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Sample records for blackgrass alopecurus myosuroides

  1. Development of herbicide resistance in black-grass (Alopecurus myosuroides in Bavaria

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    Gehring, Klaus

    2016-02-01

    Full Text Available Black-grass (Alopecurus myosuroides is one of the most important grass weeds in Bavaria. Chemical weed control with high efficacy is very important in crops like winter cereals, oilseed rape and maize. Crop rotations with more winter cereals, reduced soil cultivation and e.g. contract harvesting enhanced distribution of blackgrass in arable farming regions. Effects of herbicide resistance were observed since the last 20 years. The blackgrass herbicide resistance is well observed by the official plant protection service of Bavaria. A wide experience of resistance tests shows the development of resistant black-grass and provides an opportunity for future prospects in resistance dynamics.

  2. Field experiences with recent ALS-inhibitors on herbicide resistant blackgrass (Alopecurus myosuroides Huds.).

    Science.gov (United States)

    Desmet, E M; Bulcke, R; Maeghe, L

    2004-01-01

    In the growing season 2002-2003 two field experiments were carried out in winter wheat on the heavy clay soil of the coastal polder area at Zevekote to study the response of blackgrass (Alopecurus myosuroides Huds.) resistant or somewhat less sensitive to a wide variety of herbicides (clodinafop-propargyl, fenoxaprop-P-ethy1; flupyrsulfuron-methyl+metsulfuron-methyl, propoxycarbazone-sodium; isoproturon) representing various modes of action. In Experiment 1, preemergence applications of isoproturon+diflufenican (1500+187.5 g/ha) and isoproturon+diflufenican+flurtamone (1250+100+250 g/ha) respectively were followed in mid-March (Zadoks: 23) by one of the following treatments: none, propoxycarbazone-sodium + vegetable oil (42 g/ha + 1 l/ha), mesosulfuron-methyl + iodosulfuron-methyl-sodium (+mefenpyr-diethyl) + vegetable oil (15+3 (+45) g/ha + 1 l/ha), clodinafop-propargyl (+cloquintocet-mexyl) {60 (+15) g/ha} and flupyrsulfuron-methyl+metsulfuron-methyl (10+5 g/ha). Systems based on clodinafop-propargyl, propoxycarbazone-sodium or flupyrsulfuron-methyl+metsulfuron-methyl resulted in poor supplementary control of blackgrass compared to preemergence herbicide application only. On the contrary, systems based on postemergence application of mesosulfuron-methyl + iodosulfuron-methyl-sodium resulted in excellent control. In most cases the few surviving plants failed to produce inflorescences. In Experiment 2, fall applications in the 3 leaves stage (Zadoks: 13) of prosulfocarb + isoxaben (4000+75 g/ha), flufenacet + diflufenican + isoxaben (240+120+75 g/ha) and flufenacet + pendimethalin + chlorotoluron (180+900+1000 g/ha) respectively were followed in mid-March (Zadoks: 23) by one of the following treatments: none, propoxycarbazone-sodium + vegetable oil (42 g/ha+l l/ha), mesosulfuron-methyl + iodosulfuron-methyl-sodium (+mefenpyr-diethyl) + vegetable oil {15+3 (+45) g/ha + 1 l/ha}, clodinafop-propargyl (+cloquintocet-mexyl) {60 (+15) g/ha}, flupyrsulfuron

  3. Herbicide-resistance to mesosulfuron + iodosulfuron in Alopecurus myosuroides (black-grass).

    Science.gov (United States)

    Hull, R; Marshall, R; Tatnell, L; Moss, S R

    2008-01-01

    A formulated mixture of two sulfonylurea herbicides, mesosulfuron and iodosulfuron, combined with the safener mefenpyr-diethyl ('Atlantis') is being used extensively in Europe and there is concern that resistance will evolve in Alopecurus myosuroides (black-grass). Glasshouse screening bioassays showed that the best single discriminating dose for detecting resistance is the UK field rate of 12 g mesosulfuron + 2.4 g iodosulfuron ha(-1) applied at the 3 leaf stage, with herbicidal effects recorded 4 weeks later. Using this methodology with 466 UK seed samples, resistance was confirmed on a total of 24 farms in 11 counties by 2005, 81 farms in 19 counties by 2006 and 133 farms in 21 counties by 2007. Cultural histories for 10 resistant (R) and 7 susceptible (S) fields were obtained. Winter cereals were grown in 73% R/ 71% S years and a mean of 3.0 grass-weed active ingredients applied per year in both R and S fields. Four herbicide classes dominated, comprising almost 80% of all applications: ALS inhibitors 17% R/ 21% S; ACCase inhibitors 19% R/ 17% S; substituted ureas 18% R/ 10% S; dinitroanilines 25% R/ 30% S. Consequently, ALS inhibitor use was not excessive and field histories were not a reliable indicator of resistance risk. DNA sequencing of the ALS gene from resistant and susceptible individuals of nine populations was used to identify resistance mechanisms. All highly resistant individuals from seven populations showed a single nucleotide polymorphism in the first position of the Pro197 codon of an A. myosuroides ALS gene. One population showed resistant individuals with a single nucleotide polymorphism in the second position of the Trp574 codon. Consequently ALS target site resistance was confirmed in eight of the nine populations studied in detail.

  4. Field studies on the germination behaviour of black-grass (Alopecurus myosuroides Huds. depending on sowing date und winter wheat variety in Northern Germany

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    Landschreiber, Manja

    2014-02-01

    Full Text Available Black-grass (Alopecurus myosuroides, Huds. is the most important herbicide-resistant weed in Europe. In Germany it is not only a problem in the maritime influenced areas like Schleswig-Holstein and Lower Saxony anymore, as well in other regions black-grass develops to the most important weed in winter wheat and oilseed rape. There are multifaceted reasons for that, one reason are close winter crop rotations and early sowing dates which are economically very attractive for the farmers, another one are herbicide resistances. Black-grass germinates in autumn and in spring, but the main germination period is from late August to early October. If winter wheat is sown early in autumn, the main germination is in parallel to the wheat. Then the weeds can only be managed by culture specific herbicides. The pressure on the herbicides is therefore increasing. Herbicide resistances can be the result. As long as very effective herbicides are available, so that farmers are not dependent on weed biology and plant production weed management measures such as sowing date. Late sowing dates can reduce the black-grass populations, but this option is not attractive to many farmers in Schleswig-Holstein. In mind of the farmers the risk of delayed sowing dates in autumn is too high, because increased rainfall such as can make it difficult to marsh soils sowing, or make impossible. Objective of this trial was the germination of Black-grass to show to two sowing dates. The results of the field trial show, that black-grass populations can be reduced if winter wheat is sown later in autumn.

  5. Treatment influence on herbicide resistance level of Belgian Alopecurus myosuroides populations (black-grass).

    Science.gov (United States)

    Marechal, P Y; Henriet, F; Bodson, B

    2009-01-01

    Black-grass is a common grass weed, widely spread in Northern Europe and also in Belgium. For ages, it has been an increasing problem in industrial crops, especially winter cereals. Therefore, farmers started to spray herbicide intensively and soon cases of failure occurred for different molecules and different modes of action. Black-grass populations have been tested in greenhouses to assess the influence of an herbicide treatment as to the resistance level regarding three different herbicides: chlortoluron, fenoxaprop-P and mesosulfuron+iodosulfuron. Black-grass seeds were collected in field trials in six locations in Belgium, on individuals which have survived the herbicide treatment. Each population comes from trial plots, measuring 2 meters wide by 5 meters long and characterized by a single or a combination of products. Herbicides sprayed were isoproturon, flufenacet+diflufenican, ACCase inhibitors and ALS inhibitors. Seeds were also collected in the untreated plots. The population present in these last ones corresponds to the former population, before the herbicide selection pressure was applied. In the glasshouse assay, this population was used as the standard population to compare with other populations issued from the same field. The 'R' rating system was set up with this population to assess the evolution of resistance level, year in, year out. Rothamsted and Peldon populations were also included as cross-reference. Each field population presented different behaviours towards herbicide applied in greenhouses and some cases of resistance can be highlighted. Generally, a reduction of treatment efficiency between field and greenhouse results was clearly visible for the whole of studied active ingredients. Indeed, a distribution shift of the populations towards higher resistance classes could be observed. This is particularly remarkable for active ingredients sharing the same mode of action. For example, it has been found that populations already sprayed

  6. Control of Alopecurus myosuroides (black-grass) resistant to mesosulfuron+iodosulfuron.

    Science.gov (United States)

    Moss, S R; Hull, R; Marshall, R

    2009-01-01

    Resistance to the ALS inhibitor mesosulfuron+iodosulfuron ('Atlantis') had been identified in 293 populations of A. myosuroides in the UK by 2008. Two field trials were conducted in winter wheat crops where ALS target site resistance (Pro197Thr) occurred. Mesosulfuron+iodosulfuron (12+2.4 g a.i. ha(-1)) gave 73% - 79% reductions in head numbers in Town Mead field, but only -7% - 5% reductions in Long Covert. Mixtures and sequences improved overall control. Pre-emergence flufenacet+pendimethalin (240+1200 g a.i. ha(-1)) followed by mesosulfuron+ iodosulfuron plus pendimethalin (1320 g a.i. ha(-1)) or clodinafop+trifluralin (30+960 g a.i. ha(-1)) gave 93 - 98% reductions in Town Mead but only 60 - 73% reductions in Long Covert. A non-ALS treatment of pre-emergence flufenacet+pendimethalin followed by isoproturon+pendimethalin (1500+1320 g a.i. ha(-1)) in late October and clodinafop+trifluralin in November or February achieved 97% and 93% reductions in the two trials. Seed samples collected from surviving plants were evaluated in glasshouse assays to quantify any changes in the incidence of resistance. There was an increase in the proportion of plants resistant to mesosulfuron+iodosulfuron regardless of whether it was used alone, in mixture or sequence. No such changes occured with non-ALS treatments. The trials highlight the difficulty of achieving adequate control with alternative herbicides, especially as isoproturon and trifluralin will not be available for use in the UK after 2009.

  7. Spatial and temporal development of ACCase and ALS resistant Black-grass (Alopecurus myosuroides Huds. populations in neighboring fields in Germany

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    Herrmann, Johannes

    2014-02-01

    Full Text Available The repetitive use of herbicides of a given mode of action as primary tools to control weeds in simplified cropping systems has led to the development of resistant populations. This study reports preliminary results of the infestation level and the herbicide resistance structure of blackgrass (Alopecurus myosuroides Huds. in circa 40 neighboring fields in each of three locations in Southern Germany during 2010-2012. In each location one field with confirmed field resistance served as a starting point to survey the surrounding fields. Field infestation was assessed at the end of the season where seeds were harvested. Based on greenhouse biotests nearly all tested fields showed resistance to ACCase, but the pattern of ACCase mutations and metabolic resistance to fenoxaprop-ethyl showed differences according to space and time. High resistance to ALS was found in several fields in two locations where ALS-resistance was previously confirmed in a single field only leading to severe crop failure. Interestingly, either Pro197 or Trp574 seemed to dominate in these two locations, while almost no ALS target-site mutations were found in the third location. Target-site mutations appear to be the major mechanism for these early cases of ALS-resistance. A few fields also showed non-target site resistant plants to mesosulfuron-methyl. This unique data set provides new insights into the structure and development of 1 an established resistance (ACCase-inhibitors and 2 a developing resistance (ALS-inhibitors. Multivariate analysis including greenhouse biotests data and target-site analyses corresponding to mutations conferring resistance showed that even spatially closely related fields develop different herbicide resistance patterns. This suggests that weed control measures have a major impact within each field and that resistance can evolve independently. In the current situation black-grass infestations can still be controlled in most of the fields. Integrated

  8. Impact of non-target-site-resistance on herbicidal activity of imazamox on blackgrass (Alopecurus myosuroides Huds. in comparison to other ALS-graminicides

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    Sievernich, Bernd

    2014-02-01

    Full Text Available A black-grass (Alopecurus myosuroides Huds. resistance-monitoring conducted by BASF in 2010 - 2012 revealed a high number of accessions with resistance against imazamox. However, application of imazamoxbased products in a winter crop was limited to winter beans in France and United Kingdom only until the introduction of the Clearfield®-production system in autumn 2012 in winter oilseed rape. It is therefore assumed that the resistance mechanisms were probably selected by the frequent use of ACCase- and ALSinhibitors in winter crop rotations during the last 2 decades. Resistance level for each product-biotype combination was calculated according the “R”-classification system (S, R?, RR, RRR by directly comparing the product performance on a biotype versus untreated control. Majority of resistant biotypes did not show a target-site mutation at the known codon Pro197 or Trp574. In order to better evaluate the impact of Non-Target-Site-Resistance (NTSR on the activity of BEYOND (imazamox, ATLANTIS WG (mesosulfuron+iodosulfuron and ABAK (pyroxsulam, biotypes who have shown an ALS-target-site mutation were removed from further analysis. At the dose rate of 35 g ai/ha BEYOND provided good activity on susceptible biotypes of black-grass almost matching up with ATLANTIS WG and ABAK. However, activity of BEYOND declined stronger on biotypes classified as R? or RR for that product, while ATLANTIS WG and ABAK hardly showed any decline in control on this group of biotypes when applied at the recommended dose rate. It is assumed that the underlying NTSR-mechanism is not effective enough yet to confer resistance to ATLANTIS WG and ABAK, but on BEYOND. In contrast, biotypes classified as R? for ATLANTIS WG did show a stronger impact on the activity of BEYOND and ABAK then of ATLANTIS WG. These differences in control level probably do translate into differences in selection pressure as well.

  9. Spread and control of blackgrass (Alopecurus myosuroides according to an increasing occurrence of resistance - Evaluation of field trials in the federal states Brandenburg, Hessen, Saxony, Saxony-Anhalt and Thuringia in the years 2000 - 2014

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    Meinlschmidt, Ewa

    2016-02-01

    Full Text Available An increasing occurrence of blackgrass (Alopecurus myosuroides with high densities has been reported for Brandenburg, Hessen, Saxony-Anhalt, Saxony and Thuringia. In recent years, an increasing resistance to blackgrass especially to ALS inhibitors and partially to ACCase inhibitors has been reported for some eastern federal states and Hessen, too. It was determined to what extent dicotyledonous weeds are associated with blackgrass. The efficacy of different herbicide applications was tested in field trials between 2000 and 2014. A total of 191 trials have been included in the analysis of blackgrass. Using the HRAC-classification of herbicides tested, combinations of herbicides were used which might contribute to solve problems specifically linked to the detected resistance situation of the site. The study aimed to identify the right timing of the herbicide applications as well as applications as single or serial treatments and the use of herbicide at reduced doses according to the intensity of blackgrass. In autumn, single applications of soil active herbicides were not effective enough, especially at a high density of more than 500 heads of blackgrass per m2. The mixtures of soil active herbicides with leave active herbicides applied in autumn achieved very good control. The herbicide sequences were more effective than single applications. In order to counteract further spread of herbicide resistance, the right choice of the mode of action and highly efficacious herbicide treatments are the methods of choice, of course in addition to nonchemical controlling measures such as delayed autumn drilling, ploughing and crop rotation.

