共查询到20条相似文献，搜索用时 31 毫秒
1.
R. Kiiker I. Skrabule A. Ronis D. E. L. Cooke J. G. Hansen I. H. Williams M. Mänd E. Runno-Paurson 《Plant pathology》2019,68(6):1207-1214
Potato crop losses can be substantial when conditions for late blight (Phytophthora infestans) development and spread are favourable. In this study, drivers of differences between the P. infestans population structures in Latvia and Lithuania, two neighbouring countries with similar potato-growing traditions, were investigated. Genotypes of P. infestans and population genetic diversity were analysed using a 12-plex simple sequence repeat (SSR) marker assay. High genetic diversity was demonstrated in both populations, with population diversity being higher in Latvia. It would appear that local populations established from soilborne oospores early in the season are well adapted to the conditions in the region. However, somewhat greater spread and survival of local clones was detected in Lithuania, suggesting that potato cropping there is more vulnerable to clonal invasion than in Latvia. For effective disease management, current strategies should be adjusted according to the specific pathogen populations in the region, considering the reproduction and survival of the pathogen. Potato growers should implement late blight preventive measures such as longer field rotation to prevent oospore infections, especially in Latvia, and should use more disease resistant cultivars and high-quality seed potatoes. 相似文献
2.
The effects of strip cropping of potatoes with cereals or a grass‐clover mix in and perpendicular to the main wind direction on foliar late blight severity and tuber yield were studied in large‐scale field experiments in Germany. Disease progress was assessed in 12–18 sections per plot and yields determined from the same sections. In 2000, plot size was 3 × 10 m and there were no disease reductions apparently due to interplot interference. In 2001 and 2002, with plot sizes of 6 × 18 and 6 × 36 m in strip‐cropped potatoes, disease was significantly reduced by 9–20% and 4–12%, respectively, compared to pure stands of potato, with the greatest reductions in plots planted perpendicular to the wind and neighboured by grass‐clover. The most important factors contributing to disease reduction were loss of inoculum outside of the plots and barrier effects of neighbouring non‐potato hosts. Only 0–20% of the overall yield variation could be explained by the area under the disease progress curve, depending on cultivar and year. In one year disease effects on the yield of a moderately resistant cultivar were higher than on the yield of a susceptible cultivar. This was probably caused by differences in bulking behaviour. Nutrient limitation appeared to be more important than disease in reducing yields. Yields in the edge potato rows directly neighboured by cereals were significantly reduced in all 3 years, but competition by cereals did not change the disease–yield‐loss relationship. Strip intercropping might be a useful component in an overall management strategy to reduce incoming late blight inoculum. 相似文献
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E. Cakir 《EPPO Bulletin》2007,37(2):309-312
Prediction of potato late blight epidemics, caused by Phytophthora infestans (Mont) de Bary, was studied in three different villages of Bolu Province having large potato growing areas with the Winstel and Ullrich Schrodter models in the years 2002–05. During these years, a late blight outbreak was observed only in 2005 with the disease being less apparent in the other years. The Ullrich Schrodter model was found to poorly predict potato late blight epidemics in 2005. The Winstel model gave first warnings too early but correctly predicted late infections. Both the A1 and A2 mating types were found in Central Anatolia for the first time, in Bolu province. 相似文献
5.
