269 research outputs found
Scientific Opinion on the pest categorisation of Cryphonectria parasitica (Murrill) Barr
No full textThe European Commission requested the EFSA Panel on Plant Health to perform a pest categorisation of Cryphonectria parasitica (Murrill) Barr, the fungal pathogen responsible for chestnut blight, a highly destructive disease that kills trees through bark cankers. The pathogen is listed in Annex IIAII of Directive 2000/29/EC. Its identity is clearly defined as C. parasitica (Murrill) Barr and methods exist for its discriminative detection. Several hosts are known, but the main hosts are species of Castanea and Quercus, particularly C. sativa and Q. petraea. These two host species are present in all the EU Member States and the disease has been recorded in most parts of the risk assessment area. C. parasitica is absent in Denmark, Estonia, Finland, Ireland, Malta, Iceland and Norway. No information is available on the presence of the pathogen in Latvia, Lithuania or Luxembourg. In the Czech Republic and Poland, C. parasitica has been eradicated. There are no recognised ecological or climatic factors limiting the potential establishment of the pathogen in the EU Member States where the pathogen is not known to occur. The pathogen can spread by propagules (mainly conidia, but also ascospores and mycelium) that are dispersed by wind, rain or vectors, as well as via the movement of infected or contaminated host plants for planting and bark, particularly asymptomatic ones. Control methods used against C. parasitica include exclusion and eradication, chemical control, host genetic resistance and biological control (hypovirulence). The most successful control methods of C. parasitica in the EU are exclusion and eradication, and hypovirulence. Potential consequences of the damage caused by C. parasitica include yield losses of fruit and wood, reduction in biodiversity and habitat loss for associated organisms
Scientific Opinion on the pest categorisation of Ceratocystis platani (Walter) Engelbrecht et Harrington
No full textThe European Commission requested the EFSA Panel on Plant Health to perform a pest categorisation for Ceratocystis fimbriata f. sp. platani Walter, the fungal pathogen responsible for the “canker stain” disease of plane trees. C. fimbriata f. sp. platani is listed in Annex IIAII of Directive 2000/29/EC. Recently, the pathogen has been reclassified as Ceratocystis platani (Walter) Engelbrecht et Harrington, based on intersterility studies, progeny analysis and the morphology of isolates from different hosts. C. platani is a single taxonomic entity and sensitive and reliable methods are available for its detection and differentiation from other related fungal species. The only known hosts are Platanus occidentalis, Platanus orientalis and Platanus × acerifolia. The last two plane species are the most susceptible to C. platani and are widely grown in most of the European Union Member States. C. platani is a wound pathogen causing canker and wilt and eventually death of plane trees. It is currently present in part of the risk assessment area (Greece, France, Italy), where it causes serious consequences on P. orientalis and P. × acerifolia trees grown in natural stands, coppices, and public and private gardens in both rural and urban environments. There are no obvious ecological/climatic factors limiting the potential establishment and spread of the pathogen in the non-infested part of the risk assessment area where hosts are present. C. platani has multiple natural and human-assisted means of spread, including waterways, root anastomosis, contaminated pruning tools, insects, contaminated insect frass and sawdust. The movement of infected host plants for planting and wood is considered to be responsible for the introduction of the pathogen into new areas. Cultural practices and sanitary and chemical measures applied in the infested areas may reduce inoculum sources but they cannot eliminate the pathogen. Plane accessions resistant to C. platani are available in the European market
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The brown rot fungi of fruit crops (Monilinia spp.): I. Important features of their biology (Review paper)
No full textThe brown rot fungi of fruit crops (Monilinia spp.): Important features of their biology (Review paper
The brown rot fungi of fruit crops (Monilinia spp.): I. Important features of their biology (Review paper)
No full textThe brown rot fungi of fruit crops (Monilinia spp.): Important features of their biology (Review paper
Analyses of the pathogen and weather components of disease progress for modeling apple scab epidemics in integrated and organic production systems
No full textThe pathogen and weather components of apple scab disease progress were analysed in a three-year study, in two environmental-friendly production systems (organic and integrated) on cvs. `Idared', `Jonica' and 'Mutsu'. Linear regression analyses of transformed disease incidence and severity data and "area under the disease progress curves" (AUDPC) were used for the analysis of the pathogen component. To evaluate the role of the weather component in apple scab epidemic, first, the weekly disease increase was determined at a certain week (n). Weekly disease increase was related to rainfall, relative humidity, Mills' wetness period, temperature and interaction between temperature and relative humidity. Five different periods were used in the analyses: i) week (n-1), ii) week n(n-1), iii) week (n-2), iv) week (n-1)(n-2) and v) week n(n-1)(n-2). In the analyses of the pathogen component, the best