  10. Allelopathy—A Tool to Improve the Weed Competitive Ability of Wheat with Herbicide-Resistant Black-Grass (Alopecurus myosuroides Huds.)

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    Nils-Ove Bertholdsson

    2012-01-01

    Controlling black-grass in winter wheat production in northern Europe is an increasing problem because of more frequent winter crops and development of herbicide resistance in weeds. Alternative weed management strategies are needed, e.g., use of more competitive cultivars. Factors that increase cultivar competitiveness include early vigor and straw length, but also allelopathy. Therefore, the allelopathic properties of wheat cultivars included in the Swedish national list or in the release p...

  11. Impact of the safener Mefenpyr-diethyl on herbicide resistance evolution in Alopecurus myosuroides (Huds. biotypes

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    Rosenhauer, Maria

    2016-02-01

    Full Text Available The evolution of herbicide resistance is an important topic in plant protection and agricultural practice. Safeners are commonly used in herbicides to protect crops against herbicidal damage. Although no effect on the weed control is expected, it has been theorized that the rate of evolution of non-target site resistance (NTSR in weeds in cereals may be enhanced by use of herbicide products containing safeners. One of the most important safeners in cereals is mefenpyr-diethyl. Therefore, the possible influence of mefenpyr on herbicide resistance was studied in cooperative trials between Bayer CropScience (BCS, F-Höchst and FH Bingen. The trials tested in parallel different herbicide resistant black-grass (Alopecurus myosuroides (Huds. biotypes under greenhouse conditions. The biotypes where chosen due to known NTSR against Atlantis WG® (4 highly resistant and 5 moderately resistant as well as two susceptible biotypes. The populations were treated with the following three herbicide/safener regimes in six concentrations adjusted according to the anticipated biotype resistance levels. (1 mesosulfuron + iodosulfuron + without safener formulation, (2 mesosulfuron + iodosulfuron + constant mefenpyr concentration (45g/ha, (3 mesosulfuron + iodosulfuron + varying mefenpyr concentrations (ratio 5:1:15. The treatments were applied in post-emergence based on mesosulfuron to iodosulfuron ratios in Atlantis WG® (5:1. The trials were assessed visually (% effect and by fresh weight. Dose-response curves were performed and ED50 values for each treatment and biotype were calculated. Results showed a varying effect of safeners which was in the most cases negligible. Depending on the biotypes mostly no impact on the safener was found for herbicide resistance. In conclusion, the trials from Bingen and F-Höchst gave evidence, that there is no significant and consistent influence of the safener mefenpyr on evolution of NTSR black-grass.

  12. Resistance profile of herbicide-resistant Alopecurus myosuroides (black-grass) populations in Denmark

    DEFF Research Database (Denmark)

    Keshtkar, E.; Mathiassen, S. K; Moss, S. R.;

    2015-01-01

    with a mutation at the Ile-1781 position. No mutations conferring TSR to ALS inhibitors were detected in the 53 populations. The seed bioassay results showed that all populations had varying degrees of resistance to fenoxaprop-P. In contrast, all populations were susceptible to cycloxydim suggesting that non-target...

  13. Herbicide treatments for the control of resistant black grass (Alopecurus myosuroides Huds. in winter wheat (Triticum aestivum L.

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    Gehring, Klaus

    2014-02-01

    Full Text Available Different herbicide treatments were tested in the year 2010 – 2013 at eight locations in the north-west of Bavaria in Franken to control herbicide resistant black grass (Alopecurus myosuroides, Huds.. Application of Atlantis (Mesosulfuron + Iodosulfuron + Mefenpyr was essential for the control of black grass in winter wheat. Combination with other herbicides was also in focus of the trial program as different treatment methods, application timing, application sequences, herbicide rate and the use of adjuvants. As a result of the trials sequence applications were more effective than single applications. The use of soil active herbicides in autumn and spring application of Atlantis was one of the best solutions to control resistant black grass in winter wheat. Reduced rate of Atlantis have to be compensated by addition of appropriate adjuvants. Higher level of resistance depends on implementation of integrated weed management to serve economic wheat production.

  14. Reduction of selection pressure of herbicides - options and limits for blackgrass management by using clethodim in oilseed rape in the presence of the Leu1781 haplotype

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    Wagner, Jean

    2014-02-01

    Full Text Available In field experiments the control of blackgrass (Alopecurus myosuroides, Huds. in oilseed rape using clethodim (Select EC 240 and cycloxydim (Focus Ultra with and without subsequent treatments with propyzamide (Kerb FLO was tested at 6 locations in North and South Germany with assumed resistance problems. The field experiments were accompanied using molecular analysis leaf samples from the plots to seize the occurrence of black-grass with the Leu 1781 haplotype and to determine the frequency of the genotypes. The goal of the trials was to correlate the successes of blackgrass control with the occurrence of hetero- and homozygous resistant genotypes. It was shown in greenhouse trials that clethodim selects the haplotype Leu1781 more weakly (and it shows a higher partial efficacy than cycloxydim and that heterozygous plants have a lower resistance factor than homozygous plants. The question raised whether the frequency of heterozygous plants has influence on increased efficacy of clethodim under field conditions. At 5 sites target-site resistance was detected. At one location the high proportion of heterozygous plants correlated positive with relative higher control using Select EC 240 (80% compared to Focus Ultra (0%. At two locations with high proportion of homozygous resistant plants Select EC 240 and Focus Ultra treatments without subsequent treatments with Kerb FLO were not sufficient in solo variants. The subsequent treatments with Kerb FLO provided partly, but not sufficient control of black-grass. At one location no resistance was identified. The effect of Select EC 240 and Focus Ultra to control black-grass were comparable high in all variants with and without subsequent treatments of Kerb FLO. The investigations showed clearly a higher degree of control by plants with the haplotype Leu1781 by the active substance clethodim and pointed out the fact that the frequency of resistant genotypes (homo vs. heterozygous resistant plants has a

  15. Atlantis Star – a new herbicide in cereals with efficacy against grasses and dicots

    OpenAIRE

    Kerlen, Dirk; Naunheim, Peter

    2016-01-01

    Atlantis Star (mesosulfuron-methyl; iodosulfuron-methyl-sodium; thiencarbazone-methyl; mefenpyr-diethyl) is a new cereal herbicide to control blackgrass (Alopecurus myosuroides; sensitive and high infestation), brome grass (Bromus spec.), ryegrass (Lolium spec.), wild oat (Avena fatua), loose silky-bentgrass (Apera spica-venti L.), annual meadow-grass (Poa annua L.) and dicot weeds. Atlantis Star can be used in winter wheat, winter triticale, winter rye, winter durum wheat and spelt. The p...

  16. Cadou FORTE – a new herbicide in cereals with efficacy against grasses and dicots

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    Kerlen, Dirk

    2012-03-01

    Full Text Available Cadou FORTE (flufenacet; flurtamone; diflufenican is a new cereal herbicide with efficacy against blackgrass (Alopecurus myosuroides, loose silky-bentgrass (Apera spica-venti L., annual meadow-grass (Poa annua L. and a broad spectrum of dicot weeds. Cadou FORTE can be used in winter wheat, winter barley, winter rye, winter triticale and spelt for pre and post emergence application in autumn. This publication focuses on efficacy trials from three years of autumn application with Cadou FORTE.

  17. Atlantis Star – a new herbicide in cereals with efficacy against grasses and dicots

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    Kerlen, Dirk

    2016-02-01

    Full Text Available Atlantis Star (mesosulfuron-methyl; iodosulfuron-methyl-sodium; thiencarbazone-methyl; mefenpyr-diethyl is a new cereal herbicide to control blackgrass (Alopecurus myosuroides; sensitive and high infestation, brome grass (Bromus spec., ryegrass (Lolium spec., wild oat (Avena fatua, loose silky-bentgrass (Apera spica-venti L., annual meadow-grass (Poa annua L. and dicot weeds. Atlantis Star can be used in winter wheat, winter triticale, winter rye, winter durum wheat and spelt. The publication is based on efficacy trials from two years of spring application with Atlantis Star.

  18. Atlantis FLEX (BAY 22010 H – a new herbicide in cereals with efficacy against grasses

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    Kerlen, Dirk

    2014-02-01

    Full Text Available Atlantis FLEX (Mesosulfuron-methyl; Propoxycarbazone-sodium; Mefenpyr-diethyl is a new cereal herbicide to control blackgrass (Alopecurus myosuroides, ryegrass (Lolium spec., brome grass (Bromus spec., wild oat (Avena fatua, loose silky-bentgrass (Apera spica-venti L, annual meadow-grass (Poa annua L. and dicot weeds. Atlantis FLEX can be used in winter wheat, winter triticale, winter rye, winter durum wheat and spelt. The publication is based on efficacy trials from two years of spring application with Atlantis FLEX. It will be shown, that Atlantis FLEX generates a good to excellent efficacy against grass-weeds.

  19. Cossack Star – a new herbicide in cereals with efficacy against grasses and dicots

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    Kerlen, Dirk

    2016-02-01

    Full Text Available Cossack Star (mesosulfuron-methyl; iodosulfuron-methyl-sodium; thiencarbazone-methyl; mefenpyr-diethyl is a new cereal herbicide to control blackgrass (Alopecurus myosuroides, ryegrass (Lolium spec., wild oat (Avena fatua, loose silky-bentgrass (Apera spica-venti L., annual meadow-grass (Poa annua L. and dicot weeds. Cossack Star can be used in winter wheat, winter triticale, winter rye, winter durum wheat and spelt. The publication is based on efficacy trials from two years of spring application with Cossack Star.

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

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

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    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.

  2. Distribution of endophytic bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. from soils contaminated by polycyclic aromatic hydrocarbons.

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    Anping Peng

    Full Text Available The distributions of endophytic bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. grown in soils contaminated with different levels of polycyclic aromatic hydrocarbons (PAHs were investigated with polymerase chain reaction followed by denaturing gradient gel electrophoresis technology (PCR-DGGE and cultivation methods. Twelve types of PAHs, at concentrations varying from 0.16 to 180 mg·kg(-1, were observed in the roots and shoots of the two plants. The total PAH concentrations in Alopecurus aequalis Sobol obtained from three different PAH-contaminated stations were 184, 197, and 304 mg·kg(-1, and the total PAH concentrations in Oxalis corniculata L. were 251, 346, and 600 mg·kg(-1, respectively. The PCR-DGGE results showed that the endophytic bacterial communities in the roots and shoots of the two plants were quite different, although most bacteria belonged to Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. A total of 68 endophytic bacterial strains were isolated from different tissues of the two plants and classified into three phyla: Firmicutes, Proteobacteria and Bacteroidetes. In both plants, Bacillus spp. and Pseudomonas spp. were the dominant cultivable populations. With an increase in the PAH pollution level, the diversity and distribution of endophytic bacteria in the two plants changed correspondingly, and the number of cultivable endophytic bacterial strains decreased rapidly. Testing of the isolated endophytic bacteria for tolerance to each type of PAH showed that most isolates could grow well on Luria-Bertani media in the presence of different PAHs, and some isolates were able to grow rapidly on a mineral salt medium with a single PAH as the sole carbon and energy source, indicating that these strains may have the potential to degrade PAHs in plants. This research provides the first insight into the characteristics of endophytic bacterial populations under different PAH pollution levels and provides a

  3. The influence of nitrogen in stemflow and precipitation on epiphytic bryophytes, Isothecium myosuroides Brid., Dicranum scoparium Hewd. and Thuidium tamariscinum (Hewd.) Schimp of Atlantic oakwoods

    Energy Technology Data Exchange (ETDEWEB)

    Leith, I.D. [Centre for Ecology and Hydrology Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB (United Kingdom)], E-mail: idl@ceh.ac.uk; Mitchell, R.J.; Truscott, A.-M. [Centre for Ecology and Hydrology Banchory, Hill of Brathens, Banchory, Aberdeenshire, AB31 4BW (United Kingdom); Cape, J.N.; Dijk, N. van; Smith, R.I.; Fowler, D.; Sutton, M.A. [Centre for Ecology and Hydrology Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB (United Kingdom)

    2008-09-15

    The spatial relationship between the concentration and deposition of the major ions in precipitation and stemflow and their influence on the tissue nitrogen concentration of three epiphytic bryophytes on Quercus petraea (Matt) Liebl. and Q. robur L. was investigated at seven UK Atlantic oak woodland sites with a range of total N deposition of 55-250 mmol m{sup -2}. The main driver of change in tissue N concentrations of three epiphytic bryophytes (Isothecium myosuroides Brid. (Eurhynchium myosuroides (Brid.) Schp.), Dicranum scoparium Hewd. and Thuidium tamariscinum (Hewd.) Schimp.) was total N deposition in stemflow, dominated by ammonium deposition. The three epiphytic species also showed strong relationships between tissue N concentration and total N deposition in rainfall but a poor correlation with total N ion concentration in rainfall. This study shows that epiphytic bryophytes utilise stemflow N and thus increase their risk from inputs of total N deposition compared to terricolous species at the same site. - Stemflow increases the tissue N concentration of epiphytic bryophytes.

  4. Multiple resistance to ACCase and AHAS-inhibiting herbicides in shortawn foxtail (Alopecurus aequalis Sobol.) from China.

    Science.gov (United States)

    Guo, Wenlei; Yuan, Guohui; Liu, Weitang; Bi, Yaling; Du, Long; Zhang, Chao; Li, Qi; Wang, Jinxin

    2015-10-01

    Shortawn foxtail (Alopecurus aequalis) is a troublesome grass weed infesting winter wheat and oilseed rape productions in China. Fenoxaprop-p-ethyl and mesosulfuron-methyl failed to control shortawn foxtail of AHSX-1 population collected from a wheat field in Shou County, Anhui province. Molecular analyses revealed that Asp2078Gly mutation of ACCase and Trp574Leu mutation of AHAS were present in plants of the AHSX-1 population. The homozygous plants were isolated and cultured until seed maturity. Whole-plant herbicide bioassays were conducted in the greenhouse using the purified seeds of F1 generation. Dose-response experiments showed that the AHSX-1 population has evolved a very high level resistance to fenoxaprop-p-ethyl (RI = 275) and mesosulfuron-methyl (RI = 788). To determine the sensitivity to other herbicides, assays were conducted at the single recommended rate of each herbicide. Based on the results, the AHSX-1 population was considered to be highly resistant to clodinafop-propargyl, pyroxsulam and flucarbazone-sodium, moderately or highly resistant to quizalofop-p-ethyl, clethodim, sethoxydim and pinoxaden, and susceptible to isoproturon and chlorotoluron. This is the first report of Asp2078Gly mutation in shortawn foxtail and the two robust dCAPS markers designed could quickly detect Asp2078 and Trp574 mutations in ACCase and AHAS gene of shortawn foxtail, respectively.

