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1.
为了明确15%硝磺草酮悬浮剂防除草坪(早熟禾)杂草效果及对早熟禾的安全性,进行茎叶喷雾处理法防除草坪(早熟禾)田间药效试验。结果表明,硝磺草酮对反枝苋除草活性最高,其次为牛筋草和马唐,对马齿苋活性相对较低,总体防效好;不同草龄的杂草对药剂敏感程度有较大差异,草龄较小者则防效好。在供试剂量范围内对草坪作物早熟禾安全。  相似文献   

2.
The management of weeds in Malaysian rice fields is very much herbicide‐based. The heavy reliance on herbicide for weed control by many rice‐growers arguably eventually has led to the development and evolution of herbicide‐resistant biotypes in Malaysian rice fields over the years. The continuous use of synthetic auxin (phenoxy group) herbicides and acetohydroxyacid synthase‐inhibiting herbicides to control rice weeds was consequential in leading to the emergence and prevalence of resistant weed biotypes. This review discusses the history and confirmed cases and incidence of herbicide‐resistant weeds in Malaysian rice fields. It also reviews the Clearfield Production System and its impact on the evolution of herbicide resistance among rice weed species and biotypes. This review also emphasizes the strategies and management options for herbicide‐resistant rice field weeds within the framework of herbicide‐based integrated weed management. These include the use of optimum tillage practices, certified clean seeds, increased crop competition through high seeding rates, crop rotation, the application of multiple modes of action of herbicides in annual rotations, tank mixtures and sequential applications to enable a broad spectrum of weed control, increase the selective control of noxious weed species in a field and help to delay the resistance evolution by reducing the selection pressure that is forced on those weed populations by a specific herbicidal mode of action.  相似文献   

3.
The 1995/6 International Survey of Herbicide-Resistant Weeds recorded 183 herbicide-resistant weed biotypes (124 different species) in 42 countries. The increase in the number of new herbicide-resistant weeds has remained relatively constant since 1978, at an average of nine new cases per year worldwide. Whilst 61 weed species have evolved resistance to triazine herbicides, this figure now only accounts for one-third of all documented herbicide-resistant biotypes. Triazine-resistant weeds have been controlled successfully in many countries by the use of alternative herbicides. Due to the economic importance of ALS and ACCase inhibitor herbicides worldwide, and the ease with which weeds have evolved resistance to them, it is likely that ALS and ACCase inhibitor-resistant weeds will present farmers with greater problems in the next five years than triazine-resistant weeds have caused in the past 25 years. Thirty-three weed species have evolved resistance to ALS-inhibitor herbicides in 11 countries. ALS-inhibitor-resistant weeds are most problematic in cereal, corn/soybean and rice production. Thirteen weed species have evolved resistance to ACCase inhibitors, also in 11 countries. ACCase inhibitor resistance in Lolium and Avena spp. threatens cereal production in Australia, Canada, Chile, France, South Africa, Spain, the United Kingdom and the USA. Fourteen weed species have evolved resistance to urea herbicides. Isoproturon-resistant Phalaris minor infesting wheat fields in North West India and chlorotoluron-resistant Alopecurus myosuroides in Europe are of significant economic importance. Although 27 weed species have evolved resistance to bipyridilium herbicides, and 14 weed species have evolved resistance to synthetic auxins, the area infested and the availability of alternative herbicides have kept their impact minimal. The lack of alternative herbicides to control weeds with multiple herbicide resistance, such as Lolium rigidum and Alopecurus myosuroides, makes these the most challenging resistance problems. The recent discovery of glyphosate-resistant Lolium rigidum in Australia is a timely reminder that sound herbicide-resistant management strategies will remain important after the widespread adoption of glyphosate-resistant crops. ©1997 SCI  相似文献   

