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1.
An enhanced rate of degradation of the dicarboximide fungicides iprodione and vinclozolin was induced in the laboratory in Patumahoe clay loam soil by adding three successive applications of fungicide. Enhanced degradation of the dicarboximide fungicide procymidone could not be induced. Following the first fungicide treatment, the time to 50% loss of iprodione was greater than 35 days; for vinclozolin the time to 50% loss was 22 days. The rate of degradation accelerated with successive applications until, after a third successive application of fungicide, the time to 50% loss of iprodione was only two days and none was detectable at seven days. For vinclozolin, after the third successive application of fungicide, 50% loss occurred after 35 days. By comparison, minimal loss of procymidone was detected after 35 days following each of two successive soil treatments. The induction of enhanced degradation of iprodione and vinclozolin in this soil in the laboratory may explain the observed loss of field control of onion white rot disease. Degradation of iprodione occurred in non-sterile soil but not in sterile soil, indicating that microbial involvement may be responsible for the degradation of iprodione and vinclozolin in soil.  相似文献   

2.
采用菌丝生长速率法和孢子萌发法,分别测定了烟草灰霉病菌对多菌灵、嘧霉胺、异菌脲和丙环唑的敏感性,同时通过离体叶片法评估了这4种杀菌剂对烟草灰霉病的保护和治疗作用。结果表明:4种杀菌剂对烟草灰霉病菌的菌丝生长和孢子萌发均表现出了不同程度的抑制活性,并对灰霉病同时具有保护和治疗作用。其中多菌灵对菌丝生长的抑制活性最强,EC50平均值为0.06 mg/L,其次为丙环唑、嘧霉胺和异菌脲,EC50平均值分别为0.36、0.53和0.60 mg/L;异菌脲和丙环唑对烟草灰霉病菌孢子萌发的抑制活性较强,EC50平均值分别为2.05和2.21 mg/L,其次为嘧霉胺和多菌灵,EC50平均值分别为10.56和131.23 mg/L。异菌脲和多菌灵对灰霉病的保护作用和治疗作用均最强,当药剂质量浓度为200 mg/L时,其对离体叶片的保护和治疗作用防效分别为100%、100%和98.3%、91.8%。研究结果可为烟草灰霉病的科学防治提供依据。  相似文献   

3.
During the period January-March 1989, 15 greenhouses at 12 sites in Israel were surveyed for the presence of fungicide-resistant strains of Botrytis cinerea , using a fungicide-amended Botrytis -selective medium. Resistance to benzimidazoles (BenR) and to dicarboximides (DicR) was frequent in most sites. Resistance to carbendazim + diethofencarb (BenR NPCR) was found in all eight sites in which a mixture of these fungicides had been used against grey mould, but not in other sites. A new phenotype of multiple fungicide resistance was found among these isolates. The new phenotype, designated BenR DicR NPCR, combines the three previously described characteristics of resistance to benzimidazole, dicarboximide and N -phenylcarbamate fungicides. It was found only in cucumber greenhouses that had been sprayed with the fungicide mixture carbendazim + diethofencarb against grey mould. Isolates of this phenotype were pathogenic in artificial inoculation of cucumber cotyledons treated with carbendazim, iprodione or carbendazim + diethofencarb.  相似文献   

4.
Fungicides applied to turfgrass in temperate climates prior to snowfall are expected to suppress fungal diseases such as microdochium patch (Microdochium nivale) until infection conditions become unfavourable the following spring. However, mild winters with inconsistent snow cover may alter fungicide persistence and render the turf more susceptible to fungal infection. This study was conducted to determine the effect of snow cover on the persistence of the fungicides chlorothalonil and iprodione applied to creeping bentgrass (Agrostis stolonifera), maintained as a golf course fairway. The fungicides were applied 1 day prior to the first accumulating snowfall in Madison, Wisconsin, for four consecutive winters, beginning in 2009/10. Fungicide treatments were kept under continuous snow cover or maintained free of snow cover the entire winter to determine the effect of snow cover on fungicide persistence (2010/11 to 2012/13) and microdochium patch development in a controlled environment chamber (2009/10 to 2012/13). Iprodione concentration was not impacted by snow cover in 2010/11 but was reduced under snow cover relative to bare turf in 2011/12 and 2012/13. Chlorothalonil concentration was not impacted by snow cover in 2011/12 but was greater under snow cover in 2012/13. Microdochium patch severity in the controlled environment chamber was not impacted by snow cover with either fungicide in 2009/10 or 2011/12 but was slightly reduced under snow cover with both fungicides during 2010/11 and 2012/13. The majority of fungicide depletion occurred shortly after rainfall or snowmelt events, except in 2010/11 when both fungicides rapidly depleted during a warming trend without rainfall.  相似文献   