P. Skelsey W. Van Der Werf G. J. T. Kessel W. A. H. Rossing A. A. M. Holtslag 《EPPO Bulletin》2007,37(2):313-316
Management of potato late blight could benefit from prediction of the risk posed to potato fields from external inoculum sources of Phytophthora infestans. Influx of inoculum depends on a complex interplay of population biological, atmospheric and spore survival processes, and is difficult to predict. This research aims at building tools for such prediction. BLIGHTSPACE is a spatio‐temporal model (parameterized for potato late blight) that has been developed and utilized to study the progress of epidemics in individual fields and networks of fields. A quasi‐Gaussian plume model was developed to provide long‐range transport of spores within BLIGHTSPACE. Numerical results compared favorably with experimental data. A further submodel for the survival of spores during long‐range transportation has been added. Integration of these three submodels will create an experimental arena for comparing control options for potato late blight. 相似文献
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H. U. GUJER 《EPPO Bulletin》1991,21(1):61-66
A project has been undertaken in Switzerland to reduce the number of applications of fungicides to potato by a reduction of late blight incidence and disease pressure as well as by providing reliable and precise spraying recommendations against blight. We try to achieve this aim by combining different elements: (1) to delay and to impede disease progress, it is planned to promote less susceptible potato cultivars and to reduce the number of primary foci by advising seed potato growers to protect their crops more carefully; (2) the data of about 20 weather stations are utilized to test different forecasting systems; (3) these (theoretical) indications on the appearance of the disease are complemented by extensive monitoring of real late blight occurrence in the field; (4) the late blight susceptibility of all cultivars grown in Switzerland is being assessed by special trials. From the combination of all this information, spraying recommendations will be formulated according to regions and cultivars. 相似文献
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A. Clinckemaillie A. Decroës G. van Aubel S. Carrola dos Santos M. E. Renard P. Van Cutsem A. Legrève 《Plant pathology》2017,66(5):818-825
Phytophthora infestans is the causal agent of potato late blight. This pathogen is usually controlled by fungicides, but new European regulations have imposed changes in crop protection management that have led to a search for alternative control measures. The induction of plant defence responses by elicitors is a promising new strategy compatible with sustainable agriculture. This study investigated the effect of eliciting a defence response in potato against P. infestans using a formulation of the COS‐OGA elicitor that combines cationic chitosan oligomers (COS) and anionic pectin oligomers (OGA). Trials were conducted under greenhouse conditions to assess the ability of COS‐OGA to control P. infestans. The results showed that three foliar applications with this elicitor significantly increased potato protection against late blight in controlled conditions. The activation of potato defence genes was also evaluated by RT‐qPCR during these trials. Two pathogenesis‐related proteins, basic PR‐1 and acidic PR‐2, were rapidly and significantly up‐regulated by the elicitor treatment. Therefore, these results suggest that the COS‐OGA elicitor increases the protection of potato against P. infestans and that this protection could be explained by an increase in the expression of potato defence genes rather than by biocide activity. 相似文献
8.
Spatiotemporal variation in airborne sporangia of Phytophthora infestans: characterization and initiatives towards improving potato late blight risk estimation 
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下载免费PDF全文 M. L. Fall H. Van der Heyden L. Brodeur Y. Leclerc G. Moreau O. Carisse 《Plant pathology》2015,64(1):178-190
This study investigated the value of using real‐time monitoring of Phytophthora infestans airborne inoculum as a complement to decision support systems (DSS). The experiment was conducted during the 2010, 2011 and 2012 potato production seasons in two locations in New Brunswick, Canada. Airborne sporangia concentrations (ASC) of P. infestans were monitored using 16 rotating‐arm spore samplers placed 3 m above the ground. The first cases of late blight (2010 and 2011) were detected 6–7 days after the first ASC peak, and all samplers captured their first sporangia within the same week (at 3‐ and 9‐day periods). The cumulative ASC curve and the risk curves from two DSS (PLANT‐Plus and Pameseb Late Blight) had the same shape but different magnitudes. In both locations, the negative binomial distribution fitted the data better than the Poisson distribution, which is indicative of heterogeneity, and based on Taylor's power law, the heterogeneity increased with increasing ASC. Therefore, the present results suggest that spore‐sampling network devices may be a suitable approach for early detection of incoming inoculum and, when combined with DSS, represent a potential aid for targeting the optimal time to apply a disease‐control product. In this context, cumulative ASC can be a counterweight to the DSS risk estimate: a high risk combined with significant ASC will trigger fungicide spraying. Moreover, spore sampling can be used to assess the efficiency of management strategies by means of examining the area under the inoculum progress curve. 相似文献
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M. P. LESOVOI 《EPPO Bulletin》1998,28(4):439-445
Potato production in Ukraine is now mainly in the private sector, and the phytosanitary state of potato crops leaves much to be desired. Control of Leptinotarsa decemlineata is generally well managed, but potato late blight (Phytophthora infestons) is out of control. Potato wart disease continues to cause problems in areas where it occurs because of the unavailability or unacceptability of resistant cultivars. Potato viruses and the losses they cause are little studied or taken into account. Other fungal, bacterial and insect pests are causing increasing problems in the field and in store. Integrated pest management systems are proposed by scientific institutions, including adequate forecasting of potato blight and use of certified seed potatoes of cultivars resistant to wart and cyst nematodes, but these systems do not adequately reach private growers. The range of plant protection products authorized for sale to the general public is very limited, and this is a serious obstacle to adequate plant protection in potato. 相似文献
10.
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
11.
