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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. Ecological review of black-grass (Alopecurus myosuroides Huds. propagation abilities in relationship with herbicide resistance

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    Maréchal, PY.

    2012-01-01

    Full Text Available Alopecurus myosuroides Huds. (black-grass has always been a major concern for cereal growers, and the development of herbicide resistance does not improve the situation. This review article summarizes the different traits involved in the dispersal pattern of herbicide resistant black-grass individuals within a susceptible field population. Therefore, the whole life cycle of black-grass is depicted from the seed to the seed. From the early vegetative development to the seed falling, every stage is described, taking into account how herbicide resistance can influence or exert a different impact compared to susceptible plants.

  3. Safener responsiveness and multiple herbicide resistance in the weed black-grass (Alopecurus myosuroides).

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    Cummins, Ian; Bryant, David N; Edwards, Robert

    2009-10-01

    Safeners enhance the selectivity of graminicidal herbicides such as fenoxaprop ethyl in cereals, by increasing their rates of detoxification in the crop. While studying the selectivity of fenoxaprop ethyl in wheat, we determined that the safeners mefenpyr diethyl and fenchlorazole ethyl also enhanced herbicide tolerance in the competing weed black-grass (Alopecurus myosuroides). Fenoxaprop ethyl was detoxified by conjugation with glutathione in both wheat and black-grass, with the resulting metabolites processed to the respective cysteine derivatives, which were then N-glycosylated. In black-grass, these detoxification pathways were only slightly enhanced by safeners, suggesting that metabolism alone was unlikely to account for increased herbicide tolerance. Instead, it was determined that safening was associated with an accumulation of glutathione and hydroxymethylglutathione and enzymes with antioxidant functions including phi and lambda glutathione transferases, active as glutathione peroxidases and thiol transferases respectively. These safener-induced changes closely mirrored those determined in two independent black-grass populations that had acquired multiple herbicide resistance (MHR) in the field. In addition to enhanced glutathione metabolism, both safener treatment and MHR resulted in elevated levels of flavonoids in the foliage of black-grass plants, notably flavone-C-glycosides and anthocyanins. Our results demonstrate that safening in a grass weed is associated with an inducible activation in antioxidant and secondary metabolism which mirrors the biochemical phenotype exhibited in plants that are resistant to multiple classes of herbicides.

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

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    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

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

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    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.

  6. 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

    Alopecurus myosuroides Huds is one of the most important grass-weeds in North-western Europe and is also the most important herbicide-resistant weed species in European agricultural systems. Fifty-three Danish A. myosuroides populations, previously confirmed to be fenoxaprop-P resistant, were...... evaluated for five and two known mutation points within the ACCase and ALS genes, respectively. The resistance pattern of 28 out of the 53 populations was investigated to four herbicides using a seed bioassay technique. A whole plant dose response experiment was conducted on seven populations in 2012...... and 2013 to evaluate the accuracy of the seed bioassay results. Two resistant populations from the UK and a susceptible population from Denmark were included as reference populations in all experiments. Of the 53 populations, nine (17%) populations were ACCase target site resistant (TSR), all...

  7. 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.

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

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    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

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

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    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.

  10. O-Glucosyltransferase activities toward phenolic natural products and xenobiotics in wheat and herbicide-resistant and herbicide-susceptible black-grass (Alopecurus myosuroides).

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    Brazier, Melissa; Cole, David J; Edwards, Robert

    2002-01-01

    Herbicide safeners manipulate herbicide selectivity by enhancing the activities of detoxifying enzymes, such as glutathione transferases (GSTs) and cytochrome P450 mono-oxygenases (CYPs) in cereal crops. As part of a study examining the importance of O-glucosyltransferases (OGTs) in pesticide metabolism in hexaploid bread wheat (Triticum aestivum L.), seedlings were grown in the presence of dichlormid, a safener used in maize and cloquintocet mexyl, a wheat safener. The efficacy of the treatments was confirmed by monitoring changes in the abundance of phi and tau class GSTs. OGT activities in the root and shoot tissue were assayed using phenolics of natural and xenobiotic origin to determine if they were enhanced by safeners. Cloquintocet mexyl selectively increased OGT activities toward xenobiotics (4-nitrophenol and 2,4,5-trichlorophenol) and flavonoids, (quercetin, luteolin, genistein and coumestrol) in both the roots and shoots. However, OGT activity towards simple phenols and phenylpropanoids was not enhanced by cloquintocet mexyl. Dichlormid was a much weaker enhancer of OGT activity, with the same subset of OGT activities increased as determined with cloquintocet mexyl, but with the effect being largely restricted to the roots. OGT activities were also determined in black-grass (Alopecurus myosuroides L.), an agronomically important weed in wheat. Two populations of black-grass differing in their sensitivity to herbicides were analysed. The population Peldon, which is resistant to multiple classes of herbicides due in part to the elevated expression of CYPs and GSTs active in herbicide detoxification, contained higher OGT activities than herbicide sensitive black-grass. Unlike wheat, treatment with cloquintocet mexyl or dichlormid, had no effect on OGT activities in either black-grass population.

  11. 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.

  12. 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

  13. 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.

  14. Impact of imazamox containing herbicides on the development of resistance in black-grass (Alopecurus myosuroides Huds.

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    Rosenhauer, Maria

    2014-02-01

    Full Text Available Winter oilseed-rape was the most common crop in Western Europe where no ALS-inhibitor was used. Due to the introduction of Clearfield winter oilseed-rape varieties the use of ALS-inhibitors also in oilseed-rape is possible. If the broader use of ALS-inhibitors increases the selection pressure on herbicide resistant weeds and increases their occurrence in the crop rotation is the question of this investigation. Therefore, an outdoor container trial (á 350 l, 0.7 m² was performed starting in autumn 2011. A typical crop rotation of winter wheat/oilseed-rape/winter wheat was simulated in the following three years. Three different black-grass biotypes with characterised resistance pattern and 5 different herbicide programs were analysed. The blackgrass biotypes showed different target-site resistance against ACCase- and/or ALS-inhibitor, as well as metabolic resistance. Before and after each treatment the numbers of black-grass plants per container were counted. Also the numbers of heads were counted before harvest. Additionally genetic analysis due to PCRs and pyrosequencing of ten survivors per container and year were performed. Till now results of the winter wheat and oilseed-rape cultivation were obtained. Herbicide efficacy was between 77 and 98% for the treatments during the winter wheat cultivation. The genetic analysis showed nearly similar portion of TSR in the black-grass populations when compared with the initial frequencies. Only one container showed no TSR. The comparison of the herbicide programs sprayed during the oilseed-rape cultivation showed the best results for all black-grass biotypes for the application of: Metazachlor + dimethenamid (BBCH 09/10, imazamox + quinmerac + Dash (BBCH 14 and propyzamide (BBCH 21/22.

  15. Enhanced activity of several herbicide-degrading enzymes: a suggested mechanism responsible for multiple resistance in blackgrass (Alopecurus myosuroides Huds.)

    OpenAIRE

    2003-01-01

    International audience; Experiments were carried out to analyse enhanced herbicide metabolism mediated by cytochrome P450 monooxygenases (P450(s)) or glutathione-S transferases (GST(s)) as a possible mechanism responsible for multiple resistance in three blackgrass populations. The RA population is resistant to aryloxyphenoxypropionates (fops) and flupyrsulfuron, the RB to fenoxaprop-P, flupyrsulfuron and ureas and the RC to fenoxaprop-P, haloxyfop and clodinafop. Based on the coleoptile leng...