  5. Molecular basis of multiple resistance to ACCase- and ALS-inhibiting herbicides in Alopecurus japonicus from China.

    Science.gov (United States)

    Bi, Yaling; Liu, Weitang; Guo, Wenlei; Li, Lingxu; Yuan, Guohui; Du, Long; Wang, Jinxin

    2016-01-01

    Fenoxaprop-P-ethyl-resistant Alopecurus japonicus has become a recurring problem in winter wheat fields in eastern China. Growers have resorted to using mesosulfuron-methyl, an acetolactate synthase (ALS)-inhibiting herbicide, to control this weed. A single A. japonicus population (AH-15) resistant to fenoxaprop-P-ethyl and mesosulfuron-methyl was found in Anhui Province, China. The results of whole-plant dose-response experiments showed that AH-15 has evolved high-level resistance to fenoxaprop-P-ethyl (95.96-fold) and mesosulfuron-methyl (39.87-fold). It was shown via molecular analysis that resistance to both fenoxaprop-P-ethyl and mesosulfuron-methyl was due to an amino acid substitution of Ile1781 to Leu in acetyl-CoA carboxylase (ACCase) and a substitution of Trp 574 to Leu in ALS, respectively. Whole-plant bioassays indicated that the AH-15 population was resistant to the ACCase herbicides clodinafop-propargyl, clethodim, sethoxydim and pinoxaden as well as the ALS herbicides pyroxsulam, flucarbazone-Na and imazethapyr, but susceptible to the ACCase herbicide haloxyfop-R-methyl. This work reports for the first time that A. japonicus has developed resistance to ACCase- and ALS-inhibiting herbicides due to target site mutations in the ACCase and ALS genes.

  6. Molecular basis of ALS- and/or ACCase-inhibitor resistance in shortawn foxtail (Alopecurus aequalis Sobol.).

    Science.gov (United States)

    Xia, Wenwen; Pan, Lang; Li, Jun; Wang, Qiong; Feng, Yujuan; Dong, Liyao

    2015-07-01

    Alopecurus aequalis, a predominant weed species in wheat and oilseed rape fields, can no longer be controlled by mesosulfuron-methyl application after continuous use over several years. Based on dose-response studies, the putative resistant populations, JTJY-1 and JHHZ-1, were found to be resistant to mesosulfuron-methyl, with resistance index values of 5.5 and 14, respectively. Sensitivity assays of the mesosulfuron-methyl-resistant populations to other herbicides revealed that the JTJY-1 population had moderate or high cross resistance to sulfonylureas (SUs) and triazolopyrimidines (TPs), but displayed a low level resistance to imidazolinones (IMIs). JTJY-1 also had high multi-resistance to ACCase inhibitors, but remained susceptible to photosystem II inhibitors. The JHHZ-1 population was resistant to all ALS inhibitors tested, but was sensitive to ACCase inhibitors and photosystem II inhibitors. To clarify the molecular basis of resistance in JTJY-1 and JHHZ-1 population, the ALS and ACCase gene were sequenced. Two ALS mutations (Pro-197-Thr or Trp-574-Leu) were detected in the mesosulfuron-methyl-resistant plants. The ACCase gene analysis revealed that the resistant JTJY-1 population had an Ile-1781-Leu mutation. Furthermore, the presence of two different target site resistance (TSR) mechanisms (ALS and ACCase mutations) existing simultaneously in individual A. aequalis was firstly documented in the presented study.

  7. Validation of the chlorophyll fluorescence imaging method (CFI for early detection of herbicide resistance in weeds

    Directory of Open Access Journals (Sweden)

    Menegat, Alexander

    2014-02-01

    Full Text Available The increasing number of herbicide tolerant weed populations is illustrating the increasing demand for reliable methods for an accelerated detection of herbicide tolerance compared to greenhouse studies. Several methods for resistance quick detection have been published in previous years. One of the recent methods is the Chlorophyll Fluorescence Imaging Method (CFI. For this method changes in photosynthetic activity of the target organisms, caused by herbicides, are determined. General assumption of this method in terms of herbicide resistance detection is that each herbicidal compound, independent of the mode of action, will cause changes within the photosynthetic apparatus of the target organisms. This effect already could be confirmed for several modes of action (PSII, ALS, ACCase, EPSPS, synth. Auxins. Aim of this study is to validate this novel method on the basis of greenhouse experiments and single nucleotide polymorphisms (SNP analysis. The resistance profiles of 10 black-grass populations (Alopecurus myosuroides Huds. have been determined in greenhouse herbicide efficacy trials and constitutive SNP analyses of the survivors. With the CFI-method it was possible to detect the resistance profile as well as the resistance frequency within the populations. The results from the greenhouse experiments could be reproduced with conformity of 94%. This result is valid for the tested herbicides mesosulfuron, pyroxsulam as well as clodinafop and pinoxaden.

  8. Effect and Safety of Different Herbicides to Control Alopecurus Japonicus Steud.in Wheat Field%多种药剂防除小麦田日本看麦娘的效果及安全性

    Institute of Scientific and Technical Information of China (English)

    陈思宏; 倪运东; 马学文; 于永鑫; 杜国防

    2013-01-01

    通过对5%唑啉草酯乳油、5%唑啉·炔草酸乳油、12 g/L二磺·甲碘隆可分散油悬浮剂、3%甲基二磺隆悬浮剂4种药剂防治小麦田日本看麦娘效果的对比,表明参试的4种药剂对日本看麦娘都有较好防除效果.综合防效和药害来看,以5%唑啉草酯乳油100 mL/667 m2和12 g/L二磺·甲碘隆可分散油悬浮剂100 mL/667m2个处理对小麦田日本看麦娘的防效较为理想,在今后小麦田日本看麦娘的防除工作当中可以考虑推广使用.%A comparative experiment was conducted to determine the efficacy of pinoxaden 5%EC,alkyne oxalic - pinox-aden 50% EC, iodosulfuron - methyl - sodium + mesosulfuron - methyl 12 g/L OFK and mesosulfuron - methyl 3% OD on Alopecurus japonicus. The four herbicides tested provided effective control of A. japonicus. Considering the level of control and phytotoxicity,pinoxaden 5% EC (100 mL/667m2 ) and iodosulfuron - methyl - sodium + mesosulfuron -methyl 12 g/L OFK (100 mL/667m2 ) were the most satisfactory against A. japonicus, therefore both can be considered and recommended for field use.

  9. 4种除草剂对麦田看麦娘防效和安全性%Control Effect and Security of the 4 Herbicides against Alopecurus aequalis in Wheat Field

    Institute of Scientific and Technical Information of China (English)

    庾琴; 范仁俊; 张润祥; 李光玉; 高越

    2012-01-01

    [目的]比较4种除草剂30 g/L甲基二磺隆油悬浮剂、3.6%二磺·甲碘隆水分散粒剂、69 g/L精(噁)唑禾草灵水乳剂和15%炔草酸可湿性粉剂防除看麦娘效果和对小麦安全性.[方法]小麦返青后、拔节前一次性喷药后于不同时期调查杂草防效和对小麦影响.[结果]4种除草剂均能不同程度抑制看麦娘生长,除15%炔草酸可湿性粉剂外,其他除草剂高用量对小麦均有不良影响.[结论]在小麦返青后可使用15%炔草酸可湿性粉剂,使用其他药剂时要注意用量.%[Aims] The herbicidal efficacy and security of four herbicides, mesosulfuron-methyl 30 g/L OF, mesosulfuron-methyl ? Iodosulfuron-methyl-sodium 3.6% WG, fenoxaprop-P-ethyl 69 g/L EC and clodinafop-propargyl 15% WP was studied. [Methods] 4 Herbicides were applied at wheat recovering date and then control effect and injure to wheat were investigated at different stages. [Results] All 4 herbicides can inhibit Alopecurus aequalis at different level. Except clodinafop-propargyl 15% WP, the other three herbicides can injure wheat at higher concentration. [Conclusions] After wheat turns green, clodinafop-propargyl 15% WP can be used to prevent A. Aequalis, the other three herbicides should be payed attention to their concentration in this stage.

  10. Within-species variation in grass weeds in Sweden

    OpenAIRE

    Espeby Åkerblom, Liv

    2010-01-01

    Variation within a weed species enables it to persist through varying conditions and is thus an important component of weediness. In this thesis, intra-specific variation in two agronomically important attributes - herbicide susceptibility and seed dormancy - are studied in Swedish Apera spica-venti (L.) Beauv. and Alopecurus myosuroides Huds., both serious annual weeds in winter cereals, and with many cases of herbicide resistance. Swedish Elymus repens (L.) Gould, a perennial, rhizomatous g...

  11. 油菜田看麦娘对精喹禾灵的抗性水平及抗性机理研究%Resistance level of Alopecurus aequalis to quizalofop-P-ethyl in rape in Hunan Province

    Institute of Scientific and Technical Information of China (English)

    祝玮玮; 刘艺妩; 刘祥英; 罗坤; 柏连阳

    2014-01-01

    采用培养皿种子萌发法和盆栽法测定了湖南省境内长沙市、永州市、常德市、益阳市、浏阳市、岳阳市、娄底市7个市州10个地区油菜田看麦娘潜在抗药性种群对精喹禾灵的抗性水平,测定了常德市桃源地区看麦娘潜在抗药性种群以及敏感种群谷胱甘肽-S-转移酶(GSTs)对精喹禾灵的敏感性,对桃源地区看麦娘抗性品系及敏感品系ACCase 基因片段进行扩增和测序,比较了两种生物型的基因序列。培养皿种子萌发法测定结果表明:常德市桃源地区看麦娘抗药性生物型对精喹禾灵的抗性水平最高,抗性倍数为10.50倍,其他地区看麦娘抗性倍数在2.01~7.09倍之间,抗性水平不明显;盆栽法测定结果表明:桃源地区看麦娘抗性倍数最高,为25.30倍,其他地区看麦娘抗性倍数在2.43~9.47倍之间,尚未产生明显抗药性。经精喹禾灵处理后,看麦娘抗药性生物型的 GSTs 活力在第5天明显高于敏感生物型,表明 GSTs 的活性是引起看麦娘对精喹禾灵抗性的重要因子。通过靶标基因片段扩增与 DNA 测序比对发现,抗药性生物型氨基酸序列第93位比敏感生物型多出一个丙氨酸,抗药性的产生与靶标基因的突变是否相关需要进行进一步验证。%In order to investigate the resistance level and mechanism of Alopecurus aequalis Sobol.to quizalofop-P-ethyl in rape,10 potential resistant biotypes were collected from 7 cities in Hunan Province and the susceptible biotype was obtained from Nanjing Agricultural University.The resistance level of A.aequalis to quizalofop-P-ethyl was assessed by two methods:seed bioassay and whole-plant bioassay.The enzymology mechanism of Taoyuan Town potential resistant biotype and Nanjing Agricultural University susceptible biotype was studied with the important metabolic enzyme glutathione-s-transferase(GSTs),and the resistance mechanism at the

  12. 扬州市邗江区小麦田杂草调查与日本看麦娘的化学防除%Investigation on Weeds Species and Chemical Control of Alopecurus japonicus in Wheat Field of Hanjiang District of Yangzhou City

    Institute of Scientific and Technical Information of China (English)

    康晓霞; 袁林泽; 周奋启; 陈银凤; 耿跃; 徐蕾

    2014-01-01

    2014年对扬州市邗江区的麦田杂草进行了抽样调查,结果表明,小麦田禾本科杂草中优势种类为日本看麦娘、菵草、看麦娘和硬草;阔叶杂草优势种有猪殃殃、野老鹳草、牛繁缕和泥胡菜;日本看麦娘在所有调查田间的发生密度最大、频度最高,且丘陵山区的发生程度重于沿江地区。对日本看麦娘的田间药效试验结果表明,炔草酯、甲基二磺隆对该地区日本看麦娘的防除效果均不理想,7.5%啶磺草胺可湿性粉剂(WP)187.5 g/hm2对麦田日本看麦娘的防除效果较好,且对小麦生长安全,是该地区麦田防除日本看麦娘的理想药剂。%A weeds survey in wheat fields of Hanjiang district,Yangzhou City was carried out in 2014.Dominant grass species included Alopecurus japonicus,Beckmannia syzigachne,A.aequalis and Sclerochloa kengiana;the dominant broad-leaf weeds were Galium aparine var.tenerum,Geranium carolinianum,Malachium aquaticum and Hemistepta lyrata.A. japonicus was the most frequent species and had the highest density in all the fields investigated,and the occurrence de-gree of Alopecurus japonicus in hilly and mountain area were more serious than areas along the Yangtze River.In field control tests clodinafop-propargyl and mesosulfuron-methyl did not provide suitable control of A.japonicus but pyroxsu-lam 7.5%WP (187.5 g/hm2 ) proved effective and selective to wheat in this area.

