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1.
Sclerotinia sclerotiorum causes serious yield losses in oilseed rape and other crops worldwide. Field trials were conducted at two locations to evaluate two formulations of oilseed rape seed containing the plant-growth promoting bacterium Bacillus megaterium A6 for suppression of this pathogen. Treatments containing strain A6 in pellet and in wrap formulations resulted in oilseed rape seed yields that were similar to the chemical control and significantly greater than the untreated seed control at both locations. Treatments containing A6 in pellet and wrap formulations also resulted in an incidence of disease caused by S. sclerotiorum that was similar to the chemical control. Both of these treatments significantly decreased disease incidence relative to the untreated seed control and to the respective formulated seed controls (that did not contain strain A6) at both locations. Strain A6 applied to oilseed rape seed in these two formulations promoted growth in greenhouse pot studies conducted with autoclaved soil. In two experiments, these treatments resulted in significant increases in mean shoot dry weight per pot and mean % total N per plant relative to their respective controls containing formulated oilseed rape seed without strain A6 and to the untreated seed control. Both formulations provided stable B. megaterium A6 (≥106 CFU) and seed germination (>85%) over a six month period at room temperature. Experiments reported here indicate the commercial potential of these formulations of B. megaterium A6 for suppression of S. sclerotiorum on oilseed rape.  相似文献   

2.
The ascomycete fungus Sclerotinia sclerotiorum is a devastating necrotrophic plant pathogen with an unusually broad host range and worldwide distribution. The benzimidazole fungicide carbendazim has been widely used to control S. sclerotiorum in China for more than three decades and high levels of carbendazim resistance have been reported in eastern China. In this study, carbendazim sensitivity was assessed in a total of 5042 field isolates of S. sclerotiorum collected from different geographical regions of China from 2008 to 2013. Results showed that no carbendazim resistant isolates could be detected in northwestern and northeastern China. In 2013, 0.77% and 0.72% of the field isolates assayed were highly resistant to carbendazim in Hunan and Hubei provinces of central China, respectively. In Anhui province of eastern China, the frequencies of carbendazim resistance were 18.18%, 7.05% and 7.25% in 2008, 2011 and 2012, respectively. The decrease in frequency of carbendazim resistance in Anhui province from 2008 to 2012 was statistically significant (P = 0.001). Nevertheless, no significant differences (P ≥ 0.16) were found in fitness parameters such as mycelial growth on PDA media, virulence to oilseed rape plants and oxalic acid production between carbendazim resistant and sensitive isolates. A negative cross resistance pattern was detected between carbendazim and diethofencarb. Mixture of carbendazim and diethofencarb (4:1) applied at 200 μg/mL provided 100% and 91.5% preventive efficacy against carbendazim resistant and sensitive isolates, respectively, and 87.1% and 81.7% curative efficacy against resistant and sensitive isolates, respectively.  相似文献   

3.
湖北省油菜主产区杂草群落的数量分析   总被引:2,自引:0,他引:2  
采用七级目测法定量调查了湖北省油菜主产区28个样点的杂草发生情况,应用主成分分析法对杂草群落进行了数量分析。结果表明,28个样点可以分为4个聚类群,即江汉平原鄂北旱茬油菜田、鄂东南旱茬油菜田、江汉平原稻茬油菜田和鄂东南稻茬油菜田。轮作制度与地理因素决定了湖北省油菜主产区杂草群落的分布。根据综合草害指数和发生频率明确了各聚类群相应的优势杂草,并就该地区油菜田杂草发生的特点提出了治理策略。  相似文献   

4.
室内毒力测定结果表明,植物源化合物奥麦丁锌(ZPT)对油菜菌核病菌菌丝生长具有显著的抑制作用, EC50值为1.5 µg/mL。ZPT在离体油菜叶片上对油菜菌核病具有明显的防病效果。25%奥麦丁锌可湿性粉剂 200、500µg/mL对油菜叶片菌核病病斑扩展抑制率分别达到83.2%和100%。田间药效试验结果表明, 25%奥麦丁锌可湿性粉剂100克/666.7m2兑水喷雾,对油菜菌核病病具有80%左右的防治效果。  相似文献   

