 4 and 8 dS m(-1)). All the parameters including rice and weed measured were significantly influenced by weed control treatments at all salinity levels. Treatments including weed-free condition, Pretilachlor @0.375 kg ai ha(-1) + hand weeding, Propanil + Thiobencarb @ 0.9 kg ai ha(-1) and 1.8 kg ai ha(-1)+ hand weeding performed better under all salinity levels. Pretilachlor @ 0.375 kg ai ha(-1) with one round of hand weeding and propanil + thiobencarb 0.9 kg ai ha(-1) + 1.8 kg ai ha(-1) with one round of hand weeding were comparable to weed-free yields, and were superior to other treatments under salinity condition. Considering all the parameters, pretilachlor @ 0.375 kg ai ha(-1) + one round of hand weeding (at 65 DAT), propanil + thiobencarb 0.9 kg ai ha(-1) +1.8 kg ai ha(-1) + one round of hand weeding (at 65 DAT) gave the most effective control of weeds in rice under saline environments.

  9. 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...

  10. Biological Control in Agroecosystems

    Science.gov (United States)

    Batra, Suzanne W. T.

    1982-01-01

    Living organisms are used as biological pest control agents in (i) classical biological control, primarily for permanent control of introduced perennial weed pests or introduced pests of perennial crops; (ii) augmentative biological control, for temporary control of native or introduced pests of annual crops grown in monoculture; and (iii) conservative or natural control, in which the agroecosystem is managed to maximize the effect of native or introduced biological control agents. The effectiveness of biological control can be improved if it is based on adequate ecological information and theory, and if it is integrated with other pest management practices.

  11. Sequential applications of pelargonic acid for weed control in squash

    Science.gov (United States)

    Weed control can be a constant challenge, especially when dealing with the limited herbicide options available to organic vegetable producers. Organic squash (Cucurbita pepo L.) producers need appropriate herbicides that can effectively provide weed control throughout the production season. Although...

  12. Continuing Weed Control Benefits Young Planted Black Walnut

    Science.gov (United States)

    John E. Krajicek; Robert D. Williams

    1971-01-01

    Cultivation, atrazine, and simazine were used for weed control 1, 2, and 3 years following planting of black walnut in Iowa and Indiana. In Iowa, 2 or more years of weed control resulted in the best seedling growth, but in Indiana 3 years proved best. Method of weed control had no significant effect on seedling growth in Iowa, but chemical control resulted in better...

  13. 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...

  14. Effects of Planting Date, Time and Methods of Weed Control on Weed Density and Biomass in Cumin Fields

    Directory of Open Access Journals (Sweden)

    R. Ghorbani

    2011-01-01

    Full Text Available Abstract Two field experiments were carried out in order to evaluate the effect of planting date, method and date of weed control on weed density and biomass in the experimental research field, Faculty of Agriculture, Ferdowsi University of Mashhad, during 2006 and 2007. Treatments included planting date (30 December, 20 January and 30 February, weeding date (first true leaf, start of branching and beginning of flowering stages and weed control methods (hand weeding, fire treatment and control. The results showed that there were significant differences in the number of weeds between different sowing dates, weeding dates and control methods. The highest mean density and biomass of weeds were obtained on the planting date, 30 February, and when weed was controlled at the first leaf appearance stage with fire treatment. The most appropriate time for weed control was at the beginning of cumin flowering. Fire treatment reduced weed growth in the first half of growing season. However, hand weeding significantly reduced weed density and biomass in the second half of cumin growing season. The first planting date caused the lowest mean weed biomass and the highest cumin yield compared to later planting dates. Hand weeding treatment contained lower mean weed density and biomass compared to fire treatment, however, cumin yield was lower in hand weeding plots than fire treatment. Keywords: Cultural control, Cuminum cyminum, Fire, Hand weeding, Control time

  15. Mechanical weed control in organic winter wheat

    OpenAIRE

    Euro Pannacci; Francesco Tei; Marcello Guiducci

    2017-01-01

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

  16. 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.

  17. INFLUENCE OF WEED CONTROL METHODS, POULTRY MANURE ...

    African Journals Online (AJOL)

    User

    Mando Kaduna, in the Northern Guinea Savannah Zone of Nigeria, to determine the Influence of weed control methods, poultry manure and ... t /ha in Latin America, and 1.7 t/ha in India. Brazil currently stands out as one of the ..... for soil management for sustainable production of maize. In support of this, (Boateng et al., ...

  18. Weed Control Trials in Cottonwood Plantations

    Science.gov (United States)

    R. M. Krinard

    1964-01-01

    Weed control in the first year is essential for establishing a cottonwood plantation, for the young trees can neither survive nor grow well if they must compete with other plants. Once the light and moisture conditions are established in its favor, cottonwood becomes the fastest growing tree in the South.

  19. Weed Control in Black Walnut Plantations

    Science.gov (United States)

    Calvin F. Bey; Robert D. Williams

    1976-01-01

    Weeds must be controlled for at least 3 years to successfully establish walnut plantations. Whether by cultivating or applying chemicals, a strip or spot 4 feet wide is sufficient the first 2 years, followed by a 6-foot spot or strip for the third and fourth years.

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

    Science.gov (United States)

    Horváth, E; Szabó, R

    2014-01-01

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

  1. Control of invasive weeds with prescribed burning

    Science.gov (United States)

    DiTomaso, Joseph M.; Brooks, Matthew L.; Allen, Edith B.; Minnich, Ralph; Rice, Peter M.; Kyser, Guy B.

    2006-01-01

    Prescribed burning has primarily been used as a tool for the control of invasive late-season annual broadleaf and grass species, particularly yellow starthistle, medusahead, barb goatgrass, and several bromes. However, timely burning of a few invasive biennial broadleaves (e.g., sweetclover and garlic mustard), perennial grasses (e.g., bluegrasses and smooth brome), and woody species (e.g., brooms and Chinese tallow tree) also has been successful. In many cases, the effectiveness of prescribed burning can be enhanced when incorporated into an integrated vegetation management program. Although there are some excellent examples of successful use of prescribed burning for the control of invasive species, a limited number of species have been evaluated. In addition, few studies have measured the impact of prescribed burning on the long-term changes in plant communities, impacts to endangered plant species, effects on wildlife and insect populations, and alterations in soil biology, including nutrition, mycorrhizae, and hydrology. In this review, we evaluate the current state of knowledge on prescribed burning as a tool for invasive weed management.

  2. Weed clearance in Hudiara Nallah by chemical weed control

    International Nuclear Information System (INIS)

    Dhillon, G.S.

    1981-01-01

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

  3. 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…

  4. Developments in physical weed control in Northwest Europe

    NARCIS (Netherlands)

    Riemens, M.M.

    2016-01-01

    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

  5. Level of threshold weed density does not affect the long-term frequency of weed control.

    NARCIS (Netherlands)

    Wallinga, J.; Oijen, van M.

    1997-01-01

    Weed control thresholds are often presented as a means to reduce unnecessary control measures, thereby increasing the effectiveness of weed management. While the threshold is a useful tool for cost-effective application of control on a single-year base, its role over the longer term is more

  6. 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.

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

    Science.gov (United States)

    David B. South

    2009-01-01

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

  8. 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…

  9. Suicidal germination for parasitic weed control.

    Science.gov (United States)

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

    2016-11-01

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

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

    Science.gov (United States)

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

    2015-03-30

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

  11. 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.

  12. 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.

  13. 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.

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

    African Journals Online (AJOL)

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

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

    International Nuclear Information System (INIS)

    Khan, E.A.; Khakwani, A.A.; Ghazanfarullah, A.

    2015-01-01

    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)

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

    Directory of Open Access Journals (Sweden)

    T. Barakova

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Marulak Simarmata

    2015-10-01

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

  18. Critical period of weed control in aerobic rice.

    Science.gov (United States)

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

    2012-01-01

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

  19. Critical Period of Weed Control in Aerobic Rice

    Science.gov (United States)

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

    2012-01-01

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

  20. Aquatic weed control within an integrated water management framework

    NARCIS (Netherlands)

    Querner, E.P.

    1993-01-01

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

  1. 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 investigate the efficacy of four non-chemical weed control methods and glyphosate treatment, experiments were carried out on traffic islands in the growing seasons 2005 and 2006. Three trial sites were each divided into six treatment areas, which were either treated with glyphosate, flame, steam, hot air....../flame, hot water or left untreated. The treatments were carried out at regular, predetermined intervals throughout the growing season in 2004, whereas in 2005 and 2006 how many treatments that were required to keep weed cover below a predetermined acceptance level of 2% were investigated. Percentage weed...

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

    Directory of Open Access Journals (Sweden)

    Dorota Gawęda

    2014-04-01

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

  3. Economic assessment of tillage systems and weed control methods ...

    African Journals Online (AJOL)

    This study was conducted to appraise the economics of different land preparation systems and weed management options in maize cultivation in three ecological zones (Ikenne, Ibadan and Ilorin) of southwestern Nigeria. Four tillage systems as main treatments and six weed control methods as sub-treatments were ...

  4. Evaluation of Different Weed Control Techniques in Soyabean ...

    African Journals Online (AJOL)

    Ten weed control treatments consisting of wheel type weeder [3 and 6 weeks after planting (wap)]; hoe weeding (3 and 6 wap); Pre-emergence application of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] + prometryn [N, N'-bis (1-methylethyl)-6-(methylthio)-1,3,5-triazine-2 ...

  5. Chemical and Mechanical Control of Soybean (Glycin max L. Weeds

    Directory of Open Access Journals (Sweden)

    Ebrahim Gholamalipour Alamdari

    2016-10-01

    Full Text Available To evaluate effects of the various concentrations of two herbicides of the trifluralin and Imazethapyr and weeding on weeds control, yield and yield components of soybean (Glycin max L., an experiment was carried out based on randomized complete block design with three replications at the Agriculture Land of Ghravolhaji Village in Kallale district of Golestan province in 2014. Treatments consisted of planting soybean under weeding, without weeding and application of trifluralin and Imazethapyr as 100% trifluralin, 75% trifluralin + 25% Imazethapyr, 50% trifluralin + 50% Imazethapyr, 25% trifluralin + 75% Imazethapyr, 100% pursuit, 100% Imazethapyr + 25% trifluralin, 25% Imazethapyr + 100% trifluralin, 100% Imazethapyr + 50% trifluralin and 50% Imazethapyr + 100% trifluralin. density of each weed, their total density and inhibition percentage were measured. Results showed that the effect of chemical weed control on all traits measured, except seed number per pot, 1000 seed weight, content of chlorophyll a and total chlorophyll, were significant. The highest leaf area, plant height, number of pods per plant, aerial plant dry weight, seed number per plant and seed weight per plant were observed in the treatment of the 100% Imazethapyr (238.67 cm2, weeding (57.69 cm, both treatments of weeding (33.10 and 25% Imazethapyr +100% trifluralin (28.3, both treatment of weeding (163.92 g and 100%  Imazethapyr (163.70 g, weeding (67.10 seed per plant, both treatment of weeding and 100%  Imazethapyr + 50% trifluralin (10.27 seed per plant respectively. The highest seed yield was obtained from weeding treatment (2383 kg/h. Based on the results, the highest content of protein and chlorophyll b in soybean were obtained from weeding treatment. The highest inhibition percentage of weeds was found in the additional treatment of 50% Imazethapyr + 100% trifluralin (75.19 and 100% Imazethapyr + 25% trifluralin (72.86. The lowest and highest total phenols content and

  6. The Power and Potential of Genomics in Weed Biology and Management.

    Science.gov (United States)

    Ravet, Karl; Patterson, Eric L; Krähmer, Hansjörg; Hamouzová, Kateřina; Fan, Longjiang; Jasieniuk, Marie; Lawton-Rauh, Amy; Malone, Jenna M; Scott McElroy, J; Merotto, Aldo; Westra, Philip; Preston, Christopher; Vila-Aiub, Martin M; Busi, Roberto; Tranel, Patrick J; Reinhardt, Carl; Saski, Christopher; Beffa, Roland; Neve, Paul; Gaines, Todd A

    2018-04-24

    There have been previous calls for, and efforts focused on, realizing the power and potential of weed genomics for better understanding of weeds. Sustained advances in genome sequencing and assembly technologies now make it possible for individual research groups to generate reference genomes for multiple weed species at reasonable costs. Here, we present the outcomes from several meetings, discussions, and workshops focused on establishing an International Weed Genomics Consortium (IWGC) for a coordinated international effort in weed genomics. We review the 'state of the art' in genomics and weed genomics, including technologies, applications, and on-going weed genome projects. We also report the outcomes from a workshop and a global survey of the weed science community to identify priority species, key biological questions, and weed management applications that can be addressed through greater availability of, and access to, genomic resources. Major focus areas include the evolution of herbicide resistance and weedy traits, the development of molecular diagnostics, and the identification of novel targets and approaches for weed management. There is increasing interest in, and need for, weed genomics, and the establishment of the IWGC will provide the necessary global platform for communication and coordination of weed genomics research. This article is protected by copyright. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    M. Matinfar

    2011-06-01

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

  8. 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...... conveyor belts fully controlled by a Siemens PLC controller (programmable logic controller), a stereo vision system consisting of two cameras, a 2-axis laser beam deflection unit and a laser source. The main challenge in this project was to accurately estimate and reconstruct the weed growth center using...

  9. 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)

  10. Effectiveness of the Primextra Gold in controlling weeds of ...

    African Journals Online (AJOL)

    The efficacy of Primextra Gold herbicide in controlling weeds in cucumber was evaluated in this research. The experiment was laid out in a randomized complete block design with four replications. Seven weed control treatments – 0.0, 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5 kg a.i/pot – were applied pre-emergent for this study.

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

    Science.gov (United States)

    Gayne G. Erdmann

    1967-01-01

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

  12. Weeds of Hawaii’s lands devoted to watershed protection and biodiversity conservation: Role of biological control as the missing piece in an integrated pest management strategy

    Science.gov (United States)

    Medeiros, Arthur C.; Loope, L.L.

    2011-01-01

    Despite Hawaii’s reputation as an extinction icon, significant biological resources remain, especially in watersheds, natural areas, and specialized edaphic sites (e.g., lava dry forest, coastal). While direct habitat destruction by humans continues, human-facilitated biological invaders are currently the primary agents of continuing degradation. The ability of invasive plants to have prolific seed production, efficient dispersal systems, and to become established in dense vegetation, complicated by Hawaii’s rugged topography, appears to render mechanical and chemical control as mere holding actions. Costly, ‘environmentally unfriendly’, and often ineffective, strategies using chemical and mechanical control on a large scale, despite the most valiant of efforts, can be viewed simply as attempts to buy time. Without increased levels of safely tested biological control, the seemingly inevitable result is the landscape level transformation of native forests, with potentially catastrophic consequences to cultural, biological, water, and economic resources. Increased levels of effective biological control for certain intractable invasive species appear to comprise a conspicuous ‘missing piece’ in our efforts to protect Hawaiian watersheds and other conservation lands.

  13. Effect of Doses of Oxyfluorfen and Trifluralin Hebicides on Weeds Control and Yields of Garlic Var. Mazand (Allium sativum L.

    Directory of Open Access Journals (Sweden)

    S. Mahzari

    2014-05-01

    Full Text Available To evaluate the effects of different doses of oxyfluorfen and trifluralin herbicides on weeds control, economic and biologic yield of garlic var. Mazand (Allium sativum L.. An experiment was conducted in the form of simple randomized complete block design with three replications in 2012 - 2013 year. Factor studied were: one application of trifluralin and oxyfluorfen 1.5, 2 and 2.5 lit.ha-1, two applications of oxyfluorfen 1.5 lit.ha-1, hand weeding control and without weeding control.Results showed that using different doses of herbicides significantly affected density and biomass of weeds. Two applicarions of oxyfluorfen with 1.5 liters per hectare and hand weeding were best options to reduce of weeds biomass. Using of oxyfluorfen herbicide (2 and 2.5 liters resulted in little damage and low stable on garlic. Using of different herbicides with different doses were significant on plant height, number of cloves per bulb, 100 seed weight, biological and economical yield and harvest index. Lowest economic yield was due to control treatment (540 g.m-2 and highest was obtained by using 1.5 liter of oxyfluorfen herbicide (1661.67 g.m-2, hand weeding (1686.67 g.m-2 and split oxyfluorfen application (1670 g.m-2. Finally, oxyfluorfen treatment (1.5 liter on 3 to 4 weeds leaf, were identified as the most appropriate treatments.

  14. 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%.

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

    African Journals Online (AJOL)

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

  16. DNA Fingerprinting To Improve Data Collection Efficiency and Yield in a Host-Specificity Test of a Weed Biological Control Candidate

    Science.gov (United States)

    An open-field test was conducted in southern France to assess the host-specificity of Ceratapion basicorne, a candidate for biological control of yellow starthistle (Centaurea solstitialis; YST). Test plants were infested by naturally occurring populations of C. basicorne but were also exposed to s...

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

    NARCIS (Netherlands)

    Wallinga, J.

    1998-01-01

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

    In the first weed

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

    DEFF Research Database (Denmark)

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

    2006-01-01

    was related to wavelength, exposure time, spot size and laser power. The efficacy also varied between the weed species. The results indicate that the efficacy of laser treatments can be improved by a more precise pointing of the laser beam towards the apical meristems and optimisation of the energy density......A laser beam directed towards weeds can be an efficient weed control method as an alternative to herbicides. Lasers may deliver high-density energy to selected plant material, raising the temperature of the water in the plant cells and thereby stop or delay the growth. A commercial use of lasers...... (exposure time and spot size of the laser beam). The experiment also showed a significant difference between two wavelengths. In order to improve the performance and to validate the efficacy on a broader spectrum of weed species, further research and development is needed....

  19. The issues of weed infestation with environmentally hazardous plants and methods of their control

    Science.gov (United States)

    Bogdanov, V. L.; Posternak, T. S.; Pasko, O. A.; Kovyazin, V. F.

    2016-09-01

    The authors analyze expansion of segetal and ruderal vegetation on agricultural lands in Leningrad and Tomsk oblasts, typical for the European and Asian parts of Russia. The spreading conditions, composition of species, biological features and ecological requirements of the most aggressive species are identified. Some effective ways of weed control are suggested.

  20. Effect of Doses of Oxyfluorfen and Trifluralin Hebicides on Weeds Control and Yields of Garlic Var. Mazand (Allium sativum L.)

    OpenAIRE

    S. Mahzari; M.A. Baghestani Meibodi

    2014-01-01

    To evaluate the effects of different doses of oxyfluorfen and trifluralin herbicides on weeds control, economic and biologic yield of garlic var. Mazand (Allium sativum L.). An experiment was conducted in the form of simple randomized complete block design with three replications in 2012 - 2013 year. Factor studied were: one application of trifluralin and oxyfluorfen 1.5, 2 and 2.5 lit.ha-1, two applications of oxyfluorfen 1.5 lit.ha-1, hand weeding control and without weeding control.Results...

  1. 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.

  2. 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…

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

    Science.gov (United States)

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

    2017-08-01

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

  4. Weed Control in White Bean with Various Halosulfuron Tankmixes

    Directory of Open Access Journals (Sweden)

    Nader Soltani

    2014-01-01

    Full Text Available 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%, 83–100%, and 75–92% control of redroot pigweed; 19–28%, 30–40%, 97–99%, and 73–84% control of common ragweed; 94–96%, 63–82%, 96–100%, and 96–100% control of common lambsquarters; 14-15%, 12–35%, 100%, and 96–97% control of wild mustard; and 96–97%, 95–97%, 53–56%, and 80–82% control of green foxtail, respectively. The two- and three-way tankmixes of halosulfuron with trifluralin, s-metolachlor, or imazethapyr provided 85–100% control of redroot pigweed, 90–98% control of common ragweed, 97–100% control of common lambsquarters, 100% control of wild mustard, and 93–98% control of green foxtail. Weed density, weed biomass and white bean seed yields reflected the level of visible weed control.

  5. 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.

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

    International Nuclear Information System (INIS)

    Wells, T.C.; Shrimpton, G.M.

    1997-01-01

    A two year study was conducted by BC Hydro in which a variety of surfacing materials were tested for their suitability for use in substations. Ideally, surfacing materials should have the following characteristics: high electrical resistivity in both dry and wet conditions, resistance to invasion by weeds, good driveability, good drainage, non-flammable, reasonably priced, no dust to foul conductors, and be aesthetically pleasing. Trials at Vernon Koksilah, and Ingledow substations were conducted to test the materials. A qualitative estimate of the amount of weed control provided by each material was recorded. The trials were meant to provide operational recommendations and screening information to allow for future testing of promising materials or combination of materials. Results showed that no single material meets all the desired criteria. The surfaces that best combined good weed control, electrical resistance and surface stability was a 15 cm deep layer of crushed gravel, especially if underlain by a layer of geotextile. 4 refs., 3 tabs., 1 fig

  7. Agricultural residues are efficient abrasive tools for weed control

    Science.gov (United States)

    Non-chemical control of weeds is one of the most important needs of organic agricultural production and, ironically, herbicide resistant crops. There is a knowledge gap regarding alternative control methods that reduce the use of herbicides. This need for alternatives is motivated by increased consu...

  8. Researches regarding glyphosate effectiveness on the degree of weed control in grape plantation

    Directory of Open Access Journals (Sweden)

    Monica NEGREA

    2010-11-01

    Full Text Available In this paper was determined the control degree of weeds in grape plantation, Burgund variety, when is using chemical treatments with herbicides and agro-technique measures. Herbicide used was Roundup 3 l/ha and 4l/ha (glyphosate isopropyl amine salt 360 g/l applied in 4 experimental variants. It was determined the weed presence degree, the type of weeds destroyed and the degree of their participation. Predominant weed species in studied grape plantation, were: Agropyron repens (20.15%, Geranium dissectum (17.91%, Capsella bursa pastoris (15.67% and Avena fatua (13.43%. Ephemeral weeds Veronica hederifolia and Stellaria media had a participation rate of 8.96%. Perennial weeds represented 40.30% while annual weeds are 59.70% . The herbicide Roundup provides most effective control in a dose of 3 or 4 l/ha, combined with mechanical weeding + 1 manual weeding, control rates being over 90%.

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

    International Nuclear Information System (INIS)

    Nelson, Jody K.

    2013-01-01

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

  10. 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.

  11. WEED CONTROL AND BORON NUTRITION ON Eucalyptus IN SILVOPASTORAL SYSTEM

    Directory of Open Access Journals (Sweden)

    Alexandre Magno Brighenti

    2015-04-01

    Full Text Available The objective of this study was to evaluate the control of weeds in the rows of eucalyptus (Eucalyptus urograndis with herbicides applied singly or combined with boron (B, as well as, the response of Eucalyptus plants to this micronutrient. The experiments were carried out in a split-plot with randomized complete block design, with three replicates. Six treatments were applied to the plots: (i weeded control, (ii control without weeding, (iii glyphosate (1080 g ae ha-1 + chlorimuron-ethyl (10 g ai ha-1 + 0.05% v / v mineral oil, (iv glyphosate (1080 g ae  ha-1 + isoxaflutole (112.5 g ai ha-1,  (v glyphosate (1080 g ae ha-1 and  (vi oxyfluorfen (480 g ai ha-1. The sub-plots consisted of the absence or presence of 4 kg of boric acid (H3BO3 - 17% B in 100 L of water. The addition of boric acid in the solution containing the herbicides did not affect the weed control. There was an increase in boron content in the soil and consequently an increase in the boron levels in the eucalyptus leaves. The combined application of herbicides plus boric acid is perfectly suitable for preventing dry of the pointer on eucalyptus plants. Keywords: Eucalyptus urograndis; chemical control; herbicides; micronutrients; Urochloa decumbens.

  12. Weed control using herbicides in short-rotation intensively cultured poplar plantations.

    Science.gov (United States)

    Edward A. Hansen; Daniel A. Netzer

    1985-01-01

    Summarizes a series of studies that investigated chemical weed control from time of planting to the end of the second growing season. The studies confirm the importance of weed control with preemergents at the time of planting and the importance of additional weed control before the start of the second growing season.

  13. Weed control using ammonium nonanoate and cultivation in organic Vidalia sweet onion production

    Science.gov (United States)

    Ammonium nonanoate is registered for weed control in certified organic crop production and may be useful to control cool-season weeds in organic Vidalia® sweet onion. Cultivation with a tine weeder has been identified as a cost-effective means of weed control, but delays in cultivation cause some w...

  14. Economic potentials of oil palm products and weed control on ...

    African Journals Online (AJOL)

    A study was carried out at the Research Farm of National Root Crops Research Institute Umudike, southeastern Nigeria (05o, 29'N, 07o 33'E and 122 m above sea level), in 2015 and 2016 cropping seasons to study the economic potentials of oil palm products and weed control on sustainable turmeric production and some ...

  15. Efficacy of primextra gold in controlling weeds of melon ( Citrillus ...

    African Journals Online (AJOL)

    A field experiment was conducted in the Center of Ecological Studies, University of Port Harcourt, Rivers State to evaluate the efficacy of Primextra Gold (290g /l S – Metalochlor and 370g/l Atrazine) herbicide in controlling weeds in melon and to determine its safety for use in melon. The experiment was carried out between ...

  16. 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%.

  17. Herbaceous weed control in loblolly pine plantations using flazasulfuron

    Science.gov (United States)

    Andrew W. Ezell; Jimmie L. Yeiser

    2015-01-01

    A total of 13 treatments were applied at four sites (two in Mississippi and two in Texas) to evaluate the efficacy of flazasulfuron applied alone or in mixtures for providing control of herbaceous weeds. All sites were newly established loblolly pine (Pinus taeda L.) plantations. Plots were evaluated monthly until 180 days after treatment. No phytotoxicity on pine...

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

    African Journals Online (AJOL)

    Field trials were conducted during the 2006, 2007 and 2008 rainy seasons at the Institute for Agricultural Research Samaru, in the Northern guinea savanna zone of Nigeria to evaluate the effects of weed control and cow dung manure treatments on growth of Quality Protein Maize. The trial consisted of factorial ...

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

    African Journals Online (AJOL)

    COCOYAM

    ABSTRACT. Field studies were conducted at the research farm of the National Root Crops Research. Institute (NRCRI), Umudike, south-eastern Nigeria in 2008 and 2009 cropping seasons, to determine the effect of herbicides and the economic implications of chemical weed control in sweetpotato using herbicides.

  20. Influence of weed control methods, poultry manure and planting ...

    African Journals Online (AJOL)

    Field trials were conducted during the rainy seasons (2012 and 2013) at the Research Farm of Institute for Agricultural Research, Samaru Zaria and College of Agriculture and Animal Science, Mando Kaduna, in the Northern Guinea Savannah Zone of Nigeria, to determine the Influence of weed control methods, poultry ...

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

    Directory of Open Access Journals (Sweden)

    Dorota Gawęda

    2012-10-01

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

  2. The critical period of weed control in corn Zea mays at Mashhad, Iran

    Directory of Open Access Journals (Sweden)

    majid abaspoor

    2009-06-01

    Full Text Available In order to determine the critical period of weed control in corn, an experiment was conducted at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad in year 2000. The experiment consisted of two discrete periods, a weed-free and a weed infested period. The weed-free period consisted of removing all weeds till 4th (19 days after planting, 7th (34 days after planting, 11th (48 days after planting, 13th (52 days after planting, and 17th (59 days after planting, leaf growth stages and weed free check for growing season (123 days after planting, and the critical time of weed infested consisted of removing all weeds from fourth (19 days after planting, 7th (34 days after planting, 11th (48 days after planting, 13th (52 days after planting, and 17th (59 days after planting, leaf growth stages and weedy infested check for growing season. All treatments were compared in a randomized complete block design with four replications. The results showed that by prolonging weed-infested period, dry matter and leaf surface area of weeds per square meter were increased, but by increasing weed-infested period, weed density was decreased. The lowest weed density (23 weed plants per m2 was shown at infested all period of corn growing season. By passing the growing season, C4 weed species such as red root pigweed and barnyard grass were dominant compared with C3 weed species. At weed infested all period of corn growing season, red root pigweed had the highest dry matter (93% of all weeds dry matter and leaf surface area (86% of all weeds leaf surface compared with other weed species. At the first treatment of critical weed-free (19 days after planting the regrowth of weeds were substantial which resulted in decreasing growth of corn. Grain yield of corn were significantly higher at 52, 59 and 123 days after planting in weed free treatments compared with 48, 52, 59 and 123 days after planting in weed infested treatments. However, there were no

  3. Biological control of Salvinia molesta in some areas of Moremi ...

    African Journals Online (AJOL)

    Biological control of Salvinia molesta in some areas of Moremi Game Reserve, Botswana. ... Random samples of salvinia were collected from each site at monthly intervals in 1998 to extract weevils and to demonstrate the effect of weevil on the weed. The rate at which the weed was controlled at different sites varied with ...

  4. 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.

  5. Preemergence herbicides on weed control in elephant grass pasture

    Directory of Open Access Journals (Sweden)

    Alexandre Magno Brighenti

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

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

    African Journals Online (AJOL)

    control and cow dung manure treatments on growth of Quality Protein Maize. The trial consisted of factorial combinations of eight weed control treatments which include application of (Atrazine + Acetochlor +. Terbuthylazine at a ratio of 1:1:1, Atrazine + Metolachlor at a ratio of 1:2 each at 3.0 and 4.0kg a.i/ha, Atrazine at. 4.0 ...

  7. Determination of critical period for weed control in intensive and non ...

    African Journals Online (AJOL)

    Field experiments were conducted in Zuenoula and Yamoussoukro for determining Critical Period for Weed Control (CPWC) in sugarcane. The treatments consisted in two sets of weed interference. In the first set, the crop was kept weed-free until 31, 61, 92, 123 days after planting (DAP) in Zuenoula and until 32, 69, 98 and ...

  8. Determination of critical period for weed control in the second crop ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... nature of weed-crop interactions (Weaver and Tan,. 1987). The critical period for weed control (CPWC) is the length of time that the crop must be kept weed-free to prevent yield losses at a certain level (Weaver and Tan, 1983). CPWC studies have been conducted in many crops in varying environments ...

  9. 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

    There is an increasing concern about excessive use of herbicides for weed control in arable lands. Usually the whole field is sprayed uniformly, while the distribution of weeds often is non-uniform. Often there are spots in a field where weed pressure is very low and has no significant effect on ...... to estimate infestation of weeds at early growth stage. The image analysis method was further developed to estimate colour response of applying increasing doses of herbicides in selectivity experiments and to evaluate the weed-suppressing effect of mulches.......There is an increasing concern about excessive use of herbicides for weed control in arable lands. Usually the whole field is sprayed uniformly, while the distribution of weeds often is non-uniform. Often there are spots in a field where weed pressure is very low and has no significant effect...

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

    Directory of Open Access Journals (Sweden)

    J. Abdi

    2012-07-01

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

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

    International Nuclear Information System (INIS)

    Ashraf, M.Y.; Baig, N.A.

    1989-01-01

    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)

  12. EFFECT OF SOWING DATE AND WEED CONTROL METHOD ON THE GROWTH AND YIELD OF SOYBEAN

    Directory of Open Access Journals (Sweden)

    Nasrin Akter

    2016-06-01

    Full Text Available Sowing date and weed management play a significant role in determining soybean growth, development and seed yield. Results showed that different sowing date and weed control methods had significant effect on relative weed density, weed biomass, weed control efficiency, plant height, dry weight plant-1 and seed yield of soybean. Among the infested weed species in the experimental field the dominant weeds were Lindernia procumbens (44.78%, Echinochloa colonum (26.39% and Cynodon dactylon (16.30%. The results also revealed that early sowing (2 January brought about the highest seed yield (2.17 t ha-1 and sowing delay (1 February resulted in the lowest yield (1.64 t ha-1. Two times hand weeding (20 and 40 DAS controlled the weeds most effectively and led to highest seed yield (2.23 t ha-1 which was statistically similar (2.19 t ha-1 with herbicide application. Combination effect showed that the highest seed yield (2.50 t ha-1 was obtained from 2 January sowing when the crop was weeded by hand at 20 and 40 DAS.