5.
Budge SP  Whipps JM 《Phytopathology》2001,91(2):221-227
ABSTRACT All pesticides used in United Kingdom glasshouse lettuce production (six fungicides, four insecticides, and one herbicide) were evaluated for their effects on Coniothyrium minitans mycelial growth and spore germination in vitro agar plate tests. Only the fungicides had a significant effect with all three strains of C. minitans tested, being highly sensitive to iprodione (50% effective concentration [EC(50)] 7 to 18 mug a.i. ml(-1)), moderately sensitive to thiram (EC(50) 52 to 106 mug a.i. ml(-1)), but less sensitive to the remaining fungicides (EC(50) over 200 mug a.i. ml(-1)). Subsequently, all pesticides were assessed for their effect on the ability of C. minitans applied as a solid substrate inoculum to infect sclerotia of Sclerotinia sclerotiorum in soil tray tests. Despite weekly applications of pesticides at twice their recommended concentrations, C. minitans survived in the soil and infected sclerotia equally in all pesticide-treated and untreated control soil trays. This demonstrated the importance of assessing pesticide compatibility in environmentally relevant tests. Based on these results, solid substrate inoculum of a standard and an iprodione-tolerant strain of C. minitans were applied individually to S. sclerotiorum-infested soil in a glasshouse before planting lettuce crops. The effect of a single spray application of iprodione on disease control in the C. minitans treatments was assessed. Disease caused by S. sclerotiorum was significantly reduced by C. minitans and was enhanced by a single application of iprodione, regardless of whether the biocontrol agent was iprodione-tolerant. In a second experiment, disease control achieved by a combination of C. minitans and a single application of iprodione was shown to be equivalent to that of prophylactic sprays with iprodione every 2 weeks. The fungicide did not affect the ability of C. minitans to spread into plots where only the fungicide was applied and to infect sclerotia. These results indicate that integrated control of S. sclerotiorum with soil applications of C. minitans and reduced foliar iprodione applications was feasible, did not require a fungicide tolerant isolate, and that suppression of Sclerotinia disease by C. minitans under existing chemical control regimes has credence.  相似文献   

6.
Monilinia laxa, the incitant of blossom blight in stone fruits in Israel, is sensitive to 5μg/ml of the dicarboximide fungicides vinclozolin and iprodione in the growth medium. When a large number of spores, from an isolate never exposed to these fungicides, was seeded on a medium containing 15 μg/ml iprodione, spontaneous resistant mutants appeared at 10-5 frequency. These mutants showed cross resistance to the dicarboximide fungicides vinclozolin, procymidone, l-(3,5-dichloro-phenyl)-3-propen(2)-pyrrolidin-2,5-dion (Co 4462), l-(3,5-dichlorophenyl)-3-methoxymethyl-pyrrolidin-2,5-dion (Co 6054), and to dicloran. Growth rate on fungicide-free medium was similar to that of the parental sensitive strain but sporulation was much reduced. Growth rate on media supplemented with dicarboximide fungicides decreased gradually with increasing fungicide concentrations. The resistance has been stable for more than one year in the absence of fungicides. Artificial inoculation of cherry, apricot and plum fruits previously treated with 500 μg/ml vinclozolin, iprodione, procymidone or Co 6054, with a resistant strain, resulted in brown rot; similar treatments provided full protection of the fruits against the sensitive strain.  相似文献   

