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1.
Seventeen field isolates of Botrytis cinerea were compared by determining their radial growth on synthetic media containing various amounts of 21 antifungal compounds. Twelve of these compounds were fungicides that are recommended for the control of Botrytis infections. There were marked differences between the isolates in their sensitivity to the compounds. Individual isolates displayed high levels of resistance to some of the fungicides, including benomyl, carbendazim, iprodione, thiabendazole, thiophanate-methyl, vinclozolin and zineb. The most potent growth inhibitors were benomyl and carbendazim (ED95 values for most isolates <0.1 μg fungicide ml?1 media), dichlofluanid, iprodione, nystatin, thiabendazole, thiophanatemethyl and vinclozolin (ED95 values for most isolates < 1.0 μg ml?1), and captan, chlorothalonil, dicloran and thiram (ED95 values for most isolates < 6.0 μg ml?1). Zineb was much less potent than the other recommended anti-Botrytis fungicides; it was no more effective than carboxin, dinocap and mancozeb (ED95 values for most isolates > 25 μg ml?1).  相似文献   

2.
A technique is described for testing isolates of Septoria tritici from winter wheat for resistance to benzimidazole fungicides. Secondary spores from 23 isolates were tested on Czapek Dox V-8 agar amended with benomyl at 1–10 μg ml. Twenty-one isolates were recovered from eight crops in England in 1984 and two (PBI isolates) were obtained in 1973. Thirteen isolates, including both PBI isolates, were sensitive to benomyl at 1 μg ml?1 and nine were resistant at 10 μg ml?1. The remaining isolate had a low proportion (1:3.7 x 104) of resistant spores. The minimum inhibitory concentration for sensitive isolates was 0.2–0.4 μg ml 1 benomyl and for resistant isolates was more than 1000 μg ml 1. Benomyl-resistant isolates were cross-resistant to carbendazim, thiabendazole and thiophanate-methyl, but not to 12 other fungicides with different modes of action. The implications of these findings are discussed.  相似文献   

3.
The toxicities of five systemic fungicides [benomyl, carbendazim, methyl 4-(2- aminophenyl)-3-thioallophanate (NF48), thiabendazole and thiophanate-methyl] and of two non-systemic fungicides (guazatine and phenylmercury acetate) against Fusarium culmorum were compared on agar plates; their performance as seed treatments was measured by inoculating the shoot bases of wheat seedlings with F. culmorum in pot experiments. The two most effective compounds, benomyl and thiabendazole, and the less effective thiophanate-methyl, were evaluated in further seed treatment experiments in which leaf sheaths and roots of slightly older plants were infected. The three fungicides protected the first leaf sheath for more than 5 weeks, but thiophanate-methyl was least effective. Against root disease, they were effective when infection was mild, but only thiabendazole significantly controlled severe infection. Bioautography confirmed that fungicide levels in shoots were greater after benomyl and thiabendazole, than after carbendazim and thiophanate-methyl treatments, and that concentrations of fungicide after benomyl, carbendazim and thiophanate-methyl treatments generally declined between 5-13 weeks after treatment. Thiabendazole produced a second fungitoxic component detectable in plants after 34 days.  相似文献   

4.
The simultaneous HPLC determination of clofentezine, fenoxycarb and hexythiazox in apples, pears and their pulps is described. The method is based on a clean-up procedure carried out on a Seppak C18 cartridge followed by HPLC analysis on an RP-18 column using acetonitrile + water as mobile phase. Average recoveries were 85.0% for clofentezine, 84.8% for fenoxycarb and 75.6% for hexythiazox on apple matrix; recoveries from pear matrix were in the same range. UV detection limits at 240 nm were 0.07 mg kg?1 for clofentezine, 0.064 mg kg?1 for fenoxycarb and 0.08 mg kg?1 for hexythiazox.  相似文献   

5.
Six fungicides (benomyl, carbendazim, fuberidazole, thiabendazole, thiophanate and thiophanate-methyl) were applied as dusts to barley in concentrations of 100, 1000 and 10 000 μg g?1 and the barley then stored at 20°C and 90% relative humidity for 60, 105 and 150 days, respectively. Fungal development during storage was assessed by counting the visible patches of developing mould and by dilution plating. None of the fungicides completely prevented fungi developing but for the period up to 60 days, all provided a degree of control that was generally greatest for the highest concentration of fungicide. Benomyl was the most effective of the fungicides but no clear pattern was established for the others. Of the fungi that developed, species of Aspergillus and Penicillium accounted for 94% of the total count.  相似文献   