5.
WRKY转录因子是植物信号传导过程中的重要成员,在植物抗病过程中发挥着重要作用。为了解BnWRKY70在油菜黑胫病抗性反应中的作用机理,本研究对油菜响应黑胫病菌侵染产生的特异基因BnWRKY70进行序列分析;将克隆得到BnWRKY70基因CDS 308bp特异区段,利用烟草脆裂病毒(Tobacco rattle virus, TRV)载体构建了基于病毒诱导的油菜基因沉默体系;利用qRT-PCR验证目的基因的表达水平;最后进一步通过表型观察和病情指数统计分析评价BnWRKY70基因沉默植株在接种黑胫病菌之后油菜的抗病性。结果表明,BnWRKY70基因最长ORF为858bp,编码285个氨基酸,含有一个WRKY保守结构域,属于Ⅲ类WRKY转录因子。BnWRKY70基因沉默后的表达量显著下降,说明在油菜中成功构建了VIGS体系。表型观察发现基因沉默油菜株系叶片比未沉默株系更易感病,病斑面积更大,且病情指数显著高于对照,说明BnWRKY70基因沉默减弱了油菜的抗病性。本研究为揭示BnWRKY70在油菜病原菌分子互作机制中的作用奠定基础。  相似文献   

6.
Suspected cases of poisoning of honeybees by agricultural pesticides are investigated by the Ministry of Agriculture, Fisheries and Food (in England and Wales) and the Scottish Office Agriculture and Fisheries Department (in Scotland). Studies include field visits to sites where bee mortality is recorded, examination of dead bees for disease, and analysis for the presence of pesticide residues. This paper reviews the results of these investigations for the period 1981–1991. Pesticide poisoning is diagnosed from the detection of residues in dead bees, through interpretation in relation to the median lethal dose (LD50), and ‘subsequent residue level’ (SRL) determined from laboratory studies in which bees were exposed to one LD50 dose. Overall, an annual average of 50 incidents were confirmed as due to pesticide poisoning, involving 30 pesticide active ingredients during the 1981–1991 period. In England and Wales, the principal hazards were caused by misuse of the insecticide triazophos on oilseed rape, a problem that has been reduced to low levels during the 1980s, and by dimethoate use on a variety of arable crops. In Scotland there were fewer incidents, most of which were associated with use of fenitrothion on raspberries, and gamma-HCH on oilseed rape. Opportunities for reducing the risks of poisoning, and for refining the investigation of suspected incidents, are discussed.  相似文献   

7.
Little information is available regarding the efficacy and timing of modern fungicides for the control of plum rust. In this study, modern fungicides, including triazoles, strobilurins, and benzimidazoles, and a classic fungicide (chlorothalonil) were tested under both greenhouse and field experiments. Excellent disease control was obtained by the pre-inoculation application of all fungicides in the greenhouse experiments. However, only triazoles (tebuconazole, difenoconazole, flusilazole and hexaconazole) were effective when applied up to 6 or 7 days after inoculation. Unexpectedly, strobilurins (azoxystrobin and trifloxystrobin) and benzimidazoles (thiophanate-methyl and carbendazim) were not effective when applied at any time after inoculation. In field experiments, early-season fungicide applications effectively inhibited primary infections; however, these applications provided no apparent benefit in preventing secondary infections and premature leaf fall later in the season. All fungicides provided better control over the season and significantly reduced premature leaf fall when applied immediately after rust pustules (uredinia) were first observed. It is suggested that all fungicides tested in this study can be used for plum rust control. Disease monitoring data indicated that disease severity remained low throughout May but dramatically increased in early June. Mid-May is evidently the best time to initiate fungicide sprays against rust on plums; the spray should be applied before or when rust pustules are first observed and when rust is present at low severity.  相似文献   

8.
Under semiarid Mediterranean conditions irrigated maize has been associated to diffuse nitrate pollution of surface and groundwater. Cover crops grown during winter combined with reduced N fertilization to maize could reduce N leaching risks while maintaining maize productivity. A field experiment was conducted testing two different cover crop planting methods (direct seeding versus seeding after conventional tillage operations) and four different cover crops species (barley, oilseed rape, winter rape, and common vetch), and a control (bare soil). The experiment started in November 2006 after a maize crop fertilized with 300 kg N ha−1 and included two complete cover crop-maize rotations. Maize was fertilized with 300 kg N ha−1 at the control treatment, and this amount was reduced to 250 kg N ha−1 in maize after a cover crop. Direct seeding of the cover crops allowed earlier planting dates than seeding after conventional tillage, producing greater cover crop biomass and N uptake of all species in the first year. In the following year, direct seeding did not increase cover crop biomass due to a poorer plant establishment. Barley produced more biomass than the other species but its N concentration was much lower than in the other cover crops, resulting in higher C:N ratio (>26). Cover crops reduced the N leaching risks as soil N content in spring and at maize harvest was reduced compared to the control treatment. Maize yield was reduced by 4 Mg ha−1 after barley in 2007 and by 1 Mg ha−1 after barley and oilseed rape in 2008. The maize yield reduction was due to an N deficiency caused by insufficient N mineralization from the cover crops due to a high C:N ratio (barley) or low biomass N content (oilseed rape) and/or lack of synchronization with maize N uptake. Indirect chlorophyll measurements in maize leaves were useful to detect N deficiency in maize after cover crops. The use of vetch, winter rape and oilseed rape cover crops combined with a reduced N fertilization to maize was efficient for reducing N leaching risks while maintaining maize productivity. However, the reduction of maize yield after barley makes difficult its use as cover crop.  相似文献   