7.
A method is described for the simultaneous determination of residues of five fungicides used for foliar treatment of apple and pear trees, and for postharvest application. After extraction, the mixture of these fungicides is cleaned-up on a ‘SEP PAK C18’ cartridge and the components determined by gas-liquid chromatography with electron-capture detection. The minimum detectable amounts in apples and pears, on a fresh weight basis, were 0.005mg kg−1 for vinclozolin, 0.010mg kg−1 for captan, folpet and iprodione, and 0.020 mg kg−1 for captafol. The percentage recovery for each fungicide (calculated by analysing four samples of untreated apples and pears, to which varying concentrations of each active ingredient had been added) varied for vinclozolin between 70.0 and 89.2, for captan between 72.0 and 83.8, for folpet between 73.0 and 93.0, for captafol between 70.8 and 91.8, and for iprodione between 75.1 and 97.1.  相似文献   

8.
BACKGROUND: Greenhouse tomato production is intended exclusively for fresh consumption. Typical greenhouse conditions provide a conducive environment for the development of different fungi, principally late blight and grey mould, that can destroy plants and fruits. For this reason, different fungicides with different sites of action are used in integrated pest management strategies. Famoxadone, fenamidone, fenhexamid and iprodione (fig. 1 ) are fungicides of difference classes with different actions that could be used to control tomato pests. RESULTS: The QuEChERS method showed good recoveries, and the analytical method allowed good separation of the fungicides selected. Good results were obtained in terms of repeatability and intermediate precision, with a coefficient of variation of < 9.8%. The limits of determination and quantification of the method were far below the maximum residual levels (MRLs) set by the EU for these fungicides in tomatoes. The analysis of fungicide residues showed that cv. Shiren accounted for higher residue levels than cv. Caramba. The dissipation curves were similar in the two cultivars, indicating that the decrease in pesticides was not related to the tomato type. CONCLUSIONS: Care should be taken when using pesticides in greenhouse conditions, because degradation mainly affects fruit growth. The size of the tomato, in particular its surface/weight ratio, is very important for defining pesticide residues. All fungicides used showed residue levels below the MRLs at the preharvest interval. Copyright © 2011 Society of Chemical Industry  相似文献   

9.
10.
The development of resistance to chemical control agents needs continuous monitoring in Botrytis cinerea. 790 isolates from lettuce and other vegetable crops were collected from six widely separated sites in Greece and tested for their sensitivity to 11 fungicides from nine unrelated chemical groups. 44 of the isolates exhibited multiple resistance to fenhexamid (hydroxyanilides), azoxystrobin and pyraclostrobin (QoI’s), boscalid (SDHI’s), cyprodinil and pyrimethanil (anilinopyrimidines), fludioxonil (phenylpyrroles), carbendazim (benzimidazoles) and iprodione (dicarboximides). Thirty per cent of such phenotypes were detected in an experimental glasshouse with lettuce crops, the third year after commencing fungicide applications. The average resistance factor (Rf) for mycelial growth to fenhexamid, pyraclostrobin, boscalid, cyprodinil and fludioxonil, was over 40, 1,000, 100, 700 and 50, respectively. Some strains with high resistance to anilinopyrimidines (14 %) or moderate to fludioxonil (7 %) were detected even in isolates collected from vegetable crops prior to commercial use of these fungicides in Greece. Isolates with fludioxonil moderate resistance and fenhexamid high resistance, were detected for the first time in Greece. The results suggested the high risk in chemical control of grey mould due to development of resistance to most fungicides with site-specific modes of action. Isolates with resistance to fluazinam (phenylpyridinamines) and to chlorothalonil (phthalonitriles) were not found. The inclusion of appropriate multi-site inhibitors like chlorothalonil in fungicide anti-resistance strategies was indispensable.  相似文献   