6.
Carbendazim was quantified spectrophotometrically in leaves, petioles, stems and pods from upper and lower halves of entire soybean plants following one or two foliar applications of thiophanate-methyl fungicide (1.1 kg ha?1 a.i.). Following the first application, the highest carbendazim concentrations occurred 1-4 days post-application and declined thereafter to undetectable (?0.12 mg kg?1) or barely detectable levels by day 26. The highest concentrations were in the leaves where carbendazim levels exceeded 3.5 mg kg?1 on day 4 and remained above 1.0 mg kg?1 until day 19. Concentrations in petioles and upper pods were initially in excess of 1.0 mg kg?1 and remained above 0.5 mg kg?1 for 12 days. In lower pods and in stems, concentrations were very low and often not detectable. Typically, concentrations were higher in samples from the upper half of the plant than in those from the lower half. A second application on day 18 resulted in carbendazim concentrations similar to those immediately after the first application; however, concentrations declined rapidly coincidentally with a period of rain. This decline may have been facilitated by poor fungicide uptake due to senescence of the plants.  相似文献   

7.
HPLC was used to determine levels of the benzoylphenyl urea, CGA-184699, in cat blood, flea faeces and eggs. Rate constants were determined for the decline of CGA-184699 concentration in flea faeces of fleas that fed on both high (696 ng ml?1) and low (305 ng ml?1) host blood concentrations. There were strong correlations between the concentration of the drug in the host's blood and in flea eggs, between egg concentration and egg hatch and between the concentration of CGA-184699 in faeces and mortality to larvae feeding upon faeces.  相似文献   

8.
Wheat leaves (cv. Kormoran) floated on water and kept in darkness turned yellow. This induced senescence was accompanied by a loss of electrolytes and amino acids, and by disorganisation of all cellular organelles except cell walls. Treatment with a solution of carbendazim (20 μg ml?1) prevented the leakage of electrolytes and disorganisation of cell organelles. At 100 μg ml?1, the fungicide did not prevent the damage caused by senescence but stimulated the loss of electrolytes from the leaves. It is proposed that one of the major mechanisms of the antisenescent activity of carbendazim is its protective effect on membranes.  相似文献   

9.
1·275 dm3 of a l·3g dm?3 aqueous emulsion of permethrin (i.e. 1·658 g permethrin) was applied to the surface of a fast-flowing stream by manual injection. Water samples were collected from the top 1-cm layer at different intervals of time at various distances downstream from the site of application. Caged samples of stream detritus, crayfish, brook trout and stonefly nymphs, bottled sediment and potted aquatic plants were placed 280 m from the treatment site, and collected afterwards for residue analysis. The downstream movement of the chemical was not uniform with peak concentrations of about 12 ng ml?1 at 30 m and 0·1 ng ml?1 at 730 m from the treatment site. The peak concentrations (ng g?1) in potted aquatic plants, caged detritus, crayfish and brook trout were about 18, 39, 14 and 11 respectively. The residues were higher than the ambient water concentration (1·67 ng ml?1) and dissipated slowly. The peak concentration in the bottled sediment was 2·75 ng g?1, and the residues were lost rapidly. In contrast, the naturally occurring sediment in a beaver pond showed high residues that persisted for a longer period of time. Permethrin concentrations in invertebrate drift ranged from 9 to 357 ng g?1, depending on the distance from the application site. The study demonstrated that aquatic invertebrates, plants and stream detritus acted as the major sink for the chemical.  相似文献   

10.
Benomyl [methyl 1-(butylcarbamoyl)-benzimidazol-2-ylcarbamate] (350 × 10?6 M) decreased the respiration rate of Fusarium oxysporum conidia by 50% during germination. This inhibition was maintained at least 24 h after the treatment had begun. The treatment did not modify the relation between incubation time and respiration rate. Carbendazim [methyl benzimidazol-2-ylcarbamate], thiabendazole[2-(thiazol-4-yl)benzimidazole], thiophanate [1,2-di-(3-ethoxycarbonyl-2-thioureido)benzene] and thiophanate-methyl [1,2-di-(3-methoxycarbonyl-2-thioureido)benzene] were assayed using isolated mitochondria of Saccharomyces cerevisiae. These four compounds decreased mitochondrial respiration and oxidative phosphorylation rates to different extents when they were applied at a concentration of 250 × 10?6 M . Thiophanate-methyl was the most effective since it completely suppressed the mitochondrial respiratory control at 75 × 10?6 M .  相似文献   

