| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Chondrostereum purpureum (STERPU)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Pest category:
Fungi
1- Identity of the pest/Level of taxonomic listing:
Is the organism clearly a single taxonomic entity and can it be adequately distinguished from other entities of the same rank?
Yes
Is the pest defined at the species level or lower?:
Yes
Can listing of the pest at a taxonomic level higher than species be supported by scientific reasons or can species be identified within the taxonomic rank which are the (main) pests of concern?
- Not relevant: Fruits (including hops) sector
If necessary, please list the species:
-
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Candidate: Fruits (including hops) sector
Justification (if necessary):
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
No
Presence in the EU:
Yes
List of countries (EPPO Global Database):
-
Conclusion:
Candidate
Justification (if necessary):
The pest is reported from Finland (Vartiamäki et al., 2009), Netherlands (De Jong et al., 1990) and various other EPPO countries.
HOST PLANT N°1: Cydonia oblonga (CYDOB) for the Fruits (including hops) sector.
Origin of the listing:
Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072
Plants for planting:
Plants intended for planting
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
Yes
Conclusion:
Evaluation continues
Justification (if necessary):
Inspection for Chondrostereum purpureum recommended in EPPO Standard PM 4-27 Pathogen-tested material of Malus, Pyrus and Cydonia. However, in the responses to the questionnaire, NL and PL supported deregulation because of pathway and economic impact. Evaluation continues for these two criteria.
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
No
Conclusion:
Not candidate
Justification:
Chondrostereum purpureum is a wound pathogen that causes silverleaf disease in more than 230 woody species, including major fruit crops such as apple and pear (e.g. Spiers et al., 1998; Grinsberg et al., 2020).
From herbaria in USA and Canada Chondrostereum purpureum was not often collected from Juglandaceae (1-3%) compared to Betulaceae (45%) and Salicaceae (20%) (Setliff 2002).
This basidiomycete fungus disseminates through airborne spores from different inoculum sources such as infected fruit orchard, windblown trees, logged areas, woodpiles and pruned branches; the spores reach wounded wood, like grafts and pruning cuts, and causes infection (cited from Grinsbergs et al., 2020). Fructifications of C. purpureum form on dead wood in autumn. The dispersal of basidiospores form the fruiting bodies begins in autumn and continues until the following June. Basidiospores are released when the fruiting bodies are wet and the temperature is above freezing. They infect wood through fresh wounds, such as pruning cuts, spits for grafts or stubs left where branches have broken under heavy snow or ice. Infections of wounds more than 1 month old is uncommon.
Winter and early spring are the most critical times for infection. When infection occurs in spring, the first silvering of leaves may be visible about 1 month later. Inoculation studies indicate that apple trees are most susceptible to infection from December to April (Fujita, 1998; Biggs, 2017).
Forests with greatest vulnerability are those subjected (1) to physical forces that cause stem injuries to susceptible trees, (2) to environmental conditions conducive for infection and (3) to high levels of basidiospore inoculum from fruiting bodies on hardwood slash that result from timber harvesting and storm damage (Setliff, 2002). In orchard situations the fungus can be controlled through good cultural practices e.g. by cleaning up any dead wood which might be infected before pruning and decontaminate the pruning tools.
Plants for planting are not the major pathway since the pathogen is already present in Europe, widespread and can be dispersed by spores.
[In responses to the questionnaire, NL commented that the pest was 'airborne and widespread in nature'.]
From herbaria in USA and Canada Chondrostereum purpureum was not often collected from Juglandaceae (1-3%) compared to Betulaceae (45%) and Salicaceae (20%) (Setliff 2002).
This basidiomycete fungus disseminates through airborne spores from different inoculum sources such as infected fruit orchard, windblown trees, logged areas, woodpiles and pruned branches; the spores reach wounded wood, like grafts and pruning cuts, and causes infection (cited from Grinsbergs et al., 2020). Fructifications of C. purpureum form on dead wood in autumn. The dispersal of basidiospores form the fruiting bodies begins in autumn and continues until the following June. Basidiospores are released when the fruiting bodies are wet and the temperature is above freezing. They infect wood through fresh wounds, such as pruning cuts, spits for grafts or stubs left where branches have broken under heavy snow or ice. Infections of wounds more than 1 month old is uncommon.
Winter and early spring are the most critical times for infection. When infection occurs in spring, the first silvering of leaves may be visible about 1 month later. Inoculation studies indicate that apple trees are most susceptible to infection from December to April (Fujita, 1998; Biggs, 2017).
Forests with greatest vulnerability are those subjected (1) to physical forces that cause stem injuries to susceptible trees, (2) to environmental conditions conducive for infection and (3) to high levels of basidiospore inoculum from fruiting bodies on hardwood slash that result from timber harvesting and storm damage (Setliff, 2002). In orchard situations the fungus can be controlled through good cultural practices e.g. by cleaning up any dead wood which might be infected before pruning and decontaminate the pruning tools.
Plants for planting are not the major pathway since the pathogen is already present in Europe, widespread and can be dispersed by spores.
[In responses to the questionnaire, NL commented that the pest was 'airborne and widespread in nature'.]