11.
依据鉴别浓度检测了中国不同地理来源的114株草坪草币斑病菌对甲基硫菌灵的敏感性,并采用菌丝生长速率法测定了供试菌株对异菌脲和丙环唑的敏感性。结果显示:对甲基硫菌灵敏感的菌株共98株,占总数的85.96%,抗性菌株16株,占总数的14.04%;在8个有甲基硫菌灵施药历史的采样点中,5个点检测到了抗性菌株。异菌脲和丙环唑对草坪草币斑病菌的EC50值分别在0.012 1~1.264 4和0.000 4~0.100 4 μg/mL之间,平均EC50值分别为(0.525 6 ± 0.207 7)和(0.015 2 ± 0.020 1)μg/mL,最大EC50值和最小EC50值分别相差104.7和251.0倍。敏感性频率分布结果显示,币斑病菌对异菌脲和丙环唑已出现敏感性下降的亚群体。与从未施过相关药剂地区的币斑病菌群体相比,分离自8个有施药历史地块的菌株群体对异菌脲的敏感性均显著降低,4个有施药历史地块的群体对丙环唑的敏感性显著降低。相关性分析显示,对丙环唑最不敏感的10株币斑病菌对异菌脲的敏感性均呈现下降趋势,且两者间存在一定的正相关关系(ρ = 0.755 4,P < 0.000 1),推测这部分菌株可能存在多药抗药性。本研究结果可为杀菌剂的合理使用及币斑病的有效防治提供理论支持。  相似文献   

12.
A preparation of Trichoderma harzianum was sprayed on cucumber plants in greenhouses in order to control fruit and stem grey mould. Up to 90% control was achieved by the biocontrol agent (0·5–1·0 g/l) which in most experiments under commercial conditions was as effective as the dicarboximide fungicides iprodione or vinclozolin (0·5 g/l each) alone or alternated with diethofencarb + carbendazim (0·25 g/l each). However, in one experiment disease incidence in Trichoderma -treated plots did not differ significantly from the control. A mixture of T. harzianum with a dicarboximide fungicide resulted in up to 96% control of grey mould. In this case control was always significant ( P =0·05) but improvement of control compared with each treatment alone was not significant ( P =0·05). The alternation of sprays with the biocontrol preparation and with a dicarboximide fungicide was tested in three out of the five experiments and was found to be effective, thus enabling a reduction in the use of chemical sprays. Populations of T. harzianum were on a level of 3 × 105-8 × 105 c.f.u. per leaf and ten times lower on one fruit. They remained high after the second and third sprays. Conditions favouring the ability of T. harzianum to control grey mould were temperatures above 20°C and relative humidity between 80 and 97%.  相似文献   

13.
Two bioassay methods are described which use detached tobacco leaves to measure the sensitivity of Peronospora tabacina to systemic fungicides. Tobacco leaves (13–15 cm2), treated with fungicides before or after detachment from the plant, were inoculated with sporangia in water drops and, after incubation in beakers and Petri plates, the disease severity and/or production of sporangia was determined 4–7 days after treatment with the fungicides. Of 15 systemic fungicides applied to detached leaves, eight N-phenylamides at 0.066?1.0 μg ml?1 controlled blue mould; metalaxyl was the most effective fungicide. Isolates of P. tabacina, collected in the field from tobacco plants grown in soil treated with metalaxyl, were not resistant to the fungicide applied to detached leaves prior to inoculation. The fungicide, applied to leaves before detachment, was used to measure the efficacy of five systemic N-phenylamide fungicides sprayed on the basal and unsprayed distal portions of the leaves. Blue mould was controlled on the basal portion of the leaf by all the fungicides at 0.66?1.0 μg ml?1, but it required the application of 3–30 times more chemical on the basal portion to achieve comparable blue mould control on the distal part of the leaf.  相似文献   

14.
A combined TBZ — iprodione treatment was more effective in inhibiting growthin vitro ofBotrytis cinerea isolates obtained from decayed celery than either of the fungicides applied separately. This was exhibited for both TBZ-resistant and TBZ-sensitive isolates. TBZ at 500 (μg ml-1 plus iprodione at 1000 μg ml-1 reduced celery decay beyond the reduction obtained by each fungicide alone. When applied prior to inoculation, the combined treatment prevented decay by the TBZ-sensitive/iprodione-resistant isolates and reduced initial decay by the TBZ-resistant/iprodione-sensitive isolates to 3–10% of the level without treatment. Under natural infection conditions iprodione showed better decay control than TBZ, and at 1500 μg ml-1 it reduced initial decay during prolonged storage to 3% of the no-treatment level. Although TBZ (500 μg ml-1) or iprodione (1000 μg ml-1) applied separately reduced decay significantly, the combination of lower concentrations of each fungicide was sufficient to eliminate decay development almost totally. The combined treatment also inhibited decay bySclerotinia sclerotiorum, which contributed 3% of the total soft rot in stored celery.  相似文献   

