| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Verticillium dahliae (VERTDA)
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):
Austria (2014); Belgium (2015); Bulgaria (1986); Croatia (2016); Cyprus (2011); Czech Republic (2011); Denmark (1986); France (1986); Germany (2012); Greece (2013); Greece/Kriti (2013); Hungary (1986); Italy (2007); Malta (2007); Netherlands (2018); Portugal (1986); Slovakia (2012); Slovenia (2017); Spain (2021)
Conclusion:
Justification (if necessary):
Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/). V. dahliae is present in most EU Member States (MSs), with the exception of Ireland (absent, no pest records) and Poland (absent/uncertain). The current status of V. dahliae in the MSs where the pathogen is known to occur ranges from “restricted distribution” to “widespread” (EFSA, 2014).
HOST PLANT N°1: Fragaria (1FRAG) 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:
Qualified
Justification (if necessary):
EPPO Standard PM 4/11 Certification scheme for strawberry recommends inspection for 'Verticillium dahliae & V. albo-atrum', with 0% tolerance in inspection for all production stages, except for certified material (2%).
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
Conclusion:
Justification:
Verticillium dahlia is a soil-borne fungus that causes Verticillium wilt diseases in an extremely wide host range of annual and perennial dicotyledonous plant. Its primary economic hosts include: artichoke, aubergine, bell pepper, cotton, hop, lettuce, mints (Mentha spp.), oilseed rape, olive, potato, tomato (CAB 2021) and strawberry (Harris & Yang, 1996) ; citrus and pome fruits, however, are the exception (Smith et al. 1988).
Verticillium dahliae can survive for 14 years in soil as microsclerotia (form of resting spores) (Wilhelm, 1955), either free or embedded in plant debris, which are stimulated to germinate in response to root exudates (Mol, 1995). Infection of plants, both individuals and populations, is directly related to the inoculum density of microsclerotia in the soil (Pullman & DeVay, 1982; Harris & Yang, 1996; Mol et al., 1996; Xiao & Subbarao, 1998).
Verticillium dahliae is seed transmitted (CABI, 2021)
Verticillium dahliae can easily be dispersed by propagation material (nursery stock) of both herbaceous and woody hosts (e.g. Keykhasaber et al., 2018).
Plants for planting is a significant pathway to strawberry fruit hydroponic production.
Verticillium dahliae can survive for 14 years in soil as microsclerotia (form of resting spores) (Wilhelm, 1955), either free or embedded in plant debris, which are stimulated to germinate in response to root exudates (Mol, 1995). Infection of plants, both individuals and populations, is directly related to the inoculum density of microsclerotia in the soil (Pullman & DeVay, 1982; Harris & Yang, 1996; Mol et al., 1996; Xiao & Subbarao, 1998).
Verticillium dahliae is seed transmitted (CABI, 2021)
Verticillium dahliae can easily be dispersed by propagation material (nursery stock) of both herbaceous and woody hosts (e.g. Keykhasaber et al., 2018).
Plants for planting is a significant pathway to strawberry fruit hydroponic production.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Justification:
Disease symptoms may comprise wilting, chlorosis, stunting, necrosis and vein clearing. Brown vascular discoloration may be observed in stem tissue cross-sections (Frandin & Thomma, 2006). Symptoms of Verticillium wilt diseases can vary between hosts; thus, there are no unique symptoms that develop on all plants infected by V. dahliae (Fradin & Thomma, 2006). Moreover, symptoms can vary depending upon strains (pathotypes) of the pathogen (Korolev et al., 2008; Jiménez-Díaz et al., 2012; cited in EFSA, 2014).
Strawberry plants infected with Verticillium dahliae may initially be stunted. Outer leaves exhibit marginal and interveinal browning, followed by eventual collapse; inner leaves remain green. This last symptom sometimes helps to distinguish this disease from Phytophthora crown rot. The fungus is especially destructive in semi-arid areas where soils are irrigated. Inoculum densities may be high following planting of susceptible crops (e.g., lettuce). Disease severity is greater when high levels of nitrogen are used. Various cultivars differ in their susceptibility to Verticillium dahliae (UC PMG, 2018).
Verticillium wilt of strawberry occurs throughout the temperate zones of the world, but is most prevalent and destructive in irrigated semiarid areas. The widespread strains of Verticillium that attack potato, tomato, and cotton are also pathogenic to strawberries. Thus the disease, if unchecked, has the potential to eliminate commercial strawberry production in many localitiess (APS, 1998).
Especially strawberry crops following tomato, potato and cotton were devastated. Also common weeds can be symptomless host to V. dahliae and increased the problem. In strawberry without soil fumigation, losses of up to 75% have been recorded (Talboys, 1975; Wilhelm & Paulus, 1980).
