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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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The effect of oxadixyl-based fungicidal mixtures on the development of late blight and the buildup of resistance ofPhytophthora infestans to oxadixyl was studied in potato crops (cv. Alpha) grown in plastic houses. Half-rates of SAN 518F (mancozeb + oxadixyl)
applied weekly provided better disease control and reduced resistance buildup more effectively than the full rates of the
mixture applied biweekly. Mancozeb applied weekly at full rate was less effective than SAN 518F at half-rate. The data suggest
that lowering the dosage together with shortening the interval between sprays is an efficient strategy to combat mixed populations
— sensitive and resistant to phenylamides — ofP. infestans when phenylamide-based fungicidal sprays are used. 相似文献
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马铃薯晚疫病的研究现状及控制策略的思考 总被引:2,自引:0,他引:2
综述了近年国内对马铃薯晚疫病的病原、发病规律、抗病育种、防治技术等的研究现状,并从疫情的监测、培育抗病品种、化学药剂的使用等方面对防控策略的研究进行了思考. 相似文献
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Propamocarb (Previcur-N; propyl-[3-dimethylamino-propyl] carbamate-monohydrochloride) was testedin vivo against 32 field isolates ofPhytophthora infestans from six countries. Fungicide dosages required to achieve 90% control of the blight ranged between 676 and 1530 ppm a.i.
in potted potato (cv. ‘Alpha’) plants and between 1135 and 2648 ppm in potato tuber slices. Isolates from Israel were less
sensitive to the fungicide than isolates from Europe or North America. Toxicity of propamocarb was not related to resistance
or sensitivity to phenylamide fungicides (e.g. metalaxyl). Nevertheless, most metalaxyl-resistant isolates from Israel were less sensitive to propamocarb than most metalaxyl-sensitive
isolates from this country. Monocyclic epidemics conducted with the 20 Israeli isolates in the field showed that 1081–2012
ppm of the fungicide was required to achieve 90% control of the disease. Laboratory experiments revealed that the fungicide
was poorly active against sporangial germination and had a limited curative efficacy. It exhibited a translaminar translocation
in leaves but a poor acropetal or basipetal systemicity from foliage. Propamocarb + mancozeb mixtures (1:1, v/w) were synergistically
effective in controlling the blight. Growers in Israel use tank mixtures of propamocarb (Dynone) and mancozeb to combat late
blight in potato fields where phenylamide-resistant isolates ofP. infestans are prevalent. 相似文献
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由真菌致病疫霉Phytophthora infestans (Mont.) de Bary引起的晚疫病是马铃薯的毁灭性病害。为使新型优异杀菌剂10%氟噻唑吡乙酮可分散油悬浮剂发挥更好的作用,于2018—2019年开展了该药剂防治马铃薯晚疫病的最低有效防控剂量 (防治效果等于大于80%对应的施药剂量) 田间试验。结果表明:10%氟噻唑吡乙酮可分散油悬浮剂按有效成分9.75~14.6 g/hm2处理,于第二次施药后14 d防治效果达80%以上,此剂量即为最低有效防控剂量,比农药登记推荐低剂量少用药50.0%~25.0%。结果可为农药减施和精准施药提供依据。 相似文献
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马铃薯晚疫病预测模型与预警技术研究进展 总被引:4,自引:0,他引:4
介绍了马铃薯晚疫病11个预测模型和6个电脑化模型;描述了模型预测的判断标准和预警指标,并作了评价提出存在问题;讨论了建立网络化病害预测模型和实现自动预警配套技术;报道了2003年直接应用于田间马铃薯晚疫病监测技术。 相似文献
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马铃薯是重要的粮食作物, 由致病疫霉侵染引发的晚疫病长期严重制约马铃薯产业的健康发展, 因此, 国内外均将马铃薯晚疫病列为重大病害。目前, 抗病品种选育栽培、晚疫病预测预报和化学防治等相结合的晚疫病综合防治手段已得到普遍推广, 但晚疫病局部大流行在全世界范围内仍时有发生, 给粮食安全和生态安全带来巨大挑战。本文回顾了我国晚疫病的部分研究历史, 集中关注致病疫霉与寄主的互作机制领域, 梳理了近年来关于致病疫霉侵入机理、效应蛋白毒力功能、病原菌变异规律、马铃薯抗病机理等方面的重要研究结果并展望未来主要的研究方向, 以期为晚疫病基础研究和防治技术革新提供参考。 相似文献