15.
In field and laboratory experiments, enhanced degradation of the dicarboximide fungicides, iprodione and vinclozolin, was stimulated by only one application of the fungicides in a soil with no previous history of any pesticide input. Field and laboratory studies demonstrated the ease of stimulation by pre-treatment with even very low concentrations of the fungicides (0·5 μg g−1 soil) and at a range of temperatures and soil moisture conditions. Soils that had acquired full enhanced degradation could rapidly degrade fungicide applied at 30 times the recommended field rate. Cross-enhancement of degradation was noted with both fungicides, but not with their common metabolite, 3,5-dichloroaniline. Application of the antibiotics chloramphenicol or rifampicin to soil reduced enhanced degradation to control levels; cycloheximide had no effect. This, together with the inhibitory action of azide, mercuric chloride and repetitive microwaving, indicated that the agent(s) of enhanced degradation was probably bacterial.  相似文献   

16.
Chlorothalonil and chlorpyrifos are commonly used to control disease and insect pests on golf course greens. While they are relatively immobile in the soil profile, their respective soil degradation products, 4-hydroxy-2,5,6-trichloroisophthalonitrile and 3,5,6-trichloropyridin-2-ol are more polar and may be present in golf course green leachate. To investigate this possibility, six stainless steel lysimeters were constructed into two practice greens at a country club in a northern Atlanta, Georgia suburb. Over a period of 1 year after rainfall events, lysimeter leachate samples were collected into glass bottles, filtered and directly analyzed by HPLC with UV detection. Chlorpyrifos was not detected in any sample and chlorothalonil was detected only in one sample, at a concentration of 0.12 mg liter-1. With a limit of quantitation of 0.05 mg liter-1, hydroxychlorothalonil and trichloropyridinol were detected in 87% and 63% of the samples at maximum and median concentrations of 2.21 and 0.55 mg liter-1 for hydroxychlorothalonil and 1.77 and 0.15 mg liter-1 for trichloropyridinol. Golf course green leachate often mixes with surface water, thus more data may be warranted to determine the persistence and ecological significance of chronic exposure to these compounds of organisms in the aquatic environment.  相似文献   

17.
采用生物测定方法分析了烟草立枯病菌Rhizoctonia solani在菌丝生长、菌核形成与萌发阶段对5种杀菌剂(多菌灵、代森锰锌、菌核净、异菌脲及苯醚甲环唑)的敏感性,同时通过离体叶片法考察了5种杀菌剂对烟草立枯病的保护和治疗作用。结果表明:供试5种药剂对立枯病菌菌丝生长、菌核形成与萌发均表现出了不同程度的抑制活性,同时对烟草立枯病具有一定的保护和治疗作用。其中,对菌丝生长以及菌核形成与萌发抑制活性最强的均是多菌灵,其抑制菌丝生长的EC50平均值为(0.06 ±0.01) mg/L,0.25和20 mg/L下对菌核形成和萌发的抑制率均为100%;其次为异菌脲[EC50值为(0.35 ±0.15) mg/L,2和100 mg/L下对菌核形成和萌发的抑制率分别为(54.79 ±12.58)%和100%]、苯醚甲环唑[EC50值为(0.55 ±0.53) mg/L,5和200 mg/L下对菌核形成和萌发的抑制率分别为(97.97 ±2.64)%和100%]及菌核净[EC50值为(1.31 ±0.14) mg/L,10和100 mg/L下对菌核形成和萌发的抑制率均为100%];最弱的均是代森锰锌,其抑制菌丝生长的EC50平均值为(6 ±0.20) mg/L,10和200 mg/L下对菌核形成和萌发的抑制率分别为(43.58 ±31.87)%和0。离体试验表明:对烟草立枯病保护作用最强的是多菌灵、异菌脲和菌核净,50 mg/L时防效均 > 99%,其次为代森锰锌(50 mg/L防效为75.83%),最弱的是苯醚甲环唑(50 mg/L防效为39.29%);治疗作用最强的也是多菌灵,50 mg/L防效为93.46%,其次为菌核净、异菌脲和苯醚甲环唑(200 mg/L时防效均 > 84%),最弱的为代森锰锌(800 mg/L时防效为76.40%)。研究结果可为烟草立枯病化学防治药剂筛选提供参考和依据。  相似文献   

