1,721,627 research outputs found
Statement on the comments by Hattingh et al. (2014) on the EFSA PLH Panel (2014) Scientific Opinion on Citrus Black Spot
No full textFollowing a request from the European Commission, the EFSA Panel on Plant Health (EFSA PLH Panel) was asked to react to a document entitled “Comments on the European Union Food Safety Authority’s Pest Risk Assessment for Phyllosticta citricarpa”, authored by Hattingh et al., which was posted online in August 2014 on the website of Citrus Research International (Pty) Ltd, South Africa. Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa (McAlpine) Van der Aa, is a fruit-blemishing and leaf-spotting disease affecting citrus. P. citricarpa is not known to occur in the EU territory and is regulated as a quarantine organism in citrus (Council Directive 2000/29/EC). The Panel assessed the comments by Hattingh et al. in the light of the content of the EFSA PLH Panel Scientific Opinion on CBS and the EFSA report detailing responses to comments received during the public consultation on the draft opinion. The Panel stands by the EFSA PLH Panel Scientific Opinion on CBS and considers that the comments by Hattingh et al. have been thoroughly addressed in the EFSA report on the public consultation on the EFSA PLH Panel Scientific Opinion on CBS. A detailed point by point reply to the comments by Hattingh et al. is provided in an Appendix of this Panel statement. Since September 2014, EFSA has written to the lead author of the comments trying to engage in a scientific dialogue concerning the sources of uncertainty related to the risks posed by P. citricarpa to plant health in the EU, so as to identify ways to reduce such uncertainties (e.g. with further research and/or data exchange). The EFSA PLH Panel also remains open to such constructive dialogue in the future
Modelling plant disease epidemics for crop protection
No full textInitially plant disease models were developed as simple rules,
graphs, or tables, and later as descriptive tools. Advances in environmental
monitoring, automatic data processing, and botanical
epidemiology enabled the development of a new class of mechanistic
dynamic models, which are more accurate and robust. They
explain mathematically the relations within a pathosystem (including
both pathogens and host plants) by means of linked differential
equations, and describe the way in which the system changes
over time and space as an effect of external variables. Thus, the
equation parameters do not have fixed values but vary according
to the influencing weather conditions. These models require input
data, particularly meteorological data, to be collected over time
and space. Scales of time and space for inputs may differ according
to the application of the model: from warning services, which
use models to produce crop protection information at the collective
level on a territorial scale, to precision agriculture which uses
models at a within-plot scale. While the use of mechanistic dynamic
models in warning services for crop protection is well established,
their use in precision agriculture has yet to be developed.
These models could be used to draw dynamic maps of current
and future spatial distribution of both visible and latent infections
within a plot, so that timing, active ingredients and rates of
fungicides may be defined accordingly. The main challenge that
needs to be overcome before this can be accomplished is the lack
of meteorological inputs at the within-plot level
Stato attuale delle conoscenze su Cercospora beticola: dalla ricerca nuovi elementi per migliorare le strategie di lotta
No full textCercospora leaf spot (CLS), caused by the fungus Cercospora beticola, is the major disease of sugarbeet in Italy. The control of CLS is traditionally based on a regular fungicide schedule aimed at maintaining a sufficient foliar concentration of the active ingredients over the entire season, with repeated applications at 18-20 day intervals. This traditional approach is still pursued, and research has produced new findings that can potentially improve disease control. EU policies impose new approaches in the control of sugarbeet diseases. The following aspects will be considered: (i) the pathogen life cycle and dynamics of the epidemics it causes in relation to the influencing environmental and cultural factors, with the support of the existing epidemiological models; (ii) the host, considering its genetic resistance, its growth in relation to the development of CLS epidemics and the consequent yield losses, with the support of action thresholds for fungicide applications; (iii) the fungicides, taking into account their effectiveness and dynamics of their foliar concentration over time, as well as the sensitivity of C. beticola populations
Transferring innovation into practical agriculture to manage mycotoxins
No full textIn Italy, mycotoxins are of great concern for cereal production in generai and for durum wheat and
pasta production in particular. In an innovative project, researchers have recently developed procedures for the sustainable production of high quality pasta from high quality durum wheat. A key Starting with basic research carried out at the University of Piacenza (Italy) on the biology and
epidemiology of the main fungal species involved in the Fusarium head blight (FHB) complex, researchers developed a multispecies, mechanistic model that includes the effect of weather
(temperature, relative humidity, wetness, and rainfall) on: (i) inoculum production and dispersal; (ii)
infection and disease onset; and (iii) mycotoxin (deoxynivalenol and zearalenone) accumulation. The
ability of this weather-driven model to predict risk of infection and mycotoxin contamination was validated under a range of epidemiological conditions. The model was then expanded to include those crop management options that significantly modify the risk of FHB and mycotoxin contamination, i.e.,
plant resistance, previous crop, soil management, and fungicide sprays. The complete FHB model was then included in a web-based Decision Support System (DSS) that was developed by Horta (a
spin-off company of the University of Piacenza; www.horta-srl.com)andnamedgranoduro.net®. This
DSS qranoduro.net" provides plot-specific and up-to-date warnings and support information that helps
durum wheat farmers make decisions about multiple crop management actions (e.g., sowing, fertilisation, weed and disease control), including those that affect FHB and mycotoxins. Implemented
by Barilla, one of the top pasta producers in Italy, the DSS qrancduro.net" is currently used by
