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1.
During the period 1978–1992, phenylamide fungicides in co-formulation with the dithiocarbamate fungicide mancozeb were tested for the control of potato late-blight in 51 separate field experiments in England and Wales. Whilst there was a general trend over all the experiments which indicated that foliage blight was less severe where the phenylamide + dithiocarbamate mixture had been used, the benefit was more marked in some than in others. Despite the detection of phenylamide resistance, at some sites the mixture gave better control of foliage blight than the dithiocarbamate alone. At one site where continuous data were available, the additional benefit of the phenylamide compound for control of foliage infection was lost after 1986 coinciding with a rise in phenylamide resistance from 31.7% in 1986 to 81% in 1987. Where foliar blight epidemics occurred, yield responses to fungicide programmes compared with unsprayed controls ranged from 0 to +118.5% with a mean response of +30.2%. This is equivalent to 30.8 and 12.92 t/ha respectively. Standardized yield differences were calculated to allow inter-trial and inter-year comparisons and showed no benefit from the phenylamide fungicide applied at 14-day intervals in 33 out of 38 experiments where foliar blight epidemics occurred. At one site, Cusum analysis of standardized yield differences following treatment with the phenylamide + dithiocarbamate mixture and the dithiocarbamate alone showed a mean benefit from the phenylamide mixture of 2.23 t/ha during the period 1978 to 1986. From 1987 to 1992, the yield benefit dropped to a mean level of 0.68 t/ha a decrease of 69.5%. In experiments where blight was not recorded, fungicide treatments had no deleterious effect on yields. Over all the trials, there was no effect of fungicide treatment on the incidence of tuber blight at harvest. 相似文献
2.
A detailed study has been conducted to evaluate the residues of endosulfan and its principal metabolite (alpha-endosulfan, beta-endosulfan and endosulfan sulfate) which may have accumulated in environmental samples due to regular aerial spray application of endosulfan on cashew leaf plantation for a period of 20 years. Three months after the last spray of endosulfan 350 g litre-1 EC at 300 ml acre-1 (equivalent to 105 g AI acre-1 = 42.5 g ha-1), a total of 93 samples of cow milk, fish, water, soil and dried cashew leaf were collected from a village in Kasargode District, Kerala, India, where endosulfan contamination was likely to have occurred. All the samples were analyzed for total residues of endosulfan (comprising alpha- and beta-endosulfan), endosulfan sulfate and also the potential hydrolysis product endosulfan diol, using gas chromatography with electron capture detection. The minimum detection limits of total endosulfan was 0.001 microgram g-1. Analysis of soil samples showed the deposition of total endosulfan residues in the range < 0.001-0.010 microgram g-1, and dried leaf samples showed residues of endosulfan in the range < 0.001-3.43 micrograms g-1 dry weight. In cow milk, fish and water, endosulfan residues could not be detected above the minimum detection limit. Endosulfan diol was not observed in any sample. The data obtained was confirmed by GC-MS-EI using selective ion monitoring (SIM) mode. 相似文献
3.
A mixture (‘Fubol’) of metalaxyl with mancozeb, performed better than mixtures of propamocarb (as the hydrochloride) or the experimental fungicide cymoxanil with mancozeb, when applied as sprays to control potato blight in a small-scale field trial conducted in 1978. Another experimental fungicide, 2-chloro-N-(2-oxotetrahydrofuran-3-yl)acet-2″,6′-xylidide (RE 20615), applied at a greater rate but without mancozeb, was as effective as ‘Fubol’. The mixture of mancozeb and propamocarb or cymoxanil performed no better than mancozeb alone. In 1979, when blight incidence was greater, use of RE 20615/dithiocarbamate mixtures allowed the extension of spray intervals to 21 days, compared with a 14-day schedule for the dithiocarbamate alone. RE 20615, applied in 1979 to the soil within the furrows at planting time as a controlled-release granular formulation, gave adequate control of late blight up to early September, after which disease development accelerated. Yield was not significantly different from that obtained with a standard dithiocarbamate treatment. 相似文献
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D. N. KINN 《EPPO Bulletin》1986,16(3):461-464
Preliminary results are presented on elimination of Bursaphelenchus xylophilus from pine wood chips by dry heat, hot water treatment and immersion in dithiocarbamate solution. 相似文献
6.