  16. 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

    2012-10-01

    Full Text Available 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 pipeline were investigated using a bioassay with herbicide-resistant and herbicide-sensitive black-grass as receiver plants. Wheat-rye translocation lines were also included in this screening to identify possible sources of high allelopathic activity. The bioassay results were followed up in two-year field trials. The results revealed large variations in allelopathic activity between cultivars. Most cultivars showed interference with both herbicide-sensitive and herbicide-resistant black-grass, although the allelopathic effect was lower on the herbicide-resistant biotype. Cultivars with high allelopathic activity gave only half the black-grass biomass of low allelopathic cultivars. Dinaro, a triticale (wheat-rye hybrid cultivar and the new wheat cultivar Nimbus showed the highest allelopathy and inhibition of black-grass growth. Only a few wheat lines with rye chromatin, all or part of a rye chromosome, showed high allelopathy. Use of cultivars with high allelopathic activity can thus be important in integrated weed management of black-grass.

  17. Impact of imazamox containing herbicides on the development of resistance in black-grass (Alopecurus myosuroides Huds. within an oilseed rape / wheat crop rotation

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    Rosenhauer, Marie

    2016-02-01

    Full Text Available The application of imazamox as an herbicide in oilseed-rape got possible due to the introduction of Clearfield oilseed-rape varieties which are tolerant to ALS inhibitors. The question of this investigation was, if the broader use of ALS-inhibitors increases the selection pressure on herbicide resistant weeds and increases their occurrence in the crop rotation. An outdoor container trial with 30 containers (350 l, 0,7 m² was performed, starting in autumn 2011. A winter wheat – oilseed-rape rotation was simulated for four years. Three different black-grass biotypes with different resistance pattern and 5 different herbicide programmes were analysed in this study in order to investigate the population dynamics of target-site resistance (TSR and the development of metabolic resistance. The trials showed interactions between the black-grass biotype and the herbicide strategy on the increase of the black-grass density. There was no interaction due to the use of propyzamide. The frequency of target-site resistance to ACCase inhibitors increased for the corresponding biotypes independently of the herbicide strategy during the trial period. The low frequency of ALS-TSR at trial start did not change during the trial period, independently of the use of imazamox in the oil-seed rape cultivation. The comparison of the resistance factors between the original biotypes and the seeds harvested after the four year container trial showed increasing resistances against pinoxaden for all biotypes. Within the different black-grass biotypes there was a slightly decrease as well as an increase in imazamox efficacy observed. There was no significant increase of meso- + iodosulfuron resistance compared to the original biotypes from 2011 caused by different herbicide treatments. The results indicated that the integration of imazamox tolerant oilseed rape in winter wheat crop rotations did not necessarily increase the development of herbicide resistant black-grass.

  18. Degradation and metabolism of fenoxaprop-P-ethyl in sensitive and resistant populations of Alopecurus myosuroides

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    Kaiser, Yasmin I.

    2014-02-01

    Full Text Available Blackgrass (Alopecurus myosuroides is one of the most economically important weeds in Europe. Because of the development and distribution of herbicide resistant populations the control of this weed has become a serious challenge in agriculture. In recent years a reduced efficacy of fenoxaprop-P-ethyl towards A. myosuroides has been observed. To investigate the degradation of the active substance fenoxaprop-P-ethyl in A. myosuroides, four populations were grown in the greenhouse: One herbicide sensitive population, two populations with a non-target-site resistance (NTSR and one population with a target-site resistance (TSR. For dose response studies the plants were treated with different dosages of fenoxaprop-P-ethyl and dry weight was determined after three weeks. For the NTSR populations resistance factors of 76 and 2 could be calculated based on ED50 values. The development of the TSR plants was not restricted by the herbicide treatment, not even with the highest dosage. For the degradation and metabolism studies plants were treated with fenoxaprop-P-ethyl and harvested for laboratory analysis 2, 8, 24, 48 and 96 hours after treatment. The active substance degraded within 96 hours without any significant differences between the populations. Two hours after herbicide treatment a metabolite could be identified and quantified in all populations. The mean contents at eight and 24 hours after treatment differed significantly between the populations. Results have shown that the metabolism of fenoxaprop-P-ethyl to fenoxaprop-P is very similar in the tested populations although they have different resistance mechanisms. Further studies are intended to show if the populations differ in the formation of other unknown metabolites.

  19. 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.

  20. Weed response to herbicides: regional-scale distribution of herbicide resistance alleles in the grass weed Alopecurus myosuroides.

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    Menchari, Yosra; Camilleri, Christine; Michel, Séverine; Brunel, Dominique; Dessaint, Fabrice; Le Corre, Valérie; Délye, Christophe

    2006-01-01

    Effective herbicide resistance management requires an assessment of the range of spatial dispersion of resistance genes among weed populations and identification of the vectors of this dispersion. In the grass weed Alopecurus myosuroides (black-grass), seven alleles of the acetyl-CoA carboxylase (ACCase) gene are known to confer herbicide resistance. Here, we assessed their respective frequencies and spatial distribution on two nested geographical scales (the whole of France and the French administrative district of Côte d'Or) by genotyping 13 151 plants originating from 243 fields. Genetic variation in ACCase was structured in local populations at both geographical scales. No spatial structure in the distribution of resistant ACCase alleles and no isolation by distance were detected at either geographical scale investigated. These data, together with ACCase sequencing and data from the literature, suggest that evolution of A. myosuroides resistance to herbicides occurred at the level of the field or group of adjacent fields by multiple, independent appearances of mutant ACCase alleles that seem to have rather restricted spatial propagation. Seed transportation by farm machinery seems the most likely vector for resistance gene dispersal in A. myosuroides.

  1. 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.

  2. Assessing non-chemical weeding strategies through mechanistic modelling of blackgrass (Alopecurus myosuroides Huds.) dynamics

    NARCIS (Netherlands)

    Colbach, N.; Kurstjens, D.A.G.; Munier-Jolain, N.M.; Dalbiès, A.; Doré, T.

    2010-01-01

    Because of environmental and health safety issues, it is necessary to develop strategies that do not rely on herbicides to manage weeds. Introducing temporary grassland into annual crop rotations and mechanical weeding are the two main features that are frequently used in integrated and organic crop

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

    Science.gov (United States)

    Délye, Christophe; Deulvot, Chrystel; Chauvel, Bruno

    2013-01-01

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

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

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    Christophe Délye

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

  5. EVOLUTIONS OF A BLACK-GRASS POPULATION SUBMITTED TO DIVERSE CROP SYSTEMS.

    Science.gov (United States)

    Henriet, F; Matrheeuws, L; Verbiest, M

    2014-01-01

    Black-grass is a common grass weed, widely spread in Northern Europe and also in Belgium. The first case of resistance in Belgium was reported by Eelen et al. (1996). Since then, monitoring showed that resistant black-grass was not confined to restricted areas anymore and that all usually effective modes of action could be subject to resistance issue (Henriet and Maréchal, 2009). There is no report that agrochemical companies will soon bring a new mode of action effective against grasses on the market, in a close future. It is therefore important to preserve the still effective actives by integrating them into global weeding strategies. A long-lasting trial was set up in order to study the evolution of a black-grass population when submitted to diverse crop systems. Several factors were studied such as rotation (quadri-annual-bisannual-monoculture winter wheat), sowing date (standard date or delayed), cultivation (inversion tillage or not) and herbicide treatments. During three years, each time winter wheat occurred in the rotation, each plot gets the same factorial combination (rotation excepted). In untreated plots, black-grass head counting's showed no differences between tillage or not and bisannual or quadri-annual rotation. On the other hand, number of black-grass heads was higher in standard sowing date and monoculture than in delayed sowing date and other rotations, respectively. The general efficacy of the herbicide treatments was decreasing over the years.