  13. Resistance Monitoring of Alopecurus aequalis Sobol.to Quizalofop-P-ethyl and Cross-resistance with Clethodim in Rape Field%油菜田看麦娘对精喹禾灵抗性监测及与烯草酮交互抗性

    Institute of Scientific and Technical Information of China (English)

    唐子慧; 周小毛

    2016-01-01

    By detecting the resistance level of Alopecurus aequalis Sobol.,and studying its resistance mechanism,a theoretical basis for rational drug use can be provided for A.aequalis resistance management in rape field.The resistance levels of Alopecurus aequalis Sobol.biotypes to quizalofop-P-ethyl and the crossresistance with clethodim in 17 areas in the middle and lower reaches of Yangtze River were determined using the whole-plant assay method.The glutathione-s-transferase (GSTs) enzyme activity was studied in resistant biotype (R-TY) and susceptible biotype (S-NJ) with quizalofop-P-ethyl and clethodim.The anti-quizalofop monitoring results showed that:TY biotype had the highest relative resistance multiple,which was 28.92,GR50 was 90.183.And then were YZ and BLD biotype,of which,GR50 was 34.480 and 45.472,respectively,and the relative resistance multiple was 11.06 and 14.58,respectively.The relative resistance multiples of other biotypes were ranged from 1.62 to 9.16.The cross-resistance with clethodim showed that there was a crossresistance between quizalofop and clethodim in TY and BLD biotype,while DYX,the quizalofop sensitive biotype,was resistant to clethodim,indicating A.aequalis biotypes might have other resistance patterns.GSTs activity assay showed that:after drug treatment,the GSTs activity in R-TY biotype was always higher than that in the sensitive biotype S-N J,indicating that TY biotype' s resistance to drug might be due to the GSTs enhancing effect on drug metabolism.%通过对看麦娘抗药性水平的检测以及抗性机理的研究,以期为油菜田看麦娘的抗性治理和科学合理用药提供理论依据.采用整株法测定了长江中下游地区的4个省13个市17个地区的油菜田看麦娘生物型对精喹禾灵的抗性水平及与烯草酮的交互抗性,分别测定了精喹禾灵与烯草酮对抗性看麦娘(R-TY)、敏感看麦娘(S-NJ)体内GSTs活性.抗精喹禾灵监测结果显示:TY生物型

  14. 抗高效氟吡甲禾灵日本看麦娘生长速率与生长密度研究%Research on Growth Rate and Planting Density of Japanese Foxtail (Alopecurus japonicus) Resistant to Haloxyfop - R - methyl

    Institute of Scientific and Technical Information of China (English)

    张彬; 李俊; 董立尧

    2011-01-01

    抗性日本看麦娘种群与敏感种群种子在低温(4℃)清水浸泡处理超过6 d后萌发率均能达90%以上,但抗性种群休眠解除的时间要长于敏感种群;敏感种群在播种后的前15 d内生长速率快于抗性种群,但此后抗性种群生长速率逐渐超过敏感种群;抗性种群在播种后20 d开始长出第2片叶,比敏感种群晚2 d,播种后25 d两种群出现第2片叶的比例均超过95%,进一步说明在生长后期抗性种群生长速率超过敏感种群;在相同的播种密度下,抗性种群长势优于敏感种群,150~200株/0.11m2的密度范围内有利于日本看麦娘的生长,抗性种群的最佳生长密度为208株/0.11m2,而敏感种群为186株/0.11m2.%The germination rate of Japanese foxtail (Alopecurus japonicus)in the resistant and sensceptible population to haloxyfp -R - methyl could reach to more than 90% after 6 days for water soaking at 4 ℃ ,but dormancy breaking in the resistant population needed more time than that of sensceptible population. The resistant population presented a lower growths rate than that of sensceptible population after 15 days of sowing,but after that date the growth rate in resistant poputation was getting higher than that of sensceptible poputation. The resistant population began to appear the second leaf after 20 days for sowing that was later than sensceptible population by 2days, and the rate for the second leaf appearance in both populations could reach to 95% after 25 days of sowing which proved that the resistant population grew more rapidly than that of sensceptible population during the later period of growth time after sowing. The resistant population performed a better growth than that of sensceptible population under the same planting density. Japanese foxtail could grow well under the planting density of 150 ~ 200 plants/0. llm2. The suitable growth density for resistant population cowld he designed as 208 plants/0.11 m2, but 186 plants/0.11 m2

  15. Isparta Yöresinde Doğal Yayılış Gösteren Bazı Bitki Türlerinin Kesme ve Kuru Çiçekçilikte Kullanım Olanakları

    Directory of Open Access Journals (Sweden)

    Güliz TÜRKMENOĞLU

    2016-04-01

    Full Text Available Bu çalışmada Isparta yöresinde yayılış gösteren bazı doğal bitki taksonlarının kesme ve kuru çiçekçilikte kullanım olanakları araştırılmıştır. 2014-2015 yılları arasında gerçekleştirilen arazi çalışmalarında Acantholimon acerosum subsp. acerosum var. acerosum, Origanum sipyleum, Hypericum perforatum, Fibigia clypeata subsp. clypeata var. eriocarpa, Minuartia gracilis, Dianthus calocephalus,  Alyssum murale subsp. murale var. murale, Dactylis glomerata subsp. hispanica, Alopecurus myosuroides subsp. myosuroides, Iris pseudacorus bitki taksonları toplanmıştır. O. sipyleum ve M. gracilis ülkemiz için endemik türlerdir ve IUCN Red Data Book tehlike kategorilerine göre az tehdit altında, en az endişe verici (LR(Ic ve zarar görebilir (VU  grubuna girmektedir. Toplanan bitki taksonlarının morfolojik özelliklerden bitki boyu, çiçek sayısı, çiçeklenme ve yapraklanma başlangıcı ölçümleri yapılmıştır. Yapılan ölçümlerde bitki boyu en uzun olan takson 163 cm ile Iris pseudacorus, en kısa olan takson 10 cm ile Minuartıa gracilis’tir. Çiçek sayısı en fazla olan takson 54 adet ile Alopecurus myosuroides subsp. myosuroides, en az olan takson ise 1 adet ile Dactylis glomerata subsp. hispanica’dır. Tespit edilen bu türlerin çiçek renkleri turuncu ve sarı ağırlıklıdır. Çiçeklenme süresi genellikle Nisan-Ağustos ayları arasındadır.

  16. New xenophytes from Gran Canaria (Canary Islands, Spain, with emphasis on naturalized and (potentially invasive species

    Directory of Open Access Journals (Sweden)

    Verloove, F.

    2013-12-01

    Full Text Available Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum chrysotrichum, Tecoma stans, Tipuana tipu, Urochloa mutica, U. plantaginea y Washingtonia se citan por primera vez para las Islas Canarias, mientras que Alopecurus myosuroides, Amaranthus blitoides, Bothriochloa ischaemum var. songarica, Cardamine flexuosa subsp. debilis, Heliotropium curassavicum, Leonotis nepetifolia, Medicago lupulina, Parkinsonia aculeata, Physalis peruviana, Phytolacca americana y Turnera ulmifolia son nuevas para la flora de la isla de Gran Canaria. Finalmente, se confirma la presencia de Paspalum vaginatum, P. distichum y Cortaderia selloana en Gran Canaria.Trabajos recientes de campo en Gran Canaria han facilitado el descubrimiento de nuevas localidades para plantas vasculares no nativas. Agave attenuata, Antigonon leptopus, Atriplex nummularia, Cascabela thevetia, Cenchrus echinatus, Cuscuta campestris, Diplachne fusca subsp. uninervia, Diplotaxis tenuifolia, Dysphania anthelmintica (hasta ahora confundida con D. ambrosioides, Eclipta prostrata, Euphorbia pulcherrima, Fagopyrum esculentum, Gossypium barbadense, Lablab purpureus, Lemna minuta, Opuntia leucotricha, Passiflora edulis, Pennisetum glaucum, Phaseolus acutifolius, Pluchea carolinensis, Prosopis juliflora, Salvia microphylla, Schinus terebinthifolius, Senna spectabilis, Solanum

  17. A comparative study of drug resistance mechanism associated with active site and non-active site mutations: I388N and D425G mutants of acetyl-coenzyme-A carboxylase.

    Science.gov (United States)

    Zhu, Xiao-Lei; Yang, Guang-Fu

    2012-03-01

    A major concern in the development of acetyl-CoA carboxylase-inhibiting (ACCase; EC 6.4.1.2) herbicides is the emergence of resistance as a result of the selection of distinct mutations within the CT domain. Mutations associated with resistance have been demonstrated to include both active sites and non-active sites, including Ile-1781-Leu, Trp- 2027-Cys, Ile-2041-Asn, Asp-2078-Gly, and Gly-2096-Ala (numbered according to the Alopecurus myosuroides plastid ACCase). In the present study, extensive computational simulations, including molecular dynamics (MD) simulations and molecular mechanics-Poisson-Boltzmann surface area (MM/PBSA) calculations, were carried out to compare the molecular mechanisms of active site mutation (I388N) and non-active site mutation (D425G) in Alopecurus myosuroides resistance to some commercial herbicides targeting ACCase, including haloxyfop (HF), diclofop (DF) and fenoxaprop (FR). All of the computational model and energetic results indicated that both I388N and D425G mutations have effects on the conformational change of the binding pocket. The π-π interaction between ligand and Phe377 and Tyr161' residues, which make an important contribution to the binding affinity, was decreased after mutation. As a result, the mutant-type ACCase has a lower affinity for the inhibitor than the wild-type enzyme, which accounts for the molecular basis of herbicidal resistance. The structural and mechanistic insights obtained from the present study will deepen our understanding of the interactions between ACCase and herbicides, which provides a molecular basis for the future design of a promising inhibitor with low resistance risk. PMID:22242795

  18. Diversité des communautés de mauvaises herbes des cultures annuelles de Côte-d'Or (France

    Directory of Open Access Journals (Sweden)

    Dessaint F.

    2001-01-01

    Full Text Available Diversity of weed communities of annual crops in Cote-d'Or, France. Weed flora of annual crops in Cote-d'Or, France, were characterized in three successive growing seasons by measuring species frequencies and abundance over 245 fields. A total of 210 species in 143 genera were recorded representing a total of 43 families with Asteraceae, Poaceae, Fabaceae, Scrophulariaceae, Brassicaceae, Lamiaceae and Caryophyllaceae predominating. More than half of the species occurred in less than 5/ of the sampled plots (fields x years and only 9 species (namely Galium aparine L., Polygonum aviculare L., Fallopia convolvulus (L. A. Loeve, Alopecurus myosuroides Hudson, Stellaria media (L. Vill., Convolvulus arvensis L., Sinapis arvensis L., Veronica persica Poiret and Anagallis arvensis L. occurred in more than 50/ of the plots. The maximum plot density was greater than 20 plants per square metre for more than one third of the species. Meanwhile, the plots where the density exceeded 20 plants per square metre, were rare and represented, for the most abundant species (A. myosuroides, less than 16/ of the plots. The total number of weed species per plots varied from 4 to 65 with a median species number of 20. In most of the plots, the weed community was mainly composed of species having a small density (less than one plant per square metre and was dominated by only one or two species in half of the plots.

  19. RESISTANCE TO ALS-INHIBITING HERBICIDES IN WEED POPULATIONS FROM BELGIAN WHEAT FIELDS.

    Science.gov (United States)

    S, Claerhout; B, De Cauwer

    2015-01-01

    In modern agriculture, most farmers rely on herbicides for weed control. The intensive use of herbicides in crops has led to the development of herbicide resistance in numerous weeds worldwide. In Belgium, farmers have encountered problems with controlling populations of Alopecurus myosuroides, Matricaria recutita, Stellaria media and Popover rhoeas in some wheat fields with the conventionally used acetolactate synthase (ALS)-inhibiting herbicides. Dose response assays were conducted in the greenhouse to test the sensitivity of these populations to the key ALS-inhibiting herbicides mesosulfuron-methyl + iodosulfuron-methyl for A. myosuroides and metsulfuron-methyl and florasulam for M. recutita, S. media and P. rhoeas. The ED₉₀- and ED₅₀-values (effective dose for resp. 90% and 50% biomass reduction) were compared with those of sensitive reference populations and the resistance index (RI) was calculated. High levels of resistance were detected forA. myosuroides (RI: 24.3) after treatment with mesosulfuron-methyl and for M. recutita (RI: 36.4 to 49.5), S. media (RI > 20) and P. rhoeas (RI: 23.6) after treatment with metsulfuron-methyl. However, the metsulfuron-methyl resistant populations of M. recutita and S. media were sufficiently controlled with florasulam at the maximum authorised field dose. This was not the case for P. rhoeas. The metsulfuron-methyl resistant P. rhoeas population were also high-level resistant against florasulam (RI: 29.5). Integrated weed management practices (crop rotation, herbicide mixing, ...) should be applied to reduce the selection pressure for resistant weeds. PMID:27145589

  20. RESISTANCE TO ALS-INHIBITING HERBICIDES IN WEED POPULATIONS FROM BELGIAN WHEAT FIELDS.

    Science.gov (United States)

    S, Claerhout; B, De Cauwer

    2015-01-01

    In modern agriculture, most farmers rely on herbicides for weed control. The intensive use of herbicides in crops has led to the development of herbicide resistance in numerous weeds worldwide. In Belgium, farmers have encountered problems with controlling populations of Alopecurus myosuroides, Matricaria recutita, Stellaria media and Popover rhoeas in some wheat fields with the conventionally used acetolactate synthase (ALS)-inhibiting herbicides. Dose response assays were conducted in the greenhouse to test the sensitivity of these populations to the key ALS-inhibiting herbicides mesosulfuron-methyl + iodosulfuron-methyl for A. myosuroides and metsulfuron-methyl and florasulam for M. recutita, S. media and P. rhoeas. The ED₉₀- and ED₅₀-values (effective dose for resp. 90% and 50% biomass reduction) were compared with those of sensitive reference populations and the resistance index (RI) was calculated. High levels of resistance were detected forA. myosuroides (RI: 24.3) after treatment with mesosulfuron-methyl and for M. recutita (RI: 36.4 to 49.5), S. media (RI > 20) and P. rhoeas (RI: 23.6) after treatment with metsulfuron-methyl. However, the metsulfuron-methyl resistant populations of M. recutita and S. media were sufficiently controlled with florasulam at the maximum authorised field dose. This was not the case for P. rhoeas. The metsulfuron-methyl resistant P. rhoeas population were also high-level resistant against florasulam (RI: 29.5). Integrated weed management practices (crop rotation, herbicide mixing, ...) should be applied to reduce the selection pressure for resistant weeds.

  1. Mechanism of resistance to fenoxaprop in Japanese foxtail (Alopecurus japonicus) from China.

    Science.gov (United States)

    Xu, Hongle; Zhu, Xudong; Wang, Hongchun; Li, Jun; Dong, Liyao

    2013-09-01

    Japanese foxtail is one of the most common and troublesome weeds infesting cereal and oilseed rape fields in China. Repeated use during the last three decades of the ACCase-inhibiting herbicide fenoxaprop-P-ethyl to control this weed has resulted in the occurrence of resistance. Dose-response tests established that a population (AHFD-1) from eastern China had evolved high-level resistance to fenoxaprop-P-ethyl. Based on the resistance index, this resistant population of A. japonicus is 60.31-fold resistant to fenoxaprop-P-ethyl. Subsequently, only a tryptophan to cysteine substitution was identified to confer resistance to fenoxaprop-P-ethyl in this resistant population. ACCase activity tests further confirmed this substitution was linked to resistance. This is the first report of the occurrence of Trp-2027-Cys substitution of ACCase in A. japonicus. From whole-plant pot dose-response tests, we confirmed that this population conferred resistance to other APP herbicides, including clodinafop-propargyl, fluazifop-P-butyl, quizalofop-P-ethyl, haloxyfop-R-methyl, cyhalofop-butyl, metamifop, DEN herbicide pinoxaden, but not to CHD herbicides clethodim, sethoxydim. There was also no resistance observed to ALS-inhibiting herbicides sulfosulfuron, mesosulfuron-methyl, flucarbazone-sodium, pyroxsulam, Triazine herbicide prometryne and glyphosate. However, this resistant population was likely to confer slightly (or no) resistant to Urea herbicides chlortoluron and isoproturon.