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为了明确当前市场上具有代表性的11种防治马铃薯晚疫病杀菌剂的适宜施用时期,采用人工接种马铃薯叶片的方法,测定了其中5种药剂在接种晚疫病菌前10 d内不同时间施用的预防效果和其中7种药剂在接种后24 h内不同时间施用的治疗效果。结果显示:在保证良好防治效果的前提下,药剂在病原菌接种前保护性施用的适宜时期比在接种后治疗性施用的适宜时期要长。在测试浓度下,接种前5种供试药剂保持100%防治效果的适宜施用时期为接种前3~10 d;而接种后7种供试药剂保持相同防效的适宜施用时期仅为接种后6~12 h,在生产实际中难以操作。研究结果说明,在田间马铃薯晚疫病的化学防治中,为了取得良好防治效果,每次用药均应在病菌侵入之前采用保护性施用,尽量避免在病菌侵入之后进行治疗性施用。 相似文献
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Estimating the global severity of potato late blight with GIS-linked disease forecast models 总被引:5,自引:0,他引:5
Global severity of potato late blight was estimated by linking two disease forecast models, Blitecast and Simcast, to a climate data base in a geographic information system (GIS). The disease forecast models indirectly estimate late blight severity by determining how many sprays are needed during a growing season as a function of the weather. Global zonation of estimated late blight severity was similar for both forecast models, but Blitecast generally predicted a lower number of sprays. With both forecast models, there were strong differences between potato production zones. Zones of high late blight severity include the tropical highlands, western Europe, the east coast of Canada and northern USA, south-eastern Brazil and central-southern China. Major production zones with a low late blight severity include the western plains in India, where irrigated potato is produced in the cool dry season, north-central China, and the north-western USA. Using a global GIS data base of potato production, the average number of sprays was calculated by country. These averages were compared with estimates of current fungicide use. The results using Blitecast and Simcast were correlated but only Blitecast estimates correlated with observed data for developed countries. The estimated number of sprays, whether from Blitecast or Simcast, did not correlate with the observed number of sprays in developing countries, and in a number of developing countries the predicted optimal number of sprays was much higher than the actual number observed. In these countries, increased access to host resistance and fungicides could have a strong economic impact. 相似文献
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马铃薯晚疫病在张家口一带,初侵染的主要来源是,由于播种了带菌病薯。为此,我们曾试用药剂、温水、干热等方法处理种薯,消灭病菌,结果以温水处理种薯效果最好。试验材料是本地感病品种“紫山药”,感病程度严重,病斑占薯面1/3到1/2。 相似文献
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Effects of temperature and illumination on colonization by Phytophthora infestans of detached leaflets of five potato cultivars differing in field resistance to blight were investigated using an ELISA system to quantify the pathogen. Leaflets of cvs Teena and Shelagh, and in one experiment cv. Brodick, were more resistant to colonization when infected leaflets were incubated at 10°C than at 20°C, but temperature conditions before inoculation had little effect. Both photoperiod and light intensity during illumination of intact plants before inoculation interacted with genotype to determine subsequent colonization of infected leaflets incubated in darkness. Leaflets from plants of cv. Teena were more resistant to colonization after exposure to low, rather than to high, light intensities but photoperiod had no apparent effect. Leaflets of cv. Shelagh grown in a 20 h day were more resistant than those grown in a 10 h day but light intensity had no effect. Leaflets of cv. Brodick were more resistant after a 20 h day than a 10 h day and after exposure to low, rather than to high, light intensities. Leaflets of cv. Bintje were extensively colonized and those of cv. Torridon remained relatively resistant to colonization, irrespective of temperature and lighting conditions. There was a high level of unexplained variation in all the experiments. 相似文献