  13. Broomrape weeds. Underground mechanisms of parasitism and associated strategies for their control: a review.

    Directory of Open Access Journals (Sweden)

    Monica eFernandez-Aparicio

    2016-02-01

    Full Text Available Broomrapes are plant-parasitic weeds which constitute one of the most difficult-to-control of all biotic constraints that affect crops in Mediterranean, central and eastern Europe, and Asia. Due to their physical and metabolic overlap with the crop, their underground parasitism, their achlorophyllous nature, and hardly destructible seed bank, broomrape weeds are usually not controlled by management strategies designed for non-parasitic weeds. Instead, broomrape are in a current state of intensification and spread due to lack of broomrape-specific control programs, unconscious introduction to new areas and may be decline of herbicide use and global warming to a lesser degree. We reviewed relevant facts about the biology and physiology of broomrape weeds and the major feasible control strategies. The points of vulnerability of some underground events, key for their parasitism such as crop-induced germination or haustorial development are reviewed as inhibition targets of the broomrape-crop association. Among the reviewed strategies are those aimed 1 to reduce broomrape seed bank viability, such as fumigation, herbigation, solarization and use of broomrape-specific pathogens; 2 diversion strategies to reduce the broomrape ability to timely detect the host such as those based on promotion of suicidal germination, on introduction of allelochemical interference, or on down-regulating host exudation of germination-inducing factors; 3 strategies to inhibit the capacity of the broomrape seedling to penetrate the crop and connect with the vascular system, such as biotic or abiotic inhibition of broomrape radicle growth, crop resistance to broomrape penetration either natural, genetically engineered or elicited by biotic- or abiotic-resistance-inducing agents and 4 strategies acting once broomrape seedling has bridged its vascular system with that of the host, aimed to impede or to endure the parasitic sink such as those based on the delivery of herbicides

  14. Broomrape Weeds. Underground Mechanisms of Parasitism and Associated Strategies for their Control: A Review

    Science.gov (United States)

    Fernández-Aparicio, Mónica; Reboud, Xavier; Gibot-Leclerc, Stephanie

    2016-01-01

    Broomrapes are plant-parasitic weeds which constitute one of the most difficult-to-control of all biotic constraints that affect crops in Mediterranean, central and eastern Europe, and Asia. Due to their physical and metabolic overlap with the crop, their underground parasitism, their achlorophyllous nature, and hardly destructible seed bank, broomrape weeds are usually not controlled by management strategies designed for non-parasitic weeds. Instead, broomrapes are in current state of intensification and spread due to lack of broomrape-specific control programs, unconscious introduction to new areas and may be decline of herbicide use and global warming to a lesser degree. We reviewed relevant facts about the biology and physiology of broomrape weeds and the major feasible control strategies. The points of vulnerability of some underground events, key for their parasitism such as crop-induced germination or haustorial development are reviewed as inhibition targets of the broomrape-crop association. Among the reviewed strategies are those aimed (1) to reduce broomrape seed bank viability, such as fumigation, herbigation, solarization and use of broomrape-specific pathogens; (2) diversion strategies to reduce the broomrape ability to timely detect the host such as those based on promotion of suicidal germination, on introduction of allelochemical interference, or on down-regulating host exudation of germination-inducing factors; (3) strategies to inhibit the capacity of the broomrape seedling to penetrate the crop and connect with the vascular system, such as biotic or abiotic inhibition of broomrape radicle growth and crop resistance to broomrape penetration either natural, genetically engineered or elicited by biotic- or abiotic-resistance-inducing agents; and (4) strategies acting once broomrape seedling has bridged its vascular system with that of the host, aimed to impede or to endure the parasitic sink such as those based on the delivery of herbicides via

  15. Controlling grass weeds on hard surfaces

    DEFF Research Database (Denmark)

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

    2012-01-01

    : Annual bluegrass, Poa annua L.; perennial ryegrass, Lolium perenne L. Resumen Se realizó un experimento en una superficie dura especialmente diseñada para estudiar el impacto de los intervalos de tiempo entre los tratamientos de quema con lanzallamas en la regeneración y producción de flores de dos...... malezas gramíneas. El objetivo de este experimento fue optimizar el control de Poa annua y Lolium perenne, ambas especies muy difíciles de controlar sin herbicidas. La biomasa aérea de 72 plantas por tratamiento se cosechó y los pesos secos se registraron en intervalos regulares para investigar cómo las...... plantas respondían a la quema. La regeneración de las malezas fue medida a través de la cosecha de la biomasa aérea dos semanas después del segundo tratamiento con fuego, que a su vez fueron realizados en diferentes intervalos de tiempo. Los tratamientos con fuego disminuyeron la biomasa de ambas especies...

  16. Effect of fertilizer in controlling weeds under intercropping of pearl ...

    African Journals Online (AJOL)

    Jane

    2011-07-25

    Jul 25, 2011 ... chemical fertilizers consumption, dry matter of weeds decreased. The least dry matter of weeds was obtained from the lack of fertilizer treatment (Table 5). These result showed that in the chemical fertilizer treatments, weeds as compared with crops produced the higher dry matter by absorbing nutrients ...

  17. 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. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Effects of nitrogen application method and weed control on corn yield and yield components.

    Science.gov (United States)

    Sepahvand, Pariya; Sajedi, Nurali; Mousavi, Seyed Karim; Ghiasvand, Mohsen

    2014-04-01

    The effects of nitrogen fertilizer application and different methods for weed control on yield and yield components of corn was evaluated in Khorramabad in 2011. The experiment was conducted as a split plot based on randomized complete block design in 3 replications. Nitrogen application was as main plot in 4 levels (no nitrogen, broadcasting nitrogen, banding nitrogen and sprayed nitrogen) and methods of weed control were in 4 levels (non-control weeds, application Equip herbicide, once hand control of weeds and application Equip herbicide+once time weeding) was as subplots. Result illustrated that effects of nitrogen fertilizer application were significant on grain and forage yield, 100 seeds weight, harvest index, grain number per row and cob weight per plant. Grain yield increased by 91.4 and 3.9% in application banding and broadcasting for nitrogen fertilizer, respectively, compared to the no fertilizer treatment. The results show improved efficiency of nitrogen utilization by banding application. Grain yield, harvest index, seed rows per cob, seeds per row and cob weight were increased by weed control. In the application of Equip herbicide+ hand weeding treatment corn grain yield was increased 126% in comparison to weedy control. It represents of the intense affects of weed competition with corn. The highest corn grain yield (6758 kg h(-1)) was related to the application banding of nitrogen fertilizer and Equip herbicide+once hand weeding.

  19. Planting pattern and weed control method influence on yield production of corn (Zea mays L.)

    Science.gov (United States)

    Purba, E.; Nasution, D. P.

    2018-02-01

    Field experiment was carried out to evaluate the influence of planting patterns and weed control methods on the growth and yield of corn. The effect of the planting pattern and weed control method was studied in a split plot design. The main plots were that of planting pattern single row (25cm x 60cm), double row (25cm x 25cm x 60cm) and triangle row ( 25cm x 25cm x 25cm). Subplot was that of weed control method consisted five methods namely weed free throughout the growing season, hand weeding, sprayed with glyphosate, sprayed with paraquat, and no weeding.. Result showed that both planting pattern and weed control method did not affect the growth of corn. However, planting pattern and weed control method significantly affected yield production. Yield resulted from double row and triangle planting pattern was 14% and 41% higher, consecutively, than that of single row pattern. The triangle planting pattern combined with any weed control method produced the highest yield production of corn.

  20. Impact of the timing and duration of weed control on the establishment of a rubber tree plantation.

    Science.gov (United States)

    Guzzo, Caio D; Carvalho, Leonardo B de; Giancotti, Paulo R F; Alves, Pedro L C A; Gonçalves, Elaine C P; Martins, José V F

    2014-03-01

    Rubber tree production is reduced by weeds that compete for environmental resources; therefore, the timing and duration of weed control influences weed interference. The objectives of this study were to evaluate the growth of rubber tree (Hevea brasiliensis) plants, to determine the critical period for weed control, and to evaluate the growth recovery of rubber trees that coexisted with weeds for different periods of time after planting. Two groups of treatments were established under field conditions in the first year of the investigation: one group contained crescent periods of weed infestation, while the other contained crescent periods of weed control, also including a weed-free check and a total weedy check. In the second year of the investigation, the weeds were totally controlled. Urochloa decumbens was the dominant weed (over 90% groundcover). Crop growth was greatly reduced due to the weed interference. Plant height decreased more rapidly than did any other characteristic. Plant height, leaf dry mass, and leaf area decreased by 99%, 97% and 96%, respectively, and were the most reduced characteristics. Plant height also recovered more rapidly than did any characteristic when the period of weed control was lengthened. However, stem dry mass increased by 750%, making it the most recovered characteristic. The critical period for weed control was between 4 and 9½ months after planting in the first year; however, the rubber trees showed an expressive growth recovery when the weeds were controlled throughout the second year.

  1. 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.

  2. Growth of Loblolly Pine Treated With Hexazinone, Sulfometuron Methyl, and Metsulfuron Methyl For Herbaceous Weed Control

    Science.gov (United States)

    J.L. Michael

    1985-01-01

    Aerial application of 0.25 pounds active ingredient per acre of sulfometuron methyl [Oust(TM), formerly DPX-5648] of 2.0 pounds of hexazinone [Velpar L. (TM)] postmergent in May 1982, resulted in good weed control. Weeds controlled on the silly clay coastal plain soil included pokweed (Phytolacca americana L.) rugweed (Ambrosia sp...

  3. Impact of mustard seed meal applications on direct-seeded cucurbits and weed control

    Science.gov (United States)

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

  4. Pelargonic acid for weed control in organic Vidalia sweet onion production

    Science.gov (United States)

    Cultivation using a tine weeder is a proven means to manage weeds in organic Vidalia® sweet onion production. If the initial cultivation is delayed, emerged weeds are not controlled by the tine weeder. In these cases, herbicides derived from natural products could be used to control the emerged we...

  5. 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...

  6. Weed control in yellow squash using sequential postdirected applications of pelargonic acid

    Science.gov (United States)

    Squash (Cucurbita pepo L.) producers would benefit from appropriate herbicides that can effectively provide season-long weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) during 2010 and 2011 to determine the impact of a naturally derived herbicide on weed control ef...

  7. Herbicides as weed control agents: state of the art: I. Weed control research and safener technology: the path to modern agriculture.

    Science.gov (United States)

    Kraehmer, Hansjoerg; Laber, Bernd; Rosinger, Chris; Schulz, Arno

    2014-11-01

    The purpose of modern industrial herbicides is to control weeds. The species of weeds that plague crops today are a consequence of the historical past, being related to the history of the evolution of crops and farming practices. Chemical weed control began over a century ago with inorganic compounds and transitioned to the age of organic herbicides. Targeted herbicide research has created a steady stream of successful products. However, safeners have proven to be more difficult to find. Once found, the mode of action of the safener must be determined, partly to help in the discovery of further compounds within the same class. However, mounting regulatory and economic pressure has changed the industry completely, making it harder to find a successful herbicide. Herbicide resistance has also become a major problem, increasing the difficulty of controlling weeds. As a result, the development of new molecules has become a rare event today. © 2014 American Society of Plant Biologists. All Rights Reserved.

  8. Herbicides as Weed Control Agents: State of the Art: I. Weed Control Research and Safener Technology: The Path to Modern Agriculture

    Science.gov (United States)

    Kraehmer, Hansjoerg; Laber, Bernd; Rosinger, Chris; Schulz, Arno

    2014-01-01

    The purpose of modern industrial herbicides is to control weeds. The species of weeds that plague crops today are a consequence of the historical past, being related to the history of the evolution of crops and farming practices. Chemical weed control began over a century ago with inorganic compounds and transitioned to the age of organic herbicides. Targeted herbicide research has created a steady stream of successful products. However, safeners have proven to be more difficult to find. Once found, the mode of action of the safener must be determined, partly to help in the discovery of further compounds within the same class. However, mounting regulatory and economic pressure has changed the industry completely, making it harder to find a successful herbicide. Herbicide resistance has also become a major problem, increasing the difficulty of controlling weeds. As a result, the development of new molecules has become a rare event today. PMID:25104723

  9. Opportunities and challenges for harvest weed seed control in global cropping systems.

    Science.gov (United States)

    Walsh, Michael J; Broster, John C; Schwartz-Lazaro, Lauren M; Norsworthy, Jason K; Davis, Adam S; Tidemann, Breanne D; Beckie, Hugh J; Lyon, Drew J; Soni, Neeta; Neve, Paul; Bagavathiannan, Muthukumar V

    2017-11-28

    The opportunity to target weed seeds during grain harvest was established many decades ago following the introduction of mechanical harvesting and the recognition of high weed-seed retention levels at crop maturity; however, this opportunity remained largely neglected until more recently. The introduction and adoption of harvest weed seed control (HWSC) systems in Australia has been in response to widespread occurrence of herbicide-resistant weed populations. With diminishing herbicide resources and the need to maintain highly productive reduced tillage and stubble-retention practices, growers began to develop systems that targeted weed seeds during crop harvest. Research and development efforts over the past two decades have established the efficacy of HWSC systems in Australian cropping systems, where widespread adoption is now occurring. With similarly dramatic herbicide resistance issues now present across many of the world's cropping regions, it is timely for HWSC systems to be considered for inclusion in weed-management programs in these areas. This review describes HWSC systems and establishing the potential for this approach to weed control in several cropping regions. As observed in Australia, the inclusion of HWSC systems can reduce weed populations substantially reducing the potential for weed adaptation and resistance evolution. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Weed control in dormant alfalfa (Medicago sativa L. with active ingredients’ metribuzin, imazetapyr and pronamide

    Directory of Open Access Journals (Sweden)

    Zvonko Pacanoski

    2017-03-01

    Full Text Available Field trials were conducted during 2008 – 2010 to evaluate weed control in dormant alfalfa (Medicago sativa L. with metribuzin, imazetapyr and pronamide. The weed population in all experimental years was consisted mainly of annual winter and spring grass and broadleaf weeds, and some perennial weeds. The number of weed species and weed density increased with the years of alfalfa growing, from second to the fourth year. Weed density in the untreated control plots was 201.0, 217.2 and 240.5 plants per m2 in 2008, 2009 and 2010, respectively. The most dominant weeds were Anthemis cotula, Capsell bursa-pastoris and Taraxacum officinale in 2008, Alopecurus myosuroides and Poa pratensis in 2009 and Millium vernale and Arabidopsis thaliana in 2010. Efficacy of herbicides in control of weeds was ranged of 91.8% (pronamide to 98.4% (metribuzin 1.0 kg*ha-1 in 2008, 93.1% (imazetapyr to 97.3% (metribuzin 1.0 kg*ha-1 in 2009 and 92.1% (imazetapyr to 97.3% (metribuzin 1.0 kg*ha-1 in 2010, respectively. Efficacy of herbicides in control of prevailing weeds during the 3 years field trial period was ranged of 48.5% to 100.0%. No visual alfalfa injured was determined by any rates during the experimental period, and consequently, none of the applied herbicides reduced first-harvest alfalfa yields. Alfalfa yield was markedly affected by herbicide efficacy in all experimental years, particularly in the second year, where yields of herbicide treatments were similar to that of the weed free control.

  11. Weed control methods effect on the hydraulic attributes of a Latosol

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Pires

    2017-01-01

    Full Text Available Weed management plays a key role in the minimization of soil physical degradation processes such as compaction and hydric erosion. Different weed control managements can induce distinct changes in soil structure. One important soil physical attribute used for the analysis of modifications in soil structure is the soil water retention curve (SWRC. The objective of this work was to verify the use of physico-hydrical attributes to understand the effect of weed control managements on soil structure. Two soil layers (0–0.05 and 0.10–0.15 m and six weed control managements divided into two groups were analyzed: I. no soil disturbance and ground cover (no weed control, post-emergence herbicide, mechanical mower; and II. soil disturbance and no ground cover (hand-hoe weeding, rotary tiller, pre-emergence herbicide. An area of native forest was used as reference. The results showed that the volumetric water capacity derived from the SWRC can be an interesting tool to evaluate the impact of weed control managements on soil structure. Evaluations of the air-filled porosity variation for different pressure heads also presented interesting findings. Distinct results of the weed control managements were found for the different depths analyzed in relation to the forest.

  12. 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

  13. Integrated Weed Management Strategies for Control of Hydrilla

    National Research Council Canada - National Science Library

    Nelson, Linda S; Shearer, Judy F

    2009-01-01

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

  14. Mulching methods impact on herb production and weed control in a certified organic production system

    Science.gov (United States)

    Weed control challenges for horticulture production are formidable; however, these challenges are even greater for those considering organic crop production. Black plastic as a weed barrier is widely used and effective. The expense associated with black plastic, as well as the ecological impact of...

  15. phosphate fertilizer and weed control effects on growth and yield of ...

    African Journals Online (AJOL)

    preferred customer

    plant, total biomass and grain yields of field pea were noted to phosphate fertilizer and weeding treatments. Application of ... interaction between applied phosphate fertilizer and weed control (P×W) significantly affected field pea grain yield and total .... availability pea, lentil, chickpea and faba bean grow best in soils with pH ...

  16. Density and dry weight of pigweed by various weed control methods ...

    African Journals Online (AJOL)

    This study evaluates effects of various weeds control methods and nitrogen fertilizer resources on density and dry weight of pigweed and the performance of corn forage as factorial in full random block design with 3 repetitions in research farm of Ferdowsi Mashhad University in 2014. The test treatments include weed ...

  17. Chemical Weed Control in a Two-Year-Old Walnut Planting

    Science.gov (United States)

    Gayne G. Erdmann; Leeroy Green

    1967-01-01

    Six herbicide mixtures were sprayed directly on broadleaf weeds and grasses competing with black walnut trees. Mixtures of papquat (1/2 lb/acre) with simazine (4 lb/acre) or atrazine (4 lb/acre), and amitrole (2 lb/acre) plus simazine (4 lb/acre) gave satisfactory weed control which resulted in significantly better tree height and diameter growth.

  18. Basamid® G for weed control in forest tree nurseries

    Science.gov (United States)

    Adam Muckenfuss; Bill Isaacs

    2006-01-01

    Basamid® G is a granular soil fumigant containing dazomet, which has activity on weeds, insects, nematodes, and diseases. Basamid® G was compared to methyl bromide:chloropicrin and was equally effective as a weed control material in forest tree nurseries. Pine and hardwood plantings were treated with both materials in replicated and nonreplicated trials...

  19. Rice Tolerance to Saflufenacil in Clomazone Weed Control Program

    Directory of Open Access Journals (Sweden)

    E. R. Camargo

    2011-01-01

    Full Text Available This research was conducted to evaluate (1 rice tolerance to saflufenacil applied preemergence (PRE and postemergence (POST and (2 the combination of saflufenacil and clomazone in light-textured soils. No injury from PRE application of saflufenacil was observed in 2009, and minimal injury for saflufenacil alone was observed in 2010. Injury as high as 68% was observed with combinations of 505 g ha−1 of clomazone applied PRE and 50 g ha−1 of saflufenacil applied POST in 2009 early evaluations. No interaction between clomazone and POST saflufenacil rates was observed in 2010. Rice injury intensified with increasing rates of saflufenacil applied POST. However, rice recovered with time for herbicide treatments applied PRE and POST in both years. Consequently, rice yield was not affected by any of the saflufenacil rates applied either PRE or POST in a clomazone weed control program.

  20. Effect of ecological management of weed control on economical income, yield and yield components of cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    A. Zare Feizabadi

    2016-04-01

    Full Text Available In order to compare of ecological management of weed control on economical income, yield and yield components of cotton (Gossypium hirsutum L., a Randomized Complete Block design with 12 treatments and four replications was conducted in Mahvelat of Khorasan Razavi province, Iran. Treatments consisted of weeding, harrowing, burning, two times weeding, weeding + harrowing, weeding + burning, harrowing + harrowing, harrowing + weeding, harrowing + burning, weeding+ harrowing+ burning, weed free and weedy as a check treatment. Investigated traits were plant height, number of boll in plant, 20 boll weight, 20 boll cotton lint weight, cotton lint yield per plant, cotton yield, number and biomass of weeds, outcome, net and gross income. The result showed that treatments had significant effect (p

  1. 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...

  2. Cover crop residue management for optimizing weed control

    NARCIS (Netherlands)

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

    2009-01-01

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

  3. Appraisal of some methods of weed control during initial ...

    African Journals Online (AJOL)

    which were clean-weeded two or four times per year or treated with paraquat four times per year than when plots were slashed two or four times per year. There was strong evidence to suggest that treatments which ensured a weed-free environment to the cocoa over a long period were favourable to girth increments in the ...

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

    Science.gov (United States)

    Dean Pearson; Yvette Ortega

    2009-01-01

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

  5. Efficacy evaluation of selected herbicides on weed control and productivity evaluation of Bt cotton in Punjab.

    Science.gov (United States)

    Singh, Kulvir; Rathore, Pankaj

    2015-07-01

    Field experiments were conducted during Kharif 2012 and 2013 to evaluate the efficacy of different herbicides for weed management in cotton. Highest seed cotton yield (3537.3 kg ha(-1)) was recorded in weed free plots followed by pendimethalin @1.0 kg a.i ha(-1) as Pre.em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage + one hoeing (3318.9 kg ha") owing to improved number of bolls per plant and boll weight. Statistically least yield was recorded underweedy check (1435.4 kg ha(-1)). Application of pyrithiobac sodium could not express any visible toxic effect on crop indicating its selectivity for cotton, although none of the tested new chemicals i.e., pyrithiobac sodium@ 62.5g a.i ha(-1) and quizalofopethyl @50g a.i ha(-1) when applied alone could not outperform the existing recommended chemicals for weed management. Yield losses to the extent of 6.2-59.4% were recorded due to weed competition. Weed control efficiency (WCE) was highest under weed free check (86.8%) followed by pendimethalin @1.0 kg a.i ha(-1) as Pre. em.+quizalofopethyl @50g a.i ha(-1), at 2-4 weed leaf stage + one hoeing (73.7%), whereas minimum values were for weedy check (24.7%). Though net returns (r94660 ha(-1)) were highest for weed free check but higher B:C ratio (2:11) was observed for pendimethalin @1.0 kg a.i ha(-1) as Pre em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage+one hoeing. Therefore, for reasons such as labor shortage besides their timely availability, using these herbicides in combination with cultural practices could be the practical solution foreconomically efficient and effective weed management.

  6. Biologia e manejo de plantas daninhas em áreas de plantio direto Weed biology and management in no-tillage areas

    Directory of Open Access Journals (Sweden)

    F.G. Gomes JR.

    2008-01-01

    Full Text Available Procurou-se relacionar alguns aspectos importantes da biologia e do manejo das plantas daninhas infestantes em áreas cultivadas sob sistema de plantio direto, com o objetivo de mostrar que a viabilidade deste plantio depende do controle eficiente das plantas daninhas. Nesse sistema de cultivo ocorrem algumas espécies de plantas daninhas comumente não observadas no sistema convencional, sendo essas constatações relacionadas ao não-revolvimento do solo, favorecendo o desenvolvimento de espécies de plantas daninhas perenes, e às alterações nas condições de temperatura e incidência de luz no interior do solo, influenciando os mecanismos de dormência das sementes de algumas espécies. A estratégia adequada para o controle das plantas daninhas em plantio direto exige conhecimento da dinâmica populacional do banco de sementes do solo e deve reunir métodos integrados de controle para reduzir o uso de herbicidas. A liberação de substâncias alelopáticas de algumas culturas de cobertura e o efeito supressor da camada de palha são medidas importantes para integrar ao controle químico das plantas daninhas. Entretanto, deve-se atentar para os efeitos negativos sobre algumas espécies de plantas cultivadas. As pesquisas na área de biologia das plantas daninhas e alelopatia das culturas de cobertura, associadas com a tecnologia de aplicação de herbicidas e a agricultura de precisão, poderão contribuir para a otimização do controle das plantas daninhas em áreas de plantio direto.Some important aspects of weed biology and control under no tillage are described to show that the viability of this system depends on weed control efficiently performed. Some of the weeds infesting this cropping system are present in much greater density under the conventional system, this being probably due to the little soil disturbance under no tillage systems, where the occurrence of perennial weeds is more feasible, and changes in the temperature and

  7. 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.

  8. Estimating economic thresholds for site-specific weed control using manual weed counts and sensor technology: an example based on three winter wheat trials.

    Science.gov (United States)

    Keller, Martina; Gutjahr, Christoph; Möhring, Jens; Weis, Martin; Sökefeld, Markus; Gerhards, Roland

    2014-02-01

    Precision experimental design uses the natural heterogeneity of agricultural fields and combines sensor technology with linear mixed models to estimate the effect of weeds, soil properties and herbicide on yield. These estimates can be used to derive economic thresholds. Three field trials are presented using the precision experimental design in winter wheat. Weed densities were determined by manual sampling and bi-spectral cameras, yield and soil properties were mapped. Galium aparine, other broad-leaved weeds and Alopecurus myosuroides reduced yield by 17.5, 1.2 and 12.4 kg ha(-1) plant(-1)  m(2) in one trial. The determined thresholds for site-specific weed control with independently applied herbicides were 4, 48 and 12 plants m(-2), respectively. Spring drought reduced yield effects of weeds considerably in one trial, since water became yield limiting. A negative herbicide effect on the crop was negligible, except in one trial, in which the herbicide mixture tended to reduce yield by 0.6 t ha(-1). Bi-spectral cameras for weed counting were of limited use and still need improvement. Nevertheless, large weed patches were correctly identified. The current paper presents a new approach to conducting field trials and deriving decision rules for weed control in farmers' fields. © 2013 Society of Chemical Industry.

  9. 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

  10. 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...

  11. Economics of Increasing Wheat Competitiveness as a Weed Control Weapon

    OpenAIRE

    Brennan, John P.; Lemerle, Deirdre; Martin, Peter J.

    2001-01-01

    Crop varieties that are more competitive with weeds offer a means of reducing dependency on herbicides. On the basis of trial results, economic analysis indicates that choosing crop varieties that have stronger competitive ability against weeds can provide a clear economic advantage for farmers. In this paper, the effect of changes in seeding rate on this economic advantage is explored. The question if whether it is economic to breed for greater competitive ability is addressed by examining t...

  12. Phytochemistry and Biological Properties of Burnet Weed (Sanguisorba spp.: A Review

    Directory of Open Access Journals (Sweden)

    Anestis KARKANIS

    2014-12-01

    Full Text Available Great burnet (Sanguisorba officinalis L. and small burnet (Sansguisorba minor Scop. are edible, perennial weeds widely distributed in the world. These are the most widespread Sanguisorba species. The bioactive components of Sanguisorba plants include phenolics (phenolic acids, flavonoids and neolignans and terpenoids. Large potential exists to use burnets as medicinal plants. Sanguisorba species are known to show anticancer properties, antioxidative, antimicrobial and antiviral activities. Also, Sanguisorba extracts show anti-Alzheimer and anti-inflammatory properties. Small burnet extracts could also be a useful alternative to synthetic fungicides for crop production. This review focuses on biological activities of Sanguisorba extracts and emphasizing their potential applications in pharmaceutical areas.

  13. Non-chemical Control of Root Parasitic Weeds with Biochar

    Directory of Open Access Journals (Sweden)

    Hanan Eizenberg

    2017-06-01

    Full Text Available This study tested whether soil-applied biochar can impact the seed germination and attachment of root parasitic weeds. Three hypotheses were evaluated: (i biochar adsorbs host-exuded signaling molecules; (ii biochar activates plants’ innate system-wide defenses against invasion by the parasite; and (iii biochar has a systemic influence on the amount of seed germination stimulant produced or released by the host plant. Three types of experiments were performed: (I pot trials with tomato (Solanum lycopersicum infested with Phelipanche aegyptiaca PERS. (Egyptian broomrape and three different types of biochar at concentrations ranging from 0 to 1.5% weight, wherein tomato plant biomass, P. aegyptiaca biomass, and number of P. aegyptiaca-tomato root attachments were quantified; (II split-root biochar/no-biochar experiments under hydroponic growing conditions performed in polyethylene bags with tomato plant rootings, wherein P. aegyptiaca seed germination percentage and radicle attachment numbers were quantified; and (III germination trials, wherein the effect of biochar adsorption of GR-24 (artificial germination stimulant on P. aegyptiaca seed germination was quantified. Addition of biochar to the pot soil (Experiment I resulted in lower levels of P. aegyptiaca infection in the tomato plants, mainly through a decrease in the number of P. aegyptiaca attachments. This led to improved tomato plant growth. In Experiment II, P. aegyptiaca seed germination percentage decreased in the biochar-treated root zone as compared with the no-biochar control root zone; P. aegyptiaca radicle attachment numbers decreased accordingly. This experiment showed that biochar did not induce a systemic change in the activity of the stimulant molecules exuded by the tomato roots, toxicity to the radicles, or a change in the ability of the radicles to penetrate the tomato roots. The major cause for the decrease in germination percentage was physical adsorption of the

  14. 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.

  15. Mechanical weed control on small-size dry bean and its response to cross-flaming

    Energy Technology Data Exchange (ETDEWEB)

    Martelloni, L.; Frasconi, C.; Fontanelli, M.; Raffaelli, M.; Peruzzi, A.

    2016-11-01

    Dry bean (Phaseolus vulgaris L.) can be a profitable crop for farmers; however controlling weeds effectively without a decrease in yield remains a problem. An example where mechanical weed control is difficult to conduct is dry bean ‘Toscanello’, which is a small sized high-income niche product growing low to the ground. Concerning intra-row weed control, also flame weeding could be an opportunity but the dry bean heat tolerance needs to be studied. The aims of this research were to study the weed control efficacy of a spring-tine harrow and an inter-row cultivator in this bean variety, and to test the tolerance of dry bean cultivated under weed-free conditions to cross-flaming applied with different liquefied petroleum gas (LPG) doses. Flame weeding was applied at BBCH 13 and BBCH 14 bean growth stages by pairs of burners producing direct double flame acting into the intra-row space, with bean plants placed in the middle. The results suggest that the spring-tine harrow used two times at BBCH 13 and 14, respectively, lead to a yield similar to that of the weedy control. The inter-row cultivator could be an opportunity for small-sized dry bean crops producers, enabling them to obtain a similar yield compared to the hand-weeded control. Concerning the bean tolerance to cross-flaming the results showed that bean flamed at BBCH 13 stage had little tolerance to cross-flaming. Bean flamed at BBCH 14 stage was tolerant until an LPG dose of 39 kg/ha, giving yield responses similar to those observed in the non-flamed control. (Author)

  16. Ecophysiological responses of a young blue gum (Eucalyptus globulus) plantation to weed control.

    Science.gov (United States)

    Eyles, Alieta; Worledge, Dale; Sands, Peter; Ottenschlaeger, Maria L; Paterson, Steve C; Mendham, Daniel; O'Grady, Anthony P

    2012-08-01

    Early weed control may improve the growth of forest plantations by influencing soil water and nutrient availability. To understand eucalypt growth responses to weed control, we examined the temporal responses of leaf gas-exchange, leaf nitrogen concentration (N) and water status of 7-month-old Eucalyptus globulus L. trees in a paired-plot field trial. In addition, we monitored the growth, leaf N and water status of the competing vegetation in the weed treatment. By the end of the 11-month experiment, complete weed control (WF treatment) of largely woody competitors increased the basal diameter of E. globulus by 14%. As indicated by pre-dawn water potentials of > - 0.05 MPa, interspecies competition for water resources was minimal at this site. In contrast, competition for N appeared to be the major factor limiting growth. Estimations of total plot leaf N (g m(-2) ground) showed that competing vegetation accounted for up to 70% of the total leaf N at the start of the trial. This value fell to 15% by the end of the trial. Despite increased leaf N(area) in WF trees 5 months after imposition of weed control, the photosynthetic capacity (A(1500)) of E. globulus was unaffected by treatment suggesting that the growth gains from weed control were largely unrelated to changes in leaf-level photosynthesis. Increased nutrient availability brought about by weed control enabled trees to increase investment into leaf-area production. Estimates of whole-tree carbon budget based on direct measurements of dark respiration and A(1500) allowed us to clearly demonstrate the importance of leaf area driving greater productivity following early weed control in a nutrient-limited site.

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

    International Nuclear Information System (INIS)

    Uddin, M.K.; Ismail, M.R.; Juraimi, A.S.; Hamdani, S.A.

    2014-01-01

    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)

  18. Cruciferous weeds in oil seed rape – appearance and control

    Directory of Open Access Journals (Sweden)

    Klingenhagen, Günter

    2014-02-01

    Full Text Available Different cruciferous weeds were drilled in autumn 2011 and 2012 in a field near Münster. Beside common species like hedge mustard (Sisymbrium officinale Scop., shepherd`s purse (Capsella bursa-pastoris, pennycress (Thlaspiarvense, tall hedge mustard (Sisymbrium loeselii and flixweed (Descurainia sophia, we tried to establish weeds that are not common on arable land in Germany until now. These were: Yellow rocket (Barbarea vulgaris, hoary cress (Lepidium draba and Turkish rocket (Bunias orientalis. In autumn 2011 emergence of the sown weeds was poor. In the second year of experiment we got good emergence of the named weeds excluding hoary cress (Lepidium draba. In autumn 2011 and 2012 different herbicidecombinations were applied across the stripes. The best results were achieved with Colzor Trio (clomazone + dimethachlor + napropamid which was applied in pre-emergence state, a spray sequence Butisan Gold (metazachlor + quinmerac + dimethenamid-P applied in pre-emergence followed by Salsa (ethametsulfuronmethyl + Trend (adjuvant in post-emergence and Clearfield-Vantiga (metazachlor + quinmerac + imazamox + Dash (adjuvant, also applied in post-emergence state of the weeds.