9.
15%氟啶胺包衣悬浮剂防治油菜根肿病研究   总被引:3,自引:0,他引:3  
为防治油菜重要病害根肿病,研制15%氟啶胺包衣悬浮剂,以甘蓝型油菜品种中双9号为材料的试验结果表明:按包衣比[包衣剂质量(g)∶种子质量(g)]≥1∶50包衣油菜种子,15%氟啶胺包衣剂对种子发芽率、成苗率及油菜苗高、根长和鲜重没有显著影响。用包衣比1∶200、1∶100、1∶50和1∶25包衣的种子,盆栽试验中根肿病的防治效果为43.7%、46.4%、83.5%和92.5%;田间小区试验防治效果分别为22.2%、53.6%、44.5%和54.5%。初步结果说明,可用15%氟啶胺的包衣悬浮剂按包衣比1∶100~1∶50处理种子防治油菜根肿病。  相似文献   

10.
The pollen beetle is one of the most important oilseed rape pests wherever the crop is grown. If no control measures are applied, it can cause a greater than 50% reduction in yield. The over-use of insecticides (especially pyrethroids) to control the pollen beetle has led to the development of resistance. Thus, alternative control strategies are required. A field trial with three experimental fields with different contributions of turnip rape as a trap crop was established during the growth season of 2013–2014. A grid of GPS points was established on each field. Pollen beetle abundance was recorded at each GPS point by beating into trays, and damage was assessed by dissection of buds from terminal racemes. Data analysis was performed by two-way analysis of variance and the appearance of pollen beetle adults was processed in a geographic information system (GIS). Statistically significant differences were found in terms of the density of the pollen beetle population between trap crop plants and oilseed rape plants. Control thresholds on each oilseed rape field were not exceeded, whereas the density of the pollen beetle population on trap crop plants was greater by up to 40 fold, regardless of the contribution of trap crop plants. The data indicate that support systems should use sampling strategies that incorporate spatial information to model crop loss more accurately and that there may be the potential for spatially targeted applications of insecticides to optimize the influence of natural enemies in oilseed rape.  相似文献   

11.
在人工接种高病害压条件下,对当前生产上应用的13个油菜双低和杂交品种及14份资源材料进行了 对芜菁花叶病毒( TuMV)的抗性鉴定。结果表明,参试的13个油菜品种均不抗TuMV,但感病性低于对照品种中油 821。14份油菜资源材料间抗性差异显著,有3份材料表现高抗和中抗。大部分油菜推广品种表现的高发病率和 病情指数表明在病害流行地区和年份,这些品种不足以抵挡病毒病造成的损失。  相似文献   

12.
在轻简化施肥背景下,为减少渍害损失,解决长江流域冬油菜产区生产面临的重要问题,开展氮肥施用 对油菜渍害的缓解作用研究。设置三因素田间试验,分别为不同氮肥用量(0、60、120、180、240和300 kg N/hm2)、氮 肥类型(油菜专用控释尿素和普通尿素)和水分处理(苗期渍水和正常排水),测定各处理产量和氮肥农学利用率, 明确苗期渍水对不同氮素供应水平油菜的影响,并比较油菜专用控释尿素一次性施用和普通尿素分次施用下油菜 对苗期渍水的响应。结果表明,直播冬油菜产量随氮肥施用量增加而提高,至240 kg N/hm2时不再增加。油菜专用 控释尿素一次性施用,在氮肥用量为60~180 kg N/hm2时产量高于普通尿素分次施用;在氮肥用量为240~300 kg N/hm2时,两种氮肥类型产量基本相当。氮肥施用通过增加收获密度、单株角果数和每角粒数提高产量。苗期渍水 导致直播冬油菜产量损失1.1%~41.9%,随氮肥用量增加,渍水引起的产量损失率呈先增加后降低趋势。0~60 kg N/hm2处理时,渍水使收获密度显著降低(降幅达29.4%~45.0%),单株角果数增加;施氮量为120~180 kg N/hm2时, 渍水导致收获密度和单株角果数分别降低19.5%~33.7%和1.4%~17.7%;施氮高于180 kg N/hm2时,收获密度和单 株角果数降幅减小(降幅分别为5%~30.9%和3.6%~9.5%)。普通尿素分次施用和油菜专用控释尿素一次性施用, 分别在施氮量为120和180 kg N/hm2时产量损失率最高,分别达29.8%和41.9%。相同氮肥用量下油菜专用控释尿 素一次性施用的产量损失率大于普通尿素分次施用。渍水显著降低氮肥农学利用率,降幅为8.4%~51.9%,施氮充 足(240~300 kg N/hm2)时氮肥农学利用率降幅低于氮素用量较低处理(120~180 kg N/hm2),油菜专用控释尿素一 次施用处理的农学利用率平均降幅(36.5%)高于普通尿素分次施用(17.3%)。综上可知,苗期渍水时,油菜专用控 释尿素一次施用,会加重油菜受渍影响;土壤氮素供应能力较低时,渍害逆境解除后,适量追施速效氮肥可有效缓 解产量损失,实现油菜稳产。  相似文献   