  6. 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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Transcriptome sequencing identifies novel persistent viruses in herbicide resistant wild-grasses

    Science.gov (United States)

    Sabbadin, Federico; Glover, Rachel; Stafford, Rebecca; Rozado-Aguirre, Zuriñe; Boonham, Neil; Adams, Ian; Mumford, Rick; Edwards, Robert

    2017-01-01

    Herbicide resistance in wild grasses is widespread in the UK, with non-target site resistance (NTSR) to multiple chemistries being particularly problematic in weed control. As a complex trait, NTSR is driven by complex evolutionary pressures and the growing awareness of the role of the phytobiome in plant abiotic stress tolerance, led us to sequence the transcriptomes of herbicide resistant and susceptible populations of black-grass and annual rye-grass for the presence of endophytes. Black-grass (Alopecurus myosuroides; Am) populations, displaying no overt disease symptoms, contained three previously undescribed viruses belonging to the Partititiviridae (AMPV1 and AMPV2) and Rhabdoviridae (AMVV1) families. These infections were widespread in UK black-grass populations and evidence was obtained for similar viruses being present in annual rye grass (Lolium rigidum), perennial rye-grass (Lolium perenne) and meadow fescue (Festuca pratensis). In black-grass, while no direct causative link was established linking viral infection to herbicide resistance, transcriptome sequencing showed a high incidence of infection in the NTSR Peldon population. The widespread infection of these weeds by little characterised and persistent viruses and their potential evolutionary role in enhancing plant stress tolerance mechanisms including NTSR warrants further investigation. PMID:28165016

  10. Transcriptome sequencing identifies novel persistent viruses in herbicide resistant wild-grasses.

    Science.gov (United States)

    Sabbadin, Federico; Glover, Rachel; Stafford, Rebecca; Rozado-Aguirre, Zuriñe; Boonham, Neil; Adams, Ian; Mumford, Rick; Edwards, Robert

    2017-02-06

    Herbicide resistance in wild grasses is widespread in the UK, with non-target site resistance (NTSR) to multiple chemistries being particularly problematic in weed control. As a complex trait, NTSR is driven by complex evolutionary pressures and the growing awareness of the role of the phytobiome in plant abiotic stress tolerance, led us to sequence the transcriptomes of herbicide resistant and susceptible populations of black-grass and annual rye-grass for the presence of endophytes. Black-grass (Alopecurus myosuroides; Am) populations, displaying no overt disease symptoms, contained three previously undescribed viruses belonging to the Partititiviridae (AMPV1 and AMPV2) and Rhabdoviridae (AMVV1) families. These infections were widespread in UK black-grass populations and evidence was obtained for similar viruses being present in annual rye grass (Lolium rigidum), perennial rye-grass (Lolium perenne) and meadow fescue (Festuca pratensis). In black-grass, while no direct causative link was established linking viral infection to herbicide resistance, transcriptome sequencing showed a high incidence of infection in the NTSR Peldon population. The widespread infection of these weeds by little characterised and persistent viruses and their potential evolutionary role in enhancing plant stress tolerance mechanisms including NTSR warrants further investigation.

  11. Key role for a glutathione transferase in multiple-herbicide resistance in grass weeds.

    Science.gov (United States)

    Cummins, Ian; Wortley, David J; Sabbadin, Federico; He, Zhesi; Coxon, Christopher R; Straker, Hannah E; Sellars, Jonathan D; Knight, Kathryn; Edwards, Lesley; Hughes, David; Kaundun, Shiv Shankhar; Hutchings, Sarah-Jane; Steel, Patrick G; Edwards, Robert

    2013-04-09

    Multiple-herbicide resistance (MHR) in black-grass (Alopecurus myosuroides) and annual rye-grass (Lolium rigidum) is a global problem leading to a loss of chemical weed control in cereal crops. Although poorly understood, in common with multiple-drug resistance (MDR) in tumors, MHR is associated with an enhanced ability to detoxify xenobiotics. In humans, MDR is linked to the overexpression of a pi class glutathione transferase (GSTP1), which has both detoxification and signaling functions in promoting drug resistance. In both annual rye-grass and black-grass, MHR was also associated with the increased expression of an evolutionarily distinct plant phi (F) GSTF1 that had a restricted ability to detoxify herbicides. When the black-grass A. myosuroides (Am) AmGSTF1 was expressed in Arabidopsis thaliana, the transgenic plants acquired resistance to multiple herbicides and showed similar changes in their secondary, xenobiotic, and antioxidant metabolism to those determined in MHR weeds. Transcriptome array experiments showed that these changes in biochemistry were not due to changes in gene expression. Rather, AmGSTF1 exerted a direct regulatory control on metabolism that led to an accumulation of protective flavonoids. Further evidence for a key role for this protein in MHR was obtained by showing that the GSTP1- and MDR-inhibiting pharmacophore 4-chloro-7-nitro-benzoxadiazole was also active toward AmGSTF1 and helped restore herbicide control in MHR black-grass. These studies demonstrate a central role for specific GSTFs in MHR in weeds that has parallels with similar roles for unrelated GSTs in MDR in humans and shows their potential as targets for chemical intervention in resistant weed management.

  12. Discovering the mechanism of enhanced metabolism in flufenacet resistant grass weeds

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    Dücker, Rebecca

    2016-02-01

    Full Text Available Inhibitors of very long chain fatty acid synthesis (VLCFAs, HRAC group K3 including flufenacet-based products are key herbicides in weed management strategies in particular of Western European cereal growing areas. They offer an alternative mode of action to those of frequently applied post-emergence active ingredients e.g. ACCase and ALS chemistries. In comparison, herbicide resistance to VLCFAs inhibitors develops considerably slower. Yet, resistance to the ‘low-risk’ herbicide flufenacet was documented in multi-resistant ryegrass (Lolium spp. in the northwestern United States. A 46-fold resistance shift in a population from Washington State was observed in a dose-response bioassay. The resistance levels described in black-grass (Alopecurus myosuroides Huds. field populations are lower and generally within the range of environmentally caused inconsistency in efficacy. An artificial selection of two UK multi-resistant black-grass populations with flufenacet applied annually for eight successive years resulted in resistant progeny surviving the field rate. Besides characterizing the degree of resistance in black-grass and ryegrass populations, we demonstrated that flufenacet resistance in these populations was caused by enhanced metabolism. No cross-resistance between flufenacet and pyroxasulfone, the newest VLCFAs-inhibiting herbicide, occurred in the ryegrass population. A good understanding of the resistance mechanism and early diagnostics can help preserve the efficacy of flufenacet.

  13. 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.

  14. 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.

  15. 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.