人溶菌酶是一种天然抗生素，具有抗细菌、真菌，抗炎症，预防感染等功能。转基因溶菌酶山羊可以在乳腺中特异性表达，从而可以从羊乳中规模化制备溶菌酶。本研究旨在建立一种适用于痕量样本中转基因溶菌酶羊成分定量检测的品系特异性数字PCR方法，并利用该方法对山羊的血液、羊奶、粪便和环境土壤样本等进行检测，用于对转基因溶菌酶山羊成分的溯源。建立的数字PCR方法具有高特异性、灵敏度、准确性，检测限和定量限低至15个拷贝每个反应，可以对羊血、羊乳等制品进行准确的定量检测。研究结果还表明该方法可以准确测定粪便和环境土壤样本中的痕量转基因溶菌酶羊成分，可进一步用于转基因动物外源基因的水平转移检测及环境风险评估。 相似文献
7.
Salinas-Castillo A Fernández-Sanchez JF Segura-Carretero A Fernández-Gutiérrez A 《Pest management science》2005,61(8):816-820
A new, simple, rapid and selective phosphorimetric method for determining napropamide is proposed which demonstrates the applicability of heavy-atom-induced room-temperature phosphorescence for analyzing pesticides in real samples. The phosphorescence signals are a consequence of intermolecular protection and are found exclusively with analytes in the presence of heavy atom salts. Sodium sulfite was used as an oxygen scavenger to minimize room-temperature phosphorescence quenching. The determination was performed in 1 M potassium iodide and 6 mM sodium sulfite at 20 degrees C. The phosphorescence intensity was measured at 520 nm with excitation at 290 nm. Phosphorescence was easily developed, with a linear relation to concentration between 3.2 and 600.0 ng ml(-1) and a detection limit of 3.2 ng ml(-1). The method has been successfully applied to the analysis of napropamide in water and soil samples and an exhaustive interference study was also carried out to display the selectivity of the proposed method. 相似文献
8.
Joubert Fayette Jeffrey B. Jones Kenneth Pernezny Pamela D. Roberts Richard Raid 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(2):341-349
Clubroot, caused by Plasmodiophora brassicae, has become a serious threat to canola (Brassica napus) production in western Canada. Experiments were conducted to evaluate the effect of rate of metam sodium fumigant (dithiocarbamate; sodium N-methyldithiocarbamate; trade name Vapam) and application methods including watering, soil surface covering, and soil incorporation on clubroot of canola. At higher rates (0.4–1.6 mL?1 L soil) metam sodium increased canola seedling emergence and plant health, and reduced root hair infection, gall weight and clubroot severity under greenhouse conditions. Metam sodium application improved subsequent plant growth and reduced clubroot severity, but land preparation and volume of water applied did not affect efficacy. The incorporation of metam sodium into the soil and plastic covering after application improved fumigant efficacy. The study showed that soil fumigation with metam sodium can reduce clubroot severity and improve plant health in the subsequent canola crop. 相似文献
9.
The element sulfur has an outstanding role in the crop protection chemistry because it is used in its elemental form as a multisite fungicide, but is also part of agrochemicals in the form of aromatic or aliphatic sulfur-containing rings or sulfur-based functional groups. This review gives an exhaustive overview over the latter category. Several fundamental agrochemical compound classes are named after a sulfur-based functionality, such as the dithiocarbamate fungicides and sulfonylurea herbicides. Altogether, 16 different sulfur-based functional groups are presented with their typical synthesis approaches and most important representatives in crop protection. © 2023 Society of Chemical Industry. 相似文献
10.
采用静态批次试验法研究西北旱作农田黄土对Pb(Ⅱ)的吸附等温线和动力学特性,通过正交试验揭示Pb(Ⅱ)的解吸行为。结果表明:黄土对Pb(Ⅱ)的吸附过程更好地符合Langmuir等温线方程和准二级动力学方程,拟合系数R2分别为0.9937和0.9964;Langmuir方程计算得出的黄土对Pb(Ⅱ)的最大吸附量qm为17.0068mg/g。吸附过程自发、吸热,反应后体系自由度略有增加。对比极差R值发现:影响解吸过程的主要因素为水土比和解吸时间,在水土比为150mL/g、解吸时间为3 h、解吸液pH值为5和解吸温度为288 K时,Pb(Ⅱ)的平均解吸率r为50.15%。去除有机质农田黄土对Pb(Ⅱ)的吸附量qe仅为6.6814mg/g,推测有机质在Pb(Ⅱ)的去除过程中有重要贡献。 相似文献
11.