4.
杂草对AHAS抑制剂的抗药性分子机理研究进展   总被引:3,自引:1,他引:2  
除草剂在田间的重复及不合理使用,导致了杂草抗药性的发生和发展。其中AHAS抑制剂由于靶标单一,抗性发展十分迅速。截至2009年,已有103种杂草对AHAS抑制剂产生了抗药性,占19类化学除草剂总抗药性杂草生物型的近1/3。从AHAS基因突变位点及种类与杂草抗药性水平的关系、AHAS基因突变与AHAS酶活性的关系、AHAS基因拷贝数与杂草抗药性的关系以及AHAS酶与除草剂结合前后的三维结构等方面,综述了杂草对AHAS抑制剂产生抗药性的机理,旨在为AHAS抑制剂抗性研究提供参考。并对自然种群目标基因的等位基因检测技术(ECOTILLING)和衍生型酶切扩增多态性序列(dCAPS)两种通过检测等位基因多态性的手段快速诊断抗药性杂草的新技术进行了介绍,讨论了延缓杂草抗药性发生和发展的策略。  相似文献   

5.
An acetolactate synthase (ALS)‐resistant Amaranthus retroflexus biotype was collected in a soyabean crop after repeated exposure to imazethapyr and thifensulfuron‐methyl in north‐eastern Italy. Studies were conducted to characterise the resistance status and determine alternative post‐emergence herbicides for controlling this biotype. Whole‐plant bioassay revealed that the GR50 values were 1898‐ and 293‐fold higher than those observed for the biotype susceptible to imazethapyr and imazamox respectively. The biotype also displayed high cross‐resistance to sulfonylureas. Molecular analysis demonstrated that a single nucleotide substitution had occurred in domain B (TGG to TTG at position 574), conferring a change from the amino acid tryptophan to leucine in the resistant biotype. However, herbicides with other modes of action (PSII, 4‐HPPD and PPO inhibitors) provided excellent control. The GR50 ratios for metribuzin, terbuthylazine and mesotrione were close to 1 and treatments with fomesafen gave 100% control of both susceptible and resistant biotypes at the recommended field dose. This study documents the first case of an imidazolinone and ALS‐resistant biotype in European crops and identifies the post‐emergence herbicide options available for managing this troublesome weed in soyabean crops. Alternative management strategies are also discussed.  相似文献   

6.
Resistance to acetyl-coenzyme A carboxylase (ACCase) inhibitors has developed in at least 10 grass weed species in recent years. In most instances, resistance is conferred by an ACCase alteration in the resistant biotypes that reduces sensitivity to aryloxyphenoxypropionate (AOPP) and cyclohexanedione (CHD) herbicides. Analysis of ACCase from many of these resistant weed biotypes suggests the presence of different mutations, each conferring a different pattern and level of resistance to various AOPP and CHD herbicides. In all cases analyzed to date, resistance is controlled by a single dominant or semi-dominant nuclear gene. In several weed biotypes, resistance is conferred by enhanced herbicide detoxification, primarily through elevated expression or activity of cytochrome P450 monooxygenase(s). This mechanism can confer cross-resistance to herbicides from other chemical classes with different modes of action. Finally, multiple herbicide resistance, i.e. the acquisition of several different resistance mechanisms, has been reported in some weed biotypes. ©1997 SCI  相似文献   

7.
通过对玉米田茎叶处理除草剂烟嘧磺隆、硝磺草酮、唑嘧磺草胺、唑草酮和噻吩磺隆等与不同用量HA桶混使用效果的测定,初步明确了上述除草剂推荐剂量下对玉米田主要杂草的生物活性以及HA对其活性的影响,除烟嘧磺隆外,硝磺草酮、唑嘧磺草胺、唑草酮及噻吩磺隆等除草剂推荐剂量苗后单独使用对已萌发的稗草、牛筋草控制效果不理想,药后30 d生物量积累的控制效果低于70%。0.2%HA显著提高了硝磺草酮的除草活性,药后30 d对杂草生物量积累的控制效果较硝磺草酮单独使用提高10%~50%,有助于降低硝磺草酮的使用量。  相似文献   