13.
湖北省油菜田灾害性杂草高效防控技术研究进展   总被引:5,自引:0,他引:5  
综述了湖北省油菜田杂草及种子库种类组成和特征、油菜田主要灾害性杂草的发生危害规律以及高效化学防除和生态防除技术。探讨了建立生态调控与化学除草相结合的农田杂草可持续治理技术体系的研究前景。  相似文献   

14.
Sclerotinia sclerotiorum is one of the most important pathogens of winter oilseed rape plants. It causes the white mould disease of rape, thus significantly reducing the yield. The aim of our research was to use a spring oilseed rape variety sown in autumn or an early-flowering variety of winter oilseed rape to predict the infection pressure of S. sclerotiorum in a given year. Field experiments were conducted in 2008–2012 at the experimental station of the Czech University of Life Sciences Prague at Červený Újezd, 20 km west of Prague. In the experiment, we used one variety of spring oilseed rape (Lužnice, LU) and one early-flowering variety of winter oilseed rape (Californium, CA). The methodology of the petal test involved isolating pathogenic fungi from fallen petals on a nutrient medium (potato dextrose agar) in Petri dishes. The first term of collection was the beginning of petal fall (BBCH 61) and the last term was the end of flowering (BBCH 69). The dishes with petals were visually analysed after 1 week. The results were compared with the actual occurrence of white mould of rape in the stand. The occurrence of white mould of rape was strongly influenced by the progress of weather conditions over the given year. Infected petals and stems with symptoms of white mould of rape were found to be moderately correlated (r = 0.80). Spread of white mould spores was mostly observed in two terms (BBCH 62 and BBCH 65). Statistically significant differences were not observed in the infection of petals of spring (LU) and winter (CA) oilseed rape. Spring oilseed rape (LU) and early-flowering varieties of winter oilseed rape (CA) can be used to determine the strength of infection pressure of S. sclerotiorum in the stand in a given year, thereby improving protection against white mould of rape.  相似文献   

15.
The efficacy of emulsifiable concentrate and dust formulations of pirimiphos-methyl and etrimfos were assessed, when admixed with oilseed rape, 1 day after treatment, against susceptible beetle, moth and mite species. The minimum intended doses required to provide complete mortality differed with each pest species. If Maximum Residue Limits are introduced that are equivalent to less than one quarter of the current pesticide application rates, their effective use may be prevented, as control of Acarus siro and Tyrophagus putrescentiae may not be achieved.  相似文献   

16.
戊唑醇等四种杀菌剂防治花生冠腐病应用研究   总被引:2,自引:0,他引:2  
采用菌丝生长速率法和孢子萌发法分别测定了4种杀菌剂对花生冠腐病(Peanut crown rot)致病菌黑曲霉(Aspergillus niger v.Tiegh.)的毒力。结果表明:4种药剂中咪鲜胺、戊唑醇对菌丝生长表现明显的抑制作用,其EC50分别为0.01、0.03mg/L,其次为醚菌酯、多.福(1∶1),EC50依次为0.13、0.24mg/L;另外,咪鲜胺、戊唑醇、醚菌酯、多.福对花生冠腐病孢子萌发均有明显的抑制作用,其EC50依次为0.01、0.02、0.09和0.11mg/L。温室盆栽试验中,播种期、团棵期接菌后对照发病率分别为97.50%、92.50%,且四种药剂处理后的病情指数明显低于对照,防效接近或在90%以上。田间防治试验结果表明,戊唑醇在播种期、团棵期处理防效均最高,分别为80.63%和77.48%,同时,从对花生产量影响来看,团棵期比播种期施药后增产率高,其中团棵期施用戊唑醇增产率最高为7.01%。因此,建议选用戊唑醇于花生团棵期灌墩施用防治冠腐病,以减轻其危害,提高花生产量。  相似文献   