  19. Greenhouse and field evaluation of isoxaflutole for weed control in maize in China.

    Science.gov (United States)

    Zhao, Ning; Zuo, Lan; Li, Wei; Guo, Wenlei; Liu, Weitang; Wang, Jinxin

    2017-10-04

    Greenhouse and field studies were conducted to provide a reference for pre-emergence (PRE) application of isoxaflutole on maize in China. In greenhouse study, the isoxaflutole PRE application at 30 g active ingredient (a.i.) ha -1 could effectively control large numbers of weeds, especially some large-seeded broadleaves, tested in this study. The tolerance results indicated 21 maize hybrids showed different responses to isoxaflutole under greenhouse conditions. In 2015 and 2016, field experiments were conducted to determine and compare the weed control efficacy and safety to Zhengdan 958 maize with 6 herbicide treatments. In both years, isoxaflutole PRE at 100 to 250 g a.i. ha -1 was sufficient to provide satisfactory full-season control of the dominant common broadleaf and grass weeds in the field. Temporary injury to maize was observed with isoxaflutole treatments of 125, 150, and 250 g a.i. ha -1 in both years, but plants recovered within 4 to 6 wk. To maximize maize yield and provide satisfactory weed control, a range of 100 to 150 g a.i. ha -1 of isoxaflutole is recommended, depending on the soil characteristics, weather, and weed species present at the experimental site. Based on the results, isoxaflutole PRE has good potential for weed control in maize in China.

  20. Nematodes and Weeds Control Effects of Pueraria phaseoloides ...

    African Journals Online (AJOL)

    FIRST USER

    use systems (LUS) comprising 4–5 year-old bush fallow, dominated by Chromolaena odorata (L.) R. M. King & H. Rob, and a 20 year-old secondary .... soil:water suspension. Exchangeable basic .... Pueraria phaseoloides in both bush and forest LUS had the least biomass of broad leaf weeds, significantly lower than in F.

  1. Nematodes and Weeds Control Effects of Pueraria phaseoloides ...

    African Journals Online (AJOL)

    The yield of plantain (Musa spp., AAB Simmonds) declines sharply after 1–2 years of cropping in West and Central Africa, due mainly to weeds and nematodes. A trial was carried out from January 2002 to October 2005 under two land-use systems (LUS) comprising 4–5 year-old bush fallow, dominated by Chromolaena ...

  2. Effect of fertilizer in controlling weeds under intercropping of pearl ...

    African Journals Online (AJOL)

    The plants were planted as replacement method. The results showed that the lowest dry matter for crops and total dry matter of weeds was achieved from 50% fertilizer + 50% manure treatment. Also, the highest total dry matter of millet and bean was obtained from this treatment. The highest dry matter of millet and bean was ...

  3. 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…

  4. Robotic weeding and automated weed measurements

    DEFF Research Database (Denmark)

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

    2003-01-01

    The goal of decreasing herbicide usage has so far focused on reducing the herbicide dosage or replacing chemical weed control by hoeing and harrowing. The conventional weed control strategy is to apply the same dose of herbicide or the same intensity of hoeing and harrowing in the whole field....... 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....

  5. Effect of Row Intercropping Patterns on Yield, Yield Components, and Weed Control of Fenugreek (Trigonellafoenumgreacum L. and Anise (Pimpinellaanisum L.

    Directory of Open Access Journals (Sweden)

    F Mardani

    2016-02-01

    Full Text Available Introduction Due to population growth and food shortage agricultural production is on increasing demand. In this order increasing cultivation area and yield per unit area are two ways of obtaining higheragricultural production (20. There is another important way that without incurring additional costs and use of water and fertilizer could result in higher production. This approach is increasing agricultural production per unit area by growing more than one crop in a year. Intercropping will be successful when competition for sources issless than competition within a species. Plants in the mixture can be chosen in a way that a species benefits from environmental changes caused by other species in mixed cultures directly (7, 15. Intercropping inhibits the growth and development of weeds and leads to increased production. Since the system will reduce the pesticide use, environmental pollution will be also less proportionally (37. Materials and Methods In order to evaluate the yield, yield components and potential weeds control under intercropping fenugreek and anise, an experiment was carried out based on a randomized complete block design with three replicationsat the Agricultural Research Field of Yasouj University during growing season of 2012-2013. Treatments included pure cultures of fenugreek and anise, single-row, double-row and three-tier intercropping of fenugreek and anise at no weed control and weed control conditions. Results and Discussion The results showed that different intercropping treatments had significant effects on pod number per plant, grain weight and grain and biological yield of fenugreek and also, on number of lateral branches, number of grains per plant and grain and biological yield of anise. There were nosignificant effects on plant height, number of lateral branches, number of grain per pod, harvest index of fenugreek, as well as plant height, number of umbel let per plant, seed weight and harvest index of anise. The

  6. Germination biology of Hibiscus tridactylites in Australia and the implications for weed management

    Science.gov (United States)

    Chauhan, Bhagirath Singh

    2016-05-01

    Hibiscus tridactylites is a problematic broadleaf weed in many crops in Australia; however, very limited information is available on seed germination biology of Australian populations. Experiments were conducted to evaluate the effect of environmental factors on germination and emergence of H. tridactylites. Germination was stimulated by seed scarification, suggesting the inhibition of germination in this species is mainly due to the hard seed coat. Germination was not affected by light conditions, suggesting that seeds of this species are not photoblastic. Germination was higher at alternating day/night temperatures of 30/20 °C (74%) and 35/25 °C (69%) than at 25/15 °C (63%). Moderate salinity and water stress did not inhibit germination of H. tridactylites. Seedling emergence of H. tridactylites was highest (57%) for the seeds buried at a 2 cm depth in the soil; 18% of seedlings emerged from seeds buried at 8 cm but no seedlings emerged below this depth. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence could serve an important tool for managing H. tridactylites.

  7. Assessing the impact of revegetation and weed control on urban sensitive bird species.

    Science.gov (United States)

    Archibald, Carla L; McKinney, Matthew; Mustin, Karen; Shanahan, Danielle F; Possingham, Hugh P

    2017-06-01

    Nature in cities is concentrated in urban green spaces, which are key areas for urban biodiversity and also important areas to connect people with nature. To conserve urban biodiversity within these natural refugia, habitat restoration such as weed control and revegetation is often implemented. These actions are expected to benefit biodiversity, although species known to be affected by urbanization may not be interacting with restoration in the ways we anticipate. In this study, we use a case study to explore how urban restoration activities impact different bird species. Birds were grouped into urban sensitivity categories and species abundance, and richness was then calculated using a hierarchical species community model for individual species responses, with "urban class" used as the hierarchical parameter. We highlight variable responses of birds to revegetation and weed control based on their level of urban sensitivity. Revegetation of open grassy areas delivers significant bird conservation outcomes, but the effects of weed control are neutral or in some cases negative. Specifically, the species most reliant on remnant vegetation in cities seem to remain stable or decline in abundance in areas with weed control, which we suspect is the result of a simplification of the understorey. The literature reports mixed benefits of weed control between taxa and between locations. We recommend, in our case study site, that weed control be implemented in concert with replanting of native vegetation to provide the understory structure preferred by urban sensitive birds. Understanding the impacts of revegetation and weed control on different bird species is important information for practitioners to make restoration decisions about the allocation of funds for conservation action. This new knowledge can be used both for threatened species and invasive species management.

  8. Agronomic evaluation of cowpea as a function of weed control with herbicides and different combinations

    Directory of Open Access Journals (Sweden)

    Wando Wilson de Oliveira Souza

    2016-12-01

    Full Text Available ABSTRACT Cultivation of the cowpea is important in various regions of Brazil, but competition from weeds is one of the factors which limit productivity. The aim of this study therefore was to evaluate the pre-plant selectivity and efficiency of different herbicides, and combinations of herbicides, in the cowpea [Vigna unguiculata (L. Walp.]. An experiment was carried out in a randomised block design, in lots split over time and with three replications, using a 4 x 7 factorial scheme, where the treatments consisted of: glyphosate, glyphosate + imazethapyr, glyphosate + flumioxazin, glyphosate + imazethapyr + flumioxazin, glyphosate + ready mix (imazethapyr & flumioxazin, and two control treatments (one with no weeding and one with manual weeding. The treatments were evaluated in combination with four different sowing times, i.e. immediately after application of the herbicides, and at five, ten and fifteen days after application (DAA. The combination of glyphosate + flumioxazin at 15 DAA, gave the highest mean productivity, 1,105.32 kg ha-1, followed by manual weeding with 1,027.37 kg ha-1. The herbicide mixtures of glyphosate + imazethapyr + flumioxazin caused phyto-toxicity in the cowpea crop, limiting the production components. The best strategies for weed control in this crop are manual weeding with seeding at 10 DAA, as well as the application of a glyphosate + flumioxazin mixture with seeding at 15 DAA.

  9. Selectivity and weed control efficacy of some herbicides applied to sprinkler irrigated rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Cavero, J.; Zaragoza, C.; Cirujeda, A.; Anzalone, A.; Faci, J. M.; Blanco, O.

    2011-07-01

    Sprinkler irrigation can reduce the irrigation water needed to grow rice. However, most available information on weed control with herbicides is related to flood irrigated rice because this is the main growing method. Field experiments were conducted at Zaragoza (Spain) during two years to study weed control and tolerance of sprinkler irrigated rice to several herbicides. The main weeds were Atriplex prostrata Boucher ex DC., Cyperus rotundus L., Echinochloa crus-galli (L.) Beauv. and Sonchus oleraceus L. Rice cv Guadiamar was tolerant to preemergence (PRE) application of clomazone at 0.36 kg ha{sup -}1 and oxadiazon at 0.5 kg ha{sup -}1. PRE application of pendimethalin at 1.32 kg ha{sup -}1 combined with clomazone at 0.36 kg ha{sup -}1 decreased rice yield. Postemergence (POST) application of bentazon at 1.6 kg ha{sup -}1 + MCPA at 0.25 kg ha{sup -}1 did not injure rice but POST application of azimsulfuron at 0.025 kg ha{sup -}1 produced visual crop injury. Only treatments that controlled grassy weeds since rice was planted and by more than 80% at harvest time lead to acceptable rice yield (> 5,000 kg ha{sup -}1). Clomazone applied PRE at 0.36 kg ha{sup -}1 provided good control of grassy weeds (> 80%) and the highest rice yield, so it is recommended as a selective and efficacious PRE treatment for weed control of annual weeds in sprinkler irrigated rice. The perennial purple nutsedge was difficult to control at high plant densities (> 150 plants m{sup -}2) and the recommended herbicide is azimsulfuron applied at POST at 0.02 kg ha{sup -}1. (Author) 37 refs.

  10. Plant genotype effects on a host specific thrips and the impact on biological control

    Science.gov (United States)

    A promising thrips, Pseudophilothrips ichini (Phlaeothripidae) has been considered for biological control of the invasive weed Brazilian pepper Schinus terebinthifolius. This thrips was originally collected from a southern region of Brazil where it was frequently found associated with significant da...

  11. Host Specificity of Argopistes tsekooni (Coleoptera: Chrysomelidae), a Potential Biological Control Agent of Chinese Privet

    Science.gov (United States)

    Yan Zhuo Zhang; James Hanula; Jiang Hua Sun

    2008-01-01

    Chinese privet, Ligustrum sinense Lour., is a perennial semi-evergreen shrub that is aserious invasive weed in the United States. Classical biological control offers the best hope forcontrolling it in an economic, effective, and persistent way. Host...

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

    Directory of Open Access Journals (Sweden)

    A. Ebrahimpour Lish

    2017-02-01

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

  13. The Effect of Seed Priming and Weeds Control on Yield, Yield Components and Harvest Index of Corn

    Directory of Open Access Journals (Sweden)

    A Mehdizadeh

    2012-12-01

    Full Text Available In order to investigate effect of on-farm seed priming and weeds control on yield, yield components and harvest index of a corn hybrid, an experiment was arranged factorialy in a complete randomized block design with three replications in 2010. In the experiment investigated two factors, priming (in four levels including no-primed, priming with urea solution, priming with zinc sulfate solution and priming with tap water and weed control in three levels (including no-weeding, weeding in 20 days after planting and weeding in 20 and 40 days after planting. For on-farm priming the seeds were placed for 16 hours in solutions of urea (6 g/l, zinc sulfate (0.34 g/l and tap water, and planted after surface drying in the soil. The results showed that weed control caused an increase in grain numbers in corn and seed priming with urea solution in once weed control had higher 100 grains weight. Priming treatments with urea and zinc sulfate solution showed the highest grain yield and had no significant difference at one and two-times weeds control after planting, no significant difference was between zinc sulfate priming with one weed control and no- primed with two-times weed control. That priming with zinc sulfate solution could decrease weed interference and its control costs by increasing corn competition ability. Generally in all of no-weed control plots except in primed with zinc sulfate solution the lowest grain yield was obtained. Also harvest index was highest in plants that was primed by tap water.

  14. A combined flamer-cultivator for weed control during the harvesting season of asparagus green spears

    Directory of Open Access Journals (Sweden)

    Luisa Martelloni

    2017-07-01

    Full Text Available Weed competition during spears harvesting reduces asparagus yields. The application of herbicides during this period is illegal, and alternative non-chemical practices are needed. This research tested the effectiveness and efficiency of a custom-built combined flamer-cultivator to control weeds (both in the inter- and intra- spears production bands during the spears harvest season. It also analysed the effects of various liquefied petroleum gas (LPG doses on total asparagus yield, mean spear weight, and total number of marketable spears. In both years, the asparagus spears were generally not damaged by flame weeding using LPG doses of between 43 to 87 kg/ha. The same LPG doses were effective in controlling weeds, showing the same total marketable yields as the weed-free control. At high LPG doses (e.g. 130 and 260 kg/ha, yields decreased as a consequence of the damage caused to the spears, resulting in a lower number of marketable spears. Flaming did not affect the mean spear weight, and can be applied repeatedly during harvesting to maintain the weeds at a level that does not lead to a yield reduction. The repeated use of the combined flamer-cultivator (every seven days led to higher yields than plots where weed control was not conducted. The new machine can be used in a period when herbicides are not possible. Flaming could be introduced by asparagus producers as an alternative, or in addition to herbicides applied in the pre-emergence and post-harvest of spears.

  15. 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.

  16. 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.

  17. 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...

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

    International Nuclear Information System (INIS)

    Swamy, P.M.

    1998-01-01

    Absorption and translocation of 14 C-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)

  19. Biological control agent for mosquito larvae: Review on the killifish ...

    African Journals Online (AJOL)

    Jane

    2011-08-15

    Aug 15, 2011 ... Biological control of mosquito larvae by using fish has shown many advantages over ... number of malaria cases in India that has been reduced from 75 million to 150,000 and deaths from 750,000 to ... aquatic weeds and G. affinis on the mosquito larvae. In addition to that G. affinis has some adverse effects ...

  20. Effect of host-plant genotypes on the performance of three candidate biological control agents of Schinus terebinthifolius in Florida.

    Science.gov (United States)

    Brazilian pepper is a weed in Florida, California and Hawaii that originates from South America. In Florida we have found two distinct types of Brazilian pepper plant and a hybrid between these two types. To control this weed, three biological control agents are being evaluated from Brazil. These ar...

  1. Irrigation and weed control alter soil microbiology and nutrient availability in North Carolina Sandhill peach orchards.

    Science.gov (United States)

    Zhang, Yi; Wang, Liangju; Yuan, Yongge; Xu, Jing; Tu, Cong; Fisk, Connie; Zhang, Weijian; Chen, Xin; Ritchie, David; Hu, Shuijin

    2018-02-15

    Orchard management practices such as weed control and irrigation are primarily aimed at maximizing fruit yields and economic profits. However, the impact of these practices on soil fertility and soil microbiology is often overlooked. We conducted a two-factor experimental manipulation of weed control by herbicide and trickle irrigation in a nutrient-poor peach (Prunus persica L. cv. Contender) orchard near Jackson Springs, North Carolina. After three and eight years of treatments, an array of soil fertility parameters were examined, including soil pH, soil N, P and cation nutrients, microbial biomass and respiration, N mineralization, and presence of arbuscular mycorrhizal fungi (AMF). Three general trends emerged: 1) irrigation significantly increased soil microbial biomass and activity, 2) infection rate of mycorrhizal fungi within roots were significantly higher under irrigation than non-irrigation treatments, but no significant difference in the AMF community composition was detected among treatments, 3) weed control through herbicides reduced soil organic matter, microbial biomass and activity, and mineral nutrients, but had no significant impacts on root mycorrhizal infection and AMF communities. Weed-control treatments directly decreased availability of soil nutrients in year 8, especially soil extractable inorganic N. Weed control also appears to have altered the soil nutrients via changes in soil microbes and altered net N mineralization via changes in soil microbial biomass and activity. These results indicate that long-term weed control using herbicides reduces soil fertility through reducing organic C inputs, nutrient retention and soil microbes. Together, these findings highlight the need for alternative practices such as winter legume cover cropping that maintain and/or enhance organic inputs to sustain the soil fertility. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Are herbicides a once in a century method of weed control?

    Science.gov (United States)

    Davis, Adam S; Frisvold, George B

    2017-11-01

    The efficacy of any pesticide is an exhaustible resource that can be depleted over time. For decades, the dominant paradigm - that weed mobility is low relative to insect pests and pathogens, that there is an ample stream of new weed control technologies in the commercial pipeline, and that technology suppliers have sufficient economic incentives and market power to delay resistance - supported a laissez faire approach to herbicide resistance management. Earlier market data bolstered the belief that private incentives and voluntary actions were sufficient to manage resistance. Yet, there has been a steady growth in resistant weeds, while no new commercial herbicide modes of action (MOAs) have been discovered in 30 years. Industry has introduced new herbicide tolerant crops to increase the applicability of older MOAs. Yet, many weed species are already resistant to these compounds. Recent trends suggest a paradigm shift whereby herbicide resistance may impose greater costs to farmers, the environment, and taxpayers than earlier believed. In developed countries, herbicides have been the dominant method of weed control for half a century. Over the next half-century, will widespread resistance to multiple MOAs render herbicides obsolete for many major cropping systems? We suggest it would be prudent to consider the implications of such a low-probability, but high-cost development. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. 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

  4. What do farmers' weed control decisions imply about glyphosate resistance? Evidence from surveys of US corn fields.

    Science.gov (United States)

    Wechsler, Seth J; McFadden, Jonathan R; Smith, David J

    2018-05-01

    The first case of glyphosate-resistant weeds in the United States was documented in 1998, 2 years after the commercialization of genetically engineered herbicide-resistant (HR) corn and soybeans. Currently, over 15 glyphosate-resistant weed species affect US crop production areas. These weeds have the potential to reduce yields, increase costs, and lower farm profitability. The objective of our study is to develop a behavioral model of farmers' weed management decisions and use it to analyze weed resistance to glyphosate in US corn farms. On average, we find that weed control increased US corn yields by 3700 kg ha -1 (worth approximately $US 255 ha -1 ) in 2005 and 3500 kg ha -1 (worth approximately $US 575 ha -1 ) in 2010. If glyphosate resistant weeds were absent, glyphosate killed approximately 99% of weeds, on average, when applied at the label rate in HR production systems. Average control was dramatically lower in states where glyphosate resistance was widespread. We find that glyphosate resistance had a significant impact on weed control costs and corn yields of US farmers in 2005 and 2010. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  5. 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...

  6. Biology, host specificity tests, and risk assessment of the sawfly Heteroperreyia hubrichi, a potential biological control agent of Schinus terebinthifolius in Hawaii

    Science.gov (United States)

    Abstract. Heteroperreyia hubrichi Malaise (Hymenoptera: Pergidae), a foliage feeding sawfly of Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae), was studied to assess its suitability as a classical biological control agent of this invasive weed in Hawaii. Nochoice host-specificity tests we...

  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. Ecologically sustainable weed management

    DEFF Research Database (Denmark)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne

    2016-01-01

    Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade, and gre......Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade...... strategies with multiple complementary tactics, developing crop genotypes for enhanced weed suppression, and tailoring management strategies to better accommodate variability in weed spatial distributions. In all three cases, proof-of-concept has long been demonstrated and considerable scientific innovations...

  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. Ecologically sustainable weed management

    NARCIS (Netherlands)

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

    2016-01-01

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

  12. 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...

  13. Weed Control and Seedling Performance Using Oust, Velpar, and Velpar+Oust Impregnated Diammonium Phosphate

    Science.gov (United States)

    J.L. Yeiser

    2002-01-01

    Technology that combines herbicide and fertilizer into one treatment thereby reducing application costs while enhancing growth is needed. Four clean and well-prepared sites in TX, MS, and AL were tested. Study objectives were to evaluate the effectiveness of diammonium phosphate (DAP) impregnated with Oust, Velpar, or Velpar+Oust for herbaceous weed control and newly...

  14. 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

    , power take-off driven implements with rotating weeding devices demonstrated similar control efficacies against a mixed stand composing C. arvense, Tussilago farfara, Elytrigia repens and Artemisia vulgaris. One pass was conducted a week after barley harvest followed by another pass 3 weeks later...

  15. Effects of weed control and cow dung manure on growth indices of ...

    African Journals Online (AJOL)

    Field trials were conducted during the 2006, 2007 and 2008 rainy seasons at the Institute for Agricultural Research farm Samaru, in the Northern guinea savanna zone of Nigeria to evaluate the effects of weed control and cow dung manure treatments on growth of quality protein maize. The trials consisted of factorial ...

  16. Phosphate fertilizer and weed control effects on growth and yield of ...

    African Journals Online (AJOL)

    Soil acidity and the associated low phosphorus availability and poor crop management practices are among the major factors constraining field pea productivity in the highlands of Ethiopia. The effect of phosphate fertilizer and weed control on yield and yield components of field pea (Pisum sativum L.) were studied on ...

  17. Effect of oil palm sludge on cowpea nodulation and weed control in ...

    African Journals Online (AJOL)

    A field trial was conducted at the Rivers State University of Science and Technology Research and Training farm Port Harcourt to test the effect of oil palm sludge on cowpea nodulation and weed control. The cultivars of cowpea used were Dan Kano, Bornu local and Sokoto local while the oil palm sludge levels applied ...

  18. Evaluating subsoiling and herbaceous weed control on shortleaf pine planted in retired farm land

    Science.gov (United States)

    John D. Kushla

    2010-01-01

    In March 2005, shortleaf pine was planted on retired fields of the Mississippi Agriculture and Forestry Experiment Station in Holly Springs. The objectives were to evaluate subsoiling and herbaceous weed control on first year seedling stocking, survival, and size. First year seedling measurements were made on stocking, survival, and size. Only results for first year...

  19. Split-season herbaceous weed control for full-season seedling performance

    Science.gov (United States)

    Jimmie L. Yeiser; Andrew W. Ezell

    2010-01-01

    Results from four loblolly pine (Pinus taeda L.) sites, one in each of MS and TX in 2001 and again in 2002, are presented. Twelve herbicide treatments and an untreated check were tested. Herbicide treatments were applied early (mid-March), late (mid-May), both timings, or not at all to achieve, early- late-, full-season, or no weed control. When...

  20. 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...

  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. 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 ...

  3. Impact of weed control on arbuscular mycorrhizal fungi in a tropical agroecosystem: a long-term experiment.

    Science.gov (United States)

    Ramos-Zapata, José A; Marrufo-Zapata, Denis; Guadarrama, Patricia; Carrillo-Sánchez, Lilia; Hernández-Cuevas, Laura; Caamal-Maldonado, Arturo

    2012-11-01

    Cover crop species represent an affordable and effective weed control method in agroecosystems; nonetheless, the effect of its use on arbuscular mycorrhizal fungi (AMF) has been scantily studied. The goal of this study was to determine root colonization levels and AMF species richness in the rhizosphere of maize plants and weed species growing under different cover crop and weed control regimes in a long-term experiment. The treatment levels used were (1) cover of Mucuna deeringian (Muc), (2) "mulch" of Leucaena leucocephala (Leu), (3) "mulch" of Lysiloma latisiliquum (Lys), (4) herbicide (Her), (5) manual weeding (CD), (6) no weeding (SD), and (7) no maize and no weeding (B). A total of 18 species of AMF belonging to eight genera (Acaulospora, Ambispora, Claroideoglomus, Funneliformis, Glomus, Rhizophagus, Sclerocystis, and Scutellospora) were identified from trap cultures. Muc and Lys treatments had a positive impact on AMF species richness (11 and seven species, respectively), while Leu and B treatments on the other hand gave the lowest richness values (six species each). AMF colonization levels in roots of maize and weeds differed significantly between treatment levels. Overall, the use of cover crop species had a positive impact on AMF species richness as well as on the percentage of root colonized by AMF. These findings have important implications for the management of traditional agroecosystems and show that the use of cover crop species for weed control can result in a more diverse AMF community which should potentially increase crop production in the long run.

  4. Biological parameters and fertility life table of Aphis forbesi Weed, 1889 (Hemiptera: Aphididae on strawberry

    Directory of Open Access Journals (Sweden)

    E. S. Araujo

    Full Text Available Abstract This study provides the first contribution of the biology and life table of Aphis forbesi Weed, 1889 (Hemiptera: Aphididae, an important strawberry pest throughout the world. This species lives in the crown and leaf petioles of the plant. It is difficulty to rear this species in laboratory due to protocooperation with ants observed only in the field. We studied the life cycle of A. forbesi on the leaves of the Albion strawberry cultivar at 25 ± 2 °C, 60 ± 10% relative humidity, and a 12-h photophase. The experiment was randomised with 100 replicates. The parameters of the fertility life table were calculated using TabVida. In the population studied, 25% and 46% had four and three instars, respectively. A mean of 1.43 nymphs per female per day was generated. The mean reproductive period was seven days and the mean longevity was 10 days. In every 11 days there is a generation of A. forbesi, where each female has the potential to generate between 6 to 9 individuals daily, increasing its population by 1.2 times. The average life cycle was 16.8 days. High viability observed in all instars and the resulting values of R0, rm and λ suggest that A. forbesi has the capacity to increase their numbers in a short period of time, while generating high populations in strawberry crops, requiring differential management.

  5. 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.

  6. Use of nuclear techniques in biological control

    International Nuclear Information System (INIS)

    Greany, Patrick D.; Carpenter, James E.

    2000-01-01

    As pointed out by Benbrook (1996), pest management is at a crossroads, and there is a great need for new, biointensive pest management strategies. Among these approaches, biological control is a keystone. However, because of increasing concerns about the introduction of exotic natural enemies of insect pests and weeds (Howarth 1991, Delfosse 1997), the overall thrust of biological control has moved toward augmentative biological control, involving releases of established natural enemy species (Knipling 1992). This in turn has created a need to develop more cost-effective mass rearing technologies for beneficial insects. Nuclear techniques could play an especially important role in augmentative biological control, not only in facilitating mass rearing, but in several other ways, as indicated below. Recognising the potential value for use of nuclear techniques in biological control, the Insect and Pest Control Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, sponsored a Consultants' Group Meeting on this subject in April 1997. The Group produced a document entitled Use of Nuclear Techniques in Biological Control: Managing Pests, Facilitating Trade and Protecting the Environment. The consultants included the authors of this paper as well as Ernest Delfosse (at that time, with the USDA-APHIS National Biological Control Institute), Garry Hill (Intl. Institute for Biological Control), Sinthya Penn (Beneficial Insectary), and Felipe Jeronimo (USDA-APHIS PPQ, Guatemala). The remarks presented in this paper reflect the thoughts presented by these consultants and other participants at the IAEA-sponsored meeting. Several potential uses for nuclear techniques were identified by the Consultants' Group, including: 1) improvements in rearing media (either artificial diets or natural hosts/prey), 2) provision of sterilised natural prey to be used as food during shipment, to ameliorate concerns relating to the

  7. A new strategy for controlling invasive weeds: selecting valuable native plants to defeat them.

    Science.gov (United States)

    Li, Weihua; Luo, Jianning; Tian, Xingshan; Soon Chow, Wah; Sun, Zhongyu; Zhang, Taijie; Peng, Shaolin; Peng, Changlian

    2015-06-05

    To explore replacement control of the invasive weed Ipomoea cairica, we studied the competitive effects of two valuable natives, Pueraria lobata and Paederia scandens, on growth and photosynthetic characteristics of I. cairica, in pot and field experiments. When I. cairica was planted in pots with P. lobata or P. scandens, its total biomass decreased by 68.7% and 45.8%, and its stem length by 33.3% and 34.1%, respectively. The two natives depressed growth of the weed by their strong effects on its photosynthetic characteristics, including suppression of leaf biomass and the abundance of the CO2-fixing enzyme RUBISCO. The field experiment demonstrated that sowing seeds of P. lobata or P. scandens in plots where the weed had been largely cleared produced 11.8-fold or 2.5-fold as much leaf biomass of the two natives, respectively, as the weed. Replacement control by valuable native species is potentially a feasible and sustainable means of suppressing I. cairica.

  8. A new strategy for controlling invasive weeds: selecting valuable native plants to defeat them

    Science.gov (United States)

    Li, Weihua; Luo, Jianning; Tian, Xingshan; Soon Chow, Wah; Sun, Zhongyu; Zhang, Taijie; Peng, Shaolin; Peng, Changlian

    2015-06-01

    To explore replacement control of the invasive weed Ipomoea cairica, we studied the competitive effects of two valuable natives, Pueraria lobata and Paederia scandens, on growth and photosynthetic characteristics of I. cairica, in pot and field experiments. When I. cairica was planted in pots with P. lobata or P. scandens, its total biomass decreased by 68.7% and 45.8%, and its stem length by 33.3% and 34.1%, respectively. The two natives depressed growth of the weed by their strong effects on its photosynthetic characteristics, including suppression of leaf biomass and the abundance of the CO2-fixing enzyme RUBISCO. The field experiment demonstrated that sowing seeds of P. lobata or P. scandens in plots where the weed had been largely cleared produced 11.8-fold or 2.5-fold as much leaf biomass of the two natives, respectively, as the weed. Replacement control by valuable native species is potentially a feasible and sustainable means of suppressing I. cairica.

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

    Science.gov (United States)

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

    2015-07-01

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

  10. 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.

  11. Emerging Challenges and Opportunities for Education and Research in Weed Science.

    Science.gov (United States)

    Chauhan, Bhagirath S; Matloob, Amar; Mahajan, Gulshan; Aslam, Farhena; Florentine, Singarayer K; Jha, Prashant

    2017-01-01

    In modern agriculture, with more emphasis on high input systems, weed problems are likely to increase and become more complex. With heightened awareness of adverse effects of herbicide residues on human health and environment and the evolution of herbicide-resistant weed biotypes, a significant focus within weed science has now shifted to the development of eco-friendly technologies with reduced reliance on herbicides. Further, with the large-scale adoption of herbicide-resistant crops, and uncertain climatic optima under climate change, the problems for weed science have become multi-faceted. To handle these complex weed problems, a holistic line of action with multi-disciplinary approaches is required, including adjustments to technology, management practices, and legislation. Improved knowledge of weed ecology, biology, genetics, and molecular biology is essential for developing sustainable weed control practices. Additionally, judicious use of advanced technologies, such as site-specific weed management systems and decision support modeling, will play a significant role in reducing costs associated with weed control. Further, effective linkages between farmers and weed researchers will be necessary to facilitate the adoption of technological developments. To meet these challenges, priorities in research need to be determined and the education system for weed science needs to be reoriented. In respect of the latter imperative, closer collaboration between weed scientists and other disciplines can help in defining and solving the complex weed management challenges of the 21st century. This consensus will provide more versatile and diverse approaches to innovative teaching and training practices, which will be needed to prepare future weed science graduates who are capable of handling the anticipated challenges of weed science facing in contemporary agriculture. To build this capacity, mobilizing additional funding for both weed research and weed management

  12. Emerging Challenges and Opportunities for Education and Research in Weed Science

    Directory of Open Access Journals (Sweden)

    Bhagirath S. Chauhan

    2017-09-01

    Full Text Available In modern agriculture, with more emphasis on high input systems, weed problems are likely to increase and become more complex. With heightened awareness of adverse effects of herbicide residues on human health and environment and the evolution of herbicide-resistant weed biotypes, a significant focus within weed science has now shifted to the development of eco-friendly technologies with reduced reliance on herbicides. Further, with the large-scale adoption of herbicide-resistant crops, and uncertain climatic optima under climate change, the problems for weed science have become multi-faceted. To handle these complex weed problems, a holistic line of action with multi-disciplinary approaches is required, including adjustments to technology, management practices, and legislation. Improved knowledge of weed ecology, biology, genetics, and molecular biology is essential for developing sustainable weed control practices. Additionally, judicious use of advanced technologies, such as site-specific weed management systems and decision support modeling, will play a significant role in reducing costs associated with weed control. Further, effective linkages between farmers and weed researchers will be necessary to facilitate the adoption of technological developments. To meet these challenges, priorities in research need to be determined and the education system for weed science needs to be reoriented. In respect of the latter imperative, closer collaboration between weed scientists and other disciplines can help in defining and solving the complex weed management challenges of the 21st century. This consensus will provide more versatile and diverse approaches to innovative teaching and training practices, which will be needed to prepare future weed science graduates who are capable of handling the anticipated challenges of weed science facing in contemporary agriculture. To build this capacity, mobilizing additional funding for both weed research and

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

    Science.gov (United States)

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

  14. 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.