8.
We compared photosynthesis and growth of Zea mays L (corn) and four weed species, Setaria viridis (L) Beauv (green foxtail), Echinochloa crus-galli (L) Beauv (barnyardgrass), Abutilon theophrasti Medic (velvetleaf), and Amaranthus retroflexus L (redroot pigweed), following foliar applications with atrazine, mesotrione, or a combination of atrazine and mesotrione in two greenhouse experiments. Plant responses to the three herbicide treatments were compared with responses of untreated plants (control). Photosynthesis on day 14 and dry mass of Z mays was not reduced by any of the herbicide treatments. Photosynthesis and dry mass of E crus-galli, A retroflexus and A theophrasti were significantly reduced by mesotrione and atrazine alone and in combination. Photosynthesis on day 14 and dry mass of large Sviridis plants were not suppressed by either herbicide applied alone. The mesotrione plus atrazine treatment was the most effective treatment for grass weed control because plants did not regain photosynthetic capacity and had significantly lower dry mass. Shoot dry mass of broadleaf weeds was significantly reduced by all three herbicide treatments, except for A retroflexus treated with mesotrione alone.  相似文献   

9.
Taking stock of herbicide-resistant crops ten years after introduction   总被引:11,自引:0,他引:11  
Since transgenic, bromoxynil-resistant cotton and glufosinate-resistant canola were introduced in 1995, planting of transgenic herbicide-resistant crops has grown substantially, revolutionizing weed management where they have been available. Before 1995, several commercial herbicide-resistant crops were produced by biotechnology through selection for resistance in tissue culture. However, non-transgenic herbicide-resistant crops have had less commercial impact. Since the introduction of glyphosate-resistant soybean in 1996, and the subsequent introduction of other glyphosate-resistant crops, where available, they have taken a commanding share of the herbicide-resistant crop market, especially in soybean, cotton and canola. The high level of adoption of glyphosate-resistant crops by North American farmers has helped to significantly reduce the value of the remaining herbicide market. This has resulted in reduced investment in herbicide discovery, which may be problematic for addressing future weed-management problems. Introduction of herbicide-resistant crops that can be used with selective herbicides has apparently been hindered by the great success of glyphosate-resistant crops. Evolution of glyphosate-resistant weeds and movement of naturally resistant weed species into glyphosate-resistant crop fields will require increases in the use of other herbicides, but the speed with which these processes compromise the use of glyphosate alone is uncertain. The future of herbicide-resistant crops will be influenced by many factors, including alternative technologies, public opinion and weed resistance. Considering the relatively few recent approvals for field testing new herbicide-resistant crops and recent decisions not to grow glyphosate-resistant sugarbeet and wheat, the introduction and adoption of herbicide-resistant crops during the next 10 years is not likely to be as dramatic as in the past 10 years.  相似文献   

10.
Piperonyl butoxide (PB) is a known Synergist which enhances the activity of insecticides by inhibiting their biotransformation to less active products. We have evaluated the possible use of PB as a herbicide synergist using triazine herbicides in sensitive, tolerant, and resistant plants. The effects of PB, triazine herbicides, and their combinations were examined in whole plants as well as in chloroplasts isolated from triazine-sensitive (S) and -resistant (R) weed biotypes. PB itself, applied postemergence (0.1–0.5%, v/v), was slightly toxic to the plants tested. However, foliar application of PB combined with atrazine, terbutryn or prometryn to maize seedlings significantly increased the phytotoxicity of the herbicides. Low rates of atrazine, prometryn, and terbutryn in a tank-mixture with PB, effectively controlled Solatium nigrum L. and Abutilon theophrasli Medik. PB enhanced atrazine efficacy in both S and R biotypes of Lolium rigidum Gaud. The synergistic effect of PB was evident also in vitro when atrazine and methabenzthiazuron were used to inhibit photosystem II electron transport in chloroplasts isolated from resistant weeds. These data demonstrate the potential of PB as a herbicide synergist and its possible utilization as an aid for improving the activity of triazine herbicides in sensitive, tolerant and resistant plants.  相似文献   