Forecasting the spread of aerially transmitted crop diseases with a binary classifier for inoculum survival 下载免费PDF全文
下载免费PDF全文 The risk of between‐field spread of disease is typically omitted from crop disease warning systems, as it is difficult to know the number and location of inoculum sources and thus predict the abundance of inoculum arriving at healthy crops. This study explores the utility of a simple approach to predicting risk of between‐field spread, based on the estimated probability that inoculum will survive the transportation process. Using potato late blight as a case study, the effect of solar radiation on the viability of detached Phytophthora infestans sporangia was assessed. A model to estimate the probability of spore survival was derived using a binomial generalized linear mixed model (GLMM), and receiver operating characteristic (ROC) curve analysis and cross‐validation were used to evaluate the global performance of the model as a binary classifier for discriminating between viable and nonviable sporangia. The model yielded an area under the ROC curve of 0.92 (95% CI = 0.90–0.93), signifying an excellent classification algorithm. Inspection of the curve provided a number of suitable decision threshold (or cut‐off) probabilities for discriminating between viable and nonviable sporangia. The classifier was tested as a forecasting system for potato late blight outbreaks using 10 years of outbreak data from across Great Britain. There was a marked differentiation among the cut‐offs, but the best prediction outcome was an accuracy of 89% with an alert frequency of 1 in 7 days. This model can be easily modified or the methodology replicated for other pathosystems characterized by airborne inoculum. 相似文献
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基于地理信息系统的全国主要粮食作物病虫害实时监测预警系统的研制 总被引：10，自引：1，他引：10
为提高病虫害防治的准确性和科学性，依据植保知识、专家经验，采用人工智能、自行开发的具地理信息系统基本功能及决策支持系统（DSS）的相关技术，研制了基于Internet网络传输的全国主要粮食作物病虫害实时监测预警系统。本系统能够对小麦、玉米、水稻、马铃薯、高粱和谷子6种主要粮食作物的60余种病虫害进行实时监测、预警、诊断、提供植保知识，能够对年度间同期病情、虫情做出图形比较，可将抽象的预警数据转化成清晰简明的点图式电子地图，直观明了地显示病虫害发生点数及地域分布，可根据品种的抗病虫性、病虫害发生基数和未来天气预报等信息对小麦白粉病、赤霉病、纹枯病、稻瘟病、稻曲病、马铃薯晚疫病、麦蚜、小麦吸浆虫和玉米螟9种重要病虫害做出短期防治决策，系统的运行有助于提高人们对主要粮食作物病虫害管理的科学水平。 相似文献
13.
甘肃旱区马铃薯晚疫病始发期的预测研究 总被引：1，自引：0，他引：1
本研究利用2012—2013年甘肃省马铃薯主栽区的气象资料,结合甘肃马铃薯晚疫病发生的实情,筛选出显著影响晚疫病发生的相关气象因子,建立了甘肃干旱山区,二阴区和川塬区的马铃薯晚疫病始发期预报方程,但川塬区晚疫病始发期预报模型还需进一步的设计与优化。方程模拟结果:温度是二阴区内晚疫病始发的关键因素;降水量主要影响干旱山区马铃薯的晚疫病发生;在同一地区内,川塬区和二阴区晚疫病始发期早于干旱山区,这与干旱山区空气流动性相对强于川塬区和二阴区有关。通过对甘肃干旱山区,二阴区与川塬区马铃薯晚疫病始发期预报方程进行验证,得知预报方程对干旱山区和二阴区晚疫病始发期的预测准确率较高,预测始发期区间较小,误差小,在甘肃晚疫病预警和防治工作中具有较强的指导作用。 相似文献
14.
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
15.
Shattock RC 《Pest management science》2002,58(9):944-950
Isolates of Phytophthora infestans (Mont) de Bary (the potato and tomato late blight pathogen) resistant to phenylamides appeared in Europe and North America in the late 1970s and early 1990s respectively. Concurrent, but coincidentally, with both these events there were radical structural shifts in the pathogen populations as immigrant genotypes from Mexico displaced the indigenous populations. Both A1 and A2 mating type isolates are now present in blighted crops, permitting alternative inoculum via germinating sexually produced oospores to influence dynamics of late blight populations. Studies of inheritance of ploidy, host-specific pathogenicity, mating type and resistance to antibiotics and phenylamide fungicides have provided insight into mechanisms of variation in this potent pathogen. 相似文献
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William W Kirk Brendan A Niemira Jeffrey M Stein Raymond Hammerschmidt 《Pest management science》1999,55(12):1151-1158
Fungicides were applied as seed-piece treatments to control potato late blight, caused by Phytophthora infestans, US8, A2 biotype in controlled environment and field experiments. Efficacy of seed treatments for controlling late blight was examined under three disease development regimes simulated by artifical inoculation; (a) seed-borne infection, (b) transmission of infection resulting from spread during the seed-cutting operation, and (c) infection of foliage by aerial inoculation. Emergence of plants from the seed-borne infection was uniformly low (<40%) in controlled environment and field experiments. In controlled environment experiments some of the plants that emerged from fungicide-treated seed-pieces were infected with late blight. Following exposure of tuber surfaces to P infestans, emergence rates from seed-pieces treated with formulated products that included mancozeb in the formulation were comparable to the untreated and non-inoculated control in controlled environment and field experiments. Plants that emerged from non-inoculated seed-pieces treated with fungicides that contained active ingredients known to be effective against foliar late blight had lower percentage foliar infection after inoculation than the untreated control. Leaves close to the base of the stem had fewer infections than leaves attached at the mid region of the main stem, 14 days after inoculation, in some of the controlled environment studies. In contrast, field experiments conducted under conditions conducive to late blight development showed that none of the seed treatments applied to late blight-free seed-pieces delayed the onset and severity of late blight infection. In potato production areas at risk of early season late blight, seed treatments applied to healthy seed may confer limited protection against late blight between planting and the first scheduled applications of prophylactic foliar fungicides. © 1999 Society of Chemical Industry 相似文献
17.