  15. Insecticides and Biological Control

    Science.gov (United States)

    Furness, G. O.

    1972-01-01

    Use of insecticides has been questioned due to their harmful effects on edible items. Biological control of insects along with other effective practices for checking spread of parasites on crops are discussed. (PS)

  16. 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.

  17. Optimization of foramsulfuron doses for post-emergence weed control in maize (Zea mays L.)

    Energy Technology Data Exchange (ETDEWEB)

    Pannacci, E.

    2016-11-01

    Four field experiments were carried out from 2011 to 2014 in order to evaluate the effects of foramsulfuron, applied at the recommended (60.8 g a.i./ha) and reduced doses (1/3 and 2/3), on the efficacy against several of the most important weeds in maize. For each “year-weed” combination, dose-response curves were applied to estimate the dose of foramsulfuron required to obtain 90% and 95% weed control (ED90 and ED95). Foramsulfuron phytotoxicity on maize and crop yield were assessed. Foramsulfuron at 1/3 of the recommended dose (20.3 g a.i./ha) provided 95% efficacy against redroot pigweed (Amaranthus retroflexus L.), green foxtail (Setaria viridis (L.) Beauv.), wild mustard (Sinapis arvensis L.) and black nightshade (Solanum nigrum L.). Velvetleaf (Abutilon theophrasti Medik.), common lambsquarters (Chenopodium album L.) and barnyardgrass (Echinochloa crus-galli (L.) Beauv.) were satisfactorily controlled (95% weed efficacy) with ED95 ranged from 20 to 50 g/ha of foramsulfuron (about from 1/3 to 5/6 of the recommended dose) depending on growth stage. The recommended dose was effective against pale smartweed (Polygonum lapathifolium L.) at 2-4 true leaves (12-14 BBCH scale), but this dose did not kill plants larger than 2-4 true leaves. The ranking among weed species based on their susceptibility to foramsulfuron was: redroot pigweed = green foxtail = wild mustard = black nightshade > velvetleaf = common lambsquarters = barnyardgrass > pale smartweed. Dose of foramsulfuron can be reduced below recommended dose depending on weed species and growth stage. Foramsulfuron showed a good crop selectivity and had no negative effect on maize yield. (Author)

  18. 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.

  19. Phytochemical and biological assessments on Lipidium meyenii (maca) and Epimidium sagittatum (horny goat weed).

    Science.gov (United States)

    Qureshi, Mahmood; Mehjabeen, -; Noorjahan, -; Muhammad, Shafi; Siddiqui, Faheem Ahmed; Baig, Iftikhar; Ahmad, Mansoor

    2017-01-01

    The effects of Lipidium meyenii (maca, LM) and Epimidium sagittatum (horny goat weed, ES) have been investigated due to their involvement in fertilization. Both of the drugs showed good results before, during and after fertilization in male and female mice. The results revealed that the crude extract of Lipidium meyenii caused a significant decrease in the no. of writhes at 300 and 500mg/kg (p<0.05) as compare to control, Epimidium sagittatum and standard drug. The gross behavioral, open field, exploratory behaviour, forced swimming test for stress, diuretic activity, chronic toxicity with the effect on reproduction of both male and female and change in body weight were also studied. The phytochemical study showed the presence of tannin, alkaloid, carbohydrate, rich protein and absence of sterol in LM, whereas ES shows presence of sterol and less protein. LS improve in muscle activity and exploratory behaviours without any toxic effects on mice and their pups. It does not have diuretic effect for first two hour but act normally after initial phase of drug therapy. Epimidium sagittatum has dual action that is at low dose it has slight stimulation action and at high dose little depressive effect. ES also has some diuretic effect. Overall these results suggest that LM is highly effective remedy for treatment of impotency and reduces stress and depression, because of dual effect ES not only suggested as an anxiolytic medicine but also effective in female hormonal disorder.

  20. The status of biological control and recommendations for improving uptake for the future

    NARCIS (Netherlands)

    Barratt, B.I.P.; Moran, V.C.; Bigler, F.; Lenteren, van J.C.

    2018-01-01

    Classical and augmentative biological control of insect pests and weeds has enjoyed a long history of successes. However, biocontrol practices have not been as universally accepted or optimally utilised as they could be. An International Organisation for Biological Control (IOBC) initiative brought

  1. Achievements and problems in the weed control in grain sorghum (Sorghum Bicolor Moench.

    Directory of Open Access Journals (Sweden)

    Gr. Delchev

    2017-09-01

    Full Text Available Abstract. Chemical control has emerged as the most efficient method of weed control. Herbicides combinations and tank mixtures of herbicides with adjuvants, fertilizers, growth regulators, fungicides, insecticides are more effective than when applied alone on sorghum crops. Their combined use often leads to high synergistic effect on yield. The use of herbicide antidotes for the treatment of seeds in sorghum is a safe way to overcome its high sensitivity to many herbicides. Data regarding herbicide for chemical control of annual graminaceous weeds in sorghum crops are quite scarce even worldwide. Problem is the persistence of some herbicides used in the predecessors on succeeding crops, which is directly related to the weather conditions during their degradation. Most of the information on sorghum relates to the conventional technology for weed control. There is no information about the new Concep technology in grain sorghum. A serious problem is also the volunteers of the Clearfield and Express sun sunflower. They have resistance to herbicides different from that of conventional sunflower hybrids. There is no information yet in scientific literature on control of these volunteers.

  2. Low-impact chemical weed control techniques in UNESCO World Heritage Sites of Cuba.

    Science.gov (United States)

    Hernandez-Enriquez, O; Alvarez, R; Morelli, F; Bastida, F; Camacho, D; Menendez, J

    2012-01-01

    Dichrostachys cinerea is a thorny, acacia-like, fast-growing woody bush which invades fields, wasteland, road sides and other disturbed areas. This gregarious species has become a very aggressive invasive weed in Cuba, where no native predators or pathogens are found. It often encroaches in fallows, overgrazed areas and mismanaged veld. D. cinerea is a very difficult weed to eliminate because of its active suckering, and is liable to produce dense thickets which are quite impenetrable on account of the density and abundance of its long, stiff, sharp thorns. In the Valle de los Ingenios area (Cuba Central), the tree is unchecked and forms veritable forests in areas on which cane growing has been discontinued. Physical management by cutting and burning the plants is not a very efficient control method, since the seeds survive in the soil, and they grow very fast. Therefore, chemical methods via the use of herbicides are often necessary to eradicate this weed. A preliminary study using glyphosate and auxin-like herbicides (2,4-D + picloram, MCPA, and MCPA + 2,4-D) plus adjuvants has been carried out in order to elucidate the best mixtures rendering maximum weed control with minimum herbicide rate and environmental stress. None of the herbicides used except glyphosate and 2,4-D + picloram showed acceptable mortality rates (75-80%) at the recommended doses tested. In the failed herbicide treatments, only the use of double herbicide rates succeeded in controlling marabou. The herbicide mixture of 2,4-D + picloram formulated with either a non-ionic surfactant or a mixture of fatty acid esters was the best option to control D. cinerea in terms of maximum effectiveness and minimum environmental stress, as the reduction in active ingredients applied to the environment was x3 in these two adjuvant-amended formulations compared to 2,4-D + picloram alone.

  3. 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...

  4. Crop–weed competition

    DEFF Research Database (Denmark)

    Gallandt, Eric R.; Weiner, Jacob

    2015-01-01

    on crops. Longer term management of crop–weed competition can be achieved through crop rotations, specifically crop sequences that reduce the weed seed bank, and therefore seedling density, and prevent proliferation of perennial weeds. Key ConceptsKey Concepts * Plant growth requires sunlight, water......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...... and nutrients, which in turn are converted into biomass that captures additional resources. * In crop or weed monocultures, increasing density increases total production to a maximum that is determined by the resource status of the site, generally with a corresponding decrease in per plant mass. * In crop...

  5. Crop–weed competition

    DEFF Research Database (Denmark)

    Gallandt, Eric R.; Weiner, Jacob

    2015-01-01

    importantly, weed density and time of emergence relative to the crop. Practices that (1) reduce the density of weeds, (2) maximise occupation of space or uptake of resources by the crop or (3) establish an early-season size advantage of the crop over the weeds will minimise the competitive effects of weeds...... an early-season competitive advantage to the crop and (3) maximising resource capture by the crop using competitive species, competitive cultivars, high sowing densities, optimal spatial arrangement, intercropping complimentary species or transplanting.......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...

  6. 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.

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

    International Nuclear Information System (INIS)

    Eswaran, M.S.

    2000-01-01

    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)

  8. 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....

  9. 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.

  10. Weed Diversity Affects Soybean and Maize Yield in a Long Term Experiment in Michigan, USA.

    Science.gov (United States)

    Ferrero, Rosana; Lima, Mauricio; Davis, Adam S; Gonzalez-Andujar, Jose L

    2017-01-01

    Managing production environments in ways that promote weed community diversity may enhance both crop production and the development of a more sustainable agriculture. This study analyzed data of productivity of maize (corn) and soybean in plots in the Main Cropping System Experiment (MCSE) at the W. K. Kellogg Biological Station Long-Term Ecological Research (KBS-LTER) in Michigan, USA, from 1996 to 2011. We used models derived from population ecology to explore how weed diversity, temperature, and precipitation interact with crop yields. Using three types of models that considered internal and external (climate and weeds) factors, with additive or non-linear variants, we found that changes in weed diversity were associated with changes in rates of crop yield increase over time for both maize and soybeans. The intrinsic capacity for soybean yield increase in response to the environment was greater under more diverse weed communities. Soybean production risks were greatest in the least weed diverse systems, in which each weed species lost was associated with progressively greater crop yield losses. Managing for weed community diversity, while suppressing dominant, highly competitive weeds, may be a helpful strategy for supporting long term increases in soybean productivity. In maize, there was a negative and non-additive response of yields to the interaction between weed diversity and minimum air temperatures. When cold temperatures constrained potential maize productivity through limited resources, negative interactions with weed diversity became more pronounced. We suggest that: (1) maize was less competitive in cold years allowing higher weed diversity and the dominance of some weed species; or (2) that cold years resulted in increased weed richness and prevalence of competitive weeds, thus reducing crop yields. Therefore, we propose to control dominant weed species especially in the years of low yield and extreme minimum temperatures to improve maize yields

  11. Living Mulch Performance in a Tropical Cotton System and Impact on Yield and Weed Control

    Directory of Open Access Journals (Sweden)

    Vinay Bhaskar

    2018-01-01

    Full Text Available Cotton (Gossypium hirsutum L. is a major crop in the Vidarbha region of central India. The vertisol soils on which much of the cotton is grown have been severely degraded by the tropical climate, excessive tillage and depletion of organic matter. Living mulches have the ability to mitigate these problems but they can cause crop losses through direct competition with the cotton crop and unreliable weed control. Field experiments were conducted in 2012 and 2013 at four locations in Vidarbha to study the potential for growing living mulches in mono-cropped cotton. Living mulch species evaluated included gliricidia [Gliricidia sepium (Jacq. Kunth ex Walp.], sesbania [Sesbania sesban (L. Merr.], sorghum sudan grass [Sorghum bicolor (L. Moench × Sorghum bicolor (L. Moench ssp. Drummondii (Nees ex Steud. de Wet & Harlan] and sunnhemp (Crotalaria juncea L.. Living mulch height was controlled through mowing and herbicides were not used. Living mulches generated 1 to 13 tons ha−1 of dry matter across sites and years. Weed cover was negatively correlated with both living mulch biomass and cover. Where living mulches were vigorous and established quickly, weed cover was as low as 7%, without the use of herbicides, or inter-row tillage. In a dry year, living mulch growth had a negative impact on cotton yield; however, in a year when soil moisture was not limiting, there was a positive relationship between cotton yield and living mulch biomass. Use of living mulches in cotton production in the Vidarbha region of India is feasible and can lead to both effective weed suppression and acceptable cotton yields.

  12. Biology and host range of Omolabus piceus, a weevil rejected for biological control for Schinus terebinthifolius in the USA

    Science.gov (United States)

    Surveys for biological control agents of the invasive weed Schinus terebinthifolius (Anacardiaceae) discovered two Omolabus weevils (Coleoptera: Attelabidae) feeding on the plant in its native range. Molecular and morphological analysis indicated that one of these species consistently fed on the tar...

  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. 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. © 2014 American Society of Plant Biologists. All Rights Reserved.

  15. [Biological activity of fungi from the phyllosphere of weeds and wild herbaceous plants].

    Science.gov (United States)

    Berestitskiĭ, A O; Gasich, E L; Poluéktova, E V; Nikolaeva, E V; Sokornova, S V; Khlopunova, L B

    2014-01-01

    Antimicrobial, phytotoxic, and insecticidal activity of 30 fungal isolates obtained from leaves of weeds and wild herbaceous plants was assessed. Antibacterial, antifungal, phytotoxic, and insecticidal activity was found in over 50, 40, 47, and 40% of the isolates, respectively. These findings may be important for toxicological assessment of potential mycoherbicides, as well as provide a basis for investigation of the patterns of development of phyllosphere communities affected by fungal metabolites.

  16. Imazapyr-resistant maize technology adoption for witch weed control ...

    African Journals Online (AJOL)

    Saharan Africa. A new technology known as imazapyr-resistant maize (IRM) has proven to be effective in controlling it. This study examined the status of IRM adoption in western Kenya. A cross sectional survey that included 600 households, ...

  17. 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

  18. Efficacy of oxyfluorfen with straw cover in controlling weeds

    OpenAIRE

    Negrisoli, E.; Correa, M.R.; Rossi, C.V.S.; Carbonari, C.A.; Velini, E.D.; Perim, L.

    2009-01-01

    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 po...

  19. 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.

  20. Weeds control through tree-crop associations in a parkland of ...

    African Journals Online (AJOL)

    Seventy-six (76) weeds species from nineteen (19) families were recorded on the parkland from which only 13 families were found in the open field. Then, weeds floristic composition was more diversified in area beneath both trees species compared to the open field. The most represented weeds family in the open field was ...

  1. 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)

  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.

  3. Costs and benefits of biological control of invasive alien plants: case studies from South Africa

    CSIR Research Space (South Africa)

    Van Wilgen, BW

    2004-01-01

    Full Text Available . In many cases, plants are brought under complete control. In this paper, we describe an attempt to estimate the costs and benefits of the biological control of 6 weed species (Opuntia, aurantiaca, Sesbania punicea, Lantana camara, Acacia longifolia, A...

  4. Effect of Plowing Frequency and Weeding Methods on Weeds and ...

    African Journals Online (AJOL)

    The effect of repeated tillage and weed control methods on weed infestation and grain yield of wheat was evaluated at Arsi Negelle, southern Ethiopia, from 1993 to 1995 cropping ... Generally, four times plowing significantly reduced weed infestation and increased wheat grain yield with considerable economic benefit.

  5. Non-chemical weed management

    DEFF Research Database (Denmark)

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

    2017-01-01

    Non-chemical weed management covers all management practices that influence weeds except herbicides. This chapter summarises the major achievements in European research, as well as work undertaken in North America. Research groups from both continents have interacted strongly on the topic over...... the years and shared common interests on the development of non-chemical tactics. The chapter encompasses preventive, cultural and direct weed control methods, explaining the basic principles and the integration of these tactics in weed management strategies for agricultural and horticultural crops...... and in some cases amenity areas as well. Preventive methods reduce weed germination, cultural methods improve crop competition and direct physical weed control reduces weed survival. Non-chemical weed management is mainly adopted in organic crop production, as conventional growers still perceive it as more...

  6. Performance Of Groundnut Arachis Hypogaea L. Varieties As Influenced By Weed Control Treatments In Kano State Of Nigeria

    Directory of Open Access Journals (Sweden)

    M.S. Garko

    2015-08-01

    Full Text Available A field experiment was carried out during 2012 rainy season at the Research Farm of Bayero University Kano 110 58 N 80 26E and 475m above sea level and National Horticultural Research Institute Bagauda sub-station Bebeji local Government area of Kano State 110 33N 80 23E and 481m above sea level to find out the performance of varieties and weed control treatments on growth and development of groundnut Arachis hypogaea L.. The experiment consisted of two groundnut varieties SAMNUT-22 and SAMNUT-23 and 12 weed control treatments Metolachlor at 2 levels of 1.0 and 2.0kg a.i. ha Fluazifop-p butyl at 2 levels of 1.0 and 1.5 kg a.i. ha at pre or post-emergence or combined with hoe weeding at 15 days after sowing or supplementary hoe weeding at 30 days after sowing while weed free check at 15 and 30 days after sowing and weedy check were included as control. The treatments were laid out using split plot design with variety assigned to the main and weed control to the sub plot. The result showed that SAMNUT-22 out yielded SAMNUT-23 and exhibited superior growth and yield components such as stand count canopy height number of branches leaf area index plant dry weight. The application of Metolaclor at 1.0 kg a.i. ha followed by Fluazifop-p butyl at 1.0 kg a.i. ha as well as Metolaclor at 1.0 or 2.0 kg a.i. ha followed by supplementary hoe weeding produced significantly higher number of pods per plant and pod yield per hactare. Leaf area index and number of pod per plant were significantly and positively correlated with pod weight. Thus SAMNUT-22 can be recommended for the two study areas. Similarly application of Metolaclor at 1.0 kg a.i. ha followed by Fluazifop-p butyl at 1.0 kg a.i. ha and Metolaclor at 1.0 or 2.0 kg a.i. ha followed by supplementary hoe weeding could be recommended for weed control in groundnut in the study area.

  7. Chemical control of weeds during the acclimatization of in vitro sugarcane plants cv. 'CP52-43'

    Directory of Open Access Journals (Sweden)

    Inoel García Ruiz

    2016-07-01

    Full Text Available Control of weeds in the acclimatization phase of in vitro sugarcane (Saccharum spp. plants is done manually which raises the cost of production. In order to determine the effectiveness of the chemical control of weeds with Dual Gold CE 96 (Mesotrione, in vitro plants of sugar cane cv. 'CP52-43' were acclimatized in worm humus and cachaça compost. Doses of 0.5, 1.0 and 1.5 l ha-1 p.c. Dual Gold CE 96 herbicide, were applied before and immediately to in vitro plants transplantation and the results were compared to manual weeding. After 50 days of culture, 15 plants were extracted per treatment and the number of leaves and shoots were quantified, the length was measured and the fresh mass of the aerial part and of the roots were determined. The results showed that Dual Gold CE 96 at doses of 0.5 l ha-1 applied before or after transplant, controls the weeds Portulaca oleracea (L., Amaranthus sp. (Mart, Sida acuta (Burm. F. and Eleusine indica (L., without affecting the growth of sugarcane cv. ‘CP52-43’ plants, compared to manual weeding.   Keywords: herbicides, Saccharum, substrate, survival

  8. Weed Control Efficiency of wild Safflower (Carthamus oxyacanthus M. Bieb in Replacement Series Technique of Barley (Hordeum vulgare L. and Common Vetch (Vicia sativa L.

    Directory of Open Access Journals (Sweden)

    abdolreza ahmadi

    2017-08-01

    Full Text Available Introduction In agronomy, natural outlook has been expressed in different forms which stable agriculture is an example. Stable agriculture is ascribed to the authentic management of agricultural resources, which in addition to fulfilling the ever-changing needs of humans, maintains the health of environment and capacity of water and soil resources. Application of herbicides, besides being costly, resulted in the selection of herbicide resistant weed species and has become an environmental contamination factor. However, reduction of herbicide consumption is one of the goals of modern agriculture, with several methods being suggested, including intercropping. In natural conditions of production, environment conservation of weed existence requires cost. One of the important preparations in weed control from the perspective of sustainable agriculture, is using intercropping system. The aim of this study was to determine the role of crop diversity on weed and crop production based on the beneficial effects of intercropping system than pure. Materials and methods In order to study effects of mixed and sole cropping of barley with common vetch on their biologic yield and utilization indices, an experiment was conducted in Agricultural college of the University of Lorestan, during the growing season of 2013-2014 with 24 treatments using the method of rows replacement series technique by the randomized complete block design in a factorial arrangement with three replications. First factor included 6 levels of intercropping: sole cropping of common vetch (100%, 55-45 (Common vetch-barley, 35-65, 45-55, 65-35 and sole cropping of barley and second factor included 4 levels of weed wild safflower, control, 10, 15 and 20 plants per m2. In this experiment WCE, LER and CR were measured. The data were subjected to analysis of variance (ANOVA using Mstat-C computer software. Mean comparisons were performed using Duncan’s multiple range test at two levels of

  9. Weed Control Efficiency of wild Safflower (Carthamus oxyacanthus M. Bieb in Replacement Series Technique of Barley (Hordeum vulgare L. and Common Vetch (Vicia sativa L.

    Directory of Open Access Journals (Sweden)

    abdolreza ahmadi

    2017-01-01

    Full Text Available Introduction In agronomy, natural outlook has been expressed in different forms which stable agriculture is an example. Stable agriculture is ascribed to the authentic management of agricultural resources, which in addition to fulfilling the ever-changing needs of humans, maintains the health of environment and capacity of water and soil resources. Application of herbicides, besides being costly, resulted in the selection of herbicide resistant weed species and has become an environmental contamination factor. However, reduction of herbicide consumption is one of the goals of modern agriculture, with several methods being suggested, including intercropping. In natural conditions of production, environment conservation of weed existence requires cost. One of the important preparations in weed control from the perspective of sustainable agriculture, is using intercropping system. The aim of this study was to determine the role of crop diversity on weed and crop production based on the beneficial effects of intercropping system than pure. Materials and methods In order to study effects of mixed and sole cropping of barley with common vetch on their biologic yield and utilization indices, an experiment was conducted in Agricultural college of the University of Lorestan, during the growing season of 2013-2014 with 24 treatments using the method of rows replacement series technique by the randomized complete block design in a factorial arrangement with three replications. First factor included 6 levels of intercropping: sole cropping of common vetch (100%, 55-45 (Common vetch-barley, 35-65, 45-55, 65-35 and sole cropping of barley and second factor included 4 levels of weed wild safflower, control, 10, 15 and 20 plants per m2. In this experiment WCE, LER and CR were measured. The data were subjected to analysis of variance (ANOVA using Mstat-C computer software. Mean comparisons were performed using Duncan’s multiple range test at two levels of

  10. Biological control of broad-leaved dock infestation in wheat using plant antagonistic bacteria under field conditions.

    Science.gov (United States)

    Abbas, Tasawar; Zahir, Zahir Ahmad; Naveed, Muhammad; Aslam, Zubair

    2017-06-01

    Conventional weed management systems have produced many harmful effects on weed ecology, human health and environment. Biological control of invasive weeds may be helpful to minimize these harmful effects and economic losses incurred to crops by weeds. In our earlier studies, plant antagonistic bacteria were obtained after screening a large number of rhizobacteria for production of phytotoxic substances and effects on wheat and its associated weeds under laboratory conditions. In this study, five efficient strains inhibitory to broad-leaved dock and non-inhibitory to wheat were selected and applied to broad-leaved dock co-seeded with wheat both in pot trial and chronically infested field trial. Effects of plant antagonistic bacteria on the weed and infested wheat were studied at tillering, booting and harvesting stage of wheat. The applied strains significantly inhibited the germination and growth of the weed to variable extent. Similarly, variable recovery in losses of grain and straw yield of infested wheat from 11.6 to 68 and 13 to 72.6% was obtained in pot trial while from 17.3 to 62.9 and 22.4 to 71.3% was obtained in field trial, respectively. Effects of plant antagonistic bacteria were also evident from the improvement in physiology and nutrient contents of infested wheat. This study suggests the use of these plant antagonistic bacteria to biologically control infestation of broad-leaved dock in wheat under field conditions.

  11. Chemical control of perennial and annual weeds in herbicide resistant soybean crops.

    Science.gov (United States)

    Sarpe, N; Roibu, C; Negrila, E; Bodescu, F; Fuia, S; Popa, C; Beraru, C

    2001-01-01

    In Romania, the first tests with Roundup Ready on soybean crops were performed in 1998, on 2 soil types: a) at Teleorman Station on chernozem containing 3.5% humus, 4.5% clay b) at Brăila Station placed in Danube Meadow on alluvial soil containing 3.90% humus and 46% clay. In every locality cultivated soybean cultivar S.2254 was resistant to glyphosate. During the three years of experiments (1998-2000) the crop of soybean was infested with various species of weeds (both annual and perennial) of which the most important are: Sorghum halepense (60-80%), Echinochloa crus-galli, Setaria glauca, Amaranthus retroflexus, Solarium nigrum, Yanthium italicum, Abutilon theoprasthi, Sinapis arvensis, Datum stramonium, Polygonum persicaria, Calystegia sepium, Cirsium arvense. In 3 years of experience the best weed control and the highest soybean production were obtained in the variants treated 2 times postemergent with Roundup Ready at a dose of 3 + 3 l/ha. Similar results were also obtained in the farms of the Academy of Agricultural Forestry Sciences, where GMO soybean was cultivated on 1500 hectares.

  12. Complex Outcomes from Insect and Weed Control with Transgenic Plants: Ecological Surprises?

    Directory of Open Access Journals (Sweden)

    Thomas Bøhn

    2017-09-01

    Full Text Available Agriculture is fundamental for human survival through food production and is performed in ecosystems that, while simplified, still operate along ecological principles and retain complexity. Agricultural plants are thus part of ecological systems, and interact in complex ways with the surrounding terrestrial, soil, and aquatic habitats. We discuss three case studies that demonstrate how agricultural solutions to pest and weed control, if they overlook important ecological and evolutionary factors, cause “surprises”: (i the fast emergence of resistance against the crop-inserted Bt-toxin in South Africa, (ii the ecological changes generated by Bt-cotton landscapes in China, and (iii the decline of the monarch butterfly, Danaus plexippus, in North America. The recognition that we work with complex systems is in itself important, as it should limit the belief in reductionist solutions. Agricultural practices lacking eco-evolutionary understanding result in “surprises” like resistance evolution both in weeds and pest insects, risking the reappearance of the “pesticide treadmill”—with increased use of toxic pesticides as the follow-up. We recommend prioritization of research that counteracts the tendencies of reductionist approaches. These may be beneficial on a short term, but with trade-off costs on a medium- to long-term. Such costs include loss of biodiversity, ecosystem services, long-term soil productivity, pollution, and reduced food quality.

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

    Science.gov (United States)

    Olayinka, Bolaji U; Etejere, Emmanuel O

    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. All the weed control treatments significantly enhanced the growth and yield compared with the weedy check. The weed free check had the highest growth but the highest yield was recorded from rice straw mulch at 0.1 m depth + one hand weeding at 6 weeks after sowing (WAS) due to increase in number of matured pods per plant, seed weight per plant and 100-seed weight. The results showed that rice straw mulch at 0.1 m depth + one hand weeding at 6 WAS was better agronomical practice for enhancing growth and yield of groundnut. This enhancement could be as a result of its positive influence on physiological parameters such as leaf area index, dry matter accumulation, relative growth rate, net assimilation rate and crop growth rate. Its use is also ecofriendly as it limits the need for synthetic herbicide.

  14. Library Weeds

    Science.gov (United States)

    Martin, Jess A.; Manch, Steven B.

    1971-01-01

    Weeding is essential to the efficient operation of medical libraries and should be conducted in spite of certain barriers that exist. The mechanics of weeding are simple, and the criteria are widely known. A questionnaire survey of ninety-four medical school libraries reveals that weeding is most often shared by professional staff members, that weeding is done primarily when space is needed, and that librarians when weeding do not as a rule seek the advice or assistance of users or the Library Committee. PMID:5128703

  15. Effects of biological control agents and exotic plant invasion on deer mouse populations

    Science.gov (United States)

    Yvette K. Ortega; Dean E. Pearson; Kevin S. McKelvey

    2004-01-01

    Exotic insects are commonly introduced as biological control agents to reduce densities of invasive exotic plants. Although current biocontrol programs for weeds take precautions to minimize ecological risks, little attention is paid to the potential nontarget effects of introduced food subsidies on native consumers. Previous research demonstrated that two gall flies (...

  16. External rostral characters for differentiation of sexes in the biological control agent Mecinus janthinus (Coleoptera: Curculionidae)

    Science.gov (United States)

    Marjolein Schat; Sharlene E. Sing; Robert K. D. Peterson

    2007-01-01

    The stem-boring weevil, Mecinus janthinus (Germar), is a promising, well established classical biological control agent for the exotic invasive weed Dalmatian toadflax (Linaria dalmatica (L.) Mill.) (Scrophulariaceae). In this paper we present readily apparent rostral characters that can be used for sex differentiation of live stem-boring weevils at low magnification....

  17. 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.

  18. Biological diversity of weeds in a winter triticale (Triticum rimpaui Wittm. crop depending on different doses of herbicides and foliar fertilization

    Directory of Open Access Journals (Sweden)

    Sylwia Andruszczak

    2012-12-01

    Full Text Available A field experiment was conducted in the period 2006-2008 on incomplete podzolic soil. The present study investigated the effect of different doses of the herbicides Mustang 306 SE and Attribut 70 WG as well as of the foliar fertilizers Insol 3 and FoliCare 18:18:18 on the biodiversity of weeds in a winter triticale crop, 'Todan'. The segetal flora was assessed 6 weeks after the application of the herbicides and before the harvest of the triticale crop. The herbicides were applied together at labelled doses as well as at doses reduced to 75% and by half. Spraying with the foliar fertilizers was done twice during the growing period. Plots in which no herbicides or foliar fertilizers were used were the control treatment. Matricaria maritima and Viola arvensis from the dicotyledonous class were predominant in the winter triticale crop, whereas Apera spica-venti was the dominant species among the monocotyledons. The weed control efficacy of the reduced herbicide doses was weaker compared to the labelled rates by, respectively, from 6% to 9% at the first time of weed infestation assessment and from 4% to 8% at the second assessment time. Simultaneously, air-dry weight of weeds in the herbicide-treated plots did not differ significantly. This indicates that it is possible to reduce herbicide doses in a winter triticale crop without a risk of increased weed infestation .

  19. 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

  20. Herbaceous Weed Control Trials with a Planting Machine Sprayer and a Crawler-Tractor Sprayer--Fourth Year Pine Response.

    Science.gov (United States)

    James Miller

    1990-01-01

    Operational trials of herbaceous weed control treatments by machine application were studied at two southern alabama locations for establishing loblolly pine (Pinus taeda). The first study tested the feasibility of a spray attachment for planting machines to apply banded treatments while planting in February and March. Two rates of sulfometuron (Oust...

  1. Effects of surface seals and application shanks on nematode, pathogen and weed control with 1,3-dichloropropene

    Science.gov (United States)

    Pre-plant soil fumigation with methyl bromide (MeBr) has been used for decades for controlling plant parasitic nematodes, soilborne pathogens and weeds in many high value annual, perennial and nursery crops. However, MeBr was identified as an ozone depleting substance and its availability was restri...

  2. 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.

  3. Weed Dynamics and Management in Wheat

    DEFF Research Database (Denmark)

    Jabran, Khawar; Mahmood, Khalid; Melander, Bo

    2017-01-01

    Wheat is among the most important cereal and food crops of world and is grown in almost all parts of the world. It is a staple for a large part of the world population. Any decline in wheat yield by biotic or abiotic factors may affect global food security adversely. Weeds are the most damaging...... pest of wheat causing in total 24% losses in wheat grain yield. In this chapter, we discuss the (i) weed flora in different wheat-growing regions of world; (ii) the yield losses caused by weeds in wheat; (iii) the preventive and cultural options for weed management; (iv) physical weed control; (v......) chemical weed control; and (vi) integrated weed management strategy in wheat. A critical analysis of recent literature indicated that broadleaved weeds are the most common group of weeds in wheat fields followed by grass weeds, while sedges were rarely noted in wheat fields. Across the globe, the most...