11.
Evolved glyphosate-resistant weeds around the world: lessons to be learnt   总被引:2,自引:0,他引:2  
Glyphosate is the world's most important herbicide, with many uses that deliver effective and sustained control of a wide spectrum of unwanted (weedy) plant species. Until recently there were relatively few reports of weedy plant species evolving resistance to glyphosate. Since 1996, the advent and subsequent high adoption of transgenic glyphosate-resistant crops in the Americas has meant unprecedented and often exclusive use of glyphosate for weed control over very large areas. Consequently, in regions of the USA where transgenic glyphosate-resistant crops dominate, there are now evolved glyphosate-resistant populations of the economically damaging weed species Ambrosia artemissifolia L., Ambrosia trifida L., Amaranthus palmeri S Watson, Amaranthus rudis JD Sauer, Amaranthus tuberculatus (Moq) JD Sauer and various Conyza and Lolium spp. Likewise, in areas of transgenic glyphosate-resistant crops in Argentina and Brazil, there are now evolved glyphosate-resistant populations of Sorghum halepense (L.) Pers and Euphorbia heterophylla L. respectively. As transgenic glyphosate-resistant crops will remain very popular with producers, it is anticipated that glyphosate-resistant biotypes of other prominent weed species will evolve over the next few years. Therefore, evolved glyphosate-resistant weeds are a major risk for the continued success of glyphosate and transgenic glyphosate-resistant crops. However, glyphosate-resistant weeds are not yet a problem in many parts of the world, and lessons can be learnt and actions taken to achieve glyphosate sustainability. A major lesson is that maintenance of diversity in weed management systems is crucial for glyphosate to be sustainable. Glyphosate is essential for present and future world food production, and action to secure its sustainability for future generations is a global imperative.  相似文献   

12.
Herbicide resistance is a widespread issue that impacts management of conventional farms, but also has ramifications for the weed community assembly; it is therefore important to see how these species factor into the weed community assembly of farms throughout the countryside. This research analysed species richness and community diversity in 98 field relevés from 48 organic and 50 conventional farms evenly distributed between two major production regions of the Czech Republic and then evaluated the incidence of species which have been reported resistant in the Czech Republic and its neighbouring countries. Farms were selected independently of any acknowledged resistant species. Out of 164 species found in this survey, only eight species have had herbicide-resistant biotypes reported in the Czech Republic, while a total of 19 species had herbicide-resistant biotypes reported in neighbouring countries. Species with recorded resistance to PSII inhibitors in the Czech Republic tended to be found together and were mostly associated with the beet production region, characterised by low altitude: Amaranthus retroflexus, Chenopodium album, Echinochloa crus-galli and Solanum nigrum. Species with reported resistance to ALS and ACCase-inhibiting herbicides were not clearly associated with a particular region or farming type. Of the species which have had reported herbicide resistance in the neighbouring countries, several were found in conventional fields within the growing season and we recommend immediate screening for herbicide resistance in these species and more diligent action in management according to anti-resistance strategies: Bromus sterilis resistant to ACCase-inhibiting herbicides, A. retroflexus resistant to ALS-inhibiting herbicides or Avena fatua resistant to ACCase and ALS-inhibiting herbicides. This work is unique in that it is evaluating weed species diversity in organic and conventional farms and using the context to frame the prevalence of high-risk herbicide-resistant species; thereby putting the potential incidence of herbicide resistance into perspective at the landscape level.  相似文献   

13.
ALIZADEH  PRESTON  POWLES 《Weed Research》1998,38(2):139-142
There has been a significant increase in the area seeded to minimum- and zero-tilled crops worldwide over the past two decades. These cropping systems rely primarily on the non-selective herbicides glyphosate or paraquat/diquat to control weeds before seeding the crop. Both glyphosate and paraquat/diquat are regarded as low-risk herbicides in the ability of target weeds to develop resistance to them. Following 10–15 years of once annual applications of paraquat and diquat for weed control in zero-tilled cereals, failure of these herbicides to control Hordeum glaucum Steud. in two separate fields occurred. Dose–response experiments demonstrated high-level resistance to paraquat and diquat in both populations; however, the resistant biotypes are susceptible to other herbicides. This is the first report, worldwide, of paraquat resistance following the use of this herbicide in zero-tillage cropping systems and is therefore a harbinger of future problems in minimum-tillage systems when there is exclusive reliance on a contact herbicide for weed control.  相似文献   