  2. Analysis of spray retention on a 3D black-grass plant model as a function of spray nozzle and formulation using a process-driven approach

    OpenAIRE

    Massinon, Mathieu; Ouled Taleb Salah, Sofiene; Dumont, Benjamin; Lebeau, Frédéric

    2014-01-01

    The efficiency of spray application of foliar plant protection products can be variable because of the different amount of spray solution intercepted and retained by leaves. On one hand, the spray interception by plants is affected by nozzle kind, size and operating pressure as well as by the plant architecture. On the other hand, the spray retention is affected by application parameters resulting from droplet size and velocity as well as spray mixture physicochemical properties. In this pape...

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

    Directory of Open Access Journals (Sweden)

    Zotz, Agnes

    2016-02-01

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

  4. Recent changes of arable weeds flora and management as a basis for future adaptations

    Directory of Open Access Journals (Sweden)

    Breitsameter, Laura

    2014-02-01

    Full Text Available In the course of the past decennia, numerous shifts of the arable weeds flora have been observed as a result of climate change and of changes of land use and agricultural management practice. These shifts necessitate appropriate adaptations of weed management. The present study depicts alterations of the arable weeds flora of Lower Saxony based on data from two different sources, and describes recent changes of arable weeds management. We firstly conducted a questionnaire-based survey among plant protection consultants and experts of agronomy and plant protection in industry and the federal agriculture authorities. This survey was aimed at identifying which weed taxa have gained or lost relevance for management, and which tendencies with regard to their relevance is expected according to expert knowledge. In addition, the experts were asked for information on possible adaptations and challenges of weed management expected for the future. Secondly, we used protocols of plant protection trails published by the Lower Saxony chamber of agriculture in order to determine alterations of the weed management practice since the 1980s. The screened data gave a clear indication of an increase of the relevance during the past 30 years for a number of weed taxa, in particular for several millet taxa, Geranium species, Alopecurus myosuroides and Chenopodium album. In the evaluation of changes of the relevance of individual weed taxa, the impact of climate change cannot be segregated from effects of altered agricultural practices, which are in turn themselves influenced by climate change. Records of the agricultural practice have pointed out shifts in herbicide application dates which parallel altered sowing dates, e. g., an increase in the frequency of herbicide application in autumn rather than in spring for winter wheat. The recent shifts of weed flora and management practices can serve as a basis for the development of management adaptations for the future

  5. Controlling effects of mesosulfuron-methyl to Avena fatua L.and Alopecurus aequalis in wheat field%甲基二磺隆等防除麦田野燕麦和看麦娘的效果

    Institute of Scientific and Technical Information of China (English)

    孙影; 宋爱颖; 孙晓莉; 李敏; 张亚; 孟祥民

    2010-01-01

    防除以看麦娘和野燕麦为主的禾本科杂草,春季使用15%炔草酸WP 450 g/hm2、3%甲基二磺隆OF300~450 mL/hm2、3.6%二磺·甲碘隆WG 300~375 g/hm2、6.9%精唾唑禾草灵EW 1 500~2 250 mL/hm2和5%唑啉炔草酸EC 1 350~1 500 mL/hm2均有较理想的防效,鲜重防效均在90%以上,高于株防效.

  6. Flora survey on extensive meadows of selected area near Kobilje

    OpenAIRE

    Lainšček, Tadej

    2016-01-01

    Between the years 2009 and 2013, we mapped 273 different taxons on 70 polygones in extensively used grasslands near Kobilje village in Prekmurje. Amongs those taxons, there are 43 nature conservation important species: Achillea ptarmica, Alnus glutinosa, Alopecurus aequalis, Alopecurus pratensis, Carex acutiformis, C. appropinquata, C. canescens, C. tomentosa, C. umbrosa, C. vesicaria, Cerastium glutinosum, Clematis recta, Convallaria majalis, Dianthus carthusianorum, D. deltoides, D. superbu...

  7. Phylogenetic origin of Beckmannia (Poaceae) inferred from molecular evidence

    Institute of Scientific and Technical Information of China (English)

    Chong-Mei XU; Chang-You QU; Wen-Guang YU; Xue-Jie ZHANG; Fa-Zeng LI

    2009-01-01

    The phylogenetic origin of Beckmannia remains unknown. The genus has been placed within the Chlorideae, Aveneae (Agrostideae), Poeae, or treated as an isolate lineage, Beckmanniinae. In the present study, we used nuclear internal transcribed spacer (ITS) and chloroplast trnL-F sequences to examine the phylogenetic relationship between Beckmannia and those genera that have assumed to be related. On the basis of the results of our studies, the following conclusions could be drawn: (i) Beckmannia and Alopecurus are sister groups with high support; and (ii) Beckmannia and Alopecurus are nested in the Poeae clade with high support. The results of our analysis suggest that Beckmannia should be placed in Poeae.

  8. Aportaciones a la flora del Sistema Ibérico meridional

    OpenAIRE

    García Cardo, O.

    2006-01-01

    Se comentan 45 táxones de plantas vasculares nuevas o poco conocidas para las provincias de Cuenca, Guadalajara y Teruel. Merecen destacarse las primeras citas de Alopecurus aequalis, Armeria arenaria subsp. bilbilitana, Avenula pubescens, Elatine alsinastrum, Gnaphalium uliginosum, Juncus bulbosus, Myosotis laxa subsp. caespitosa, Sedum nevadense, Tribulus terrestris y Viola parvula en la provincia de Cuenca y Potentilla anserina en las de Cuenca y Teruel.

  9. Increasing efficacy of graminicides with a forward angled spray

    DEFF Research Database (Denmark)

    Jensen, Peter Kryger

    2012-01-01

    Control of annual grass species with vertically oriented leaves in agricultural crops by application of foliar acting herbicides with conventional hydraulic sprayers can be increased using forward angled nozzles. Changing the spray angle from the normally predominantly vertical spray towards...... efficacy on L. perenne at early growth stages using nozzles with different spray quality, at different driving speeds and in different wind conditions. Similarly graminicide efficacy was increased when nozzles were angled 60° forward controlling A. myosuroides. Experiments investigating control of the two...

  10. Diversity and distribution of 16S rRNA and phenol monooxygenase genes in the rhizosphere and endophytic bacteria isolated from PAH-contaminated sites

    OpenAIRE

    Anping Peng; Juan Liu; Wanting Ling; Zeyou Chen; Yanzheng Gao

    2015-01-01

    This is the first investigation of the diversity and distribution of 16S rRNA and phenol monooxygenase (PHE) genes in endophytic and rhizosphere bacteria of plants at sites contaminated with different levels of PAHs. Ten PAHs at concentrations from 34.22 to 55.29 and 45.79 to 97.81 mg·kg−1 were measured in rhizosphere soils of Alopecurus aequalis Sobol and Oxalis corniculata L., respectively. The diversity of 16S rRNA and PHE genes in rhizosphere soils or plants changed with varying PAH pollu...

  11. Root discrimination of closely related crop and weed species using FT MIR-ATR spectroscopy.

    Science.gov (United States)

    Meinen, Catharina; Rauber, Rolf

    2015-01-01

    Root discrimination of species is a pre-condition for studying belowground competition processes between crop and weed species. In this experiment, we tested Fourier transform mid-infrared (FT MIR)-attenuated total reflection (ATR) spectroscopy to discriminate roots of closely related crop and weed species grown in the greenhouse: maize/barnyard grass, barley/wild oat, wheat/blackgrass (Poaceae), and sugar beet/common lambsquarters (Chenopodiaceae). Fresh (moist) and dried root segments as well as ground roots were analyzed by FT MIR-ATR spectroscopy. Root absorption spectra showed species specific peak distribution and peak height. A clear separation according to species was not possible with fresh root segments. Dried root segments (including root basis, middle section, and root tip) of maize/barnyard grass and sugar beet/common lambsquarters formed completely separated species clusters. Wheat and blackgrass separated in species specific clusters when root tips were removed from cluster analysis. A clear separation of dried root segments according to species was not possible in the case of barley and wild oat. Cluster analyses of ground roots revealed a 100% separation of all tested crop and weed species combinations. Spectra grouped in Poaceae and Chenopodiaceae clusters. Within the Poaceae cluster, C3 and C4 species differed significantly in heterogeneity. Thus, root spectra reflected the degree of kinship. To quantify species proportion in root mixtures, a two- and a three-species model for species quantification in root mixtures of maize, barnyard grass, and wild oat was calculated. The models showed low standard errors of prediction (RMSEP) and high residual predictive deviation values in an external test set validation. Hence, FT MIR-ATR spectroscopy seems to be a promising tool for root research even between closely related plant species. PMID:26483799

  12. Root discrimination of closely related crop and weed species using FT MIR-ATR spectroscopy

    Directory of Open Access Journals (Sweden)

    Catharina eMeinen

    2015-09-01

    Full Text Available Root discrimination of species is a pre-condition for studying belowground competition processes between crop and weed species. In this experiment, we tested Fourier transform mid-infrared (FT MIR-attenuated total reflection (ATR spectroscopy to discriminate roots of closely related crop and weed species grown in the greenhouse: maize/barnyard grass, barley/wild oat, wheat/blackgrass (Poaceae, and sugar beet/common lambsquarters (Chenopodiaceae. Fresh (moist and dried root segments as well as ground roots were analyzed by FT MIR-ATR spectroscopy. Root absorption spectra showed species specific peak distribution and peak height. A clear separation according to species was not possible with fresh root segments. Dried root segments (including root basis, middle section and root tip of maize/barnyard grass and sugar beet/common lambsquarters formed completely separated species clusters. Wheat and blackgrass separated in species specific clusters when root tips were removed from cluster analysis. A clear separation of dried root segments according to species was not possible in the case of barley and wild oat. Cluster analyses of ground roots revealed a 100 % separation of all tested crop and weed species combinations. Spectra grouped in Poaceae and Chenopodiaceae clusters. Within the Poaceae cluster, C3 and C4 species differed significantly in heterogeneity. Thus, root spectra reflected the degree of kinship. To quantify species proportion in root mixtures, a two- and a three-species model for species quantification in root mixtures of maize, barnyard grass, and wild oat was calculated. The models showed low standard errors of prediction (RMSEP and high residual predictive deviation (RPD values in an external test set validation. Hence, FT MIR-ATR spectroscopy seems to be a promising tool for root research even between closely related plant species.

  13. Arctic ground squirrels of the mammoth-steppe: paleoecology of Late Pleistocene middens (˜24 000 29 450 14C yr BP), Yukon Territory, Canada

    Science.gov (United States)

    Zazula, Grant D.; Froese, Duane G.; Elias, Scott A.; Kuzmina, Svetlana; Mathewes, Rolf W.

    2007-04-01

    This paper presents paleoecological analyses of 48 fossil arctic ground squirrel ( Spermophilus parryii) middens (nests and caches) recovered from ice-rich loess sediments in the Klondike region of west-central Yukon Territory. AMS radiocarbon dates and stratigraphic association of middens with Dawson tephra (˜25 300 14C yr BP), indicate these paleoecological data reflect the onset of glacial conditions of early Marine Isotope Stage (MIS) 2 and terminal MIS 3 (˜24 000-29 450 14C yr BP). Plant macrofossils include at least 60 plant taxa, including diverse graminoids ( Poa, Elymus trachycaulus, Kobresia myosuroides), steppe forbs ( Penstemon gormanii, Anemone patens var. multifida, Plantago cf. canescens), tundra forbs ( Draba spp., Bistorta vivipara), dwarf shrubs ( Salix cf. arctica, S. cf. polaris), sage ( Artemisia frigida) and rare trees ( Picea mariana). Many of these taxa identified in the middens represent the first recorded fossils for these plants in Eastern Beringia and add to our knowledge of the floristic composition of Pleistocene vegetation and biogeography in this region. Fossil beetles include typical members of the Eastern Beringian steppe-tundra fauna ( Lepidophorus lineaticollis and Connatichela artemisiae) and others suggesting predominantly dry, open habitats. Cache forage selection is suggested by some plant taxa which were particularly frequent and abundant in the middens ( Bistorta vivipara, Kobresia myosuroides, Ranunculus spp., Potentilla, Erysimum cf. cheiranthoides, Poa, Carex and Draba). Factors such as proximity of vegetation to burrows and abundance of fruits and seeds per plant were probably important in cache selection. Glacial conditions enabled arctic ground squirrels to form widespread and dense populations in regions such as the Klondike in which they are rare or absent at present. This fossil midden record supports previous hypotheses that suggest arctic ground squirrels evolved in and are well-adapted to the open, steppe

  14. Multivariate Analysis, Description, and Ecological Interpretation of Weed Vegetation in the Summer Crop Fields of Anhui Province, China

    Institute of Scientific and Technical Information of China (English)

    Sheng QIANG

    2005-01-01

    Province; Alopecurus aequalis Sobol. was the dominant weed in this group. Other main weeds in this group included Malachium aquaticum (L.) Fries, Stellaria alsine Grimm, Alopecurus japonicus Steud., and Lapsana apogonoides Maxim. Thus, the weed community distributions in this group were described as the Alopecurus weed vegetation type. The paddy soil group could be divided into two subgroups, one southern and one central paddy soil subgroup. A strategy for integrated weed management is suggested according to the weed distribution pattern. The present study serves as a good example of how a quantitative researchmethod was used to associate a visual estimate of weed infestation with multivariate analyses, such as PCA and CCA, and how this method can be applied to the study of weed vegetation on arable land.

  15. The benefits of being big: effects of body size on energy budgets of three wintering goose species grazing Carex beds in the Yangtze River Floodplain, China

    DEFF Research Database (Denmark)

    Wang, Xin; Zhang, Yong; Zhao, Meijuan;

    2013-01-01

    which failed to do so and could only maintain positive energy budgets by grazing high-quality Alopecurus, Cynodon and Eleocharis. However, all three species failed to maintain positive energy balance and lost mass in midwinter. These results have important implications for explaining the divergent...... partitioning in the distribution of closely related species. By estimating daily energy expenditure (based on observed activity budgets) and energy intake (using the indigestible marker method in food and faeces), we compared the field energy budgets of three wintering herbivorous goose species differing...... in body size feeding on the same Carex meadows. Throughout the winter, the larger Bean Geese Anser fabalis serrirostris and Greater White-fronted Geese Anser albifrons maintained positive energy budgets grazing lower quality Carex, in contrast to the smaller Lesser White-fronted Geese Anser erythropus...