    Science.gov (United States)

    Leith, I D; Mitchell, R J; Truscott, A-M; Cape, J N; van Dijk, N; Smith, R I; Fowler, D; Sutton, M A

    2008-09-01

    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(-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.

  16. 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

  17. ISOTHECIUM MYOSUROIDES AND THUIDIUM TAMARISCINUM MOSSES AS BIOINDICATORS OF NITROGEN AND HEAVY METAL DEPOSITION IN ATLANTIC OAK WOODLANDS

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    K. Wilkins

    2015-04-01

    Full Text Available Moss tissue chemistry is widely used as a bioindicator of atmospheric deposition. The objective of this study was to compare the tissue chemistry of two moss species in Irish Atlantic oak woodlands, Isothecium myosuroides [Im] and Thuidium tamariscinum [Tt], and to determine their relationship to indices of atmospheric deposition. Moss species were collected from twenty-two woodland sites during April 2013 and analysed for nitrogen, sulphur, and eleven heavy metals. Nitrogen content was significantly correlated between species (rs = 0.84, but their mean values (Im = 1.23%, Tt = 1.34% were significantly different. A simple linear regression suggested that nitrogen content was significantly related to atmospheric ammonia (R2 = 0.67 [Im], R2 = 0.65 [Tt] and total nitrogen deposition (R2 = 0.57 [Im], R2 = 0.54 [Tt]. Many heavy metals had significant interspecies correlations (Al, V, Ni, Cu, Zn, As, Sb, Pb; rs = 0.46−0.77. A few metals (As, Sb and Pb were positively correlated with easting and northing for both species, which may suggest transboundary or national industrial emissions sources. The results suggest that both species could be used as bioindicators of deposition for nitrogen and some heavy metals, although further study of the relationship between tissue concentrations and atmospheric deposition is warranted. Furthermore, interspecies calibration is required to use both species in conjunction.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Role of a novel I1781T mutation and other mechanisms in conferring resistance to acetyl-CoA carboxylase inhibiting herbicides in a black-grass population.

    Directory of Open Access Journals (Sweden)

    Shiv Shankhar Kaundun

    Full Text Available BACKGROUND: Knowledge of the mechanisms of herbicide resistance is important for designing long term sustainable weed management strategies. Here, we have used an integrated biology and molecular approach to investigate the mechanisms of resistance to acetyl-CoA carboxylase inhibiting herbicides in a UK black-grass population (BG2. METHODOLOGY/PRINCIPAL FINDINGS: Comparison between BG2 phenotypes using single discriminant rates of herbicides and genotypes based on ACCase gene sequencing showed that the I1781L, a novel I1781T, but not the W2027C mutations, were associated with resistance to cycloxydim. All plants were killed with clethodim and a few individuals containing the I1781L mutation were partially resistant to tepraloxydim. Whole plant dose response assays demonstrated that a single copy of the mutant T1781 allele conferred fourfold resistance levels to cycloxydim and clodinafop-propargyl. In contrast, the impact of the I1781T mutation was low (Rf = 1.6 and non-significant on pinoxaden. BG2 was also characterised by high levels of resistance, very likely non-target site based, to the two cereal selective herbicides clodinafop-propargyl and pinoxaden and not to the poorly metabolisable cyclohexanedione herbicides. Analysis of 480 plants from 40 cycloxydim resistant black grass populations from the UK using two very effective and high throughput dCAPS assays established for detecting any amino acid changes at the 1781 ACCase codon and for positively identifying the threonine residue, showed that the occurrence of the T1781 is extremely rare compared to the L1781 allele. CONCLUSION/SIGNIFICANCE: This study revealed a novel mutation at ACCase codon position 1781 and adequately assessed target site and non-target site mechanisms in conferring resistance to several ACCase herbicides in a black-grass population. It highlights that over time the level of suspected non-target site resistance to some cereal selective ACCase herbicides have in some

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

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    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.

  4. 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.

  5. 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.

  6. 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.

  7. 从《生活秀》《看麦娘》论池莉女性主义小说的叙事艺术%On the Narrative Art of Chili's Feminism Novels from The Sailor of Living and Alopecurus

    Institute of Scientific and Technical Information of China (English)

    翟喜凤

    2008-01-01

    作家池莉以开创了"新写实小说"而在当代文坛占据一席之地.但身为女性作家,她更是自觉地从女性主义视角出发,关注时代变迁给女性生活和情感所带来的变化,从而创作出了具有鲜明的女性意识的女性主义小说.和便是这方面的代表作.这两部小说分别表现了商品经济背景下底层女性与知识女性的现实生活与精神状态.无论是小说的叙事视角,还是小说的写实手法,抑或是小说的情节建构,这两部小说都表现了现代社会女性对于自我价值的寻求,进而有力地凸显了女性的生存意义.%Chili won a place for herself in the world of the literary. As a woman novelist, Chili pays attention to the change of women's life and emotions with the development of the times from the view of feminism. So, Chili creates a lot of feminism novels with distinctive female consciousness. The Sailor of Living and Alopecurus are the novels on this theme. From both of the narrative angle, the writing technique, and the plots, the two novels both show the women in modern society seeking the value of ego, highlighting the significance of women's subsistence.

  8. 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.

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

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    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

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

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    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.

  11. 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.

  12. 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.

  13. Fitness cost due to herbicide resistance may trigger genetic background evolution.

    Science.gov (United States)

    Darmency, Henri; Menchari, Yosra; Le Corre, Valérie; Délye, Christophe

    2015-01-01

    This article investigates the possible existence of mechanisms counterbalancing the negative pleiotropic effects on development and reproduction that are conferred by alleles responsible for herbicide resistance in the weed Alopecurus myosuroides. We considered three herbicide-resistant, mutant acetyl-coenzyme A carboxylase (ACCase) alleles, Leu1781, Asn2041, and Gly2078, found in eight resistant populations. Of these, Gly2078 is the only allele with a known fitness cost. We compared plants homozygous for wild-type ACCase alleles that were siblings of plants carrying a given mutant resistant ACCase allele with plants from three populations where resistance did not evolve. In each of two series of experiments, we measured germination dynamics, seedling vigor, plant height, vegetative biomass, and seed production. The wild-type siblings of plants carrying Gly2078 performed better in the field, on average, than wild-type plants that were sibling of plants carrying other mutant ACCase alleles, and particularly those carrying Leu1781. We propose that rapid evolution of the genetic background of plants from the populations where the Gly2078 allele originally arose could partially counterbalance Gly2078 fitness cost, enhancing the spread of the resistant genotypes.

  14. Effect of herbicide resistance endowing Ile-1781-Leu and Asp-2078-Gly ACCase gene mutations on ACCase kinetics and growth traits in Lolium rigidum.

    Science.gov (United States)

    Vila-Aiub, Martin M; Yu, Qin; Han, Heping; Powles, Stephen B

    2015-08-01

    The rate of herbicide resistance evolution in plants depends on fitness traits endowed by alleles in both the presence and absence (resistance cost) of herbicide selection. The effect of two Lolium rigidum spontaneous homozygous target-site resistance-endowing mutations (Ile-1781-Leu, Asp-2078-Gly) on both ACCase activity and various plant growth traits have been investigated here. Relative growth rate (RGR) and components (net assimilation rate, leaf area ratio), resource allocation to different organs, and growth responses in competition with a wheat crop were assessed. Unlike plants carrying the Ile-1781-Leu resistance mutation, plants homozygous for the Asp-2078-Gly mutation exhibited a significantly lower RGR (30%), which translated into lower allocation of biomass to roots, shoots, and leaves, and poor responses to plant competition. Both the negligible and significant growth reductions associated, respectively, with the Ile-1781-Leu and Asp-2078-Gly resistance mutations correlated with their impact on ACCase activity. Whereas the Ile-1781-Leu mutation showed no pleiotropic effects on ACCase kinetics, the Asp-2078-Gly mutation led to a significant reduction in ACCase activity. The impaired growth traits are discussed in the context of resistance costs and the effects of each resistance allele on ACCase activity. Similar effects of these two particular ACCase mutations on the ACCase activity of Alopecurus myosuroides were also confirmed.