The weed flora (comprising seven species) of a field continuously grown with soyabean was simulated for 4 years, using semivariograms established from previous field observations. Various sampling methods were applied and compared for accurately estimating mean plant densities, for differing weed species and years. The tested methods were based on (a) random selection wherein samples were chosen either entirely randomly, randomly with at least 10 or 20 m between samples, or randomly after stratifying the field; (b) systematic selection where samples were placed along diagonals or along zig‐zagged lines across the field; (c) predicted Setaria viridis (L.) P. Beauv seedling maps which were used to divide the field into low‐ and high‐density areas and to choose the largest sample proportion in the high‐density area. For each method, sampling was performed with 5–40 samples. Systematic methods generally resulted in the lowest estimation error, followed by the random methods and finally by the predicted‐map methods. In case of species over‐ or under‐represented along the diagonals or the zig‐zag sampling line, the systematic methods performed badly, especially with low sample numbers. In those instances, random methods were best, especially those imposing a minimal distance between samples. Even for S. viridis, the methods based on predicted S. viridis maps were not satisfactory, except with low sample numbers. The relationships between sampling error and species characteristics (mean density, variability, spatial structures) were also studied. 相似文献
12.
The carbon disulphide evolution method is suitable for establishing the group specificity of an unknown dithiocarbamate fungicide. At 55°C methyldithiocarbamates release all their as CS2 whether hydrolysed in sulphuric acid or acetic acid solution, whereas the liberation of CS2 from bisdithiocarbamates in sulphuric acid is at least 2–5 times as high as in acetic acid. 相似文献
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D. A. COOKE P. L. MATHIAS DAPHENE M. CHAWARSZCZYNSKA L. J. COPPOCK 《Plant pathology》1983,32(3):339-343
Population assessment methods for Heterodera schachtü were compared in two tests. In the first there were no consistent differences between numbers of H. schachrü extracted by Fenwick cans (at two laboratories), a flotation column and an automatic cyst extraction apparatus, from dried soils from three sites containing no other cyst nematodes. The second, made on 54 commercial sugar beet fields, compared numbers of H. schachtü extracted from dried soil samples by Fenwick cans (at two laboratories) with results of a bioassay of soil samples and a subsequent examination of roots in the field. Most samples were placed into the same broad groups by the cyst extraction and bioassay methods and the two techniques were equally good at predicting field infestations. 相似文献
14.
In order to evaluate trapping and standard sampling methods for Coleoptera adult detection in bulked wheat, three commercial
types of traps (WBII, Pitfall Cone Trap and Grain Probe Trap) and a 2-m long grain trier (9 openings, 750 g capacity) were
compared. The comparison, which took place in 9 steel bins containing wheat in Central Greece, indicated that the traps were
more effective in detecting adults belonging to the 21 beetle species that were found. Traps contained up to 45 times more
adults than the grain trier samples, while at the same time traps produced noticeable levels of detection sensitivity for
all species found, as compared to the grain trier samples. For most species, mean trap catches in WBII and Pitfall Cone traps
were significantly higher than the means of the other two methods. The correlation coefficient values between trap catches
and adult numbers in samples were not significantly different than zero, indicating that the effort to relate trapping to
absolute estimation sampling methods is a very complex procedure. 相似文献
15.