  4. Effect of Tillage in Day or Night and Application of Reduced Dosage of Imazethapyr and Trifluralin on Weed Control, Yield and Yield Components of Chickpea

    Directory of Open Access Journals (Sweden)

    A Abbasian

    2015-07-01

    Full Text Available This Experiment was arranged as a strip-plot on the base of a completely randomized block design with three replications to study the effect of tillage (whether in day or night or in day by light-proof cover and application of reduced dosage of imazethapyr and trifluralin on weed control, yield and yield components of chickpea. Main plots consisted of tillage methods and subplots consisted of trifluralin (at doses of 480, 960 and 1440 g ai /ha and imazethapyr (at doses of 50, 100 and 150 g ai /ha, plus weed free and weedy checks. Results showed weed biomass in day tillage, night tillage and in light-proof cover tillage were respectively 86, 127 and 148 g m-2. Therefore tillage at night or by light-proof cover in day time showed not enough efficiency in weed control. Weed biomass increased when application dose of herbicides decreased. Chickpea grain yield showed significant differences when different doses of herbicides applied. The minimum and the maximum seed yield were obtained respectively in weed free (by 208 g m-2 and weedy checks (by 123 g m-2. Reduced dosage of imazethapyr and trifluralin could control weeds good enough by no significant decrease in chickpea yield. Efficacy of imazethapyr to control weeds grown in chickpea was significantly better than that of trifluralin

  5. Controle das plantas daninhas na cultura de alface transplantada com o herbicida oxadiazom Weed control in transplanted lettuce by oxadiazon

    Directory of Open Access Journals (Sweden)

    Edison Martins Paulo

    1990-01-01

    Full Text Available Efetuou-se um experimento com o herbicida oxadiazom, objetivando estudar o efeito do seu uso no controle das plantas daninhas e na, produção da cultura da alface transplantada. Os tratamentos, em número de sete, consistiram em três doses de oxadiazom formulado em grânulos, 1,0,1,5 e 2,0kg/ha, aplicadas após o transplante da alface, dois fratamentos de 1,0kg/ha do herbicida formulado em concentrado emulsionável, um pulverizado antes e, outro, após o transplante, em área total, e duas testemunhas, uma capinada e outra mantida com o mato até a colheita. As principais plantas daninhas que infestaram o experimento foram: beldroega (Portulacca oleracea L., picão-branco (Galinsoga parvifiora Cav., caruru (Amaranthus hibridus L., capim-colchão (Digitaria sanguinalis (L. Scop. e capim-pé-de-galinha (Eleusine indica (L. Gaertn.. Constatou-se o controle dessas espécies pelo oxadiazom, 51 dias após a aplicação, até que se mostrou seletivo à cultura, exceto na sua formulação concentrado emulsionável pulverizada após o transplante, quando reduziu o número e o peso das alfaces colhidas.A trial was carried out in order to study the performance of oxadiazon on yield of transplanted lettuce. The treatments were: oxadiazon granular formulation at rates of 1.0,1.5 and 2.0 kg/ha applied after transplanting and pre emergence of weeds; oxadiazom emulsifiable concentrate at 1.0 kg/ha applied before and after transplanting both as preemergence of weeds. Two controls were used: one without any control of weeds and another free from weeds 33 days after transplanting. Oxadiazon gave good control of Portulacca oleracea L, Galinsoga parviflora Cav., Amaranthus hibridus L, Digitaria sanguinalis (L. Scop, and Eleusine indica (L. Gaertn. up to 51 days after application. Except for oxadiazon emulsifiable formulation, when applied after transplanting, no phototoxicity to lettuce was observed with the herbicide whether applied at preemergence or before

  6. 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

  7. Mulching methods for weed control in a certified organic production system

    Science.gov (United States)

    Reducing weed competition is a critical step in organic cropping systems. Use of black plastic as a weed barrier is widely used and effective. The expense associated with black plastic as well as the ecological impact of disposal has a negative impact with its use. Research was conducted at Lane,...

  8. Impact of mulching methods on herb production and weed control in a certified organic production system

    Science.gov (United States)

    Reducing weed competition is a critical step in organic cropping systems. Use of black plastic as a weed barrier is widely used and effective. The expense associated with black plastic as well as the ecological impact of disposal has a negative impact with its use. Research was conducted at Lane,...

  9. Original Paper Weeds control through tree-crop associations in a ...

    African Journals Online (AJOL)

    2012; Ludwig et al., 2004). In sum, trees in parklands agroforestry systems seem to increase weeds problem which is known as the most pest in West. African savannah agriculture. Indeed, the major cereal crops (C4 plants) are less competitive than C3 weeds species under tree. (Bayala et al., 2015). In addition, due to the.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... residue present at time of application of pre-emergence herbicide usually intercepts herbicides (Banks and .... were significant differences in weed biomass between the. NT and P+H and P, throughout the period of the study, ... the Central Greek plains. Weed Technol. 18: 186-192. Ball DA, Miller SD (1990) ...

  11. Evaluation of tillage, cover crop, and herbicide effects on weed control, yield, and grade in peanut

    Science.gov (United States)

    Peanut production plays a large role in agriculture in the Southeastern United States. Weeds are detrimental to their production because of the competition that they create; weeds will compete with crops for resources such as nutrients and sunlight, among others. Therefore, it is important to reduce...

  12. Chemical and Mechanical Weed Control Methods and Their Effects on Photosynthetic Pigments and Grain Yield of Kidney Bean

    Directory of Open Access Journals (Sweden)

    A.S Ghatari

    2015-11-01

    Full Text Available To evaluate the integrated management of weeds in red kidney bean, a split-plot experiment using randomized complete block design with three replications was conducted in 2013 in the Damavand County. In this experiment, the mechanical control treatments consisted of two levels (no cultivation and one cultivation asseigned to main plots and controlling chemical treatments consisted of six levels (non-application of herbicides, pre-emergence herbicide application of Pursuit with full dose of 1 liter per hectare, pre-emergence herbicide application of Pursuit a dose decreased 0.5 liters per hectare, post-emergence herbicide application of Pursuit dose reduced to 0.3 liters per hectare + 2 thousand citogate, post-emergence herbicide application of Pursuit with a reduced dose of 0.5 liters per hectare + 2 thousand citogate, post-emergence herbicide application of Pursuit full dose of 1 liter per hectar + 2 thousand citogate to subplots. The results showed that the effects of interaction between herbicide application and cultivation for traits of carotenoids, chlorophyll a, chlorophyll b and total chlorophyll contents, density of weeds and their dry weights were significant at 1 %, and grain yield at the 5% probability levels. The highest bean seed yield with an average of 5461.6 kg.ha-1 and lowest weed dry weight with an average of 345.9 kg.ha-1 were related to pre-emergence herbicide and cultivation with a dose of 1 liter per hectare treatment. The difference between full and reduced doses of chemical weed control was non-significant. It could be concluded that integrated mechanical and chemical weed control not only may increase seed yield but also reduce, environmental hazards.

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

    Directory of Open Access Journals (Sweden)

    Patrick W. Geier

    2013-04-01

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

  14. Influence of plasma radiation on weed plants

    International Nuclear Information System (INIS)

    Tsyganov, A.R.; Gordeev, Yu.A.; Poddubnaya, O.V.

    2009-01-01

    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

  15. Weed Control in Corn (Zea mays L. as Influenced by Preemergence Herbicides

    Directory of Open Access Journals (Sweden)

    Travis W. Janak

    2016-01-01

    Full Text Available Field studies were conducted in central and south-central Texas from 2013 through 2015 to evaluate crop tolerance and efficacy of various preemergence herbicides alone and in combination for weed control in field corn. Acetochlor and pendimethalin alone, S-metolachlor plus mesotrione, and the three-way combination of S-metolachlor plus atrazine plus mesotrione provided the most consistent control of annual grasses including browntop panicum (Panicum fasciculatum L., Texas millet (Urochloa texana L., barnyardgrass (Echinochloa crus-galli L., and sprawling signalgrass (Brachiaria reptans L.. Palmer amaranth [Amaranthus palmeri (S. Wats.] control was at least 90% with fluthiacet-methyl plus pyroxasulfone, atrazine plus either acetochlor, alachlor, dimethenamid-P, S-metolachlor, or S-metolachlor plus mesotrione, saflufenacil plus dimethenamid-P, and S-metolachlor plus mesotrione. Hophornbeam copperleaf (Acalypha ostryifolia L. was difficult to control; however, acetochlor, saflufenacil or pyroxasulfone alone, saflufenacil plus dimethenamid-P, and S-metolachlor plus mesotrione provided at least 90% control. Acetochlor or saflufenacil alone, thiencarbazone-methyl plus isoxaflutole, dimethenamid-P plus atrazine, rimsulfuron plus mesotrione, and saflufenacil plus dimethenamid-P controlled common sunflower (Helianthus annuus L. at least 90%. Corn injury was minimal (≤3% with all herbicides. In general, corn grain yield was greatest with herbicide treatments containing more than one active ingredient compared with a single active ingredient.

  16. Weed Mapping with Co-Kriging Using Soil Properties

    DEFF Research Database (Denmark)

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

    1999-01-01

    Our aim is to build reliable weed maps to control weeds in patches. Weed sampling is time consuming but there are some shortcuts. If an intensively sampled variable (e.g. soil property) can be used to improve estimation of a sparsely sampled variable (e.g. weed distribution), one can reduce weed...

  17. Crescimento do milho com controle de plantas daninhas via consorciação com gliricídia Maize Growth with weed control via intercropping with gliricidia

    Directory of Open Access Journals (Sweden)

    B.B. Araújo Jr.

    2012-12-01

    Full Text Available A consorciação com a gliricídia controla as plantas daninhas do milho. Com o objetivo de entender melhor esse controle, realizou-se uma análise do crescimento do milho em consorciação com a gliricídia. O híbrido duplo AG 1051 foi cultivado com capinas (duas capinas, aos 20 e 40 dias após a semeadura, sem capinas e em consorciação com a gliricídia. Na consorciação, a gliricídia foi semeada a lanço, com 25 sementes viáveis m-2, por ocasião da semeadura do milho, entre as fileiras desta cultura. Utilizou-se o delineamento de blocos completos casualizados com parcelas subdivididas e oito repetições. O controle de plantas daninhas foi aplicado às parcelas, e as 13 coletas da parte aérea das plantas, para avaliação da área foliar e da matéria seca, às subparcelas. As coletas foram feitas de sete em sete dias, a partir dos 14 dias após a semeadura. Pode ser concluído que o controle das plantas daninhas com duas capinas determinou maiores valores na área e matéria seca foliares, bem como na matéria seca total da planta. Nessas características, as plantas das parcelas consorciadas apresentaram comportamento intermediário entre plantas das parcelas capinadas e das não capinadas. Portanto, as plantas daninhas reduzem o crescimento do milho, e a gliricídia provavelmente controla parcialmente o mato, beneficiando o milho. Não houve diferenças entre tratamentos de controle de plantas daninhas nas taxas de crescimento absolutas e relativas, área foliar específica e taxa assimilatória líquida. A maior razão de área foliar foi observada com a consorciação com gliricídia.The maize/gliricidia intercropping is known to control weeds. The aim of this work was to carry out a growth analysis of maize intercropped with gliricidia, to better evaluate the weed control. The double-hybrid AG 1051 was used and the crop was managed with three weed control procedures: (a no-weeding; (b two manual-weedings (at 20 and 40 days after

  18. Biological control of toxic cyanobacteria

    CSIR Research Space (South Africa)

    Ndlela, L

    2016-04-01

    Full Text Available harmful algal blooms and their impacts in over 30 countries. Biological control is a method of introducing natural enemies to control an organism and has been more successful using microorganisms....

  19. Autonomous Mower vs. Rotary Mower: Effects on Turf Quality and Weed Control in Tall Fescue Lawn

    Directory of Open Access Journals (Sweden)

    Michel Pirchio

    2018-02-01

    Full Text Available Autonomous mowers are battery-powered machines designed for lawn mowing that require very low human labour. Autonomous mowers can increase turf quality and reduce local noise and pollution compared with gasoline-powered rotary mowers. However, very little is known about the effects of autonomous mowing on encroaching weeds. The aim of this research was to compare the effects of an autonomous mower and an ordinary gasoline-powered mower on weed development in an artificially infested tall fescue (Festuca arundinacea Schreb. turf with different nitrogen (N rates. A three-way factor experimental design with three replications was adopted. Factor A consisted of three N rates (0, 75, and 150 kg ha−1, factor B consisted of two mowing systems (autonomous mower vs. walk-behind gasoline rotary mower equipped for mulching, and factor C which consisted of four different transplanted weed species: (a Bellis perennis L., (b Trifolium repens L.; (c Trifolium subterraneum L.; and (d Lotus corniculatus L. Of these, B. perennis is a rosette-type plant, while the other three species are creeping-type plants. The interaction between mowing system and transplanted weed species showed that the four transplanted weed species were larger when mowed by the autonomous mower than by the rotary mower. The autonomous mower yielded larger weeds probably because the constant mowing height caused the creeping weed species to grow sideways, since the turfgrass offered no competition for light. N fertilization increased turf quality and mowing quality, and also reduced spontaneous weed infestation. Autonomous mowing increased turf quality, mowing quality, but also the percentage of spontaneous weed cover.

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

    International Nuclear Information System (INIS)

    Bakht, T.; Khan, I.A.

    2014-01-01

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

  1. Analysis of biologically active compounds in potatoes (Solanum tuberosum), tomatoes (Lycopersicon esculentum), and jimson weed (Datura stramonium) seeds.

    Science.gov (United States)

    Friedman, Mendel

    2004-10-29

    Potatoes and tomatoes, members of the Solanaceae plant family, serve as major, inexpensive low-fat food sources providing for energy, high-quality protein, fiber, vitamins, pigments, as well as other nutrients. These crops also produce biologically active secondary metabolites, which may have both adverse and beneficial effects in the diet. This limited overview, based largely on our studies with the aid of HPLC, TLC, ELISA, GC-MS, and UV spectroscopy, covers analytical aspects of two major potato trisaccharide glycoalkaloids, alpha-chaconine and alpha-solanine, and their hydrolysis products (metabolites) with two, one, and zero carbohydrate groups; the potato water-soluble nortropane alkaloids calystegine A3 and B2; the principal potato polyphenolic compound chlorogenic acid; potato inhibitors of digestive enzymes; the tomato tetrasaccharide glycoalkaloids dehydrotomatine and alpha-tomatine and hydrolysis products; the tomato pigments beta-carotene, lycopene, and chlorophyll; and the anticholinergic alkaloids atropine and scopolamine present in Datura stramonium (jimson weed) seeds that contaminate grain and animal feed. Related studies by other investigators are also mentioned. Accurate analytical methods for these food ingredients help assure the consumer of eating a good-quality and safe diet.

  2. Selective Herbicides Reduce Weeding Costs in Two Mississippi Nurseries

    Science.gov (United States)

    W. B. Smyly; T. H. Filer

    1979-01-01

    In tests conducted from 1974 to 1977, the preemergence herbicides, Treflan, Eptam, Dymid, and Dectun reduced weeds and weeding costs in seedling beds of loblolly, slash, and short leaf pine. Velpar and Roundup controlled weeds along riser lines.

  3. THE STRUCTURE AND YIELD LEVEL OF SWEET CORN DEPENDING ON THE TYPE OF WINTER CATCH CROPS AND WEED CONTROL METHOD

    Directory of Open Access Journals (Sweden)

    Robert Rosa

    2014-10-01

    Full Text Available Organic manuring is suggested to be necessary in sweet corn cultivation. It is not always possible to use farmyard manure due to economic, production or technical reasons. Catch crops used as green manures can be an alternative source of organic matter. The experiment was carried out in central-east Poland (52°06’N, 22°55’E, in years 2008–2011. The successive effect of winter catch crops (hairy vetch, white clover, winter rye, Italian ryegrass, winter turnip rape and the type of weed control on the growth and yielding of sweet corn was examined. The catch crops were sown in early September, incorporated in early May. The effect of the winter catch crops on yield was compared to the effect of FYM at a rate of 30 t·ha-1 and the control without organic manuring. The sweet corn was grown directly after organic fertilization. Three methods of weed control was used: Hw – hand weeding, twice during the growing period, GCM – herbicide Guardian CompleteMix 664 SE, immediately after sowing the seed corn, Z+T – a mixture of herbicides Zeagran 340 SE + Titus 25 WG, in the 3–4 leaf stage sweet corn. The highest yields of biomass were found for winter rye (35.5 t·ha-1 FM and 7.3 t·ha-1 DM, the most of macroelements accumulated winter turnip rape (480.2 kg N+P+K+Ca+Mg·ha-1. Generally, leguminous catch crops had similar to the FYM and better than non-leguminous catch crops yield-forming effect. The highest yield of marketable ears of sweet corn was obtained after FYM (14.4 t·ha-1 and after hairy vetch catch crop (14.0 t·ha-1. A similar yield-forming effect also had white clover and Italian ryegrass. The most of ears from 1 ha was achieved after white clover catch crop (59.3 tausend, similar after FYM and hairy vetch catch crop. The highest kernel yields were found after FYM (10.7 t·ha-1. The yields of kernel after hairy vetch and white clover catch crops were significantly higher than after non-leguminous catch crops. Z+T weed control

  4. Population-level compensation impedes biological control of an invasive forb and indirect release of a native grass

    Science.gov (United States)

    Yvette K. Ortega; Dean E. Pearson; Lauren P. Waller; Nancy J. Sturdevant; John L. Maron

    2012-01-01

    The intentional introduction of specialist insect herbivores for biological control of exotic weeds provides ideal but understudied systems for evaluating important ecological concepts related to top-down control, plant compensatory responses, indirect effects, and the influence of environmental context on these processes. Centaurea stoebe (spotted knapweed) is a...

  5. Three-way interaction between biological control insects, a congener and their shared parasitoid: Evidence of biotic resistance

    Science.gov (United States)

    Invasive plants are one of the strongest drivers of species extinctions. Weed biological control offers a sustainable and safe means of long-term population reduction of their target. Herbivores introduced for the control of invasive plants interact with the native community in addition to the top-d...

  6. INTEGRATED MANAGEMENT OF CHROMOLAENA ODORATA EMPHASIZING THE CLASSICAL BIOLOGICAL CONTROL

    Directory of Open Access Journals (Sweden)

    SOEKISMAN TJITROSEMITO

    1998-01-01

    Full Text Available Chromolaena odorata, Siam weed, a very important weed of Java Island (Indonesia is native to Central and South America. In the laboratory it showed rapid growth (1.15 g/g/week in the first 8 weeks of its growth. The biomass was mainly as leaves (LAR : 317.50 cm'/g total weight. It slowed down in the following month as the biomass was utilized for stem and branch formation. This behavior supported the growth of C. odorata into a very dense stand. It flowered, fruited during the dry season, and senesced following maturation of seeds from inflorescence branches. These branches dried out, but soon the stem resumed aggressive growth following the wet season. Leaf biomass was affected by the size of the stem in its early phase of regrowth, but later on it was more affected by the number of branches. The introduction of Pareuchaetes pseudoinsulata to Indonesia, was successful only in North Sumatera. In Java it has not been reported to establish succesfully. The introduction of another biological control agent, Procecidochares conneca to Indonesia was shown to be sp ecific and upon release in West Java it established immediately. It spread exponentia lly in the first 6 months of its release. Field monitoring continues to eval uate the impact of the agents. Other biocontrol agents (Actmole anteas and Conotrachelus wilt be introduced to Indonesia in 1997 through ACIAR Project on the Biological Control of Chromolaena odorata in Indonesia and Papua New Guinea.

  7. RESEARCH REGARDING THE INFLUENCE WEED CONTROL TREATMENTS ON PRODUCTION AND QUALITATIVE INDICATORS SOYBEAN CULTIVATED IN MINIMUM TILLAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Cornel Chetan

    2016-11-01

    Full Text Available The use of herbicides abused, without a thorough knowledge can be dangerous for the environment through the introduction of toxic waste in agricultural ecosystems. It is necessary to reduce the doses used in relation to the use of conservative technology, finding solutions optimized for effective weed control. Research conducted at ARDS Turda in the years 2013 and 2014 have followed the effect of 12 variants of herbicides used to control weeds in soybean crop, sown in two tillage systems (classical system and minimal tillage system, on the soybean production and quality indicators. Tillage system significantly influenced both qualitative indices and soybean crop production (being 2635 kg/ha to the classical and 2131 kg/ha minimum tillage system. The significant influence of tillage soybeans in fat content (20.34% in minimum tillage system; 19.94% to the classical and on protein (39.89% minimum tillage system; 40.56% in the classic.

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

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

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

    2017-01-01

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

  10. 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.

  11. Managing weeds with a population dynamics approach

    Science.gov (United States)

    No-till cropping systems are increasing land productivity. A critical aspect of no-till is controlling weeds. Herbicides are a crucial tool for weed management, but weed resistance is decreasing control efficacy and increasing input costs. Scientists and producers are seeking a broader perspectiv...

  12. 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.

  13. 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)

    Mburu, D.N; Drennan, D.S.H

    1999-01-01

    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

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

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... 91 which has never been possible (Rao, 2000). Weed management is not accomplished by using cultural practices exclusively. Herbicides offer an additional tool to control weeds in conjunction with cultural practices. Jarwar et al. (1999) observed that chemical weed control is effective in controlling weeds.

  15. 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.

  16. Effecacy of Diffrent Herbicides on Weed Control of Garlic (Allium Sativum

    Directory of Open Access Journals (Sweden)

    M. Hosseni

    2012-04-01

    Full Text Available A field experiment was conducted to evaluate the effect of diffrent herbicides on weeds and garlic in a randomized complete-block design with 12 treatments and three replications, at Siahdasht, Farooj, Khorasan, Iran. Treatments were included rates of 4, 8, 12 and 16 kg.ha-1 Chlorthal-dimethyl (Dacthal, rates of 0.75, 1.5, 3 and 5 lit.ha-1 Oxyfluorfen (Goal, rates of 1, 2, 3 and 6 lit.ha-1 Ioxynil (Totril, and a plot which was hand weeded at the beginning of growing season. Results of three stages sampling showed that weed response to type and amount of herbicide which was significantly (p

  17. 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.

  18. Weeding Your Collection.

    Science.gov (United States)

    Kerby, Ramona

    2002-01-01

    Offers guidelines for weeding as part of school library collection development. Highlights include developing a weeding policy; and the CREW (Continuous Review Evaluation and Weeding) method, including reasons for weeding, scheduling, and guidelines for fiction and for nonfiction. (LRW)

  19. Phenology and temperature-dependent development of Ceutorhynchus assimilis, a potential biological control agent for Lepidium draba

    Science.gov (United States)

    Heart-podded hoary cress (Lepidium draba) is an alien weed that has invaded rangeland in the northwestern USA. A host race (i;e; host-specific biotype) of the weevil, Ceutorhynchus assimilis, is being evaluated as a prospective biological control agent. This biotype is only known from southern Eur...

  20. Ecological host-range of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of Dioscorea bulbifera L.

    Science.gov (United States)

    Open-field host-specificity testing assesses the host-range of a biological control agent in a setting that permits the agent to use its full complement of host-seeking behaviors. This form of testing, particularly when it includes a no-choice phase in which the target weed is killed, may provide th...

  1. 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.

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

    Science.gov (United States)

    Ansong, Michael; Pickering, Catherine

    2015-01-01

    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.

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

    Science.gov (United States)

    Ansong, Michael; Pickering, Catherine

    2015-01-01

    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. PMID:26252004

  4. Analysis of Satellite and Airborne Imagery for Detection of Water Hyacinth and Other Invasive Floating Macrophytes and Tracking of Aquatic Weed Control Efficacy

    Science.gov (United States)

    Potter, Christopher

    2016-01-01

    Waterways of the Sacramento San Joaquin Delta have recently become infested with invasive aquatic weeds such as floating water hyacinth (Eichhoria crassipes) and water primrose (Ludwigia peploides). These invasive plants cause many negative impacts, including, but not limited to: the blocking of waterways for commercial shipping and boating; clogging of irrigation screens, pumps and canals; and degradation of biological habitat through shading. Zhang et al. (1997, Ecological Applications, 7(3), 1039-1053) used NASA Landsat satellite imagery together with field calibration measurements to map physical and biological processes within marshlands of the San Francisco Bay. Live green biomass (LGB) and related variables were correlated with a simple vegetation index ratio of red and near infra-red bands from Landsat images. More recently, the percent (water area) cover of water hyacinth plotted against estimated LGB of emergent aquatic vegetation in the Delta from September 2014 Landsat imagery showed an 80 percent overall accuracy. For the past two years, we have partnered with the U. S. Department of Agriculture (USDA) and the Department of Plant Sciences, University of California at Davis to conduct new validation surveys of water hyacinth and water primrose coverage and LGB in Delta waterways. A plan is underway to transfer decision support tools developed at NASA's Ames Research Center based on Landsat satellite images to improve Delta-wide integrated management of floating aquatic weeds, while reducing chemical control costs. The main end-user for this application project will be the Division of Boating and Waterways (DBW) of the California Department of Parks and Recreation, who has the responsibility for chemical control of water hyacinth in the Delta.

  5. 35-40 The Effect of Tillage Frequency and Weed Control on Yield of ...

    African Journals Online (AJOL)

    The objective of the experiment was to determine the optimum tillage frequency, time and weeding frequency for tef production in the Yielmana ... post-harvest management cost, low risk crop and the straw provides better animal feed than ..... Kalyani publishers, New Delhi- 110 002, India. Rezene, F. and Zerihun, T. 2001.

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

    African Journals Online (AJOL)

    The subplots were herbicide (H) and no herbicide (NH). Weed regeneration was significantly higher under NT compared with other methods of land preparation. The herbicide treatment depressed maize yield. Grain yields were 1619.58 and 277.46 kg/ha for H and NH, respectively. Tillage treatment significantly affected ...

  7. Spent coffee grounds as air-propelled abrasive grit for weed control

    Science.gov (United States)

    Spent coffee grounds (SCG) represent a significant food waste residue. Value-added uses for this material would be beneficial. Gritty agricultural residues, such as corncob grit, can be employed as abrasive air-propelled agents for organically-compatible postemergence shredding of weed seedlings sel...

  8. 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...

  9. Effect of oil palm sludge on cowpea nodulation and weed control in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... enough sunlight to penetrate soil surface thereby smo- thering the weeds especially the low growing ones. It also displaces air from soil pores creating anaerobic condition. This is in accordance with Kloke and Ley (1963) who reported on complete elimination of grass growth by 3.3%. (by weight) in soil.

  10. Growth stage of Phalaris minor Retz. and wheat determines weed control and crop tolerance of four post-emergence herbicides

    Directory of Open Access Journals (Sweden)

    Rubia Rasool

    2017-04-01

    Full Text Available Phalaris minor Retz. has evolved multiple herbicide resistance in wheat growing areas in northwestern India. An understanding of the effect of growth stage on herbicide tolerance of wheat and control of P. minor will help in selecting the most appropriate herbicide for different situations. The weed control and crop safety of four commonly used wheat herbicides (sulfosulfuron, pinoxaden, fenoxaprop plus metribuzin and mesosulfuron plus iodosulfuron, each applied at four different wheat growth stages was investigated in field studies for two years. P. minor plants were at 1, 2-3, 3-4 and 7-8 leaf stages when the herbicides were applied at Zadok 12-Z12, Z13, Z21 and Z23 stages of wheat, respectively. Sulfosulfuron application at Z12 and Z13 wheat stages (before first irrigation, provided >80% control of P. minor and produced wheat grain yield (4.5-4.7 t/ha similar to the weed-free check (4.9 t/ha in both years. Pinoxaden, fenoxaprop plus metribuzin and mesosulfuron plus iodosulfuron application at Z12 and Z13 wheat stages recorded significantly lower wheat grain yield (3.62-3.95 t/ha due to poor weed control, crop toxicity or both. All the four herbicides were equally effective on P. minor when applied at Z21 wheat stage. At Z23 wheat stage, pinoxaden gave >90% control of P. minor and the highest wheat grain yield (4.82 t/ha. The results are expected to allow changes in the current recommendation of the timing of post-emergence herbicides for the management of P. minor in wheat.

  11. Integrating chemical and biological control

    Science.gov (United States)

    Scott Salom; Albert Mayfield; Tom McAvoy

    2011-01-01

    Research and management efforts to establish an effective biological control program against HWA has received significant support by the U.S. Forest Service over the past 17 years. Other federal and state agencies, universities, and private entities have also contributed to this overall research and management effort. Although a number of HWA-specific predator species...

  12. Integrated weed management in wheat

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  13. 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)

    Hussain, N.; Khan, M.B.; Khan, M.A.; Hameed, R.A.

    2005-01-01

    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)

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

    International Nuclear Information System (INIS)

    Farag, I.A.A; Abd El Hameed, I.M

    2013-01-01

    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 Cm 3 ⁄200 ;liters water⁄fad. Sprayed at pre-emergence. 5-48⁒ sprayed at pre-emergence with the rate of 500 cm 3 ⁄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.

  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 and...

  16. Weed control in organic rice using plastic mulch and water seeding methods in addition to cover crops

    Science.gov (United States)

    Weeds are a major yield limiting factor in organic rice farming and are more problematic than in conventional production systems. Water seeding is a common method of reducing weed pressure in rice fields as many weeds connot tolerate flooded field conditions. The use of cover crops is another method...

  17. Competitive influence of Eleusine indica and other weeds on the ...

    African Journals Online (AJOL)

    (Received 13 December, 2000; accepted 5 February, 2002) ABSTRACT Delayed weed removal is the primary cause of maize yield loss in smallholder agriculture. The slog for weed management could probably be reduced if the initial weed control removal is restricted to the in-row weeds, followed soon after by elimation of ...

  18. Control theory meets synthetic biology.

    Science.gov (United States)

    Del Vecchio, Domitilla; Dy, Aaron J; Qian, Yili

    2016-07-01

    The past several years have witnessed an increased presence of control theoretic concepts in synthetic biology. This review presents an organized summary of how these control design concepts have been applied to tackle a variety of problems faced when building synthetic biomolecular circuits in living cells. In particular, we describe success stories that demonstrate how simple or more elaborate control design methods can be used to make the behaviour of synthetic genetic circuits within a single cell or across a cell population more reliable, predictable and robust to perturbations. The description especially highlights technical challenges that uniquely arise from the need to implement control designs within a new hardware setting, along with implemented or proposed solutions. Some engineering solutions employing complex feedback control schemes are also described, which, however, still require a deeper theoretical analysis of stability, performance and robustness properties. Overall, this paper should help synthetic biologists become familiar with feedback control concepts as they can be used in their application area. At the same time, it should provide some domain knowledge to control theorists who wish to enter the rising and exciting field of synthetic biology. © 2016 The Author(s).

  19. Effect of Roundup-Salt Mixtures on Weed Control and Soil Microbial ...

    African Journals Online (AJOL)

    The efficacy of roundup at 0.47 kg a.i./ha mixed with either 0.23 kg/ha of sodium chloride or 0.53 kg/ha of ammonium sulphate or 0.24 kg/ha of urea was compared with roundup at 1.44 kg a.i/ha and manual weeding. The treatments were arranged in randomized complete block design and replicated four times. The roundup ...

  20. EFFECTIVENESS OF GLYPHOSATE AND 2.4 D AMIN HERBICIDES TO CONTROL WEEDS UNDER Shorea selanica Bl. PLANTATION IN CARITA TRIAL GARDEN, BANTEN

    Directory of Open Access Journals (Sweden)

    Ari Wibowo

    2007-03-01

    Full Text Available A trial was carried out in Carita, West Java, to identify the effectiveness of Glyphosate and 2.4 D Amin Herbicide to control weeds under Shorea selanica Bl. plantation. The trial was conducted through the application of Glyphosate and 2.4 D Amin Herbicide with dosages of 5, 6, 7, 8 and 9 liter per ha and compared with Glyphosate herbicide 5 liter per ha, manual treatment, and control (no treatment. The result showed that Glyphosate and 2.4 D Amin Herbicide could be used to control weeds in order to maintaining S. selanica Bl. plantation. Minimum dosage of 6 liter/ha was effective to control weeds such as Chromolaena odorata DC, Mikania micrantha Will, Lantana camara L, Imperata cylindrica Beauv., Melastoma malabathricum L, and Boreria latifolia Bl. Furthermore, there was no symptom of poison on S. selanica Bl. plantation after herbicide application with all dosages applied.

  1. Green Weeding

    Science.gov (United States)

    Penniman, Sarah; McColl, Lisa

    2008-01-01

    Gone are the days of tiptoeing to the dumpsters with boxes of weeded books in tow. Lots of libraries are now taking advantage of the many low-cost services and solutions that promise to help extend the lives of collection discards. Some of these options can be very profitable. Some create goodwill within the local community. Some may seem more…

  2. Southern Idaho student "bug crews": Weeds, youth, and biocontrol in the rangelands of Idaho

    Science.gov (United States)

    Sharlyn Gunderson-Izurieta; George P. Markin; Nan Reedy; Becky. Frieberg

    2009-01-01

    Biological control of noxious weeds is an effective and widespread method often used by rangeland managers in the western United States. However, once biological control agents, usually insects, are released onto public and private lands there are few, if any, programs to follow up and monitor the effectiveness of these agents. A technique being used by some...

  3. Image analysis as a non-destructive method to assess regrowth of weeds after repeated flame weeding

    DEFF Research Database (Denmark)

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

    2013-01-01

    Efficient non-chemical weed control like flame weeding often requires repeated treatments. In weed control experiments the effect of each treatment may be estimated by removing and weighing the remaining weed biomass after the treatment, but the method influences the weed plants ability to regrow...... picture of the long-term effect of repeated treatments. Image analysis was most useful for assessing the effect of repeated treatments when weed cover was relatively low (below 40%) and when plots contained relatively much withered plant material. However, when weed cover is close to 100%, dry weight...