  15. Metabolism-based herbicide resistance and cross-resistance in crop weeds: a threat to herbicide sustainability and global crop production.

    Science.gov (United States)

    Yu, Qin; Powles, Stephen

    2014-11-01

    Weedy plant species that have evolved resistance to herbicides due to enhanced metabolic capacity to detoxify herbicides (metabolic resistance) are a major issue. Metabolic herbicide resistance in weedy plant species first became evident in the 1980s in Australia (in Lolium rigidum) and the United Kingdom (in Alopecurus myosuroides) and is now increasingly recognized in several crop-weed species as a looming threat to herbicide sustainability and thus world crop production. Metabolic resistance often confers resistance to herbicides of different chemical groups and sites of action and can extend to new herbicide(s). Cytochrome P450 monooxygenase, glycosyl transferase, and glutathione S-transferase are often implicated in herbicide metabolic resistance. However, precise biochemical and molecular genetic elucidation of metabolic resistance had been stalled until recently. Complex cytochrome P450 superfamilies, high genetic diversity in metabolic resistant weedy plant species (especially cross-pollinated species), and the complexity of genetic control of metabolic resistance have all been barriers to advances in understanding metabolic herbicide resistance. However, next-generation sequencing technologies and transcriptome-wide gene expression profiling are now revealing the genes endowing metabolic herbicide resistance in plants. This Update presents an historical review to current understanding of metabolic herbicide resistance evolution in weedy plant species.

  16. Determination of ploidy level and isolation of genes encoding acetyl-CoA carboxylase in Japanese Foxtail (Alopecurus japonicus.

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    Hongle Xu

    Full Text Available Ploidy level is important in biodiversity studies and in developing strategies for isolating important plant genes. Many herbicide-resistant weed species are polyploids, but our understanding of these polyploid weeds is limited. Japanese foxtail, a noxious agricultural grass weed, has evolved herbicide resistance. However, most studies on this weed have ignored the fact that there are multiple copies of target genes. This may complicate the study of resistance mechanisms. Japanese foxtail was found to be a tetraploid by flow cytometer and chromosome counting, two commonly used methods in the determination of ploidy levels. We found that there are two copies of the gene encoding plastidic acetyl-CoA carboxylase (ACCase in Japanese foxtail and all the homologous genes are expressed. Additionally, no difference in ploidy levels or ACCase gene copy numbers was observed between an ACCase-inhibiting herbicide-resistant and a herbicide-sensitive population in this study.

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

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    Zvonko Pacanoski

    2017-03-01

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

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

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    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.

  19. 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

  20. Reduced herbicide rates: present and future

    Directory of Open Access Journals (Sweden)

    Kudsk, Per

    2014-02-01

    Full Text Available Applying herbicides at rates lower than the label recommendation has been the rule rather than the exception in Denmark since the late 1980’s. Justifications for reducing herbicide rates can be 1 that the dominant weed species in the field are very susceptible to the herbicide, i.e. even reduced rates will result in maximum effects, 2 that the conditions at and around the time of application, e.g. growth stage of weeds, crop vigour and climatic condition are optimum promoting the activity of the herbicide and thus allows for the use of reduced herbicides rates, or 3 that less than maximum effects are accepted because the weed flora is not considered to have a significant effect on crop yield. “Crop Protection Online-Weed” (CPO-Weed is a web-based decision support system that was developed to support farmers in their choice of herbicide and herbicide rate. CPOWeed will, based on information on crop development and status and the composition of the weed flora, provide farmers with a list of herbicide solutions often recommending the use of reduced rates. The potential of CPO-Weed to reduced herbicide input has been proven in numerous validation trials. In recent years the use of reduced herbicide rates has been linked to the increasing number of cases of non-target resistance in outcrossing grass weed species like Alopecurus myosuroides and Lolium ssp. The underlying hypothesis is that the least susceptible individuals in the population will survive the use of reduced rates and that recombination will lead to a gradual increase in the resistance level in the weed population. This scenario is only valid if the use of reduced herbicide rates is prompted by acceptance of a lower effect but not if a high susceptibility of the weed species present in the field or optimum conditions are the reasons for reducing herbicide rates. This is an aspect that is often overlooked in the on-going discussion on herbicide rates and resistance. Large weed

  1. 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.

  2. 日本看麦娘对芳基苯氧基丙酸类除草剂的耐性%Resistance of Alopecurus japonicum to aryloxy- phenoxy propionic acid herbicides

    Institute of Scientific and Technical Information of China (English)

    潘以楼; 朱桂梅; 杨敬辉

    2007-01-01

    油菜田中的日本看麦娘对芳基苯氧基丙酸类除草剂出现耐性群体,此类除草剂中的高效氟吡甲禾灵、精吡氟禾草灵、精喹禾灵在高于推荐剂量1倍的用量下,对日本看麦娘的防除效果极低,而相同剂量对菵草仍有极好的防除效果.

  3. 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.

  4. Allergen identification in 5 grasses by means of crossed radioimmunoelectrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Diener, C.; Skibbe, K.; Jaeger, L. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic))

    1984-01-01

    Using crossed radioimmunoelectrophoresis aqueous extracts from pollen of Phleum pratense, Lolium perenne, Poa pratensis, Festuca pratensis and Alopecurus pratensis were investigated for allergen composition. Between 24 and 32 antigens were detected. Employing sera from 11 patients with well established hay fever, IgE binding could be demonstrated in 15 out of 28 antigens in Phleum pratense, 13 out of 32 in Lolium perenne, 14 out of 26 in Poa pratensis, 12 out of 24 Festuca pratensis and 12 out of 24 antigens in Alopecurus pratensis. The 11 patients showed an individual pattern of sensitization against the various pollen allergens.

  5. HIGH NATURE VALUE GRASSLANDS FROM ARRHENATHERION ALLIANCE IDENTIFIED IN MUREŞ COUNTY

    OpenAIRE

    Silvia Oroian; Mihaela Samarghitan; MARIANA Hiritiu; SANDA Cosarca; CORNELIU Tanase

    2016-01-01

    Arrhenatherion alliance meadows are recognized to be among the best pastures in our country due to high productivity and good nutrition value. The research was conducted in several areas of Mures County. The studied grasslands were classified into two types of Natura 2000 habitats: 6510 Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) and 6520 Mountain hay meadows. The identified phytocoenosis belong to two plant associations: Arrhenatheretum elatioris Br.-Bl. Ex Scherrer 1...

  6. 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.

  7. 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.

  8. 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。

  9. 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.