14.
在荷兰瓦赫宁根国际植物研究所温室内,用植物光合作用测定法研究了光合作用抑制型除草剂灭草松和特丁津桶混防除6种常见阔叶杂草的最低致死剂量。结果表明,药剂对杂草的生长有明显的抑制作用,在施药2 d后可观察到明显的灭草松的防效,在施药8 d后可观察到明显的特丁津的防效。随着施药剂量的增加,杂草叶片的植物光合作用测定(PPM)值和杂草地上部分鲜重显著下降。供试的6种杂草对该混剂的敏感性存在显著差异:红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感,ED90值分别为47.65、71.67和29.17 g/hm2;春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感,ED90值分别为96.91、114.20 g/hm2;而番茄不敏感。比较施药后2、4和6 d时杂草叶片的PPM值与施药后16 d时杂草地上部分鲜重防效的相关性可以发现,施药后4 d杂草叶片的PPM值与鲜重防效的相关性最好,相应的R2为0.924 7。表明PPM值可以较好地预测防效,在本试验条件下,施药后4 d的PPM值的预测效果最好。  相似文献   

15.
In an effort to determine the physical basis of the maternal inheritance of triazine resistance in Amaranthus hybridus L. the fate of plastids and other organelles in developing pollen was investigated in triazine-resistant and susceptible biotypes. In both types, immediately after microspore mitosis, the newly formed generative cells contained an array of organelles (golgi bodies, endoplasmic reticulum, plastids and mitochondria) similar to that in the larger vegetative cells. No selective exclusion of organelles from the generative cell was noted although only small plastids were present. The immature generative cells contained small vacuoles, within which degenerate organelles were frequently observed, and no ultrastucturally recognizable plastids were found in mature cells. Maternal transmission of the triazine resistance factor thus appears to be due to a selective destruction of paternal plastids.  相似文献   

16.
Herbicide-resistant weed biotypes are an increasing problem in agriculture, with reports of resistance to almost every herbicide class at some place in the world, and the total number of resistant biotypes at over 250. Agricultural Research Service (ARS) scientists have been key players in this area since the first substantiated occurrence of these resistant biotypes in the 1970s. The most significant of their contributions is the complete unraveling of the mechanism of triazine resistance by Arntzen and colleagues, then with ARS at the University of Illinois. These studies established a high benchmark for research in this area and are a model for all studies in this area. Other ARS scientists have investigated a large number of weed biotypes with resistance to a wide range of herbicide classes and mechanisms of resistance. Collectively, these studies have been used to generate herbicide resistance-management schemes for growers, based upon the herbicide site and the potential for resistance development.  相似文献   

17.
杂草对ACCase抑制剂的抗性   总被引:3,自引:0,他引:3  
以乙酰辅酶A羧化酶(ACCase)为作用靶标的除草剂是高效、选择性的禾本科杂草除草剂,其在全球范围内的广泛、重复使用,导致了抗药性杂草的发生和发展。到目前为止,已经在30个国家有37种抗此类除草剂的杂草生物型。抗药性杂草严重威胁杂草治理和农业生产,由此引发的生态问题及粮食安全问题引起了广泛的关注。文章概述了ACCase抑制剂抗药性杂草的发生现状,从杂草ACCase突变、代谢解毒等几个方面综述了杂草抗ACCase抑制剂的抗性机制,以期为ACCase抑制剂抗性研究提供参考。最后讨论了阻止或延缓抗药性发生的杂草管理措施。  相似文献   