  16. Bioassay of Mixtures of ZJ0777 and Ethametsulfuron to Weeds in Rape Field%溴嘧草醚与胺苯磺隆混配制剂对油菜田杂草的室内防除效果筛选研究

    Institute of Scientific and Technical Information of China (English)

    付群梅; 董德臻; 陈杰; 王永华

    2007-01-01

    溴嘧草醚(代号:ZJ0777)为化学结构新颖的油菜田专用除草剂,为扩大其杀草谱,提高除草活性,我们以日本看麦娘(Alopecurus aequalis)和小藜(Chenopodium album)等为试验靶标进行了与胺苯磺隆(Ethametsulfuron)混用的室内防除效果配方筛选研究,并采用共毒系数法和等效线法对二者混用的联合作用进行评价.结果表明,两者混用后表现相加或增效作用,最佳配比为溴嘧草醚:胺苯磺隆质量比为1:0.2.

  17. Experiment of 30%Glyphosate Oil Miscible Flowable Concentrate Against Weeds Control in Citrus Garden%30%草甘膦油悬浮剂防治柑橘园杂草药效试验

    Institute of Scientific and Technical Information of China (English)

    王平

    2013-01-01

    30%草甘膦油悬浮剂防治柑橘园杂草药效试验结果表明,30%草甘膦油悬浮剂相比较于50%草甘膦可溶性粉剂,对柑橘园杂草鼠麴草、繁缕、看麦娘等有很好的防治效果。%The experiment of 30% glyphosate oil miscible flowable concentrate agarinst weed control in citrus garden showed that ,30%glyphosate oil miscible flowable concentrate had good control effect compared to 50% glyphosate soluble powder on the weeds in citrus garden , including Herba Gnaphaii Affinis,Stellaria media(Linn.) Cyrill.,Alopecurus aequalis etc.

  18. Seasonal pattern of photosynthesis in individual grass leaves and other plant parts in Arctic Alaska with a portable 14CO2 system

    International Nuclear Information System (INIS)

    A portable system for photosynthesis determinations has been used under field conditions in the Arctic at Barrow, Alaska. Maximum photosynthetic rates were greater than 18 mg CO2.dm-2.h-1 in a number of species and were comparable with those of other C3 plants in arctic and temperate areas. Rates were closely coupled to irradiance. Plant components other than expanded blades were active in CO2 uptake. In Dupontia fischeri, leaf sheaths and culms possessed rates greater than 50 percent those of mature leaves. The leaves of D. fischeri and Alopecurus alpinus are produced sequentially and possess distinct seasonal patterns which appear related to leaf growth, maturation, and senescence stages. Thus, even in the short growing season of the Arctic, these grasses possess sequential patterns of leaf development and photosynthesis rather than a synchronized early season burst of leaf production. (U.S.)

  19. 节水覆盖措施下桃园杂草发生的物候学规律

    Institute of Scientific and Technical Information of China (English)

    常宏志

    2007-01-01

    监测和分析了不同覆盖措施对桃园杂草生长的影响.结果表明,不同覆盖措施能有效抑制桃园杂草的发生.利用秸秆覆盖能明显抑制马齿苋(portulaca oleracea L.)、看麦娘(Alopecurus aequalis Sobol)和婆婆纳(Veronica didyma Tenore)的种群发生率,石竹(dianthus chinensis L.)和酢浆草(Oxalis corniculata L.)覆盖由于生化他感作用可以有效抑制其它杂草.地膜覆盖则通过改变地表生态因子从而减少葎草(Humulus scandens L.)的发生.

  20. 啶磺草胺等8种除草剂对小麦田8种禾本科杂草的生物活性%Biological activity of eight herbicides to eight species of major grasses in wheat fields

    Institute of Scientific and Technical Information of China (English)

    高兴祥; 李美; 葛秋岭; 张建华; 高宗军; 张悦丽

    2011-01-01

    Whole plant dose-response experiments were conducted to evaluate the efficacy of eight herbicides(pyroxsulam,flucarbazone-Na,mesosuifuron-methyl,pinoxaden,clodinafop-propargyl,fenoxaprop-p-ethyl,traloxydim,isoproturon) on eight main grasses(Bromus tectorum L.,Sclerochloa dura(L.) Beauv.,Beckmannia syzigachne(Steud.) Fern.,Avena fatua L.,Phleum paniculatum Huds.,Alopecurus japonicus Steud.,Alopecurus aequalis Sobol.,Aegilops tauschii Coss.).The results showed that pyroxsulam,flucarbazone-Na and mesosulfuron-methyl achieved 66.74%-100% control of Bromus tectorum,Alopecurus japonicus and Alopecurus aequalis at the field rate of 14,22.5 and 9g/hm2,respectively.However,these herbicides only had slightly effects or no effect to S.dura,Avena fatua,and A.tauschii.In particular,flucarbazone-Na has better control of Beckmannia syzigachne,and pyroxsulam has better control of Phleum paniculatum.Pinoxaden,tralkoxydim,clodinafop-propargyl,fenoxaprop-p-ethyl and isoproturon had high efficacy on A.japonicus,A.aequalis,P.paniculatum,S.dura,B.syzigachne and A.fatua with 71.73%-100% control effect at the field rate.In contrast,these herbicides had inefficient control on A.tauschii and B.tectorum.%在温室内采用盆栽整株喷雾法研究了啶磺草胺等8种除草剂对雀麦、节节麦等8种禾本科杂草的生物活性,探讨各除草剂对这些禾本科杂草的防除谱及防除效果。结果表明:啶磺草胺、氟唑磺隆和甲基二磺隆对雀麦、日本看麦娘和看麦娘的防效均较好,田间推荐剂量下(14、22.5、9 g/hm2)防效为66.74%~100%;对硬草的防效略差;对野燕麦和节节麦的防效较差;对菵草、蜡烛草略有差异,氟唑磺隆对菵草防效较好,而啶磺草胺对蜡烛草防效较好。唑啉草酯、肟草酮、炔草酯、精恶唑禾草灵和异丙隆对日本看麦娘、看麦娘、蜡烛草、硬草、菵草和野燕麦防效均较好,田间推荐剂量下防效为71.73%~100%,对节节麦、雀麦防效较差或无效。

  1. Measurement and conceptual modelling of herbicide transport to field drains in a heavy clay soil with implications for catchment-scale water quality management.

    Science.gov (United States)

    Tediosi, A; Whelan, M J; Rushton, K R; Thompson, T R E; Gandolfi, C; Pullan, S P

    2012-11-01

    Propyzamide and carbetamide are essential for blackgrass control in oilseed rape production. However, both of these compounds can contaminate surface waters and pose compliance problems for water utilities. The transport of propyzamide and carbetamide to an instrumented field drain in a small clay headwater tributary of the Upper Cherwell catchment was monitored over a winter season. Despite having very different sorption and dissipation properties, both herbicides were transported rapidly to the drain outlet in the first storm event after application, although carbetamide was leached more readily than propyzamide. A simple conceptual model was constructed to represent solute displacement from mobile pore water and preferential flow to drains. The model was able to reproduce the timing and magnitude of herbicide losses well, lending support to its conceptual basis. Measured losses in drainflow in the month following application were 1.1 and 8.1%, respectively, for propyzamide and carbetamide. Differences were due to a combination of differences in herbicide mobility and due to the fact that the monitoring period for carbetamide was hydrologically more active. For both compounds, losses were greater than those typically reported elsewhere for other herbicides. The data suggest that drainflow is the dominant pathway for the transfer of these herbicides to the catchment outlet, where water is abstracted for municipal supply. This imposes considerable constraints on the management options available to reduce surface water concentrations of herbicides in this catchment. PMID:22982449

  2. 西藏嵩草属(莎草科)的修订%Revision of Kobresia (Cyperaceae) in Xizang (Tibet)

    Institute of Scientific and Technical Information of China (English)

    张树仁

    2004-01-01

    在标本观察和野外调查的基础上,对西藏的嵩草属Kobresia植物进行了分类学修订,共确认了36种和1亚种.更正了6个类群的学名,它们正确的名称是K. esenbeckii,K. fissiglumis,K. gammiei,K. littledalei,K. myosuroides ssp. bistaminata和K. vaginosa.有13个名称,即K. angusta,K. cercostachys var. capillacea,K. clarkeana,K. curticeps var. gyirongensis,K. deasyi,K. glaucifolia,K. hookeri,K. nudicarpa,K. prainii var. elliptica,K. seticulmis,K. stenocarpa,K. stenocarpa var. simplex和K. williamsii处理为异名,其中K. prainii var. elliptica,K. glaucifolia和K. stenocarpa var. simplex为新异名.发现了西藏分布的一个新记录种密穗嵩草K. handel-mazzettii.还收录了最近发表的假钩状嵩草K. pseuduncinoides和阔鳞嵩草K. woodii.此外,重新编制了西藏嵩草属分种和亚种检索表,并较为详细地登记了各类群在西藏的分布地点.

  3. Growth and Competition of Fourteen Herb Species in Experimental Microcoenosium s%实验群落十四种草本植物的生长和竞争研究

    Institute of Scientific and Technical Information of China (English)

    陈章和

    2001-01-01

    研究了高肥力和低肥力、割草和不割草、微生物接种和不接种处理对实验群落中14种常见草本植物的生长和竞争的影响.高肥力不割草的群落,不同种间的生物量差别最大,竞争最激烈; 割草和低肥力减弱竞争者的生长而导致种间生物量差异减小.多次的割草减少群落的总生物量; 微生物接种明显增加2种豆科植物百脉根(Lotus corniculatus L.)和红车轴草(Trifolium pratense L.)的生长,也有利于非豆科植物大看麦娘(Alopecurus p ratensis L.)的生长,而鸭茅(Dactylis glomerata L.)在无微生物接种的群落生物量较多,微生物接种对其他植物的生长无显著的影响.在低肥力群落,接种微生物的促进作用更加显著.%Growth and competition of 14 herb species were investigated in t he experimental microcoenosiums in laboratory under the following environmental factors and treatment levels: high and low fertility, clipping and un-clipping, and with and without microbial infusion. The most intense competition and the bi ggest difference in biomass among the species were detected in the high fertilit y microcoenosiums subjected to no clipping disturbance. Clippings or low fertili ty r educed the growth of the competitors and resulted in more even biomass distribut ion among the species. Successive clippings reduced the total accumulative bioma ss of the microcoenosiums. Microbial infusion significantly increased the growth of legume species Lotus corniculatus L. and Trifolium pratense L. The grow th of Alopecurus pratensis L. was also raised by microbial infusion, whereas Dactylis glomerata L. had more biomass in without-microbial-infusion microc oenosiums than in microbial infusion ones. Most of the 14 species were not obvio usly affected. The positive effect of microbial infusion was more marked in the low fertility microcoenosiums.

  4. Metals and arsenic in soils and corresponding vegetation at Central Elbe river floodplains (Germany)

    Energy Technology Data Exchange (ETDEWEB)

    Overesch, M. [Department for Geo- and Agroecology, Institute of Spatial Analysis and Planning in Areas of Intensive Agriculture, University of Vechta, P.O. Box 1553, D-49364 Vechta (Germany)]. E-mail: moveresch@ispa.uni-vechta.de; Rinklebe, J. [Department of Soil Science, UFZ Center for Environmental Research Leipzig-Halle, Theodor-Lieser-Strasse 4, D-06120 Halle (Germany)]. E-mail: joerg.rinklebe@ufz.de; Broll, G. [Department for Geo- and Agroecology, Institute of Spatial Analysis and Planning in Areas of Intensive Agriculture, University of Vechta, P.O. Box 1553, D-49364 Vechta (Germany)]. E-mail: gbroll@ispa.uni-vechta.de; Neue, H.-U. [Department of Soil Science, UFZ Center for Environmental Research Leipzig-Halle, Theodor-Lieser-Strasse 4, D-06120 Halle (Germany)]. E-mail: heinz-ulrich.neue@ufz.de

    2007-02-15

    Floodplain soils at the Elbe river are frequently polluted with metals and arsenic. High contents of these pollutants were detected down to subsoil layers. NH{sub 4}NO{sub 3}-extractable (phytoavailable) Cd, Ni, and Zn were elevated in horizons with high acidity. Among five common floodplain plant species, Artemisia vulgaris showed highest concentrations of Cd, Cu, and Hg, Alopecurus pratensis of As and Phalaris arundinacea of Ni, Pb, and Zn. Relationships were weak between metal concentrations in plants and phytoavailable stocks in soil. As and Hg uptake seems to be enhanced on long submerged soils. Enrichments of Cd and Hg are linked to a special plant community composition. Grassland herbage sampled in July/August revealed higher concentrations of As (+122%), Hg (+124%), and Pb (+3723%) than in May. To limit harmful transfers into the food chain, low-lying terraces and flood channels revealing highest contaminations or phytoavailabilities should be excluded from mowing and grazing. - Soils in the Elbe river floodplains are highly polluted with metals and arsenic and a critical enrichment in the grassland herbage seems to be most likely in flood channels or within special plant species.

  5. Application Control Technology of Pinoxaden 50 g/L EC in Barley Field%50 g/L 唑啉草酯乳油防除大麦田杂草应用技术

    Institute of Scientific and Technical Information of China (English)

    李涛; 钱振官; 温广月; 李国梁; 石建福; 陈谊君; 沈国辉

    2014-01-01

    50 g/L唑啉草酯乳油可安全应用于大麦田,有效防除硬草、看麦娘等禾本科杂草。50 g/L唑啉草酯乳油80~120 mL/667 m2于杂草2~3分蘖期使用,药后90 d对硬草、看麦娘等禾本科杂草的防效仍高达95%以上,显著优于对照药剂50%异丙隆可湿性粉剂150 g/667 m2处理。%Pinoxaden 50 g/L EC applied at 80~120 mL/667 m2 ( equivalent to 60~90 g a.i./hm2 ) to grass weeds at the 2~3 tiller growth stage provided excellent control,especially of Sclerochloa kengiana and Alopecurus aequalis at 90 days after treatment with good selectivity to barley.The pinoxaden formulation was superior to isoproturon WP applied at 150 g/667 m2 .