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

    Science.gov (United States)

    Overesch, M; Rinklebe, J; Broll, G; Neue, H-U

    2007-02-01

    Floodplain soils at the Elbe river are frequently polluted with metals and arsenic. High contents of these pollutants were detected down to subsoil layers. NH4NO3-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.

  11. 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.

  12. 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.

  13. 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.

  14. Optimization of pressurized liquid extraction using a multivariate chemometric approach and comparison of solid-phase extraction cleanup steps for the determination of polycyclic aromatic hydrocarbons in mosses.

    Science.gov (United States)

    Foan, L; Simon, V

    2012-09-21

    A factorial design was used to optimize the extraction of polycyclic aromatic hydrocarbons (PAHs) from mosses, plants used as biomonitors of air pollution. The analytical procedure consists of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) cleanup, in association with analysis by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). For method development, homogeneous samples were prepared with large quantities of the mosses Isothecium myosuroides Brid. and Hypnum cupressiforme Hedw., collected from a Spanish Nature Reserve. A factorial design was used to identify the optimal PLE operational conditions: 2 static cycles of 5 min at 80 °C. The analytical procedure performed with PLE showed similar recoveries (∼70%) and total PAH concentrations (∼200 ng g(-1)) as found using Soxtec extraction, with the advantage of reducing solvent consumption by 3 (30 mL against 100mL per sample), and taking a fifth of the time (24 samples extracted automatically in 8h against 2 samples in 3.5h). The performance of SPE normal phases (NH(2), Florisil, silica and activated aluminium) generally used for organic matrix cleanup was also compared. Florisil appeared to be the most selective phase and ensured the highest PAH recoveries. The optimal analytical procedure was validated with a reference material and applied to moss samples from a remote Spanish site in order to determine spatial and inter-species variability.

  15. 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.

  16. Using transplants to measure accumulation rates of epiphytic bryophytes in forests of western Oregon

    Science.gov (United States)

    Rosso, A.L.; Muir, Patricia S.; Rambo, T.

    2001-01-01

    We sought a simple and effective transplant method that could be used to measure biomass accumulation rates of epiphytic bryophytes. Trials were carried out in the Pseudotsuga menziesii-dominated forests of western Oregon. We tested multiple transplant methods over a 13-month period while comparing accumulation rates of Antitrichia curtipendula (Hedw.) Brid. and Isothecium myosuroides Brid. among an old-growth stand, a young stand, and a recent clearcut. In our study area, Antitrichia is considered to be an old-growth associate while Isothecium is a more ubiquitous species. Methods tested included containment in net bags, containment in hairnets, and directly tying mats to substrates. Three sizes of transplants were tested with both natural and inert artificial substrates. Transplants of approximately five g enclosed in plastic net bags and tied to either natural or artificial substrates worked well for our purposes. Only minor differences were found in mean accumulation rates between the old growth and young stand, though variation in accumulation rates was higher in the old growth. Neither species appeared capable of surviving in the clearcut. Antitrichia accumulated biomass 60% faster in the canopy than in the understory on average. Antitrichia also accumulated at a faster rate than Isothecium, with mean 13-month biomass increases of 11.8 and 3.7% respectively for 5 g transplants in the understory. Our results suggest that Antitrichia's association with old growth may be due more to dispersal or establishment limitations than to a decreased ability to grow in young stands.

  17. Changes in the timing of hay cutting in Germany do not keep pace with climate warming.

    Science.gov (United States)

    Bock, Anna; Sparks, Tim H; Estrella, Nicole; Menzel, Annette

    2013-10-01

    A unique long-term phenological data set of over 110 000 records of 1st cutting dates for haymaking across Germany, spanning the years 1951-2011 was examined. In addition, we analyzed a long-term data set in the beginning of flowering of meadow foxtail (Alopecurus pratensis) covering the last 20 years. We tested whether hay-cutting dates (based on a human decision when to cut) showed trends, temperature relationships and spatial distribution similar to the development of this grassland species, and if these trends could be related to climate change. The timing of 1st hay cut was strongly influenced (P cutting, with the majority of German federal states having significant (P cutting) were likely to be responsible for the regional differences, while the general increase in AES appears to have confounded the overall trend in hay cutting in the last 20 years. Trends over time and responses to temperature were small relative to those associated with the phenology of meadow foxtail. The advance in phenology of this species is greater than the advance in hay cutting, implying that hay cutting may not be keeping pace with a changing climate, which may have a positive effect on grassland ecology.

  18. HIGH NATURE VALUE GRASSLANDS FROM ARRHENATHERION ALLIANCE IDENTIFIED IN MUREŞ COUNTY

    Directory of Open Access Journals (Sweden)

    Silvia Oroian

    2016-11-01

    Full Text Available Arrhenatherion alliance meadows are recognized to be among the best pastures in our country due to high productivity and good nutrition value. The research was conducted in several areas of Mures County. The studied grasslands were classified into two types of Natura 2000 habitats: 6510 Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis and 6520 Mountain hay meadows. The identified phytocoenosis belong to two plant associations: Arrhenatheretum elatioris Br.-Bl. Ex Scherrer 1925 and Poo Trisetetum flavescentis (Knapp 1951 Oberd. 1957. The analysis of data collected in the field reveals that the current state of conservation of the two types of habitat is good and very good. Habitats in a good and very good state of preservation is distinguish by a great floristic composition: approx. 100-150 cormophyte species with good and very good forage value. As habitats are more susceptible to the management applied and any changes to land use can affect habitat quality (eg abandoning  mowing and turning the land into pasture, the ecological functions of this habitat will be satisfied as long as they are mowed after Poaceae species matured.

  19. Post-harvest longevity of ornamental grasses conditioned in gibberellic acid and 8-hydroxyquinoline sulphate

    Directory of Open Access Journals (Sweden)

    Henschke Monika

    2016-06-01

    Full Text Available Florists’ greens are becoming increasingly important in contemporary floristry. Numerous studies conducted on cut flowers have led to the development of technologies for their post-harvest handling; however, in the case of florists’ greens they are still insufficient. Moreover, the extensive range of florists’ greens lacks leaves and the leafy culms of grasses. The aim of this study was to determine the post-harvest longevity of the leaves and leafy culms of ornamental grasses conditioned in water solutions of gibberellic acid and 8-hydroxyquinoline sulphate. The post-harvest longevity of leaves was examined in cultivars of the following species: Glyceria maxima Hartm. ‘Variegata’, Miscanthus sinensis Thunb. ‘Zebrinus’ and Spartina pectinata Link. ‘Aureomarginata’. The post-harvest longevity of leafy culms was investigated in Alopecurus pratensis L. ‘Aureovariegatus’, Chasmanthium latifolium Michx., Miscanthus sinensis Thunb. ‘Silberspinne’, Pennisetum alopecuroides L. and Phalaris arundinacea L. ‘Picta’. Conditioning in gibberellic acid had a positive effect on the post-harvest longevity and fresh weight loss and the index of leaf greenness of leaves in the case of Miscanthus sinensis ‘Zebrinus’, while conditioning in 8-hydroxyquinoline sulphate improved fresh weight loss and the index of leaf greenness of the leafy culms of Miscanthus sinensis ‘Zebrinus’, Pennisetum alopecuroides and the leaves of Glyceria maxima ‘Variegata’.

  20. 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.

  1. New species and records of phytoptid mites (Acari: Eriophyoidea: Phytoptidae) on sedges (Cyperaceae) from the Russian Far East.