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  5. Controle de plantas daninhas na cultura do milho com gliricídia em consorciação Weed control in maize crop with gliricidia intercropping

    Directory of Open Access Journals (Sweden)

    B.B. Araújo Jr.

    2012-12-01

    Full Text Available A gliricídia (Gliricidia sepium é leguminosa perene, cultivada para propósitos múltiplos, que apresenta crescimento rápido e várias substâncias com propriedades alelopáticas. Existem indicações de que a consorciação com gliricídia também pode trazer benefícios no controle das plantas daninhas do milho. O objetivo deste trabalho foi avaliar o controle das plantas daninhas no milho (híbrido duplo AG 1051 com gliricídia em consorciação. Utilizou-se o delineamento em blocos completos casualizados, com oito repetições. Os tratamentos consistiram em: cultivo do milho com capinas (duas, aos 20 e 40 dias após a semeadura, sem capinas e em consorciação com a gliricídia. A gliricídia foi semeada a lanço, com 25 sementes m-2, por ocasião da semeadura do milho, entre as fileiras deste. Quinze espécies de plantas daninhas foram catalogadas na área experimental, sendo Commelina benghalensis a mais frequente. Os rendimentos de espigas verdes (empalhadas e despalhadas obtidos com a consorciação foram iguais ou superiores a 85% dos rendimentos obtidos com capinas. Além disso, o rendimento de grãos no consórcio chegou a 80% do rendimento de grãos do milho capinado. Portanto, a consorciação com a gliricídia pode ser uma alternativa viável para as produções de milho verde e de grãos, embora essa consorciação não tenha influenciado a densidade e a biomassa seca das plantas daninhas.Gliricidia (Gliricidia sepium, a perennial leguminous species presenting fast growth and several allelopathic substances, is cultivated for multiple purposes. There are good evidences that gliricidia intercropped with maize efficiently controls weeds. This work aimed to evaluate the use of gliricidia intercropped with maize as a method of weed control in maize (hybrid AG 1051. The experiment was carried out in a randomized complete block design with eight replications. The treatments consisted of: maize cropping with hand-hoeing weed control

  6. 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

  7. 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

  8. [Effects of weeding methods on weed community and its diversity in a citrus orchard in southwest Zhejiang].

    Science.gov (United States)

    Yao, He-Jin; Jin, Zong-Lai; Yang, Wei-Bin; Zhao, Jian-Hua; Zhang, Fan

    2010-01-01

    By using the research methods of ecological community, the effects of different weed management strategies including chemical weeding, manual weeding, and their combination on the weed community and its diversity in a citrus chard of main orange producing region in Quzhou City, Zhejiang Province were studied from June 2005 to May 2008. In control plots, there were 75 species and 25 families of weeds; after chemical weeding, manual weeding, and their combination, there were 46 species and 17 families, 59 species and 20 families, and 51 species and 18 families of weeds, respectively. The Margalef's species richness index, Shannon's diversity index, and Shannon's evenness index were the lowest after chemical weeding, but the highest after manual weeding, suggesting that chemical weeding had the greatest effects on the weed diversity in the citrus orchard. It was suggested that to sufficiently control the weeds while to maintain the weed diversity in the orchard weeds in southwest Zhejiang, the combination of chemical and manual weeding would be the best management strategy.

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

    Directory of Open Access Journals (Sweden)

    P. C. Abhilash

    2008-03-01

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

  10. Weed Recognition Framework for Robotic Precision Farming

    DEFF Research Database (Denmark)

    Kounalakis, Tsampikos; Triantafyllidis, Georgios; Nalpantidis, Lazaros

    2016-01-01

    In this paper, we introduce a novel framework which applies known image features combined with advanced linear image representations for weed recognition. Our proposed weed recognition framework, is based on state-of-the-the art object/image categorization methods exploiting enhanced performance...... using advanced encoding and machine learning algorithms. The resulting system can be applied in a variety of environments, plantation or weed types. This results in a novel and generic weed control approach, that in our knowledge is unique among weed recognition methods and systems. For the experimental...... evaluation of our system, we introduce a challenging image dataset for weed recognition. We experimentally show that the proposed system achieves significant performance improvements in weed recognition in comparison with other known methods....

  11. Controle de plantas daninhas com herbicidas cloroacetamidas em sistemas convencional e de semeadura direta Weed control with chloroacetamide herbicides in conventional and no-tillage systems

    Directory of Open Access Journals (Sweden)

    M.V.W. Ferri

    2003-04-01

    Full Text Available Os sistemas de manejo do solo podem alterar a bioatividade dos herbicidas cloroacetamidas e influir na sua persistência no solo, seletividade às culturas e eficácia de controle das plantas daninhas. Um experimento foi conduzido na Universidade Federal do Rio Grande do Sul, durante o ano agrícola de 2000/2001, para avaliar a eficácia de controle das plantas daninhas pelos herbicidas cloroacetamidas, em solo Argissolo Vermelho, manejado sob semeadura direta e preparo convencional. Foram avaliados os herbicidas acetochlor e alachlor, cada um na dose de 3.360 g ha-1, metolachlor a 2.400 g ha-1, s-metolachlor a 1.440 g ha-1, s-metolachlor + antídoto à 1.440 e 1.800 g ha-1, respectivamente, além da testemunha sem herbicida, nos sistemas convencionais e semeadura direta. As avaliações foram de eficácia de controle, população de plantas daninhas e matéria seca da parte aérea das plantas daninhas, realizadas aos 30 e 50 dias após aplicação dos tratamentos (DAT. Os herbicidas cloroacetamidas foram mais eficientes no controle das plantas daninhas no preparo convencional, comparado à semeadura direta, em ambas as épocas de avaliação. Os herbicidas acetochlor, alachlor a 3.600 g ha-1 e s-metolachlor + protetor a 2.400 g ha-1 foram mais eficientes no controle destas plantas, em relação aos demais herbicidas e formulações. A produção de matéria seca e a população das plantas daninhas foram menores no preparo convencional.Soil management systems can affect chloroacetamide herbicide bioactivity and its soil persistence, crop selectivity and weed control. An experiment was carried out at the University of Rio Grande do Sul, Brazil, during the growing season 2000/2001, to evaluate the weed control efficacy of the chloroacetamide herbicides, in a Paleudult soil, under conventional tillage and no-tillage systems. The following treatments were tested: acetochlor and alachlor, each at the rate of 3.360 g ha-1, metolachlor at 2.400 g ha-1

  12. 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...

  13. 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)

  14. Overview of glyphosate-resistant weeds worldwide.

    Science.gov (United States)

    Heap, Ian; Duke, Stephen O

    2018-05-01

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

  15. "Protected biological control"- Biological pest management in the greenhouse industry

    NARCIS (Netherlands)

    Pilkington, L.J.; Messelink, G.J.; Lenteren, van J.C.; Mottee, Le K.

    2010-01-01

    This paper briefly describes the foundations and characteristics of biological control in protected cropping and what drivers are behind adoption of this management system within this industry. Examining a brief history of biological control in greenhouses and what makes it a successful management

  16. 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

  17. Evaluation of sowing patterns and weed control on mung bean (Vigna radiate L. Wilczek - black cumin (Nigella sativa L. intercropping system

    Directory of Open Access Journals (Sweden)

    parviz Rezvani Moghadam

    2016-04-01

    Full Text Available In order to study different arrangements and weed controls effects on mung bean (Vigna radiate L. Wilczek – black cumin (Nigella sativa L. intercropping an experiment was conducted at the Research Station of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season 2005 – 2006. Sixteen treatments comprising combinations of eight sowing patterns [A1: Sole black cumin, A2: Sole mung bean, A3: 3 rows black cumin– 2 rows mung bean, A4: 3 rows black cumin – 2 rows mung bean, A5: 2 rows black cumin – 1 rows mung bean, A6: 1 row black cumin – 2 rows mung bean, A7: 3 rows black cumin – 3 rows mung bean (Striped, A8: 1 row black cumin – 1 row mung bean (alternative rows] and two weed controls [V1: unweeded, V2: completely hand weeding] were arranged in a factorial experiment based on randomized complete block design with three replications. Results showed that in intercropping systems leaf area index (LAI of mung bean reduced but in the case of black cumin increased. Mung bean total dry matter in intercropping system did not differ comparing with sole crop but total dry matter in black cumin increased. All yield components in both crops affected by sowing patterns and weed control treatments. Number of branches/plant, number of pods or follicules/plant and number of seed/pods or follicules increased in A8, A4, A5 and A3 sowing patterns in mung bean and A3, A5 and A7 sowing patterns in black cumin compared with other arrangements. By increasing mung bean ratio in rows, the number of weed species, weed density, dry weight of weeds and abundance of weed species decreased. In unweeded treatment, number of branches/plant, number of pods or follicules/plant and number of seed/pods or follicules decreased in both crops. Land equivalent ratio (LER was more than 1.00 in all sowing patterns.

  18. 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.

  19. 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.

  20. Controle de plantas daninhas em feijão-de-corda em sistema de semeadura direta Weed control in cowpea under no-nill system

    Directory of Open Access Journals (Sweden)

    J.B.F. Silva

    2003-04-01

    Full Text Available O objetivo deste estudo foi avaliar a eficiência dos herbicidas glyphosate (1.800 g ha-1 e paraquat (800 g ha-1, aplicados antes da semeadura como dessecantes, e imazamox (0, 21, 42 e 63 g ha-1 ou fenoxaprop-p-ethyl (0, 40, 80 e 120 g ha-1, aplicados em condições de pós-emergência, no controle das plantas daninhas, bem como os efeitos tóxicos ao feijão-decorda (Vigna unguiculata cv. Epace 10, em sistema de semeadura direta com irrigação. Utilizou-se o delineamento experimental em blocos ao acaso, com os tratamentos arranjados em parcelas sub-subdivididas, com quatro repetições. Os tratamentos com glyphosate associado a imazamox ou fenoxaprop-p-ethyl resultaram em menor infestação das plantas daninhas, avaliadas através da fitomassa seca da parte aérea, maior produção de grãos e maior número de vagens por planta de feijão-de-corda, quando comparado com os tratamentos com paraquat associado aos herbicidas pós-emergentes. Os herbicidas imazamox e fenoxaprop-p-ethyl não causaram sintomas visuais de toxicidade ao feijão-de-corda. A dose de 80 g ha-1 de fenoxaprop-p-ethyl associada com o glyphosate (1.800 g ha-1 foi a mais eficiente no controle das plantas daninhas, na avaliação realizada 45 dias após a aplicação (DAA do fenoxaprop-p-ethyl. Este herbicida não controlou o capim-carrapicho (Cenchrus echinatus e o capim-colchão (Digitaria horizontalis nas avaliações realizadas aos 15 e 28 DAA. O imazamox não foi eficaz no controle das espécies erva-de-santa-luzia (Chamaesyce hirta e leiteira (Euphorbia heterophylla.This research was conducted to determine the effectiveness of the herbicides glyphosate (1.800 g ha-1 and paraquat (800 g ha-1, applied as desiccants before sowing and fenoxaprop-p-ethyl (0, 40, 80 and 120 g ha-1 and imazamox (0, 21, 42 and 63 g ha-1, applied in post-emergence conditions, on the weed control and the phytotoxicity to cowpea plants (Vigna unguiculata cv. Epace 10, under a no-till system, with

  1. Influence of Temperature, Humidity, and Plant Terpenoid Profiles on Life History Characteristics of Boreioglycaspis melaleucae (Hemiptera: Psyllidae), a Biological Control Agent of the Invasive Tree Melaleuca quinquenervia

    Science.gov (United States)

    Although the introduced weed biological control agent Boreioglycaspis melaleucae Moore is widely established among stands of its host Melaleuca quinquenervia (Cav.) Blake (Myrtaceae) in south Florida, it’s population densities decline markedly during summer months. We investigated the hypothesis tha...

  2. The leafmining Leurocephala schinusae (Lepidoptera Gracillariidae): Not suitable for the biological control of Schinus terebinthifolius (Sapindales Anacardiaceae)in continental USA

    Science.gov (United States)

    Leurocephala schinusae Davis & Mc Kay (Lepidoptera: Gracillariidae) was studied to assess its suitability as a biological control agent of Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae), a serious environmental weed in the USA and elsewhere in the world. The host range was determined by ...

  3. Life history and host range of the leaf blotcher Eucosmophora schinusivora; a candidate for biological control of Schinus terebinthifolius in the USA

    Science.gov (United States)

    The host range of Eucosmophora schinusivora Davis & Wheeler (Lepidoptera: Gracillariidae) was studied to assess its suitability as a biological control agent of Schinus terebinthifolius Raddi (Anacardiaceae), a serious environmental and agricultural weed in the USA and elsewhere in the world. The l...

  4. Growth inhibition of Dalmatian toadflax, Linaria dalmatica (L.) Miller, in response to herbivory by the biological control agent Mecinus janthinus Germar

    Science.gov (United States)

    Marjolein Schat; Sharlene E. Sing; Robert K. D. Peterson; Fabian D. Menalled; David K. Weaver

    2011-01-01

    Our study reports the results of field and garden experiments designed to quantitatively evaluate the impact of herbivory by a weed biological control agent, the stem-mining weevil Mecinus janthinus Germar, on the growth of its exotic host Dalmatian toadflax, Linaria dalmatica (L.) Miller. Herbivory by M. janthinus under both natural and manipulated environmental...

  5. Establishment, population increase, spread, and ecological host range of Lophodiplosis trifida (Diptera: Cecidomyiidae), a biological control agent of the invasive tree Melaleuca quinquenervia (Myrtales:Myrtaceae).

    Science.gov (United States)

    The Australian tree Melaleuca quinquenervia (Cav.) Blake is an invasive weed in wetland systems of Florida, USA. A biological control program targeting M. quinquenervia has culminated in the release of the gall forming midge Lophodiplosis trifida Gagné (Cecidomyiidae). Populations of the introduced ...

  6. 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

    2012-01-01

    in 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......There is much research on technical aspects related to sensor and mapping techniques, which enable so-called intelligent cultivators to target the intra-row spaces within crop rows. This study investigates (i) an expected advantage of an intelligent rotor tine cultivator (the cycloid hoe) in terms...... of crop-weed selectivity and (ii) an expected synergistic effect between punch planting and post-emergence weed harrowing, in terms of improved crop-weed selectivity. Selectivity is defined as the relationship between weed density decline and associated crop density decline 1 week after cultivation. Punch...

  7. Biological control and sustainable food production

    NARCIS (Netherlands)

    Bale, J.S.; Lenteren, van J.C.; Bigler, F.

    2008-01-01

    The use of biological control for the management of pest insects pre-dates the modern pesticide era. The first major successes in biological control occurred with exotic pests controlled by natural enemy species collected from the country or area of origin of the pest (classical control).

  8. Floral biology and breeding system of three Ipomoea weeds Biologia floral e sistema reprodutivo de três espécies daninhas de Ipomoea

    Directory of Open Access Journals (Sweden)

    R.C.S. Maimoni-Rodella

    2007-03-01

    Full Text Available The floral biology of three weeds, Ipomoea cairica, I. grandifolia and I. nil (Convolvulaceae, was studied in Botucatu and Jaboticabal, São Paulo, in southeastern Brazil. The three species are melittophilous, with a varied set of floral visitors, but with some overlapping. Cluster analysis using Jacquard similarity index indicated a greater similarity among different plant species in the same locality than among the populations at different places, in relation to floral visitor sets. The promiscuous and opportunistic features of the flowers were shown, with such type of adaptation to pollination being advantageous to weeds since pollinator availability is unpredictable at ruderal environments.A biologia floral de Ipomoea cairica, I. grandifolia e I. nil - plantas daninhas da família Convolvulaceae - foi estudada em Botucatu e Jaboticabal, Estado de São Paulo, Brasil. As três espécies são melitófilas, apresentando conjuntos de visitantes florais bastante diversificados, embora haja alguma sobreposição entre eles. Com relação aos visitantes florais, a análise de agrupamento, empregando-se o índice de similaridade de Jaccard, indicou maior similaridade entre diferentes espécies de Ipomoea ocorrentes no mesmo local do que entre populações da mesma espécie em diferentes localidades. O caráter promíscuo e oportunista da adaptação à polinização, presente nessas espécies, foi demonstrado, sendo essa adaptação vantajosa para plantas daninhas, uma vez que em ambientes ruderais a disponibilidade de polinizadores é imprevisível.

  9. Guidelines for management of noxious weeds at Hanford

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  10. 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

  11. Effect of Weed Interference on Yield and Agronomical Characteristics of Fenugreek (Trigonella foenum gracum in Different Plant Density under Birjand Conditions

    Directory of Open Access Journals (Sweden)

    R Baradaran

    2016-02-01

    Full Text Available Introduction Iran is among the countries with a climate appropriate for growing a wide range of herbs, and can be a great source of producing and exporting plants. Fenugreek (Trigonella foenum gracum is one of the oldest plant and it is an annual herbaceous plant of the Fabaceae family (Fabaceae which are dry, brown or reddish-yellow to gray to over 5.3 mm. Seeds of this plant are used as a spice and its leaves are used as a vegetable. Among the most important factors in farming, it is important to use appropriate planting density. Therefore, if all the necessary conditions, including the right, but density is inappropriate, it will not get the optimum yield per unit area. The effective management of weeds increase the performance of weed management practices, reduce weed population and the costs associated with it over time. Weeds compete with crops for a variety of sources such as light, water and minerals. Given that the best time weeding the weeds and the most appropriate density of fenugreek is not much information available, this study aimed to determine the appropriate density of weed infested and fenugreek was used. Materials and Methods In order to determine the effects of weed interference and appropriate density of fenugreek, a field trial was conducted in research farm of Birjand Islamic Azad University during the spring of year 2011. The experiment was a factorial based on randomized complete block design. The treatments were fenugreek density at 10, 20 and 40 plants m-2 and weed interference in five levels included weed-free to maturity, 20, 40 and 60 days after emergence, and no weeding. Fenugreek seeds (spherical, brown of pure seed before planting desert of preparation and sterilization by benomyl and then do planting trees and irrigation was done immediately. Irrigation was applied every seven days. During the study, pests and diseases were completely controlled. Weed control was done manually in three stages. Traits such as

  12. Surveys for Biological Control Agents of Hydrilla verticillata in the People’s Republic of China in 2013

    Science.gov (United States)

    2017-03-01

    ERDC) solves the nation’s toughest engineering and environmental challenges. ERDC develops innovative solutions in civil and military engineering... Ecology and Invasive Species Branch; Mark Farr, Chief of the Ecosystem Evaluation and Engineering Division; and Dr. Beth C. Fleming, Director of the...Matching the origin of an invasive weed for selection of a herbivore haplotype for a biological control programme. Molecular Ecology 15:287-297

  13. Biology and Water Pollution Control.

    Science.gov (United States)

    Warren, Charles E.

    Within this text, the reader is attuned to the role biology can and should play in combating the alarming increase in water pollution. Both the urgency of the problem and the biological techniques that are being developed to cope with the water pollution crisis are scrutinized; what is and is not known about the problem is explained; past,…

  14. 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.

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

    Science.gov (United States)

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

  16. Herbicide-resistant weeds: Management strategies and upcoming technologies

    Science.gov (United States)

    Herbicides have contributed to substantial increase in crop yields over the past seven decades. Over reliance on herbicides for weed control has led to rapid evolution of herbicide-resistant (HR) weeds. Increased awareness of herbicide resistance and adoption of diversified weed control tactics by f...

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  18. Surfactant-induced deposit structures in relation to the biological efficacy of glyphosate on easy- and difficult-to-wet weed species.

    Science.gov (United States)

    Kraemer, Thorsten; Hunsche, Mauricio; Noga, Georg

    2009-08-01

    Typical active ingredient (AI) residue patterns are formed during droplet drying on plant surfaces owing to the interaction of spray solution characteristics and leaf micromorphology. Currently, comparatively little is known about the influence of AI deposit patterns within a spray droplet residue area on the penetration and biological efficacy of glyphosate. A scanning electron microscope with energy dispersive X-ray microanalysis has been used to characterise residue patterns and to quantify the area ultimately covered by glyphosate within the droplet spread area. The easy-to-wet weed species Stellaria media L. and Viola arvensis L., as well as the difficult-to-wet Chenopodium album L. and Setaria viridis L., differing in their surface micromorphology, have been used. Rapeseed oil ethoxylates (RSO 5 or RSO 60) were added to glyphosate solutions to provide different droplet spread areas. Addition of RSO 5 enhanced droplet spread area more than RSO 60, and both caused distinct glyphosate residue patterns. The biological efficacy of treatment solutions showed no significant correlation with the area ultimately covered by glyphosate. The results have implications on herbicide uptake models. This study shows that droplet spread area does not correspond to the area ultimately covered by glyphosate, and that the latter does not affect glyphosate phytotoxicity.

  19. Avaliação de herbicidas no controle de plantas daninhas em mandioquinha-salsa Herbicide efficiency in controlling weeds in peruvian carrot

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Nogueira Sediyama

    2008-12-01

    Full Text Available Avaliou-se a eficiência de herbicidas aplicados em pré e pós-emergência no controle de plantas daninhas e na produção de mandioquinha-salsa na Fazenda Experimental da EPAMIG, em Oratórios (MG, de maio a dezembro de 2002. Utilizou-se o delineamento de blocos casualizados com quatro repetições e 15 tratamentos incluindo duas testemunhas, com e sem capina. Em cada tratamento, foi usado um herbicida em pré e outro em pós-emergência das plantas, aplicados aos três e aos 45 dias após o plantio (DAP respectivamente. A eficiência de controle e a toxidez dos herbicidas foram avaliadas aos 60 DAP e a produção de matéria seca de plantas daninhas aos 60 e 130 DAP. Na colheita, avaliou-se produção de raízes, coroa e parte aérea. A emergência de plantas foi máxima aos 45 DAP e, posteriormente, houve redução no estande, quando se utilizaram os herbicidas atrazine + óleo mineral e oxadiazon, em pós-emergência. Esses herbicidas, apesar de eficientes no controle de plantas daninhas, causaram toxidez à cultura. Na produção de raízes, destacaram-se os tratamentos: atrazine +fluazifop-p-butil; diuron + fluazifop-p-butil; diuron + Oxadiazon; linuron + fluazifop-p-butil; metolachlor + metribuzin + linuron e oxadiazon + diuron, com bom controle de plantas daninhas e rendimentos de raízes comerciais semelhantes ao da testemunha mantida no limpo (8,62 t ha-1.The efficiency of herbicides applied in pre- and post-emergence for weed control in Peruvian carrot production was evaluated at the EPAMIG Experimental Farm, Oratórios, Minas Gerais State, from May to December, 2002. The experiment was arranged in a randomized block design, with four replications and 15 treatments, including two controls (with and without weeding. Pre- and post-emergence herbicides were used in each treatment applied at 3 and 45 days after planting (DAP, respectively. Efficiency and toxicity were evaluated at 60 DAP and weed dry matter yield at 60 and 130 DAP. At

  20. Análise matemática e biológica dos modelos de estimativa de perdas de rendimento na cultura devido à interferência de plantas daninhas Mathematical and biological analysis of the models for estimating culture yield losses due to weed interference

    Directory of Open Access Journals (Sweden)

    C. Adati

    2006-01-01

    Full Text Available As plantas daninhas acarretam reduções no rendimento das culturas agrícolas. Os modelos matemáticos de estimativa de perda de rendimento na cultura devido à interferência dessas plantas podem ser instrumentos úteis à tomada de decisão de manejo. Se for possível prever as perdas de rendimento, será possível decidir se é viável ou não a aplicação de uma medida de controle. Há na literatura vários modelos matemáticos empíricos de regressão lineares, não-lineares e polinomiais usados para estimar as perdas de rendimento devido às plantas daninhas. O presente trabalho teve como objetivo apresentar uma análise dos modelos matemáticos presentes na literatura utilizados para estimar as perdas de rendimento que as plantas daninhas acarretam à cultura, considerando o ajuste matemático às observações e a descrição biológica do comportamento dessas perdas.The presence of weeds in any production system involving plants causes crop yield losses. Mathematical models for crop yield loss estimation due to the interference of weeds can be useful tools for decision-making management strategies. If it is possible to predict crop yield loss, it will be possible to decide whether it is viable to apply control measures. There are several empirical models in the literature used to estimate crop yield loss due to the presence of weeds, which are linear, non linear and polynomial. The goal of this work is to present an analysis of the existing mathematical models used to estimate crop yield loss due to weeds by considering both their mathematical fit and biological behavior.

  1. 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

  2. The efficiency of adjuvants combined with flupyrsulfuron-methyl plus metsulfuron-methyl (Lexus XPE) on weed control.

    Science.gov (United States)

    Heremans, B; Isebaert, S; Verhoeven, R; Haesaert, G

    2007-01-01

    This paper presents the results of laboratory tests on a selection of weeds (Viola arvensis, Polygonum persicaria, Chamomilla recutita, Chenopodium album, Veronica persicaria, Alopecurus myosusroides) to investigate the efficiency of flupyrsulfuron-methyl plus metsutfuronmethyl (Lexus XPE) in combination with different adjuvants. The efficiency of the herbicide improved in combination of adjuvants. The level of phytotoxicity of the adjuvants-herbicide treatments appllied varied among the different weed species.

  3. Split application of glyphosate in herbicide-tolerant maize provides efficient weed control and favors beneficial epigeic arthropods

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Zdeňka; Skoková Habuštová, Oxana; Holec, J.; Holec, M.; Boháč, J.; Jursík, M.; Soukup, J.; Sehnal, František

    2018-01-01

    Roč. 251, JAN 01 (2018), s. 171-179 ISSN 0167-8809 Grant - others:GA ČR(CZ) L200961652 Institutional support: RVO:60077344 Keywords : herbicide-tolerant maize * weed management * conventional tillage Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection OBOR OECD: Agronomy, plant breeding and plant protection Impact factor: 4.099, year: 2016 http://www. science direct.com/ science /article/pii/S0167880917304188

  4. 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

  5. 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.

  6. Transgenic glyphosate-resistant oilseed rape (Brassica napus) as an invasive weed in Argentina: detection, characterization, and control alternatives.

    Science.gov (United States)

    Pandolfo, Claudio E; Presotto, Alejandro; Carbonell, Francisco Torres; Ureta, Soledad; Poverene, Mónica; Cantamutto, Miguel

    2016-12-01

    The presence of glyphosate-resistant oilseed rape populations in Argentina was detected and characterized. The resistant plants were found as weeds in RR soybeans and other fields. The immunological and molecular analysis showed that the accessions presented the GT73 transgenic event. The origin of this event was uncertain, as the cultivation of transgenic oilseed rape cultivars is prohibited in Argentina. This finding might suggest that glyphosate resistance could come from unauthorized transgenic oilseed rape crops cultivated in the country or as seed contaminants in imported oilseed rape cultivars or other seed imports. Experimentation showed that there are alternative herbicides for controlling resistant Brassica napus populations in various situations and crops. AHAS-inhibiting herbicides (imazethapyr, chlorimuron and diclosulam), glufosinate, 2,4-D, fluroxypyr and saflufenacil proved to be very effective in controlling these plants. Herbicides evaluated in this research were employed by farmers in one of the fields invaded with this biotype and monitoring of this field showed no evidence of its presence in the following years.

  7. Parthenium Weed (Parthenium hysterophorus L.) Research in

    African Journals Online (AJOL)

    Parthenium weed (Parthenium hysterophorus L.), here after referred to as parthenium is an herbaceous invasive weed ... management is of high concern by the government, researchers and the farmers. Although there are ..... control of Parthenium has been exhausted in India with limited practical application due to the low ...

  8. Obsolescence, Weeding, and the Utilization of Space.

    Science.gov (United States)

    Lancaster, F. W.

    1988-01-01

    Suggests an objective approach to weeding library materials and discusses ways of measuring obsolescence and of controlling variables to provide a true picture of aging. Weeding is shown to improve space utilization and the quality of a collection. (5 references) (MES)

  9. 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.

  10. Image-based thresholds for weeds in maize fields

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one of the

  12. Biological control of cattle fever ticks

    Science.gov (United States)

    Cattle fever ticks (CFT) Rhipicephalus microplus and Rhipicephalus annulatus are invasive livestock pests that are endemic to Mexico and invasive along the Texas – Mexico border. Acaricide resistance, alternate wildlife hosts, and pathogenic landscape forming weeds present challenges for sustainable...

  13. 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)

    Ahari Mostafavi, H.; Fathollahi, H.; Naserian, B.; Rafiee, H.; Matlobi, M.; Bahaee, M.

    2003-01-01

    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

  14. Manejo de plantas de cobertura no controle de plantas daninhas na cultura do milho Cover crop management and weed control in corn

    Directory of Open Access Journals (Sweden)

    P.V.D. Moraes

    2009-06-01

    Full Text Available O sistema de semeadura direta na cultura do milho tem apresentado expansão na região Sul do Brasil. A escolha adequada de espécies de cobertura, associada ao manejo em pré-semeadura da cobertura, pode intensificar o efeito alelopático sobre plantas daninhas. Foi avaliada a adaptabilidade de espécies vegetais e os efeitos alelopáticos, associados às práticas de manejo da cobertura e ao uso de herbicida pós-emergente, no controle de plantas daninhas na cultura do milho. O delineamento experimental utilizado foi em blocos ao acaso, com quatro repetições. Os tratamentos foram: espécies de cobertura, manejo das coberturas e aplicação ou não de herbicida em pós-emergência. As variáveis avaliadas foram: porcentagem de cobertura, matéria seca da cobertura, número de plantas daninhas, além de estatura, área foliar, matéria seca de plantas de milho e produtividade de grãos. As espécies nabo forrageiro e azevém apresentaram maior cobertura do solo. A cobertura de azevém proporciona maior redução de plantas daninhas e maior crescimento de plantas de milho. A dessecação das culturas de cobertura com glyphosate e paraquat, em geral, reduz o número de plantas daninhas e favorece o crescimento da cultura do milho. A influência do manejo da cobertura de solo na produtividade de grãos depende da espécie utilizada. A aplicação do herbicida nicosulfuron aumentou a produtividade do milho, independentemente da cultura de cobertura ou do manejo adotado.No-till planting system in corn cropping is widely used in southern Brazil. Adequate choice of cover species, associated to cover pre-sowing management, can intensify the allelopathic effect over weed plants. Adaptability of plant species and their allelopathic effects were evaluated, associated to management practices of cover crops and use of pre-emergent herbicide to control weeds in corn. The experimental design consisted of complete randomized blocks, with 4 replications

  15. Effects of Intercropping (Canola-Faba Bean on Density and Diversity of Weeds

    Directory of Open Access Journals (Sweden)

    Mohamad Hossain GHARINEH

    2010-03-01

    Full Text Available In order to evaluate the biological effect and interference of crop and weed in canola-faba bean intercropping in comparison with mono culture, an experiment was conducted in randomize completely blocks design with three replication at Ramin Agriculture and Natural Resources, University. In this experiment treatments were different compositions of canola (Brassica napus L. var. haylo and faba bean (local cultivar. Plant densities (0, 20 and 40 plants per m2 for canola and four levels include (0, 20, 40 and 60 plants per m2 for faba bean in accordance with additive form mixed culture system respectively. Weed dry weight was affected by culture system and different levels of plant densities in mixed culture and there were significant difference 1%. Lowest weed dry weight was obtained in 20-60 and 40-60 plants m-2 canola-bean intercropping. In the intercropping parts only two species was observed while in the sole culture more than three species were exist. Results showed that with increasing in bean diversity, weed dry weight declines. According to our results, it is possible to control weed effectively by using intercropping system, but more studied is required. Diversity of weeds had been clearly affected. Results showed that only Beta and Malva species were existed in intercropping comparing to sole cultures that Brassica, Beta, Rumex and Malva were existed.