Strawberry plants infected with Verticillium dahliae may initially be stunted. Outer leaves exhibit marginal and interveinal browning, followed by eventual collapse; inner leaves remain green. This last symptom sometimes helps to distinguish this disease from Phytophthora crown rot. The fungus is especially destructive in semi-arid areas where soils are irrigated. Inoculum densities may be high following planting of susceptible crops (e.g., lettuce). Disease severity is greater when high levels of nitrogen are used. Various cultivars differ in their susceptibility to Verticillium dahliae (UC PMG, 2018).
Verticillium wilt of strawberry occurs throughout the temperate zones of the world, but is most prevalent and destructive in irrigated semiarid areas. The widespread strains of Verticillium that attack potato, tomato, and cotton are also pathogenic to strawberries. Thus the disease, if unchecked, has the potential to eliminate commercial strawberry production in many localitiess (APS, 1998).
Especially strawberry crops following tomato, potato and cotton were devastated. Also common weeds can be symptomless host to V. dahliae and increased the problem. In strawberry without soil fumigation, losses of up to 75% have been recorded (Talboys, 1975; Wilhelm & Paulus, 1980).
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?
No
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:
Healthy plant material
Resistant cultivars
Resistant cultivars
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Conclusion:
Justification:
CONCLUSION ON THE STATUS:
Recommended for listing as an RNQP, based on EPPO PM4 Standard.
8 - Tolerance level:
Is there a need to change the Tolerance level:
No
Proposed Tolerance levels:
9 - Risk management measures:
Is there a need to change the Risk management measure:
No
Proposed Risk management measure:
REFERENCES:
- APS (1998) Verticillium wilts. In Compendium of strawberry diseases. American Phytopathological Society, St Paul, MN, USA. pages 51-52
- CABI (2020) Verticillium dahliae (verticillium wilt), CABI Digital Library (Accessed 30/May/2024).
- EFSA (2014) Scientific opinion on the pest categorisation of Verticillium dahliae Kleb.1. EFSA Panel on Plant Health (PLH). EFSA Journal 12(12), 3928, 54 pp.
- Fradin EF & Thomma BP (2006) Physiology and molecular aspects of Verticillium wilt diseases caused by V. dahliae and V. albo-atrum. Molecular Plant Pathology 7(2), 71-86. doi: 10.1111/j.1364-3703.2006.00323.x.
- Harris DC & Yang JR (1996) The relationship between the amount of Verticillium dahliae in soil and the incidence of strawberry wilt as a basis for disease risk prediction. Plant Pathology 45(1), 106-114.
- Jiménez-Díaz RM, Cirulli M, Bubici G, Jiménez-Gasco MM, Antoniou PP & Tjamos EC (2012). Verticillium wilt: a major threat to olive production. Current status and future prospects for its management. Plant Disease 96, 304–329.
- Keykhasaber M., Thomma BPHJ & Hiemstra JA (2018) Verticillium wilt caused by Verticillium dahliae in woody plants with emphasis on olive and shade trees. European Journal of Plant Pathology 150, 21-37.
- Korolev N, Pérez-Artés E, Mercado-Blanco J, Bejarano-Alcázar J, Rodríguez-Jurado D, Jiménez-Díaz RM &, Katan T & Katan J (2008) Vegetative compatibility of cotton-defoliating Verticillium dahliae in Israel and its pathogenicity to various crop plants. European Journal of Plant Pathology 122, 603–617. DOI 10.1007/s10658-008-9330-1
- Mol L, Halteren JM van, Scholte K & Struik PC (1996) Effects of crop species, crop cultivars and isolates of Verticillium dahliae on the population of microsclerotia in the soil, and consequences for crop yield. Plant Pathology 45(2), 205-214.
- Pullman GS & DeVay JE (1982) Epidemiology of Verticillium wilt of cotton: a relationship between inoculum density and disease progression. Phytopathology 72(5), 549-554.
- Smith IM, Dunez J, Phillips DH, Lelliot RA & Archer SA (eds) (1988) European handbook of diseases: Verticillium dahlia Kleb. and Verticillium albo-atrum Reinke & Berthold. Blackwell Scientific Publications Oxford, UK. 299-302.
- Talboys PW (1984) Chemical control of verticillium wilts. Phytopathologia Mediterranea 23(2/3),163-175..
- Wilhelm S (1955) Longevity of Verticillium wilt fungus in the laboratory and the field. Phytopathology 45, 180-181.
- Wilhelm S & Paulus AO (1980) How soil fumigation benefits the California strawberry industry. Plant Disease 64, 264-270.
- UC PMG (2018) Verticillium wilt. In Pest management guidelines for agriculture – Strawberry. University of California, Agriculture and Natural Resources, publication 3468, pages 1 & 90-92.
- Xiao CL & Subbarao KV (1998) Relationships between Verticillium dahliae inoculum density and wilt incidence, severity, and growth of cauliflower. Phytopathology 88(10), 1108-1115.