黄土高原马铃薯晚疫病发生发展与气象条件关系的研究—以甘肃定西市为例 总被引：8，自引：0，他引：8
应用1991-2005年马铃薯晚疫病发生地点、面积、发展趋势等资料,结合气象要素观测资料,采用数理统计方法,分析马铃薯晚疫病发生发展及其与气象条件的关系。结果表明:研究区域马铃薯晚疫病历年发病面积比例呈显著上升趋势,发病面积比例以每年3.5437%的速度增加。马铃薯晚疫病发病面积比例与5~10月马铃薯生长季相对湿度、降水量、气温等呈正相关,而与日照时数、平均风速呈负相关。当可控条件一定时,气象条件是马铃薯晚疫病发生发展的主导因素。本文建立了马铃薯晚疫病发病面积比例气候预测模型,为马铃薯晚疫病的积极防治及科学决策提供了依据。 相似文献
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P. Skelsey J. G. Elphinstone G. S. Saddler S. J. Wale I. K. Toth 《Plant pathology》2016,65(4):570-576
Potato blackleg, caused by Pectobacterium and Dickeya species, is one of the most significant bacterial diseases affecting potato production globally. Although it is generally accepted to be a seedborne disease, the processes underlying the spread of disease largely remain unknown. Spatial point pattern analysis was applied to blackleg occurrence in seed potato crops in Scotland during the period of 2010–2013 (approximately 8000 blackleg‐affected crops), to assess whether its distribution was random, regular or aggregated, and the spatial scales at which these patterns occurred. Blackleg‐affected crops derived from mother stocks with symptoms were omitted from the analyses in order to examine the statistical evidence for horizontal transmission of blackleg. The pair correlation function was used to test for global spatial autocorrelation, and results indicated significant (P < 0·05) clustering of incidence at a wide range of spatial scales. Strength of clustering (degree of aggregation) among blackleg‐affected crops was notably larger at spatial scales of 25 km or less. A hot‐ and coldspot analysis was performed to test for local spatial autocorrelation, and statistically significant clusters of high and low values of disease were found across the country. These analyses provide the first quantitative evidence of localized and large‐scale spatial clustering of potato blackleg. Understanding the mode(s) of inoculum dispersal will be important for developing new management strategies that minimize host–pathogen contacts in potato and numerous other crops affected by pathogenic Pectobacterium and Dickeya species. 相似文献
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中国马铃薯晚疫病监测预警系统“China-blight”的组建及运行 总被引：4，自引：0，他引：4
马铃薯晚疫病是严重威胁世界马铃薯生产和粮食安全的重要病害之一,同时也是植物病害中流行速度最快的病害之一。由于品种多不抗病,目前国内外主要依靠化学防治控制该病害。为了提高用药的时效性,将信息技术与植物病害流行学原理相结合,设计并组建了中国马铃薯晚疫病监测预警系统"China-blight"(www.china-blight.net)。该系统由"中国晚疫病实时分布"、"未来48小时不同区域晚疫病菌侵染危险性预测"和"晚疫病化学防治决策支持系统"等子系统构成,此外还包括"晚疫病防治方法"、"品种抗病性"、"化学药剂库"、"其他病虫害"、"问题与经验交流"和"用户田间管理电子档案"等知识信息与服务功能。通过对2009年我国北方马铃薯一作区6-7月份病害侵染时段出现次数与晚疫病实际发生情况进行比较,预测信息与病害实际发生程度相符,该系统可以用于对马铃薯晚疫病田间防治的指导。 相似文献