  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

  18. Biological Systems Thinking for Control Engineering Design

    Directory of Open Access Journals (Sweden)

    D. J. Murray-Smith

    2004-01-01

    Full Text Available Artificial neural networks and genetic algorithms are often quoted in discussions about the contribution of biological systems thinking to engineering design. This paper reviews work on the neuromuscular system, a field in which biological systems thinking could make specific contributions to the development and design of automatic control systems for mechatronics and robotics applications. The paper suggests some specific areas in which a better understanding of this biological control system could be expected to contribute to control engineering design methods in the future. Particular emphasis is given to the nonlinear nature of elements within the neuromuscular system and to processes of neural signal processing, sensing and system adaptivity. Aspects of the biological system that are of particular significance for engineering control systems include sensor fusion, sensor redundancy and parallelism, together with advanced forms of signal processing for adaptive and learning control

  19. Evaluation effect of density and weeds control in corn (Zea mays L and peanut (Arachis hypogaea L intercropping by competition indices

    Directory of Open Access Journals (Sweden)

    Mahdieh Rajaii

    2016-03-01

    treatments and increasing sowing ratio with bush density change (the distance change between two bushes on a row and variable distance between two rows (40 and 50 cm were carried out. In monoculture and alternative intercropping systems, the distance between bushes for both plants was identical, but alternative intercropping, a row of corn and a row peanut were planted and there were 30 plants of corn and 40 plants of peanut per unit area on each row. To intensify the intercropping, the distance between plants on the rows decreased and due to variable spacing between rows, number of plants per unit area increased and there were 60 corn plants and 80 peanuts plants per unit area on each row. Results and discussion The highest yield for corn (3.18 t.ha-1 was obtained in a intercropping of 100% corn+100% peanut and peanut (9.43 t.ha-1 in 50% corn+50% intercropping of peanut respectively. This means that the proximity of the legumes and grasses can be more productive in terms of intercropping than mono cropping system. The reason could be due to biological nitrogen fixation and increases in light absorption by roots of peanuts. Results indicated that various factors had significant effects on valuated index. The highest and least LER was in 100% corn + 100% peanut and 50% corn + 50% peanut. The highest RCC was for peanut, treatment non-weedy at higher population (7.41 and least was in the corn, treatment once-weedy at lower population (0.4. Corn competitive ratio on peanut in all treatments was less than one, which indicated peanut had advantage over corn. Based on this scale treatment with less density and twice-weedy was more dominate. The Aggressivity index for corn in all the treatments were negative but increased. Therefore in the all indices peanut was the dominant species, this was referred to better use of resources and weed control. Conclusion The results showed that both morphology and structure of the components of a intercropping, in dominant and recessive forms are

  20. 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.

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

    International Nuclear Information System (INIS)

    Hopping, P.N.

    1991-01-01

    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

  2. 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.

  3. 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.

  4. 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.

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

    Science.gov (United States)

    Andújar, Dionisio; Weis, Martin; Gerhards, Roland

    2012-12-13

    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.

  6. Chemical weed management in wheat at higher altitudes.

    Science.gov (United States)

    Khan, Ikramullah; Marwat, Khan Bahadar; Hussain, Zahid

    2007-01-01

    To evaluate the effect of different herbicides for controlling weeds in wheat (variety Fakhr-i-Sarhad),at higher attitude, an experiment was conducted at Agriculture Research Station, Chitral during Rabi season 2003-04, using Randomized Complete Block Design, keeping four replications. The experiment, sown in November comprised of eight treatments, viz; seven herbicides and a weedy check. Each treatment consisted of 5 rows each 30 cm apart and 5 m long thus giving a total size of 5 m x 1.5 m. The herbicides used included; terbutryn + triasulfuron at 0.16 kg, 2,4-D at 0.7 kg, fenoxaprop-P-ethyl at 0.93 kg, clodinafop at 0.05 kg, bromoxynil + MCPA at 0.49 kg, carfentrazon-ethyl at 0.02 kg and isoproturon at 1.0 kg a.i ha(-1). The data were recorded on weed kill efficiency (%), fresh weed biomass (kg ha(-1)), plant height (cm), spike length (cm), number of tillers m(-2), number of grains spike(-1), thousand grains weight (g), biological yield (kg ha(-1)), grain yield (kg ha(-1)) and harvest index (%). The data recorded on weed kill efficiency, weed biomass (kg ha1), grains yield (kg ha(-1)) and harvest index (%) were significantly affected by the different herbicidal treatments. Statistically isoproturon treatment exhibited the best performance, with maximum weed kill efficiency (48.26%) and minimum fresh weed biomass (433.3 kg ha(-1)) as compared to weedy check (6 %) and (1102 kg ha(-1)), respectively. Similarly, the spike length (8.34 cm), number of tillers (427 m(-2)), number of grains spike(-1) (38.0), thousand grains weight (39.85 g), biological yield (8475 kg ha(-1)), grain yield (2530 kg ha(-1)) and harvest index (31.3%) were the highest in isoproturon treatments as compared to weedy check having (7.64 cm), (356 m(-2)), (34.1), (37.12 g), (6858 kg), (1913 kg ha(-1)) and (27%), respectively.

  7. 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.

  8. 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

    2014-10-01

    Full Text Available A field experiment was conducted on Chromolaena odorata dominated pasture with the objectivesof evaluating efficacy of integrated of mechanical and cultural control on weed suppression anddetermining botanical composition of plant species after treatment started. The treatments were, T1slashing 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 byburning and sowing with Centrosema pubescens and T5 digging up of Chromolaena followed byburning and planting with Brachiaria decumbens. Results of experiment showed that under droughtconditions, digging up Chromolaena was very effective in suppressing regrowth of Chromolaena but itwas not effective to other weeds. Among treatments, digging out of Chromolaena followed by burningand planting with Brachiaria decumbens was the most effective and slashing of Chromolaena everymonth was the least effective in suppressing weeds. Botanical composition was shifted with treatments.Stachytarpheta jamaicensis and Chromolaena were the dominant species in monthly slashedChromolaena plots, Stachytarpheta and Calopogonium muconoides were the dominant species inmulched plots while Mimosa pudica, Brachiaria and Centrosema were the dominant species in burntplots.

  9. 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.

  10. Biological Control in Brazil: an overview

    Directory of Open Access Journals (Sweden)

    José Roberto Postali Parra

    2014-10-01

    Full Text Available The use of Biological Control methods is on the increase, mainly as a result of the mobilization of human resources in entomology studies since the establishment of graduate programs in this country in the 1960s. This review approaches the retrospective of Biological Control in Brazil in recent decades, with an emphasis on the "culture of applying agrochemicals" adopted by Brazilian growers, which constrains progress in this area. Successful cases of Biological Control have been reported on in Brazil and there are, in fact, excellent programs in place that use insects or entomopathogenic microrganisms for insect pest control. Most of the studies in this area have been published in Portuguese and are, therefore, not readily available internationally. Importantly, half of the planted sugarcane (Saccharum officinarum, around four million hectares, is treated with natural enemies (insects and/or pathogens. In contrast to other countries that employ Biological Control in small areas, the challenge in Brazil is to implement programs in large farms. Many obstacles must be overcome and discussed in working groups so that we can assume a world leadership position in the use of Biological Control in tropical regions as Brazil is already considered the leader in tropical agriculture. In this review, use of Biological Control is discussed within the Integrated Pest Management philosophy, as a path toward sustainable agriculture that is in harmony with other pest control methods. We must develop a technology of Biological Control adapted to tropical regions, rather than copying models developed for temperate regions, which are usually inappropriate for Brazilian conditions.

  11. Análise de crescimento em amendoinzeiro (Arachis hypogaea L. submetido à matocompetição Analysis of peanut growth under a weed control

    Directory of Open Access Journals (Sweden)

    Luiz Mauro Barbosa

    1995-07-01

    Full Text Available Foram verificados os efeitos de diferentes períodos de controle e convivência de plantas daninhas (0; 14; 28; 42; 56; 70; 84 e 98 dias na cultura do amendoinzeiro (Arachis hypogaea L. em Moji-Guaçu (SP. As principais espécies invasoras da área experimental foram: Acanthospermum australe (Loef. O. Kuntz, Waltheria indica L., Borreria alata DC., Richardia scabra L., Rhynchelytrum repens (Nees Stapf. et Hubb. e Diodia teres Walt. De maneira geral, durante quase todo o ciclo, a espécie de maior importância relativa foi A. australe, sendo suplantada por outras espécies apenas na colheita, quando já estava encerrando seu ciclo de desenvolvimento. O período inicial de controle das plantas daninhas, além de reduzir a densidade da comunidade infestante, diminuiu sua riqueza em espécies e alterou a importância relativa das populações. A matocompetição resultou na redução do crescimento do amendoinzeiro, principalmente a partir de 42 dias de convivência, afetando a altura das plantas, a área foliar, o índice de área foliar e o acúmulo epígeo de matéria seca. Não foram afetados os números de ramos e de folíolos por planta, nem a qualidade dos grãos e o vigor das sementes do amendoim. A produção de frutos foi reduzida ao redor de 31,5% em decorrência da interferência das plantas daninhas. O período total de prevenção da interferência na produção foi de 14 dias e o período anterior à interferência foi de 70 dias.Effects of different periods (0-14-28-42-56-70-84 and 98 days of weed control in peanut plants (Arachis hypogaea L. were studied in Moji-Guaçu region (State of São Paulo. The main weed species in the experimental area were: Acanthospermum australe (Loef. O. Kuntz, Waltheria indica L.; Borreria alata D.C.; Richardia scabra L.; Rhynchelytrum repens (Ness Stapf. et Hubb and Diodia teres Walt. During the whole peanut life cycle, except at harvest time, the most important weed species was A. australe. The

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

    Science.gov (United States)

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

    2018-02-01

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

  13. Weed Mapping with Co-Kriging Using Soil Properties

    DEFF Research Database (Denmark)

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

    1999-01-01

    Our aim is to build reliable weed maps to control weeds in patches. Weed sampling is time consuming but there are some shortcuts. If an intensively sampled variable (e.g. soil property) can be used to improve estimation of a sparsely sampled variable (e.g. weed distribution), one can reduce weed...... sampling. The geostatistical estimation method co-kriging uses two or more sampled variables, which are correlated, to improve the estimation of one of the variables at locations where it was not sampled. We did an experiment on a 2.1 ha winter wheat field to compare co-kriging using soil properties...

  14. Effect of soil solarization on weed emergencee

    International Nuclear Information System (INIS)

    Rodriguez, J.

    2012-01-01

    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

  15. Research Note Study on the early effects of several weed-control ...

    African Journals Online (AJOL)

    Broadleaf species, 10 out of 15 of which were alien, were severely affected by herbicides but alien forbs appeared to benefit by the selective removal of parthenium in the manual control treatments. Native grasses filled the space vacated by broadleaf species in the plots treated with herbicide. However, none of the ...

  16. phosphate fertilizer and weed control effects on growth and yield of ...

    African Journals Online (AJOL)

    preferred customer

    (Rezene Fessehaie, 1986; Knott and Halila, 1988;. Alem Berhe et al., 1990). The growth and grain yield of field pea is affected by the application of fertilizer. Experi- mental results indicated that grain yield of field pea significantly increased over the control due to application of phosphate fertilizer (Getachew. Agegnehu et al.

  17. Effect of weed control treatments on total leaf area of plantation black walnut (Juglans nigra)

    Science.gov (United States)

    Jason Cook; Michael R. Saunders

    2013-01-01

    Determining total tree leaf area is necessary for describing tree carbon balance, growth efficiency, and other measures used in tree-level and stand-level physiological growth models. We examined the effects of vegetation control methods on the total leaf area of sapling-size plantation black walnut trees using allometric approaches. We found significant differences in...

  18. Exploration for the Biological Control of Flowering Rush, Butomus umbellatus

    Science.gov (United States)

    2015-06-01

    mid- May and early August onto about 70 potted flowering rush plants covered with gauze bags. An additional 66 adults were kept for oviposition on 17... flowering rush plants . Ten replicates were established per density. Only egg laying females were used. Prior to set up plant size was measured and it...maintained flowering rush and test plants . Finally, we are very grateful to Jennifer Andreas (Integrated Weed Control Project, Washington State

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

    African Journals Online (AJOL)

    Among the treatments, oxadiazon and oxyfluorfen provided a better control than pendimethalin and tepraloxydim on weed coverage and density, but oxyfluorfen caused phytotoxicicity on onion even at reduced doses. Weed-free plots gave the highest yield (16.2a kg/m2) and were followed by oxadiazon (11.9b kg/m2), ...

  20. Weed seeds on clothing: a global review.

    Science.gov (United States)

    Ansong, Michael; Pickering, Catherine

    2014-11-01

    Weeds are a major threat to biodiversity including in areas of high conservation value. Unfortunately, people may be unintentionally introducing and dispersing weed seeds on their clothing when they visit these areas. To inform the management of these areas, we conducted a systematic quantitative literature review to determine the diversity and characteristics of species with seeds that can attach and be dispersed from clothing. Across 21 studies identified from systematic literature searches on this topic, seeds from 449 species have been recorded on clothing, more than double the diversity found in a previous review. Nearly all of them, 391 species, are listed weeds in one or more countries, with 58 classified as internationally-recognised environmental weeds. When our database was compared with weed lists from different countries and continents we found that clothing can carry the seeds of important regional weeds. A total of 287 of the species are listed as aliens in one or more countries in Europe, 156 are invasive species/noxious weeds in North America, 211 are naturalized alien plants in Australia, 97 are alien species in India, 33 are invasive species in China and 5 are declared weeds/invaders in South Africa. Seeds on the clothing of hikers can be carried to an average distance of 13 km, and where people travel in cars, trains, planes and boats, the seeds on their clothing can be carried much further. Factors that affect this type of seed dispersal include the type of clothing, the type of material the clothing is made from, the number and location of the seeds on plants, and seed traits such as adhesive and attachment structures. With increasing use of protected areas by tourists, including in remote regions, popular protected areas may be at great risk of biological invasions by weeds with seeds carried on clothing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Weeding out bad waves: towards selective cannabinoid circuit control in epilepsy.

    Science.gov (United States)

    Soltesz, Ivan; Alger, Bradley E; Kano, Masanobu; Lee, Sang-Hun; Lovinger, David M; Ohno-Shosaku, Takako; Watanabe, Masahiko

    2015-05-01

    Endocannabinoids are lipid-derived messengers, and both their synthesis and breakdown are under tight spatiotemporal regulation. As retrograde signalling molecules, endocannabinoids are synthesized postsynaptically but activate presynaptic cannabinoid receptor 1 (CB1) receptors to inhibit neurotransmitter release. In turn, CB1-expressing inhibitory and excitatory synapses act as strategically placed control points for activity-dependent regulation of dynamically changing normal and pathological oscillatory network activity. Here, we highlight emerging principles of cannabinoid circuit control and plasticity, and discuss their relevance for epilepsy and related comorbidities. New insights into cannabinoid signalling may facilitate the translation of the recent interest in cannabis-related substances as antiseizure medications to evidence-based treatment strategies.

  2. Herbicides synthesis and biological tests to determine its activity on the weeds; Sintesis de herbicidas y pruebas biologicas para determinar su actividad sobre la maleza

    Energy Technology Data Exchange (ETDEWEB)

    Romero M, Artemisa [Universidad Autonoma Metropolitana-Xochimilco, Mexico, D. F. (Mexico); James M, Guillermo [Universidad Autonoma Metropolitana-Xochimilco, Mexico, D. F. (Mexico); Miramontes F, Benjamin [Universidad Autonoma Metropolitana-Xochimilco, Mexico, D. F. (Mexico); Haro C, Jorge [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D.F. (Mexico)

    1995-02-01

    Four derivatives of Dicamba (2-methoxy-3, 6-dichlorobenzoic acid) were obtained: 2-methoxy-3, 6-dichlorobenzyl alcohol, 2-methoxy-3, 6-dichlorobenzaldehyde, 2-methoxy-3, 6-dichlorobenzaldoxime, tested on weed, and 2-methoxy-3, 6-dichlorobenzylamine. The weeds were Taraxacum officinale Weber, Amaranthus silvester and Sonchus oleraceus L. The oxime did not show activity on Amaranthus silvester, all the substances were active on the other two weeds. [Spanish] Se sintetizaron cuatro derivados del herbicida Dicamba (acido 2-metoxi-3, 6-diclorobenzoico), y se hicieron pruebas de la actividad de tres de ellos sobre maleza de Xochimilco. Se probaron el alcohol 2-metoxi-3, 6-diclorobencilico, 2-metoxi-3, 6-diclorobenzaldehido, 2-metoxi-3, 6-diclorobenzaldoxima. La maleza fue Taraxacum officinale Weber (Diente de leon), Amaranthus silvester (Amaranto silvestre) y Sonchus oleraceus L. (Sonchus). En amaranto, la oxima fue el unico que no presento actividad. En diente de leon y Sonchus, todas las sustancias probadas presentaron actividad.

  3. Biological control of livestock pests : Parasitoids

    Science.gov (United States)

    House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), are common pests on livestock, poultry, and equine facilities. Biological control of filth flies with pupal parasitoids can be used in conjunction with other control methods as part of an integrated fly management program. ...

  4. 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

  5. Efeitos de dessecantes no controle de plantas daninhas na cultura da soja Effects of burndown herbicides in weed control in soybean crop

    Directory of Open Access Journals (Sweden)

    S.O. Procópio

    2006-01-01

    Full Text Available Este trabalho teve como objetivo avaliar a eficiência do glyphosate e da mistura comercial paraquat + diuron, bem como o efeito do intervalo entre as aplicações desses herbicidas e a semeadura da soja, sobre o controle e a rebrota de Digitaria insularis, Synedrellopsis grisebachii e Leptochloa filiformis. O experimento foi conduzido em área de soja em sistema de plantio direto, utilizando-se o delineamento de blocos casualizados com nove tratamentos e quatro repetições. Foram avaliados os seguintes tratamentos: glyphosate no dia da semeadura e um, dois e cinco dias antes desta; paraquat + diuron 20 dias antes e no dia da semeadura; glyphosate 10 dias antes da semeadura e paraquat + diuron no dia da semeadura; glyphosate 15 dias antes da semeadura e paraquat + diuron no dia da semeadura; glyphosate 20 dias antes da semeadura e paraquat + diuron no dia da semeadura; e testemunha infestada. Verificou-se controle satisfatório e impedimento de rebrota de D. insularis e L. filiformis quando o glyphosate foi aplicado cinco dias antes da semeadura da soja ou quando foi realizada aplicação seqüencial de glyphosate e paraquat + diuron. Aplicações seqüenciais da mistura comercial de paraquat + diuron não foram eficientes no controle e no impedimento da rebrota de D. insularis e L. filiformis. S. grisebachii mostrou-se tolerante ao glyphosate.The objectives of this work were to evaluate the efficiency of glyphosate and preformulated mixture paraquat + diuron as well as the effect of the interval between herbicide applications and soybean sowing on the control and re-growth impairment of the following weeds: Digitaria insularis, Synedrellopsis grisebach and Leptochloa filiformis. The experiment was carried out in a soybean area under no-till system and was arranged in a randomized block design, with 9 treatments and four replications. The following treatments were evaluated: glyphosate applied on sowing day; one day before sowing day; two days

  6. Invertebrate fauna associated with Torpedograss, Panicum repens (Cyperales: Poaceae), in Lake Okeechobee, Florida, and prospects for biological control

    International Nuclear Information System (INIS)

    Cuda, J.P.; Dunford, J.C.; Leavengood, J.M. Jr.

    2007-01-01

    Torpedograss, Panicum repens L., is an adventive, rhizomatous grass species that has become an invasive weed of terrestrial, wetland, and aquatic environments in tropical and subtropical regions worldwide. Until recently, strategies for controlling torpedograss in the USA have focused almost exclusively on mechanical and chemical methods, either alone or in combination, with varied results. A survey of the arthropods and nematodes currently associated with the plant in Lake Okeechobee, Florida, was conducted as part of a feasibility study to determine whether torpedograss is an appropriate target for a classical biological control program. Overall, approximately 4,000 arthropods and 400 nematode specimens were collected. Sweep, clipped vegetation, and soil core samples were dominated by representatives of the arthropod orders Hemiptera, Hymenoptera, Diptera, and Acari. Lesion nematodes of the genus Pratylenchus were commonly associated with the roots of torpedograss. None of the organisms collected were torpedograss specialists. Although classical biological control of torpedograss is feasible based on the extent of the infestation, economic losses, resistance to conventional controls, and the report of a potentially host specific natural enemy in India, the botanical position of this grass weed will require a formal risk assessment before proceeding with a classical biological control program. (author) [es

  7. 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

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

    NARCIS (Netherlands)

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

    1996-01-01

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

  9. 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.

  10. Leguminosa no controle integrado de plantas daninhas para aumentar a produtividade da laranja-'Pêra' Legume plants in the integrated weeds control to improve orange 'Pera' yield

    Directory of Open Access Journals (Sweden)

    JOSÉ EDUARDO B. DE CARVALHO

    2002-04-01

    Full Text Available Objetivou-se avaliar a produtividade da laranja-'Pêra', em dois ecossistemas, considerando dois diferentes manejos de solo para o controle integrado de plantas daninhas. O experimento foi instalado nos municípios de Rio Real e Conceição do Almeida, Bahia, no período de 1994 a 1999, em área total de 6000 m², em cada local. O manejo utilizado pelo produtor constou de três capinas manuais nas linhas de plantio e três gradagens nas entrelinhas, enquanto o manejo proposto utilizou como cobertura vegetal o feijão-de-porco (Canavalia ensiformes L., nas entrelinhas do pomar, associado a uma subsolagem. O controle químico das plantas daninhas nas linhas do pomar foi realizado duas vezes ao ano com glifosate. O manejo proposto apresentou melhores resultados em relação ao manejo do produtor nos dois municípios para todos os parâmetros analisados: peso do fruto, número de frutos por planta e produtividade. Em Conceição do Almeida, o sistema proposto foi 56,8% mais produtivo que o do produtor e, em Rio Real, 64,9%.Aimed to evaluate the productivity of sweet orange "Pera" grown considering two different ecosystems and under two soil management systems to control weeds. This work was carried out at the cities of Rio Real and Conceição de Almeida, Bahia State, during the period from 1994 to 1999. The soil management used by the farmer comprised three hoeings within planting lines and three harrowings between the planting lines. The new soil management proposed used a green cover of pig beans (Canavalia ensiformes, L. between the planting lines along with subsoiling, associated with a chemical control of the weeds by Gliphosate, on the planting lines, twice a year. The soil management proposed yielded better results than the farmer soil management at both ecosystems for fruit weight of fruit, number, and plant productivity. At Conceição do Almeida and Rio Real the proposed soil management was 56,8% and 64,9%, respectively, superior than the

  11. Controle de plantas daninhas na cultura do milho (Zea mays L. por meio de herbicidas Weed control in maize (Zea mays L. with herbicides

    Directory of Open Access Journals (Sweden)

    C. A. L. dos Santos

    1979-12-01

    Full Text Available Com o objetivo de se verificar a ação do butylate, aplicado isoladamente e em mistura com atrazine, no controle de plantas daninhas da cultura do milho, foi instalado um experimento de campo em solo fino areno-argiloso. Foram utilizados os seguintes tratamentos: butylate a 2,80; 3,60 e 4,32 kg/ha (p.p.i.; butylate + atrazine a 3,24 + 0,80; 3,24 + 1,20 e 3,60 + 0,96 kg/ha (p.p.i.; atrazine a 3,00 kg/ha e atrazine + metolachlor a 1,40 + 2,10 kg/ha, ambos aplicados em pré-emergência e empregados como herbicidas padrão para a cultura. As plantas daninhas encontradas foram: tiririca - Cyperus rotundus L., carurú comum - .:maranthus viridis L., capim de colchão - Digitaria sanguinalis (L. Scop. e capim pé-de-galinha Eleusine indica (L. Gaertn. Butylate nas três doses apresentou-se bem contra C. rotundus e E. indica; nas doses de 3,60 e 4,32 kg foram obtidos bons resultados sobre D. sanguinalis. Butylate + atrazine controlou, nas três doses, todas as espécies incidentes, o mesmo ocorrendo com a mistura atrazine + metolachlor. Atrazine foi mais eficiente para A. viridis e E. indica. Nas condições em que foi conduzido o experimento nenhum dos herbicidas foi prejudicial para a cultura.Butylate at 2.80; 3.60 and 4.32 kg/ha and butylate + atrazine at. 3.24 + 0.80; 3.24 + 1.20 and 3.60 + 0.96 kg, were applied in preplant incorporated; atrazine at 3.00 kg and atrazine + metolachlor at 1.40 + 2.10 kg were applied in preemergence on corn. The weeds were represented by Cyperus rotundus L., Amaranthus viridis L., Digitaria sanguinalis (L. Scop. and Eleusine indica (L. Gaertn. Butylate + atrazine, in all rates, atrazine + metolachlor and atrazine gave good control of the weeds in general. Butylate, in the three rates, controlled C. rotundus and E. indica; at 3.60 and 4.32 kg/ha controlled well D. sanguinalis. The herbicides did not cause injuries to the crop.

  12. 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

  13. The reproductive biology of Saccharum spontaneum L.: implications for management of this invasive weed in Panama

    Directory of Open Access Journals (Sweden)

    Graham Bonnett

    2014-01-01

    Full Text Available Saccharum spontaneum L. is an invasive grass that has spread extensively in disturbed areas throughout the Panama Canal watershed (PCW, where it has created a fire hazard and inhibited reforestation efforts. Currently physical removal of aboveground biomass is the primary means of controlling this weed, which is largely ineffective and does little to inhibit spread of the species. Little is known about reproduction of this species, although it is both rhizomatous and produces abundant seed. Here we report a series of studies looking at some of the basic reproductive mechanisms and strategies utilised by S. spontaneum to provide information to support development of better targeted management strategies.We found that seed produced between September and November was germinable both in the lab and in situ. Genetic diversity of mature stands was assessed using microsatellite markers and found to be high, even at small scales. Studies of vegetative reproduction showed that buds on stems that had been dried for up to six weeks were still capable of sprouting. Separate experiments showed that stem fragments could sprout when left on the surface or buried shallowly and that larger pieces sprouted more readily than smaller pieces.Collectively these results demonstrate that S. spontaneum in the PCW has the capability to produce many propagules that can successfully recruit and it is likely that seed dispersal drives the spread of the species. Timing of management actions to reduce flowering would significantly reduce the seed load into the environment and help to prevent spread to new sites. Similarly, where biomass is cut, cutting stems into smaller pieces will allow the stems to dry out and reduce the ability of buds to sprout. Additionally, attention should be paid to prevent accidental transport to new sites on machinery.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  15. Integrated weed management for sustainable rice production: concepts, perspectives and options

    International Nuclear Information System (INIS)

    Amartalingam Rajan

    2002-01-01

    Weed management has always been in some way integrated with cultural and biological methods, probably occurring more fortuitously than purposefully. Experience has shown that repeated use of any weed control technique especially in monocultures production systems results in rapid emergence of weeds more adapted to the new practice. In intensive high input farming systems, heavy selection pressure for herbicide tolerant weeds and the environmental impacts of these inputs are important tissues that require a good understanding of agroecosystem for successful integration of available options. Rice culture, in particular flooded rice culture has always employed integration through an evolution of management practices over the generations. However, a vast majority office farmers in Asia have yet to achieve the high returns realised by farmers elsewhere, where a near optimum combination of high inputs are being effectively integrated for maximum productivity. In addition to technological and management limitations, farmers in developing countries are faced with social, economic and policy constraints. On the other hand, farmers who had achieved considerable increases in productivity through labour replacing technologies, in particular direct seeding with the aid of herbicides, are now faced with issues related to environmental concerns due to high levels of these inputs. The issues facing weed scientists and farmers alike in managing weeds effectively and in a manner to ensure sustainability have become more challenging than ever before. In the last two decades, no issue has been discussed so. intensively as Sustainable Farming, Sustainable Agriculture or Alternative Agriculture within the broader global concept of Sustainable Development. To address these challenges a clear perspective of sustainable farming is essential. This paper addresses these concepts, perspectives and options for choices in weed management for sustainable rice production. (Author)

  16. Characterization and control of biological microrobots

    NARCIS (Netherlands)

    Khalil, I.S.M.; Pichel, Marc Philippe; Zondervan, L.; Abelmann, Leon; Misra, Sarthak; Desai, Jaydev P.; Dudek, Gregory; Khatib, Oussama; Kumar, Vijay

    2013-01-01

    This work addresses the characterization and control of Magnetotactic Bacterium (MTB) which can be considered as a biological microrobot. Magnetic dipole moment of the MTB and response to a field-with-alternating-direction are characterized. First, the magnetic dipole moment is characterized using

  17. Characterization and Control of Biological Microrobots

    NARCIS (Netherlands)

    Khalil, I.S.M.; Pichel, Marc Philippe; Pichel, M.P.; Zondervan, L.; Abelmann, Leon; Misra, Sarthak

    2012-01-01

    This work addresses the characterization and control of Magnetotactic Bacterium (MTB) which can be considered as a biological microrobot. Magnetic dipole moment of the MTB and response to a field-with-alternating-direction are characterized. First, the magnetic dipole moment is characterized using

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

    NARCIS (Netherlands)

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

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

  19. Glyphosate-resistant weeds of South American cropping systems: an overview.

    Science.gov (United States)

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. Copyright (c) 2007 Society of Chemical Industry.

  20. Weeding Library Collections.

    Science.gov (United States)

    Slote, Stanley J.

    This work, based on two recent research projects in the weeding of library collections and the identification of core collections, provides a comprehensive summary of the literature and research on these topics. It also presents practical guidance in weeding for the professional librarian or for the library school student. The book is divided into…

  1. Fungal Phytotoxins in Sustainable Weed Management.

    Science.gov (United States)

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

    2018-01-01

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

  2. Contrôle de ervas daninhas em cultura de feijão-vagem pelo uso de herbicidas Control of weeds in snap beans with herbicides

    Directory of Open Access Journals (Sweden)

    Aldo Alves

    1968-01-01

    Full Text Available Visando eliminar as práticas convencionais de cultivo, nas lavouras de feijão-vagem (Phaseolus vulgarisL., fêz-se uso, no combate às ervas daninhas, dos herbicidas EPTC, cloroxuron, trifluralin e DNBP. Quanto à produção total de vagens, não houve diferença significativa entre os diversos tratamentos. Todos os herbicidas experimentados revelaram eficácia no combate às ervas daninhas, sendo que o cloroxuron e o DNBP tiveram ação mais duradoura. O herbicida cloroxuron revelou-se fitotóxico para essa cultura, causando clorose pronunciada e consequent? morte de muitas plantas.Four herbicides were tested ot control weeds in snap bean (Phascolus vulgarisL. cultures, in pre-emergent conditions. EPTC and Irifluralin were incorporated before, whereas cloroxuron and DNBP after planting, but without incorporation iu the soil. A plot was cultivated by usual practices as check. Under the conditions of this experiment, there was no appreciable increase in the bean yield, but all the herbicides tested were efficacious in controlling the weeds. Those applied after planting showed better residual effects. Some toxicity of cloroxuron on snap beans was noted.

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

    Directory of Open Access Journals (Sweden)

    Husni Thamrin Sebayang

    2018-04-01

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

  4. Impact of fungicides on weed growth

    Directory of Open Access Journals (Sweden)

    Nordmeyer, Henning

    2014-02-01

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

  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. Controle de plantas daninhas em feijão num sistema de rotação culturas em plantio direto Weed control in beans in a no-tillage crop rotation system

    Directory of Open Access Journals (Sweden)

    Benedito N. Rodrigues

    1995-01-01

    Full Text Available O objetivo deste trabalho foi selecionar culturas de inverno para formação de cobertura morta que reduza a população de plantas daninhas na cultura do feijão (Phaseolus vulgaris. Ocupou-se o terreno durante o ano todo, com a sucessão, em plantio direto, de pousio ou cultura de inverno/feijão/cultura para silagem, estudando-se três modalidades de controle de plantas daninhas na cultura do feijão. A maior renda líquida acumulada após duas safras foi obtida com feijão semeado sobre palha de aveia-preta e controle de plantas daninhas com um gramicida pré-emergente, completando-se com capinas, quando necessário.This study was undertaken to select winter crops for mulching to reduce the weed infestation and to lower weed control costs in bean (Phaseolus vulgaris production. The soil was kept convered all the year under no-tillage with a sequence of a winter crop or fallow/beans/silage crop. Three weed control methods for beans were studied. After two complete crop sequences, the highest total net income was obtained with the beans directly drilled on the black oats (Avena strigosa mulching, spraying a pre-emergence grasskiller plus hoeing when needed.

  7. Weed infestation of onion in soil reduced cultivation system

    Directory of Open Access Journals (Sweden)

    Marzena Błażej-Woźniak

    2013-12-01

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

  8. Weed ecology and population dynamics

    Science.gov (United States)

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

  9. A functional overview of conservation biological control

    DEFF Research Database (Denmark)

    Begg, Graham S; Cook, Samantha M; Dye, Richard

    2017-01-01

    Conservation biological control (CBC) is a sustainable approach to pest management that can contribute to a reduction in pesticide use as part of an Integrated Pest Management (IPM) strategy. CBC is based on the premise that countering habitat loss and environmental disturbance associated...... limitation to the development of effective CBC is due to a failure to adequately direct biological control services to achieve suppression of the target pests. By considering the performance of these and other components of CBC within the context of an integrated system, we believe that the limiting factors...... with intensive crop production will conserve natural enemies, thus contributing to pest suppression. The abundance and diversity of natural enemies increases in response to a variety of conservation measures, including plant and habitat diversification, a reduction in cropping intensity, and increased landscape...