18.
湖南省草莓灰霉病菌对4种杀菌剂的抗药性检测   总被引:2,自引:0,他引:2  
为明确湖南省草莓灰霉病菌菌株的抗药性状况,2013-2015年从湖南省不同地区草莓灰霉病病果或病叶上经单孢分离获得草莓灰霉病菌454株,采用最小抑制浓度法(MIC)检测不同地区草莓灰霉病菌株对多菌灵、腐霉利、异菌脲、嘧霉胺的抗药性。结果表明:草莓灰霉病菌对多菌灵、腐霉利、异菌脲、嘧霉胺的抗性频率分别为55.73%,77.31%、3.52%和77.31%;所测菌株对4种杀菌剂的敏感性类型有Cbz~RPcm~RIpd~RPmt~R、CbzSPcm~RIpd~RPmt~R、Cbz~RPcm~RIpdSPmt~R、Cbz~SPcm~RIpdSPmt~S、Cbz~RPcm~SIpd~SPmt~R、Cbz~SPcm~RIpd~SPmt ~R等6种,其所占比例分别为33.26%、5.07%、41.41%、4.63%、3.96%、11.67%,未发现对4种杀菌剂均敏感的类型,表明湖南省草莓灰霉病菌已对多菌灵、腐霉利和嘧霉胺产生抗药性,对异菌脲的抗药性较低。  相似文献   

19.
梨黑斑病菌抗药性检测及其对啶酰菌胺的敏感性基线   总被引:1,自引:1,他引:0  
黑斑病是梨的主要病害之一,近年来不少地区反映多菌灵等传统常用杀菌剂对其防治效果已出现下降。作者从浙江、江苏和安徽3省分离了252株梨黑斑病菌Alternaria kikuchiana,采用菌丝生长速率法检测了其抗药性发生情况。结果发现:所检测的黑斑病菌群体(n=252)对苯并咪唑类杀菌剂多菌灵的抗性频率为57.1%,且全部为高水平抗性(HR);对二甲酰亚胺类杀菌剂异菌脲的抗性频率为46.8%,全部为低水平抗性(LR);对甾醇脱甲基抑制剂类杀菌剂苯醚甲环唑的抗性为低水平(LR)及中等水平(MR),抗性频率均为28.6%;表明梨黑斑病菌对常用杀菌剂已产生较为严重的抗性。供试252株梨黑斑病菌对琥珀酸脱氢酶抑制剂啶酰菌胺的EC50值分布在0.12~3.85μg/m L之间,平均EC50值为(1.21±0.12)μg/m L,且其分布呈近似正态的单峰曲线。研究表明,啶酰菌胺可作为潜在的梨黑斑病防治替代药剂,其平均EC50值(1.21±0.12)μg/m L可作为梨黑斑病菌对啶酰菌胺的敏感性基线。  相似文献   

20.
Field occurrence of vinclozolin resistance in Monilinia fructicola   总被引:1,自引:1,他引:0  
Strains of Monilinia fructicola resistant to vinclozolin were isolated from fruit affected by brown rot from an orchard where the fungicide had been used over four seasons. Resistant isolates were pathogenic to peach fruit, and resistance of one isolate was confirmed following dipping of inoculated fruit in fungicide suspensions. In culture, one of four resistant isolates was identical in colony morphology and sporulation to sensitive isolates from different geographic areas. The other resistant isolates produced dark mycelium on PDA and were slower growing. Vinclozolin-resistant isolates were resistant in vitro to two other dicarboximide fungicides, iprodione and procymidone.  相似文献   

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