    Science.gov (United States)

    Chetverikov, Philipp E

    2016-01-08

    Two new phytoptine species, Oziella virgata n. sp. and O. ovalis n. sp., were collected from the Russian Far East on sedges, Carex appendiculata (Trautv. & C.A. Mey) Kükenthal and Kobresia myosuroides (Villars) Fiori, respectively, and are described herein using conventional light microscopy (LM) and confocal laser scanning microscopy (CLSM). In addition, Oziella cf. rigida (Roivainen 1950) was recorded from Carex scita var. riishirensis (Franch.) Kük. in the Kamchatka Peninsula whilst Novophytoptus rostratae Roivainen 1947 was found on Carex saxatilis L. and C. appendiculata in the Sakha Republic (Yakutia) of Russia and Carex soczavaeana Gorodkov on the Kamchatka Peninsula. Oziella virgata n. sp. has a unique rod-like seta u' on the medial-lower surface of tarsi I & II, a character not previously described in eriophyoid mites. Additionally, the position of setae 3a in nymphs and females differs: these are located on the same annulus as tubercles of setae c2 in nymphs whereas in females, those are situated notably ahead of tubercles c2 (closer to coxae II). Males of O. virgata n. sp. possess a well-developed genital coverflap, resembling that of Mackiella reclinata Chetverikov & Craemer, 2014, Pentasetacus araucariae (Schliesske, 1985) and Loboquintus subsquamatus Chetverikov & Petanović, 2013. The original slidemounted specimens of the new Oziella species described herein were inappropriate for LM study. However, CLSM microscopy images obtained prior to remounting were sharp enough for diagnostic purposes indicating that this is a useful method for studying poor quality specimens which may otherwise be difficult to remount or, in some cases, are very rare.

  2. 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.

  3. 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.

  4. Weed Characteristics and Control Strategies in Wheat Fields in Yangzhou City%扬州市麦田草相特点及杂草防除对策

    Institute of Scientific and Technical Information of China (English)

    杨进; 刘学儒; 丁涛; 秦玉金; 焦骏森

    2014-01-01

    为了摸清扬州地区麦田杂草种类、分布状况,通过倒“W”形九点取样法调查,结果表明麦田杂草有26科81种,其中里下河地区优势种为日本看麦娘、牛繁缕、菵草等;沿江地区优势种为菵草、日本看麦娘、牛繁缕等;丘陵山区优势种为日本看麦娘、猪秧秧、野老鹳等;同时发现当前存在着杂草抗药性增强、防治技术不到位等方面问题,提出了强抓土壤封闭处理、合理选用除草剂及开展技术宣传培训等对策。%Weed species and their distribution in wheat fields in Yangzhou area were determined by sampling nine plots according to a“W” pattern.Weeds belonged to 81 species of 26 families.The dominant species in Lixiahe region and the area along the Yangtze River were Alopecurus japonicus Steud.,Malachium aquaticum ( L.) Fries., and Beckmannia syzigachne ( Steud.) Fernald, whereas A.japonicus Steud.,Galium aparine L.and Geranium carolinianum L.were dom-inant in hilly areas.Currently,problems with herbicide resistant weeds are becoming more serious and outdated control technologies must be improved.Therefore,a series of control strategies are proposed including improving the use of resid-ual soil applied herbicides,judicious selection of herbicides and carrying out technical outreach and training.

  5. Resistance to acetyl-CoA carboxylase-inhibiting herbicides.

    Science.gov (United States)

    Kaundun, Shiv S

    2014-09-01

    Resistance to acetyl-CoA carboxylase herbicides is documented in at least 43 grass weeds and is particularly problematic in Lolium, Alopecurus and Avena species. Genetic studies have shown that resistance generally evolves independently and can be conferred by target-site mutations at ACCase codon positions 1781, 1999, 2027, 2041, 2078, 2088 and 2096. The level of resistance depends on the herbicides, recommended field rates, weed species, plant growth stages, specific amino acid changes and the number of gene copies and mutant ACCase alleles. Non-target-site resistance, or in essence metabolic resistance, is prevalent, multigenic and favoured under low-dose selection. Metabolic resistance can be specific but also broad, affecting other modes of action. Some target-site and metabolic-resistant biotypes are characterised by a fitness penalty. However, the significance for resistance regression in the absence of ACCase herbicides is yet to be determined over a practical timeframe. More recently, a fitness benefit has been reported in some populations containing the I1781L mutation in terms of vegetative and reproductive outputs and delayed germination. Several DNA-based methods have been developed to detect known ACCase resistance mutations, unlike metabolic resistance, as the genes remain elusive to date. Therefore, confirmation of resistance is still carried out via whole-plant herbicide bioassays. A growing number of monocotyledonous crops have been engineered to resist ACCase herbicides, thus increasing the options for grass weed control. While the science of ACCase herbicide resistance has progressed significantly over the past 10 years, several avenues provided in the present review remain to be explored for a better understanding of resistance to this important mode of action.

  6. 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.

  7. 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.

  8. Nutrient removal by grasses irrigated with wastewater and nitrogen balance for reed canarygrass

    Energy Technology Data Exchange (ETDEWEB)

    Geber, U.

    2000-04-01

    To develop complementary wastewater treatment systems that increase nutrient reduction and recycling, an experiment was conducted to evaluate the efficiency of three grass species as catch crops for N, P, and K at Aurahammar wastewater treatment plant (WWTP) in the southern part of Sweden. Another objective was also to assess soil accumulation of N, P, and K and the risk of N leaching by drainage. Three grasses--reed canarygrass (Phalaris arundinacea L.), meadow foxtail (Alopecurus pratensis L.), and smooth bromegrass (Bromus inermis Leyss.)--were irrigated with a mixture of treated effluent and supernatant at two levels of intensity [optimum level (equal to evapotranspiration) and over-optimal level] and at two nutrient levels, approximately 150 and 300 kg N ha{sup {minus}1}. There were small differences in dry matter (DM) yield between grass species and no difference in N removal among species. The amount of N removed in harvested biomass to N applied was 0.58 in 1995 and 0.63 in 1996. The amount of N removed increased with increased nutrient load. Applied amounts of P were the same as P in harvested biomass. All species removed K amounts several times greater than applied amounts. Increased nutrient load increased overall K removal. The low amount of mineral N and especially NO{sub 3}{sup {minus}}-N in the soil profile in autumn samplings indicate the risk for leaching is small. Soil water NO{sub 3}{sup {minus}} contents were also low, <2.5 mg NO{sub 3}{sup {minus}}-N L{sup {minus}1} during the growing season, with a mean value of <1 mg NO{sub 3}{sup {minus}}-N L{sup {minus}1}.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. Integration of wastewater treatment in agro-ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Geber, Ulrika [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Crop Production Science

    2000-07-01

    There is a need to find more ecologically sustainable wastewater treatment systems where increased reuse of phosphorus and nitrogen is combined with efficient resource use and decreased eutrophication of recipients. This thesis concerns the ecological sustainability in systems for treatment of municipal wastewater where processes at the WWTP are substituted for ecosystem services. A crop irrigation system was chosen for a study of how natural treatment of pre-treated municipal wastewater could be integrated with agricultural production. Reuse efficiency of nutrients and suitability as substrate for biogas generation was studied in reed canary grass (Phalaris arundinacea L.), meadow foxtail (Alopecurus pratensis L.) and smooth bromegrass (Bromus inermis Leyss.) irrigated with pre-treated wastewater. Crop management in order to increase potential biomass quality for biogas generation was studied in reed canary grass. Resource use in treatment systems differing in their demand of land area and purchased input was evaluated in an emergy analysis. There were only small differences between species in N and P removal and in the yield of dry matter and digestible organic matter. The reed canary grass and meadow foxtail can function well as catch crops in wastewater treatment and potentially as substrates for biogas production. The risk of N leaching in the harvested reed canary grass ley, receiving 175 to 350 kg N ha{sup -1} applied as 300 to 700 mm wastewater, is considered low due to an observed low content soil water NO{sub 3}{sup -}N during the vegetation period and of soil NO{sub 3}{sup -}N in autumn. Increased cutting frequency did not increase the yield of digestible organic matter in reed canary grass. Increased stubble height could not compensate for the effects of increased harvest frequency on the yield of dry matter and digestible organic matter. The emergy analysis did not reveal any differences in the use of purchased inputs between treatment systems. A high

  15. 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.