  6. An experimental approach to assessing the effects of mining subsidence on a flood meadow community

    International Nuclear Information System (INIS)

    The Lower Derwent Valley (LDV) is a candidate Special Area of Conservation (SAC) under the provisions of the UK 1994 Conservation Regulations for its internationally important Alopecurus pratense-Sanguisorba officinalis flood meadow vegetation. Mining from RJB's Selby Complex (UK's largest mine) has taken place around and under the LDV since the 1980s. Under the provisions of the Regulations the potential effects of mining subsidence have been recently reviewed. From field data and models it has been predicted that the resulting small amount of subsidence is unlikely to have a deleterious effect on the composition and extent of the key community. While the proposed long-term monitoring will verify the prediction, it will be some years before the results will be available. In order to identify incipient changes in grassland community and to implement any necessary mitigation measures before significant changes occur, a field experiment was set up in late 1996 to assess the effects of increased wetness and inundation which might be induced by subsidence. This involved the transplantation of turves from the different grassland communities within and along a previously defined gradient of relative wetness and inundation. The response of the communities to the different conditions is being monitored. The background studies and the results of the transplantation so far will be presented

  7. Computational simulations of structural role of the active-site W374C mutation of acetyl-coenzyme-A carboxylase: multi-drug resistance mechanism.

    Science.gov (United States)

    Zhu, Xiao-Lei; Yang, Wen-Chao; Yu, Ning-Xi; Yang, Sheng-Gang; Yang, Guang-Fu

    2011-03-01

    Herbicides targeting grass plastidic acetyl-CoA carboxylase (ACCase, EC 6.4.1.2) are selectively effective against graminicides. The intensive worldwide use of this herbicide family has selected for resistance genes in a number of grass weed species. Recently, the active-site W374C mutation was found to confer multi-drug resistance toward haloxyfop (HF), fenoxaprop (FR), Diclofop (DF), and clodinafop (CF) in A. myosuroides. In order to uncover the resistance mechanism due to W374C mutation, the binding of above-mentioned four herbicides to both wild-type and the mutant-type ACCase was investigated in the current work by molecular docking and molecular dynamics (MD) simulations. The binding free energies were calculated by molecular mechanics-Poisson-Boltzmann surface area (MM/PBSA) method. The calculated binding free energy values for four herbicides were qualitatively consistent with the experimental order of IC(50) values. All the computational model and energetic results indicated that the W374C mutation has great effects on the conformational change of the binding pocket and the ligand-protein interactions. The most significant conformational change was found to be associated with the aromatic amino acid residues, such as Phe377, Tyr161' and Trp346. As a result, the π-π interaction between the ligand and the residue of Phe377 and Tyr161', which make important contributions to the binding affinity, was decreased after mutation and the binding affinity for the inhibitors to the mutant-type ACCase was less than that to the wild-type enzyme, which accounts for the molecular basis of herbicidal resistance. The structural role and mechanistic insights obtained from computational simulations will provide a new starting point for the rational design of novel inhibitors to overcome drug resistance associated with W374C mutation. PMID:20499260

  8. Global perspective of herbicide-resistant weeds.

    Science.gov (United States)

    Heap, Ian

    2014-09-01

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

  9. Herbicide Application and Resistance in Wheat Field of China%我国小麦田除草剂应用及杂草抗药性现状

    Institute of Scientific and Technical Information of China (English)

    吴明荣; 唐伟; 陈杰

    2013-01-01

    我国常年遭受严重草害的麦田面积有0.4亿亩,造成产量损失约30%,运用化学除草剂防除麦田杂草已经成为小麦生产中的重要手段,形成了包括多种作用类别的除草剂品种和全方位化学防除体系.但随着化学除草剂的不断推广和应用,杂草抗药性问题也日益凸显和加重,目前播娘蒿、日本看麦娘、菵草等杂草抗药性已经较为严重.通过查阅相关文献,综述了近几年我国小麦田的优势杂草种类,主要应用的除草剂以及麦田杂草的抗药性现状及防治对策.%About 40 million hectares of wheat fields are heavily infested by weeds and the annual reduction of crop yields is 30% (weighted average) in China.Chemical weed control has changed cultural practices to save weeding labor in wheat.At the same time,continuous use of the same herbicides has caused weed shift problems and weed resistance to herbicides.Resistant biotypes of Descuminia sophia,Alopecurus japonicus and Beckmannia syzigachne were reported in recent years.The main worst weed species,application status of herbicides and herbicide-resistant weeds in wheat fields of China were introduced in this paper,and integrated management strategies for resistant weeds were also described.

  10. First Record of the European Rusted Flea Beetle, Neocrepidodera ferruginea (Scopoli, 1763, in North America (Coleoptera: Chrysomelidae: Galerucinae: Alticini

    Directory of Open Access Journals (Sweden)

    Laurent LeSage

    2012-01-01

    Full Text Available The European rusted flea beetle Neocrepidodera ferruginea (Scopoli, 1763 is reported for the first time from Québec and Ontario, Canada. It was likely introduced into southern Ontario at an international port on the Great Lakes in early 1970s, or possibly earlier in the 1960s. However, the exact location and date of introduction could not be precisely determined. The flea beetle has since dispersed northeastwards and reached Aylmer, north of Ottawa River, in Québec, by 2003. This is about 375 km from Niagara Falls, where the oldest known specimens were collected in 1977. In 2009, various wild habitats and cultivated areas of Aylmer were surveyed. The host plants of the larvae could not be determined, but adults were swept from many plant species including various weeds and cultivated grasses: Alopecurus pratense (meadow foxtail, Dactylis glomerata (orchard-grass, Festuca rubra (red fescue-grass, and Poa pratensis (Kentucky blue-grass. Adults were also collected from flowers of several weeds: Aster sp. (undetermined species, Aster novae-angliae (New England aster, Ambrosia artemisiifolia (small ragweed, Echium vulgare (viper’s bugloss, Nasturtium officinale (water cress, Melilotus alba (white sweet-clover, Hypericum perforatum (common St. John’s-wort, Lythrum salicaria (purple loosestrife, Ranunculus acris (buttercup, and Solidago spp. (goldenrods. Since larvae are known to develop inside the roots and central stems of cereals, this new alien species represents a threat to Canadian agriculture, particularly if it reaches the Prairies in western Canada, where cereals represent a considerable part of their economy. European rusted flea beetle and Altise ferrugineuse européenne are suggested for the English and French common names of this flea beetle, respectively.

  11. Diversity and distribution of 16S rRNA and phenol monooxygenase genes in the rhizosphere and endophytic bacteria isolated from PAH-contaminated sites

    Science.gov (United States)

    Peng, Anping; Liu, Juan; Ling, Wanting; Chen, Zeyou; Gao, Yanzheng

    2015-07-01

    This is the first investigation of the diversity and distribution of 16S rRNA and phenol monooxygenase (PHE) genes in endophytic and rhizosphere bacteria of plants at sites contaminated with different levels of PAHs. Ten PAHs at concentrations from 34.22 to 55.29 and 45.79 to 97.81 mg·kg-1 were measured in rhizosphere soils of Alopecurus aequalis Sobol and Oxalis corniculata L., respectively. The diversity of 16S rRNA and PHE genes in rhizosphere soils or plants changed with varying PAH pollution levels, as shown based on PCR-DGGE data. Generally, higher Shannon-Weiner indexes were found in mild or moderate contaminated areas. A total of 82 different bacterial 16S rRNA gene sequences belonging to five phyla; namely, Acfinobacteria, Proteobacteria, Chloroflexi, Cyanophyta, and Bacteroidetes, were obtained from rhizosphere soils. For the 57 identified PHE gene sequences, 18 were excised from rhizosphere bacteria and 39 from endophytic bacteria. The copy numbers of 16S rRNA and PHE genes in rhizosphere and endophytic bacteria varied from 3.83 × 103 to 2.28 × 106 and 4.17 × 102 to 1.99 × 105, respectively. The copy numbers of PHE genes in rhizosphere bacteria were significantly higher than in endophytic bacteria. Results increase our understanding of the diversity of rhizosphere and endophytic bacteria from plants grown in PAH-contaminated sites.

  12. Diversity and distribution of 16S rRNA and phenol monooxygenase genes in the rhizosphere and endophytic bacteria isolated from PAH-contaminated sites.

    Science.gov (United States)

    Peng, Anping; Liu, Juan; Ling, Wanting; Chen, Zeyou; Gao, Yanzheng

    2015-07-17

    This is the first investigation of the diversity and distribution of 16S rRNA and phenol monooxygenase (PHE) genes in endophytic and rhizosphere bacteria of plants at sites contaminated with different levels of PAHs. Ten PAHs at concentrations from 34.22 to 55.29 and 45.79 to 97.81 mg·kg(-1) were measured in rhizosphere soils of Alopecurus aequalis Sobol and Oxalis corniculata L., respectively. The diversity of 16S rRNA and PHE genes in rhizosphere soils or plants changed with varying PAH pollution levels, as shown based on PCR-DGGE data. Generally, higher Shannon-Weiner indexes were found in mild or moderate contaminated areas. A total of 82 different bacterial 16S rRNA gene sequences belonging to five phyla; namely, Acfinobacteria, Proteobacteria, Chloroflexi, Cyanophyta, and Bacteroidetes, were obtained from rhizosphere soils. For the 57 identified PHE gene sequences, 18 were excised from rhizosphere bacteria and 39 from endophytic bacteria. The copy numbers of 16S rRNA and PHE genes in rhizosphere and endophytic bacteria varied from 3.83 × 10(3) to 2.28 × 10(6) and 4.17 × 10(2) to 1.99 × 10(5), respectively. The copy numbers of PHE genes in rhizosphere bacteria were significantly higher than in endophytic bacteria. Results increase our understanding of the diversity of rhizosphere and endophytic bacteria from plants grown in PAH-contaminated sites.

  13. 低氮胁迫下小麦抑草作用的化感效应与资源竞争分析%Analysis of allelopathic effects and resource competition of weed suppression ability of wheat (Triticum aestivum) under low nitrogen stress condition

    Institute of Scientific and Technical Information of China (English)

    陈珊; 谢惠玲; 李圆萍; 王微; 肖清铁; 林瑞余; 林文雄

    2014-01-01

    Allelopathic effects and resource competition are critical factors of weed suppression ability of crops. To separate the allelopathic effects from resource competition of weed suppression ability of wheat under low nitrogen stress condition, two strong allelopathic wheat accessions (‘115/Q’ and‘92L89’) and one weak allelopathic wheat accession (‘K10103’) were used in two sets of separate experiments (co-cultivated Alopecurus aequalis with wheat and treating Alopecurus aequalis with hydroponic solutions of co-cultured wheat root exudates) to evaluate bio-interference, allelopathy and resource competition effects. The experiments were conducted in gradient N concentration hydroponic solutions with N levels of 25 mg·L-1, 50 mg·L-1, 100 mg·L-1 and 200 mg·L-1. The results showed significantly differences in the abilities of inhibition to the growth of Alopecurus aequalis in the three wheat accessions in both experiments. Weed suppression ability (inhibitory rate, IR) increased with decreasing N level in all the wheat accessions. The rank order of IR for different wheat accessions was‘115/Q’ (55.1%-73.9%)>‘92L89’ (48.9%-65.9%)>‘K10103’ (15.4%-45.5%). Generally, IR increased with decreasing N level in hydroponic solutions. Both allelopathic effects and resources competition were critical for wheat weed suppression. Different ecological strategies were noted in different allelopathic potential wheat accessions under low N stress condition. Weed suppression ability improved by increasing allelopathic effects of strong allelopathic wheat accessions. This was triggered by enhanced resources competition of weak allelopathic wheat accessions. Allelopathic effects increased with decreasing N level and the changes in inhibitory rate with N level well fitted quadratic equations.%化感效应和资源竞争在作物抑草中起重要作用。为区分低氮胁迫下小麦抑草作用的化感效应与资源竞争,以强化感小麦品种‘115/

  14. Traffic-related trace element accumulation in roadside soils and wild grasses in the Qinghai-Tibet Plateau, China.

    Science.gov (United States)

    Wang, Guanxing; Yan, Xuedong; Zhang, Fan; Zeng, Chen; Gao, Dan

    2013-12-30

    This research examines traffic-source trace elements accumulations and distributions in roadside soils and wild grasses in the Qinghai-Tibet Plateau. A total of 100 soil samples and 100 grass samples including Achnatherum splendens, Anaphalis nepalensis, Artemisia sphaerocephala, Carex moorcroftii, Iris lacteal, Kobresia myosuroides, Oreosolen wattii, Oxytropis ochrocephala and Stellera chamaejasme were collected at 100 sites from different road segments. The contents of metals and metalloids, including Cu, Zn, Cd, Pb, Cr, Co, Ni and As, in the soil and grass samples were analyzed using ICP-MS. The total mean concentrations of the eight trace elements in soils are Cu (22.84 mg/kg), Zn (100.56 mg/kg), Cd (0.28 mg/kg), Pb (28.75 mg/kg), Cr (36.82 mg/kg), Co (10.24 mg/kg), Ni (32.44 mg/kg) and As (21.43 mg/kg), while in grasses are Cu (9.85 mg/kg), Zn (31.47 mg/kg), Cd (0.05 mg/kg), Pb (2.06 mg/kg), Cr (14.16 mg/kg), Co (0.55 mg/kg), Ni (4.03 mg/kg) and As (1.33 mg/kg). The metal and metalloid concentrations in the nine grass species were all below the critical values of hyperaccumulators. The mean values and Multivariate Analysis of Variance (MANOVA) results indicate that: (1) the concentrations of the trace elements in the soils are higher than those in the grasses, (2) the concentrations of Cu, Zn, Cd, Pb in the soils decrease as the roadside distance increases, (3) the concentrations of trace elements in the grasses are the highest at 10 m from the road edge, (4) the higher the traffic volume, the higher the concentrations of the trace elements in the roadside soils and grasses, and (5) when the land cover is meadow, the lower the sand content in the soil, the lower the trace element concentrations. With a trace element's bioavailability represented by its transfer factor (TF) from the soil to the grass, the TFs of the eight trace elements are not in the same orders for different grass species.