hundreds of farmers to sustainably manage the durum wheat crops used for pasta production. Use of the DSS has reduced external inputs (e.g., fungicides and fertilisers) and costs, maintained or increased crop yield, greatly reduced mycotoxin contamination, reduced emission of greenhouse gasses, and increased farmer income. New DSS functionalities are being developed, and these include the addition of Fusarium species and
mycotoxins to the mechanistic model. Similar DSSs are under development for common wheat and barley. DSSs would also be useful for grain buyers. The idea is to develop a scenario-based system for optimising sampling for mycotoxin analyses, depending on the predicted risk in the area where the
grain is produced
A model to predict the risk infection of Gibberella zeae ascospores
No full textFusarium Head Blight (FHB) is caused by a species complex of Fusarium and Microdochium. This disease, common in wheat, can induce losses of yield but also degrade safety quality of grains. Indeed, the most common species of Fusarium in France is Fusarium graminearum (teleomorph=Gibberella zeae) and it can produce toxins, in particular deoxynivalenol (DON) regulated by the European Commission for cereals intended for human consumption. In France, the presence of DON in wheat is clearly linked to crop debris remaining on soil at flowering stage. Crop debris is usually colonized by F. graminearum which can produce sexual fruiting bodies named perithecia. Those perithecia release ascospores under specific environmental conditions which are assumed to be the major part of inoculum for wheat infection. The objective of this work was to develop a model to predict ascospore risk. The model was developed following a mechanistic approach where the sexual stage of G. zeae was divided in 5 stages: perithecia formation and maturation, ascospore maturation, discharge and germination. For each stage, a specific equation was developed using weather variables (rain, relative humidity, temperature) from literature as independent variables. The final model combines each stage and provides a daily relative risk for ascospores. Specific experiments are on‐going to further validate the model and develop a decision‐making support system to help farmers decide whether or not to spray against FHB at wheat flowering stage
Scientific Opinion on the risks to plant health posed by Phytophthora fragariae Hickman var. fragariae in the EU. territory, with the identification and evaluation of risk reduction options
No full textThe Panel on Plant Health assessed the risk to plant health from Phytophthora fragariae for the European Union and evaluated the current EU legislation and possible risk reduction options. The pest is present in most areas of Europe except southern Mediterranean regions. Entry through the plants for planting, but not seeds, pathway, is assessed as a major pathway, with the probability of entry rated as unlikely and the uncertainty as high. The probability of establishment is likely in the absence of existing disease control practices with low uncertainty. The probability of spread in the absence of a scheme for the production of certified plants for planting is considered to be very likely. With certification, spread is considered to be unlikely to moderately likely, depending on the inclusion of testing for the pathogen as part of certification. These ratings have medium uncertainty. Potential impact is rated as minor with medium uncertainty. The Panel evaluated the effectiveness of current EU legislation regarding the introduction and spread of P. fragariae. According to the regulation the import of Fragaria plants for planting, other than seeds, is prohibited from specified countries, whereas for import of these plants from other countries and for movement of these plants within the EU special requirements with respect to P. fragariae must be fulfilled. If the current legislation specific to P. fragariae were removed, no major consequences would be expected, unless the industry simultaneously ceased its voluntary certification activity. This is largely because of the important level of protection afforded to the industry by the widely used certification schemes for Fragaria, which significantly reduce the risks of entry, establishment, spread and impact. Certification schemes for the movement of Fragaria plants for planting offer the greatest efficiency and feasibility and the least uncertainty, especially if effective detection is incorporated into them
Scientific opinion on the risk to plant health posed by Arabis mosaic virus, Raspberry ringspot virus, Strawberry latent ringspot virus and Tomato black ring virus to the EU territory with the identification and evaluation of risk reduction options
No full textThe Panel on Plant Health assessed the risk to plant health of Arabis mosaic virus (ArMV), Strawberry latent ringspot virus (SLRSV), Raspberry ringspot virus (RpRSV) and Tomato black ring virus (TBRV) for the European Union (EU) territory, and evaluated the current EU legislation and possible risk reduction options. These viruses are largely restricted to Europe and their vector nematodes and at-risk hosts occur widely in Europe. Plants for planting were identified as the most significant entry pathway and the probability of entry is rated as unlikely to moderately likely for ArMV and as very unlikely to unlikely for RpRSV, SLRSV and TBRV. These ratings have moderate uncertainty. The probability of establishment is rated very likely with low uncertainty. The probability of local spread by natural means is likely, with low to medium uncertainty, whereas that of human-assisted long-distance spread is unlikely to moderately likely, with high uncertainty. Potential impact is rated minimal to minor in all hosts, with the exception of ArMV in grapevine, for which it is minor to
moderate. These ratings have medium or high uncertainty. The current legislation addresses only two of the
many host species of these viruses, but other weaknesses were also identified. If the current legislation were removed, no major consequences would be expected unless the industry simultaneously ceased its voluntary certification activity. Prohibition and the use of phytosanitary certificates, if covering the complete host ranges of
the viruses and relying on appropriate tests, are the options with highest effectiveness against the risk of introduction whereas certification schemes and pest-free areas or production sites are those with the highest effectiveness against the spread and impact risks. All options have limitations in feasibility, with uncertainty ratings from moderate to high. The combination of partially effective options may be highly effective in some crop
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