  16. Colonization and infection of Ralstonia Solanacearum in weed roots%烟草青枯菌在杂草根部的定殖和传病作用

    Institute of Scientific and Technical Information of China (English)

    方树民; 顾钢; 陈玉森; 黄春梅; 陈顺辉

    2013-01-01

    Parasitism and saprophytism of Ralstonia Solanacearum in different weeds were studied to provide basis for preventing tobacco bacterial wilt. Growth and decline trends and infectivity ability of the bacteria in winter were monitored. Disease was induced by inoculating tobacco seedlings with rifampicin-resistant R. solanacearum. Bacteria in 49 weed roots in tobacco planting land. Weed roots from infected soil in winter were determined using a selective culture medium containing rifampicin. The occurrence of tobacco bacterial wilt was monitored by planting tobacco seedlings in pots with uninfected soil. 7 weeds such as Polygonum plebeium R.Br and Cyperus rotundus L. were susceptible, 18 such as Pospalum orbiculare Forst. and Solanum mgrum L. were moderately susceptible, while 24 weeds such as Youngia japonica (Linn.) DC and Echinochloa crusgalli (L.) Beauv. were low susceptible. R.Solanacearum were just noted on the root surface of Bidens bipinnata L. and Phytolacca acinosa Raxb. , but were both noted in vivo and in vitro of 6 weed roots such as Poa annua L. and Pospalum orbiculare Forst..3 weeds, i.e. Eleusine indica (L.) Gaertn and Portutulaca oleracea. R.Solanacearum was highly saprophytic in 8 rotten roots such as Eleusine indica (L.) Gaertn and Polygonum hydropiper L., moderately saprophytic in 7 rotten roots such as Pospalum orbiculare Forst. and Soliva anthemifolia (Juss), low saprophytic in 6 rotten roots such as Ranunculus sceleratus L. and Siegesbeckia orientalis L. Result showed R.Solanacearum can overwinter in roots of 6 annual weeds and then cause tobacco bacterial wilt in the following year. The disease occurrence can be induced by 7 weeds, while the disease was early and serious in Alopecurus aequalis Sobol. 4 weeds such as Polygonum orientale L. and Altemanthera philoxeroides(Mart) Griseb had the strongest infectivity ability, the morbidity was 85.7% ~ 100%. R. Solanacearum can colonize in weed roots, then proliferate during root decay and overwinter

  17. 六蕊假稻Leersia hexandra病原真菌稻平脐蠕孢Bipolaris oryzae的分子鉴定及致病性研究%Molecular Identification and Pathogenicity Research of Bipolaris oryzae on Leersia hexandra

    Institute of Scientific and Technical Information of China (English)

    韩川; 段桂芳; 张建萍; 陆永良; 余柳青

    2013-01-01

    In order to obtain potential pathogenic fungi for biological control of weeds, we isolated from natural-infected Leersia hexandra six strains which was then identified as Bipolaris oryzae via morphology and rDNA ITS sequence analysis. Herbicidal activity of toxins in culture filtrates and mycelial suspension were evaluated by petri dish and pot bioassay, and the safety to main crops of mycelia suspension was also tested using pot bioassay. Results showed that the 14 day culture filtrates of the six strains were highly inhibitory against growth of barnyardgrass, Echinochloa crusgalli (L.) Beauv. , with inhibitory rate of 100%on roots and 80.38%on shoots respectively. Disease incidence, disease infection index, inhibition rates of plant height and fresh weight of barnyardgrass treated with 7 day mycelia suspension reached 100%, 72 , 50.29%and 63.31%, respectively. The 7 day mycelia suspension was pathogenic with various degrees to E. crusgalli, Leptochloa chinensis, L. hexandra, Monochoria vaginalis, Sagittaria pygmaea and Eleocharis plantaginerformis, but not pathogenic to Paspalum distichum, Cyperus difformis and Alopecurus aequalis. The six strains were safe or weak pathogenic to main crops, and showed potential as biological herbicides.%  为了筛选获得具除草潜力的病原真菌菌株,经形态学观察和18s rDNA ITS序列分析,6株分离自感病六蕊假稻的菌株被鉴定为稻平脐蠕孢Bipolaris oryzae。采用培养皿生测法和盆栽生测法分别评价其发酵液毒素和菌丝体悬浮液的除草活性,同时用盆栽生测法测定了菌丝体悬浮液对主要作物的安全性。试验结果表明:6株稻平脐蠕孢培养14 d的发酵液对稗草根长、芽长均有很高的抑制作用,根长和芽长最高抑制率分别为100%和80.38%。培养7 d的菌丝体悬浮液对稗草的感病率、感病指数、株高抑制率、鲜重抑制率最高可达100%、72.00、50.29%和63.31%。6株稻平脐蠕孢菌丝体悬

  18. 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.

  19. 太子河河岸带植物群落特征及其物种多样性研究%Study on Plant Community Characteristics and Species Diversity of Riparian Zone Along Taizi River

    Institute of Scientific and Technical Information of China (English)

    李悦; 马溪平; 李法云; 侯伟; 杨春璐; 程志辉

    2011-01-01

    plots of riparian zone along Taizi River. The species composition of the community is relatively rich, but all are confined to herbaceous plant. The main families are dominated by the Compositae, Gramineae, Polygonaceae, Cyperaceae, and Rosaceae. The compositions of the community are concentrated, and the plant species give first place to Juncus effusus L., Beckmannia syzigachne (Steud.) Fern., Polygonum hydropiper L. Angustifolium A. Br., Echinochloa crusgalli (L.) Beauv., Alopecurus aequalis Sobol., Polygonum hydropiper L., Rumex acetosa L., Artemisia adamsii Bess., Carex dispalata Boott ex A. Gray, Zoysia sinica Hance, Poa subfastigiata Trin., Scirpus orienudis Ohwi, etc. The community structure of riparian zone along Taizi River is simple in studied area. The ecosystem is deteriorating with richness indexes changing between 3.00-28.00, Pielou indexes changing between 0.66-0.89, Simpson indexes changing between 0.54-0.91, Shannon-wiener indexes changing between 0.86-2.73, Simpson dominance indexes changing between 0.09-0.46. The riparian zone along Taizi River is disturbed by human activities, such as agricultural production, dredging, and other human activities that result in the reduction of the level of community diversity.

  20. 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