分散固相萃取-高效液相色谱-串联质谱法测定水稻和土壤中的福美双与甲霜灵残留 总被引：4，自引：3，他引：1
建立了一种同步分析水稻和土壤中福美双和甲霜灵残留的分散固相萃取-高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。样品经乙腈提取,PSA、C18吸附剂净化,C18色谱柱分离,0.2%甲酸水-乙腈等度洗脱,质谱采用电喷雾正离子(ESI+)模式电离,多反应离子监测模式定性分析,基质匹配标准曲线外标法定量。结果表明:在1~500μg/L浓度范围内,不同基质中的福美双和甲霜灵的线性相关系数均大于0.991。在0.01~1.5 mg/kg添加水平范围内,土壤、水稻植株、稻壳和糙米样品中福美双和甲霜灵的日内平均回收率为76%~104%,日内相对标准偏差(RSD)为1.2%~13.2%(n=5);日间平均回收率为74%~102%,日间RSD为2.8%~10.4%(n=5)。该方法简单、快速、灵敏度及准确度高,能够满足水稻及土壤中福美双和甲霜灵残留量的检测要求。 相似文献
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本研究从武汉周边采集表现典型花叶症状的桃样品,提取总RNA为模板,采用RT-PCR方法对这些样品进了分析,结果显示所分析的5个样品(P1～P5)均获得了预期大小约为337bp的目标扩增条带,表明样品均带有PLMVd.通过回收RT-PCR产物,用生物素标记制备探针,分别采用DNA斑点杂交、RNA斑点杂交和组织印迹杂交3种杂交方法对这些样品进行检测比较,3种杂交方法中,组织印迹杂交操作步骤相对简单快捷,适合于对PLMVd进行大田快速检测. 相似文献
18.
C. R. Lane E. Hobden L. Walker V. C. Barton A. J. Inman K. J. D. Hughes H. Swan A. Colyer I. Barker 《Plant pathology》2007,56(5):828-835
Plant health regulations to prevent the introduction and spread of Phytophthora ramorum and P. kernoviae require rapid, cost effective diagnostic methods for screening large numbers of plant samples at the time of inspection. Current on-site techniques require expensive equipment, considerable expertise and are not suited for plant health inspectors. Therefore, an extensive evaluation of a commercially available lateral flow device (LFD) for Phytophthora species was performed involving four separate trials and 634 samples. The assay proved simple to use, provided results in a few minutes and on every occasion a control line reacted positively confirming the validity of the test. LFD results were compared with those from testing a parallel sample, using laboratory methods (isolation and real-time PCR). The diagnostic sensitivity of the LFD (87·6%) compared favourably with the standard laboratory methods although the diagnostic specificity was not as stringent (82·9%). There were a small number ( n = 28) of false negatives, but for statutory purposes where all positive samples must be identified to species level by laboratory testing, overall efficiency was 95·6% as compared with visual assessment of symptoms of between 20-30% for P. ramorum and P. kernoviae . This work demonstrates the value of the LFD for diagnosing Phytophthora species at the time of inspection and as a useful primary screen for selecting samples for laboratory testing to determine the species identification. 相似文献
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关于JMPR植物源产品残留定义中含有代谢产物的农药在进行膳食风险评估时残留数据计算的介绍 总被引：3，自引：0，他引：3
联合国粮农组织和世界卫生组织农药残留联席会议(JMPR)将农药残留定义分为2类,即植物源产品残留定义和动物源产品残留定义;同时根据使用目的不同,又将农药残留定义分为风险评估残留定义和监测残留定义。JMPR在植物源产品农药风险评估残留定义中包含的代谢产物类型主要分4种情况:一是残留定义包含母体和代谢产物,代谢产物是农药;二是残留定义包含母体和代谢产物,代谢产物不是农药;三是残留物定义只包括代谢产物,且代谢产物不是农药;四是二硫代氨基甲酸酯类农药。本文综述了JMPR关于植物源产品残留定义中含有代谢产物的农药进行农药残留膳食风险评估时残留数据的计算,旨在为我国制定农药最大残留限量标准进行农药残留膳食风险评估时提供借鉴和参考。 相似文献
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内蒙古典型草原动态监测的取样问题 总被引：1，自引：2，他引：1
本文用数理统计方法 ,对内蒙古典型草原地带的羊草 +大针茅草原群落 2 0年 ( 1 981-2 0 0 0 )的采样数据进行分析、检验 ,选择出群落中的重要种 ,验证了草原的物种生物量服从正态分布 ,并证明了在采样中取 1 0个样方的生物量统计 ,即可替代 2 0个样方 相似文献