11.
In 2014 and 2015, a total of 151 tobacco brown spot (Alternaria alternata) isolates were collected from Guizhou Province in China to evaluate their resistance to the benzimidazole thiophanate-methyl, the carbamate diethofencarb, and the dicarboximide procymidone. Resistance to thiophanate-methyl and diethofencarb was observed in all isolates. Resistance to all the three fungicides, thiophanate-methyl, diethofencarb, and procymidone was detected at a frequency of 6.0%. The F167Y single mutation in the β-tubulin gene was found to be associated with resistance to thiophanate-methyl,but no mutation was found in the coiled-coil region of the histidine kinase-encoding gene OS1, a fungal gene for dicarboximide resistance. Procymidone applied at the rate of 20 mg l?1 inhibited spot lesion formation on tobacco leaves with an efficacy of 51.7% for the low resistance (LR) isolates and 74.2% for the procymidone-sensitive isolates. Thiophanate-methyl applied at 100 mg l?1, however, slightly promoted the expansion of disease lesions with an efficacy of ?7.7%. Azoxystrobin applied at 10 and 20 mg l?1 provided efficacies of 91.1 and 100%, respectively, regardless of whether the isolates were thiophanate-methyl resistant or procymidone-LR. Further studies suggested that azoxystrobin exhibited excellent protective activity and good curative activity against A. alternata in plants. The baseline sensitivity to azoxystrobin was then determined. In the presence SHAM, the mean EC50 values for conidial germination inhibition were 0.49?±?0.22 (Mean?±?SD) mg l?1. Interestingly, no resistance was recovered through UV irradiation or Agrobacterium tumefaciens-mediated mutagenesis. This research indicated widespread resistance to thiophanate-methyl and diethofencarb, low frequency of (6.0%) resistance to procymidone in A. alternata populations from tobacco, and suggested that azoxystrobin could potentially constitute a good alternative for the management of tobacco brown spot disease.  相似文献   

12.
Determination of sugarbeet herbicides such as chloridazon, metamitron and phenmedipham in soil samples is described. After extraction with acetone, pesticides were determined by HPLC on an RP-18 column using methanol/water as mobile phase. Average recoveries were 82% for chloridazon, 93% for metamitron and 77% for phenmedipham. Quantification limits were 3·5 μg kg?1 for chloridazon, 6·3 μg kg?1 for metamitron and 3·6 μg kg?1 for phenmedipham.  相似文献   

13.
建立了QuEChERS-超高效液相色谱-串联质谱同时检测草莓中甲基硫菌灵、多菌灵和乙嘧酚残留的方法。样品经0.5%甲酸-乙腈提取,QuEChERS方法净化,以Agilent XDB-C18色谱柱(2.1 mm×150 mm,3.5 μm)进行UPLC分离,采用三重四极杆串联质谱以正离子多反应监测模式(MRM)进行测定。结果表明:在20~1 000 μg/L范围内,甲基硫菌灵、多菌灵及乙嘧酚的质量浓度与其相应的峰面积间呈现良好的线性关系,相关系数均大于0.997 8。在50~500 μg/kg添加水平下,草莓中甲基硫菌灵、多菌灵和乙嘧酚的平均回收率在86%~109%之间,相对标准偏差(RSD)在1.9%~13%(n=5)之间,检出限分别为2.5、0.50和1.0 μg/kg,定量限均为50 μg/kg。该方法样品前处理过程简单快速,分析时间短,灵敏度、准确度及精密度均符合农药残留检测要求,适用于草莓中甲基硫菌灵、多菌灵和乙嘧酚残留的检测。  相似文献   

14.
T. KATAN 《EPPO Bulletin》1985,15(3):371-377
Field isolates of Botrytis cinerea with moderate levels of resistance to dicarboximide fungicides (ED50 1.0–4.9 μg ml?1) and to dicloran were obtained from glasshouses where vinclozolin and iprodione failed to control grey mould. From sensitive and moderatcly-resistant cultures, laboratory isolates were selected on dicarboximide-amended medium, which were highly resistant to these fungicides (ED50 125->3000 μg ml?1). Conidia of all the resistant isolates germinated well on media amended with 100 μg ml?1 of the dicarboximides vinclozolin, iprodione, procymidone and myclozolin and with 5 μg ml?1 of metomeclan. However, the spores of the moderately resistant isolates did not germinate on 100 μg ml?1 metomeclan while the spores of the highly resistant isolates germinated well. Using media with 100 μg ml?1 of metomeclan to distinguish between the two phenotypes, no highly resistant strain was detected among 312 resistant samples from five cucumber glasshouses with a high frequency of moderately resistant strains. From air-borne inoculum of five glasshouses with 100% resistant populations, 1604 colonies were recovered on vinclozolin-amended (100 μg ml?1) medium and none on metomeclan-amended (100 μg ml?1) medium. It is concluded that strains of B. cinerea highly resistant to dicarboximides are absent from field populations.  相似文献   