18.
BACKGROUND: Mesotrione is a carotenoid biosynthesis‐inhibiting herbicide currently labeled for crabgrass (Digitaria spp.) control. Mesotrione control of large crabgrass has been reported to vary with temperature and relative humidity; however, the effect of irradiance on mesotrione efficacy has not previously been reported. Likewise, little is known about pigment concentrations of Digitaria spp. The present research investigated the effects of mesotrione on large crabgrass, Digitaria sanguinalis (L.) Scop., control and pigment concentrations under varying irradiance at three temperatures. RESULTS: Mesotrione (0.28 kg ha?1) control of large crabgrass did not differ between temperature levels (18, 26 and 32 °C). Control was similar at tested irradiance levels (600, 1100 and 1600 µmol m?2 s?1). Mesotrione reduced large crabgrass chlorophyll a, chlorophyll b and total carotenoid concentrations, as well as chlorophyll a to b ratios. Treated plant bleaching was highest 7 days after treatment (DAT) but decreased by 21 DAT. Treated plants were less than 10% necrotic 3 and 7 DAT but nearly 35% necrotic 21 DAT. Treated large crabgrass bleaching was highest and photochemical efficiency was lowest 7 DAT. These results indicate that some plant recovery occurs prior to 21 DAT. CONCLUSION: Although mesotrione efficacy has previously been reported to vary according to environmental factors, mesotrione control of large crabgrass did not vary with measured temperature and irradiance levels in this study. On account of crabgrass convalescence, secondary applications of mesotrione may control large crabgrass more effectively when applied prior to 21 DAT. Copyright © 2009 Society of Chemical Industry  相似文献   

19.
Ambrosia artemisüfolia L. (common ragweed) and Digitaria ischaemum Schreb. (smooth crabgrass) are not controlled by nicosulfuron and rimsulfuron at the highest recommended application rates, whereas Panicum miliaceum L. (wild proso millet), Amaranthus retroflexus L. (redroot pigweed) and Avena fatua L. (wild oat) are susceptible. The foliar absorption and translocation of 14C-nicosulfuron and 14C-rimsulf uron were studied in these weed species up to 48 h after treatment (HAT). Differences in herbicide uptake and translocation were not correlated with the species susceptibility. By 48 HAT, more than 50% of both herbicides remained on the treated leaf surface. Foliar absorption of rimsulfuron was greater than that of nicosulfuron in A. retroflexus, P. miliaceum and A. artemisüfolia. Most of the absorbed herbicide remained in the treated leaf of each weed species. Export of 14C–nicosulfuron ranged from 28 to 54% of that absorbed, in contrast to 15 to 39% for 14C–rimsulfuron. The absorption and translocation rates of both herbicides were highest within the initial 6 HAT, and decreased thereafter. Both herbicides showed approximately the same distribution pattern within each weed species.  相似文献   

20.
Summary Two Sonchus asper (spiny annual sow-thistle) biotypes, suspected of being resistant to the sulfonylurea herbicide metsulfuron-methyl, were collected in 1996 from two barley ( Hordeum vulgare ) fields in central Alberta, Canada. Both fields had received at least six applications of acetolactate synthase (ALS)-inhibiting herbicide(s). The responses of the two resistant (R) biotypes and two susceptible (S) biotypes to several sulfonylurea herbicides, and to herbicides and herbicide mixtures with other mechanisms of action, were compared. Both R biotypes were highly resistant to all sulfonylurea herbicides, but their control with other herbicides and mixtures was effective and comparable to that of the S biotypes. ALS extracted from an R biotype was about 440 times more resistant to metsulfuron-methyl than that of an S biotype, indicating that resistance was conferred by an ALS enzyme that was less sensitive to inhibition by the herbicide. Competitiveness and seed production of S. asper varied among biotypes, but the differences were probably the result of ecotype differences rather than resistance or susceptibility to sulfonylurea herbicides. This is the first reported occurrence of target site-based S. asper resistance to ALS-inhibiting herbicides.  相似文献   

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