  10. Effect of tillage system on yield and weed populations of soybean ( Glycin Max L.

    Directory of Open Access Journals (Sweden)

    Seyed Z. Hosseini

    2016-03-01

    Full Text Available Field experiment was conducted at Agricultural and Natural Resources Research Center of Golestan Province, Iran, to determine the effects of tillage system and weed management regime on yield and weed populations in soybean ( Glycin max L.. The experimental design was a split plot where the whole plot portion was a randomized complete block with three replicates. Main plots were tillage system: 1- No-till row crop seeding, 2- No-till seed drilling, 3- Tillage with disc harrow and drill planting, 4- Tillage with chisel packer and drill planting. The subplots were weed management regimes: 1-Weed control with herbicide application, 2- Hand weeding, 3- Herbicide application plus hand weeding, and 4- Non-weeding. Results indicated that the main effects of tillage system and weed management regime were significant for seed yield, pod number per plant, seed number per pod, weed density and biomass, while their interaction were significant only for weed density, weed biomass, and seed number per pod. The highest grain yields (3838 kg ha-1 were recorded for No-till row crop seeding. The highest seed yield (3877 kg ha-1 also was recorded for weed control with herbicide and hand weeding treatment, followed by hand weeding (3379 kg ha-1.

  11. Effect of tillage system on yield and weed populations of soybean ( Glycin Max L.).

    Science.gov (United States)

    Hosseini, Seyed Z; Firouzi, Saeed; Aminpanah, Hashem; Sadeghnejhad, Hamid R

    2016-03-01

    Field experiment was conducted at Agricultural and Natural Resources Research Center of Golestan Province, Iran, to determine the effects of tillage system and weed management regime on yield and weed populations in soybean ( Glycin max L.). The experimental design was a split plot where the whole plot portion was a randomized complete block with three replicates. Main plots were tillage system: 1- No-till row crop seeding, 2- No-till seed drilling, 3- Tillage with disc harrow and drill planting, 4- Tillage with chisel packer and drill planting. The subplots were weed management regimes: 1-Weed control with herbicide application, 2- Hand weeding, 3- Herbicide application plus hand weeding, and 4- Non-weeding. Results indicated that the main effects of tillage system and weed management regime were significant for seed yield, pod number per plant, seed number per pod, weed density and biomass, while their interaction were significant only for weed density, weed biomass, and seed number per pod. The highest grain yields (3838 kg ha-1) were recorded for No-till row crop seeding. The highest seed yield (3877 kg ha-1) also was recorded for weed control with herbicide and hand weeding treatment, followed by hand weeding (3379 kg ha-1).

  12. Biology and host range of Tecmessa elegans (Lepidoptera: Notodontidae), a leaf-feeding moth evaluated as a potential biological control agent for Schinus terebinthifolius (Sapindales: Anacardiaceae) in the United States.

    Science.gov (United States)

    Oleiro, Marina; Mc Kay, Fernando; Wheeler, Gregory S

    2011-06-01

    During surveys for natural enemies that could be used as classical biological control agents of Schinus terebinthifolius Raddi (Brazilian pepper), the caterpillar, Tecmessa elegans Schaus (Lepidoptera: Notodontidae), was recorded feeding on the leaves of the shrub in South America. The biology and larval and adult host range of this species were examined to determine the insect's suitability for biological control of this invasive weed in North America and Hawaii. Biological observations indicate that the larvae have five instars. When disturbed, the late instar larvae emit formic acid from a prothoracic gland that may protect larvae from generalist predators. Larval host range tests conducted both in South and North America indicated that this species feeds and completes development primarily on members of the Anacardiaceae within the tribe Rhoeae. Oviposition tests indicated that when given a choice in large cages the adults will select the target weed over Pistacia spp. However, considering the many valued plant species in its host range, especially several North American natives, this species will not be considered further for biological control of S. terebinthifolius in North America.

  13. Onchocerciasis control: biological research is still needed

    Directory of Open Access Journals (Sweden)

    Boussinesq M.

    2008-09-01

    Full Text Available Achievements obtained by the onchocerciasis control programmes should not lead to a relaxation in the biological research on Onchocerca volvulus. Issues such as the Loa loa-related postivermectin serious adverse events, the uncertainties as to whether onchocerciasis can be eliminated by ivermectin treatments, and the possible emergence of ivermectin-resistant O. volvulus populations should be addressed proactively. Doxycycline, moxidectin and emodepside appear to be promising as alternative drugs against onchocerciasis but support to researches in immunology and genomics should also be increased to develop new control tools, including both vaccines and macrofilaricidal drugs.

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

    Science.gov (United States)

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

  15. Development of a multispectral imagery device devoted to weed detection

    Science.gov (United States)

    Vioix, Jean-Baptiste; Douzals, Jean-Paul; Truchetet, Frederic; Navar, Pierre

    2003-04-01

    Multispectral imagery is a large domain with number of practical applications: thermography, quality control in industry, food science and agronomy, etc. The main interest is to obtain spectral information of the objects for which reflectance signal can be associated with physical, chemical and/or biological properties. Agronomic applications of multispectral imagery generally involve the acquisition of several images in the wavelengths of visible and near infrared. This paper will first present different kind of multispectral devices used for agronomic issues and will secondly introduce an original multispectral design based on a single CCD. Third, early results obtained for weed detection are presented.

  16. 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. © 2013 Society of Chemical Industry.

  17. Métodos de controle de plantas invasoras na cultura do cafeeiro (Coffea arabica L. e componentes da acidez do solo Weed control methods and soil acidity components in coffee plantation (Coffea arabica L.

    Directory of Open Access Journals (Sweden)

    Elifas Nunes Alcântara

    2007-12-01

    Full Text Available Em lavouras perenes, como na cultura do cafeeiro, o controle de plantas invasoras tem sido feito por meio de métodos manuais, mecanizados, químicos e associações destes. De modo geral, têm-se avaliado os diferentes métodos sob o ponto de vista de eficiência e de custo no controle das plantas invasoras; no entanto, a influência deles sobre as condições químicas do solo, praticamente, não tem sido estudada, principalmente a longo prazo. O objetivo deste estudo foi avaliar o efeito de diferentes métodos de controle de plantas invasoras na cultura do cafeeiro sobre os componentes da acidez de um Latossolo Vermelho distroférrico da região de São Sebastião do Paraíso, MG. Sete tratamentos de controle de plantas invasoras foram avaliados: roçadora (RÇ, grade (GR, enxada rotativa (RT, herbicida de pós-emergência (HC, herbicida de pré-emergência (HR, capina manual (CM e testemunha sem capina (SC, dispostos em blocos casualizados com três repetições. Amostras de solo, em cada tratamento, foram coletadas a cada dois anos, a partir de 1980, nas camadas de 0-0,15 e 0,15-0,30 m, para avaliação de pH, Al3+, acidez potencial (H + Al e saturação por Al3+ (m. O sistema HR aumentou o teor e a saturação por Al3+ e a acidez potencial e diminuiu o pH, quando comparado com os demais métodos de controle de plantas invasoras, principalmente com a testemunha (SC. O tratamento SC mostrou efeito contrário ao do HR, aumentando os valores de pH e diminuindo o teor de Al3+ e a saturação por Al3+, em ambas as camadas de solo. O RÇ foi o tratamento que mais se aproximou do SC, e os demais tratamentos, no geral, não apresentaram comportamento diferenciado.In perennial agriculture, such as coffee plantation, weeds are controlled by hand, mechanized, and chemical weeding and their combinations. Methods that differ in terms of efficiency and costs have been evaluated; however, the influence of these methods on the soil chemical conditions has

  18. Sistemas de dessecação antecedendo a semeadura direta de milho e controle de plantas daninhas Desiccation systems prior to no-till corn sowing and weed control

    Directory of Open Access Journals (Sweden)

    Jamil Constantin

    2009-07-01

    Full Text Available No sistema de plantio direto, a escolha do momento adequado para a dessecação da cobertura vegetal antecedente à semeadura é fundamental para o êxito da cultura do milho. O objetivo do trabalho foi avaliar os efeitos sobre a cultura do milho de três sistemas de dessecação de manejo antecedendo o plantio direto combinados com três métodos de controle de plantas daninhas, em áreas com alta densidade de infestação de ervas. Os tratamentos foram arranjados em esquema fatorial (3x3 + 1, em delineamento de blocos casualizados, com cinco repetições. Os três sistemas de dessecação avaliados foram: (1 dessecação de manejo realizada imediatamente antes da semeadura - sistema Aplique-Plante ("AP"; (2 dessecação de manejo realizada sete dias antes da semeadura direta (DAS ("7 DAS"; e (3 manejo antecipado ("MA", quando as dessecações foram realizadas aos 25 e 1 DAS do milho. Após a emergência da cultura, as opções de controle foram: (1 nenhum controle de plantas daninhas; (2 capina manual e (3 aplicação de mesotrione + atrazine + óleo mineral em pós-emergência, além de uma testemunha sem manejo e sem controle em pós-emergência. Verificou-se que, após a emergência da cultura, a utilização do MA proporcionou maior controle das plantas daninhas, em comparação com os sistemas AP e 7 DAS. Evidenciou-se um atraso de crescimento nas plantas de milho crescidas nas áreas onde foi utilizado o sistema AP. Observou ainda que, independentemente do método de controle de plantas daninhas utilizado em pós-emergência, os maiores rendimentos de grãos de milho ocorreram no MA com ganhos que variaram entre 593 a 1060 kg ha-1.The adequate timing for cover crop management before sowing is fundamental for the success of no-till corn. This research aimed to evaluate the effects on corn growth and yield of three burndown systems before no-till sowing, combined with three weeds control methods after crop emergence, in areas with high

  19. 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

  20. Controle de plantas daninhas na cultura da soja através do herbicida acetochlor em sistemas de semeadura direta e preparo convencional Weed control in soybean crop using the herbicide acetochlor under direct seeding and conventional system

    Directory of Open Access Journals (Sweden)

    M.V.W. Ferri

    2002-08-01

    Full Text Available O manejo do solo altera a bioatividade dos herbicidas residuais e influi na persistência, na eficácia de controle das plantas daninhas e na fitotoxicidade para as culturas. Um experimento foi conduzido na Faculdade de Agronomia da Universidade Federal do Rio Grande do Sul, com objetivo de avaliar a eficácia de controle das plantas daninhas pelo herbicida acetochlor aplicado em solo Argissolo Vermelho sob semeadura direta e preparo convencional. O delineamento experimental foi o de blocos casualizados com quatro repetições em parcelas subsubdivididas. O acetochlor foi utilizado nas doses de 0, 1.680, 2.520, 3.360 e 4.200 g ha¹. Foi avaliado o controle das plantas daninhas aos 15, 30 e 45 dias após aplicação do acetochlor (DAT. Foram avaliados também a injúria na cultura da soja aos 14, 21 e 28 DAT e a matéria seca das plantas daninhas aos 40 e 60 DAT. O herbicida acetochlor foi mais eficiente no controle das plantas daninhas no solo sob preparo convencional que sob semeadura direta. A produção de matéria seca dessas plantas foi menor no preparo convencional comparado à semeadura direta. Não ocorreu injúria à cultura da soja.Soil management affects herbicide bioactivity and changes persistence, weed control and crop selectivity. An experiment was carried out at the Federal University of Rio Grande do Sul - Brazil, to evaluate the efficacy of the herbicide acetochlor in controling weeds in a Paleudult soil under direct seeding and conventional system. The following treatments were tested: acetochlor at 0, 1,680, 2,520, 3,360 and 4,200 g ha-1, applied under tillage and no-till systems. Assessments included crop injury at 14, 21 and 28 days after acetochlor aplication, weed dry matter at 40 and 60 days after herbicide aplication and weed control at 15, 30 and 45 days after acetochlor aplication. Acetochlor was more efficient under conventional than direct seeding system. Weed dry biomass was lower under conventional than direct

  1. Application of poly(epsilon-caprolactone) nanoparticles containing atrazine herbicide as an alternative technique to control weeds and reduce damage to the environment.

    Science.gov (United States)

    Pereira, Anderson E S; Grillo, Renato; Mello, Nathalie F S; Rosa, Andre H; Fraceto, Leonardo F

    2014-03-15

    Nanoparticles of poly(epsilon-caprolactone) containing the herbicide atrazine were prepared, characterized, and evaluated in terms of their herbicidal activity and genotoxicity. The stability of the nanoparticles was evaluated over a period of three months, considering the variables: size, polydispersion index, pH, and encapsulation efficiency. Tests on plants were performed with target (Brassica sp.) and non-target (Zea mays) organisms, and the nanoparticle formulations were shown to be effective for the control of the target species. Experiments using soil columns revealed that the use of nanoparticles reduced the mobility of atrazine in the soil. Application of the Allium cepa chromosome aberration assay demonstrated that the nanoparticle systems were able to reduce the genotoxicity of the herbicide. The formulations developed offer a useful means of controlling agricultural weeds, while at the same time reducing the risk of harm to the environment and human health. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Weed population in citrus based cropping system as affected by ...

    African Journals Online (AJOL)

    Sole plots of Sweet orange (sct), maize (sm), cowpea (scp), cassava (sca) and pineapple (sp) were planted as control. Weed control efficiency of the intercrops was evaluated by 1m x 1m permanent quadrat technique. Sole citrus recorded a significantly higher (P<0.05) weed biomass in the three years of cropping than other ...

  3. Role of herbicide-resistant crops in integrated weed management

    Science.gov (United States)

    Chemical weed control began with the use of 2,4-D in the mid-1940s. Since then, a wide array of herbicides has been commercialized and that has greatly contributed to increased crop yields. With the introduction of several new, more specific and more effective herbicides, the cost of weed control wi...

  4. 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

  5. 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...

  6. Organic Highbush Blueberry Production Systems Research – Management of Plant Nutrition, Irrigation Requirements, and Weeds

    Science.gov (United States)

    A 0.4 ha planting of blueberry was established in October 2006 to evaluate the effects of cultivar (Duke and Liberty), bed type (flat versus raised beds), weed management (sawdust mulch and hand-weed control; sawdust+compost mulch with acetic acid, flaming, and hand control used as needed; and weed ...

  7. The Politics of Weeding.

    Science.gov (United States)

    Tillman, Hope N.

    1988-01-01

    Reviews the literature that deals with the political ramifications of weeding material from academic library collections and the need to involve users and other libraries within the institution in the decision process. (14 references) (CLB)

  8. Diferentes densidades de plantas daninhas e métodos de controle nos componentes de produção do milho orgânico Different weed densities and control methods of organic corn production components

    Directory of Open Access Journals (Sweden)

    M.G. Chiovato

    2007-01-01

    por vaso foi a que proporcionou maior redução de MS das folhas do milho, independentemente do manejo.The objective of this work was to verify the efficiency of mechanic control methods and different populational densities of Bidens pilosa, Brachiaria decumbens and Brachiaria plantaginea and their interference in corn production components, for organic management purposes. The experiment was conducted in a green house, in a completely randomized design, with three replicates, in a factorial scheme 3x3+1. The first trial was composed by three weed densities and the second by the treatments (weed cutting at four and eight developed leaf stages, hand-weeding at four developed leaf stage, corn without weed control, and an additional treatment, corn without weed (control. The corn cultivar UFVM 100 was sowed simultaneously with the weeds in 18L pots filled with substrate (soil + organic matter. For Bidens pilosa, the greatest interference in leaf dry matter was observed in the cutting and without weed control treatments. When corn was cultivated without weeds and hand-weeded, no significant differences were observed in leaf dry matter, stem and reproductive organs, indicating that cutting was not efficient at controlling Bidens pilosa under organic corn crop conditions. When corn was planted together with B. plantaginea plants, cutting and hand-weeding provided the same dry matter accumulation; however, at higher densities (four and six plants/vase, the cutting and corn without weed control treatments were similar showing that cutting is efficient in controlling B. plantaginea at a low population density. B. decumbens showed the highest leaf dry matter reduction at a six plant/vase density, regardless of the type of treatment.

  9. 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

  10. Robotic weed monitoring

    DEFF Research Database (Denmark)

    Bochtis, Dionysis; Sørensen, Claus Aage Grøn; Jørgensen, Rasmus Nyholm

    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...... of the weed monitoring operation.Key words: autonomous vehicles, farm management, mission planning, route planning,sampling....

  11. AN INTEGRATED BIOLOGICAL CONTROL SYSTEM AT HANFORD

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON AR; CAUDILL JG; GIDDINGS RF; RODRIGUEZ JM; ROOS RC; WILDE JW

    2010-02-11

    In 1999 an integrated biological control system was instituted at the U.S. Department of Energy's Hanford Site. Successes and changes to the program needed to be communicated to a large and diverse mix of organizations and individuals. Efforts at communication are directed toward the following: Hanford Contractors (Liquid or Tank Waste, Solid Waste, Environmental Restoration, Science and Technology, Site Infrastructure), General Hanford Employees, and Hanford Advisory Board (Native American Tribes, Environmental Groups, Local Citizens, Washington State and Oregon State regulatory agencies). Communication was done through direct interface meetings, individual communication, where appropriate, and broadly sharing program reports. The objectives of the communication efforts was to have the program well coordinated with Hanford contractors, and to have the program understood well enough that all stakeholders would have confidence in the work performed by the program to reduce or elimated spread of radioactive contamination by biotic vectors. Communication of successes and changes to an integrated biological control system instituted in 1999 at the Department of Energy's Hanford Site have required regular interfaces with not only a diverse group of Hanford contractors (i.e., those responsible for liquid or tank waste, solid wastes, environmental restoration, science and technology, and site infrastructure), and general Hanford employees, but also with a consortium of designated stake holders organized as the Hanford Advisory Board (i.e., Native American tribes, various environmental groups, local citizens, Washington state and Oregon regulatory agencies, etc.). Direct interface meetings, individual communication where appropriate, and transparency of the biological control program were the methods and outcome of this effort.

  12. An Integrated Biological Control System At Hanford

    International Nuclear Information System (INIS)

    Johnson, A.R.; Caudill, J.G.; Giddings, R.F.; Rodriguez, J.M.; Roos, R.C.; Wilde, J.W.

    2010-01-01

    In 1999 an integrated biological control system was instituted at the U.S. Department of Energy's Hanford Site. Successes and changes to the program needed to be communicated to a large and diverse mix of organizations and individuals. Efforts at communication are directed toward the following: Hanford Contractors (Liquid or Tank Waste, Solid Waste, Environmental Restoration, Science and Technology, Site Infrastructure), General Hanford Employees, and Hanford Advisory Board (Native American Tribes, Environmental Groups, Local Citizens, Washington State and Oregon State regulatory agencies). Communication was done through direct interface meetings, individual communication, where appropriate, and broadly sharing program reports. The objectives of the communication efforts was to have the program well coordinated with Hanford contractors, and to have the program understood well enough that all stakeholders would have confidence in the work performed by the program to reduce or elimate spread of radioactive contamination by biotic vectors. Communication of successes and changes to an integrated biological control system instituted in 1999 at the Department of Energy's Hanford Site have required regular interfaces with not only a diverse group of Hanford contractors (i.e., those responsible for liquid or tank waste, solid wastes, environmental restoration, science and technology, and site infrastructure), and general Hanford employees, but also with a consortium of designated stake holders organized as the Hanford Advisory Board (i.e., Native American tribes, various environmental groups, local citizens, Washington state and Oregon regulatory agencies, etc.). Direct interface meetings, individual communication where appropriate, and transparency of the biological control program were the methods and outcome of this effort.

  13. Influence of corn sowing density and gliricidia intercropping on weed control Influências da densidade de semeadura do milho e da consorciação com gliricídia sobre o controle de plantas daninhas

    Directory of Open Access Journals (Sweden)

    P.S.L. Silva

    2010-06-01

    Full Text Available There is interest in the identification of the best seeding density for new corn hybrids and on reduced use of herbicides for weed control. The objective of this study was to evaluate the effects of seeding density (30, 50, 70, and 90 thousand plants ha-1 and weed control on green ear yield and grain yield in corn cultivar AG 1051. A completely randomized block design was adopted with split-plots (seeding densities assigned to plots and ten replicates. Weed control was achieved by means of two hoeings and by planting corn intercropped with gliricidia (between corn rows, in pits spaced 0.3 m apart. A "no weeding"treatment was included as well. Increased seeding density increased the total number and weight of marketable green ears and decreased the biomass of both weeds and gliricidia. In non-weeded, intercropped and hoed plots, the maximum grain yield values achieved as seeding density increased were 7,881, 7,021, and 9,213 kg ha-1, respectively, obtained with populations of 67 thousand, 74 thousand, and 67 thousand plants per hectare, respectively. Intercropping did not control weeds (26 species and provided weed growth, green ear yield, and grain yield (at the lowest densities similar to those obtained without hoeing, except for total number of green ears, in which no influence of weed control was observed. At densities of 70 thousand and 90 thousand plants per hectare, grain yield with two hoeings was not different from yield values obtained without weeding or in the treatment intercropped with gliricidia, respectively, indicating that increased corn seeding density as well as gliricidiamay help to control weeds.Existe interesse na identificação da densidade de semeadura ideal para os novos híbridos de milho e na redução do uso de herbicidas no controle de plantas daninhas. O objetivo deste trabalho foi avaliar os efeitos da densidade de semeadura (30, 50, 70 e 90 mil plantas ha-1 e do controle de plantas daninhas sobre os rendimentos de

  14. 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

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

    Science.gov (United States)

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

    2011-01-01

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

  16. Can arbuscular mycorrhizal fungi reduce the growth of agricultural weeds?

    Directory of Open Access Journals (Sweden)

    Rita S L Veiga

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

  17. Can arbuscular mycorrhizal fungi reduce the growth of agricultural weeds?

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

    Beckie, Hugh J

    2011-09-01

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

  19. Weed occurrence on pavements in five North European towns

    NARCIS (Netherlands)

    Melander, B.; Holst, N.; Grundy, A.; Kempenaar, C.; Riemens, M.M.; Verschwele, A.; Hansson, D.

    2009-01-01

    Weeds on pavements in urban areas are unwanted mainly because they cause an untidy appearance or sometimes structural damage. Glyphosate has been the principal weed control method for years, but policies in several European towns have changed to lower dependence on herbicides. Instead, less

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

    African Journals Online (AJOL)

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

  1. Economics of herbicide weed management in wheat in Ethiopia ...

    African Journals Online (AJOL)

    Among the annual grass weeds, Snowdenia polystachya, Avena fatua, Bromus pectinatus, Phalaris paradoxa and Setaria pumila; and most broad leaf weeds like Polygonum nepalense, Guizotia scabra, Galinsoga parviflora and Gallium spurium were controlled with herbicide efficacy ranging from 75 to 100%. Mesosulfron ...

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

    African Journals Online (AJOL)

    to search for alternative weed control methods globally. The current study was conducted to test the inhibitory potential of essential oils extracted from eight locally available plants and three inert minerals against common weed species of coffee with emphasis on Bidens pilosa both under lath house and field conditions with ...

  3. Is there a Weed Shift in Roundup Ready Maize?

    OpenAIRE

    Arnd Verschwele

    2010-01-01

    The cultivation of transgenic glyphosate-resistant crop varieties can simplify weed control in crops such as maize and others. On the other hand, the repeated use of broadly effective herbicides like glyphosate, especially in the same crop, can have a negative effect on biodiversity. Additionally there is a risk for a spread of more tolerant or even resistant weed species.

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

    African Journals Online (AJOL)

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

  5. Critical period for weed control in potatoes in the Huambo Province (Angola Período crítico do controle de infestantes na cultura da batateira na Província do Huambo (Angola

    Directory of Open Access Journals (Sweden)

    A. Monteiro

    2011-06-01

    Full Text Available The effects of different weed management periods on potatoes were studied in three areas (Bailundo, Chianga and Calenga of the central highlands of Angola and in three cropping seasons, from June 2005 to May 2007. Six weed-management treatments were used to identify critical periods of competition and to allow the development of more precise management recommendations. Total potato yield ranged from about 22 t ha-1 in weed-free plots to about 3 t ha-1 with no weed control a yield loss of 86%. Major weed species Galinsoga parviflora, Cyperus esculentus, Bidens biternata, Amaranthus hybridus, Nicandra physaloides, Portulaca oleracea and Datura stramonium differed from area to area. The species G. parviflora dominated the weed flora in all three areas 73, 97 and 72 plants m² 50 days after crop emergence in Bailundo, Chianga and Calenga respectively, in dry season trials; while C. esculentus was also present in Chianga and Calenga, with an average density of ca 30 plants m-2 in dry season trials. Gompertz and logistic equations were fitted to data representing increasing periods of weed-free growth and weed interference, respectively. Critical periods for weed control, with a 95% weed-free total yield, were estimated from 26 to 66 and from 20 to 61 days after emergence for the rainy and dry seasons, respectively. Weed competition before or after these critical periods had negligible effects on crop yield.Com o objectivo de obter recomendações mais precisas para a gestão das infestantes na cultura da batata 'Romano' avaliou-se o efeito de diferentes períodos de controle e de convivência em três locais do Planalto Central de Angola e em três épocas de crescimento da cultura. O delineamento experimental, por local, consistiu em blocos casualizados com três repetições. Os tratamentos consistiram de seis intervalos de controle nos quais a cultura foi mantida livre de infestantes e após cada período estas foram deixadas crescer livremente; e

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Felix Ogar Takim

    2014-06-01

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

  8. Weed map generation from UAV image mosaics based on crop row detection

    DEFF Research Database (Denmark)

    Midtiby, Henrik Skov

    To control weed in a field effectively with a minimum of herbicides, knowledge about the weed patches is required. Based on images acquired by Unmanned Aerial Vehicles (UAVs), a vegetation map of the entire field can be generated. Manual analysis, which is often required, to detect weed patches...

  9. Narrow rows reduce biomass and seed production of weeds and increase maize yield

    NARCIS (Netherlands)

    Mashingaidze, A.B.; Werf, van der W.; Lotz, L.A.P.; Chipomho, J.; Kropff, M.J.

    2009-01-01

    Smallholder farmers in southern African countries rely primarily on cultural control and hoe weeding to combat weeds, but often times, they are unable to keep up with the weeding requirements of the crop because of its laboriousness, causing them to incur major yield losses. Optimisation of crop

  10. Fuels planning: science synthesis and integration; environmental consequences fact sheet 07: fire and weeds

    Science.gov (United States)

    Steve Sutherland

    2004-01-01

    Weed infestations cause an economic loss of $13 billion per year even though $9.5 billion per year is spent on weed control measures. In addition to these economic costs, weeds are replacing native species, altering native plant and animal communities, affecting ecosystem health and function, threatening biodiversity and Threatened, Endangered, and Sensitive (TES)...

  11. A weed compaction roller system for use with mechanical herbicide application

    Science.gov (United States)

    Adam H. Wiese; Daniel A. Netzer; Don E. Riemenschneider; Ronald S., Jr. Zalesny

    2006-01-01

    We designed, constructed, and field-tested a versatile and unique weed compaction roller system that can be used with mechanical herbicide application for invasive weed control in tree plantations, agronomic settings, and areas where localized flora and fauna are in danger of elimination from the landscape. The weed compaction roller system combined with herbicide...

  12. Reducing tillage intensity affects the cumulative emergence dynamics of annual grass weeds in winter cereals

    DEFF Research Database (Denmark)

    Scherner, A; Melander, B; Jensen, P K

    2017-01-01

    Annual grass weeds such as Apera spica-venti and Vulpia myuros are promoted in non-inversion tillage systems and winter cereal-based crop rotations. Unsatisfactory weed control in these conditions is often associated with a poor understanding of the emergence pattern of these weed species. The ai...

  13. 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...

  14. Herbicide-Resistant Crops: Utilities and Limitations for Herbicide-Resistant Weed Management

    OpenAIRE

    Green, Jerry M.; Owen, Micheal D. K.

    2010-01-01

    Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effec...

  15. Biological control agents elevate hantavirus by subsidizing deer mouse populations

    Science.gov (United States)

    Dean E. Pearson; Ragan M. Callaway

    2006-01-01

    Biological control of exotic invasive plants using exotic insects is practiced under the assumption that biological control agents are safe if they do not directly attack non-target species. We tested this assumption by evaluating the potential for two host-specific biological control agents (Urophora spp.), widely established in North America for spotted...

  16. Benchmark study on glyphosate-resistant cropping systems in the United States. Part 7: Effects of weed management strategy (grower practices versus academic recommendations) on the weed soil seedbank over 6 years.

    Science.gov (United States)

    Gibson, David J; Young, Bryan G; Owen, Micheal D K; Gage, Karla L; Matthews, Joseph L; Jordan, David L; Shaw, David R; Weller, Stephen C; Wilson, Robert G

    2016-04-01

    Shifts in weed species composition and richness resulting from near-exclusive reliance on herbicides in glyphosate-resistant (GR) cropping systems has necessitated the implementation of alternative weed management tactics to reduce selection pressures of herbicides. We contrasted the response of the weed soil seedbank to effects of weed management strategy, comparing grower practices with academic recommendations for best management practices (BMPs) over 6 years and across five weed hardiness zones in the US Midwest at sites subject to GR cropping systems. Total weed population density and species richness varied according to cropping system, location and prior year's crop, but less so to weed management strategy. The seedbank population density for 11 of the 14 most frequent weed species was affected by weed management strategy either alone or in an interaction with hardiness zone or year, or both. In only 29% of comparisons was weed population density lower following academic recommendations, and this depended upon prior crop and cropping system. The population density of high-risk weed species was reduced by academic recommendations, but only in two of six years and under continuous GR maize. Overall, the weed population density was decreasing in field halves subject to the BMPs in the academic recommendations relative to grower practices. The soil seedbank is slow to respond to academic recommendations to mitigate glyphosate-resistant weeds, but represents a biological legacy that growers need to keep in mind even when management practices reduce emerged field weed population densities. © 2015 Society of Chemical Industry.

  17. 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.

  18. Transdisciplinary weed research: new leverage on challenging weed problems?

    NARCIS (Netherlands)

    Jordan, N.; Schut, M.; Graham, S.; Barney, J.N.; Childs, D.Z.; Christensen, S.B.; Cousens, R.D.; Davis, A.S.; Eizenberg, H.; Ervin, D.E.; Fernandez-Quintanilla, C.; Harrison, L.J.; Harsch, M.A.; Heijting, S.; Liebman, M.; Loddo, D.; Mirsky, S.B.; Riemens, M.; Neve, P.; Peltzer, D.A.; Renton, M.; Williams, M.; Recasens, J.; Sønderskov, M.

    2016-01-01

    Transdisciplinary weed research (TWR) is a promising path to more effective management of challenging weed problems. We define TWR as an integrated process of inquiry and action that addresses complex weed problems in the context of broader efforts to improve economic, environmental and social

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

    African Journals Online (AJOL)

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

  20. EFICIÊNCIA DO HERBICIDA OXADIARGYL NO CONTROLE DE PLANTAS DANINHAS NA CULTURA DO ARROZ (Oryza sativa L. IRRIGADO WEED CONTROL EFFICIENCY OF THE HERBICIDE OXADIARGYL IN IRRIGATED RICE (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Geraldo José Aparecido Dario

    1999-01-01

    Full Text Available Visando avaliar a eficiência agronômica do herbicida oxadiargyl no controle de plantas daninhas ocorrentes na cultura do arroz (Oryza sativa L. irrigado, semeado em solo drenado, instalou-se ensaio em condição de campo no município de Mococa, SP, em novembro de 1993. O produto foi aplicado em pré-emergência da cultura e das plantas daninhas, nas doses de 320, 400, 480 e 560 g/ha e como padrão utilizou-se duas formulações de oxadiazon, ambas em doses de 1.000 g./ha. Os resultados obtidos permitem concluir: o herbicida oxadiargyl é eficiente no controle da tiririca-do-brejo (Cyperus iria nas quatro doses testadas e do capim-arroz (Echinochloa colonum e capim-macho (Ischaemum rugosum nas três maiores doses; o herbicida oxadiargyl causa leve fitointoxicação à cultura quando aplicado nas duas maiores doses, com os sintomas desaparecendo aos 60 dias após a aplicação; em função do controle das plantas daninhas, o herbicida oxadiargyl aumenta significativamente a produção de grãos de arroz em relação à testemunha não-capinada.In order to evaluate the agronomical efficiency of the herbicide oxadiargyl on weed control in irrigated rice (Oryza sativa L., sowm in a drained field, an experiment was established in Mococa, SP, Brazil, in November 1993. The product was applied in pre-emergence conditions of the crop and weeds, at rates of 320, 400, 480 and 560g/ha, plus a control product (oxadiazon, used in two formulations at rates of 1,000g/ha. The results allowed to conclude that: oxadiargyl is highly efficient against Cyperus iria at all rates tested; and against Echinochloa colonum and Ischaemum rugosum at rates of 400, 480 and 560g/ha. Oxadiargyl caused light phytotoxicity to the rice plants, when applied at rates of 480 and 560g/ha, but the symptoms disappeared 60 days after application. Due to weed control, oxadiargyl caused an increase in rice yield as compared to the non-weeded control.