15.
The fungicides tebuconazole, tebuconazole + dichlofluanid, fenethanil, diethofencarb + carbendazim, and vinclozolin combined with chlorothalonil were tested for their ability to control grey mould (Botrytis cinerea Pers. ex Fr.) of cucumber and tomato grey mould in greenhouses under commercial conditions. In winter 1987/88 the number of diseased female fruits of cucumber (Cucumis sativus L.) was reduced by diethofencarb + carbendazim (2·5 mg dm?3 each) by 93% and by tebuconazole (2·5 mg dm?3)(phytotoxic when alone) or tebuconazole (1 mg dm?3) + dichlofluanid (4 mg dm?3) by 54–57%. Vinclozolin (5 mg dm?3) + chlorothalonil (25 mg dm?3) significantly reduced disease incidence on fruits by 40%. Infection foci on cucumber stems were significantly decreased by vinclozolin + chlorothalonil. A more pronounced decrease was obtained with diethofencarb + carbendazim, tebuconazole, or tebuconazole + dichlofluanid. During the season of winter 1988/89, tebuconazole + dichlofluanid (1·5 + 6 and 3 + 12 mg dm?3) and RH7592 (1 mg dm?3) significantly reduced diseased fruits by 30–71%. Grey mould of tomato (Lycopersicon esculentum Mill.) leaves was reduced by more than 90% and on fruits by 78–87% when tebuconazole + dichlofluanid (1·5 + 6 and 3 + 12 mg dm?3) or diethofencarb + carbendazim (2·5 mg dm?3 each) were applied. Yields of cucumber fruits of the common parthenocarpic cv. Kasem 292 were weighed. There was no correlation between disease level and yield in any experiment, plot or date except for two measurements. Compesation in fruit production by the plant may be regarded as the reason for no positive yield response to efficient control. The possibility of reducing fungicide application is discussed. Control of grey mould on tomato resulted in yield increase.  相似文献   

16.
Carbendazim and thiabendazole applied to the rhizosphere of peanut plants by injection into the soil at doses of 0.1, 0.5 and 2.5 g per 1 m row, accumulated in the leaves during the first week after treatment, the concentrations being related to the doses applied. Two weeks after treatment the concentrations of both fungicides dropped sharply. During the rest of the season, whilst the concentration of carbendazim in the high-dose treatment was 0.1 mg/kg fresh weight, the concentration of thiabendazole increased from 0.1 to 2.0 mg/kg and remained at this level until harvest. At the end of the growing season treated plants were less infected with Cercospora leaf spot (Cercospora per sonata) than the untreated control, thiabendazole affording better protection than carbendazim. Plants treated with the highest dose of thiabendazole were the only ones that did not wilt, even though infected. Laboratory studies of the adsorption of these fungicides on soil revealed that carbendazim is less adsorbed and also less persistent than thiabendazole.  相似文献   

17.
2-Methoxyethylmercury chloride (MEMC) applied to cowpea seeds with Rhizobium provided little or no control of seedling rot caused by Rhizoctonia solani; similar treatment, but without Rhizobium, gave >40% control of disease. Treating seeds with quintozene and then with Rhizobium rendered the fungicide completely ineffective against R. solani infections; disease control was >70% when seeds were treated with quintozene only, and >60% when seeds were coated first with Rhizobium and then with quintozene; treatment with quintozene+Rhizobium gave about 25% control. Simultaneous treatment with Rhizobium considerably reduced the efficacy of captafol, chloroneb, carbendazim and thiophanate-methyl. Disease control by carboxin, benomyl and thiabendazole remained unaltered in the presence of Rhizobium, but only thiabendazole gave good control. Seeds treated with MEMC and Rhizobium produced seedlings without root nodules; nodulation was also decreased by captafol and by carboxin but six other fungicides had no effect. The implications of Rhizobium-fungicides interactions are discussed in the context of fungicidal control of root diseases.  相似文献   