  15. Traffic-Related Trace Element Accumulation in Roadside Soils and Wild Grasses in the Qinghai-Tibet Plateau, China

    Directory of Open Access Journals (Sweden)

    Guanxing Wang

    2013-12-01

    Full Text Available This research examines traffic-source trace elements accumulations and distributions in roadside soils and wild grasses in the Qinghai-Tibet Plateau. A total of 100 soil samples and 100 grass samples including Achnatherum splendens, Anaphalis nepalensis, Artemisia sphaerocephala, Carex moorcroftii, Iris lacteal, Kobresia myosuroides, Oreosolen wattii, Oxytropis ochrocephala and Stellera chamaejasme were collected at 100 sites from different road segments. The contents of metals and metalloids, including Cu, Zn, Cd, Pb, Cr, Co, Ni and As, in the soil and grass samples were analyzed using ICP-MS. The total mean concentrations of the eight trace elements in soils are Cu (22.84 mg/kg, Zn (100.56 mg/kg, Cd (0.28 mg/kg, Pb (28.75 mg/kg, Cr (36.82 mg/kg, Co (10.24 mg/kg, Ni (32.44 mg/kg and As (21.43 mg/kg, while in grasses are Cu (9.85 mg/kg, Zn (31.47 mg/kg, Cd (0.05 mg/kg, Pb (2.06 mg/kg, Cr (14.16 mg/kg, Co (0.55 mg/kg, Ni (4.03 mg/kg and As (1.33 mg/kg. The metal and metalloid concentrations in the nine grass species were all below the critical values of hyperaccumulators. The mean values and Multivariate Analysis of Variance (MANOVA results indicate that: (1 the concentrations of the trace elements in the soils are higher than those in the grasses, (2 the concentrations of Cu, Zn, Cd, Pb in the soils decrease as the roadside distance increases, (3 the concentrations of trace elements in the grasses are the highest at 10 m from the road edge, (4 the higher the traffic volume, the higher the concentrations of the trace elements in the roadside soils and grasses, and (5 when the land cover is meadow, the lower the sand content in the soil, the lower the trace element concentrations. With a trace element's bioavailability represented by its transfer factor (TF from the soil to the grass, the TFs of the eight trace elements are not in the same orders for different grass species.

  16. 甘肃尕海湿地不同海拔草地群落组分及物种多样性研究%Study on grassland community characteristics and species diversity along altitudinal gradients in the Gahai wetland, Gansu province

    Institute of Scientific and Technical Information of China (English)

    徐鹏彬; 邓建明; 赵长明

    2012-01-01

    of these genera is the temperate,and the majority of these species are the perennial and non-leguminous nitrogen-fixing plants.The six grassland community types were classified along the aititudinal gradients,namely Poa annua -Anemone obtusiloba com-munity,Potentilla plumose -Plantago depressa community,Stipa purpurea community,Poa annua-Koele-ria cristata community,Poa annua-Kobresia myosuroides community,and Kobresia myosuroides - Cyperus community.The dominant species in the natural grassland are mostly consist of Gramineae and Cyperaceae families,while the species were replaced by the Potentilla plumose -Plantago depressa and Stipa purpurea in the human strongly active area,and herein human activities strongly influence the grassland community characteristics.In addition,the negative relationships between altitude and indexes of species diversity (such as,species abundance,species density,similarity index,and the number of common species) were also found.Obviously,both altitude and human activities strongly affect the community characteristics and diversity of the alpine grassland,even the human activities are more pronounced.Therefore,in order to sustain the species diversity and ensure sustainable development of alpine grassland,we should take the reasonable and effective protection and minimize the impact of human activities.

  17. Evaluation of selected wild plants flowering season 1991 - 2009 (1991 - 2000 & 2001 - 2009)

    Science.gov (United States)

    Hajkova, L.; Nekovar, J.; Novak, M.; Richterova, D.

    2009-09-01

    The subsequent wild plants are observed by volunteer observers at CHMI phenological network: CALTHA palustris L., ANEMONE nemorosa L., HEPATICA nobilis Mill., RANUNCULUS acer L., FRAGARIA vesca L., TRIFOLIUM repens L., HYPERICUM perforatum L., CHAMAENERION angustifolium L. Holub, VACCINIUM myrtillus L., LAMIUM album L., CHRYSANTHEMUM leucanthemum L., TUSSILAGO farfara L., PETASITES albus (L.) Gaert., PETASITES hybridus (L.) G. M. Sch., CONVALLARIA majalis L., GALANTHUS nivalis L., DACTYLIS glomerata L., ALOPECURUS pratensis L. and others. Some of them start to blossom in early spring, some others in the summer. Part of them belong to very important allergens, part of them have medicinal effects. Phenophases first leaves (FL - BBCH11), inflorescence emergence (IE - BBCH 51), beginning and end of flowering (BF - BBCH 61, EF - BBCH 69) are observed by these species. Statistical parameters (average, median, lower quartile, upper quartile, minimum, maximum, standard deviation, variation range and variation coefficient) of phenophase onset are computed from all of phenological stations in Czechia for the period 1991 - 2009. The phenophase onset and phenophase duration depend not only on genetic base but also on external effects such as weather. We have compiled dynamics of temperature to phenophase onset according CHMI meteorological stations for the same period 1991 - 2009 (especially sums of active temperatures above biological minimum 5°C and progression of extreme temperatures). We have also compared results between two periods (1991 - 2000, 2001 - 2009). Phenological stations are at different altitude. At this case study were used results from 4 phenological stations at altitude ( 500 m asl). GALANTHUS nivalis L. Station: Lednice (165 m n. m.) Period: 1991 - 2000 Statistical parameter/phenophase BBCH 61 BBCH 69 Average 62 94 Median 60 97 Lower quartile 57 86 Upper quartile 66 101 Minimum 51 70 Maximum 79 116 Variation range 28 46 Standard deviation 8,6 12

  18. 杂草对土壤重金属的富集与含量特征研究%Characteristics of accumulation and content of heavy metals of weeds

    Institute of Scientific and Technical Information of China (English)

    王广林; 王立龙; 李征; 丁佳红; 刘登义

    2005-01-01

    对冶炼厂周围的土壤和杂草中的4种重金属元素含量进行测定和统计.结果表明,杂草不同器官重金属的平均含量由高到低分别为根>叶>茎,重金属在植物体内含量的分布为Cu>Zn>Ni>Pb,富集系数由大到小为Zn>Cu>Pb>Ni.看麦娘(Alopecurus aequalis)、菰(Zizania latifolia)、鬼针草(Bidens pilosa)、丁香蓼(Ludwigia prostrata)、双穗雀稗(Paspalum distichum)、芦苇(Phragmites australis)等植物的根对Cu有较强的富集能力,其富集系数分别为2.54、2.69、4.82、10.74、7.33和4.60.看麦娘、双穗雀稗、丁香蓼、芦苇、鬼针草的根以及井口边草(Pteris multifida)地下部分和小飞蓬(Conyza canadensis)叶中的Cu含量分别高达813.4、1 338、1 959.65、840.1、1 066.6、2 030和334.5 mg·kg-1.水蓼(Ploygonum hydropiper)叶对Pb有较强的富集能力,其富集系数是2.15.丁香蓼、蛇床(Cnidium monnieri)和婆婆纳(Veronica didyma)叶以及野艾蒿(Artemisia lavandulaefolia)的茎和叶对Zn有较强的富集能力,富集系数分别是2.28、2.45、3.02、2.25和2.54.杂草重金属含量与土壤中重金属含量的相关性不大.丁香蓼较适合作为重金属Cu、Zn污染地区的恢复植物.

  19. 4种除草剂防除麦田禾本科杂草效果及安全性%The Control Effect and Security of 4 Herbicides against Gramineal Weeds in Wheat Field

    Institute of Scientific and Technical Information of China (English)

    王绍敏; 陈春利

    2011-01-01

    [方法]采用目测5级分级法,调查山东省麦田禾本科杂草种群的分布;在全省选有代表性的8个地点做4种除草剂田间药效试验;并测定对17个小麦品种的安全性.[结果]山东省麦田优势禾本科杂草为雀麦、看麦娘、硬草、节节麦、野燕麦、茼草等,各种杂草呈区域性分布;甲基二磺隆有良好的防效,氟唑磺隆对雀麦防效最高,但对节节麦无效;精噁唑禾草灵、炔草酸在稻茬麦田有良好的防效,对雀麦、节节麦无效;鲁麦14、徐麦29、济麦19、龙麦1号耐药性最强.%[Methods]The distribution of gramineal weeds populations in wheat field of Shandong province were invested by using Visual Grade Rules.Eight representative locations were selected for field trial.And the safety on 17 wheat varieties was determined.[Results]The dominant varieties of gramineal weeds were Bromus japonicus Thunb.,Alopecurus aequalis Sobol., Paspalum sphondylodes Trin.ex Bge., Aegilops squarrosa L., Avena fatua L., Beckmannia syzigachne (Steud.) Fern.etc., and all kinds of weeds showed a regional distribution.Mesosuifuron-methyl provided good control effects, Flucarbazone-sodium showed the maximum control effect on Bromus japonicus Thunb., but have not activity against Aegilops squarrosa L., fenoxaprop-ethyl, clodinafop-propargyl provided good control effects in rice-wheat rotation field, but exhibited no activity against Bromus japonicus Thunb., Aegilops squarrosa L., Lumai 14,Xunmai 29, Jimai 19, Longmai 1 had the strongest drug resistance.

  20. Effect of Sowing Rate of Wheat on the Weed Community and Wheat Yield%小麦播种量对杂草群落及小麦产量的影响

    Institute of Scientific and Technical Information of China (English)

    崔翠; 唐银

    2011-01-01

    农田生态系统中杂草与作物争光、争水、争肥,也是各种害虫的寄主,最终影响作物的产量和品质.该文分析小麦"绵农6号"不同播种量对农田杂草发生种类、发展规律及小麦经济产量的影响,为实现农田杂草的生态管理提供参考.结果表明:麦田杂草群落主要由看麦娘、荠菜、猪殃殃、蔊菜、短辐水芹、碎米荠和野薄荷等构成,其中看麦娘、荠菜、猪殃殃和野薄荷等为主要杂草.在低播种量B1(4.47g/m2)时,杂草生物量较高,增大播种量B4(17.88g/m2)可抑制麦田中杂草数量的发生.适宜的小麦播种量B2(8.94g/m2)和B3(13.41g/m2)能抑制麦田杂草的发生,降低生产成本,获得较高的经济产量.%Weeds are potential competitors of the crop for light,water and fertilizers,and also provide host plants for various insect pests,which results in decreased crop yield.In this experiment,wheat cv.Miannong 6 was sown at four different sowing rates in order to highlight the principle of weed occurrence and boost ecological management of weeds.The results showed that the weed community in the wheat field was mainly composed of Alopecurus aequalis,Capsella bursa-pastoris,Rorippa indica and Oenanthe benghalensis.Lower sowing rate(4.47 g/m2) of wheat increased the biomass of weeds,while higher sowing rate(17.88 g/m2) of wheat inhibited the germination and growth of weeds.The sowing rates of 8.94×103 kg/m2 and 13.41×103 kg/m2 proved to be suitable,for they helped to improve the ecological management of weeds in the field and achieve relatively high economic yield of wheat with reasonable production cost.

  1. Effects of long-term fertilization on spring season weed community in winter fallow paddy field in red soil area under double-rice cropping system%长期施肥对红壤双季稻冬闲田春季杂草群落的影响

    Institute of Scientific and Technical Information of China (English)

    董春华; 曾希柏; 石林; 高菊生

    2015-01-01

    -term fertilization experiment included five fertilization treatments of application of organic fertilizer, chemical fertilizer and combined application of organic and inorganic fertilizers with the same rates of nitrogen (N), phosphorus (P) and potassium (K) in both the organic and chemical fertilizers, which were no fertilizer (CK), organic fertilizer (composted cattle manure, M), combined application of P and K inorganic fertilizer and organic fertilizer (PKM), application of inorganic N, P, and K fertilizer (NPK), combined application of N, K inorganic fertilizer and organic fertilizer (NKM), combined application of N, P inorganic fertilizer and organic fertilizer (NPM), and combined application of N, P, K inorganic fertilizer and organic fertilizer (NPKM). The results showed that the dominant weed species changed and the total density and total biomass of weed communities increased under combined application of organic and inorganic fertilizers. NKM treatment had the largest number of weed species, while the least weed species number was under NPM treatment. Species diversity index (1.118 6), evenness index (0.732 3) and dominance index (0.629 7) of weed communities under M treatment were larger than those under the other treatments. However, M treatment had the lowest total weed density (297.0 plant×0.25m-2). Also NPK treatment had the lowest total weed biomass (58.0 g×0.25m-2). Compared with other treatments, NPM treatment significantly decreased diversity, evenness and dominance indexes of weed communities, and had the highest total weed density (539.7 plant×0.25m-2) and total weed biomass (109.5 g×0.25m-2), respectively. Alopecurus japonicas was the dominant weed species, and had weed density of 428.0 plant×0.25m-2 and relative weed density of 79.31%under NPM treatment, which were significantly higher than those of dominant weeds under other treatments. It was noted in this study that total dry biomass of weeds was positively correlated with content of soil alkali

  2. 长期施肥对红壤双季稻冬闲田春季杂草群落的影响%Effects of long-term fertilization on spring season weed community in winter fallow paddy field in red soil area under double-rice cropping system

    Institute of Scientific and Technical Information of China (English)

    董春华; 曾希柏; 石林; 高菊生

    2015-01-01

    -term fertilization experiment included five fertilization treatments of application of organic fertilizer, chemical fertilizer and combined application of organic and inorganic fertilizers with the same rates of nitrogen (N), phosphorus (P) and potassium (K) in both the organic and chemical fertilizers, which were no fertilizer (CK), organic fertilizer (composted cattle manure, M), combined application of P and K inorganic fertilizer and organic fertilizer (PKM), application of inorganic N, P, and K fertilizer (NPK), combined application of N, K inorganic fertilizer and organic fertilizer (NKM), combined application of N, P inorganic fertilizer and organic fertilizer (NPM), and combined application of N, P, K inorganic fertilizer and organic fertilizer (NPKM). The results showed that the dominant weed species changed and the total density and total biomass of weed communities increased under combined application of organic and inorganic fertilizers. NKM treatment had the largest number of weed species, while the least weed species number was under NPM treatment. Species diversity index (1.118 6), evenness index (0.732 3) and dominance index (0.629 7) of weed communities under M treatment were larger than those under the other treatments. However, M treatment had the lowest total weed density (297.0 plant×0.25m-2). Also NPK treatment had the lowest total weed biomass (58.0 g×0.25m-2). Compared with other treatments, NPM treatment significantly decreased diversity, evenness and dominance indexes of weed communities, and had the highest total weed density (539.7 plant×0.25m-2) and total weed biomass (109.5 g×0.25m-2), respectively. Alopecurus japonicas was the dominant weed species, and had weed density of 428.0 plant×0.25m-2 and relative weed density of 79.31%under NPM treatment, which were significantly higher than those of dominant weeds under other treatments. It was noted in this study that total dry biomass of weeds was positively correlated with content of soil alkali