17.
施肥对贵州直播油菜产量和养分吸收的影响   总被引:3,自引:0,他引:3  
2011-2012年于贵州省油菜主产区设置直播油菜氮磷钾硼肥田间试验,以推广品种油研599为材料,研究施肥对产量、养分累积量、肥料利用率及经济效益的影响,以期明确当地(典型的南方水稻土)的养分限制因子,为该地区直播油菜的合理施肥提供依据。结果表明,与不施肥相比,施肥提高了直播油菜的产量,各处理中以NPKB处理的产量最高,平均为2 189kg/hm2。缺氮、缺磷、缺钾和缺硼处理相比NPKB处理分别减产961、342、295和184kg/hm2,表明该地区直播油菜的养分限制因子依次为N > P > K > B。与当地农民习惯施肥(FFP)相比,NPKB处理增加了施肥量,产量明显提升,平均增产430kg/hm2;养分累积量和肥料利用率也均有明显提高,氮、磷、钾分别增加28.6kg/hm2和13.5%、9.6kg/hm2和3.3%、71.4kg/hm2和23.9%。从经济效益看,NPKB处理相比FFP处理收益平均增加1 109元/hm2。肥料合理配施可以明显提高直播油菜产量、养分累积和经济效益,在当前贵州省直播油菜的生产中,应积极推行合理的平衡施用技术和科学的施肥方法,从而达到高产、高效、高收益的目的。  相似文献   

18.
Reducing the high nitrogen (N) balance surpluses occurring in oilseed rape production through the cultivation of N-efficient cultivars is imperative for environmental reasons. In this study, seed yield and N efficiency parameters of oilseed rape cultivars grown under three N rates were investigated in field experiments performed during five years. Seed yields differed significantly among cultivars especially at limiting N supply, with significant shifts in cultivar ranking according to the N level. At high N supply, cultivar differences relied more on year effects. The importance of N efficiency parameters for yield varied owing to year and N rate effects. N uptake was an important parameter for yield at all N rates. While at low N, the duration of N uptake was most decisive, shoot N uptake capacity during vegetative growth was relatively more important under high N conditions. N utilization efficiency became more important with increasing N supply. At high N supply, cultivars with low seed N concentrations were superior in yield. Harvest index was also significantly correlated to yield across N rates; however, its importance depended much on environmental conditions. In conclusion, the specification of plant traits that might contribute to enhanced N efficiency in oilseed rape will depend very much on the N supply of the target environment and the target yield level.  相似文献   

19.
Transgenic bromoxynil (BX)-resistant spring oilseed rape (Brassica napus L.) was grown commercially in Canada only for two crop seasons – 2000 and 2001. We investigated the persistence of suspected BX-resistant oilseed rape volunteers in a 64-ha wheat field in Saskatchewan, Canada in 2007, 7 years after the BX-resistant cultivar BX Armor was grown. A small oilseed rape volunteer population, estimated at less than 100 plants, was observed in three main areas or patches in the field. These patches were located in low-lying areas that were too wet to plant or spray with herbicides in 2007. Viable seed was collected from 35 mature volunteers and F1 progeny screened with BX at 280 g ai/ha in the greenhouse. Progeny of all of the volunteers were visually rated as BX-resistant; the presence of the Oxy 235 transgene in leaf tissue of progeny of all volunteers was confirmed by PCR analysis. This study has documented the longest persistence of oilseed rape volunteers in Canada. Volunteers were not observed in 2008 or 2009, because of drought conditions in spring of both years. Results support the findings from previous studies that persistence of volunteer oilseed rape populations in western Canada is generally ephemeral or transitory in the absence of seed bank immigration. However, this study shows that oilseed rape transgenes can persist in the environment for a number of years even after all cultivars with the conferred trait are removed from the market.  相似文献   

20.
生物肥料对油菜的促生及菌核病防治的研究   总被引:1,自引:0,他引:1  
盆栽试验证明,施用枯草芽孢杆Tu-100制作的生物肥料,在油菜5叶期时,植株干重比对照增加1.80%,叶绿素含量增加17.15%;油菜根际的好气性细菌总数比对照有一定的提高,产量比对照增加7.90%。田间小区试验表明,施用生物肥料的处理,在油菜5叶期时,植株干重比对照增加3.88%,叶绿素含量增加3.67%,植株的全磷和全钾的含量也有不同程度的增加,产量增加4.90%;此生物肥料对油菜菌核病菌核的萌发有一定的抑制作用。  相似文献   

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