transformation function was the logistic one. Regression analyses showed that disease growth rates were higher for disease incidence and for the organic production system than for disease severity and for the integrated production system, respectively. Disease growth rates for leaf incidence were higher than fruit incidence on all the three cultivars. AUDPC values showed great differences in both leaf and fruit incidences among cultivars and between the two production systems. The results the of analyses of the weather component showed that the best relationships between disease increase and weather parameters were found for fruit incidence and leaf incidence in week (n-2) in the organic and integrated production systems, respectively. Results also demonstrated that in week n(n-1) temperature played a more important role in the fungus development than the water parameters (relative humidity, rainfall and leaf wetness). Consequently, infection process is significantly dependent on almost all weather parameters, but during the incubation period the most important weather parameter is the temperature. Results were compared with similar studies and biological interpretations of the analyses are discussed
Apple powdery mildew caused by Podosphaera leucotricha: some aspects of biology
No full textApple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. Biology of the pathogen is widely investigated all over the world in the past 100 years. In this review, a summary from this enormous research is made for biology of apple powdery mildew in the following aspects: geographical distribution, morphology, taxonomy of the causal agent, symptoms, host susceptibility, resistance durability and disease cycle
Apple powdery mildew caused by Podosphaera leucotricha: some aspects of biology
No full textApple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. Biology of the pathogen is widely investigated all over the world in the past 100 years. In this review, a summary from this enormous research is made for biology of apple powdery mildew in the following aspects: geographical distribution, morphology, taxonomy of the causal agent, symptoms, host susceptibility, resistance durability and disease cycle
Analyses of the pathogen and weather components of disease progress for modeling apple scab epidemics in integrated and organic production systems
No full textThe pathogen and weather components of apple scab disease progress were analysed in a three-year study, in two environmental-friendly production systems (organic and integrated) on cvs. `Idared', `Jonica' and 'Mutsu'. Linear regression analyses of transformed disease incidence and severity data and "area under the disease progress curves" (AUDPC) were used for the analysis of the pathogen component. To evaluate the role of the weather component in apple scab epidemic, first, the weekly disease increase was determined at a certain week (n). Weekly disease increase was related to rainfall, relative humidity, Mills' wetness period, temperature and interaction between temperature and relative humidity. Five different periods were used in the analyses: i) week (n-1), ii) week n(n-1), iii) week (n-2), iv) week (n-1)(n-2) and v) week n(n-1)(n-2). In the analyses of the pathogen component, the best transformation function was the logistic one. Regression analyses showed that disease growth rates were higher for disease incidence and for the organic production system than for disease severity and for the integrated production system, respectively. Disease growth rates for leaf incidence were higher than fruit incidence on all the three cultivars. AUDPC values showed great differences in both leaf and fruit incidences among cultivars and between the two production systems. The results the of analyses of the weather component showed that the best relationships between disease increase and weather parameters were found for fruit incidence and leaf incidence in week (n-2) in the organic and integrated production systems, respectively. Results also demonstrated that in week n(n-1) temperature played a more important role in the fungus development than the water parameters (relative humidity, rainfall and leaf wetness). Consequently, infection process is significantly dependent on almost all weather parameters, but during the incubation period the most important weather parameter is the temperature. Results were compared with similar studies and biological interpretations of the analyses are discussed
Organic apple growing using sanitation treatments against apple scab
No full textEffects or sanitation practices were evaluated on primary and autumn infection by Venturia inaequalis in an organic apple orchard at Eperjeske on the moderately scab-susceptible apple cultivar Jonathan in 2005 and 2006. Evaluated sanitation practices were: i) collection of fallen leaves in autumn; ii) destroying fallen leaves by disc cultivation in autumn; iii) spraying fallen leaves with 2% lime sulphur in autumn; iv) spraying fallen leaves with 2% lime sulphur in autumn and then collection of fallen leaves in autumn; and v) untreated control. In both years, most sanitation practices reduced significantly (P< 0.05) scab incidence in the primary infection periods compared to untreated control. The highest leaf scab incidence was observed in the untreated plots (26:2 and 24.3% in 2005 and 2006, respectively), while the lowest was in the treatments of spraying fallen leaves with 2% lime sulphur combined with collection of fallen leaves (11.7 and 12.3% in 2005 and 2006, respectively)
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