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Justification:
Silver leaf (Condrostereum purpureum) is a minor disease of apple and pear. It is more common on old trees, particularly trees that have been topworked several times or those with large pruning wounds made to remove scaffold limbs, that on young vigorous trees (Fujita, 1990; Biggs, 2017)
[In responses to the questionnaire, NL commented that infection during pruning was only causing damage on weak plants.]
[In responses to the questionnaire, NL commented that infection during pruning was only causing damage on weak plants.]
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Is the economic impact due to the presence of the pest on the named host plant for planting, acceptable to the propagation and end user sectors concerned?
Is there unacceptable economic impact caused to other hosts (or the same host with a different intended use) produced at the same place of production due to the transfer of the pest from the named host plant for planting?
Conclusion:
Justification:
6 - Are there feasible and effective measures available to prevent the presence of the pest on the plants for planting at an incidence above a certain threshold (including zero) to avoid an unacceptable economic impact as regards the relevant host plants?
Conclusion:
Justification:
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Conclusion:
Justification:
CONCLUSION ON THE STATUS:
Disqualified: plants for planting is not a significant pathway.
8 - Tolerance level:
Is there a need to change the Tolerance level:
Yes
Proposed Tolerance levels:
Delisting
9 - Risk management measures:
Is there a need to change the Risk management measure:
Yes
Proposed Risk management measure:
Delisting
REFERENCES:
- De Jong MD, Scheepens PC & Zadoks JC (1990) Risk analysis for biological control: A Dutch case study in biocontrol of Prunus serotina by the fungus Chondrostereum purpureum. Plant Disease 74, 189-194.
- De Jong Y, Kouwenberg J, Boumans L, Hussey C, Hyam T, Nicolson N, Kirk P, Paton A, Michel E, Guiry MD, Boegh PS, Ærenlund Pedersen H, Enghoff H, Von Raab-Straube E, Güntsch A, Geoffroy M, Müller A, Kohlbecker A, Berendsohn W, Appeltans W, Arvanitidis C, Vanhoorne B, Declerck G, Vandepitte L, Hernandez F, Nash R, Costello MJ, Ouvrard D, Bezard-Falgas P, Bourgoin T, Wetzel FT, Glöckler F, Korb G, Ring C, Hagedorn G, Häuser C, Aktaç N, Asan A, Ardelean A, Vieira Borges PA, Dhora D, Khachatryan H, Malicky M, Ibrahimov S, Tuzikov A, De Wever A, Moncheva S, Spassov N, Chobot K, Popov A, Boršić I, Sfenthourakis S, Kõljalg U, Uotila P, Olivier G, Dauvin JC, Tarkhnishvili D, Chaladze G, Tuerkay M, Legakis A, Peregovits L, Gudmundsson G, Ólafsson E, Lysaght L, Galil BS, Raimondo FM, Domina G, Stoch F, Minelli A, Spungis V, Budrys E, Olenin S, Turpel A, Walisch T, Krpach V, Gambin MT, Ungureanu L, Karaman G, Kleukers RMJC, Stur E, Aagaard K, Valland N, Loennechen Moen T, Bogdanowicz W, Tykarski P, Węsławski JM, Kędra M, De Frias Martins AM, Domingos Abreu A, Silva T, Medvedev S, Ryss A, Šimić S, Marhold K, Stloukal E, Tome D, Ramos MA, Valdés B, Pina F, Kullander S, Telenius A, Gonseth Y, Tschudin P, Sergeyeva O, Vladymyrov V, Bohdanovych Rizun V, Raper C, Lear D, Stoev P, Penev L, Casino Rubio A, Backeljau T, Saarenmaa H, Ulenberg S (2015) PESI - a taxonomic backbone for Europe. Biodiversity Data Journal 3: e5848. https://doi.org/10.3897/BDJ.3.e5848.
- Fujita K (1990) Silver leaf. In Compendium of Apple and Pear Diseases 1st edition (ed Jones AL & Aldwinckle HS). American Phytopathological Society, St Paul, MN, USA. pages 42-43.
- Grinbergs D, Chilian J, Carrasco-Fernández J, France A, Moya-Elizondo E & Gerding M (2020) A PCR-Based method for the rapid detection of Chondrostereum purpureum in apple. Plant Disease 104, 702-707.
- PESI (2024) Pan-European Species directories Infrastructure. www.eu-nomen.eu/portal (accessed 10/Jul/2024)
- Spiers AG, Brewster DT, Bus VG & Hopcroft DH (1998). Seasonal variation in susceptibility of xylem tissue of Malus, Pyrus, Prunus, and Salix species to Chondrostereum purpureum in New Zealand. Mycological Research 102(7), 881-890.
- Setliff EC (2002) The wound pathogen Chondrostereum purpureum, its history and incidence on trees in North America. Australian Journal of Botany 50(5), 645 – 651.
- Vartiamäki H, Hantula J, Uotila A (1990) Susceptibility of silver birch pruning wounds to infection by white-rot fungus (Chondrostereum purpureum), a potential bioherbicide. Silva Fennica 43(4), 537–547.