18.
Mycelial isolates (115) of Pseudocercosporella herpotrichoides were obtained from five field sites in England. Carbendazim-resistant isolates were detected by their mycelial growth on agar containing 1 μg/ml carbendazim. Resistant isolates were found at two of the five sites examined and one of these had never been treated with benzimidazole fungicides. Amongst the carbendazim- resistant isolates there was a predominance of isolates with pale mycelium, an irregular colony margin and a relatively slow growth rate; however, this association was not absolute. Large differences in the effects of carbendazim on mycelial growth of sensitive and resistant isolates were demonstrated; growth of sensitive isolates was completely inhibited at 0.5 μg /ml carbendazim whilst five of the six resistant isolates examined grew on agar containing 1000 μg/ml fungicide. The carbendazim-resistant isolates were cross-resistant to benomyl, thiophanate-methyl and to a Icsser degree thiabendazole, but not to prochloraz. Conidia of carbendazim-resistant isolates were as resistant. Carbendazim-resistant isolates were just as pathogenic to wheat as sensitive isolates. The implications of these results and other reports of benzimidazole resistance in P. herpotrichoides are discussed in relation to disease control.  相似文献   

19.
Stem rot caused by Lasiodiplodia theobromae is an important postharvest disease of papaya in Brazil, responsible for reducing the quality and quantity of fruits. Fungicide use is one of the main disease management measures. However, there are no estimates available of pathogen sensitivity to commonly employed fungicides. Therefore, the EC50 from 120 isolates of L. theobromae from northeastern Brazil, representative of six populations of the pathogen, was estimated in vitro for fungicides of the methyl benzimidazole carbamates—MBC (benomyl and thiabendazole) and demethylation-inhibiting—DMI (imazalil, prochloraz, tebuconazole) groups. Mycelial growth on fungicide-free media and virulence on papaya fruits of the MBC-sensitive and non-sensitive isolates were compared. For MBCs, 8.4% of isolates were non-sensitive to fungicides. For the remaining 91.6%, the mean EC50 ranged from 0.002 to 0.13 μg ml−1 and 0.36 to 1.27 μg ml−1 for benomyl and thiabendazole, respectively. For DMIs, the mean EC50 range for imazalil was 0.001 to 2.27 μg ml−1, 0.04 to 1.75 μg ml−1 for prochloraz, and 0.14 to 4.05 μg ml−1 for tebuconazole. The EC50 values of non-sensitive isolates were significantly (P≤0.05) higher those for the sensitive isolates for each of the DMI fungicides. Differences (P≤0.05) were found in the levels of sensitivity to DMI fungicides among the isolate populations associated with orchards. The populations from two orchards were less sensitive to DMIs. No solid evidence was found for fitness costs relating to MBC non-sensitive isolates because mycelial growth in fungicide-free media and virulence on papaya fruits were similar to those of sensitive isolates.  相似文献   

20.
为了评估甲基硫菌灵在猕猴桃上使用的安全性,采用QuEChERS-超高效液相色谱-串联质谱分析方法,对甲基硫菌灵及其代谢物多菌灵在猕猴桃上的残留量进行了分析,明确了其消解规律及半衰期,通过进行膳食摄入风险评估,以推荐甲基硫菌灵在猕猴桃上的最大残留限量 (MRL),并对其代谢物多菌灵的残留量进行了安全性评价。结果表明:在0.01、0.1和1.0 mg/kg 3个添加水平下,甲基硫菌灵的回收率为85%~102%,相对标准偏差 (RSD) 为1.0%~7.1%;多菌灵的回收率为86%~101%,RSD为2.1%~5.2%;两者的定量限均为0.01 mg/kg。甲基硫菌灵在猕猴桃上的消解符合一级反应动力学方程,半衰期为10.1~10.5 d,属易消解农药。70%甲基硫菌灵可湿性粉剂在猕猴桃上按照推荐剂量及1.5倍推荐剂量 (875和1 166.7 mg/kg) 分别施药3次和4次,推荐采收间隔期为21 d,膳食风险商为78.7%,推荐MRL值为5 mg/kg,该结果通常不会对一般人群健康产生不可接受的风险。依据GB 2763多菌灵在猕猴桃上的MRL值0.5 mg/kg,代谢物多菌灵存在较大的超标风险。建议有关部门制定甲基硫菌灵在猕猴桃上的MRL值,并重新评估多菌灵在猕猴桃上的MRL值。  相似文献   

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